src/lib/dhcp.c

   1 /*
   2  * dhcp.c       Functions to send/receive dhcp packets.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This library is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU Lesser General Public
   8  *   License as published by the Free Software Foundation; either
   9  *   version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *   This library 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 GNU
  14  *   Lesser General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Lesser General Public
  17  *   License along with this library; 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 Alan DeKok <aland@deployingradius.com>
  22  */
  23
  24 #include        <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include <freeradius-devel/libradius.h>
  28 #include <freeradius-devel/udpfromto.h>
  29 #include <freeradius-devel/dhcp.h>
  30
  31 /*
  32  *      This doesn't appear to work right now.
  33  */
  34 #undef WITH_UDPFROMTO
  35
  36 #ifdef WITH_DHCP
  37
  38 #include <sys/ioctl.h>
  39
  40 #ifdef HAVE_SYS_SOCKET_H
  41 #include <sys/socket.h>
  42 #endif
  43 #ifdef HAVE_SYS_TYPES_H
  44 #include <sys/types.h>
  45 #endif
  46
  47 #include <net/if_arp.h>
  48
  49
  50 #define DHCP_CHADDR_LEN (16)
  51 #define DHCP_SNAME_LEN  (64)
  52 #define DHCP_FILE_LEN   (128)
  53 #define DHCP_VEND_LEN   (308)
  54 #define DHCP_OPTION_MAGIC_NUMBER (0x63825363)
  55
  56 #ifndef INADDR_BROADCAST
  57 #define INADDR_BROADCAST INADDR_NONE
  58 #endif
  59
  60 typedef struct dhcp_packet_t {
  61         uint8_t         opcode;
  62         uint8_t         htype;
  63         uint8_t         hlen;
  64         uint8_t         hops;
  65         uint32_t        xid;    /* 4 */
  66         uint16_t        secs;   /* 8 */
  67         uint16_t        flags;
  68         uint32_t        ciaddr; /* 12 */
  69         uint32_t        yiaddr; /* 16 */
  70         uint32_t        siaddr; /* 20 */
  71         uint32_t        giaddr; /* 24 */
  72         uint8_t         chaddr[DHCP_CHADDR_LEN]; /* 28 */
  73         uint8_t         sname[DHCP_SNAME_LEN]; /* 44 */
  74         uint8_t         file[DHCP_FILE_LEN]; /* 108 */
  75         uint32_t        option_format; /* 236 */
  76         uint8_t         options[DHCP_VEND_LEN];
  77 } dhcp_packet_t;
  78
  79 typedef struct dhcp_option_t {
  80         uint8_t         code;
  81         uint8_t         length;
  82 } dhcp_option_t;
  83
  84 /*
  85  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        DISCOVER
  86  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         OFFER
  87  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        REQUEST
  88  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         ACK
  89  */
  90 static const char *dhcp_header_names[] = {
  91         "DHCP-Opcode",
  92         "DHCP-Hardware-Type",
  93         "DHCP-Hardware-Address-Length",
  94         "DHCP-Hop-Count",
  95         "DHCP-Transaction-Id",
  96         "DHCP-Number-of-Seconds",
  97         "DHCP-Flags",
  98         "DHCP-Client-IP-Address",
  99         "DHCP-Your-IP-Address",
 100         "DHCP-Server-IP-Address",
 101         "DHCP-Gateway-IP-Address",
 102         "DHCP-Client-Hardware-Address",
 103         "DHCP-Server-Host-Name",
 104         "DHCP-Boot-Filename",
 105
 106         NULL
 107 };
 108
 109 static const char *dhcp_message_types[] = {
 110         "invalid",
 111         "DHCP-Discover",
 112         "DHCP-Offer",
 113         "DHCP-Request",
 114         "DHCP-Decline",
 115         "DHCP-Ack",
 116         "DHCP-NAK",
 117         "DHCP-Release",
 118         "DHCP-Inform",
 119         "DHCP-Force-Renew",
 120 };
 121
 122 static int dhcp_header_sizes[] = {
 123         1, 1, 1, 1,
 124         4, 2, 2, 4,
 125         4, 4, 4,
 126         DHCP_CHADDR_LEN,
 127         DHCP_SNAME_LEN,
 128         DHCP_FILE_LEN
 129 };
 130
 131
 132 /*
 133  *      Some clients silently ignore responses less than 300 bytes.
 134  */
 135 #define MIN_PACKET_SIZE (244)
 136 #define DEFAULT_PACKET_SIZE (300)
 137 #define MAX_PACKET_SIZE (1500 - 40)
 138
 139 #define DHCP_OPTION_FIELD (0)
 140 #define DHCP_FILE_FIELD   (1)
 141 #define DHCP_SNAME_FIELD  (2)
 142
 143 static uint8_t *dhcp_get_option(dhcp_packet_t *packet, size_t packet_size,
 144                                 unsigned int option)
 145
 146 {
 147         int overload = 0;
 148         int field = DHCP_OPTION_FIELD;
 149         size_t where, size;
 150         uint8_t *data = packet->options;
 151
 152         where = 0;
 153         size = packet_size - offsetof(dhcp_packet_t, options);
 154         data = &packet->options[where];
 155
 156         while (where < size) {
 157                 if (data[0] == 0) { /* padding */
 158                         where++;
 159                         continue;
 160                 }
 161
 162                 if (data[0] == 255) { /* end of options */
 163                         if ((field == DHCP_OPTION_FIELD) &&
 164                             (overload & DHCP_FILE_FIELD)) {
 165                                 data = packet->file;
 166                                 where = 0;
 167                                 size = sizeof(packet->file);
 168                                 field = DHCP_FILE_FIELD;
 169                                 continue;
 170
 171                         } else if ((field == DHCP_FILE_FIELD) &&
 172                                    (overload && DHCP_SNAME_FIELD)) {
 173                                 data = packet->sname;
 174                                 where = 0;
 175                                 size = sizeof(packet->sname);
 176                                 field = DHCP_SNAME_FIELD;
 177                                 continue;
 178                         }
 179
 180                         return NULL;
 181                 }
 182
 183                 /*
 184                  *      We MUST have a real option here.
 185                  */
 186                 if ((where + 2) > size) {
 187                         fr_strerror_printf("Options overflow field at %u",
 188                                            (unsigned int) (data - (uint8_t *) packet));
 189                         return NULL;
 190                 }
 191
 192                 if ((where + 2 + data[1]) > size) {
 193                         fr_strerror_printf("Option length overflows field at %u",
 194                                            (unsigned int) (data - (uint8_t *) packet));
 195                         return NULL;
 196                 }
 197
 198                 if (data[0] == option) return data;
 199
 200                 if (data[0] == 52) { /* overload sname and/or file */
 201                         overload = data[3];
 202                 }
 203
 204                 where += data[1] + 2;
 205                 data += data[1] + 2;
 206         }
 207
 208         return NULL;
 209 }
 210
 211 /*
 212  *      DHCPv4 is only for IPv4.  Broadcast only works if udpfromto is
 213  *      defined.
