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>
41 #include <net/if_dl.h>
49 /* this is a portability hack */
50 #ifndef IPV6_ADD_MEMBERSHIP
51 #ifdef IPV6_JOIN_GROUP
52 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
56 #ifndef IPV6_DROP_MEMBERSHIP
57 #ifdef IPV6_LEAVE_GROUP
58 #define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
62 static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
65 memset(ret_sa, 0, sizeof(struct sockaddr_in));
66 ret_sa->sin_family = AF_INET;
67 ret_sa->sin_port = htons(AVAHI_MDNS_PORT);
68 inet_pton(AF_INET, AVAHI_IPV4_MCAST_GROUP, &ret_sa->sin_addr);
71 static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
74 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
75 ret_sa->sin6_family = AF_INET6;
76 ret_sa->sin6_port = htons(AVAHI_MDNS_PORT);
77 inet_pton(AF_INET6, AVAHI_IPV6_MCAST_GROUP, &ret_sa->sin6_addr);
80 static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, uint16_t port) {
85 memset(ret_sa, 0, sizeof(struct sockaddr_in));
86 ret_sa->sin_family = AF_INET;
87 ret_sa->sin_port = htons(port);
88 memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address));
91 static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, uint16_t port) {
96 memset(ret_sa, 0, sizeof(struct sockaddr_in6));
97 ret_sa->sin6_family = AF_INET6;
98 ret_sa->sin6_port = htons(port);
99 memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address));
102 #ifdef HAVE_STRUCT_IP_MREQN
103 int avahi_mdns_mcast_join_ipv4(int fd, int idx, int join) {
104 struct ip_mreqn mreq;
106 int avahi_mdns_mcast_join_ipv4(int fd, const AvahiAddress *a, int join) {
110 struct sockaddr_in sa;
111 memset(&mreq, 0, sizeof(mreq));
113 #ifdef HAVE_STRUCT_IP_MREQN
114 mreq.imr_ifindex = idx;
117 assert(a->proto == AVAHI_PROTO_INET);
118 mreq.imr_interface.s_addr = a->data.ipv4.address;
121 mdns_mcast_group_ipv4(&sa);
122 mreq.imr_multiaddr = sa.sin_addr;
124 if (setsockopt(fd, IPPROTO_IP, join ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
125 avahi_log_warn("%s failed: %s", join ? "IP_ADD_MEMBERSHIP" : "IP_DROP_MEMBERSHIP", strerror(errno));
132 int avahi_mdns_mcast_join_ipv6(int fd, int idx, int join) {
133 struct ipv6_mreq mreq6;
134 struct sockaddr_in6 sa6;
136 mdns_mcast_group_ipv6 (&sa6);
138 memset(&mreq6, 0, sizeof(mreq6));
139 mreq6.ipv6mr_multiaddr = sa6.sin6_addr;
140 mreq6.ipv6mr_interface = idx;
142 if (setsockopt(fd, IPPROTO_IPV6, join ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
143 avahi_log_warn("%s failed: %s", join ? "IPV6_ADD_MEMBERSHIP" : "IPV6_DROP_MEMBERSHIP", strerror(errno));
150 static int bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) {
157 if (bind(fd, sa, l) < 0) {
159 if (errno != EADDRINUSE) {
160 avahi_log_warn("bind() failed: %s", strerror(errno));
164 avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***",
165 sa->sa_family == AF_INET ? "IPv4" : "IPv6");
167 /* Try again, this time with SO_REUSEADDR set */
169 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
170 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
176 if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes)) < 0) {
177 avahi_log_warn("SO_REUSEPORT failed: %s", strerror(errno));
182 if (bind(fd, sa, l) < 0) {
183 avahi_log_warn("bind() failed: %s", strerror(errno));
188 /* We enable SO_REUSEADDR afterwards, to make sure that the
189 * user may run other mDNS implementations if he really
193 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
194 avahi_log_warn("SO_REUSEADDR failed: %s", strerror(errno));
202 static int ip_pktinfo (int fd, int yes)
207 if ((ret = setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes))) < 0) {
208 avahi_log_warn("IP_PKTINFO failed: %s", strerror(errno));
