[thirdparty/systemd.git] / src / resolve / resolved-llmnr.c

/* SPDX-License-Identifier: LGPL-2.1+ */

#include <netinet/in.h>
#include <resolv.h>

#include "fd-util.h"
#include "resolved-llmnr.h"
#include "resolved-manager.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 == RESOLVE_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("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);

        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;

        assert(s);
        assert(fd >= 0);
        assert(m);

        r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p);
        if (r <= 0)
                return r;

        if (manager_our_packet(m, p))
                return 0;

        scope = manager_find_scope(m, p);
        if (!scope) {
                log_debug("Got LLMNR UDP packet on unknown scope. Ignoring.");
                return 0;
        }

        if (dns_packet_validate_reply(p) > 0) {
                log_debug("Got LLMNR UDP 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 UDP query packet for id %u", DNS_PACKET_ID(p));

                dns_scope_process_query(scope, NULL, p);
        } else
                log_debug("Invalid LLMNR UDP packet, ignoring.");

        return 0;
}

int manager_llmnr_ipv4_udp_fd(Manager *m) {
        union sockaddr_union sa = {
                .in.sin_family = AF_INET,
                .in.sin_port = htobe16(LLMNR_PORT),
        };
        _cleanup_close_ int s = -1;
        int r;

        assert(m);

        if (m->llmnr_ipv4_udp_fd >= 0)
                return m->llmnr_ipv4_udp_fd;

        s = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
        if (s < 0)
                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_int(s, IPPROTO_IP, IP_TTL, 255);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_TTL: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_TTL, 255);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_TTL: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_LOOP, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_LOOP: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_PKTINFO: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_RECVTTL: %m");

        /* Disable Don't-Fragment bit in the IP header */
        r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MTU_DISCOVER: %m");

        /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
        r = bind(s, &sa.sa, sizeof(sa.in));
        if (r < 0) {
                if (errno != EADDRINUSE)
                        return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m");

                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_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m");

                r = bind(s, &sa.sa, sizeof(sa.in));
                if (r < 0)
                        return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m");
        } else {
                /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
                r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m");
        }

        r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, s, EPOLLIN, on_llmnr_packet, m);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to create event source: %m");

        (void) sd_event_source_set_description(m->llmnr_ipv4_udp_event_source, "llmnr-ipv4-udp");

        return m->llmnr_ipv4_udp_fd = TAKE_FD(s);
}

int manager_llmnr_ipv6_udp_fd(Manager *m) {
        union sockaddr_union sa = {
                .in6.sin6_family = AF_INET6,
                .in6.sin6_port = htobe16(LLMNR_PORT),
        };
        _cleanup_close_ int s = -1;
        int r;

        assert(m);

        if (m->llmnr_ipv6_udp_fd >= 0)
                return m->llmnr_ipv6_udp_fd;

        s = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
        if (s < 0)
                return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to create socket: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_UNICAST_HOPS: %m");

        /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_HOPS: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_LOOP: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_V6ONLY: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVPKTINFO: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVHOPLIMIT: %m");

        /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
        r = bind(s, &sa.sa, sizeof(sa.in6));
        if (r < 0) {
                if (errno != EADDRINUSE)
                        return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m");

                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_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m");

                r = bind(s, &sa.sa, sizeof(sa.in6));
                if (r < 0)
                        return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m");
        } else {
                /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
                r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m");
        }

        r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, s, EPOLLIN, on_llmnr_packet, m);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to create event source: %m");

        (void) sd_event_source_set_description(m->llmnr_ipv6_udp_event_source, "llmnr-ipv6-udp");

        return m->llmnr_ipv6_udp_fd = TAKE_FD(s);
}

static int on_llmnr_stream_packet(DnsStream *s) {
        DnsScope *scope;

        assert(s);
        assert(s->read_packet);

        scope = manager_find_scope(s->manager, s->read_packet);
        if (!scope)
                log_debug("Got LLMNR TCP packet on unknown scope. Ignoring.");
        else if (dns_packet_validate_query(s->read_packet) > 0) {
                log_debug("Got LLMNR TCP query packet for id %u", DNS_PACKET_ID(s->read_packet));