 214  */
 215 RADIUS_PACKET *fr_dhcp_recv(int sockfd)
 216 {
 217         ssize_t                 len;
 218         uint32_t                magic;
 219         struct sockaddr_storage src;
 220         struct sockaddr_storage dst;
 221         socklen_t               sizeof_src;
 222         socklen_t               sizeof_dst;
 223         RADIUS_PACKET           *packet;
 224         int port;
 225         uint8_t                 *code;
 226
 227         packet = rad_alloc(NULL, 0);
 228         if (!packet) {
 229                 fr_strerror_printf("Failed allocating packet");
 230                 return NULL;
 231         }
 232         memset(packet, 0, sizeof(*packet));
 233
 234         packet->data = malloc(MAX_PACKET_SIZE);
 235         if (!packet->data) {
 236                 fr_strerror_printf("Failed in malloc");
 237                 rad_free(&packet);
 238                 return NULL;
 239         }
 240
 241         packet->sockfd = sockfd;
 242         sizeof_src = sizeof(src);
 243 #ifdef WITH_UDPFROMTO
 244         sizeof_dst = sizeof(dst);
 245         len = recvfromto(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 246                          (struct sockaddr *)&src, &sizeof_src,
 247                          (struct sockaddr *)&dst, &sizeof_dst);
 248 #else
 249         len = recvfrom(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 250                        (struct sockaddr *)&src, &sizeof_src);
 251 #endif
 252
 253         if (len <= 0) {
 254                 fr_strerror_printf("Failed reading DHCP socket: %s", strerror(errno));
 255                 rad_free(&packet);
 256                 return NULL;
 257         }
 258
 259         if (len < MIN_PACKET_SIZE) {
 260                 fr_strerror_printf("DHCP packet is too small (%d < %d)",
 261                                    (int) len, MIN_PACKET_SIZE);
 262                 rad_free(&packet);
 263                 return NULL;
 264         }
 265
 266         if (packet->data[1] != 1) {
 267                 fr_strerror_printf("DHCP can only receive ethernet requests, not type %02x",
 268                       packet->data[1]);
 269                 rad_free(&packet);
 270                 return NULL;
 271         }
 272
 273         if (packet->data[2] != 6) {
 274                 fr_strerror_printf("Ethernet HW length is wrong length %d",
 275                         packet->data[2]);
 276                 rad_free(&packet);
 277                 return NULL;
 278         }
 279
 280         packet->data_len = len;
 281
 282         memcpy(&magic, packet->data + 236, 4);
 283         magic = ntohl(magic);
 284         if (magic != DHCP_OPTION_MAGIC_NUMBER) {
 285                 fr_strerror_printf("Cannot do BOOTP");
 286                 rad_free(&packet);
 287                 return NULL;
 288         }
 289
 290         /*
 291          *      Create unique keys for the packet.
 292          */
 293         memcpy(&magic, packet->data + 4, 4);
 294         packet->id = ntohl(magic);
 295
 296         code = dhcp_get_option((dhcp_packet_t *) packet->data,
 297                                packet->data_len, 53);
 298         if (!code) {
 299                 fr_strerror_printf("No message-type option was found in the packet");
 300                 rad_free(&packet);
 301                 return NULL;
 302         }
 303
 304         if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
 305                 fr_strerror_printf("Unknown value for message-type option");
 306                 rad_free(&packet);
 307                 return NULL;
 308         }
 309
 310         packet->code = code[2] | PW_DHCP_OFFSET;
 311
 312         /*
 313          *      Create a unique vector from the MAC address and the
 314          *      DHCP opcode.  This is a hack for the RADIUS
 315          *      infrastructure in the rest of the server.
 316          *
 317          *      Note: packet->data[2] == 6, which is smaller than
 318          *      sizeof(packet->vector)
 319          *
 320          *      FIXME:  Look for client-identifier in packet,
 321          *      and use that, too?
 322          */
 323         memset(packet->vector, 0, sizeof(packet->vector));
 324         memcpy(packet->vector, packet->data + 28, packet->data[2]);
 325         packet->vector[packet->data[2]] = packet->code & 0xff;
 326
 327         /*
 328          *      FIXME: for DISCOVER / REQUEST: src_port == dst_port + 1
 329          *      FIXME: for OFFER / ACK       : src_port = dst_port - 1
 330          */
 331
 332         /*
 333          *      Unique keys are xid, client mac, and client ID?
 334          */
 335
 336         /*
 337          *      FIXME: More checks, like DHCP packet type?
 338          */
 339
 340         sizeof_dst = sizeof(dst);
 341
 342 #ifndef WITH_UDPFROMTO
 343         /*
 344          *      This should never fail...
 345          */
 346         if (getsockname(sockfd, (struct sockaddr *) &dst, &sizeof_dst) < 0) {
 347                 fr_strerror_printf("getsockname failed: %s", strerror(errno));
 348                 rad_free(&packet);
 349                 return NULL;
 350         }
 351 #endif
 352
 353         fr_sockaddr2ipaddr(&dst, sizeof_dst, &packet->dst_ipaddr, &port);
 354         packet->dst_port = port;
 355
 356         fr_sockaddr2ipaddr(&src, sizeof_src, &packet->src_ipaddr, &port);
 357         packet->src_port = port;
 358
 359         if (fr_debug_flag > 1) {
 360                 char type_buf[64];
 361                 const char *name = type_buf;
 362                 char src_ip_buf[256], dst_ip_buf[256];
 363
 364                 if ((packet->code >= PW_DHCP_DISCOVER) &&
 365                     (packet->code <= PW_DHCP_INFORM)) {
 366                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
 367                 } else {
 368                         snprintf(type_buf, sizeof(type_buf), "%d",
 369                                  packet->code - PW_DHCP_OFFSET);
 370                 }
 371
 372                 DEBUG("Received %s of id %08x from %s:%d to %s:%d\n",
 373                        name, (unsigned int) packet->id,
 374                        inet_ntop(packet->src_ipaddr.af,
 375                                  &packet->src_ipaddr.ipaddr,
 376                                  src_ip_buf, sizeof(src_ip_buf)),
 377                        packet->src_port,
 378                        inet_ntop(packet->dst_ipaddr.af,
 379                                  &packet->dst_ipaddr.ipaddr,
 380                                  dst_ip_buf, sizeof(dst_ip_buf)),
 381                        packet->dst_port);
 382         }
 383
 384         return packet;
 385 }
 386
 387
 388 /*
 389  *      Send a DHCP packet.
