grub-core/net/bootp.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2010,2011  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/net.h>
  20 #include <grub/env.h>
  21 #include <grub/i18n.h>
  22 #include <grub/command.h>
  23 #include <grub/net/ip.h>
  24 #include <grub/net/netbuff.h>
  25 #include <grub/net/udp.h>
  26 #include <grub/datetime.h>
  27
  28 static void
  29 parse_dhcp_vendor (const char *name, const void *vend, int limit, int *mask)
  30 {
  31   const grub_uint8_t *ptr, *ptr0;
  32
  33   ptr = ptr0 = vend;
  34
  35   if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
  36       || ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
  37       || ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
  38       || ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
  39     return;
  40   ptr = ptr + sizeof (grub_uint32_t);
  41   while (ptr - ptr0 < limit)
  42     {
  43       grub_uint8_t tagtype;
  44       grub_uint8_t taglength;
  45
  46       tagtype = *ptr++;
  47
  48       /* Pad tag.  */
  49       if (tagtype == GRUB_NET_BOOTP_PAD)
  50         continue;
  51
  52       /* End tag.  */
  53       if (tagtype == GRUB_NET_BOOTP_END)
  54         return;
  55
  56       taglength = *ptr++;
  57
  58       switch (tagtype)
  59         {
  60         case GRUB_NET_BOOTP_NETMASK:
  61           if (taglength == 4)
  62             {
  63               int i;
  64               for (i = 0; i < 32; i++)
  65                 if (!(ptr[i / 8] & (1 << (7 - (i % 8)))))
  66                   break;
  67               *mask = i;
  68             }
  69           break;
  70
  71         case GRUB_NET_BOOTP_ROUTER:
  72           if (taglength == 4)
  73             {
  74               grub_net_network_level_netaddress_t target;
  75               grub_net_network_level_address_t gw;
  76               char *rname;
  77
  78               target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
  79               target.ipv4.base = 0;
  80               target.ipv4.masksize = 0;
  81               gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
  82               grub_memcpy (&gw.ipv4, ptr, sizeof (gw.ipv4));
  83               rname = grub_xasprintf ("%s:default", name);
  84               if (rname)
  85                 grub_net_add_route_gw (rname, target, gw);
  86               grub_free (rname);
  87             }
  88           break;
  89         case GRUB_NET_BOOTP_DNS:
  90           {
  91             int i;
  92             for (i = 0; i < taglength / 4; i++)
  93               {
  94                 struct grub_net_network_level_address s;
  95                 s.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
  96                 s.ipv4 = grub_get_unaligned32 (ptr);
  97                 s.option = DNS_OPTION_PREFER_IPV4;
  98                 grub_net_add_dns_server (&s);
  99                 ptr += 4;
 100               }
 101           }
 102           continue;
 103         case GRUB_NET_BOOTP_HOSTNAME:
 104           grub_env_set_net_property (name, "hostname", (const char *) ptr,
 105                                      taglength);
 106           break;
 107
 108         case GRUB_NET_BOOTP_DOMAIN:
 109           grub_env_set_net_property (name, "domain", (const char *) ptr,
 110                                      taglength);
 111           break;
 112
 113         case GRUB_NET_BOOTP_ROOT_PATH:
 114           grub_env_set_net_property (name, "rootpath", (const char *) ptr,
 115                                      taglength);
 116           break;
 117
 118         case GRUB_NET_BOOTP_EXTENSIONS_PATH:
 119           grub_env_set_net_property (name, "extensionspath", (const char *) ptr,
 120                                      taglength);
 121           break;
 122
 123           /* If you need any other options please contact GRUB
 124              development team.  */
 125         }
 126
 127       ptr += taglength;
 128     }
 129 }
 130
 131 #define OFFSET_OF(x, y) ((grub_size_t)((grub_uint8_t *)((y)->x) - (grub_uint8_t *)(y)))
