src/lib/dhcp.c

   1 /*
   2  * dhcp.c       Functions to send/receive dhcp packets.
   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 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 #ifdef WITH_DHCP
  32 #define DHCP_CHADDR_LEN (16)
  33 #define DHCP_SNAME_LEN  (64)
  34 #define DHCP_FILE_LEN   (128)
  35 #define DHCP_VEND_LEN   (308)
  36 #define DHCP_OPTION_MAGIC_NUMBER (0x63825363)
  37
  38 #ifndef INADDR_BROADCAST
  39 #define INADDR_BROADCAST INADDR_NONE
  40 #endif
  41
  42 typedef struct dhcp_packet_t {
  43         uint8_t         opcode;
  44         uint8_t         htype;
  45         uint8_t         hlen;
  46         uint8_t         hops;
  47         uint32_t        xid;    /* 4 */
  48         uint16_t        secs;   /* 8 */
  49         uint16_t        flags;
  50         uint32_t        ciaddr; /* 12 */
  51         uint32_t        yiaddr; /* 16 */
  52         uint32_t        siaddr; /* 20 */
  53         uint32_t        giaddr; /* 24 */
  54         uint8_t         chaddr[DHCP_CHADDR_LEN]; /* 28 */
  55         uint8_t         sname[DHCP_SNAME_LEN]; /* 44 */
  56         uint8_t         file[DHCP_FILE_LEN]; /* 108 */
  57         uint32_t        option_format; /* 236 */
  58         uint8_t         options[DHCP_VEND_LEN];
  59 } dhcp_packet_t;
  60
  61 typedef struct dhcp_option_t {
  62         uint8_t         code;
  63         uint8_t         length;
  64 } dhcp_option_t;
  65
  66 /*
  67  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        DISCOVER
  68  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         OFFER
  69  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        REQUEST
  70  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         ACK
  71  */
  72 static const char *dhcp_header_names[] = {
  73         "DHCP-Opcode",
  74         "DHCP-Hardware-Type",
  75         "DHCP-Hardware-Address-Length",
  76         "DHCP-Hop-Count",
  77         "DHCP-Transaction-Id",
  78         "DHCP-Number-of-Seconds",
  79         "DHCP-Flags",
  80         "DHCP-Client-IP-Address",
  81         "DHCP-Your-IP-Address",
  82         "DHCP-Server-IP-Address",
  83         "DHCP-Gateway-IP-Address",
  84         "DHCP-Client-Hardware-Address",
  85         "DHCP-Server-Host-Name",
  86         "DHCP-Boot-Filename",
  87
  88         NULL
  89 };
  90
  91 static const char *dhcp_message_types[] = {
  92         "invalid",
  93         "DHCP-Discover",
  94         "DHCP-Offer",
  95         "DHCP-Request",
  96         "DHCP-Decline",
  97         "DHCP-Ack",
  98         "DHCP-NAK",
  99         "DHCP-Release",
 100         "DHCP-Inform",
 101         "DHCP-Force-Renew",
 102 };
 103
 104 static int dhcp_header_sizes[] = {
 105         1, 1, 1, 1,
 106         4, 2, 2, 4,
 107         4, 4, 4,
 108         DHCP_CHADDR_LEN,
 109         DHCP_SNAME_LEN,
 110         DHCP_FILE_LEN
 111 };
 112
 113
 114 /*
 115  *      Some clients silently ignore responses less than 300 bytes.
 116  */
 117 #define MIN_PACKET_SIZE (244)
 118 #define DEFAULT_PACKET_SIZE (300)
 119 #define MAX_PACKET_SIZE (1500 - 40)
 120
 121 #define DHCP_OPTION_FIELD (0)
 122 #define DHCP_FILE_FIELD   (1)
 123 #define DHCP_SNAME_FIELD  (2)
 124
 125 static uint8_t *dhcp_get_option(dhcp_packet_t *packet, size_t packet_size,
 126                                 unsigned int option)
 127
 128 {
 129         int overload = 0;
 130         int field = DHCP_OPTION_FIELD;
 131         size_t where, size;
 132         uint8_t *data = packet->options;
 133
 134         where = 0;
 135         size = packet_size - offsetof(dhcp_packet_t, options);
 136         data = &packet->options[where];
 137
 138         while (where < size) {
 139                 if (data[0] == 0) { /* padding */
 140                         where++;
 141                         continue;
 142                 }
 143
 144                 if (data[0] == 255) { /* end of options */
 145                         if ((field == DHCP_OPTION_FIELD) &&
 146                             (overload & DHCP_FILE_FIELD)) {
 147                                 data = packet->file;
 148                                 where = 0;
 149                                 size = sizeof(packet->file);
 150                                 field = DHCP_FILE_FIELD;
 151                                 continue;
 152
 153                         } else if ((field == DHCP_FILE_FIELD) &&
 154                                    (overload && DHCP_SNAME_FIELD)) {
 155                                 data = packet->sname;
 156                                 where = 0;
 157                                 size = sizeof(packet->sname);
 158                                 field = DHCP_SNAME_FIELD;
 159                                 continue;
 160                         }
 161
 162                         return NULL;
 163                 }
 164
 165                 /*
 166                  *      We MUST have a real option here.
 167                  */
 168                 if ((where + 2) > size) {
 169                         fr_strerror_printf("Options overflow field at %u",
 170                                            (unsigned int) (data - (uint8_t *) packet));
 171                         return NULL;
 172                 }
 173
 174                 if ((where + 2 + data[1]) > size) {
 175                         fr_strerror_printf("Option length overflows field at %u",
 176                                            (unsigned int) (data - (uint8_t *) packet));
 177                         return NULL;
 178                 }
 179
 180                 if (data[0] == option) return data;
 181
 182                 if (data[0] == 52) { /* overload sname and/or file */
 183                         overload = data[3];
 184                 }
 185
 186                 where += data[1] + 2;
 187                 data += data[1] + 2;
 188         }
 189
 190         return NULL;
 191 }
 192
 193 /*
 194  *      DHCPv4 is only for IPv4.  Broadcast only works if udpfromto is
 195  *      defined.
