interface.c

   1 /*
   2  * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
   3  * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #define _GNU_SOURCE
  16 #include <sys/socket.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <sys/utsname.h>
  21 #include <net/if.h>
  22 #include <netinet/in.h>
  23 #include <arpa/inet.h>
  24 #include <sys/types.h>
  25
  26 #include <ifaddrs.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <stdio.h>
  31 #include <errno.h>
  32
  33 #include <libubox/usock.h>
  34 #include <libubox/uloop.h>
  35 #include <libubox/avl-cmp.h>
  36 #include <libubox/utils.h>
  37 #include "interface.h"
  38 #include "util.h"
  39 #include "dns.h"
  40 #include "announce.h"
  41 #include "service.h"
  42
  43 static int
  44 interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct iovec *iov, int iov_len)
  45 {
  46         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
  47         static struct sockaddr_in a;
  48         static struct msghdr m = {
  49                 .msg_name = (struct sockaddr *) &a,
  50                 .msg_namelen = sizeof(a),
  51                 .msg_control = cmsg_data,
  52                 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
  53         };
  54         struct in_pktinfo *pkti;
  55         struct cmsghdr *cmsg;
  56         int fd = iface->fd.fd;
  57
  58         a.sin_family = AF_INET;
  59         a.sin_port = htons(MCAST_PORT);
  60         m.msg_iov = iov;
  61         m.msg_iovlen = iov_len;
  62
  63         memset(cmsg_data, 0, sizeof(cmsg_data));
  64         cmsg = CMSG_FIRSTHDR(&m);
  65         cmsg->cmsg_len = m.msg_controllen;
  66         cmsg->cmsg_level = IPPROTO_IP;
  67         cmsg->cmsg_type = IP_PKTINFO;
  68
  69         pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
  70         pkti->ipi_ifindex = iface->ifindex;
  71
  72         if (iface->multicast) {
  73                 a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
  74                 if (to)
  75                         fprintf(stderr, "Ignoring IPv4 address for multicast interface\n");
  76         } else {
  77                 a.sin_addr.s_addr = to->sin_addr.s_addr;
  78         }
  79
  80         return sendmsg(fd, &m, 0);
  81 }
  82
  83 static int
  84 interface_send_packet6(struct interface *iface, struct sockaddr_in6 *to, struct iovec *iov, int iov_len)
  85 {
  86         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in6_pktinfo)) / sizeof(size_t)) + 1];
  87         static struct sockaddr_in6 a;
  88         static struct msghdr m = {
  89                 .msg_name = (struct sockaddr *) &a,
  90                 .msg_namelen = sizeof(a),
  91                 .msg_control = cmsg_data,
  92                 .msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)),
  93         };
  94         struct in6_pktinfo *pkti;
  95         struct cmsghdr *cmsg;
  96         int fd = iface->fd.fd;
  97
  98         a.sin6_family = AF_INET6;
  99         a.sin6_port = htons(MCAST_PORT);
 100         m.msg_iov = iov;
 101         m.msg_iovlen = iov_len;
 102
 103         memset(cmsg_data, 0, sizeof(cmsg_data));
 104         cmsg = CMSG_FIRSTHDR(&m);
 105         cmsg->cmsg_len = m.msg_controllen;
 106         cmsg->cmsg_level = IPPROTO_IPV6;
 107         cmsg->cmsg_type = IPV6_PKTINFO;
 108
 109         pkti = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 110         pkti->ipi6_ifindex = iface->ifindex;
 111
 112         if (iface->multicast) {
 113                 inet_pton(AF_INET6, MCAST_ADDR6, &a.sin6_addr);
 114                 if (to)
 115                         fprintf(stderr, "Ignoring IPv6 address for multicast interface\n");
 116         } else {
 117                 a.sin6_addr = to->sin6_addr;
 118         }
 119
 120         return sendmsg(fd, &m, 0);
 121 }
 122
 123 int
 124 interface_send_packet(struct interface *iface, struct sockaddr *to, struct iovec *iov, int iov_len)
 125 {
 126         if (!iface->multicast && !to) {
 127                 fprintf(stderr, "No IP address specified for unicast interface\n");
 128                 errno = EINVAL;
 129                 return -1;
 130         }
 131
 132         if (debug > 1) {
 133                 fprintf(stderr, "TX ipv%d: %s\n", iface->v6 * 2 + 4, iface->name);
 134                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 135         }
 136
 137         if (iface->v6)
 138                 return interface_send_packet6(iface, (struct sockaddr_in6 *)to, iov, iov_len);
 139
 140         return interface_send_packet4(iface, (struct sockaddr_in *)to, iov, iov_len);
 141 }
 142
 143 static void interface_close(struct interface *iface)
 144 {
 145         if (iface->fd.fd < 0)
 146                 return;
 147
 148         announce_free(iface);
 149         uloop_fd_delete(&iface->fd);
 150         close(iface->fd.fd);
