/* $Id$ */ /*** This file is part of avahi. avahi is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. avahi is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with avahi; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. ***/ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include "dns.h" #include "util.h" #include "socket.h" #include "log.h" static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) { g_assert(ret_sa); memset(ret_sa, 0, sizeof(struct sockaddr_in)); ret_sa->sin_family = AF_INET; ret_sa->sin_port = htons(AVAHI_MDNS_PORT); inet_pton(AF_INET, "224.0.0.251", &ret_sa->sin_addr); } static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) { g_assert(ret_sa); memset(ret_sa, 0, sizeof(struct sockaddr_in6)); ret_sa->sin6_family = AF_INET6; ret_sa->sin6_port = htons(AVAHI_MDNS_PORT); inet_pton(AF_INET6, "ff02::fb", &ret_sa->sin6_addr); } static void ipv4_address_to_sockaddr(struct sockaddr_in *ret_sa, const AvahiIPv4Address *a, guint16 port) { g_assert(ret_sa); g_assert(a); g_assert(port > 0); memset(ret_sa, 0, sizeof(struct sockaddr_in)); ret_sa->sin_family = AF_INET; ret_sa->sin_port = htons(port); memcpy(&ret_sa->sin_addr, a, sizeof(AvahiIPv4Address)); } static void ipv6_address_to_sockaddr(struct sockaddr_in6 *ret_sa, const AvahiIPv6Address *a, guint16 port) { g_assert(ret_sa); g_assert(a); g_assert(port > 0); memset(ret_sa, 0, sizeof(struct sockaddr_in6)); ret_sa->sin6_family = AF_INET6; ret_sa->sin6_port = htons(port); memcpy(&ret_sa->sin6_addr, a, sizeof(AvahiIPv6Address)); } int avahi_mdns_mcast_join_ipv4 (int index, int fd) { struct ip_mreqn mreq; struct sockaddr_in sa; mdns_mcast_group_ipv4 (&sa); memset(&mreq, 0, sizeof(mreq)); mreq.imr_multiaddr = sa.sin_addr; mreq.imr_ifindex = index; if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { avahi_log_warn("IP_ADD_MEMBERSHIP failed: %s\n", strerror(errno)); return -1; } return 0; } int avahi_mdns_mcast_join_ipv6 (int index, int fd) { struct ipv6_mreq mreq6; struct sockaddr_in6 sa6; mdns_mcast_group_ipv6 (&sa6); memset(&mreq6, 0, sizeof(mreq6)); mreq6.ipv6mr_multiaddr = sa6.sin6_addr; mreq6.ipv6mr_interface = index; if (setsockopt(fd, SOL_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) { avahi_log_warn("IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno)); return -1; } return 0; } int avahi_mdns_mcast_leave_ipv4 (int index, int fd) { struct ip_mreqn mreq; struct sockaddr_in sa; mdns_mcast_group_ipv4 (&sa); memset(&mreq, 0, sizeof(mreq)); mreq.imr_multiaddr = sa.sin_addr; mreq.imr_ifindex = index; if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { avahi_log_warn("IP_DROP_MEMBERSHIP failed: %s\n", strerror(errno)); return -1; } return 0; } int avahi_mdns_mcast_leave_ipv6 (int index, int fd) { struct ipv6_mreq mreq6; struct sockaddr_in6 sa6; mdns_mcast_group_ipv6 (&sa6); memset(&mreq6, 0, sizeof(mreq6)); mreq6.ipv6mr_multiaddr = sa6.sin6_addr; mreq6.ipv6mr_interface = index; if (setsockopt(fd, SOL_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) { avahi_log_warn("IPV6_DROP_MEMBERSHIP failed: %s\n", strerror(errno)); return -1; } return 0; } static gint bind_with_warn(int fd, const struct sockaddr *sa, socklen_t l) { gint yes; g_assert(fd >= 0); g_assert(sa); g_assert(l > 0); if (bind(fd, sa, l) < 0) { if (errno != EADDRINUSE) { avahi_log_warn("bind() failed: %s\n", strerror(errno)); return -1; } avahi_log_warn("*** WARNING: Detected another %s mDNS stack running on this host. This makes mDNS unreliable and is thus not