resolved: transaction - introduce dns_transaction_emit()

This function emits the UDP packet via the scope, but first it will
determine the current server (and connect to it) and store the
server in the transaction.

This should not change the behavior, but simplifies the code.

1 files changed, 20 insertions, 25 deletions

diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index c4e055dfd8..956c2e9973 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -460,33 +460,33 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use
         return 0;
 }
 
-int transaction_dns_fd(DnsTransaction *t, DnsServer **_server) {
-        DnsServer *server;
+static int dns_transaction_emit(DnsTransaction *t) {
         int r;
 
         assert(t);
-        assert(t->scope);
-        assert(t->scope->manager);
 
-        if (t->dns_fd >= 0)
-                return t->dns_fd;
+        if (t->scope->protocol == DNS_PROTOCOL_DNS && !t->server) {
+                DnsServer *server = NULL;
+                _cleanup_close_ int fd = -1;
 
-        t->dns_fd = dns_scope_udp_dns_socket(t->scope, &server);
-        if (t->dns_fd < 0)
-                return t->dns_fd;
+                fd = dns_scope_udp_dns_socket(t->scope, &server);
+                if (fd < 0)
+                        return fd;
 
-        r = sd_event_add_io(t->scope->manager->event, &t->dns_event_source, t->dns_fd, EPOLLIN, on_dns_packet, t);
-        if (r < 0)
-                goto fail;
+                r = sd_event_add_io(t->scope->manager->event, &t->dns_event_source, fd, EPOLLIN, on_dns_packet, t);
+                if (r < 0)
+                        return r;
 
-        if (_server)
-                *_server = server;
+                t->dns_fd = fd;
+                fd = -1;
+                t->server = dns_server_ref(server);
+        }
 
-        return t->dns_fd;
+        r = dns_scope_emit(t->scope, t->dns_fd, t->sent);
+        if (r < 0)
+                return r;
 
-fail:
-        t->dns_fd = safe_close(t->dns_fd);
-        return r;
+        return 0;
 }
 
 static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) {
@@ -574,7 +574,6 @@ int dns_transaction_go(DnsTransaction *t) {
         }
 
         t->n_attempts++;
-        t->server = dns_server_unref(t->server);
         t->received = dns_packet_unref(t->received);
         t->cached = dns_answer_unref(t->cached);
         t->cached_rcode = 0;
@@ -654,13 +653,9 @@ int dns_transaction_go(DnsTransaction *t) {
                  * always be made via TCP on LLMNR */
                 r = dns_transaction_open_tcp(t);
         } else {
-                DnsServer *server;
-
                 /* Try via UDP, and if that fails due to large size try via TCP */
-                r = dns_scope_emit(t->scope, t, t->sent, &server);
-                if (r >= 0)
-                        t->server = dns_server_ref(server);
-                else if (r == -EMSGSIZE)
+                r = dns_transaction_emit(t);
+                if (r == -EMSGSIZE)
                         r = dns_transaction_open_tcp(t);
         }
         if (r == -ESRCH) {