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         uint32_t                magic;
 218         struct sockaddr_storage src;
 219         struct sockaddr_storage dst;
 220         socklen_t               sizeof_src;
 221         socklen_t               sizeof_dst;
 222         RADIUS_PACKET           *packet;
 223         int port;
 224         uint8_t                 *code;
 225
 226         packet = rad_alloc(0);
 227         if (!packet) {
 228                 fr_strerror_printf("Failed allocating packet");
 229                 return NULL;
 230         }
 231         memset(packet, 0, sizeof(packet));
 232
 233         packet->data = malloc(MAX_PACKET_SIZE);
 234         if (!packet->data) {
 235                 fr_strerror_printf("Failed in malloc");
 236                 rad_free(&packet);
 237                 return NULL;
 238         }
 239
 240         packet->sockfd = sockfd;
 241         sizeof_src = sizeof(src);
 242 #ifdef WITH_UDPFROMTO
 243         sizeof_dst = sizeof(dst);
 244         packet->data_len = recvfromto(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 245                                       (struct sockaddr *)&src, &sizeof_src,
 246                                       (struct sockaddr *)&dst, &sizeof_dst);
 247 #else
 248         packet->data_len = recvfrom(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 249                                     (struct sockaddr *)&src, &sizeof_src);
 250 #endif
 251
 252         if (packet->data_len <= 0) {
 253                 fr_strerror_printf("Failed reading DHCP socket: %s", strerror(errno));
 254                 rad_free(&packet);
 255                 return NULL;
 256         }
 257
 258         if (packet->data_len < MIN_PACKET_SIZE) {
 259                 fr_strerror_printf("DHCP packet is too small (%d < %d)",
 260                                    (int) packet->data_len, MIN_PACKET_SIZE);
 261                 rad_free(&packet);
 262                 return NULL;
 263         }
 264
 265         if (packet->data[1] != 1) {
 266                 fr_strerror_printf("DHCP can only receive ethernet requests, not type %02x",
 267                       packet->data[1]);
 268                 rad_free(&packet);
 269                 return NULL;
 270         }
 271
 272         if (packet->data[2] != 6) {
 273                 fr_strerror_printf("Ethernet HW length is wrong length %d",
 274                         packet->data[2]);
 275                 rad_free(&packet);
 276                 return NULL;
 277         }
 278
 279         memcpy(&magic, packet->data + 236, 4);
 280         magic = ntohl(magic);
 281         if (magic != DHCP_OPTION_MAGIC_NUMBER) {
 282                 fr_strerror_printf("Cannot do BOOTP");
 283                 rad_free(&packet);
 284                 return NULL;
 285         }
 286
 287         /*
 288          *      Create unique keys for the packet.
 289          */
 290         memcpy(&magic, packet->data + 4, 4);
 291         packet->id = ntohl(magic);
 292
 293         code = dhcp_get_option((dhcp_packet_t *) packet->data,
 294                                packet->data_len, 53);
 295         if (!code) {
 296                 fr_strerror_printf("No message-type option was found in the packet");
 297                 rad_free(&packet);
 298                 return NULL;
 299         }
 300
 301         if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
 302                 fr_strerror_printf("Unknown value for message-type option");
 303                 rad_free(&packet);
 304                 return NULL;
 305         }
 306
 307         packet->code = code[2] | PW_DHCP_OFFSET;
 308
 309         /*
 310          *      Create a unique vector from the MAC address and the
 311          *      DHCP opcode.  This is a hack for the RADIUS
 312          *      infrastructure in the rest of the server.
 313          *
 314          *      Note: packet->data[2] == 6, which is smaller than
 315          *      sizeof(packet->vector)
 316          *
 317          *      FIXME:  Look for client-identifier in packet,
 318          *      and use that, too?
 319          */
 320         memset(packet->vector, 0, sizeof(packet->vector));
 321         memcpy(packet->vector, packet->data + 28, packet->data[2]);
 322         packet->vector[packet->data[2]] = packet->code & 0xff;
 323
 324         /*
 325          *      FIXME: for DISCOVER / REQUEST: src_port == dst_port + 1
 326          *      FIXME: for OFFER / ACK       : src_port = dst_port - 1
 327          */
 328
 329         /*
 330          *      Unique keys are xid, client mac, and client ID?
 331          */
 332
 333         /*
 334          *      FIXME: More checks, like DHCP packet type?
 335          */
 336
 337         sizeof_dst = sizeof(dst);
 338
 339 #ifndef WITH_UDPFROMTO
 340         /*
 341          *      This should never fail...
 342          */
 343         getsockname(sockfd, (struct sockaddr *) &dst, &sizeof_dst);
 344 #endif
 345
 346         fr_sockaddr2ipaddr(&dst, sizeof_dst, &packet->dst_ipaddr, &port);
 347         packet->dst_port = port;
 348
 349         fr_sockaddr2ipaddr(&src, sizeof_src, &packet->src_ipaddr, &port);
 350         packet->src_port = port;
 351
 352         if (fr_debug_flag > 1) {
 353                 char type_buf[64];
 354                 const char *name = type_buf;
 355                 char src_ip_buf[256], dst_ip_buf[256];
 356
 357                 if ((packet->code >= PW_DHCP_DISCOVER) &&
 358                     (packet->code <= PW_DHCP_INFORM)) {
 359                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
 360                 } else {
 361                         snprintf(type_buf, sizeof(type_buf), "%d",
 362                                  packet->code - PW_DHCP_OFFSET);
 363                 }
 364
 365                 DEBUG("Received %s of id %08x from %s:%d to %s:%d\n",
 366                        name, (unsigned int) packet->id,
 367                        inet_ntop(packet->src_ipaddr.af,
 368                                  &packet->src_ipaddr.ipaddr,
 369                                  src_ip_buf, sizeof(src_ip_buf)),
 370                        packet->src_port,
 371                        inet_ntop(packet->dst_ipaddr.af,
 372                                  &packet->dst_ipaddr.ipaddr,
 373                                  dst_ip_buf, sizeof(dst_ip_buf)),
 374                        packet->dst_port);
 375         }
 376
 377         return packet;
 378 }
 379
 380
 381 /*
 382  *      Send a DHCP packet.
