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