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->flags & (IFF_BROADCAST|IFF_LOOPBACK))) {
  91                 DEBUG(3,("not adding non-broadcast interface %s\n",
  92                                         ifs->name ));
  93                 return;
  94         }
  95
  96         if (!enable_ipv6 && ifs->ip.ss_family != AF_INET) {
  97                 return;
  98         }
  99
 100         iface = talloc(*interfaces == NULL ? mem_ctx : *interfaces, struct interface);
 101         if (iface == NULL)
 102                 return;
 103
 104         ZERO_STRUCTPN(iface);
 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, NULL);
 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                                 bool enable_ipv6)
 157 {
 158         struct sockaddr_storage ss;
 159         struct sockaddr_storage ss_mask;
 160         struct sockaddr_storage ss_net;
 161         struct sockaddr_storage ss_bcast;
 162         struct iface_struct ifs;
 163         char *p;
 164         int i;
 165         bool added=false;
 166         bool goodaddr = false;
 167
 168         /* first check if it is an interface name */
 169         for (i=0;i<total_probed;i++) {
 170                 if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
 171                         add_interface(mem_ctx, &probed_ifaces[i],
 172                                       local_interfaces, enable_ipv6);
 173                         added = true;
 174                 }
 175         }
 176         if (added) {
 177                 return;
 178         }
 179
 180         /* maybe it is a DNS name */
 181         p = strchr_m(token,'/');
 182         if (p == NULL) {
 183                 if (!interpret_string_addr(&ss, token, 0)) {
 184                         DEBUG(2, ("interpret_interface: Can't find address "
 185                                   "for %s\n", token));
 186                         return;
 187                 }
 188
 189                 for (i=0;i<total_probed;i++) {
 190                         if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&probed_ifaces[i].ip)) {
 191                                 add_interface(mem_ctx, &probed_ifaces[i],
 192                                               local_interfaces, enable_ipv6);
 193                                 return;
 194                         }
 195                 }
 196                 DEBUG(2,("interpret_interface: "
 197                         "can't determine interface for %s\n",
 198                         token));
 199                 return;
 200         }
 201
 202         /* parse it into an IP address/netmasklength pair */
 203         *p = 0;
 204         goodaddr = interpret_string_addr(&ss, token, 0);
 205         *p++ = '/';
 206
 207         if (!goodaddr) {
 208                 DEBUG(2,("interpret_interface: "
 209                         "can't determine interface for %s\n",
 210                         token));
 211                 return;
 212         }
 213
 214         if (strlen(p) > 2) {
 215                 goodaddr = interpret_string_addr(&ss_mask, p, 0);
 216                 if (!goodaddr) {
 217                         DEBUG(2,("interpret_interface: "
 218                                 "can't determine netmask from %s\n",
 219                                 p));
 220                         return;
 221                 }
 222         } else {
 223                 char *endp = NULL;
 224                 unsigned long val = strtoul(p, &endp, 0);
 225                 if (p == endp || (endp && *endp != '\0')) {
 226                         DEBUG(2,("interpret_interface: "
 227                                 "can't determine netmask value from %s\n",
 228                                 p));
 229                         return;
 230                 }
 231                 if (!make_netmask(&ss_mask, &ss, val)) {
 232                         DEBUG(2,("interpret_interface: "
 233                                 "can't apply netmask value %lu from %s\n",
 234                                 val,
 235                                 p));
 236                         return;
 237                 }
 238         }
 239
 240         make_bcast(&ss_bcast, &ss, &ss_mask);
 241         make_net(&ss_net, &ss, &ss_mask);
 242
 243         /* Maybe the first component was a broadcast address. */
 244         if (sockaddr_equal((struct sockaddr *)&ss_bcast, (struct sockaddr *)&ss) ||
 245                 sockaddr_equal((struct sockaddr *)&ss_net, (struct sockaddr *)&ss)) {
 246                 for (i=0;i<total_probed;i++) {
 247                         if (same_net((struct sockaddr *)&ss,
 248                                                  (struct sockaddr *)&probed_ifaces[i].ip,
 249                                                  (struct sockaddr *)&ss_mask)) {
