San Mehat | ffd6872 | 2010-01-20 09:56:15 -0800 | [diff] [blame^] | 1 | /* dnsmasq is Copyright (c) 2000-2009 Simon Kelley |
| 2 | |
| 3 | This program is free software; you can redistribute it and/or modify |
| 4 | it under the terms of the GNU General Public License as published by |
| 5 | the Free Software Foundation; version 2 dated June, 1991, or |
| 6 | (at your option) version 3 dated 29 June, 2007. |
| 7 | |
| 8 | This program is distributed in the hope that it will be useful, |
| 9 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | GNU General Public License for more details. |
| 12 | |
| 13 | You should have received a copy of the GNU General Public License |
| 14 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 15 | */ |
| 16 | |
| 17 | #include "dnsmasq.h" |
| 18 | |
| 19 | #ifdef HAVE_LINUX_NETWORK |
| 20 | |
| 21 | int indextoname(int fd, int index, char *name) |
| 22 | { |
| 23 | struct ifreq ifr; |
| 24 | |
| 25 | if (index == 0) |
| 26 | return 0; |
| 27 | |
| 28 | ifr.ifr_ifindex = index; |
| 29 | if (ioctl(fd, SIOCGIFNAME, &ifr) == -1) |
| 30 | return 0; |
| 31 | |
| 32 | strncpy(name, ifr.ifr_name, IF_NAMESIZE); |
| 33 | |
| 34 | return 1; |
| 35 | } |
| 36 | |
| 37 | #else |
| 38 | |
| 39 | int indextoname(int fd, int index, char *name) |
| 40 | { |
| 41 | if (index == 0 || !if_indextoname(index, name)) |
| 42 | return 0; |
| 43 | |
| 44 | return 1; |
| 45 | } |
| 46 | |
| 47 | #endif |
| 48 | |
| 49 | int iface_check(int family, struct all_addr *addr, char *name, int *indexp) |
| 50 | { |
| 51 | struct iname *tmp; |
| 52 | int ret = 1; |
| 53 | |
| 54 | /* Note: have to check all and not bail out early, so that we set the |
| 55 | "used" flags. */ |
| 56 | |
| 57 | if (indexp) |
| 58 | { |
| 59 | /* One form of bridging on BSD has the property that packets |
| 60 | can be recieved on bridge interfaces which do not have an IP address. |
| 61 | We allow these to be treated as aliases of another interface which does have |
| 62 | an IP address with --dhcp-bridge=interface,alias,alias */ |
| 63 | struct dhcp_bridge *bridge, *alias; |
| 64 | for (bridge = daemon->bridges; bridge; bridge = bridge->next) |
| 65 | { |
| 66 | for (alias = bridge->alias; alias; alias = alias->next) |
| 67 | if (strncmp(name, alias->iface, IF_NAMESIZE) == 0) |
| 68 | { |
| 69 | int newindex; |
| 70 | |
| 71 | if (!(newindex = if_nametoindex(bridge->iface))) |
| 72 | { |
| 73 | my_syslog(LOG_WARNING, _("unknown interface %s in bridge-interface"), name); |
| 74 | return 0; |
| 75 | } |
| 76 | else |
| 77 | { |
| 78 | *indexp = newindex; |
| 79 | strncpy(name, bridge->iface, IF_NAMESIZE); |
| 80 | break; |
| 81 | } |
| 82 | } |
| 83 | if (alias) |
| 84 | break; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | if (daemon->if_names || (addr && daemon->if_addrs)) |
| 89 | { |
| 90 | ret = 0; |
| 91 | |
| 92 | for (tmp = daemon->if_names; tmp; tmp = tmp->next) |
| 93 | if (tmp->name && (strcmp(tmp->name, name) == 0)) |
| 94 | ret = tmp->used = 1; |
| 95 | |
| 96 | for (tmp = daemon->if_addrs; tmp; tmp = tmp->next) |
| 97 | if (addr && tmp->addr.sa.sa_family == family) |
| 98 | { |
| 99 | if (family == AF_INET && |
| 100 | tmp->addr.in.sin_addr.s_addr == addr->addr.addr4.s_addr) |
| 101 | ret = tmp->used = 1; |
| 102 | #ifdef HAVE_IPV6 |
| 103 | else if (family == AF_INET6 && |
| 104 | IN6_ARE_ADDR_EQUAL(&tmp->addr.in6.sin6_addr, |
| 105 | &addr->addr.addr6)) |
| 106 | ret = tmp->used = 1; |
| 107 | #endif |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | for (tmp = daemon->if_except; tmp; tmp = tmp->next) |
| 112 | if (tmp->name && (strcmp(tmp->name, name) == 0)) |
| 113 | ret = 0; |
| 114 | |
| 115 | return ret; |
| 116 | } |
| 117 | |