 383  */
 384 int fr_dhcp_send(RADIUS_PACKET *packet)
 385 {
 386         struct sockaddr_storage dst;
 387         socklen_t               sizeof_dst;
 388 #ifdef WITH_UDPFROMTO
 389         struct sockaddr_storage src;
 390         socklen_t               sizeof_src;
 391 #endif
 392
 393         fr_ipaddr2sockaddr(&packet->dst_ipaddr, packet->dst_port,
 394                            &dst, &sizeof_dst);
 395
 396         /*
 397          *      The client doesn't yet have an IP address, but is
 398          *      expecting an ethernet packet unicast to it's MAC
 399          *      address.  We need to build a raw frame.
 400          */
 401         if (packet->offset == 0) {
 402                 /*
 403                  *      FIXME: Insert code here!
 404                  */
 405         }
 406
 407 #ifndef WITH_UDPFROMTO
 408         /*
 409          *      Assume that the packet is encoded before sending it.
 410          */
 411         return sendto(packet->sockfd, packet->data, packet->data_len, 0,
 412                       (struct sockaddr *)&dst, sizeof_dst);
 413 #else
 414         fr_ipaddr2sockaddr(&packet->src_ipaddr, packet->src_port,
 415                            &src, &sizeof_src);
 416
 417         return sendfromto(packet->sockfd,
 418                           packet->data, packet->data_len, 0,
 419                           (struct sockaddr *)&src, sizeof_src,
 420                           (struct sockaddr *)&dst, sizeof_dst);
 421 #endif
 422 }
 423
 424 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen);
 425
 426 static int decode_tlv(VALUE_PAIR *tlv, const uint8_t *data, size_t data_len)
 427 {
 428         const uint8_t *p;
 429         VALUE_PAIR *head, **tail, *vp;
 430
 431         /*
 432          *      Take a pass at parsing it.
 433          */
 434         p = data;
 435         while (p < (data + data_len)) {
 436                 if ((p + 2) > (data + data_len)) goto make_tlv;
 437
 438                 if ((p + p[1] + 2) > (data + data_len)) goto make_tlv;
 439                 p += 2 + p[1];
 440         }
 441
 442         /*
 443          *      Got here... must be well formed.
 444          */
 445         head = NULL;
 446         tail = &head;
 447
 448         p = data;
 449         while (p < (data + data_len)) {
 450                 vp = paircreate(tlv->attribute | (p[0] << 8), DHCP_MAGIC_VENDOR, PW_TYPE_OCTETS);
 451                 if (!vp) {
 452                         pairfree(&head);
 453                         goto make_tlv;
 454                 }
 455
 456                 if (fr_dhcp_attr2vp(vp, p + 2, p[1]) < 0) {
 457                         pairfree(&head);
 458                         goto make_tlv;
 459                 }
 460
 461                 *tail = vp;
 462                 tail = &(vp->next);
 463                 p += 2 + p[1];
 464         }
 465
 466         /*
 467          *      The caller allocated TLV, so we need to copy the FIRST
 468          *      attribute over top of that.
 469          */
 470         if (head) {
 471                 memcpy(tlv, head, sizeof(*tlv));
 472                 head->next = NULL;
 473                 pairfree(&head);
 474         }
 475
 476         return 0;
 477
 478 make_tlv:
 479         tlv->vp_tlv = malloc(data_len);
 480         if (!tlv->vp_tlv) {
 481                 fr_strerror_printf("No memory");
 482                 return -1;
 483         }
 484         memcpy(tlv->vp_tlv, data, data_len);
 485         tlv->length = data_len;
 486
 487         return 0;
 488 }
 489
 490
 491 /*
 492  *      Decode ONE value into a VP
 493  */
 494 static int fr_dhcp_attr2vp(VALUE_PAIR *vp, const uint8_t *p, size_t alen)
 495 {
 496         switch (vp->type) {
 497         case PW_TYPE_BYTE:
 498                 if (alen != 1) goto raw;
 499                 vp->vp_integer = p[0];
 500                 break;
 501
 502         case PW_TYPE_SHORT:
 503                 if (alen != 2) goto raw;
 504                 vp->vp_integer = (p[0] << 8) | p[1];
 505                 break;
 506
 507         case PW_TYPE_INTEGER:
 508                 if (alen != 4) goto raw;
 509                 memcpy(&vp->vp_integer, p, 4);
 510                 vp->vp_integer = ntohl(vp->vp_integer);
 511                 break;
 512
 513         case PW_TYPE_IPADDR:
 514                 if (alen != 4) goto raw;
 515                 memcpy(&vp->vp_ipaddr, p , 4);
 516                 vp->length = 4;
 517                 break;
 518
 519         case PW_TYPE_STRING:
 520                 if (alen > 253) return -1;
 521                 memcpy(vp->vp_strvalue, p , alen);
 522                 vp->vp_strvalue[alen] = '\0';
 523                 break;
 524
 525         raw:
 526                 vp->type = PW_TYPE_OCTETS;
 527
 528         case PW_TYPE_OCTETS:
 529                 if (alen > 253) return -1;
 530                 memcpy(vp->vp_octets, p, alen);
 531                 break;
 532
 533         case PW_TYPE_TLV:
 534                 return decode_tlv(vp, p, alen);
 535
 536         default:
 537                 fr_strerror_printf("Internal sanity check %d %d", vp->type, __LINE__);
 538                 return -1;
 539         } /* switch over type */
 540
 541         vp->length = alen;
 542         return 0;
 543 }
 544
 545 ssize_t fr_dhcp_decode_options(uint8_t *data, size_t len, VALUE_PAIR **head)
 546 {
 547         int i;
 548         VALUE_PAIR *vp, **tail;
 549         uint8_t *p, *next;
 550         next = data;
 551
 552         *head = NULL;
 553         tail = head;
 554         /*
 555          *      FIXME: This should also check sname && file fields.
