Do not use the result of the dns cache when the query type of the result is different from the type of the query. #66

2 files changed, 36 insertions, 28 deletions

diff --git a/include/dns.h b/include/dns.h
index 27c3c8848..95abaaf80 100644
--- a/include/dns.h
+++ b/include/dns.h
@@ -44,6 +44,28 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "hashcomp.h"
 
 /**
+ * Query and resource record types
+ */
+enum QueryType
+{
+	/** Uninitialized Query */
+	DNS_QUERY_NONE	= 0,
+	/** 'A' record: an ipv4 address */
+	DNS_QUERY_A	= 1,
+	/** 'CNAME' record: An alias */
+	DNS_QUERY_CNAME	= 5,
+	/** 'PTR' record: a hostname */
+	DNS_QUERY_PTR	= 12,
+	/** 'AAAA' record: an ipv6 address */
+	DNS_QUERY_AAAA	= 28,
+
+	/** Force 'PTR' to use IPV4 scemantics */
+	DNS_QUERY_PTR4	= 0xFFFD,
+	/** Force 'PTR' to use IPV6 scemantics */
+	DNS_QUERY_PTR6	= 0xFFFE
+};
+
+/**
  * Result status, used internally
  */
 class CoreExport DNSResult
@@ -61,6 +83,9 @@ class CoreExport DNSResult
 	/** The original request, a hostname or IP address
 	 */
 	std::string original;
+	/** The type of the request
+	 */
+	QueryType type;
 
 	/** Build a DNS result.
 	 * @param i The request ID
@@ -68,7 +93,7 @@ class CoreExport DNSResult
 	 * @param timetolive The request time-to-live
 	 * @param orig The original request, a hostname or IP
 	 */
-	DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig) : id(i), result(res), ttl(timetolive), original(orig) { }
+	DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig, QueryType qt = DNS_QUERY_NONE) : id(i), result(res), ttl(timetolive), original(orig), type(qt) { }
 };
 
 /**
@@ -84,6 +109,9 @@ class CoreExport CachedQuery
 	/** The cached result data, an IP or hostname
 	 */
 	std::string data;
+	/** The type of result this is
+	 */
+	QueryType type;
 	/** The time when the item is due to expire
 	 */
 	time_t expires;
@@ -92,7 +120,7 @@ class CoreExport CachedQuery
 	 * @param res The result data, an IP or hostname
 	 * @param ttl The time-to-live value of the query result
 	 */
-	CachedQuery(const std::string &res, unsigned int ttl);
+	CachedQuery(const std::string &res, QueryType qt, unsigned int ttl);
 
 	/** Returns the number of seconds remaining before this
 	 * cache item has expired and should be removed.
@@ -118,28 +146,6 @@ enum ResolverError
 };
 
 /**
- * Query and resource record types
- */
-enum QueryType
-{
-	/** Uninitialized Query */
-	DNS_QUERY_NONE	= 0,
-	/** 'A' record: an ipv4 address */
-	DNS_QUERY_A	= 1,
-	/** 'CNAME' record: An alias */
-	DNS_QUERY_CNAME	= 5,
-	/** 'PTR' record: a hostname */
-	DNS_QUERY_PTR	= 12,
-	/** 'AAAA' record: an ipv6 address */
-	DNS_QUERY_AAAA	= 28,
-
-	/** Force 'PTR' to use IPV4 scemantics */
-	DNS_QUERY_PTR4	= 0xFFFD,
-	/** Force 'PTR' to use IPV6 scemantics */
-	DNS_QUERY_PTR6	= 0xFFFE
-};
-
-/**
  * Used internally to force PTR lookups to use a certain protocol scemantics,
  * e.g. x.x.x.x.in-addr.arpa for v4, and *.ip6.arpa for v6.
  */
diff --git a/src/dns.cpp b/src/dns.cpp
index 63bde0ecc..8ad94e9e1 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -160,7 +160,7 @@ class RequestTimeout : public Timer
 	}
 };
 
-CachedQuery::CachedQuery(const std::string &res, unsigned int ttl) : data(res)
+CachedQuery::CachedQuery(const std::string &res, QueryType qt, unsigned int ttl) : data(res), type(qt)
 {
 	expires = ServerInstance->Time() + ttl;
 }
@@ -716,8 +716,9 @@ DNSResult DNS::GetResult()
 
 		/* Build the reply with the id and hostname/ip in it */
 		std::string ro = req->orig;
+		DNSResult result = DNSResult(this_id,resultstr,ttl,ro,req->type);
 		delete req;
-		return DNSResult(this_id,resultstr,ttl,ro);
+		return result;
 	}
 }
 
@@ -945,11 +946,12 @@ Resolver::Resolver(const std::string &source, QueryType qt, bool &cached, Module
 		{
 			ServerInstance->Res->DelCache(source);
 		}
-		else
+		else if (CQ->type == qt)
 		{
 			cached = true;
 			return;
 		}
+		CQ = NULL;
 	}
 
 	switch (querytype)
@@ -1054,7 +1056,7 @@ void DNS::HandleEvent(EventType, int)
 					ServerInstance->stats->statsDnsGood++;
 
 				if (!this->GetCache(res.original.c_str()))
-					this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.ttl)));
+					this->cache->insert(std::make_pair(res.original.c_str(), CachedQuery(res.result, res.type, res.ttl)));
 
 				Classes[res.id]->OnLookupComplete(res.result, res.ttl, false);
 				delete Classes[res.id];