 390  */
 391 int fr_dhcp_send(RADIUS_PACKET *packet)
 392 {
 393         struct sockaddr_storage dst;
 394         socklen_t               sizeof_dst;
 395 #ifdef WITH_UDPFROMTO
 396         struct sockaddr_storage src;
 397         socklen_t               sizeof_src;
 398 #endif
 399
 400         if (!fr_ipaddr2sockaddr(&packet->dst_ipaddr, packet->dst_port,
 401                                 &dst, &sizeof_dst)) {
 402                 return -1;
 403         }
 404
 405         /*
 406          *      The client doesn't yet have an IP address, but is
 407          *      expecting an ethernet packet unicast to it's MAC
 408          *      address.  We need to build a raw frame.
 409          */
 410         if (packet->offset == 0) {
 411                 /*
 412                  *      FIXME: Insert code here!
 413                  */
 414         }
 415
 416 #ifndef WITH_UDPFROMTO
 417         /*
 418          *      Assume that the packet is encoded before sending it.
 419          */
 420         return sendto(packet->sockfd, packet->data, packet->data_len, 0,
 421                       (struct sockaddr *)&dst, sizeof_dst);
 422 #else
 423         if (!fr_ipaddr2sockaddr(&packet->src_ipaddr, packet->src_port,
 424                                 &src, &sizeof_src)) {
 425                 return -1;
 426         }
 427
 428         return sendfromto(packet->sockfd,
 429                           packet->data, packet->data_len, 0,
 430                           (struct sockaddr *)&src, sizeof_src,
 431                           (struct sockaddr *)&dst, sizeof_dst);
 432 #endif
 433 }
 434
 435 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen);
 436
 437 static int decode_tlv(VALUE_PAIR *tlv, const uint8_t *data, size_t data_len)
 438 {
 439         const uint8_t *p;
 440         VALUE_PAIR *head, **tail, *vp;
 441
 442         /*
 443          *      Take a pass at parsing it.
 444          */
 445         p = data;
 446         while (p < (data + data_len)) {
 447                 if ((p + 2) > (data + data_len)) goto make_tlv;
 448
 449                 if ((p + p[1] + 2) > (data + data_len)) goto make_tlv;
 450                 p += 2 + p[1];
 451         }
 452
 453         /*
 454          *      Got here... must be well formed.
 455          */
 456         head = NULL;
 457         tail = &head;
 458
 459         p = data;
 460         while (p < (data + data_len)) {
 461                 vp = paircreate(tlv->da->attr | (p[0] << 8), DHCP_MAGIC_VENDOR);
 462                 if (!vp) {
 463                         pairfree(&head);
 464                         goto make_tlv;
 465                 }
 466
 467                 if (fr_dhcp_attr2vp(vp, p + 2, p[1]) < 0) {
 468                         pairfree(&head);
 469                         goto make_tlv;
 470                 }
 471
 472                 *tail = vp;
 473                 tail = &(vp->next);
 474                 p += 2 + p[1];
 475         }
 476
 477         /*
 478          *      The caller allocated TLV, so we need to copy the FIRST
 479          *      attribute over top of that.
 480          */
 481         if (head) {
 482                 memcpy(tlv, head, sizeof(*tlv));
 483                 head->next = NULL;
 484                 pairfree(&head);
 485         }
 486
 487         return 0;
 488
 489 make_tlv:
 490         tlv->vp_tlv = malloc(data_len);
 491         if (!tlv->vp_tlv) {
 492                 fr_strerror_printf("No memory");
 493                 return -1;
 494         }
 495         memcpy(tlv->vp_tlv, data, data_len);
 496         tlv->length = data_len;
 497
 498         return 0;
 499 }
 500
 501
 502 /*
 503  *      Decode ONE value into a VP
 504  */
 505 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen)
 506 {
 507         switch (vp->da->type) {
 508         case PW_TYPE_BYTE:
 509                 if (alen != 1) goto raw;
 510                 vp->vp_integer = p[0];
 511                 break;
 512
 513         case PW_TYPE_SHORT:
 514                 if (alen != 2) goto raw;
 515                 vp->vp_integer = (p[0] << 8) | p[1];
 516                 break;
 517
 518         case PW_TYPE_INTEGER:
 519                 if (alen != 4) goto raw;
 520                 memcpy(&vp->vp_integer, p, 4);
 521                 vp->vp_integer = ntohl(vp->vp_integer);
 522                 break;
 523
 524         case PW_TYPE_IPADDR:
 525                 if (alen != 4) goto raw;
 526                 memcpy(&vp->vp_ipaddr, p , 4);
 527                 vp->length = 4;
 528                 break;
 529
 530         case PW_TYPE_STRING:
 531                 if (alen > 253) return -1;
 532                 memcpy(vp->vp_strvalue, p , alen);
 533                 vp->vp_strvalue[alen] = '\0';
 534                 break;
 535
 536         /*
 537          *      Value doesn't match up with attribute type, overwrite the
 538          *      vp's original DICT_ATTR with an unknown one.
 539          */
 540         raw:
 541                 if (pair2unknown(vp) < 0) return -1;
 542
 543         case PW_TYPE_OCTETS:
 544                 if (alen > 253) return -1;
 545                 memcpy(vp->vp_octets, p, alen);
 546                 break;
 547
 548         case PW_TYPE_TLV:
 549                 return decode_tlv(vp, p, alen);
 550
 551         default:
 552                 fr_strerror_printf("Internal sanity check %d %d", vp->da->type, __LINE__);
 553                 return -1;
 554         } /* switch over type */
 555
 556         vp->length = alen;
 557         return 0;
 558 }
 559
 560 ssize_t fr_dhcp_decode_options(uint8_t *data, size_t len, VALUE_PAIR **head)
 561 {
 562         int i;
 563         VALUE_PAIR *vp, **tail;
 564         uint8_t *p, *next;
 565         next = data;
 566
 567         *head = NULL;
 568         tail = head;
 569         /*
 570          *      FIXME: This should also check sname && file fields.
 571          *      See the dhcp_get_option() function above.
 572          */
 573         while (next < (data + len)) {
 574                 int num_entries, alen;
 575                 const DICT_ATTR *da;
 576
 577                 p = next;
 578
 579                 if (*p == 0) break;
 580                 if (*p == 255) break; /* end of options signifier */
 581                 if ((p + 2) > (data + len)) break;
 582
 583                 next = p + 2 + p[1];
 584
 585                 if (p[1] >= 253) {
 586                         fr_strerror_printf("Attribute too long %u %u",
 587                                            p[0], p[1]);
 588                         continue;
 589                 }
 590
 591                 da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
 592                 if (!da) {
 593                         fr_strerror_printf("Attribute not in our dictionary: %u",
 594                                            p[0]);
 595                         continue;
 596                 }
 597
 598                 vp = NULL;
 599                 num_entries = 1;
 600                 alen = p[1];
 601                 p += 2;
 602
 603                 /*
 604                  *      Could be an array of bytes, integers, etc.
