main/acl.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Various sorts of access control
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  */
  25
  26 #include "asterisk.h"
  27
  28 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <sys/time.h>
  34 #include <signal.h>
  35 #include <errno.h>
  36 #include <unistd.h>
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39 #include <sys/socket.h>
  40 #include <netdb.h>
  41 #include <net/if.h>
  42 #include <netinet/in_systm.h>
  43 #include <netinet/ip.h>
  44 #include <sys/ioctl.h>
  45
  46 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__Darwin__)
  47 #include <fcntl.h>
  48 #include <net/route.h>
  49 #endif
  50
  51 #if defined(SOLARIS)
  52 #include <sys/sockio.h>
  53 #include <net/if.h>
  54 #elif defined(HAVE_GETIFADDRS)
  55 #include <ifaddrs.h>
  56 #endif
  57
  58 /* netinet/ip.h may not define the following (See RFCs 791 and 1349) */
  59 #if !defined(IPTOS_LOWCOST)
  60 #define       IPTOS_LOWCOST           0x02
  61 #endif
  62
  63 #if !defined(IPTOS_MINCOST)
  64 #define       IPTOS_MINCOST           IPTOS_LOWCOST
  65 #endif
  66
  67 #include "asterisk/acl.h"
  68 #include "asterisk/logger.h"
  69 #include "asterisk/channel.h"
  70 #include "asterisk/options.h"
  71 #include "asterisk/utils.h"
  72 #include "asterisk/lock.h"
  73 #include "asterisk/srv.h"
  74
  75 struct ast_ha {
  76         /* Host access rule */
  77         struct in_addr netaddr;
  78         struct in_addr netmask;
  79         int sense;
  80         struct ast_ha *next;
  81 };
  82
  83 /* Default IP - if not otherwise set, don't breathe garbage */
  84 static struct in_addr __ourip = { .s_addr = 0x00000000, };
  85
  86 struct my_ifreq {
  87         char ifrn_name[IFNAMSIZ];       /* Interface name, e.g. "eth0", "ppp0", etc.  */
  88         struct sockaddr_in ifru_addr;
  89 };
  90
  91 #if (!defined(SOLARIS) && !defined(HAVE_GETIFADDRS))
  92 static int get_local_address(struct in_addr *ourip)
  93 {
  94         return -1;
  95 }
  96 #else
  97 static void score_address(const struct sockaddr_in *sin, struct in_addr *best_addr, int *best_score)
  98 {
  99         const char *address;
 100         int score;
 101
 102         address = ast_inet_ntoa(sin->sin_addr);
 103
 104         /* RFC 1700 alias for the local network */
 105         if (address[0] == '0')
 106                 score = -25;
 107         /* RFC 1700 localnet */
 108         else if (strncmp(address, "127", 3) == 0)
 109                 score = -20;
 110         /* RFC 1918 non-public address space */
 111         else if (strncmp(address, "10.", 3) == 0)
 112                 score = -5;
 113         /* RFC 1918 non-public address space */
 114         else if (strncmp(address, "172", 3) == 0) {
 115                 /* 172.16.0.0 - 172.19.255.255, but not 172.160.0.0 - 172.169.255.255 */
 116                 if (address[4] == '1' && address[5] >= '6' && address[6] == '.')
 117                         score = -5;
 118                 /* 172.20.0.0 - 172.29.255.255, but not 172.200.0.0 - 172.255.255.255 nor 172.2.0.0 - 172.2.255.255 */
 119                 else if (address[4] == '2' && address[6] == '.')
 120                         score = -5;
 121                 /* 172.30.0.0 - 172.31.255.255 */
 122                 else if (address[4] == '3' && address[5] <= '1')
 123                         score = -5;
 124                 /* All other 172 addresses are public */
 125                 else
 126                         score = 0;
 127         /* RFC 2544 Benchmark test range */
 128         } else if (strncmp(address, "198.1", 5) == 0 && address[5] >= '8' && address[6] == '.')
 129                 score = -10;
 130         /* RFC 1918 non-public address space */
 131         else if (strncmp(address, "192.168", 7) == 0)
 132                 score = -5;
 133         /* RFC 3330 Zeroconf network */
 134         else if (strncmp(address, "169.254", 7) == 0)
 135                 /*!\note Better score than a test network, but not quite as good as RFC 1918
 136                  * address space.  The reason is that some Linux distributions automatically
 137                  * configure a Zeroconf address before trying DHCP, so we want to prefer a
 138                  * DHCP lease to a Zeroconf address.