 250                                 /* Temporarily replace netmask on
 251                                  * the detected interface - user knows
 252                                  * best.... */
 253                                 struct sockaddr_storage saved_mask =
 254                                         probed_ifaces[i].netmask;
 255                                 probed_ifaces[i].netmask = ss_mask;
 256                                 DEBUG(2,("interpret_interface: "
 257                                         "using netmask value %s from "
 258                                         "config file on interface %s\n",
 259                                         p,
 260                                         probed_ifaces[i].name));
 261                                 add_interface(mem_ctx, &probed_ifaces[i],
 262                                               local_interfaces, enable_ipv6);
 263                                 probed_ifaces[i].netmask = saved_mask;
 264                                 return;
 265                         }
 266                 }
 267                 DEBUG(2,("interpret_interface: Can't determine ip for "
 268                         "broadcast address %s\n",
 269                         token));
 270                 return;
 271         }
 272
 273         /* Just fake up the interface definition. User knows best. */
 274
 275         DEBUG(2,("interpret_interface: Adding interface %s\n",
 276                 token));
 277
 278         ZERO_STRUCT(ifs);
 279         (void)strlcpy(ifs.name, token, sizeof(ifs.name));
 280         ifs.flags = IFF_BROADCAST;
 281         ifs.ip = ss;
 282         ifs.netmask = ss_mask;
 283         ifs.bcast = ss_bcast;
 284         add_interface(mem_ctx, &ifs,
 285                       local_interfaces, enable_ipv6);
 286 }
 287
 288
 289 /**
 290 load the list of network interfaces
 291 **/
 292 void load_interface_list(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct interface **local_interfaces)
 293 {
 294         const char **ptr = lpcfg_interfaces(lp_ctx);
 295         int i;
 296         struct iface_struct *ifaces = NULL;
 297         int total_probed;
 298         bool enable_ipv6 = lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", true);
 299
 300         *local_interfaces = NULL;
 301
 302         /* probe the kernel for interfaces */
 303         total_probed = get_interfaces(mem_ctx, &ifaces);
 304
 305         /* if we don't have a interfaces line then use all interfaces
 306            except loopback */
 307         if (!ptr || !*ptr || !**ptr) {
 308                 if (total_probed <= 0) {
 309                         DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
 310                 }
 311                 for (i=0;i<total_probed;i++) {
 312                         if (!is_loopback_addr((struct sockaddr *)&ifaces[i].ip)) {
 313                                 add_interface(mem_ctx, &ifaces[i], local_interfaces, enable_ipv6);
 314                         }
 315                 }
 316         }
 317
 318         while (ptr && *ptr) {
 319                 interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces, enable_ipv6);
 320                 ptr++;
 321         }
 322
 323         if (!*local_interfaces) {
 324                 DEBUG(0,("WARNING: no network interfaces found\n"));
 325         }
 326         talloc_free(ifaces);
 327 }
 328
 329 /**
 330   how many interfaces do we have
 331   **/
 332 int iface_list_count(struct interface *ifaces)
 333 {
 334         int ret = 0;
 335         struct interface *i;
 336
 337         for (i=ifaces;i;i=i->next)
 338                 ret++;
 339         return ret;
 340 }
 341
 342 /**
 343   return IP of the Nth interface
 344   **/
 345 const char *iface_list_n_ip(struct interface *ifaces, int n)
 346 {
 347         struct interface *i;
 348
 349         for (i=ifaces;i && n;i=i->next)
 350                 n--;
 351
 352         if (i) {
 353                 return i->ip_s;
 354         }
 355         return NULL;
 356 }
 357
 358
 359 /**
 360   return the first IPv4 interface address we have registered
 361   **/
 362 const char *iface_list_first_v4(struct interface *ifaces)
 363 {
 364         struct interface *i;
 365
 366         for (i=ifaces; i; i=i->next) {
 367                 if (i->ip.ss_family == AF_INET) {
 368                         return i->ip_s;
 369                 }
 370         }
 371         return NULL;
 372 }
 373
 374 /**
 375   return the first IPv6 interface address we have registered
 376   **/
 377 static const char *iface_list_first_v6(struct interface *ifaces)
 378 {
 379         struct interface *i;
 380
 381 #ifdef HAVE_IPV6
 382         for (i=ifaces; i; i=i->next) {
 383                 if (i->ip.ss_family == AF_INET6) {
 384                         return i->ip_s;
 385                 }