 556          *      See the dhcp_get_option() function above.
 557          */
 558         while (next < (data + len)) {
 559                 int num_entries, alen;
 560                 const DICT_ATTR *da;
 561
 562                 p = next;
 563
 564                 if (*p == 0) break;
 565                 if (*p == 255) break; /* end of options signifier */
 566                 if ((p + 2) > (data + len)) break;
 567
 568                 next = p + 2 + p[1];
 569
 570                 if (p[1] >= 253) {
 571                         fr_strerror_printf("Attribute too long %u %u",
 572                                            p[0], p[1]);
 573                         continue;
 574                 }
 575
 576                 da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
 577                 if (!da) {
 578                         fr_strerror_printf("Attribute not in our dictionary: %u",
 579                                            p[0]);
 580                         continue;
 581                 }
 582
 583                 vp = NULL;
 584                 num_entries = 1;
 585                 alen = p[1];
 586                 p += 2;
 587
 588                 /*
 589                  *      Could be an array of bytes, integers, etc.
 590                  */
 591                 if (da->flags.array) {
 592                         switch (da->type) {
 593                         case PW_TYPE_BYTE:
 594                                 num_entries = alen;
 595                                 alen = 1;
 596                                 break;
 597
 598                         case PW_TYPE_SHORT: /* ignore any trailing data */
 599                                 num_entries = alen >> 1;
 600                                 alen = 2;
 601                                 break;
 602
 603                         case PW_TYPE_IPADDR:
 604                         case PW_TYPE_INTEGER:
 605                         case PW_TYPE_DATE: /* ignore any trailing data */
 606                                 num_entries = alen >> 2;
 607                                 alen = 4;
 608                                 break;
 609
 610                         default:
 611
 612                                 break; /* really an internal sanity failure */
 613                         }
 614                 }
 615
 616                 /*
 617                  *      Loop over all of the entries, building VPs
 618                  */
 619                 for (i = 0; i < num_entries; i++) {
 620                         vp = pairmake(da->name, NULL, T_OP_ADD);
 621                         if (!vp) {
 622                                 fr_strerror_printf("Cannot build attribute %s",
 623                                         fr_strerror());
 624                                 pairfree(head);
 625                                 return -1;
 626                         }
 627
 628                         /*
 629                          *      Hack for ease of use.
 630                          */
 631                         if ((da->attr == 0x3d) &&
 632                             !da->flags.array &&
 633                             (alen == 7) && (*p == 1) && (num_entries == 1)) {
 634                                 vp->type = PW_TYPE_ETHERNET;
 635                                 memcpy(vp->vp_octets, p + 1, 6);
 636                                 vp->length = alen;
 637
 638                         } else if (fr_dhcp_attr2vp(vp, p, alen) < 0) {
 639                                 pairfree(&vp);
 640                                 pairfree(head);
 641                                 return -1;
 642                         }
 643
 644                         *tail = vp;
 645                         while (*tail) {
 646                                 debug_pair(*tail);
 647                                 tail = &(*tail)->next;
 648                         }
 649                         p += alen;
 650                 } /* loop over array entries */
 651         } /* loop over the entire packet */
 652
 653         return next - data;
 654 }
 655
 656 int fr_dhcp_decode(RADIUS_PACKET *packet)
 657 {
 658         ssize_t i;
 659         uint8_t *p;
 660         uint32_t giaddr;
 661         VALUE_PAIR *head, *vp, **tail;
 662         VALUE_PAIR *maxms, *mtu;
 663
 664         head = NULL;
 665         tail = &head;
 666         p = packet->data;
 667
 668         if ((fr_debug_flag > 2) && fr_log_fp) {
 669                 for (i = 0; i < packet->data_len; i++) {
 670                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
 671                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
 672                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 673                 }
 674                 fprintf(fr_log_fp, "\n");
 675         }
 676
 677         if (packet->data[1] != 1) {
 678                 fr_strerror_printf("Packet is not Ethernet: %u",
 679                       packet->data[1]);
 680                 return -1;
 681         }
 682
 683         /*
 684          *      Decode the header.
 685          */
 686         for (i = 0; i < 14; i++) {
 687                 vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
 688                 if (!vp) {
 689                         fr_strerror_printf("Parse error %s", fr_strerror());
 690                         pairfree(&head);
 691                         return -1;
 692                 }
 693
 694                 if ((i == 11) &&
 695                     (packet->data[1] == 1) &&
 696                     (packet->data[2] == 6)) {
 697                         vp->type = PW_TYPE_ETHERNET;
 698                 }
 699
 700                 switch (vp->type) {
 701                 case PW_TYPE_BYTE:
 702                         vp->vp_integer = p[0];
 703                         vp->length = 1;
 704                         break;
 705
 706                 case PW_TYPE_SHORT:
 707                         vp->vp_integer = (p[0] << 8) | p[1];
 708                         vp->length = 2;
 709                         break;
 710
 711                 case PW_TYPE_INTEGER:
 712                         memcpy(&vp->vp_integer, p, 4);
 713                         vp->vp_integer = ntohl(vp->vp_integer);
 714                         vp->length = 4;
 715                         break;
 716
 717                 case PW_TYPE_IPADDR:
 718                         memcpy(&vp->vp_ipaddr, p, 4);
 719                         vp->length = 4;
 720                         break;
 721
 722                 case PW_TYPE_STRING:
 723                         memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
 724                         vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
 725                         vp->length = strlen(vp->vp_strvalue);
 726                         if (vp->length == 0) {
 727                                 pairfree(&vp);
 728                         }
 729                         break;
 730
 731                 case PW_TYPE_OCTETS:
 732                         memcpy(vp->vp_octets, p, packet->data[2]);
 733                         vp->length = packet->data[2];
 734                         break;
 735
 736                 case PW_TYPE_ETHERNET:
 737                         memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 738                         vp->length = sizeof(vp->vp_ether);
 739                         break;
 740
 741                 default:
 742                         fr_strerror_printf("BAD TYPE %d", vp->type);
 743                         pairfree(&vp);
 744                         break;
 745                 }
 746                 p += dhcp_header_sizes[i];
 747
 748                 if (!vp) continue;
 749
 750                 debug_pair(vp);
 751                 *tail = vp;
 752                 tail = &vp->next;
 753         }
 754
 755         /*
 756          *      Loop over the options.
