Add checks for Linux && OSX

[freeradius.git] / src / lib / misc.c

/*
 * misc.c       Various miscellaneous functions.
 *
 * Version:     $Id$
 *
 *   This library is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   This library 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
 *   Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * Copyright 2000,2006  The FreeRADIUS server project
 */

RCSID("$Id$")

#include <freeradius-devel/libradius.h>

#include <ctype.h>
#include <sys/file.h>
#include <fcntl.h>
#include <grp.h>
#include <pwd.h>
#include <sys/uio.h>

#ifdef HAVE_DIRENT_H
#include <dirent.h>

/*
 *      Some versions of Linux don't have closefrom(), but they will
 *      have /proc.
 *
 *      BSD systems will generally have closefrom(), but not proc.
 *
 *      OSX doesn't have closefrom() or /proc/self/fd, but it does
 *      have /dev/fd
 */
#ifdef __linux__
#define CLOSEFROM_DIR "/proc/self/fd"
#elif defined(__APPLE__)
#define CLOSEFROM_DIR "/dev/fd"
#else
#undef HAVE_DIRENT_H
#endif

#endif

#define FR_PUT_LE16(a, val)\
        do {\
                a[1] = ((uint16_t) (val)) >> 8;\
                a[0] = ((uint16_t) (val)) & 0xff;\
        } while (0)

bool    fr_dns_lookups = false;     /* IP -> hostname lookups? */
bool    fr_hostname_lookups = true; /* hostname -> IP lookups? */
int     fr_debug_lvl = 0;

static char const *months[] = {
        "jan", "feb", "mar", "apr", "may", "jun",
        "jul", "aug", "sep", "oct", "nov", "dec" };

fr_thread_local_setup(char *, fr_inet_ntop_buffer)      /* macro */

typedef struct fr_talloc_link {
        bool armed;
        TALLOC_CTX *child;
} fr_talloc_link_t;

/** Sets a signal handler using sigaction if available, else signal
 *
 * @param sig to set handler for.
 * @param func handler to set.
 */
int fr_set_signal(int sig, sig_t func)
{
#ifdef HAVE_SIGACTION
        struct sigaction act;

        memset(&act, 0, sizeof(act));
        act.sa_flags = 0;
        sigemptyset(&act.sa_mask);
        act.sa_handler = func;

        if (sigaction(sig, &act, NULL) < 0) {
                fr_strerror_printf("Failed setting signal %i handler via sigaction(): %s", sig, fr_syserror(errno));
                return -1;
        }
#else
        if (signal(sig, func) < 0) {
                fr_strerror_printf("Failed setting signal %i handler via signal(): %s", sig, fr_syserror(errno));
                return -1;
        }
#endif
        return 0;
}

/** Uninstall a signal for a specific handler
 *
 * man sigaction says these are fine to call from a signal handler.
 *
 * @param sig SIGNAL
 */
int fr_unset_signal(int sig)
{
#ifdef HAVE_SIGACTION
        struct sigaction act;

        memset(&act, 0, sizeof(act));
        act.sa_flags = 0;
        sigemptyset(&act.sa_mask);
        act.sa_handler = SIG_DFL;

        return sigaction(sig, &act, NULL);
#else
        return signal(sig, SIG_DFL);
#endif
}

static int _fr_trigger_talloc_ctx_free(fr_talloc_link_t *trigger)
{
        if (trigger->armed) talloc_free(trigger->child);

        return 0;
}

static int _fr_disarm_talloc_ctx_free(bool **armed)
{
        **armed = false;
        return 0;
}

/** Link a parent and a child context, so the child is freed before the parent
 *
 * @note This is not thread safe. Do not free parent before threads are joined, do not call from a child thread.
 * @note It's OK to free the child before threads are joined, but this will leak memory until the parent is freed.
 *
 * @param parent who's fate the child should share.
 * @param child bound to parent's lifecycle.
 * @return 0 on success -1 on failure.
 */
int fr_link_talloc_ctx_free(TALLOC_CTX *parent, TALLOC_CTX *child)
{
        fr_talloc_link_t *trigger;
        bool **disarm;

        trigger = talloc(parent, fr_talloc_link_t);
        if (!trigger) return -1;

        disarm = talloc(child, bool *);
        if (!disarm) {
                talloc_free(trigger);
                return -1;
        }

        trigger->child = child;
        trigger->armed = true;
        *disarm = &trigger->armed;

        talloc_set_destructor(trigger, _fr_trigger_talloc_ctx_free);
        talloc_set_destructor(disarm, _fr_disarm_talloc_ctx_free);

        return 0;
}

/*
 *      Explicitly cleanup the memory allocated to the error inet_ntop
 *      buffer.
 */
static void _fr_inet_ntop_free(void *arg)
{
        free(arg);
}

/** Wrapper around inet_ntop, prints IPv4/IPv6 addresses
 *
 * inet_ntop requires the caller pass in a buffer for the address.
 * This would be annoying and cumbersome, seeing as quite often the ASCII
 * address is only used for logging output.
 *
 * So as with lib/log.c use TLS to allocate thread specific buffers, and
 * write the IP address there instead.
 *
 * @param af address family, either AF_INET or AF_INET6.
 * @param src pointer to network address structure.
 * @return NULL on error, else pointer to ASCII buffer containing text version of address.
 */
char const *fr_inet_ntop(int af, void const *src)
{
        char *buffer;

        if (!src) {
                return NULL;
        }

        buffer = fr_thread_local_init(fr_inet_ntop_buffer, _fr_inet_ntop_free);
        if (!buffer) {
                int ret;

                /*
                 *      malloc is thread safe, talloc is not
                 */
                buffer = malloc(sizeof(char) * INET6_ADDRSTRLEN);
                if (!buffer) {
                        fr_perror("Failed allocating memory for inet_ntop buffer");
                        return NULL;
                }

                ret = fr_thread_local_set(fr_inet_ntop_buffer, buffer);
                if (ret != 0) {
                        fr_perror("Failed setting up TLS for inet_ntop buffer: %s", fr_syserror(ret));
                        free(buffer);
                        return NULL;
                }
        }
        buffer[0] = '\0';

        return inet_ntop(af, src, buffer, INET6_ADDRSTRLEN);
}

/*
 *      Return an IP address in standard dot notation
 *
 *      FIXME: DELETE THIS
 */
char const *ip_ntoa(char *buffer, uint32_t ipaddr)
{
        ipaddr = ntohl(ipaddr);

        sprintf(buffer, "%d.%d.%d.%d",
                (ipaddr >> 24) & 0xff,
                (ipaddr >> 16) & 0xff,
                (ipaddr >>  8) & 0xff,
                (ipaddr      ) & 0xff);
        return buffer;
}

/*
 *      Parse decimal digits until we run out of decimal digits.
 */
static int ip_octet_from_str(char const *str, uint32_t *poctet)
{
        uint32_t octet;
        char const *p = str;

        if ((*p < '0') || (*p > '9')) {
                return -1;
        }

        octet = 0;

        while ((*p >= '0') && (*p <= '9')) {
                octet *= 10;
                octet += *p - '0';
                p++;

                if (octet > 255) return -1;
        }


        *poctet = octet;
        return p - str;
}

static int ip_prefix_from_str(char const *str, uint32_t *paddr)
{
        int shift, length;
        uint32_t octet;
        uint32_t addr;
        char const *p = str;

        addr = 0;

        for (shift = 24; shift >= 0; shift -= 8) {
                length = ip_octet_from_str(p, &octet);
                if (length <= 0) return -1;

                addr |= octet << shift;
                p += length;