 605                  */
 606                 if (da->flags.array) {
 607                         switch (da->type) {
 608                         case PW_TYPE_BYTE:
 609                                 num_entries = alen;
 610                                 alen = 1;
 611                                 break;
 612
 613                         case PW_TYPE_SHORT: /* ignore any trailing data */
 614                                 num_entries = alen >> 1;
 615                                 alen = 2;
 616                                 break;
 617
 618                         case PW_TYPE_IPADDR:
 619                         case PW_TYPE_INTEGER:
 620                         case PW_TYPE_DATE: /* ignore any trailing data */
 621                                 num_entries = alen >> 2;
 622                                 alen = 4;
 623                                 break;
 624
 625                         default:
 626
 627                                 break; /* really an internal sanity failure */
 628                         }
 629                 }
 630
 631                 /*
 632                  *      Loop over all of the entries, building VPs
 633                  */
 634                 for (i = 0; i < num_entries; i++) {
 635                         vp = pairmake(da->name, NULL, T_OP_ADD);
 636                         if (!vp) {
 637                                 fr_strerror_printf("Cannot build attribute %s",
 638                                         fr_strerror());
 639                                 pairfree(head);
 640                                 return -1;
 641                         }
 642
 643                         /*
 644                          *      Hack for ease of use.
 645                          */
 646                         if (fr_dhcp_attr2vp(vp, p, alen) < 0) {
 647                                 pairfree(&vp);
 648                                 pairfree(head);
 649                                 return -1;
 650                         }
 651
 652                         *tail = vp;
 653                         while (*tail) {
 654                                 debug_pair(*tail);
 655                                 tail = &(*tail)->next;
 656                         }
 657                         p += alen;
 658                 } /* loop over array entries */
 659         } /* loop over the entire packet */
 660
 661         return next - data;
 662 }
 663
 664 int fr_dhcp_decode(RADIUS_PACKET *packet)
 665 {
 666         size_t i;
 667         uint8_t *p;
 668         uint32_t giaddr;
 669         VALUE_PAIR *head, *vp, **tail;
 670         VALUE_PAIR *maxms, *mtu;
 671
 672         head = NULL;
 673         tail = &head;
 674         p = packet->data;
 675
 676         if ((fr_debug_flag > 2) && fr_log_fp) {
 677                 for (i = 0; i < packet->data_len; i++) {
 678                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
 679                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
 680                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 681                 }
 682                 fprintf(fr_log_fp, "\n");
 683         }
 684
 685         if (packet->data[1] != 1) {
 686                 fr_strerror_printf("Packet is not Ethernet: %u",
 687                       packet->data[1]);
 688                 return -1;
 689         }
 690
 691         /*
 692          *      Decode the header.
 693          */
 694         for (i = 0; i < 14; i++) {
 695                 vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
 696                 if (!vp) {
 697                         fr_strerror_printf("Parse error %s", fr_strerror());
 698                         pairfree(&head);
 699                         return -1;
 700                 }
 701
 702                 if ((i == 11) &&
 703                     (packet->data[1] == 1) &&
 704                     (packet->data[2] != 6)) {
 705                         fr_strerror_printf("chaddr of incorrect length for ethernet");
 706                 }
 707
 708                 switch (vp->da->type) {
 709                 case PW_TYPE_BYTE:
 710                         vp->vp_integer = p[0];
 711                         vp->length = 1;
 712                         break;
 713
 714                 case PW_TYPE_SHORT:
 715                         vp->vp_integer = (p[0] << 8) | p[1];
 716                         vp->length = 2;
 717                         break;
 718
 719                 case PW_TYPE_INTEGER:
 720                         memcpy(&vp->vp_integer, p, 4);
 721                         vp->vp_integer = ntohl(vp->vp_integer);
 722                         vp->length = 4;
 723                         break;
 724
 725                 case PW_TYPE_IPADDR:
 726                         memcpy(&vp->vp_ipaddr, p, 4);
 727                         vp->length = 4;
 728                         break;
 729
 730                 case PW_TYPE_STRING:
 731                         memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
 732                         vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
 733                         vp->length = strlen(vp->vp_strvalue);
 734                         if (vp->length == 0) {
 735                                 pairfree(&vp);
 736                         }
 737                         break;
 738
 739                 case PW_TYPE_OCTETS:
 740                         memcpy(vp->vp_octets, p, packet->data[2]);
 741                         vp->length = packet->data[2];
 742                         break;
 743
 744                 case PW_TYPE_ETHERNET:
 745                         memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 746                         vp->length = sizeof(vp->vp_ether);
 747                         break;
 748
 749                 default:
 750                         fr_strerror_printf("BAD TYPE %d", vp->da->type);
 751                         pairfree(&vp);
 752                         break;
 753                 }
 754                 p += dhcp_header_sizes[i];
 755
 756                 if (!vp) continue;
 757
 758                 debug_pair(vp);
 759                 *tail = vp;
 760                 tail = &vp->next;
 761         }
 762
 763         /*
 764          *      Loop over the options.
 765          */
 766
 767         /*
 768          *  Nothing uses tail after this call, if it does in the future
 769          *  it'll need to find the new tail...
 770          */
 771         if (fr_dhcp_decode_options(packet->data + 240, packet->data_len - 240,
 772                                    tail) < 0) {
 773                 return -1;
 774         }
 775
 776         /*
 777          *      If DHCP request, set ciaddr to zero.
 778          */
 779
 780         /*
 781          *      Set broadcast flag for broken vendors, but only if
 782          *      giaddr isn't set.
 783          */
 784         memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
 785         if (giaddr == htonl(INADDR_ANY)) {
 786                 /*
 787                  *      DHCP Opcode is request
 788                  */
 789                 vp = pairfind(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
 790                 if (vp && vp->vp_integer == 3) {
 791                         /*
 792                          *      Vendor is "MSFT 98"
 793                          */
 794                         vp = pairfind(head, 63, DHCP_MAGIC_VENDOR, TAG_ANY);
 795                         if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
 796                                 vp = pairfind(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
 797
 798                                 /*
 799                                  *      Reply should be broadcast.
 800                                  */
 801                                 if (vp) vp->vp_integer |= 0x8000;
 802                                 packet->data[10] |= 0x80;
 803                         }
 804                 }
 805         }
 806
 807         /*
 808          *      FIXME: Nuke attributes that aren't used in the normal
 809          *      header for discover/requests.
 810          */
 811         packet->vps = head;
 812
 813         /*
 814          *      Client can request a LARGER size, but not a smaller
 815          *      one.  They also cannot request a size larger than MTU.