 196  */
 197 RADIUS_PACKET *fr_dhcp_recv(int sockfd)
 198 {
 199         uint32_t                magic;
 200         struct sockaddr_storage src;
 201         struct sockaddr_storage dst;
 202         socklen_t               sizeof_src;
 203         socklen_t               sizeof_dst;
 204         RADIUS_PACKET           *packet;
 205         int port;
 206         uint8_t                 *code;
 207
 208         packet = rad_alloc(0);
 209         if (!packet) {
 210                 fr_strerror_printf("Failed allocating packet");
 211                 return NULL;
 212         }
 213         memset(packet, 0, sizeof(packet));
 214
 215         packet->data = malloc(MAX_PACKET_SIZE);
 216         if (!packet->data) {
 217                 fr_strerror_printf("Failed in malloc");
 218                 rad_free(&packet);
 219                 return NULL;
 220         }
 221
 222         packet->sockfd = sockfd;
 223         sizeof_src = sizeof(src);
 224 #ifdef WITH_UDPFROMTO
 225         sizeof_dst = sizeof(dst);
 226         packet->data_len = recvfromto(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 227                                       (struct sockaddr *)&src, &sizeof_src,
 228                                       (struct sockaddr *)&dst, &sizeof_dst);
 229 #else
 230         packet->data_len = recvfrom(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 231                                     (struct sockaddr *)&src, &sizeof_src);
 232 #endif
 233
 234         if (packet->data_len <= 0) {
 235                 fr_strerror_printf("Failed reading DHCP socket: %s", strerror(errno));
 236                 rad_free(&packet);
 237                 return NULL;
 238         }
 239
 240         if (packet->data_len < MIN_PACKET_SIZE) {
 241                 fr_strerror_printf("DHCP packet is too small (%d < %d)",
 242                       packet->data_len, MIN_PACKET_SIZE);
 243                 rad_free(&packet);
 244                 return NULL;
 245         }
 246
 247         if (packet->data[1] != 1) {
 248                 fr_strerror_printf("DHCP can only receive ethernet requests, not type %02x",
 249                       packet->data[1]);
 250                 rad_free(&packet);
 251                 return NULL;
 252         }
 253
 254         if (packet->data[2] != 6) {
 255                 fr_strerror_printf("Ethernet HW length is wrong length %d",
 256                         packet->data[2]);
 257                 rad_free(&packet);
 258                 return NULL;
 259         }
 260
 261         memcpy(&magic, packet->data + 236, 4);
 262         magic = ntohl(magic);
 263         if (magic != DHCP_OPTION_MAGIC_NUMBER) {
 264                 fr_strerror_printf("Cannot do BOOTP");
 265                 rad_free(&packet);
 266                 return NULL;
 267         }
 268
 269         /*
 270          *      Create unique keys for the packet.
 271          */
 272         memcpy(&magic, packet->data + 4, 4);
 273         packet->id = ntohl(magic);
 274
 275         code = dhcp_get_option((dhcp_packet_t *) packet->data,
 276                                packet->data_len, 53);
 277         if (!code) {
 278                 fr_strerror_printf("No message-type option was found in the packet");
 279                 rad_free(&packet);
 280                 return NULL;
 281         }
 282
 283         if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
 284                 fr_strerror_printf("Unknown value for message-type option");
 285                 rad_free(&packet);
 286                 return NULL;
 287         }
 288
 289         packet->code = code[2] | PW_DHCP_OFFSET;
 290
 291         /*
 292          *      Create a unique vector from the MAC address and the
 293          *      DHCP opcode.  This is a hack for the RADIUS
 294          *      infrastructure in the rest of the server.
 295          *
 296          *      Note: packet->data[2] == 6, which is smaller than
 297          *      sizeof(packet->vector)
 298          *
 299          *      FIXME:  Look for client-identifier in packet,
 300          *      and use that, too?
 301          */
 302         memset(packet->vector, 0, sizeof(packet->vector));
 303         memcpy(packet->vector, packet->data + 28, packet->data[2]);
 304         packet->vector[packet->data[2]] = packet->code & 0xff;
 305
 306         /*
 307          *      FIXME: for DISCOVER / REQUEST: src_port == dst_port + 1
 308          *      FIXME: for OFFER / ACK       : src_port = dst_port - 1
 309          */
 310
 311         /*
 312          *      Unique keys are xid, client mac, and client ID?
 313          */
 314
 315         /*
 316          *      FIXME: More checks, like DHCP packet type?
 317          */
 318
 319         sizeof_dst = sizeof(dst);
 320
 321 #ifndef WITH_UDPFROMTO
 322         /*
 323          *      This should never fail...
 324          */
 325         getsockname(sockfd, (struct sockaddr *) &dst, &sizeof_dst);
 326 #endif
 327
 328         fr_sockaddr2ipaddr(&dst, sizeof_dst, &packet->dst_ipaddr, &port);
 329         packet->dst_port = port;
 330
 331         fr_sockaddr2ipaddr(&src, sizeof_src, &packet->src_ipaddr, &port);
 332         packet->src_port = port;
 333
 334         if (fr_debug_flag > 1) {
 335                 char type_buf[64];
 336                 const char *name = type_buf;
 337                 char src_ip_buf[256], dst_ip_buf[256];
 338
 339                 if ((packet->code >= PW_DHCP_DISCOVER) &&
 340                     (packet->code <= PW_DHCP_INFORM)) {
 341                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
 342                 } else {
 343                         snprintf(type_buf, sizeof(type_buf), "%d",
 344                                  packet->code - PW_DHCP_OFFSET);
 345                 }
 346
 347                 DEBUG("Received %s of id %08x from %s:%d to %s:%d",
 348                        name, (unsigned int) packet->id,
 349                        inet_ntop(packet->src_ipaddr.af,
 350                                  &packet->src_ipaddr.ipaddr,
 351                                  src_ip_buf, sizeof(src_ip_buf)),
 352                        packet->src_port,
 353                        inet_ntop(packet->dst_ipaddr.af,
 354                                  &packet->dst_ipaddr.ipaddr,
 355                                  dst_ip_buf, sizeof(dst_ip_buf)),
 356                        packet->dst_port);
 357         }
 358
 359         return packet;
 360 }
 361
 362
 363 /*
 364  *      Send a DHCP packet.