 757          */
 758
 759         /*
 760          *  Nothing uses tail after this call, if it does in the future
 761          *  it'll need to find the new tail...
 762          */
 763         if (fr_dhcp_decode_options(packet->data + 240, packet->data_len - 240,
 764                                    tail) < 0) {
 765                 return -1;
 766         }
 767
 768         /*
 769          *      If DHCP request, set ciaddr to zero.
 770          */
 771
 772         /*
 773          *      Set broadcast flag for broken vendors, but only if
 774          *      giaddr isn't set.
 775          */
 776         memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
 777         if (giaddr == htonl(INADDR_ANY)) {
 778                 /*
 779                  *      DHCP Opcode is request
 780                  */
 781                 vp = pairfind(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
 782                 if (vp && vp->vp_integer == 3) {
 783                         /*
 784                          *      Vendor is "MSFT 98"
 785                          */
 786                         vp = pairfind(head, 63, DHCP_MAGIC_VENDOR, TAG_ANY);
 787                         if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
 788                                 vp = pairfind(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
 789
 790                                 /*
 791                                  *      Reply should be broadcast.
 792                                  */
 793                                 if (vp) vp->vp_integer |= 0x8000;
 794                                 packet->data[10] |= 0x80;
 795                         }
 796                 }
 797         }
 798
 799         /*
 800          *      FIXME: Nuke attributes that aren't used in the normal
 801          *      header for discover/requests.
 802          */
 803         packet->vps = head;
 804
 805         /*
 806          *      Client can request a LARGER size, but not a smaller
 807          *      one.  They also cannot request a size larger than MTU.
 808          */
 809         maxms = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
 810         mtu = pairfind(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
 811
 812         if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
 813                 fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
 814                 return -1;
 815         }
 816
 817         if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
 818                 fr_strerror_printf("DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
 819                 maxms->vp_integer = DEFAULT_PACKET_SIZE;
 820         }
 821
 822         if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
 823                 fr_strerror_printf("DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
 824                 maxms->vp_integer = mtu->vp_integer;
 825         }
 826
 827         if (fr_debug_flag > 0) {
 828                 for (vp = packet->vps; vp != NULL; vp = vp->next) {
 829
 830                 }
 831         }
 832
 833         if (fr_debug_flag) fflush(stdout);
 834
 835         return 0;
 836 }
 837
 838
 839 static int attr_cmp(const void *one, const void *two)
 840 {
 841         const VALUE_PAIR * const *a = one;
 842         const VALUE_PAIR * const *b = two;
 843
 844         /*
 845          *      DHCP-Message-Type is first, for simplicity.
 846          */
 847         if (((*a)->attribute == 53) &&
 848             (*b)->attribute != 53) return -1;
 849
 850         /*
 851          *      Relay-Agent is last
 852          */
 853         if (((*a)->attribute == 82) &&
 854             (*b)->attribute != 82) return +1;
 855
 856         return ((*a)->attribute - (*b)->attribute);
 857 }
 858
 859
 860 static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, size_t room)
 861 {
 862         size_t length;
 863         uint32_t lvalue;
 864
 865         /*
 866          *      FIXME: Check room!
 867          */
 868         room = room;            /* -Wunused */
 869
 870         /*
 871          *      Search for all attributes of the same
 872          *      type, and pack them into the same
 873          *      attribute.
 874          */
 875         switch (vp->type) {
 876         case PW_TYPE_BYTE:
 877                 length = 1;
 878                 *p = vp->vp_integer & 0xff;
 879                 break;
 880
 881         case PW_TYPE_SHORT:
 882                 length = 2;
 883                 p[0] = (vp->vp_integer >> 8) & 0xff;
 884                 p[1] = vp->vp_integer & 0xff;
 885                 break;
 886
 887         case PW_TYPE_INTEGER:
 888                 length = 4;
 889                 lvalue = htonl(vp->vp_integer);
 890                 memcpy(p, &lvalue, 4);
 891                 break;
 892
 893         case PW_TYPE_IPADDR:
 894                 length = 4;
 895                 memcpy(p, &vp->vp_ipaddr, 4);
 896                 break;
 897
 898         case PW_TYPE_ETHERNET:
 899                 length = 6;
 900                 memcpy(p, &vp->vp_ether, 6);
 901                 break;
 902
 903         case PW_TYPE_STRING:
 904                 memcpy(p, vp->vp_strvalue, vp->length);
 905                 length = vp->length;
 906                 break;
 907
 908         case PW_TYPE_TLV:       /* FIXME: split it on 255? */
 909                 memcpy(p, vp->vp_tlv, vp->length);
 910                 length = vp->length;
 911                 break;
 912
 913         case PW_TYPE_OCTETS:
 914                 memcpy(p, vp->vp_octets, vp->length);
 915                 length = vp->length;
 916                 break;
 917
 918         default:
 919                 fr_strerror_printf("BAD TYPE2 %d", vp->type);
 920                 length = 0;
 921                 break;
 922         }
 923
 924         return length;
 925 }
 926
 927 static VALUE_PAIR *fr_dhcp_vp2suboption(VALUE_PAIR *vps)
 928 {
 929         int length;
 930         unsigned int attribute;
 931         uint8_t *ptr;
 932         VALUE_PAIR *vp, *tlv;
 933
 934         attribute = vps->attribute & 0xffff00ff;
 935
 936         tlv = paircreate(attribute, DHCP_MAGIC_VENDOR, PW_TYPE_TLV);
 937         if (!tlv) return NULL;
 938
 939         tlv->length = 0;
 940         for (vp = vps; vp != NULL; vp = vp->next) {
 941                 /*
 942                  *      Group the attributes ONLY until we see a
 943                  *      non-TLV attribute.
