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 struct uloop_fd ufd[] = {
  45         [SOCK_UC_IPV4] = { .fd = -1 },
  46         [SOCK_UC_IPV6] = { .fd = -1 },
  47         [SOCK_MC_IPV4] = { .fd = -1 },
  48         [SOCK_MC_IPV6] = { .fd = -1 },
  49 };
  50
  51 static int
  52 interface_send_packet4(struct interface *iface, struct sockaddr_in *to, struct iovec *iov, int iov_len)
  53 {
  54         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
  55         static struct sockaddr_in a = {};
  56         static struct msghdr m = {
  57                 .msg_name = (struct sockaddr *) &a,
  58                 .msg_namelen = sizeof(a),
  59                 .msg_control = cmsg_data,
  60                 .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
  61         };
  62         struct in_pktinfo *pkti;
  63         struct cmsghdr *cmsg;
  64         int fd;
  65
  66         a.sin_family = AF_INET;
  67         a.sin_port = htons(MCAST_PORT);
  68         m.msg_iov = iov;
  69         m.msg_iovlen = iov_len;
  70
  71         memset(cmsg_data, 0, sizeof(cmsg_data));
  72         cmsg = CMSG_FIRSTHDR(&m);
  73         cmsg->cmsg_len = m.msg_controllen;
  74         cmsg->cmsg_level = IPPROTO_IP;
  75         cmsg->cmsg_type = IP_PKTINFO;
  76
  77         pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
  78         pkti->ipi_ifindex = iface->ifindex;
  79
  80         fd = ufd[iface->type].fd;
  81         if (interface_multicast(iface)) {
  82                 a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
  83                 if (to)
  84                         fprintf(stderr, "Ignoring IPv4 address for multicast interface\n");
  85         } else {
  86                 a.sin_addr.s_addr = to->sin_addr.s_addr;
  87         }
  88
  89         return sendmsg(fd, &m, 0);
  90 }
  91
  92 static int
  93 interface_send_packet6(struct interface *iface, struct sockaddr_in6 *to, struct iovec *iov, int iov_len)
  94 {
  95         static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in6_pktinfo)) / sizeof(size_t)) + 1];
  96         static struct sockaddr_in6 a = {};
  97         static struct msghdr m = {
  98                 .msg_name = (struct sockaddr *) &a,
  99                 .msg_namelen = sizeof(a),
 100                 .msg_control = cmsg_data,
 101                 .msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)),
 102         };
 103         struct in6_pktinfo *pkti;
 104         struct cmsghdr *cmsg;
 105         int fd;
 106
 107         a.sin6_family = AF_INET6;
 108         a.sin6_port = htons(MCAST_PORT);
 109         a.sin6_scope_id = iface->ifindex;
 110         m.msg_iov = iov;
 111         m.msg_iovlen = iov_len;
 112
 113         memset(cmsg_data, 0, sizeof(cmsg_data));
 114         cmsg = CMSG_FIRSTHDR(&m);
 115         cmsg->cmsg_len = m.msg_controllen;
 116         cmsg->cmsg_level = IPPROTO_IPV6;
 117         cmsg->cmsg_type = IPV6_PKTINFO;
 118
 119         pkti = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 120         pkti->ipi6_ifindex = iface->ifindex;
 121
 122         fd = ufd[iface->type].fd;
 123         if (interface_multicast(iface)) {
 124                 inet_pton(AF_INET6, MCAST_ADDR6, &a.sin6_addr);
 125                 if (to)
 126                         fprintf(stderr, "Ignoring IPv6 address for multicast interface\n");
 127         } else {
 128                 a.sin6_addr = to->sin6_addr;
 129         }
 130
 131         return sendmsg(fd, &m, 0);
 132 }
 133
 134 int
 135 interface_send_packet(struct interface *iface, struct sockaddr *to, struct iovec *iov, int iov_len)
 136 {
 137         if (!interface_multicast(iface) && !to) {
 138                 fprintf(stderr, "No IP address specified for unicast interface\n");
 139                 errno = EINVAL;
 140                 return -1;
 141         }
 142
 143         if (debug > 1) {
 144                 fprintf(stderr, "TX ipv%d: %s\n", interface_ipv6(iface) ? 6 : 4, iface->name);
 145                 fprintf(stderr, "  multicast: %d\n", interface_multicast(iface));
 146         }
 147
 148         if (interface_ipv6(iface))
 149                 return interface_send_packet6(iface, (struct sockaddr_in6 *)to, iov, iov_len);
 150
 151         return interface_send_packet4(iface, (struct sockaddr_in *)to, iov, iov_len);
 152 }
 153
 154 static struct interface *interface_lookup(unsigned int ifindex, enum umdns_socket_type type)
 155 {
 156         struct interface *iface;
 157
 158         vlist_for_each_element(&interfaces, iface, node)
 159                 if (iface->ifindex == ifindex && iface->type == type)
 160                         return iface;
 161
 162         return NULL;
 163 }
 164
 165 static void interface_free(struct interface *iface)
 166 {
 167         announce_free(iface);
 168         free(iface->addrs.v4);
 169         free(iface);
 170 }
 171
 172 static int
 173 interface_valid_src(void *ip1, void *mask, void *ip2, int len)
 174 {
 175         uint8_t *i1 = ip1;
 176         uint8_t *i2 = ip2;
 177         uint8_t *m = mask;
 178         int i;
 179
 180         if (cfg_no_subnet)
 181                 return 0;
 182
 183         for (i = 0; i < len; i++, i1++, i2++, m++) {
 184                 if ((*i1 & *m) != (*i2 & *m))
 185                         return -1;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static void
 192 read_socket4(struct uloop_fd *u, unsigned int events)
 193 {
 194         enum umdns_socket_type type = (enum umdns_socket_type)(u - ufd);
 195         struct interface *iface;
 196         static uint8_t buffer[8 * 1024];
 197         struct iovec iov[1];
 198         char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 199         struct cmsghdr *cmsgptr;
 200         struct msghdr msg;
 201         socklen_t len;
 202         struct sockaddr_in from;
 203         int flags = 0;
 204         uint8_t ttl = 0;
 205         struct in_pktinfo *inp = NULL;
 206         bool valid_src = false;
 207
 208         if (u->eof) {
 209                 uloop_end();
 210                 return;
 211         }
 212
 213         iov[0].iov_base = buffer;
 214         iov[0].iov_len = sizeof(buffer);
 215
 216         memset(&msg, 0, sizeof(msg));
 217         msg.msg_name = (struct sockaddr *) &from;
 218         msg.msg_namelen = sizeof(struct sockaddr_in);
 219         msg.msg_iov = iov;
 220         msg.msg_iovlen = 1;
 221         msg.msg_control = &cmsg;
 222         msg.msg_controllen = sizeof(cmsg);
 223
 224         len = recvmsg(u->fd, &msg, flags);
 225         if (len == -1) {
 226                 perror("read failed");
 227                 return;
 228         }
 229         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 230                 void *c = CMSG_DATA(cmsgptr);
 231
 232                 switch (cmsgptr->cmsg_type) {
 233                 case IP_PKTINFO:
 234                         inp = ((struct in_pktinfo *) c);
 235                         break;
 236
 237                 case IP_TTL:
 238                         ttl = (uint8_t) *((int *) c);
 239                         break;
 240
 241                 default:
 242                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 243                         return;
 244                 }
 245         }
 246
 247         if (!inp)
 248                 return;
 249
 250         iface = interface_lookup(inp->ipi_ifindex, type);
 251         if (!iface)
 252                 return;
 253
 254         if (debug > 1) {
 255                 char buf[256];
 256
 257                 fprintf(stderr, "RX ipv4: %s\n", iface->name);
 258                 fprintf(stderr, "  multicast: %d\n", interface_multicast(iface));
 259                 inet_ntop(AF_INET, &from.sin_addr, buf, 256);