recommended. ***", sa->sa_family == AF_INET ? "IPv4" : "IPv6"); /* Try again, this time with SO_REUSEADDR set */ yes = 1; if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { avahi_log_warn("SO_REUSEADDR failed: %s\n", strerror(errno)); return -1; } if (bind(fd, sa, l) < 0) { avahi_log_warn("bind() failed: %s\n", strerror(errno)); return -1; } } else { /* We enable SO_REUSEADDR afterwards, to make sure that the * user may run other mDNS implementations if he really * wants. */ yes = 1; if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { avahi_log_warn("SO_REUSEADDR failed: %s\n", strerror(errno)); return -1; } } return 0; } gint avahi_open_socket_ipv4(void) { struct sockaddr_in local; int fd = -1, ttl, yes; if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { avahi_log_warn("socket() failed: %s\n", strerror(errno)); goto fail; } ttl = 255; if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) { avahi_log_warn("IP_MULTICAST_TTL failed: %s\n", strerror(errno)); goto fail; } ttl = 255; if (setsockopt(fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) { avahi_log_warn("IP_TTL failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { avahi_log_warn("IP_MULTICAST_LOOP failed: %s\n", strerror(errno)); goto fail; } memset(&local, 0, sizeof(local)); local.sin_family = AF_INET; local.sin_port = htons(AVAHI_MDNS_PORT); if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0) goto fail; yes = 1; if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) { avahi_log_warn("IP_RECVTTL failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) { avahi_log_warn("IP_PKTINFO failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_cloexec(fd) < 0) { avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_nonblock(fd) < 0) { avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno)); goto fail; } return fd; fail: if (fd >= 0) close(fd); return -1; } gint avahi_open_socket_ipv6(void) { struct sockaddr_in6 sa, local; int fd = -1, ttl, yes; mdns_mcast_group_ipv6(&sa); if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { avahi_log_warn("socket() failed: %s\n", strerror(errno)); goto fail; } ttl = 255; if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) { avahi_log_warn("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno)); goto fail; } ttl = 255; if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) { avahi_log_warn("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_V6ONLY failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_MULTICAST_LOOP failed: %s\n", strerror(errno)); goto fail; } memset(&local, 0, sizeof(local)); local.sin6_family = AF_INET6; local.sin6_port = htons(AVAHI_MDNS_PORT); if (bind_with_warn(fd, (struct sockaddr*) &local, sizeof(local)) < 0) goto fail; yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_HOPLIMIT failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_PKTINFO failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_cloexec(fd) < 0) { avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_nonblock(fd) < 0) { avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno)); goto fail; } return fd; fail: if (fd >= 0) close(fd); return -1; } static gint sendmsg_loop(gint fd, struct msghdr *msg, gint flags) { g_assert(fd >= 0); g_assert(msg); for (;;) { if (sendmsg(fd, msg, flags) >= 0) break; if (errno != EAGAIN) { avahi_log_debug("sendmsg() failed: %s\n", strerror(errno)); return -1; } if (avahi_wait_for_write(fd) < 0) return -1; } return 0; } gint avahi_send_dns_packet_ipv4(gint