 944                  */
 945                 if (!vp->flags.is_tlv ||
 946                     vp->flags.extended ||
 947                     ((vp->attribute & 0xffff00ff) != attribute)) {
 948                         break;
 949                 }
 950
 951                 tlv->length += vp->length + 2;
 952         }
 953
 954         if (!tlv->length) {
 955                 pairfree(&tlv);
 956                 return NULL;
 957         }
 958
 959         tlv->vp_tlv = malloc(tlv->length);
 960         if (!tlv->vp_tlv) {
 961                 pairfree(&tlv);
 962                 return NULL;
 963         }
 964
 965         ptr = tlv->vp_tlv;
 966         for (vp = vps; vp != NULL; vp = vp->next) {
 967                 if (!vp->flags.is_tlv ||
 968                     vp->flags.extended ||
 969                     ((vp->attribute & 0xffff00ff) != attribute)) {
 970                         break;
 971                 }
 972
 973                 length = fr_dhcp_vp2attr(vp, ptr + 2,
 974                                          tlv->vp_tlv + tlv->length - ptr);
 975                 if (length > 255) return NULL;
 976
 977                 /*
 978                  *      Pack the attribute.
 979                  */
 980                 ptr[0] = (vp->attribute & 0xff00) >> 8;
 981                 ptr[1] = length;
 982
 983                 ptr += length + 2;
 984                 vp->flags.extended = 1;
 985         }
 986
 987         return tlv;
 988 }
 989
 990
 991 int fr_dhcp_encode(RADIUS_PACKET *packet, RADIUS_PACKET *original)
 992 {
 993         int i, num_vps;
 994         uint8_t *p;
 995         VALUE_PAIR *vp;
 996         uint32_t lvalue, mms;
 997         size_t dhcp_size, length;
 998         dhcp_packet_t *dhcp;
 999
1000         if (packet->data) return 0;
1001
1002         packet->data = malloc(MAX_PACKET_SIZE);
1003         if (!packet->data) return -1;
1004
1005         packet->data_len = MAX_PACKET_SIZE;
1006
1007         if (packet->code == 0) packet->code = PW_DHCP_NAK;
1008
1009         /*
1010          *      If there's a request, use it as a template.
1011          *      Otherwise, assume that the caller has set up
1012          *      everything appropriately.
1013          */
1014         if (original) {
1015                 packet->dst_ipaddr.af = AF_INET;
1016                 packet->src_ipaddr.af = AF_INET;
1017
1018                 packet->dst_port = original->src_port;
1019                 packet->src_port = original->dst_port;
1020
1021                 /*
1022                  *      Note that for DHCP, we NEVER send the response
1023                  *      to the source IP address of the request.  It
1024                  *      may have traversed multiple relays, and we
1025                  *      need to send the request to the relay closest
1026                  *      to the client.
1027                  *
1028                  *      if giaddr, send to giaddr.
1029                  *      if NAK, send broadcast.
1030                  *      if broadcast flag, send broadcast.
1031                  *      if ciaddr is empty, send broadcast.
1032                  *      otherwise unicast to ciaddr.
1033                  */
1034
1035                 /*
1036                  *      FIXME: alignment issues.  We likely don't want to
1037                  *      de-reference the packet structure directly..
1038                  */
1039                 dhcp = (dhcp_packet_t *) original->data;
1040
1041                 /*
1042                  *      Default to sending it via sendto(), without using
1043                  *      raw sockets.
1044                  */
1045                 packet->offset = 1;
1046
1047                 if (dhcp->giaddr != htonl(INADDR_ANY)) {
1048                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->giaddr;
1049
1050                         if (dhcp->giaddr != htonl(INADDR_LOOPBACK)) {
1051                                 packet->dst_port = original->dst_port;
1052                         } else {
1053                                 packet->dst_port = original->src_port; /* debugging */
1054                         }
1055
1056                 } else if ((packet->code == PW_DHCP_NAK) ||
1057                            ((dhcp->flags & 0x8000) != 0) ||
1058                            (dhcp->ciaddr == htonl(INADDR_ANY))) {
1059                         /*
1060                          *      The kernel will take care of sending it to
1061                          *      the broadcast MAC.
1062                          */
1063                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_BROADCAST);
1064
1065                 } else {
1066                         /*
1067                          *      It was broadcast to us: we need to
1068                          *      broadcast the response.
1069                          */
1070                         if (packet->src_ipaddr.ipaddr.ip4addr.s_addr != dhcp->ciaddr) {
1071                                 packet->offset = 0;
1072                         }
1073                         packet->dst_ipaddr.ipaddr.ip4addr.s_addr = dhcp->ciaddr;
1074                 }
1075
1076                 /*
1077                  *      Rewrite the source IP to be our own, if we know it.