 151         iface->fd.fd = -1;
 152 }
 153
 154 static void interface_free(struct interface *iface)
 155 {
 156         uloop_timeout_cancel(&iface->reconnect);
 157         interface_close(iface);
 158         free(iface);
 159 }
 160
 161 static int
 162 interface_valid_src(void *ip1, void *mask, void *ip2, int len)
 163 {
 164         uint8_t *i1 = ip1;
 165         uint8_t *i2 = ip2;
 166         uint8_t *m = mask;
 167         int i;
 168
 169         if (cfg_no_subnet)
 170                 return 0;
 171
 172         for (i = 0; i < len; i++, i1++, i2++, m++) {
 173                 if ((*i1 & *m) != (*i2 & *m))
 174                         return -1;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static void
 181 read_socket4(struct uloop_fd *u, unsigned int events)
 182 {
 183         struct interface *iface = container_of(u, struct interface, fd);
 184         static uint8_t buffer[8 * 1024];
 185         struct iovec iov[1];
 186         char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 187         struct cmsghdr *cmsgptr;
 188         struct msghdr msg;
 189         socklen_t len;
 190         struct sockaddr_in from;
 191         int flags = 0, ifindex = -1;
 192         uint8_t ttl = 0;
 193         struct in_pktinfo *inp = NULL;
 194
 195         if (u->eof) {
 196                 interface_close(iface);
 197                 uloop_timeout_set(&iface->reconnect, 1000);
 198                 return;
 199         }
 200
 201         iov[0].iov_base = buffer;
 202         iov[0].iov_len = sizeof(buffer);
 203
 204         memset(&msg, 0, sizeof(msg));
 205         msg.msg_name = (struct sockaddr *) &from;
 206         msg.msg_namelen = sizeof(struct sockaddr_in);
 207         msg.msg_iov = iov;
 208         msg.msg_iovlen = 1;
 209         msg.msg_control = &cmsg;
 210         msg.msg_controllen = sizeof(cmsg);
 211
 212         len = recvmsg(u->fd, &msg, flags);
 213         if (len == -1) {
 214                 perror("read failed");
 215                 return;
 216         }
 217         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 218                 void *c = CMSG_DATA(cmsgptr);
 219
 220                 switch (cmsgptr->cmsg_type) {
 221                 case IP_PKTINFO:
 222                         inp = ((struct in_pktinfo *) c);
 223                         break;
 224
 225                 case IP_TTL:
 226                         ttl = (uint8_t) *((int *) c);
 227                         break;
 228
 229                 default:
 230                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 231                         return;
 232                 }
 233         }
 234
 235         if (ttl != 255)
 236                 return;
 237
 238         if (debug > 1) {
 239                 char buf[256];
 240
 241                 fprintf(stderr, "RX ipv4: %s\n", iface->name);
 242                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 243                 inet_ntop(AF_INET, &from.sin_addr, buf, 256);
 244                 fprintf(stderr, "  src %s:%d\n", buf, from.sin_port);
 245                 inet_ntop(AF_INET, &inp->ipi_spec_dst, buf, 256);
 246                 fprintf(stderr, "  dst %s\n", buf);
 247                 inet_ntop(AF_INET, &inp->ipi_addr, buf, 256);
 248                 fprintf(stderr, "  real %s\n", buf);
 249         }
 250
 251         if (inp->ipi_ifindex != iface->ifindex)
 252                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 253         else if (!interface_valid_src((void *) &iface->v4_addr, (void *) &iface->v4_netmask, (void *) &from.sin_addr, 4))
 254                 dns_handle_packet(iface, (struct sockaddr *) &from, from.sin_port, buffer, len);
 255 }
 256
 257 static void
 258 read_socket6(struct uloop_fd *u, unsigned int events)
 259 {
 260         struct interface *iface = container_of(u, struct interface, fd);
 261         static uint8_t buffer[8 * 1024];
 262         struct iovec iov[1];
 263         char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 264         struct cmsghdr *cmsgptr;
 265         struct msghdr msg;
 266         socklen_t len;
 267         struct sockaddr_in6 from;
 268         int flags = 0, ifindex = -1;
 269         int ttl = 0;
 270         struct in6_pktinfo *inp = NULL;
 271
 272         if (u->eof) {
 273                 interface_close(iface);
 274                 uloop_timeout_set(&iface->reconnect, 1000);
 275                 return;
 276         }
 277
 278         iov[0].iov_base = buffer;
 279         iov[0].iov_len = sizeof(buffer);
 280
 281         memset(&msg, 0, sizeof(msg));
 282         msg.msg_name = (struct sockaddr *) &from;
 283         msg.msg_namelen = sizeof(struct sockaddr_in6);
 284         msg.msg_iov = iov;
 285         msg.msg_iovlen = 1;
 286         msg.msg_control = &cmsg6;
 287         msg.msg_controllen = sizeof(cmsg6);
 288