                /*
                 *      EOS or / means we're done.
                 */
                if (!*p || (*p == '/')) break;

                /*
                 *      We require dots between octets.
                 */
                if (*p != '.') return -1;
                p++;
        }

        *paddr = htonl(addr);
        return p - str;
}


/** Parse an IPv4 address or IPv4 prefix in presentation format (and others)
 *
 * @param out Where to write the ip address value.
 * @param value to parse, may be dotted quad [+ prefix], or integer, or octal number, or '*' (INADDR_ANY).
 * @param inlen Length of value, if value is \0 terminated inlen may be -1.
 * @param resolve If true and value doesn't look like an IP address, try and resolve value as a hostname.
 * @param fallback to IPv6 resolution if no A records can be found.
 * @return 0 if ip address was parsed successfully, else -1 on error.
 */
int fr_pton4(fr_ipaddr_t *out, char const *value, ssize_t inlen, bool resolve, bool fallback)
{
        char *p;
        unsigned int mask;
        char *eptr;

        /* Dotted quad + / + [0-9]{1,2} */
        char buffer[INET_ADDRSTRLEN + 3];

        /*
         *      Copy to intermediary buffer if we were given a length
         */
        if (inlen >= 0) {
                if (inlen >= (ssize_t)sizeof(buffer)) {
                        fr_strerror_printf("Invalid IPv4 address string \"%s\"", value);
                        return -1;
                }
                memcpy(buffer, value, inlen);
                buffer[inlen] = '\0';
                value = buffer;
        }

        p = strchr(value, '/');

        /*
         *      192.0.2.2 is parsed as if it was /32
         */
        if (!p) {
                out->prefix = 32;
                out->af = AF_INET;

                /*
                 *      Allow '*' as the wildcard address usually 0.0.0.0
                 */
                if ((value[0] == '*') && (value[1] == '\0')) {
                        out->ipaddr.ip4addr.s_addr = htonl(INADDR_ANY);

                /*
                 *      Convert things which are obviously integers to IP addresses
                 *
                 *      We assume the number is the bigendian representation of the
                 *      IP address.
                 */
                } else if (is_integer(value) || ((value[0] == '0') && (value[1] == 'x'))) {
                        out->ipaddr.ip4addr.s_addr = htonl(strtoul(value, NULL, 0));

                } else if (!resolve) {
                        if (inet_pton(AF_INET, value, &out->ipaddr.ip4addr.s_addr) <= 0) {
                                fr_strerror_printf("Failed to parse IPv4 addreess string \"%s\"", value);
                                return -1;
                        }
                } else if (ip_hton(out, AF_INET, value, fallback) < 0) return -1;

                return 0;
        }

        /*
         *      Copy the IP portion into a temporary buffer if we haven't already.
         */
        if (inlen < 0) memcpy(buffer, value, p - value);
        buffer[p - value] = '\0';

        if (ip_prefix_from_str(buffer, &out->ipaddr.ip4addr.s_addr) <= 0) {
                fr_strerror_printf("Failed to parse IPv4 address string \"%s\"", value);
                return -1;
        }

        mask = strtoul(p + 1, &eptr, 10);
        if (mask > 32) {
                fr_strerror_printf("Invalid IPv4 mask length \"%s\".  Should be between 0-32", p);
                return -1;
        }

        if (eptr[0] != '\0') {
                fr_strerror_printf("Failed to parse IPv4 address string \"%s\", "
                                   "got garbage after mask length \"%s\"", value, eptr);
                return -1;
        }

        if (mask < 32) {
                out->ipaddr.ip4addr = fr_inaddr_mask(&out->ipaddr.ip4addr, mask);
        }

        out->prefix = (uint8_t) mask;
        out->af = AF_INET;

        return 0;
}

/** Parse an IPv6 address or IPv6 prefix in presentation format (and others)
 *
 * @param out Where to write the ip address value.
 * @param value to parse.
 * @param inlen Length of value, if value is \0 terminated inlen may be -1.
 * @param resolve If true and value doesn't look like an IP address, try and resolve value as a hostname.
 * @param fallback to IPv4 resolution if no AAAA records can be found.
 * @return 0 if ip address was parsed successfully, else -1 on error.
 */
int fr_pton6(fr_ipaddr_t *out, char const *value, ssize_t inlen, bool resolve, bool fallback)
{
        char const *p;
        unsigned int prefix;
        char *eptr;

        /* IPv6  + / + [0-9]{1,3} */
        char buffer[INET6_ADDRSTRLEN + 4];

        /*
         *      Copy to intermediary buffer if we were given a length
         */
        if (inlen >= 0) {
                if (inlen >= (ssize_t)sizeof(buffer)) {
                        fr_strerror_printf("Invalid IPv6 address string \"%s\"", value);
                        return -1;
                }
                memcpy(buffer, value, inlen);
                buffer[inlen] = '\0';
                value = buffer;
        }

        p = strchr(value, '/');
        if (!p) {
                out->prefix = 128;
                out->af = AF_INET6;

                /*
                 *      Allow '*' as the wildcard address
                 */
                if ((value[0] == '*') && (value[1] == '\0')) {
                        memset(out->ipaddr.ip6addr.s6_addr, 0, sizeof(out->ipaddr.ip6addr.s6_addr));
                } else if (!resolve) {
                        if (inet_pton(AF_INET6, value, out->ipaddr.ip6addr.s6_addr) <= 0) {
                                fr_strerror_printf("Failed to parse IPv6 address string \"%s\"", value);
                                return -1;
                        }
                } else if (ip_hton(out, AF_INET6, value, fallback) < 0) return -1;

                return 0;
        }

        if ((p - value) >= INET6_ADDRSTRLEN) {
                fr_strerror_printf("Invalid IPv6 address string \"%s\"", value);
                return -1;
        }

        /*
         *      Copy string to temporary buffer if we didn't do it earlier
         */
        if (inlen < 0) memcpy(buffer, value, p - value);
        buffer[p - value] = '\0';

        if (!resolve) {
                if (inet_pton(AF_INET6, buffer, out->ipaddr.ip6addr.s6_addr) <= 0) {
                        fr_strerror_printf("Failed to parse IPv6 address string \"%s\"", value);
                        return -1;
                }
        } else if (ip_hton(out, AF_INET6, buffer, fallback) < 0) return -1;

        prefix = strtoul(p + 1, &eptr, 10);
        if (prefix > 128) {
                fr_strerror_printf("Invalid IPv6 mask length \"%s\".  Should be between 0-128", p);
                return -1;
        }
        if (eptr[0] != '\0') {
                fr_strerror_printf("Failed to parse IPv6 address string \"%s\", "
                                   "got garbage after mask length \"%s\"", value, eptr);
                return -1;
        }

        if (prefix < 128) {
                struct in6_addr addr;

                addr = fr_in6addr_mask(&out->ipaddr.ip6addr, prefix);
                memcpy(out->ipaddr.ip6addr.s6_addr, addr.s6_addr, sizeof(out->ipaddr.ip6addr.s6_addr));
        }

        out->prefix = (uint8_t) prefix;
        out->af = AF_INET6;

        return 0;
}

/** Simple wrapper to decide whether an IP value is v4 or v6 and call the appropriate parser.
 *
 * @param[out] out Where to write the ip address value.
 * @param[in] value to parse.
 * @param[in] inlen Length of value, if value is \0 terminated inlen may be -1.
 * @param[in] resolve If true and value doesn't look like an IP address, try and resolve value as a
 *      hostname.
 * @param[in] af If the address type is not obvious from the format, and resolve is true, the DNS
 *      record (A or AAAA) we require.  Also controls which parser we pass the address to if
 *      we have no idea what it is.
 * @return
 *      - 0 if ip address was parsed successfully.
 *      - -1 on failure.
 */
int fr_pton(fr_ipaddr_t *out, char const *value, ssize_t inlen, int af, bool resolve)
{
        size_t len, i;

        len = (inlen >= 0) ? (size_t)inlen : strlen(value);
        for (i = 0; i < len; i++) switch (value[i]) {
        /*
         *      ':' is illegal in domain names and IPv4 addresses.
         *      Must be v6 and cannot be a domain.
         */
        case ':':
                return fr_pton6(out, value, inlen, false, false);

