Allow response_delay to be microseconds, too

[freeradius.git] / src / main / process.c

/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

/**
 * $Id$
 *
 * @file process.c
 * @brief Defines the state machines that control how requests are processed.
 *
 * @copyright 2012  The FreeRADIUS server project
 * @copyright 2012  Alan DeKok <aland@deployingradius.com>
 */

RCSID("$Id$")

#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/process.h>
#include <freeradius-devel/modules.h>
#include <freeradius-devel/state.h>

#include <freeradius-devel/rad_assert.h>

#ifdef WITH_DETAIL
#include <freeradius-devel/detail.h>
#endif

#include <signal.h>
#include <fcntl.h>

#ifdef HAVE_SYS_WAIT_H
#       include <sys/wait.h>
#endif

extern pid_t radius_pid;
extern fr_cond_t *debug_condition;

static bool spawn_flag = false;
static bool just_started = true;
time_t fr_start_time = (time_t)-1;
static rbtree_t *pl = NULL;
static fr_event_list_t *el = NULL;

fr_event_list_t *radius_event_list_corral(UNUSED event_corral_t hint) {
        /* Currently we do not run a second event loop for modules. */
        return el;
}

static char const *action_codes[] = {
        "INVALID",
        "run",
        "done",
        "dup",
        "timer",
#ifdef WITH_PROXY
        "proxy-reply"
#endif
};

#ifdef DEBUG_STATE_MACHINE
#  define TRACE_STATE_MACHINE \
if (rad_debug_lvl) do { \
        struct timeval debug_tv; \
        gettimeofday(&debug_tv, NULL); \
        debug_tv.tv_sec -= fr_start_time; \
        printf("(%u) %d.%06d ********\tSTATE %s action %s live M-%s C-%s\t********\n",\
               request->number, (int) debug_tv.tv_sec, (int) debug_tv.tv_usec, \
               __FUNCTION__, action_codes[action], master_state_names[request->master_state], \
               child_state_names[request->child_state]); \
} while (0)

static char const *master_state_names[REQUEST_MASTER_NUM_STATES] = {
        "?",
        "active",
        "stop-processing",
        "counted"
};

static char const *child_state_names[REQUEST_CHILD_NUM_STATES] = {
        "?",
        "queued",
        "running",
        "proxied",
        "reject-delay",
        "cleanup-delay",
        "done"
};

#else
#  define TRACE_STATE_MACHINE {}
#endif

static NEVER_RETURNS void _rad_panic(char const *file, unsigned int line, char const *msg)
{
        ERROR("%s[%u]: %s", file, line, msg);
        fr_exit_now(1);
}

#define rad_panic(x) _rad_panic(__FILE__, __LINE__, x)

/** Declare a state in the state machine
 *
 * Expands to the start of a function definition for a given state.
 *
 * @param _x the name of the state.
 */
#define STATE_MACHINE_DECL(_x) static void _x(REQUEST *request, int action)

static void request_timer(void *ctx);

/** Insert #REQUEST back into the event heap, to continue executing at a future time
 *
 * @param file the state machine timer call occurred in.
 * @param line the state machine timer call occurred on.
 * @param request to set add the timer event for.
 * @param when the event should fine.
 * @param action to perform when we resume processing the request.
 */
static inline void state_machine_timer(char const *file, int line, REQUEST *request,
                                       struct timeval *when, fr_state_action_t action)
{
        request->timer_action = action;
        if (!fr_event_insert(el, request_timer, request, when, &request->ev)) {
                _rad_panic(file, line, "Failed to insert event");
        }
}

/** @copybrief state_machine_timer
 *
 * @param _x the action to perform when we resume processing the request.
 */
#define STATE_MACHINE_TIMER(_x) state_machine_timer(__FILE__, __LINE__, request, &when, _x)

/*
 *      We need a different VERIFY_REQUEST macro in process.c
 *      To avoid the race conditions with the master thread
 *      checking the REQUEST whilst it's being worked on by
 *      the child.
 */
#if defined(WITH_VERIFY_PTR) && defined(HAVE_PTHREAD_H)
#  undef VERIFY_REQUEST
#  define VERIFY_REQUEST(_x) if (pthread_equal(pthread_self(), _x->child_pid) != 0) verify_request(__FILE__, __LINE__, _x)
#endif

/**
 * @section request_timeline
 *
 *      Time sequence of a request
 * @code
 *
 *      RQ-----------------P=============================Y-J-C
 *       ::::::::::::::::::::::::::::::::::::::::::::::::::::::::M
 * @endcode
 *
 * -    R: received.  Duplicate detection is done, and request is
 *         cached.
 *
 * -    Q: Request is placed onto a queue for child threads to pick up.
 *         If there are no child threads, the request goes immediately
 *         to P.
 *
 * -    P: Processing the request through the modules.
 *
 * -    Y: Reply is ready.  Rejects MAY be delayed here.  All other
 *         replies are sent immediately.
 *
 * -    J: Reject is sent "response_delay" after the reply is ready.
 *
 * -    C: For Access-Requests, After "cleanup_delay", the request is
 *         deleted.  Accounting-Request packets go directly from Y to C.
 *
 * -    M: Max request time.  If the request hits this timer, it is
 *         forcibly stopped.
 *
 *      Other considerations include duplicate and conflicting
 *      packets.  When a dupicate packet is received, it is ignored
 *      until we've reached Y, as no response is ready.  If the reply
 *      is a reject, duplicates are ignored until J, when we're ready
 *      to send the reply.  In between the reply being sent (Y or J),
 *      and C, the server responds to duplicates by sending the cached
 *      reply.
 *
 *      Conflicting packets are sent in 2 situations.
 *
 *      The first is in between R and Y.  In that case, we consider
 *      it as a hint that we're taking too long, and the NAS has given
 *      up on the request.  We then behave just as if the M timer was
 *      reached, and we discard the current request.  This allows us
 *      to process the new one.
 *
 *      The second case is when we're at Y, but we haven't yet
 *      finished processing the request.  This is a race condition in
 *      the threading code (avoiding locks is faster).  It means that
 *      a thread has actually encoded and sent the reply, and that the
 *      NAS has responded with a new packet.  The server can then
 *      safely mark the current request as "OK to delete", and behaves
 *      just as if the M timer was reached.  This usually happens only
 *      in high-load situations.
 *
 *      Duplicate packets are sent when the NAS thinks we're taking
 *      too long, and wants a reply.  From R-Y, duplicates are
 *      ignored.  From Y-J (for Access-Rejects), duplicates are also
 *      ignored.  From Y-C, duplicates get a duplicate reply.  *And*,
 *      they cause the "cleanup_delay" time to be extended.  This
 *      extension means that we're more likely to send a duplicate
 *      reply (if we have one), or to suppress processing the packet
 *      twice if we didn't reply to it.
 *
 *      All functions in this file should be thread-safe, and should
 *      assume thet the REQUEST structure is being accessed
 *      simultaneously by the main thread, and by the child worker
 *      threads.  This means that timers, etc. cannot be updated in
 *      the child thread.
 *
 *      Instead, the master thread periodically calls request->process
 *      with action TIMER.  It's up to the individual functions to
 *      determine how to handle that.  They need to check if they're
 *      being called from a child thread or the master, and then do
 *      different things based on that.
 */
#ifdef WITH_PROXY
static fr_packet_list_t *proxy_list = NULL;
static TALLOC_CTX *proxy_ctx = NULL;
#endif

#ifdef HAVE_PTHREAD_H
#  ifdef WITH_PROXY
static pthread_mutex_t proxy_mutex;
static bool proxy_no_new_sockets = false;
#  endif

#  define PTHREAD_MUTEX_LOCK if (spawn_flag) pthread_mutex_lock
#  define PTHREAD_MUTEX_UNLOCK if (spawn_flag) pthread_mutex_unlock

static pthread_t NO_SUCH_CHILD_PID;
#  define NO_CHILD_THREAD request->child_pid = NO_SUCH_CHILD_PID

#else
/*
 *      This is easier than ifdef's throughout the code.
 */
#  define PTHREAD_MUTEX_LOCK(_x)
#  define PTHREAD_MUTEX_UNLOCK(_x)
#  define NO_CHILD_THREAD
#endif

#ifdef HAVE_PTHREAD_H
static bool we_are_master(void)
{
        if (spawn_flag &&
            (pthread_equal(pthread_self(), NO_SUCH_CHILD_PID) == 0)) {
                return false;
        }

        return true;
}

/*
 *      Assertions are debug checks.
 */
#  ifndef NDEBUG
#    define ASSERT_MASTER       if (!we_are_master()) rad_panic("We are not master")
#    endif
#else

/*
 *      No threads: we're always master.
 */
#  define we_are_master(_x) (1)
#endif  /* HAVE_PTHREAD_H */

#ifndef ASSERT_MASTER
#  define ASSERT_MASTER
#endif

static int event_new_fd(rad_listen_t *this);

/*
 *      We need mutexes around the event FD list *only* in certain
 *      cases.
 */
#if defined (HAVE_PTHREAD_H) && (defined(WITH_PROXY) || defined(WITH_TCP))
static rad_listen_t *new_listeners = NULL;

static pthread_mutex_t  fd_mutex;
#  define FD_MUTEX_LOCK if (spawn_flag) pthread_mutex_lock
#  define FD_MUTEX_UNLOCK if (spawn_flag) pthread_mutex_unlock

void radius_update_listener(rad_listen_t *this)
{
        /*
         *      Just do it ourselves.
         */
        if (we_are_master()) {
                event_new_fd(this);
                return;
        }

        FD_MUTEX_LOCK(&fd_mutex);

        /*
         *      If it's already in the list, don't add it again.
         */
        if (this->next) {
                FD_MUTEX_UNLOCK(&fd_mutex);
                return;
        }

        /*
         *      Otherwise, add it to the list
         */
        this->next = new_listeners;
        new_listeners = this;
        FD_MUTEX_UNLOCK(&fd_mutex);
        radius_signal_self(RADIUS_SIGNAL_SELF_NEW_FD);
}
#else
void radius_update_listener(rad_listen_t *this)
{
        /*
         *      No threads.  Just insert it.
         */
        event_new_fd(this);
}
/*
 *      This is easier than ifdef's throughout the code.
 */
#  define FD_MUTEX_LOCK(_x)
#  define FD_MUTEX_UNLOCK(_x)
#endif

static int request_num_counter = 1;
#ifdef WITH_PROXY
static int request_will_proxy(REQUEST *request) CC_HINT(nonnull);
static int request_proxy(REQUEST *request, int retransmit) CC_HINT(nonnull);
STATE_MACHINE_DECL(request_ping) CC_HINT(nonnull);

STATE_MACHINE_DECL(request_response_delay) CC_HINT(nonnull);
STATE_MACHINE_DECL(request_cleanup_delay) CC_HINT(nonnull);
STATE_MACHINE_DECL(request_running) CC_HINT(nonnull);
STATE_MACHINE_DECL(request_done) CC_HINT(nonnull);

STATE_MACHINE_DECL(proxy_no_reply) CC_HINT(nonnull);
STATE_MACHINE_DECL(proxy_running) CC_HINT(nonnull);
STATE_MACHINE_DECL(proxy_wait_for_reply) CC_HINT(nonnull);

static int process_proxy_reply(REQUEST *request, RADIUS_PACKET *reply) CC_HINT(nonnull (1));
static void remove_from_proxy_hash(REQUEST *request) CC_HINT(nonnull);
static void remove_from_proxy_hash_nl(REQUEST *request, bool yank) CC_HINT(nonnull);
static int insert_into_proxy_hash(REQUEST *request) CC_HINT(nonnull);
#endif

static REQUEST *request_setup(TALLOC_CTX *ctx, rad_listen_t *listener, RADIUS_PACKET *packet,
                              RADCLIENT *client, RAD_REQUEST_FUNP fun);
static int request_pre_handler(REQUEST *request, UNUSED int action) CC_HINT(nonnull);

#ifdef WITH_COA
static void request_coa_originate(REQUEST *request) CC_HINT(nonnull);
STATE_MACHINE_DECL(coa_wait_for_reply) CC_HINT(nonnull);
STATE_MACHINE_DECL(coa_no_reply) CC_HINT(nonnull);
STATE_MACHINE_DECL(coa_running) CC_HINT(nonnull);
static void coa_separate(REQUEST *request) CC_HINT(nonnull);
#  define COA_SEPARATE if (request->coa) coa_separate(request->coa);
#else
#  define COA_SEPARATE
#endif

#define CHECK_FOR_STOP do { if (request->master_state == REQUEST_STOP_PROCESSING) {request_done(request, FR_ACTION_DONE);return;}} while (0)

#undef USEC
#define USEC (1000000)

#define INSERT_EVENT(_function, _ctx) if (!fr_event_insert(el, _function, _ctx, &((_ctx)->when), &((_ctx)->ev))) { _rad_panic(__FILE__, __LINE__, "Failed to insert event"); }

static void tv_add(struct timeval *tv, int usec_delay)
{
        if (usec_delay >= USEC) {
                tv->tv_sec += usec_delay / USEC;
                usec_delay %= USEC;
        }
        tv->tv_usec += usec_delay;

        if (tv->tv_usec >= USEC) {
                tv->tv_sec += tv->tv_usec / USEC;
                tv->tv_usec %= USEC;
        }
}

/*
 *      Debug the packet if requested.
 */
static void debug_packet(REQUEST *request, RADIUS_PACKET *packet, bool received)
{
        char src_ipaddr[128];
        char dst_ipaddr[128];

        if (!packet) return;
        if (!RDEBUG_ENABLED) return;

        /*
         *      Client-specific debugging re-prints the input
         *      packet into the client log.
         *
         *      This really belongs in a utility library
         */
        if (is_radius_code(packet->code)) {
                RDEBUG("%s %s Id %i from %s%s%s:%i to %s%s%s:%i length %zu",
                       received ? "Received" : "Sent",
                       fr_packet_codes[packet->code],
                       packet->id,
                       packet->src_ipaddr.af == AF_INET6 ? "[" : "",
                       inet_ntop(packet->src_ipaddr.af,
                                 &packet->src_ipaddr.ipaddr,
                                 src_ipaddr, sizeof(src_ipaddr)),
                       packet->src_ipaddr.af == AF_INET6 ? "]" : "",
                       packet->src_port,
                       packet->dst_ipaddr.af == AF_INET6 ? "[" : "",
                       inet_ntop(packet->dst_ipaddr.af,
                                 &packet->dst_ipaddr.ipaddr,
                                 dst_ipaddr, sizeof(dst_ipaddr)),
                       packet->dst_ipaddr.af == AF_INET6 ? "]" : "",
                       packet->dst_port,
                       packet->data_len);
        } else {
                RDEBUG("%s code %u Id %i from %s%s%s:%i to %s%s%s:%i length %zu\n",
                       received ? "Received" : "Sent",
                       packet->code,
                       packet->id,
                       packet->src_ipaddr.af == AF_INET6 ? "[" : "",
                       inet_ntop(packet->src_ipaddr.af,
                                 &packet->src_ipaddr.ipaddr,
                                 src_ipaddr, sizeof(src_ipaddr)),
                       packet->src_ipaddr.af == AF_INET6 ? "]" : "",
                       packet->src_port,
                       packet->dst_ipaddr.af == AF_INET6 ? "[" : "",
                       inet_ntop(packet->dst_ipaddr.af,
                                 &packet->dst_ipaddr.ipaddr,
                                 dst_ipaddr, sizeof(dst_ipaddr)),
                       packet->dst_ipaddr.af == AF_INET6 ? "]" : "",
                       packet->dst_port,
                       packet->data_len);
        }

        if (received) {
                rdebug_pair_list(L_DBG_LVL_1, request, packet->vps, NULL);
        } else {
                rdebug_proto_pair_list(L_DBG_LVL_1, request, packet->vps);
        }
}


/***********************************************************************
 *
 *      Start of RADIUS server state machine.
 *
 ***********************************************************************/

static struct timeval *request_response_window(REQUEST *request)
{
        VERIFY_REQUEST(request);

        if (request->client) {
                /*
                 *      The client hasn't set the response window.  Return
                 *      either the home server one, if set, or the global one.
                 */
                if (!timerisset(&request->client->response_window)) {
                        return &request->home_server->response_window;
                }

                if (timercmp(&request->client->response_window,
                             &request->home_server->response_window, <)) {
                        return &request->client->response_window;
                }
        }

        rad_assert(request->home_server != NULL);
        return &request->home_server->response_window;
}

/*
 * Determine initial request processing delay.
 */
static int request_init_delay(REQUEST *request)
{
        struct timeval half_response_window;

        VERIFY_REQUEST(request);

        /* Allow client response window to lower initial delay */
        if (timerisset(&request->client->response_window)) {
                half_response_window.tv_sec = request->client->response_window.tv_sec >> 1;
                half_response_window.tv_usec =
                        ((request->client->response_window.tv_sec & 1) * USEC +
                                request->client->response_window.tv_usec) >> 1;
                if (timercmp(&half_response_window, &request->root->init_delay, <))
                        return (int)half_response_window.tv_sec * USEC +
                                (int)half_response_window.tv_usec;
        }

        return (int)request->root->init_delay.tv_sec * USEC +
                (int)request->root->init_delay.tv_usec;
}

/*
 *      Callback for ALL timer events related to the request.
 */
static void request_timer(void *ctx)
{
        REQUEST *request = talloc_get_type_abort(ctx, REQUEST);
        int action;

        action = request->timer_action;

        TRACE_STATE_MACHINE;

        request->process(request, action);
}

/*
 *      Wrapper for talloc pools.  If there's no parent, just free the
 *      request.  If there is a parent, free the parent INSTEAD of the
 *      request.
 */
static void request_free(REQUEST *request)
{
        void *ptr;

        rad_assert(request->ev == NULL);
        rad_assert(!request->in_request_hash);
        rad_assert(!request->in_proxy_hash);

        if ((request->options & RAD_REQUEST_OPTION_CTX) == 0) {
                talloc_free(request);
                return;
        }

        ptr = talloc_parent(request);
        rad_assert(ptr != NULL);
        talloc_free(ptr);
}


#ifdef WITH_PROXY
static void proxy_reply_too_late(REQUEST *request)
{
        char buffer[128];

        RDEBUG2("Reply from home server %s port %d  - ID: %d arrived too late.  Try increasing 'retry_delay' or 'max_request_time'",
                inet_ntop(request->proxy->dst_ipaddr.af,
                          &request->proxy->dst_ipaddr.ipaddr,
                          buffer, sizeof(buffer)),
                request->proxy->dst_port, request->proxy->id);
}
#endif


/** Mark a request DONE and clean it up.
 *
 *  When a request is DONE, it can have ties to a number of other
 *  portions of the server.  The request hash, proxy hash, events,
 *  child threads, etc.  This function takes care of either cleaning
 *  up the request, or managing the timers to wait for the ties to be
 *  removed.
 *
 *  \dot
 *      digraph done {
 *              done -> done [ label = "still running" ];
 *      }
 *  \enddot
 */
static void request_done(REQUEST *request, int action)
{
        struct timeval now, when;

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;

        /*
         *      Force this no matter what.
         */
        request->process = request_done;

#ifdef WITH_DETAIL
        /*
         *      Tell the detail listener that we're done.
         */
        if (request->listener &&
            (request->listener->type == RAD_LISTEN_DETAIL) &&
            (request->simul_max != 1)) {
                request->simul_max = 1;
                request->listener->send(request->listener,
                                        request);
        }
#endif

#ifdef HAVE_PTHREAD_H
        /*
         *      If called from a child thread, mark ourselves as done,
         *      and wait for the master thread timer to clean us up.
         */
        if (!we_are_master()) {
                NO_CHILD_THREAD;
                request->child_state = REQUEST_DONE;
                return;
        }
#endif

        /*
         *      Mark the request as STOP.
         */
        request->master_state = REQUEST_STOP_PROCESSING;

#ifdef WITH_COA
        /*
         *      Move the CoA request to its own handler.
         */
        if (request->coa) {
                coa_separate(request->coa);
        } else if (request->parent && (request->parent->coa == request)) {
                coa_separate(request);
        }
#endif

