Tue Jun 23 08:18:24 CDT 2009 Mikhail Zabaluev <mikhail.zabaluev@nokia.com>

* sresolv/sres.c: implemented automatic CNAME resolution
  Ignore-this: 1483f6b65deb976e372921ef7ff1b0a0
  
  Fixes sf.net bug #2531152
  
  Behavioral change: intermediate CNAME results are not retrieved to the client.
  The only cases where CNAME results are retrieved are queries for
  sres_type_cname and sres_qtype_any, meaning no CNAME resolution is performed.



git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13919 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/sofia-sip/.update

@@ -1 +1 @@
-Tue Jun 23 14:45:32 CDT 2009
+Tue Jun 23 14:46:33 CDT 2009

libs/sofia-sip/libsofia-sip-ua/sresolv/sres.c

@@ -311,6 +311,7 @@ struct sres_query_s {
   uint16_t        q_retry_count;
   uint8_t         q_n_servers;
   uint8_t         q_i_server;
+  int8_t          q_aliased;
   int8_t          q_edns;
   uint8_t         q_n_subs;
   sres_query_t   *q_subqueries[1 + SRES_MAX_SEARCH];
@@ -3069,6 +3070,18 @@ sres_resend_dns_query(sres_resolver_t *res, sres_query_t *q, int timeout)
   sres_query_report_error(q, NULL);
 }
 
+static void
+sres_resolve_cname(sres_resolver_t *res,
+                   const sres_query_t *orig_query,
+                   const char *alias)
+{
+  sres_query_t *query;
+  query = sres_query_alloc(res,
+      orig_query->q_callback, orig_query->q_context, orig_query->q_type,
+      alias);
+  query->q_aliased = 1;
+  sres_send_dns_query(res, query);
+}
 
 /** Get a server by socket */
 static
@@ -3456,10 +3469,30 @@ sres_resolver_receive(sres_resolver_t *res, int socket)
     query->q_retry_count++;
   }
   else if (!error && reply) {
-    /* Remove the query from the pending list and notify the listener */
+    /* Remove the query from the pending list */
     sres_remove_query(res, query, 1);
+
+    /* Resolve the CNAME alias, if necessary */
+    if (query->q_type != sres_type_cname && query->q_type != sres_qtype_any &&
+        reply[0] && reply[0]->sr_type == sres_type_cname) {
+      const char *alias = reply[0]->sr_cname[0].cn_cname;
+      sres_record_t **cached = NULL;
+
+      /* Check for the aliased results in the cache */
+      if (sres_cache_get(res->res_cache, query->q_type, alias, &cached)
+          > 0) {
+        reply = cached;
+      } else {
+        /* Resubmit the query with the aliased name, dropping this result */
+        sres_resolve_cname(res, query, alias);
+        reply = NULL;
+      }
+    }
+    if (reply) {
+      /* Notify the listener */
       if (query->q_callback != NULL)
         (query->q_callback)(query->q_context, query, reply);
+    }
     sres_free_query(res, query);
   }
   else {
@@ -3630,15 +3663,17 @@ sres_decode_msg(sres_resolver_t *res,
     return -1;
   }
 
-  if (m->m_ancount > 0 && errorcount == 0 && query->q_type < sres_qtype_tsig) {
+  if (m->m_ancount > 0 && errorcount == 0 && query->q_type < sres_qtype_tsig
-    char b0[8], b1[8];
+      && (query->q_aliased || answers[0]->sr_type != sres_type_cname)) {
+
     for (i = 0; i < m->m_ancount; i++) {
       if (query->q_type == answers[i]->sr_type)
 	break;
     }
 
     if (i == m->m_ancount) {
-      /* The queried request was not found. CNAME? */
+      char b0[8], b1[8];
+      /* The queried request was not found */
       SU_DEBUG_5(("sres_decode_msg: sent query %s, got %s\n",
 		  sres_record_type(query->q_type, b0),
 		  sres_record_type(answers[0]->sr_type, b1)));

libs/sofia-sip/libsofia-sip-ua/sresolv/sres_cache.c

@@ -226,14 +226,6 @@ sres_cache_get0(sres_htable_t *htable,
     struct frame *f, frame = { previous, domain };
     unsigned hash = sres_hash_key(domain = cname->cn_cname);
 