fd, gint interface, AvahiDnsPacket *p, const AvahiIPv4Address *a, guint16 port) { struct sockaddr_in sa; struct msghdr msg; struct iovec io; struct cmsghdr *cmsg; struct in_pktinfo *pkti; uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)]; g_assert(fd >= 0); g_assert(p); g_assert(avahi_dns_packet_check_valid(p) >= 0); g_assert(!a || port > 0); if (!a) mdns_mcast_group_ipv4(&sa); else ipv4_address_to_sockaddr(&sa, a, port); memset(&io, 0, sizeof(io)); io.iov_base = AVAHI_DNS_PACKET_DATA(p); io.iov_len = p->size; memset(cmsg_data, 0, sizeof(cmsg_data)); cmsg = (struct cmsghdr*) cmsg_data; cmsg->cmsg_len = sizeof(cmsg_data); cmsg->cmsg_level = IPPROTO_IP; cmsg->cmsg_type = IP_PKTINFO; pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr)); pkti->ipi_ifindex = interface; memset(&msg, 0, sizeof(msg)); msg.msg_name = &sa; msg.msg_namelen = sizeof(sa); msg.msg_iov = &io; msg.msg_iovlen = 1; msg.msg_control = cmsg_data; msg.msg_controllen = sizeof(cmsg_data); msg.msg_flags = 0; return sendmsg_loop(fd, &msg, MSG_DONTROUTE); } gint avahi_send_dns_packet_ipv6(gint fd, gint interface, AvahiDnsPacket *p, const AvahiIPv6Address *a, guint16 port) { struct sockaddr_in6 sa; struct msghdr msg; struct iovec io; struct cmsghdr *cmsg; struct in6_pktinfo *pkti; uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)]; g_assert(fd >= 0); g_assert(p); g_assert(avahi_dns_packet_check_valid(p) >= 0); if (!a) mdns_mcast_group_ipv6(&sa); else ipv6_address_to_sockaddr(&sa, a, port); memset(&io, 0, sizeof(io)); io.iov_base = AVAHI_DNS_PACKET_DATA(p); io.iov_len = p->size; memset(cmsg_data, 0, sizeof(cmsg_data)); cmsg = (struct cmsghdr*) cmsg_data; cmsg->cmsg_len = sizeof(cmsg_data); cmsg->cmsg_level = IPPROTO_IPV6; cmsg->cmsg_type = IPV6_PKTINFO; pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr)); pkti->ipi6_ifindex = interface; memset(&msg, 0, sizeof(msg)); msg.msg_name = &sa; msg.msg_namelen = sizeof(sa); msg.msg_iov = &io; msg.msg_iovlen = 1; msg.msg_control = cmsg_data; msg.msg_controllen = sizeof(cmsg_data); msg.msg_flags = 0; return sendmsg_loop(fd, &msg, MSG_DONTROUTE); } AvahiDnsPacket* avahi_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa, gint *ret_iface, guint8* ret_ttl) { AvahiDnsPacket *p= NULL; struct msghdr msg; struct iovec io; uint8_t aux[1024]; ssize_t l; struct cmsghdr *cmsg; gboolean found_ttl = FALSE, found_iface = FALSE; guint ms; g_assert(fd >= 0); g_assert(ret_sa); g_assert(ret_iface); g_assert(ret_ttl); if (ioctl(fd, FIONREAD, &ms) < 0) { avahi_log_warn("ioctl(): %s", strerror(errno)); goto fail; } p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE); io.iov_base = AVAHI_DNS_PACKET_DATA(p); io.iov_len = p->max_size; memset(&msg, 0, sizeof(msg)); msg.msg_name = ret_sa; msg.msg_namelen = sizeof(struct sockaddr_in); msg.msg_iov = &io; msg.msg_iovlen = 1; msg.msg_control = aux; msg.msg_controllen = sizeof(aux); msg.msg_flags = 0; if ((l = recvmsg(fd, &msg, 0)) < 0) { avahi_log_warn("recvmsg(): %s", strerror(errno)); goto fail; } if (ret_sa->sin_addr.s_addr == INADDR_ANY) { /* Linux 2.4 behaves very strangely sometimes! */ avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), l); goto fail; } g_assert(!(msg.msg_flags & MSG_CTRUNC)); g_assert(!