Allow support for multiple dns results per request. This is a significant change and should probably not be backported to stable.

This will allow for a fix to feature request bug #384


git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@7753 e03df62e-2008-0410-955e-edbf42e46eb7

10 files changed, 88 insertions, 55 deletions

diff --git a/include/dns.h b/include/dns.h
index b00c57201..adb9fdab8 100644
--- a/include/dns.h
+++ b/include/dns.h
@@ -286,8 +286,10 @@ class CoreExport Resolver : public Extensible
 	 * result, this is the number of seconds remaining before refresh/expiry.
 	 * @param cached True if the result is a cached result, false if it was requested
 	 * from the DNS server.
+	 * @param resultnum Result number, for records with multiple matching results.
+	 * Normally, you will only want to act on this when the result is 0.
 	 */
-	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached) = 0;
+	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0) = 0;
 	/**
 	 * If an error occurs (such as NXDOMAIN, no domain name found) then this method
 	 * will be called.
@@ -439,8 +441,9 @@ class CoreExport DNS : public EventHandler
 	/**
 	 * Fetch the result string (an ip or host)
 	 * and/or an error message to go with it.
+	 * @param resultnum Result number to fetch
 	 */
-	DNSResult GetResult();
+	DNSResult GetResult(int resultnum);
 
 	/**
 	 * Handle a SocketEngine read event
diff --git a/include/users.h b/include/users.h
index 0443b24d2..a2d89b0a7 100644
--- a/include/users.h
+++ b/include/users.h
@@ -106,8 +106,9 @@ class CoreExport UserResolver : public Resolver
 	 * @param result Result string
 	 * @param ttl Time to live for result
 	 * @param cached True if the result was found in the cache
+	 * @param resultnum Result number, we are only interested in result 0
 	 */
-	void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached);
+	void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0);
 
 	/** Called on failed lookup
 	 * @param e Error code
diff --git a/src/dns.cpp b/src/dns.cpp
index 292ca00ac..a714794bf 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -104,7 +104,7 @@ class DNSRequest
 
 	DNSRequest(InspIRCd* Instance, DNS* dns, int id, const std::string &original);
 	~DNSRequest();
-	DNSInfo ResultIsReady(DNSHeader &h, int length);
+	DNSInfo ResultIsReady(DNSHeader &h, int length, int result_we_want);
 	int SendRequests(const DNSHeader *header, const int length, QueryType qt);
 };
 
@@ -612,7 +612,7 @@ void DNS::MakeIP6Int(char* query, const in6_addr *ip)
 }
 
 /** Return the next id which is ready, and the result attached to it */
-DNSResult DNS::GetResult()
+DNSResult DNS::GetResult(int resultnum)
 {
 	/* Fetch dns query response and decide where it belongs */
 	DNSHeader header;
@@ -702,7 +702,7 @@ DNSResult DNS::GetResult()
 	 * When its finished it will return a DNSInfo which is a pair of
 	 * unsigned char* resource record data, and an error message.
 	 */
-	DNSInfo data = req->ResultIsReady(header, length);
+	DNSInfo data = req->ResultIsReady(header, length, resultnum);
 	std::string resultstr;
 
 	/* Check if we got a result, if we didnt, its an error */
@@ -787,7 +787,7 @@ DNSResult DNS::GetResult()
 }
 
 /** A result is ready, process it */
-DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
+DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length, int result_we_want)
 {
 	int i = 0;
 	int q = 0;
@@ -857,7 +857,9 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
 			return std::make_pair((unsigned char*)NULL,"Incorrectly sized DNS reply");
 
 		/* XXX: We actually initialise 'rr' here including its ttl field */
-		DNS::FillResourceRecord(&rr,&header.payload[i]);
+		if (curanswer == result_we_want)
+			DNS::FillResourceRecord(&rr,&header.payload[i]);
+	
 		i += 10;
 		if (rr.type != this->type)
 		{
@@ -874,7 +876,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
 		break;
 	}
 	if ((unsigned int)curanswer == header.ancount)
-		return std::make_pair((unsigned char*)NULL,"No valid answers");
+		return std::make_pair((unsigned char*)NULL,"No more records");
 
 	if (i + rr.rdlength > (unsigned int)length)
 		return std::make_pair((unsigned char*)NULL,"Resource record larger than stated");
@@ -930,7 +932,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
 			res[rr.rdlength] = 0;
 		break;
 	}
-	return std::make_pair(res,"No error");;
+	return std::make_pair(res,"No error");
 }
 