                dns_scope_process_query(scope, s, s->read_packet);
        } else
                log_debug("Invalid LLMNR TCP packet, ignoring.");

        dns_stream_unref(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 (IN_SET(errno, EAGAIN, EINTR))
                        return 0;

                return -errno;
        }

        r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd, NULL);
        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(LLMNR_PORT),
        };
        _cleanup_close_ int s = -1;
        int r;

        assert(m);

        if (m->llmnr_ipv4_tcp_fd >= 0)
                return m->llmnr_ipv4_tcp_fd;

        s = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
        if (s < 0)
                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_int(s, IPPROTO_IP, IP_TTL, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_TTL: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_PKTINFO: %m");

        r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_RECVTTL: %m");

        /* Disable Don't-Fragment bit in the IP header */
        r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_MTU_DISCOVER: %m");

        /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
        r = bind(s, &sa.sa, sizeof(sa.in));
        if (r < 0) {
                if (errno != EADDRINUSE)
                        return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m");

                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_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m");

                r = bind(s, &sa.sa, sizeof(sa.in));
                if (r < 0)
                        return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m");
        } else {
                /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
                r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m");
        }

        r = listen(s, SOMAXCONN);
        if (r < 0)
                return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to listen the stream: %m");

        r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to create event source: %m");

        (void) sd_event_source_set_description(m->llmnr_ipv4_tcp_event_source, "llmnr-ipv4-tcp");

        return m->llmnr_ipv4_tcp_fd = TAKE_FD(s);
}

int manager_llmnr_ipv6_tcp_fd(Manager *m) {
        union sockaddr_union sa = {
                .in6.sin6_family = AF_INET6,
                .in6.sin6_port = htobe16(LLMNR_PORT),
        };
        _cleanup_close_ int s = -1;
        int r;

        assert(m);

        if (m->llmnr_ipv6_tcp_fd >= 0)
                return m->llmnr_ipv6_tcp_fd;

        s = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
        if (s < 0)
                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_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_UNICAST_HOPS: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_V6ONLY: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVPKTINFO: %m");

        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVHOPLIMIT: %m");

        /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
        r = bind(s, &sa.sa, sizeof(sa.in6));
        if (r < 0) {
                if (errno != EADDRINUSE)
                        return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m");

                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_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m");

                r = bind(s, &sa.sa, sizeof(sa.in6));
                if (r < 0)
                        return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m");
        } else {
                /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
                r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
                if (r < 0)
                        return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m");
        }

        r = listen(s, SOMAXCONN);
        if (r < 0)
                return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to listen the stream: %m");

        r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m);
        if (r < 0)
                return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to create event source: %m");

        (void) sd_event_source_set_description(m->llmnr_ipv6_tcp_event_source, "llmnr-ipv6-tcp");