        /*
         *      It doesn't hurt to send duplicate replies.  All other
         *      signals are ignored, as the request will be cleaned up
         *      soon anyways.
         */
        switch (action) {
        case FR_ACTION_DUP:
#ifdef WITH_DETAIL
                rad_assert(request->listener != NULL);
#endif
                if (request->reply->code != 0) {
                        request->listener->send(request->listener, request);
                        return;
                } else {
                        RDEBUG("No reply.  Ignoring retransmit");
                }
                break;

                /*
                 *      Mark the request as done.
                 */
        case FR_ACTION_DONE:
#ifdef HAVE_PTHREAD_H
                /*
                 *      If the child is still running, leave it alone.
                 */
                if (spawn_flag && (request->child_state <= REQUEST_RUNNING)) {
                        break;
                }
#endif

#ifdef DEBUG_STATE_MACHINE
                if (rad_debug_lvl) printf("(%u) ********\tSTATE %s C-%s -> C-%s\t********\n",
                                       request->number, __FUNCTION__,
                                       child_state_names[request->child_state],
                                       child_state_names[REQUEST_DONE]);
#endif
                request->child_state = REQUEST_DONE;
                break;

                /*
                 *      Called when the child is taking too long to
                 *      finish.  We've already marked it "please
                 *      stop", so we don't complain any more.
                 */
        case FR_ACTION_TIMER:
                break;

#ifdef WITH_PROXY
        case FR_ACTION_PROXY_REPLY:
                proxy_reply_too_late(request);
                break;
#endif

        default:
                break;
        }

        /*
         *      Remove it from the request hash.
         */
        if (request->in_request_hash) {
                if (!rbtree_deletebydata(pl, &request->packet)) {
                        rad_assert(0 == 1);
                }
                request->in_request_hash = false;
        }

#ifdef WITH_PROXY
        /*
         *      Wait for the proxy ID to expire.  This allows us to
         *      avoid re-use of proxy IDs for a while.
         */
        if (request->in_proxy_hash) {
                rad_assert(request->proxy != NULL);

                fr_event_now(el, &now);
                when = request->proxy->timestamp;

#ifdef WITH_COA
                if (((request->proxy->code == PW_CODE_COA_REQUEST) ||
                     (request->proxy->code == PW_CODE_DISCONNECT_REQUEST)) &&
                    (request->packet->code != request->proxy->code)) {
                        when.tv_sec += request->home_server->coa_mrd;
                } else
#endif
                        timeradd(&when, request_response_window(request), &when);

                /*
                 *      We haven't received all responses, AND there's still
                 *      time to wait.  Do so.
                 */
                if ((request->num_proxied_requests > request->num_proxied_responses) &&
#ifdef WITH_TCP
                    (request->home_server->proto != IPPROTO_TCP) &&
#endif
                    timercmp(&now, &when, <)) {
                        RDEBUG("Waiting for more responses from the home server");
                        goto wait_some_more;
                }

                /*
                 *      Time to remove it.
                 */
                remove_from_proxy_hash(request);
        }
#endif

#ifdef HAVE_PTHREAD_H
        /*
         *      If there's no children, we can mark the request as done.
         */
        if (!spawn_flag) request->child_state = REQUEST_DONE;
#endif

        /*
         *      If the child is still running, wait for it to be finished.
         */
        if (request->child_state <= REQUEST_RUNNING) {
                gettimeofday(&now, NULL);
#ifdef WITH_PROXY
        wait_some_more:
#endif
                when = now;
                if (request->delay < (USEC / 3)) request->delay = USEC / 3;
                tv_add(&when, request->delay);
                request->delay += request->delay >> 1;
                if (request->delay > (10 * USEC)) request->delay = 10 * USEC;

                STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                return;
        }

#ifdef HAVE_PTHREAD_H
        rad_assert(request->child_pid == NO_SUCH_CHILD_PID);
#endif

        /*
         *      @todo: do final states for TCP sockets, too?
         */
        request_stats_final(request);
#ifdef WITH_TCP
        if (request->listener) {
                request->listener->count--;

                /*
                 *      If we're the last one, remove the listener now.
                 */
                if ((request->listener->count == 0) &&
                    (request->listener->status >= RAD_LISTEN_STATUS_FROZEN)) {
                        event_new_fd(request->listener);
                }
        }
#endif

        if (request->packet) {
                RDEBUG2("Cleaning up request packet ID %u with timestamp +%d",
                        request->packet->id,
                        (unsigned int) (request->timestamp - fr_start_time));
        } /* else don't print anything */

        ASSERT_MASTER;
        fr_event_delete(el, &request->ev);
        request_free(request);
}


static void request_cleanup_delay_init(REQUEST *request)
{
        struct timeval now, when;

        VERIFY_REQUEST(request);

        /*
         *      Do cleanup delay ONLY for RADIUS packets from a real
         *      client.  Everything else just gets cleaned up
         *      immediately.
         */
        if (request->packet->dst_port == 0) goto done;

        /*
         *      Accounting packets shouldn't be retransmitted.  They
         *      should always be updated with Acct-Delay-Time.
         */
#ifdef WITH_ACCOUNTING
        if (request->packet->code == PW_CODE_ACCOUNTING_REQUEST) goto done;
#endif

#ifdef WITH_DHCP
        if (request->listener->type == RAD_LISTEN_DHCP) goto done;
#endif

#ifdef WITH_VMPS
        if (request->listener->type == RAD_LISTEN_VQP) goto done;
#endif

        if (!request->root->cleanup_delay) goto done;

        gettimeofday(&now, NULL);

        rad_assert(request->reply->timestamp.tv_sec != 0);
        when = request->reply->timestamp;

        request->delay = request->root->cleanup_delay;
        when.tv_sec += request->delay;

        /*
         *      Set timer for when we need to clean it up.
         */
        if (timercmp(&when, &now, >)) {
#ifdef DEBUG_STATE_MACHINE
                if (rad_debug_lvl) printf("(%u) ********\tNEXT-STATE %s -> %s\n", request->number, __FUNCTION__, "request_cleanup_delay");
#endif
                request->process = request_cleanup_delay;
                request->child_state = REQUEST_CLEANUP_DELAY;

                /*
                 *      Update this if we can, otherwise let the timers pick it up.
                 */
                if (we_are_master()) {
                        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                } else {
                        NO_CHILD_THREAD;
                }
                return;
        }

        /*
         *      Otherwise just clean it up.
         */
done:
        request_done(request, FR_ACTION_DONE);
}


/*
 *      Enforce max_request_time.
 */
static bool request_max_time(REQUEST *request)
{
        struct timeval now, when;
        rad_assert(request->magic == REQUEST_MAGIC);
#ifdef DEBUG_STATE_MACHINE
        int action = FR_ACTION_TIMER;
#endif

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;

        /*
         *      The child thread has acknowledged it's done.
         *      Transition to the DONE state.
         *
         *      If the request was marked STOP, then the "check for
         *      stop" macro already took care of it.
         */
        if (request->child_state == REQUEST_DONE) {
        done:
                request_done(request, FR_ACTION_DONE);
                return true;
        }

        /*
         *      The request is still running.  Enforce max_request_time.
         */
        fr_event_now(el, &now);
        when = request->packet->timestamp;
        when.tv_sec += request->root->max_request_time;

        /*
         *      Taking too long: tell it to die.
         */
        if (timercmp(&now, &when, >=)) {
#ifdef HAVE_PTHREAD_H
                /*
                 *      If there's a child thread processing it,
                 *      complain.
                 */
                if (spawn_flag &&
                    (pthread_equal(request->child_pid, NO_SUCH_CHILD_PID) == 0)) {
                        ERROR("Unresponsive child for request %u, in component %s module %s",
                              request->number,
                              request->component ? request->component : "<core>",
                              request->module ? request->module : "<core>");
                        exec_trigger(request, NULL, "server.thread.unresponsive", true);
                }
#endif
                /*
                 *      Tell the request that it's done.
                 */
                goto done;
        }

        /*
         *      Sleep for some more.  We HOPE that the child will
         *      become responsive at some point in the future.  We do
         *      this by adding 50% to the current timer.
         */
        when = now;
        tv_add(&when, request->delay);
        request->delay += request->delay >> 1;
        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
        return false;
}

static void request_queue_or_run(REQUEST *request,
                                 fr_request_process_t process)
{
#ifdef DEBUG_STATE_MACHINE
        int action = FR_ACTION_TIMER;
#endif

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;

        /*
         *      Do this here so that fewer other functions need to do
         *      it.
         */
        if (request->master_state == REQUEST_STOP_PROCESSING) {
#ifdef DEBUG_STATE_MACHINE
                if (rad_debug_lvl) printf("(%u) ********\tSTATE %s M-%s causes C-%s-> C-%s\t********\n",
                                       request->number, __FUNCTION__,
                                       master_state_names[request->master_state],
                                       child_state_names[request->child_state],
                                       child_state_names[REQUEST_DONE]);
#endif
                request_done(request, FR_ACTION_DONE);
                return;
        }

        request->process = process;

        if (we_are_master()) {
                struct timeval when;

                /*
                 *      (re) set the initial delay.
                 */
                request->delay = request_init_delay(request);
                if (request->delay > USEC) request->delay = USEC;
                gettimeofday(&when, NULL);
                tv_add(&when, request->delay);
                request->delay += request->delay >> 1;

                STATE_MACHINE_TIMER(FR_ACTION_TIMER);

#ifdef HAVE_PTHREAD_H
                if (spawn_flag) {
                        /*
                         *      A child thread will eventually pick it up.
                         */
                        if (request_enqueue(request)) return;

                        /*
                         *      Otherwise we're not going to do anything with
                         *      it...
                         */
                        request_done(request, FR_ACTION_DONE);
                        return;
                }
#endif
        }

        request->child_state = REQUEST_RUNNING;
        request->process(request, FR_ACTION_RUN);

#ifdef WNOHANG
        /*
         *      Requests that care about child process exit
         *      codes have already either called
         *      rad_waitpid(), or they've given up.
         */
        while (waitpid(-1, NULL, WNOHANG) > 0);
#endif
}


static void request_dup(REQUEST *request)
{
        ERROR("(%u) Ignoring duplicate packet from "
              "client %s port %d - ID: %u due to unfinished request "
              "in component %s module %s",
              request->number, request->client->shortname,
              request->packet->src_port,request->packet->id,
              request->component, request->module);
}


/** Sit on a request until it's time to clean it up.
 *
 *  A NAS may not see a response from the server.  When the NAS
 *  retransmits, we want to be able to send a cached reply back.  The
 *  alternative is to re-process the packet, which does bad things for
 *  EAP, among others.
 *
 *  IF we do see a NAS retransmit, we extend the cleanup delay,
 *  because the NAS might miss our cached reply.
 *
 *  Otherwise, once we reach cleanup_delay, we transition to DONE.
 *
 *  \dot
 *      digraph cleanup_delay {
 *              cleanup_delay;
 *              send_reply [ label = "send_reply\nincrease cleanup delay" ];
 *
 *              cleanup_delay -> send_reply [ label = "DUP" ];
 *              send_reply -> cleanup_delay;
 *              cleanup_delay -> proxy_reply_too_late [ label = "PROXY_REPLY", arrowhead = "none" ];
 *              cleanup_delay -> cleanup_delay [ label = "TIMER < timeout" ];
 *              cleanup_delay -> done [ label = "TIMER >= timeout" ];
 *      }
 *  \enddot
 */
static void request_cleanup_delay(REQUEST *request, int action)
{
        struct timeval when, now;

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;
        COA_SEPARATE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_DUP:
                if (request->reply->code != 0) {
                        request->listener->send(request->listener, request);
                } else {
                        RDEBUG("No reply.  Ignoring retransmit");
                }

                /*
                 *      Double the cleanup_delay to catch retransmits.
                 */
                when = request->reply->timestamp;
                request->delay += request->delay;
                when.tv_sec += request->delay;

                STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                break;

#ifdef WITH_PROXY
        case FR_ACTION_PROXY_REPLY:
                proxy_reply_too_late(request);
                break;
#endif

        case FR_ACTION_TIMER:
                fr_event_now(el, &now);

                rad_assert(request->root->cleanup_delay > 0);

                when = request->reply->timestamp;
                when.tv_sec += request->root->cleanup_delay;

                if (timercmp(&when, &now, >)) {
#ifdef DEBUG_STATE_MACHINE
                        if (rad_debug_lvl) printf("(%u) ********\tNEXT-STATE %s -> %s\n", request->number, __FUNCTION__, "request_cleanup_delay");
#endif
                        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                        return;
                } /* else it's time to clean up */

                request_done(request, REQUEST_DONE);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}


/** Sit on a request until it's time to respond to it.
 *
 *  For security reasons, rejects (and maybe some other) packets are
 *  delayed for a while before we respond.  This delay means that
 *  badly behaved NASes don't hammer the server with authentication
 *  attempts.
 *
 *  Otherwise, once we reach response_delay, we send the reply, and
 *  transition to cleanup_delay.
 *
 *  \dot
 *      digraph response_delay {
 *              response_delay -> proxy_reply_too_late [ label = "PROXY_REPLY", arrowhead = "none" ];
 *              response_delay -> response_delay [ label = "DUP, TIMER < timeout" ];
 *              response_delay -> send_reply [ label = "TIMER >= timeout" ];
 *              send_reply -> cleanup_delay;
 *      }
 *  \enddot
 */
static void request_response_delay(REQUEST *request, int action)
{
        struct timeval when, now;

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;
        COA_SEPARATE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_DUP:
                ERROR("(%u) Discarding duplicate request from "
                      "client %s port %d - ID: %u due to delayed response",
                      request->number, request->client->shortname,
                      request->packet->src_port,request->packet->id);
                break;

#ifdef WITH_PROXY
        case FR_ACTION_PROXY_REPLY:
                proxy_reply_too_late(request);
                break;
#endif

        case FR_ACTION_TIMER:
                fr_event_now(el, &now);

                /*
                 *      See if it's time to send the reply.  If not,
                 *      we wait some more.
                 */
                when = request->reply->timestamp;

                tv_add(&when, request->response_delay.tv_sec * USEC);
                tv_add(&when, request->response_delay.tv_usec);

                if (timercmp(&when, &now, >)) {
#ifdef DEBUG_STATE_MACHINE
                        if (rad_debug_lvl) printf("(%u) ********\tNEXT-STATE %s -> %s\n", request->number, __FUNCTION__, "request_response_delay");
#endif
                        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                        return;
                } /* else it's time to send the reject */

                RDEBUG2("Sending delayed response");
                debug_packet(request, request->reply, false);
                request->listener->send(request->listener, request);

                /*
                 *      Clean up the request.
                 */
                request_cleanup_delay_init(request);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}


static int request_pre_handler(REQUEST *request, UNUSED int action)
{
        int rcode;

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;

        if (request->master_state == REQUEST_STOP_PROCESSING) return 0;

        /*
         *      Don't decode the packet if it's an internal "fake"
         *      request.  Instead, just return so that the caller can
         *      process it.
         */
        if (request->packet->dst_port == 0) {
                request->username = fr_pair_find_by_num(request->packet->vps, PW_USER_NAME, 0, TAG_ANY);
                request->password = fr_pair_find_by_num(request->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);
                return 1;
        }

        if (!request->packet->vps) { /* FIXME: check for correct state */
                rcode = request->listener->decode(request->listener, request);

#ifdef WITH_UNLANG
                if (debug_condition) {
                        /*
                         *      Ignore parse errors.
                         */
                        if (radius_evaluate_cond(request, RLM_MODULE_OK, 0, debug_condition)) {
                                request->log.lvl = L_DBG_LVL_2;
                                request->log.func = vradlog_request;
                        }
                }
#endif

                debug_packet(request, request->packet, true);
        } else {
                rcode = 0;
        }

        if (rcode < 0) {
                RATE_LIMIT(INFO("Dropping packet without response because of error: %s", fr_strerror()));
                request->reply->offset = -2; /* bad authenticator */
                return 0;
        }

        if (!request->username) {
                request->username = fr_pair_find_by_num(request->packet->vps, PW_USER_NAME, 0, TAG_ANY);
        }

        return 1;
}


/**  Do the final processing of a request before we reply to the NAS.
 *
 *  Various cleanups, suppress responses, copy Proxy-State, and set
 *  response_delay or cleanup_delay;
 */
static void request_finish(REQUEST *request, int action)
{
        VALUE_PAIR *vp;

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        (void) action;  /* -Wunused */

#ifdef WITH_COA
        /*
         *      Don't do post-auth if we're a CoA request originated
         *      from an Access-Request.  See request_alloc_coa() for
         *      details.
         */
        if ((request->options & RAD_REQUEST_OPTION_COA) != 0) goto done;
#endif

        /*
         *      Override the response code if a control:Response-Packet-Type attribute is present.
         */
        vp = fr_pair_find_by_num(request->config, PW_RESPONSE_PACKET_TYPE, 0, TAG_ANY);
        if (vp) {
                if (vp->vp_integer == 256) {
                        RDEBUG2("Not responding to request");
                        request->reply->code = 0;
                } else {
                        request->reply->code = vp->vp_integer;
                }
        }
        /*
         *      Catch Auth-Type := Reject BEFORE proxying the packet.
         */
        else if (request->packet->code == PW_CODE_ACCESS_REQUEST) {
                if (request->reply->code == 0) {
                        vp = fr_pair_find_by_num(request->config, PW_AUTH_TYPE, 0, TAG_ANY);
                        if (!vp || (vp->vp_integer != 5)) {
                                RDEBUG2("There was no response configured: "
                                        "rejecting request");
                        }

                        request->reply->code = PW_CODE_ACCESS_REJECT;
                }
        }

        /*
         *      Copy Proxy-State from the request to the reply.
         */
        vp = fr_pair_list_copy_by_num(request->reply, request->packet->vps,
                       PW_PROXY_STATE, 0, TAG_ANY);
        if (vp) fr_pair_add(&request->reply->vps, vp);

        /*
         *      Call Post-Auth for Access-Request packets.
         */
        if (request->packet->code == PW_CODE_ACCESS_REQUEST) {
                rad_postauth(request);
        }

#ifdef WITH_COA
        /*
         *      Maybe originate a CoA request.
         */
        if ((action == FR_ACTION_RUN) && !request->proxy && request->coa) {
                request_coa_originate(request);
        }
#endif

        /*
         *      Clean up.  These are no longer needed.
         */
        gettimeofday(&request->reply->timestamp, NULL);

        /*
         *      Fake packets get marked as "done", and have the
         *      proxy-reply section deal with the reply attributes.
         *      We therefore don't free the reply attributes.
         */
        if (request->packet->dst_port == 0) {
                RDEBUG("Finished internally proxied request.");
                NO_CHILD_THREAD;
                request->child_state = REQUEST_DONE;
                return;
        }

#ifdef WITH_DETAIL
        /*
         *      Always send the reply to the detail listener.
         */
        if (request->listener->type == RAD_LISTEN_DETAIL) {
                request->simul_max = 1;

                /*
                 *      But only print the reply if there is one.
                 */
                if (request->reply->code != 0) {
                        debug_packet(request, request->reply, false);
                }

                request->listener->send(request->listener, request);
                goto done;
        }
#endif

        /*
         *      Ignore all "do not respond" packets.
         *      Except for the detail ones, which need to ping
         *      the detail file reader so that it will retransmit.
         */
        if (!request->reply->code) {
                RDEBUG("Not sending reply to client.");
                goto done;
        }

        /*
         *      If it's not in the request hash, we MIGHT not want to
         *      send a reply.
         *
         *      If duplicate packets are allowed, then then only
         *      reason to NOT be in the request hash is because we
         *      don't want to send a reply.
         *
         *      FIXME: this is crap.  The rest of the state handling
         *      should use a different field so that we don't have two
         *      meanings for it.
         *
         *      Otherwise duplicates are forbidden, and the request is
         *      SUPPOSED to avoid the request hash.
         *
         *      In that case, we need to send a reply.
         */
        if (!request->in_request_hash &&
            !request->listener->nodup) {
                RDEBUG("Suppressing reply to client.");
                goto done;
        }

        /*
         *      See if we need to delay an Access-Reject packet.
         */
        if ((request->reply->code == PW_CODE_ACCESS_REJECT) &&
            (request->root->reject_delay.tv_sec > 0)) {
                request->response_delay = request->root->reject_delay;

#ifdef WITH_PROXY
                /*
                 *      If we timed out a proxy packet, don't delay
                 *      the reject any more.
                 */
                if (request->proxy && !request->proxy_reply) {
                        request->response_delay.tv_sec = 0;
                        request->response_delay.tv_usec = 0;
                }
#endif
        }

