diff options
Diffstat (limited to 'llmnr.c')
| -rw-r--r-- | llmnr.c | 130 |
1 files changed, 88 insertions, 42 deletions
@@ -16,6 +16,7 @@ * along with llmnrd. If not, see <http://www.gnu.org/licenses/>. */ +#define _GNU_SOURCE #include <ctype.h> #include <errno.h> #include <stdbool.h> @@ -36,8 +37,8 @@ #include "llmnr-packet.h" #include "llmnr.h" -static int llmnr_sock = -1; -static int llmnr_sock_v6 = -1; +static int llmnr_sock_ipv4 = -1; +static int llmnr_sock_ipv6 = -1; static bool llmnr_running = true; /* * Host name in DNS name format (length octet + name + 0 byte) @@ -48,10 +49,10 @@ static void llmnr_iface_event_handle(enum iface_event_type type, int af, unsigne { switch (af) { case AF_INET: - socket_mcast_group_ipv4(llmnr_sock, ifindex, type == IFACE_ADD); + socket_mcast_group_ipv4(llmnr_sock_ipv4, ifindex, type == IFACE_ADD); break; case AF_INET6: - socket_mcast_group_ipv6(llmnr_sock_v6, ifindex, type == IFACE_ADD); + socket_mcast_group_ipv6(llmnr_sock_ipv6, ifindex, type == IFACE_ADD); break; default: /* ignore */ @@ -59,17 +60,23 @@ static void llmnr_iface_event_handle(enum iface_event_type type, int af, unsigne } } -int llmnr_init(const char *hostname, uint16_t port) +int llmnr_init(const char *hostname, uint16_t port, bool ipv6) { llmnr_hostname[0] = strlen(hostname); strncpy(&llmnr_hostname[1], hostname, LLMNR_LABEL_MAX_SIZE); llmnr_hostname[LLMNR_LABEL_MAX_SIZE + 1] = '\0'; log_info("Starting llmnrd on port %u, hostname %s\n", port, hostname); - llmnr_sock = socket_open_ipv4(port); - if (llmnr_sock < 0) + llmnr_sock_ipv4 = socket_open_ipv4(port); + if (llmnr_sock_ipv4 < 0) return -1; + if (ipv6) { + llmnr_sock_ipv6 = socket_open_ipv6(port); + if (llmnr_sock_ipv6 < 0) + return -1; + } + iface_register_event_handler(&llmnr_iface_event_handle); return 0; @@ -94,7 +101,7 @@ static bool llmnr_name_matches(const uint8_t *query) static void llmnr_respond(unsigned int ifindex, const struct llmnr_hdr *hdr, const uint8_t *query, size_t query_len, int sock, - const struct sockaddr *sa) + const struct sockaddr_storage *sst) { uint16_t qtype, qclass; uint8_t name_len = query[0]; @@ -196,14 +203,14 @@ static void llmnr_respond(unsigned int ifindex, const struct llmnr_hdr *hdr, memcpy(pkt_put(p, addr_size), addr, addr_size); } - if (sendto(sock, p->data, pkt_len(p), 0, sa, sizeof(struct sockaddr_in)) < 0) + if (sendto(sock, p->data, pkt_len(p), 0, (struct sockaddr *)sst, sizeof(*sst)) < 0) log_err("Failed to send response: %s\n", strerror(errno)); pkt_free(p); } static void llmnr_packet_process(unsigned int ifindex, const uint8_t *pktbuf, size_t len, - int sock, const struct sockaddr *sa) + int sock, const struct sockaddr_storage *sst) { const struct llmnr_hdr *hdr = (const struct llmnr_hdr *)pktbuf; uint16_t flags, qdcount; @@ -232,7 +239,51 @@ static void llmnr_packet_process(unsigned int ifindex, const uint8_t *pktbuf, si /* Authoritative? */ if (llmnr_name_matches(query)) - llmnr_respond(ifindex, hdr, query, query_len, sock, sa); + llmnr_respond(ifindex, hdr, query, query_len, sock, sst); +} + +static