if (q->request_dns_stream) {
/* Detach the stream from our query, in case something else keeps a reference to it. */
- q->request_dns_stream->complete = NULL;
- q->request_dns_stream->on_packet = NULL;
- q->request_dns_stream->query = NULL;
- dns_stream_unref(q->request_dns_stream);
+ (void) set_remove(q->request_dns_stream->queries, q);
+ q->request_dns_stream = dns_stream_unref(q->request_dns_stream);
}
free(q->request_address_string);
#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
#define DNS_STREAMS_MAX 128
+#define DNS_QUERIES_PER_STREAM 32
+
static void dns_stream_stop(DnsStream *s) {
assert(s);
s->n_written = 0;
f |= EPOLLOUT;
}
- if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size)
+
+ /* Let's read a packet if we haven't queued any yet. Except if we already hit a limit of parallel
+ * queries for this connection. */
+ if ((!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size) &&
+ set_size(s->queries) < DNS_QUERIES_PER_STREAM)
f |= EPOLLIN;
#if ENABLE_DNS_OVER_TLS
return 0;
}
-static void dns_stub_detach_stream(DnsStream *s) {
- assert(s);
-
- s->complete = NULL;
- s->on_packet = NULL;
- s->query = NULL;
-}
-
static int dns_stub_send(Manager *m, DnsStream *s, DnsPacket *p, DnsPacket *reply) {
int r;
assert_not_reached("Impossible state");
}
- /* If there's a packet to write set, let's leave the stream around */
- if (q->request_dns_stream && DNS_STREAM_QUEUED(q->request_dns_stream)) {
-
- /* Detach the stream from our query (make it an orphan), but do not drop the reference to it. The
- * default completion action of the stream will drop the reference. */
-
- dns_stub_detach_stream(q->request_dns_stream);
- q->request_dns_stream = NULL;
- }
-
dns_query_free(q);
}
static int dns_stub_stream_complete(DnsStream *s, int error) {
assert(s);
- log_debug_errno(error, "DNS TCP connection terminated, destroying query: %m");
+ log_debug_errno(error, "DNS TCP connection terminated, destroying queries: %m");
+
+ for (;;) {
+ DnsQuery *q;
+
+ q = set_first(s->queries);
+ if (!q)
+ break;
- assert(s->query);
- dns_query_free(s->query);
+ dns_query_free(q);
+ }
+ /* This drops the implicit ref we keep around since it was allocated, as incoming stub connections
+ * should be kept as long as the client wants to. */
+ dns_stream_unref(s);
return 0;
}
assert(p);
assert(p->protocol == DNS_PROTOCOL_DNS);
- /* Takes ownership of the *s stream object */
-
if (in_addr_is_localhost(p->family, &p->sender) <= 0 ||
in_addr_is_localhost(p->family, &p->destination) <= 0) {
log_error("Got packet on unexpected IP range, refusing.");
q->complete = dns_stub_query_complete;
if (s) {
- s->on_packet = NULL;
- s->complete = dns_stub_stream_complete;
- s->query = q;
+ /* Remember which queries belong to this stream, so that we can cancel them when the stream
+ * is disconnected early */
+
+ r = set_ensure_allocated(&s->queries, &trivial_hash_ops);
+ if (r < 0) {
+ log_oom();
+ goto fail;
+ }
+
+ if (set_put(s->queries, q) < 0) {
+ log_oom();
+ goto fail;
+ }
}
r = dns_query_go(q);
return;
fail:
- if (s && DNS_STREAM_QUEUED(s))
- dns_stub_detach_stream(s);
-
dns_query_free(q);
}
} else
log_debug("Invalid DNS stub TCP packet, ignoring.");
- /* Drop the reference to the stream. Either a query was created and added its own reference to the stream now,
- * or that didn't happen in which case we want to free the stream */
- dns_stream_unref(s);
-
return 0;
}
}
stream->on_packet = on_dns_stub_stream_packet;
+ stream->complete = dns_stub_stream_complete;
- /* We let the reference to the stream dangling here, it will either be dropped by the default "complete" action
- * of the stream, or by our packet callback, or when the manager is shut down. */
+ /* We let the reference to the stream dangle here, it will be dropped later by the complete callback. */
return 0;
}