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          *      This is a pretty awful hack, but we should be able to
 510          *      clean it up when we get nested VPs so lets leave it for
 511          *      now.
 512          */
 513         if (head) {
 514                 /* Cleanup any old TLV data */
 515                 talloc_free(tlv->vp_tlv);
 516
 517                 /* @fixme fragile */
 518                 memcpy(tlv, head, sizeof(*tlv));
 519
 520                 /* If the VP has a talloced value we need to reparent it to the original TLV attribute */
 521                 switch (head->da->type) {
 522                         case PW_TYPE_STRING:
 523                         case PW_TYPE_OCTETS:
 524                         case PW_TYPE_TLV:
 525                                 talloc_steal(tlv, head->data.ptr);
 526                         default:
 527                                 break;
 528                 }
 529                 tlv->next = head->next;
 530                 talloc_free(head);
 531         }
 532
 533         return 0;
 534
 535 make_tlv:
 536         tlv->vp_tlv = talloc_array(tlv, uint8_t, data_len);
 537         if (!tlv->vp_tlv) {
 538                 fr_strerror_printf("No memory");
 539                 return -1;
 540         }
 541         memcpy(tlv->vp_tlv, data, data_len);
 542         tlv->length = data_len;
 543
 544         return 0;
 545 }
 546
 547
 548 /*
 549  *      Decode ONE value into a VP
 550  */
 551 static int fr_dhcp_attr2vp(RADIUS_PACKET *packet, VALUE_PAIR *vp, uint8_t const *p, size_t alen)
 552 {
 553         char *q;
 554
 555         switch (vp->da->type) {
 556         case PW_TYPE_BYTE:
 557                 if (alen != 1) goto raw;
 558                 vp->vp_integer = p[0];
 559                 break;
 560
 561         case PW_TYPE_SHORT:
 562                 if (alen != 2) goto raw;
 563                 memcpy(&vp->vp_integer, p, 2);
 564                 vp->vp_integer = ntohs(vp->vp_integer);
 565                 break;
 566
 567         case PW_TYPE_INTEGER:
 568                 if (alen != 4) goto raw;
 569                 memcpy(&vp->vp_integer, p, 4);
 570                 vp->vp_integer = ntohl(vp->vp_integer);
 571                 break;
 572
 573         case PW_TYPE_IPADDR:
 574                 if (alen != 4) goto raw;
 575                 /*
 576                  *      Keep value in Network Order!
 577                  */
 578                 memcpy(&vp->vp_ipaddr, p , 4);
 579                 vp->length = 4;
 580                 break;
 581
 582         case PW_TYPE_STRING:
 583                 vp->vp_strvalue = q = talloc_array(vp, char, alen + 1);
 584                 vp->type = VT_DATA;
 585                 memcpy(q, p , alen);
 586                 q[alen] = '\0';
 587                 break;
 588
 589         case PW_TYPE_ETHERNET:
 590                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 591                 vp->length = sizeof(vp->vp_ether);
 592                 break;
 593
 594         /*
 595          *      Value doesn't match up with attribute type, overwrite the
 596          *      vp's original DICT_ATTR with an unknown one.
 597          */
 598         raw:
 599                 if (pair2unknown(vp) < 0) return -1;
 600
 601         case PW_TYPE_OCTETS:
 602                 if (alen > 253) return -1;
 603                 pairmemcpy(vp, p, alen);
 604                 break;
 605
 606         case PW_TYPE_TLV:
 607                 return decode_tlv(packet, vp, p, alen);
 608
 609         default:
 610                 fr_strerror_printf("Internal sanity check %d %d", vp->da->type, __LINE__);
 611                 return -1;
 612         } /* switch over type */
 613
 614         vp->length = alen;
 615         return 0;
 616 }
 617
 618 ssize_t fr_dhcp_decode_options(RADIUS_PACKET *packet,
 619                                uint8_t const *data, size_t len, VALUE_PAIR **head)
 620 {
 621         int i;
 622         VALUE_PAIR *vp;
 623         vp_cursor_t cursor;
 624         uint8_t const *p, *next;
 625         next = data;
 626
 627         *head = NULL;
 628         paircursor(&cursor, head);
 629
 630         /*
 631          *      FIXME: This should also check sname && file fields.
 632          *      See the dhcp_get_option() function above.
