src/modules/proto_dhcp/dhcpd.c

   1 /*
   2  * dhcp.c       DHCP processing.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2008 The FreeRADIUS server project
  21  * Copyright 2008,2011 Alan DeKok <aland@deployingradius.com>
  22  */
  23
  24 /*
  25  * Standard sequence:
  26  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        DISCOVER
  27  *      CLIENT_IP : 68 <- DHCP_SERVER_IP : 67           OFFER
  28  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        REQUEST
  29  *      CLIENT_IP : 68 <- DHCP_SERVER_IP : 67           ACK
  30  *
  31  * Relay sequence:
  32  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        DISCOVER
  33  *      RELAY_IP : 67 -> NEXT_SERVER_IP : 67            DISCOVER
  34  *                              (NEXT_SERVER_IP can be a relay itself)
  35  *      FIRST_RELAY_IP : 67 <- DHCP_SERVER_IP : 67      OFFER
  36  *      CLIENT_IP : 68 <- FIRST_RELAY_IP : 67           OFFER
  37  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        REQUEST
  38  *      RELAY_IP : 67 -> NEXT_SERVER_IP : 67            REQUEST
  39  *                              (NEXT_SERVER_IP can be a relay itself)
  40  *      FIRST_RELAY_IP : 67 <- DHCP_SERVER_IP : 67      ACK
  41  *      CLIENT_IP : 68 <- FIRST_RELAY_IP : 67           ACK
  42  *
  43  * Note: NACK are broadcasted, rest is unicast, unless client asked
  44  * for a broadcast
  45  */
  46
  47
  48 #include <freeradius-devel/radiusd.h>
  49 #include <freeradius-devel/modules.h>
  50 #include <freeradius-devel/protocol.h>
  51 #include <freeradius-devel/process.h>
  52 #include <freeradius-devel/dhcp.h>
  53 #include <freeradius-devel/rad_assert.h>
  54
  55 #ifndef __MINGW32__
  56 #include <sys/ioctl.h>
  57 #endif
  58
  59 extern bool check_config;       /* @todo globals are bad, m'kay? */
  60
  61 /*
  62  *      Same contents as listen_socket_t.
  63  */
  64 typedef struct dhcp_socket_t {
  65         listen_socket_t lsock;
  66
  67         /*
  68          *      DHCP-specific additions.
  69          */
  70         bool            suppress_responses;
  71         RADCLIENT       dhcp_client;
  72         char const      *src_interface;
  73         fr_ipaddr_t     src_ipaddr;
  74 } dhcp_socket_t;
  75
  76 #ifdef WITH_UDPFROMTO
  77 static int dhcprelay_process_client_request(REQUEST *request)
  78 {
  79         uint8_t maxhops = 16;
  80         VALUE_PAIR *vp, *giaddr;
  81         dhcp_socket_t *sock;
  82
  83         rad_assert(request->packet->data[0] == 1);
  84
  85         /*
  86          *      Do the forward by ourselves, do not rely on dhcp_socket_send()
  87          */
  88         request->reply->code = 0;
  89
  90         /*
  91          * It's invalid to have giaddr=0 AND a relay option
  92          */
  93         giaddr = pairfind(request->packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Gateway-IP-Address */
  94         if (giaddr && (giaddr->vp_ipaddr == htonl(INADDR_ANY)) &&
  95             pairfind(request->packet->vps, 82, DHCP_MAGIC_VENDOR, TAG_ANY)) { /* DHCP-Relay-Agent-Information */
  96                 DEBUG("DHCP: Received packet with giaddr = 0 and containing relay option: Discarding packet\n");
  97                 return 1;
  98         }
  99
 100         /*
 101          * RFC 1542 (BOOTP), page 15
 102          *
 103          * Drop requests if hop-count > 16 or admin specified another value
 104          */
 105         if ((vp = pairfind(request->config_items, 271, DHCP_MAGIC_VENDOR, TAG_ANY))) { /* DHCP-Relay-Max-Hop-Count */
 106             maxhops = vp->vp_integer;
 107         }
 108         vp = pairfind(request->packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Hop-Count */
 109         rad_assert(vp != NULL);
 110         if (vp->vp_integer > maxhops) {
 111                 DEBUG("DHCP: Number of hops is greater than %d: not relaying\n", maxhops);
 112                 return 1;
 113         } else {
 114             /* Increment hop count */
 115             vp->vp_integer++;
 116         }
 117
 118         sock = request->listener->data;
 119
 120         /*
 121          *      Forward the request to the next server using the
 122          *      incoming request as a template.
