- Phil Blundell added the internal function ares__expand_name_for_response()

that is now used by the ares_parse_*_reply() functions instead of the
  ares_expand_name() simply to easier return ARES_EBADRESP for the cases where
  the name expansion fails as in responses that really isn't expected.

ares/CHANGES

@@ -1,5 +1,13 @@
   Changelog for the c-ares project
 
+* January 11 2008 (Daniel Stenberg)
+- Phil Blundell added the internal function ares__expand_name_for_response()
+  that is now used by the ares_parse_*_reply() functions instead of the
+  ares_expand_name() simply to easier return ARES_EBADRESP for the cases where
+  the name expansion fails as in responses that really isn't expected.
+
+Version 1.6.0 (Dec 9, 2008)
+
 * December 9 2008 (Gisle Vanem)
 
   Fixes for Win32 targets using the Watt-32 tcp/ip stack.

ares/RELEASE-NOTES

@@ -6,10 +6,11 @@ Changed:
 
 Fixed:
 
- o 
+ o ares_parse_*_reply() functions now return ARES_EBADRESP instead of
+   ARES_EBADNAME if the name in the response failed to decode
 
 Thanks go to these friendly people for their efforts and contributions:
 
- 
+ Phil Blundell
 
 Have fun!

ares/ares_expand_name.c

@@ -177,3 +177,14 @@ static int name_length(const unsigned char *encoded, const unsigned char *abuf,
    */
   return (n) ? n - 1 : n;
 }
+
+/* Like ares_expand_name but returns EBADRESP in case of invalid input. */
+int ares__expand_name_for_response(const unsigned char *encoded,
+                                   const unsigned char *abuf, int alen,
+                                   char **s, long *enclen)
+{
+  int status = ares_expand_name(encoded, abuf, alen, s, enclen);
+  if (status == ARES_EBADNAME)
+    status = ARES_EBADRESP;
+  return status;
+}

ares/ares_parse_a_reply.c

@@ -83,7 +83,7 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
 
   /* Expand the name from the question, and skip past the question. */
   aptr = abuf + HFIXEDSZ;
-  status = ares_expand_name(aptr, abuf, alen, &hostname, &len);
+  status = ares__expand_name_for_response(aptr, abuf, alen, &hostname, &len);
   if (status != ARES_SUCCESS)
     return status;
   if (aptr + len + QFIXEDSZ > abuf + alen)
@@ -95,7 +95,8 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
 
   if (host)
     {
-      /* Allocate addresses and aliases; ancount gives an upper bound for both. */
+      /* Allocate addresses and aliases; ancount gives an upper bound for
+         both. */
       addrs = malloc(ancount * sizeof(struct in_addr));
       if (!addrs)
         {
@@ -115,7 +116,7 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
       addrs = NULL;
       aliases = NULL;
     }
-  
+
   naddrs = 0;
   naliases = 0;
 
@@ -123,7 +124,7 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
   for (i = 0; i < (int)ancount; i++)
     {
       /* Decode the RR up to the data field. */
-      status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
+      status = ares__expand_name_for_response(aptr, abuf, alen, &rr_name, &len);
       if (status != ARES_SUCCESS)
         break;
       aptr += len;
@@ -176,7 +177,8 @@ int ares_parse_a_reply(const unsigned char *abuf, int alen,
           naliases++;
 
           /* Decode the RR data and replace the hostname with it. */
-          status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
+          status = ares__expand_name_for_response(aptr, abuf, alen, &rr_data,
+                                                  &len);
           if (status != ARES_SUCCESS)
             break;
           free(hostname);

ares/ares_parse_aaaa_reply.c

@@ -84,7 +84,7 @@ int ares_parse_aaaa_reply(const unsigned char *abuf, int alen,
 
   /* Expand the name from the question, and skip past the question. */
   aptr = abuf + HFIXEDSZ;
-  status = ares_expand_name(aptr, abuf, alen, &hostname, &len);
+  status = ares__expand_name_for_response(aptr, abuf, alen, &hostname, &len);
   if (status != ARES_SUCCESS)
     return status;
   if (aptr + len + QFIXEDSZ > abuf + alen)
@@ -123,7 +123,7 @@ int ares_parse_aaaa_reply(const unsigned char *abuf, int alen,
   for (i = 0; i < (int)ancount; i++)
     {
       /* Decode the RR up to the data field. */
-      status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
+      status = ares__expand_name_for_response(aptr, abuf, alen, &rr_name, &len);
       if (status != ARES_SUCCESS)
         break;
       aptr += len;
@@ -176,7 +176,8 @@ int ares_parse_aaaa_reply(const unsigned char *abuf, int alen,
           naliases++;
 