 633          */
 634         while (next < (data + len)) {
 635                 int num_entries, alen;
 636                 DICT_ATTR const *da;
 637
 638                 p = next;
 639
 640                 if (*p == 0) break;
 641                 if (*p == 255) break; /* end of options signifier */
 642                 if ((p + 2) > (data + len)) break;
 643
 644                 next = p + 2 + p[1];
 645
 646                 if (p[1] >= 253) {
 647                         fr_strerror_printf("Attribute too long %u %u",
 648                                            p[0], p[1]);
 649                         continue;
 650                 }
 651
 652                 da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
 653                 if (!da) {
 654                         fr_strerror_printf("Attribute not in our dictionary: %u",
 655                                            p[0]);
 656                         continue;
 657                 }
 658
 659                 vp = NULL;
 660                 num_entries = 1;
 661                 alen = p[1];
 662                 p += 2;
 663
 664                 /*
 665                  *      Could be an array of bytes, integers, etc.
 666                  */
 667                 if (da->flags.array) {
 668                         switch (da->type) {
 669                         case PW_TYPE_BYTE:
 670                                 num_entries = alen;
 671                                 alen = 1;
 672                                 break;
 673
 674                         case PW_TYPE_SHORT: /* ignore any trailing data */
 675                                 num_entries = alen >> 1;
 676                                 alen = 2;
 677                                 break;
 678
 679                         case PW_TYPE_IPADDR:
 680                         case PW_TYPE_INTEGER:
 681                         case PW_TYPE_DATE: /* ignore any trailing data */
 682                                 num_entries = alen >> 2;
 683                                 alen = 4;
 684                                 break;
 685
 686                         default:
 687
 688                                 break; /* really an internal sanity failure */
 689                         }
 690                 }
 691
 692                 /*
 693                  *      Loop over all of the entries, building VPs
 694                  */
 695                 for (i = 0; i < num_entries; i++) {
 696                         vp = pairmake(packet, NULL, da->name, NULL, T_OP_ADD);
 697                         if (!vp) {
 698                                 fr_strerror_printf("Cannot build attribute %s",
 699                                         fr_strerror());
 700                                 pairfree(head);
 701                                 return -1;
 702                         }
 703
 704                         /*
 705                          *      Hack for ease of use.
 706                          */
 707                         if ((da->vendor == DHCP_MAGIC_VENDOR) &&
 708                             (da->attr == 61) && !da->flags.array &&
 709                             (alen == 7) && (*p == 1) && (num_entries == 1)) {
 710                                 pairmemcpy(vp, p + 1, 6);
 711
 712                         } else if (fr_dhcp_attr2vp(packet, vp, p, alen) < 0) {
 713                                 pairfree(&vp);
 714                                 pairfree(head);
 715                                 return -1;
 716                         }
 717
 718                         pairinsert(&cursor, vp);
 719
 720                         for (vp = paircurrent(&cursor);
 721                              vp;
 722                              vp = pairnext(&cursor)) {
 723                                 debug_pair(vp);
 724                         }
 725                         p += alen;
 726                 } /* loop over array entries */
 727         } /* loop over the entire packet */
 728
 729         return next - data;
 730 }
 731
 732 int fr_dhcp_decode(RADIUS_PACKET *packet)
 733 {
 734         size_t i;
 735         uint8_t *p;
 736         uint32_t giaddr;
 737         vp_cursor_t cursor;
 738         VALUE_PAIR *head = NULL, *vp;
 739         VALUE_PAIR *maxms, *mtu;
 740
 741         paircursor(&cursor, &head);
 742         p = packet->data;
 743
 744         if ((fr_debug_flag > 2) && fr_log_fp) {
 745                 for (i = 0; i < packet->data_len; i++) {
 746                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
 747                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
 748                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
 749                 }
 750                 fprintf(fr_log_fp, "\n");
 751         }
 752
 753         if (packet->data[1] != 1) {
 754                 fr_strerror_printf("Packet is not Ethernet: %u",
 755                       packet->data[1]);
 756                 return -1;
 757         }
 758
 759         /*
 760          *      Decode the header.
 761          */
 762         for (i = 0; i < 14; i++) {
 763                 char *q;
 764
 765                 vp = pairmake(packet, NULL, dhcp_header_names[i], NULL, T_OP_EQ);
 766                 if (!vp) {
 767                         char buffer[256];
 768                         strlcpy(buffer, fr_strerror(), sizeof(buffer));
 769                         fr_strerror_printf("Cannot decode packet due to internal error: %s", buffer);
 770                         pairfree(&head);
 771                         return -1;
 772                 }
 773
 774                 /*
 775                  *      If chaddr does != 6 bytes it's probably not ethernet, and we should store
 776                  *      it as an opaque type (octets).