 123          */
 124         /* set SRC ipaddr/port to the listener ipaddr/port */
 125         request->packet->src_ipaddr.af = AF_INET;
 126         request->packet->src_ipaddr.ipaddr.ip4addr.s_addr = sock->lsock.my_ipaddr.ipaddr.ip4addr.s_addr;
 127         request->packet->src_port = sock->lsock.my_port;
 128
 129         vp = pairfind(request->config_items, 270, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Relay-To-IP-Address */
 130         rad_assert(vp != NULL);
 131
 132         /* set DEST ipaddr/port to the next server ipaddr/port */
 133         request->packet->dst_ipaddr.af = AF_INET;
 134         request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 135
 136         if (fr_dhcp_encode(request->packet) < 0) {
 137                 DEBUG("dhcprelay_process_client_request: ERROR in fr_dhcp_encode\n");
 138                 return -1;
 139         }
 140
 141         return fr_dhcp_send(request->packet);
 142 }
 143
 144
 145 /*
 146  *      We've seen a reply from a server.
 147  *      i.e. we're a relay.
 148  */
 149 static int dhcprelay_process_server_reply(REQUEST *request)
 150 {
 151         VALUE_PAIR *vp, *giaddr;
 152         dhcp_socket_t *sock;
 153
 154         rad_assert(request->packet->data[0] == 2);
 155
 156         /*
 157          * Do the forward by ourselves, do not rely on dhcp_socket_send()
 158          */
 159         request->reply->code = 0;
 160
 161         sock = request->listener->data;
 162
 163         /*
 164          * Check that packet is for us.
 165          */
 166         giaddr = pairfind(request->packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Gateway-IP-Address */
 167
 168         /* --with-udpfromto is needed just for the following test */
 169         if (!giaddr || giaddr->vp_ipaddr != request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr) {
 170                 DEBUG("DHCP: Packet received from server was not for us (was for 0x%x). Discarding packet",
 171                     ntohl(request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr));
 172                 return 1;
 173         }
 174
 175         /* set SRC ipaddr/port to the listener ipaddr/port */
 176         request->packet->src_ipaddr.af = AF_INET;
 177         request->packet->src_port = sock->lsock.my_port;
 178
 179         /* set DEST ipaddr/port to clientip/68 or broadcast in specific cases */
 180         request->packet->dst_ipaddr.af = AF_INET;
 181
 182         /*
 183          *      We're a relay, and send the reply to giaddr.
 184          */
 185         request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = giaddr->vp_ipaddr;
 186         request->reply->dst_port = request->packet->dst_port;           /* server port */
 187
 188         if ((request->packet->code == PW_DHCP_NAK) ||
 189             !sock->src_interface ||
 190             ((vp = pairfind(request->packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY)) /* DHCP-Flags */ &&
 191              (vp->vp_integer & 0x8000) &&
 192              ((vp = pairfind(request->packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY)) /* DHCP-Client-IP-Address */ &&
 193               (vp->vp_ipaddr == htonl(INADDR_ANY))))) {
 194                 /*
 195                  * RFC 2131, page 23
 196                  *
 197                  * Broadcast on
 198                  * - DHCPNAK
 199                  * or
 200                  * - Broadcast flag is set up and ciaddr == NULL
 201                  */
 202                 RDEBUG("DHCP: response will be  broadcast");
 203                 request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
 204         } else {
 205                 /*
 206                  * RFC 2131, page 23
 207                  *
 208                  * Unicast to
 209                  * - ciaddr if present
 210                  * otherwise to yiaddr
 211                  */
 212                 if ((vp = pairfind(request->packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY)) /* DHCP-Client-IP-Address */ &&
 213                     (vp->vp_ipaddr != htonl(INADDR_ANY))) {
 214                         request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 215                 } else {
 216                         vp = pairfind(request->packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Your-IP-Address */
 217                         if (!vp) {
 218                                 DEBUG("DHCP: Failed to find IP Address for request.");
 219                                 return -1;
 220                         }
 221
 222                         RDEBUG("DHCP: response will be unicast to your-ip-address");
 223                         request->packet->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 224
 225                         /*
 226                          * When sending a DHCP_OFFER, make sure our ARP table
 227                          * contains an entry for the client IP address, or else
 228                          * packet may not be forwarded if it was the first time
 229                          * the client was requesting an IP address.
