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 (ttl != 255)
 237                 return;
 238
 239         if (debug > 1) {
 240                 char buf[256];
 241
 242                 fprintf(stderr, "RX ipv4: %s\n", iface->name);
 243                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 244                 inet_ntop(AF_INET, &from.sin_addr, buf, 256);
 245                 fprintf(stderr, "  src %s:%d\n", buf, ntohs(from.sin_port));
 246                 inet_ntop(AF_INET, &inp->ipi_spec_dst, buf, 256);
 247                 fprintf(stderr, "  dst %s\n", buf);
 248                 inet_ntop(AF_INET, &inp->ipi_addr, buf, 256);
 249                 fprintf(stderr, "  real %s\n", buf);
 250         }
 251
 252         if (inp->ipi_ifindex != iface->ifindex)
 253                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 254         else if (!interface_valid_src((void *) &iface->v4_addr, (void *) &iface->v4_netmask, (void *) &from.sin_addr, 4))
 255                 dns_handle_packet(iface, (struct sockaddr *) &from, ntohs(from.sin_port), buffer, len);
 256 }
 257
 258 static void
 259 read_socket6(struct uloop_fd *u, unsigned int events)
 260 {
 261         struct interface *iface = container_of(u, struct interface, fd);
 262         static uint8_t buffer[8 * 1024];
 263         struct iovec iov[1];
 264         char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 265         struct cmsghdr *cmsgptr;
 266         struct msghdr msg;
 267         socklen_t len;
 268         struct sockaddr_in6 from;
 269         int flags = 0, ifindex = -1;
 270         int ttl = 0;
 271         struct in6_pktinfo *inp = NULL;
 272
 273         if (u->eof) {
 274                 interface_close(iface);
 275                 uloop_timeout_set(&iface->reconnect, 1000);
 276                 return;
 277         }
 278
 279         iov[0].iov_base = buffer;
 280         iov[0].iov_len = sizeof(buffer);
 281
 282         memset(&msg, 0, sizeof(msg));
 283         msg.msg_name = (struct sockaddr *) &from;
 284         msg.msg_namelen = sizeof(struct sockaddr_in6);
 285         msg.msg_iov = iov;
 286         msg.msg_iovlen = 1;
 287         msg.msg_control = &cmsg6;
 288         msg.msg_controllen = sizeof(cmsg6);
 289
 290         len = recvmsg(u->fd, &msg, flags);
 291         if (len == -1) {
 292                 perror("read failed");
 293                 return;
 294         }
 295         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 296                 void *c = CMSG_DATA(cmsgptr);
 297
 298                 switch (cmsgptr->cmsg_type) {
 299                 case IPV6_PKTINFO:
 300                         inp = ((struct in6_pktinfo *) c);
 301                         break;
 302
 303                 case IPV6_HOPLIMIT:
 304                         ttl = (uint8_t) *((int *) c);
 305                         break;
 306
 307                 default:
 308                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 309                         return;
 310                 }
 311         }
 312
 313         if (ttl != 255)
 314                 return;
 315
 316         if (debug > 1) {
 317                 char buf[256];
 318
 319                 fprintf(stderr, "RX ipv6: %s\n", iface->name);
 320                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 321                 inet_ntop(AF_INET6, &from.sin6_addr, buf, 256);
 322                 fprintf(stderr, "  src %s:%d\n", buf, ntohs(from.sin6_port));
 323                 inet_ntop(AF_INET6, &inp->ipi6_addr, buf, 256);
 324                 fprintf(stderr, "  dst %s\n", buf);
 325         }
 326
 327         if (inp->ipi6_ifindex != iface->ifindex)
 328                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 329         else if (!interface_valid_src((void *) &iface->v6_addr, (void *) &iface->v6_netmask, (void *) &from.sin6_addr, 16))
 330                 dns_handle_packet(iface, (struct sockaddr *) &from, ntohs(from.sin6_port), buffer, len);
 331 }
 332
 333 static int
 334 interface_mcast_setup4(struct interface *iface)
 335 {
 336         struct ip_mreqn mreq;
 337         uint8_t ttl = 255;
 338         int no = 0;
 339         struct sockaddr_in sa = { 0 };
 340         int fd = iface->fd.fd;
 341
 342         sa.sin_family = AF_INET;
 343         sa.sin_port = htons(MCAST_PORT);
 344         inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
 345
 346         memset(&mreq, 0, sizeof(mreq));
 347         mreq.imr_address.s_addr = iface->v4_addr.s_addr;
 348         mreq.imr_multiaddr = sa.sin_addr;
 349         mreq.imr_ifindex = iface->ifindex;
 350
 351         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 352                 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
 353
 354         /* Some network drivers have issues with dropping membership of
 355          * mcast groups when the iface is down, but don't allow rejoining
 356          * when it comes back up. This is an ugly workaround
 357          * -- this was copied from avahi --
 358          */
 359         setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
 360
 361         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 362                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 363                 close(fd);
 364                 fd = -1;
 365                 return -1;
 366         }
 367
 368         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 369                 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
 370
 371         return 0;
 372 }
 373
 374 static int
 375 interface_socket_setup6(struct interface *iface)
 376 {
