source4/lib/socket/interface.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    multiple interface handling
   5
   6    Copyright (C) Andrew Tridgell 1992-2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "system/network.h"
  24 #include "param/param.h"
  25 #include "lib/socket/netif.h"
  26 #include "../lib/util/util_net.h"
  27 #include "../lib/util/dlinklist.h"
  28 #include "lib/util/smb_strtox.h"
  29
  30 /* used for network interfaces */
  31 struct interface {
  32         struct interface *next, *prev;
  33         char *name;
  34         int flags;
  35         struct sockaddr_storage ip;
  36         struct sockaddr_storage netmask;
  37         struct sockaddr_storage bcast;
  38         const char *ip_s;
  39         const char *bcast_s;
  40         const char *nmask_s;
  41 };
  42
  43 #define ALLONES  ((uint32_t)0xFFFFFFFF)
  44 /*
  45   address construction based on a patch from fred@datalync.com
  46 */
  47 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
  48 #define MKNETADDR(_IP, _NM) (_IP & _NM)
  49
  50 /****************************************************************************
  51 Try and find an interface that matches an ip. If we cannot, return NULL
  52   **************************************************************************/
  53 static struct interface *iface_list_find(struct interface *interfaces,
  54                                          const struct sockaddr *ip,
  55                                          bool check_mask)
  56 {
  57         struct interface *i;
  58
  59         if (is_address_any(ip)) {
  60                 return interfaces;
  61         }
  62
  63         for (i=interfaces;i;i=i->next) {
  64                 if (check_mask) {
  65                         if (same_net(ip, (struct sockaddr *)&i->ip, (struct sockaddr *)&i->netmask)) {
  66                                 return i;
  67                         }
  68                 } else if (sockaddr_equal((struct sockaddr *)&i->ip, ip)) {
  69                         return i;
  70                 }
  71         }
  72
  73         return NULL;
  74 }
  75
  76 /****************************************************************************
  77 add an interface to the linked list of interfaces
  78 ****************************************************************************/
  79 static void add_interface(TALLOC_CTX *mem_ctx, const struct iface_struct *ifs, struct interface **interfaces)
  80 {
  81         char addr[INET6_ADDRSTRLEN];
  82         struct interface *iface;
  83
  84         if (iface_list_find(*interfaces, (const struct sockaddr *)&ifs->ip, false)) {
  85                 DEBUG(3,("add_interface: not adding duplicate interface %s\n",
  86                         print_sockaddr(addr, sizeof(addr), &ifs->ip) ));
  87                 return;
  88         }
  89
  90         if (ifs->ip.ss_family == AF_INET &&
  91                 !(ifs->flags & (IFF_BROADCAST|IFF_LOOPBACK))) {
  92                 DEBUG(3,("not adding non-broadcast interface %s\n",
  93                                         ifs->name ));
  94                 return;
  95         }
  96
  97         if (*interfaces != NULL) {
  98                 mem_ctx = *interfaces;
  99         }
 100
 101         iface = talloc_zero(mem_ctx, struct interface);
 102         if (iface == NULL) {
 103                 return;
 104         }
 105
 106         iface->name = talloc_strdup(iface, ifs->name);
 107         if (!iface->name) {
 108                 SAFE_FREE(iface);
 109                 return;
 110         }
 111         iface->flags = ifs->flags;
 112         iface->ip = ifs->ip;
 113         iface->netmask = ifs->netmask;
 114         iface->bcast = ifs->bcast;
 115
 116         /* keep string versions too, to avoid people tripping over the implied
 117            static in inet_ntoa() */
 118         print_sockaddr(addr, sizeof(addr), &iface->ip);
 119         DEBUG(4,("added interface %s ip=%s ",
 120                  iface->name, addr));
 121         iface->ip_s = talloc_strdup(iface, addr);
 122
 123         print_sockaddr(addr, sizeof(addr),
 124                        &iface->bcast);
 125         DEBUG(4,("bcast=%s ", addr));
 126         iface->bcast_s = talloc_strdup(iface, addr);
 127
 128         print_sockaddr(addr, sizeof(addr),
 129                        &iface->netmask);
 130         DEBUG(4,("netmask=%s\n", addr));
 131         iface->nmask_s = talloc_strdup(iface, addr);
 132
 133         /*
 134            this needs to be a ADD_END, as some tests (such as the
