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.h>
  43 #include <netinet/in_systm.h>
  44 #include <netinet/ip.h>
  45 #include <sys/ioctl.h>
  46
  47 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__)
  48 #include <fcntl.h>
  49 #include <net/route.h>
  50 #endif
  51
  52 #if defined(SOLARIS)
  53 #include <sys/sockio.h>
  54 #endif
  55
  56 /* netinet/ip.h may not define the following (See RFCs 791 and 1349) */
  57 #if !defined(IPTOS_LOWCOST)
  58 #define       IPTOS_LOWCOST           0x02
  59 #endif
  60
  61 #if !defined(IPTOS_MINCOST)
  62 #define       IPTOS_MINCOST           IPTOS_LOWCOST
  63 #endif
  64
  65 #include "asterisk/acl.h"
  66 #include "asterisk/logger.h"
  67 #include "asterisk/channel.h"
  68 #include "asterisk/options.h"
  69 #include "asterisk/utils.h"
  70 #include "asterisk/lock.h"
  71 #include "asterisk/srv.h"
  72
  73 struct ast_ha {
  74         /* Host access rule */
  75         struct in_addr netaddr;
  76         struct in_addr netmask;
  77         int sense;
  78         struct ast_ha *next;
  79 };
  80
  81 /* Default IP - if not otherwise set, don't breathe garbage */
  82 static struct in_addr __ourip = { 0x00000000 };
  83
  84 struct my_ifreq {
  85         char ifrn_name[IFNAMSIZ];       /* Interface name, e.g. "eth0", "ppp0", etc.  */
  86         struct sockaddr_in ifru_addr;
  87 };
  88
  89 /* Free HA structure */
  90 void ast_free_ha(struct ast_ha *ha)
  91 {
  92         struct ast_ha *hal;
  93         while (ha) {
  94                 hal = ha;
  95                 ha = ha->next;
  96                 free(hal);
  97         }
  98 }
  99
 100 /* Copy HA structure */
 101 static void ast_copy_ha(struct ast_ha *from, struct ast_ha *to)
 102 {
 103         memcpy(&to->netaddr, &from->netaddr, sizeof(from->netaddr));
 104         memcpy(&to->netmask, &from->netmask, sizeof(from->netmask));
 105         to->sense = from->sense;
 106 }
 107
 108 /* Create duplicate of ha structure */
 109 static struct ast_ha *ast_duplicate_ha(struct ast_ha *original)
 110 {
 111         struct ast_ha *new_ha;
 112
 113         if ((new_ha = ast_malloc(sizeof(*new_ha)))) {
 114                 /* Copy from original to new object */
 115                 ast_copy_ha(original, new_ha);
 116         }
 117
 118         return new_ha;
 119 }
 120
 121 /* Create duplicate HA link list */
 122 /*  Used in chan_sip2 templates */
 123 struct ast_ha *ast_duplicate_ha_list(struct ast_ha *original)
 124 {
 125         struct ast_ha *start = original;
 126         struct ast_ha *ret = NULL;
 127         struct ast_ha *link, *prev = NULL;
 128
 129         while (start) {
 130                 link = ast_duplicate_ha(start);  /* Create copy of this object */
 131                 if (prev)
 132                         prev->next = link;              /* Link previous to this object */
 133
 134                 if (!ret)
 135                         ret = link;             /* Save starting point */
 136
 137                 start = start->next;            /* Go to next object */
 138                 prev = link;                    /* Save pointer to this object */
 139         }
 140         return ret;                     /* Return start of list */
 141 }
 142
 143 struct ast_ha *ast_append_ha(char *sense, char *stuff, struct ast_ha *path)
 144 {
 145         struct ast_ha *ha;
 146         char *nm = "255.255.255.255";
 147         char tmp[256];
 148         struct ast_ha *prev = NULL;
 149         struct ast_ha *ret;
 150         int x, z;
 151         unsigned int y;
 152
 153         ret = path;
 154         while (path) {
 155                 prev = path;
 156                 path = path->next;
 157         }
 158         if ((ha = ast_malloc(sizeof(*ha)))) {
 159                 ast_copy_string(tmp, stuff, sizeof(tmp));
 160                 nm = strchr(tmp, '/');
 161                 if (!nm) {
 162                         nm = "255.255.255.255";
 163                 } else {
 164                         *nm = '\0';
 165                         nm++;
 166                 }
 167                 if (!strchr(nm, '.')) {
 168                         if ((sscanf(nm, "%d", &x) == 1) && (x >= 0) && (x <= 32)) {
 169                                 y = 0;
 170                                 for (z = 0; z < x; z++) {
 171                                         y >>= 1;
 172                                         y |= 0x80000000;
 173                                 }
 174                                 ha->netmask.s_addr = htonl(y);
 175                         }
