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
  29 /* used for network interfaces */
  30 struct interface {
  31         struct interface *next, *prev;
  32         char *name;
  33         int flags;
  34         struct sockaddr_storage ip;
  35         struct sockaddr_storage netmask;
  36         struct sockaddr_storage bcast;
  37         const char *ip_s;
  38         const char *bcast_s;
  39         const char *nmask_s;
  40 };
  41
  42 #define ALLONES  ((uint32_t)0xFFFFFFFF)
  43 /*
  44   address construction based on a patch from fred@datalync.com
  45 */
  46 #define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
  47 #define MKNETADDR(_IP, _NM) (_IP & _NM)
  48
  49 /****************************************************************************
  50 Try and find an interface that matches an ip. If we cannot, return NULL
  51   **************************************************************************/
  52 static struct interface *iface_list_find(struct interface *interfaces,
  53                                          const struct sockaddr *ip,
  54                                          bool check_mask)
  55 {
  56         struct interface *i;
  57
  58         if (is_address_any(ip)) {
  59                 return interfaces;
  60         }
  61
  62         for (i=interfaces;i;i=i->next) {
  63                 if (check_mask) {
  64                         if (same_net(ip, (struct sockaddr *)&i->ip, (struct sockaddr *)&i->netmask)) {
  65                                 return i;
  66                         }
  67                 } else if (sockaddr_equal((struct sockaddr *)&i->ip, ip)) {
  68                         return i;
  69                 }
  70         }
  71
  72         return NULL;
  73 }
  74
  75 /****************************************************************************
  76 add an interface to the linked list of interfaces
  77 ****************************************************************************/
  78 static void add_interface(TALLOC_CTX *mem_ctx, const struct iface_struct *ifs, struct interface **interfaces,
  79                           bool enable_ipv6)
  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 (!enable_ipv6 && ifs->ip.ss_family != AF_INET) {
  98                 return;
  99         }
 100
 101         iface = talloc(*interfaces == NULL ? mem_ctx : *interfaces, struct interface);
 102         if (iface == NULL)
 103                 return;
 104
 105         ZERO_STRUCTPN(iface);
 106
 107         iface->name = talloc_strdup(iface, ifs->name);
 108         if (!iface->name) {
 109                 SAFE_FREE(iface);
 110                 return;
 111         }
 112         iface->flags = ifs->flags;
 113         iface->ip = ifs->ip;
 114         iface->netmask = ifs->netmask;
 115         iface->bcast = ifs->bcast;
 116
 117         /* keep string versions too, to avoid people tripping over the implied
 118            static in inet_ntoa() */
 119         print_sockaddr(addr, sizeof(addr), &iface->ip);
 120         DEBUG(4,("added interface %s ip=%s ",
 121                  iface->name, addr));
 122         iface->ip_s = talloc_strdup(iface, addr);
 123
 124         print_sockaddr(addr, sizeof(addr),
 125                        &iface->bcast);
 126         DEBUG(4,("bcast=%s ", addr));
 127         iface->bcast_s = talloc_strdup(iface, addr);
 128
 129         print_sockaddr(addr, sizeof(addr),
 130                        &iface->netmask);
 131         DEBUG(4,("netmask=%s\n", addr));
 132         iface->nmask_s = talloc_strdup(iface, addr);
 133
 134         /*
 135            this needs to be a ADD_END, as some tests (such as the
 136            spoolss notify test) depend on the interfaces ordering
 137         */
 138         DLIST_ADD_END(*interfaces, iface, NULL);
 139 }
 140
 141 /**
 142 interpret a single element from a interfaces= config line
 143
 144 This handles the following different forms:
 145
 146 1) wildcard interface name
 147 2) DNS name
 148 3) IP/masklen
 149 4) ip/mask
 150 5) bcast/mask
 151 **/
 152 static void interpret_interface(TALLOC_CTX *mem_ctx,
 153                                 const char *token,
 154                                 struct iface_struct *probed_ifaces,
 155                                 int total_probed,
 156                                 struct interface **local_interfaces,
 157                                 bool enable_ipv6)
 158 {
 159         struct sockaddr_storage ss;
 160         struct sockaddr_storage ss_mask;
 161         struct sockaddr_storage ss_net;