        /*
         *      Chars which don't really tell us anything
         */
        case '.':
        case '/':
                continue;

        default:
                /*
                 *      Outside the range of IPv4 chars, must be a domain
                 *      Use A record in preference to AAAA record.
                 */
                if ((value[i] < '0') || (value[i] > '9')) {
                        if (!resolve) {
                                fr_strerror_printf("Not IPv4/6 address, and asked not to resolve");
                                return -1;
                        }
                        switch (af) {
                        case AF_UNSPEC:
                                return fr_pton4(out, value, inlen, resolve, true);

                        case AF_INET:
                                return fr_pton4(out, value, inlen, resolve, false);

                        case AF_INET6:
                                return fr_pton6(out, value, inlen, resolve, false);

                        default:
                                fr_strerror_printf("Invalid address family %i", af);
                                return -1;
                        }
                }
                break;
        }

        /*
         *      All chars were in the IPv4 set [0-9/.], must be an IPv4
         *      address.
         */
        return fr_pton4(out, value, inlen, false, false);
}

/** Parses IPv4/6 address + port, to fr_ipaddr_t and integer
 *
 * @param[out] out Where to write the ip address value.
 * @param[out] port_out Where to write the port (0 if no port found).
 * @param[in] value to parse.
 * @param[in] inlen Length of value, if value is \0 terminated inlen may be -1.
 * @param[in] af If the address type is not obvious from the format, and resolve is true, the DNS
 *      record (A or AAAA) we require.  Also controls which parser we pass the address to if
 *      we have no idea what it is.
 * @param[in] resolve If true and value doesn't look like an IP address, try and resolve value as a
 *      hostname.
 */
int fr_pton_port(fr_ipaddr_t *out, uint16_t *port_out, char const *value, ssize_t inlen, int af, bool resolve)
{
        char const      *p = value, *q;
        char            *end;
        unsigned long   port;
        char            buffer[6];
        size_t          len;

        *port_out = 0;

        len = (inlen >= 0) ? (size_t)inlen : strlen(value);

        if (*p == '[') {
                if (!(q = memchr(p + 1, ']', len - 1))) {
                        fr_strerror_printf("Missing closing ']' for IPv6 address");
                        return -1;
                }

                /*
                 *      inet_pton doesn't like the address being wrapped in []
                 */
                if (fr_pton6(out, p + 1, (q - p) - 1, false, false) < 0) return -1;

                if (q[1] == ':') {
                        q++;
                        goto do_port;
                }

                return 0;
        }

        /*
         *      Host, IPv4 or IPv6 with no port
         */
        q = memchr(p, ':', len);
        if (!q) return fr_pton(out, p, len, af, resolve);

        /*
         *      IPv4 or host, with port
         */
        if (fr_pton(out, p, (q - p), af, resolve) < 0) return -1;

do_port:
        /*
         *      Valid ports are a maximum of 5 digits, so if the
         *      input length indicates there are more than 5 chars
         *      after the ':' then there's an issue.
         */
        if (inlen > ((q + sizeof(buffer)) - value)) {
        error:
                fr_strerror_printf("IP string contains trailing garbage after port delimiter");
                return -1;
        }

        p = q + 1;                      /* Move to first digit */

        strlcpy(buffer, p, (len - (p - value)) + 1);
        port = strtoul(buffer, &end, 10);
        if (*end != '\0') goto error;   /* Trailing garbage after integer */

        if ((port > UINT16_MAX) || (port == 0)) {
                fr_strerror_printf("Port %lu outside valid port range 1-" STRINGIFY(UINT16_MAX), port);
                return -1;
        }
        *port_out = port;

        return 0;
}

int fr_ntop(char *out, size_t outlen, fr_ipaddr_t *addr)
{
        char buffer[INET6_ADDRSTRLEN];

        if (inet_ntop(addr->af, &(addr->ipaddr), buffer, sizeof(buffer)) == NULL) return -1;

        return snprintf(out, outlen, "%s/%i", buffer, addr->prefix);
}

/*
 *      cppcheck apparently can't pick this up from the system headers.
 */
#ifdef CPPCHECK
#define F_WRLCK
#endif

/*
 *      Internal wrapper for locking, to minimize the number of ifdef's
 *
 *      Use fcntl or error
 */
int rad_lockfd(int fd, int lock_len)
{
#ifdef F_WRLCK
        struct flock fl;

        fl.l_start = 0;
        fl.l_len = lock_len;
        fl.l_pid = getpid();
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_CUR;

        return fcntl(fd, F_SETLKW, (void *)&fl);
#else
#error "missing definition for F_WRLCK, all file locks will fail"

        return -1;
#endif
}

/*
 *      Internal wrapper for locking, to minimize the number of ifdef's
 *
 *      Lock an fd, prefer lockf() over flock()
 *      Nonblocking version.
 */
int rad_lockfd_nonblock(int fd, int lock_len)
{
#ifdef F_WRLCK
        struct flock fl;

        fl.l_start = 0;
        fl.l_len = lock_len;
        fl.l_pid = getpid();
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_CUR;

        return fcntl(fd, F_SETLK, (void *)&fl);
#else
#error "missing definition for F_WRLCK, all file locks will fail"

        return -1;
#endif
}

/*
 *      Internal wrapper for unlocking, to minimize the number of ifdef's
 *      in the source.
 *
 *      Unlock an fd, prefer lockf() over flock()
 */
int rad_unlockfd(int fd, int lock_len)
{
#ifdef F_WRLCK
        struct flock fl;

        fl.l_start = 0;
        fl.l_len = lock_len;
        fl.l_pid = getpid();
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_CUR;

        return fcntl(fd, F_UNLCK, (void *)&fl);
#else
#error "missing definition for F_WRLCK, all file locks will fail"

        return -1;
#endif
}

/*
 *      Return an interface-id in standard colon notation
 */
char *ifid_ntoa(char *buffer, size_t size, uint8_t const *ifid)
{
        snprintf(buffer, size, "%x:%x:%x:%x",
                 (ifid[0] << 8) + ifid[1], (ifid[2] << 8) + ifid[3],
                 (ifid[4] << 8) + ifid[5], (ifid[6] << 8) + ifid[7]);
        return buffer;
}


