diff options
Diffstat (limited to 'libavahi-core/socket.c')
-rw-r--r-- | libavahi-core/socket.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/libavahi-core/socket.c b/libavahi-core/socket.c new file mode 100644 index 0000000..1ef8131 --- /dev/null +++ b/libavahi-core/socket.c @@ -0,0 +1,488 @@ +#include <inttypes.h> +#include <errno.h> +#include <string.h> +#include <stdio.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/time.h> +#include <net/if.h> +#include <sys/ioctl.h> + +#include "dns.h" +#include "util.h" +#include "socket.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); +} + +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) { + g_warning("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) { + g_warning("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) { + g_warning("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) { + g_warning("IPV6_DROP_MEMBERSHIP failed: %s\n", strerror(errno)); + return -1; + } + + return 0; +} + +gint avahi_open_socket_ipv4(void) { + struct sockaddr_in sa, local; + int fd = -1, ttl, yes; + + if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { + g_warning("socket() failed: %s\n", strerror(errno)); + goto fail; + } + + ttl = 255; + if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) { + g_warning("IP_MULTICAST_TTL failed: %s\n", strerror(errno)); + goto fail; + } + + ttl = 255; + if (setsockopt(fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) { + g_warning("IP_TTL failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { + g_warning("SO_REUSEADDR failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { + g_warning("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(fd, (struct sockaddr*) &local, sizeof(local)) < 0) { + g_warning("bind() failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) { + g_warning("IP_RECVTTL failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) { + g_warning("IP_PKTINFO failed: %s\n", strerror(errno)); + goto fail; + } + + if (avahi_set_cloexec(fd) < 0) { + g_warning("FD_CLOEXEC failed: %s\n", strerror(errno)); + goto fail; + } + + if (avahi_set_nonblock(fd) < 0) { + g_warning("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) { + g_warning("socket() failed: %s\n", strerror(errno)); + goto fail; + } + + ttl = 255; + if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) { + g_warning("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno)); + goto fail; + } + + ttl = 255; + if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) { + g_warning("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) { + g_warning("SO_REUSEADDR failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) { + g_warning("IPV6_V6ONLY failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) { + g_warning("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(fd, (struct sockaddr*) &local, sizeof(local)) < 0) { + g_warning("bind() failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) { + g_warning("IPV6_HOPLIMIT failed: %s\n", strerror(errno)); + goto fail; + } + + yes = 1; + if (setsockopt(fd, SOL_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) { + g_warning("IPV6_PKTINFO failed: %s\n", strerror(errno)); + goto fail; + } + + if (avahi_set_cloexec(fd) < 0) { + g_warning("FD_CLOEXEC failed: %s\n", strerror(errno)); + goto fail; + } + + if (avahi_set_nonblock(fd) < 0) { + g_warning("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) { + g_message("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) { + 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)]; + int i, n; + + g_assert(fd >= 0); + g_assert(p); + g_assert(avahi_dns_packet_check_valid(p) >= 0); + + mdns_mcast_group_ipv4(&sa); + + 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) { + 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)]; + int i, n; + + g_assert(fd >= 0); + g_assert(p); + g_assert(avahi_dns_packet_check_valid(p) >= 0); + + mdns_mcast_group_ipv6(&sa); + + 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[64]; + ssize_t l; + 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); + + p = avahi_dns_packet_new(0); + + 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) + 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_IP && cmsg->cmsg_type == IP_TTL) { + *ret_ttl = *(uint8_t *) CMSG_DATA(cmsg); + found_ttl = TRUE; + } + + if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_PKTINFO) { + *ret_iface = ((struct in_pktinfo*) CMSG_DATA(cmsg))->ipi_ifindex; + found_iface = TRUE; + } + } + + 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; + 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); + + p = avahi_dns_packet_new(0); + + 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) + 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 *) 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; +} + |