 777                  */
 778                 if ((i == 11) && (packet->data[1] == 1) && (packet->data[2] != sizeof(vp->vp_ether))) {
 779                         DICT_ATTR const *da = dict_attrunknown(vp->da->attr, vp->da->vendor, true);
 780                         if (!da) {
 781                                 return -1;
 782                         }
 783                         vp->da = da;
 784                 }
 785
 786                 switch (vp->da->type) {
 787                 case PW_TYPE_BYTE:
 788                         vp->vp_integer = p[0];
 789                         vp->length = 1;
 790                         break;
 791
 792                 case PW_TYPE_SHORT:
 793                         vp->vp_integer = (p[0] << 8) | p[1];
 794                         vp->length = 2;
 795                         break;
 796
 797                 case PW_TYPE_INTEGER:
 798                         memcpy(&vp->vp_integer, p, 4);
 799                         vp->vp_integer = ntohl(vp->vp_integer);
 800                         vp->length = 4;
 801                         break;
 802
 803                 case PW_TYPE_IPADDR:
 804                         memcpy(&vp->vp_ipaddr, p, 4);
 805                         vp->length = 4;
 806                         break;
 807
 808                 case PW_TYPE_STRING:
 809                         vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
 810                         vp->type = VT_DATA;
 811                         memcpy(q, p, dhcp_header_sizes[i]);
 812                         q[dhcp_header_sizes[i]] = '\0';
 813                         vp->length = strlen(vp->vp_strvalue);
 814                         if (vp->length == 0) {
 815                                 pairfree(&vp);
 816                         }
 817                         break;
 818
 819                 case PW_TYPE_OCTETS:
 820                         pairmemcpy(vp, p, packet->data[2]);
 821                         break;
 822
 823                 case PW_TYPE_ETHERNET:
 824                         memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
 825                         vp->length = sizeof(vp->vp_ether);
 826                         break;
 827
 828                 default:
 829                         fr_strerror_printf("BAD TYPE %d", vp->da->type);
 830                         pairfree(&vp);
 831                         break;
 832                 }
 833                 p += dhcp_header_sizes[i];
 834
 835                 if (!vp) continue;
 836
 837                 debug_pair(vp);
 838                 pairinsert(&cursor, vp);
 839         }
 840
 841         /*
 842          *      Loop over the options.
 843          */
 844
 845         /*
 846          *      Nothing uses tail after this call, if it does in the future
 847          *      it'll need to find the new tail...
 848          */
 849         {
 850                 VALUE_PAIR *options = NULL;
 851
 852                 if (fr_dhcp_decode_options(packet,
 853                                            packet->data + 240, packet->data_len - 240,
 854                                            &options) < 0) {
 855                         return -1;
 856                 }
 857
 858                 if (options) {
 859                         pairinsert(&cursor, options);
 860                 }
 861         }
 862
 863         /*
 864          *      If DHCP request, set ciaddr to zero.
 865          */
 866
 867         /*
 868          *      Set broadcast flag for broken vendors, but only if
 869          *      giaddr isn't set.
 870          */
 871         memcpy(&giaddr, packet->data + 24, sizeof(giaddr));
 872         if (giaddr == htonl(INADDR_ANY)) {
 873                 /*
 874                  *      DHCP Opcode is request
 875                  */
 876                 vp = pairfind(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
 877                 if (vp && vp->vp_integer == 3) {
 878                         /*
 879                          *      Vendor is "MSFT 98"
 880                          */
 881                         vp = pairfind(head, 63, DHCP_MAGIC_VENDOR, TAG_ANY);
 882                         if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
 883                                 vp = pairfind(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
 884
 885                                 /*
 886                                  *      Reply should be broadcast.
 887                                  */
 888                                 if (vp) vp->vp_integer |= 0x8000;
 889                                 packet->data[10] |= 0x80;
 890                         }
 891                 }
 892         }
 893
 894         /*
 895          *      FIXME: Nuke attributes that aren't used in the normal
 896          *      header for discover/requests.
 897          */
 898         packet->vps = head;
 899
 900         /*
 901          *      Client can request a LARGER size, but not a smaller
 902          *      one.  They also cannot request a size larger than MTU.
 903          */
 904         maxms = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
 905         mtu = pairfind(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
 906
 907         if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
 908                 fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
 909                 return -1;
 910         }
 911
 912         if (maxms && (maxms->vp_integer < DEFAULT_PACKET_SIZE)) {
 913                 fr_strerror_printf("DHCP WARNING: Client says maximum message size is smaller than minimum permitted by the specification: fixing it");
 914                 maxms->vp_integer = DEFAULT_PACKET_SIZE;
 915         }
 916
 917         if (maxms && mtu && (maxms->vp_integer > mtu->vp_integer)) {
 918                 fr_strerror_printf("DHCP WARNING: Client says MTU is smaller than maximum message size: fixing it");
 919                 maxms->vp_integer = mtu->vp_integer;
 920         }
 921
 922         if (fr_debug_flag) fflush(stdout);
 923
 924         return 0;
 925 }
 926
 927
 928 static int attr_cmp(void const *one, void const *two)
 929 {
 930         VALUE_PAIR const * const *a = one;
 931         VALUE_PAIR const * const *b = two;
 932
 933         /*
 934          *      DHCP-Message-Type is first, for simplicity.
