src/modules/proto_dhcp/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 RCSID("$Id$")
  25
  26 #include <freeradius-devel/libradius.h>
  27 #include <freeradius-devel/udpfromto.h>
  28 #include <freeradius-devel/dhcp.h>
  29
  30 #ifndef __MINGW32__
  31 #include <sys/ioctl.h>
  32 #endif
  33
  34 #ifdef HAVE_SYS_SOCKET_H
  35 #include <sys/socket.h>
  36 #endif
  37 #ifdef HAVE_SYS_TYPES_H
  38 #include <sys/types.h>
  39 #endif
  40
  41 #ifndef __MINGW32__
  42 #include <net/if_arp.h>
  43 #endif
  44
  45 #define DHCP_CHADDR_LEN (16)
  46 #define DHCP_SNAME_LEN  (64)
  47 #define DHCP_FILE_LEN   (128)
  48 #define DHCP_VEND_LEN   (308)
  49 #define DHCP_OPTION_MAGIC_NUMBER (0x63825363)
  50
  51 #ifndef INADDR_BROADCAST
  52 #define INADDR_BROADCAST INADDR_NONE
  53 #endif
  54
  55 /* @todo: this is a hack */
  56 #  define DEBUG                 if (fr_debug_flag && fr_log_fp) fr_printf_log
  57 void fr_strerror_printf(char const *fmt, ...);
  58 #  define debug_pair(vp)        do { if (fr_debug_flag && fr_log_fp) { \
  59                                         vp_print(fr_log_fp, vp); \
  60                                      } \
  61                                 } while(0)
  62
  63 typedef struct dhcp_packet_t {
  64         uint8_t         opcode;
  65         uint8_t         htype;
  66         uint8_t         hlen;
  67         uint8_t         hops;
  68         uint32_t        xid;    /* 4 */
  69         uint16_t        secs;   /* 8 */
  70         uint16_t        flags;
  71         uint32_t        ciaddr; /* 12 */
  72         uint32_t        yiaddr; /* 16 */
  73         uint32_t        siaddr; /* 20 */
  74         uint32_t        giaddr; /* 24 */
  75         uint8_t         chaddr[DHCP_CHADDR_LEN]; /* 28 */
  76         uint8_t         sname[DHCP_SNAME_LEN]; /* 44 */
  77         uint8_t         file[DHCP_FILE_LEN]; /* 108 */
  78         uint32_t        option_format; /* 236 */
  79         uint8_t         options[DHCP_VEND_LEN];
  80 } dhcp_packet_t;
  81
  82 typedef struct dhcp_option_t {
  83         uint8_t         code;
  84         uint8_t         length;
  85 } dhcp_option_t;
  86
  87 /*
  88  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        DISCOVER
  89  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         OFFER
  90  *      INADDR_ANY : 68 -> INADDR_BROADCAST : 67        REQUEST
  91  *      INADDR_BROADCAST : 68 <- SERVER_IP : 67         ACK
  92  */
  93 static char const *dhcp_header_names[] = {
  94         "DHCP-Opcode",
  95         "DHCP-Hardware-Type",
  96         "DHCP-Hardware-Address-Length",
  97         "DHCP-Hop-Count",
  98         "DHCP-Transaction-Id",
  99         "DHCP-Number-of-Seconds",
 100         "DHCP-Flags",
 101         "DHCP-Client-IP-Address",
 102         "DHCP-Your-IP-Address",
 103         "DHCP-Server-IP-Address",
 104         "DHCP-Gateway-IP-Address",
 105         "DHCP-Client-Hardware-Address",
 106         "DHCP-Server-Host-Name",
 107         "DHCP-Boot-Filename",
 108
 109         NULL
 110 };
 111
 112 static char const *dhcp_message_types[] = {
 113         "invalid",
 114         "DHCP-Discover",
 115         "DHCP-Offer",
 116         "DHCP-Request",
 117         "DHCP-Decline",
 118         "DHCP-Ack",
 119         "DHCP-NAK",
 120         "DHCP-Release",
 121         "DHCP-Inform",
 122         "DHCP-Force-Renew",
 123 };
 124
 125 static int dhcp_header_sizes[] = {
 126         1, 1, 1, 1,
 127         4, 2, 2, 4,
 128         4, 4, 4,
 129         DHCP_CHADDR_LEN,
 130         DHCP_SNAME_LEN,
 131         DHCP_FILE_LEN
 132 };
 133
 134
 135 /*
 136  *      Some clients silently ignore responses less than 300 bytes.
 137  */
 138 #define MIN_PACKET_SIZE (244)
 139 #define DEFAULT_PACKET_SIZE (300)
 140 #define MAX_PACKET_SIZE (1500 - 40)
 141
 142 #define DHCP_OPTION_FIELD (0)
 143 #define DHCP_FILE_FIELD   (1)
 144 #define DHCP_SNAME_FIELD  (2)
 145
 146 static uint8_t *dhcp_get_option(dhcp_packet_t *packet, size_t packet_size,
 147                                 unsigned int option)
 148 {
 149         int overload = 0;
 150         int field = DHCP_OPTION_FIELD;
 151         size_t where, size;
 152         uint8_t *data;
 153
 154         where = 0;
 155         size = packet_size - offsetof(dhcp_packet_t, options);
 156         data = &packet->options[where];
 157
 158         while (where < size) {
 159                 if (data[0] == 0) { /* padding */
 160                         where++;
 161                         continue;
 162                 }
 163
 164                 if (data[0] == 255) { /* end of options */
 165                         if ((field == DHCP_OPTION_FIELD) &&
 166                             (overload & DHCP_FILE_FIELD)) {
 167                                 data = packet->file;
 168                                 where = 0;
 169                                 size = sizeof(packet->file);
 170                                 field = DHCP_FILE_FIELD;
 171                                 continue;
 172
 173                         } else if ((field == DHCP_FILE_FIELD) &&
 174                                    (overload & DHCP_SNAME_FIELD)) {
 175                                 data = packet->sname;
 176                                 where = 0;
 177                                 size = sizeof(packet->sname);
 178                                 field = DHCP_SNAME_FIELD;
 179                                 continue;
 180                         }
 181
 182                         return NULL;
 183                 }
 184
 185                 /*
 186                  *      We MUST have a real option here.
 187                  */
 188                 if ((where + 2) > size) {
 189                         fr_strerror_printf("Options overflow field at %u",
 190                                            (unsigned int) (data - (uint8_t *) packet));
 191                         return NULL;
 192                 }
 193
 194                 if ((where + 2 + data[1]) > size) {
 195                         fr_strerror_printf("Option length overflows field at %u",
 196                                            (unsigned int) (data - (uint8_t *) packet));
 197                         return NULL;
 198                 }
 199
 200                 if (data[0] == option) return data;
 201
 202                 if (data[0] == 52) { /* overload sname and/or file */
 203                         overload = data[3];
 204                 }
 205
 206                 where += data[1] + 2;
 207                 data += data[1] + 2;
 208         }
 209
 210         return NULL;
 211 }
 212
 213 /*
 214  *      DHCPv4 is only for IPv4.  Broadcast only works if udpfromto is
 215  *      defined.