        return m->llmnr_ipv6_tcp_fd = TAKE_FD(s);
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
5f402ae8	2
5f402ae8	3	#include <netinet/in.h>
cf0fbc49	4	#include <resolv.h>
5f402ae8	5
3ffd4af2	6	#include "fd-util.h"
5f402ae8	7	#include "resolved-llmnr.h"
3ffd4af2	8	#include "resolved-manager.h"
5f402ae8 DM	9
	10	void manager_llmnr_stop(Manager *m) {
	11	assert(m);
	12
	13	m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source);
	14	m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd);
	15
	16	m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source);
	17	m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd);
	18
	19	m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source);
	20	m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd);
	21
	22	m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source);
	23	m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd);
	24	}
	25
	26	int manager_llmnr_start(Manager *m) {
	27	int r;
	28
	29	assert(m);
	30
af49ca27	31	if (m->llmnr_support == RESOLVE_SUPPORT_NO)
5f402ae8 DM	32	return 0;
	33
	34	r = manager_llmnr_ipv4_udp_fd(m);
	35	if (r == -EADDRINUSE)
	36	goto eaddrinuse;
	37	if (r < 0)
	38	return r;
	39
	40	r = manager_llmnr_ipv4_tcp_fd(m);
	41	if (r == -EADDRINUSE)
	42	goto eaddrinuse;
	43	if (r < 0)
	44	return r;
	45
	46	if (socket_ipv6_is_supported()) {
	47	r = manager_llmnr_ipv6_udp_fd(m);
	48	if (r == -EADDRINUSE)
	49	goto eaddrinuse;
	50	if (r < 0)
	51	return r;
	52
	53	r = manager_llmnr_ipv6_tcp_fd(m);
	54	if (r == -EADDRINUSE)
	55	goto eaddrinuse;
	56	if (r < 0)
	57	return r;
	58	}
	59
	60	return 0;
	61
	62	eaddrinuse:
007ef0a2	63	log_warning("Another LLMNR responder prohibits binding the socket to the same port. Turning off LLMNR support.");
af49ca27	64	m->llmnr_support = RESOLVE_SUPPORT_NO;
5f402ae8 DM	65	manager_llmnr_stop(m);
	66
	67	return 0;
	68	}
	69
	70	static int on_llmnr_packet(sd_event_source s, int fd, uint32_t revents, void userdata) {
	71	_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
	72	DnsTransaction *t = NULL;
	73	Manager *m = userdata;
	74	DnsScope *scope;
	75	int r;
	76
b30bf55d LP	77	assert(s);
	78	assert(fd >= 0);
	79	assert(m);
	80
5f402ae8 DM	81	r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p);
	82	if (r <= 0)
	83	return r;
	84
6cae1ebe LP	85	if (manager_our_packet(m, p))
	86	return 0;
	87
5f402ae8	88	scope = manager_find_scope(m, p);
f1b1a5c4 LP	89	if (!scope) {
	90	log_debug("Got LLMNR UDP packet on unknown scope. Ignoring.");
	91	return 0;
	92	}
	93
	94	if (dns_packet_validate_reply(p) > 0) {
b30bf55d	95	log_debug("Got LLMNR UDP reply packet for id %u", DNS_PACKET_ID(p));
5f402ae8 DM	96
	97	dns_scope_check_conflicts(scope, p);
	98
	99	t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
	100	if (t)
	101	dns_transaction_process_reply(t, p);
	102
	103	} else if (dns_packet_validate_query(p) > 0) {
b30bf55d	104	log_debug("Got LLMNR UDP query packet for id %u", DNS_PACKET_ID(p));
5f402ae8 DM	105
	106	dns_scope_process_query(scope, NULL, p);
	107	} else
2c6bf498	108	log_debug("Invalid LLMNR UDP packet, ignoring.");
5f402ae8 DM	109
	110	return 0;
	111	}
	112
	113	int manager_llmnr_ipv4_udp_fd(Manager *m) {
	114	union sockaddr_union sa = {
	115	.in.sin_family = AF_INET,
22a37591	116	.in.sin_port = htobe16(LLMNR_PORT),
5f402ae8	117	};
3f548fff	118	_cleanup_close_ int s = -1;
5f402ae8 DM	119	int r;
	120
	121	assert(m);
	122
	123	if (m->llmnr_ipv4_udp_fd >= 0)
	124	return m->llmnr_ipv4_udp_fd;
	125
3f548fff YW	126	s = socket(AF_INET, SOCK_DGRAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
3f548fff YW	127	if (s < 0)
007ef0a2	128	return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to create socket: %m");
5f402ae8 DM	129
5f402ae8 DM	130	/* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
3f548fff YW	131	r = setsockopt_int(s, IPPROTO_IP, IP_TTL, 255);
	132	if (r < 0)
	133	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_TTL: %m");
5f402ae8	134
3f548fff YW	135	r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_TTL, 255);
	136	if (r < 0)
	137	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_TTL: %m");
5f402ae8	138