 139                  */
 140                 score = -10;
 141         /* RFC 3330 Test network */
 142         else if (strncmp(address, "192.0.2.", 8) == 0)
 143                 score = -15;
 144         /* Every other address should be publically routable */
 145         else
 146                 score = 0;
 147
 148         if (score > *best_score) {
 149                 *best_score = score;
 150                 memcpy(best_addr, &sin->sin_addr, sizeof(*best_addr));
 151         }
 152 }
 153
 154 static int get_local_address(struct in_addr *ourip)
 155 {
 156         int s, res = -1;
 157 #ifdef SOLARIS
 158         struct lifreq *ifr = NULL;
 159         struct lifnum ifn;
 160         struct lifconf ifc;
 161         struct sockaddr_in *sa;
 162         char *buf = NULL;
 163         int bufsz, x;
 164 #endif /* SOLARIS */
 165 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__linux__) || defined(__Darwin__)
 166         struct ifaddrs *ifap, *ifaphead;
 167         int rtnerr;
 168         const struct sockaddr_in *sin;
 169 #endif /* BSD_OR_LINUX */
 170         struct in_addr best_addr;
 171         int best_score = -100;
 172         memset(&best_addr, 0, sizeof(best_addr));
 173
 174 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__linux__) || defined(__Darwin__)
 175         rtnerr = getifaddrs(&ifaphead);
 176         if (rtnerr) {
 177                 perror(NULL);
 178                 return -1;
 179         }
 180 #endif /* BSD_OR_LINUX */
 181
 182         s = socket(AF_INET, SOCK_STREAM, 0);
 183
 184         if (s > 0) {
 185 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__linux__) || defined(__Darwin__)
 186                 for (ifap = ifaphead; ifap; ifap = ifap->ifa_next) {
 187
 188                         if (ifap->ifa_addr && ifap->ifa_addr->sa_family == AF_INET) {
 189                                 sin = (const struct sockaddr_in *) ifap->ifa_addr;
 190                                 score_address(sin, &best_addr, &best_score);
 191                                 res = 0;
 192
 193                                 if (best_score == 0)
 194                                         break;
 195                         }
 196                 }
 197 #endif /* BSD_OR_LINUX */
 198
 199                 /* There is no reason whatsoever that this shouldn't work on Linux or BSD also. */
 200 #ifdef SOLARIS
 201                 /* Get a count of interfaces on the machine */
 202                 ifn.lifn_family = AF_INET;
 203                 ifn.lifn_flags = 0;
 204                 ifn.lifn_count = 0;
 205                 if (ioctl(s, SIOCGLIFNUM, &ifn) < 0) {
 206                         close(s);
 207                         return -1;
 208                 }
 209
 210                 bufsz = ifn.lifn_count * sizeof(struct lifreq);
 211                 if (!(buf = malloc(bufsz))) {
 212                         close(s);
 213                         return -1;
 214                 }
 215                 memset(buf, 0, bufsz);
 216
 217                 /* Get a list of interfaces on the machine */
 218                 ifc.lifc_len = bufsz;
 219                 ifc.lifc_buf = buf;
 220                 ifc.lifc_family = AF_INET;
 221                 ifc.lifc_flags = 0;
 222                 if (ioctl(s, SIOCGLIFCONF, &ifc) < 0) {
 223                         close(s);
 224                         free(buf);
 225                         return -1;
 226                 }
 227
 228                 for (ifr = ifc.lifc_req, x = 0; x < ifn.lifn_count; ifr++, x++) {
 229                         sa = (struct sockaddr_in *)&(ifr->lifr_addr);
 230                         score_address(sa, &best_addr, &best_score);
 231                         res = 0;
 232
 233                         if (best_score == 0)
 234                                 break;
 235                 }
 236
 237                 free(buf);
 238 #endif /* SOLARIS */
 239
 240                 close(s);
 241         }
 242 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__linux__) || defined(__Darwin__)
 243         freeifaddrs(ifaphead);
 244 #endif /* BSD_OR_LINUX */
 245
 246         if (res == 0 && ourip)
