4 This file is part of avahi.
6 avahi is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 avahi is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
14 Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with avahi; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
37 #include <sys/ioctl.h>
45 static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
48 memset(ret_sa, 0, sizeof(struct sockaddr_in));
49 ret_sa->sin_family = AF_INET;
50 ret_sa->sin_port = htons(AVAHI_MDNS_PORT);
51 inet_pton(AF_INET, AVAHI_IPV4_MCAST_GROUP, &ret_sa->sin_addr);
54 static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
57 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
58 ret_sa->sin6_family = AF_INET6;
59 ret_sa->sin6_port = htons(AVAHI_MDNS_PORT);
60 inet_pton(AF_INET6, AVAHI_IPV6_MCAST_GROUP, &ret_sa->sin6_addr);
63 static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, uint16_t port) {
68 memset(ret_sa, 0, sizeof(struct sockaddr_in));
69 ret_sa->sin_family = AF_INET;
70 ret_sa->sin_port = htons(port);
71 memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address));
74 static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, uint16_t port) {
79 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
80 ret_sa->sin6_family = AF_INET6;
81 ret_sa->sin6_port = htons(port);
82 memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
85 int avahi_mdns_mcast_join_ipv4(int fd, int idx) {
87 struct sockaddr_in sa;
89 mdns_mcast_group_ipv4 (&sa);
91 memset(&mreq, 0, sizeof(mreq));
92 mreq.imr_multiaddr = sa.sin_addr;
93 mreq.imr_ifindex = idx;
95 if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
96 avahi_log_warn("IP_ADD_MEMBERSHIP failed: %s", strerror(errno));
103 int avahi_mdns_mcast_join_ipv6(int fd, int idx) {
104 struct ipv6_mreq mreq6;
105 struct sockaddr_in6 sa6;
107 mdns_mcast_group_ipv6 (&sa6);
109 memset(&mreq6, 0, sizeof(mreq6));
110 mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
111 mreq6.ipv6mr_interface = idx;
113 if (setsockopt(fd, SOL_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
114 avahi_log_warn("IPV6_ADD_MEMBERSHIP failed: %s", strerror(errno));
121 int avahi_mdns_mcast_leave_ipv4(int fd, int idx) {
122 struct ip_mreqn mreq;
123 struct sockaddr_in sa;
125 mdns_mcast_group_ipv4 (&sa);
127 memset(&mreq, 0, sizeof(mreq));
128 mreq.imr_multiaddr = sa.sin_addr;
129 mreq.imr_ifindex = idx;
131 if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
132 avahi_log_warn("IP_DROP_MEMBERSHIP failed: %s", strerror(errno));
139 int avahi_mdns_mcast_leave_ipv6(int fd, int idx) {
140 struct ipv6_mreq mreq6;
141 struct sockaddr_in6 sa6;
143 mdns_mcast_group_ipv6 (&sa6);
145 memset(&mreq6, 0, sizeof(mreq6));
146 mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
147 mreq6.ipv6mr_interface = idx;
149 if (setsockopt(fd, SOL_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
150 avahi_log_warn("IPV6_DROP_MEMBERSHIP failed: %s", strerror(errno));
157 static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
164 if (bind(fd, sa, l) < 0) {
166 if (errno != EADDRINUSE) {
167 avahi_log_warn("bind() failed: %s", strerror(errno));
171 avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***",
172 sa->sa_family == AF_INET ? "IPv4" : "IPv6");
174 /* Try again, this time with SO_REUSEADDR set */
176 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
177 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
181 if (bind(fd, sa, l) < 0) {
182 avahi_log_warn("bind() failed: %s", strerror(errno));
187 /* We enable SO_REUSEADDR afterwards, to make sure that the
188 * user may run other mDNS implementations if he really
192 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
193 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
201 int avahi_open_socket_ipv4(int no_reuse) {
202 struct sockaddr_in local;
203 int fd = -1, ttl, yes, r;
205 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
206 avahi_log_warn("socket() failed: %s", strerror(errno));
211 if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
212 avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
217 if (setsockopt(fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
218 avahi_log_warn("IP_TTL failed: %s", strerror(errno));
223 if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
224 avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