211 #ifdef IP_RECVINTERFACE
212 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVINTERFACE, &yes, sizeof (yes))) < 0) {
213 avahi_log_warn("IP_RECVINTERFACE failed: %s", strerror(errno));
217 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVIF, &yes, sizeof (yes))) < 0) {
218 avahi_log_warn("IP_RECVIF failed: %s", strerror(errno));
220 #endif /* IP_RECVIF */
221 #endif /* IP_RECVINTERFACE */
222 #if defined (IP_RECVDSTADDR) /* && !defined(solaris) */
223 if ((ret = setsockopt (fd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof (yes))) < 0) {
224 avahi_log_warn("IP_RECVDSTADDR failed: %s", strerror(errno));
226 #endif /* IP_RECVDSTADDR */
227 #endif /* IP_PKTINFO */
232 int avahi_open_socket_ipv4(int no_reuse) {
233 struct sockaddr_in local;
234 int fd = -1, ttl, yes, r;
236 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
237 avahi_log_warn("socket() failed: %s", strerror(errno));
242 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
243 avahi_log_warn("IP_MULTICAST_TTL failed: %s", strerror(errno));
248 if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
249 avahi_log_warn("IP_TTL failed: %s", strerror(errno));
254 if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
255 avahi_log_warn("IP_MULTICAST_LOOP failed: %s", strerror(errno));
259 memset(&local, 0, sizeof(local));
260 local.sin_family = AF_INET;
261 local.sin_port = htons(AVAHI_MDNS_PORT);
264 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
266 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
272 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
273 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
278 if (ip_pktinfo (fd, yes) < 0) {
282 if (avahi_set_cloexec(fd) < 0) {
283 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
287 if (avahi_set_nonblock(fd) < 0) {
288 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
301 int avahi_open_socket_ipv6(int no_reuse) {
302 struct sockaddr_in6 sa, local;
303 int fd = -1, ttl, yes, r;
305 mdns_mcast_group_ipv6(&sa);
307 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
308 avahi_log_warn("socket() failed: %s", strerror(errno));
313 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
314 avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s", strerror(errno));
319 if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
320 avahi_log_warn("IPV6_UNICAST_HOPS failed: %s", strerror(errno));
325 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
326 avahi_log_warn("IPV6_V6ONLY failed: %s", strerror(errno));
331 if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
332 avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s", strerror(errno));
336 memset(&local, 0, sizeof(local));
337 local.sin6_family = AF_INET6;
338 local.sin6_port = htons(AVAHI_MDNS_PORT);
341 r = bind(fd, (struct sockaddr*) &local, sizeof(local));
343 r = bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local));
350 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
351 avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
354 #elif IPV6_RECVHOPLIMIT
356 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
357 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
362 if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
363 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
368 #ifdef IPV6_RECVPKTINFO
370 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
371 avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
376 if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
377 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
382 if (avahi_set_cloexec(fd) < 0) {
383 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
387 if (avahi_set_nonblock(fd) < 0) {
388 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