 816          */
 817         maxms = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
 818         mtu = pairfind(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
 819
 820         if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
 821                 fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
 822                 return -1;
 823         }
 824
 825         if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
 826                 fr_strerror_printf("DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
 827                 maxms->vp_integer = DEFAULT_PACKET_SIZE;
 828         }
 829
 830         if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
 831                 fr_strerror_printf("DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
 832                 maxms->vp_integer = mtu->vp_integer;
 833         }
 834
 835         if (fr_debug_flag > 0) {
 836                 for (vp = packet->vps; vp != NULL; vp = vp->next) {
 837
 838                 }
 839         }
 840
 841         if (fr_debug_flag) fflush(stdout);
 842
 843         return 0;
 844 }
 845
 846
 847 static int attr_cmp(const void *one, const void *two)
 848 {
 849         const VALUE_PAIR * const *a = one;
 850         const VALUE_PAIR * const *b = two;
 851
 852         /*
 853          *      DHCP-Message-Type is first, for simplicity.
 854          */
 855         if (((*a)->da->attr == 53) &&
 856             (*b)->da->attr != 53) return -1;
 857
 858         /*
 859          *      Relay-Agent is last
 860          */
 861         if (((*a)->da->attr == 82) &&
 862             (*b)->da->attr != 82) return +1;
 863
 864         return ((*a)->da->attr - (*b)->da->attr);
 865 }
 866
 867
 868 static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, size_t room)
 869 {
 870         size_t length;
 871         uint32_t lvalue;
 872
 873         /*
 874          *      FIXME: Check room!
 875          */
 876         room = room;            /* -Wunused */
 877
 878         /*
 879          *      Search for all attributes of the same
 880          *      type, and pack them into the same
 881          *      attribute.
 882          */
 883         switch (vp->da->type) {
 884         case PW_TYPE_BYTE:
 885                 length = 1;
 886                 *p = vp->vp_integer & 0xff;
 887                 break;
 888
 889         case PW_TYPE_SHORT:
 890                 length = 2;
 891                 p[0] = (vp->vp_integer >> 8) & 0xff;
 892                 p[1] = vp->vp_integer & 0xff;
 893                 break;
 894
 895         case PW_TYPE_INTEGER:
 896                 length = 4;
 897                 lvalue = htonl(vp->vp_integer);
 898                 memcpy(p, &lvalue, 4);
 899                 break;
 900
 901         case PW_TYPE_IPADDR:
 902                 length = 4;
 903                 memcpy(p, &vp->vp_ipaddr, 4);
 904                 break;
 905
 906         case PW_TYPE_ETHERNET:
 907                 length = 6;
 908                 memcpy(p, &vp->vp_ether, 6);
 909                 break;
 910
 911         case PW_TYPE_STRING:
 912                 memcpy(p, vp->vp_strvalue, vp->length);
 913                 length = vp->length;
 914                 break;
 915
 916         case PW_TYPE_TLV:       /* FIXME: split it on 255? */
 917                 memcpy(p, vp->vp_tlv, vp->length);
 918                 length = vp->length;
 919                 break;
 920
 921         case PW_TYPE_OCTETS:
 922                 memcpy(p, vp->vp_octets, vp->length);
 923                 length = vp->length;
 924                 break;
 925
 926         default:
 927                 fr_strerror_printf("BAD TYPE2 %d", vp->da->type);
 928                 length = 0;
 929                 break;
 930         }
 931
 932         return length;
 933 }
 934
 935 static VALUE_PAIR *fr_dhcp_vp2suboption(VALUE_PAIR *vps)
 936 {
 937         int length;
 938         unsigned int attribute;
 939         uint8_t *ptr;
 940         VALUE_PAIR *vp, *tlv;
 941
 942         attribute = vps->da->attr & 0xffff00ff;
 943
 944         tlv = paircreate(attribute, DHCP_MAGIC_VENDOR);
 945         if (!tlv) return NULL;
 946
 947         tlv->length = 0;
 948         for (vp = vps; vp != NULL; vp = vp->next) {
 949                 /*
 950                  *      Group the attributes ONLY until we see a
 951                  *      non-TLV attribute.
 952                  */
 953                 if (!vp->da->flags.is_tlv ||
 954                     vp->da->flags.extended ||
 955                     ((vp->da->attr & 0xffff00ff) != attribute)) {
 956                         break;
 957                 }
 958
 959                 tlv->length += vp->length + 2;
 960         }
 961
 962         if (!tlv->length) {
 963                 pairfree(&tlv);
 964                 return NULL;
 965         }
 966
 967         tlv->vp_tlv = malloc(tlv->length);
 968         if (!tlv->vp_tlv) {
 969                 pairfree(&tlv);
 970                 return NULL;
 971         }
 972
 973         ptr = tlv->vp_tlv;
 974         for (vp = vps; vp != NULL; vp = vp->next) {
 975                 if (!vp->da->flags.is_tlv ||
 976                     vp->da->flags.extended ||
 977                     ((vp->da->attr & 0xffff00ff) != attribute)) {
 978                         break;
 979                 }
 980
 981                 length = fr_dhcp_vp2attr(vp, ptr + 2,
 982                                          tlv->vp_tlv + tlv->length - ptr);
 983                 if (length > 255) {
 984                         pairfree(&tlv);
 985                         return NULL;
 986                 }
 987
 988                 /*
 989                  *      Pack the attribute.
 990                  */
 991                 ptr[0] = (vp->da->attr & 0xff00) >> 8;
 992                 ptr[1] = length;
 993
 994                 ptr += length + 2;
 995         }
 996
 997         return tlv;
 998 }
 999
1000
1001 int fr_dhcp_encode(RADIUS_PACKET *packet, RADIUS_PACKET *original)
1002 {
1003         unsigned int i, num_vps;
1004         uint8_t *p;
1005         VALUE_PAIR *vp;
1006         uint32_t lvalue, mms;
1007         size_t dhcp_size, length;
1008         dhcp_packet_t *dhcp;
1009
1010         if (packet->data) return 0;
1011
1012         packet->data = malloc(MAX_PACKET_SIZE);
1013         if (!packet->data) return -1;
1014
1015         packet->data_len = MAX_PACKET_SIZE;
1016
1017         if (packet->code == 0) packet->code = PW_DHCP_NAK;
1018
1019         /*
1020          *      If there's a request, use it as a template.
1021          *      Otherwise, assume that the caller has set up
1022          *      everything appropriately.
1023          */
1024         if (original) {
1025                 packet->dst_ipaddr.af = AF_INET;
1026                 packet->src_ipaddr.af = AF_INET;
1027
1028                 packet->dst_port = original->src_port;
1029                 packet->src_port = original->dst_port;
1030
1031                 /*
1032                  *      Note that for DHCP, we NEVER send the response
1033                  *      to the source IP address of the request.  It
1034                  *      may have traversed multiple relays, and we
1035                  *      need to send the request to the relay closest
1036                  *      to the client.
1037                  *
1038                  *      if giaddr, send to giaddr.
1039                  *      if NAK, send broadcast.