 162         struct sockaddr_storage ss_bcast;
 163         struct iface_struct ifs;
 164         char *p;
 165         int i;
 166         bool added=false;
 167         bool goodaddr = false;
 168
 169         /* first check if it is an interface name */
 170         for (i=0;i<total_probed;i++) {
 171                 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
 172                         add_interface(mem_ctx, &probed_ifaces[i],
 173                                       local_interfaces, enable_ipv6);
 174                         added = true;
 175                 }
 176         }
 177         if (added) {
 178                 return;
 179         }
 180
 181         /* maybe it is a DNS name */
 182         p = strchr_m(token,'/');
 183         if (p == NULL) {
 184                 if (!interpret_string_addr(&ss, token, 0)) {
 185                         DEBUG(2, ("interpret_interface: Can't find address "
 186                                   "for %s\n", token));
 187                         return;
 188                 }
 189
 190                 for (i=0;i<total_probed;i++) {
 191                         if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&probed_ifaces[i].ip)) {
 192                                 add_interface(mem_ctx, &probed_ifaces[i],
 193                                               local_interfaces, enable_ipv6);
 194                                 return;
 195                         }
 196                 }
 197                 DEBUG(2,("interpret_interface: "
 198                         "can't determine interface for %s\n",
 199                         token));
 200                 return;
 201         }
 202
 203         /* parse it into an IP address/netmasklength pair */
 204         *p = 0;
 205         goodaddr = interpret_string_addr(&ss, token, 0);
 206         *p++ = '/';
 207
 208         if (!goodaddr) {
 209                 DEBUG(2,("interpret_interface: "
 210                         "can't determine interface for %s\n",
 211                         token));
 212                 return;
 213         }
 214
 215         if (strlen(p) > 2) {
 216                 goodaddr = interpret_string_addr(&ss_mask, p, 0);
 217                 if (!goodaddr) {
 218                         DEBUG(2,("interpret_interface: "
 219                                 "can't determine netmask from %s\n",
 220                                 p));
 221                         return;
 222                 }
 223         } else {
 224                 char *endp = NULL;
 225                 unsigned long val = strtoul(p, &endp, 0);
 226                 if (p == endp || (endp && *endp != '\0')) {
 227                         DEBUG(2,("interpret_interface: "
 228                                 "can't determine netmask value from %s\n",
 229                                 p));
 230                         return;
 231                 }
 232                 if (!make_netmask(&ss_mask, &ss, val)) {
 233                         DEBUG(2,("interpret_interface: "
 234                                 "can't apply netmask value %lu from %s\n",
 235                                 val,
 236                                 p));
 237                         return;
 238                 }
 239         }
 240
 241         make_bcast(&ss_bcast, &ss, &ss_mask);
 242         make_net(&ss_net, &ss, &ss_mask);
 243
 244         /* Maybe the first component was a broadcast address. */
 245         if (sockaddr_equal((struct sockaddr *)&ss_bcast, (struct sockaddr *)&ss) ||
 246                 sockaddr_equal((struct sockaddr *)&ss_net, (struct sockaddr *)&ss)) {
 247                 for (i=0;i<total_probed;i++) {
 248                         if (same_net((struct sockaddr *)&ss,
 249                                                  (struct sockaddr *)&probed_ifaces[i].ip,
 250                                                  (struct sockaddr *)&ss_mask)) {
 251                                 /* Temporarily replace netmask on
 252                                  * the detected interface - user knows
 253                                  * best.... */
 254                                 struct sockaddr_storage saved_mask =
 255                                         probed_ifaces[i].netmask;
 256                                 probed_ifaces[i].netmask = ss_mask;
 257                                 DEBUG(2,("interpret_interface: "
 258                                         "using netmask value %s from "
 259                                         "config file on interface %s\n",