 365  */
 366 int fr_dhcp_send(RADIUS_PACKET *packet)
 367 {
 368         struct sockaddr_storage dst;
 369         socklen_t               sizeof_dst;
 370 #ifdef WITH_UDPFROMTO
 371         struct sockaddr_storage src;
 372         socklen_t               sizeof_src;
 373 #endif
 374
 375         fr_ipaddr2sockaddr(&packet->dst_ipaddr, packet->dst_port,
 376                            &dst, &sizeof_dst);
 377
 378 #ifndef WITH_UDPFROMTO
 379         /*
 380          *      Assume that the packet is encoded before sending it.
 381          */
 382         return sendto(packet->sockfd, packet->data, packet->data_len, 0,
 383                       (struct sockaddr *)&dst, sizeof_dst);
 384 #else
 385         fr_ipaddr2sockaddr(&packet->src_ipaddr, packet->src_port,
 386                            &src, &sizeof_src);
 387
 388         return sendfromto(packet->sockfd,
 389                           packet->data, packet->data_len, 0,
 390                           (struct sockaddr *)&src, sizeof_src,
 391                           (struct sockaddr *)&dst, sizeof_dst);
 392 #endif
 393 }
 394
 395 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen);
 396
 397 static int decode_tlv(VALUE_PAIR *tlv, const uint8_t *data, size_t data_len)
 398 {
 399         const uint8_t *p;
 400         VALUE_PAIR *head, **tail, *vp;
 401
 402         /*
 403          *      Take a pass at parsing it.
 404          */
 405         p = data;
 406         while (p < (data + data_len)) {
 407                 if ((p + 2) > (data + data_len)) goto make_tlv;
 408
 409                 if ((p + p[1] + 2) > (data + data_len)) goto make_tlv;
 410                 p += 2 + p[1];
 411         }
 412
 413         /*
 414          *      Got here... must be well formed.
 415          */
 416         head = NULL;
 417         tail = &head;
 418
 419         p = data;
 420         while (p < (data + data_len)) {
 421                 vp = paircreate(tlv->attribute | (p[0] << 8), PW_TYPE_OCTETS);
 422                 if (!vp) {
 423                         pairfree(&head);
 424                         goto make_tlv;
 425                 }
 426
 427                 if (fr_dhcp_attr2vp(vp, p + 2, p[1]) < 0) {
 428                         pairfree(&head);
 429                         goto make_tlv;
 430                 }
 431
 432                 *tail = vp;
 433                 tail = &(vp->next);
 434                 p += 2 + p[1];
 435         }
 436
 437         /*
 438          *      The caller allocated TLV, so we need to copy the FIRST
 439          *      attribute over top of that.
 440          */
 441         memcpy(tlv, head, sizeof(*tlv));
 442         head->next = NULL;
 443         pairfree(&head);
 444         return 0;
 445
 446 make_tlv:
 447         tlv->vp_tlv = malloc(data_len);
 448         if (!tlv->vp_tlv) {
 449                 fr_strerror_printf("No memory");
 450                 return -1;
 451         }
 452         memcpy(tlv->vp_tlv, data, data_len);
 453         tlv->length = data_len;
 454
 455         return 0;
 456 }
 457
 458
 459 /*
 460  *      Decode ONE value into a VP
 461  */
 462 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen)
 463 {
 464         switch (vp->type) {
 465         case PW_TYPE_BYTE:
 466                 if (alen != 1) goto raw;
 467                 vp->vp_integer = p[0];
 468                 break;
 469
 470         case PW_TYPE_SHORT:
 471                 if (alen != 2) goto raw;
 472                 vp->vp_integer = (p[0] << 8) | p[1];
 473                 break;
 474
 475         case PW_TYPE_INTEGER:
 476                 if (alen != 4) goto raw;
 477                 memcpy(&vp->vp_integer, p, 4);
 478                 vp->vp_integer = ntohl(vp->vp_integer);
 479                 break;
 480
 481         case PW_TYPE_IPADDR:
 482                 if (alen != 4) goto raw;
 483                 memcpy(&vp->vp_ipaddr, p , 4);
 484                 vp->length = 4;
 485                 break;
 486
 487         case PW_TYPE_STRING:
 488                 if (alen > 253) return -1;
 489                 memcpy(vp->vp_strvalue, p , alen);
 490                 vp->vp_strvalue[alen] = '\0';
 491                 break;
 492
 493         raw:
 494                 vp->type = PW_TYPE_OCTETS;
 495
 496         case PW_TYPE_OCTETS:
 497                 if (alen > 253) return -1;
 498                 memcpy(vp->vp_octets, p, alen);
 499                 break;
 500
 501         case PW_TYPE_TLV:
 502                 return decode_tlv(vp, p, alen);
 503
 504         default:
 505                 fr_strerror_printf("Internal sanity check %d %d", vp->type, __LINE__);
 506                 break;
 507         } /* switch over type */
 508
 509         vp->length = alen;
 510         return 0;
 511 }
 512
 513 int fr_dhcp_decode(RADIUS_PACKET *packet)
 514 {
 515         int i;
 516         uint8_t *p, *next;
 517         uint32_t giaddr;
 518         VALUE_PAIR *head, *vp, **tail;
 519         VALUE_PAIR *maxms, *mtu;
 520         char buffer[2048];
 521
 522         head = NULL;
 523         tail = &head;
 524         p = packet->data;
 525
 526         if ((fr_debug_flag > 2) && fr_log_fp) {
 527                 for (i = 0; i < packet->data_len; i++) {
 528                         if ((i & 0x0f) == 0x00) fr_strerror_printf("%d: ", i);
 529                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
 530                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 531                 }
 532                 fprintf(fr_log_fp, "\n");
 533         }
 534
 535         if (packet->data[1] != 1) {
 536                 fr_strerror_printf("Packet is not Ethernet: %u",
 537                       packet->data[1]);
 538                 return -1;
 539         }
 540
 541         /*
 542          *      Decode the header.