1078                  */
1079                 if (packet->src_ipaddr.ipaddr.ip4addr.s_addr == htonl(INADDR_BROADCAST)) {
1080                         packet->src_ipaddr.ipaddr.ip4addr.s_addr = htonl(INADDR_ANY);
1081                 }
1082         } else {
1083                 memset(packet->data, 0, packet->data_len);
1084         }
1085
1086         if (fr_debug_flag > 1) {
1087                 char type_buf[64];
1088                 const char *name = type_buf;
1089                 char src_ip_buf[256], dst_ip_buf[256];
1090
1091                 if ((packet->code >= PW_DHCP_DISCOVER) &&
1092                     (packet->code <= PW_DHCP_INFORM)) {
1093                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
1094                 } else {
1095                         snprintf(type_buf, sizeof(type_buf), "%d",
1096                                  packet->code - PW_DHCP_OFFSET);
1097                 }
1098
1099                 DEBUG("Sending %s of id %08x from %s:%d to %s:%d\n",
1100                        name, (unsigned int) packet->id,
1101                        inet_ntop(packet->src_ipaddr.af,
1102                                  &packet->src_ipaddr.ipaddr,
1103                                  src_ip_buf, sizeof(src_ip_buf)),
1104                        packet->src_port,
1105                        inet_ntop(packet->dst_ipaddr.af,
1106                                  &packet->dst_ipaddr.ipaddr,
1107                                  dst_ip_buf, sizeof(dst_ip_buf)),
1108                        packet->dst_port);
1109
1110                 if (fr_debug_flag) {
1111                         for (i = 256; i < 269; i++) {
1112                                 vp = pairfind(packet->vps, i, DHCP_MAGIC_VENDOR, TAG_ANY);
1113                                 if (!vp) continue;
1114
1115                                 debug_pair(vp);
1116                         }
1117                 }
1118         }
1119
1120         p = packet->data;
1121
1122         mms = DEFAULT_PACKET_SIZE; /* maximum message size */
1123
1124         if (original) {
1125                 /*
1126                  *      Clients can request a LARGER size, but not a
1127                  *      smaller one.  They also cannot request a size
1128                  *      larger than MTU.
1129                  */
1130                 vp = pairfind(original->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
1131                 if (vp && (vp->vp_integer > mms)) {
1132                         mms = vp->vp_integer;
1133
1134                         if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
1135                 }
1136         }
1137
1138         /*
1139          *      RFC 3118: Authentication option.
1140          */
1141         vp = pairfind(packet->vps, 90, DHCP_MAGIC_VENDOR, TAG_ANY);
1142         if (vp) {
1143                 if (vp->length < 2) {
1144                         memset(vp->vp_octets + vp->length, 0,
1145                                2 - vp->length);
1146                         vp->length = 2;
1147                 }
1148
1149                 if (vp->length < 3) {
1150                         struct timeval tv;
1151
1152                         gettimeofday(&tv, NULL);
1153                         vp->vp_octets[2] = 0;
1154                         timeval2ntp(&tv, vp->vp_octets + 3);
1155                         vp->length = 3 + 8;
1156                 }
1157
1158                 /*
1159                  *      Configuration token (clear-text token)
1160                  */
1161                 if (vp->vp_octets[0] == 0) {
1162                         VALUE_PAIR *pass;
1163                         vp->vp_octets[1] = 0;
1164
1165                         pass = pairfind(packet->vps, PW_CLEARTEXT_PASSWORD, DHCP_MAGIC_VENDOR, TAG_ANY);
1166                         if (pass) {
1167                                 length = pass->length;
1168                                 if ((length + 11) > sizeof(vp->vp_octets)) {
1169                                         length -= ((length + 11) - sizeof(vp->vp_octets));
1170                                 }
1171                                 memcpy(vp->vp_octets + 11, pass->vp_strvalue,
1172                                        length);
1173                                 vp->length = length + 11;
1174                         } else {
1175                                 vp->length = 11 + 8;
1176                                 memset(vp->vp_octets + 11, 0, 8);
1177                                 vp->length = 11 + 8;
1178                         }
1179                 } else {        /* we don't support this type! */
1180                         fr_strerror_printf("DHCP-Authentication %d unsupported",
1181                                 vp->vp_octets[0]);
1182                 }
1183         }
1184
1185         vp = pairfind(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
1186         if (vp) {
1187                 *p++ = vp->vp_integer & 0xff;
1188         } else {
1189                 if (!original) {
1190                         *p++ = 1;       /* client message */
1191                 } else {
1192                         *p++ = 2;       /* server message */
1193                 }
1194         }
1195         *p++ = 1;               /* hardware type = ethernet */
1196         *p++ = 6;               /* 6 bytes of ethernet */
1197
1198         vp = pairfind(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY);
1199         if (vp) {
1200                 *p++ = vp->vp_integer & 0xff;
1201         } else {
1202                 *p++ = 0;               /* hops */
1203         }
1204
1205         if (original) { /* Xid */
1206                 memcpy(p, original->data + 4, 4);
1207         } else {
1208                 lvalue = fr_rand();
1209                 memcpy(p, &lvalue, 4);
1210         }
1211         p += 4;
1212
1213         memset(p, 0, 2);        /* secs are zero */
1214         p += 2;
1215
1216         if (original) {
1217                 memcpy(p, original->data + 10, 6); /* copy flags && ciaddr */
1218         }
1219
1220         /*
1221          *      Allow the admin to set the broadcast flag.
1222          */
1223         vp = pairfind(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
1224         if (vp) {
1225                 p[0] |= (vp->vp_integer & 0xff00) >> 8;
1226                 p[1] |= (vp->vp_integer & 0xff);
1227         }
1228
1229         p += 6;
1230
1231         /*
1232          *      Set client IP address.
1233          */
1234         vp = pairfind(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY); /* Your IP address */
1235         if (vp) {
1236                 lvalue = vp->vp_ipaddr;
1237         } else {
1238                 lvalue = htonl(INADDR_ANY);
1239         }
1240         memcpy(p, &lvalue, 4);  /* your IP address */
1241         p += 4;
1242
1243         vp = pairfind(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY); /* server IP address */
1244         if (!vp) vp = pairfind(packet->vps, 54, DHCP_MAGIC_VENDOR, TAG_ANY); /* identifier */
1245         if (vp) {
1246                 lvalue = vp->vp_ipaddr;
1247         } else {
1248                 lvalue = htonl(INADDR_ANY);
1249         }
1250         memcpy(p, &lvalue, 4);  /* Server IP address */
1251         p += 4;
1252
1253         if (original) {
1254                 memcpy(p, original->data + 24, 4); /* copy gateway IP address */
1255         } else {
1256                 vp = pairfind(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY);
1257                 if (vp) {
1258                         lvalue = vp->vp_ipaddr;
1259                 } else {
1260                         lvalue = htonl(INADDR_NONE);
1261                 }
1262                 memcpy(p, &lvalue, 4);
1263         }
1264         p += 4;
1265
1266         if (original) {
1267                 memcpy(p, original->data + 28, DHCP_CHADDR_LEN);
1268         } else {
1269                 vp = pairfind(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY);
1270                 if (vp) {
1271                         if (vp->length > DHCP_CHADDR_LEN) {
1272                                 memcpy(p, vp->vp_octets, DHCP_CHADDR_LEN);
1273                         } else {
1274                                 memcpy(p, vp->vp_octets, vp->length);
1275                         }
1276                 }
1277         }
1278         p += DHCP_CHADDR_LEN;
1279
1280         /*
1281          *      Zero our sname && filename fields.
