From 5f402ae84bbc08fe8de5682e371b3f66c387da52 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Fri, 10 Jul 2015 15:02:38 -0400 Subject: [PATCH 1/4] resolved: move LLMNR related functions into separate file --- Makefile.am | 2 + src/resolve/resolved-dns-scope.c | 1 + src/resolve/resolved-llmnr.c | 473 +++++++++++++++++++++++++++++++ src/resolve/resolved-llmnr.h | 32 +++ src/resolve/resolved-manager.c | 448 +---------------------------- src/resolve/resolved-manager.h | 4 - 6 files changed, 509 insertions(+), 451 deletions(-) create mode 100644 src/resolve/resolved-llmnr.c create mode 100644 src/resolve/resolved-llmnr.h diff --git a/Makefile.am b/Makefile.am index e178bdcb99..c038fed36b 100644 --- a/Makefile.am +++ b/Makefile.am @@ -5102,6 +5102,8 @@ systemd_resolved_SOURCES = \ src/resolve/resolved-bus.h \ src/resolve/resolved-link.h \ src/resolve/resolved-link.c \ + src/resolve/resolved-llmnr.h \ + src/resolve/resolved-llmnr.c \ src/resolve/resolved-def.h \ src/resolve/resolved-dns-rr.h \ src/resolve/resolved-dns-rr.c \ diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index c25ac2216d..cc7e268529 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -28,6 +28,7 @@ #include "random-util.h" #include "hostname-util.h" #include "dns-domain.h" +#include "resolved-llmnr.h" #include "resolved-dns-scope.h" #define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) diff --git a/src/resolve/resolved-llmnr.c b/src/resolve/resolved-llmnr.c new file mode 100644 index 0000000000..ee9a416372 --- /dev/null +++ b/src/resolve/resolved-llmnr.c @@ -0,0 +1,473 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen + + systemd 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. + + systemd 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 systemd; If not, see . + ***/ + +#include +#include + +#include "resolved-manager.h" +#include "resolved-llmnr.h" + +void manager_llmnr_stop(Manager *m) { + assert(m); + + m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source); + m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); + + m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source); + m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); + + m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + + m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); +} + +int manager_llmnr_start(Manager *m) { + int r; + + assert(m); + + if (m->llmnr_support == SUPPORT_NO) + return 0; + + r = manager_llmnr_ipv4_udp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + r = manager_llmnr_ipv4_tcp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + if (socket_ipv6_is_supported()) { + r = manager_llmnr_ipv6_udp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + r = manager_llmnr_ipv6_tcp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + } + + return 0; + +eaddrinuse: + log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); + m->llmnr_support = SUPPORT_NO; + manager_llmnr_stop(m); + + return 0; +} + +static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; + DnsTransaction *t = NULL; + Manager *m = userdata; + DnsScope *scope; + int r; + + r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p); + if (r <= 0) + return r; + + scope = manager_find_scope(m, p); + if (!scope) { + log_warning("Got LLMNR UDP packet on unknown scope. Ignoring."); + return 0; + } + + if (dns_packet_validate_reply(p) > 0) { + log_debug("Got LLMNR reply packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_check_conflicts(scope, p); + + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + if (t) + dns_transaction_process_reply(t, p); + + } else if (dns_packet_validate_query(p) > 0) { + log_debug("Got LLMNR query packet for id %u", DNS_PACKET_ID(p)); + + dns_scope_process_query(scope, NULL, p); + } else + log_debug("Invalid LLMNR UDP packet."); + + return 0; +} + +int manager_llmnr_ipv4_udp_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(5355), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; + int r; + + assert(m); + + if (m->llmnr_ipv4_udp_fd >= 0) + return m->llmnr_ipv4_udp_fd; + + m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv4_udp_fd < 0) + return -errno; + + /* 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + 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; + goto fail; + } + + r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + 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); + if (r < 0) + goto fail; + + return m->llmnr_ipv4_udp_fd; + +fail: + m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); + return r; +} + +int manager_llmnr_ipv6_udp_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(5355), + }; + static const int one = 1, ttl = 255; + int r; + + assert(m); + + if (m->llmnr_ipv6_udp_fd >= 0) + return m->llmnr_ipv6_udp_fd; + + m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv6_udp_fd < 0) + return -errno; + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); + if (r < 0) { + r = -errno; + 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); + if (r < 0) { + r = -errno; + 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + 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); + if (r < 0) { + r = -errno; + goto fail; + } + + return m->llmnr_ipv6_udp_fd; + +fail: + m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); + return r; +} + +static int on_llmnr_stream_packet(DnsStream *s) { + DnsScope *scope; + + assert(s); + + scope = manager_find_scope(s->manager, s->read_packet); + if (!scope) { + log_warning("Got LLMNR TCP packet on unknown scope. Ignroing."); + return 0; + } + + if (dns_packet_validate_query(s->read_packet) > 0) { + log_debug("Got query packet for id %u", DNS_PACKET_ID(s->read_packet)); + + dns_scope_process_query(scope, s, s->read_packet); + + /* If no reply packet was set, we free the stream */ + if (s->write_packet) + return 0; + } else + log_debug("Invalid LLMNR TCP packet."); + + dns_stream_free(s); + return 0; +} + +static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + DnsStream *stream; + Manager *m = userdata; + int cfd, r; + + cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (cfd < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd); + if (r < 0) { + safe_close(cfd); + return r; + } + + stream->on_packet = on_llmnr_stream_packet; + return 0; +} + +int manager_llmnr_ipv4_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in.sin_family = AF_INET, + .in.sin_port = htobe16(5355), + }; + static const int one = 1, pmtu = IP_PMTUDISC_DONT; + int r; + + assert(m); + + if (m->llmnr_ipv4_tcp_fd >= 0) + return m->llmnr_ipv4_tcp_fd; + + m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv4_tcp_fd < 0) + return -errno; + + /* 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); + if (r < 0) { + r = -errno; + 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; + goto fail; + } + + r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) + goto fail; + + return m->llmnr_ipv4_tcp_fd; + +fail: + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + return r; +} + +int manager_llmnr_ipv6_tcp_fd(Manager *m) { + union sockaddr_union sa = { + .in6.sin6_family = AF_INET6, + .in6.sin6_port = htobe16(5355), + }; + static const int one = 1; + int r; + + assert(m); + + if (m->llmnr_ipv6_tcp_fd >= 0) + return m->llmnr_ipv6_tcp_fd; + + m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); + if (m->llmnr_ipv6_tcp_fd < 0) + return -errno; + + /* 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; + 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; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); + if (r < 0) { + r = -errno; + goto fail; + } + + r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN); + if (r < 0) { + r = -errno; + goto fail; + } + + r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m); + if (r < 0) { + r = -errno; + goto fail; + } + + return m->llmnr_ipv6_tcp_fd; + +fail: + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); + return r; +} diff --git a/src/resolve/resolved-llmnr.h b/src/resolve/resolved-llmnr.h new file mode 100644 index 0000000000..640644000a --- /dev/null +++ b/src/resolve/resolved-llmnr.h @@ -0,0 +1,32 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd 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. + + systemd 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 systemd; If not, see . +***/ + +#include "resolved-manager.h" + +int manager_llmnr_ipv4_udp_fd(Manager *m); +int manager_llmnr_ipv6_udp_fd(Manager *m); +int manager_llmnr_ipv4_tcp_fd(Manager *m); +int manager_llmnr_ipv6_tcp_fd(Manager *m); + +void manager_llmnr_stop(Manager *m); +int manager_llmnr_start(Manager *m); diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index dee5e61922..6785a2e3c7 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -38,6 +38,7 @@ #include "resolved-conf.h" #include "resolved-bus.h" #include "resolved-manager.h" +#include "resolved-llmnr.h" #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC) @@ -393,66 +394,6 @@ static int manager_watch_hostname(Manager *m) { return 0; } -static void manager_llmnr_stop(Manager *m) { - assert(m); - - m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source); - m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); - - m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source); - m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); - - m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); - m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); - - m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); - m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); -} - -static int manager_llmnr_start(Manager *m) { - int r; - - assert(m); - - if (m->llmnr_support == SUPPORT_NO) - return 0; - - r = manager_llmnr_ipv4_udp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; - - r = manager_llmnr_ipv4_tcp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; - - if (socket_ipv6_is_supported()) { - r = manager_llmnr_ipv6_udp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; - - r = manager_llmnr_ipv6_tcp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; - } - - return 0; - -eaddrinuse: - log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); - m->llmnr_support = SUPPORT_NO; - manager_llmnr_stop(m); - - return 0; -} - int manager_new(Manager **ret) { _cleanup_(manager_freep) Manager *m = NULL; int r; @@ -1316,393 +1257,6 @@ uint32_t manager_find_mtu(Manager *m) { return mtu; } -static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsTransaction *t = NULL; - Manager *m = userdata; - DnsScope *scope; - int r; - - r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p); - if (r <= 0) - return r; - - scope = manager_find_scope(m, p); - if (!scope) { - log_warning("Got LLMNR UDP packet on unknown scope. Ignoring."); - return 0; - } - - if (dns_packet_validate_reply(p) > 0) { - log_debug("Got reply packet for id %u", DNS_PACKET_ID(p)); - - dns_scope_check_conflicts(scope, p); - - t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); - if (t) - dns_transaction_process_reply(t, p); - - } else if (dns_packet_validate_query(p) > 0) { - log_debug("Got query packet for id %u", DNS_PACKET_ID(p)); - - dns_scope_process_query(scope, NULL, p); - } else - log_debug("Invalid LLMNR UDP packet."); - - return 0; -} - -int manager_llmnr_ipv4_udp_fd(Manager *m) { - union sockaddr_union sa = { - .in.sin_family = AF_INET, - .in.sin_port = htobe16(5355), - }; - static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; - int r; - - assert(m); - - if (m->llmnr_ipv4_udp_fd >= 0) - return m->llmnr_ipv4_udp_fd; - - m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (m->llmnr_ipv4_udp_fd < 0) - return -errno; - - /* 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); - if (r < 0) { - r = -errno; - 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); - if (r < 0) { - r = -errno; - 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; - goto fail; - } - - r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in)); - if (r < 0) { - r = -errno; - 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); - if (r < 0) - goto fail; - - return m->llmnr_ipv4_udp_fd; - -fail: - m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); - return r; -} - -int manager_llmnr_ipv6_udp_fd(Manager *m) { - union sockaddr_union sa = { - .in6.sin6_family = AF_INET6, - .in6.sin6_port = htobe16(5355), - }; - static const int one = 1, ttl = 255; - int r; - - assert(m); - - if (m->llmnr_ipv6_udp_fd >= 0) - return m->llmnr_ipv6_udp_fd; - - m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (m->llmnr_ipv6_udp_fd < 0) - return -errno; - - r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)); - if (r < 0) { - r = -errno; - 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one)); - if (r < 0) { - r = -errno; - 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6)); - if (r < 0) { - r = -errno; - 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); - if (r < 0) { - r = -errno; - goto fail; - } - - return m->llmnr_ipv6_udp_fd; - -fail: - m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); - return r; -} - -static int on_llmnr_stream_packet(DnsStream *s) { - DnsScope *scope; - - assert(s); - - scope = manager_find_scope(s->manager, s->read_packet); - if (!scope) { - log_warning("Got LLMNR TCP packet on unknown scope. Ignroing."); - return 0; - } - - if (dns_packet_validate_query(s->read_packet) > 0) { - log_debug("Got query packet for id %u", DNS_PACKET_ID(s->read_packet)); - - dns_scope_process_query(scope, s, s->read_packet); - - /* If no reply packet was set, we free the stream */ - if (s->write_packet) - return 0; - } else - log_debug("Invalid LLMNR TCP packet."); - - dns_stream_free(s); - return 0; -} - -static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { - DnsStream *stream; - Manager *m = userdata; - int cfd, r; - - cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); - if (cfd < 0) { - if (errno == EAGAIN || errno == EINTR) - return 0; - - return -errno; - } - - r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd); - if (r < 0) { - safe_close(cfd); - return r; - } - - stream->on_packet = on_llmnr_stream_packet; - return 0; -} - -int manager_llmnr_ipv4_tcp_fd(Manager *m) { - union sockaddr_union sa = { - .in.sin_family = AF_INET, - .in.sin_port = htobe16(5355), - }; - static const int one = 1, pmtu = IP_PMTUDISC_DONT; - int r; - - assert(m); - - if (m->llmnr_ipv4_tcp_fd >= 0) - return m->llmnr_ipv4_tcp_fd; - - m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (m->llmnr_ipv4_tcp_fd < 0) - return -errno; - - /* 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one)); - if (r < 0) { - r = -errno; - 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; - goto fail; - } - - r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN); - if (r < 0) { - r = -errno; - goto fail; - } - - r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m); - if (r < 0) - goto fail; - - return m->llmnr_ipv4_tcp_fd; - -fail: - m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); - return r; -} - -int manager_llmnr_ipv6_tcp_fd(Manager *m) { - union sockaddr_union sa = { - .in6.sin6_family = AF_INET6, - .in6.sin6_port = htobe16(5355), - }; - static const int one = 1; - int r; - - assert(m); - - if (m->llmnr_ipv6_tcp_fd >= 0) - return m->llmnr_ipv6_tcp_fd; - - m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (m->llmnr_ipv6_tcp_fd < 0) - return -errno; - - /* 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; - 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; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6)); - if (r < 0) { - r = -errno; - goto fail; - } - - r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN); - if (r < 0) { - r = -errno; - goto fail; - } - - r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m); - if (r < 0) { - r = -errno; - goto fail; - } - - return m->llmnr_ipv6_tcp_fd; - -fail: - m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); - return r; -} - int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { LinkAddress *a; diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index 0f4ffad141..4e70a5b500 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -130,10 +130,6 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret); int manager_dns_ipv4_fd(Manager *m); int manager_dns_ipv6_fd(Manager *m); -int manager_llmnr_ipv4_udp_fd(Manager *m); -int manager_llmnr_ipv6_udp_fd(Manager *m); -int manager_llmnr_ipv4_tcp_fd(Manager *m); -int manager_llmnr_ipv6_tcp_fd(Manager *m); int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr); LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr); From 22a37591ede1e9d5f325d6f10495cc91b40b775f Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Fri, 10 Jul 2015 15:28:09 -0400 Subject: [PATCH 2/4] resolved: use a #define for LLMNR port De-duplicate some magic numbers. --- src/resolve/resolved-dns-scope.c | 2 +- src/resolve/resolved-dns-transaction.c | 3 ++- src/resolve/resolved-llmnr.c | 8 ++++---- src/resolve/resolved-llmnr.h | 2 ++ 4 files changed, 9 insertions(+), 6 deletions(-) diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index cc7e268529..596181fa4c 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -181,7 +181,7 @@ int dns_scope_emit(DnsScope *s, DnsPacket *p) { return -EBUSY; family = s->family; - port = 5355; + port = LLMNR_PORT; if (family == AF_INET) { addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 214938986d..21247e8a0b 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -21,6 +21,7 @@ #include "af-list.h" +#include "resolved-llmnr.h" #include "resolved-dns-transaction.h" #include "random-util.h" @@ -264,7 +265,7 @@ static int dns_transaction_open_tcp(DnsTransaction *t) { if (r == 0) return -EINVAL; - fd = dns_scope_tcp_socket(t->scope, family, &address, 5355); + fd = dns_scope_tcp_socket(t->scope, family, &address, LLMNR_PORT); } } else return -EAFNOSUPPORT; diff --git a/src/resolve/resolved-llmnr.c b/src/resolve/resolved-llmnr.c index ee9a416372..8afaf8db6e 100644 --- a/src/resolve/resolved-llmnr.c +++ b/src/resolve/resolved-llmnr.c @@ -124,7 +124,7 @@ static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *u int manager_llmnr_ipv4_udp_fd(Manager *m) { union sockaddr_union sa = { .in.sin_family = AF_INET, - .in.sin_port = htobe16(5355), + .in.sin_port = htobe16(LLMNR_PORT), }; static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255; int r; @@ -202,7 +202,7 @@ fail: int manager_llmnr_ipv6_udp_fd(Manager *m) { union sockaddr_union sa = { .in6.sin6_family = AF_INET6, - .in6.sin6_port = htobe16(5355), + .in6.sin6_port = htobe16(LLMNR_PORT), }; static const int one = 1, ttl = 255; int r; @@ -330,7 +330,7 @@ static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *u int manager_llmnr_ipv4_tcp_fd(Manager *m) { union sockaddr_union sa = { .in.sin_family = AF_INET, - .in.sin_port = htobe16(5355), + .in.sin_port = htobe16(LLMNR_PORT), }; static const int one = 1, pmtu = IP_PMTUDISC_DONT; int r; @@ -402,7 +402,7 @@ fail: int manager_llmnr_ipv6_tcp_fd(Manager *m) { union sockaddr_union sa = { .in6.sin6_family = AF_INET6, - .in6.sin6_port = htobe16(5355), + .in6.sin6_port = htobe16(LLMNR_PORT), }; static const int one = 1; int r; diff --git a/src/resolve/resolved-llmnr.h b/src/resolve/resolved-llmnr.h index 640644000a..d489d481e8 100644 --- a/src/resolve/resolved-llmnr.h +++ b/src/resolve/resolved-llmnr.h @@ -23,6 +23,8 @@ #include "resolved-manager.h" +#define LLMNR_PORT 5355 + int manager_llmnr_ipv4_udp_fd(Manager *m); int manager_llmnr_ipv6_udp_fd(Manager *m); int manager_llmnr_ipv4_tcp_fd(Manager *m); From 8b757a38611006a751c90933d1810cccaa47e1af Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Fri, 10 Jul 2015 20:35:16 -0400 Subject: [PATCH 3/4] resolved: separate LLMNR specific header bits The C and T bits in the DNS packet header definitions are specific to LLMNR. In regular DNS, they are called AA and RD instead. Reflect that by calling the macros accordingly, and alias LLMNR specific macros. While at it, define RA, AD and CD getters as well. --- src/resolve/resolved-dns-packet.h | 14 +++++++++++--- src/resolve/resolved-dns-scope.c | 6 +++--- src/resolve/resolved-dns-transaction.c | 2 +- 3 files changed, 15 insertions(+), 7 deletions(-) diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index c5867386c6..bf998aa84e 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -99,10 +99,18 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { #define DNS_PACKET_ID(p) DNS_PACKET_HEADER(p)->id #define DNS_PACKET_QR(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 15) & 1) #define DNS_PACKET_OPCODE(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 11) & 15) -#define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15) +#define DNS_PACKET_AA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 10) & 1) #define DNS_PACKET_TC(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 9) & 1) -#define DNS_PACKET_C(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 10) & 1) -#define DNS_PACKET_T(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 8) & 1) +#define DNS_PACKET_RD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 8) & 1) +#define DNS_PACKET_RA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 7) & 1) +#define DNS_PACKET_AD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 5) & 1) +#define DNS_PACKET_CD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 4) & 1) +#define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15) + +/* LLMNR defines some bits differently */ +#define DNS_PACKET_LLMNR_C(p) DNS_PACKET_AA(p) +#define DNS_PACKET_LLMNR_T(p) DNS_PACKET_RD(p) + #define DNS_PACKET_QDCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->qdcount) #define DNS_PACKET_ANCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->ancount) #define DNS_PACKET_NSCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->nscount) diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c index 596181fa4c..25392d21d7 100644 --- a/src/resolve/resolved-dns-scope.c +++ b/src/resolve/resolved-dns-scope.c @@ -547,7 +547,7 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { return; } - if (DNS_PACKET_C(p)) { + if (DNS_PACKET_LLMNR_C(p)) { /* Somebody notified us about a possible conflict */ dns_scope_verify_conflicts(s, p); return; @@ -761,10 +761,10 @@ void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) { if (DNS_PACKET_RRCOUNT(p) <= 0) return; - if (DNS_PACKET_C(p) != 0) + if (DNS_PACKET_LLMNR_C(p) != 0) return; - if (DNS_PACKET_T(p) != 0) + if (DNS_PACKET_LLMNR_T(p) != 0) return; if (manager_our_packet(scope->manager, p)) diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 21247e8a0b..3f4673df7a 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -324,7 +324,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { /* Tentative packets are not full responses but still * useful for identifying uniqueness conflicts during * probing. */ - if (DNS_PACKET_T(p)) { + if (DNS_PACKET_LLMNR_T(p)) { dns_transaction_tentative(t, p); return; } From 818ef443f0281acd952878cdb01cbdaa42195912 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Sat, 11 Jul 2015 12:37:17 -0400 Subject: [PATCH 4/4] resolved: make LLMNR checks conditional Make all LLMNR related packet inspections conditional to p->protocol. Use switch-case statements while at it, which will make future additions more readable. --- src/resolve/resolved-dns-packet.c | 42 ++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c index 47cc9751ed..fa0516f8a0 100644 --- a/src/resolve/resolved-dns-packet.c +++ b/src/resolve/resolved-dns-packet.c @@ -166,10 +166,17 @@ int dns_packet_validate_reply(DnsPacket *p) { if (DNS_PACKET_OPCODE(p) != 0) return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; + + break; + + default: + break; + } return 1; } @@ -192,18 +199,25 @@ int dns_packet_validate_query(DnsPacket *p) { if (DNS_PACKET_TC(p)) return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ - if (DNS_PACKET_ANCOUNT(p) > 0) - return -EBADMSG; + /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ + if (DNS_PACKET_ANCOUNT(p) > 0) + return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ - if (DNS_PACKET_NSCOUNT(p) > 0) - return -EBADMSG; + /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ + if (DNS_PACKET_NSCOUNT(p) > 0) + return -EBADMSG; + + break; + + default: + break; + } return 1; }