 543          */
 544         for (i = 0; i < 14; i++) {
 545                 vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
 546                 if (!vp) {
 547                         fr_strerror_printf("Parse error %s", fr_strerror());
 548                         pairfree(&head);
 549                         return -1;
 550                 }
 551
 552                 if ((i == 11) &&
 553                     (packet->data[1] == 1) &&
 554                     (packet->data[2] == 6)) {
 555                         vp->type = PW_TYPE_ETHERNET;
 556                 }
 557
 558                 switch (vp->type) {
 559                 case PW_TYPE_BYTE:
 560                         vp->vp_integer = p[0];
 561                         vp->length = 1;
 562                         break;
 563
 564                 case PW_TYPE_SHORT:
 565                         vp->vp_integer = (p[0] << 8) | p[1];
 566                         vp->length = 2;
 567                         break;
 568
 569                 case PW_TYPE_INTEGER:
 570                         memcpy(&vp->vp_integer, p, 4);
 571                         vp->vp_integer = ntohl(vp->vp_integer);
 572                         vp->length = 4;
 573                         break;
 574
 575                 case PW_TYPE_IPADDR:
 576                         memcpy(&vp->vp_ipaddr, p, 4);
 577                         vp->length = 4;
 578                         break;
 579
 580                 case PW_TYPE_STRING:
 581                         memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
 582                         vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
 583                         vp->length = strlen(vp->vp_strvalue);
 584                         if (vp->length == 0) {
 585                                 pairfree(&vp);
 586                         }
 587                         break;
 588
 589                 case PW_TYPE_OCTETS:
 590                         memcpy(vp->vp_octets, p, packet->data[2]);
 591                         vp->length = packet->data[2];
 592                         break;
 593
 594                 case PW_TYPE_ETHERNET:
 595                         memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 596                         vp->length = sizeof(vp->vp_ether);
 597                         break;
 598
 599                 default:
 600                         fr_strerror_printf("BAD TYPE %d", vp->type);
 601                         pairfree(&vp);
 602                         break;
 603                 }
 604                 p += dhcp_header_sizes[i];
 605
 606                 if (!vp) continue;
 607
 608                 if (fr_debug_flag > 1) {
 609                         vp_prints(buffer, sizeof(buffer), vp);
 610                         fr_strerror_printf("\t%s", buffer);
 611                 }
 612                 *tail = vp;
 613                 tail = &vp->next;
 614         }
 615
 616         /*
 617          *      Loop over the options.
 618          */
 619         next = packet->data + 240;
 620
 621         /*
 622          *      FIXME: This should also check sname && file fields.
 623          *      See the dhcp_get_option() function above.
 624          */
 625         while (next < (packet->data + packet->data_len)) {
 626                 int num_entries, alen;
 627                 DICT_ATTR *da;
 628
 629                 p = next;
 630
 631                 if (*p == 0) break;
 632                 if (*p == 255) break; /* end of options signifier */
 633                 if ((p + 2) > (packet->data + packet->data_len)) break;
 634
 635                 next = p + 2 + p[1];
 636
 637                 if (p[1] >= 253) {
 638                         fr_strerror_printf("Attribute too long %u %u",
 639                               p[0], p[1]);
 640                         continue;
 641                 }
 642
 643                 da = dict_attrbyvalue(DHCP2ATTR(p[0]));
 644                 if (!da) {
 645                         fr_strerror_printf("Attribute not in our dictionary: %u",
 646                               p[0]);
 647                         continue;
 648                 }
 649
 650                 vp = NULL;
 651                 num_entries = 1;
 652                 alen = p[1];
 653                 p += 2;
 654
 655                 /*
 656                  *      Could be an array of bytes, integers, etc.
 657                  */
 658                 if (da->flags.array) {
 659                         switch (da->type) {
 660                         case PW_TYPE_BYTE:
 661                                 num_entries = alen;
 662                                 alen = 1;
 663                                 break;
 664
 665                         case PW_TYPE_SHORT: /* ignore any trailing data */
 666                                 num_entries = alen >> 1;
 667                                 alen = 2;
 668                                 break;
 669
 670                         case PW_TYPE_IPADDR:
 671                         case PW_TYPE_INTEGER:
 672                         case PW_TYPE_DATE: /* ignore any trailing data */
 673                                 num_entries = alen >> 2;
 674                                 alen = 4;
 675                                 break;
 676
 677                         default:
 678
 679                                 break; /* really an internal sanity failure */
 680                         }
 681                 }
 682
 683                 /*
 684                  *      Loop over all of the entries, building VPs
 685                  */
 686                 for (i = 0; i < num_entries; i++) {
 687                         vp = pairmake(da->name, NULL, T_OP_EQ);
 688                         if (!vp) {
 689                                 fr_strerror_printf("Cannot build attribute %s",
 690                                         fr_strerror());
 691                                 pairfree(&head);
 692                                 return -1;
 693                         }
 694
 695                         /*
 696                          *      Hack for ease of use.
 697                          */
 698                         if ((da->attr == DHCP2ATTR(0x3d)) &&
 699                             !da->flags.array &&
 700                             (alen == 7) && (*p == 1) && (num_entries == 1)) {
 701                                 vp->type = PW_TYPE_ETHERNET;
 702                                 memcpy(vp->vp_octets, p + 1, 6);
 703                                 vp->length = alen;
 704
 705                         } else if (fr_dhcp_attr2vp(vp, p, alen) < 0) {
 706                                         pairfree(&vp);
 707                                         pairfree(&head);
 708                                         return -1;
 709                         }
 710
 711                         if (fr_debug_flag > 1) {
 712                                 vp_prints(buffer, sizeof(buffer), vp);
 713                                 fr_strerror_printf("\t%s", buffer);
 714                         }
 715
 716                         *tail = vp;
 717                         while (*tail) tail = &vp->next;
 718                         p += alen;
 719                 } /* loop over array entries */
 720         } /* loop over the entire packet */
 721
 722         /*
 723          *      If DHCP request, set ciaddr to zero.
 724          */
 725
 726         /*
 727          *      Set broadcast flag for broken vendors, but only if
 728          *      giaddr isn't set.
 729          */
 730         memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
 731         if (giaddr == htonl(INADDR_ANY)) {
 732                 /*
 733                  *      DHCP Opcode is request
 734                  */
 735                 vp = pairfind(head, DHCP2ATTR(256));
 736                 if (vp && vp->lvalue == 3) {
 737                         /*
 738                          *      Vendor is "MSFT 98"
 739                          */
 740                         vp = pairfind(head, DHCP2ATTR(63));
 741                         if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
 742                                 vp = pairfind(head, DHCP2ATTR(262));
 743
 744                                 /*
 745                                  *      Reply should be broadcast.