 176                 } else if (!inet_aton(nm, &ha->netmask)) {
 177                         ast_log(LOG_WARNING, "%s is not a valid netmask\n", nm);
 178                         free(ha);
 179                         return path;
 180                 }
 181                 if (!inet_aton(tmp, &ha->netaddr)) {
 182                         ast_log(LOG_WARNING, "%s is not a valid IP\n", tmp);
 183                         free(ha);
 184                         return path;
 185                 }
 186                 ha->netaddr.s_addr &= ha->netmask.s_addr;
 187                 if (!strncasecmp(sense, "p", 1)) {
 188                         ha->sense = AST_SENSE_ALLOW;
 189                 } else {
 190                         ha->sense = AST_SENSE_DENY;
 191                 }
 192                 ha->next = NULL;
 193                 if (prev) {
 194                         prev->next = ha;
 195                 } else {
 196                         ret = ha;
 197                 }
 198         }
 199         ast_log(LOG_DEBUG, "%s/%s appended to acl for peer\n", stuff, nm);
 200         return ret;
 201 }
 202
 203 int ast_apply_ha(struct ast_ha *ha, struct sockaddr_in *sin)
 204 {
 205         /* Start optimistic */
 206         int res = AST_SENSE_ALLOW;
 207         while (ha) {
 208                 char iabuf[INET_ADDRSTRLEN];
 209                 char iabuf2[INET_ADDRSTRLEN];
 210                 /* DEBUG */
 211                 ast_log(LOG_DEBUG,
 212                         "##### Testing %s with %s\n",
 213                         ast_inet_ntoa(iabuf, sizeof(iabuf), sin->sin_addr),
 214                         ast_inet_ntoa(iabuf2, sizeof(iabuf2), ha->netaddr));
 215                 /* For each rule, if this address and the netmask = the net address
 216                    apply the current rule */
 217                 if ((sin->sin_addr.s_addr & ha->netmask.s_addr) == ha->netaddr.s_addr)
 218                         res = ha->sense;
 219                 ha = ha->next;
 220         }
 221         return res;
 222 }
 223
 224 int ast_get_ip_or_srv(struct sockaddr_in *sin, const char *value, const char *service)
 225 {
 226         struct hostent *hp;
 227         struct ast_hostent ahp;
 228         char srv[256];
 229         char host[256];
 230         int tportno = ntohs(sin->sin_port);
 231         if (inet_aton(value, &sin->sin_addr))
 232                 return 0;
 233         if (service) {
 234                 snprintf(srv, sizeof(srv), "%s.%s", service, value);
 235                 if (ast_get_srv(NULL, host, sizeof(host), &tportno, srv) > 0) {
 236                         sin->sin_port = htons(tportno);
 237                         value = host;
 238                 }
 239         }
 240         hp = ast_gethostbyname(value, &ahp);
 241         if (hp) {
 242                 memcpy(&sin->sin_addr, hp->h_addr, sizeof(sin->sin_addr));
 243         } else {
 244                 ast_log(LOG_WARNING, "Unable to lookup '%s'\n", value);
 245                 return -1;
 246         }
 247         return 0;
 248 }
 249
 250 struct dscp_codepoint {
 251         char *name;
 252         unsigned int space;
 253 };
 254
 255 /* IANA registered DSCP codepoints */
 256
 257 static const struct dscp_codepoint dscp_pool1[] = {
 258         { "CS0", 0x00 },
 259         { "CS1", 0x08 },
 260         { "CS2", 0x10 },
 261         { "CS3", 0x18 },
 262         { "CS4", 0x20 },
 263         { "CS5", 0x28 },
 264         { "CS6", 0x30 },
 265         { "CS7", 0x38 },
 266         { "AF11", 0x0A },
 267         { "AF12", 0x0C },
 268         { "AF13", 0x0E },
 269         { "AF21", 0x12 },
 270         { "AF22", 0x14 },
 271         { "AF23", 0x16 },
 272         { "AF31", 0x1A },
 273         { "AF32", 0x1C },
 274         { "AF33", 0x1E },
 275         { "AF41", 0x22 },
 276         { "AF42", 0x24 },
 277         { "AF43", 0x26 },
 278         { "EF", 0x2E },
 279 };
 280
 281 int ast_str2tos(const char *value, unsigned int *tos)
 282 {
 283         int fval;
 284         unsigned int x;
 285
 286         if (sscanf(value, "%i", &fval) == 1) {
 287                 *tos = fval & 0xFF;
 288                 return 0;
 289         }
 290
 291         for (x = 0; x < sizeof(dscp_pool1) / sizeof(dscp_pool1[0]); x++) {
 292                 if (!strcasecmp(value, dscp_pool1[x].name)) {
 293                         *tos = dscp_pool1[x].space << 2;
 294                         return 0;
 295                 }
 296         }
 297
 298         if (!strcasecmp(value, "lowdelay"))
 299                 *tos = IPTOS_LOWDELAY;
