diff options
Diffstat (limited to 'src/resolve')
| -rw-r--r-- | src/resolve/resolve-tool.c | 4 | ||||
| -rw-r--r-- | src/resolve/resolved-bus.c | 3 | ||||
| -rw-r--r-- | src/resolve/resolved-gperf.gperf | 1 | ||||
| -rw-r--r-- | src/resolve/resolved-link.c | 17 | ||||
| -rw-r--r-- | src/resolve/resolved-llmnr.c | 194 | ||||
| -rw-r--r-- | src/resolve/resolved-manager.c | 8 | ||||
| -rw-r--r-- | src/resolve/resolved-mdns.c | 102 | ||||
| -rw-r--r-- | src/resolve/resolved.conf.in | 1 |
8 files changed, 230 insertions, 100 deletions
diff --git a/src/resolve/resolve-tool.c b/src/resolve/resolve-tool.c index 32537ce6e8..c62058917f 100644 --- a/src/resolve/resolve-tool.c +++ b/src/resolve/resolve-tool.c @@ -114,8 +114,8 @@ static void print_source(uint64_t flags, usec_t rtt) { flags & SD_RESOLVED_DNS ? " DNS" :"", flags & SD_RESOLVED_LLMNR_IPV4 ? " LLMNR/IPv4" : "", flags & SD_RESOLVED_LLMNR_IPV6 ? " LLMNR/IPv6" : "", - flags & SD_RESOLVED_MDNS_IPV4 ? "mDNS/IPv4" : "", - flags & SD_RESOLVED_MDNS_IPV6 ? "mDNS/IPv6" : ""); + flags & SD_RESOLVED_MDNS_IPV4 ? " mDNS/IPv4" : "", + flags & SD_RESOLVED_MDNS_IPV6 ? " mDNS/IPv6" : ""); assert_se(format_timespan(rtt_str, sizeof(rtt_str), rtt, 100)); diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c index 2c50109388..efa16ad93d 100644 --- a/src/resolve/resolved-bus.c +++ b/src/resolve/resolved-bus.c @@ -1450,6 +1450,8 @@ static int bus_property_get_ntas( return sd_bus_message_close_container(reply); } +static BUS_DEFINE_PROPERTY_GET_ENUM(bus_property_get_dns_stub_listener_mode, dns_stub_listener_mode, DnsStubListenerMode); + static int bus_method_reset_statistics(sd_bus_message *message, void *userdata, sd_bus_error *error) { Manager *m = userdata; DnsScope *s; @@ -1577,6 +1579,7 @@ static const sd_bus_vtable resolve_vtable[] = { SD_BUS_PROPERTY("DNSSECStatistics", "(tttt)", bus_property_get_dnssec_statistics, 0, 0), SD_BUS_PROPERTY("DNSSECSupported", "b", bus_property_get_dnssec_supported, 0, 0), SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", bus_property_get_ntas, 0, 0), + SD_BUS_PROPERTY("DNSStubListener", "s", bus_property_get_dns_stub_listener_mode, offsetof(Manager, dns_stub_listener_mode), 0), SD_BUS_METHOD("ResolveHostname", "isit", "a(iiay)st", bus_method_resolve_hostname, SD_BUS_VTABLE_UNPRIVILEGED), SD_BUS_METHOD("ResolveAddress", "iiayt", "a(is)t", bus_method_resolve_address, SD_BUS_VTABLE_UNPRIVILEGED), diff --git a/src/resolve/resolved-gperf.gperf b/src/resolve/resolved-gperf.gperf index 446f85cdf4..5153563b99 100644 --- a/src/resolve/resolved-gperf.gperf +++ b/src/resolve/resolved-gperf.gperf @@ -18,6 +18,7 @@ Resolve.DNS, config_parse_dns_servers, DNS_SERVER_SYSTEM, Resolve.FallbackDNS, config_parse_dns_servers, DNS_SERVER_FALLBACK, 0 Resolve.Domains, config_parse_search_domains, 0, 0 Resolve.LLMNR, config_parse_resolve_support, 0, offsetof(Manager, llmnr_support) +Resolve.MulticastDNS, config_parse_resolve_support, 0, offsetof(Manager, mdns_support) Resolve.DNSSEC, config_parse_dnssec_mode, 0, offsetof(Manager, dnssec_mode) Resolve.Cache, config_parse_bool, 0, offsetof(Manager, enable_cache) Resolve.DNSStubListener, config_parse_dns_stub_listener_mode, 0, offsetof(Manager, dns_stub_listener_mode) diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c index 3f7f9035cf..d06096f3f2 100644 --- a/src/resolve/resolved-link.c +++ b/src/resolve/resolved-link.c @@ -28,6 +28,8 @@ #include "mkdir.h" #include "parse-util.h" #include "resolved-link.h" +#include "resolved-llmnr.h" +#include "resolved-mdns.h" #include "string-util.h" #include "strv.h" @@ -523,10 +525,25 @@ static void link_read_settings(Link *l) { } int link_update(Link *l) { + int r; + assert(l); link_read_settings(l); link_load_user(l); + + if (l->llmnr_support != RESOLVE_SUPPORT_NO) { + r = manager_llmnr_start(l->manager); + if (r < 0) + return r; + } + + if (l->mdns_support != RESOLVE_SUPPORT_NO) { + r = manager_mdns_start(l->manager); + if (r < 0) + return r; + } + link_allocate_scopes(l); link_add_rrs(l, false); diff --git a/src/resolve/resolved-llmnr.c b/src/resolve/resolved-llmnr.c index 3516af58ee..29396e9973 100644 --- a/src/resolve/resolved-llmnr.c +++ b/src/resolve/resolved-llmnr.c @@ -77,7 +77,7 @@ int