        /*
         *      Send the reply.
         */
        if ((request->response_delay.tv_sec == 0) &&
            (request->response_delay.tv_usec == 0)) {

                /*
                 *      Don't print a reply if there's none to send.
                 */
                if (request->reply->code != 0) {
                        debug_packet(request, request->reply, false);
                        request->listener->send(request->listener, request);
                }

        done:
                RDEBUG2("Finished request");
                request->component = "<core>";
                request->module = "<done>";

                request_cleanup_delay_init(request);

        } else {
                /*
                 *      Encode and sign it here, so that the master
                 *      thread can just send the encoded data, which
                 *      means it does less work.
                 */
                RDEBUG2("Delaying response for %d.%06d seconds",
                        (int) request->response_delay.tv_sec, (int) request->response_delay.tv_usec);
                request->listener->encode(request->listener, request);
                request->component = "<core>";
                request->module = "<delay>";
                request->process = request_response_delay;
                NO_CHILD_THREAD;
                request->child_state = REQUEST_RESPONSE_DELAY;
        }
}

/** Process a request from a client.
 *
 *  The outcome might be that the request is proxied.
 *
 *  \dot
 *      digraph running {
 *              running -> running [ label = "TIMER < max_request_time" ];
 *              running -> done [ label = "TIMER >= max_request_time" ];
 *              running -> proxy [ label = "proxied" ];
 *              running -> dup [ label = "DUP", arrowhead = "none" ];
 *      }
 *  \enddot
 */
static void request_running(REQUEST *request, int action)
{
        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_TIMER:
                COA_SEPARATE;
                (void) request_max_time(request);
                break;

        case FR_ACTION_DUP:
                request_dup(request);
                break;

        case FR_ACTION_RUN:
                if (!request_pre_handler(request, action)) {
#ifdef DEBUG_STATE_MACHINE
                        if (rad_debug_lvl) printf("(%u) ********\tSTATE %s failed in pre-handler C-%s -> C-%s\t********\n",
                                               request->number, __FUNCTION__,
                                               child_state_names[request->child_state],
                                               child_state_names[REQUEST_DONE]);
#endif

                        NO_CHILD_THREAD;
                        request->child_state = REQUEST_DONE;
                        break;
                }

                rad_assert(request->handle != NULL);
                request->handle(request);

#ifdef WITH_PROXY
                /*
                 *      We may need to send a proxied request.
                 */
                if ((action == FR_ACTION_RUN) &&
                    request_will_proxy(request)) {
#ifdef DEBUG_STATE_MACHINE
                        if (rad_debug_lvl) printf("(%u) ********\tWill Proxy\t********\n", request->number);
#endif
                        /*
                         *      If this fails, it
                         *      takes care of setting
                         *      up the post proxy fail
                         *      handler.
                         */
                        if (request_proxy(request, 0) < 0) goto req_finished;
                } else
#endif
                {
#ifdef DEBUG_STATE_MACHINE
                        if (rad_debug_lvl) printf("(%u) ********\tFinished\t********\n", request->number);
#endif

#ifdef WITH_PROXY
                req_finished:
#endif
                        request_finish(request, action);
                }
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}

int request_receive(TALLOC_CTX *ctx, rad_listen_t *listener, RADIUS_PACKET *packet,
                    RADCLIENT *client, RAD_REQUEST_FUNP fun)
{
        uint32_t count;
        RADIUS_PACKET **packet_p;
        REQUEST *request = NULL;
        struct timeval now;
        listen_socket_t *sock = NULL;

        VERIFY_PACKET(packet);

        /*
         *      Set the last packet received.
         */
        gettimeofday(&now, NULL);

        packet->timestamp = now;

#ifdef WITH_ACCOUNTING
        if (listener->type != RAD_LISTEN_DETAIL)
#endif
        {
                sock = listener->data;
                sock->last_packet = now.tv_sec;

#ifdef WITH_TCP
                packet->proto = sock->proto;
#endif
        }

        /*
         *      Skip everything if required.
         */
        if (listener->nodup) goto skip_dup;

        packet_p = rbtree_finddata(pl, &packet);
        if (packet_p) {
                rad_child_state_t child_state;

                request = fr_packet2myptr(REQUEST, packet, packet_p);
                rad_assert(request->in_request_hash);
                child_state = request->child_state;

                /*
                 *      Same src/dst ip/port, length, and
                 *      authentication vector: must be a duplicate.
                 */
                if ((request->packet->data_len == packet->data_len) &&
                    (memcmp(request->packet->vector, packet->vector,
                            sizeof(packet->vector)) == 0)) {

#ifdef WITH_STATS
                        switch (packet->code) {
                        case PW_CODE_ACCESS_REQUEST:
                                FR_STATS_INC(auth, total_dup_requests);
                                break;

#ifdef WITH_ACCOUNTING
                        case PW_CODE_ACCOUNTING_REQUEST:
                                FR_STATS_INC(acct, total_dup_requests);
                                break;
#endif
#ifdef WITH_COA
                        case PW_CODE_COA_REQUEST:
                                FR_STATS_INC(coa, total_dup_requests);
                                break;

                        case PW_CODE_DISCONNECT_REQUEST:
                                FR_STATS_INC(dsc, total_dup_requests);
                                break;
#endif

                        default:
                                break;
                        }
#endif  /* WITH_STATS */

                        /*
                         *      Tell the state machine that there's a
                         *      duplicate request.
                         */
                        request->process(request, FR_ACTION_DUP);
                        return 0; /* duplicate of live request */
                }

                /*
                 *      Mark the request as done ASAP, and before we
                 *      log anything.  The child may stop processing
                 *      the request just as we're logging the
                 *      complaint.
                 */
                request_done(request, FR_ACTION_DONE);
                request = NULL;

                /*
                 *      It's a new request, not a duplicate.  If the
                 *      old one is done, then we can clean it up.
                 */
                if (child_state <= REQUEST_RUNNING) {
                        /*
                         *      The request is still QUEUED or RUNNING.  That's a problem.
                         */
                        ERROR("Received conflicting packet from "
                              "client %s port %d - ID: %u due to "
                              "unfinished request.  Giving up on old request.",
                              client->shortname,
                              packet->src_port, packet->id);
                }

                /*
                 *      Mark the old request as done.  If there's no
                 *      child, the request will be cleaned up
                 *      immediately.  If there is a child, we'll set a
                 *      timer to go clean up the request.
                 */
        } /* else the new packet is unique */

        /*
         *      Quench maximum number of outstanding requests.
         */
        if (main_config.max_requests &&
            ((count = rbtree_num_elements(pl)) > main_config.max_requests)) {
                RATE_LIMIT(ERROR("Dropping request (%d is too many): from client %s port %d - ID: %d", count,
                                 client->shortname,
                                 packet->src_port, packet->id);
                           WARN("Please check the configuration file.\n"
                                "\tThe value for 'max_requests' is probably set too low.\n"));

                exec_trigger(NULL, NULL, "server.max_requests", true);
                return 0;
        }

skip_dup:
        /*
         *      Rate-limit the incoming packets
         */
        if (sock && sock->max_rate) {
                uint32_t pps;

                pps = rad_pps(&sock->rate_pps_old, &sock->rate_pps_now, &sock->rate_time, &now);
                if (pps > sock->max_rate) {
                        DEBUG("Dropping request due to rate limiting");
                        return 0;
                }
                sock->rate_pps_now++;
        }

        /*
         *      Allocate a pool for the request.
         */
        if (!ctx) {
                ctx = talloc_pool(NULL, main_config.talloc_pool_size);
                if (!ctx) return 0;
                talloc_set_name_const(ctx, "request_receive_pool");

                /*
                 *      The packet is still allocated from a different
                 *      context, but oh well.
                 */
                (void) talloc_steal(ctx, packet);
        }

        request = request_setup(ctx, listener, packet, client, fun);
        if (!request) {
                talloc_free(ctx);
                return 1;
        }

        /*
         *      Mark it as a "real" request with a context.
         */
        request->options |= RAD_REQUEST_OPTION_CTX;

        /*
         *      Remember the request in the list.
         */
        if (!listener->nodup) {
                if (!rbtree_insert(pl, &request->packet)) {
                        RERROR("Failed to insert request in the list of live requests: discarding it");
                        request_done(request, FR_ACTION_DONE);
                        return 1;
                }

                request->in_request_hash = true;
        }

        /*
         *      Process it.  Send a response, and free it.
         */
        if (listener->synchronous) {
#ifdef WITH_DETAIL
                rad_assert(listener->type != RAD_LISTEN_DETAIL);
#endif

                request->listener->decode(request->listener, request);
                request->username = fr_pair_find_by_num(request->packet->vps, PW_USER_NAME, 0, TAG_ANY);
                request->password = fr_pair_find_by_num(request->packet->vps, PW_USER_PASSWORD, 0, TAG_ANY);

                fun(request);

                if (request->reply->code != 0) {
                        request->listener->send(request->listener, request);
                } else {
                        RDEBUG("Not sending reply");
                }

                /*
                 *      Don't do delayed reject.  Oh well.
                 */
                request_free(request);
                return 1;
        }

        /*
         *      Otherwise, insert it into the state machine.
         *      The child threads will take care of processing it.
         */
        request_queue_or_run(request, request_running);

        return 1;
}


static REQUEST *request_setup(TALLOC_CTX *ctx, rad_listen_t *listener, RADIUS_PACKET *packet,
                              RADCLIENT *client, RAD_REQUEST_FUNP fun)
{
        REQUEST *request;

        /*
         *      Create and initialize the new request.
         */
        request = request_alloc(ctx);
        if (!request) {
                ERROR("No memory");
                return NULL;
        }
        request->reply = rad_alloc(request, false);
        if (!request->reply) {
                ERROR("No memory");
                talloc_free(request);
                return NULL;
        }

        request->listener = listener;
        request->client = client;
        request->packet = talloc_steal(request, packet);
        request->number = request_num_counter++;
        request->priority = listener->type;
        request->master_state = REQUEST_ACTIVE;
        request->child_state = REQUEST_RUNNING;
#ifdef DEBUG_STATE_MACHINE
        if (rad_debug_lvl) printf("(%u) ********\tSTATE %s C-%s -> C-%s\t********\n",
                               request->number, __FUNCTION__,
                               child_state_names[request->child_state],
                               child_state_names[REQUEST_RUNNING]);
#endif
#ifdef HAVE_PTHREAD_H
        request->child_pid = NO_SUCH_CHILD_PID;
#endif
        request->handle = fun;
        NO_CHILD_THREAD;

#ifdef WITH_STATS
        request->listener->stats.last_packet = request->packet->timestamp.tv_sec;
        if (packet->code == PW_CODE_ACCESS_REQUEST) {
                request->client->auth.last_packet = request->packet->timestamp.tv_sec;
                radius_auth_stats.last_packet = request->packet->timestamp.tv_sec;
#ifdef WITH_ACCOUNTING
        } else if (packet->code == PW_CODE_ACCOUNTING_REQUEST) {
                request->client->acct.last_packet = request->packet->timestamp.tv_sec;
                radius_acct_stats.last_packet = request->packet->timestamp.tv_sec;
#endif
        }
#endif  /* WITH_STATS */

        /*
         *      Status-Server packets go to the head of the queue.
         */
        if (request->packet->code == PW_CODE_STATUS_SERVER) request->priority = 0;

        /*
         *      Set virtual server identity
         */
        if (client->server) {
                request->server = client->server;
        } else if (listener->server) {
                request->server = listener->server;
        } else {
                request->server = NULL;
        }

        request->root = &main_config;
#ifdef WITH_TCP
        request->listener->count++;
#endif

        /*
         *      The request passes many of our sanity checks.
         *      From here on in, if anything goes wrong, we
         *      send a reject message, instead of dropping the
         *      packet.
         */

        /*
         *      Build the reply template from the request.
         */

        request->reply->sockfd = request->packet->sockfd;
        request->reply->dst_ipaddr = request->packet->src_ipaddr;
        request->reply->src_ipaddr = request->packet->dst_ipaddr;
        request->reply->dst_port = request->packet->src_port;
        request->reply->src_port = request->packet->dst_port;
        request->reply->id = request->packet->id;
        request->reply->code = 0; /* UNKNOWN code */
        memcpy(request->reply->vector, request->packet->vector,
               sizeof(request->reply->vector));
        request->reply->vps = NULL;
        request->reply->data = NULL;
        request->reply->data_len = 0;

        return request;
}

#ifdef WITH_TCP
/***********************************************************************
 *
 *      TCP Handlers.
 *
 ***********************************************************************/

/*
 *      Timer function for all TCP sockets.
 */
static void tcp_socket_timer(void *ctx)
{
        rad_listen_t *listener = talloc_get_type_abort(ctx, rad_listen_t);
        listen_socket_t *sock = listener->data;
        struct timeval end, now;
        char buffer[256];
        fr_socket_limit_t *limit;

        ASSERT_MASTER;

        if (listener->status != RAD_LISTEN_STATUS_KNOWN) return;

        fr_event_now(el, &now);

        switch (listener->type) {
#ifdef WITH_PROXY
        case RAD_LISTEN_PROXY:
                limit = &sock->home->limit;
                break;
#endif

        case RAD_LISTEN_AUTH:
#ifdef WITH_ACCOUNTING
        case RAD_LISTEN_ACCT:
#endif
                limit = &sock->limit;
                break;

        default:
                return;
        }

        /*
         *      If we enforce a lifetime, do it now.
         */
        if (limit->lifetime > 0) {
                end.tv_sec = sock->opened + limit->lifetime;
                end.tv_usec = 0;

                if (timercmp(&end, &now, <=)) {
                        listener->print(listener, buffer, sizeof(buffer));
                        DEBUG("Reached maximum lifetime on socket %s", buffer);

                do_close:

#ifdef WITH_PROXY
                        /*
                         *      Proxy sockets get frozen, so that we don't use
                         *      them for new requests.  But we do keep them
                         *      open to listen for replies to requests we had
                         *      previously sent.
                         */
                        if (listener->type == RAD_LISTEN_PROXY) {
                                PTHREAD_MUTEX_LOCK(&proxy_mutex);
                                if (!fr_packet_list_socket_freeze(proxy_list,
                                                                  listener->fd)) {
                                        ERROR("Fatal error freezing socket: %s", fr_strerror());
                                        fr_exit(1);
                                }
                                PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                        }
#endif

                        /*
                         *      Mark the socket as "don't use if at all possible".
                         */
                        listener->status = RAD_LISTEN_STATUS_FROZEN;
                        event_new_fd(listener);
                        return;
                }
        } else {
                end = now;
                end.tv_sec += 3600;
        }

        /*
         *      Enforce an idle timeout.
         */
        if (limit->idle_timeout > 0) {
                struct timeval idle;

                rad_assert(sock->last_packet != 0);
                idle.tv_sec = sock->last_packet + limit->idle_timeout;
                idle.tv_usec = 0;

                if (timercmp(&idle, &now, <=)) {
                        listener->print(listener, buffer, sizeof(buffer));
                        DEBUG("Reached idle timeout on socket %s", buffer);
                        goto do_close;
                }

                /*
                 *      Enforce the minimum of idle timeout or lifetime.
                 */
                if (timercmp(&idle, &end, <)) {
                        end = idle;
                }
        }

        /*
         *      Wake up at t + 0.5s.  The code above checks if the timers
         *      are <= t.  This addition gives us a bit of leeway.
         */
        end.tv_usec = USEC / 2;

        ASSERT_MASTER;
        if (!fr_event_insert(el, tcp_socket_timer, listener, &end, &sock->ev)) {
                rad_panic("Failed to insert event");
        }
}


#ifdef WITH_PROXY
/*
 *      Add +/- 2s of jitter, as suggested in RFC 3539
 *      and in RFC 5080.
 */
static void add_jitter(struct timeval *when)
{
        uint32_t jitter;

        when->tv_sec -= 2;

        jitter = fr_rand();
        jitter ^= (jitter >> 10);
        jitter &= ((1 << 22) - 1); /* 22 bits of 1 */

        /*
         *      Add in ~ (4 * USEC) of jitter.
         */
        tv_add(when, jitter);
}

/*
 *      Called by socket_del to remove requests with this socket
 */
static int eol_proxy_listener(void *ctx, void *data)
{
        rad_listen_t *this = talloc_get_type_abort(ctx, rad_listen_t);
        RADIUS_PACKET **proxy_p = data;
        REQUEST *request;

        request = fr_packet2myptr(REQUEST, proxy, proxy_p);
        if (request->proxy_listener != this) return 0;

        /*
         *      The normal "remove_from_proxy_hash" tries to grab the
         *      proxy mutex.  We already have it held, so grabbing it
         *      again will cause a deadlock.  Instead, call the "no
         *      lock" version of the function.
         */
        rad_assert(request->in_proxy_hash == true);
        remove_from_proxy_hash_nl(request, false);

        /*
         *      Don't mark it as DONE.  The client can retransmit, and
         *      the packet SHOULD be re-proxied somewhere else.
         *
         *      Return "2" means that the rbtree code will remove it
         *      from the tree, and we don't need to do it ourselves.
         */
        return 2;
}
#endif  /* WITH_PROXY */

static int eol_listener(void *ctx, void *data)
{
        rad_listen_t *this = talloc_get_type_abort(ctx, rad_listen_t);
        RADIUS_PACKET **packet_p = data;
        REQUEST *request;

        request = fr_packet2myptr(REQUEST, packet, packet_p);
        if (request->listener != this) return 0;

        request->master_state = REQUEST_STOP_PROCESSING;
        request->process = request_done;

        return 0;
}
#endif  /* WITH_TCP */

#ifdef WITH_PROXY
/***********************************************************************
 *
 *      Proxy handlers for the state machine.
 *
 ***********************************************************************/

/*
 *      Called with the proxy mutex held
 */
static void remove_from_proxy_hash_nl(REQUEST *request, bool yank)
{
        VERIFY_REQUEST(request);

        if (!request->in_proxy_hash) return;

        fr_packet_list_id_free(proxy_list, request->proxy, yank);
        request->in_proxy_hash = false;

        /*
         *      On the FIRST reply, decrement the count of outstanding
         *      requests.  Note that this is NOT the count of sent
         *      packets, but whether or not the home server has
         *      responded at all.
         */
        if (request->home_server &&
            request->home_server->currently_outstanding) {
                request->home_server->currently_outstanding--;

                /*
                 *      If we're NOT sending it packets, AND it's been
                 *      a while since we got a response, then we don't
                 *      know if it's alive or dead.
                 */
                if ((request->home_server->currently_outstanding == 0) &&
                    (request->home_server->state == HOME_STATE_ALIVE)) {
                        struct timeval when, now;

                        when.tv_sec = request->home_server->last_packet_recv ;
                        when.tv_usec = 0;

                        timeradd(&when, request_response_window(request), &when);
                        gettimeofday(&now, NULL);

                        /*
                         *      last_packet + response_window
                         *
                         *      We *administratively* mark the home
                         *      server as "unknown" state, because we
                         *      haven't seen a packet for a while.
                         */
                        if (timercmp(&now, &when, >)) {
                                request->home_server->state = HOME_STATE_UNKNOWN;
                                request->home_server->last_packet_sent = 0;
                                request->home_server->last_packet_recv = 0;
                        }
                }
        }

#ifdef WITH_TCP
        rad_assert(request->proxy_listener != NULL);
        request->proxy_listener->count--;
#endif
        request->proxy_listener = NULL;

        /*
         *      Got from YES in hash, to NO, not in hash while we hold
         *      the mutex.  This guarantees that when another thread
         *      grabs the mutex, the "not in hash" flag is correct.
         */
}

static void remove_from_proxy_hash(REQUEST *request)
{
        VERIFY_REQUEST(request);

        /*
         *      Check this without grabbing the mutex because it's a
         *      lot faster that way.
         */
        if (!request->in_proxy_hash) return;

        /*
         *      The "not in hash" flag is definitive.  However, if the
         *      flag says that it IS in the hash, there might still be
         *      a race condition where it isn't.
         */
        PTHREAD_MUTEX_LOCK(&proxy_mutex);

        if (!request->in_proxy_hash) {
                PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                return;
        }

        remove_from_proxy_hash_nl(request, true);

