[CritFix] Fix upstreams name resolution when there is also a port

This fix is intended to address the case when Rspamd queries for a hostname with
a port part when re-resolving upstreams addresses via the upstreams module.

Found by: @slavkoja
Confirmed by: @moisseev

diff --git a/src/libutil/upstream.c b/src/libutil/upstream.c
index 835785acbe64790624887043e907c602bf39f251..37918dd48b4680dec7b1d9a4124df798cfc66300 100644 (file)
--- a/src/libutil/upstream.c
+++ b/src/libutil/upstream.c
@@ -132,6 +132,10 @@ struct upstream_ctx {
         "upstream", upstream->uid, \
         G_STRFUNC, \
         __VA_ARGS__)
+#define msg_err_upstream(...)   rspamd_default_log_function (G_LOG_LEVEL_INFO, \
+        "upstream", upstream->uid, \
+        G_STRFUNC, \
+        __VA_ARGS__)
 
 INIT_LOG_MODULE(upstream)
 
@@ -653,11 +657,33 @@ rspamd_upstream_resolve_addrs (const struct upstream_list *ls,
                if (upstream->name[0] != '/') {
                        upstream->last_resolve = now;
 
+                       /*
+                        * If upstream name has a port, then we definitely need to resolve
+                        * merely host part!
+                        */
+                       char dns_name[253 + 1]; /* 253 == max dns name + \0 */
+                       const char *semicolon_pos = strchr(upstream->name, ':');
+
+                       if (semicolon_pos != NULL) {
+                               if (sizeof (dns_name) > semicolon_pos - upstream->name) {
+                                       rspamd_strlcpy(dns_name, upstream->name, semicolon_pos - upstream->name);
+                               }
+                               else {
+                                       /* XXX: truncated */
+                                       msg_err_upstream ("internal error: upstream name is larger than"
+                                                                         "max DNS name: %s", upstream->name);
+                                       rspamd_strlcpy(dns_name, upstream->name, sizeof(dns_name));
+                               }
+                       }
+                       else {
+                               rspamd_strlcpy(dns_name, upstream->name, sizeof(dns_name));
+                       }
+
                        if (upstream->flags & RSPAMD_UPSTREAM_FLAG_SRV_RESOLVE) {
                                if (rdns_make_request_full (upstream->ctx->res,
                                                rspamd_upstream_dns_srv_cb, upstream,
                                                ls->limits->dns_timeout, ls->limits->dns_retransmits,
-                                               1, upstream->name, RDNS_REQUEST_SRV) != NULL) {
+                                               1, dns_name, RDNS_REQUEST_SRV) != NULL) {
                                        upstream->dns_requests++;
                                        REF_RETAIN (upstream);
                                }
@@ -666,7 +692,7 @@ rspamd_upstream_resolve_addrs (const struct upstream_list *ls,
                                if (rdns_make_request_full (upstream->ctx->res,
                                                rspamd_upstream_dns_cb, upstream,
                                                ls->limits->dns_timeout, ls->limits->dns_retransmits,
-                                               1, upstream->name, RDNS_REQUEST_A) != NULL) {
+                                               1, dns_name, RDNS_REQUEST_A) != NULL) {
                                        upstream->dns_requests++;
                                        REF_RETAIN (upstream);
                                }
@@ -674,7 +700,7 @@ rspamd_upstream_resolve_addrs (const struct upstream_list *ls,
                                if (rdns_make_request_full (upstream->ctx->res,
                                                rspamd_upstream_dns_cb, upstream,
                                                ls->limits->dns_timeout, ls->limits->dns_retransmits,
-                                               1, upstream->name, RDNS_REQUEST_AAAA) != NULL) {
+                                               1, dns_name, RDNS_REQUEST_AAAA) != NULL) {
                                        upstream->dns_requests++;
                                        REF_RETAIN (upstream);
                                }