 377         struct ipv6_mreq mreq;
 378         int ttl = 255;
 379         int no = 0;
 380         struct sockaddr_in6 sa = { 0 };
 381         int fd = iface->fd.fd;
 382
 383         sa.sin6_family = AF_INET6;
 384         sa.sin6_port = htons(MCAST_PORT);
 385         inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
 386
 387         memset(&mreq, 0, sizeof(mreq));
 388         mreq.ipv6mr_multiaddr = sa.sin6_addr;
 389         mreq.ipv6mr_interface = iface->ifindex;
 390
 391         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 392                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_HOPS\n");
 393
 394         setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
 395         if (setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 396                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 397                 close(fd);
 398                 fd = -1;
 399                 return -1;
 400         }
 401
 402         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 403                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_LOOP\n");
 404
 405         return 0;
 406 }
 407
 408 static void
 409 reconnect_socket4(struct uloop_timeout *timeout)
 410 {
 411         struct interface *iface = container_of(timeout, struct interface, reconnect);
 412         int ttl = 255;
 413         int yes = 1;
 414
 415         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV4ONLY,
 416                 (iface->multicast) ? (iface->mcast_addr) : (iface->v4_addrs), "5353");
 417         if (iface->fd.fd < 0) {
 418                 fprintf(stderr, "failed to add listener %s: %s\n", iface->mcast_addr, strerror(errno));
 419                 goto retry;
 420         }
 421
 422         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 423                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 424
 425         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 426                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 427
 428         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
 429                 fprintf(stderr, "ioctl failed: IP_TTL\n");
 430
 431         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
 432                 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
 433
 434         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
 435                 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
 436
 437         if (iface->multicast && interface_mcast_setup4(iface)) {
 438                 iface->fd.fd = -1;
 439                 goto retry;
 440         }
 441
 442         uloop_fd_add(&iface->fd, ULOOP_READ);
 443         if (iface->multicast) {
 444                 dns_send_question(iface, NULL, C_DNS_SD, TYPE_PTR, 0);
 445                 announce_init(iface);
 446         }
 447
 448         return;
 449
 450 retry:
 451         uloop_timeout_set(timeout, 1000);
 452 }
 453
 454 static void
 455 reconnect_socket6(struct uloop_timeout *timeout)
 456 {
 457         struct interface *iface = container_of(timeout, struct interface, reconnect);
 458         char mcast_addr[128];
 459         int ttl = 255;
 460         int yes = 1;
 461
 462         snprintf(mcast_addr, sizeof(mcast_addr), "%s%%%s", (iface->multicast) ? (iface->mcast_addr) : (iface->v6_addrs), iface->name);
 463         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV6ONLY, mcast_addr, "5353");
 464         if (iface->fd.fd < 0) {
 465                 fprintf(stderr, "failed to add listener %s: %s\n", mcast_addr, strerror(errno));
 466                 goto retry;
 467         }
 468
 469         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 470                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 471
 472         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 473                 fprintf(stderr, "ioctl failed: IPV6_UNICAST_HOPS\n");
 474
 475         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0)
 476                 fprintf(stderr, "ioctl failed: IPV6_RECVPKTINFO\n");
 477
 478         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0)
 479                 fprintf(stderr, "ioctl failed: IPV6_RECVHOPLIMIT\n");
 480
 481         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 482                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 483
 484         if (iface->multicast && interface_socket_setup6(iface)) {
 485                 iface->fd.fd = -1;
 486                 goto retry;
 487         }
 488
 489         uloop_fd_add(&iface->fd, ULOOP_READ);
 490
 491         if (iface->multicast) {
 492                 dns_send_question(iface, NULL, C_DNS_SD, TYPE_PTR, 0);
 493                 announce_init(iface);
 494         }
 495
 496         return;
 497
 498 retry:
 499         uloop_timeout_set(timeout, 1000);
 500 }
 501
 502
 503 static void interface_start(struct interface *iface)
 504 {
 505         if (iface->v6) {
 506                 iface->fd.cb = read_socket6;
 507                 iface->reconnect.cb = reconnect_socket6;
 508         } else {
 509                 iface->fd.cb = read_socket4;
 510                 iface->reconnect.cb = reconnect_socket4;
 511         }
 512         uloop_timeout_set(&iface->reconnect, 100);
 513 }
 514
 515 static void
 516 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
 517                 struct vlist_node *node_old)
 518 {
 519         struct interface *iface;
 520
 521         if (node_old) {
 522                 iface = container_of(node_old, struct interface, node);
 523                 cache_cleanup(iface);
 524                 interface_free(iface);