        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
}

static int insert_into_proxy_hash(REQUEST *request)
{
        char buf[128];
        int tries;
        bool success = false;
        void *proxy_listener;

        VERIFY_REQUEST(request);

        rad_assert(request->proxy != NULL);
        rad_assert(request->home_server != NULL);
        rad_assert(proxy_list != NULL);


        PTHREAD_MUTEX_LOCK(&proxy_mutex);
        proxy_listener = NULL;
        request->num_proxied_requests = 1;
        request->num_proxied_responses = 0;

        for (tries = 0; tries < 2; tries++) {
                rad_listen_t *this;
                listen_socket_t *sock;

                RDEBUG3("proxy: Trying to allocate ID (%d/2)", tries);
                success = fr_packet_list_id_alloc(proxy_list,
                                                request->home_server->proto,
                                                &request->proxy, &proxy_listener);
                if (success) break;

                if (tries > 0) continue; /* try opening new socket only once */

#ifdef HAVE_PTHREAD_H
                if (proxy_no_new_sockets) break;
#endif

                RDEBUG3("proxy: Trying to open a new listener to the home server");
                this = proxy_new_listener(proxy_ctx, request->home_server, 0);
                if (!this) {
                        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                        goto fail;
                }

                request->proxy->src_port = 0; /* Use any new socket */
                proxy_listener = this;

                sock = this->data;
                if (!fr_packet_list_socket_add(proxy_list, this->fd,
                                               sock->proto,
                                               &sock->other_ipaddr, sock->other_port,
                                               this)) {

#ifdef HAVE_PTHREAD_H
                        proxy_no_new_sockets = true;
#endif
                        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);

                        /*
                         *      This is bad.  However, the
                         *      packet list now supports 256
                         *      open sockets, which should
                         *      minimize this problem.
                         */
                        ERROR("Failed adding proxy socket: %s",
                              fr_strerror());
                        goto fail;
                }

                /*
                 *      Add it to the event loop.  Ensure that we have
                 *      only one mutex locked at a time.
                 */
                PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                radius_update_listener(this);
                PTHREAD_MUTEX_LOCK(&proxy_mutex);
        }

        if (!proxy_listener || !success) {
                PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                REDEBUG2("proxy: Failed allocating Id for proxied request");
        fail:
                request->proxy_listener = NULL;
                request->in_proxy_hash = false;
                return 0;
        }

        rad_assert(request->proxy->id >= 0);

        request->proxy_listener = proxy_listener;
        request->in_proxy_hash = true;
        RDEBUG3("proxy: request is now in proxy hash");

        /*
         *      Keep track of maximum outstanding requests to a
         *      particular home server.  'max_outstanding' is
         *      enforced in home_server_ldb(), in realms.c.
         */
        request->home_server->currently_outstanding++;

#ifdef WITH_TCP
        request->proxy_listener->count++;
#endif

        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);

        RDEBUG3("proxy: allocating destination %s port %d - Id %d",
               inet_ntop(request->proxy->dst_ipaddr.af,
                         &request->proxy->dst_ipaddr.ipaddr, buf, sizeof(buf)),
               request->proxy->dst_port,
               request->proxy->id);

        return 1;
}

static int process_proxy_reply(REQUEST *request, RADIUS_PACKET *reply)
{
        int rcode;
        int post_proxy_type = 0;
        VALUE_PAIR *vp;

        VERIFY_REQUEST(request);

        /*
         *      There may be a proxy reply, but it may be too late.
         */
        if (!request->home_server->server && !request->proxy_listener) return 0;

        /*
         *      Delete any reply we had accumulated until now.
         */
        RDEBUG2("Clearing existing &reply: attributes");
        fr_pair_list_free(&request->reply->vps);

        /*
         *      Run the packet through the post-proxy stage,
         *      BEFORE playing games with the attributes.
         */
        vp = fr_pair_find_by_num(request->config, PW_POST_PROXY_TYPE, 0, TAG_ANY);
        if (vp) {
                post_proxy_type = vp->vp_integer;
        /*
         *      If we have a proxy_reply, and it was a reject, or a NAK
         *      setup Post-Proxy <type>.
         *
         *      If the <type> doesn't have a section, then the Post-Proxy
         *      section is ignored.
         */
        } else if (reply) {
                DICT_VALUE *dval = NULL;

                switch (reply->code) {
                case PW_CODE_ACCESS_REJECT:
                        dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, "Reject");
                        if (dval) post_proxy_type = dval->value;
                        break;

                case PW_CODE_DISCONNECT_NAK:
                        dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, fr_packet_codes[reply->code]);
                        if (dval) post_proxy_type = dval->value;
                        break;

                case PW_CODE_COA_NAK:
                        dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, fr_packet_codes[reply->code]);
                        if (dval) post_proxy_type = dval->value;
                        break;

                default:
                        break;
                }

                /*
                 *      Create config:Post-Proxy-Type
                 */
                if (dval) {
                        vp = radius_pair_create(request, &request->config, PW_POST_PROXY_TYPE, 0);
                        vp->vp_integer = dval->value;
                }
        }

        if (post_proxy_type > 0) RDEBUG2("Found Post-Proxy-Type %s",
                                         dict_valnamebyattr(PW_POST_PROXY_TYPE, 0, post_proxy_type));

        if (reply) {
                VERIFY_PACKET(reply);

                /*
                 *      Decode the packet if required.
                 */
                if (request->proxy_listener) {
                        rcode = request->proxy_listener->decode(request->proxy_listener, request);
                        debug_packet(request, reply, true);

                        /*
                         *      Pro-actively remove it from the proxy hash.
                         *      This is later than in 2.1.x, but it means that
                         *      the replies are authenticated before being
                         *      removed from the hash.
                         */
                        if ((rcode == 0) &&
                            (request->num_proxied_requests <= request->num_proxied_responses)) {
                                remove_from_proxy_hash(request);
                        }
                } else {
                        rad_assert(!request->in_proxy_hash);
                }
        } else if (request->in_proxy_hash) {
                remove_from_proxy_hash(request);
        }

        if (request->home_pool && request->home_pool->virtual_server) {
                char const *old_server = request->server;

                request->server = request->home_pool->virtual_server;
                RDEBUG2("server %s {", request->server);
                RINDENT();
                rcode = process_post_proxy(post_proxy_type, request);
                REXDENT();
                RDEBUG2("}");
                request->server = old_server;
        } else {
                rcode = process_post_proxy(post_proxy_type, request);
        }

#ifdef WITH_COA
        if (request->packet->code == request->proxy->code)
          /*
           *    Don't run the next bit if we originated a CoA
           *    packet, after receiving an Access-Request or
           *    Accounting-Request.
           */
#endif

        /*
         *      There may NOT be a proxy reply, as we may be
         *      running Post-Proxy-Type = Fail.
         */
        if (reply) {
                fr_pair_add(&request->reply->vps, fr_pair_list_copy(request->reply, reply->vps));

                /*
                 *      Delete the Proxy-State Attributes from
                 *      the reply.  These include Proxy-State
                 *      attributes from us and remote server.
                 */
                fr_pair_delete_by_num(&request->reply->vps, PW_PROXY_STATE, 0, TAG_ANY);
        }

        switch (rcode) {
        default:  /* Don't do anything */
                break;
        case RLM_MODULE_FAIL:
                return 0;

        case RLM_MODULE_HANDLED:
                return 0;
        }

        return 1;
}

static void mark_home_server_alive(REQUEST *request, home_server_t *home)
{
        char buffer[128];

        home->state = HOME_STATE_ALIVE;
        home->response_timeouts = 0;
        exec_trigger(request, home->cs, "home_server.alive", false);
        home->currently_outstanding = 0;
        home->num_sent_pings = 0;
        home->num_received_pings = 0;
        gettimeofday(&home->revive_time, NULL);

        fr_event_delete(el, &home->ev);

        RPROXY("Marking home server %s port %d alive",
               inet_ntop(request->proxy->dst_ipaddr.af,
                         &request->proxy->dst_ipaddr.ipaddr,
                         buffer, sizeof(buffer)),
               request->proxy->dst_port);
}


int request_proxy_reply(RADIUS_PACKET *packet)
{
        RADIUS_PACKET **proxy_p;
        REQUEST *request;
        struct timeval now;
        char buffer[128];

        VERIFY_PACKET(packet);

        PTHREAD_MUTEX_LOCK(&proxy_mutex);
        proxy_p = fr_packet_list_find_byreply(proxy_list, packet);

        if (!proxy_p) {
                PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                PROXY("No outstanding request was found for %s packet from host %s port %d - ID %u",
                       fr_packet_codes[packet->code],
                       inet_ntop(packet->src_ipaddr.af,
                                 &packet->src_ipaddr.ipaddr,
                                 buffer, sizeof(buffer)),
                       packet->src_port, packet->id);
                return 0;
        }

        request = fr_packet2myptr(REQUEST, proxy, proxy_p);
        request->num_proxied_responses++; /* needs to be protected by lock */

        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);

        /*
         *      No reply, BUT the current packet fails verification:
         *      ignore it.  This does the MD5 calculations in the
         *      server core, but I guess we can fix that later.
         */
        if (!request->proxy_reply &&
            (rad_verify(packet, request->proxy,
                        request->home_server->secret) != 0)) {
                DEBUG("Ignoring spoofed proxy reply.  Signature is invalid");
                return 0;
        }

        /*
         *      The home server sent us a packet which doesn't match
         *      something we have: ignore it.  This is done only to
         *      catch the case of broken systems.
         */
        if (request->proxy_reply &&
            (memcmp(request->proxy_reply->vector,
                    packet->vector,
                    sizeof(request->proxy_reply->vector)) != 0)) {
                RDEBUG2("Ignoring conflicting proxy reply");
                return 0;
        }

        gettimeofday(&now, NULL);

        /*
         *      Status-Server packets don't count as real packets.
         */
        if (request->proxy->code != PW_CODE_STATUS_SERVER) {
                listen_socket_t *sock = request->proxy_listener->data;

                request->home_server->last_packet_recv = now.tv_sec;
                sock->last_packet = now.tv_sec;
        }

        /*
         *      If we have previously seen a reply, ignore the
         *      duplicate.
         */
        if (request->proxy_reply) {
                RDEBUG2("Discarding duplicate reply from host %s port %d  - ID: %d",
                        inet_ntop(packet->src_ipaddr.af,
                                  &packet->src_ipaddr.ipaddr,
                                  buffer, sizeof(buffer)),
                        packet->src_port, packet->id);
                return 0;
        }

        /*
         *      Call the state machine to do something useful with the
         *      request.
         */
        request->proxy_reply = talloc_steal(request, packet);
        packet->timestamp = now;
        request->priority = RAD_LISTEN_PROXY;

#ifdef WITH_STATS
        /*
         *      Update the proxy listener stats here, because only one
         *      thread accesses that at a time.  The home_server and
         *      main proxy_*_stats structures are updated once the
         *      request is cleaned up.
         */
        request->proxy_listener->stats.total_responses++;

        request->home_server->stats.last_packet = packet->timestamp.tv_sec;
        request->proxy_listener->stats.last_packet = packet->timestamp.tv_sec;

        switch (request->proxy->code) {
        case PW_CODE_ACCESS_REQUEST:
                proxy_auth_stats.last_packet = packet->timestamp.tv_sec;

                if (request->proxy_reply->code == PW_CODE_ACCESS_ACCEPT) {
                        request->proxy_listener->stats.total_access_accepts++;

                } else if (request->proxy_reply->code == PW_CODE_ACCESS_REJECT) {
                        request->proxy_listener->stats.total_access_rejects++;

                } else if (request->proxy_reply->code == PW_CODE_ACCESS_CHALLENGE) {
                        request->proxy_listener->stats.total_access_challenges++;
                }
                break;

#ifdef WITH_ACCOUNTING
        case PW_CODE_ACCOUNTING_REQUEST:
                request->proxy_listener->stats.total_responses++;
                proxy_acct_stats.last_packet = packet->timestamp.tv_sec;
                break;

#endif

#ifdef WITH_COA
        case PW_CODE_COA_REQUEST:
                request->proxy_listener->stats.total_responses++;
                proxy_coa_stats.last_packet = packet->timestamp.tv_sec;
                break;

        case PW_CODE_DISCONNECT_REQUEST:
                request->proxy_listener->stats.total_responses++;
                proxy_dsc_stats.last_packet = packet->timestamp.tv_sec;
                break;

#endif
        default:
                break;
        }
#endif

        /*
         *      If we hadn't been sending the home server packets for
         *      a while, just mark it alive.  Or, if it was zombie,
         *      it's now responded, and is therefore alive.
         */
        if ((request->home_server->state == HOME_STATE_UNKNOWN) ||
            (request->home_server->state == HOME_STATE_ZOMBIE)) {
                mark_home_server_alive(request, request->home_server);
        }

        /*
         *      Tell the request state machine that we have a proxy
         *      reply.  Depending on the function, this should either
         *      ignore it, or process it.
         */
        request->process(request, FR_ACTION_PROXY_REPLY);

        return 1;
}


static int setup_post_proxy_fail(REQUEST *request)
{
        DICT_VALUE const *dval = NULL;
        VALUE_PAIR *vp;

        VERIFY_REQUEST(request);

        if (request->proxy->code == PW_CODE_ACCESS_REQUEST) {
                dval = dict_valbyname(PW_POST_PROXY_TYPE, 0,
                                      "Fail-Authentication");
#ifdef WITH_ACCOUNTING
        } else if (request->proxy->code == PW_CODE_ACCOUNTING_REQUEST) {
                dval = dict_valbyname(PW_POST_PROXY_TYPE, 0,
                                      "Fail-Accounting");
#endif

#ifdef WITH_COA
        } else if (request->proxy->code == PW_CODE_COA_REQUEST) {
                dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, "Fail-CoA");

        } else if (request->proxy->code == PW_CODE_DISCONNECT_REQUEST) {
                dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, "Fail-Disconnect");
#endif
        } else {
                WARN("Unknown packet type in Post-Proxy-Type Fail: ignoring");
                return 0;
        }

        if (!dval) dval = dict_valbyname(PW_POST_PROXY_TYPE, 0, "Fail");

        if (!dval) {
                fr_pair_delete_by_num(&request->config, PW_POST_PROXY_TYPE, 0, TAG_ANY);
                return 0;
        }

        vp = fr_pair_find_by_num(request->config, PW_POST_PROXY_TYPE, 0, TAG_ANY);
        if (!vp) vp = radius_pair_create(request, &request->config,
                                        PW_POST_PROXY_TYPE, 0);
        vp->vp_integer = dval->value;

        return 1;
}


/** Process a request after the proxy has timed out.
 *
 *  Run the packet through Post-Proxy-Type Fail
 *
 *  \dot
 *      digraph proxy_no_reply {
 *              proxy_no_reply;
 *
 *              proxy_no_reply -> dup [ label = "DUP", arrowhead = "none" ];
 *              proxy_no_reply -> timer [ label = "TIMER < max_request_time" ];
 *              proxy_no_reply -> proxy_reply_too_late [ label = "PROXY_REPLY" arrowhead = "none"];
 *              proxy_no_reply -> process_proxy_reply [ label = "RUN" ];
 *              proxy_no_reply -> done [ label = "TIMER >= timeout" ];
 *      }
 *  \enddot
 */
static void proxy_no_reply(REQUEST *request, int action)
{
        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_DUP:
                request_dup(request);
                break;

        case FR_ACTION_TIMER:
                (void) request_max_time(request);
                break;

        case FR_ACTION_PROXY_REPLY:
                proxy_reply_too_late(request);
                break;

        case FR_ACTION_RUN:
                if (process_proxy_reply(request, NULL)) {
                        request->handle(request);
                }
                request_finish(request, action);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}

/** Process the request after receiving a proxy reply.
 *
 *  Throught the post-proxy section, and the through the handler
 *  function.
 *
 *  \dot
 *      digraph proxy_running {
 *              proxy_running;
 *
 *              proxy_running -> dup [ label = "DUP", arrowhead = "none" ];
 *              proxy_running -> timer [ label = "TIMER < max_request_time" ];
 *              proxy_running -> process_proxy_reply [ label = "RUN" ];
 *              proxy_running -> done [ label = "TIMER >= timeout" ];
 *      }
 *  \enddot
 */
static void proxy_running(REQUEST *request, int action)
{
        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_DUP:
                request_dup(request);
                break;

        case FR_ACTION_TIMER:
                (void) request_max_time(request);
                break;

        case FR_ACTION_RUN:
                if (process_proxy_reply(request, request->proxy_reply)) {
                        request->handle(request);
                }
                request_finish(request, action);
                break;

        default:                /* duplicate proxy replies are suppressed */
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}

/** Determine if a #REQUEST needs to be proxied, and perform pre-proxy operations
 *
 * Whether a request will be proxied is determined by the attributes present
 * in request->config. If any of the following attributes are found, the
 * request may be proxied.
 *
 * The key attributes are:
 *   - PW_PROXY_TO_REALM          - Specifies a realm the request should be proxied to.
 *   - PW_HOME_SERVER_POOL        - Specifies a specific home server pool to proxy to.
 *   - PW_PACKET_DST_IP_ADDRESS   - Specifies a specific IPv4 home server to proxy to.
 *   - PW_PACKET_DST_IPV6_ADDRESS - Specifies a specific IPv6 home server to proxy to.
 *
 * Certain packet types such as #PW_CODE_STATUS_SERVER will never be proxied.
 *
 * If request should be proxied, will:
 *   - Add request:Proxy-State
 *   - Strip the current username value of its realm (depending on config)
 *   - Create a CHAP-Challenge from the original request vector, if one doesn't already
 *     exist.
 *   - Call the pre-process section in the current server, or in the virtual server
 *     associated with the home server pool we're proxying to.
 *
 * @todo A lot of this logic is RADIUS specific, and should be moved out into a protocol
 *      specific function.
 *
 * @param request The #REQUEST to evaluate for proxying.
 * @return 0 if not proxying, 1 if request should be proxied, -1 on error.
 */
static int request_will_proxy(REQUEST *request)
{
        int rcode, pre_proxy_type = 0;
        char const *realmname = NULL;
        VALUE_PAIR *vp, *strippedname;
        home_server_t *home;
        REALM *realm = NULL;
        home_pool_t *pool = NULL;

        VERIFY_REQUEST(request);

        if (!request->root->proxy_requests) return 0;
        if (request->packet->dst_port == 0) return 0;
        if (request->packet->code == PW_CODE_STATUS_SERVER) return 0;
        if (request->in_proxy_hash) return 0;

        /*
         *      FIXME: for 3.0, allow this only for rejects?
         */
        if (request->reply->code != 0) return 0;

        vp = fr_pair_find_by_num(request->config, PW_PROXY_TO_REALM, 0, TAG_ANY);
        if (vp) {
                realm = realm_find2(vp->vp_strvalue);
                if (!realm) {
                        REDEBUG2("Cannot proxy to unknown realm %s",
                                vp->vp_strvalue);
                        return 0;
                }

                realmname = vp->vp_strvalue;

                /*
                 *      Figure out which pool to use.
                 */
                if (request->packet->code == PW_CODE_ACCESS_REQUEST) {
                        pool = realm->auth_pool;

#ifdef WITH_ACCOUNTING
                } else if (request->packet->code == PW_CODE_ACCOUNTING_REQUEST) {
                        pool = realm->acct_pool;
#endif

#ifdef WITH_COA
                } else if ((request->packet->code == PW_CODE_COA_REQUEST) ||
                           (request->packet->code == PW_CODE_DISCONNECT_REQUEST)) {
                        pool = realm->coa_pool;
#endif

                } else {
                        return 0;
                }

        } else if ((vp = fr_pair_find_by_num(request->config, PW_HOME_SERVER_POOL, 0, TAG_ANY)) != NULL) {
                int pool_type;

                switch (request->packet->code) {
                case PW_CODE_ACCESS_REQUEST:
                        pool_type = HOME_TYPE_AUTH;
                        break;

#ifdef WITH_ACCOUNTING
                case PW_CODE_ACCOUNTING_REQUEST:
                        pool_type = HOME_TYPE_ACCT;
                        break;
#endif

#ifdef WITH_COA
                case PW_CODE_COA_REQUEST:
                case PW_CODE_DISCONNECT_REQUEST:
                        pool_type = HOME_TYPE_COA;
                        break;
#endif

                default:
                        return 0;
                }

                pool = home_pool_byname(vp->vp_strvalue, pool_type);