 746                                  */
 747                                 if (vp) vp->lvalue |= 0x8000;
 748                                 packet->data[10] |= 0x80;
 749                         }
 750                 }
 751         }
 752
 753         /*
 754          *      FIXME: Nuke attributes that aren't used in the normal
 755          *      header for discover/requests.
 756          */
 757         packet->vps = head;
 758
 759         /*
 760          *      Client can request a LARGER size, but not a smaller
 761          *      one.  They also cannot request a size larger than MTU.
 762          */
 763         maxms = pairfind(packet->vps, DHCP2ATTR(57));
 764         mtu = pairfind(packet->vps, DHCP2ATTR(26));
 765
 766         if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
 767                 fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
 768                 return -1;
 769         }
 770
 771         if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
 772                 fr_strerror_printf("DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
 773                 maxms->vp_integer = DEFAULT_PACKET_SIZE;
 774         }
 775
 776         if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
 777                 fr_strerror_printf("DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
 778                 maxms->vp_integer = mtu->vp_integer;
 779         }
 780
 781         if (fr_debug_flag) fflush(stdout);
 782
 783         return 0;
 784 }
 785
 786
 787 static int attr_cmp(const void *one, const void *two)
 788 {
 789         const VALUE_PAIR * const *a = one;
 790         const VALUE_PAIR * const *b = two;
 791
 792         /*
 793          *      DHCP-Message-Type is first, for simplicity.
 794          */
 795         if (((*a)->attribute == DHCP2ATTR(53)) &&
 796             (*b)->attribute != DHCP2ATTR(53)) return -1;
 797
 798         /*
 799          *      Relay-Agent is last
 800          */
 801         if (((*a)->attribute == DHCP2ATTR(82)) &&
 802             (*b)->attribute != DHCP2ATTR(82)) return +1;
 803
 804         return ((*a)->attribute - (*b)->attribute);
 805 }
 806
 807
 808 static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, size_t room)
 809 {
 810         size_t length;
 811         uint32_t lvalue;
 812
 813         /*
 814          *      FIXME: Check room!
 815          */
 816         room = room;            /* -Wunused */
 817
 818         /*
 819          *      Search for all attributes of the same
 820          *      type, and pack them into the same
 821          *      attribute.
 822          */
 823         switch (vp->type) {
 824         case PW_TYPE_BYTE:
 825                 length = 1;
 826                 *p = vp->vp_integer & 0xff;
 827                 break;
 828
 829         case PW_TYPE_SHORT:
 830                 length = 2;
 831                 p[0] = (vp->vp_integer >> 8) & 0xff;
 832                 p[1] = vp->vp_integer & 0xff;
 833                 break;
 834
 835         case PW_TYPE_INTEGER:
 836                 length = 4;
 837                 lvalue = htonl(vp->vp_integer);
 838                 memcpy(p, &lvalue, 4);
 839                 break;
 840
 841         case PW_TYPE_IPADDR:
 842                 length = 4;
 843                 memcpy(p, &vp->vp_ipaddr, 4);
 844                 break;
 845
 846         case PW_TYPE_ETHERNET:
 847                 length = 6;
 848                 memcpy(p, &vp->vp_ether, 6);
 849                 break;
 850
 851         case PW_TYPE_STRING:
 852                 memcpy(p, vp->vp_strvalue, vp->length);
 853                 length = vp->length;
 854                 break;
 855
 856         case PW_TYPE_TLV:       /* FIXME: split it on 255? */
 857                 memcpy(p, vp->vp_tlv, vp->length);
 858                 length = vp->length;
 859                 break;
 860
 861         case PW_TYPE_OCTETS:
 862                 memcpy(p, vp->vp_octets, vp->length);
 863                 length = vp->length;
 864                 break;
 865
 866         default:
 867                 fr_strerror_printf("BAD TYPE2 %d", vp->type);
 868                 length = 0;
 869                 break;
 870         }
 871
 872         return length;
 873 }
 874
 875 static VALUE_PAIR *fr_dhcp_vp2suboption(VALUE_PAIR *vps)
 876 {
 877         int length;
 878         unsigned int attribute;
 879         uint8_t *ptr;
 880         VALUE_PAIR *vp, *tlv;
 881
 882         attribute = vps->attribute & 0xffff00ff;
 883
 884         tlv = paircreate(attribute, PW_TYPE_TLV);
 885         if (!tlv) return NULL;
 886
 887         tlv->length = 0;
 888         for (vp = vps; vp != NULL; vp = vp->next) {
 889                 /*
 890                  *      Group the attributes ONLY until we see a
 891                  *      non-TLV attribute.
 892                  */
 893                 if (!vp->flags.is_tlv ||
 894                     vp->flags.encoded ||
 895                     ((vp->attribute & 0xffff00ff) != attribute)) {
 896                         break;
 897                 }
 898
 899                 tlv->length += vp->length + 2;
 900         }
 901
 902         if (!tlv->length) {
 903                 pairfree(&tlv);
 904                 return NULL;
 905         }
 906
 907         tlv->vp_tlv = malloc(tlv->length);
 908         if (!tlv->vp_tlv) {
 909                 pairfree(&tlv);
 910                 return NULL;
 911         }
 912
 913         ptr = tlv->vp_tlv;
 914         for (vp = vps; vp != NULL; vp = vp->next) {
 915                 if (!vp->flags.is_tlv ||
 916                     vp->flags.encoded ||
 917                     ((vp->attribute & 0xffff00ff) != attribute)) {
 918                         break;
 919                 }
 920
 921                 length = fr_dhcp_vp2attr(vp, ptr + 2,
 922                                          tlv->vp_tlv + tlv->length - ptr);
 923                 if (length > 255) return NULL;
 924
 925                 /*
 926                  *      Pack the attribute.