 135            spoolss notify test) depend on the interfaces ordering
 136         */
 137         DLIST_ADD_END(*interfaces, iface);
 138 }
 139
 140 /**
 141 interpret a single element from a interfaces= config line
 142
 143 This handles the following different forms:
 144
 145 1) wildcard interface name
 146 2) DNS name
 147 3) IP/masklen
 148 4) ip/mask
 149 5) bcast/mask
 150 **/
 151 static void interpret_interface(TALLOC_CTX *mem_ctx,
 152                                 const char *token,
 153                                 struct iface_struct *probed_ifaces,
 154                                 int total_probed,
 155                                 struct interface **local_interfaces)
 156 {
 157         struct sockaddr_storage ss;
 158         struct sockaddr_storage ss_mask;
 159         struct sockaddr_storage ss_net;
 160         struct sockaddr_storage ss_bcast;
 161         struct iface_struct ifs;
 162         char *p;
 163         int i;
 164         bool added=false;
 165         bool goodaddr = false;
 166
 167         /* first check if it is an interface name */
 168         for (i=0;i<total_probed;i++) {
 169                 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
 170                         add_interface(mem_ctx, &probed_ifaces[i],
 171                                       local_interfaces);
 172                         added = true;
 173                 }
 174         }
 175         if (added) {
 176                 return;
 177         }
 178
 179         p = strchr_m(token, ';');
 180         if (p != NULL) {
 181                 /*
 182                  * skip smbd-specific extra data:
 183                  * link speed, capabilities, and interface index
 184                  */
 185                 *p = 0;
 186         }
 187
 188         /* maybe it is a DNS name */
 189         p = strchr_m(token,'/');
 190         if (p == NULL) {
 191                 if (!interpret_string_addr(&ss, token, 0)) {
 192                         DEBUG(2, ("interpret_interface: Can't find address "
 193                                   "for %s\n", token));
 194                         return;
 195                 }
 196
 197                 for (i=0;i<total_probed;i++) {
 198                         if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&probed_ifaces[i].ip)) {
 199                                 add_interface(mem_ctx, &probed_ifaces[i],
 200                                               local_interfaces);
 201                                 return;
 202                         }
 203                 }
 204                 DEBUG(2,("interpret_interface: "
 205                         "can't determine interface for %s\n",
 206                         token));
 207                 return;
 208         }
 209
 210         /* parse it into an IP address/netmasklength pair */
 211         *p = 0;
 212         goodaddr = interpret_string_addr(&ss, token, 0);
 213         *p++ = '/';
 214
 215         if (!goodaddr) {
 216                 DEBUG(2,("interpret_interface: "
 217                         "can't determine interface for %s\n",
 218                         token));
 219                 return;
 220         }
 221
 222         if (strlen(p) > 2) {
 223                 goodaddr = interpret_string_addr(&ss_mask, p, 0);
 224                 if (!goodaddr) {
 225                         DEBUG(2,("interpret_interface: "
 226                                 "can't determine netmask from %s\n",
 227                                 p));
 228                         return;
 229                 }
 230         } else {
 231                 int error = 0;
 232
 233                 unsigned long val = smb_strtoul(p,
 234                                                 NULL,
 235                                                 0,
 236                                                 &error,
 237                                                 SMB_STR_FULL_STR_CONV);
 238                 if (error != 0) {
 239                         DEBUG(2,("interpret_interface: "
 240                                 "can't determine netmask value from %s\n",
 241                                 p));
 242                         return;
 243                 }
 244                 if (!make_netmask(&ss_mask, &ss, val)) {
 245                         DEBUG(2,("interpret_interface: "
 246                                 "can't apply netmask value %lu from %s\n",
 247                                 val,
 248                                 p));