 525         }
 526
 527         if (node_new) {
 528                 iface = container_of(node_new, struct interface, node);
 529                 interface_start(iface);
 530         }
 531 }
 532
 533 static struct interface* _interface_add(const char *name, int multicast, int v6)
 534 {
 535         struct interface *iface;
 536         char *name_buf;
 537         char *id_buf;
 538
 539         iface = calloc_a(sizeof(*iface),
 540                 &name_buf, strlen(name) + 1,
 541                 &id_buf, strlen(name) + 5);
 542
 543         sprintf(id_buf, "%d_%d_%s", multicast, v6, name);
 544         iface->name = strcpy(name_buf, name);
 545         iface->id = id_buf;
 546         iface->ifindex = if_nametoindex(name);
 547         iface->fd.fd = -1;
 548         iface->multicast = multicast;
 549         iface->v6 = v6;
 550         if (v6)
 551                 iface->mcast_addr = MCAST_ADDR6;
 552         else
 553                 iface->mcast_addr = MCAST_ADDR;
 554
 555         if (iface->ifindex <= 0)
 556                 goto error;
 557
 558         vlist_add(&interfaces, &iface->node, iface->id);
 559         return iface;
 560
 561 error:
 562         free(iface);
 563         return NULL;
 564 }
 565
 566 int interface_add(const char *name)
 567 {
 568         struct interface *v4 = NULL, *v6 = NULL, *unicast;
 569         struct ifaddrs *ifap, *ifa;
 570
 571         getifaddrs(&ifap);
 572
 573         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 574                 if (strcmp(ifa->ifa_name, name))
 575                         continue;
 576                 if (ifa->ifa_addr->sa_family == AF_INET && !v4) {
 577                         struct sockaddr_in *sa;
 578
 579                         if (cfg_proto && (cfg_proto != 4))
 580                                 continue;
 581
 582                         unicast = _interface_add(name, 0, 0);
 583                         if (!unicast)
 584                                 continue;
 585                         v4 = _interface_add(name, 1, 0);
 586                         if (!v4)
 587                                 continue;
 588
 589                         sa = (struct sockaddr_in *) ifa->ifa_addr;
 590                         memcpy(&v4->v4_addr, &sa->sin_addr, sizeof(v4->v4_addr));
 591                         memcpy(&unicast->v4_addr, &sa->sin_addr, sizeof(unicast->v4_addr));
 592
 593                         inet_ntop(AF_INET, &sa->sin_addr, v4->v4_addrs, sizeof(v4->v4_addrs));
 594                         inet_ntop(AF_INET, &sa->sin_addr, unicast->v4_addrs, sizeof(unicast->v4_addrs));
 595
 596                         sa = (struct sockaddr_in *) ifa->ifa_netmask;
 597                         memcpy(&unicast->v4_netmask, &sa->sin_addr, sizeof(unicast->v4_netmask));
 598                         memcpy(&v4->v4_netmask, &sa->sin_addr, sizeof(v4->v4_netmask));
 599
 600                         v4->peer = unicast;
 601                         unicast->peer = v4;
 602                 }
 603
 604                 if (ifa->ifa_addr->sa_family == AF_INET6 && !v6) {
 605                         uint8_t ll_prefix[] = {0xfe, 0x80 };
 606                         struct sockaddr_in6 *sa6;
 607
 608                         if (cfg_proto && (cfg_proto != 6))
 609                                 continue;
 610
 611                         sa6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 612                         if (memcmp(&sa6->sin6_addr, &ll_prefix, 2))
 613                                 continue;
 614
 615                         unicast = _interface_add(name, 0, 1);
 616                         if (!unicast)
 617                                 continue;
 618                         v6 = _interface_add(name, 1, 1);
 619                         if (!v6)
 620                                 continue;
 621
 622                         memcpy(&v6->v6_addr, &sa6->sin6_addr, sizeof(v6->v6_addr));
 623                         memcpy(&unicast->v6_addr, &sa6->sin6_addr, sizeof(unicast->v6_addr));
 624
 625                         inet_ntop(AF_INET6, &sa6->sin6_addr, v6->v6_addrs, sizeof(v6->v6_addrs));
 626                         inet_ntop(AF_INET6, &sa6->sin6_addr, unicast->v6_addrs, sizeof(unicast->v6_addrs));
 627
 628                         sa6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
 629                         memcpy(&v6->v6_netmask, &sa6->sin6_addr, sizeof(v6->v6_netmask));
 630                         memcpy(&unicast->v6_netmask, &sa6->sin6_addr, sizeof(unicast->v6_netmask));
 631
 632                         v6->peer = unicast;
 633                         unicast->peer = v6;
 634                 }
 635         }
 636
 637         freeifaddrs(ifap);
 638
 639         return !v4 && !v6;
 640 }
 641
 642 void interface_shutdown(void)
 643 {
 644         struct interface *iface;
 645
 646         vlist_for_each_element(&interfaces, iface, node)
 647                 if (iface->fd.fd > 0 && iface->multicast) {
 648                         dns_reply_a(iface, NULL, 0);
 649                         service_announce_services(iface, NULL, 0);
 650                 }
 651         vlist_for_each_element(&interfaces, iface, node)
 652                 interface_close(iface);
 653 }
 654
 655 struct interface*
 656 interface_get(const char *name, int v6, int multicast)
 657 {
 658         char id_buf[32];
 659         snprintf(id_buf, sizeof(id_buf), "%d_%d_%s", multicast, v6, name);
 660         struct interface *iface = vlist_find(&interfaces, id_buf, iface, node);
 661         return iface;
 662 }
 663
 664 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);