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-rw-r--r--src/resolve/resolved-dns-transaction.c149
1 files changed, 106 insertions, 43 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index acfe987cbe..5d3f6bae27 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -51,9 +51,11 @@ static void dns_transaction_close_connection(DnsTransaction *t) {
if (t->stream) {
/* Let's detach the stream from our transaction, in case something else keeps a reference to it. */
- t->stream->complete = NULL;
- t->stream->on_packet = NULL;
- t->stream->transaction = NULL;
+ LIST_REMOVE(transactions_by_stream, t->stream->transactions, t);
+
+ /* Remove packet in case it's still in the queue */
+ dns_packet_unref(ordered_set_remove(t->stream->write_queue, t->sent));
+
t->stream = dns_stream_unref(t->stream);
}
@@ -448,42 +450,31 @@ static int dns_transaction_maybe_restart(DnsTransaction *t) {
return 1;
}
-static int on_stream_complete(DnsStream *s, int error) {
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- DnsTransaction *t;
-
- assert(s);
- assert(s->transaction);
-
- /* Copy the data we care about out of the stream before we
- * destroy it. */
- t = s->transaction;
- p = dns_packet_ref(s->read_packet);
+static void on_transaction_stream_error(DnsTransaction *t, int error) {
+ assert(t);
dns_transaction_close_connection(t);
if (ERRNO_IS_DISCONNECT(error)) {
- usec_t usec;
-
if (t->scope->protocol == DNS_PROTOCOL_LLMNR) {
/* If the LLMNR/TCP connection failed, the host doesn't support LLMNR, and we cannot answer the
* question on this scope. */
dns_transaction_complete(t, DNS_TRANSACTION_NOT_FOUND);
- return 0;
}
- log_debug_errno(error, "Connection failure for DNS TCP stream: %m");
- assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0);
- dns_server_packet_lost(t->server, IPPROTO_TCP, t->current_feature_level, usec - t->start_usec);
-
dns_transaction_retry(t, true);
- return 0;
}
if (error != 0) {
t->answer_errno = error;
dns_transaction_complete(t, DNS_TRANSACTION_ERRNO);
- return 0;
}
+}
+
+static int dns_transaction_on_stream_packet(DnsTransaction *t, DnsPacket *p) {
+ assert(t);
+ assert(p);
+
+ dns_transaction_close_connection(t);
if (dns_packet_validate_reply(p) <= 0) {
log_debug("Invalid TCP reply packet.");
@@ -508,8 +499,64 @@ static int on_stream_complete(DnsStream *s, int error) {
return 0;
}
-static int dns_transaction_open_tcp(DnsTransaction *t) {
+static int on_stream_complete(DnsStream *s, int error) {
+ DnsTransaction *t, *n;
+ int r = 0;
+
+ /* Do not let new transactions use this stream */
+ if (s->server && s->server->stream == s)
+ s->server->stream = dns_stream_unref(s->server->stream);
+
+ if (ERRNO_IS_DISCONNECT(error) && s->protocol != DNS_PROTOCOL_LLMNR) {
+ usec_t usec;
+
+ log_debug_errno(error, "Connection failure for DNS TCP stream: %m");
+
+ if (s->transactions) {
+ t = s->transactions;
+ assert_se(sd_event_now(t->scope->manager->event, clock_boottime_or_monotonic(), &usec) >= 0);
+ dns_server_packet_lost(t->server, IPPROTO_UDP, t->current_feature_level, usec - t->start_usec);
+ }
+ }
+
+ LIST_FOREACH_SAFE(transactions_by_stream, t, n, s->transactions)
+ if (error != 0)
+ on_transaction_stream_error(t, error);
+ else if (DNS_PACKET_ID(s->read_packet) == t->id)
+ /* As each transaction have a unique id the return code is only set once */
+ r = dns_transaction_on_stream_packet(t, s->read_packet);
+
+ return r;
+}
+
+static int dns_stream_on_packet(DnsStream *s) {
+ _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