 230                          */
 231                         if (request->packet->code == PW_DHCP_OFFER) {
 232                                 VALUE_PAIR *hwvp = pairfind(request->packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Client-Hardware-Address */
 233                                 if (hwvp == NULL) {
 234                                         DEBUG("DHCP: DHCP_OFFER packet received with "
 235                                             "no Client Hardware Address. Discarding packet");
 236                                         return 1;
 237                                 }
 238                                 if (fr_dhcp_add_arp_entry(request->packet->sockfd, sock->src_interface, hwvp, vp) < 0) {
 239                                         DEBUG("%s", fr_strerror());
 240                                         return -1;
 241                                 }
 242                         }
 243                 }
 244         }
 245
 246         if (fr_dhcp_encode(request->packet) < 0) {
 247                 DEBUG("dhcprelay_process_server_reply: ERROR in fr_dhcp_encode\n");
 248                 return -1;
 249         }
 250
 251         return fr_dhcp_send(request->packet);
 252 }
 253 #else  /* WITH_UDPFROMTO */
 254 static int dhcprelay_process_server_reply(UNUSED REQUEST *request)
 255 {
 256         WDEBUG("DHCP Relaying requires the server to be configured with UDPFROMTO");
 257         return -1;
 258 }
 259
 260 static int dhcprelay_process_client_request(UNUSED REQUEST *request)
 261 {
 262         WDEBUG("DHCP Relaying requires the server to be configured with UDPFROMTO");
 263         return -1;
 264 }
 265
 266 #endif  /* WITH_UDPFROMTO */
 267
 268 static const uint32_t attrnums[] = {
 269         57,     /* DHCP-DHCP-Maximum-Msg-Size */
 270         256,    /* DHCP-Opcode */
 271         257,    /* DHCP-Hardware-Type */
 272         258,    /* DHCP-Hardware-Address-Length */
 273         259,    /* DHCP-Hop-Count */
 274         260,    /* DHCP-Transaction-Id */
 275         262,    /* DHCP-Flags */
 276         263,    /* DHCP-Client-IP-Address */
 277         266,    /* DHCP-Gateway-IP-Address */
 278         267     /* DHCP-Client-Hardware-Address */
 279 };
 280
 281 static int dhcp_process(REQUEST *request)
 282 {
 283         int rcode;
 284         unsigned int i;
 285         VALUE_PAIR *vp;
 286         dhcp_socket_t *sock;
 287
 288         /*
 289          *      If there's a giaddr, save it as the Relay-IP-Address
 290          *      in the response.  That way the later code knows where
 291          *      to send the reply.