                /*
                 *      Send it directly to a home server (i.e. NAS)
                 */
        } else if (((vp = fr_pair_find_by_num(request->config, PW_PACKET_DST_IP_ADDRESS, 0, TAG_ANY)) != NULL) ||
                   ((vp = fr_pair_find_by_num(request->config, PW_PACKET_DST_IPV6_ADDRESS, 0, TAG_ANY)) != NULL)) {
                uint16_t dst_port;
                fr_ipaddr_t dst_ipaddr;

                memset(&dst_ipaddr, 0, sizeof(dst_ipaddr));

                if (vp->da->attr == PW_PACKET_DST_IP_ADDRESS) {
                        dst_ipaddr.af = AF_INET;
                        dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
                        dst_ipaddr.prefix = 32;
                } else {
                        dst_ipaddr.af = AF_INET6;
                        memcpy(&dst_ipaddr.ipaddr.ip6addr, &vp->vp_ipv6addr, sizeof(vp->vp_ipv6addr));
                        dst_ipaddr.prefix = 128;
                }

                vp = fr_pair_find_by_num(request->config, PW_PACKET_DST_PORT, 0, TAG_ANY);
                if (!vp) {
                        if (request->packet->code == PW_CODE_ACCESS_REQUEST) {
                                dst_port = PW_AUTH_UDP_PORT;

#ifdef WITH_ACCOUNTING
                        } else if (request->packet->code == PW_CODE_ACCOUNTING_REQUEST) {
                                dst_port = PW_ACCT_UDP_PORT;
#endif

#ifdef WITH_COA
                        } else if ((request->packet->code == PW_CODE_COA_REQUEST) ||
                                   (request->packet->code == PW_CODE_DISCONNECT_REQUEST)) {
                                dst_port = PW_COA_UDP_PORT;
#endif
                        } else { /* shouldn't happen for RADIUS... */
                                return 0;
                        }

                } else {
                        dst_port = vp->vp_integer;
                }

                /*
                 *      Nothing does CoA over TCP.
                 */
                home = home_server_find(&dst_ipaddr, dst_port, IPPROTO_UDP);
                if (!home) {
                        char buffer[256];

                        WARN("No such home server %s port %u",
                             inet_ntop(dst_ipaddr.af, &dst_ipaddr.ipaddr, buffer, sizeof(buffer)),
                             (unsigned int) dst_port);
                        return 0;
                }

                /*
                 *      The home server is alive (or may be alive).
                 *      Send the packet to the IP.
                 */
                if (home->state != HOME_STATE_IS_DEAD) goto do_home;

                /*
                 *      The home server is dead.  If you wanted
                 *      fail-over, you should have proxied to a pool.
                 *      Sucks to be you.
                 */

                return 0;

        } else {
                return 0;
        }

        if (!pool) {
                RWDEBUG2("Cancelling proxy as no home pool exists");
                return 0;
        }

        if (request->listener->synchronous) {
                WARN("Cannot proxy a request which is from a 'synchronous' socket");
                return 0;
        }

        request->home_pool = pool;

        home = home_server_ldb(realmname, pool, request);

        if (!home) {
                REDEBUG2("Failed to find live home server: Cancelling proxy");
                return 0;
        }

do_home:
        home_server_update_request(home, request);

#ifdef WITH_COA
        /*
         *      Once we've decided to proxy a request, we cannot send
         *      a CoA packet.  So we free up any CoA packet here.
         */
        if (request->coa) request_done(request->coa, FR_ACTION_DONE);
#endif

        /*
         *      Remember that we sent the request to a Realm.
         */
        if (realmname) pair_make_request("Realm", realmname, T_OP_EQ);

        /*
         *      Strip the name, if told to.
         *
         *      Doing it here catches the case of proxied tunneled
         *      requests.
         */
        if (realm && (realm->strip_realm == true) &&
           (strippedname = fr_pair_find_by_num(request->proxy->vps, PW_STRIPPED_USER_NAME, 0, TAG_ANY)) != NULL) {
                /*
                 *      If there's a Stripped-User-Name attribute in
                 *      the request, then use THAT as the User-Name
                 *      for the proxied request, instead of the
                 *      original name.
                 *
                 *      This is done by making a copy of the
                 *      Stripped-User-Name attribute, turning it into
                 *      a User-Name attribute, deleting the
                 *      Stripped-User-Name and User-Name attributes
                 *      from the vps list, and making the new
                 *      User-Name the head of the vps list.
                 */
                vp = fr_pair_find_by_num(request->proxy->vps, PW_USER_NAME, 0, TAG_ANY);
                if (!vp) {
                        vp_cursor_t cursor;
                        vp = radius_pair_create(NULL, NULL,
                                               PW_USER_NAME, 0);
                        rad_assert(vp != NULL); /* handled by above function */
                        /* Insert at the START of the list */
                        /* FIXME: Can't make assumptions about ordering */
                        fr_cursor_init(&cursor, &vp);
                        fr_cursor_merge(&cursor, request->proxy->vps);
                        request->proxy->vps = vp;
                }
                fr_pair_value_strcpy(vp, strippedname->vp_strvalue);

                /*
                 *      Do NOT delete Stripped-User-Name.
                 */
        }

        /*
         *      If there is no PW_CHAP_CHALLENGE attribute but
         *      there is a PW_CHAP_PASSWORD we need to add it
         *      since we can't use the request authenticator
         *      anymore - we changed it.
         */
        if ((request->packet->code == PW_CODE_ACCESS_REQUEST) &&
            fr_pair_find_by_num(request->proxy->vps, PW_CHAP_PASSWORD, 0, TAG_ANY) &&
            fr_pair_find_by_num(request->proxy->vps, PW_CHAP_CHALLENGE, 0, TAG_ANY) == NULL) {
                vp = radius_pair_create(request->proxy, &request->proxy->vps, PW_CHAP_CHALLENGE, 0);
                fr_pair_value_memcpy(vp, request->packet->vector, sizeof(request->packet->vector));
        }

        /*
         *      The RFC's say we have to do this, but FreeRADIUS
         *      doesn't need it.
         */
        vp = radius_pair_create(request->proxy, &request->proxy->vps, PW_PROXY_STATE, 0);
        fr_pair_value_sprintf(vp, "%u", request->packet->id);

        /*
         *      Should be done BEFORE inserting into proxy hash, as
         *      pre-proxy may use this information, or change it.
         */
        request->proxy->code = request->packet->code;

        /*
         *      Call the pre-proxy routines.
         */
        vp = fr_pair_find_by_num(request->config, PW_PRE_PROXY_TYPE, 0, TAG_ANY);
        if (vp) {
                DICT_VALUE const *dval = dict_valbyattr(vp->da->attr, vp->da->vendor, vp->vp_integer);
                /* Must be a validation issue */
                rad_assert(dval);
                RDEBUG2("Found Pre-Proxy-Type %s", dval->name);
                pre_proxy_type = vp->vp_integer;
        }

        /*
         *      home_pool may be NULL when originating CoA packets,
         *      because they go directly to an IP address.
         */
        if (request->home_pool && request->home_pool->virtual_server) {
                char const *old_server = request->server;

                request->server = request->home_pool->virtual_server;

                RDEBUG2("server %s {", request->server);
                RINDENT();
                rcode = process_pre_proxy(pre_proxy_type, request);
                REXDENT();
                RDEBUG2("}");

                request->server = old_server;
        } else {
                rcode = process_pre_proxy(pre_proxy_type, request);
        }

        switch (rcode) {
        case RLM_MODULE_FAIL:
        case RLM_MODULE_INVALID:
        case RLM_MODULE_NOTFOUND:
        case RLM_MODULE_USERLOCK:
        default:
                /* FIXME: debug print failed stuff */
                return -1;

        case RLM_MODULE_REJECT:
        case RLM_MODULE_HANDLED:
                return 0;

        /*
         *      Only proxy the packet if the pre-proxy code succeeded.
         */
        case RLM_MODULE_NOOP:
        case RLM_MODULE_OK:
        case RLM_MODULE_UPDATED:
                return 1;
        }
}

static int proxy_to_virtual_server(REQUEST *request)
{
        REQUEST *fake;

        if (request->packet->dst_port == 0) {
                WARN("Cannot proxy an internal request");
                return 0;
        }

        DEBUG("Proxying to virtual server %s",
              request->home_server->server);

        /*
         *      Packets to virtual servers don't get
         *      retransmissions sent to them.  And the virtual
         *      server is run ONLY if we have no child
         *      threads, or we're running in a child thread.
         */
        rad_assert(!spawn_flag || !we_are_master());

        fake = request_alloc_fake(request);

        fake->packet->vps = fr_pair_list_copy(fake->packet, request->packet->vps);
        talloc_free(request->proxy);

        fake->server = request->home_server->server;
        fake->handle = request->handle;
        fake->process = NULL; /* should never be run for anything */

        /*
         *      Run the virtual server.
         */
        request_running(fake, FR_ACTION_RUN);

        request->proxy = talloc_steal(request, fake->packet);
        fake->packet = NULL;
        request->proxy_reply = talloc_steal(request, fake->reply);
        fake->reply = NULL;

        talloc_free(fake);

        /*
         *      No reply code, toss the reply we have,
         *      and do post-proxy-type Fail.
         */
        if (!request->proxy_reply->code) {
                TALLOC_FREE(request->proxy_reply);
                setup_post_proxy_fail(request);
        }

        /*
         *      Do the proxy reply (if any)
         */
        if (process_proxy_reply(request, request->proxy_reply)) {
                request->handle(request);
        }

        return -1;      /* so we call request_finish */
}


static int request_proxy(REQUEST *request, int retransmit)
{
        char buffer[128];

        VERIFY_REQUEST(request);

        rad_assert(request->parent == NULL);
        rad_assert(request->home_server != NULL);

        if (request->master_state == REQUEST_STOP_PROCESSING) return 0;

#ifdef WITH_COA
        if (request->coa) {
                RWDEBUG("Cannot proxy and originate CoA packets at the same time.  Cancelling CoA request");
                request_done(request->coa, FR_ACTION_DONE);
        }
#endif

        /*
         *      The request may need sending to a virtual server.
         *      This code is more than a little screwed up.  The rest
         *      of the state machine doesn't handle parent / child
         *      relationships well.  i.e. if the child request takes
         *      too long, the core will mark the *parent* as "stop
         *      processing".  And the child will continue without
         *      knowing anything...
         *
         *      So, we have some horrible hacks to get around that.
         */
        if (request->home_server->server) return proxy_to_virtual_server(request);

        /*
         *      We're actually sending a proxied packet.  Do that now.
         */
        if (!request->in_proxy_hash && !insert_into_proxy_hash(request)) {
                RPROXY("Failed to insert request into the proxy list");
                return -1;
        }

        rad_assert(request->proxy->id >= 0);

        if (rad_debug_lvl) {
                struct timeval *response_window;

                response_window = request_response_window(request);

#ifdef WITH_TLS
                if (request->home_server->tls) {
                        RDEBUG2("Proxying request to home server %s port %d (TLS) timeout %d.%06d",
                                inet_ntop(request->proxy->dst_ipaddr.af,
                                          &request->proxy->dst_ipaddr.ipaddr,
                                          buffer, sizeof(buffer)),
                                request->proxy->dst_port,
                                (int) response_window->tv_sec, (int) response_window->tv_usec);
                } else
#endif
                        RDEBUG2("Proxying request to home server %s port %d timeout %d.%06d",
                                inet_ntop(request->proxy->dst_ipaddr.af,
                                          &request->proxy->dst_ipaddr.ipaddr,
                                          buffer, sizeof(buffer)),
                                request->proxy->dst_port,
                                (int) response_window->tv_sec, (int) response_window->tv_usec);


        }

        gettimeofday(&request->proxy_retransmit, NULL);
        if (!retransmit) {
                request->proxy->timestamp = request->proxy_retransmit;
        }
        request->home_server->last_packet_sent = request->proxy_retransmit.tv_sec;

        /*
         *      Encode the packet before we do anything else.
         */
        request->proxy_listener->encode(request->proxy_listener, request);
        debug_packet(request, request->proxy, false);

        /*
         *      Set the state function, then the state, no child, and
         *      send the packet.
         */
        request->process = proxy_wait_for_reply;
        request->child_state = REQUEST_PROXIED;
        NO_CHILD_THREAD;

        /*
         *      And send the packet.
         */
        request->proxy_listener->send(request->proxy_listener, request);
        return 1;
}

/*
 *      Proxy the packet as if it was new.
 */
static int request_proxy_anew(REQUEST *request)
{
        home_server_t *home;

        VERIFY_REQUEST(request);

        /*
         *      Delete the request from the proxy list.
         *
         *      The packet list code takes care of ensuring that IDs
         *      aren't reused until all 256 IDs have been used.  So
         *      there's a 1/256 chance of re-using the same ID when
         *      we're sending to the same home server.  Which is
         *      acceptable.
         */
        remove_from_proxy_hash(request);

        /*
         *      Find a live home server for the request.
         */
        home = home_server_ldb(NULL, request->home_pool, request);
        if (!home) {
                REDEBUG2("Failed to find live home server for request");
        post_proxy_fail:
                if (setup_post_proxy_fail(request)) {
                        request_queue_or_run(request, proxy_running);
                } else {
                        gettimeofday(&request->reply->timestamp, NULL);
                        request_cleanup_delay_init(request);
                }
                return 0;
        }

#ifdef WITH_ACCOUNTING
        /*
         *      Update the Acct-Delay-Time attribute.
         */
        if (request->packet->code == PW_CODE_ACCOUNTING_REQUEST) {
                VALUE_PAIR *vp;

                vp = fr_pair_find_by_num(request->proxy->vps, PW_ACCT_DELAY_TIME, 0, TAG_ANY);
                if (!vp) vp = radius_pair_create(request->proxy,
                                                &request->proxy->vps,
                                                PW_ACCT_DELAY_TIME, 0);
                if (vp) {
                        struct timeval now;

                        gettimeofday(&now, NULL);
                        vp->vp_integer += now.tv_sec - request->proxy_retransmit.tv_sec;
                }
        }
#endif

        /*
         *      May have failed over to a "fallback" virtual server.
         *      If so, run that instead of doing proxying to a real
         *      server.
         */
        if (home->server) {
                request->home_server = home;
                TALLOC_FREE(request->proxy);

                (void) proxy_to_virtual_server(request);
                return 0;
        }

        home_server_update_request(home, request);

        if (!insert_into_proxy_hash(request)) {
                RPROXY("Failed to insert retransmission into the proxy list");
                goto post_proxy_fail;
        }

        /*
         *      Free the old packet, to force re-encoding
         */
        talloc_free(request->proxy->data);
        request->proxy->data = NULL;
        request->proxy->data_len = 0;

        if (request_proxy(request, 1) != 1) goto post_proxy_fail;

        return 1;
}


/** Ping a home server.
 *
 */
static void request_ping(REQUEST *request, int action)
{
        home_server_t *home = request->home_server;
        char buffer[128];

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;

        switch (action) {
        case FR_ACTION_TIMER:
                ERROR("No response to status check %d ID %u for home server %s port %d",
                       request->number,
                       request->proxy->id,
                       inet_ntop(request->proxy->dst_ipaddr.af,
                                 &request->proxy->dst_ipaddr.ipaddr,
                                 buffer, sizeof(buffer)),
                       request->proxy->dst_port);
                break;

        case FR_ACTION_PROXY_REPLY:
                rad_assert(request->in_proxy_hash);

                request->home_server->num_received_pings++;
                RPROXY("Received response to status check %d ID %u (%d in current sequence)",
                       request->number, request->proxy->id, home->num_received_pings);

                /*
                 *      Remove the request from any hashes
                 */
                fr_event_delete(el, &request->ev);
                remove_from_proxy_hash(request);

                /*
                 *      The control socket may have marked the home server as
                 *      alive.  OR, it may have suddenly started responding to
                 *      requests again.  If so, don't re-do the "make alive"
                 *      work.
                 */
                if (home->state == HOME_STATE_ALIVE) break;

                /*
                 *      It's dead, and we haven't received enough ping
                 *      responses to mark it "alive".  Wait a bit.
                 *
                 *      If it's zombie, we mark it alive immediately.
                 */
                if ((home->state == HOME_STATE_IS_DEAD) &&
                    (home->num_received_pings < home->num_pings_to_alive)) {
                        return;
                }

                /*
                 *      Mark it alive and delete any outstanding
                 *      pings.
                 */
                mark_home_server_alive(request, home);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }

        rad_assert(!request->in_request_hash);
        rad_assert(request->ev == NULL);
        NO_CHILD_THREAD;
        request_done(request, FR_ACTION_DONE);
}

/*
 *      Called from start of zombie period, OR after control socket
 *      marks the home server dead.
 */
static void ping_home_server(void *ctx)
{
        home_server_t *home = talloc_get_type_abort(ctx, home_server_t);
        REQUEST *request;
        VALUE_PAIR *vp;
        struct timeval when, now;

        if ((home->state == HOME_STATE_ALIVE) ||
#ifdef WITH_TCP
            (home->proto == IPPROTO_TCP) ||
#endif
            (home->ev != NULL)) {
                return;
        }

        gettimeofday(&now, NULL);
        ASSERT_MASTER;

        /*
         *      We've run out of zombie time.  Mark it dead.
         */
        if (home->state == HOME_STATE_ZOMBIE) {
                when = home->zombie_period_start;
                when.tv_sec += home->zombie_period;

                if (timercmp(&when, &now, <)) {
                        DEBUG("PING: Zombie period is over for home server %s", home->log_name);
                        mark_home_server_dead(home, &now);
                }
        }

        /*
         *      We're not supposed to be pinging it.  Just wake up
         *      when we're supposed to mark it dead.
         */
        if (home->ping_check == HOME_PING_CHECK_NONE) {
                if (home->state == HOME_STATE_ZOMBIE) {
                        home->when = home->zombie_period_start;
                        home->when.tv_sec += home->zombie_period;
                        INSERT_EVENT(ping_home_server, home);
                }

                /*
                 *      Else mark_home_server_dead will set a timer
                 *      for revive_interval.
                 */
                return;
        }


        request = request_alloc(NULL);
        if (!request) return;
        request->number = request_num_counter++;
        NO_CHILD_THREAD;

        request->proxy = rad_alloc(request, true);
        rad_assert(request->proxy != NULL);

        if (home->ping_check == HOME_PING_CHECK_STATUS_SERVER) {
                request->proxy->code = PW_CODE_STATUS_SERVER;

                fr_pair_make(request->proxy, &request->proxy->vps,
                         "Message-Authenticator", "0x00", T_OP_SET);

        } else if (home->type == HOME_TYPE_AUTH) {
                request->proxy->code = PW_CODE_ACCESS_REQUEST;

                fr_pair_make(request->proxy, &request->proxy->vps,
                         "User-Name", home->ping_user_name, T_OP_SET);
                fr_pair_make(request->proxy, &request->proxy->vps,
                         "User-Password", home->ping_user_password, T_OP_SET);
                fr_pair_make(request->proxy, &request->proxy->vps,
                         "Service-Type", "Authenticate-Only", T_OP_SET);
                fr_pair_make(request->proxy, &request->proxy->vps,
                         "Message-Authenticator", "0x00", T_OP_SET);

        } else {
#ifdef WITH_ACCOUNTING
                request->proxy->code = PW_CODE_ACCOUNTING_REQUEST;

                fr_pair_make(request->proxy, &request->proxy->vps,
                         "User-Name", home->ping_user_name, T_OP_SET);
                fr_pair_make(request->proxy, &request->proxy->vps,
                         "Acct-Status-Type", "Stop", T_OP_SET);
                fr_pair_make(request->proxy, &request->proxy->vps,
                         "Acct-Session-Id", "00000000", T_OP_SET);
                vp = fr_pair_make(request->proxy, &request->proxy->vps,
                              "Event-Timestamp", "0", T_OP_SET);
                vp->vp_date = now.tv_sec;
#else
                rad_assert("Internal sanity check failed");
#endif
        }

        vp = fr_pair_make(request->proxy, &request->proxy->vps,
                      "NAS-Identifier", "", T_OP_SET);
        if (vp) {
                fr_pair_value_sprintf(vp, "Status Check %u. Are you alive?",
                            home->num_sent_pings);
        }