 300         else if (!strcasecmp(value, "throughput"))
 301                 *tos = IPTOS_THROUGHPUT;
 302         else if (!strcasecmp(value, "reliability"))
 303                 *tos = IPTOS_RELIABILITY;
 304         else if (!strcasecmp(value, "mincost"))
 305                 *tos = IPTOS_MINCOST;
 306         else if (!strcasecmp(value, "none"))
 307                 *tos = 0;
 308         else
 309                 return -1;
 310
 311         ast_log(LOG_WARNING, "TOS value %s is deprecated. Please see doc/ip-tos.txt for more information.\n", value);
 312
 313         return 0;
 314 }
 315
 316 const char *ast_tos2str(unsigned int tos)
 317 {
 318         unsigned int x;
 319
 320         switch (tos) {
 321         case 0:
 322                 return "none";
 323         case IPTOS_LOWDELAY:
 324                 return "lowdelay";
 325         case IPTOS_THROUGHPUT:
 326                 return "throughput";
 327         case IPTOS_RELIABILITY:
 328                 return "reliability";
 329         case IPTOS_MINCOST:
 330                 return "mincost";
 331         default:
 332                 for (x = 0; x < sizeof(dscp_pool1) / sizeof(dscp_pool1[0]); x++) {
 333                         if (dscp_pool1[x].space == (tos >> 2))
 334                                 return dscp_pool1[x].name;
 335                 }
 336         }
 337
 338         return "unknown";
 339 }
 340
 341 int ast_get_ip(struct sockaddr_in *sin, const char *value)
 342 {
 343         return ast_get_ip_or_srv(sin, value, NULL);
 344 }
 345
 346 /* iface is the interface (e.g. eth0); address is the return value */
 347 int ast_lookup_iface(char *iface, struct in_addr *address)
 348 {
 349         int mysock, res = 0;
 350         struct my_ifreq ifreq;
 351
 352         memset(&ifreq, 0, sizeof(ifreq));
 353         ast_copy_string(ifreq.ifrn_name, iface, sizeof(ifreq.ifrn_name));
 354
 355         mysock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
 356         res = ioctl(mysock, SIOCGIFADDR, &ifreq);
 357
 358         close(mysock);
 359         if (res < 0) {
 360                 ast_log(LOG_WARNING, "Unable to get IP of %s: %s\n", iface, strerror(errno));
 361                 memcpy((char *)address, (char *)&__ourip, sizeof(__ourip));
 362                 return -1;
 363         } else {
 364                 memcpy((char *)address, (char *)&ifreq.ifru_addr.sin_addr, sizeof(ifreq.ifru_addr.sin_addr));
 365                 return 0;
 366         }
 367 }
 368
 369 int ast_ouraddrfor(struct in_addr *them, struct in_addr *us)
 370 {
 371         int s;
 372         struct sockaddr_in sin;
 373         socklen_t slen;
 374
 375         s = socket(PF_INET, SOCK_DGRAM, 0);
 376         if (s < 0) {
 377                 ast_log(LOG_WARNING, "Cannot create socket\n");
 378                 return -1;
 379         }
 380         sin.sin_family = AF_INET;
 381         sin.sin_port = 5060;
 382         sin.sin_addr = *them;
 383         if (connect(s, (struct sockaddr *)&sin, sizeof(sin))) {
 384                 ast_log(LOG_WARNING, "Cannot connect\n");
 385                 close(s);
 386                 return -1;
 387         }
 388         slen = sizeof(sin);
 389         if (getsockname(s, (struct sockaddr *)&sin, &slen)) {
 390                 ast_log(LOG_WARNING, "Cannot get socket name\n");
 391                 close(s);
 392                 return -1;
 393         }
 394         close(s);
 395         *us = sin.sin_addr;
 396         return 0;
 397 }
 398
 399 int ast_find_ourip(struct in_addr *ourip, struct sockaddr_in bindaddr)
 400 {
 401         char ourhost[MAXHOSTNAMELEN] = "";
 402         struct ast_hostent ahp;
 403         struct hostent *hp;
 404         struct in_addr saddr;
 405
 406         /* just use the bind address if it is nonzero */
 407         if (ntohl(bindaddr.sin_addr.s_addr)) {
 408                 memcpy(ourip, &bindaddr.sin_addr, sizeof(*ourip));
 409                 return 0;
 410         }
 411         /* try to use our hostname */
 412         if (gethostname(ourhost, sizeof(ourhost) - 1)) {
 413                 ast_log(LOG_WARNING, "Unable to get hostname\n");
 414         } else {
 415                 hp = ast_gethostbyname(ourhost, &ahp);
 416                 if (hp) {
 417                         memcpy(ourip, hp->h_addr, sizeof(*ourip));
 418                         return 0;
 419                 }
 420         }
 421         /* A.ROOT-SERVERS.NET. */
 422         if (inet_aton("198.41.0.4", &saddr) && !ast_ouraddrfor(&saddr, ourip))
 423                 return 0;
 424         return -1;
 425 }
 426