 292          */
 293         vp = pairfind(request->packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Gateway-IP-Address */
 294         if (vp && (vp->vp_ipaddr != htonl(INADDR_ANY))) {
 295                 VALUE_PAIR *relay;
 296
 297                 /* DHCP-Relay-IP-Address */
 298                 relay = radius_paircreate(request, &request->reply->vps,
 299                                           272, DHCP_MAGIC_VENDOR);
 300                 if (relay) relay->vp_ipaddr = vp->vp_ipaddr;
 301         }
 302
 303         vp = pairfind(request->packet->vps, 53, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Message-Type */
 304         if (vp) {
 305                 DICT_VALUE *dv = dict_valbyattr(53, DHCP_MAGIC_VENDOR, vp->vp_integer);
 306                 DEBUG("Trying sub-section dhcp %s {...}",
 307                       dv->name ? dv->name : "<unknown>");
 308                 rcode = process_post_auth(vp->vp_integer, request);
 309         } else {
 310                 DEBUG("DHCP: Failed to find DHCP-Message-Type in packet!");
 311                 rcode = RLM_MODULE_FAIL;
 312         }
 313
 314         vp = pairfind(request->reply->vps, 53, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Message-Type */
 315         if (vp) {
 316                 request->reply->code = vp->vp_integer;
 317                 if ((request->reply->code != 0) &&
 318                     (request->reply->code < PW_DHCP_OFFSET)) {
 319                         request->reply->code += PW_DHCP_OFFSET;
 320                 }
 321         }
 322         else switch (rcode) {
 323         case RLM_MODULE_OK:
 324         case RLM_MODULE_UPDATED:
 325                 if (request->packet->code == PW_DHCP_DISCOVER) {
 326                         request->reply->code = PW_DHCP_OFFER;
 327                         break;
 328
 329                 } else if (request->packet->code == PW_DHCP_REQUEST) {
 330                         request->reply->code = PW_DHCP_ACK;
 331                         break;
 332                 }
 333                 request->reply->code = PW_DHCP_NAK;
 334                 break;
 335
 336         default:
 337         case RLM_MODULE_REJECT:
 338         case RLM_MODULE_FAIL:
 339         case RLM_MODULE_INVALID:
 340         case RLM_MODULE_NOOP:
 341         case RLM_MODULE_NOTFOUND:
 342                 if (request->packet->code == PW_DHCP_DISCOVER) {
 343                         request->reply->code = 0; /* ignore the packet */
 344                 } else {
 345                         request->reply->code = PW_DHCP_NAK;
 346                 }
 347                 break;
 348
 349         case RLM_MODULE_HANDLED:
 350                 request->reply->code = 0; /* ignore the packet */
 351                 break;
 352         }
 353
 354         /*
 355          *      TODO: Handle 'output' of RLM_MODULE when acting as a
 356          *      DHCP relay We may want to not forward packets in
 357          *      certain circumstances.
 358          */
 359
 360         /*
 361          *      Handle requests when acting as a DHCP relay
 362          */
 363         vp = pairfind(request->packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Opcode */
 364         if (!vp) {
 365                 RDEBUG("FAILURE: Someone deleted the DHCP-Opcode!");
 366                 return 1;
 367         }
 368
 369         /* BOOTREPLY received on port 67 (i.e. from a server) */
 370         if (vp->vp_integer == 2) {
 371                 return dhcprelay_process_server_reply(request);
 372         }
 373
 374         /* Packet from client, and we have DHCP-Relay-To-IP-Address */
 375         if (pairfind(request->config_items, 270, DHCP_MAGIC_VENDOR, TAG_ANY)) {
 376                 return dhcprelay_process_client_request(request);
 377         }
 378
 379         /* else it's a packet from a client, without relaying */
 380         rad_assert(vp->vp_integer == 1); /* BOOTREQUEST */
 381
 382         sock = request->listener->data;
 383
 384         /*
 385          *      Handle requests when acting as a DHCP server
 386          */
 387
 388         /*
 389          *      Releases don't get replies.