 260                                         p,
 261                                         probed_ifaces[i].name));
 262                                 add_interface(mem_ctx, &probed_ifaces[i],
 263                                               local_interfaces, enable_ipv6);
 264                                 probed_ifaces[i].netmask = saved_mask;
 265                                 return;
 266                         }
 267                 }
 268                 DEBUG(2,("interpret_interface: Can't determine ip for "
 269                         "broadcast address %s\n",
 270                         token));
 271                 return;
 272         }
 273
 274         /* Just fake up the interface definition. User knows best. */
 275
 276         DEBUG(2,("interpret_interface: Adding interface %s\n",
 277                 token));
 278
 279         ZERO_STRUCT(ifs);
 280         (void)strlcpy(ifs.name, token, sizeof(ifs.name));
 281         ifs.flags = IFF_BROADCAST;
 282         ifs.ip = ss;
 283         ifs.netmask = ss_mask;
 284         ifs.bcast = ss_bcast;
 285         add_interface(mem_ctx, &ifs,
 286                       local_interfaces, enable_ipv6);
 287 }
 288
 289
 290 /**
 291 load the list of network interfaces
 292 **/
 293 void load_interface_list(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct interface **local_interfaces)
 294 {
 295         const char **ptr = lpcfg_interfaces(lp_ctx);
 296         int i;
 297         struct iface_struct *ifaces = NULL;
 298         int total_probed;
 299         bool enable_ipv6 = lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", true);
 300
 301         *local_interfaces = NULL;
 302
 303         /* probe the kernel for interfaces */
 304         total_probed = get_interfaces(mem_ctx, &ifaces);
 305
 306         /* if we don't have a interfaces line then use all interfaces
 307            except loopback */
 308         if (!ptr || !*ptr || !**ptr) {
 309                 if (total_probed <= 0) {
 310                         DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
 311                 }
 312                 for (i=0;i<total_probed;i++) {
 313                         if (!is_loopback_addr((struct sockaddr *)&ifaces[i].ip)) {
 314                                 add_interface(mem_ctx, &ifaces[i], local_interfaces, enable_ipv6);
 315                         }
 316                 }
 317         }
 318
 319         while (ptr && *ptr) {
 320                 interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces, enable_ipv6);
 321                 ptr++;
 322         }
 323
 324         if (!*local_interfaces) {
 325                 DEBUG(0,("WARNING: no network interfaces found\n"));
 326         }
 327         talloc_free(ifaces);
 328 }
 329
 330 /**
 331   how many interfaces do we have
 332   **/
 333 int iface_list_count(struct interface *ifaces)
 334 {
 335         int ret = 0;
 336         struct interface *i;
 337
 338         for (i=ifaces;i;i=i->next)
 339                 ret++;
 340         return ret;
 341 }
 342
 343 /**
 344   return IP of the Nth interface
 345   **/
 346 const char *iface_list_n_ip(struct interface *ifaces, int n)
 347 {
 348         struct interface *i;
 349
 350         for (i=ifaces;i && n;i=i->next)
 351                 n--;
 352
 353         if (i) {
 354                 return i->ip_s;
 355         }
 356         return NULL;
 357 }
 358
 359
 360 /**
 361   return the first IPv4 interface address we have registered
 362   **/
 363 const char *iface_list_first_v4(struct interface *ifaces)
 364 {
 365         struct interface *i;
 366
 367         for (i=ifaces; i; i=i->next) {
 368                 if (i->ip.ss_family == AF_INET) {
 369                         return i->ip_s;
 370                 }
 371         }
 372         return NULL;
 373 }
 374
 375 /**
 376   return the first IPv6 interface address we have registered
 377   **/
 378 static const char *iface_list_first_v6(struct interface *ifaces)
 379 {
 380         struct interface *i;
 381
 382 #ifdef HAVE_IPV6
 383         for (i=ifaces; i; i=i->next) {
 384                 if (i->ip.ss_family == AF_INET6) {
 385                         return i->ip_s;
 386                 }
 387         }
 388 #endif
 389         return NULL;
 390 }
 391
 392 /**
 393    check if an interface is IPv4
 394   **/
 395 bool iface_list_n_is_v4(struct interface *ifaces, int n)
 396 {
 397         struct interface *i;
 398
 399         for (i=ifaces;i && n;i=i->next)