 260                 fprintf(stderr, "  src %s:%d\n", buf, ntohs(from.sin_port));
 261                 inet_ntop(AF_INET, &inp->ipi_spec_dst, buf, 256);
 262                 fprintf(stderr, "  dst %s\n", buf);
 263                 inet_ntop(AF_INET, &inp->ipi_addr, buf, 256);
 264                 fprintf(stderr, "  real %s\n", buf);
 265                 fprintf(stderr, "  ttl %u\n", ttl);
 266         }
 267
 268         for (size_t i = 0; i < iface->addrs.n_addr; i++) {
 269                 if (!interface_valid_src((void *)&iface->addrs.v4[i].addr,
 270                                          (void *)&iface->addrs.v4[i].mask,
 271                                          (void *) &from.sin_addr, 4)) {
 272                         valid_src = true;
 273                         break;
 274                 }
 275         }
 276
 277         if (!valid_src)
 278                 return;
 279
 280         dns_handle_packet(iface, (struct sockaddr *) &from, ntohs(from.sin_port), buffer, len);
 281 }
 282
 283 static void
 284 read_socket6(struct uloop_fd *u, unsigned int events)
 285 {
 286         enum umdns_socket_type type = (enum umdns_socket_type)(u - ufd);
 287         struct interface *iface;
 288         static uint8_t buffer[8 * 1024];
 289         struct iovec iov[1];
 290         char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int)) + 1];
 291         struct cmsghdr *cmsgptr;
 292         struct msghdr msg;
 293         socklen_t len;
 294         struct sockaddr_in6 from;
 295         int flags = 0;
 296         int ttl = 0;
 297         struct in6_pktinfo *inp = NULL;
 298         bool valid_src = false;
 299
 300         if (u->eof) {
 301                 uloop_end();
 302                 return;
 303         }
 304
 305         iov[0].iov_base = buffer;
 306         iov[0].iov_len = sizeof(buffer);
 307
 308         memset(&msg, 0, sizeof(msg));
 309         msg.msg_name = (struct sockaddr *) &from;
 310         msg.msg_namelen = sizeof(struct sockaddr_in6);
 311         msg.msg_iov = iov;
 312         msg.msg_iovlen = 1;
 313         msg.msg_control = &cmsg6;
 314         msg.msg_controllen = sizeof(cmsg6);
 315
 316         len = recvmsg(u->fd, &msg, flags);
 317         if (len == -1) {
 318                 perror("read failed");
 319                 return;
 320         }
 321         for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
 322                 void *c = CMSG_DATA(cmsgptr);
 323
 324                 switch (cmsgptr->cmsg_type) {
 325                 case IPV6_PKTINFO:
 326                         inp = ((struct in6_pktinfo *) c);
 327                         break;
 328
 329                 case IPV6_HOPLIMIT:
 330                         ttl = (uint8_t) *((int *) c);
 331                         break;
 332
 333                 default:
 334                         fprintf(stderr, "unknown cmsg %x\n", cmsgptr->cmsg_type);
 335                         return;
 336                 }
 337         }
 338
 339         if (!inp)
 340                 return;
 341
 342         iface = interface_lookup(inp->ipi6_ifindex, type);
 343         if (!iface)
 344                 return;
 345
 346         if (debug > 1) {
 347                 char buf[256];
 348
 349                 fprintf(stderr, "RX ipv6: %s\n", iface->name);
 350                 fprintf(stderr, "  multicast: %d\n", interface_multicast(iface));
 351                 inet_ntop(AF_INET6, &from.sin6_addr, buf, 256);
 352                 fprintf(stderr, "  src %s:%d\n", buf, ntohs(from.sin6_port));
 353                 inet_ntop(AF_INET6, &inp->ipi6_addr, buf, 256);
 354                 fprintf(stderr, "  dst %s\n", buf);
 355                 fprintf(stderr, "  ttl %u\n", ttl);
 356         }
 357
 358         for (size_t i = 0; i < iface->addrs.n_addr; i++) {
 359                 if (!interface_valid_src((void *)&iface->addrs.v6[i].addr,