228 memset(&local, 0, sizeof(local));
229 local.sin_family = AF_INET;
230 local.sin_port = htons(AVAHI_MDNS_PORT);
233 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
235 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
241 if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
242 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
247 if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
248 avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
252 if (avahi_set_cloexec(fd) < 0) {
253 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
257 if (avahi_set_nonblock(fd) < 0) {
258 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
271 int avahi_open_socket_ipv6(int no_reuse) {
272 struct sockaddr_in6 sa, local;
273 int fd = -1, ttl, yes, r;
275 mdns_mcast_group_ipv6(&sa);
277 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
278 avahi_log_warn("socket() failed: %s", strerror(errno));
283 if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
284 avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
289 if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
290 avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
295 if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
296 avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
301 if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
302 avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
306 memset(&local, 0, sizeof(local));
307 local.sin6_family = AF_INET6;
308 local.sin6_port = htons(AVAHI_MDNS_PORT);
311 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
313 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
319 if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
320 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
325 if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
326 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
330 if (avahi_set_cloexec(fd) < 0) {
331 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
335 if (avahi_set_nonblock(fd) < 0) {
336 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
349 static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
355 if (sendmsg(fd, msg, flags) >= 0)
358 if (errno != EAGAIN) {
359 avahi_log_debug("sendmsg() failed: %s", strerror(errno));
363 if (avahi_wait_for_write(fd) < 0)
370 int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, uint16_t port) {
371 struct sockaddr_in sa;
374 struct cmsghdr *cmsg;
375 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
379 assert(avahi_dns_packet_check_valid(p) >= 0);
380 assert(!a || port > 0);
383 mdns_mcast_group_ipv4(&sa);
385 ipv4_address_to_sockaddr(&sa, a, port);
387 memset(&io, 0, sizeof(io));
388 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
389 io.iov_len = p->size;
391 memset(&msg, 0, sizeof(msg));
393 msg.msg_namelen = sizeof(sa);
398 if (interface >= 0) {
399 struct in_pktinfo *pkti;
401 memset(cmsg_data, 0, sizeof(cmsg_data));
402 cmsg = (struct cmsghdr*) cmsg_data;
403 cmsg->cmsg_len = sizeof(cmsg_data);
404 cmsg->cmsg_level = IPPROTO_IP;
405 cmsg->cmsg_type = IP_PKTINFO;
407 pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
408 pkti->ipi_ifindex = interface;
410 msg.msg_control = cmsg_data;
411 msg.msg_controllen = sizeof(cmsg_data);
413 msg.msg_control = NULL;
414 msg.msg_controllen = 0;
417 return sendmsg_loop(fd, &msg, 0);
420 int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, uint16_t port) {
421 struct sockaddr_in6 sa;
424 struct cmsghdr *cmsg;
425 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
429 assert(avahi_dns_packet_check_valid(p) >= 0);
432 mdns_mcast_group_ipv6(&sa);
434 ipv6_address_to_sockaddr(&sa, a, port);
436 memset(&io, 0, sizeof(io));
437 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
438 io.iov_len = p->size;
441 memset(&msg, 0, sizeof(msg));
443 msg.msg_namelen = sizeof(sa);
448 if (interface >= 0) {
449 struct in6_pktinfo *pkti;
451 memset(cmsg_data, 0, sizeof(cmsg_data));
452 cmsg = (struct cmsghdr*) cmsg_data;
453 cmsg->cmsg_len = sizeof(cmsg_data);
454 cmsg->cmsg_level = IPPROTO_IPV6;
455 cmsg->cmsg_type = IPV6_PKTINFO;
457 pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
458 pkti->ipi6_ifindex = interface;
460 msg.msg_control = cmsg_data;
461 msg.msg_controllen = sizeof(cmsg_data);