 400                 n--;
 401
 402         if (i) {
 403                 return i->ip.ss_family == AF_INET;
 404         }
 405         return false;
 406 }
 407
 408 /**
 409   return bcast of the Nth interface
 410   **/
 411 const char *iface_list_n_bcast(struct interface *ifaces, int n)
 412 {
 413         struct interface *i;
 414
 415         for (i=ifaces;i && n;i=i->next)
 416                 n--;
 417
 418         if (i) {
 419                 return i->bcast_s;
 420         }
 421         return NULL;
 422 }
 423
 424 /**
 425   return netmask of the Nth interface
 426   **/
 427 const char *iface_list_n_netmask(struct interface *ifaces, int n)
 428 {
 429         struct interface *i;
 430
 431         for (i=ifaces;i && n;i=i->next)
 432                 n--;
 433
 434         if (i) {
 435                 return i->nmask_s;
 436         }
 437         return NULL;
 438 }
 439
 440 /**
 441   return the local IP address that best matches a destination IP, or
 442   our first interface if none match
 443 */
 444 const char *iface_list_best_ip(struct interface *ifaces, const char *dest)
 445 {
 446         struct interface *iface;
 447         struct sockaddr_storage ss;
 448
 449         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 450                 return iface_list_n_ip(ifaces, 0);
 451         }
 452         iface = iface_list_find(ifaces, (const struct sockaddr *)&ss, true);
 453         if (iface) {
 454                 return iface->ip_s;
 455         }
 456 #ifdef HAVE_IPV6
 457         if (ss.ss_family == AF_INET6) {
 458                 return iface_list_first_v6(ifaces);
 459         }
 460 #endif
 461         return iface_list_first_v4(ifaces);
 462 }
 463
 464 /**
 465   return true if an IP is one one of our local networks
 466 */
 467 bool iface_list_is_local(struct interface *ifaces, const char *dest)
 468 {
 469         struct sockaddr_storage ss;
 470
 471         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 472                 return false;
 473         }
 474         if (iface_list_find(ifaces, (const struct sockaddr *)&ss, true)) {
 475                 return true;
 476         }
 477         return false;
 478 }
 479
 480 /**
 481   return true if a IP matches a IP/netmask pair
 482 */
 483 bool iface_list_same_net(const char *ip1, const char *ip2, const char *netmask)
 484 {
 485         struct sockaddr_storage ip1_ss, ip2_ss, nm_ss;
 486
 487         if (!interpret_string_addr(&ip1_ss, ip1, AI_NUMERICHOST)) {
 488                 return false;
 489         }
 490         if (!interpret_string_addr(&ip2_ss, ip2, AI_NUMERICHOST)) {
 491                 return false;
 492         }
 493         if (!interpret_string_addr(&nm_ss, netmask, AI_NUMERICHOST)) {
 494                 return false;
 495         }
 496
 497         return same_net((struct sockaddr *)&ip1_ss,
 498                         (struct sockaddr *)&ip2_ss,
 499                         (struct sockaddr *)&nm_ss);
 500 }
 501
 502 /**
 503    return the list of wildcard interfaces
 504    this will include the IPv4 0.0.0.0, and may include IPv6 ::
 505    it is overridden by the 'socket address' option in smb.conf
 506 */
 507 const char **iface_list_wildcard(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
 508 {
 509         const char **ret;
 510         const char *socket_address;
 511
 512         /* the user may have configured a specific address */
 513         socket_address = lpcfg_socket_address(lp_ctx);
 514         if (strcmp(socket_address, "") != 0) {
 515                 ret = (const char **)str_list_make(mem_ctx, socket_address, NULL);
 516                 return ret;
 517         }
 518
 519         ret = (const char **)str_list_make(mem_ctx, "0.0.0.0", NULL);
 520         if (ret == NULL) return NULL;
 521
 522 #ifdef HAVE_IPV6
 523         if (lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", true)) {
 524                 struct interface *local_interfaces = NULL;
 525
 526                 load_interface_list(ret, lp_ctx, &local_interfaces);
 527
 528                 if (iface_list_first_v6(local_interfaces)) {
 529                         TALLOC_FREE(local_interfaces);
 530                         /*
 531                          * only add "::" if we have at least
 532                          * one ipv6 interface
 533                          */
 534                         return str_list_add(ret, "::");
 535                 }
 536                 TALLOC_FREE(local_interfaces);
 537         }
 538 #endif
 539
 540         return ret;
 541 }