 935          */
 936         if (((*a)->da->attr == 53) &&
 937             (*b)->da->attr != 53) return -1;
 938
 939         /*
 940          *      Relay-Agent is last
 941          */
 942         if (((*a)->da->attr == 82) &&
 943             (*b)->da->attr != 82) return 1;
 944
 945         return ((*a)->da->attr - (*b)->da->attr);
 946 }
 947
 948 /*
 949  * @todo Check room!
 950  */
 951 static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, UNUSED size_t room)
 952 {
 953         size_t length;
 954         uint32_t lvalue;
 955
 956         /*
 957          *      Search for all attributes of the same
 958          *      type, and pack them into the same
 959          *      attribute.
 960          */
 961         switch (vp->da->type) {
 962         case PW_TYPE_BYTE:
 963                 length = 1;
 964                 *p = vp->vp_integer & 0xff;
 965                 break;
 966
 967         case PW_TYPE_SHORT:
 968                 length = 2;
 969                 p[0] = (vp->vp_integer >> 8) & 0xff;
 970                 p[1] = vp->vp_integer & 0xff;
 971                 break;
 972
 973         case PW_TYPE_INTEGER:
 974                 length = 4;
 975                 lvalue = htonl(vp->vp_integer);
 976                 memcpy(p, &lvalue, 4);
 977                 break;
 978
 979         case PW_TYPE_IPADDR:
 980                 length = 4;
 981                 memcpy(p, &vp->vp_ipaddr, 4);
 982                 break;
 983
 984         case PW_TYPE_ETHERNET:
 985                 length = 6;
 986                 memcpy(p, &vp->vp_ether, 6);
 987                 break;
 988
 989         case PW_TYPE_STRING:
 990                 memcpy(p, vp->vp_strvalue, vp->length);
 991                 length = vp->length;
 992                 break;
 993
 994         case PW_TYPE_TLV:       /* FIXME: split it on 255? */
 995                 memcpy(p, vp->vp_tlv, vp->length);
 996                 length = vp->length;
 997                 break;
 998
 999         case PW_TYPE_OCTETS:
1000                 memcpy(p, vp->vp_octets, vp->length);
1001                 length = vp->length;
1002                 break;
1003
1004         default:
1005                 fr_strerror_printf("BAD TYPE2 %d", vp->da->type);
1006                 length = 0;
1007                 break;
1008         }
1009
1010         return length;
1011 }
1012
1013 static VALUE_PAIR *fr_dhcp_vp2suboption(RADIUS_PACKET *packet, VALUE_PAIR *vps)
1014 {
1015         int length;
1016         unsigned int attribute;
1017         uint8_t *ptr;
1018         vp_cursor_t cursor;
1019         VALUE_PAIR *vp, *tlv;
1020
1021         attribute = vps->da->attr & 0xffff00ff;
1022
1023         tlv = paircreate(packet, attribute, DHCP_MAGIC_VENDOR);
1024         if (!tlv) return NULL;
1025
1026         tlv->length = 0;
1027         for (vp = paircursor(&cursor, &vps);
1028              vp;
1029              vp = pairnext(&cursor)) {
1030                 /*
1031                  *      Group the attributes ONLY until we see a
1032                  *      non-TLV attribute.
1033                  */
1034                 if (!vp->da->flags.is_tlv ||
1035                     vp->da->flags.extended ||
1036                     ((vp->da->attr & 0xffff00ff) != attribute)) {
1037                         break;
1038                 }
1039
1040                 tlv->length += vp->length + 2;
1041         }
1042
1043         if (!tlv->length) {
1044                 pairfree(&tlv);
1045                 return NULL;
1046         }
1047
1048         tlv->vp_tlv = talloc_array(tlv, uint8_t, tlv->length);
1049         if (!tlv->vp_tlv) {
1050                 pairfree(&tlv);
1051                 return NULL;
1052         }
1053
1054         ptr = tlv->vp_tlv;
1055         for (vp = paircursor(&cursor, &vps);
1056              vp;
1057              vp = pairnext(&cursor)) {
1058                 if (!vp->da->flags.is_tlv ||
1059                     vp->da->flags.extended ||
1060                     ((vp->da->attr & 0xffff00ff) != attribute)) {
1061                         break;
1062                 }
1063
1064                 length = fr_dhcp_vp2attr(vp, ptr + 2,
1065                                          tlv->vp_tlv + tlv->length - ptr);
1066                 if (length > 255) {
1067                         pairfree(&tlv);
1068                         return NULL;
1069                 }
1070
1071                 /*
1072                  *      Pack the attribute.