 216  */
 217 RADIUS_PACKET *fr_dhcp_recv(int sockfd)
 218 {
 219         uint32_t                magic;
 220         struct sockaddr_storage src;
 221         struct sockaddr_storage dst;
 222         socklen_t               sizeof_src;
 223         socklen_t               sizeof_dst;
 224         RADIUS_PACKET           *packet;
 225         int                     port;
 226         uint8_t                 *code;
 227         ssize_t                 data_len;
 228
 229         packet = rad_alloc(NULL, 0);
 230         if (!packet) {
 231                 fr_strerror_printf("Failed allocating packet");
 232                 return NULL;
 233         }
 234
 235         packet->data = talloc_zero_array(packet, uint8_t, MAX_PACKET_SIZE);
 236         if (!packet->data) {
 237                 fr_strerror_printf("Out of memory");
 238                 rad_free(&packet);
 239                 return NULL;
 240         }
 241
 242         packet->sockfd = sockfd;
 243         sizeof_src = sizeof(src);
 244 #ifdef WITH_UDPFROMTO
 245         sizeof_dst = sizeof(dst);
 246         data_len = recvfromto(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 247                               (struct sockaddr *)&src, &sizeof_src,
 248                               (struct sockaddr *)&dst, &sizeof_dst);
 249 #else
 250         data_len = recvfrom(sockfd, packet->data, MAX_PACKET_SIZE, 0,
 251                             (struct sockaddr *)&src, &sizeof_src);
 252 #endif
 253
 254         if (data_len <= 0) {
 255                 fr_strerror_printf("Failed reading DHCP socket: %s", fr_syserror(errno));
 256                 rad_free(&packet);
 257                 return NULL;
 258         }
 259
 260         packet->data_len = data_len;
 261         if (packet->data_len < MIN_PACKET_SIZE) {
 262                 fr_strerror_printf("DHCP packet is too small (%zu < %d)",
 263                                    packet->data_len, MIN_PACKET_SIZE);
 264                 rad_free(&packet);
 265                 return NULL;
 266         }
 267
 268         if (packet->data_len > MAX_PACKET_SIZE) {
 269                 fr_strerror_printf("DHCP packet is too large (%zx > %d)",
 270                                    packet->data_len, MAX_PACKET_SIZE);
 271                 rad_free(&packet);
 272                 return NULL;
 273         }
 274
 275         if (packet->data[1] != 1) {
 276                 fr_strerror_printf("DHCP can only receive ethernet requests, not type %02x",
 277                       packet->data[1]);
 278                 rad_free(&packet);
 279                 return NULL;
 280         }
 281
 282         if (packet->data[2] != 6) {
 283                 fr_strerror_printf("Ethernet HW length is wrong length %d",
 284                         packet->data[2]);
 285                 rad_free(&packet);
 286                 return NULL;
 287         }
 288
 289         memcpy(&magic, packet->data + 236, 4);
 290         magic = ntohl(magic);
 291         if (magic != DHCP_OPTION_MAGIC_NUMBER) {
 292                 fr_strerror_printf("Cannot do BOOTP");
 293                 rad_free(&packet);
 294                 return NULL;
 295         }
 296
 297         /*
 298          *      Create unique keys for the packet.
 299          */
 300         memcpy(&magic, packet->data + 4, 4);
 301         packet->id = ntohl(magic);
 302
 303         code = dhcp_get_option((dhcp_packet_t *) packet->data,
 304                                packet->data_len, 53);
 305         if (!code) {
 306                 fr_strerror_printf("No message-type option was found in the packet");
 307                 rad_free(&packet);
 308                 return NULL;
 309         }
 310
 311         if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
 312                 fr_strerror_printf("Unknown value for message-type option");
 313                 rad_free(&packet);
 314                 return NULL;
 315         }
 316
 317         packet->code = code[2] | PW_DHCP_OFFSET;
 318
 319         /*
 320          *      Create a unique vector from the MAC address and the
 321          *      DHCP opcode.  This is a hack for the RADIUS
 322          *      infrastructure in the rest of the server.
 323          *
 324          *      Note: packet->data[2] == 6, which is smaller than
 325          *      sizeof(packet->vector)
 326          *
 327          *      FIXME:  Look for client-identifier in packet,
 328          *      and use that, too?
 329          */
 330         memset(packet->vector, 0, sizeof(packet->vector));
 331         memcpy(packet->vector, packet->data + 28, packet->data[2]);
 332         packet->vector[packet->data[2]] = packet->code & 0xff;
 333
 334         /*
 335          *      FIXME: for DISCOVER / REQUEST: src_port == dst_port + 1
 336          *      FIXME: for OFFER / ACK       : src_port = dst_port - 1
 337          */
 338
 339         /*
 340          *      Unique keys are xid, client mac, and client ID?
 341          */
 342
 343         /*
 344          *      FIXME: More checks, like DHCP packet type?
 345          */
 346
 347         sizeof_dst = sizeof(dst);
 348
 349 #ifndef WITH_UDPFROMTO
 350         /*
 351          *      This should never fail...
 352          */
 353         if (getsockname(sockfd, (struct sockaddr *) &dst, &sizeof_dst) < 0) {
 354                 fr_strerror_printf("getsockname failed: %s", fr_syserror(errno));
 355                 rad_free(&packet);
 356                 return NULL;
 357         }
 358 #endif
 359
 360         fr_sockaddr2ipaddr(&dst, sizeof_dst, &packet->dst_ipaddr, &port);
 361         packet->dst_port = port;
 362
 363         fr_sockaddr2ipaddr(&src, sizeof_src, &packet->src_ipaddr, &port);
 364         packet->src_port = port;
 365
 366         if (fr_debug_flag > 1) {
 367                 char type_buf[64];
 368                 char const *name = type_buf;
 369                 char src_ip_buf[256], dst_ip_buf[256];
 370
 371                 if ((packet->code >= PW_DHCP_DISCOVER) &&
 372                     (packet->code <= PW_DHCP_INFORM)) {
 373                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
 374                 } else {
 375                         snprintf(type_buf, sizeof(type_buf), "%d",
 376                                  packet->code - PW_DHCP_OFFSET);
 377                 }
 378
 379                 DEBUG("Received %s of id %08x from %s:%d to %s:%d\n",
 380                        name, (unsigned int) packet->id,
 381                        inet_ntop(packet->src_ipaddr.af,
 382                                  &packet->src_ipaddr.ipaddr,
 383                                  src_ip_buf, sizeof(src_ip_buf)),
 384                        packet->src_port,
 385                        inet_ntop(packet->dst_ipaddr.af,
 386                                  &packet->dst_ipaddr.ipaddr,
 387                                  dst_ip_buf, sizeof(dst_ip_buf)),
 388                        packet->dst_port);
 389         }
 390
 391         return packet;
 392 }
 393
 394
 395 /*
 396  *      Send a DHCP packet.