| 118 | static int iface_allowed(struct irec **irecp, int if_index, |
| 119 | union mysockaddr *addr, struct in_addr netmask) |
| 120 | { |
| 121 | struct irec *iface; |
| 122 | int fd, mtu = 0, loopback; |
| 123 | struct ifreq ifr; |
| 124 | int dhcp_ok = 1; |
| 125 | struct iname *tmp; |
| 126 | |
| 127 | /* check whether the interface IP has been added already |
| 128 | we call this routine multiple times. */ |
| 129 | for (iface = *irecp; iface; iface = iface->next) |
| 130 | if (sockaddr_isequal(&iface->addr, addr)) |
| 131 | return 1; |
| 132 | |
| 133 | if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1 || |
| 134 | !indextoname(fd, if_index, ifr.ifr_name) || |
| 135 | ioctl(fd, SIOCGIFFLAGS, &ifr) == -1) |
| 136 | { |
| 137 | if (fd != -1) |
| 138 | { |
| 139 | int errsave = errno; |
| 140 | close(fd); |
| 141 | errno = errsave; |
| 142 | } |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | loopback = ifr.ifr_flags & IFF_LOOPBACK; |
| 147 | |
| 148 | if (ioctl(fd, SIOCGIFMTU, &ifr) != -1) |
| 149 | mtu = ifr.ifr_mtu; |
| 150 | |
| 151 | close(fd); |
| 152 | |
| 153 | /* If we are restricting the set of interfaces to use, make |
| 154 | sure that loopback interfaces are in that set. */ |
| 155 | if (daemon->if_names && loopback) |
| 156 | { |
| 157 | struct iname *lo; |
| 158 | for (lo = daemon->if_names; lo; lo = lo->next) |
| 159 | if (lo->name && strcmp(lo->name, ifr.ifr_name) == 0) |
| 160 | { |
| 161 | lo->isloop = 1; |
| 162 | break; |
| 163 | } |
| 164 | |
| 165 | if (!lo && |
| 166 | (lo = whine_malloc(sizeof(struct iname))) && |
| 167 | (lo->name = whine_malloc(strlen(ifr.ifr_name)+1))) |
| 168 | { |
| 169 | strcpy(lo->name, ifr.ifr_name); |
| 170 | lo->isloop = lo->used = 1; |
| 171 | lo->next = daemon->if_names; |
| 172 | daemon->if_names = lo; |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | if (addr->sa.sa_family == AF_INET && |
| 177 | !iface_check(AF_INET, (struct all_addr *)&addr->in.sin_addr, ifr.ifr_name, NULL)) |
| 178 | return 1; |
| 179 | |
| 180 | for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next) |
| 181 | if (tmp->name && (strcmp(tmp->name, ifr.ifr_name) == 0)) |
| 182 | dhcp_ok = 0; |
| 183 | |
| 184 | #ifdef HAVE_IPV6 |
| 185 | if (addr->sa.sa_family == AF_INET6 && |
| 186 | !iface_check(AF_INET6, (struct all_addr *)&addr->in6.sin6_addr, ifr.ifr_name, NULL)) |
| 187 | return 1; |
| 188 | #endif |
| 189 | |
| 190 | /* add to list */ |
| 191 | if ((iface = whine_malloc(sizeof(struct irec)))) |
| 192 | { |
| 193 | iface->addr = *addr; |
| 194 | iface->netmask = netmask; |
| 195 | iface->dhcp_ok = dhcp_ok; |
| 196 | iface->mtu = mtu; |
| 197 | iface->next = *irecp; |
| 198 | *irecp = iface; |
| 199 | return 1; |
| 200 | } |
| 201 | |
| 202 | errno = ENOMEM; |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | #ifdef HAVE_IPV6 |
| 207 | static int iface_allowed_v6(struct in6_addr *local, |
| 208 | int scope, int if_index, void *vparam) |
| 209 | { |
| 210 | union mysockaddr addr; |
| 211 | struct in_addr netmask; /* dummy */ |
| 212 | |
| 213 | netmask.s_addr = 0; |
| 214 | |
| 215 | memset(&addr, 0, sizeof(addr)); |
| 216 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 217 | addr.in6.sin6_len = sizeof(addr.in6); |
| 218 | #endif |
| 219 | addr.in6.sin6_family = AF_INET6; |
| 220 | addr.in6.sin6_addr = *local; |
| 221 | addr.in6.sin6_port = htons(daemon->port); |
| 222 | addr.in6.sin6_scope_id = scope; |
| 223 | |
| 224 | return iface_allowed((struct irec **)vparam, if_index, &addr, netmask); |
| 225 | } |
| 226 | #endif |
| 227 | |
| 228 | static int iface_allowed_v4(struct in_addr local, int if_index, |
| 229 | struct in_addr netmask, struct in_addr broadcast, void *vparam) |
| 230 | { |
| 231 | union mysockaddr addr; |