 249                         return;
 250                 }
 251         }
 252
 253         make_bcast(&ss_bcast, &ss, &ss_mask);
 254         make_net(&ss_net, &ss, &ss_mask);
 255
 256         /* Maybe the first component was a broadcast address. */
 257         if (sockaddr_equal((struct sockaddr *)&ss_bcast, (struct sockaddr *)&ss) ||
 258                 sockaddr_equal((struct sockaddr *)&ss_net, (struct sockaddr *)&ss)) {
 259                 for (i=0;i<total_probed;i++) {
 260                         if (same_net((struct sockaddr *)&ss,
 261                                                  (struct sockaddr *)&probed_ifaces[i].ip,
 262                                                  (struct sockaddr *)&ss_mask)) {
 263                                 /* Temporarily replace netmask on
 264                                  * the detected interface - user knows
 265                                  * best.... */
 266                                 struct sockaddr_storage saved_mask =
 267                                         probed_ifaces[i].netmask;
 268                                 probed_ifaces[i].netmask = ss_mask;
 269                                 DEBUG(2,("interpret_interface: "
 270                                         "using netmask value %s from "
 271                                         "config file on interface %s\n",
 272                                         p,
 273                                         probed_ifaces[i].name));
 274                                 add_interface(mem_ctx, &probed_ifaces[i],
 275                                               local_interfaces);
 276                                 probed_ifaces[i].netmask = saved_mask;
 277                                 return;
 278                         }
 279                 }
 280                 DEBUG(2,("interpret_interface: Can't determine ip for "
 281                         "broadcast address %s\n",
 282                         token));
 283                 return;
 284         }
 285
 286         /* Just fake up the interface definition. User knows best. */
 287
 288         DEBUG(2,("interpret_interface: Adding interface %s\n",
 289                 token));
 290
 291         ZERO_STRUCT(ifs);
 292         (void)strlcpy(ifs.name, token, sizeof(ifs.name));
 293         ifs.flags = IFF_BROADCAST;
 294         ifs.ip = ss;
 295         ifs.netmask = ss_mask;
 296         ifs.bcast = ss_bcast;
 297         add_interface(mem_ctx, &ifs, local_interfaces);
 298 }
 299
 300
 301 /**
 302 load the list of network interfaces
 303 **/
 304 void load_interface_list(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct interface **local_interfaces)
 305 {
 306         const char **ptr = lpcfg_interfaces(lp_ctx);
 307         int i;
 308         struct iface_struct *ifaces = NULL;
 309         int total_probed;
 310
 311         *local_interfaces = NULL;
 312
 313         /* probe the kernel for interfaces */
 314         total_probed = get_interfaces(mem_ctx, &ifaces);
 315
 316         /* if we don't have a interfaces line then use all interfaces
 317            except loopback */
 318         if (!ptr || !*ptr || !**ptr) {
 319                 if (total_probed <= 0) {
 320                         DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
 321                 }
 322                 for (i=0;i<total_probed;i++) {
 323                         if (!is_loopback_addr((struct sockaddr *)&ifaces[i].ip)) {
 324                                 add_interface(mem_ctx, &ifaces[i], local_interfaces);
 325                         }
 326                 }
 327         }
 328
 329         while (ptr && *ptr) {
 330                 interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces);
 331                 ptr++;
 332         }
 333
 334         if (!*local_interfaces) {
 335                 DEBUG(0,("WARNING: no network interfaces found\n"));
 336         }
 337         talloc_free(ifaces);
 338 }
 339
 340 /**
 341   how many interfaces do we have
 342   **/
 343 int iface_list_count(struct interface *ifaces)
 344 {
 345         int ret = 0;
 346         struct interface *i;
 347
 348         for (i=ifaces;i;i=i->next)
 349                 ret++;
 350         return ret;
 351 }
 352
 353 /**
 354   return IP of the Nth interface
 355   **/
 356 const char *iface_list_n_ip(struct interface *ifaces, int n)
 357 {
 358         struct interface *i;
 359
 360         for (i=ifaces;i && n;i=i->next)
 361                 n--;
 362
 363         if (i) {
 364                 return i->ip_s;