 132
 133 struct grub_net_network_level_interface *
 134 grub_net_configure_by_dhcp_ack (const char *name,
 135                                 struct grub_net_card *card,
 136                                 grub_net_interface_flags_t flags,
 137                                 const struct grub_net_bootp_packet *bp,
 138                                 grub_size_t size,
 139                                 int is_def, char **device, char **path)
 140 {
 141   grub_net_network_level_address_t addr;
 142   grub_net_link_level_address_t hwaddr;
 143   struct grub_net_network_level_interface *inter;
 144   int mask = -1;
 145
 146   addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
 147   addr.ipv4 = bp->your_ip;
 148
 149   if (device)
 150     *device = 0;
 151   if (path)
 152     *path = 0;
 153
 154   grub_memcpy (hwaddr.mac, bp->mac_addr,
 155                bp->hw_len < sizeof (hwaddr.mac) ? bp->hw_len
 156                : sizeof (hwaddr.mac));
 157   hwaddr.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
 158
 159   inter = grub_net_add_addr (name, card, &addr, &hwaddr, flags);
 160   if (bp->gateway_ip)
 161     {
 162       grub_net_network_level_netaddress_t target;
 163       grub_net_network_level_address_t gw;
 164       char *rname;
 165
 166       target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
 167       target.ipv4.base = bp->server_ip;
 168       target.ipv4.masksize = 32;
 169       gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
 170       gw.ipv4 = bp->gateway_ip;
 171       rname = grub_xasprintf ("%s:gw", name);
 172       if (rname)
 173         grub_net_add_route_gw (rname, target, gw);
 174       grub_free (rname);
 175
 176       target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
 177       target.ipv4.base = bp->gateway_ip;
 178       target.ipv4.masksize = 32;
 179       grub_net_add_route (name, target, inter);
 180     }
 181
 182   if (size > OFFSET_OF (boot_file, bp))
 183     grub_env_set_net_property (name, "boot_file", bp->boot_file,
 184                                sizeof (bp->boot_file));
 185   if (is_def)
 186     grub_net_default_server = 0;
 187   if (is_def && !grub_net_default_server && bp->server_ip)
 188     {
 189       grub_net_default_server = grub_xasprintf ("%d.%d.%d.%d",
 190                                                 ((grub_uint8_t *) &bp->server_ip)[0],
 191                                                 ((grub_uint8_t *) &bp->server_ip)[1],
 192                                                 ((grub_uint8_t *) &bp->server_ip)[2],
 193                                                 ((grub_uint8_t *) &bp->server_ip)[3]);
 194       grub_print_error ();
 195     }
 196
 197   if (is_def)
 198     {
 199       grub_env_set ("net_default_interface", name);
 200       grub_env_export ("net_default_interface");
 201     }
 202
 203   if (device && !*device && bp->server_ip)
 204     {
 205       *device = grub_xasprintf ("tftp,%d.%d.%d.%d",
 206                                 ((grub_uint8_t *) &bp->server_ip)[0],
 207                                 ((grub_uint8_t *) &bp->server_ip)[1],
 208                                 ((grub_uint8_t *) &bp->server_ip)[2],
 209                                 ((grub_uint8_t *) &bp->server_ip)[3]);
 210       grub_print_error ();
 211     }
 212   if (size > OFFSET_OF (server_name, bp)
 213       && bp->server_name[0])
 214     {
 215       grub_env_set_net_property (name, "dhcp_server_name", bp->server_name,
 216                                  sizeof (bp->server_name));
 217       if (is_def && !grub_net_default_server)
 218         {
 219           grub_net_default_server = grub_strdup (bp->server_name);
 220           grub_print_error ();
 221         }
 222       if (device && !*device)
 223         {
 224           *device = grub_xasprintf ("tftp,%s", bp->server_name);
 225           grub_print_error ();
 226         }
 227     }
 228
 229   if (size > OFFSET_OF (boot_file, bp) && path)