 /** Close the master socket */
@@ -959,7 +961,7 @@ void DNS::DelCache(const std::string &source)
 void Resolver::TriggerCachedResult()
 {
 	if (CQ)
-		OnLookupComplete(CQ->data, time_left, true);
+		OnLookupComplete(CQ->data, time_left, true, 0);
 }
 
 /** High level abstraction of dns used by application at large */
@@ -1062,47 +1064,60 @@ Module* Resolver::GetCreator()
 void DNS::HandleEvent(EventType et, int errornum)
 {
 	/* Fetch the id and result of the next available packet */
-	DNSResult res = this->GetResult();
-	/* Is there a usable request id? */
-	if (res.id != -1)
+	int resultnum = 0;
+	DNSResult res(0,"",0,"");
+	res.id = 0;
+	ServerInstance->Log(DEBUG,"Handle DNS event");
+	while ((res.id & ERROR_MASK) == 0)
 	{
-		/* Its an error reply */
-		if (res.id & ERROR_MASK)
+		res = this->GetResult(resultnum);
+
+		ServerInstance->Log(DEBUG,"Result %d id %d", resultnum, res.id);
+	
+		/* Is there a usable request id? */
+		if (res.id != -1)
 		{
-			/* Mask off the error bit */
-			res.id -= ERROR_MASK;
-			/* Marshall the error to the correct class */
-			if (Classes[res.id])
+			/* Its an error reply */
+			if (res.id & ERROR_MASK)
 			{
-				if (ServerInstance && ServerInstance->stats)
-					ServerInstance->stats->statsDnsBad++;
-				Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result);
-				delete Classes[res.id];
-				Classes[res.id] = NULL;
+				/* Mask off the error bit */
+				res.id -= ERROR_MASK;
+				/* Marshall the error to the correct class */
+				if (Classes[res.id])
+				{
+					if (ServerInstance && ServerInstance->stats)
+						ServerInstance->stats->statsDnsBad++;
+					Classes[res.id]->OnError(RESOLVER_NXDOMAIN, res.result);
+					delete Classes[res.id];
+					Classes[res.id] = NULL;
+				}
+				break;
 			}
-		}
-		else
-		{
-			/* It is a non-error result, marshall the result to the correct class */
-			if (Classes[res.id])
+			else
 			{
-				if (ServerInstance && ServerInstance->stats)
-					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)));
-
-				Classes[res.id]->OnLookupComplete(res.result, res.ttl, false);
-				delete Classes[res.id];
-				Classes[res.id] = NULL;
+				/* It is a non-error result, marshall the result to the correct class */
+				if (Classes[res.id])
+				{
+					if (ServerInstance && ServerInstance->stats)
+						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)));
+	
+					Classes[res.id]->OnLookupComplete(res.result, res.ttl, false, resultnum);
+					delete Classes[res.id];
+					Classes[res.id] = NULL;
+				}
 			}
+	
+			if (ServerInstance && ServerInstance->stats)
+				ServerInstance->stats->statsDns++;
 		}
 
-		if (ServerInstance && ServerInstance->stats)
-			ServerInstance->stats->statsDns++;
+		resultnum++;
 	}
 }
-
+	
 /** Add a derived Resolver to the working set */
 bool DNS::AddResolverClass(Resolver* r)
 {
diff --git a/src/modules/extra/m_pgsql.cpp b/src/modules/extra/m_pgsql.cpp
index 5d267fc1a..393cbd1d7 100644
--- a/src/modules/extra/m_pgsql.cpp
+++ b/src/modules/extra/m_pgsql.cpp
@@ -107,7 +107,7 @@ class SQLresolver : public Resolver
 	{
 	}
 
-	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached);
+	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0);
 
 	virtual void OnError(ResolverError e, const std::string &errormessage)
 	{
@@ -963,11 +963,14 @@ class ModulePgSQL : public Module
 /* move this here to use AddConn, rather that than having the whole
  * module above SQLConn, since this is buggin me right now :/
  */
-void SQLresolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+void SQLresolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum)
 {
-	host.ip = result;
-	((ModulePgSQL*)mod)->AddConn(host);
-	((ModulePgSQL*)mod)->ClearOldConnections();
+	if (!resultnum)
+	{
+		host.ip = result;
+		((ModulePgSQL*)mod)->AddConn(host);
+		((ModulePgSQL*)mod)->ClearOldConnections();
+	}
 }
 