 386         }
 387 #endif
 388         return NULL;
 389 }
 390
 391 /**
 392    check if an interface is IPv4
 393   **/
 394 bool iface_list_n_is_v4(struct interface *ifaces, int n)
 395 {
 396         struct interface *i;
 397
 398         for (i=ifaces;i && n;i=i->next)
 399                 n--;
 400
 401         if (i) {
 402                 return i->ip.ss_family == AF_INET;
 403         }
 404         return false;
 405 }
 406
 407 /**
 408   return bcast of the Nth interface
 409   **/
 410 const char *iface_list_n_bcast(struct interface *ifaces, int n)
 411 {
 412         struct interface *i;
 413
 414         for (i=ifaces;i && n;i=i->next)
 415                 n--;
 416
 417         if (i) {
 418                 return i->bcast_s;
 419         }
 420         return NULL;
 421 }
 422
 423 /**
 424   return netmask of the Nth interface
 425   **/
 426 const char *iface_list_n_netmask(struct interface *ifaces, int n)
 427 {
 428         struct interface *i;
 429
 430         for (i=ifaces;i && n;i=i->next)
 431                 n--;
 432
 433         if (i) {
 434                 return i->nmask_s;
 435         }
 436         return NULL;
 437 }
 438
 439 /**
 440   return the local IP address that best matches a destination IP, or
 441   our first interface if none match
 442 */
 443 const char *iface_list_best_ip(struct interface *ifaces, const char *dest)
 444 {
 445         struct interface *iface;
 446         struct sockaddr_storage ss;
 447
 448         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 449                 return iface_list_n_ip(ifaces, 0);
 450         }
 451         iface = iface_list_find(ifaces, (const struct sockaddr *)&ss, true);
 452         if (iface) {
 453                 return iface->ip_s;
 454         }
 455 #ifdef HAVE_IPV6
 456         if (ss.ss_family == AF_INET6) {
 457                 return iface_list_first_v6(ifaces);
 458         }
 459 #endif
 460         return iface_list_first_v4(ifaces);
 461 }
 462
 463 /**
 464   return true if an IP is one one of our local networks
 465 */
 466 bool iface_list_is_local(struct interface *ifaces, const char *dest)
 467 {
 468         struct sockaddr_storage ss;
 469
 470         if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
 471                 return false;
 472         }
 473         if (iface_list_find(ifaces, (const struct sockaddr *)&ss, true)) {
 474                 return true;
 475         }
 476         return false;
 477 }
 478
 479 /**
 480   return true if a IP matches a IP/netmask pair
 481 */
 482 bool iface_list_same_net(const char *ip1, const char *ip2, const char *netmask)
 483 {
 484         struct sockaddr_storage ip1_ss, ip2_ss, nm_ss;
 485
 486         if (!interpret_string_addr(&ip1_ss, ip1, AI_NUMERICHOST)) {
 487                 return false;
 488         }
 489         if (!interpret_string_addr(&ip2_ss, ip2, AI_NUMERICHOST)) {
 490                 return false;
 491         }
 492         if (!interpret_string_addr(&nm_ss, netmask, AI_NUMERICHOST)) {
 493                 return false;
 494         }
 495
 496         return same_net((struct sockaddr *)&ip1_ss,
 497                         (struct sockaddr *)&ip2_ss,
 498                         (struct sockaddr *)&nm_ss);
 499 }
 500
 501 /**
 502    return the list of wildcard interfaces
 503    this will include the IPv4 0.0.0.0, and may include IPv6 ::
 504    it is overridden by the 'socket address' option in smb.conf
 505 */
 506 const char **iface_list_wildcard(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
 507 {
 508         const char **ret;
 509         const char *socket_address;
 510
 511         /* the user may have configured a specific address */
 512         socket_address = lpcfg_socket_address(lp_ctx);
 513         if (strcmp(socket_address, "") != 0) {
 514                 ret = (const char **)str_list_make(mem_ctx, socket_address, NULL);
 515                 return ret;
 516         }
 517
 518         ret = (const char **)str_list_make(mem_ctx, "0.0.0.0", NULL);
 519         if (ret == NULL) return NULL;
 520
 521 #ifdef HAVE_IPV6
 522         if (lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", true)) {
 523                 struct interface *local_interfaces = NULL;
 524
 525                 load_interface_list(ret, lp_ctx, &local_interfaces);
 526
 527                 if (iface_list_first_v6(local_interfaces)) {
 528                         TALLOC_FREE(local_interfaces);
 529                         /*
 530                          * only add "::" if we have at least
 531                          * one ipv6 interface
 532                          */
 533                         return str_list_add(ret, "::");
 534                 }
 535                 TALLOC_FREE(local_interfaces);
 536         }
 537 #endif
 538
 539         return ret;
 540 }