 230     {
 231       *path = grub_strndup (bp->boot_file, sizeof (bp->boot_file));
 232       grub_print_error ();
 233       if (*path)
 234         {
 235           char *slash;
 236           slash = grub_strrchr (*path, '/');
 237           if (slash)
 238             *slash = 0;
 239           else
 240             **path = 0;
 241         }
 242     }
 243   if (size > OFFSET_OF (vendor, bp))
 244     parse_dhcp_vendor (name, &bp->vendor, size - OFFSET_OF (vendor, bp), &mask);
 245   grub_net_add_ipv4_local (inter, mask);
 246
 247   inter->dhcp_ack = grub_malloc (size);
 248   if (inter->dhcp_ack)
 249     {
 250       grub_memcpy (inter->dhcp_ack, bp, size);
 251       inter->dhcp_acklen = size;
 252     }
 253   else
 254     grub_errno = GRUB_ERR_NONE;
 255
 256   return inter;
 257 }
 258
 259 void
 260 grub_net_process_dhcp (struct grub_net_buff *nb,
 261                        struct grub_net_card *card)
 262 {
 263   char *name;
 264   struct grub_net_network_level_interface *inf;
 265
 266   name = grub_xasprintf ("%s:dhcp", card->name);
 267   if (!name)
 268     {
 269       grub_print_error ();
 270       return;
 271     }
 272   grub_net_configure_by_dhcp_ack (name, card,
 273                                   0, (const struct grub_net_bootp_packet *) nb->data,
 274                                   (nb->tail - nb->data), 0, 0, 0);
 275   grub_free (name);
 276   if (grub_errno)
 277     grub_print_error ();
 278   else
 279     {
 280       FOR_NET_NETWORK_LEVEL_INTERFACES(inf)
 281         if (grub_memcmp (inf->name, card->name, grub_strlen (card->name)) == 0
 282             && grub_memcmp (inf->name + grub_strlen (card->name),
 283                             ":dhcp_tmp", sizeof (":dhcp_tmp") - 1) == 0)
 284           {
 285             grub_net_network_level_interface_unregister (inf);
 286             break;
 287           }
 288     }
 289 }
 290
 291 static char
 292 hexdigit (grub_uint8_t val)
 293 {
 294   if (val < 10)
 295     return val + '0';
 296   return val + 'a' - 10;
 297 }
 298
 299 static grub_err_t
 300 grub_cmd_dhcpopt (struct grub_command *cmd __attribute__ ((unused)),
 301                   int argc, char **args)
 302 {
 303   struct grub_net_network_level_interface *inter;
 304   int num;
 305   grub_uint8_t *ptr;
 306   grub_uint8_t taglength;
 307
 308   if (argc < 4)
 309     return grub_error (GRUB_ERR_BAD_ARGUMENT,
 310                        N_("four arguments expected"));
 311
 312   FOR_NET_NETWORK_LEVEL_INTERFACES (inter)
 313     if (grub_strcmp (inter->name, args[1]) == 0)
 314       break;
 315
 316   if (!inter)
 317     return grub_error (GRUB_ERR_BAD_ARGUMENT,
 318                        N_("unrecognised network interface `%s'"), args[1]);
 319
 320   if (!inter->dhcp_ack)
 321     return grub_error (GRUB_ERR_IO, N_("no DHCP info found"));
 322
 323   if (inter->dhcp_acklen <= OFFSET_OF (vendor, inter->dhcp_ack))
 324     return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
 325
 326   num = grub_strtoul (args[2], 0, 0);
 327   if (grub_errno)
 328     return grub_errno;
 329
 330   ptr = inter->dhcp_ack->vendor;
 331
 332   if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
 333       || ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
 334       || ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
 335       || ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
 336     return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
 337   ptr = ptr + sizeof (grub_uint32_t);
 338   while (1)
 339     {
 340       grub_uint8_t tagtype;
 341
 342       if (ptr >= ((grub_uint8_t *) inter->dhcp_ack) + inter->dhcp_acklen)
 343         return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
 344
 345       tagtype = *ptr++;
 346
 347       /* Pad tag.  */
 348       if (tagtype == 0)
 349         continue;
 350
 351       /* End tag.  */
 352       if (tagtype == 0xff)
 353         return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
 354
 355       taglength = *ptr++;
