tree-wide: use ASSERT_PTR more

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

diff --git a/src/resolve/resolved-dns-stub.c b/src/resolve/resolved-dns-stub.c
index 9e34161eb3283587d2fffb771c13c931c19f4392..8a8a0b19eee53f561388214c9c68c0512edfbf68 100644 (file)
--- a/src/resolve/resolved-dns-stub.c
+++ b/src/resolve/resolved-dns-stub.c
@@ -528,18 +528,26 @@ static int dns_stub_send(
         if (s)
                 r = dns_stream_write_packet(s, reply);
         else {
-                int fd;
+                int fd, ifindex;
 
-                fd = find_socket_fd(m, l, p->family, &p->sender, SOCK_DGRAM);
+                fd = find_socket_fd(m, l, p->family, &p->destination, SOCK_DGRAM);
                 if (fd < 0)
                         return fd;
 
+                if (address_is_proxy(p->family, &p->destination))
+                        /* Force loopback iface if this is the loopback proxy stub
+                         * and ifindex was normalized to 0 by manager_recv(). */
+                        ifindex = p->ifindex ?: LOOPBACK_IFINDEX;
+                else
+                        /* Force loopback iface if this is the main listener stub. */
+                        ifindex = l ? p->ifindex : LOOPBACK_IFINDEX;
+
                 /* Note that it is essential here that we explicitly choose the source IP address for this
                  * packet. This is because otherwise the kernel will choose it automatically based on the
-                 * routing table and will thus pick 127.0.0.1 rather than 127.0.0.53. */
+                 * routing table and will thus pick 127.0.0.1 rather than 127.0.0.53/54. */
                 r = manager_send(m,
                                  fd,
-                                 l || address_is_proxy(p->family, &p->destination) ? p->ifindex : LOOPBACK_IFINDEX, /* force loopback iface if this is the main listener stub */
+                                 ifindex,
                                  p->family, &p->sender, p->sender_port, &p->destination,
                                  reply);
         }
@@ -1030,9 +1038,7 @@ static int on_dns_stub_packet(sd_event_source *s, int fd, uint32_t revents, void
 }
 
 static int on_dns_stub_packet_extra(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
-        DnsStubListenerExtra *l = userdata;
-
-        assert(l);
+        DnsStubListenerExtra *l = ASSERT_PTR(userdata);
 
         return on_dns_stub_packet_internal(s, fd, revents, l->manager, l);
 }
@@ -1083,9 +1089,8 @@ static int on_dns_stub_stream(sd_event_source *s, int fd, uint32_t revents, void
 }
 
 static int on_dns_stub_stream_extra(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
-        DnsStubListenerExtra *l = userdata;
+        DnsStubListenerExtra *l = ASSERT_PTR(userdata);
 
-        assert(l);
         return on_dns_stub_stream_internal(s, fd, revents, l->manager, l);
 }