 390          */
 391         if (request->packet->code == PW_DHCP_RELEASE) {
 392                 request->reply->code = 0;
 393         }
 394
 395         if (request->reply->code == 0) {
 396                 return 1;
 397         }
 398
 399         request->reply->sockfd = request->packet->sockfd;
 400
 401         /*
 402          *      Copy specific fields from packet to reply, if they
 403          *      don't already exist
 404          */
 405         for (i = 0; i < sizeof(attrnums) / sizeof(attrnums[0]); i++) {
 406                 uint32_t attr = attrnums[i];
 407
 408                 if (pairfind(request->reply->vps, attr, DHCP_MAGIC_VENDOR, TAG_ANY)) continue;
 409
 410                 vp = pairfind(request->packet->vps, attr, DHCP_MAGIC_VENDOR, TAG_ANY);
 411                 if (vp) {
 412                         pairadd(&request->reply->vps, paircopyvp(request->reply, vp));
 413                 }
 414         }
 415
 416         vp = pairfind(request->reply->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Opcode */
 417         rad_assert(vp != NULL);
 418         vp->vp_integer = 2; /* BOOTREPLY */
 419
 420         /*
 421          * Prepare the reply packet for sending through dhcp_socket_send()
 422          */
 423         request->reply->dst_ipaddr.af = AF_INET;
 424         request->reply->src_ipaddr.af = AF_INET;
 425         request->reply->src_ipaddr.ipaddr.ip4addr.s_addr = sock->src_ipaddr.ipaddr.ip4addr.s_addr;
 426
 427         request->reply->dst_port = request->packet->src_port;
 428         request->reply->src_port = request->packet->dst_port;
 429
 430         /*
 431          *      Answer to client's nearest DHCP relay.
 432          *
 433          *      Which may be different than the giaddr given in the
 434          *      packet to the client.  i.e. the relay may have a
 435          *      public IP, but the gateway a private one.
 436          */
 437         vp = pairfind(request->reply->vps, 272, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Relay-IP-Address */
 438         if (vp) {
 439                 RDEBUG("DHCP: Reply will be unicast to giaddr from original packet");
 440                 request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 441                 return 1;
 442         }
 443
 444         /*
 445          *      Answer to client's nearest DHCP gateway.  In this
 446          *      case, the client can reach the gateway, as can the
 447          *      server.
 448          *
 449          *      We also use *our* source port as the destination port.
 450          *      Gateways are servers, and listen on the server port,
 451          *      not the client port.
 452          */
 453         vp = pairfind(request->reply->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Gateway-IP-Address */
 454         if (vp && (vp->vp_ipaddr != htonl(INADDR_ANY))) {
 455                 RDEBUG("DHCP: Reply will be unicast to giaddr");
 456                 request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 457                 request->reply->dst_port = request->packet->dst_port;
 458                 return 1;
 459         }
 460
 461         /*
 462          *      If it's a NAK, or the broadcast flag was set, ond
 463          *      there's no client-ip-address, send a broadcast.
 464          */
 465         if ((request->reply->code == PW_DHCP_NAK) ||
 466             ((vp = pairfind(request->reply->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY)) && /* DHCP-Flags */
 467              (vp->vp_integer & 0x8000) &&
 468              ((vp = pairfind(request->reply->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY)) && /* DHCP-Client-IP-Address */
 469               (vp->vp_ipaddr == htonl(INADDR_ANY))))) {
 470                 /*
 471                  * RFC 2131, page 23
 472                  *
 473                  * Broadcast on
 474                  * - DHCPNAK
 475                  * or
 476                  * - Broadcast flag is set up and ciaddr == NULL
 477                  */
 478                 RDEBUG("DHCP: Reply will be broadcast");
 479                 request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
 480                 return 1;
 481         }
 482
 483         /*
 484          *      RFC 2131, page 23
 485          *
 486          *      Unicast to ciaddr if present, otherwise to yiaddr.
 487          */
 488         if ((vp = pairfind(request->reply->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY)) && /* DHCP-Client-IP-Address */
 489             (vp->vp_ipaddr != htonl(INADDR_ANY))) {
 490                 RDEBUG("DHCP: Reply will be sent unicast to client-ip-address");
 491                 request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 492                 return 1;
 493         }
 494
 495         vp = pairfind(request->reply->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Your-IP-Address */
 496         if (!vp) {
 497                 DEBUG("DHCP: Failed to find DHCP-Client-IP-Address or DHCP-Your-IP-Address");
 498                 DEBUG("      for request; not responding.");
 499                 /*
 500                  *      There is nowhere to send the response to, so don't bother.
