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authorVsevolod Stakhov <vsevolod@highsecure.ru>2022-01-04 21:46:40 +0000
committerVsevolod Stakhov <vsevolod@highsecure.ru>2022-01-04 21:46:40 +0000
commit92f6ee1a75207737ace87b19b66ef6492d10c151 (patch)
tree29eececfba769c8942fa55826c58e1018c3aac9a /contrib
parent19d0e55011f75fce39c8bb8c7d733043b8a0babd (diff)
downloadrspamd-92f6ee1a75207737ace87b19b66ef6492d10c151.tar.gz
rspamd-92f6ee1a75207737ace87b19b66ef6492d10c151.zip
[Project] Rdns: Send truncated replies via TCP
Diffstat (limited to 'contrib')
-rw-r--r--contrib/librdns/dns_private.h1
-rw-r--r--contrib/librdns/resolver.c70
2 files changed, 67 insertions, 4 deletions
diff --git a/contrib/librdns/dns_private.h b/contrib/librdns/dns_private.h
index 137b317e8..a5eebfd97 100644
--- a/contrib/librdns/dns_private.h
+++ b/contrib/librdns/dns_private.h
@@ -134,7 +134,6 @@ struct rdns_request {
void *curve_plugin_data;
#endif
- UT_hash_handle hh;
ref_entry_t ref;
};
diff --git a/contrib/librdns/resolver.c b/contrib/librdns/resolver.c
index a576135db..ff1acf789 100644
--- a/contrib/librdns/resolver.c
+++ b/contrib/librdns/resolver.c
@@ -437,6 +437,55 @@ rdns_process_tcp_connect (int fd, struct rdns_io_channel *ioc)
}
}
+static bool
+rdns_reschedule_req_over_tcp (struct rdns_request *req, struct rdns_server *serv)
+{
+ struct rdns_resolver *resolver;
+ struct rdns_io_channel *old_ioc = req->io,
+ *ioc = serv->tcp_io_channels[ottery_rand_uint32 () % serv->tcp_io_cnt];
+
+ resolver = req->resolver;
+
+ if (ioc != NULL) {
+ if (!IS_CHANNEL_CONNECTED(ioc)) {
+ if (!rdns_ioc_tcp_connect(ioc)) {
+ return false;
+ }
+ }
+
+ struct rdns_tcp_output_chain *oc;
+
+ oc = calloc(1, sizeof(*oc));
+
+ if (oc == NULL) {
+ rdns_err("failed to allocate output buffer for TCP ioc: %s",
+ strerror(errno));
+ return false;
+ }
+
+ oc->req = req;
+ oc->next_write_size = req->packet_len;
+
+ DL_APPEND(ioc->tcp->output_chain, oc);
+
+ if (ioc->tcp->async_write == NULL) {
+ ioc->tcp->async_write = resolver->async->add_write (
+ resolver->async->data,
+ ioc->sock, ioc);
+ }
+
+ req->state = RDNS_REQUEST_TCP;
+ /* Switch IO channel from UDP to TCP */
+ req->io = ioc;
+ REF_RETAIN(ioc);
+ REF_RELEASE(old_ioc);
+
+ return true;
+ }
+
+ return false;
+}
+
static void
rdns_process_udp_read (int fd, struct rdns_io_channel *ioc)
{
@@ -475,9 +524,24 @@ rdns_process_udp_read (int fd, struct rdns_io_channel *ioc)
}
rdns_request_unschedule (req);
- req->state = RDNS_REQUEST_REPLIED;
- req->func (rep, req->arg);
- REF_RELEASE (req);
+
+ if (!(rep->flags & RDNS_TRUNCATED)) {
+ req->state = RDNS_REQUEST_REPLIED;
+ req->func(rep, req->arg);
+ REF_RELEASE (req);
+ }
+ else {
+ rdns_debug("truncated UDP reply for %s", req->requested_names[0].name);
+ if (req->io->srv->tcp_io_cnt > 0) {
+ /* Reschedule via TCP */
+ if (!rdns_reschedule_req_over_tcp (req, req->io->srv)) {
+ /* Use truncated reply as we have no other options */
+ req->state = RDNS_REQUEST_REPLIED;
+ req->func(rep, req->arg);
+ REF_RELEASE (req);
+ }
+ }
+ }
}
}
else {