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