 927                  */
 928                 ptr[0] = (vp->attribute & 0xff00) >> 8;
 929                 ptr[1] = length;
 930
 931                 ptr += length + 2;
 932                 vp->flags.encoded = 1;
 933         }
 934
 935         return tlv;
 936 }
 937
 938
 939 int fr_dhcp_encode(RADIUS_PACKET *packet, RADIUS_PACKET *original)
 940 {
 941         int i, num_vps;
 942         uint8_t *p;
 943         VALUE_PAIR *vp;
 944         uint32_t lvalue, mms;
 945         size_t dhcp_size, length;
 946         dhcp_packet_t *dhcp;
 947         char buffer[1024];
 948
 949         if (packet->data) return 0;
 950
 951         packet->data = malloc(MAX_PACKET_SIZE);
 952         if (!packet->data) return -1;
 953
 954         packet->data_len = MAX_PACKET_SIZE;
 955
 956         if (packet->code == 0) packet->code = PW_DHCP_NAK;
 957
 958         /*
 959          *      If there's a request, use it as a template.
 960          *      Otherwise, assume that the caller has set up
 961          *      everything appropriately.
 962          */
 963         if (original) {
 964                 packet->dst_ipaddr.af = AF_INET;
 965                 packet->src_ipaddr.af = AF_INET;
 966
 967                 packet->dst_port = original->src_port;
 968                 packet->src_port = original->dst_port;
 969
 970                 /*
 971                  *      Note that for DHCP, we NEVER send the response
 972                  *      to the source IP address of the request.  It
 973                  *      may have traversed multiple relays, and we
 974                  *      need to send the request to the relay closest
 975                  *      to the client.
 976                  *
 977                  *      if giaddr, send to giaddr.
 978                  *      if NAK, send broadcast packet
 979                  *      if ciaddr, unicast to ciaddr
 980                  *      if flags & 0x8000, broadcast (client request)
 981                  *      if sent from 0.0.0.0, broadcast response
 982                  *      unicast to client yiaddr
 983                  */
 984
 985                 /*
 986                  *      FIXME: alignment issues.  We likely don't want to
 987                  *      de-reference the packet structure directly..
 988                  */
 989                 dhcp = (dhcp_packet_t *) original->data;
 990
 991                 if (dhcp->giaddr != htonl(INADDR_ANY)) {
 992                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->giaddr;
 993
 994                         if (dhcp->giaddr != htonl(INADDR_LOOPBACK)) {
 995                                 packet->dst_port = original->dst_port;
 996                         } else {
 997                                 packet->dst_port = original->src_port; /* debugging */
 998                         }
 999
1000                 } else if (packet->code == PW_DHCP_NAK) {
1001                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
1002
1003                 } else if (dhcp->ciaddr != htonl(INADDR_ANY)) {
1004                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->ciaddr;
1005
1006                 } else if ((dhcp->flags & 0x8000) != 0) {
1007                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
1008
1009                 } else if (packet->dst_ipaddr.ipaddr.ip4addr.s_addr == htonl(INADDR_ANY)) {
1010                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
1011
1012                 } else if (dhcp->yiaddr != htonl(INADDR_ANY)) {
1013                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->yiaddr;
1014
1015                 } else {
1016                         /* leave destination IP alone. */
1017                 }
1018
1019                 /*
1020                  *      Rewrite the source IP to be our own, if we know it.
1021                  */
1022                 if (packet->src_ipaddr.ipaddr.ip4addr.s_addr == htonl(INADDR_BROADCAST)) {
1023                         packet->src_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_ANY);
1024                 }
1025         } else {
1026                 memset(packet->data, 0, packet->data_len);
1027         }
1028
1029         if (fr_debug_flag > 1) {
1030                 char type_buf[64];
1031                 const char *name = type_buf;
1032                 char src_ip_buf[256], dst_ip_buf[256];
1033
1034                 if ((packet->code >= PW_DHCP_DISCOVER) &&
1035                     (packet->code <= PW_DHCP_INFORM)) {
1036                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
1037                 } else {
1038                         snprintf(type_buf, sizeof(type_buf), "%d",
1039                                  packet->code - PW_DHCP_OFFSET);
1040                 }
1041
1042                 DEBUG("Sending %s of id %08x from %s:%d to %s:%d",
1043                        name, (unsigned int) packet->id,
1044                        inet_ntop(packet->src_ipaddr.af,
1045                                  &packet->src_ipaddr.ipaddr,
1046                                  src_ip_buf, sizeof(src_ip_buf)),
1047                        packet->src_port,
1048                        inet_ntop(packet->dst_ipaddr.af,
1049                                  &packet->dst_ipaddr.ipaddr,
1050                                  dst_ip_buf, sizeof(dst_ip_buf)),
1051                        packet->dst_port);
1052                 fflush(stdout);
1053         }
1054
1055         p = packet->data;
1056
1057         mms = DEFAULT_PACKET_SIZE; /* maximum message size */
1058
1059         if (original) {
1060                 /*
1061                  *      Clients can request a LARGER size, but not a
1062                  *      smaller one.  They also cannot request a size
1063                  *      larger than MTU.
1064                  */
1065                 vp = pairfind(original->vps, DHCP2ATTR(57));
1066                 if (vp && (vp->vp_integer > mms)) {
1067                         mms = vp->vp_integer;
1068
1069                         if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
1070                 }
1071         }
1072
1073         /*
1074          *      RFC 3118: Authentication option.