(msg.msg_flags & MSG_TRUNC)); p->size = (size_t) l; *ret_ttl = 0; /* avahi_hexdump(msg.msg_control, msg.msg_controllen); */ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { /* avahi_hexdump(CMSG_DATA(cmsg), cmsg->cmsg_len - sizeof(struct cmsghdr)); */ if (cmsg->cmsg_level == SOL_IP) { if (cmsg->cmsg_type == IP_TTL) { *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg)); found_ttl = TRUE; } else if (cmsg->cmsg_type == IP_PKTINFO) { *ret_iface = (gint) ((struct in_pktinfo*) CMSG_DATA(cmsg))->ipi_ifindex; found_iface = TRUE; } } } /* avahi_log_debug("ttl=%u iface=%i", *ret_ttl, *ret_iface); */ g_assert(found_iface); g_assert(found_ttl); return p; fail: if (p) avahi_dns_packet_free(p); return NULL; } AvahiDnsPacket* avahi_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa, gint *ret_iface, guint8* ret_ttl) { AvahiDnsPacket *p = NULL; struct msghdr msg; struct iovec io; uint8_t aux[64]; ssize_t l; guint ms; struct cmsghdr *cmsg; gboolean found_ttl = FALSE, found_iface = FALSE; g_assert(fd >= 0); g_assert(ret_sa); g_assert(ret_iface); g_assert(ret_ttl); if (ioctl(fd, FIONREAD, &ms) < 0) { avahi_log_warn("ioctl(): %s", strerror(errno)); goto fail; } p = avahi_dns_packet_new(ms + AVAHI_DNS_PACKET_EXTRA_SIZE); io.iov_base = AVAHI_DNS_PACKET_DATA(p); io.iov_len = p->max_size; memset(&msg, 0, sizeof(msg)); msg.msg_name = ret_sa; msg.msg_namelen = sizeof(struct sockaddr_in6); msg.msg_iov = &io; msg.msg_iovlen = 1; msg.msg_control = aux; msg.msg_controllen = sizeof(aux); msg.msg_flags = 0; if ((l = recvmsg(fd, &msg, 0)) < 0) { avahi_log_warn("recvmsg(): %s", strerror(errno)); goto fail; } p->size = (size_t) l; *ret_ttl = 0; for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_HOPLIMIT) { *ret_ttl = (uint8_t) (*(int *) CMSG_DATA(cmsg)); found_ttl = TRUE; } if (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) { *ret_iface = ((struct in6_pktinfo*) CMSG_DATA(cmsg))->ipi6_ifindex; found_iface = TRUE; } } g_assert(found_iface); g_assert(found_ttl); return p; fail: if (p) avahi_dns_packet_free(p); return NULL; } gint avahi_open_legacy_unicast_socket_ipv4(void) { struct sockaddr_in local; int fd = -1, yes; if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { avahi_log_warn("socket() failed: %s\n", strerror(errno)); goto fail; } memset(&local, 0, sizeof(local)); local.sin_family = AF_INET; if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) { avahi_log_warn("bind() failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) { avahi_log_warn("IP_RECVTTL failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) { avahi_log_warn("IP_PKTINFO failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_cloexec(fd) < 0) { avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_nonblock(fd) < 0) { avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno)); goto fail; } return fd; fail: if (fd >= 0) close(fd); return -1; } gint avahi_open_legacy_unicast_socket_ipv6(void) { struct sockaddr_in local; int fd = -1, yes; if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { avahi_log_warn("socket() failed: %s\n", strerror(errno)); goto fail; } memset(&local, 0, sizeof(local)); local.sin_family = AF_INET; if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) { avahi_log_warn("bind() failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_HOPLIMIT failed: %s\n", strerror(errno)); goto fail; } yes = 1; if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) { avahi_log_warn("IPV6_PKTINFO failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_cloexec(fd) < 0) { avahi_log_warn("FD_CLOEXEC failed: %s\n", strerror(errno)); goto fail; } if (avahi_set_nonblock(fd) < 0) { avahi_log_warn("O_NONBLOCK failed: %s\n", strerror(errno)); goto fail; } return fd; fail: if (fd >= 0) close(fd); return -1; }