/*
 *      Return an interface-id from
 *      one supplied in standard colon notation.
 */
uint8_t *ifid_aton(char const *ifid_str, uint8_t *ifid)
{
        static char const xdigits[] = "0123456789abcdef";
        char const *p, *pch;
        int num_id = 0, val = 0, idx = 0;

        for (p = ifid_str; ; ++p) {
                if (*p == ':' || *p == '\0') {
                        if (num_id <= 0)
                                return NULL;

                        /*
                         *      Drop 'val' into the array.
                         */
                        ifid[idx] = (val >> 8) & 0xff;
                        ifid[idx + 1] = val & 0xff;
                        if (*p == '\0') {
                                /*
                                 *      Must have all entries before
                                 *      end of the string.
                                 */
                                if (idx != 6)
                                        return NULL;
                                break;
                        }
                        val = 0;
                        num_id = 0;
                        if ((idx += 2) > 6)
                                return NULL;
                } else if ((pch = strchr(xdigits, tolower(*p))) != NULL) {
                        if (++num_id > 4)
                                return NULL;
                        /*
                         *      Dumb version of 'scanf'
                         */
                        val <<= 4;
                        val |= (pch - xdigits);
                } else
                        return NULL;
        }
        return ifid;
}


#ifndef HAVE_INET_PTON
static int inet_pton4(char const *src, struct in_addr *dst)
{
        int octet;
        unsigned int num;
        char const *p, *off;
        uint8_t tmp[4];
        static char const digits[] = "0123456789";

        octet = 0;
        p = src;
        while (1) {
                num = 0;
                while (*p && ((off = strchr(digits, *p)) != NULL)) {
                        num *= 10;
                        num += (off - digits);

                        if (num > 255) return 0;

                        p++;
                }
                if (!*p) break;

                /*
                 *      Not a digit, MUST be a dot, else we
                 *      die.
                 */
                if (*p != '.') {
                        return 0;
                }

                tmp[octet++] = num;
                p++;
        }

        /*
         *      End of the string.  At the fourth
         *      octet is OK, anything else is an
         *      error.
         */
        if (octet != 3) {
                return 0;
        }
        tmp[3] = num;

        memcpy(dst, &tmp, sizeof(tmp));
        return 1;
}


#ifdef HAVE_STRUCT_SOCKADDR_IN6
/** Convert presentation level address to network order binary form
 *
 * @note Does not touch dst unless it's returning 1.
 * @note :: in a full address is silently ignored.
 * @note Inspired by Mark Andrews.
 * @author Paul Vixie, 1996.
 *
 * @param src presentation level address.
 * @param dst where to write output address.
 * @return 1 if `src' is a valid [RFC1884 2.2] address, else 0.
 */
static int inet_pton6(char const *src, unsigned char *dst)
{
        static char const xdigits_l[] = "0123456789abcdef",
                          xdigits_u[] = "0123456789ABCDEF";
        u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
        char const *xdigits, *curtok;
        int ch, saw_xdigit;
        u_int val;

        memset((tp = tmp), 0, IN6ADDRSZ);
        endp = tp + IN6ADDRSZ;
        colonp = NULL;
        /* Leading :: requires some special handling. */
        if (*src == ':')
                if (*++src != ':')
                        return (0);
        curtok = src;
        saw_xdigit = 0;
        val = 0;
        while ((ch = *src++) != '\0') {
                char const *pch;

                if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
                        pch = strchr((xdigits = xdigits_u), ch);
                if (pch != NULL) {
                        val <<= 4;
                        val |= (pch - xdigits);
                        if (val > 0xffff)
                                return (0);
                        saw_xdigit = 1;
                        continue;
                }
                if (ch == ':') {
                        curtok = src;
                        if (!saw_xdigit) {
                                if (colonp)
                                        return (0);
                                colonp = tp;
                                continue;
                        }
                        if (tp + INT16SZ > endp)
                                return (0);
                        *tp++ = (u_char) (val >> 8) & 0xff;
                        *tp++ = (u_char) val & 0xff;
                        saw_xdigit = 0;
                        val = 0;
                        continue;
                }
                if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
                    inet_pton4(curtok, (struct in_addr *) tp) > 0) {
                        tp += INADDRSZ;
                        saw_xdigit = 0;
                        break;  /* '\0' was seen by inet_pton4(). */
                }
                return (0);
        }
        if (saw_xdigit) {
                if (tp + INT16SZ > endp)
                        return (0);
                *tp++ = (u_char) (val >> 8) & 0xff;
                *tp++ = (u_char) val & 0xff;
        }
        if (colonp != NULL) {
                /*
                 * Since some memmove()'s erroneously fail to handle
                 * overlapping regions, we'll do the shift by hand.
                 */
                int const n = tp - colonp;
                int i;

                for (i = 1; i <= n; i++) {
                        endp[- i] = colonp[n - i];
                        colonp[n - i] = 0;
                }
                tp = endp;
        }
        if (tp != endp)
                return (0);
        /* bcopy(tmp, dst, IN6ADDRSZ); */
        memcpy(dst, tmp, IN6ADDRSZ);
        return (1);
}
#endif

/*
 *      Utility function, so that the rest of the server doesn't
 *      have ifdef's around IPv6 support
 */
int inet_pton(int af, char const *src, void *dst)
{
        if (af == AF_INET) {
                return inet_pton4(src, dst);
        }
#ifdef HAVE_STRUCT_SOCKADDR_IN6

        if (af == AF_INET6) {
                return inet_pton6(src, dst);
        }
#endif

        return -1;
}
#endif

#ifndef HAVE_INET_NTOP
/*
 *      Utility function, so that the rest of the server doesn't
 *      have ifdef's around IPv6 support
 */
char const *inet_ntop(int af, void const *src, char *dst, size_t cnt)
{
        if (af == AF_INET) {
                uint8_t const *ipaddr = src;

                if (cnt <= INET_ADDRSTRLEN) return NULL;

                snprintf(dst, cnt, "%d.%d.%d.%d",
                         ipaddr[0], ipaddr[1],
                         ipaddr[2], ipaddr[3]);
                return dst;
        }

        /*
         *      If the system doesn't define this, we define it
         *      in missing.h
         */
        if (af == AF_INET6) {
                struct in6_addr const *ipaddr = src;

                if (cnt <= INET6_ADDRSTRLEN) return NULL;

                snprintf(dst, cnt, "%x:%x:%x:%x:%x:%x:%x:%x",
                         (ipaddr->s6_addr[0] << 8) | ipaddr->s6_addr[1],
                         (ipaddr->s6_addr[2] << 8) | ipaddr->s6_addr[3],
                         (ipaddr->s6_addr[4] << 8) | ipaddr->s6_addr[5],
                         (ipaddr->s6_addr[6] << 8) | ipaddr->s6_addr[7],
                         (ipaddr->s6_addr[8] << 8) | ipaddr->s6_addr[9],
                         (ipaddr->s6_addr[10] << 8) | ipaddr->s6_addr[11],
                         (ipaddr->s6_addr[12] << 8) | ipaddr->s6_addr[13],
                         (ipaddr->s6_addr[14] << 8) | ipaddr->s6_addr[15]);
                return dst;
        }

        return NULL;            /* don't support IPv6 */
}
#endif

/** Wrappers for IPv4/IPv6 host to IP address lookup
 *
 * This function returns only one IP address, of the specified address family,
 * or the first address (of whatever family), if AF_UNSPEC is used.
 *
 * If fallback is specified and af is AF_INET, but no AF_INET records were
 * found and a record for AF_INET6 exists that record will be returned.
 *
 * If fallback is specified and af is AF_INET6, and a record with AF_INET4 exists
 * that record will be returned instead.
 *
 * @param out Where to write result.
 * @param af To search for in preference.
 * @param hostname to search for.
 * @param fallback to the other adress family, if no records matching af, found.
 * @return 0 on success, else -1 on failure.
 */
int ip_hton(fr_ipaddr_t *out, int af, char const *hostname, bool fallback)
{
        int rcode;
        struct addrinfo hints, *ai = NULL, *alt = NULL, *res = NULL;

        /*
         *      Avoid malloc for IP addresses.  This helps us debug
         *      memory errors when using talloc.
         */
#ifdef TALLOC_DEBUG
        if (true) {
#else
        if (!fr_hostname_lookups) {
#endif
#ifdef HAVE_STRUCT_SOCKADDR_IN6
                if (af == AF_UNSPEC) {
                        char const *p;

                        for (p = hostname; *p != '\0'; p++) {
                                if ((*p == ':') ||
                                    (*p == '[') ||
                                    (*p == ']')) {
                                        af = AF_INET6;
                                        break;
                                }
                        }
                }
#endif

                if (af == AF_UNSPEC) af = AF_INET;

                if (!inet_pton(af, hostname, &(out->ipaddr))) return -1;

                out->af = af;
                return 0;
        }

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

        /*
         *      If we're falling back we need both IPv4 and IPv6 records
         */
        if (fallback) {
                hints.ai_family = AF_UNSPEC;
        } else {
                hints.ai_family = af;
        }

        if ((rcode = getaddrinfo(hostname, NULL, &hints, &res)) != 0) {
                switch (af) {
                default:
                case AF_UNSPEC:
                        fr_strerror_printf("Failed resolving \"%s\" to IP address: %s",
                                           hostname, gai_strerror(rcode));
                        return -1;

                case AF_INET:
                        fr_strerror_printf("Failed resolving \"%s\" to IPv4 address: %s",
                                           hostname, gai_strerror(rcode));
                        return -1;

                case AF_INET6:
                        fr_strerror_printf("Failed resolving \"%s\" to IPv6 address: %s",
                                           hostname, gai_strerror(rcode));
                        return -1;
                }
        }

        for (ai = res; ai; ai = ai->ai_next) {
                if ((af == ai->ai_family) || (af == AF_UNSPEC)) break;
                if (!alt && fallback && ((ai->ai_family == AF_INET) || (ai->ai_family == AF_INET6))) alt = ai;
        }

        if (!ai) ai = alt;
        if (!ai) {
                fr_strerror_printf("ip_hton failed to find requested information for host %.100s", hostname);
                freeaddrinfo(res);
                return -1;
        }

        rcode = fr_sockaddr2ipaddr((struct sockaddr_storage *)ai->ai_addr,
                                   ai->ai_addrlen, out, NULL);
        freeaddrinfo(res);
        if (!rcode) {
                fr_strerror_printf("Failed converting sockaddr to ipaddr");
                return -1;
        }

        return 0;
}

/*
 *      Look IP addresses up, and print names (depending on DNS config)
 */
char const *ip_ntoh(fr_ipaddr_t const *src, char *dst, size_t cnt)
{
        struct sockaddr_storage ss;
        int error;
        socklen_t salen;

        /*
         *      No DNS lookups
         */
        if (!fr_dns_lookups) {
                return inet_ntop(src->af, &(src->ipaddr), dst, cnt);
        }

        if (!fr_ipaddr2sockaddr(src, 0, &ss, &salen)) {
                return NULL;
        }

        if ((error = getnameinfo((struct sockaddr *)&ss, salen, dst, cnt, NULL, 0,
                                 NI_NUMERICHOST | NI_NUMERICSERV)) != 0) {
                fr_strerror_printf("ip_ntoh: %s", gai_strerror(error));
                return NULL;
        }
        return dst;
}

/** Mask off a portion of an IPv4 address
 *
 * @param ipaddr to mask.
 * @param prefix Number of contiguous bits to mask.
 * @return an ipv4 address with the host portion zeroed out.
 */
struct in_addr fr_inaddr_mask(struct in_addr const *ipaddr, uint8_t prefix)
{
        uint32_t ret;

        if (prefix > 32) prefix = 32;

        /* Short circuit */
        if (prefix == 32) return *ipaddr;

        if (prefix == 0) ret = 0;
        else ret = htonl(~((0x00000001UL << (32 - prefix)) - 1)) & ipaddr->s_addr;

        return (*(struct in_addr *)&ret);
}

/** Mask off a portion of an IPv6 address
 *
 * @param ipaddr to mask.
 * @param prefix Number of contiguous bits to mask.
 * @return an ipv6 address with the host portion zeroed out.
 */
struct in6_addr fr_in6addr_mask(struct in6_addr const *ipaddr, uint8_t prefix)
{
        uint64_t const *p = (uint64_t const *) ipaddr;
        uint64_t ret[2], *o = ret;

        if (prefix > 128) prefix = 128;

        /* Short circuit */
        if (prefix == 128) return *ipaddr;

        if (prefix >= 64) {
                prefix -= 64;
                *o++ = 0xffffffffffffffffULL & *p++;    /* lhs portion masked */
        } else {
                ret[1] = 0;                             /* rhs portion zeroed */
        }

        /* Max left shift is 63 else we get overflow */
        if (prefix > 0) {
                *o = htonll(~((uint64_t)(0x0000000000000001ULL << (64 - prefix)) - 1)) & *p;
        } else {
                *o = 0;
        }

        return *(struct in6_addr *) &ret;
}

/** Zeroes out the host portion of an fr_ipaddr_t
 *
 * @param[in,out] addr to mask
 * @param[in] prefix Length of the network portion.
 */
void fr_ipaddr_mask(fr_ipaddr_t *addr, uint8_t prefix)
{

        switch (addr->af) {
        case AF_INET:
                addr->ipaddr.ip4addr = fr_inaddr_mask(&addr->ipaddr.ip4addr, prefix);
                break;

        case AF_INET6:
                addr->ipaddr.ip6addr = fr_in6addr_mask(&addr->ipaddr.ip6addr, prefix);
                break;

        default:
                return;
        }
        addr->prefix = prefix;
}

static char const hextab[] = "0123456789abcdef";

/** Convert hex strings to binary data
 *
 * @param bin Buffer to write output to.
 * @param outlen length of output buffer (or length of input string / 2).
 * @param hex input string.
 * @param inlen length of the input string
 * @return length of data written to buffer.
 */
size_t fr_hex2bin(uint8_t *bin, size_t outlen, char const *hex, size_t inlen)
{
        size_t i;
        size_t len;
        char *c1, *c2;