 247                 memcpy(ourip, &best_addr, sizeof(*ourip));
 248         return res;
 249 }
 250 #endif /* HAVE_GETIFADDRS */
 251
 252 /* Free HA structure */
 253 void ast_free_ha(struct ast_ha *ha)
 254 {
 255         struct ast_ha *hal;
 256         while (ha) {
 257                 hal = ha;
 258                 ha = ha->next;
 259                 free(hal);
 260         }
 261 }
 262
 263 /* Copy HA structure */
 264 static void ast_copy_ha(struct ast_ha *from, struct ast_ha *to)
 265 {
 266         memcpy(&to->netaddr, &from->netaddr, sizeof(from->netaddr));
 267         memcpy(&to->netmask, &from->netmask, sizeof(from->netmask));
 268         to->sense = from->sense;
 269 }
 270
 271 /* Create duplicate of ha structure */
 272 static struct ast_ha *ast_duplicate_ha(struct ast_ha *original)
 273 {
 274         struct ast_ha *new_ha;
 275
 276         if ((new_ha = ast_malloc(sizeof(*new_ha)))) {
 277                 /* Copy from original to new object */
 278                 ast_copy_ha(original, new_ha);
 279         }
 280
 281         return new_ha;
 282 }
 283
 284 /* Create duplicate HA link list */
 285 /*  Used in chan_sip2 templates */
 286 struct ast_ha *ast_duplicate_ha_list(struct ast_ha *original)
 287 {
 288         struct ast_ha *start = original;
 289         struct ast_ha *ret = NULL;
 290         struct ast_ha *link, *prev = NULL;
 291
 292         while (start) {
 293                 link = ast_duplicate_ha(start);  /* Create copy of this object */
 294                 if (prev)
 295                         prev->next = link;              /* Link previous to this object */
 296
 297                 if (!ret)
 298                         ret = link;             /* Save starting point */
 299
 300                 start = start->next;            /* Go to next object */
 301                 prev = link;                    /* Save pointer to this object */
 302         }
 303         return ret;                     /* Return start of list */
 304 }
 305
 306 struct ast_ha *ast_append_ha(char *sense, char *stuff, struct ast_ha *path)
 307 {
 308         struct ast_ha *ha;
 309         char *nm = "255.255.255.255";
 310         char tmp[256];
 311         struct ast_ha *prev = NULL;
 312         struct ast_ha *ret;
 313         int x, z;
 314         unsigned int y;
 315
 316         ret = path;
 317         while (path) {
 318                 prev = path;
 319                 path = path->next;
 320         }
 321         if ((ha = ast_malloc(sizeof(*ha)))) {
 322                 ast_copy_string(tmp, stuff, sizeof(tmp));
 323                 nm = strchr(tmp, '/');
 324                 if (!nm) {
 325                         nm = "255.255.255.255";
 326                 } else {
 327                         *nm = '\0';
 328                         nm++;
 329                 }
 330                 if (!strchr(nm, '.')) {
 331                         if ((sscanf(nm, "%d", &x) == 1) && (x >= 0) && (x <= 32)) {
 332                                 y = 0;
 333                                 for (z = 0; z < x; z++) {
 334                                         y >>= 1;
 335                                         y |= 0x80000000;
 336                                 }
 337                                 ha->netmask.s_addr = htonl(y);
 338                         }
 339                 } else if (!inet_aton(nm, &ha->netmask)) {
 340                         ast_log(LOG_WARNING, "%s is not a valid netmask\n", nm);
 341                         free(ha);
 342                         return ret;
 343                 }
 344                 if (!inet_aton(tmp, &ha->netaddr)) {
 345                         ast_log(LOG_WARNING, "%s is not a valid IP\n", tmp);
 346                         free(ha);
 347                         return ret;
 348                 }
 349                 ha->netaddr.s_addr &= ha->netmask.s_addr;
 350                 if (!strncasecmp(sense, "p", 1)) {
 351                         ha->sense = AST_SENSE_ALLOW;
 352                 } else {
 353                         ha->sense = AST_SENSE_DENY;
 354                 }
 355                 ha->next = NULL;
 356                 if (prev) {
 357                         prev->next = ha;