1073                  */
1074                 ptr[0] = (vp->da->attr & 0xff00) >> 8;
1075                 ptr[1] = length;
1076
1077                 ptr += length + 2;
1078         }
1079
1080         return tlv;
1081 }
1082
1083
1084 int fr_dhcp_encode(RADIUS_PACKET *packet)
1085 {
1086         unsigned int i, num_vps;
1087         uint8_t *p;
1088         vp_cursor_t cursor;
1089         VALUE_PAIR *vp;
1090         uint32_t lvalue;
1091         size_t dhcp_size, length;
1092 #ifndef NDEBUG
1093         char const *name;
1094 #  ifdef WITH_UDPFROMTO
1095         char src_ip_buf[256];
1096 #  endif
1097         char dst_ip_buf[256];
1098 #endif
1099
1100         if (packet->data) return 0;
1101
1102         packet->data_len = MAX_PACKET_SIZE;
1103         packet->data = talloc_zero_array(packet, uint8_t, packet->data_len);
1104
1105         /* XXX Ugly ... should be set by the caller */
1106         if (packet->code == 0) packet->code = PW_DHCP_NAK;
1107
1108 #ifndef NDEBUG
1109         if ((packet->code >= PW_DHCP_DISCOVER) &&
1110             (packet->code <= PW_DHCP_INFORM)) {
1111                 name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
1112         } else {
1113                 name = "?Unknown?";
1114         }
1115
1116         DEBUG(
1117 #  ifdef WITH_UDPFROMTO
1118               "Encoding %s of id %08x from %s:%d to %s:%d\n",
1119 #  else
1120               "Encoding %s of id %08x to %s:%d\n",
1121 #  endif
1122               name, (unsigned int) packet->id,
1123 #  ifdef WITH_UDPFROMTO
1124               inet_ntop(packet->src_ipaddr.af,
1125                         &packet->src_ipaddr.ipaddr,
1126                         src_ip_buf, sizeof(src_ip_buf)),
1127               packet->src_port,
1128 #  endif
1129               inet_ntop(packet->dst_ipaddr.af,
1130                         &packet->dst_ipaddr.ipaddr,
1131                      dst_ip_buf, sizeof(dst_ip_buf)),
1132               packet->dst_port);
1133 #endif
1134
1135         p = packet->data;
1136
1137         /*
1138          *      @todo: Make this work again.
1139          */
1140 #if 0
1141         mms = DEFAULT_PACKET_SIZE; /* maximum message size */
1142
1143         /*
1144          *      Clients can request a LARGER size, but not a
1145          *      smaller one.  They also cannot request a size
1146          *      larger than MTU.
1147          */
1148
1149         /* DHCP-DHCP-Maximum-Msg-Size */
1150         vp = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
1151         if (vp && (vp->vp_integer > mms)) {
1152                 mms = vp->vp_integer;
1153
1154                 if (mms > MAX_PACKET_SIZE) mms = MAX_PACKET_SIZE;
1155         }
1156 #endif
1157
1158         vp = pairfind(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
1159         if (vp) {
1160                 *p++ = vp->vp_integer & 0xff;
1161         } else {
1162                 *p++ = 1;       /* client message */
1163         }
1164
1165         /* DHCP-Hardware-Type */
1166         if ((vp = pairfind(packet->vps, 257, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1167                 *p++ = vp->vp_integer & 0xFF;
1168         } else {
1169                 *p++ = 1;               /* hardware type = ethernet */
1170         }
1171
1172         /* DHCP-Hardware-Address-Length */
1173         if ((vp = pairfind(packet->vps, 258, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1174                 *p++ = vp->vp_integer & 0xFF;
1175         } else {
1176                 *p++ = 6;               /* 6 bytes of ethernet */
1177         }
1178
1179         /* DHCP-Hop-Count */
1180         if ((vp = pairfind(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1181                 *p = vp->vp_integer & 0xff;
1182         }
1183         p++;
1184
1185         /* DHCP-Transaction-Id */
1186         if ((vp = pairfind(packet->vps, 260, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1187                 lvalue = htonl(vp->vp_integer);
1188         } else {
1189                 lvalue = fr_rand();
1190         }
1191         memcpy(p, &lvalue, 4);
1192         p += 4;
1193
1194         /* DHCP-Number-of-Seconds */
1195         if ((vp = pairfind(packet->vps, 261, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1196                 lvalue = htonl(vp->vp_integer);
1197                 memcpy(p, &lvalue, 2);
1198         }
1199         p += 2;
1200
1201         /* DHCP-Flags */
1202         if ((vp = pairfind(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1203                 lvalue = htons(vp->vp_integer);
1204                 memcpy(p, &lvalue, 2);
1205         }
1206         p += 2;
1207
1208         /* DHCP-Client-IP-Address */
1209         if ((vp = pairfind(packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1210                 memcpy(p, &vp->vp_ipaddr, 4);
1211         }
1212         p += 4;
1213
1214         /* DHCP-Your-IP-address */
1215         if ((vp = pairfind(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1216                 lvalue = vp->vp_ipaddr;
1217         } else {
1218                 lvalue = htonl(INADDR_ANY);
1219         }
1220         memcpy(p, &lvalue, 4);
1221         p += 4;
1222
1223         /* DHCP-Server-IP-Address */
1224         vp = pairfind(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY);
1225
1226         /* DHCP-DHCP-Server-Identifier */
1227         if (!vp && (vp = pairfind(packet->vps, 54, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1228                 lvalue = vp->vp_ipaddr;
1229         } else {
1230                 lvalue = htonl(INADDR_ANY);
1231         }