 365         }
 366         return NULL;
 367 }
 368
 369
 370 /**
 371   return the first IPv4 interface address we have registered
 372   **/
 373 const char *iface_list_first_v4(struct interface *ifaces)
 374 {
 375         struct interface *i;
 376
 377         for (i=ifaces; i; i=i->next) {
 378                 if (i->ip.ss_family == AF_INET) {
 379                         return i->ip_s;
 380                 }
 381         }
 382         return NULL;
 383 }
 384
 385 /**
 386   return the first IPv6 interface address we have registered
 387   **/
 388 static const char *iface_list_first_v6(struct interface *ifaces)
 389 {
 390         struct interface *i;
 391
 392 #ifdef HAVE_IPV6
 393         for (i=ifaces; i; i=i->next) {
 394                 if (i->ip.ss_family == AF_INET6) {
 395                         return i->ip_s;
 396                 }
 397         }
 398 #endif
 399         return NULL;
 400 }
 401
 402 /**
 403    check if an interface is IPv4
 404   **/
 405 bool iface_list_n_is_v4(struct interface *ifaces, int n)
 406 {
 407         struct interface *i;
 408
 409         for (i=ifaces;i && n;i=i->next)
 410                 n--;
 411
 412         if (i) {
 413                 return i->ip.ss_family == AF_INET;
 414         }
 415         return false;
 416 }
 417
 418 /**
 419   return bcast of the Nth interface
 420   **/
 421 const char *iface_list_n_bcast(struct interface *ifaces, int n)
 422 {
 423         struct interface *i;
 424
 425         for (i=ifaces;i && n;i=i->next)
 426                 n--;
 427
 428         if (i) {
 429                 return i->bcast_s;
 430         }
 431         return NULL;
 432 }
 433
 434 /**
 435   return netmask of the Nth interface
 436   **/
 437 const char *iface_list_n_netmask(struct interface *ifaces, int n)
 438 {
 439         struct interface *i;
 440
 441         for (i=ifaces;i && n;i=i->next)
 442                 n--;
 443
 444         if (i) {
 445                 return i->nmask_s;
 446         }
 447         return NULL;
 448 }
 449
 450 /**
 451   return the local IP address that best matches a destination IP, or
 452   our first interface if none match
 453 */
 454 const char *iface_list_best_ip(struct interface *ifaces, const char *dest)
 455 {
 456         struct interface *iface;
 457         struct sockaddr_storage ss;
 458
 459         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 460                 return iface_list_n_ip(ifaces, 0);
 461         }
 462         iface = iface_list_find(ifaces, (const struct sockaddr *)&ss, true);
 463         if (iface) {
 464                 return iface->ip_s;
 465         }
 466 #ifdef HAVE_IPV6
 467         if (ss.ss_family == AF_INET6) {
 468                 return iface_list_first_v6(ifaces);
 469         }
 470 #endif
 471         return iface_list_first_v4(ifaces);
 472 }
 473
 474 /**
 475   return true if an IP is one one of our local networks
 476 */
 477 bool iface_list_is_local(struct interface *ifaces, const char *dest)
 478 {
 479         struct sockaddr_storage ss;
 480
 481         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 482                 return false;
 483         }
 484         if (iface_list_find(ifaces, (const struct sockaddr *)&ss, true)) {
 485                 return true;
 486         }
 487         return false;
 488 }
 489
 490 /**
 491   return true if a IP matches a IP/netmask pair
 492 */
 493 bool iface_list_same_net(const char *ip1, const char *ip2, const char *netmask)
 494 {
 495         struct sockaddr_storage ip1_ss, ip2_ss, nm_ss;
 496
 497         if (!interpret_string_addr(&ip1_ss, ip1, AI_NUMERICHOST)) {
 498                 return false;
 499         }
 500         if (!interpret_string_addr(&ip2_ss, ip2, AI_NUMERICHOST)) {
 501                 return false;
 502         }
 503         if (!interpret_string_addr(&nm_ss, netmask, AI_NUMERICHOST)) {
 504                 return false;
 505         }
 506
 507         return same_net((struct sockaddr *)&ip1_ss,
 508                         (struct sockaddr *)&ip2_ss,
 509                         (struct sockaddr *)&nm_ss);
 510 }
 511
 512 /**
 513    return the list of wildcard interfaces
 514    this will include the IPv4 0.0.0.0, and may include IPv6 ::
 515 */
 516 char **iface_list_wildcard(TALLOC_CTX *mem_ctx)
 517 {
 518         char **ret;
 519 #ifdef HAVE_IPV6
 520         ret = str_list_make(mem_ctx, "::,0.0.0.0", NULL);
 521 #else
 522         ret = str_list_make(mem_ctx, "0.0.0.0", NULL);
 523 #endif
 524         return ret;
 525 }