1282          */
1283         memset(p, 0, DHCP_SNAME_LEN + DHCP_FILE_LEN);
1284         p += DHCP_SNAME_LEN;
1285
1286         /*
1287          *      Copy over DHCP-Boot-Filename.
1288          *
1289          *      FIXME: This copy should be delayed until AFTER the options
1290          *      have been processed.  If there are too many options for
1291          *      the packet, then they go into the sname && filename fields.
1292          *      When that happens, the boot filename is passed as an option,
1293          *      instead of being placed verbatim in the filename field.
1294          */
1295         vp = pairfind(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY);
1296         if (vp) {
1297                 if (vp->length > DHCP_FILE_LEN) {
1298                         memcpy(p, vp->vp_strvalue, DHCP_FILE_LEN);
1299                 } else {
1300                         memcpy(p, vp->vp_strvalue, vp->length);
1301                 }
1302         }
1303         p += DHCP_FILE_LEN;
1304
1305         lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER); /* DHCP magic number */
1306         memcpy(p, &lvalue, 4);
1307         p += 4;
1308
1309         /*
1310          *      Print the header.
1311          */
1312         if (fr_debug_flag > 1) {
1313                 uint8_t *pp = p;
1314
1315                 p = packet->data;
1316
1317                 for (i = 0; i < 14; i++) {
1318                         vp = pairmake(dhcp_header_names[i], NULL, T_OP_EQ);
1319                         if (!vp) {
1320                                 fr_strerror_printf("Parse error %s", fr_strerror());
1321                                 return -1;
1322                         }
1323
1324                         switch (vp->type) {
1325                         case PW_TYPE_BYTE:
1326                                 vp->vp_integer = p[0];
1327                                 vp->length = 1;
1328                                 break;
1329
1330                         case PW_TYPE_SHORT:
1331                                 vp->vp_integer = (p[0] << 8) | p[1];
1332                                 vp->length = 2;
1333                                 break;
1334
1335                         case PW_TYPE_INTEGER:
1336                                 memcpy(&vp->vp_integer, p, 4);
1337                                 vp->vp_integer = ntohl(vp->vp_integer);
1338                                 vp->length = 4;
1339                                 break;
1340
1341                         case PW_TYPE_IPADDR:
1342                                 memcpy(&vp->vp_ipaddr, p, 4);
1343                                 vp->length = 4;
1344                                 break;
1345
1346                         case PW_TYPE_STRING:
1347                                 memcpy(vp->vp_strvalue, p, dhcp_header_sizes[i]);
1348                                 vp->vp_strvalue[dhcp_header_sizes[i]] = '\0';
1349                                 vp->length = strlen(vp->vp_strvalue);
1350                                 break;
1351
1352                         case PW_TYPE_OCTETS: /* only for Client HW Address */
1353                                 memcpy(vp->vp_octets, p, packet->data[2]);
1354                                 vp->length = packet->data[2];
1355                                 break;
1356
1357                         case PW_TYPE_ETHERNET: /* only for Client HW Address */
1358                                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
1359                                 vp->length = sizeof(vp->vp_ether);
1360                                 break;
1361
1362                         default:
1363                                 fr_strerror_printf("Internal sanity check failed %d %d", vp->type, __LINE__);
1364                                 pairfree(&vp);
1365                                 break;
1366                         }
1367
1368                         p += dhcp_header_sizes[i];
1369
1370                         debug_pair(vp);
1371                         pairfree(&vp);
1372                 }
1373
1374                 /*
1375                  *      Jump over DHCP magic number, response, etc.
1376                  */
1377                 p = pp;
1378         }
1379
1380         /*
1381          *      Before packing the attributes, re-order them so that
1382          *      the array ones are all contiguous.  This simplifies
1383          *      the later code.
1384          */
1385         num_vps = 0;
1386         for (vp = packet->vps; vp != NULL; vp = vp->next) {
1387                 num_vps++;
1388         }
1389         if (num_vps > 1) {
1390                 VALUE_PAIR **array, **last;
1391
1392                 array = malloc(num_vps * sizeof(VALUE_PAIR *));
1393
1394                 i = 0;
1395                 for (vp = packet->vps; vp != NULL; vp = vp->next) {
1396                         array[i++] = vp;
1397                 }
1398
1399                 /*
1400                  *      Sort the attributes.
1401                  */
1402                 qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *),
1403                       attr_cmp);
1404
1405                 last = &packet->vps;
1406                 for (i = 0; i < num_vps; i++) {
1407                         *last = array[i];
1408                         array[i]->next = NULL;
1409                         last = &(array[i]->next);
1410                 }
1411                 free(array);
1412         }
1413
1414         p[0] = 0x35;            /* DHCP-Message-Type */
1415         p[1] = 1;
1416         p[2] = packet->code - PW_DHCP_OFFSET;
1417         p += 3;
1418
1419         /*
1420          *      Pack in the attributes.