1232         memcpy(p, &lvalue, 4);
1233         p += 4;
1234
1235         /*
1236          *      DHCP-Gateway-IP-Address
1237          */
1238         if ((vp = pairfind(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1239                 lvalue = vp->vp_ipaddr;
1240         } else {
1241                 lvalue = htonl(INADDR_ANY);
1242         }
1243         memcpy(p, &lvalue, 4);
1244         p += 4;
1245
1246         /* DHCP-Client-Hardware-Address */
1247         if ((vp = pairfind(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1248                 if (vp->length == sizeof(vp->vp_ether)) {
1249                         memcpy(p, vp->vp_ether, vp->length);
1250                 } /* else ignore it */
1251         }
1252         p += DHCP_CHADDR_LEN;
1253
1254         /* DHCP-Server-Host-Name */
1255         if ((vp = pairfind(packet->vps, 268, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1256                 if (vp->length > DHCP_SNAME_LEN) {
1257                         memcpy(p, vp->vp_strvalue, DHCP_SNAME_LEN);
1258                 } else {
1259                         memcpy(p, vp->vp_strvalue, vp->length);
1260                 }
1261         }
1262         p += DHCP_SNAME_LEN;
1263
1264         /*
1265          *      Copy over DHCP-Boot-Filename.
1266          *
1267          *      FIXME: This copy should be delayed until AFTER the options
1268          *      have been processed.  If there are too many options for
1269          *      the packet, then they go into the sname && filename fields.
1270          *      When that happens, the boot filename is passed as an option,
1271          *      instead of being placed verbatim in the filename field.
1272          */
1273
1274         /* DHCP-Boot-Filename */
1275         if ((vp = pairfind(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY))) {
1276                 if (vp->length > DHCP_FILE_LEN) {
1277                         memcpy(p, vp->vp_strvalue, DHCP_FILE_LEN);
1278                 } else {
1279                         memcpy(p, vp->vp_strvalue, vp->length);
1280                 }
1281         }
1282         p += DHCP_FILE_LEN;
1283
1284         /* DHCP magic number */
1285         lvalue = htonl(DHCP_OPTION_MAGIC_NUMBER);
1286         memcpy(p, &lvalue, 4);
1287         p += 4;
1288
1289         /*
1290          *      Print the header.
1291          */
1292         if (fr_debug_flag > 1) {
1293                 uint8_t *pp = p;
1294
1295                 p = packet->data;
1296
1297                 for (i = 0; i < 14; i++) {
1298                         char *q;
1299
1300                         vp = pairmake(packet, NULL,
1301                                       dhcp_header_names[i], NULL, T_OP_EQ);
1302                         if (!vp) {
1303                                 char buffer[256];
1304                                 strlcpy(buffer, fr_strerror(), sizeof(buffer));
1305                                 fr_strerror_printf("Cannot decode packet due to internal error: %s", buffer);
1306                                 return -1;
1307                         }
1308
1309                         switch (vp->da->type) {
1310                         case PW_TYPE_BYTE:
1311                                 vp->vp_integer = p[0];
1312                                 vp->length = 1;
1313                                 break;
1314
1315                         case PW_TYPE_SHORT:
1316                                 vp->vp_integer = (p[0] << 8) | p[1];
1317                                 vp->length = 2;
1318                                 break;
1319
1320                         case PW_TYPE_INTEGER:
1321                                 memcpy(&vp->vp_integer, p, 4);
1322                                 vp->vp_integer = ntohl(vp->vp_integer);
1323                                 vp->length = 4;
1324                                 break;
1325
1326                         case PW_TYPE_IPADDR:
1327                                 memcpy(&vp->vp_ipaddr, p, 4);
1328                                 vp->length = 4;
1329                                 break;
1330
1331                         case PW_TYPE_STRING:
1332                                 vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
1333                                 vp->type = VT_DATA;
1334                                 memcpy(q, p, dhcp_header_sizes[i]);
1335                                 q[dhcp_header_sizes[i]] = '\0';
1336                                 vp->length = strlen(vp->vp_strvalue);
1337                                 break;
1338
1339                         case PW_TYPE_OCTETS: /* only for Client HW Address */
1340                                 pairmemcpy(vp, p, packet->data[2]);
1341                                 break;
1342
1343                         case PW_TYPE_ETHERNET: /* only for Client HW Address */
1344                                 memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
1345                                 vp->length = sizeof(vp->vp_ether);
1346                                 break;
1347
1348                         default:
1349                                 fr_strerror_printf("Internal sanity check failed %d %d", vp->da->type, __LINE__);
1350                                 pairfree(&vp);
1351                                 break;
1352                         }
1353
1354                         p += dhcp_header_sizes[i];
1355
1356                         debug_pair(vp);
1357                         pairfree(&vp);
1358                 }
1359
1360                 /*
1361                  *      Jump over DHCP magic number, response, etc.