manager_llmnr_start(Manager *m) { return 0; eaddrinuse: - log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); + log_warning("Another LLMNR responder prohibits binding the socket to the same port. Turning off LLMNR support."); m->llmnr_support = RESOLVE_SUPPORT_NO; manager_llmnr_stop(m); @@ -136,56 +136,75 @@ int manager_llmnr_ipv4_udp_fd(Manager *m) { m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->llmnr_ipv4_udp_fd < 0) - return -errno; + return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to create socket: %m"); /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_TTL: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_TTL: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_LOOP: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_PKTINFO: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_RECVTTL: %m"); goto fail; } /* Disable Don't-Fragment bit in the IP header */ r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set IP_MTU_DISCOVER: %m"); goto fail; } + /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m"); + goto fail; + } + + log_warning("LLMNR-IPv4(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ + r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, m->llmnr_ipv4_udp_fd, EPOLLIN, on_llmnr_packet, m); @@ -216,55 +235,74 @@ int manager_llmnr_ipv6_udp_fd(Manager *m) { m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->llmnr_ipv6_udp_fd < 0) - return -errno; + return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to create socket: %m"); r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_UNICAST_HOPS: %m"); goto fail; } /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_HOPS: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_LOOP: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_V6ONLY: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVPKTINFO: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVHOPLIMIT: %m"); goto fail; } + /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m"); + goto fail; + } + + log_warning("LLMNR-IPv6(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ + r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, m->llmnr_ipv6_udp_fd, EPOLLIN, on_llmnr_packet, m); @@ -338,49 +376,68 @@ int manager_llmnr_ipv4_tcp_fd(Manager *m) { m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->llmnr_ipv4_tcp_fd < 0) - return -errno; + return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to create socket: %m"); /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set IP_TTL: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set IP_PKTINFO: %m"); goto fail; } r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set IP_RECVTTL: %m"); goto fail; } /* Disable Don't-Fragment bit in the IP header */ r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set IP_MTU_DISCOVER: %m"); goto fail; } + /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m"); + goto fail; + } + + log_warning("LLMNR-IPv4(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ + r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to listen the stream: %m"); goto fail; } @@ -412,48 +469,67 @@ int manager_llmnr_ipv6_tcp_fd(Manager *m) { m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->llmnr_ipv6_tcp_fd < 0) - return -errno; + return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to create socket: %m"); /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set IPV6_UNICAST_HOPS: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set IPV6_V6ONLY: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVPKTINFO: %m"); goto fail; } r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVHOPLIMIT: %m"); goto fail; } + /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m"); + goto fail; + } + + log_warning("LLMNR-IPv6(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ + r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to listen the stream: %m"); goto fail; } diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index c4e4409fe3..9db8b8f616 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -612,14 +612,6 @@ int manager_start(Manager *m) { if (r < 0) return r; - r = manager_llmnr_start(m); - if (r < 0) - return r; - - r = manager_mdns_start(m); - if (r < 0) - return r; - return 0; } diff --git a/src/resolve/resolved-mdns.c b/src/resolve/resolved-mdns.c index c40e8f75f0..415dc1a532 100644 --- a/src/resolve/resolved-mdns.c +++ b/src/resolve/resolved-mdns.c @@ -60,7 +60,7 @@ int manager_mdns_start(Manager *m) { return 0; eaddrinuse: - log_warning("There appears to be another mDNS responder running. Turning off mDNS support."); + log_warning("Another mDNS responder prohibits binding the socket to the same port. Turning off mDNS support."); m->mdns_support = RESOLVE_SUPPORT_NO; manager_mdns_stop(m); @@ -217,55 +217,75 @@ int manager_mdns_ipv4_fd(Manager *m) { m->mdns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->mdns_ipv4_fd < 0) - return -errno; + return log_error_errno(errno, "mDNS-IPv4: Failed to create socket: %m"); r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_TTL: %m"); goto fail; } r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_MULTICAST_TTL: %m"); goto fail; } r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_MULTICAST_LOOP: %m"); goto fail; } r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_PKTINFO: %m"); goto fail; } r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_RECVTTL: %m"); goto fail; } /* Disable Don't-Fragment bit in the IP header */ r = setsockopt(m->mdns_ipv4_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv4: Failed to set IP_MTU_DISCOVER: %m"); goto fail; } + /* See the section 15.1 of RFC6762 */ + /* first try to bind without SO_REUSEADDR to detect another mDNS responder */ r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m"); + goto fail; + } + + log_warning("mDNS-IPv4: There appears to be another mDNS responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple mDNS responders */ + r = setsockopt(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = sd_event_add_io(m->event, &m->mdns_ipv4_event_source, m->mdns_ipv4_fd, EPOLLIN, on_mdns_packet, m); @@ -294,55 +314,75 @@ int manager_mdns_ipv6_fd(Manager *m) { m->mdns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); if (m->mdns_ipv6_fd < 0) - return -errno; + return log_error_errno(errno, "mDNS-IPv6: Failed to create socket: %m"); r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_UNICAST_HOPS: %m"); goto fail; } /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_MULTICAST_HOPS: %m"); goto fail; } r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_MULTICAST_LOOP: %m"); goto fail; } r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); - if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_V6ONLY: %m"); goto fail; } r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_RECVPKTINFO: %m"); goto fail; } r = setsockopt(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); if (r < 0) { - r = -errno; + r = log_error_errno(errno, "mDNS-IPv6: Failed to set IPV6_RECVHOPLIMIT: %m"); goto fail; } + /* See the section 15.1 of RFC6762 */ + /* first try to bind without SO_REUSEADDR to detect another mDNS responder */ r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6)); if (r < 0) { - r = -errno; - goto fail; + if (errno != EADDRINUSE) { + r = log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m"); + goto fail; + } + + log_warning("mDNS-IPv6: There appears to be another mDNS responder running, or previously systemd-resolved crashed with some outstanding transfers."); + + /* try again with SO_REUSEADDR */ + r = setsockopt(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m"); + goto fail; + } + + r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m"); + goto fail; + } + } else { + /* enable SO_REUSEADDR for the case that the user really wants multiple mDNS responders */ + r = setsockopt(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (r < 0) { + r = log_error_errno(errno, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m"); + goto fail; + } } r = sd_event_add_io(m->event, &m->mdns_ipv6_event_source, m->mdns_ipv6_fd, EPOLLIN, on_mdns_packet, m); diff --git a/src/resolve/resolved.conf.in b/src/resolve/resolved.conf.in index 60afa151e3..e6b20620e2 100644 --- a/src/resolve/resolved.conf.in +++ b/src/resolve/resolved.conf.in @@ -16,6 +16,7 @@ #FallbackDNS=@DNS_SERVERS@ #Domains= #LLMNR=yes +#MulticastDNS=yes #DNSSEC=@DEFAULT_DNSSEC_MODE@ #Cache=yes #DNSStubListener=udp |