 358                 } else {
 359                         ret = ha;
 360                 }
 361         }
 362         if (option_debug)
 363                 ast_log(LOG_DEBUG, "%s/%s appended to acl for peer\n", stuff, nm);
 364         return ret;
 365 }
 366
 367 int ast_apply_ha(struct ast_ha *ha, struct sockaddr_in *sin)
 368 {
 369         /* Start optimistic */
 370         int res = AST_SENSE_ALLOW;
 371         while (ha) {
 372                 char iabuf[INET_ADDRSTRLEN];
 373                 char iabuf2[INET_ADDRSTRLEN];
 374                 /* DEBUG */
 375                 ast_copy_string(iabuf, ast_inet_ntoa(sin->sin_addr), sizeof(iabuf));
 376                 ast_copy_string(iabuf2, ast_inet_ntoa(ha->netaddr), sizeof(iabuf2));
 377                 if (option_debug)
 378                         ast_log(LOG_DEBUG, "##### Testing %s with %s\n", iabuf, iabuf2);
 379                 /* For each rule, if this address and the netmask = the net address
 380                    apply the current rule */
 381                 if ((sin->sin_addr.s_addr & ha->netmask.s_addr) == ha->netaddr.s_addr)
 382                         res = ha->sense;
 383                 ha = ha->next;
 384         }
 385         return res;
 386 }
 387
 388 int ast_get_ip_or_srv(struct sockaddr_in *sin, const char *value, const char *service)
 389 {
 390         struct hostent *hp;
 391         struct ast_hostent ahp;
 392         char srv[256];
 393         char host[256];
 394         int tportno = ntohs(sin->sin_port);
 395         if (inet_aton(value, &sin->sin_addr))
 396                 return 0;
 397         if (service) {
 398                 snprintf(srv, sizeof(srv), "%s.%s", service, value);
 399                 if (ast_get_srv(NULL, host, sizeof(host), &tportno, srv) > 0) {
 400                         sin->sin_port = htons(tportno);
 401                         value = host;
 402                 }
 403         }
 404         hp = ast_gethostbyname(value, &ahp);
 405         if (hp) {
 406                 memcpy(&sin->sin_addr, hp->h_addr, sizeof(sin->sin_addr));
 407         } else {
 408                 ast_log(LOG_WARNING, "Unable to lookup '%s'\n", value);
 409                 return -1;
 410         }
 411         return 0;
 412 }
 413
 414 struct dscp_codepoint {
 415         char *name;
 416         unsigned int space;
 417 };
 418
 419 /* IANA registered DSCP codepoints */
 420
 421 static const struct dscp_codepoint dscp_pool1[] = {
 422         { "CS0", 0x00 },
 423         { "CS1", 0x08 },
 424         { "CS2", 0x10 },
 425         { "CS3", 0x18 },
 426         { "CS4", 0x20 },
 427         { "CS5", 0x28 },
 428         { "CS6", 0x30 },
 429         { "CS7", 0x38 },
 430         { "AF11", 0x0A },
 431         { "AF12", 0x0C },
 432         { "AF13", 0x0E },
 433         { "AF21", 0x12 },
 434         { "AF22", 0x14 },
 435         { "AF23", 0x16 },
 436         { "AF31", 0x1A },
 437         { "AF32", 0x1C },
 438         { "AF33", 0x1E },
 439         { "AF41", 0x22 },
 440         { "AF42", 0x24 },
 441         { "AF43", 0x26 },
 442         { "EF", 0x2E },
 443 };
 444
 445 int ast_str2tos(const char *value, unsigned int *tos)
 446 {
 447         int fval;
 448         unsigned int x;
 449
 450         if (sscanf(value, "%i", &fval) == 1) {
 451                 *tos = fval & 0xFF;
 452                 return 0;
 453         }
 454
 455         for (x = 0; x < sizeof(dscp_pool1) / sizeof(dscp_pool1[0]); x++) {
 456                 if (!strcasecmp(value, dscp_pool1[x].name)) {
 457                         *tos = dscp_pool1[x].space << 2;
 458                         return 0;
 459                 }
 460         }
 461
 462         if (!strcasecmp(value, "lowdelay"))
 463                 *tos = IPTOS_LOWDELAY;
 464         else if (!strcasecmp(value, "throughput"))
 465                 *tos = IPTOS_THROUGHPUT;
 466         else if (!strcasecmp(value, "reliability"))
 467                 *tos = IPTOS_RELIABILITY;
 468         else if (!strcasecmp(value, "mincost"))
 469                 *tos = IPTOS_MINCOST;
 470         else if (!strcasecmp(value, "none"))
 471                 *tos = 0;
 472         else
 473                 return -1;