 397  */
 398 int fr_dhcp_send(RADIUS_PACKET *packet)
 399 {
 400         struct sockaddr_storage dst;
 401         socklen_t               sizeof_dst;
 402 #ifdef WITH_UDPFROMTO
 403         struct sockaddr_storage src;
 404         socklen_t               sizeof_src;
 405
 406         fr_ipaddr2sockaddr(&packet->src_ipaddr, packet->src_port,
 407             &src, &sizeof_src);
 408 #endif
 409
 410         fr_ipaddr2sockaddr(&packet->dst_ipaddr, packet->dst_port,
 411                            &dst, &sizeof_dst);
 412
 413         if (packet->data_len == 0) {
 414                 fr_strerror_printf("No data to send");
 415                 return -1;
 416         }
 417
 418         if (fr_debug_flag > 1) {
 419                 char type_buf[64];
 420                 char const *name = type_buf;
 421 #ifdef WITH_UDPFROMTO
 422                 char src_ip_buf[INET6_ADDRSTRLEN];
 423 #endif
 424                 char dst_ip_buf[INET6_ADDRSTRLEN];
 425
 426                 if ((packet->code >= PW_DHCP_DISCOVER) &&
 427                     (packet->code <= PW_DHCP_INFORM)) {
 428                         name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
 429                 } else {
 430                         snprintf(type_buf, sizeof(type_buf), "%d",
 431                             packet->code - PW_DHCP_OFFSET);
 432                 }
 433
 434                 DEBUG(
 435 #ifdef WITH_UDPFROMTO
 436                 "Sending %s of id %08x from %s:%d to %s:%d\n",
 437 #else
 438                 "Sending %s of id %08x to %s:%d\n",
 439 #endif
 440                    name, (unsigned int) packet->id,
 441 #ifdef WITH_UDPFROMTO
 442                    inet_ntop(packet->src_ipaddr.af, &packet->src_ipaddr.ipaddr, src_ip_buf, sizeof(src_ip_buf)),
 443                    packet->src_port,
 444 #endif
 445                    inet_ntop(packet->dst_ipaddr.af, &packet->dst_ipaddr.ipaddr, dst_ip_buf, sizeof(dst_ip_buf)),
 446                    packet->dst_port);
 447         }
 448
 449 #ifndef WITH_UDPFROMTO
 450         /*
 451          *      Assume that the packet is encoded before sending it.
 452          */
 453         return sendto(packet->sockfd, packet->data, packet->data_len, 0,
 454                       (struct sockaddr *)&dst, sizeof_dst);
 455 #else
 456
 457         return sendfromto(packet->sockfd, packet->data, packet->data_len, 0,
 458                           (struct sockaddr *)&src, sizeof_src,
 459                           (struct sockaddr *)&dst, sizeof_dst);
 460 #endif
 461 }
 462
 463 static int fr_dhcp_attr2vp(RADIUS_PACKET *packet, VALUE_PAIR *vp, uint8_t const *p, size_t alen);
 464
 465 static int decode_tlv(RADIUS_PACKET *packet, VALUE_PAIR *tlv, uint8_t const *data, size_t data_len)
 466 {
 467         uint8_t const *p;
 468         VALUE_PAIR *head, *vp;
 469         vp_cursor_t cursor;
 470
 471         /*
 472          *      Take a pass at parsing it.
 473          */
 474         p = data;
 475         while (p < (data + data_len)) {
 476                 if ((p + 2) > (data + data_len)) goto make_tlv;
 477
 478                 if ((p + p[1] + 2) > (data + data_len)) goto make_tlv;
 479                 p += 2 + p[1];
 480         }
 481
 482         /*
 483          *      Got here... must be well formed.
 484          */
 485         head = NULL;
 486         paircursor(&cursor, &head);
 487
 488         p = data;
 489         while (p < (data + data_len)) {
 490                 vp = paircreate(packet, tlv->da->attr | (p[0] << 8), DHCP_MAGIC_VENDOR);
 491                 if (!vp) {
 492                         pairfree(&head);
 493                         goto make_tlv;
 494                 }
 495
 496                 if (fr_dhcp_attr2vp(packet, vp, p + 2, p[1]) < 0) {
 497                         pairfree(&head);
 498                         goto make_tlv;
 499                 }
 500
 501                 pairinsert(&cursor, vp);
 502                 p += 2 + p[1];
 503         }
 504
 505         /*
 506          *      The caller allocated TLV, so we need to copy the FIRST
 507          *      attribute over top of that.
 508          */
 509         if (head) {
 510                 memcpy(tlv, head, sizeof(*tlv));
 511                 head->next = NULL;
 512                 pairfree(&head);
 513         }
 514
 515         return 0;
 516
 517 make_tlv:
 518         tlv->vp_tlv = talloc_array(tlv, uint8_t, data_len);
 519         if (!tlv->vp_tlv) {
 520                 fr_strerror_printf("No memory");
 521                 return -1;
 522         }
 523         memcpy(tlv->vp_tlv, data, data_len);
 524         tlv->length = data_len;
 525
 526         return 0;
 527 }
 528
 529
 530 /*
 531  *      Decode ONE value into a VP
 532  */
 533 static int fr_dhcp_attr2vp(RADIUS_PACKET *packet, VALUE_PAIR *vp, uint8_t const *p, size_t alen)
 534 {
 535         char *q;
 536
 537         switch (vp->da->type) {
 538         case PW_TYPE_BYTE:
 539                 if (alen != 1) goto raw;
 540                 vp->vp_integer = p[0];
 541                 break;
 542
 543         case PW_TYPE_SHORT:
 544                 if (alen != 2) goto raw;
 545                 memcpy(&vp->vp_integer, p, 2);
 546                 vp->vp_integer = ntohs(vp->vp_integer);
 547                 break;
 548
 549         case PW_TYPE_INTEGER:
 550                 if (alen != 4) goto raw;
 551                 memcpy(&vp->vp_integer, p, 4);
 552                 vp->vp_integer = ntohl(vp->vp_integer);
 553                 break;
 554
 555         case PW_TYPE_IPADDR:
 556                 if (alen != 4) goto raw;
 557                 /*
 558                  *      Keep value in Network Order!