 501                  */
 502                 request->reply->code = 0;
 503                 return -1;
 504         }
 505
 506 #ifdef SIOCSARP
 507         /*
 508          *      The system is configured to listen for broadcast
 509          *      packets, which means we'll need to send unicast
 510          *      replies, to IPs which haven't yet been assigned.
 511          *      Therefore, we need to update the ARP table.
 512          *
 513          *      However, they haven't specified a interface.  So we
 514          *      can't update the ARP table.  And we must send a
 515          *      broadcast response.
 516          */
 517         if (sock->lsock.broadcast && !sock->src_interface) {
 518                 WARN("You MUST set \"interface\" if you have \"broadcast = yes\"");
 519                 RDEBUG("DHCP: Reply will be broadcast as no interface was defined");
 520                 request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
 521                 return 1;
 522         }
 523
 524         RDEBUG("DHCP: Reply will be unicast to your-ip-address");
 525         request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = vp->vp_ipaddr;
 526
 527         /*
 528          *      When sending a DHCP_OFFER, make sure our ARP table
 529          *      contains an entry for the client IP address.
 530          *      Otherwise the packet may not be sent to the client, as
 531          *      the OS has no ARP entry for it.
 532          *
 533          *      This is a cute hack to avoid us having to create a raw
 534          *      socket to send DHCP packets.
 535          */
 536         if (request->reply->code == PW_DHCP_OFFER) {
 537                 VALUE_PAIR *hwvp = pairfind(request->reply->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY); /* DHCP-Client-Hardware-Address */
 538
 539                 if (!hwvp) return -1;
 540
 541                 if (fr_dhcp_add_arp_entry(request->reply->sockfd, sock->src_interface, hwvp, vp) < 0) {
 542                         RDEBUG("Failed adding arp entry: %s", fr_strerror());
 543                         return -1;
 544                 }
 545         }
 546 #else
 547         RDEBUG("DHCP: Reply will be broadcast as this system does not support ARP updates");
 548         request->reply->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
 549 #endif
 550
 551         return 1;
 552 }
 553
 554 static int dhcp_socket_parse(CONF_SECTION *cs, rad_listen_t *this)
 555 {
 556         int rcode, broadcast = 1;
 557         int on = 1;
 558         dhcp_socket_t *sock;
 559         RADCLIENT *client;
 560         CONF_PAIR *cp;
 561
 562         rcode = common_socket_parse(cs, this);
 563         if (rcode != 0) return rcode;
 564
 565         if (check_config) return 0;
 566
 567         sock = this->data;
 568
 569         if (!sock->lsock.interface) {
 570                 WDEBUG("No \"interface\" setting is defined.  Only unicast DHCP will work.");
 571         }
 572
 573         /*
 574          *      See whether or not we enable broadcast packets.
 575          */
 576         cp = cf_pair_find(cs, "broadcast");
 577         if (cp) {
 578                 char const *value = cf_pair_value(cp);
 579                 if (value && (strcmp(value, "no") == 0)) {
 580                         broadcast = 0;
 581                 }
 582         }
 583
 584         if (broadcast) {
 585                 if (setsockopt(this->fd, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
 586                         ERROR("Can't set broadcast option: %s\n",
 587                                fr_syserror(errno));
 588                         return -1;
 589                 }
 590         }
 591
 592         if (setsockopt(this->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) {
 593                 ERROR("Can't set re-use addres option: %s\n",
 594                        fr_syserror(errno));
 595                 return -1;
 596         }
 597
 598         /*
 599          *      Undocumented extension for testing without
 600          *      destroying your network!
