---------------------
PatchSet 4767 
Date: 2007/06/21 12:29:39
Author: amosjeffries
Branch: squid3-ipv6
Tag: (none) 
Log:
Fix logic bug which caused DNS failover to always lookup A records.

Members: 
	lib/IPAddress.cc:1.1.2.47->1.1.2.48 
	src/PeerDigest.h:1.1.12.4->1.1.12.5 
	src/dns_internal.cc:1.15.6.24->1.15.6.25 

Index: squid3/lib/IPAddress.cc
===================================================================
RCS file: /cvsroot/squid-sf//squid3/lib/Attic/IPAddress.cc,v
retrieving revision 1.1.2.47
retrieving revision 1.1.2.48
diff -u -r1.1.2.47 -r1.1.2.48
--- squid3/lib/IPAddress.cc	10 Jun 2007 10:53:27 -0000	1.1.2.47
+++ squid3/lib/IPAddress.cc	21 Jun 2007 12:29:39 -0000	1.1.2.48
@@ -1,6 +1,6 @@
 
 /*
- * $Id: IPAddress.cc,v 1.1.2.47 2007/06/10 10:53:27 amosjeffries Exp $
+ * $Id: IPAddress.cc,v 1.1.2.48 2007/06/21 12:29:39 amosjeffries Exp $
  *
  * DEBUG: section 14   IP Storage and Handling
  * AUTHOR: Amos Jeffries
@@ -899,7 +899,10 @@
 #endif
     }
     else {
-        assert(false);
+        debugs(14,0,"WARNING: Corrupt IP Address details found!");
+        fprintf(stderr,"WARNING: Corrupt IP Address details found!");
+        memcpy(buf,"dead:beef::",12);
+//        assert(false);
     }
 
     return buf;
Index: squid3/src/PeerDigest.h
===================================================================
RCS file: /cvsroot/squid-sf//squid3/src/PeerDigest.h,v
retrieving revision 1.1.12.4
retrieving revision 1.1.12.5
diff -u -r1.1.12.4 -r1.1.12.5
--- squid3/src/PeerDigest.h	30 May 2007 05:06:07 -0000	1.1.12.4
+++ squid3/src/PeerDigest.h	21 Jun 2007 12:29:39 -0000	1.1.12.5
@@ -1,6 +1,6 @@
 
 /*
- * $Id: PeerDigest.h,v 1.1.12.4 2007/05/30 05:06:07 amosjeffries Exp $
+ * $Id: PeerDigest.h,v 1.1.12.5 2007/06/21 12:29:39 amosjeffries Exp $
  *
  *
  * SQUID Web Proxy Cache          http://www.squid-cache.org/
@@ -95,7 +95,7 @@
     void *operator new (size_t);
     void operator delete(void *);
 
-    struct _peer *peer;			/* pointer back to peer structure, argh */
+    struct _peer *peer;		/* pointer back to peer structure, argh */
     CacheDigest *cd;		/* actual digest structure */
     String host;		/* copy of peer->host */
     const char *req_result;	/* text status of the last request */
Index: squid3/src/dns_internal.cc
===================================================================
RCS file: /cvsroot/squid-sf//squid3/src/dns_internal.cc,v
retrieving revision 1.15.6.24
retrieving revision 1.15.6.25
diff -u -r1.15.6.24 -r1.15.6.25
--- squid3/src/dns_internal.cc	10 Jun 2007 11:01:24 -0000	1.15.6.24
+++ squid3/src/dns_internal.cc	21 Jun 2007 12:29:39 -0000	1.15.6.25
@@ -1,6 +1,6 @@
 
 /*
- * $Id: dns_internal.cc,v 1.15.6.24 2007/06/10 11:01:24 amosjeffries Exp $
+ * $Id: dns_internal.cc,v 1.15.6.25 2007/06/21 12:29:39 amosjeffries Exp $
  *
  * DEBUG: section 78    DNS lookups; interacts with lib/rfc1035.c
  * AUTHOR: Duane Wessels
@@ -896,7 +896,7 @@
         return;
     }
 
-    debugs(78, 3, "idnsGrokReply: ID 0x" << std::hex << message->id << ", " << std::dec << n << "answers");
+    debugs(78, 3, "idnsGrokReply: ID 0x" << std::hex << message->id << ", " << std::dec << n << " answers");
 
     q = idnsFindQuery(message->id);
 
@@ -993,19 +993,33 @@
             return;
         }
     }
+
 #if USE_IPV6
-    else if(q->need_A) {
-            /* have tried and failed to find AAAA. Now try for A. */
-            debugs(78, 3, "idnsGrokReply: AAAA Query failed. Trying A now instead.");
-            rfc1035MessageDestroy(message);
-            q->start_t = current_time;
-            q->id = idnsQueryID();
-            rfc1035SetQueryID(q->buf, q->id);
-            q->sz = rfc3596BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id, &q->query);
-            q->need_A = false;
-            idnsCacheQuery(q);
-            idnsSendQuery(q);
-            return;
+    if(n <= 0 && q->need_A)
+    {
+        /* ERROR or NO AAA exist. Failover to A records. */
+        if(n == 0)
+            debugs(78, 3, "idnsGrokReply: " << q->name << " has no AAAA records. Looking up A record instead.");
+        else
+            debugs(78, 3, "idnsGrokReply: " << q->name << " AAAA query failed. Trying A now instead.");
+
+        rfc1035MessageDestroy(message);
+
+        /* BUG 1968: Unlink previously linked q->hash */
+        /* previously susceptable to infinite loop testing dead hash entries */
+        if (q->hash.key) {
+            hash_remove_link(idns_lookup_hash, &q->hash);
+            q->hash.key = NULL;
+        }
+
+        q->start_t = current_time;
+        q->id = idnsQueryID();
+        rfc1035SetQueryID(q->buf, q->id);
+        q->sz = rfc3596BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id, &q->query);
+        q->need_A = false;
+        idnsCacheQuery(q);
+        idnsSendQuery(q);
+        return;
     }
 #endif