 559                  */
 560                 memcpy(&vp->vp_ipaddr, p , 4);
 561                 vp->length = 4;
 562                 break;
 563
 564         case PW_TYPE_STRING:
 565                 vp->vp_strvalue = q = talloc_array(vp, char, alen + 1);
 566                 vp->type = VT_DATA;
 567                 memcpy(q, p , alen);
 568                 q[alen] = '\0';
 569                 break;
 570
 571         case PW_TYPE_ETHERNET:
 572                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 573                 vp->length = sizeof(vp->vp_ether);
 574                 break;
 575
 576         /*
 577          *      Value doesn't match up with attribute type, overwrite the
 578          *      vp's original DICT_ATTR with an unknown one.
 579          */
 580         raw:
 581                 if (pair2unknown(vp) < 0) return -1;
 582
 583         case PW_TYPE_OCTETS:
 584                 if (alen > 253) return -1;
 585                 pairmemcpy(vp, p, alen);
 586                 break;
 587
 588         case PW_TYPE_TLV:
 589                 return decode_tlv(packet, vp, p, alen);
 590
 591         default:
 592                 fr_strerror_printf("Internal sanity check %d %d", vp->da->type, __LINE__);
 593                 return -1;
 594         } /* switch over type */
 595
 596         vp->length = alen;
 597         return 0;
 598 }
 599
 600 ssize_t fr_dhcp_decode_options(RADIUS_PACKET *packet,
 601                                uint8_t const *data, size_t len, VALUE_PAIR **head)
 602 {
 603         int i;
 604         VALUE_PAIR *vp;
 605         vp_cursor_t cursor;
 606         uint8_t const *p, *next;
 607         next = data;
 608
 609         *head = NULL;
 610         paircursor(&cursor, head);
 611
 612         /*
 613          *      FIXME: This should also check sname && file fields.
 614          *      See the dhcp_get_option() function above.
 615          */
 616         while (next < (data + len)) {
 617                 int num_entries, alen;
 618                 DICT_ATTR const *da;
 619
 620                 p = next;
 621
 622                 if (*p == 0) break;
 623                 if (*p == 255) break; /* end of options signifier */
 624                 if ((p + 2) > (data + len)) break;
 625
 626                 next = p + 2 + p[1];
 627
 628                 if (p[1] >= 253) {
 629                         fr_strerror_printf("Attribute too long %u %u",
 630                                            p[0], p[1]);
 631                         continue;
 632                 }
 633
 634                 da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
 635                 if (!da) {
 636                         fr_strerror_printf("Attribute not in our dictionary: %u",
 637                                            p[0]);
 638                         continue;
 639                 }
 640
 641                 vp = NULL;
 642                 num_entries = 1;
 643                 alen = p[1];
 644                 p += 2;
 645
 646                 /*
 647                  *      Could be an array of bytes, integers, etc.
 648                  */
 649                 if (da->flags.array) {
 650                         switch (da->type) {
 651                         case PW_TYPE_BYTE:
 652                                 num_entries = alen;
 653                                 alen = 1;
 654                                 break;
 655
 656                         case PW_TYPE_SHORT: /* ignore any trailing data */
 657                                 num_entries = alen >> 1;
 658                                 alen = 2;
 659                                 break;
 660
 661                         case PW_TYPE_IPADDR:
 662                         case PW_TYPE_INTEGER:
 663                         case PW_TYPE_DATE: /* ignore any trailing data */
 664                                 num_entries = alen >> 2;
 665                                 alen = 4;
 666                                 break;
 667
 668                         default:
 669
 670                                 break; /* really an internal sanity failure */
 671                         }
 672                 }
 673
 674                 /*
 675                  *      Loop over all of the entries, building VPs
 676                  */
 677                 for (i = 0; i < num_entries; i++) {
 678                         vp = pairmake(packet, NULL, da->name, NULL, T_OP_ADD);
 679                         if (!vp) {
 680                                 fr_strerror_printf("Cannot build attribute %s",
 681                                         fr_strerror());
 682                                 pairfree(head);
 683                                 return -1;
 684                         }
 685
 686                         /*
 687                          *      Hack for ease of use.
 688                          */
 689                         if ((da->vendor == DHCP_MAGIC_VENDOR) &&
 690                             (da->attr == 61) && !da->flags.array &&
 691                             (alen == 7) && (*p == 1) && (num_entries == 1)) {
 692                                 pairmemcpy(vp, p + 1, 6);
 693
 694                         } else if (fr_dhcp_attr2vp(packet, vp, p, alen) < 0) {
 695                                 pairfree(&vp);
 696                                 pairfree(head);
 697                                 return -1;
 698                         }
 699
 700                         pairinsert(&cursor, vp);
 701
 702                         for (vp = paircurrent(&cursor);
 703                              vp;
 704                              vp = pairnext(&cursor)) {
 705                                 debug_pair(vp);
 706                         }
 707                         p += alen;
 708                 } /* loop over array entries */
 709         } /* loop over the entire packet */
 710
 711         return next - data;
 712 }
 713
 714 int fr_dhcp_decode(RADIUS_PACKET *packet)
 715 {
 716         size_t i;
 717         uint8_t *p;
 718         uint32_t giaddr;
 719         vp_cursor_t cursor;
 720         VALUE_PAIR *head = NULL, *vp;
 721         VALUE_PAIR *maxms, *mtu;
 722
 723         paircursor(&cursor, &head);
 724         p = packet->data;
 725
 726         if ((fr_debug_flag > 2) && fr_log_fp) {
 727                 for (i = 0; i < packet->data_len; i++) {
 728                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
 729                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
 730                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 731                 }
 732                 fprintf(fr_log_fp, "\n");
 733         }
 734
 735         if (packet->data[1] != 1) {
 736                 fr_strerror_printf("Packet is not Ethernet: %u",
 737                       packet->data[1]);
 738                 return -1;
 739         }
 740
 741         /*
 742          *      Decode the header.
 743          */
 744         for (i = 0; i < 14; i++) {
 745                 char *q;
 746
 747                 vp = pairmake(packet, NULL, dhcp_header_names[i], NULL, T_OP_EQ);
 748                 if (!vp) {
 749                         char buffer[256];
 750                         strlcpy(buffer, fr_strerror(), sizeof(buffer));
 751                         fr_strerror_printf("Cannot decode packet due to internal error: %s", buffer);
 752                         pairfree(&head);
 753                         return -1;
 754                 }
 755
 756                 /*
 757                  *      If chaddr does != 6 bytes it's probably not ethernet, and we should store
 758                  *      it as an opaque type (octets).