| 232 | |
| 233 | memset(&addr, 0, sizeof(addr)); |
| 234 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 235 | addr.in.sin_len = sizeof(addr.in); |
| 236 | #endif |
| 237 | addr.in.sin_family = AF_INET; |
| 238 | addr.in.sin_addr = broadcast; /* warning */ |
| 239 | addr.in.sin_addr = local; |
| 240 | addr.in.sin_port = htons(daemon->port); |
| 241 | |
| 242 | return iface_allowed((struct irec **)vparam, if_index, &addr, netmask); |
| 243 | } |
| 244 | |
| 245 | int enumerate_interfaces(void) |
| 246 | { |
| 247 | #ifdef HAVE_IPV6 |
| 248 | return iface_enumerate(&daemon->interfaces, iface_allowed_v4, iface_allowed_v6); |
| 249 | #else |
| 250 | return iface_enumerate(&daemon->interfaces, iface_allowed_v4, NULL); |
| 251 | #endif |
| 252 | } |
| 253 | |
| 254 | /* set NONBLOCK bit on fd: See Stevens 16.6 */ |
| 255 | int fix_fd(int fd) |
| 256 | { |
| 257 | int flags; |
| 258 | |
| 259 | if ((flags = fcntl(fd, F_GETFL)) == -1 || |
| 260 | fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) |
| 261 | return 0; |
| 262 | |
| 263 | return 1; |
| 264 | } |
| 265 | |
| 266 | #if defined(HAVE_IPV6) |
| 267 | static int create_ipv6_listener(struct listener **link, int port) |
| 268 | { |
| 269 | union mysockaddr addr; |
| 270 | int tcpfd, fd; |
| 271 | struct listener *l; |
| 272 | int opt = 1; |
| 273 | |
| 274 | memset(&addr, 0, sizeof(addr)); |
| 275 | addr.in6.sin6_family = AF_INET6; |
| 276 | addr.in6.sin6_addr = in6addr_any; |
| 277 | addr.in6.sin6_port = htons(port); |
| 278 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 279 | addr.in6.sin6_len = sizeof(addr.in6); |
| 280 | #endif |
| 281 | |
| 282 | /* No error of the kernel doesn't support IPv6 */ |
| 283 | if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) |
| 284 | return (errno == EPROTONOSUPPORT || |
| 285 | errno == EAFNOSUPPORT || |
| 286 | errno == EINVAL); |
| 287 | |
| 288 | if ((tcpfd = socket(AF_INET6, SOCK_STREAM, 0)) == -1) |
| 289 | return 0; |
| 290 | |
| 291 | if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 292 | setsockopt(tcpfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 293 | setsockopt(fd, IPV6_LEVEL, IPV6_V6ONLY, &opt, sizeof(opt)) == -1 || |
| 294 | setsockopt(tcpfd, IPV6_LEVEL, IPV6_V6ONLY, &opt, sizeof(opt)) == -1 || |
| 295 | !fix_fd(fd) || |
| 296 | !fix_fd(tcpfd) || |
| 297 | #ifdef IPV6_RECVPKTINFO |
| 298 | setsockopt(fd, IPV6_LEVEL, IPV6_RECVPKTINFO, &opt, sizeof(opt)) == -1 || |
| 299 | #else |
| 300 | setsockopt(fd, IPV6_LEVEL, IPV6_PKTINFO, &opt, sizeof(opt)) == -1 || |
| 301 | #endif |
| 302 | bind(tcpfd, (struct sockaddr *)&addr, sa_len(&addr)) == -1 || |
| 303 | listen(tcpfd, 5) == -1 || |
| 304 | bind(fd, (struct sockaddr *)&addr, sa_len(&addr)) == -1) |
| 305 | return 0; |
| 306 | |
| 307 | l = safe_malloc(sizeof(struct listener)); |
| 308 | l->fd = fd; |
| 309 | l->tcpfd = tcpfd; |
| 310 | l->tftpfd = -1; |
| 311 | l->family = AF_INET6; |
| 312 | l->next = NULL; |
| 313 | *link = l; |
| 314 | |
| 315 | return 1; |
| 316 | } |
| 317 | #endif |
| 318 | |
| 319 | struct listener *create_wildcard_listeners(void) |
| 320 | { |
| 321 | union mysockaddr addr; |
| 322 | int opt = 1; |
| 323 | struct listener *l, *l6 = NULL; |
| 324 | int tcpfd = -1, fd = -1, tftpfd = -1; |
| 325 | |
| 326 | memset(&addr, 0, sizeof(addr)); |
| 327 | addr.in.sin_family = AF_INET; |
| 328 | addr.in.sin_addr.s_addr = INADDR_ANY; |
| 329 | addr.in.sin_port = htons(daemon->port); |
| 330 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 331 | addr.in.sin_len = sizeof(struct sockaddr_in); |
| 332 | #endif |
| 333 | |
| 334 | if (daemon->port != 0) |
| 335 | { |
| 336 | |
| 337 | if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1 || |
| 338 | (tcpfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) |
| 339 | return NULL; |
| 340 | |
| 341 | if (setsockopt(tcpfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 342 | bind(tcpfd, (struct sockaddr *)&addr, sa_len(&addr)) == -1 || |
| 343 | listen(tcpfd, 5) == -1 || |
| 344 | !fix_fd(tcpfd) || |
| 345 | #ifdef HAVE_IPV6 |
| 346 | !create_ipv6_listener(&l6, daemon->port) || |
| 347 | #endif |
| 348 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 349 | !fix_fd(fd) || |
| 350 | #if defined(HAVE_LINUX_NETWORK) |
| 351 | setsockopt(fd, SOL_IP, IP_PKTINFO, &opt, sizeof(opt)) == -1 || |
| 352 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) |
| 353 | setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &opt, sizeof(opt)) == -1 || |
| 354 | setsockopt(fd, IPPROTO_IP, IP_RECVIF, &opt, sizeof(opt)) == -1 || |
| 355 | #endif |
| 356 | bind(fd, (struct sockaddr *)&addr, sa_len(&addr)) == -1) |
| 357 | return NULL; |
| 358 | } |
| 359 | |
| 360 | #ifdef HAVE_TFTP |
| 361 | if (daemon->options & OPT_TFTP) |
| 362 | { |
| 363 | addr.in.sin_port = htons(TFTP_PORT); |
| 364 | if ((tftpfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) |
| 365 | return NULL; |
| 366 | |
| 367 | if (!fix_fd(tftpfd) || |
| 368 | #if defined(HAVE_LINUX_NETWORK) |
| 369 | setsockopt(tftpfd, SOL_IP, IP_PKTINFO, &opt, sizeof(opt)) == -1 || |
| 370 | #elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF) |
| 371 | setsockopt(tftpfd, IPPROTO_IP, IP_RECVDSTADDR, &opt, sizeof(opt)) == -1 || |
| 372 | setsockopt(tftpfd, IPPROTO_IP, IP_RECVIF, &opt, sizeof(opt)) == -1 || |
| 373 | #endif |
| 374 | bind(tftpfd, (struct sockaddr *)&addr, sa_len(&addr)) == -1) |
| 375 | return NULL; |
| 376 | } |
| 377 | #endif |
| 378 | |
| 379 | l = safe_malloc(sizeof(struct listener)); |
| 380 | l->family = AF_INET; |
| 381 | l->fd = fd; |
| 382 | l->tcpfd = tcpfd; |
| 383 | l->tftpfd = tftpfd; |
| 384 | l->next = l6; |
| 385 | |
| 386 | return l; |
| 387 | } |
| 388 | |
| 389 | struct listener *create_bound_listeners(void) |
| 390 | { |
| 391 | struct listener *listeners = NULL; |
| 392 | struct irec *iface; |
| 393 | int rc, opt = 1; |
| 394 | #ifdef HAVE_IPV6 |
| 395 | static int dad_count = 0; |
| 396 | #endif |
| 397 | |
| 398 | for (iface = daemon->interfaces; iface; iface = iface->next) |
| 399 | { |
| 400 | struct listener *new = safe_malloc(sizeof(struct listener)); |
| 401 | new->family = iface->addr.sa.sa_family; |
| 402 | new->iface = iface; |
| 403 | new->next = listeners; |
| 404 | new->tftpfd = -1; |
| 405 | new->tcpfd = -1; |
| 406 | new->fd = -1; |
| 407 | listeners = new; |
| 408 | |
| 409 | if (daemon->port != 0) |
| 410 | { |
| 411 | if ((new->tcpfd = socket(iface->addr.sa.sa_family, SOCK_STREAM, 0)) == -1 || |
| 412 | (new->fd = socket(iface->addr.sa.sa_family, SOCK_DGRAM, 0)) == -1 || |
| 413 | setsockopt(new->fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 414 | setsockopt(new->tcpfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 415 | !fix_fd(new->tcpfd) || |
| 416 | !fix_fd(new->fd)) |
| 417 | die(_("failed to create listening socket: %s"), NULL, EC_BADNET); |
| 418 | |
| 419 | #ifdef HAVE_IPV6 |
| 420 | if (iface->addr.sa.sa_family == AF_INET6) |
| 421 | { |
| 422 | if (setsockopt(new->fd, IPV6_LEVEL, IPV6_V6ONLY, &opt, sizeof(opt)) == -1 || |
| 423 | setsockopt(new->tcpfd, IPV6_LEVEL, IPV6_V6ONLY, &opt, sizeof(opt)) == -1) |
| 424 | die(_("failed to set IPV6 options on listening socket: %s"), NULL, EC_BADNET); |
| 425 | } |
| 426 | #endif |
| 427 | |
| 428 | while(1) |
| 429 | { |
| 430 | if ((rc = bind(new->fd, &iface->addr.sa, sa_len(&iface->addr))) != -1) |
| 431 | break; |
| 432 | |
| 433 | #ifdef HAVE_IPV6 |