1362                  */
1363                 p = pp;
1364         }
1365
1366         /*
1367          *      Before packing the attributes, re-order them so that
1368          *      the array ones are all contiguous.  This simplifies
1369          *      the later code.
1370          */
1371         num_vps = 0;
1372         for (vp = paircursor(&cursor, &packet->vps);
1373              vp;
1374              vp = pairnext(&cursor)) {
1375                 num_vps++;
1376         }
1377         if (num_vps > 1) {
1378                 VALUE_PAIR **array;
1379
1380                 array = talloc_array(packet, VALUE_PAIR*, num_vps);
1381
1382                 i = 0;
1383                 for (vp = paircursor(&cursor, &packet->vps);
1384                      vp;
1385                      vp = pairnext(&cursor)) {
1386                         array[i++] = vp;
1387                 }
1388
1389                 /*
1390                  *      Sort the attributes.
1391                  */
1392                 qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *), attr_cmp);
1393
1394                 packet->vps = NULL;
1395                 paircursor(&cursor, &packet->vps);
1396                 for (i = 0; i < num_vps; i++) {
1397                         array[i]->next = NULL;
1398                         pairinsert(&cursor, array[i]);
1399                 }
1400                 talloc_free(array);
1401         }
1402
1403         p[0] = 0x35;            /* DHCP-Message-Type */
1404         p[1] = 1;
1405         p[2] = packet->code - PW_DHCP_OFFSET;
1406         p += 3;
1407
1408         /*
1409          *      Pack in the attributes.
1410          */
1411         vp = packet->vps;
1412         while (vp) {
1413                 unsigned int num_entries = 1;
1414                 VALUE_PAIR *same;
1415                 uint8_t *plength;
1416
1417                 if (vp->da->vendor != DHCP_MAGIC_VENDOR) goto next;
1418                 if (vp->da->attr == 53) goto next; /* already done */
1419                 if ((vp->da->attr > 255) &&
1420                     (DHCP_BASE_ATTR(vp->da->attr) != PW_DHCP_OPTION_82)) goto next;
1421
1422                 debug_pair(vp);
1423                 if (vp->da->flags.extended) goto next;
1424
1425                 for (same = paircursor(&cursor, &vp->next);
1426                      same;
1427                      same = pairnext(&cursor)) {
1428                         if (same->da->attr != vp->da->attr) break;
1429                         num_entries++;
1430                 }
1431
1432                 /*
1433                  *      For client-identifier
1434                  * @todo What's this meant to be doing?!
1435                  */
1436 #if 0
1437                 if ((vp->da->type == PW_TYPE_ETHERNET) &&
1438                     (vp->length == 6) &&
1439                     (num_entries == 1)) {
1440                         vp->da->type = PW_TYPE_OCTETS;
1441                         memmove(vp->vp_octets + 1, vp->vp_octets, 6);
1442                         vp->vp_octets[0] = 1;
1443                 }
1444 #endif
1445                 *(p++) = vp->da->attr & 0xff;
1446                 plength = p;
1447                 *(p++) = 0;     /* header isn't included in attr length */
1448
1449                 for (i = 0; i < num_entries; i++) {
1450                         if (i != 0) debug_pair(vp);
1451
1452                         if (vp->da->flags.is_tlv) {
1453                                 VALUE_PAIR *tlv;
1454
1455                                 /*
1456                                  *      Should NOT have been encoded yet!
1457                                  */
1458                                 tlv = fr_dhcp_vp2suboption(packet, vp);
1459
1460                                 /*
1461                                  *      Ignore it if there's an issue
1462                                  *      encoding it.