 759                  */
 760                 if ((i == 11) && (packet->data[1] == 1) && (packet->data[2] != sizeof(vp->vp_ether))) {
 761                         DICT_ATTR const *da = dict_attrunknown(vp->da->attr, vp->da->vendor, true);
 762                         if (!da) {
 763                                 return -1;
 764                         }
 765                         vp->da = da;
 766                 }
 767
 768                 switch (vp->da->type) {
 769                 case PW_TYPE_BYTE:
 770                         vp->vp_integer = p[0];
 771                         vp->length = 1;
 772                         break;
 773
 774                 case PW_TYPE_SHORT:
 775                         vp->vp_integer = (p[0] << 8) | p[1];
 776                         vp->length = 2;
 777                         break;
 778
 779                 case PW_TYPE_INTEGER:
 780                         memcpy(&vp->vp_integer, p, 4);
 781                         vp->vp_integer = ntohl(vp->vp_integer);
 782                         vp->length = 4;
 783                         break;
 784
 785                 case PW_TYPE_IPADDR:
 786                         memcpy(&vp->vp_ipaddr, p, 4);
 787                         vp->length = 4;
 788                         break;
 789
 790                 case PW_TYPE_STRING:
 791                         vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
 792                         vp->type = VT_DATA;
 793                         memcpy(q, p, dhcp_header_sizes[i]);
 794                         q[dhcp_header_sizes[i]] = '\0';
 795                         vp->length = strlen(vp->vp_strvalue);
 796                         if (vp->length == 0) {
 797                                 pairfree(&vp);
 798                         }
 799                         break;
 800
 801                 case PW_TYPE_OCTETS:
 802                         pairmemcpy(vp, p, packet->data[2]);
 803                         break;
 804
 805                 case PW_TYPE_ETHERNET:
 806                         memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 807                         vp->length = sizeof(vp->vp_ether);
 808                         break;
 809
 810                 default:
 811                         fr_strerror_printf("BAD TYPE %d", vp->da->type);
 812                         pairfree(&vp);
 813                         break;
 814                 }
 815                 p += dhcp_header_sizes[i];
 816
 817                 if (!vp) continue;
 818
 819                 debug_pair(vp);
 820                 pairinsert(&cursor, vp);
 821         }
 822
 823         /*
 824          *      Loop over the options.
 825          */
 826
 827         /*
 828          *      Nothing uses tail after this call, if it does in the future
 829          *      it'll need to find the new tail...
 830          */
 831         {
 832                 VALUE_PAIR *options = NULL;
 833
 834                 if (fr_dhcp_decode_options(packet,
 835                                            packet->data + 240, packet->data_len - 240,
 836                                            &options) < 0) {
 837                         return -1;
 838                 }
 839
 840                 if (options) {
 841                         pairinsert(&cursor, options);
 842                 }
 843         }
 844
 845         /*
 846          *      If DHCP request, set ciaddr to zero.
 847          */
 848
 849         /*
 850          *      Set broadcast flag for broken vendors, but only if
 851          *      giaddr isn't set.
 852          */
 853         memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
 854         if (giaddr == htonl(INADDR_ANY)) {
 855                 /*
 856                  *      DHCP Opcode is request
 857                  */
 858                 vp = pairfind(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
 859                 if (vp && vp->vp_integer == 3) {
 860                         /*
 861                          *      Vendor is "MSFT 98"
 862                          */
 863                         vp = pairfind(head, 63, DHCP_MAGIC_VENDOR, TAG_ANY);
 864                         if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
 865                                 vp = pairfind(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
 866
 867                                 /*
 868                                  *      Reply should be broadcast.
 869                                  */
 870                                 if (vp) vp->vp_integer |= 0x8000;
 871                                 packet->data[10] |= 0x80;
 872                         }
 873                 }
 874         }
 875
 876         /*
 877          *      FIXME: Nuke attributes that aren't used in the normal
 878          *      header for discover/requests.
 879          */
 880         packet->vps = head;
 881
 882         /*
 883          *      Client can request a LARGER size, but not a smaller
 884          *      one.  They also cannot request a size larger than MTU.
 885          */
 886         maxms = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
 887         mtu = pairfind(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
 888
 889         if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
 890                 fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
 891                 return -1;
 892         }
 893
 894         if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
 895                 fr_strerror_printf("DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
 896                 maxms->vp_integer = DEFAULT_PACKET_SIZE;
 897         }
 898
 899         if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
 900                 fr_strerror_printf("DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
 901                 maxms->vp_integer = mtu->vp_integer;
 902         }
 903
 904         if (fr_debug_flag) fflush(stdout);
 905
 906         return 0;
 907 }
 908
 909
 910 static int attr_cmp(void const *one, void const *two)
 911 {
 912         VALUE_PAIR const * const *a = one;
 913         VALUE_PAIR const * const *b = two;
 914
 915         /*
 916          *      DHCP-Message-Type is first, for simplicity.
 917          */
 918         if (((*a)->da->attr == 53) &&
 919             (*b)->da->attr != 53) return -1;
 920
 921         /*
 922          *      Relay-Agent is last
 923          */
 924         if (((*a)->da->attr == 82) &&
 925             (*b)->da->attr != 82) return 1;
 926
 927         return ((*a)->da->attr - (*b)->da->attr);
 928 }
 929
 930 /*
 931  * @todo Check room!
 932  */
 933 static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, UNUSED size_t room)
 934 {
 935         size_t length;
 936         uint32_t lvalue;
 937
 938         /*
 939          *      Search for all attributes of the same
 940          *      type, and pack them into the same
 941          *      attribute.
 942          */
 943         switch (vp->da->type) {
 944         case PW_TYPE_BYTE:
 945                 length = 1;
 946                 *p = vp->vp_integer & 0xff;
 947                 break;
 948
 949         case PW_TYPE_SHORT:
 950                 length = 2;
 951                 p[0] = (vp->vp_integer >> 8) & 0xff;
 952                 p[1] = vp->vp_integer & 0xff;
 953                 break;
 954
 955         case PW_TYPE_INTEGER:
 956                 length = 4;
 957                 lvalue = htonl(vp->vp_integer);
 958                 memcpy(p, &lvalue, 4);
 959                 break;
 960
 961         case PW_TYPE_IPADDR:
 962                 length = 4;
 963                 memcpy(p, &vp->vp_ipaddr, 4);
 964                 break;
 965
 966         case PW_TYPE_ETHERNET:
 967                 length = 6;
 968                 memcpy(p, &vp->vp_ether, 6);
 969                 break;
 970
 971         case PW_TYPE_STRING:
 972                 memcpy(p, vp->vp_strvalue, vp->length);
 973                 length = vp->length;
 974                 break;
 975
 976         case PW_TYPE_TLV:       /* FIXME: split it on 255? */
 977                 memcpy(p, vp->vp_tlv, vp->length);
 978                 length = vp->length;
 979                 break;
 980
 981         case PW_TYPE_OCTETS:
 982                 memcpy(p, vp->vp_octets, vp->length);
 983                 length = vp->length;
 984                 break;
 985
 986         default:
 987                 fr_strerror_printf("BAD TYPE2 %d", vp->da->type);
 988                 length = 0;
 989                 break;
 990         }
 991
 992         return length;
 993 }
 994
 995 static VALUE_PAIR *fr_dhcp_vp2suboption(RADIUS_PACKET *packet, VALUE_PAIR *vps)
 996 {
 997         int length;
 998         unsigned int attribute;
 999         uint8_t *ptr;
1000         vp_cursor_t cursor;
1001         VALUE_PAIR *vp, *tlv;
1002
1003         attribute = vps->da->attr & 0xffff00ff;
1004
1005         tlv = paircreate(packet, attribute, DHCP_MAGIC_VENDOR);
1006         if (!tlv) return NULL;
1007
1008         tlv->length = 0;
1009         for (vp = paircursor(&cursor, &vps);
1010              vp;
1011              vp = pairnext(&cursor)) {
1012                 /*
1013                  *      Group the attributes ONLY until we see a
1014                  *      non-TLV attribute.
