dcap client: close tunnel when closing control channel

The dcap client includes the concept of optionally encoding the control 
channel.  This is enabled through loading a DSO plugin.  In addition to 
the encoding and decoding functions, the plugins also have an 
initialise and destroy functions.

The dcap code calls the initialise method but fails to ever call the 
destroy function of the plugin.  Under certain circumstances this can 
lead to a memory leak.

This patch updates the dcap client so it calls the tunnel's destroy 
function (if a tunnel is being used) when the control channel is 
closed.

FOR RELEASE NOTES:

Mention that a memory leak for gsidcap under rare conditions has been 
fixed.

Target: trunk
Require-notes: yes
Require-book: no
Patch: http://rb.dcache.org/r/5043/
Acked-by: Tigran Mkrtchyan
Require-notes: yes
Require-book: no

modules/dcap/src/dcap.c

@@ -420,7 +420,7 @@ serverConnect(struct vsp_node * node)
 						pollDelete(node->fd);
 
 						/* file descriptor can be reused by system */
-						system_close(node->fd);
+						close_control_socket(node->fd, node->tunnel);
 						node->fd = -1;
 						continue;
 					}
@@ -733,7 +733,7 @@ cache_connect(server * srv)
 	setTunnelPair(fd, srv->tunnel);
 
 	if( sayHello(fd, srv->tunnel) < 0 ) {
-		system_close(fd);
+		close_control_socket(fd, srv->tunnel);
 		dc_errno = DEHELLO;
 		return -1;
 	}
@@ -1158,9 +1158,20 @@ ascii_open_conversation(struct vsp_node * node)
 int
 close_data_socket(int dataFd)
 {
-	return system_close(dataFd);
+ 	return system_close(dataFd);
 }
 
+
+int close_control_socket(int ctlFd, ioTunnel *tunnel)
+{
+	if(tunnel != NULL) {
+		tunnel->eDestroy(ctlFd);
+	}
+
+	return system_close(ctlFd);
+}
+
+
 int sendControlMessage(int to, const char *buff, size_t len, ioTunnel *en)
 {
 	int n;
@@ -1856,7 +1867,7 @@ int newControlLine(struct vsp_node *node)
 	pollDelete(node->fd);
 
 	/* file descriptor can be reused by system */
-	system_close(node->fd);
+	close_control_socket(node->fd, node->tunnel);
 
 	if ( initControlLine(node) < 0) {
 		return 0;

modules/dcap/src/dcap_close.c

@@ -191,7 +191,7 @@ dc_close(int fd)
 					deleteMemberByValue(node->fd);
 					unlockMember();
 					pollDelete(node->fd);
-					system_close(node->fd);
+					close_control_socket(node->fd, node->tunnel);
 				}
 			}
 		}

modules/dcap/src/dcap_functions.h

@@ -26,6 +26,7 @@
 
 int cache_open(struct vsp_node *);
 int close_data_socket(int);
+int close_control_socket(int, ioTunnel *);
 int sendControlMessage(int, const char *, size_t, ioTunnel *);
 asciiMessage *getControlMessage(int, struct vsp_node *);
 int data_hello_conversation(struct vsp_node *);

modules/dcap/src/dcap_poll.c

@@ -253,7 +253,7 @@ dcap_poll(int mode, struct vsp_node *node, int what)
 
 							int_pollDelete(node->fd);
 							/* file descriptor can be reused by system */
-							system_close(node->fd);
+							close_control_socket(node->fd, node->tunnel);
 
 							break;
 						case ASCII_CONNECT: