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Merge pull request #576 from zonque/resolved-cleanups 

resolved: assorted cleanups
This commit is contained in:
Tom Gundersen 2015-07-13 19:30:30 +02:00
parent f7c735017e 818ef443f0
commit ff89f8b917
9 changed files with 557 additions and 474 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Makefile.am
View File

@ -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 \

42
src/resolve/resolved-dns-packet.c
View File

@ -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;
}

14
src/resolve/resolved-dns-packet.h
View File

@ -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)

9
src/resolve/resolved-dns-scope.c
View File

@ -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)
@ -180,7 +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;
@ -546,7 +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;
@ -760,10 +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))

5
src/resolve/resolved-dns-transaction.c
View File

@ -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;
@ -323,7 +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;
}

473
src/resolve/resolved-llmnr.c Normal file
View File

@ -0,0 +1,473 @@
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Tom Gundersen <teg@jklm.no>
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 <http://www.gnu.org/licenses/>.
***/
#include <resolv.h>
#include <netinet/in.h>
#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(LLMNR_PORT),
};
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(LLMNR_PORT),
};
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(LLMNR_PORT),
};
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(LLMNR_PORT),
};
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;
}

34
src/resolve/resolved-llmnr.h Normal file
View File

@ -0,0 +1,34 @@
/*-*- 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 <http://www.gnu.org/licenses/>.
***/
#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);
int manager_llmnr_ipv6_tcp_fd(Manager *m);
void manager_llmnr_stop(Manager *m);
int manager_llmnr_start(Manager *m);

448
src/resolve/resolved-manager.c
View File

@ -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;

4
src/resolve/resolved-manager.h
View File

@ -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);