void llmnr_recv(int sock) +{ + uint8_t pktbuf[2048], aux[128]; + struct msghdr msg; + struct iovec io; + struct sockaddr_storage sin_r; + struct cmsghdr *cmsg; + ssize_t recvlen; + int ifindex = -1; + + io.iov_base = pktbuf; + io.iov_len = sizeof(pktbuf); + + memset(&msg, 0, sizeof(msg)); + msg.msg_name = &sin_r; + msg.msg_namelen = sizeof(sin_r); + msg.msg_iov = &io; + msg.msg_iovlen = 1; + msg.msg_control = aux; + msg.msg_controllen = sizeof(aux); + + if ((recvlen = recvmsg(sock, &msg, 0)) < 0) { + if (errno != EINTR) + log_err("Failed to receive packet: %s\n", strerror(errno)); + return; + } + + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) { + struct in_pktinfo *in = (struct in_pktinfo *)CMSG_DATA(cmsg); + ifindex = in->ipi_ifindex; + } else if (cmsg->cmsg_level == IPPROTO_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) { + struct in6_pktinfo *in6 = (struct in6_pktinfo *)CMSG_DATA(cmsg); + ifindex = in6->ipi6_ifindex; + } + } + + if (ifindex >= 0) + llmnr_packet_process(ifindex, pktbuf, recvlen, sock, + (const struct sockaddr_storage *)&sin_r); + else + log_warn("Could not get interface of incoming packet\n"); } int llmnr_run(void) @@ -240,44 +291,39 @@ int llmnr_run(void) int ret = -1; while (llmnr_running) { - uint8_t pktbuf[2048], aux[128]; - struct msghdr msg; - struct iovec io; - struct sockaddr_in saddr_r; - struct cmsghdr *cmsg; - ssize_t recvlen; - unsigned int ifindex = 0; - - io.iov_base = pktbuf; - io.iov_len = sizeof(pktbuf); - - memset(&msg, 0, sizeof(msg)); - msg.msg_name = &saddr_r; - msg.msg_namelen = sizeof(saddr_r); - msg.msg_iov = &io; - msg.msg_iovlen = 1; - msg.msg_control = aux; - msg.msg_controllen = sizeof(aux); - - if ((recvlen = recvmsg(llmnr_sock, &msg, 0)) < 0) { + fd_set rfds; + struct timeval tv; + int nfds, ret; + + FD_ZERO(&rfds); + FD_SET(llmnr_sock_ipv4, &rfds); + if (llmnr_sock_ipv6 >= 0) { + FD_SET(llmnr_sock_ipv6, &rfds); + nfds = max(llmnr_sock_ipv4, llmnr_sock_ipv6) + 1; + } else + nfds = llmnr_sock_ipv4 + 1; + + tv.tv_sec = 0; + tv.tv_usec = 200; + + ret = select(nfds, &rfds, NULL, NULL, &tv); + if (ret < 0) { if (errno != EINTR) - log_err("Failed to receive packet: %s\n", strerror(errno)); + log_err("Failed to select() on socket: %s\n", strerror(errno)); goto out; + } else if (ret) { + if (FD_ISSET(llmnr_sock_ipv4, &rfds)) + llmnr_recv(llmnr_sock_ipv4); + if (llmnr_sock_ipv6 >= 0 && FD_ISSET(llmnr_sock_ipv6, &rfds)) + llmnr_recv(llmnr_sock_ipv6); } - - for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { - if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO) { - struct in_pktinfo *info = (struct in_pktinfo *)CMSG_DATA(cmsg); - ifindex = info->ipi_ifindex; - } - } - - llmnr_packet_process(ifindex, pktbuf, recvlen, llmnr_sock, (const struct sockaddr *)&saddr_r); } ret = 0; out: - close(llmnr_sock); + close(llmnr_sock_ipv4); + if (llmnr_sock_ipv6 >= 0) + close(llmnr_sock_ipv6); return ret; } |