463 msg.msg_control = NULL;
464 msg.msg_controllen = 0;
467 return sendmsg_loop(fd, &msg, 0);
470 AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
471 AvahiDnsPacket *p= NULL;
476 struct cmsghdr *cmsg;
477 int found_ttl = 0, found_iface = 0;
482 if (ioctl(fd, FIONREAD, &ms) < 0) {
483 avahi_log_warn("ioctl(): %s", strerror(errno));
487 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
489 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
490 io.iov_len = p->max_size;
492 memset(&msg, 0, sizeof(msg));
494 msg.msg_name = ret_sa;
495 msg.msg_namelen = sizeof(struct sockaddr_in);
502 msg.msg_control = aux;
503 msg.msg_controllen = sizeof(aux);
506 if ((l = recvmsg(fd, &msg, 0)) < 0) {
507 avahi_log_warn("recvmsg(): %s", strerror(errno));
511 if (ret_sa && ret_sa->sin_addr.s_addr == INADDR_ANY) {
512 /* Linux 2.4 behaves very strangely sometimes! */
514 /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
518 assert(!(msg.msg_flags & MSG_CTRUNC));
519 assert(!(msg.msg_flags & MSG_TRUNC));
520 p->size = (size_t) l;
525 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
527 if (cmsg->cmsg_level == SOL_IP) {
529 if (cmsg->cmsg_type == IP_TTL) {
531 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
533 } else if (cmsg->cmsg_type == IP_PKTINFO) {
534 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
537 *ret_iface = (int) i->ipi_ifindex;
539 if (ret_dest_address)
540 ret_dest_address->address = i->ipi_addr.s_addr;
553 avahi_dns_packet_free(p);
558 AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa, AvahiIPv6Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
559 AvahiDnsPacket *p = NULL;
566 struct cmsghdr *cmsg;
567 int found_ttl = 0, found_iface = 0;
571 if (ioctl(fd, FIONREAD, &ms) < 0) {
572 avahi_log_warn("ioctl(): %s", strerror(errno));
576 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
578 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
579 io.iov_len = p->max_size;
581 memset(&msg, 0, sizeof(msg));
583 msg.msg_name = ret_sa;
584 msg.msg_namelen = sizeof(struct sockaddr_in6);
592 msg.msg_control = aux;
593 msg.msg_controllen = sizeof(aux);
596 if ((l = recvmsg(fd, &msg, 0)) < 0) {
597 avahi_log_warn("recvmsg(): %s", strerror(errno));
601 p->size = (size_t) l;
606 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
607 if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
610 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
615 if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
616 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
619 *ret_iface = i->ipi6_ifindex;
621 if (ret_dest_address)
622 memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
634 avahi_dns_packet_free(p);
639 int avahi_open_unicast_socket_ipv4(void) {
640 struct sockaddr_in local;
643 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
644 avahi_log_warn("socket() failed: %s", strerror(errno));
648 memset(&local, 0, sizeof(local));
649 local.sin_family = AF_INET;
651 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
652 avahi_log_warn("bind() failed: %s", strerror(errno));
657 if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
658 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
663 if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
664 avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
668 if (avahi_set_cloexec(fd) < 0) {
669 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
673 if (avahi_set_nonblock(fd) < 0) {
674 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
687 int avahi_open_unicast_socket_ipv6(void) {
688 struct sockaddr_in6 local;
691 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
692 avahi_log_warn("socket() failed: %s", strerror(errno));
696 memset(&local, 0, sizeof(local));
697 local.sin6_family = AF_INET6;
699 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
700 avahi_log_warn("bind() failed: %s", strerror(errno));
705 if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
706 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
711 if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
712 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
716 if (avahi_set_cloexec(fd) < 0) {
717 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
721 if (avahi_set_nonblock(fd) < 0) {
722 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));