1015                  */
1016                 if (!vp->da->flags.is_tlv ||
1017                     vp->da->flags.extended ||
1018                     ((vp->da->attr & 0xffff00ff) != attribute)) {
1019                         break;
1020                 }
1021
1022                 tlv->length += vp->length + 2;
1023         }
1024
1025         if (!tlv->length) {
1026                 pairfree(&tlv);
1027                 return NULL;
1028         }
1029
1030         tlv->vp_tlv = talloc_array(tlv, uint8_t, tlv->length);
1031         if (!tlv->vp_tlv) {
1032                 pairfree(&tlv);
1033                 return NULL;
1034         }
1035
1036         ptr = tlv->vp_tlv;
1037         for (vp = paircursor(&cursor, &vps);
1038              vp;
1039              vp = pairnext(&cursor)) {
1040                 if (!vp->da->flags.is_tlv ||
1041                     vp->da->flags.extended ||
1042                     ((vp->da->attr & 0xffff00ff) != attribute)) {
1043                         break;
1044                 }
1045
1046                 length = fr_dhcp_vp2attr(vp, ptr + 2,
1047                                          tlv->vp_tlv + tlv->length - ptr);
1048                 if (length > 255) {
1049                         pairfree(&tlv);
1050                         return NULL;
1051                 }
1052
1053                 /*
1054                  *      Pack the attribute.
1055                  */
1056                 ptr[0] = (vp->da->attr & 0xff00) >> 8;
1057                 ptr[1] = length;
1058
1059                 ptr += length + 2;
1060         }
1061
1062         return tlv;
1063 }
1064
1065
1066 int fr_dhcp_encode(RADIUS_PACKET *packet)
1067 {
1068         unsigned int i, num_vps;
1069         uint8_t *p;
1070         vp_cursor_t cursor;
1071         VALUE_PAIR *vp;
1072         uint32_t lvalue;
1073         size_t dhcp_size, length;
1074 #ifndef NDEBUG
1075         char const *name;
1076 #  ifdef WITH_UDPFROMTO
1077         char src_ip_buf[256];
1078 #  endif
1079         char dst_ip_buf[256];
1080 #endif
1081
1082         if (packet->data) return 0;
1083
1084         packet->data_len = MAX_PACKET_SIZE;
1085         packet->data = talloc_zero_array(packet, uint8_t, packet->data_len);
1086
1087         /* XXX Ugly ... should be set by the caller */
1088         if (packet->code == 0) packet->code = PW_DHCP_NAK;
1089
1090 #ifndef NDEBUG
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                 name = "?Unknown?";
1096         }
1097
1098         DEBUG(
1099 #ifdef WITH_UDPFROMTO
1100               "Encoding %s of id %08x from %s:%d to %s:%d\n",
1101 #else
1102               "Encoding %s of id %08x to %s:%d\n",
1103 #endif
1104               name, (unsigned int) packet->id,
1105 #ifdef WITH_UDPFROMTO
1106               inet_ntop(packet->src_ipaddr.af,
1107                         &packet->src_ipaddr.ipaddr,
1108                         src_ip_buf, sizeof(src_ip_buf)),
1109               packet->src_port,
1110 #endif
1111               inet_ntop(packet->dst_ipaddr.af,
1112                         &packet->dst_ipaddr.ipaddr,
1113                      dst_ip_buf, sizeof(dst_ip_buf)),
1114               packet->dst_port);
1115 #endif
1116
1117         p = packet->data;
1118
1119         /*
1120          *      @todo: Make this work again.
1121          */
1122 #if 0
1123         mms = DEFAULT_PACKET_SIZE; /* maximum message size */
1124
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
1131         /* DHCP-DHCP-Maximum-Msg-Size */
1132         vp = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
1133         if (vp && (vp->vp_integer > mms)) {
1134                 mms = vp->vp_integer;
1135
1136                 if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
1137         }
1138 #endif
1139
1140         vp = pairfind(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
1141         if (vp) {
1142                 *p++ = vp->vp_integer & 0xff;
1143         } else {
1144                 *p++ = 1;       /* client message */
1145         }
1146
1147         /* DHCP-Hardware-Type */
1148         if ((vp = pairfind(packet->vps, 257, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1149                 *p++ = vp->vp_integer & 0xFF;
1150         } else {
1151                 *p++ = 1;               /* hardware type = ethernet */
1152         }
1153
1154         /* DHCP-Hardware-Address-Length */
1155         if ((vp = pairfind(packet->vps, 258, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1156                 *p++ = vp->vp_integer & 0xFF;
1157         } else {
1158                 *p++ = 6;               /* 6 bytes of ethernet */
1159         }
1160
1161         /* DHCP-Hop-Count */
1162         if ((vp = pairfind(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1163                 *p = vp->vp_integer & 0xff;
1164         }
1165         p++;
1166
1167         /* DHCP-Transaction-Id */
1168         if ((vp = pairfind(packet->vps, 260, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1169                 lvalue = htonl(vp->vp_integer);
1170         } else {
1171                 lvalue = fr_rand();
1172         }
1173         memcpy(p, &lvalue, 4);
1174         p += 4;
1175
1176         /* DHCP-Number-of-Seconds */
1177         if ((vp = pairfind(packet->vps, 261, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1178                 lvalue = htonl(vp->vp_integer);
1179                 memcpy(p, &lvalue, 2);
1180         }
1181         p += 2;
1182
1183         /* DHCP-Flags */
1184         if ((vp = pairfind(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1185                 lvalue = htons(vp->vp_integer);
1186                 memcpy(p, &lvalue, 2);
1187         }
1188         p += 2;
1189
1190         /* DHCP-Client-IP-Address */
1191         if ((vp = pairfind(packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1192                 memcpy(p, &vp->vp_ipaddr, 4);
1193         }
1194         p += 4;
1195
1196         /* DHCP-Your-IP-address */
1197         if ((vp = pairfind(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1198                 lvalue = vp->vp_ipaddr;
1199         } else {
1200                 lvalue = htonl(INADDR_ANY);
1201         }
1202         memcpy(p, &lvalue, 4);
1203         p += 4;
1204
1205         /* DHCP-Server-IP-Address */
1206         vp = pairfind(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY);
1207
1208         /* DHCP-DHCP-Server-Identifier */
1209         if (!vp && (vp = pairfind(packet->vps, 54, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1210                 lvalue = vp->vp_ipaddr;
1211         } else {
1212                 lvalue = htonl(INADDR_ANY);
1213         }
1214         memcpy(p, &lvalue, 4);
1215         p += 4;
1216
1217         /*
1218          *      DHCP-Gateway-IP-Address
1219          */
1220         if ((vp = pairfind(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1221                 lvalue = vp->vp_ipaddr;
1222         } else {
1223                 lvalue = htonl(INADDR_ANY);
1224         }
1225         memcpy(p, &lvalue, 4);
1226         p += 4;
1227
1228         /* DHCP-Client-Hardware-Address */
1229         if ((vp = pairfind(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1230                 if (vp->length == sizeof(vp->vp_ether)) {
1231                         memcpy(p, vp->vp_ether, vp->length);
1232                 } /* else ignore it */
1233         }
1234         p += DHCP_CHADDR_LEN;
1235
1236         /* DHCP-Server-Host-Name */
1237         if ((vp = pairfind(packet->vps, 268, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1238                 if (vp->length > DHCP_SNAME_LEN) {
1239                         memcpy(p, vp->vp_strvalue, DHCP_SNAME_LEN);
1240                 } else {
1241                         memcpy(p, vp->vp_strvalue, vp->length);
1242                 }
1243         }
1244         p += DHCP_SNAME_LEN;
1245
1246         /*
1247          *      Copy over DHCP-Boot-Filename.