3f548fff YW	139	r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_LOOP, true);
	140	if (r < 0)
	141	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_LOOP: %m");
5f402ae8	142
3f548fff YW	143	r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
	144	if (r < 0)
	145	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_PKTINFO: %m");
5f402ae8	146
3f548fff YW	147	r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true);
	148	if (r < 0)
	149	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_RECVTTL: %m");
5f402ae8 DM	150
5f402ae8 DM	151	/* Disable Don't-Fragment bit in the IP header */
3f548fff YW	152	r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
	153	if (r < 0)
	154	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MTU_DISCOVER: %m");
5f402ae8	155
007ef0a2	156	/* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
3f548fff	157	r = bind(s, &sa.sa, sizeof(sa.in));
5f402ae8	158	if (r < 0) {
3f548fff YW	159	if (errno != EADDRINUSE)
3f548fff YW	160	return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m");
007ef0a2 YW	161
	162	log_warning("LLMNR-IPv4(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers.");
	163
	164	/* try again with SO_REUSEADDR */
3f548fff YW	165	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	166	if (r < 0)
	167	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m");
	168
	169	r = bind(s, &sa.sa, sizeof(sa.in));
	170	if (r < 0)
	171	return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m");
007ef0a2 YW	172	} else {
007ef0a2 YW	173	/* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
3f548fff YW	174	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	175	if (r < 0)
	176	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m");
5f402ae8 DM	177	}
5f402ae8 DM	178
3f548fff	179	r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, s, EPOLLIN, on_llmnr_packet, m);
5f402ae8	180	if (r < 0)
3f548fff	181	return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to create event source: %m");
5f402ae8	182
aa4a9deb LP	183	(void) sd_event_source_set_description(m->llmnr_ipv4_udp_event_source, "llmnr-ipv4-udp");
aa4a9deb LP	184
3f548fff	185	return m->llmnr_ipv4_udp_fd = TAKE_FD(s);
5f402ae8 DM	186	}
	187
	188	int manager_llmnr_ipv6_udp_fd(Manager *m) {
	189	union sockaddr_union sa = {
	190	.in6.sin6_family = AF_INET6,
22a37591	191	.in6.sin6_port = htobe16(LLMNR_PORT),
5f402ae8	192	};
3f548fff	193	_cleanup_close_ int s = -1;
5f402ae8 DM	194	int r;
	195
	196	assert(m);
	197
	198	if (m->llmnr_ipv6_udp_fd >= 0)
	199	return m->llmnr_ipv6_udp_fd;
	200
3f548fff YW	201	s = socket(AF_INET6, SOCK_DGRAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
3f548fff YW	202	if (s < 0)
007ef0a2	203	return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to create socket: %m");
5f402ae8	204
3f548fff YW	205	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255);
	206	if (r < 0)
	207	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_UNICAST_HOPS: %m");
5f402ae8 DM	208
5f402ae8 DM	209	/* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
3f548fff YW	210	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
	211	if (r < 0)
	212	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_HOPS: %m");
5f402ae8	213
3f548fff YW	214	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, true);
	215	if (r < 0)
	216	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_LOOP: %m");
5f402ae8	217
3f548fff YW	218	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
	219	if (r < 0)
	220	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_V6ONLY: %m");
5f402ae8	221
3f548fff YW	222	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
	223	if (r < 0)
	224	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVPKTINFO: %m");
5f402ae8	225
3f548fff YW	226	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
	227	if (r < 0)
	228	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVHOPLIMIT: %m");
5f402ae8	229
007ef0a2	230	/* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
3f548fff	231	r = bind(s, &sa.sa, sizeof(sa.in6));
5f402ae8	232	if (r < 0) {
3f548fff YW	233	if (errno != EADDRINUSE)
3f548fff YW	234	return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m");
007ef0a2 YW	235