           /* Decode the RR data and replace the hostname with it. */
-          status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
+          status = ares__expand_name_for_response(aptr, abuf, alen, &rr_data,
+                                                  &len);
           if (status != ARES_SUCCESS)
             break;
           free(hostname);

ares/ares_parse_ns_reply.c

@@ -73,7 +73,7 @@ int ares_parse_ns_reply( const unsigned char* abuf, int alen,
 
   /* Expand the name from the question, and skip past the question. */
   aptr = abuf + HFIXEDSZ;
-  status = ares_expand_name( aptr, abuf, alen, &hostname, &len );
+  status = ares__expand_name_for_response( aptr, abuf, alen, &hostname, &len);
   if ( status != ARES_SUCCESS )
     return status;
   if ( aptr + len + QFIXEDSZ > abuf + alen )
@@ -96,7 +96,7 @@ int ares_parse_ns_reply( const unsigned char* abuf, int alen,
   for ( i = 0; i < ( int ) ancount; i++ )
   {
     /* Decode the RR up to the data field. */
-    status = ares_expand_name( aptr, abuf, alen, &rr_name, &len );
+    status = ares__expand_name_for_response( aptr, abuf, alen, &rr_name, &len );
     if ( status != ARES_SUCCESS )
       break;
     aptr += len;
@@ -113,7 +113,8 @@ int ares_parse_ns_reply( const unsigned char* abuf, int alen,
     if ( rr_class == C_IN && rr_type == T_NS )
     {
       /* Decode the RR data and add it to the nameservers list */
-      status = ares_expand_name( aptr, abuf, alen, &rr_data, &len );
+      status = ares__expand_name_for_response( aptr, abuf, alen, &rr_data,
+                                               &len);
       if ( status != ARES_SUCCESS )
       {
         break;

ares/ares_parse_ptr_reply.c

@@ -73,7 +73,7 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr,
 
   /* Expand the name from the question, and skip past the question. */
   aptr = abuf + HFIXEDSZ;
-  status = ares_expand_name(aptr, abuf, alen, &ptrname, &len);
+  status = ares__expand_name_for_response(aptr, abuf, alen, &ptrname, &len);
   if (status != ARES_SUCCESS)
     return status;
   if (aptr + len + QFIXEDSZ > abuf + alen)
@@ -94,7 +94,7 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr,
   for (i = 0; i < (int)ancount; i++)
     {
       /* Decode the RR up to the data field. */
-      status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
+      status = ares__expand_name_for_response(aptr, abuf, alen, &rr_name, &len);
       if (status != ARES_SUCCESS)
         break;
       aptr += len;
@@ -112,7 +112,8 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr,
           && strcasecmp(rr_name, ptrname) == 0)
         {
           /* Decode the RR data and set hostname to it. */
-          status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
+          status = ares__expand_name_for_response(aptr, abuf, alen, &rr_data,
+                                                  &len);
           if (status != ARES_SUCCESS)
             break;
           if (hostname)
@@ -141,7 +142,8 @@ int ares_parse_ptr_reply(const unsigned char *abuf, int alen, const void *addr,
       if (rr_class == C_IN && rr_type == T_CNAME)
         {
           /* Decode the RR data and replace ptrname with it. */
-          status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
+          status = ares__expand_name_for_response(aptr, abuf, alen, &rr_data,
+                                                  &len);
           if (status != ARES_SUCCESS)
             break;
           free(ptrname);

ares/ares_private.h

@@ -319,6 +319,9 @@ int ares__read_line(FILE *fp, char **buf, int *bufsize);
 void ares__free_query(struct query *query);
 unsigned short ares__generate_new_id(rc4_key* key);
 struct timeval ares__tvnow(void);
+int ares__expand_name_for_response(const unsigned char *encoded,
+                                   const unsigned char *abuf, int alen,
+                                   char **s, long *enclen);
 #if 0 /* Not used */
 long ares__tvdiff(struct timeval t1, struct timeval t2);
 #endif