1040                  *      if broadcast flag, send broadcast.
1041                  *      if ciaddr is empty, send broadcast.
1042                  *      otherwise unicast to ciaddr.
1043                  */
1044
1045                 /*
1046                  *      FIXME: alignment issues.  We likely don't want to
1047                  *      de-reference the packet structure directly..
1048                  */
1049                 dhcp = (dhcp_packet_t *) original->data;
1050
1051                 /*
1052                  *      Default to sending it via sendto(), without using
1053                  *      raw sockets.
1054                  */
1055                 packet->offset = 1;
1056
1057                 if (dhcp->giaddr != htonl(INADDR_ANY)) {
1058                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->giaddr;
1059
1060                         if (dhcp->giaddr != htonl(INADDR_LOOPBACK)) {
1061                                 packet->dst_port = original->dst_port;
1062                         } else {
1063                                 packet->dst_port = original->src_port; /* debugging */
1064                         }
1065
1066                 } else if ((packet->code == PW_DHCP_NAK) ||
1067                            ((dhcp->flags & 0x8000) != 0) ||
1068                            (dhcp->ciaddr == htonl(INADDR_ANY))) {
1069                         /*
1070                          *      The kernel will take care of sending it to
1071                          *      the broadcast MAC.
1072                          */
1073                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
1074
1075                 } else {
1076                         /*
1077                          *      It was broadcast to us: we need to
1078                          *      broadcast the response.
1079                          */
1080                         if (packet->src_ipaddr.ipaddr.ip4addr.s_addr != dhcp->ciaddr) {
1081                                 packet->offset = 0;
1082                         }
1083                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->ciaddr;
1084                 }
1085
1086                 /*
1087                  *      Rewrite the source IP to be our own, if we know it.
1088                  */
1089                 if (packet->src_ipaddr.ipaddr.ip4addr.s_addr == htonl(INADDR_BROADCAST)) {
1090                         packet->src_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_ANY);
1091                 }
1092         } else {
1093                 memset(packet->data, 0, packet->data_len);
1094         }
1095
1096         if (fr_debug_flag > 1) {
1097                 char type_buf[64];
1098                 const char *name = type_buf;
1099                 char src_ip_buf[256], dst_ip_buf[256];
1100
1101                 if ((packet->code >= PW_DHCP_DISCOVER) &&
1102                     (packet->code <= PW_DHCP_INFORM)) {
1103                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
1104                 } else {
1105                         snprintf(type_buf, sizeof(type_buf), "%d",
1106                                  packet->code - PW_DHCP_OFFSET);
1107                 }
1108
1109                 DEBUG("Sending %s of id %08x from %s:%d to %s:%d\n",
1110                        name, (unsigned int) packet->id,
1111                        inet_ntop(packet->src_ipaddr.af,
1112                                  &packet->src_ipaddr.ipaddr,
1113                                  src_ip_buf, sizeof(src_ip_buf)),
1114                        packet->src_port,
1115                        inet_ntop(packet->dst_ipaddr.af,
1116                                  &packet->dst_ipaddr.ipaddr,
1117                                  dst_ip_buf, sizeof(dst_ip_buf)),
1118                        packet->dst_port);
1119
1120                 if (fr_debug_flag) {
1121                         for (i = 256; i < 269; i++) {
1122                                 vp = pairfind(packet->vps, i, DHCP_MAGIC_VENDOR, TAG_ANY);
1123                                 if (!vp) continue;
1124
1125                                 debug_pair(vp);
1126                         }
1127                 }
1128         }
1129
1130         p = packet->data;
1131
1132         mms = DEFAULT_PACKET_SIZE; /* maximum message size */
1133
1134         if (original) {
1135                 /*
1136                  *      Clients can request a LARGER size, but not a
1137                  *      smaller one.  They also cannot request a size
1138                  *      larger than MTU.
1139                  */
1140                 vp = pairfind(original->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
1141                 if (vp && (vp->vp_integer > mms)) {
1142                         mms = vp->vp_integer;
1143
1144                         if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
1145                 }
1146         }
1147
1148         /*
1149          *      RFC 3118: Authentication option.
1150          */
1151         vp = pairfind(packet->vps, 90, DHCP_MAGIC_VENDOR, TAG_ANY);
1152         if (vp) {
1153                 if (vp->length < 2) {
1154                         memset(vp->vp_octets + vp->length, 0,
1155                                2 - vp->length);
1156                         vp->length = 2;
1157                 }
1158
1159                 if (vp->length < 3) {
1160                         struct timeval tv;
1161
1162                         gettimeofday(&tv, NULL);
1163                         vp->vp_octets[2] = 0;
1164                         timeval2ntp(&tv, vp->vp_octets + 3);
1165                         vp->length = 3 + 8;
1166                 }
1167
1168                 /*
1169                  *      Configuration token (clear-text token)
1170                  */
1171                 if (vp->vp_octets[0] == 0) {
1172                         VALUE_PAIR *pass;
1173                         vp->vp_octets[1] = 0;
1174
1175                         pass = pairfind(packet->vps, PW_CLEARTEXT_PASSWORD, DHCP_MAGIC_VENDOR, TAG_ANY);
1176                         if (pass) {
1177                                 length = pass->length;
1178                                 if ((length + 11) > sizeof(vp->vp_octets)) {
1179                                         length -= ((length + 11) - sizeof(vp->vp_octets));
1180                                 }
1181                                 memcpy(vp->vp_octets + 11, pass->vp_strvalue,
1182                                        length);
1183                                 vp->length = length + 11;
1184                         } else {
1185                                 vp->length = 11 + 8;
1186                                 memset(vp->vp_octets + 11, 0, 8);
1187                                 vp->length = 11 + 8;
1188                         }
1189                 } else {        /* we don't support this type! */
1190                         fr_strerror_printf("DHCP-Authentication %d unsupported",
1191                                 vp->vp_octets[0]);
1192                 }
1193         }
1194
1195         vp = pairfind(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
1196         if (vp) {
1197                 *p++ = vp->vp_integer & 0xff;
1198         } else {
1199                 if (!original) {
1200                         *p++ = 1;       /* client message */
1201                 } else {
1202                         *p++ = 2;       /* server message */
1203                 }
1204         }
1205         *p++ = 1;               /* hardware type = ethernet */
1206         *p++ = 6;               /* 6 bytes of ethernet */
1207
1208         vp = pairfind(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY);
1209         if (vp) {
1210                 *p++ = vp->vp_integer & 0xff;
1211         } else {
1212                 *p++ = 0;               /* hops */
1213         }
1214
1215         if (original) { /* Xid */
1216                 memcpy(p, original->data + 4, 4);
1217         } else {
1218                 lvalue = fr_rand();
1219                 memcpy(p, &lvalue, 4);
1220         }
1221         p += 4;
1222
1223         memset(p, 0, 2);        /* secs are zero */
1224         p += 2;
1225
1226         if (original) {
1227                 memcpy(p, original->data + 10, 6); /* copy flags && ciaddr */
1228         }
1229
1230         /*
1231          *      Allow the admin to set the broadcast flag.
1232          */
1233         vp = pairfind(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
1234         if (vp) {
1235                 p[0] |= (vp->vp_integer & 0xff00) >> 8;
1236                 p[1] |= (vp->vp_integer & 0xff);
1237         }
1238
1239         p += 6;
1240
1241         /*
1242          *      Set client IP address.
1243          */
1244         vp = pairfind(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY); /* Your IP address */
1245         if (vp) {
1246                 lvalue = vp->vp_ipaddr;
1247         } else {
1248                 lvalue = htonl(INADDR_ANY);
1249         }
1250         memcpy(p, &lvalue, 4);  /* your IP address */
1251         p += 4;
1252
1253         vp = pairfind(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY); /* server IP address */
1254         if (!vp) vp = pairfind(packet->vps, 54, DHCP_MAGIC_VENDOR, TAG_ANY); /* identifier */
1255         if (vp) {
1256                 lvalue = vp->vp_ipaddr;
1257         } else {
1258                 lvalue = htonl(INADDR_ANY);
1259         }
1260         memcpy(p, &lvalue, 4);  /* Server IP address */
1261         p += 4;
1262
1263         if (original) {
1264                 memcpy(p, original->data + 24, 4); /* copy gateway IP address */
1265         } else {
1266                 vp = pairfind(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY);
1267                 if (vp) {
1268                         lvalue = vp->vp_ipaddr;
1269                 } else {
1270                         lvalue = htonl(INADDR_NONE);
1271                 }
1272                 memcpy(p, &lvalue, 4);
1273         }
1274         p += 4;
1275
1276         if (original) {
1277                 memcpy(p, original->data + 28, DHCP_CHADDR_LEN);
1278         } else {
1279                 vp = pairfind(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY);
1280                 if (vp) {
1281                         if (vp->length > DHCP_CHADDR_LEN) {
1282                                 memcpy(p, vp->vp_octets, DHCP_CHADDR_LEN);
1283                         } else {
1284                                 memcpy(p, vp->vp_octets, vp->length);
1285                         }
1286                 }
1287         }
1288         p += DHCP_CHADDR_LEN;
1289
1290         /*
1291          *      Zero our sname && filename fields.
1292          */
1293         memset(p, 0, DHCP_SNAME_LEN + DHCP_FILE_LEN);
1294         p += DHCP_SNAME_LEN;
1295
1296         /*
1297          *      Copy over DHCP-Boot-Filename.
1298          *
1299          *      FIXME: This copy should be delayed until AFTER the options
1300          *      have been processed.  If there are too many options for
1301          *      the packet, then they go into the sname && filename fields.
1302          *      When that happens, the boot filename is passed as an option,
1303          *      instead of being placed verbatim in the filename field.
1304          */
1305         vp = pairfind(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY);
1306         if (vp) {
1307                 if (vp->length > DHCP_FILE_LEN) {
1308                         memcpy(p, vp->vp_strvalue, DHCP_FILE_LEN);
1309                 } else {
1310                         memcpy(p, vp->vp_strvalue, vp->length);
1311                 }
1312         }
1313         p += DHCP_FILE_LEN;
1314
1315         lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER); /* DHCP magic number */
1316         memcpy(p, &lvalue, 4);
1317         p += 4;
1318
1319         /*
1320          *      Print the header.
1321          */
1322         if (fr_debug_flag > 1) {
1323                 uint8_t *pp = p;
1324
1325                 p = packet->data;
1326
1327                 for (i = 0; i < 14; i++) {
1328                         vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
1329                         if (!vp) {
1330                                 fr_strerror_printf("Parse error %s", fr_strerror());
1331                                 return -1;
1332                         }
1333
1334                         switch (vp->da->type) {
1335                         case PW_TYPE_BYTE:
1336                                 vp->vp_integer = p[0];
1337                                 vp->length = 1;
1338                                 break;
1339
1340                         case PW_TYPE_SHORT:
1341                                 vp->vp_integer = (p[0] << 8) | p[1];
1342                                 vp->length = 2;
1343                                 break;
1344
1345                         case PW_TYPE_INTEGER:
1346                                 memcpy(&vp->vp_integer, p, 4);
1347                                 vp->vp_integer = ntohl(vp->vp_integer);
1348                                 vp->length = 4;
1349                                 break;
1350
1351                         case PW_TYPE_IPADDR:
1352                                 memcpy(&vp->vp_ipaddr, p, 4);
1353                                 vp->length = 4;
1354                                 break;
1355
1356                         case PW_TYPE_STRING:
1357                                 memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
1358                                 vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
1359                                 vp->length = strlen(vp->vp_strvalue);
1360                                 break;
1361
1362                         case PW_TYPE_OCTETS: /* only for Client HW Address */
1363                                 memcpy(vp->vp_octets, p, packet->data[2]);
1364                                 vp->length = packet->data[2];
1365                                 break;
1366
1367                         case PW_TYPE_ETHERNET: /* only for Client HW Address */
1368                                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
1369                                 vp->length = sizeof(vp->vp_ether);
1370                                 break;
1371
1372                         default:
1373                                 fr_strerror_printf("Internal sanity check failed %d %d", vp->da->type, __LINE__);
1374                                 pairfree(&vp);
1375                                 break;
1376                         }
1377
1378                         p += dhcp_header_sizes[i];
1379
1380                         debug_pair(vp);
1381                         pairfree(&vp);
1382                 }
1383
1384                 /*
1385                  *      Jump over DHCP magic number, response, etc.
1386                  */
1387                 p = pp;
1388         }
1389
1390         /*
1391          *      Before packing the attributes, re-order them so that
1392          *      the array ones are all contiguous.  This simplifies
1393          *      the later code.
1394          */
1395         num_vps = 0;
1396         for (vp = packet->vps; vp != NULL; vp = vp->next) {
1397                 num_vps++;
1398         }
1399         if (num_vps > 1) {
1400                 VALUE_PAIR **array, **last;
1401
1402                 array = malloc(num_vps * sizeof(VALUE_PAIR *));
1403
1404                 i = 0;
1405                 for (vp = packet->vps; vp != NULL; vp = vp->next) {
1406                         array[i++] = vp;
1407                 }
1408
1409                 /*
1410                  *      Sort the attributes.
1411                  */
1412                 qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *),
1413                       attr_cmp);
1414
1415                 last = &packet->vps;
1416                 for (i = 0; i < num_vps; i++) {
1417                         *last = array[i];
1418                         array[i]->next = NULL;
1419                         last = &(array[i]->next);
1420                 }
1421                 free(array);
1422         }
1423
1424         p[0] = 0x35;            /* DHCP-Message-Type */
1425         p[1] = 1;
1426         p[2] = packet->code - PW_DHCP_OFFSET;
1427         p += 3;
1428
1429         /*
1430          *      Pack in the attributes.