	236	log_warning("LLMNR-IPv6(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers.");
	237
	238	/* try again with SO_REUSEADDR */
3f548fff YW	239	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	240	if (r < 0)
	241	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m");
	242
	243	r = bind(s, &sa.sa, sizeof(sa.in6));
	244	if (r < 0)
	245	return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m");
007ef0a2 YW	246	} else {
007ef0a2 YW	247	/* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
3f548fff YW	248	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	249	if (r < 0)
	250	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m");
5f402ae8 DM	251	}
5f402ae8 DM	252
3f548fff	253	r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, s, EPOLLIN, on_llmnr_packet, m);
35908b98	254	if (r < 0)
3f548fff	255	return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to create event source: %m");
5f402ae8	256
aa4a9deb LP	257	(void) sd_event_source_set_description(m->llmnr_ipv6_udp_event_source, "llmnr-ipv6-udp");
aa4a9deb LP	258
3f548fff	259	return m->llmnr_ipv6_udp_fd = TAKE_FD(s);
5f402ae8 DM	260	}
	261
	262	static int on_llmnr_stream_packet(DnsStream *s) {
	263	DnsScope *scope;
	264
	265	assert(s);
b30bf55d	266	assert(s->read_packet);
5f402ae8 DM	267
5f402ae8 DM	268	scope = manager_find_scope(s->manager, s->read_packet);
b30bf55d	269	if (!scope)
f1b1a5c4	270	log_debug("Got LLMNR TCP packet on unknown scope. Ignoring.");
b30bf55d LP	271	else if (dns_packet_validate_query(s->read_packet) > 0) {
b30bf55d LP	272	log_debug("Got LLMNR TCP query packet for id %u", DNS_PACKET_ID(s->read_packet));
5f402ae8 DM	273
5f402ae8 DM	274	dns_scope_process_query(scope, s, s->read_packet);
5f402ae8	275	} else
b30bf55d	276	log_debug("Invalid LLMNR TCP packet, ignoring.");
5f402ae8	277
b30bf55d	278	dns_stream_unref(s);
5f402ae8 DM	279	return 0;
	280	}
	281
	282	static int on_llmnr_stream(sd_event_source s, int fd, uint32_t revents, void userdata) {
	283	DnsStream *stream;
	284	Manager *m = userdata;
	285	int cfd, r;
	286
	287	cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK\|SOCK_CLOEXEC);
	288	if (cfd < 0) {
3742095b	289	if (IN_SET(errno, EAGAIN, EINTR))
5f402ae8 DM	290	return 0;
	291
	292	return -errno;
	293	}
	294
91ccab1e	295	r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd, NULL);
5f402ae8 DM	296	if (r < 0) {
	297	safe_close(cfd);
	298	return r;
	299	}
	300
	301	stream->on_packet = on_llmnr_stream_packet;
	302	return 0;
	303	}
	304
	305	int manager_llmnr_ipv4_tcp_fd(Manager *m) {
	306	union sockaddr_union sa = {
	307	.in.sin_family = AF_INET,
22a37591	308	.in.sin_port = htobe16(LLMNR_PORT),
5f402ae8	309	};
3f548fff	310	_cleanup_close_ int s = -1;
5f402ae8 DM	311	int r;
	312
	313	assert(m);
	314
	315	if (m->llmnr_ipv4_tcp_fd >= 0)
	316	return m->llmnr_ipv4_tcp_fd;
	317
3f548fff YW	318	s = socket(AF_INET, SOCK_STREAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
3f548fff YW	319	if (s < 0)
007ef0a2	320	return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to create socket: %m");
5f402ae8 DM	321
5f402ae8 DM	322	/* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */
3f548fff YW	323	r = setsockopt_int(s, IPPROTO_IP, IP_TTL, true);
	324	if (r < 0)
	325	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_TTL: %m");
5f402ae8	326
3f548fff YW	327	r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
	328	if (r < 0)
	329	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_PKTINFO: %m");
5f402ae8	330
3f548fff YW	331	r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true);
	332	if (r < 0)
	333	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_RECVTTL: %m");
5f402ae8 DM	334
5f402ae8 DM	335	/* Disable Don't-Fragment bit in the IP header */
3f548fff YW	336	r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
	337	if (r < 0)
	338	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_MTU_DISCOVER: %m");
5f402ae8	339
007ef0a2	340	/* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
3f548fff	341	r = bind(s, &sa.sa, sizeof(sa.in));
5f402ae8	342	if (r < 0) {
3f548fff YW	343	if (errno != EADDRINUSE)
3f548fff YW	344	return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m");
007ef0a2 YW	345