        /*
         *      Smartly truncate output, caller should check number of bytes
         *      written.
         */
        len = inlen >> 1;
        if (len > outlen) len = outlen;

        for (i = 0; i < len; i++) {
                if(!(c1 = memchr(hextab, tolower((int) hex[i << 1]), sizeof(hextab))) ||
                   !(c2 = memchr(hextab, tolower((int) hex[(i << 1) + 1]), sizeof(hextab))))
                        break;
                bin[i] = ((c1-hextab)<<4) + (c2-hextab);
        }

        return i;
}

/** Convert binary data to a hex string
 *
 * Ascii encoded hex string will not be prefixed with '0x'
 *
 * @warning If the output buffer isn't long enough, we have a buffer overflow.
 *
 * @param[out] hex Buffer to write hex output.
 * @param[in] bin input.
 * @param[in] inlen of bin input.
 * @return length of data written to buffer.
 */
size_t fr_bin2hex(char *hex, uint8_t const *bin, size_t inlen)
{
        size_t i;

        for (i = 0; i < inlen; i++) {
                hex[0] = hextab[((*bin) >> 4) & 0x0f];
                hex[1] = hextab[*bin & 0x0f];
                hex += 2;
                bin++;
        }

        *hex = '\0';
        return inlen * 2;
}

/** Convert binary data to a hex string
 *
 * Ascii encoded hex string will not be prefixed with '0x'
 *
 * @param[in] ctx to alloc buffer in.
 * @param[in] bin input.
 * @param[in] inlen of bin input.
 * @return length of data written to buffer.
 */
char *fr_abin2hex(TALLOC_CTX *ctx, uint8_t const *bin, size_t inlen)
{
        char *buff;

        buff = talloc_array(ctx, char, (inlen << 2));
        if (!buff) return NULL;

        fr_bin2hex(buff, bin, inlen);

        return buff;
}

/** Consume the integer (or hex) portion of a value string
 *
 * @param value string to parse.
 * @param end pointer to the first non numeric char.
 * @return integer value.
 */
uint32_t fr_strtoul(char const *value, char **end)
{
        if ((value[0] == '0') && (value[1] == 'x')) {
                return strtoul(value, end, 16);
        }

        return strtoul(value, end, 10);
}

/** Check whether the string is all whitespace
 *
 * @return true if the entirety of the string is whitespace, else false.
 */
bool is_whitespace(char const *value)
{
        do {
                if (!isspace(*value)) return false;
        } while (*++value);

        return true;
}

/** Check whether the string is made up of printable UTF8 chars
 *
 * @param value to check.
 * @param len of value.
 *
 * @return
 *      - true if the string is printable.
 *      - false if the string contains non printable chars
 */
 bool is_printable(void const *value, size_t len)
 {
        uint8_t const *p = value;
        int     clen;
        size_t  i;

        for (i = 0; i < len; i++) {
                clen = fr_utf8_char(p, len - i);
                if (clen == 0) return false;
                i += (size_t)clen;
                p += clen;
        }
        return true;
 }

/** Check whether the string is all numbers
 *
 * @return true if the entirety of the string is all numbers, else false.
 */
bool is_integer(char const *value)
{
        do {
                if (!isdigit(*value)) return false;
        } while (*++value);

        return true;
}

/** Check whether the string is allzeros
 *
 * @return true if the entirety of the string is all zeros, else false.
 */
bool is_zero(char const *value)
{
        do {
                if (*value != '0') return false;
        } while (*++value);

        return true;
}

/*
 *      So we don't have ifdef's in the rest of the code
 */
#ifndef HAVE_CLOSEFROM
int closefrom(int fd)
{
        int i;
        int maxfd = 256;
#ifdef HAVE_DIRENT_H
        DIR *dir;
#endif

#ifdef F_CLOSEM
        if (fcntl(fd, F_CLOSEM) == 0) {
                return 0;
        }
#endif

#ifdef F_MAXFD
        maxfd = fcntl(fd, F_F_MAXFD);
        if (maxfd >= 0) goto do_close;
#endif

#ifdef _SC_OPEN_MAX
        maxfd = sysconf(_SC_OPEN_MAX);
        if (maxfd < 0) {
                maxfd = 256;
        }
#endif

#ifdef HAVE_DIRENT_H
        /*
         *      Use /proc/self/fd directory if it exists.
         */
        dir = opendir(CLOSEFROM_DIR);
        if (dir != NULL) {
                long my_fd;
                char *endp;
                struct dirent *dp;

                while ((dp = readdir(dir)) != NULL) {
                        my_fd = strtol(dp->d_name, &endp, 10);
                        if (my_fd <= 0) continue;

                        if ((endp > dp->d_name) && *endp) continue;

                        if (my_fd == dirfd(dir)) continue;

                        if ((my_fd >= fd) && (my_fd <= maxfd)) {
                                (void) close((int) my_fd);
                        }
                }
                (void) closedir(dir);
                return 0;
        }
#endif

#ifdef F_MAXFD
do_close:
#endif

        if (fd > maxfd) return 0;

        /*
         *      FIXME: return EINTR?
         */
        for (i = fd; i < maxfd; i++) {
                close(i);
        }

        return 0;
}
#endif

int fr_ipaddr_cmp(fr_ipaddr_t const *a, fr_ipaddr_t const *b)
{
        if (a->af < b->af) return -1;
        if (a->af > b->af) return +1;

        if (a->prefix < b->prefix) return -1;
        if (a->prefix > b->prefix) return +1;

        switch (a->af) {
        case AF_INET:
                return memcmp(&a->ipaddr.ip4addr,
                              &b->ipaddr.ip4addr,
                              sizeof(a->ipaddr.ip4addr));

#ifdef HAVE_STRUCT_SOCKADDR_IN6
        case AF_INET6:
                if (a->scope < b->scope) return -1;
                if (a->scope > b->scope) return +1;

                return memcmp(&a->ipaddr.ip6addr,
                              &b->ipaddr.ip6addr,
                              sizeof(a->ipaddr.ip6addr));
#endif

        default:
                break;
        }

        return -1;
}

int fr_ipaddr2sockaddr(fr_ipaddr_t const *ipaddr, uint16_t port,
                       struct sockaddr_storage *sa, socklen_t *salen)
{
        memset(sa, 0, sizeof(*sa));

        if (ipaddr->af == AF_INET) {
                struct sockaddr_in s4;

                *salen = sizeof(s4);

                memset(&s4, 0, sizeof(s4));
                s4.sin_family = AF_INET;
                s4.sin_addr = ipaddr->ipaddr.ip4addr;
                s4.sin_port = htons(port);
                memset(sa, 0, sizeof(*sa));
                memcpy(sa, &s4, sizeof(s4));

#ifdef HAVE_STRUCT_SOCKADDR_IN6
        } else if (ipaddr->af == AF_INET6) {
                struct sockaddr_in6 s6;

                *salen = sizeof(s6);

                memset(&s6, 0, sizeof(s6));
                s6.sin6_family = AF_INET6;
                s6.sin6_addr = ipaddr->ipaddr.ip6addr;
                s6.sin6_port = htons(port);
                s6.sin6_scope_id = ipaddr->scope;
                memset(sa, 0, sizeof(*sa));
                memcpy(sa, &s6, sizeof(s6));
#endif
        } else {
                return 0;
        }

        return 1;
}


int fr_sockaddr2ipaddr(struct sockaddr_storage const *sa, socklen_t salen,
                       fr_ipaddr_t *ipaddr, uint16_t *port)
{
        memset(ipaddr, 0, sizeof(*ipaddr));

        if (sa->ss_family == AF_INET) {
                struct sockaddr_in      s4;

                if (salen < sizeof(s4)) {
                        fr_strerror_printf("IPv4 address is too small");
                        return 0;
                }

                memcpy(&s4, sa, sizeof(s4));
                ipaddr->af = AF_INET;
                ipaddr->prefix = 32;
                ipaddr->ipaddr.ip4addr = s4.sin_addr;
                if (port) *port = ntohs(s4.sin_port);