#ifdef WITH_TCP
        request->proxy->proto = home->proto;
#endif
        request->proxy->src_ipaddr = home->src_ipaddr;
        request->proxy->dst_ipaddr = home->ipaddr;
        request->proxy->dst_port = home->port;
        request->home_server = home;
#ifdef DEBUG_STATE_MACHINE
        if (rad_debug_lvl) printf("(%u) ********\tSTATE %s C-%s -> C-%s\t********\n", request->number, __FUNCTION__,
                               child_state_names[request->child_state],
                               child_state_names[REQUEST_DONE]);
        if (rad_debug_lvl) printf("(%u) ********\tNEXT-STATE %s -> %s\n", request->number, __FUNCTION__, "request_ping");
#endif
#ifdef HAVE_PTHREAD_H
        rad_assert(request->child_pid == NO_SUCH_CHILD_PID);
#endif
        request->child_state = REQUEST_PROXIED;
        request->process = request_ping;

        rad_assert(request->proxy_listener == NULL);

        if (!insert_into_proxy_hash(request)) {
                RPROXY("Failed to insert status check %d into proxy list.  Discarding it.",
                       request->number);

                rad_assert(!request->in_request_hash);
                rad_assert(!request->in_proxy_hash);
                rad_assert(request->ev == NULL);
                talloc_free(request);
                return;
        }

        /*
         *      Set up the timer callback.
         */
        when = now;
        when.tv_sec += home->ping_timeout;

        DEBUG("PING: Waiting %u seconds for response to ping",
              home->ping_timeout);

        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
        home->num_sent_pings++;

        rad_assert(request->proxy_listener != NULL);
        debug_packet(request, request->proxy, false);
        request->proxy_listener->send(request->proxy_listener,
                                      request);

        /*
         *      Add +/- 2s of jitter, as suggested in RFC 3539
         *      and in the Issues and Fixes draft.
         */
        home->when = now;
        home->when.tv_sec += home->ping_interval;

        add_jitter(&home->when);

        DEBUG("PING: Next status packet in %u seconds", home->ping_interval);
        INSERT_EVENT(ping_home_server, home);
}

static void home_trigger(home_server_t *home, char const *trigger)
{
        REQUEST *my_request;
        RADIUS_PACKET *my_packet;

        my_request = talloc_zero(NULL, REQUEST);
        my_packet = talloc_zero(my_request, RADIUS_PACKET);
        my_request->proxy = my_packet;
        my_packet->dst_ipaddr = home->ipaddr;
        my_packet->src_ipaddr = home->src_ipaddr;

        exec_trigger(my_request, home->cs, trigger, false);
        talloc_free(my_request);
}

static void mark_home_server_zombie(home_server_t *home, struct timeval *now, struct timeval *response_window)
{
        time_t start;
        char buffer[128];

        ASSERT_MASTER;

        rad_assert((home->state == HOME_STATE_ALIVE) ||
                   (home->state == HOME_STATE_UNKNOWN));

#ifdef WITH_TCP
        if (home->proto == IPPROTO_TCP) {
                WARN("Not marking TCP server %s zombie", home->log_name);
                return;
        }
#endif

        /*
         *      We've received a real packet recently.  Don't mark the
         *      server as zombie until we've received NO packets for a
         *      while.  The "1/4" of zombie period was chosen rather
         *      arbitrarily.  It's a balance between too short, which
         *      gives quick fail-over and fail-back, or too long,
         *      where the proxy still sends packets to an unresponsive
         *      home server.
         */
        start = now->tv_sec - ((home->zombie_period + 3) / 4);
        if (home->last_packet_recv >= start) {
                DEBUG("Recieved reply from home server %d seconds ago.  Might not be zombie.",
                      (int) (now->tv_sec - home->last_packet_recv));
                return;
        }

        home->state = HOME_STATE_ZOMBIE;
        home_trigger(home, "home_server.zombie");

        /*
         *      Set the home server to "zombie", as of the time
         *      calculated above.
         */
        home->zombie_period_start.tv_sec = start;
        home->zombie_period_start.tv_usec = USEC / 2;

        fr_event_delete(el, &home->ev);

        home->num_sent_pings = 0;
        home->num_received_pings = 0;

        PROXY( "Marking home server %s port %d as zombie (it has not responded in %d.%06d seconds).",
               inet_ntop(home->ipaddr.af, &home->ipaddr.ipaddr,
                         buffer, sizeof(buffer)),
               home->port, (int) response_window->tv_sec, (int) response_window->tv_usec);

        ping_home_server(home);
}


void revive_home_server(void *ctx)
{
        home_server_t *home = talloc_get_type_abort(ctx, home_server_t);
        char buffer[128];

#ifdef WITH_TCP
        rad_assert(home->proto != IPPROTO_TCP);
#endif

        home->state = HOME_STATE_ALIVE;
        home->response_timeouts = 0;
        home_trigger(home, "home_server.alive");
        home->currently_outstanding = 0;
        gettimeofday(&home->revive_time, NULL);

        /*
         *      Delete any outstanding events.
         */
        ASSERT_MASTER;
        if (home->ev) fr_event_delete(el, &home->ev);

        PROXY( "Marking home server %s port %d alive again... we have no idea if it really is alive or not.",
               inet_ntop(home->ipaddr.af, &home->ipaddr.ipaddr,
                         buffer, sizeof(buffer)),
               home->port);
}

void mark_home_server_dead(home_server_t *home, struct timeval *when)
{
        int previous_state = home->state;
        char buffer[128];

#ifdef WITH_TCP
        if (home->proto == IPPROTO_TCP) {
                WARN("Not marking TCP server dead");
                return;
        }
#endif

        PROXY( "Marking home server %s port %d as dead.",
               inet_ntop(home->ipaddr.af, &home->ipaddr.ipaddr,
                         buffer, sizeof(buffer)),
               home->port);

        home->state = HOME_STATE_IS_DEAD;
        home_trigger(home, "home_server.dead");

        if (home->ping_check != HOME_PING_CHECK_NONE) {
                /*
                 *      If the control socket marks us dead, start
                 *      pinging.  Otherwise, we already started
                 *      pinging when it was marked "zombie".
                 */
                if (previous_state == HOME_STATE_ALIVE) {
                        ping_home_server(home);
                } else {
                        DEBUG("PING: Already pinging home server %s", home->log_name);
                }

        } else {
                /*
                 *      Revive it after a fixed period of time.  This
                 *      is very, very, bad.
                 */
                home->when = *when;
                home->when.tv_sec += home->revive_interval;

                DEBUG("PING: Reviving home server %s in %u seconds", home->log_name, home->revive_interval);
                ASSERT_MASTER;
                INSERT_EVENT(revive_home_server, home);
        }
}

/** Wait for a reply after proxying a request.
 *
 *  Retransmit the proxied packet, or time out and go to
 *  proxy_no_reply.  Mark the home server unresponsive, etc.
 *
 *  If we do receive a reply, we transition to proxy_running.
 *
 *  \dot
 *      digraph proxy_wait_for_reply {
 *              proxy_wait_for_reply;
 *
 *              proxy_wait_for_reply -> retransmit_proxied_request [ label = "DUP", arrowhead = "none" ];
 *              proxy_wait_for_reply -> proxy_no_reply [ label = "TIMER >= response_window" ];
 *              proxy_wait_for_reply -> timer [ label = "TIMER < max_request_time" ];
 *              proxy_wait_for_reply -> proxy_running [ label = "PROXY_REPLY" arrowhead = "none"];
 *              proxy_wait_for_reply -> done [ label = "TIMER >= max_request_time" ];
 *      }
 *  \enddot
 */
static void proxy_wait_for_reply(REQUEST *request, int action)
{
        struct timeval now, when;
        struct timeval *response_window = NULL;
        home_server_t *home = request->home_server;
        char buffer[128];

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        rad_assert(request->packet->code != PW_CODE_STATUS_SERVER);
        rad_assert(request->home_server != NULL);

        gettimeofday(&now, NULL);

        switch (action) {
        case FR_ACTION_DUP:
                /*
                 *      We have a reply, ignore the retransmit.
                 */
                if (request->proxy_reply) return;

                /*
                 *      The request was proxied to a virtual server.
                 *      Ignore the retransmit.
                 */
                if (request->home_server->server) return;

                /*
                 *      Use a new connection when the home server is
                 *      dead, or when there's no proxy listener, or
                 *      when the listener is failed or dead.
                 *
                 *      If the listener is known or frozen, use it for
                 *      retransmits.
                 */
                if ((home->state == HOME_STATE_IS_DEAD) ||
                    !request->proxy_listener ||
                    (request->proxy_listener->status >= RAD_LISTEN_STATUS_EOL)) {
                        request_proxy_anew(request);
                        return;
                }

#ifdef WITH_TCP
                /*
                 *      The home server is still alive, but TCP.  We
                 *      rely on TCP to get the request and reply back.
                 *      So there's no need to retransmit.
                 */
                if (home->proto == IPPROTO_TCP) {
                        DEBUG2("Suppressing duplicate proxied request (tcp) to home server %s port %d proto TCP - ID: %d",
                               inet_ntop(request->proxy->dst_ipaddr.af,
                                         &request->proxy->dst_ipaddr.ipaddr,
                                         buffer, sizeof(buffer)),
                               request->proxy->dst_port,
                               request->proxy->id);
                        return;
                }
#endif

                /*
                 *      More than one retransmit a second is stupid,
                 *      and should be suppressed by the proxy.
                 */
                when = request->proxy_retransmit;
                when.tv_sec++;

                if (timercmp(&now, &when, <)) {
                        DEBUG2("Suppressing duplicate proxied request (too fast) to home server %s port %d proto TCP - ID: %d",
                               inet_ntop(request->proxy->dst_ipaddr.af,
                                         &request->proxy->dst_ipaddr.ipaddr,
                                         buffer, sizeof(buffer)),
                               request->proxy->dst_port,
                               request->proxy->id);
                        return;
                }

#ifdef WITH_ACCOUNTING
                /*
                 *      If we update the Acct-Delay-Time, we need to
                 *      get a new ID.
                 */
                if ((request->packet->code == PW_CODE_ACCOUNTING_REQUEST) &&
                    fr_pair_find_by_num(request->proxy->vps, PW_ACCT_DELAY_TIME, 0, TAG_ANY)) {
                        request_proxy_anew(request);
                        return;
                }
#endif

                RDEBUG2("Sending duplicate proxied request to home server %s port %d - ID: %d",
                        inet_ntop(request->proxy->dst_ipaddr.af,
                                  &request->proxy->dst_ipaddr.ipaddr,
                                  buffer, sizeof(buffer)),
                        request->proxy->dst_port,
                        request->proxy->id);
                request->num_proxied_requests++;

                rad_assert(request->proxy_listener != NULL);
                FR_STATS_TYPE_INC(home->stats.total_requests);
                home->last_packet_sent = now.tv_sec;
                request->proxy_retransmit = now;
                debug_packet(request, request->proxy, false);
                request->proxy_listener->send(request->proxy_listener, request);
                break;

        case FR_ACTION_TIMER:
                response_window = request_response_window(request);

#ifdef WITH_TCP
                if (!request->proxy_listener ||
                    (request->proxy_listener->status >= RAD_LISTEN_STATUS_EOL)) {
                        remove_from_proxy_hash(request);

                        when = request->packet->timestamp;
                        when.tv_sec += request->root->max_request_time;

                        if (timercmp(&when, &now, >)) {
                                RDEBUG("Waiting for client retransmission in order to do a proxy retransmit");
                                STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                                return;
                        }
                } else
#endif
                {
                        /*
                         *      Wake up "response_window" time in the future.
                         *      i.e. when MY packet hasn't received a response.
                         *
                         *      Note that we DO NOT mark the home server as
                         *      zombie if it doesn't respond to us.  It may be
                         *      responding to other (better looking) packets.
                         */
                        when = request->proxy->timestamp;
                        timeradd(&when, response_window, &when);

                        /*
                         *      Not at the response window.  Set the timer for
                         *      that.
                         */
                        if (timercmp(&when, &now, >)) {
                                struct timeval diff;
                                timersub(&when, &now, &diff);

                                RDEBUG("Expecting proxy response no later than %d.%06d seconds from now",
                                       (int) diff.tv_sec, (int) diff.tv_usec);
                                STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                                return;
                        }
                }

                RDEBUG("No proxy response, giving up on request and marking it done");

                /*
                 *      If we haven't received any packets for
                 *      "response_window", then mark the home server
                 *      as zombie.
                 *
                 *      If the connection is TCP, then another
                 *      "watchdog timer" function takes care of pings,
                 *      etc.  So we don't need to do it here.
                 *
                 *      This check should really be part of a home
                 *      server state machine.
                 */
                if (((home->state == HOME_STATE_ALIVE) ||
                     (home->state == HOME_STATE_UNKNOWN))
#ifdef WITH_TCP
                    && (home->proto != IPPROTO_TCP)
#endif
                        ) {
                        home->response_timeouts++;
                        if (home->response_timeouts >= home->max_response_timeouts)
                                mark_home_server_zombie(home, &now, response_window);
                }

                FR_STATS_TYPE_INC(home->stats.total_timeouts);
                if (home->type == HOME_TYPE_AUTH) {
                        if (request->proxy_listener) FR_STATS_TYPE_INC(request->proxy_listener->stats.total_timeouts);
                        FR_STATS_TYPE_INC(proxy_auth_stats.total_timeouts);
                }
#ifdef WITH_ACCT
                else if (home->type == HOME_TYPE_ACCT) {
                        if (request->proxy_listener) FR_STATS_TYPE_INC(request->proxy_listener->stats.total_timeouts);
                        FR_STATS_TYPE_INC(proxy_acct_stats.total_timeouts);
                }
#endif

                /*
                 *      There was no response within the window.  Stop
                 *      the request.  If the client retransmitted, it
                 *      may have failed over to another home server.
                 *      But that one may be dead, too.
                 *
                 *      The extra verbose message if we have a username,
                 *      is extremely useful if the proxy is part of a chain
                 *      and the final home server, is not the one we're
                 *      proxying to.
                 */
                if (request->username) {
                        RERROR("Failing proxied request for user \"%s\", due to lack of any response from home "
                               "server %s port %d",
                               request->username->vp_strvalue,
                               inet_ntop(request->proxy->dst_ipaddr.af,
                                         &request->proxy->dst_ipaddr.ipaddr,
                                         buffer, sizeof(buffer)),
                               request->proxy->dst_port);
                } else {
                        RERROR("Failing proxied request, due to lack of any response from home server %s port %d",
                               inet_ntop(request->proxy->dst_ipaddr.af,
                                         &request->proxy->dst_ipaddr.ipaddr,
                                         buffer, sizeof(buffer)),
                               request->proxy->dst_port);
                }

                if (setup_post_proxy_fail(request)) {
                        request_queue_or_run(request, proxy_no_reply);
                } else {
                        gettimeofday(&request->reply->timestamp, NULL);
                        request_cleanup_delay_init(request);
                }
                break;

                /*
                 *      We received a new reply.  Go process it.
                 */
        case FR_ACTION_PROXY_REPLY:
                request_queue_or_run(request, proxy_running);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}
#endif  /* WITH_PROXY */


/***********************************************************************
 *
 *  CoA code
 *
 ***********************************************************************/
#ifdef WITH_COA
static int null_handler(UNUSED REQUEST *request)
{
        return 0;
}

/*
 *      See if we need to originate a CoA request.
 */
static void request_coa_originate(REQUEST *request)
{
        int rcode, pre_proxy_type = 0;
        VALUE_PAIR *vp;
        REQUEST *coa;
        fr_ipaddr_t ipaddr;
        char buffer[256];

        VERIFY_REQUEST(request);

        rad_assert(request->coa != NULL);
        rad_assert(request->proxy == NULL);
        rad_assert(!request->in_proxy_hash);
        rad_assert(request->proxy_reply == NULL);

        /*
         *      Check whether we want to originate one, or cancel one.
         */
        vp = fr_pair_find_by_num(request->config, PW_SEND_COA_REQUEST, 0, TAG_ANY);
        if (!vp) {
                vp = fr_pair_find_by_num(request->coa->proxy->vps, PW_SEND_COA_REQUEST, 0, TAG_ANY);
        }

        if (vp) {
                if (vp->vp_integer == 0) {
                fail:
                        TALLOC_FREE(request->coa);
                        return;
                }
        }

        coa = request->coa;

        /*
         *      src_ipaddr will be set up in proxy_encode.
         */
        memset(&ipaddr, 0, sizeof(ipaddr));
        vp = fr_pair_find_by_num(coa->proxy->vps, PW_PACKET_DST_IP_ADDRESS, 0, TAG_ANY);
        if (vp) {
                ipaddr.af = AF_INET;
                ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
                ipaddr.prefix = 32;
        } else if ((vp = fr_pair_find_by_num(coa->proxy->vps, PW_PACKET_DST_IPV6_ADDRESS, 0, TAG_ANY)) != NULL) {
                ipaddr.af = AF_INET6;
                ipaddr.ipaddr.ip6addr = vp->vp_ipv6addr;
                ipaddr.prefix = 128;
        } else if ((vp = fr_pair_find_by_num(coa->proxy->vps, PW_HOME_SERVER_POOL, 0, TAG_ANY)) != NULL) {
                coa->home_pool = home_pool_byname(vp->vp_strvalue,
                                                  HOME_TYPE_COA);
                if (!coa->home_pool) {
                        RWDEBUG2("No such home_server_pool %s",
                               vp->vp_strvalue);
                        goto fail;
                }

                /*
                 *      Prefer the pool to one server
                 */
        } else if (request->client->coa_pool) {
                coa->home_pool = request->client->coa_pool;

        } else if (request->client->coa_server) {
                coa->home_server = request->client->coa_server;

        } else {
                /*
                 *      If all else fails, send it to the client that
                 *      originated this request.
                 */
                memcpy(&ipaddr, &request->packet->src_ipaddr, sizeof(ipaddr));
        }

        /*
         *      Use the pool, if it exists.
         */
        if (coa->home_pool) {
                coa->home_server = home_server_ldb(NULL, coa->home_pool, coa);
                if (!coa->home_server) {
                        RWDEBUG("No live home server for home_server_pool %s", coa->home_pool->name);
                        goto fail;
                }
                home_server_update_request(coa->home_server, coa);

        } else if (!coa->home_server) {
                uint16_t port = PW_COA_UDP_PORT;

                vp = fr_pair_find_by_num(coa->proxy->vps, PW_PACKET_DST_PORT, 0, TAG_ANY);
                if (vp) port = vp->vp_integer;

                coa->home_server = home_server_find(&ipaddr, port, IPPROTO_UDP);
                if (!coa->home_server) {
                        RWDEBUG2("Unknown destination %s:%d for CoA request.",
                               inet_ntop(ipaddr.af, &ipaddr.ipaddr,
                                         buffer, sizeof(buffer)), port);
                        goto fail;
                }
        }

        vp = fr_pair_find_by_num(coa->proxy->vps, PW_PACKET_TYPE, 0, TAG_ANY);
        if (vp) {
                switch (vp->vp_integer) {
                case PW_CODE_COA_REQUEST:
                case PW_CODE_DISCONNECT_REQUEST:
                        coa->proxy->code = vp->vp_integer;
                        break;

                default:
                        DEBUG("Cannot set CoA Packet-Type to code %d",
                              vp->vp_integer);
                        goto fail;
                }
        }

        if (!coa->proxy->code) coa->proxy->code = PW_CODE_COA_REQUEST;

        /*
         *      The rest of the server code assumes that
         *      request->packet && request->reply exist.  Copy them
         *      from the original request.
         */
        rad_assert(coa->packet != NULL);
        rad_assert(coa->packet->vps == NULL);

        coa->packet = rad_copy_packet(coa, request->packet);
        coa->reply = rad_copy_packet(coa, request->reply);

        coa->config = fr_pair_list_copy(coa, request->config);
        coa->num_coa_requests = 0;
        coa->handle = null_handler;
        coa->number = request->number; /* it's associated with the same request */

        /*
         *      Call the pre-proxy routines.
         */
        vp = fr_pair_find_by_num(request->config, PW_PRE_PROXY_TYPE, 0, TAG_ANY);
        if (vp) {
                DICT_VALUE const *dval = dict_valbyattr(vp->da->attr, vp->da->vendor, vp->vp_integer);
                /* Must be a validation issue */
                rad_assert(dval);
                RDEBUG2("Found Pre-Proxy-Type %s", dval->name);
                pre_proxy_type = vp->vp_integer;
        }

        if (coa->home_pool && coa->home_pool->virtual_server) {
                char const *old_server = coa->server;

                coa->server = coa->home_pool->virtual_server;
                RDEBUG2("server %s {", coa->server);
                RINDENT();
                rcode = process_pre_proxy(pre_proxy_type, coa);
                REXDENT();
                RDEBUG2("}");
                coa->server = old_server;
        } else {
                rcode = process_pre_proxy(pre_proxy_type, coa);
        }
        switch (rcode) {
        default:
                goto fail;

        /*
         *      Only send the CoA packet if the pre-proxy code succeeded.
         */
        case RLM_MODULE_NOOP:
        case RLM_MODULE_OK:
        case RLM_MODULE_UPDATED:
                break;
        }

        /*
         *      Source IP / port is set when the proxy socket
         *      is chosen.
         */
        coa->proxy->dst_ipaddr = coa->home_server->ipaddr;
        coa->proxy->dst_port = coa->home_server->port;

        if (!insert_into_proxy_hash(coa)) {
                radlog_request(L_PROXY, 0, coa, "Failed to insert CoA request into proxy list");
                goto fail;
        }

        /*
         *      We CANNOT divorce the CoA request from the parent
         *      request.  This function is running in a child thread,
         *      and we need access to the main event loop in order to
         *      to add the timers for the CoA packet.
         *
         *      Instead, we wait for the timer on the parent request
         *      to fire.
         */
        gettimeofday(&coa->proxy->timestamp, NULL);
        coa->packet->timestamp = coa->proxy->timestamp; /* for max_request_time */
        coa->home_server->last_packet_sent = coa->proxy->timestamp.tv_sec;
        coa->delay = 0;         /* need to calculate a new delay */

        /*
         *      If requested, put a State attribute into the packet,
         *      and cache the VPS.
         */
        fr_state_put_vps(coa, NULL, coa->packet);

        /*
         *      Encode the packet before we do anything else.
         */
        coa->proxy_listener->encode(coa->proxy_listener, coa);
        debug_packet(coa, coa->proxy, false);

#ifdef DEBUG_STATE_MACHINE
        if (rad_debug_lvl) printf("(%u) ********\tSTATE %s C-%s -> C-%s\t********\n", request->number, __FUNCTION__,
                               child_state_names[request->child_state],
                               child_state_names[REQUEST_PROXIED]);
#endif

        /*
         *      Set the state function, then the state, no child, and
         *      send the packet.
         */
        coa->process = coa_wait_for_reply;
        coa->child_state = REQUEST_PROXIED;

#ifdef HAVE_PTHREAD_H
        coa->child_pid = NO_SUCH_CHILD_PID;
#endif

        if (we_are_master()) coa_separate(request->coa);

        /*
         *      And send the packet.
         */
        coa->proxy_listener->send(coa->proxy_listener, coa);
}


static void coa_retransmit(REQUEST *request)
{
        uint32_t delay, frac;
        struct timeval now, when, mrd;
        char buffer[128];

        VERIFY_REQUEST(request);

        fr_event_now(el, &now);

        if (request->delay == 0) {
                /*
                 *      Implement re-transmit algorithm as per RFC 5080
                 *      Section 2.2.1.
                 *
                 *      We want IRT + RAND*IRT
                 *      or 0.9 IRT + rand(0,.2) IRT
                 *
                 *      2^20 ~ USEC, and we want 2.
                 *      rand(0,0.2) USEC ~ (rand(0,2^21) / 10)
                 */
                delay = (fr_rand() & ((1 << 22) - 1)) / 10;
                request->delay = delay * request->home_server->coa_irt;
                delay = request->home_server->coa_irt * USEC;
                delay -= delay / 10;
                delay += request->delay;
                request->delay = delay;

                when = request->proxy->timestamp;
                tv_add(&when, delay);

                if (timercmp(&when, &now, >)) {
                        STATE_MACHINE_TIMER(FR_ACTION_TIMER);
                        return;
                }
        }

        /*
         *      Retransmit CoA request.
         */

        /*
         *      Cap count at MRC, if it is non-zero.
         */
        if (request->home_server->coa_mrc &&
            (request->num_coa_requests >= request->home_server->coa_mrc)) {
                RERROR("Failing request - originate-coa ID %u, due to lack of any response from coa server %s port %d",
                       request->proxy->id,
                               inet_ntop(request->proxy->dst_ipaddr.af,
                                         &request->proxy->dst_ipaddr.ipaddr,
                                         buffer, sizeof(buffer)),
                               request->proxy->dst_port);

                if (setup_post_proxy_fail(request)) {
                        request_queue_or_run(request, coa_no_reply);
                } else {
                        request_done(request, FR_ACTION_DONE);
                }
                return;
        }

        /*
         *      RFC 5080 Section 2.2.1
         *
         *      RT = 2*RTprev + RAND*RTprev
         *         = 1.9 * RTprev + rand(0,.2) * RTprev
         *         = 1.9 * RTprev + rand(0,1) * (RTprev / 5)
         */
        delay = fr_rand();
        delay ^= (delay >> 16);
        delay &= 0xffff;
        frac = request->delay / 5;
        delay = ((frac >> 16) * delay) + (((frac & 0xffff) * delay) >> 16);

        delay += (2 * request->delay) - (request->delay / 10);

        /*
         *      Cap delay at MRT, if MRT is non-zero.
         */
        if (request->home_server->coa_mrt &&
            (delay > (request->home_server->coa_mrt * USEC))) {
                int mrt_usec = request->home_server->coa_mrt * USEC;

                /*
                 *      delay = MRT + RAND * MRT
                 *            = 0.9 MRT + rand(0,.2)  * MRT
                 */
                delay = fr_rand();
                delay ^= (delay >> 15);
                delay &= 0x1ffff;
                delay = ((mrt_usec >> 16) * delay) + (((mrt_usec & 0xffff) * delay) >> 16);
                delay += mrt_usec - (mrt_usec / 10);
        }

        request->delay = delay;
        when = now;
        tv_add(&when, request->delay);
        mrd = request->proxy->timestamp;
        mrd.tv_sec += request->home_server->coa_mrd;

        /*
         *      Cap duration at MRD.
         */
        if (timercmp(&mrd, &when, <)) {
                when = mrd;
        }
        STATE_MACHINE_TIMER(FR_ACTION_TIMER);

        request->num_coa_requests++; /* is NOT reset by code 3 lines above! */

        FR_STATS_TYPE_INC(request->home_server->stats.total_requests);

        RDEBUG2("Sending duplicate CoA request to home server %s port %d - ID: %d",
                inet_ntop(request->proxy->dst_ipaddr.af,
                          &request->proxy->dst_ipaddr.ipaddr,
                          buffer, sizeof(buffer)),
                request->proxy->dst_port,
                request->proxy->id);

        request->proxy_listener->send(request->proxy_listener,
                                      request);
}


/** Wait for a reply after originating a CoA a request.
 *
 *  Retransmit the proxied packet, or time out and go to
 *  coa_no_reply.  Mark the home server unresponsive, etc.
 *
 *  If we do receive a reply, we transition to coa_running.
 *
 *  \dot
 *      digraph coa_wait_for_reply {
 *              coa_wait_for_reply;
 *
 *              coa_wait_for_reply -> coa_no_reply [ label = "TIMER >= response_window" ];
 *              coa_wait_for_reply -> timer [ label = "TIMER < max_request_time" ];
 *              coa_wait_for_reply -> coa_running [ label = "PROXY_REPLY" arrowhead = "none"];
 *              coa_wait_for_reply -> done [ label = "TIMER >= max_request_time" ];
 *      }
 *  \enddot
 */
static void coa_wait_for_reply(REQUEST *request, int action)
{
        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;
        CHECK_FOR_STOP;

        if (request->parent) coa_separate(request);

        switch (action) {
        case FR_ACTION_TIMER:
                if (request_max_time(request)) break;

                coa_retransmit(request);
                break;

        case FR_ACTION_PROXY_REPLY:
                request_queue_or_run(request, coa_running);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}

static void coa_separate(REQUEST *request)
{
        VERIFY_REQUEST(request);
#ifdef DEBUG_STATE_MACHINE
        int action = FR_ACTION_TIMER;
#endif

        TRACE_STATE_MACHINE;
        ASSERT_MASTER;

        rad_assert(request->parent != NULL);
        rad_assert(request->parent->coa == request);
        rad_assert(request->ev == NULL);
        rad_assert(!request->in_request_hash);
        rad_assert(request->coa == NULL);

        rad_assert(request->proxy_reply || request->proxy_listener);

        (void) talloc_steal(NULL, request);
        request->parent->coa = NULL;
        request->parent = NULL;

        if (we_are_master()) {
                request->delay = 0;
                coa_retransmit(request);
        }
}


/** Process a request after the CoA has timed out.
 *
 *  Run the packet through Post-Proxy-Type Fail
 *
 *  \dot
 *      digraph coa_no_reply {
 *              coa_no_reply;
 *
 *              coa_no_reply -> dup [ label = "DUP", arrowhead = "none" ];
 *              coa_no_reply -> timer [ label = "TIMER < max_request_time" ];
 *              coa_no_reply -> coa_reply_too_late [ label = "PROXY_REPLY" arrowhead = "none"];
 *              coa_no_reply -> process_proxy_reply [ label = "RUN" ];
 *              coa_no_reply -> done [ label = "TIMER >= timeout" ];
 *      }
 *  \enddot
 */
static void coa_no_reply(REQUEST *request, int action)
{
        char buffer[128];

        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_TIMER:
                (void) request_max_time(request);
                break;

        case FR_ACTION_PROXY_REPLY: /* too late! */
                RDEBUG2("Reply from CoA server %s port %d  - ID: %d arrived too late.",
                        inet_ntop(request->proxy->src_ipaddr.af,
                                  &request->proxy->src_ipaddr.ipaddr,
                                  buffer, sizeof(buffer)),
                        request->proxy->dst_port, request->proxy->id);
                break;

        case FR_ACTION_RUN:
                if (process_proxy_reply(request, NULL)) {
                        request->handle(request);
                }
                request_done(request, FR_ACTION_DONE);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}


/** Process the request after receiving a coa reply.
 *
 *  Throught the post-proxy section, and the through the handler
 *  function.
 *
 *  \dot
 *      digraph coa_running {
 *              coa_running;
 *
 *              coa_running -> timer [ label = "TIMER < max_request_time" ];
 *              coa_running -> process_proxy_reply [ label = "RUN" ];
 *              coa_running -> done [ label = "TIMER >= timeout" ];
 *      }
 *  \enddot
 */
static void coa_running(REQUEST *request, int action)
{
        VERIFY_REQUEST(request);

        TRACE_STATE_MACHINE;
        CHECK_FOR_STOP;

        switch (action) {
        case FR_ACTION_TIMER:
                (void) request_max_time(request);
                break;

        case FR_ACTION_RUN:
                if (process_proxy_reply(request, request->proxy_reply)) {
                        request->handle(request);
                }
                request_done(request, FR_ACTION_DONE);
                break;

        default:
                RDEBUG3("%s: Ignoring action %s", __FUNCTION__, action_codes[action]);
                break;
        }
}
#endif  /* WITH_COA */

/***********************************************************************
 *
 *  End of the State machine.  Start of additional helper code.
 *
 ***********************************************************************/

/***********************************************************************
 *
 *      Event handlers.
 *
 ***********************************************************************/
static void event_socket_handler(fr_event_list_t *xel, UNUSED int fd, void *ctx)
{
        rad_listen_t *listener = talloc_get_type_abort(ctx, rad_listen_t);

        rad_assert(xel == el);

        if ((listener->fd < 0)
#ifdef WITH_DETAIL
#ifndef WITH_DETAIL_THREAD
            && (listener->type != RAD_LISTEN_DETAIL)
#endif
#endif
                ) {
                char buffer[256];

                listener->print(listener, buffer, sizeof(buffer));
                ERROR("FATAL: Asked to read from closed socket: %s",
                       buffer);

                rad_panic("Socket was closed on us!");
                fr_exit_now(1);
        }

        listener->recv(listener);
}

#ifdef WITH_DETAIL
#ifdef WITH_DETAIL_THREAD
#else
/*
 *      This function is called periodically to see if this detail
 *      file is available for reading.
 */
static void event_poll_detail(void *ctx)
{
        int delay;
        rad_listen_t *this = talloc_get_type_abort(ctx, rad_listen_t);
        struct timeval when, now;
        listen_detail_t *detail = this->data;

        rad_assert(this->type == RAD_LISTEN_DETAIL);

 redo:
        event_socket_handler(el, this->fd, this);

        fr_event_now(el, &now);
        when = now;

        /*
         *      Backdoor API to get the delay until the next poll
         *      time.
         */
        delay = this->encode(this, NULL);
        if (delay == 0) goto redo;

        tv_add(&when, delay);

        ASSERT_MASTER;
        if (!fr_event_insert(el, event_poll_detail, this,
                             &when, &detail->ev)) {
                ERROR("Failed creating handler");
                fr_exit(1);
        }
}
#endif  /* WITH_DETAIL_THREAD */
#endif  /* WITH_DETAIL */

static void event_status(struct timeval *wake)
{
#if !defined(HAVE_PTHREAD_H) && defined(WNOHANG)
        int argval;
#endif

        if (rad_debug_lvl == 0) {
                if (just_started) {
                        INFO("Ready to process requests");
                        just_started = false;
                }
                return;
        }

        if (!wake) {
                INFO("Ready to process requests");

        } else if ((wake->tv_sec != 0) ||
                   (wake->tv_usec >= 100000)) {
                DEBUG("Waking up in %d.%01u seconds.",
                      (int) wake->tv_sec, (unsigned int) wake->tv_usec / 100000);
        }


        /*
         *      FIXME: Put this somewhere else, where it isn't called
         *      all of the time...
         */

#if !defined(HAVE_PTHREAD_H) && defined(WNOHANG)
        /*
         *      If there are no child threads, then there may
         *      be child processes.  In that case, wait for
         *      their exit status, and throw that exit status
         *      away.  This helps get rid of zxombie children.
         */
        while (waitpid(-1, &argval, WNOHANG) > 0) {
                /* do nothing */
        }
#endif

}

#ifdef WITH_TCP
static void listener_free_cb(void *ctx)
{
        rad_listen_t *this = talloc_get_type_abort(ctx, rad_listen_t);
        char buffer[1024];

        if (this->count > 0) {
                struct timeval when;
                listen_socket_t *sock = this->data;

                fr_event_now(el, &when);
                when.tv_sec += 3;

                ASSERT_MASTER;
                if (!fr_event_insert(el, listener_free_cb, this, &when,
                                     &(sock->ev))) {
                        rad_panic("Failed to insert event");
                }

                return;
        }

        /*
         *      It's all free, close the socket.
         */

        this->print(this, buffer, sizeof(buffer));
        DEBUG("... cleaning up socket %s", buffer);
        rad_assert(this->next == NULL);
        talloc_free(this);
}
#endif

#ifdef WITH_PROXY
static int proxy_eol_cb(void *ctx, void *data)
{
        struct timeval when;
        REQUEST *request = fr_packet2myptr(REQUEST, proxy, data);

        if (request->proxy_listener != ctx) return 0;

        /*
         *      We don't care if it's being processed in a child thread.
         */

#ifdef WITH_ACCOUNTING
        /*
         *      Accounting packets should be deleted immediately.
         *      They will never be retransmitted by the client.
         */
        if (request->proxy->code == PW_CODE_ACCOUNTING_REQUEST) {
                RDEBUG("Stopping request due to failed connection to home server");
                request->master_state = REQUEST_STOP_PROCESSING;
        }
#endif

        /*
         *      Reset the timer to be now, so that the request is
         *      quickly updated.  But spread the requests randomly
         *      over the next second, so that we don't overload the
         *      server.
         */
        fr_event_now(el, &when);
        tv_add(&when, fr_rand() % USEC);
        STATE_MACHINE_TIMER(FR_ACTION_TIMER);

        /*
         *      Don't delete it from the list.
         */
        return 0;
}
#endif

static int event_new_fd(rad_listen_t *this)
{
        char buffer[1024];

        ASSERT_MASTER;

        if (this->status == RAD_LISTEN_STATUS_KNOWN) return 1;

        this->print(this, buffer, sizeof(buffer));

        if (this->status == RAD_LISTEN_STATUS_INIT) {
                listen_socket_t *sock = this->data;

                rad_assert(sock != NULL);
                if (just_started) {
                        DEBUG("Listening on %s", buffer);
                } else {
                        INFO(" ... adding new socket %s", buffer);
                }

#ifdef WITH_PROXY
                if (!just_started && (this->type == RAD_LISTEN_PROXY)) {
                        home_server_t *home;
                        
                        home = sock->home;
                        if (!home || !home->limit.max_connections) {
                                INFO(" ... adding new socket %s", buffer);
                        } else {
                                INFO(" ... adding new socket %s (%u of %u)", buffer,
                                     home->limit.num_connections, home->limit.max_connections);
                        }

#endif
                }

                switch (this->type) {
#ifdef WITH_DETAIL
                /*
                 *      Detail files are always known, and aren't
                 *      put into the socket event loop.
                 */
                case RAD_LISTEN_DETAIL:
                        this->status = RAD_LISTEN_STATUS_KNOWN;

#ifndef WITH_DETAIL_THREAD
                        /*
                         *      Set up the first poll interval.
                         */
                        event_poll_detail(this);
                        return 1;
#else
                        break;  /* add the FD to the list */
#endif
#endif  /* WITH_DETAIL */

#ifdef WITH_PROXY
                /*
                 *      Add it to the list of sockets we can use.
                 *      Server sockets (i.e. auth/acct) are never
                 *      added to the packet list.
                 */
                case RAD_LISTEN_PROXY:
#ifdef WITH_TCP
                        rad_assert((sock->proto == IPPROTO_UDP) || (sock->home != NULL));

                        /*
                         *      Add timers to outgoing child sockets, if necessary.
                         */
                        if (sock->proto == IPPROTO_TCP && sock->opened &&
                            (sock->home->limit.lifetime || sock->home->limit.idle_timeout)) {
                                struct timeval when;

                                when.tv_sec = sock->opened + 1;
                                when.tv_usec = 0;

                                ASSERT_MASTER;
                                if (!fr_event_insert(el, tcp_socket_timer, this, &when,
                                                     &(sock->ev))) {
                                        rad_panic("Failed to insert event");
                                }
                        }
#endif
                        break;
#endif  /* WITH_PROXY */

                        /*
                         *      FIXME: put idle timers on command sockets.
                         */

                default:
#ifdef WITH_TCP
                        /*
                         *      Add timers to incoming child sockets, if necessary.
                         */
                        if (sock->proto == IPPROTO_TCP && sock->opened &&
                            (sock->limit.lifetime || sock->limit.idle_timeout)) {
                                struct timeval when;

                                when.tv_sec = sock->opened + 1;
                                when.tv_usec = 0;

                                ASSERT_MASTER;
                                if (!fr_event_insert(el, tcp_socket_timer, this, &when,
                                                     &(sock->ev))) {
                                        ERROR("Failed adding timer for socket: %s", fr_strerror());
                                        fr_exit(1);
                                }
                        }
#endif
                        break;
                } /* switch over listener types */

                /*
                 *      All sockets: add the FD to the event handler.
                 */
                if (!fr_event_fd_insert(el, 0, this->fd,
                                        event_socket_handler, this)) {
                        ERROR("Failed adding event handler for socket: %s", fr_strerror());
                        fr_exit(1);
                }

                this->status = RAD_LISTEN_STATUS_KNOWN;
                return 1;
        } /* end of INIT */

#ifdef WITH_TCP
        /*
         *      The socket has reached a timeout.  Try to close it.
         */
        if (this->status == RAD_LISTEN_STATUS_FROZEN) {
                /*
                 *      Requests are still using the socket.  Wait for
                 *      them to finish.
                 */
                if (this->count > 0) {
                        struct timeval when;
                        listen_socket_t *sock = this->data;

                        /*
                         *      Try again to clean up the socket in 30
                         *      seconds.
                         */
                        gettimeofday(&when, NULL);
                        when.tv_sec += 30;