 356
 357       if (tagtype == num)
 358         break;
 359       ptr += taglength;
 360     }
 361
 362   if (grub_strcmp (args[3], "string") == 0)
 363     {
 364       char *val = grub_malloc (taglength + 1);
 365       if (!val)
 366         return grub_errno;
 367       grub_memcpy (val, ptr, taglength);
 368       val[taglength] = 0;
 369       if (args[0][0] == '-' && args[0][1] == 0)
 370         grub_printf ("%s\n", val);
 371       else
 372         return grub_env_set (args[0], val);
 373       return GRUB_ERR_NONE;
 374     }
 375
 376   if (grub_strcmp (args[3], "number") == 0)
 377     {
 378       grub_uint64_t val = 0;
 379       int i;
 380       for (i = 0; i < taglength; i++)
 381         val = (val << 8) | ptr[i];
 382       if (args[0][0] == '-' && args[0][1] == 0)
 383         grub_printf ("%llu\n", (unsigned long long) val);
 384       else
 385         {
 386           char valn[64];
 387           grub_snprintf (valn, sizeof (valn), "%lld\n", (unsigned long long) val);
 388           return grub_env_set (args[0], valn);
 389         }
 390       return GRUB_ERR_NONE;
 391     }
 392
 393   if (grub_strcmp (args[3], "hex") == 0)
 394     {
 395       char *val = grub_malloc (2 * taglength + 1);
 396       int i;
 397       if (!val)
 398         return grub_errno;
 399       for (i = 0; i < taglength; i++)
 400         {
 401           val[2 * i] = hexdigit (ptr[i] >> 4);
 402           val[2 * i + 1] = hexdigit (ptr[i] & 0xf);
 403         }
 404       val[2 * taglength] = 0;
 405       if (args[0][0] == '-' && args[0][1] == 0)
 406         grub_printf ("%s\n", val);
 407       else
 408         return grub_env_set (args[0], val);
 409       return GRUB_ERR_NONE;
 410     }
 411
 412   return grub_error (GRUB_ERR_BAD_ARGUMENT,
 413                      N_("unrecognised DHCP option format specification `%s'"),
 414                      args[3]);
 415 }
 416
 417 /* FIXME: allow to specify mac address.  */
 418 static grub_err_t
 419 grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
 420                 int argc, char **args)
 421 {
 422   struct grub_net_card *card;
 423   struct grub_net_network_level_interface *ifaces;
 424   grub_size_t ncards = 0;
 425   unsigned j = 0;
 426   int interval;
 427   grub_err_t err;
 428
 429   FOR_NET_CARDS (card)
 430   {
 431     if (argc > 0 && grub_strcmp (card->name, args[0]) != 0)
 432       continue;
 433     ncards++;
 434   }
 435
 436   if (ncards == 0)
 437     return grub_error (GRUB_ERR_NET_NO_CARD, N_("no network card found"));
 438
 439   ifaces = grub_zalloc (ncards * sizeof (ifaces[0]));
 440   if (!ifaces)
 441     return grub_errno;
 442
 443   j = 0;
 444   FOR_NET_CARDS (card)
 445   {
 446     if (argc > 0 && grub_strcmp (card->name, args[0]) != 0)
 447       continue;
 448     ifaces[j].card = card;
 449     ifaces[j].next = &ifaces[j+1];
 450     if (j)
 451       ifaces[j].prev = &ifaces[j-1].next;
 452     ifaces[j].name = grub_xasprintf ("%s:dhcp_tmp", card->name);
 453     card->num_ifaces++;
 454     if (!ifaces[j].name)
 455       {
 456         unsigned i;
 457         for (i = 0; i < j; i++)
 458           grub_free (ifaces[i].name);
 459         grub_free (ifaces);
 460         return grub_errno;
 461       }
 462     ifaces[j].address.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_DHCP_RECV;
 463     grub_memcpy (&ifaces[j].hwaddress, &card->default_address,
 464                  sizeof (ifaces[j].hwaddress));
 465     j++;
 466   }
 467   ifaces[ncards - 1].next = grub_net_network_level_interfaces;
 468   if (grub_net_network_level_interfaces)
 469     grub_net_network_level_interfaces->prev = & ifaces[ncards - 1].next;
 470   grub_net_network_level_interfaces = &ifaces[0];
 471   ifaces[0].prev = &grub_net_network_level_interfaces;
 472   for (interval = 200; interval < 10000; interval *= 2)
 473     {
 474       int done = 0;
 475       for (j = 0; j < ncards; j++)
 476         {
 477           struct grub_net_bootp_packet *pack;
 478           struct grub_datetime date;