 360                                          (void *)&iface->addrs.v6[i].mask,
 361                                          (void *)&from.sin6_addr, 6)) {
 362                         valid_src = true;
 363                         break;
 364                 }
 365         }
 366
 367         if (!valid_src)
 368                 return;
 369
 370         dns_handle_packet(iface, (struct sockaddr *) &from, ntohs(from.sin6_port), buffer, len);
 371 }
 372
 373 static int
 374 interface_mcast_setup4(struct interface *iface)
 375 {
 376         struct ip_mreqn mreq;
 377         struct sockaddr_in sa = {};
 378         int fd = ufd[SOCK_MC_IPV4].fd;
 379
 380         sa.sin_family = AF_INET;
 381         sa.sin_port = htons(MCAST_PORT);
 382         inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
 383
 384         memset(&mreq, 0, sizeof(mreq));
 385         mreq.imr_multiaddr = sa.sin_addr;
 386         mreq.imr_ifindex = iface->ifindex;
 387         mreq.imr_address.s_addr = iface->addrs.v4[0].addr.s_addr;
 388
 389         /* Some network drivers have issues with dropping membership of
 390          * mcast groups when the iface is down, but don't allow rejoining
 391          * when it comes back up. This is an ugly workaround
 392          * -- this was copied from avahi --
 393          */
 394         setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
 395         setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
 396
 397         return 0;
 398 }
 399
 400 static int
 401 interface_mcast_setup6(struct interface *iface)
 402 {
 403         struct ipv6_mreq mreq;
 404         struct sockaddr_in6 sa = {};
 405         int fd = ufd[SOCK_MC_IPV6].fd;
 406
 407         sa.sin6_family = AF_INET6;
 408         sa.sin6_port = htons(MCAST_PORT);
 409         inet_pton(AF_INET6, MCAST_ADDR6, &sa.sin6_addr);
 410
 411         memset(&mreq, 0, sizeof(mreq));
 412         mreq.ipv6mr_multiaddr = sa.sin6_addr;
 413         mreq.ipv6mr_interface = iface->ifindex;
 414
 415         setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq, sizeof(mreq));
 416         setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
 417
 418         return 0;
 419 }
 420
 421 static void interface_start(struct interface *iface)
 422 {
 423         if (iface->type & SOCKTYPE_BIT_UNICAST)
 424                 return;
 425
 426         if (iface->type & SOCKTYPE_BIT_IPV6)
 427                 interface_mcast_setup6(iface);
 428         else
 429                 interface_mcast_setup4(iface);
 430
 431         dns_send_question(iface, NULL, C_DNS_SD, TYPE_PTR, 0);
 432         announce_init(iface);
 433 }
 434
 435 static bool
 436 iface_equal(struct interface *if_old, struct interface *if_new)
 437 {
 438         size_t addr_size;
 439
 440         if (if_old->ifindex != if_new->ifindex ||
 441             if_old->addrs.n_addr != if_new->addrs.n_addr)
 442                 return false;
 443
 444         if (if_old->type & SOCKTYPE_BIT_IPV6)
 445                 addr_size = sizeof(*if_old->addrs.v6);
 446         else
 447                 addr_size = sizeof(*if_old->addrs.v4);
 448         addr_size *= if_old->addrs.n_addr;
 449         if (memcmp(if_old->addrs.v4, if_new->addrs.v4, addr_size) != 0)
 450                 return false;
 451
 452         return true;
 453 }
 454
 455 static void
 456 iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
 457                 struct vlist_node *node_old)
 458 {
 459         struct interface *if_old = container_of_safe(node_old, struct interface, node);
 460         struct interface *if_new = container_of_safe(node_new, struct interface, node);
 461
 462         if (if_old && if_new) {
 463                 if (!iface_equal(if_old, if_new))
 464                         cache_cleanup(if_old);
 465                 free(if_old->addrs.v4);
 466                 if_old->addrs = if_new->addrs;