1075          */
1076         vp = pairfind(packet->vps, DHCP2ATTR(90));
1077         if (vp) {
1078                 if (vp->length < 2) {
1079                         memset(vp->vp_octets + vp->length, 0,
1080                                2 - vp->length);
1081                         vp->length = 2;
1082                 }
1083
1084                 if (vp->length < 3) {
1085                         struct timeval tv;
1086
1087                         gettimeofday(&tv, NULL);
1088                         vp->vp_octets[2] = 0;
1089                         timeval2ntp(&tv, vp->vp_octets + 3);
1090                         vp->length = 3 + 8;
1091                 }
1092
1093                 /*
1094                  *      Configuration token (clear-text token)
1095                  */
1096                 if (vp->vp_octets[0] == 0) {
1097                         VALUE_PAIR *pass;
1098                         vp->vp_octets[1] = 0;
1099
1100                         pass = pairfind(packet->vps, PW_CLEARTEXT_PASSWORD);
1101                         if (pass) {
1102                                 length = pass->length;
1103                                 if ((length + 11) > sizeof(vp->vp_octets)) {
1104                                         length -= ((length + 11) - sizeof(vp->vp_octets));
1105                                 }
1106                                 memcpy(vp->vp_octets + 11, pass->vp_strvalue,
1107                                        length);
1108                                 vp->length = length + 11;
1109                         } else {
1110                                 vp->length = 11 + 8;
1111                                 memset(vp->vp_octets + 11, 0, 8);
1112                                 vp->length = 11 + 8;
1113                         }
1114                 } else {        /* we don't support this type! */
1115                         fr_strerror_printf("DHCP-Authentication %d unsupported",
1116                                 vp->vp_octets[0]);
1117                 }
1118         }
1119
1120         if (!original) {
1121                 *p++ = 1;       /* client message */
1122         } else {
1123                 *p++ = 2;       /* server message */
1124         }
1125         *p++ = 1;               /* hardware type = ethernet */
1126         *p++ = 6;               /* 6 bytes of ethernet */
1127         *p++ = 0;               /* hops */
1128
1129         if (original) { /* Xid */
1130                 memcpy(p, original->data + 4, 4);
1131         } else {
1132                 lvalue = fr_rand();
1133                 memcpy(p, &lvalue, 4);
1134         }
1135         p += 4;
1136
1137         memset(p, 0, 2);        /* secs are zero */
1138         p += 2;
1139
1140         if (original) {
1141                 memcpy(p, original->data + 10, 6); /* copy flags && ciaddr */
1142         }
1143
1144         /*
1145          *      Allow the admin to set the broadcast flag.
1146          */
1147         vp = pairfind(packet->vps, DHCP2ATTR(262));
1148         if (vp) {
1149                 p[0] |= (vp->vp_integer & 0xff00) >> 8;
1150                 p[1] |= (vp->vp_integer & 0xff);
1151         }
1152
1153         p += 6;
1154
1155         /*
1156          *      Set client IP address.
1157          */
1158         vp = pairfind(packet->vps, DHCP2ATTR(264)); /* Your IP address */
1159         if (vp) {
1160                 lvalue = vp->vp_ipaddr;
1161         } else {
1162                 lvalue = htonl(INADDR_ANY);
1163         }
1164         memcpy(p, &lvalue, 4);  /* your IP address */
1165         p += 4;
1166
1167         vp = pairfind(packet->vps, DHCP2ATTR(265)); /* server IP address */
1168         if (!vp) vp = pairfind(packet->vps, DHCP2ATTR(54)); /* identifier */
1169         if (vp) {
1170                 lvalue = vp->vp_ipaddr;
1171         } else {
1172                 lvalue = htonl(INADDR_ANY);
1173         }
1174         memcpy(p, &lvalue, 4);  /* Server IP address */
1175         p += 4;
1176
1177         if (original) {
1178                 memcpy(p, original->data + 24, 4); /* copy gateway IP address */
1179         } else {
1180                 vp = pairfind(packet->vps, DHCP2ATTR(266));
1181                 if (vp) {
1182                         lvalue = vp->vp_ipaddr;
1183                 } else {
1184                         lvalue = htonl(INADDR_NONE);
1185                 }
1186                 memcpy(p, &lvalue, 4);
1187         }
1188         p += 4;
1189
1190         if (original) {
1191                 memcpy(p, original->data + 28, DHCP_CHADDR_LEN);
1192         } else {
1193                 vp = pairfind(packet->vps, DHCP2ATTR(267));
1194                 if (vp) {
1195                         if (vp->length > DHCP_CHADDR_LEN) {
1196                                 memcpy(p, vp->vp_octets, DHCP_CHADDR_LEN);
1197                         } else {
1198                                 memcpy(p, vp->vp_octets, vp->length);
1199                         }
1200                 }
1201         }
1202         p += DHCP_CHADDR_LEN;
1203
1204         memset(p, 0, 192);      /* bootp legacy */
1205         p += 192;
1206
1207         lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER); /* DHCP magic number */
1208         memcpy(p, &lvalue, 4);
1209         p += 4;
1210
1211         /*
1212          *      Print the header.
1213          */
1214         if (fr_debug_flag > 1) {
1215                 uint8_t *pp = p;
1216
1217                 p = packet->data;
1218
1219                 for (i = 0; i < 14; i++) {
1220                         vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
1221                         if (!vp) {
1222                                 fr_strerror_printf("Parse error %s", fr_strerror());
1223                                 return -1;
1224                         }
1225
1226                         switch (vp->type) {
1227                         case PW_TYPE_BYTE:
1228                                 vp->vp_integer = p[0];
1229                                 vp->length = 1;
1230                                 break;
1231
1232                         case PW_TYPE_SHORT:
1233                                 vp->vp_integer = (p[0] << 8) | p[1];
1234                                 vp->length = 2;
1235                                 break;
1236
1237                         case PW_TYPE_INTEGER:
1238                                 memcpy(&vp->vp_integer, p, 4);
1239                                 vp->vp_integer = ntohl(vp->vp_integer);
1240                                 vp->length = 4;
1241                                 break;
1242
1243                         case PW_TYPE_IPADDR:
1244                                 memcpy(&vp->vp_ipaddr, p, 4);
1245                                 vp->length = 4;
1246                                 break;
1247
1248                         case PW_TYPE_STRING:
1249                                 memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
1250                                 vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
1251                                 vp->length = strlen(vp->vp_strvalue);
1252                                 break;
1253
1254                         case PW_TYPE_OCTETS: /* only for Client HW Address */
1255                                 memcpy(vp->vp_octets, p, packet->data[2]);
1256                                 vp->length = packet->data[2];
1257                                 break;
1258
1259                         case PW_TYPE_ETHERNET: /* only for Client HW Address */
1260                                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
1261                                 vp->length = sizeof(vp->vp_ether);
1262                                 break;
1263
1264                         default:
1265                                 fr_strerror_printf("Internal sanity check failed %d %d", vp->type, __LINE__);
1266                                 pairfree(&vp);
1267                                 break;
1268                         }
1269
1270                         p += dhcp_header_sizes[i];
1271
1272                         vp_prints(buffer, sizeof(buffer), vp);
1273                         fr_strerror_printf("\t%s", buffer);
1274                         pairfree(&vp);
1275                 }
1276
1277                 /*
1278                  *      Jump over DHCP magic number, response, etc.
