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Diffstat (limited to 'src/grp-resolve/systemd-resolved/resolved-dns-stub.c')
-rw-r--r--src/grp-resolve/systemd-resolved/resolved-dns-stub.c162
1 files changed, 64 insertions, 98 deletions
diff --git a/src/grp-resolve/systemd-resolved/resolved-dns-stub.c b/src/grp-resolve/systemd-resolved/resolved-dns-stub.c
index e7aa7a1c38..ad49862a70 100644
--- a/src/grp-resolve/systemd-resolved/resolved-dns-stub.c
+++ b/src/grp-resolve/systemd-resolved/resolved-dns-stub.c
@@ -26,6 +26,9 @@
* IP and UDP header sizes */
#define ADVERTISE_DATAGRAM_SIZE_MAX (65536U-14U-20U-8U)
+static int manager_dns_stub_udp_fd(Manager *m);
+static int manager_dns_stub_tcp_fd(Manager *m);
+
static int dns_stub_make_reply_packet(
uint16_t id,
int rcode,
@@ -355,66 +358,48 @@ static int on_dns_stub_packet(sd_event_source *s, int fd, uint32_t revents, void
return 0;
}
-int manager_dns_stub_udp_fd(Manager *m) {
+static int manager_dns_stub_udp_fd(Manager *m) {
static const int one = 1;
-
union sockaddr_union sa = {
.in.sin_family = AF_INET,
.in.sin_port = htobe16(53),
.in.sin_addr.s_addr = htobe32(INADDR_DNS_STUB),
};
-
+ _cleanup_close_ int fd = -1;
int r;
if (m->dns_stub_udp_fd >= 0)
return m->dns_stub_udp_fd;
- m->dns_stub_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
- if (m->dns_stub_udp_fd < 0)
+ fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (fd < 0)
return -errno;
- r = setsockopt(m->dns_stub_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one) < 0)
+ return -errno;
- r = setsockopt(m->dns_stub_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof one) < 0)
+ return -errno;
- r = setsockopt(m->dns_stub_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof one) < 0)
+ return -errno;
/* Make sure no traffic from outside the local host can leak to onto this socket */
- r = setsockopt(m->dns_stub_udp_fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3);
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0)
+ return -errno;
- r = bind(m->dns_stub_udp_fd, &sa.sa, sizeof(sa.in));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (bind(fd, &sa.sa, sizeof(sa.in)) < 0)
+ return -errno;
- r = sd_event_add_io(m->event, &m->dns_stub_udp_event_source, m->dns_stub_udp_fd, EPOLLIN, on_dns_stub_packet, m);
+ r = sd_event_add_io(m->event, &m->dns_stub_udp_event_source, fd, EPOLLIN, on_dns_stub_packet, m);
if (r < 0)
- goto fail;
+ return r;
(void) sd_event_source_set_description(m->dns_stub_udp_event_source, "dns-stub-udp");
+ m->dns_stub_udp_fd = fd;
+ fd = -1;
return m->dns_stub_udp_fd;
-
-fail:
- m->dns_stub_udp_fd = safe_close(m->dns_stub_udp_fd);
- return r;
}
static int on_dns_stub_stream_packet(DnsStream *s) {
@@ -462,102 +447,83 @@ static int on_dns_stub_stream(sd_event_source *s, int fd, uint32_t revents, void
return 0;
}
-int manager_dns_stub_tcp_fd(Manager *m) {
+static int manager_dns_stub_tcp_fd(Manager *m) {
static const int one = 1;
-
union sockaddr_union sa = {
.in.sin_family = AF_INET,
.in.sin_addr.s_addr = htobe32(INADDR_DNS_STUB),
.in.sin_port = htobe16(53),
};
-
+ _cleanup_close_ int fd = -1;
int r;
if (m->dns_stub_tcp_fd >= 0)
return m->dns_stub_tcp_fd;
- m->dns_stub_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
- if (m->dns_stub_tcp_fd < 0)
+ fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (fd < 0)
return -errno;
- r = setsockopt(m->dns_stub_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof one) < 0)
+ return -errno;
- r = setsockopt(m->dns_stub_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one) < 0)
+ return -errno;
- r = setsockopt(m->dns_stub_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof one) < 0)
+ return -errno;
- r = setsockopt(m->dns_stub_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof one) < 0)
+ return -errno;
/* Make sure no traffic from outside the local host can leak to onto this socket */
- r = setsockopt(m->dns_stub_tcp_fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3);
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0)
+ return -errno;
- r = bind(m->dns_stub_tcp_fd, &sa.sa, sizeof(sa.in));
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (bind(fd, &sa.sa, sizeof(sa.in)) < 0)
+ return -errno;
- r = listen(m->dns_stub_tcp_fd, SOMAXCONN);
- if (r < 0) {
- r = -errno;
- goto fail;
- }
+ if (listen(fd, SOMAXCONN) < 0)
+ return -errno;
- r = sd_event_add_io(m->event, &m->dns_stub_tcp_event_source, m->dns_stub_tcp_fd, EPOLLIN, on_dns_stub_stream, m);
+ r = sd_event_add_io(m->event, &m->dns_stub_tcp_event_source, fd, EPOLLIN, on_dns_stub_stream, m);
if (r < 0)
- goto fail;
+ return r;
(void) sd_event_source_set_description(m->dns_stub_tcp_event_source, "dns-stub-tcp");
+ m->dns_stub_tcp_fd = fd;
+ fd = -1;
return m->dns_stub_tcp_fd;
-
-fail:
- m->dns_stub_tcp_fd = safe_close(m->dns_stub_tcp_fd);
- return r;
}
int manager_dns_stub_start(Manager *m) {
- int r;
+ const char *t = "UDP";
+ int r = 0;
assert(m);
- r = manager_dns_stub_udp_fd(m);
- if (r == -EADDRINUSE)
- goto eaddrinuse;
- if (r < 0)
- return r;
-
- r = manager_dns_stub_tcp_fd(m);
- if (r == -EADDRINUSE)
- goto eaddrinuse;
- if (r < 0)
- return r;
+ if (IN_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_YES, DNS_STUB_LISTENER_UDP))
+ r = manager_dns_stub_udp_fd(m);
- return 0;
+ if (r >= 0 &&
+ IN_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_YES, DNS_STUB_LISTENER_TCP)) {
+ t = "TCP";
+ r = manager_dns_stub_tcp_fd(m);
+ }
-eaddrinuse:
- log_warning("Another process is already listening on 127.0.0.53:53. Turning off local DNS stub support.");
- manager_dns_stub_stop(m);
+ if (IN_SET(r, -EADDRINUSE, -EPERM)) {
+ if (r == -EADDRINUSE)
+ log_warning_errno(r,
+ "Another process is already listening on %s socket 127.0.0.53:53.\n"
+ "Turning off local DNS stub support.", t);
+ else
+ log_warning_errno(r,
+ "Failed to listen on %s socket 127.0.0.53:53: %m.\n"
+ "Turning off local DNS stub support.", t);
+ manager_dns_stub_stop(m);
+ } else if (r < 0)
+ return log_error_errno(r, "Failed to listen on %s socket 127.0.0.53:53: %m", t);
return 0;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-22 19:51:44 +0000