+ int r = 0;
+ DnsTransaction *t;
+
+ /* Take ownership of packet to be able to receive new packets */
+ p = TAKE_PTR(s->read_packet);
+ s->n_read = 0;
+
+ t = hashmap_get(s->manager->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
+
+ /* Ignore incorrect transaction id as transaction can have been canceled */
+ if (t)
+ r = dns_transaction_on_stream_packet(t, p);
+ else {
+ if (dns_packet_validate_reply(p) <= 0) {
+ log_debug("Invalid TCP reply packet.");
+ on_stream_complete(s, 0);
+ }
+ return 0;
+ }
+
+ return r;
+}
+
+static int dns_transaction_emit_tcp(DnsTransaction *t) {
_cleanup_close_ int fd = -1;
+ _cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
int r;
assert(t);
@@ -530,7 +577,11 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
if (r < 0)
return r;
- fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53);
+ if (t->server->stream)
+ s = dns_stream_ref(t->server->stream);
+ else
+ fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53);
+
break;
case DNS_PROTOCOL_LLMNR:
@@ -562,28 +613,40 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
return -EAFNOSUPPORT;
}
- if (fd < 0)
- return fd;
+ if (!s) {
+ if (fd < 0)
+ return fd;
- r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd);
- if (r < 0)
- return r;
- fd = -1;
+ r = dns_stream_new(t->scope->manager, &s, t->scope->protocol, fd);
+ if (r < 0)
+ return r;
+
+ fd = -1;
+
+ if (t->server) {
+ dns_stream_unref(t->server->stream);
+ t->server->stream = dns_stream_ref(s);
+ s->server = dns_server_ref(t->server);
+ }
+
+ s->complete = on_stream_complete;
+ s->on_packet = dns_stream_on_packet;
+
+ /* The interface index is difficult to determine if we are
+ * connecting to the local host, hence fill this in right away
+ * instead of determining it from the socket */
+ s->ifindex = dns_scope_ifindex(t->scope);
+ }
+
+ t->stream = TAKE_PTR(s);
+ LIST_PREPEND(transactions_by_stream, t->stream->transactions, t);
r = dns_stream_write_packet(t->stream, t->sent);
if (r < 0) {
- t->stream = dns_stream_unref(t->stream);
+ dns_transaction_close_connection(t);
return r;
}
- t->stream->complete = on_stream_complete;
- t->stream->transaction = t;
-
- /* The interface index is difficult to determine if we are
- * connecting to the local host, hence fill this in right away
- * instead of determining it from the socket */
- t->stream->ifindex = dns_scope_ifindex(t->scope);
-
dns_transaction_reset_answer(t);
t->tried_stream = true;
@@ -971,7 +1034,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
log_debug("Reply truncated, retrying via TCP.");
/* Response was truncated, let's try again with good old TCP */
- r = dns_transaction_open_tcp(t);
+ r = dns_transaction_emit_tcp(t);
if (r == -ESRCH) {
/* No servers found? Damn! */
dns_transaction_complete(t, DNS_TRANSACTION_NO_SERVERS);
@@ -1627,7 +1690,7 @@ int dns_transaction_go(DnsTransaction *t) {
/* RFC 4795, Section 2.4. says reverse lookups shall
* always be made via TCP on LLMNR */
- r = dns_transaction_open_tcp(t);
+ r = dns_transaction_emit_tcp(t);
} else {
/* Try via UDP, and if that fails due to large size or lack of
* support try via TCP */
@@ -1637,7 +1700,7 @@ int dns_transaction_go(DnsTransaction *t) {
else if (r == -EAGAIN)
log_debug("Sending query via TCP since server doesn't support UDP.");
if (IN_SET(r, -EMSGSIZE, -EAGAIN))
- r = dns_transaction_open_tcp(t);
+ r = dns_transaction_emit_tcp(t);
}
if (r == -ESRCH) {
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-19 10:18:28 +0100