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         interface_close(iface);
 157         free(iface);
 158 }
 159
 160 static int
 161 interface_valid_src(void *ip1, void *mask, void *ip2, int len)
 162 {
 163         uint8_t *i1 = ip1;
 164         uint8_t *i2 = ip2;
 165         uint8_t *m = mask;
 166         int i;
 167
 168         if (cfg_no_subnet)
 169                 return 0;
 170
 171         for (i = 0; i < len; i++, i1++, i2++, m++) {
 172                 if ((*i1 & *m) != (*i2 & *m))
 173                         return -1;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static void
 180 read_socket4(struct uloop_fd *u, unsigned int events)
 181 {
 182         struct interface *iface = container_of(u, struct interface, fd);
 183         static uint8_t buffer[8 * 1024];
 184         struct iovec iov[1];
 185         char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 186         struct cmsghdr *cmsgptr;
 187         struct msghdr msg;
 188         socklen_t len;
 189         struct sockaddr_in from;
 190         int flags = 0, ifindex = -1;
 191         uint8_t ttl = 0;
 192         struct in_pktinfo *inp = NULL;
 193
 194         if (u->eof) {
 195                 interface_close(iface);
 196                 uloop_timeout_set(&iface->reconnect, 1000);
 197                 return;
 198         }
 199
 200         iov[0].iov_base = buffer;
 201         iov[0].iov_len = sizeof(buffer);
 202
 203         memset(&msg, 0, sizeof(msg));
 204         msg.msg_name = (struct sockaddr *) &from;
 205         msg.msg_namelen = sizeof(struct sockaddr_in);
 206         msg.msg_iov = iov;
 207         msg.msg_iovlen = 1;
 208         msg.msg_control = &cmsg;
 209         msg.msg_controllen = sizeof(cmsg);
 210
 211         len = recvmsg(u->fd, &msg, flags);
 212         if (len == -1) {
 213                 perror("read failed");
 214                 return;
 215         }
 216         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 217                 void *c = CMSG_DATA(cmsgptr);
 218
 219                 switch (cmsgptr->cmsg_type) {
 220                 case IP_PKTINFO:
 221                         inp = ((struct in_pktinfo *) c);
 222                         break;
 223
 224                 case IP_TTL:
 225                         ttl = (uint8_t) *((int *) c);
 226                         break;
 227
 228                 default:
 229                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 230                         return;
 231                 }
 232         }
 233
 234         if (ttl != 255)
 235                 return;
 236
 237         if (debug > 1) {
 238                 char buf[256];
 239
 240                 fprintf(stderr, "RX ipv4: %s\n", iface->name);
 241                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 242                 inet_ntop(AF_INET, &from.sin_addr, buf, 256);
 243                 fprintf(stderr, "  src %s:%d\n", buf, from.sin_port);
 244                 inet_ntop(AF_INET, &inp->ipi_spec_dst, buf, 256);
 245                 fprintf(stderr, "  dst %s\n", buf);
 246                 inet_ntop(AF_INET, &inp->ipi_addr, buf, 256);
 247                 fprintf(stderr, "  real %s\n", buf);
 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, 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 (ttl != 255)
 312                 return;
 313
 314         if (debug > 1) {
 315                 char buf[256];
 316
 317                 fprintf(stderr, "RX ipv6: %s\n", iface->name);
 318                 fprintf(stderr, "  multicast: %d\n", iface->multicast);
 319                 inet_ntop(AF_INET6, &from.sin6_addr, buf, 256);
 320                 fprintf(stderr, "  src %s:%d\n", buf, from.sin6_port);
 321                 inet_ntop(AF_INET6, &inp->ipi6_addr, buf, 256);
 322                 fprintf(stderr, "  dst %s\n", buf);
 323         }
 324
 325         if (inp->ipi6_ifindex != iface->ifindex)
 326                 fprintf(stderr, "invalid iface index %d != %d\n", ifindex, iface->ifindex);
 327         else if (!interface_valid_src((void *) &iface->v6_addr, (void *) &iface->v6_netmask, (void *) &from.sin6_addr, 16))
 328                 dns_handle_packet(iface, (struct sockaddr *) &from, from.sin6_port, buffer, len);
 329 }
 330
 331 static int
 332 interface_mcast_setup4(struct interface *iface)