#ifdef HAVE_STRUCT_SOCKADDR_IN6
        } else if (sa->ss_family == AF_INET6) {
                struct sockaddr_in6     s6;

                if (salen < sizeof(s6)) {
                        fr_strerror_printf("IPv6 address is too small");
                        return 0;
                }

                memcpy(&s6, sa, sizeof(s6));
                ipaddr->af = AF_INET6;
                ipaddr->prefix = 128;
                ipaddr->ipaddr.ip6addr = s6.sin6_addr;
                if (port) *port = ntohs(s6.sin6_port);
                ipaddr->scope = s6.sin6_scope_id;
#endif

        } else {
                fr_strerror_printf("Unsupported address famility %d",
                                   sa->ss_family);
                return 0;
        }

        return 1;
}

#ifdef O_NONBLOCK
/** Set O_NONBLOCK on a socket
 *
 * @note O_NONBLOCK is POSIX.
 *
 * @param fd to set nonblocking flag on.
 * @return flags set on the socket, or -1 on error.
 */
int fr_nonblock(int fd)
{
        int flags;

        flags = fcntl(fd, F_GETFL, NULL);
        if (flags < 0)  {
                fr_strerror_printf("Failure getting socket flags: %s", fr_syserror(errno));
                return -1;
        }

        flags |= O_NONBLOCK;
        if (fcntl(fd, F_SETFL, flags) < 0) {
                fr_strerror_printf("Failure setting socket flags: %s", fr_syserror(errno));
                return -1;
        }

        return flags;
}

/** Unset O_NONBLOCK on a socket
 *
 * @note O_NONBLOCK is POSIX.
 *
 * @param fd to set nonblocking flag on.
 * @return flags set on the socket, or -1 on error.
 */
int fr_blocking(int fd)
{
        int flags;

        flags = fcntl(fd, F_GETFL, NULL);
        if (flags < 0)  {
                fr_strerror_printf("Failure getting socket flags: %s", fr_syserror(errno));
                return -1;
        }

        flags ^= O_NONBLOCK;
        if (fcntl(fd, F_SETFL, flags) < 0) {
                fr_strerror_printf("Failure setting socket flags: %s", fr_syserror(errno));
                return -1;
        }

        return flags;
}
#else
int fr_nonblock(UNUSED int fd)
{
        fr_strerror_printf("Non blocking sockets are not supported");
        return -1;
}
int fr_blocking(UNUSED int fd)
{
        fr_strerror_printf("Non blocking sockets are not supported");
        return -1;
}
#endif

/** Write out a vector to a file descriptor
 *
 * Wraps writev, calling it as necessary. If timeout is not NULL,
 * timeout is applied to each call that returns EAGAIN or EWOULDBLOCK
 *
 * @note Should only be used on nonblocking file descriptors.
 * @note Socket should likely be closed on timeout.
 * @note iovec may be modified in such a way that it's not re-usable.
 * @note Leaves errno set to the last error that ocurred.
 *
 * @param fd to write to.
 * @param vector to write.
 * @param iovcnt number of elements in iovec.
 * @param timeout how long to wait for fd to become writeable before timing out.
 * @return number of bytes written, -1 on error.
 */
ssize_t fr_writev(int fd, struct iovec vector[], int iovcnt, struct timeval *timeout)
{
        struct iovec *vector_p = vector;
        ssize_t total = 0;

        while (iovcnt > 0) {
                ssize_t wrote;

                wrote = writev(fd, vector_p, iovcnt);
                if (wrote > 0) {
                        total += wrote;
                        while (wrote > 0) {
                                /*
                                 *      An entire vector element was written
                                 */
                                if (wrote >= (ssize_t)vector_p->iov_len) {
                                        iovcnt--;
                                        wrote -= vector_p->iov_len;
                                        vector_p++;
                                        continue;
                                }

                                /*
                                 *      Partial vector element was written
                                 */
                                vector_p->iov_len -= wrote;
                                vector_p->iov_base = ((char *)vector_p->iov_base) + wrote;
                                break;
                        }
                        continue;
                } else if (wrote == 0) return total;

                switch (errno) {
                /* Write operation would block, use select() to implement a timeout */
#if EWOULDBLOCK != EAGAIN
                case EWOULDBLOCK:
                case EAGAIN:
#else
                case EAGAIN:
#endif
                {
                        int     ret;
                        fd_set  write_set;

                        FD_ZERO(&write_set);
                        FD_SET(fd, &write_set);

                        /* Don't let signals mess up the select */
                        do {
                                ret = select(fd + 1, NULL, &write_set, NULL, timeout);
                        } while ((ret == -1) && (errno == EINTR));

                        /* Select returned 0 which means it reached the timeout */
                        if (ret == 0) {
                                fr_strerror_printf("Write timed out");
                                return -1;
                        }

                        /* Other select error */
                        if (ret < 0) {
                                fr_strerror_printf("Failed waiting on socket: %s", fr_syserror(errno));
                                return -1;
                        }

                        /* select said a file descriptor was ready for writing */
                        if (!fr_assert(FD_ISSET(fd, &write_set))) return -1;

                        break;
                }

                default:
                        return -1;
                }
        }

        return total;
}

/** Convert UTF8 string to UCS2 encoding
 *
 * @note Borrowed from src/crypto/ms_funcs.c of wpa_supplicant project (http://hostap.epitest.fi/wpa_supplicant/)
 *
 * @param[out] out Where to write the ucs2 string.
 * @param[in] outlen Size of output buffer.
 * @param[in] in UTF8 string to convert.
 * @param[in] inlen length of UTF8 string.
 * @return the size of the UCS2 string written to the output buffer (in bytes).
 */
ssize_t fr_utf8_to_ucs2(uint8_t *out, size_t outlen, char const *in, size_t inlen)
{
        size_t i;
        uint8_t *start = out;

        for (i = 0; i < inlen; i++) {
                uint8_t c, c2, c3;

                c = in[i];
                if ((size_t)(out - start) >= outlen) {
                        /* input too long */
                        return -1;
                }

                /* One-byte encoding */
                if (c <= 0x7f) {
                        FR_PUT_LE16(out, c);
                        out += 2;
                        continue;
                } else if ((i == (inlen - 1)) || ((size_t)(out - start) >= (outlen - 1))) {
                        /* Incomplete surrogate */
                        return -1;
                }

                c2 = in[++i];
                /* Two-byte encoding */
                if ((c & 0xe0) == 0xc0) {
                        FR_PUT_LE16(out, ((c & 0x1f) << 6) | (c2 & 0x3f));
                        out += 2;
                        continue;
                }
                if ((i == inlen) || ((size_t)(out - start) >= (outlen - 1))) {
                        /* Incomplete surrogate */
                        return -1;
                }