 479           grub_int32_t t = 0;
 480           struct grub_net_buff *nb;
 481           struct udphdr *udph;
 482           grub_net_network_level_address_t target;
 483           grub_net_link_level_address_t ll_target;
 484
 485           if (!ifaces[j].prev)
 486             continue;
 487           nb = grub_netbuff_alloc (sizeof (*pack) + 64 + 128);
 488           if (!nb)
 489             {
 490               grub_netbuff_free (nb);
 491               return grub_errno;
 492             }
 493           err = grub_netbuff_reserve (nb, sizeof (*pack) + 64 + 128);
 494           if (err)
 495             {
 496               grub_netbuff_free (nb);
 497               return err;
 498             }
 499           err = grub_netbuff_push (nb, sizeof (*pack) + 64);
 500           if (err)
 501             {
 502               grub_netbuff_free (nb);
 503               return err;
 504             }
 505           pack = (void *) nb->data;
 506           done = 1;
 507           grub_memset (pack, 0, sizeof (*pack) + 64);
 508           pack->opcode = 1;
 509           pack->hw_type = 1;
 510           pack->hw_len = 6;
 511           err = grub_get_datetime (&date);
 512           if (err || !grub_datetime2unixtime (&date, &t))
 513             {
 514               grub_errno = GRUB_ERR_NONE;
 515               t = 0;
 516             }
 517           pack->ident = grub_cpu_to_be32 (t);
 518           pack->seconds = grub_cpu_to_be16 (t);
 519
 520           grub_memcpy (&pack->mac_addr, &ifaces[j].hwaddress.mac, 6);
 521
 522           grub_netbuff_push (nb, sizeof (*udph));
 523
 524           udph = (struct udphdr *) nb->data;
 525           udph->src = grub_cpu_to_be16_compile_time (68);
 526           udph->dst = grub_cpu_to_be16_compile_time (67);
 527           udph->chksum = 0;
 528           udph->len = grub_cpu_to_be16 (nb->tail - nb->data);
 529           target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
 530           target.ipv4 = 0xffffffff;
 531           err = grub_net_link_layer_resolve (&ifaces[j], &target, &ll_target);
 532           if (err)
 533             return err;
 534
 535           udph->chksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_UDP,
 536                                                          &ifaces[j].address,
 537                                                          &target);
 538
 539           err = grub_net_send_ip_packet (&ifaces[j], &target, &ll_target, nb,
 540                                          GRUB_NET_IP_UDP);
 541           grub_netbuff_free (nb);
 542           if (err)
 543             return err;
 544         }
 545       if (!done)
 546         break;
 547       grub_net_poll_cards (interval, 0);
 548     }
 549
 550   err = GRUB_ERR_NONE;
 551   for (j = 0; j < ncards; j++)
 552     {
 553       grub_free (ifaces[j].name);
 554       if (!ifaces[j].prev)
 555         continue;
 556       grub_error_push ();
 557       grub_net_network_level_interface_unregister (&ifaces[j]);
 558       err = grub_error (GRUB_ERR_FILE_NOT_FOUND,
 559                         N_("couldn't autoconfigure %s"),
 560                         ifaces[j].card->name);
 561     }
 562
 563   grub_free (ifaces);
 564   return err;
 565 }
 566
 567 static grub_command_t cmd_getdhcp, cmd_bootp;
 568
 569 void
 570 grub_bootp_init (void)
 571 {
 572   cmd_bootp = grub_register_command ("net_bootp", grub_cmd_bootp,
 573                                      N_("[CARD]"),
 574                                      N_("perform a bootp autoconfiguration"));
 575   cmd_getdhcp = grub_register_command ("net_get_dhcp_option", grub_cmd_dhcpopt,
 576                                        N_("VAR INTERFACE NUMBER DESCRIPTION"),
 577                                        N_("retrieve DHCP option and save it into VAR. If VAR is - then print the value."));
 578 }
 579
 580 void
 581 grub_bootp_fini (void)
 582 {
 583   grub_unregister_command (cmd_getdhcp);
 584   grub_unregister_command (cmd_bootp);
 585 }