| 434 | /* An interface may have an IPv6 address which is still undergoing DAD. |
| 435 | If so, the bind will fail until the DAD completes, so we try over 20 seconds |
| 436 | before failing. */ |
| 437 | if (iface->addr.sa.sa_family == AF_INET6 && (errno == ENODEV || errno == EADDRNOTAVAIL) && |
| 438 | dad_count++ < DAD_WAIT) |
| 439 | { |
| 440 | sleep(1); |
| 441 | continue; |
| 442 | } |
| 443 | #endif |
| 444 | break; |
| 445 | } |
| 446 | |
| 447 | if (rc == -1 || bind(new->tcpfd, &iface->addr.sa, sa_len(&iface->addr)) == -1) |
| 448 | { |
| 449 | prettyprint_addr(&iface->addr, daemon->namebuff); |
| 450 | die(_("failed to bind listening socket for %s: %s"), |
| 451 | daemon->namebuff, EC_BADNET); |
| 452 | } |
| 453 | |
| 454 | if (listen(new->tcpfd, 5) == -1) |
| 455 | die(_("failed to listen on socket: %s"), NULL, EC_BADNET); |
| 456 | } |
| 457 | |
| 458 | #ifdef HAVE_TFTP |
| 459 | if ((daemon->options & OPT_TFTP) && iface->addr.sa.sa_family == AF_INET && iface->dhcp_ok) |
| 460 | { |
| 461 | short save = iface->addr.in.sin_port; |
| 462 | iface->addr.in.sin_port = htons(TFTP_PORT); |
| 463 | if ((new->tftpfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1 || |
| 464 | setsockopt(new->tftpfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || |
| 465 | !fix_fd(new->tftpfd) || |
| 466 | bind(new->tftpfd, &iface->addr.sa, sa_len(&iface->addr)) == -1) |
| 467 | die(_("failed to create TFTP socket: %s"), NULL, EC_BADNET); |
| 468 | iface->addr.in.sin_port = save; |
| 469 | } |
| 470 | #endif |
| 471 | |
| 472 | } |
| 473 | |
| 474 | return listeners; |
| 475 | } |
| 476 | |
| 477 | |
| 478 | /* return a UDP socket bound to a random port, have to cope with straying into |
| 479 | occupied port nos and reserved ones. */ |
| 480 | int random_sock(int family) |
| 481 | { |
| 482 | int fd; |
| 483 | |
| 484 | if ((fd = socket(family, SOCK_DGRAM, 0)) != -1) |
| 485 | { |
| 486 | union mysockaddr addr; |
| 487 | unsigned int ports_avail = 65536u - (unsigned short)daemon->min_port; |
| 488 | int tries = ports_avail < 30 ? 3 * ports_avail : 100; |
| 489 | |
| 490 | memset(&addr, 0, sizeof(addr)); |
| 491 | addr.sa.sa_family = family; |
| 492 | |
| 493 | /* don't loop forever if all ports in use. */ |
| 494 | |
| 495 | if (fix_fd(fd)) |
| 496 | while(tries--) |
| 497 | { |
| 498 | unsigned short port = rand16(); |
| 499 | |
| 500 | if (daemon->min_port != 0) |
| 501 | port = htons(daemon->min_port + (port % ((unsigned short)ports_avail))); |
| 502 | |
| 503 | if (family == AF_INET) |
| 504 | { |
| 505 | addr.in.sin_addr.s_addr = INADDR_ANY; |
| 506 | addr.in.sin_port = port; |
| 507 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 508 | addr.in.sin_len = sizeof(struct sockaddr_in); |
| 509 | #endif |
| 510 | } |
| 511 | #ifdef HAVE_IPV6 |
| 512 | else |
| 513 | { |
| 514 | addr.in6.sin6_addr = in6addr_any; |
| 515 | addr.in6.sin6_port = port; |
| 516 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 517 | addr.in6.sin6_len = sizeof(struct sockaddr_in6); |
| 518 | #endif |
| 519 | } |
| 520 | #endif |
| 521 | |
| 522 | if (bind(fd, (struct sockaddr *)&addr, sa_len(&addr)) == 0) |
| 523 | return fd; |
| 524 | |
| 525 | if (errno != EADDRINUSE && errno != EACCES) |
| 526 | break; |
| 527 | } |
| 528 | |
| 529 | close(fd); |
| 530 | } |
| 531 | |
| 532 | return -1; |
| 533 | } |
| 534 | |
| 535 | |
| 536 | int local_bind(int fd, union mysockaddr *addr, char *intname, int is_tcp) |
| 537 | { |
| 538 | union mysockaddr addr_copy = *addr; |
| 539 | |
| 540 | /* cannot set source _port_ for TCP connections. */ |
| 541 | if (is_tcp) |
| 542 | { |
| 543 | if (addr_copy.sa.sa_family == AF_INET) |
| 544 | addr_copy.in.sin_port = 0; |
| 545 | #ifdef HAVE_IPV6 |
| 546 | else |