 289         len = recvmsg(u->fd, &msg, flags);
 290         if (len == -1) {
 291                 perror("read failed");
 292                 return;
 293         }
 294         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 295                 void *c = CMSG_DATA(cmsgptr);
 296
 297                 switch (cmsgptr->cmsg_type) {
 298                 case IPV6_PKTINFO:
 299                         inp = ((struct in6_pktinfo *) c);
 300                         break;
 301
 302                 case IPV6_HOPLIMIT:
 303                         ttl = (uint8_t) *((int *) c);
 304                         break;
 305
 306                 default:
 307                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 308                         return;
 309                 }
 310         }
 311
 312         if (ttl != 255)
 313                 return;
 314
 315         if (debug > 1) {
 316                 char buf[256];
 317
 318                 fprintf(stderr, "RX ipv6: %s\n", iface->name);
 319                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 320                 inet_ntop(AF_INET6, &from.sin6_addr, buf, 256);
 321                 fprintf(stderr, "  src %s:%d\n", buf, from.sin6_port);
 322                 inet_ntop(AF_INET6, &inp->ipi6_addr, buf, 256);
 323                 fprintf(stderr, "  dst %s\n", buf);
 324         }
 325
 326         if (inp->ipi6_ifindex != iface->ifindex)
 327                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 328         else if (!interface_valid_src((void *) &iface->v6_addr, (void *) &iface->v6_netmask, (void *) &from.sin6_addr, 16))
 329                 dns_handle_packet(iface, (struct sockaddr *) &from, from.sin6_port, buffer, len);
 330 }
 331
 332 static int
 333 interface_mcast_setup4(struct interface *iface)
 334 {
 335         struct ip_mreqn mreq;
 336         uint8_t ttl = 255;
 337         int no = 0;
 338         struct sockaddr_in sa = { 0 };
 339         int fd = iface->fd.fd;
 340
 341         sa.sin_family = AF_INET;
 342         sa.sin_port = htons(MCAST_PORT);
 343         inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
 344
 345         memset(&mreq, 0, sizeof(mreq));
 346         mreq.imr_address.s_addr = iface->v4_addr.s_addr;
 347         mreq.imr_multiaddr = sa.sin_addr;
 348         mreq.imr_ifindex = iface->ifindex;
 349
 350         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 351                 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
 352
 353         /* Some network drivers have issues with dropping membership of
 354          * mcast groups when the iface is down, but don't allow rejoining
 355          * when it comes back up. This is an ugly workaround
 356          * -- this was copied from avahi --
 357          */
 358         setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
 359
 360         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 361                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 362                 close(fd);
 363                 fd = -1;
 364                 return -1;
 365         }
 366
 367         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 368                 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
 369
 370         return 0;
 371 }
 372
 373 static int
 374 interface_socket_setup6(struct interface *iface)
 375 {
 376         struct ipv6_mreq mreq;
 377         int ttl = 255;
 378         int no = 0;
 379         struct sockaddr_in6 sa = { 0 };
 380         int fd = iface->fd.fd;
 381
 382         sa.sin6_family = AF_INET6;
 383         sa.sin6_port = htons(MCAST_PORT);
 384         inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
 385
 386         memset(&mreq, 0, sizeof(mreq));
 387         mreq.ipv6mr_multiaddr = sa.sin6_addr;
 388         mreq.ipv6mr_interface = iface->ifindex;
 389
 390         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 391                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_HOPS\n");
 392
 393         setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
 394         if (setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 395                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 396                 close(fd);
 397                 fd = -1;
 398                 return -1;
 399         }
 400
 401         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 402                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_LOOP\n");
 403
 404         return 0;
 405 }
 406
 407 static void
 408 reconnect_socket4(struct uloop_timeout *timeout)
 409 {
 410         struct interface *iface = container_of(timeout, struct interface, reconnect);
 411         int ttl = 255;
 412         int yes = 1;
 413
 414         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV4ONLY,
 415                 (iface->multicast) ? (iface->mcast_addr) : (iface->v4_addrs), "5353");
 416         if (iface->fd.fd < 0) {
 417                 fprintf(stderr, "failed to add listener %s: %s\n", iface->mcast_addr, strerror(errno));
 418                 goto retry;
 419         }
 420
 421         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 422                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 423
 424         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 425                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 426
 427         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
 428                 fprintf(stderr, "ioctl failed: IP_TTL\n");
 429
 430         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
 431                 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
 432
 433         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
 434                 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
 435
 436         if (iface->multicast && interface_mcast_setup4(iface)) {
 437                 iface->fd.fd = -1;
 438                 goto retry;
 439         }
 440
 441         uloop_fd_add(&iface->fd, ULOOP_READ);
 442         if (iface->multicast) {
 443                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 444                 announce_init(iface);
 445         }
 446
 447         return;
 448
 449 retry:
 450         uloop_timeout_set(timeout, 1000);
 451 }
 452
 453 static void
 454 reconnect_socket6(struct uloop_timeout *timeout)
 455 {
 456         struct interface *iface = container_of(timeout, struct interface, reconnect);
 457         char mcast_addr[128];
 458         int ttl = 255;
 459         int yes = 1;
 460
 461         snprintf(mcast_addr, sizeof(mcast_addr), "%s%%%s", (iface->multicast) ? (iface->mcast_addr) : (iface->v6_addrs), iface->name);
 462         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV6ONLY, mcast_addr, "5353");
 463         if (iface->fd.fd < 0) {
 464                 fprintf(stderr, "failed to add listener %s: %s\n", mcast_addr, strerror(errno));
 465                 goto retry;
 466         }
 467
 468         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 469                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 470
 471         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 472                 fprintf(stderr, "ioctl failed: IPV6_UNICAST_HOPS\n");
 473
 474         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0)
 475                 fprintf(stderr, "ioctl failed: IPV6_RECVPKTINFO\n");
 476
 477         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0)
 478                 fprintf(stderr, "ioctl failed: IPV6_RECVHOPLIMIT\n");
 479
 480         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 481                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 482
 483         if (iface->multicast && interface_socket_setup6(iface)) {
 484                 iface->fd.fd = -1;
 485                 goto retry;
 486         }
 487
 488         uloop_fd_add(&iface->fd, ULOOP_READ);
 489
 490         if (iface->multicast) {
 491                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 492                 announce_init(iface);
 493         }
 494
 495         return;
 496
 497 retry:
 498         uloop_timeout_set(timeout, 1000);
 499 }
 500
 501
 502 static void interface_start(struct interface *iface)
 503 {
 504         if (iface->v6) {
 505                 iface->fd.cb = read_socket6;
 506                 iface->reconnect.cb = reconnect_socket6;
 507         } else {
 508                 iface->fd.cb = read_socket4;
 509                 iface->reconnect.cb = reconnect_socket4;
 510         }
 511         uloop_timeout_set(&iface->reconnect, 100);
 512 }
 513
 514 static void
 515 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
 516                 struct vlist_node *node_old)
 517 {
 518         struct interface *iface;
 519
 520         if (node_old) {
 521                 iface = container_of(node_old, struct interface, node);
 522                 interface_free(iface);
 523         }
 524
 525         if (node_new) {
 526                 iface = container_of(node_new, struct interface, node);
 527                 interface_start(iface);
 528         }
 529 }
 530
 531 static struct interface* _interface_add(const char *name, int multicast, int v6)
 532 {
 533         struct interface *iface;
 534         char *name_buf;
 535         char *id_buf;
 536
 537         iface = calloc_a(sizeof(*iface),
 538                 &name_buf, strlen(name) + 1,
 539                 &id_buf, strlen(name) + 5);
 540
 541         sprintf(id_buf, "%d_%d_%s", multicast, v6, name);
 542         iface->name = strcpy(name_buf, name);
 543         iface->id = id_buf;
 544         iface->ifindex = if_nametoindex(name);
 545         iface->fd.fd = -1;