1248          *
1249          *      FIXME: This copy should be delayed until AFTER the options
1250          *      have been processed.  If there are too many options for
1251          *      the packet, then they go into the sname && filename fields.
1252          *      When that happens, the boot filename is passed as an option,
1253          *      instead of being placed verbatim in the filename field.
1254          */
1255
1256         /* DHCP-Boot-Filename */
1257         if ((vp = pairfind(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1258                 if (vp->length > DHCP_FILE_LEN) {
1259                         memcpy(p, vp->vp_strvalue, DHCP_FILE_LEN);
1260                 } else {
1261                         memcpy(p, vp->vp_strvalue, vp->length);
1262                 }
1263         }
1264         p += DHCP_FILE_LEN;
1265
1266         /* DHCP magic number */
1267         lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER);
1268         memcpy(p, &lvalue, 4);
1269         p += 4;
1270
1271         /*
1272          *      Print the header.
1273          */
1274         if (fr_debug_flag > 1) {
1275                 uint8_t *pp = p;
1276
1277                 p = packet->data;
1278
1279                 for (i = 0; i < 14; i++) {
1280                         char *q;
1281
1282                         vp = pairmake(packet, NULL,
1283                                       dhcp_header_names[i], NULL, T_OP_EQ);
1284                         if (!vp) {
1285                                 char buffer[256];
1286                                 strlcpy(buffer, fr_strerror(), sizeof(buffer));
1287                                 fr_strerror_printf("Cannot decode packet due to internal error: %s", buffer);
1288                                 return -1;
1289                         }
1290
1291                         switch (vp->da->type) {
1292                         case PW_TYPE_BYTE:
1293                                 vp->vp_integer = p[0];
1294                                 vp->length = 1;
1295                                 break;
1296
1297                         case PW_TYPE_SHORT:
1298                                 vp->vp_integer = (p[0] << 8) | p[1];
1299                                 vp->length = 2;
1300                                 break;
1301
1302                         case PW_TYPE_INTEGER:
1303                                 memcpy(&vp->vp_integer, p, 4);
1304                                 vp->vp_integer = ntohl(vp->vp_integer);
1305                                 vp->length = 4;
1306                                 break;
1307
1308                         case PW_TYPE_IPADDR:
1309                                 memcpy(&vp->vp_ipaddr, p, 4);
1310                                 vp->length = 4;
1311                                 break;
1312
1313                         case PW_TYPE_STRING:
1314                                 vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
1315                                 vp->type = VT_DATA;
1316                                 memcpy(q, p, dhcp_header_sizes[i]);
1317                                 q[dhcp_header_sizes[i]] = '\0';
1318                                 vp->length = strlen(vp->vp_strvalue);
1319                                 break;
1320
1321                         case PW_TYPE_OCTETS: /* only for Client HW Address */
1322                                 pairmemcpy(vp, p, packet->data[2]);
1323                                 break;
1324
1325                         case PW_TYPE_ETHERNET: /* only for Client HW Address */
1326                                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
1327                                 vp->length = sizeof(vp->vp_ether);
1328                                 break;
1329
1330                         default:
1331                                 fr_strerror_printf("Internal sanity check failed %d %d", vp->da->type, __LINE__);
1332                                 pairfree(&vp);
1333                                 break;
1334                         }
1335
1336                         p += dhcp_header_sizes[i];
1337
1338                         debug_pair(vp);
1339                         pairfree(&vp);
1340                 }
1341
1342                 /*
1343                  *      Jump over DHCP magic number, response, etc.
1344                  */
1345                 p = pp;
1346         }
1347
1348         /*
1349          *      Before packing the attributes, re-order them so that
1350          *      the array ones are all contiguous.  This simplifies
1351          *      the later code.
1352          */
1353         num_vps = 0;
1354         for (vp = paircursor(&cursor, &packet->vps);
1355              vp;
1356              vp = pairnext(&cursor)) {
1357                 num_vps++;
1358         }
1359         if (num_vps > 1) {
1360                 VALUE_PAIR **array;
1361
1362                 array = talloc_array(packet, VALUE_PAIR*, num_vps);
1363
1364                 i = 0;
1365                 for (vp = paircursor(&cursor, &packet->vps);
1366                      vp;
1367                      vp = pairnext(&cursor)) {
1368                         array[i++] = vp;
1369                 }
1370
1371                 /*
1372                  *      Sort the attributes.
1373                  */
1374                 qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *), attr_cmp);
1375
1376                 packet->vps = NULL;
1377                 paircursor(&cursor, &packet->vps);
1378                 for (i = 0; i < num_vps; i++) {
1379                         array[i]->next = NULL;
1380                         pairinsert(&cursor, array[i]);
1381                 }
1382                 talloc_free(array);
1383         }
1384
1385         p[0] = 0x35;            /* DHCP-Message-Type */
1386         p[1] = 1;
1387         p[2] = packet->code - PW_DHCP_OFFSET;
1388         p += 3;
1389
1390         /*
1391          *      Pack in the attributes.