	346	log_warning("LLMNR-IPv4(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers.");
	347
	348	/* try again with SO_REUSEADDR */
3f548fff YW	349	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	350	if (r < 0)
	351	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m");
	352
	353	r = bind(s, &sa.sa, sizeof(sa.in));
	354	if (r < 0)
	355	return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m");
007ef0a2 YW	356	} else {
007ef0a2 YW	357	/* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
3f548fff YW	358	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	359	if (r < 0)
	360	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m");
5f402ae8 DM	361	}
5f402ae8 DM	362
3f548fff YW	363	r = listen(s, SOMAXCONN);
	364	if (r < 0)
	365	return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to listen the stream: %m");
5f402ae8	366
3f548fff	367	r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m);
5f402ae8	368	if (r < 0)
3f548fff	369	return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to create event source: %m");
5f402ae8	370
aa4a9deb LP	371	(void) sd_event_source_set_description(m->llmnr_ipv4_tcp_event_source, "llmnr-ipv4-tcp");
aa4a9deb LP	372
3f548fff	373	return m->llmnr_ipv4_tcp_fd = TAKE_FD(s);
5f402ae8 DM	374	}
	375
	376	int manager_llmnr_ipv6_tcp_fd(Manager *m) {
	377	union sockaddr_union sa = {
	378	.in6.sin6_family = AF_INET6,
22a37591	379	.in6.sin6_port = htobe16(LLMNR_PORT),
5f402ae8	380	};
3f548fff	381	_cleanup_close_ int s = -1;
5f402ae8 DM	382	int r;
	383
	384	assert(m);
	385
	386	if (m->llmnr_ipv6_tcp_fd >= 0)
	387	return m->llmnr_ipv6_tcp_fd;
	388
3f548fff YW	389	s = socket(AF_INET6, SOCK_STREAM\|SOCK_CLOEXEC\|SOCK_NONBLOCK, 0);
3f548fff YW	390	if (s < 0)
007ef0a2	391	return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to create socket: %m");
5f402ae8 DM	392
5f402ae8 DM	393	/* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */
3f548fff YW	394	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, true);
	395	if (r < 0)
	396	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_UNICAST_HOPS: %m");
5f402ae8	397
3f548fff YW	398	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
	399	if (r < 0)
	400	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_V6ONLY: %m");
5f402ae8	401
3f548fff YW	402	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
	403	if (r < 0)
	404	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVPKTINFO: %m");
5f402ae8	405
3f548fff YW	406	r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
	407	if (r < 0)
	408	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVHOPLIMIT: %m");
5f402ae8	409
007ef0a2	410	/* first try to bind without SO_REUSEADDR to detect another LLMNR responder */
3f548fff	411	r = bind(s, &sa.sa, sizeof(sa.in6));
5f402ae8	412	if (r < 0) {
3f548fff YW	413	if (errno != EADDRINUSE)
3f548fff YW	414	return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m");
007ef0a2 YW	415
	416	log_warning("LLMNR-IPv6(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers.");
	417
	418	/* try again with SO_REUSEADDR */
3f548fff YW	419	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	420	if (r < 0)
	421	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m");
	422
	423	r = bind(s, &sa.sa, sizeof(sa.in6));
	424	if (r < 0)
	425	return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m");
007ef0a2 YW	426	} else {
007ef0a2 YW	427	/* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */
3f548fff YW	428	r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
	429	if (r < 0)
	430	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m");
5f402ae8 DM	431	}
5f402ae8 DM	432
3f548fff YW	433	r = listen(s, SOMAXCONN);
	434	if (r < 0)
	435	return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to listen the stream: %m");
5f402ae8	436
3f548fff	437	r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m);
ee8d9305	438	if (r < 0)
3f548fff	439	return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to create event source: %m");
5f402ae8	440
aa4a9deb LP	441	(void) sd_event_source_set_description(m->llmnr_ipv6_tcp_event_source, "llmnr-ipv6-tcp");
aa4a9deb LP	442
3f548fff	443	return m->llmnr_ipv6_tcp_fd = TAKE_FD(s);
5f402ae8	444	}