usrloc: new param to close TCP connections

the new `close_expired_tcp`, if set, forces Kamailio to close the TCP
connections of expired contacts

modules/usrloc/doc/usrloc_admin.xml

@@ -896,6 +896,27 @@ modparam("usrloc", "handle_lost_tcp", 1)
 		</example>
 	</section>
 
+	<section id="usrloc.p.close_expired_tcp">
+		<title><varname>close_expired_tcp</varname> (int)</title>
+		<para>
+            If set to 1, Kamailio will close the TCP connection when a contact
+            has expired, if the corresponding transport is TCP/TLS/WS/WSS.
+        </para>
+		<para>
+		<emphasis>
+			Default value is <quote>0</quote>.
+		</emphasis>
+		</para>
+		<example>
+		<title>Set <varname>close_expired_tcp</varname> parameter</title>
+		<programlisting format="linespecific">
+...
+modparam("usrloc", "close_expired_tcp", 1)
+...
+</programlisting>
+		</example>
+	</section>
+
 	<section id="usrloc.p.expires_type">
 		<title><varname>expires_type</varname> (int)</title>
 		<para>

modules/usrloc/ul_mod.c

@@ -152,6 +152,7 @@ int db_mode         = 0;				/*!< Database sync scheme: 0-no db, 1-write through,
 int use_domain      = 0;				/*!< Whether usrloc should use domain part of aor */
 int desc_time_order = 0;				/*!< By default do not enable timestamp ordering */
 int handle_lost_tcp = 0;				/*!< By default do not remove contacts before expiration time */
+int close_expired_tcp = 0;				/*!< By default do not close TCP connections for expired contacts */
 
 int ul_fetch_rows = 2000;				/*!< number of rows to fetch from result */
 int ul_hash_size = 10;
@@ -207,6 +208,7 @@ static param_export_t params[] = {
 	{"hash_size",           INT_PARAM, &ul_hash_size    },
 	{"nat_bflag",           INT_PARAM, &nat_bflag       },
 	{"handle_lost_tcp",     INT_PARAM, &handle_lost_tcp },
+	{"close_expired_tcp",   INT_PARAM, &close_expired_tcp },
 	{"preload",             PARAM_STRING|USE_FUNC_PARAM, (void*)ul_preload_param},
 	{"db_update_as_insert", INT_PARAM, &ul_db_update_as_insert},
 	{"timer_procs",         INT_PARAM, &ul_timer_procs},

modules/usrloc/ul_mod.h

@@ -81,6 +81,8 @@ extern int ul_db_update_as_insert;
 extern int ul_db_check_update;
 extern int ul_keepalive_timeout;
 extern int handle_lost_tcp;
+extern int close_expired_tcp;
+
 
 /*! nat branch flag */
 extern unsigned int nat_bflag;

modules/usrloc/urecord.c

@@ -34,6 +34,7 @@
 #include "../../ut.h"
 #include "../../hashes.h"
 #include "../../tcp_conn.h"
+#include "../../pass_fd.h"
 #include "ul_mod.h"
 #include "usrloc.h"
 #include "utime.h"
@@ -236,6 +237,31 @@ static inline int is_tcp_alive(ucontact_t *c)
 	return rc;
 }
 
+/*!
+ * \brief Close a TCP connection
+ *
+ * Requests the TCP main process to close the specified TCP connection
+ * \param conid the internal connection ID
+ */
+static inline int close_connection(int conid) {
+	struct tcp_connection *con;
+	long msg[2];
+	int n;
+	if ((con = tcpconn_get(conid, 0, 0, 0, 0))) {
+		msg[0] = (long)con;
+		msg[1] = CONN_EOF;
+
+		n = send_all(unix_tcp_sock, msg, sizeof(msg));
+		tcpconn_put(con);
+		if (unlikely(n <= 0)){
+			LM_ERR("failed to send close request: %s (%d)\n", strerror(errno), errno);
+			return 0;
+		}
+		return 1;
+	}
+	return 0;
+}
+
 /*!
  * \brief Expires timer for NO_DB db_mode
  *
@@ -247,6 +273,7 @@ static inline void nodb_timer(urecord_t* _r)
 {
 	ucontact_t* ptr, *t;
 
+
 	ptr = _r->contacts;
 
 	while(ptr) {
@@ -264,6 +291,10 @@ static inline void nodb_timer(urecord_t* _r)
 				ptr->aor->len, ZSW(ptr->aor->s),
 				ptr->c.len, ZSW(ptr->c.s));
 
+			if (close_expired_tcp && is_valid_tcpconn(ptr)) {
+				close_connection(ptr->tcpconn_id);
+			}
+
 			t = ptr;
 			ptr = ptr->next;
 
@@ -301,6 +332,10 @@ static inline void wt_timer(urecord_t* _r)
 				ptr->aor->len, ZSW(ptr->aor->s),
 				ptr->c.len, ZSW(ptr->c.s));
 
+			if (close_expired_tcp && is_valid_tcpconn(ptr)) {
+				close_connection(ptr->tcpconn_id);
+			}
+
 			t = ptr;
 			ptr = ptr->next;
 
@@ -350,6 +385,10 @@ static inline void wb_timer(urecord_t* _r)
 				ptr->c.len, ZSW(ptr->c.s));
 			update_stat( _r->slot->d->expires, 1);
 
+			if (close_expired_tcp && is_valid_tcpconn(ptr)) {
+				close_connection(ptr->tcpconn_id);
+			}
+
 			t = ptr;
 			ptr = ptr->next;