| 547 | addr_copy.in6.sin6_port = 0; |
| 548 | #endif |
| 549 | } |
| 550 | |
| 551 | if (bind(fd, (struct sockaddr *)&addr_copy, sa_len(&addr_copy)) == -1) |
| 552 | return 0; |
| 553 | |
| 554 | #if defined(SO_BINDTODEVICE) |
| 555 | if (intname[0] != 0 && |
| 556 | setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, intname, strlen(intname)) == -1) |
| 557 | return 0; |
| 558 | #endif |
| 559 | |
| 560 | return 1; |
| 561 | } |
| 562 | |
| 563 | static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname) |
| 564 | { |
| 565 | struct serverfd *sfd; |
| 566 | int errsave; |
| 567 | |
| 568 | /* when using random ports, servers which would otherwise use |
| 569 | the INADDR_ANY/port0 socket have sfd set to NULL */ |
| 570 | if (!daemon->osport && intname[0] == 0) |
| 571 | { |
| 572 | errno = 0; |
| 573 | |
| 574 | if (addr->sa.sa_family == AF_INET && |
| 575 | addr->in.sin_addr.s_addr == INADDR_ANY && |
| 576 | addr->in.sin_port == htons(0)) |
| 577 | return NULL; |
| 578 | |
| 579 | #ifdef HAVE_IPV6 |
| 580 | if (addr->sa.sa_family == AF_INET6 && |
| 581 | memcmp(&addr->in6.sin6_addr, &in6addr_any, sizeof(in6addr_any)) == 0 && |
| 582 | addr->in6.sin6_port == htons(0)) |
| 583 | return NULL; |
| 584 | #endif |
| 585 | } |
| 586 | |
| 587 | /* may have a suitable one already */ |
| 588 | for (sfd = daemon->sfds; sfd; sfd = sfd->next ) |
| 589 | if (sockaddr_isequal(&sfd->source_addr, addr) && |
| 590 | strcmp(intname, sfd->interface) == 0) |
| 591 | return sfd; |
| 592 | |
| 593 | /* need to make a new one. */ |
| 594 | errno = ENOMEM; /* in case malloc fails. */ |
| 595 | if (!(sfd = whine_malloc(sizeof(struct serverfd)))) |
| 596 | return NULL; |
| 597 | |
| 598 | if ((sfd->fd = socket(addr->sa.sa_family, SOCK_DGRAM, 0)) == -1) |
| 599 | { |
| 600 | free(sfd); |
| 601 | return NULL; |
| 602 | } |
| 603 | |
| 604 | if (!local_bind(sfd->fd, addr, intname, 0) || !fix_fd(sfd->fd)) |
| 605 | { |
| 606 | errsave = errno; /* save error from bind. */ |
| 607 | close(sfd->fd); |
| 608 | free(sfd); |
| 609 | errno = errsave; |
| 610 | return NULL; |
| 611 | } |
| 612 | |
| 613 | strcpy(sfd->interface, intname); |
| 614 | sfd->source_addr = *addr; |
| 615 | sfd->next = daemon->sfds; |
| 616 | daemon->sfds = sfd; |
| 617 | return sfd; |
| 618 | } |
| 619 | |
| 620 | /* create upstream sockets during startup, before root is dropped which may be needed |
| 621 | this allows query_port to be a low port and interface binding */ |
| 622 | void pre_allocate_sfds(void) |
| 623 | { |
| 624 | struct server *srv; |
| 625 | |
| 626 | if (daemon->query_port != 0) |
| 627 | { |
| 628 | union mysockaddr addr; |
| 629 | memset(&addr, 0, sizeof(addr)); |
| 630 | addr.in.sin_family = AF_INET; |
| 631 | addr.in.sin_addr.s_addr = INADDR_ANY; |
| 632 | addr.in.sin_port = htons(daemon->query_port); |
| 633 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 634 | addr.in.sin_len = sizeof(struct sockaddr_in); |
| 635 | #endif |
| 636 | allocate_sfd(&addr, ""); |
| 637 | #ifdef HAVE_IPV6 |
| 638 | memset(&addr, 0, sizeof(addr)); |
| 639 | addr.in6.sin6_family = AF_INET6; |
| 640 | addr.in6.sin6_addr = in6addr_any; |
| 641 | addr.in6.sin6_port = htons(daemon->query_port); |
| 642 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 643 | addr.in6.sin6_len = sizeof(struct sockaddr_in6); |
| 644 | #endif |
| 645 | allocate_sfd(&addr, ""); |
| 646 | #endif |
| 647 | } |
| 648 | |
| 649 | for (srv = daemon->servers; srv; srv = srv->next) |
| 650 | if (!(srv->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR)) && |
| 651 | !allocate_sfd(&srv->source_addr, srv->interface) && |
| 652 | errno != 0 && |
| 653 | (daemon->options & OPT_NOWILD)) |
| 654 | { |