 467                 free(if_new);
 468                 return;
 469         }
 470
 471         if (if_old)
 472                 interface_free(if_old);
 473
 474         if (if_new)
 475                 interface_start(if_new);
 476 }
 477
 478 static int interface_init_socket(enum umdns_socket_type type)
 479 {
 480         struct sockaddr_in6 local6 = {
 481                 .sin6_family = AF_INET6
 482         };
 483         struct sockaddr_in local = {
 484                 .sin_family = AF_INET
 485         };
 486         uint8_t ttl = 255;
 487         int ittl = 255;
 488         int yes = 1;
 489         int no = 0;
 490         int fd;
 491         int af = (type & SOCKTYPE_BIT_IPV6) ? AF_INET6 : AF_INET;
 492
 493         if (ufd[type].fd >= 0)
 494                 return 0;
 495
 496         ufd[type].fd = fd = socket(af, SOCK_DGRAM, 0);
 497         if (fd < 0)
 498                 return -1;
 499
 500         setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
 501 #ifdef SO_REUSEPORT
 502         setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
 503 #endif
 504
 505         switch (type) {
 506         case SOCK_UC_IPV4:
 507         case SOCK_UC_IPV6:
 508                 break;
 509         case SOCK_MC_IPV4:
 510                 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
 511                 setsockopt(fd, IPPROTO_IP, IP_TTL, &ittl, sizeof(ittl));
 512                 setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no));
 513                 local.sin_port = htons(MCAST_PORT);
 514                 break;
 515         case SOCK_MC_IPV6:
 516                 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
 517                 setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
 518                 setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes));
 519                 setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &no, sizeof(no));
 520                 local6.sin6_port = htons(MCAST_PORT);
 521                 break;
 522         }
 523
 524         if (type & SOCKTYPE_BIT_IPV6) {
 525                 ufd[type].cb = read_socket6;
 526                 if (bind(fd, (struct sockaddr *)&local6, sizeof(local6)) < 0)
 527                         goto error;
 528
 529                 setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes));
 530                 setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes));
 531         } else {
 532                 ufd[type].cb = read_socket4;
 533                 if (bind(fd, (struct sockaddr *)&local, sizeof(local)) < 0)
 534                         goto error;
 535
 536                 setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes));
 537                 setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes));
 538         }
 539
 540         uloop_fd_add(&ufd[type], ULOOP_READ);
 541
 542         return 0;
 543
 544 error:
 545         close(ufd[type].fd);
 546         return -1;
 547 }
 548
 549 static void
 550 __interface_add(const char *name, enum umdns_socket_type type,
 551                                 struct interface_addr_list *list)
 552 {
 553         struct interface *iface;
 554         unsigned int ifindex;
 555         char *id_buf;
 556
 557         if (interface_init_socket(type))
 558                 goto error;
 559
 560         ifindex = if_nametoindex(name);
 561         if (!ifindex)
 562                 goto error;
 563
 564         iface = calloc_a(sizeof(*iface),
 565                 &id_buf, strlen(name) + 3);
 566
 567         sprintf(id_buf, "%d_%s", type, name);
 568         iface->name = id_buf + 2;
 569         iface->ifindex = ifindex;
 570         iface->type = type;
 571         iface->addrs = *list;
 572
 573         vlist_add(&interfaces, &iface->node, id_buf);
 574         return;
 575
 576 error:
 577         free(list->v4);
 578 }