1279                  */
1280                 p = pp;
1281         }
1282
1283         /*
1284          *      Before packing the attributes, re-order them so that
1285          *      the array ones are all contiguous.  This simplifies
1286          *      the later code.
1287          */
1288         num_vps = 0;
1289         for (vp = packet->vps; vp != NULL; vp = vp->next) {
1290                 num_vps++;
1291         }
1292         if (num_vps > 1) {
1293                 VALUE_PAIR **array, **last;
1294
1295                 array = malloc(num_vps * sizeof(VALUE_PAIR *));
1296
1297                 i = 0;
1298                 for (vp = packet->vps; vp != NULL; vp = vp->next) {
1299                         array[i++] = vp;
1300                 }
1301
1302                 /*
1303                  *      Sort the attributes.
1304                  */
1305                 qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *),
1306                       attr_cmp);
1307
1308                 last = &packet->vps;
1309                 for (i = 0; i < num_vps; i++) {
1310                         *last = array[i];
1311                         array[i]->next = NULL;
1312                         last = &(array[i]->next);
1313                 }
1314                 free(array);
1315         }
1316
1317         p[0] = 0x35;            /* DHCP-Message-Type */
1318         p[1] = 1;
1319         p[2] = packet->code - PW_DHCP_OFFSET;
1320         p += 3;
1321
1322         /*
1323          *      Pack in the attributes.
1324          */
1325         vp = packet->vps;
1326         while (vp) {
1327                 int num_entries = 1;
1328
1329                 VALUE_PAIR *same;
1330                 uint8_t *plength, *pattr;
1331
1332                 if (!IS_DHCP_ATTR(vp)) goto next;
1333                 if (vp->attribute == DHCP2ATTR(53)) goto next; /* already done */
1334                 if (((vp->attribute & 0xffff) > 255) &&
1335                     (DHCP_BASE_ATTR(vp->attribute) != PW_DHCP_OPTION_82)) goto next;
1336
1337                 length = vp->length;
1338
1339                 for (same = vp->next; same != NULL; same = same->next) {
1340                         if (same->attribute != vp->attribute) break;
1341                         num_entries++;
1342                 }
1343
1344                 /*
1345                  *      For client-identifier
1346                  */
1347                 if ((vp->type == PW_TYPE_ETHERNET) &&
1348                     (vp->length == 6) &&
1349                     (num_entries == 1)) {
1350                         vp->type = PW_TYPE_OCTETS;
1351                         memmove(vp->vp_octets + 1, vp->vp_octets, 6);
1352                         vp->vp_octets[0] = 1;
1353                 }
1354
1355                 pattr = p;
1356                 *(p++) = vp->attribute & 0xff;
1357                 plength = p;
1358                 *(p++) = 0;     /* header isn't included in attr length */
1359
1360                 for (i = 0; i < num_entries; i++) {
1361                         if (fr_debug_flag > 1) {
1362                                 vp_prints(buffer, sizeof(buffer), vp);
1363                                 fr_strerror_printf("\t%s", buffer);
1364                         }
1365
1366                         if (vp->flags.is_tlv) {
1367                                 VALUE_PAIR *tlv = fr_dhcp_vp2suboption(vp);
1368                                 if (vp) {
1369                                         tlv->next = vp->next;
1370                                         vp->next = tlv;
1371                                 }
1372
1373                                 /*
1374                                  *      The encoded flag MUST be set in the vp!
1375                                  */
1376                                 vp = vp->next;
1377                         }
1378
1379                         length = fr_dhcp_vp2attr(vp, p, 0);
1380
1381                         /*
1382                          *      This will never happen due to FreeRADIUS
1383                          *      limitations: sizeof(vp->vp_octets) < 255
1384                          */
1385                         if (length > 255) {
1386                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->name);
1387                                 break;
1388                         }
1389
1390                         /*
1391                          *      More than one attribute of the same type
1392                          *      in a row: they are packed together
1393                          *      into the same TLV.  If we overflow,
1394                          *      go bananas!
1395                          */
1396                         if ((*plength + length) > 255) {
1397                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->name);
1398                                 break;
1399                         }
1400
1401                         *plength += length;
1402                         p += length;
1403
1404                         if (vp->next &&
1405                             (vp->next->attribute == vp->attribute))
1406                                 vp = vp->next;
1407                 } /* loop over num_entries */
1408
1409         next:
1410                 vp = vp->next;
1411         }
1412
1413         p[0] = 0xff;            /* end of option option */
1414         p[1] = 0x00;
1415         p += 2;
1416         dhcp_size = p - packet->data;
1417
1418         /*
1419          *      FIXME: if (dhcp_size > mms),
1420          *        then we put the extra options into the "sname" and "file"
1421          *        fields, AND set the "end option option" in the "options"
1422          *        field.  We also set the "overload option",
1423          *        and put options into the "file" field, followed by
1424          *        the "sname" field.  Where each option is completely
1425          *        enclosed in the "file" and/or "sname" field, AND
1426          *        followed by the "end of option", and MUST be followed
1427          *        by padding option.
1428          *
1429          *      Yuck.  That sucks...
1430          */
1431         packet->data_len = dhcp_size;
1432
1433         if (original) {
1434                 /*
1435                  *      FIXME: This may set it to broadcast, which we don't
1436                  *      want.  Instead, set it to the real address of the
1437                  *      socket.
1438                  */
1439                 packet->src_ipaddr = original->dst_ipaddr;
1440
1441                 packet->sockfd = original->sockfd;
1442         }
1443
1444         if (packet->data_len < DEFAULT_PACKET_SIZE) {
1445                 memset(packet->data + packet->data_len, 0,
1446                        DEFAULT_PACKET_SIZE - packet->data_len);
1447                 packet->data_len = DEFAULT_PACKET_SIZE;
1448         }
1449
1450         if ((fr_debug_flag > 2) && fr_log_fp) {
1451                 for (i = 0; i < packet->data_len; i++) {
1452                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
1453                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
1454                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1455                 }
1456                 fprintf(fr_log_fp, "\n");
1457         }
1458
1459         return 0;
1460 }
1461 #endif /* WITH_DHCP */