| 655 | prettyprint_addr(&srv->addr, daemon->namebuff); |
| 656 | if (srv->interface[0] != 0) |
| 657 | { |
| 658 | strcat(daemon->namebuff, " "); |
| 659 | strcat(daemon->namebuff, srv->interface); |
| 660 | } |
| 661 | die(_("failed to bind server socket for %s: %s"), |
| 662 | daemon->namebuff, EC_BADNET); |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | |
| 667 | void check_servers(void) |
| 668 | { |
| 669 | struct irec *iface; |
| 670 | struct server *new, *tmp, *ret = NULL; |
| 671 | int port = 0; |
| 672 | |
| 673 | for (new = daemon->servers; new; new = tmp) |
| 674 | { |
| 675 | tmp = new->next; |
| 676 | |
| 677 | if (!(new->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR))) |
| 678 | { |
| 679 | port = prettyprint_addr(&new->addr, daemon->namebuff); |
| 680 | |
| 681 | /* 0.0.0.0 is nothing, the stack treats it like 127.0.0.1 */ |
| 682 | if (new->addr.sa.sa_family == AF_INET && |
| 683 | new->addr.in.sin_addr.s_addr == 0) |
| 684 | { |
| 685 | free(new); |
| 686 | continue; |
| 687 | } |
| 688 | |
| 689 | for (iface = daemon->interfaces; iface; iface = iface->next) |
| 690 | if (sockaddr_isequal(&new->addr, &iface->addr)) |
| 691 | break; |
| 692 | if (iface) |
| 693 | { |
| 694 | my_syslog(LOG_WARNING, _("ignoring nameserver %s - local interface"), daemon->namebuff); |
| 695 | free(new); |
| 696 | continue; |
| 697 | } |
| 698 | |
| 699 | /* Do we need a socket set? */ |
| 700 | if (!new->sfd && |
| 701 | !(new->sfd = allocate_sfd(&new->source_addr, new->interface)) && |
| 702 | errno != 0) |
| 703 | { |
| 704 | my_syslog(LOG_WARNING, |
| 705 | _("ignoring nameserver %s - cannot make/bind socket: %s"), |
| 706 | daemon->namebuff, strerror(errno)); |
| 707 | free(new); |
| 708 | continue; |
| 709 | } |
| 710 | } |
| 711 | |
| 712 | /* reverse order - gets it right. */ |
| 713 | new->next = ret; |
| 714 | ret = new; |
| 715 | |
| 716 | if (new->flags & (SERV_HAS_DOMAIN | SERV_FOR_NODOTS)) |
| 717 | { |
| 718 | char *s1, *s2; |
| 719 | if (!(new->flags & SERV_HAS_DOMAIN)) |
| 720 | s1 = _("unqualified"), s2 = _("names"); |
| 721 | else if (strlen(new->domain) == 0) |
| 722 | s1 = _("default"), s2 = ""; |
| 723 | else |
| 724 | s1 = _("domain"), s2 = new->domain; |
| 725 | |
| 726 | if (new->flags & SERV_NO_ADDR) |
| 727 | my_syslog(LOG_INFO, _("using local addresses only for %s %s"), s1, s2); |
| 728 | else if (!(new->flags & SERV_LITERAL_ADDRESS)) |
| 729 | my_syslog(LOG_INFO, _("using nameserver %s#%d for %s %s"), daemon->namebuff, port, s1, s2); |
| 730 | } |
| 731 | else if (new->interface[0] != 0) |
| 732 | my_syslog(LOG_INFO, _("using nameserver %s#%d(via %s)"), daemon->namebuff, port, new->interface); |
| 733 | else |
| 734 | my_syslog(LOG_INFO, _("using nameserver %s#%d"), daemon->namebuff, port); |
| 735 | } |
| 736 | |
| 737 | daemon->servers = ret; |
| 738 | } |
| 739 | |
| 740 | /* Return zero if no servers found, in that case we keep polling. |
| 741 | This is a protection against an update-time/write race on resolv.conf */ |
| 742 | int reload_servers(char *fname) |
| 743 | { |
| 744 | FILE *f; |
| 745 | char *line; |
| 746 | struct server *old_servers = NULL; |
| 747 | struct server *new_servers = NULL; |
| 748 | struct server *serv; |
| 749 | int gotone = 0; |
| 750 | |
| 751 | /* buff happens to be MAXDNAME long... */ |
| 752 | if (!(f = fopen(fname, "r"))) |
| 753 | { |
| 754 | my_syslog(LOG_ERR, _("failed to read %s: %s"), fname, strerror(errno)); |
| 755 | return 0; |
| 756 | } |
| 757 | |
| 758 | /* move old servers to free list - we can reuse the memory |
| 759 | and not risk malloc if there are the same or fewer new servers. |
| 760 | Servers which were specced on the command line go to the new list. */ |
| 761 | for (serv = daemon->servers; serv;) |