                        ASSERT_MASTER;
                        if (!fr_event_insert(el,
                                             (fr_event_callback_t) event_new_fd,
                                             this, &when, &sock->ev)) {
                                rad_panic("Failed to insert event");
                        }

                        return 1;
                }

                fr_event_fd_delete(el, 0, this->fd);
                this->status = RAD_LISTEN_STATUS_REMOVE_NOW;
        }

        /*
         *      The socket has had a catastrophic error.  Close it.
         */
        if (this->status == RAD_LISTEN_STATUS_EOL) {
                /*
                 *      Remove it from the list of live FD's.
                 */
                fr_event_fd_delete(el, 0, this->fd);

#ifdef WITH_PROXY
                /*
                 *      Tell all requests using this socket that the socket is dead.
                 */
                if (this->type == RAD_LISTEN_PROXY) {
                        PTHREAD_MUTEX_LOCK(&proxy_mutex);
                        if (!fr_packet_list_socket_freeze(proxy_list,
                                                          this->fd)) {
                                ERROR("Fatal error freezing socket: %s", fr_strerror());
                                fr_exit(1);
                        }

                        if (this->count > 0) {
                                fr_packet_list_walk(proxy_list, this, proxy_eol_cb);
                        }
                        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                }
#endif

                /*
                 *      Requests are still using the socket.  Wait for
                 *      them to finish.
                 */
                if (this->count > 0) {
                        struct timeval when;
                        listen_socket_t *sock = this->data;

                        /*
                         *      Try again to clean up the socket in 30
                         *      seconds.
                         */
                        gettimeofday(&when, NULL);
                        when.tv_sec += 30;

                        ASSERT_MASTER;
                        if (!fr_event_insert(el,
                                             (fr_event_callback_t) event_new_fd,
                                             this, &when, &sock->ev)) {
                                rad_panic("Failed to insert event");
                        }

                        return 1;
                }

                /*
                 *      No one is using the socket.  We can remove it now.
                 */
                this->status = RAD_LISTEN_STATUS_REMOVE_NOW;
        } /* socket is at EOL */
#endif

        /*
         *      Nuke the socket.
         */
        if (this->status == RAD_LISTEN_STATUS_REMOVE_NOW) {
                int devnull;
#ifdef WITH_TCP
                listen_socket_t *sock = this->data;
#endif
                struct timeval when;

                /*
                 *      Re-open the socket, pointing it to /dev/null.
                 *      This means that all writes proceed without
                 *      blocking, and all reads return "no data".
                 *
                 *      This leaves the socket active, so any child
                 *      threads won't go insane.  But it means that
                 *      they cannot send or receive any packets.
                 *
                 *      This is EXTRA work in the normal case, when
                 *      sockets are closed without error.  But it lets
                 *      us have one simple processing method for all
                 *      sockets.
                 */
                devnull = open("/dev/null", O_RDWR);
                if (devnull < 0) {
                        ERROR("FATAL failure opening /dev/null: %s",
                               fr_syserror(errno));
                        fr_exit(1);
                }
                if (dup2(devnull, this->fd) < 0) {
                        ERROR("FATAL failure closing socket: %s",
                               fr_syserror(errno));
                        fr_exit(1);
                }
                close(devnull);

#ifdef WITH_DETAIL
                rad_assert(this->type != RAD_LISTEN_DETAIL);
#endif

#ifdef WITH_TCP
#ifdef WITH_PROXY
                /*
                 *      The socket is dead.  Force all proxied packets
                 *      to stop using it.  And then remove it from the
                 *      list of outgoing sockets.
                 */
                if (this->type == RAD_LISTEN_PROXY) {
                        home_server_t *home;

                        home = sock->home;
                        if (!home || !home->limit.max_connections) {
                                INFO(" ... shutting down socket %s", buffer);
                        } else {
                                INFO(" ... shutting down socket %s (%u of %u)", buffer,
                                     home->limit.num_connections, home->limit.max_connections);
                        }

                        PTHREAD_MUTEX_LOCK(&proxy_mutex);
                        fr_packet_list_walk(proxy_list, this, eol_proxy_listener);

                        if (!fr_packet_list_socket_del(proxy_list, this->fd)) {
                                ERROR("Fatal error removing socket %s: %s",
                                      buffer, fr_strerror());
                                fr_exit(1);
                        }
                        PTHREAD_MUTEX_UNLOCK(&proxy_mutex);
                } else
#endif
                {
                        INFO(" ... shutting down socket %s", buffer);

                        /*
                         *      EOL all requests using this socket.
                         */
                        rbtree_walk(pl, RBTREE_DELETE_ORDER, eol_listener, this);
                }

                /*
                 *      No child threads, clean it up now.
                 */
                if (!spawn_flag) {
                        ASSERT_MASTER;
                        if (sock->ev) fr_event_delete(el, &sock->ev);
                        listen_free(&this);
                        return 1;
                }

                /*
                 *      Wait until all requests using this socket are done.
                 */
                gettimeofday(&when, NULL);
                when.tv_sec += 3;

                ASSERT_MASTER;
                if (!fr_event_insert(el, listener_free_cb, this, &when,
                                     &(sock->ev))) {
                        rad_panic("Failed to insert event");
                }
        }
#endif  /* WITH_TCP */

        return 1;
}

/***********************************************************************
 *
 *      Signal handlers.
 *
 ***********************************************************************/

static void handle_signal_self(int flag)
{
        ASSERT_MASTER;

        if ((flag & (RADIUS_SIGNAL_SELF_EXIT | RADIUS_SIGNAL_SELF_TERM)) != 0) {
                if ((flag & RADIUS_SIGNAL_SELF_EXIT) != 0) {
                        INFO("Signalled to exit");
                        fr_event_loop_exit(el, 1);
                } else {
                        INFO("Signalled to terminate");
                        fr_event_loop_exit(el, 2);
                }

                return;
        } /* else exit/term flags weren't set */

        /*
         *      Tell the even loop to stop processing.
         */
        if ((flag & RADIUS_SIGNAL_SELF_HUP) != 0) {
                time_t when;
                static time_t last_hup = 0;

                when = time(NULL);
                if ((int) (when - last_hup) < 5) {
                        INFO("Ignoring HUP (less than 5s since last one)");
                        return;
                }

                INFO("Received HUP signal");

                last_hup = when;

                exec_trigger(NULL, NULL, "server.signal.hup", true);
                fr_event_loop_exit(el, 0x80);
        }

#if defined(WITH_DETAIL) && !defined(WITH_DETAIL_THREAD)
        if ((flag & RADIUS_SIGNAL_SELF_DETAIL) != 0) {
                rad_listen_t *this;

                /*
                 *      FIXME: O(N) loops suck.
                 */
                for (this = main_config.listen;
                     this != NULL;
                     this = this->next) {
                        if (this->type != RAD_LISTEN_DETAIL) continue;

                        /*
                         *      This one didn't send the signal, skip
                         *      it.
                         */
                        if (!this->decode(this, NULL)) continue;

                        /*
                         *      Go service the interrupt.
                         */
                        event_poll_detail(this);
                }
        }
#endif

#if defined(WITH_TCP) && defined(WITH_PROXY) && defined(HAVE_PTHREAD_H)
        /*
         *      There are new listeners in the list.  Run
         *      event_new_fd() on them.
         */
        if ((flag & RADIUS_SIGNAL_SELF_NEW_FD) != 0) {
                rad_listen_t *this, *next;

                FD_MUTEX_LOCK(&fd_mutex);

                /*
                 *      FIXME: unlock the mutex before calling
                 *      event_new_fd()?
                 */
                for (this = new_listeners; this != NULL; this = next) {
                        next = this->next;
                        this->next = NULL;

                        event_new_fd(this);
                }

                new_listeners = NULL;
                FD_MUTEX_UNLOCK(&fd_mutex);
        }
#endif
}

#ifndef HAVE_PTHREAD_H
void radius_signal_self(int flag)
{
        return handle_signal_self(flag);
}

#else
static int self_pipe[2] = { -1, -1 };

/*
 *      Inform ourselves that we received a signal.
 */
void radius_signal_self(int flag)
{
        ssize_t rcode;
        uint8_t buffer[16];

        /*
         *      The read MUST be non-blocking for this to work.
         */
        rcode = read(self_pipe[0], buffer, sizeof(buffer));
        if (rcode > 0) {
                ssize_t i;

                for (i = 0; i < rcode; i++) {
                        buffer[0] |= buffer[i];
                }
        } else {
                buffer[0] = 0;
        }

        buffer[0] |= flag;

        if (write(self_pipe[1], buffer, 1) < 0) fr_exit(0);
}


static void event_signal_handler(UNUSED fr_event_list_t *xel,
                                 UNUSED int fd, UNUSED void *ctx)
{
        ssize_t i, rcode;
        uint8_t buffer[32];

        rcode = read(self_pipe[0], buffer, sizeof(buffer));
        if (rcode <= 0) return;

        /*
         *      Merge pending signals.
         */
        for (i = 0; i < rcode; i++) {
                buffer[0] |= buffer[i];
        }

        handle_signal_self(buffer[0]);
}
#endif  /* HAVE_PTHREAD_H */

/***********************************************************************
 *
 *      Bootstrapping code.
 *
 ***********************************************************************/

/*
 *      Externally-visibly functions.
 */
int radius_event_init(TALLOC_CTX *ctx) {
        el = fr_event_list_create(ctx, event_status);
        if (!el) return 0;

        return 1;
}

static int packet_entry_cmp(void const *one, void const *two)
{
        RADIUS_PACKET const * const *a = one;
        RADIUS_PACKET const * const *b = two;

        return fr_packet_cmp(*a, *b);
}

#ifdef WITH_PROXY
/*
 *      They haven't defined a proxy listener.  Automatically
 *      add one for them, with the correct address family.
 */
static void create_default_proxy_listener(int af)
{
        uint16_t        port = 0;
        home_server_t   home;
        listen_socket_t *sock;
        rad_listen_t    *this;

        memset(&home, 0, sizeof(home));

        /*
         *      Open a default UDP port
         */
        home.proto = IPPROTO_UDP;
        port = 0;

        /*
         *      Set the address family.
         */
        home.src_ipaddr.af = af;
        home.ipaddr.af = af;

        /*
         *      Get the correct listener.
         */
        this = proxy_new_listener(proxy_ctx, &home, port);
        if (!this) {
                fr_exit_now(1);
        }

        sock = this->data;
        if (!fr_packet_list_socket_add(proxy_list, this->fd,
                                       sock->proto,
                                       &sock->other_ipaddr, sock->other_port,
                                       this)) {
                ERROR("Failed adding proxy socket");
                fr_exit_now(1);
        }

        /*
         *      Insert the FD into list of FDs to listen on.
         */
        radius_update_listener(this);
}

/*
 *      See if we automatically need to open a proxy socket.
 */
static void check_proxy(rad_listen_t *head)
{
        bool            defined_proxy;
        bool            has_v4, has_v6;
        rad_listen_t    *this;

        if (check_config) return;
        if (!main_config.proxy_requests) return;
        if (!head) return;
        if (!home_servers_udp) return;

        /*
         *      We passed "-i" on the command line.  Use that address
         *      family for the proxy socket.
         */
        if (main_config.myip.af != AF_UNSPEC) {
                create_default_proxy_listener(main_config.myip.af);
                return;
        }

        defined_proxy = has_v4 = has_v6 = false;

        /*
         *      Figure out if we need to open a proxy socket, and if
         *      so, which one.
         */
        for (this = head; this != NULL; this = this->next) {
                listen_socket_t *sock;

                switch (this->type) {
                case RAD_LISTEN_PROXY:
                        defined_proxy = true;
                        break;

                case RAD_LISTEN_AUTH:
#ifdef WITH_ACCT
                case RAD_LISTEN_ACCT:
#endif
#ifdef WITH_COA
                case RAD_LISTEN_COA:
#endif
                        sock = this->data;
                        if (sock->my_ipaddr.af == AF_INET) has_v4 = true;
                        if (sock->my_ipaddr.af == AF_INET6) has_v6 = true;
                        break;
                        
                default:
                        break;
                }
        }

        /*
         *      Assume they know what they're doing.
         */
        if (defined_proxy) return;

        if (has_v4) create_default_proxy_listener(AF_INET);

        if (has_v6) create_default_proxy_listener(AF_INET6);
}
#endif

int radius_event_start(CONF_SECTION *cs, bool have_children)
{
        rad_listen_t *head = NULL;

        if (fr_start_time != (time_t)-1) return 0;

        time(&fr_start_time);

        if (!check_config) {
                /*
                 *  radius_event_init() must be called first
                 */
                rad_assert(el);

                pl = rbtree_create(NULL, packet_entry_cmp, NULL, 0);
                if (!pl) return 0;      /* leak el */
        }

        request_num_counter = 0;

#ifdef WITH_PROXY
        if (main_config.proxy_requests && !check_config) {
                /*
                 *      Create the tree for managing proxied requests and
                 *      responses.
                 */
                proxy_list = fr_packet_list_create(1);
                if (!proxy_list) return 0;

#ifdef HAVE_PTHREAD_H
                if (pthread_mutex_init(&proxy_mutex, NULL) != 0) {
                        ERROR("FATAL: Failed to initialize proxy mutex: %s",
                               fr_syserror(errno));
                        fr_exit(1);
                }
#endif

                /*
                 *      The "init_delay" is set to "response_window".
                 *      Reset it to half of "response_window" in order
                 *      to give the event loop enough time to service
                 *      the event before hitting "response_window".
                 */
                main_config.init_delay.tv_usec += (main_config.init_delay.tv_sec & 0x01) * USEC;
                main_config.init_delay.tv_usec >>= 1;
                main_config.init_delay.tv_sec >>= 1;

                proxy_ctx = talloc_init("proxy");
        }
#endif

        /*
         *      Move all of the thread calls to this file?
         *
         *      It may be best for the mutexes to be in this file...
         */
        spawn_flag = have_children;

#ifdef HAVE_PTHREAD_H
        NO_SUCH_CHILD_PID = pthread_self(); /* not a child thread */

        /*
         *      Initialize the threads ONLY if we're spawning, AND
         *      we're running normally.
         */
        if (have_children && !check_config &&
            (thread_pool_init(cs, &spawn_flag) < 0)) {
                fr_exit(1);
        }
#endif

        if (check_config) {
                DEBUG("%s: #### Skipping IP addresses and Ports ####",
                       main_config.name);
                if (listen_init(cs, &head, spawn_flag) < 0) {
                        fflush(NULL);
                        fr_exit(1);
                }
                return 1;
        }

#ifdef HAVE_PTHREAD_H
        /*
         *      Child threads need a pipe to signal us, as do the
         *      signal handlers.
         */
        if (pipe(self_pipe) < 0) {
                ERROR("Error opening internal pipe: %s", fr_syserror(errno));
                fr_exit(1);
        }
        if ((fcntl(self_pipe[0], F_SETFL, O_NONBLOCK) < 0) ||
            (fcntl(self_pipe[0], F_SETFD, FD_CLOEXEC) < 0)) {
                ERROR("Error setting internal flags: %s", fr_syserror(errno));
                fr_exit(1);
        }
        if ((fcntl(self_pipe[1], F_SETFL, O_NONBLOCK) < 0) ||
            (fcntl(self_pipe[1], F_SETFD, FD_CLOEXEC) < 0)) {
                ERROR("Error setting internal flags: %s", fr_syserror(errno));
                fr_exit(1);
        }
        DEBUG4("Created signal pipe.  Read end FD %i, write end FD %i", self_pipe[0], self_pipe[1]);

        if (!fr_event_fd_insert(el, 0, self_pipe[0], event_signal_handler, el)) {
                ERROR("Failed creating signal pipe handler: %s", fr_strerror());
                fr_exit(1);
        }
#endif

        DEBUG("%s: #### Opening IP addresses and Ports ####", main_config.name);

        /*
         *      The server temporarily switches to an unprivileged
         *      user very early in the bootstrapping process.
         *      However, some sockets MAY require privileged access
         *      (bind to device, or to port < 1024, or to raw
         *      sockets).  Those sockets need to call suid up/down
         *      themselves around the functions that need a privileged
         *      uid.
         */
        if (listen_init(cs, &head, spawn_flag) < 0) {
                fr_exit_now(1);
        }

        main_config.listen = head;

#ifdef WITH_PROXY
        check_proxy(head);
#endif

        /*
         *      At this point, no one has any business *ever* going
         *      back to root uid.
         */
        rad_suid_down_permanent();

        return 1;
}


#ifdef WITH_PROXY
static int proxy_delete_cb(UNUSED void *ctx, void *data)
{
        REQUEST *request = fr_packet2myptr(REQUEST, proxy, data);

        VERIFY_REQUEST(request);

        request->master_state = REQUEST_STOP_PROCESSING;

#ifdef HAVE_PTHREAD_H
        if (pthread_equal(request->child_pid, NO_SUCH_CHILD_PID) == 0) return 0;
#endif

        /*
         *      If it's queued we can't delete it from the queue.
         *
         *      Otherwise, it's OK to delete it.  Even RUNNING, because
         *      that will get caught by the check above.
         */
        if (request->child_state == REQUEST_QUEUED) return 0;

        request->in_proxy_hash = false;

        if (!request->in_request_hash) {
                request_done(request, FR_ACTION_DONE);
        }

        /*
         *      Delete it from the list.
         */
        return 2;
}
#endif


static int request_delete_cb(UNUSED void *ctx, void *data)
{
        REQUEST *request = fr_packet2myptr(REQUEST, packet, data);

        VERIFY_REQUEST(request);

        request->master_state = REQUEST_STOP_PROCESSING;

        /*
         *      Not done, or the child thread is still processing it.
         */
        if (request->child_state < REQUEST_RESPONSE_DELAY) return 0; /* continue */

#ifdef HAVE_PTHREAD_H
        if (pthread_equal(request->child_pid, NO_SUCH_CHILD_PID) == 0) return 0;
#endif

#ifdef WITH_PROXY
        rad_assert(request->in_proxy_hash == false);
#endif

        request->in_request_hash = false;
        ASSERT_MASTER;
        if (request->ev) fr_event_delete(el, &request->ev);

        if (main_config.memory_report) {
                RDEBUG2("Cleaning up request packet ID %u with timestamp +%d",
                        request->packet->id,
                        (unsigned int) (request->timestamp - fr_start_time));
        }

#ifdef WITH_COA
        if (request->coa) {
                rad_assert(!request->coa->in_proxy_hash);
        }
#endif

        request_free(request);

        /*
         *      Delete it from the list, and continue;
         */
        return 2;
}


void radius_event_free(void)
{
        ASSERT_MASTER;

#ifdef WITH_PROXY
        /*
         *      There are requests in the proxy hash that aren't
         *      referenced from anywhere else.  Remove them first.
         */
        if (proxy_list) {
                fr_packet_list_walk(proxy_list, NULL, proxy_delete_cb);
        }
#endif

        rbtree_walk(pl, RBTREE_DELETE_ORDER,  request_delete_cb, NULL);

        if (spawn_flag) {
                /*
                 *      Now that all requests have been marked "please stop",
                 *      ensure that all of the threads have exited.
                 */
#ifdef HAVE_PTHREAD_H
                thread_pool_stop();
#endif

                /*
                 *      Walk the lists again, ensuring that all
                 *      requests are done.
                 */
                if (main_config.memory_report) {
                        int num;

#ifdef WITH_PROXY
                        if (proxy_list) {
                                fr_packet_list_walk(proxy_list, NULL, proxy_delete_cb);
                                num = fr_packet_list_num_elements(proxy_list);
                                if (num > 0) {
                                        ERROR("Proxy list has %d requests still in it.", num);
                                }
                        }
#endif

                        rbtree_walk(pl, RBTREE_DELETE_ORDER, request_delete_cb, NULL);
                        num = rbtree_num_elements(pl);
                        if (num > 0) {
                                ERROR("Request list has %d requests still in it.", num);
                        }
                }
        }

        rbtree_free(pl);
        pl = NULL;

#ifdef WITH_PROXY
        fr_packet_list_free(proxy_list);
        proxy_list = NULL;

        if (proxy_ctx) talloc_free(proxy_ctx);
#endif

        TALLOC_FREE(el);

        if (debug_condition) talloc_free(debug_condition);
}

int radius_event_process(void)
{
        if (!el) return 0;

        return fr_event_loop(el);
}