 333 {
 334         struct ip_mreqn mreq;
 335         uint8_t ttl = 255;
 336         int no = 0;
 337         struct sockaddr_in sa = { 0 };
 338         int fd = iface->fd.fd;
 339
 340         sa.sin_family = AF_INET;
 341         sa.sin_port = htons(MCAST_PORT);
 342         inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
 343
 344         memset(&mreq, 0, sizeof(mreq));
 345         mreq.imr_address.s_addr = iface->v4_addr.s_addr;
 346         mreq.imr_multiaddr = sa.sin_addr;
 347         mreq.imr_ifindex = iface->ifindex;
 348
 349         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 350                 fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
 351
 352         /* Some network drivers have issues with dropping membership of
 353          * mcast groups when the iface is down, but don't allow rejoining
 354          * when it comes back up. This is an ugly workaround
 355          * -- this was copied from avahi --
 356          */
 357         setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
 358
 359         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 360                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 361                 close(fd);
 362                 fd = -1;
 363                 return -1;
 364         }
 365
 366         if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 367                 fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
 368
 369         return 0;
 370 }
 371
 372 static int
 373 interface_socket_setup6(struct interface *iface)
 374 {
 375         struct ipv6_mreq mreq;
 376         int ttl = 255;
 377         int no = 0;
 378         struct sockaddr_in6 sa = { 0 };
 379         int fd = iface->fd.fd;
 380
 381         sa.sin6_family = AF_INET6;
 382         sa.sin6_port = htons(MCAST_PORT);
 383         inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
 384
 385         memset(&mreq, 0, sizeof(mreq));
 386         mreq.ipv6mr_multiaddr = sa.sin6_addr;
 387         mreq.ipv6mr_interface = iface->ifindex;
 388
 389         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 390                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_HOPS\n");
 391
 392         setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
 393         if (setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
 394                 fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
 395                 close(fd);
 396                 fd = -1;
 397                 return -1;
 398         }
 399
 400         if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no)) < 0)
 401                 fprintf(stderr, "ioctl failed: IPV6_MULTICAST_LOOP\n");
 402
 403         return 0;
 404 }
 405
 406 static void
 407 reconnect_socket4(struct uloop_timeout *timeout)
 408 {
 409         struct interface *iface = container_of(timeout, struct interface, reconnect);
 410         int ttl = 255;
 411         int yes = 1;
 412
 413         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV4ONLY,
 414                 (iface->multicast) ? (iface->mcast_addr) : (iface->v4_addrs), "5353");
 415         if (iface->fd.fd < 0) {
 416                 fprintf(stderr, "failed to add listener %s: %s\n", iface->mcast_addr, strerror(errno));
 417                 goto retry;
 418         }
 419
 420         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 421                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 422
 423         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 424                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 425
 426         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
 427                 fprintf(stderr, "ioctl failed: IP_TTL\n");
 428
 429         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
 430                 fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
 431
 432         if (setsockopt(iface->fd.fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
 433                 fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
 434
 435         if (iface->multicast && interface_mcast_setup4(iface)) {
 436                 iface->fd.fd = -1;
 437                 goto retry;
 438         }
 439
 440         uloop_fd_add(&iface->fd, ULOOP_READ);
 441         if (iface->multicast) {