1431          */
1432         vp = packet->vps;
1433         while (vp) {
1434                 unsigned int num_entries = 1;
1435                 VALUE_PAIR *same;
1436                 uint8_t *plength, *pattr;
1437
1438                 if (vp->da->vendor != DHCP_MAGIC_VENDOR) goto next;
1439                 if (vp->da->attr == 53) goto next; /* already done */
1440                 if ((vp->da->attr > 255) &&
1441                     (DHCP_BASE_ATTR(vp->da->attr) != PW_DHCP_OPTION_82)) goto next;
1442
1443                 debug_pair(vp);
1444                 if (vp->da->flags.extended) goto next;
1445
1446                 length = vp->length;
1447
1448                 for (same = vp->next; same != NULL; same = same->next) {
1449                         if (same->da->attr != vp->da->attr) break;
1450                         num_entries++;
1451                 }
1452
1453                 /*
1454                  *      For client-identifier
1455                  * @fixme What's this meant to be doing?!
1456                  */
1457 #if 0
1458                 if ((vp->da->type == PW_TYPE_ETHERNET) &&
1459                     (vp->length == 6) &&
1460                     (num_entries == 1)) {
1461                         vp->da->type = PW_TYPE_OCTETS;
1462                         memmove(vp->vp_octets + 1, vp->vp_octets, 6);
1463                         vp->vp_octets[0] = 1;
1464                 }
1465 #endif
1466                 pattr = p;
1467                 *(p++) = vp->da->attr & 0xff;
1468                 plength = p;
1469                 *(p++) = 0;     /* header isn't included in attr length */
1470
1471                 for (i = 0; i < num_entries; i++) {
1472                         debug_pair(vp);
1473
1474                         if (vp->da->flags.is_tlv) {
1475                                 VALUE_PAIR *tlv;
1476
1477                                 /*
1478                                  *      Should NOT have been encoded yet!
1479                                  */
1480                                 tlv = fr_dhcp_vp2suboption(vp);
1481
1482                                 /*
1483                                  *      Ignore it if there's an issue
1484                                  *      encoding it.
1485                                  */
1486                                 if (!tlv) goto next;
1487
1488                                 tlv->next = vp->next;
1489                                 vp->next = tlv;
1490                                 vp = tlv;
1491                         }
1492
1493                         length = fr_dhcp_vp2attr(vp, p, 0);
1494
1495                         /*
1496                          *      This will never happen due to FreeRADIUS
1497                          *      limitations: sizeof(vp->vp_octets) < 255
1498                          */
1499                         if (length > 255) {
1500                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1501                                 break;
1502                         }
1503
1504                         /*
1505                          *      More than one attribute of the same type
1506                          *      in a row: they are packed together
1507                          *      into the same TLV.  If we overflow,
1508                          *      go bananas!
1509                          */
1510                         if ((*plength + length) > 255) {
1511                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1512                                 break;
1513                         }
1514
1515                         *plength += length;
1516                         p += length;
1517
1518                         if (vp->next &&
1519                             (vp->next->da->attr == vp->da->attr))
1520                                 vp = vp->next;
1521                 } /* loop over num_entries */
1522
1523         next:
1524                 vp = vp->next;
1525         }
1526
1527         p[0] = 0xff;            /* end of option option */
1528         p[1] = 0x00;
1529         p += 2;
1530         dhcp_size = p - packet->data;
1531
1532         /*
1533          *      FIXME: if (dhcp_size > mms),
1534          *        then we put the extra options into the "sname" and "file"
1535          *        fields, AND set the "end option option" in the "options"
1536          *        field.  We also set the "overload option",
1537          *        and put options into the "file" field, followed by
1538          *        the "sname" field.  Where each option is completely
1539          *        enclosed in the "file" and/or "sname" field, AND
1540          *        followed by the "end of option", and MUST be followed
1541          *        by padding option.
1542          *
1543          *      Yuck.  That sucks...
1544          */
1545         packet->data_len = dhcp_size;
1546
1547         if (original) {
1548                 /*
1549                  *      FIXME: This may set it to broadcast, which we don't
1550                  *      want.  Instead, set it to the real address of the
1551                  *      socket.
1552                  */
1553                 packet->src_ipaddr = original->dst_ipaddr;
1554
1555                 packet->sockfd = original->sockfd;
1556         }
1557
1558         if (packet->data_len < DEFAULT_PACKET_SIZE) {
1559                 memset(packet->data + packet->data_len, 0,
1560                        DEFAULT_PACKET_SIZE - packet->data_len);
1561                 packet->data_len = DEFAULT_PACKET_SIZE;
1562         }
1563
1564         if ((fr_debug_flag > 2) && fr_log_fp) {
1565                 for (i = 0; i < packet->data_len; i++) {
1566                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
1567                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
1568                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1569                 }
1570                 fprintf(fr_log_fp, "\n");
1571         }
1572
1573         return 0;
1574 }
1575
1576 int fr_dhcp_add_arp_entry(int fd, const char *interface,
1577                           VALUE_PAIR *macaddr, VALUE_PAIR *ip)
1578 {
1579 #ifdef SIOCSARP
1580         struct sockaddr_in *sin;
1581         struct arpreq req;
1582
1583         if (macaddr->length > sizeof (req.arp_ha.sa_data)) {
1584                 fr_strerror_printf("ERROR: DHCP only supports up to %zu octets "
1585                                    "for Client Hardware Address "
1586                                    "(got %zu octets)\n",
1587                                    sizeof(req.arp_ha.sa_data),
1588                                    macaddr->length);
1589                 return -1;
1590         }
1591
1592         memset(&req, 0, sizeof(req));
1593         sin = (struct sockaddr_in *) &req.arp_pa;
1594         sin->sin_family = AF_INET;
1595         sin->sin_addr.s_addr = ip->vp_ipaddr;
1596         strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
1597         memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->length);
1598
1599         req.arp_flags = ATF_COM;
1600         if (ioctl(fd, SIOCSARP, &req) < 0) {
1601                 fr_strerror_printf("DHCP: Failed to add entry in ARP cache: %s (%d)",
1602                                    strerror(errno), errno);
1603                 return -1;
1604         }
1605
1606         return 0;
1607 #else
1608         fd = fd;                /* -Wunused */
1609         interface = interface;  /* -Wunused */
1610         macaddr = macaddr;      /* -Wunused */
1611         ip = ip;                /* -Wunused */
1612
1613         fr_strerror_printf("Adding ARP entry is unsupported on this system");
1614         return -1;
1615 #endif
1616 }
1617
1618 #endif /* WITH_DHCP */