401 static int sendmsg_loop(int fd, struct msghdr *msg, int flags) {
407 if (sendmsg(fd, msg, flags) >= 0)
410 if (errno != EAGAIN) {
411 avahi_log_debug("sendmsg() failed: %s", strerror(errno));
415 if (avahi_wait_for_write(fd) < 0)
422 int avahi_send_dns_packet_ipv4(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, uint16_t port) {
423 struct sockaddr_in sa;
427 struct cmsghdr *cmsg;
428 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
433 assert(avahi_dns_packet_check_valid(p) >= 0);
434 assert(!a || port > 0);
437 mdns_mcast_group_ipv4(&sa);
439 ipv4_address_to_sockaddr(&sa, a, port);
441 memset(&io, 0, sizeof(io));
442 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
443 io.iov_len = p->size;
445 memset(&msg, 0, sizeof(msg));
447 msg.msg_namelen = sizeof(sa);
453 if (interface >= 0) {
454 memset(cmsg_data, 0, sizeof(cmsg_data));
455 cmsg = (struct cmsghdr*) cmsg_data;
456 cmsg->cmsg_len = sizeof(cmsg_data);
457 cmsg->cmsg_level = IPPROTO_IP;
459 struct in_pktinfo *pkti;
461 cmsg->cmsg_type = IP_PKTINFO;
462 pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
463 pkti->ipi_ifindex = interface;
465 msg.msg_control = cmsg_data;
466 msg.msg_controllen = sizeof(cmsg_data);
468 msg.msg_control = NULL;
469 msg.msg_controllen = 0;
473 return sendmsg_loop(fd, &msg, 0);
476 int avahi_send_dns_packet_ipv6(int fd, int interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, uint16_t port) {
477 struct sockaddr_in6 sa;
480 struct cmsghdr *cmsg;
481 uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
485 assert(avahi_dns_packet_check_valid(p) >= 0);
488 mdns_mcast_group_ipv6(&sa);
490 ipv6_address_to_sockaddr(&sa, a, port);
492 memset(&io, 0, sizeof(io));
493 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
494 io.iov_len = p->size;
497 memset(&msg, 0, sizeof(msg));
499 msg.msg_namelen = sizeof(sa);
504 if (interface >= 0) {
505 struct in6_pktinfo *pkti;
507 memset(cmsg_data, 0, sizeof(cmsg_data));
508 cmsg = (struct cmsghdr*) cmsg_data;
509 cmsg->cmsg_len = sizeof(cmsg_data);
510 cmsg->cmsg_level = IPPROTO_IPV6;
511 cmsg->cmsg_type = IPV6_PKTINFO;
513 pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
514 pkti->ipi6_ifindex = interface;
516 msg.msg_control = cmsg_data;
517 msg.msg_controllen = sizeof(cmsg_data);
519 msg.msg_control = NULL;
520 msg.msg_controllen = 0;
523 return sendmsg_loop(fd, &msg, 0);
526 AvahiDnsPacket* avahi_recv_dns_packet_ipv4(int fd, struct sockaddr_in *ret_sa, AvahiIPv4Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
527 AvahiDnsPacket *p= NULL;
532 struct cmsghdr *cmsg;
533 int found_ttl = 0, found_iface = 0, found_addr = 0;
538 if (ioctl(fd, FIONREAD, &ms) < 0) {
539 avahi_log_warn("ioctl(): %s", strerror(errno));
543 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
545 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
546 io.iov_len = p->max_size;
548 memset(&msg, 0, sizeof(msg));
550 msg.msg_name = ret_sa;
551 msg.msg_namelen = sizeof(struct sockaddr_in);
558 msg.msg_control = aux;
559 msg.msg_controllen = sizeof(aux);
562 if ((l = recvmsg(fd, &msg, 0)) < 0) {
563 avahi_log_warn("recvmsg(): %s", strerror(errno));
567 if (ret_sa && ret_sa->sin_addr.s_addr == INADDR_ANY) {
568 /* Linux 2.4 behaves very strangely sometimes! */
570 /*avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); */
574 assert(!(msg.msg_flags & MSG_CTRUNC));
575 assert(!(msg.msg_flags & MSG_TRUNC));
576 p->size = (size_t) l;
581 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
583 if (cmsg->cmsg_level == IPPROTO_IP) {
584 switch (cmsg->cmsg_type) {
590 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
596 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
599 *ret_iface = (int) i->ipi_ifindex;
601 if (ret_dest_address)