 442                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 443                 announce_init(iface);
 444         }
 445
 446         return;
 447
 448 retry:
 449         uloop_timeout_set(timeout, 1000);
 450 }
 451
 452 static void
 453 reconnect_socket6(struct uloop_timeout *timeout)
 454 {
 455         struct interface *iface = container_of(timeout, struct interface, reconnect);
 456         char mcast_addr[128];
 457         int ttl = 255;
 458         int yes = 1;
 459
 460         snprintf(mcast_addr, sizeof(mcast_addr), "%s%%%s", (iface->multicast) ? (iface->mcast_addr) : (iface->v6_addrs), iface->name);
 461         iface->fd.fd = usock(USOCK_UDP | USOCK_SERVER | USOCK_NONBLOCK | USOCK_IPV6ONLY, mcast_addr, "5353");
 462         if (iface->fd.fd < 0) {
 463                 fprintf(stderr, "failed to add listener %s: %s\n", mcast_addr, strerror(errno));
 464                 goto retry;
 465         }
 466
 467         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name, strlen(iface->name) < 0))
 468                 fprintf(stderr, "ioctl failed: SO_BINDTODEVICE\n");
 469
 470         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 471                 fprintf(stderr, "ioctl failed: IPV6_UNICAST_HOPS\n");
 472
 473         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0)
 474                 fprintf(stderr, "ioctl failed: IPV6_RECVPKTINFO\n");
 475
 476         if (setsockopt(iface->fd.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0)
 477                 fprintf(stderr, "ioctl failed: IPV6_RECVHOPLIMIT\n");
 478
 479         if (setsockopt(iface->fd.fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
 480                 fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
 481
 482         if (iface->multicast && interface_socket_setup6(iface)) {
 483                 iface->fd.fd = -1;
 484                 goto retry;
 485         }
 486
 487         uloop_fd_add(&iface->fd, ULOOP_READ);
 488
 489         if (iface->multicast) {
 490                 dns_send_question(iface, "_services._dns-sd._udp.local", TYPE_PTR, 0);
 491                 announce_init(iface);
 492         }
 493
 494         return;
 495
 496 retry:
 497         uloop_timeout_set(timeout, 1000);
 498 }
 499
 500
 501 static void interface_start(struct interface *iface)
 502 {
 503         if (iface->v6) {
 504                 iface->fd.cb = read_socket6;
 505                 iface->reconnect.cb = reconnect_socket6;
 506         } else {
 507                 iface->fd.cb = read_socket4;
 508                 iface->reconnect.cb = reconnect_socket4;
 509         }
 510         uloop_timeout_set(&iface->reconnect, 100);
 511 }
 512
 513 static void
 514 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
 515                 struct vlist_node *node_old)
 516 {
 517         struct interface *iface;
 518
 519         if (node_old) {
 520                 iface = container_of(node_old, struct interface, node);
 521                 interface_free(iface);
 522         }
 523
 524         if (node_new) {
 525                 iface = container_of(node_new, struct interface, node);
 526                 interface_start(iface);
 527         }
 528 }
 529
 530 static struct interface* _interface_add(const char *name, int multicast, int v6)
 531 {
 532         struct interface *iface;
 533         char *name_buf;
 534         char *id_buf;
 535
 536         iface = calloc_a(sizeof(*iface),
 537                 &name_buf, strlen(name) + 1,
 538                 &id_buf, strlen(name) + 5);
 539
 540         sprintf(id_buf, "%d_%d_%s", multicast, v6, name);
 541         iface->name = strcpy(name_buf, name);
 542         iface->id = id_buf;
 543         iface->ifindex = if_nametoindex(name);
 544         iface->fd.fd = -1;
 545         iface->multicast = multicast;
 546         iface->v6 = v6;
 547         if (v6)
 548                 iface->mcast_addr = MCAST_ADDR6;
 549         else
 550                 iface->mcast_addr = MCAST_ADDR;
 551
 552         if (iface->ifindex <= 0)
 553                 goto error;
 554
 555         vlist_add(&interfaces, &iface->node, iface->id);
 556         return iface;
 557
 558 error:
 559         free(iface);
 560         return NULL;
 561 }
 562
 563 int interface_add(const char *name)
 564 {