 474
 475         ast_log(LOG_WARNING, "TOS value %s is deprecated. Please see doc/ip-tos.txt for more information.\n", value);
 476
 477         return 0;
 478 }
 479
 480 const char *ast_tos2str(unsigned int tos)
 481 {
 482         unsigned int x;
 483
 484         switch (tos) {
 485         case 0:
 486                 return "none";
 487         case IPTOS_LOWDELAY:
 488                 return "lowdelay";
 489         case IPTOS_THROUGHPUT:
 490                 return "throughput";
 491         case IPTOS_RELIABILITY:
 492                 return "reliability";
 493         case IPTOS_MINCOST:
 494                 return "mincost";
 495         default:
 496                 for (x = 0; x < sizeof(dscp_pool1) / sizeof(dscp_pool1[0]); x++) {
 497                         if (dscp_pool1[x].space == (tos >> 2))
 498                                 return dscp_pool1[x].name;
 499                 }
 500         }
 501
 502         return "unknown";
 503 }
 504
 505 int ast_get_ip(struct sockaddr_in *sin, const char *value)
 506 {
 507         return ast_get_ip_or_srv(sin, value, NULL);
 508 }
 509
 510 /* iface is the interface (e.g. eth0); address is the return value */
 511 int ast_lookup_iface(char *iface, struct in_addr *address)
 512 {
 513         int mysock, res = 0;
 514         struct my_ifreq ifreq;
 515
 516         memset(&ifreq, 0, sizeof(ifreq));
 517         ast_copy_string(ifreq.ifrn_name, iface, sizeof(ifreq.ifrn_name));
 518
 519         mysock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
 520         res = ioctl(mysock, SIOCGIFADDR, &ifreq);
 521
 522         close(mysock);
 523         if (res < 0) {
 524                 ast_log(LOG_WARNING, "Unable to get IP of %s: %s\n", iface, strerror(errno));
 525                 memcpy((char *)address, (char *)&__ourip, sizeof(__ourip));
 526                 return -1;
 527         } else {
 528                 memcpy((char *)address, (char *)&ifreq.ifru_addr.sin_addr, sizeof(ifreq.ifru_addr.sin_addr));
 529                 return 0;
 530         }
 531 }
 532
 533 int ast_ouraddrfor(struct in_addr *them, struct in_addr *us)
 534 {
 535         int s;
 536         struct sockaddr_in sin;
 537         socklen_t slen;
 538
 539         s = socket(PF_INET, SOCK_DGRAM, 0);
 540         if (s < 0) {
 541                 ast_log(LOG_WARNING, "Cannot create socket\n");
 542                 return -1;
 543         }
 544         sin.sin_family = AF_INET;
 545         sin.sin_port = 5060;
 546         sin.sin_addr = *them;
 547         if (connect(s, (struct sockaddr *)&sin, sizeof(sin))) {
 548                 ast_log(LOG_WARNING, "Cannot connect\n");
 549                 close(s);
 550                 return -1;
 551         }
 552         slen = sizeof(sin);
 553         if (getsockname(s, (struct sockaddr *)&sin, &slen)) {
 554                 ast_log(LOG_WARNING, "Cannot get socket name\n");
 555                 close(s);
 556                 return -1;
 557         }
 558         close(s);
 559         *us = sin.sin_addr;
 560         return 0;
 561 }
 562
 563 int ast_find_ourip(struct in_addr *ourip, struct sockaddr_in bindaddr)
 564 {
 565         char ourhost[MAXHOSTNAMELEN] = "";
 566         struct ast_hostent ahp;
 567         struct hostent *hp;
 568         struct in_addr saddr;
 569
 570         /* just use the bind address if it is nonzero */
 571         if (ntohl(bindaddr.sin_addr.s_addr)) {
 572                 memcpy(ourip, &bindaddr.sin_addr, sizeof(*ourip));
 573                 return 0;
 574         }
 575         /* try to use our hostname */
 576         if (gethostname(ourhost, sizeof(ourhost) - 1)) {
 577                 ast_log(LOG_WARNING, "Unable to get hostname\n");
 578         } else {
 579                 hp = ast_gethostbyname(ourhost, &ahp);
 580                 if (hp) {
 581                         memcpy(ourip, hp->h_addr, sizeof(*ourip));
 582                         return 0;
 583                 }
 584         }
 585         /* A.ROOT-SERVERS.NET. */
 586         if (inet_aton("198.41.0.4", &saddr) && !ast_ouraddrfor(&saddr, ourip))
 587                 return 0;
 588         return get_local_address(ourip);
 589 }
 590