 579
 580 int interface_add(const char *name)
 581 {
 582         struct ifaddrs *ifap, *ifa;
 583         struct interface_addr_list addr4 = {}, addr6 = {};
 584
 585         getifaddrs(&ifap);
 586
 587         for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
 588                 if (strcmp(ifa->ifa_name, name))
 589                         continue;
 590                 if (ifa->ifa_addr->sa_family == AF_INET) {
 591                         struct sockaddr_in *sin;
 592
 593                         if (cfg_proto && (cfg_proto != 4))
 594                                 continue;
 595
 596                         addr4.v4 = realloc(addr4.v4, (addr4.n_addr + 1) * sizeof(*addr4.v4));
 597                         sin = (struct sockaddr_in *) ifa->ifa_addr;
 598                         addr4.v4[addr4.n_addr].addr = sin->sin_addr;
 599                         sin = (struct sockaddr_in *) ifa->ifa_netmask;
 600                         addr4.v4[addr4.n_addr++].mask = sin->sin_addr;
 601                 }
 602
 603                 if (ifa->ifa_addr->sa_family == AF_INET6) {
 604                         uint8_t ll_prefix[] = {0xfe, 0x80 };
 605                         struct sockaddr_in6 *sin6;
 606
 607                         if (cfg_proto && (cfg_proto != 6))
 608                                 continue;
 609
 610                         sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 611                         if (memcmp(&sin6->sin6_addr, &ll_prefix, 2))
 612                                 continue;
 613
 614                         addr6.v6 = realloc(addr6.v6, (addr6.n_addr + 1) * sizeof(*addr6.v6));
 615                         sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 616                         addr6.v6[addr6.n_addr].addr = sin6->sin6_addr;
 617                         sin6 = (struct sockaddr_in6 *) ifa->ifa_netmask;
 618                         addr6.v6[addr6.n_addr++].mask = sin6->sin6_addr;
 619                 }
 620         }
 621
 622         freeifaddrs(ifap);
 623
 624         if (addr4.n_addr) {
 625                 size_t addr_size = addr4.n_addr * sizeof(*addr4.v4);
 626                 void *addr_dup = malloc(addr_size);
 627
 628                 memcpy(addr_dup, addr4.v4, addr_size);
 629                 __interface_add(name, SOCK_UC_IPV4, &addr4);
 630                 addr4.v4 = addr_dup;
 631                 __interface_add(name, SOCK_MC_IPV4, &addr4);
 632         }
 633
 634         if (addr6.n_addr) {
 635                 size_t addr_size = addr6.n_addr * sizeof(*addr6.v6);
 636                 void *addr_dup = malloc(addr_size);
 637
 638                 memcpy(addr_dup, addr6.v6, addr_size);
 639                 __interface_add(name, SOCK_UC_IPV6, &addr6);
 640                 addr6.v6 = addr_dup;
 641                 __interface_add(name, SOCK_MC_IPV6, &addr6);
 642         }
 643
 644         return !addr4.n_addr && !addr6.n_addr;
 645 }
 646
 647 void interface_shutdown(void)
 648 {
 649         struct interface *iface;
 650
 651         vlist_for_each_element(&interfaces, iface, node)
 652                 if (interface_multicast(iface)) {
 653                         dns_reply_a(iface, NULL, 0);
 654                         service_announce_services(iface, NULL, 0);
 655                 }
 656
 657         for (size_t i = 0; i < ARRAY_SIZE(ufd); i++) {
 658                 uloop_fd_delete(&ufd[i]);
 659                 close(ufd[i].fd);
 660                 ufd[i].fd = -1;
 661         }
 662 }
 663
 664 struct interface *interface_get(const char *name, enum umdns_socket_type type)
 665 {
 666         char id_buf[32];
 667         snprintf(id_buf, sizeof(id_buf), "%d_%s", type, name);
 668         struct interface *iface = vlist_find(&interfaces, id_buf, iface, node);
 669         return iface;
 670 }
 671
 672 VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);