 565         struct interface *v4 = NULL, *v6 = NULL, *unicast;
 566         struct ifaddrs *ifap, *ifa;
 567
 568         getifaddrs(&ifap);
 569
 570         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 571                 if (strcmp(ifa->ifa_name, name))
 572                         continue;
 573                 if (ifa->ifa_addr->sa_family == AF_INET && !v4) {
 574                         struct sockaddr_in *sa;
 575
 576                         if (cfg_proto && (cfg_proto != 4))
 577                                 continue;
 578
 579                         unicast = _interface_add(name, 0, 0);
 580                         if (!unicast)
 581                                 continue;
 582                         v4 = _interface_add(name, 1, 0);
 583                         if (!v4)
 584                                 continue;
 585
 586                         sa = (struct sockaddr_in *) ifa->ifa_addr;
 587                         memcpy(&v4->v4_addr, &sa->sin_addr, sizeof(v4->v4_addr));
 588                         memcpy(&unicast->v4_addr, &sa->sin_addr, sizeof(unicast->v4_addr));
 589
 590                         inet_ntop(AF_INET, &sa->sin_addr, v4->v4_addrs, sizeof(v4->v4_addrs));
 591                         inet_ntop(AF_INET, &sa->sin_addr, unicast->v4_addrs, sizeof(unicast->v4_addrs));
 592
 593                         sa = (struct sockaddr_in *) ifa->ifa_netmask;
 594                         memcpy(&unicast->v4_netmask, &sa->sin_addr, sizeof(unicast->v4_netmask));
 595                         memcpy(&v4->v4_netmask, &sa->sin_addr, sizeof(v4->v4_netmask));
 596
 597                         v4->peer = unicast;
 598                         unicast->peer = v4;
 599                 }
 600
 601                 if (ifa->ifa_addr->sa_family == AF_INET6 && !v6) {
 602                         uint8_t ll_prefix[] = {0xfe, 0x80 };
 603                         struct sockaddr_in6 *sa6;
 604
 605                         if (cfg_proto && (cfg_proto != 6))
 606                                 continue;
 607
 608                         sa6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 609                         if (memcmp(&sa6->sin6_addr, &ll_prefix, 2))
 610                                 continue;
 611
 612                         unicast = _interface_add(name, 0, 1);
 613                         if (!unicast)
 614                                 continue;
 615                         v6 = _interface_add(name, 1, 1);
 616                         if (!v6)
 617                                 continue;
 618
 619                         memcpy(&v6->v6_addr, &sa6->sin6_addr, sizeof(v6->v6_addr));
 620                         memcpy(&unicast->v6_addr, &sa6->sin6_addr, sizeof(unicast->v6_addr));
 621
 622                         inet_ntop(AF_INET6, &sa6->sin6_addr, v6->v6_addrs, sizeof(v6->v6_addrs));
 623                         inet_ntop(AF_INET6, &sa6->sin6_addr, unicast->v6_addrs, sizeof(unicast->v6_addrs));
 624
 625                         sa6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
 626                         memcpy(&v6->v6_netmask, &sa6->sin6_addr, sizeof(v6->v6_netmask));
 627                         memcpy(&unicast->v6_netmask, &sa6->sin6_addr, sizeof(unicast->v6_netmask));
 628
 629                         v6->peer = unicast;
 630                         unicast->peer = v6;
 631                 }
 632         }
 633
 634         freeifaddrs(ifap);
 635
 636         return !v4 && !v6;
 637 }
 638
 639 void interface_shutdown(void)
 640 {
 641         struct interface *iface;
 642
 643         vlist_for_each_element(&interfaces, iface, node)
 644                 if (iface->fd.fd > 0 && iface->multicast) {
 645                         dns_reply_a(iface, NULL, 0);
 646                         service_announce_services(iface, NULL, 0);
 647                 }
 648         vlist_for_each_element(&interfaces, iface, node)
 649                 interface_close(iface);
 650 }
 651
 652 struct interface*
 653 interface_get(const char *name, int v6, int multicast)
 654 {
 655         char id_buf[32];
 656         snprintf(id_buf, sizeof(id_buf), "%d_%d_%s", multicast, v6, name);
 657         struct interface *iface = vlist_find(&interfaces, id_buf, iface, node);
 658         return iface;
 659 }
 660
 661 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);