-    if (cached) {
-      if (dcount >= len)
-	return -1;
-      cached[dcount] = (sres_record_t *)cname;
-      cname->cn_record->r_refcount++;
-    }
-    dcount++;
-
     /* Check for cname loops */
     for (f = previous; f; f = f->previous) {
       if (su_casematch(domain, f->domain))

libs/sofia-sip/libsofia-sip-ua/sresolv/test_sresolv.c

@@ -998,22 +998,12 @@ int test_cname(sres_context_t *ctx)
   TEST_1(result = ctx->result);
   TEST_1(sr = result[0]);
   TEST_1(sr->sr_record->r_status == SRES_RECORD_ERR);
-  TEST_1(cn = result[1]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "sip00.example.com.");
 
   sres_free_answers(res, ctx->result), ctx->result = NULL;
 
   TEST_1(result = sres_cached_answers(res, sres_type_naptr, domain));
   TEST_1(sr = result[0]);
   TEST_1(sr->sr_record->r_status == SRES_RECORD_ERR);
-  TEST_1(cn = result[1]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "sip00.example.com.");
 
   sres_free_answers(res, result), ctx->result = NULL;
 
@@ -1031,24 +1021,14 @@ int test_cname(sres_context_t *ctx)
   TEST_RUN(ctx);
 
   TEST_1(result = ctx->result);
-  TEST_1(cn = result[0]->sr_cname);
+  TEST_1(sr = result[0]);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "sip00.example.com.");
-  TEST_1(sr = result[1]);
   TEST(sr->sr_record->r_class, sres_class_in);
   TEST(sr->sr_record->r_type, sres_type_a);
 
   sres_free_answers(res, ctx->result), ctx->result = NULL;
 
   TEST_1(result = sres_cached_answers(res, sres_type_a, domain));
-  TEST_1(cn = result[0]->sr_cname);
+  TEST_1(sr = result[0]);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "sip00.example.com.");
-  TEST_1(sr = result[1]);
   TEST(sr->sr_record->r_class, sres_class_in);
   TEST(sr->sr_record->r_type, sres_type_a);
 
@@ -1062,54 +1042,12 @@ int test_cname(sres_context_t *ctx)
   TEST_1(result = ctx->result);
   TEST_1(sr = result[0]);
   TEST_1(sr->sr_record->r_status == SRES_RECORD_ERR);
-  TEST_1(cn = result[1]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop0.example.com.");
-  TEST_1(cn = result[2]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop1.example.com.");
-  TEST_1(cn = result[3]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop2.example.com.");
-  TEST_1(cn = result[4]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop0.example.com.");
-  TEST_1(result[5] == NULL);
 
   sres_free_answers(res, ctx->result), ctx->result = NULL;
 
   TEST_1(result = sres_cached_answers(res, sres_type_a, domain));
   TEST_1(sr = result[0]);
   TEST_1(sr->sr_record->r_status == SRES_RECORD_ERR);
-  TEST_1(cn = result[1]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop0.example.com.");
-  TEST_1(cn = result[2]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop1.example.com.");
-  TEST_1(cn = result[3]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop2.example.com.");
-  TEST_1(cn = result[4]->sr_cname);
-  TEST(cn->cn_record->r_class, sres_class_in);
-  TEST(cn->cn_record->r_type, sres_type_cname);
-  TEST(cn->cn_record->r_ttl, 60);
-  TEST_S(cn->cn_cname, "cloop0.example.com.");
-  TEST_1(result[5] == NULL);
 
   sres_free_answers(res, result);