| 762 | { |
| 763 | struct server *tmp = serv->next; |
| 764 | if (serv->flags & SERV_FROM_RESOLV) |
| 765 | { |
| 766 | serv->next = old_servers; |
| 767 | old_servers = serv; |
| 768 | /* forward table rules reference servers, so have to blow them away */ |
| 769 | server_gone(serv); |
| 770 | } |
| 771 | else |
| 772 | { |
| 773 | serv->next = new_servers; |
| 774 | new_servers = serv; |
| 775 | } |
| 776 | serv = tmp; |
| 777 | } |
| 778 | |
| 779 | while ((line = fgets(daemon->namebuff, MAXDNAME, f))) |
| 780 | { |
| 781 | union mysockaddr addr, source_addr; |
| 782 | char *token = strtok(line, " \t\n\r"); |
| 783 | |
| 784 | if (!token) |
| 785 | continue; |
| 786 | if (strcmp(token, "nameserver") != 0 && strcmp(token, "server") != 0) |
| 787 | continue; |
| 788 | if (!(token = strtok(NULL, " \t\n\r"))) |
| 789 | continue; |
| 790 | |
| 791 | memset(&addr, 0, sizeof(addr)); |
| 792 | memset(&source_addr, 0, sizeof(source_addr)); |
| 793 | |
| 794 | if ((addr.in.sin_addr.s_addr = inet_addr(token)) != (in_addr_t) -1) |
| 795 | { |
| 796 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 797 | source_addr.in.sin_len = addr.in.sin_len = sizeof(source_addr.in); |
| 798 | #endif |
| 799 | source_addr.in.sin_family = addr.in.sin_family = AF_INET; |
| 800 | addr.in.sin_port = htons(NAMESERVER_PORT); |
| 801 | source_addr.in.sin_addr.s_addr = INADDR_ANY; |
| 802 | source_addr.in.sin_port = htons(daemon->query_port); |
| 803 | } |
| 804 | #ifdef HAVE_IPV6 |
| 805 | else if (inet_pton(AF_INET6, token, &addr.in6.sin6_addr) > 0) |
| 806 | { |
| 807 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 808 | source_addr.in6.sin6_len = addr.in6.sin6_len = sizeof(source_addr.in6); |
| 809 | #endif |
| 810 | source_addr.in6.sin6_family = addr.in6.sin6_family = AF_INET6; |
| 811 | addr.in6.sin6_port = htons(NAMESERVER_PORT); |
| 812 | source_addr.in6.sin6_addr = in6addr_any; |
| 813 | source_addr.in6.sin6_port = htons(daemon->query_port); |
| 814 | } |
| 815 | #endif /* IPV6 */ |
| 816 | else |
| 817 | continue; |
| 818 | |
| 819 | if (old_servers) |
| 820 | { |
| 821 | serv = old_servers; |
| 822 | old_servers = old_servers->next; |
| 823 | } |
| 824 | else if (!(serv = whine_malloc(sizeof (struct server)))) |
| 825 | continue; |
| 826 | |
| 827 | /* this list is reverse ordered: |
| 828 | it gets reversed again in check_servers */ |
| 829 | serv->next = new_servers; |
| 830 | new_servers = serv; |
| 831 | serv->addr = addr; |
| 832 | serv->source_addr = source_addr; |
| 833 | serv->domain = NULL; |
| 834 | serv->interface[0] = 0; |
| 835 | serv->sfd = NULL; |
| 836 | serv->flags = SERV_FROM_RESOLV; |
| 837 | serv->queries = serv->failed_queries = 0; |
| 838 | gotone = 1; |
| 839 | } |
| 840 | |
| 841 | /* Free any memory not used. */ |
| 842 | while (old_servers) |
| 843 | { |
| 844 | struct server *tmp = old_servers->next; |
| 845 | free(old_servers); |
| 846 | old_servers = tmp; |
| 847 | } |
| 848 | |
| 849 | daemon->servers = new_servers; |
| 850 | fclose(f); |
| 851 | |
| 852 | return gotone; |
| 853 | } |
| 854 | |
| 855 | |
| 856 | /* Use an IPv4 listener socket for ioctling */ |
| 857 | struct in_addr get_ifaddr(char *intr) |
| 858 | { |
| 859 | struct listener *l; |
| 860 | struct ifreq ifr; |
| 861 | |
| 862 | for (l = daemon->listeners; l && l->family != AF_INET; l = l->next); |
| 863 | |
| 864 | strncpy(ifr.ifr_name, intr, IF_NAMESIZE); |
| 865 | ifr.ifr_addr.sa_family = AF_INET; |
| 866 | |
| 867 | if (!l || ioctl(l->fd, SIOCGIFADDR, &ifr) == -1) |
| 868 | ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = -1; |
| 869 | |
| 870 | return ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr; |
| 871 | } |
| 872 | |
| 873 | |
| 874 | |