1463                                  */
1464                                 if (!tlv) goto next;
1465
1466                                 tlv->next = vp->next;
1467                                 vp->next = tlv;
1468                                 vp = tlv;
1469                         }
1470
1471                         length = fr_dhcp_vp2attr(vp, p, 0);
1472
1473                         /*
1474                          *      This will never happen due to FreeRADIUS
1475                          *      limitations: sizeof(vp->vp_octets) < 255
1476                          */
1477                         if (length > 255) {
1478                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1479                                 break;
1480                         }
1481
1482                         /*
1483                          *      More than one attribute of the same type
1484                          *      in a row: they are packed together
1485                          *      into the same TLV.  If we overflow,
1486                          *      go bananas!
1487                          */
1488                         if ((*plength + length) > 255) {
1489                                 fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
1490                                 break;
1491                         }
1492
1493                         *plength += length;
1494                         p += length;
1495
1496                         if (vp->next && (vp->next->da->attr == vp->da->attr)) {
1497                                 vp = vp->next;
1498                         }
1499                 } /* loop over num_entries */
1500
1501         next:
1502                 vp = vp->next;
1503         }
1504
1505         p[0] = 0xff;            /* end of option option */
1506         p[1] = 0x00;
1507         p += 2;
1508         dhcp_size = p - packet->data;
1509
1510         /*
1511          *      FIXME: if (dhcp_size > mms),
1512          *        then we put the extra options into the "sname" and "file"
1513          *        fields, AND set the "end option option" in the "options"
1514          *        field.  We also set the "overload option",
1515          *        and put options into the "file" field, followed by
1516          *        the "sname" field.  Where each option is completely
1517          *        enclosed in the "file" and/or "sname" field, AND
1518          *        followed by the "end of option", and MUST be followed
1519          *        by padding option.
1520          *
1521          *      Yuck.  That sucks...
1522          */
1523         packet->data_len = dhcp_size;
1524
1525         if (packet->data_len < DEFAULT_PACKET_SIZE) {
1526                 memset(packet->data + packet->data_len, 0,
1527                        DEFAULT_PACKET_SIZE - packet->data_len);
1528                 packet->data_len = DEFAULT_PACKET_SIZE;
1529         }
1530
1531         if ((fr_debug_flag > 2) && fr_log_fp) {
1532                 fprintf(fr_log_fp, "DHCP Sending %zu bytes\n", packet->data_len);
1533                 for (i = 0; i < packet->data_len; i++) {
1534                         if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
1535                         fprintf(fr_log_fp, "%02x ", packet->data[i]);
1536                         if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
1537                 }
1538                 fprintf(fr_log_fp, "\n");
1539         }
1540
1541         return 0;
1542 }
1543
1544 #ifdef SIOCSARP
1545 int fr_dhcp_add_arp_entry(int fd, char const *interface,
1546                           VALUE_PAIR *macaddr, VALUE_PAIR *ip)
1547 {
1548         struct sockaddr_in *sin;
1549         struct arpreq req;
1550
1551         if (!interface) {
1552                 fr_strerror_printf("No interface specified.  Cannot update ARP table");
1553                 return -1;
1554         }
1555
1556         if (!fr_assert(macaddr) ||
1557             !fr_assert((macaddr->da->type == PW_TYPE_ETHERNET) || (macaddr->da->type == PW_TYPE_OCTETS))) {
1558                 fr_strerror_printf("Wrong VP type (%s) for chaddr",
1559                                    fr_int2str(dict_attr_types, macaddr->da->type, "<invalid>"));
1560                 return -1;
1561         }
1562
1563         if (macaddr->length > sizeof(req.arp_ha.sa_data)) {
1564                 fr_strerror_printf("arp sa_data field too small (%zu octets) to contain chaddr (%zu octets)",
1565                                    sizeof(req.arp_ha.sa_data), macaddr->length);
1566                 return -1;
1567         }
1568
1569         memset(&req, 0, sizeof(req));
1570         sin = (struct sockaddr_in *) &req.arp_pa;
1571         sin->sin_family = AF_INET;
1572         sin->sin_addr.s_addr = ip->vp_ipaddr;
1573
1574         strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
1575
1576         if (macaddr->da->type == PW_TYPE_ETHERNET) {
1577                 memcpy(&req.arp_ha.sa_data, &macaddr->vp_ether, sizeof(macaddr->vp_ether));
1578         } else {
1579                 memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->length);
1580         }
1581
1582         req.arp_flags = ATF_COM;
1583         if (ioctl(fd, SIOCSARP, &req) < 0) {
1584                 fr_strerror_printf("Failed to add entry in ARP cache: %s (%d)", fr_syserror(errno), errno);
1585                 return -1;
1586         }
1587
1588         return 0;
1589 }
1590 #else
1591 int fr_dhcp_add_arp_entry(UNUSED int fd, UNUSED char const *interface,
1592                           UNUSED VALUE_PAIR *macaddr, UNUSED VALUE_PAIR *ip)
1593 {
1594         fr_strerror_printf("Adding ARP entry is unsupported on this system");
1595         return -1;
1596 }
1597 #endif