1392          */
1393         vp = packet->vps;
1394         while (vp) {
1395                 unsigned int num_entries = 1;
1396                 VALUE_PAIR *same;
1397                 uint8_t *plength;
1398
1399                 if (vp->da->vendor != DHCP_MAGIC_VENDOR) goto next;
1400                 if (vp->da->attr == 53) goto next; /* already done */
1401                 if ((vp->da->attr > 255) &&
1402                     (DHCP_BASE_ATTR(vp->da->attr) != PW_DHCP_OPTION_82)) goto next;
1403
1404                 debug_pair(vp);
1405                 if (vp->da->flags.extended) goto next;
1406
1407                 for (same = paircursor(&cursor, &vp->next);
1408                      same;
1409                      same = pairnext(&cursor)) {
1410                         if (same->da->attr != vp->da->attr) break;
1411                         num_entries++;
1412                 }
1413
1414                 /*
1415                  *      For client-identifier
1416                  * @todo What's this meant to be doing?!
1417                  */
1418 #if 0
1419                 if ((vp->da->type == PW_TYPE_ETHERNET) &&
1420                     (vp->length == 6) &&
1421                     (num_entries == 1)) {
1422                         vp->da->type = PW_TYPE_OCTETS;
1423                         memmove(vp->vp_octets + 1, vp->vp_octets, 6);
1424                         vp->vp_octets[0] = 1;
1425                 }
1426 #endif
1427                 *(p++) = vp->da->attr & 0xff;
1428                 plength = p;
1429                 *(p++) = 0;     /* header isn't included in attr length */
1430
1431                 for (i = 0; i < num_entries; i++) {
1432                         if (i != 0) debug_pair(vp);
1433
1434                         if (vp->da->flags.is_tlv) {
1435                                 VALUE_PAIR *tlv;
1436
1437                                 /*
1438                                  *      Should NOT have been encoded yet!
1439                                  */
1440                                 tlv = fr_dhcp_vp2suboption(packet, vp);
1441
1442                                 /*
1443                                  *      Ignore it if there's an issue
1444                                  *      encoding it.
1445                                  */
1446                                 if (!tlv) goto next;
1447
1448                                 tlv->next = vp->next;
1449                                 vp->next = tlv;
1450                                 vp = tlv;
1451                         }
1452
1453                         length = fr_dhcp_vp2attr(vp, p, 0);
1454
1455                         /*
1456                          *      This will never happen due to FreeRADIUS
1457                          *      limitations: sizeof(vp->vp_octets) < 255
1458                          */
1459                         if (length > 255) {
1460                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1461                                 break;
1462                         }
1463
1464                         /*
1465                          *      More than one attribute of the same type
1466                          *      in a row: they are packed together
1467                          *      into the same TLV.  If we overflow,
1468                          *      go bananas!
1469                          */
1470                         if ((*plength + length) > 255) {
1471                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1472                                 break;
1473                         }
1474
1475                         *plength += length;
1476                         p += length;
1477
1478                         if (vp->next &&
1479                             (vp->next->da->attr == vp->da->attr))
1480                                 vp = vp->next;
1481                 } /* loop over num_entries */
1482
1483         next:
1484                 vp = vp->next;
1485         }
1486
1487         p[0] = 0xff;            /* end of option option */
1488         p[1] = 0x00;
1489         p += 2;
1490         dhcp_size = p - packet->data;
1491
1492         /*
1493          *      FIXME: if (dhcp_size > mms),
1494          *        then we put the extra options into the "sname" and "file"
1495          *        fields, AND set the "end option option" in the "options"
1496          *        field.  We also set the "overload option",
1497          *        and put options into the "file" field, followed by
1498          *        the "sname" field.  Where each option is completely
1499          *        enclosed in the "file" and/or "sname" field, AND
1500          *        followed by the "end of option", and MUST be followed
1501          *        by padding option.
1502          *
1503          *      Yuck.  That sucks...
1504          */
1505         packet->data_len = dhcp_size;
1506
1507         if (packet->data_len < DEFAULT_PACKET_SIZE) {
1508                 memset(packet->data + packet->data_len, 0,
1509                        DEFAULT_PACKET_SIZE - packet->data_len);
1510                 packet->data_len = DEFAULT_PACKET_SIZE;
1511         }
1512
1513         if ((fr_debug_flag > 2) && fr_log_fp) {
1514                 fprintf(fr_log_fp, "DHCP Sending %zu bytes\n", packet->data_len);
1515                 for (i = 0; i < packet->data_len; i++) {
1516                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
1517                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
1518                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1519                 }
1520                 fprintf(fr_log_fp, "\n");
1521         }
1522
1523         return 0;
1524 }
1525
1526 #ifdef SIOCSARP
1527 int fr_dhcp_add_arp_entry(int fd, char const *interface,
1528                           VALUE_PAIR *macaddr, VALUE_PAIR *ip)
1529 {
1530         struct sockaddr_in *sin;
1531         struct arpreq req;
1532
1533         if (!interface) {
1534                 fr_strerror_printf("No interface specified.  Cannot update ARP table");
1535                 return -1;
1536         }
1537
1538         if (!fr_assert(macaddr) ||
1539             !fr_assert((macaddr->da->type == PW_TYPE_ETHERNET) || (macaddr->da->type == PW_TYPE_OCTETS))) {
1540                 fr_strerror_printf("Wrong VP type (%s) for chaddr",
1541                                    fr_int2str(dict_attr_types, macaddr->da->type, "<invalid>"));
1542                 return -1;
1543         }
1544
1545         if (macaddr->length > sizeof(req.arp_ha.sa_data)) {
1546                 fr_strerror_printf("arp sa_data field too small (%zu octets) to contain chaddr (%zu octets)",
1547                                    sizeof(req.arp_ha.sa_data), macaddr->length);
1548                 return -1;
1549         }
1550
1551         memset(&req, 0, sizeof(req));
1552         sin = (struct sockaddr_in *) &req.arp_pa;
1553         sin->sin_family = AF_INET;
1554         sin->sin_addr.s_addr = ip->vp_ipaddr;
1555
1556         strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
1557
1558         if (macaddr->da->type == PW_TYPE_ETHERNET) {
1559                 memcpy(&req.arp_ha.sa_data, &macaddr->vp_ether, sizeof(macaddr->vp_ether));
1560         } else {
1561                 memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->length);
1562         }
1563
1564         req.arp_flags = ATF_COM;
1565         if (ioctl(fd, SIOCSARP, &req) < 0) {
1566                 fr_strerror_printf("Failed to add entry in ARP cache: %s (%d)", fr_syserror(errno), errno);
1567                 return -1;
1568         }
1569
1570         return 0;
1571 }
1572 #else
1573 int fr_dhcp_add_arp_entry(UNUSED int fd, UNUSED char const *interface,
1574                           UNUSED VALUE_PAIR *macaddr, UNUSED VALUE_PAIR *ip)
1575 {
1576         fr_strerror_printf("Adding ARP entry is unsupported on this system");
1577         return -1;
1578 }
1579 #endif