602 ret_dest_address->address = i->ipi_addr.s_addr;
603 found_addr = found_iface = 1;
609 struct sockaddr_dl *sdl = (struct sockaddr_dl *) CMSG_DATA (cmsg);
612 *ret_iface = (int) sdl->sdl_index;
617 #ifdef IP_RECVDSTADDR
619 if (ret_dest_address)
620 memcpy (&ret_dest_address->address, CMSG_DATA (cmsg), 4);
625 avahi_log_warn("Unhandled cmsg_type : %d",cmsg->cmsg_type);
639 avahi_dns_packet_free(p);
644 AvahiDnsPacket* avahi_recv_dns_packet_ipv6(int fd, struct sockaddr_in6 *ret_sa, AvahiIPv6Address *ret_dest_address, int *ret_iface, uint8_t* ret_ttl) {
645 AvahiDnsPacket *p = NULL;
652 struct cmsghdr *cmsg;
653 int found_ttl = 0, found_iface = 0;
657 if (ioctl(fd, FIONREAD, &ms) < 0) {
658 avahi_log_warn("ioctl(): %s", strerror(errno));
662 p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE);
664 io.iov_base = AVAHI_DNS_PACKET_DATA(p);
665 io.iov_len = p->max_size;
667 memset(&msg, 0, sizeof(msg));
669 msg.msg_name = ret_sa;
670 msg.msg_namelen = sizeof(struct sockaddr_in6);
678 msg.msg_control = aux;
679 msg.msg_controllen = sizeof(aux);
682 if ((l = recvmsg(fd, &msg, 0)) < 0) {
683 avahi_log_warn("recvmsg(): %s", strerror(errno));
687 p->size = (size_t) l;
692 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
693 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) {
696 *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg));
701 if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) {
702 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
705 *ret_iface = i->ipi6_ifindex;
707 if (ret_dest_address)
708 memcpy(ret_dest_address->address, i->ipi6_addr.s6_addr, 16);
720 avahi_dns_packet_free(p);
725 int avahi_open_unicast_socket_ipv4(void) {
726 struct sockaddr_in local;
729 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
730 avahi_log_warn("socket() failed: %s", strerror(errno));
734 memset(&local, 0, sizeof(local));
735 local.sin_family = AF_INET;
737 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
738 avahi_log_warn("bind() failed: %s", strerror(errno));
743 if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
744 avahi_log_warn("IP_RECVTTL failed: %s", strerror(errno));
749 if (ip_pktinfo (fd, yes) < 0) {
753 if (avahi_set_cloexec(fd) < 0) {
754 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
758 if (avahi_set_nonblock(fd) < 0) {
759 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));
772 int avahi_open_unicast_socket_ipv6(void) {
773 struct sockaddr_in6 local;
776 if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
777 avahi_log_warn("socket() failed: %s", strerror(errno));
781 memset(&local, 0, sizeof(local));
782 local.sin6_family = AF_INET6;
784 if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
785 avahi_log_warn("bind() failed: %s", strerror(errno));
791 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPS, &yes, sizeof(yes)) < 0) {
792 avahi_log_warn("IPV6_RECVHOPS failed: %s", strerror(errno));
795 #elif IPV6_RECVHOPLIMIT
797 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &yes, sizeof(yes)) < 0) {
798 avahi_log_warn("IPV6_RECVHOPLIMIT failed: %s", strerror(errno));
803 if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
804 avahi_log_warn("IPV6_HOPLIMIT failed: %s", strerror(errno));
809 #ifdef IPV6_RECVPKTINFO
811 if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &yes, sizeof(yes)) < 0) {
812 avahi_log_warn("IPV6_RECVPKTINFO failed: %s", strerror(errno));
817 if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
818 avahi_log_warn("IPV6_PKTINFO failed: %s", strerror(errno));
823 if (avahi_set_cloexec(fd) < 0) {
824 avahi_log_warn("FD_CLOEXEC failed: %s", strerror(errno));
828 if (avahi_set_nonblock(fd) < 0) {
829 avahi_log_warn("O_NONBLOCK failed: %s", strerror(errno));