Added better checking to packet sending (MUST receive an ack)

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@530 e03df62e-2008-0410-955e-edbf42e46eb7

2 files changed, 59 insertions, 3 deletions

diff --git a/src/connection.cpp b/src/connection.cpp
index eb0af9833..1296e7d93 100644
--- a/src/connection.cpp
+++ b/src/connection.cpp
@@ -12,6 +12,9 @@ extern std::vector<ircd_module*> factory;
 
 extern int MODCOUNT;
 
+#define STATE_CLEAR 1
+#define STATE_WAIT_FOR_ACK 2
+
 packet::packet()
 {
 	srand(time(NULL));
@@ -26,6 +29,7 @@ connection::connection()
 {
 	key = GenKey();
 	fd = 0;
+	state = STATE_CLEAR;
 }
 
 
@@ -127,7 +131,59 @@ bool connection::SendPacket(char *message, char* host, int port, long ourkey)
 		log(DEBUG,"sendto() failed for Connection::SendPacket() with a packet of size %d",sizeof(p));
 		return false;
 	}
-	return true;
+	this->state = STATE_WAIT_FOR_ACK;
+
+
+	socklen_t host_address_size;
+	// host_address remains unchanged. we only want to receive from where we just sent the packet to.
+	
+	// retry the packet up to 5 times
+	for (int retries = 0; retries < 5; retries++)
+	{
+		host_address.sin_family=AF_INET;
+		host_address_size=sizeof(host_address);
+	
+		// wait for ack, or timeout.
+		// if reached a timeout, send again.
+		// the packet id in the ack must match that in the original packet
+		// this MUST operate in lock/step fashion!!!
+		int cycles = 0;
+		packet p2;
+		while ((recvfrom(fd,&p2,sizeof(p2),0,(sockaddr*)&host_address,&host_address_size)<0) && (cycles < 10))
+		{
+			fd_set sfd;
+			timeval tval;
+			tval.tv_usec = 10;
+			tval.tv_sec = 0;
+			FD_ZERO(&sfd);
+			FD_SET(fd,&sfd);
+			int res = select(65535, &sfd, NULL, NULL, &tval);
+			cycles++;
+		}
+		if (cycles >= 10)
+		{
+			log(DEFAULT,"ERROR! connection::SendPacket() waited >100 nanosecs for an ACK. Will resend up to 5 times");
+		}
+		else
+		{
+			if (p2.id != p.id)
+			{
+				log(DEFAULT,"ERROR! connection::SendPacket() received an ack for a packet it didnt send!");
+				this->state = STATE_CLEAR;
+				return false;
+			}
+			else
+			{
+				log(DEFAULT,"Successfully received ACK");
+				this->state = STATE_CLEAR;
+				return true;
+				break;
+			}
+		}
+	}
+	log(DEFAULT,"We never received an ack. Something fishy going on, host is dead.");
+	this->state = STATE_CLEAR;
+	return false;
 
 }
 
@@ -180,7 +236,6 @@ bool connection::SendACK(char* host, int port, int reply_id)
 	{
 		return false;
 	}
-	return true;
 
 }
 
@@ -248,6 +303,7 @@ bool connection::RecvPacket(char *message, char* host, int &prt, long &theirkey)
 		strcpy(message,p.data);
 		strcpy(host,inet_ntoa(host_address.sin_addr));
 		prt = ntohs(host_address.sin_port);
+		this->state = STATE_CLEAR;
 		return false;
 	}
 
diff --git a/src/inspircd.cpp b/src/inspircd.cpp
index 0d09c22d4..8a8dbc761 100644
--- a/src/inspircd.cpp
+++ b/src/inspircd.cpp
@@ -6893,7 +6893,7 @@ int InspIRCd(void)
 	{
 
 		fd_set sfd;
-		struct timeval tval;
+		timeval tval;
 		FD_ZERO(&sfd);
 
 		user_hash::iterator count2 = clientlist.begin();