1421          */
1422         vp = packet->vps;
1423         while (vp) {
1424                 unsigned int num_entries = 1;
1425                 VALUE_PAIR *same;
1426                 uint8_t *plength, *pattr;
1427
1428                 if (vp->vendor != DHCP_MAGIC_VENDOR) goto next;
1429                 if (vp->attribute == 53) goto next; /* already done */
1430                 if ((vp->attribute > 255) &&
1431                     (DHCP_BASE_ATTR(vp->attribute) != PW_DHCP_OPTION_82)) goto next;
1432
1433                 debug_pair(vp);
1434                 if (vp->flags.extended) goto next;
1435
1436                 length = vp->length;
1437
1438                 for (same = vp->next; same != NULL; same = same->next) {
1439                         if (same->attribute != vp->attribute) break;
1440                         num_entries++;
1441                 }
1442
1443                 /*
1444                  *      For client-identifier
1445                  */
1446                 if ((vp->type == PW_TYPE_ETHERNET) &&
1447                     (vp->length == 6) &&
1448                     (num_entries == 1)) {
1449                         vp->type = PW_TYPE_OCTETS;
1450                         memmove(vp->vp_octets + 1, vp->vp_octets, 6);
1451                         vp->vp_octets[0] = 1;
1452                 }
1453
1454                 pattr = p;
1455                 *(p++) = vp->attribute & 0xff;
1456                 plength = p;
1457                 *(p++) = 0;     /* header isn't included in attr length */
1458
1459                 for (i = 0; i < num_entries; i++) {
1460                         debug_pair(vp);
1461
1462                         if (vp->flags.is_tlv) {
1463                                 VALUE_PAIR *tlv;
1464
1465                                 /*
1466                                  *      Should NOT have been encoded yet!
1467                                  */
1468                                 tlv = fr_dhcp_vp2suboption(vp);
1469
1470                                 /*
1471                                  *      Ignore it if there's an issue
1472                                  *      encoding it.
1473                                  */
1474                                 if (!tlv) goto next;
1475
1476                                 tlv->next = vp->next;
1477                                 vp->next = tlv;
1478                                 vp = tlv;
1479                         }
1480
1481                         length = fr_dhcp_vp2attr(vp, p, 0);
1482
1483                         /*
1484                          *      This will never happen due to FreeRADIUS
1485                          *      limitations: sizeof(vp->vp_octets) < 255
1486                          */
1487                         if (length > 255) {
1488                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->name);
1489                                 break;
1490                         }
1491
1492                         /*
1493                          *      More than one attribute of the same type
1494                          *      in a row: they are packed together
1495                          *      into the same TLV.  If we overflow,
1496                          *      go bananas!
1497                          */
1498                         if ((*plength + length) > 255) {
1499                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->name);
1500                                 break;
1501                         }
1502
1503                         *plength += length;
1504                         p += length;
1505
1506                         if (vp->next &&
1507                             (vp->next->attribute == vp->attribute))
1508                                 vp = vp->next;
1509                 } /* loop over num_entries */
1510
1511         next:
1512                 vp = vp->next;
1513         }
1514
1515         p[0] = 0xff;            /* end of option option */
1516         p[1] = 0x00;
1517         p += 2;
1518         dhcp_size = p - packet->data;
1519
1520         /*
1521          *      FIXME: if (dhcp_size > mms),
1522          *        then we put the extra options into the "sname" and "file"
1523          *        fields, AND set the "end option option" in the "options"
1524          *        field.  We also set the "overload option",
1525          *        and put options into the "file" field, followed by
1526          *        the "sname" field.  Where each option is completely
1527          *        enclosed in the "file" and/or "sname" field, AND
1528          *        followed by the "end of option", and MUST be followed
1529          *        by padding option.
1530          *
1531          *      Yuck.  That sucks...
1532          */
1533         packet->data_len = dhcp_size;
1534
1535         if (original) {
1536                 /*
1537                  *      FIXME: This may set it to broadcast, which we don't
1538                  *      want.  Instead, set it to the real address of the
1539                  *      socket.
1540                  */
1541                 packet->src_ipaddr = original->dst_ipaddr;
1542
1543                 packet->sockfd = original->sockfd;
1544         }
1545
1546         if (packet->data_len < DEFAULT_PACKET_SIZE) {
1547                 memset(packet->data + packet->data_len, 0,
1548                        DEFAULT_PACKET_SIZE - packet->data_len);
1549                 packet->data_len = DEFAULT_PACKET_SIZE;
1550         }
1551
1552         if ((fr_debug_flag > 2) && fr_log_fp) {
1553                 for (i = 0; i < packet->data_len; i++) {
1554                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
1555                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
1556                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1557                 }
1558                 fprintf(fr_log_fp, "\n");
1559         }
1560
1561         return 0;
1562 }
1563
1564 int fr_dhcp_add_arp_entry(int fd, const char *interface,
1565                           VALUE_PAIR *macaddr, VALUE_PAIR *ip)
1566 {
1567 #ifdef SIOCSARP
1568         struct sockaddr_in *sin;
1569         struct arpreq req;
1570
1571         if (macaddr->length > sizeof (req.arp_ha.sa_data)) {
1572                 fr_strerror_printf("ERROR: DHCP only supports up to %u octets for "
1573                                    "Client Hardware Address (got %zu octets)\n",
1574                                    sizeof(req.arp_ha.sa_data),
1575                                    macaddr->length);
1576                 return -1;
1577         }
1578
1579         memset(&req, 0, sizeof(req));
1580         sin = (struct sockaddr_in *) &req.arp_pa;
1581         sin->sin_family = AF_INET;
1582         sin->sin_addr.s_addr = ip->vp_ipaddr;
1583         strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
1584         memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->length);
1585
1586         req.arp_flags = ATF_COM;
1587         if (ioctl(fd, SIOCSARP, &req) < 0) {
1588                 fr_strerror_printf("DHCP: Failed to add entry in ARP cache: %s (%d)",
1589                                    strerror(errno), errno);
1590                 return -1;
1591         }
1592
1593         return 0;
1594 #else
1595         fd = fd;                /* -Wunused */
1596         interface = interface;  /* -Wunused */
1597         macaddr = macaddr;      /* -Wunused */
1598         ip = ip;                /* -Wunused */
1599
1600         fr_strerror_printf("Adding ARP entry is unsupported on this system");
1601         return -1;
1602 #endif
1603 }
1604
1605 #endif /* WITH_DHCP */