 546         iface->multicast = multicast;
 547         iface->v6 = v6;
 548         if (v6)
 549                 iface->mcast_addr = MCAST_ADDR6;
 550         else
 551                 iface->mcast_addr = MCAST_ADDR;
 552
 553         if (iface->ifindex <= 0)
 554                 goto error;
 555
 556         vlist_add(&interfaces, &iface->node, iface->id);
 557         return iface;
 558
 559 error:
 560         free(iface);
 561         return NULL;
 562 }
 563
 564 int interface_add(const char *name)
 565 {
 566         struct interface *v4 = NULL, *v6 = NULL, *unicast;
 567         struct ifaddrs *ifap, *ifa;
 568
 569         getifaddrs(&ifap);
 570
 571         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 572                 if (strcmp(ifa->ifa_name, name))
 573                         continue;
 574                 if (ifa->ifa_addr->sa_family == AF_INET && !v4) {
 575                         struct sockaddr_in *sa;
 576
 577                         if (cfg_proto && (cfg_proto != 4))
 578                                 continue;
 579
 580                         unicast = _interface_add(name, 0, 0);
 581                         if (!unicast)
 582                                 continue;
 583                         v4 = _interface_add(name, 1, 0);
 584                         if (!v4)
 585                                 continue;
 586
 587                         sa = (struct sockaddr_in *) ifa->ifa_addr;
 588                         memcpy(&v4->v4_addr, &sa->sin_addr, sizeof(v4->v4_addr));
 589                         memcpy(&unicast->v4_addr, &sa->sin_addr, sizeof(unicast->v4_addr));
 590
 591                         inet_ntop(AF_INET, &sa->sin_addr, v4->v4_addrs, sizeof(v4->v4_addrs));
 592                         inet_ntop(AF_INET, &sa->sin_addr, unicast->v4_addrs, sizeof(unicast->v4_addrs));
 593
 594                         sa = (struct sockaddr_in *) ifa->ifa_netmask;
 595                         memcpy(&unicast->v4_netmask, &sa->sin_addr, sizeof(unicast->v4_netmask));
 596                         memcpy(&v4->v4_netmask, &sa->sin_addr, sizeof(v4->v4_netmask));
 597
 598                         v4->peer = unicast;
 599                         unicast->peer = v4;
 600                 }
 601
 602                 if (ifa->ifa_addr->sa_family == AF_INET6 && !v6) {
 603                         uint8_t ll_prefix[] = {0xfe, 0x80 };
 604                         struct sockaddr_in6 *sa6;
 605
 606                         if (cfg_proto && (cfg_proto != 6))
 607                                 continue;
 608
 609                         sa6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 610                         if (memcmp(&sa6->sin6_addr, &ll_prefix, 2))
 611                                 continue;
 612
 613                         unicast = _interface_add(name, 0, 1);
 614                         if (!unicast)
 615                                 continue;
 616                         v6 = _interface_add(name, 1, 1);
 617                         if (!v6)
 618                                 continue;
 619
 620                         memcpy(&v6->v6_addr, &sa6->sin6_addr, sizeof(v6->v6_addr));
 621                         memcpy(&unicast->v6_addr, &sa6->sin6_addr, sizeof(unicast->v6_addr));
 622
 623                         inet_ntop(AF_INET6, &sa6->sin6_addr, v6->v6_addrs, sizeof(v6->v6_addrs));
 624                         inet_ntop(AF_INET6, &sa6->sin6_addr, unicast->v6_addrs, sizeof(unicast->v6_addrs));
 625
 626                         sa6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
 627                         memcpy(&v6->v6_netmask, &sa6->sin6_addr, sizeof(v6->v6_netmask));
 628                         memcpy(&unicast->v6_netmask, &sa6->sin6_addr, sizeof(unicast->v6_netmask));
 629
 630                         v6->peer = unicast;
 631                         unicast->peer = v6;
 632                 }
 633         }
 634
 635         freeifaddrs(ifap);
 636
 637         return !v4 && !v6;
 638 }
 639
 640 void interface_shutdown(void)
 641 {
 642         struct interface *iface;
 643
 644         vlist_for_each_element(&interfaces, iface, node)
 645                 if (iface->fd.fd > 0 && iface->multicast) {
 646                         dns_reply_a(iface, NULL, 0);
 647                         service_announce_services(iface, NULL, 0);
 648                 }
 649         vlist_for_each_element(&interfaces, iface, node)
 650                 interface_close(iface);
 651 }
 652
 653 struct interface*
 654 interface_get(const char *name, int v6, int multicast)
 655 {
 656         char id_buf[32];
 657         snprintf(id_buf, sizeof(id_buf), "%d_%d_%s", multicast, v6, name);
 658         struct interface *iface = vlist_find(&interfaces, id_buf, iface, node);
 659         return iface;
 660 }
 661
 662 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);