 void ReconnectTimer::Tick(time_t time)
diff --git a/src/modules/m_cgiirc.cpp b/src/modules/m_cgiirc.cpp
index d82705d81..c99d6b5eb 100644
--- a/src/modules/m_cgiirc.cpp
+++ b/src/modules/m_cgiirc.cpp
@@ -91,8 +91,11 @@ class CGIResolver : public Resolver
 	CGIResolver(Module* me, InspIRCd* ServerInstance, bool NotifyOpers, const std::string &source, bool forward, userrec* u, int userfd, const std::string &type, bool &cached)
 		: Resolver(ServerInstance, source, forward ? DNS_QUERY_A : DNS_QUERY_PTR4, cached, me), typ(type), theirfd(userfd), them(u), notify(NotifyOpers) { }
 
-	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0)
 	{
+		if (resultnum)
+			return;
+
 		/* Check the user still exists */
 		if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
 		{
diff --git a/src/modules/m_dnsbl.cpp b/src/modules/m_dnsbl.cpp
index d07b268f7..aaf4de05c 100644
--- a/src/modules/m_dnsbl.cpp
+++ b/src/modules/m_dnsbl.cpp
@@ -60,7 +60,7 @@ class DNSBLResolver : public Resolver
 		ConfEntry = conf;
 	}
 
-	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+	virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0)
 	{
 		/* Check the user still exists */
 		if ((them) && (them == ServerInstance->SE->GetRef(theirfd)))
diff --git a/src/modules/m_http_client.cpp b/src/modules/m_http_client.cpp
index 35b93b581..7e1b94f11 100644
--- a/src/modules/m_http_client.cpp
+++ b/src/modules/m_http_client.cpp
@@ -56,9 +56,10 @@ class HTTPResolver : public Resolver
 	{
 	}
 	
-	void OnLookupComplete(const string &result, unsigned int ttl, bool cached)
+	void OnLookupComplete(const string &result, unsigned int ttl, bool cached, int resultnum = 0)
 	{
-		socket->Connect(result);
+		if (!resultnum)
+			socket->Connect(result);
 	}
 	
 	void OnError(ResolverError e, const string &errmsg)
diff --git a/src/modules/m_spanningtree/resolvers.cpp b/src/modules/m_spanningtree/resolvers.cpp
index 0d94da99f..ac14833a5 100644
--- a/src/modules/m_spanningtree/resolvers.cpp
+++ b/src/modules/m_spanningtree/resolvers.cpp
@@ -43,8 +43,11 @@ ServernameResolver::ServernameResolver(Module* me, SpanningTreeUtilities* Util,
 	/* Nothing in here, folks */
 }
 
-void ServernameResolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+void ServernameResolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum)
 {
+	if (resultnum)
+		return;
+
 	/* Initiate the connection, now that we have an IP to use.
 	 * Passing a hostname directly to InspSocket causes it to
 	 * just bail and set its FD to -1.
diff --git a/src/modules/m_spanningtree/resolvers.h b/src/modules/m_spanningtree/resolvers.h
index 06fd05bad..53adaa50f 100644
--- a/src/modules/m_spanningtree/resolvers.h
+++ b/src/modules/m_spanningtree/resolvers.h
@@ -45,7 +45,7 @@ class SecurityIPResolver : public Resolver
 	{
 	}
 
-	void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+	void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0)
 	{
 		Utils->ValidIPs.push_back(result);
 	}
@@ -83,7 +83,7 @@ class ServernameResolver : public Resolver
 	Module* mine;
  public:
         ServernameResolver(Module* me, SpanningTreeUtilities* Util, InspIRCd* Instance, const std::string &hostname, Link x, bool &cached, QueryType qt);
-        void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached);
+        void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0);
         void OnError(ResolverError e, const std::string &errormessage);
 };
 
diff --git a/src/users.cpp b/src/users.cpp
index cbf9de0cd..bc8dc51e4 100644
--- a/src/users.cpp
+++ b/src/users.cpp
@@ -164,8 +164,12 @@ UserResolver::UserResolver(InspIRCd* Instance, userrec* user, std::string to_res
 	this->bound_fd = user->GetFd();
 }
 
-void UserResolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached)
+void UserResolver::OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum)
 {
+	/* We are only interested in the first matching result */
+	if (resultnum)
+		return;
+
 	if ((!this->fwd) && (ServerInstance->SE->GetRef(this->bound_fd) == this->bound_user))
 	{
 		this->bound_user->stored_host = result;