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