 601          */
 602         sock->suppress_responses = false;
 603         cp = cf_pair_find(cs, "suppress_responses");
 604         if (cp) {
 605                 cf_item_parse(cs, "suppress_responses", PW_TYPE_BOOLEAN,
 606                               &sock->suppress_responses, NULL);
 607         }
 608
 609         cp = cf_pair_find(cs, "src_interface");
 610         if (cp) {
 611                 cf_item_parse(cs, "src_interface", PW_TYPE_STRING_PTR,
 612                               &sock->src_interface, NULL);
 613         } else {
 614                 sock->src_interface = sock->lsock.interface;
 615         }
 616
 617         if (!sock->src_interface && sock->lsock.interface) {
 618                 sock->src_interface = talloc_strdup(sock, sock->lsock.interface);
 619         }
 620
 621         cp = cf_pair_find(cs, "src_ipaddr");
 622         if (cp) {
 623                 memset(&sock->src_ipaddr, 0, sizeof(sock->src_ipaddr));
 624                 sock->src_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_NONE);
 625                 rcode = cf_item_parse(cs, "src_ipaddr", PW_TYPE_IPADDR,
 626                                       &sock->src_ipaddr.ipaddr.ip4addr, NULL);
 627                 if (rcode < 0) return -1;
 628
 629                 sock->src_ipaddr.af = AF_INET;
 630         } else {
 631                 memcpy(&sock->src_ipaddr, &sock->lsock.my_ipaddr, sizeof(sock->src_ipaddr));
 632         }
 633
 634         /*
 635          *      Initialize the fake client.
 636          */
 637         client = &sock->dhcp_client;
 638         memset(client, 0, sizeof(*client));
 639         client->ipaddr.af = AF_INET;
 640         client->ipaddr.ipaddr.ip4addr.s_addr = INADDR_NONE;
 641         client->prefix = 0;
 642         client->longname = client->shortname = "dhcp";
 643         client->secret = client->shortname;
 644         client->nas_type = talloc_strdup(sock, "none");
 645
 646         return 0;
 647 }
 648
 649
 650 /*
 651  *      Check if an incoming request is "ok"
 652  *
 653  *      It takes packets, not requests.  It sees if the packet looks
 654  *      OK.  If so, it does a number of sanity checks on it.
 655  */
 656 static int dhcp_socket_recv(rad_listen_t *listener)
 657 {
 658         RADIUS_PACKET   *packet;
 659         dhcp_socket_t   *sock;
 660
 661         packet = fr_dhcp_recv(listener->fd);
 662         if (!packet) {
 663                 ERROR("%s", fr_strerror());
 664                 return 0;
 665         }
 666
 667         sock = listener->data;
 668         if (!request_receive(listener, packet, &sock->dhcp_client, dhcp_process)) {
 669                 rad_free(&packet);
 670                 return 0;
 671         }
 672
 673         return 1;
 674 }
 675
 676
 677 /*
 678  *      Send an authentication response packet
 679  */
 680 static int dhcp_socket_send(rad_listen_t *listener, REQUEST *request)
 681 {
 682         dhcp_socket_t   *sock;
 683
 684         rad_assert(request->listener == listener);
 685         rad_assert(listener->send == dhcp_socket_send);
 686
 687         if (request->reply->code == 0) return 0; /* don't reply */
 688
 689         if (fr_dhcp_encode(request->reply) < 0) {
 690                 DEBUG("dhcp_socket_send: ERROR\n");
 691                 return -1;
 692         }
 693
 694         sock = listener->data;
 695         if (sock->suppress_responses) return 0;
 696
 697         return fr_dhcp_send(request->reply);
 698 }
 699
 700
 701 static int dhcp_socket_encode(UNUSED rad_listen_t *listener, UNUSED REQUEST *request)
 702 {
 703         DEBUG2("NO ENCODE!");
 704         return 0;
 705 }
 706
 707
 708 static int dhcp_socket_decode(UNUSED rad_listen_t *listener, REQUEST *request)
 709 {
 710         return fr_dhcp_decode(request->packet);
 711 }
 712
 713 fr_protocol_t proto_dhcp = {
 714         RLM_MODULE_INIT,
 715         "dhcp",
 716         sizeof(dhcp_socket_t),
 717         NULL,
 718         dhcp_socket_parse, NULL,
 719         dhcp_socket_recv, dhcp_socket_send,
 720         common_socket_print, dhcp_socket_encode, dhcp_socket_decode
 721 };