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resolved-mdns: use TAKE_FD()

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This commit is contained in:
Yu Watanabe
2018-10-19 06:03:19 +09:00
parent 3f548ffff4
commit 73c7676756
1 changed files with 72 additions and 118 deletions
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src/resolve/resolved-mdns.c
+72 -118
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@@ -339,6 +339,7 @@ int manager_mdns_ipv4_fd(Manager *m) {
.in.sin_family = AF_INET,
.in.sin_port = htobe16(MDNS_PORT),
};
_cleanup_close_ int s = -1;
int r;
assert(m);
@@ -346,88 +347,64 @@ int manager_mdns_ipv4_fd(Manager *m) {
if (m->mdns_ipv4_fd >= 0)
return m->mdns_ipv4_fd;
m->mdns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (m->mdns_ipv4_fd < 0)
s = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (s < 0)
return log_error_errno(errno, "mDNS-IPv4: Failed to create socket: %m");
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_TTL, 255);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_TTL: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_TTL, 255);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_TTL: %m");
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_TTL, 255);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_MULTICAST_TTL: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_TTL, 255);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_MULTICAST_TTL: %m");
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_MULTICAST_LOOP, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_MULTICAST_LOOP: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_LOOP, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_MULTICAST_LOOP: %m");
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_PKTINFO: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_PKTINFO: %m");
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_RECVTTL, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_RECVTTL: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_RECVTTL: %m");
/* Disable Don't-Fragment bit in the IP header */
r = setsockopt_int(m->mdns_ipv4_fd, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set IP_MTU_DISCOVER: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set IP_MTU_DISCOVER: %m");
/* See the section 15.1 of RFC6762 */
/* first try to bind without SO_REUSEADDR to detect another mDNS responder */
r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in));
r = bind(s, &sa.sa, sizeof(sa.in));
if (r < 0) {
if (errno != EADDRINUSE) {
r = log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m");
goto fail;
}
if (errno != EADDRINUSE)
return log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m");
log_warning("mDNS-IPv4: There appears to be another mDNS responder running, or previously systemd-resolved crashed with some outstanding transfers.");
/* try again with SO_REUSEADDR */
r = setsockopt_int(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m");
goto fail;
}
r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m");
r = bind(m->mdns_ipv4_fd, &sa.sa, sizeof(sa.in));
if (r < 0) {
r = log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m");
goto fail;
}
r = bind(s, &sa.sa, sizeof(sa.in));
if (r < 0)
return log_error_errno(errno, "mDNS-IPv4: Failed to bind socket: %m");
} else {
/* enable SO_REUSEADDR for the case that the user really wants multiple mDNS responders */
r = setsockopt_int(m->mdns_ipv4_fd, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m");
goto fail;
}
r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv4: Failed to set SO_REUSEADDR: %m");
}
r = sd_event_add_io(m->event, &m->mdns_ipv4_event_source, m->mdns_ipv4_fd, EPOLLIN, on_mdns_packet, m);
r = sd_event_add_io(m->event, &m->mdns_ipv4_event_source, s, EPOLLIN, on_mdns_packet, m);
if (r < 0)
goto fail;
return log_error_errno(r, "mDNS-IPv4: Failed to create event source: %m");
return m->mdns_ipv4_fd;
fail:
m->mdns_ipv4_fd = safe_close(m->mdns_ipv4_fd);
return r;
return m->mdns_ipv4_fd = TAKE_FD(s);
}
int manager_mdns_ipv6_fd(Manager *m) {
@@ -435,6 +412,7 @@ int manager_mdns_ipv6_fd(Manager *m) {
.in6.sin6_family = AF_INET6,
.in6.sin6_port = htobe16(MDNS_PORT),
};
_cleanup_close_ int s = -1;
int r;
assert(m);
@@ -442,86 +420,62 @@ int manager_mdns_ipv6_fd(Manager *m) {
if (m->mdns_ipv6_fd >= 0)
return m->mdns_ipv6_fd;
m->mdns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (m->mdns_ipv6_fd < 0)
s = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (s < 0)
return log_error_errno(errno, "mDNS-IPv6: Failed to create socket: %m");
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_UNICAST_HOPS: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_UNICAST_HOPS: %m");
/* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_MULTICAST_HOPS: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_MULTICAST_HOPS: %m");
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_MULTICAST_LOOP: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_MULTICAST_LOOP: %m");
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_V6ONLY, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_V6ONLY: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_V6ONLY: %m");
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_RECVPKTINFO: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_RECVPKTINFO: %m");
r = setsockopt_int(m->mdns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_RECVHOPLIMIT: %m");
goto fail;
}
r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set IPV6_RECVHOPLIMIT: %m");
/* See the section 15.1 of RFC6762 */
/* first try to bind without SO_REUSEADDR to detect another mDNS responder */
r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6));
r = bind(s, &sa.sa, sizeof(sa.in6));
if (r < 0) {
if (errno != EADDRINUSE) {
r = log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m");
goto fail;
}
if (errno != EADDRINUSE)
return log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m");
log_warning("mDNS-IPv6: There appears to be another mDNS responder running, or previously systemd-resolved crashed with some outstanding transfers.");
/* try again with SO_REUSEADDR */
r = setsockopt_int(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m");
goto fail;
}
r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m");
r = bind(m->mdns_ipv6_fd, &sa.sa, sizeof(sa.in6));
if (r < 0) {
r = log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m");
goto fail;
}
r = bind(s, &sa.sa, sizeof(sa.in6));
if (r < 0)
return log_error_errno(errno, "mDNS-IPv6: Failed to bind socket: %m");
} else {
/* enable SO_REUSEADDR for the case that the user really wants multiple mDNS responders */
r = setsockopt_int(m->mdns_ipv6_fd, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0) {
log_error_errno(r, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m");
goto fail;
}
r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true);
if (r < 0)
return log_error_errno(r, "mDNS-IPv6: Failed to set SO_REUSEADDR: %m");
}
r = sd_event_add_io(m->event, &m->mdns_ipv6_event_source, m->mdns_ipv6_fd, EPOLLIN, on_mdns_packet, m);
r = sd_event_add_io(m->event, &m->mdns_ipv6_event_source, s, EPOLLIN, on_mdns_packet, m);
if (r < 0)
goto fail;
return log_error_errno(r, "mDNS-IPv6: Failed to create event source: %m");
return m->mdns_ipv6_fd;
fail:
m->mdns_ipv6_fd = safe_close(m->mdns_ipv6_fd);
return r;
return m->mdns_ipv6_fd = TAKE_FD(s);
}