                /* Three-byte encoding */
                c3 = in[++i];
                FR_PUT_LE16(out, ((c & 0xf) << 12) | ((c2 & 0x3f) << 6) | (c3 & 0x3f));
                out += 2;
        }

        return out - start;
}

/** Write 128bit unsigned integer to buffer
 *
 * @author Alexey Frunze
 *
 * @param out where to write result to.
 * @param outlen size of out.
 * @param num 128 bit integer.
 */
size_t fr_prints_uint128(char *out, size_t outlen, uint128_t const num)
{
        char buff[128 / 3 + 1 + 1];
        uint64_t n[2];
        char *p = buff;
        int i;
#ifdef FR_LITTLE_ENDIAN
        const size_t l = 0;
        const size_t h = 1;
#else
        const size_t l = 1;
        const size_t h = 0;
#endif

        memset(buff, '0', sizeof(buff) - 1);
        buff[sizeof(buff) - 1] = '\0';

        memcpy(n, &num, sizeof(n));

        for (i = 0; i < 128; i++) {
                ssize_t j;
                int carry;

                carry = (n[h] >= 0x8000000000000000);

                // Shift n[] left, doubling it
                n[h] = ((n[h] << 1) & 0xffffffffffffffff) + (n[l] >= 0x8000000000000000);
                n[l] = ((n[l] << 1) & 0xffffffffffffffff);

                // Add s[] to itself in decimal, doubling it
                for (j = sizeof(buff) - 2; j >= 0; j--) {
                        buff[j] += buff[j] - '0' + carry;
                        carry = (buff[j] > '9');
                        if (carry) {
                                buff[j] -= 10;
                        }
                }
        }

        while ((*p == '0') && (p < &buff[sizeof(buff) - 2])) {
                p++;
        }

        return strlcpy(out, p, outlen);
}

/*
 *      Sort of strtok/strsep function.
 */
static char *mystrtok(char **ptr, char const *sep)
{
        char    *res;

        if (**ptr == 0) {
                return NULL;
        }

        while (**ptr && strchr(sep, **ptr)) {
                (*ptr)++;
        }
        if (**ptr == 0) {
                return NULL;
        }

        res = *ptr;
        while (**ptr && strchr(sep, **ptr) == NULL) {
                (*ptr)++;
        }

        if (**ptr != 0) {
                *(*ptr)++ = 0;
        }
        return res;
}

/** Convert string in various formats to a time_t
 *
 * @param date_str input date string.
 * @param date time_t to write result to.
 * @return 0 on success or -1 on error.
 */
int fr_get_time(char const *date_str, time_t *date)
{
        int             i;
        time_t          t;
        struct tm       *tm, s_tm;
        char            buf[64];
        char            *p;
        char            *f[4];
        char            *tail = NULL;

        /*
         * Test for unix timestamp date
         */
        *date = strtoul(date_str, &tail, 10);
        if (*tail == '\0') {
                return 0;
        }

        tm = &s_tm;
        memset(tm, 0, sizeof(*tm));
        tm->tm_isdst = -1;      /* don't know, and don't care about DST */

        strlcpy(buf, date_str, sizeof(buf));

        p = buf;
        f[0] = mystrtok(&p, " \t");
        f[1] = mystrtok(&p, " \t");
        f[2] = mystrtok(&p, " \t");
        f[3] = mystrtok(&p, " \t"); /* may, or may not, be present */
        if (!f[0] || !f[1] || !f[2]) return -1;

        /*
         *      The time has a colon, where nothing else does.
         *      So if we find it, bubble it to the back of the list.
         */
        if (f[3]) {
                for (i = 0; i < 3; i++) {
                        if (strchr(f[i], ':')) {
                                p = f[3];
                                f[3] = f[i];
                                f[i] = p;
                                break;
                        }
                }
        }

        /*
         *  The month is text, which allows us to find it easily.
         */
        tm->tm_mon = 12;
        for (i = 0; i < 3; i++) {
                if (isalpha( (int) *f[i])) {
                        /*
                         *  Bubble the month to the front of the list
                         */
                        p = f[0];
                        f[0] = f[i];
                        f[i] = p;

                        for (i = 0; i < 12; i++) {
                                if (strncasecmp(months[i], f[0], 3) == 0) {
                                        tm->tm_mon = i;
                                        break;
                                }
                        }
                }
        }

        /* month not found? */
        if (tm->tm_mon == 12) return -1;

        /*
         *  The year may be in f[1], or in f[2]
         */
        tm->tm_year = atoi(f[1]);
        tm->tm_mday = atoi(f[2]);

        if (tm->tm_year >= 1900) {
                tm->tm_year -= 1900;

        } else {
                /*
                 *  We can't use 2-digit years any more, they make it
                 *  impossible to tell what's the day, and what's the year.
                 */
                if (tm->tm_mday < 1900) return -1;

                /*
                 *  Swap the year and the day.
                 */
                i = tm->tm_year;
                tm->tm_year = tm->tm_mday - 1900;
                tm->tm_mday = i;
        }

        /*
         *  If the day is out of range, die.
         */
        if ((tm->tm_mday < 1) || (tm->tm_mday > 31)) {
                return -1;
        }

        /*
         *      There may be %H:%M:%S.  Parse it in a hacky way.
         */
        if (f[3]) {
                f[0] = f[3];    /* HH */
                f[1] = strchr(f[0], ':'); /* find : separator */
                if (!f[1]) return -1;

                *(f[1]++) = '\0'; /* nuke it, and point to MM:SS */

                f[2] = strchr(f[1], ':'); /* find : separator */
                if (f[2]) {
                  *(f[2]++) = '\0';     /* nuke it, and point to SS */
                  tm->tm_sec = atoi(f[2]);
                }                       /* else leave it as zero */

                tm->tm_hour = atoi(f[0]);
                tm->tm_min = atoi(f[1]);
        }

        /*
         *  Returns -1 on error.
         */
        t = mktime(tm);
        if (t == (time_t) -1) return -1;

        *date = t;

        return 0;
}

/** Compares two pointers
 *
 * @param a first pointer to compare.
 * @param b second pointer to compare.
 * @return -1 if a < b, +1 if b > a, or 0 if both equal.
 */
int8_t fr_pointer_cmp(void const *a, void const *b)
{
        if (a < b) return -1;
        if (a == b) return 0;

        return 1;
}

static int _quick_partition(void const *to_sort[], int min, int max, fr_cmp_t cmp) {
        void const *pivot = to_sort[min];
        int i = min;
        int j = max + 1;
        void const *tmp;

        for (;;) {
                do ++i; while((cmp(to_sort[i], pivot) <= 0) && i <= max);
                do --j; while(cmp(to_sort[j], pivot) > 0);

                if (i >= j) break;

                tmp = to_sort[i];
                to_sort[i] = to_sort[j];
                to_sort[j] = tmp;
        }

        tmp = to_sort[min];
        to_sort[min] = to_sort[j];
        to_sort[j] = tmp;

        return j;
}

/** Quick sort an array of pointers using a comparator
 *
 * @param to_sort array of pointers to sort.
 * @param min_idx the lowest index (usually 0).
 * @param max_idx the highest index (usually length of array - 1).
 * @param cmp the comparison function to use to sort the array elements.
 */
void fr_quick_sort(void const *to_sort[], int min_idx, int max_idx, fr_cmp_t cmp)
{
        int part;

        if (min_idx >= max_idx) return;

        part = _quick_partition(to_sort, min_idx, max_idx, cmp);
        fr_quick_sort(to_sort, min_idx, part - 1, cmp);
        fr_quick_sort(to_sort, part + 1, max_idx, cmp);
}

#ifdef TALLOC_DEBUG
void fr_talloc_verify_cb(UNUSED const void *ptr, UNUSED int depth,
                         UNUSED int max_depth, UNUSED int is_ref,
                         UNUSED void *private_data)
{
        /* do nothing */
}
#endif