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Diffstat (limited to 'src/resolve/resolved-dns-transaction.c')
-rw-r--r--src/resolve/resolved-dns-transaction.c115
1 files changed, 74 insertions, 41 deletions
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index e708559137..97aceae381 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -308,6 +308,27 @@ void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) {
dns_transaction_gc(t);
}
+static int dns_transaction_pick_server(DnsTransaction *t) {
+ DnsServer *server;
+
+ assert(t);
+ assert(t->scope->protocol == DNS_PROTOCOL_DNS);
+
+ server = dns_scope_get_dns_server(t->scope);
+ if (!server)
+ return -ESRCH;
+
+ t->current_features = dns_server_possible_features(server);
+
+ if (server == t->server)
+ return 0;
+
+ dns_server_unref(t->server);
+ t->server = dns_server_ref(server);
+
+ return 1;
+}
+
static int on_stream_complete(DnsStream *s, int error) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
DnsTransaction *t;
@@ -344,7 +365,9 @@ static int on_stream_complete(DnsStream *s, int error) {
dns_transaction_process_reply(t, p);
t->block_gc--;
- /* If the response wasn't useful, then complete the transition now */
+ /* If the response wasn't useful, then complete the transition
+ * now. After all, we are the worst feature set now with TCP
+ * sockets, and there's really no point in retrying. */
if (t->state == DNS_TRANSACTION_PENDING)
dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY);
else
@@ -354,24 +377,31 @@ static int on_stream_complete(DnsStream *s, int error) {
}
static int dns_transaction_open_tcp(DnsTransaction *t) {
- DnsServer *server = NULL;
_cleanup_close_ int fd = -1;
int r;
assert(t);
- if (t->stream)
- return 0;
+ dns_transaction_close_connection(t);
switch (t->scope->protocol) {
+
case DNS_PROTOCOL_DNS:
- fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, 53, &server);
+ r = dns_transaction_pick_server(t);
+ if (r < 0)
+ return r;
+
+ r = dns_server_adjust_opt(t->server, t->sent, t->current_features);
+ if (r < 0)
+ return r;
+
+ fd = dns_scope_socket_tcp(t->scope, AF_UNSPEC, NULL, t->server, 53);
break;
case DNS_PROTOCOL_LLMNR:
/* When we already received a reply to this (but it was truncated), send to its sender address */
if (t->received)
- fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, t->received->sender_port, NULL);
+ fd = dns_scope_socket_tcp(t->scope, t->received->family, &t->received->sender, NULL, t->received->sender_port);
else {
union in_addr_union address;
int family = AF_UNSPEC;
@@ -388,7 +418,7 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
if (family != t->scope->family)
return -ESRCH;
- fd = dns_scope_socket_tcp(t->scope, family, &address, LLMNR_PORT, NULL);
+ fd = dns_scope_socket_tcp(t->scope, family, &address, NULL, LLMNR_PORT);
}
break;
@@ -403,7 +433,6 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
r = dns_stream_new(t->scope->manager, &t->stream, t->scope->protocol, fd);
if (r < 0)
return r;
-
fd = -1;
r = dns_stream_write_packet(t->stream, t->sent);
@@ -412,11 +441,6 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
return r;
}
- dns_server_unref(t->server);
- t->server = dns_server_ref(server);
-
- dns_transaction_reset_answer(t);
-
t->stream->complete = on_stream_complete;
t->stream->transaction = t;
@@ -426,21 +450,13 @@ static int dns_transaction_open_tcp(DnsTransaction *t) {
if (t->scope->link)
t->stream->ifindex = t->scope->link->ifindex;
+ dns_transaction_reset_answer(t);
+
t->tried_stream = true;
return 0;
}
-static void dns_transaction_next_dns_server(DnsTransaction *t) {
- assert(t);
-
- t->server = dns_server_unref(t->server);
- t->dns_udp_event_source = sd_event_source_unref(t->dns_udp_event_source);
- t->dns_udp_fd = safe_close(t->dns_udp_fd);
-
- dns_scope_next_dns_server(t->scope);
-}
-
static void dns_transaction_cache_answer(DnsTransaction *t) {
assert(t);
@@ -662,7 +678,7 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) {
}
/* On DNS, couldn't send? Try immediately again, with a new server */
- dns_transaction_next_dns_server(t);
+ dns_scope_next_dns_server(t->scope);
r = dns_transaction_go(t);
if (r < 0) {
@@ -743,29 +759,44 @@ static int dns_transaction_emit_udp(DnsTransaction *t) {
assert(t);
- if (t->scope->protocol == DNS_PROTOCOL_DNS && !t->server) {
- DnsServer *server = NULL;
- _cleanup_close_ int fd = -1;
-
- fd = dns_scope_socket_udp(t->scope, &server);
- if (fd < 0)
- return fd;
+ if (t->scope->protocol == DNS_PROTOCOL_DNS) {
- r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t);
+ r = dns_transaction_pick_server(t);
if (r < 0)
return r;
- t->dns_udp_fd = fd;
- fd = -1;
- t->server = dns_server_ref(server);
- }
+ if (t->current_features < DNS_SERVER_FEATURE_LEVEL_UDP)
+ return -EAGAIN;
+
+ if (r > 0 || t->dns_udp_fd < 0) { /* Server changed, or no connection yet. */
+ int fd;
+
+ dns_transaction_close_connection(t);
- r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->server, t->sent);
+ fd = dns_scope_socket_udp(t->scope, t->server, 53);
+ if (fd < 0)
+ return fd;
+
+ r = sd_event_add_io(t->scope->manager->event, &t->dns_udp_event_source, fd, EPOLLIN, on_dns_packet, t);
+ if (r < 0) {
+ safe_close(fd);
+ return r;
+ }
+
+ t->dns_udp_fd = fd;
+ }
+
+ r = dns_server_adjust_opt(t->server, t->sent, t->current_features);
+ if (r < 0)
+ return r;
+ } else
+ dns_transaction_close_connection(t);
+
+ r = dns_scope_emit_udp(t->scope, t->dns_udp_fd, t->sent);
if (r < 0)
return r;
- if (t->server)
- t->current_features = t->server->possible_features;
+ dns_transaction_reset_answer(t);
return 0;
}
@@ -802,7 +833,7 @@ static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdat
log_debug("Timeout reached on transaction %" PRIu16 ".", t->id);
/* ...and try again with a new server */
- dns_transaction_next_dns_server(t);
+ dns_scope_next_dns_server(t->scope);
r = dns_transaction_go(t);
if (r < 0)
@@ -1084,10 +1115,12 @@ int dns_transaction_go(DnsTransaction *t) {
random_bytes(&jitter, sizeof(jitter));
switch (t->scope->protocol) {
+
case DNS_PROTOCOL_LLMNR:
jitter %= LLMNR_JITTER_INTERVAL_USEC;
accuracy = LLMNR_JITTER_INTERVAL_USEC;
break;
+
case DNS_PROTOCOL_MDNS:
jitter %= MDNS_JITTER_RANGE_USEC;
jitter += MDNS_JITTER_MIN_USEC;
@@ -1152,7 +1185,7 @@ int dns_transaction_go(DnsTransaction *t) {
}
/* Couldn't send? Try immediately again, with a new server */
- dns_transaction_next_dns_server(t);
+ dns_scope_next_dns_server(t->scope);
return dns_transaction_go(t);
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-08-16 15:01:37 +0000