db: Fixing problem with incorrect initialization of db connections

The sip-router core is based on the ser core and thus has a slightly
different initialization sequence of the main sr process. Namely we
also call the child_init function of all modules in the main process
with rank PROC_INIT. This is a kind of delayed initialization (called
after all mod_init functions have finished but before the main
process started forking children).

There should be no database connections opened in child_init called
with PROC_INIT parameter. This would result in database connections
opened in the main process and inherited by all children. Such
connections could then be used from multiple processes simultaneously
and that can cause race conditions.

This change checks for the value of the rank parameter in child_init
functions and skips database initialization if the value is PROC_INIT,
PROC_MAIN, or PROC_TCP_MAIN.

The problem was reported by Juha and he deserves the credit for helping to
investigate the issue.

modules/carrierroute/carrierroute.c

@@ -229,6 +229,9 @@ static int mod_init(void) {
 
 
 static int child_init(int rank) {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if(mode == CARRIERROUTE_MODE_DB){
 		return carrierroute_db_open();
 	}

modules/utils/utils.c

@@ -280,6 +280,9 @@ static int mod_init(void)
 /* Child initialization function */
 static int child_init(int rank)
 {	
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
     return pres_db_open();
 }
 

modules_k/acc/acc_mod.c

@@ -527,6 +527,9 @@ static int mod_init( void )
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 #ifdef SQL_ACC
 	if(db_url.s && acc_db_init_child(&db_url)<0) {
 		LM_ERR("could not open database connection");

modules_k/alias_db/alias_db.c

@@ -111,6 +111,9 @@ struct module_exports exports = {
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	db_handle = adbf.init(&db_url);
 	if (!db_handle)
 	{

modules_k/auth_db/authdb_mod.c

@@ -156,6 +156,9 @@ struct module_exports exports = {
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+	
 	auth_db_handle = auth_dbf.init(&db_url);
 	if (auth_db_handle == 0){
 		LM_ERR("unable to connect to the database\n");

modules_k/avpops/avpops.c

@@ -201,7 +201,7 @@ static int avpops_child_init(int rank)
 	if (db_url.s==0)
 		return 0;
 	/* skip main process and TCP manager process */
-	if (rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
 		return 0;
 	/* init DB connection */
 	return avpops_db_init(&db_url, &db_table, db_columns);

modules_k/cpl-c/cpl.c

@@ -398,6 +398,9 @@ error:
 
 static int cpl_child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	return cpl_db_init(&db_url, &db_table);
 }
 

modules_k/group/group_mod.c

@@ -180,6 +180,9 @@ struct module_exports exports = {
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	return group_db_init(&db_url);
 }
 

modules_k/imc/imc.c

@@ -415,6 +415,9 @@ static int mod_init(void)
  */
 static int child_init(int rank)
 {	
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (imc_dbf.init==0)
 	{
 		LM_ERR("database not bound\n");

modules_k/msilo/msilo.c

@@ -441,6 +441,9 @@ static int mod_init(void)
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	LM_DBG("rank #%d / pid <%d>\n", rank, getpid());
 	if (msilo_dbf.init==0)
 	{

modules_k/pdt/pdt.c

@@ -288,6 +288,9 @@ static int child_init(void)
 /* each child get a new connection to the database */
 static int mod_child_init(int r)
 {
+	if (r=PROC_INIT || r==PROC_MAIN || r==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if ( child_init()!=0 )
 		return -1;
 

modules_k/permissions/trusted.c

@@ -226,6 +226,9 @@ error:
  */
 int init_child_trusted(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (!db_url.s) {
 		return 0;
 	}

modules_k/presence/presence.c

@@ -350,6 +350,9 @@ static int mod_init(void)
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	pid = my_pid();
 	
 	if(library_mode)

modules_k/presence_xml/presence_xml.c

@@ -283,6 +283,9 @@ static int child_init(int rank)
 {
 	LM_DBG("[%d]  pid [%d]\n", rank, getpid());
 	
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (pxml_dbf.init==0)
 	{
 		LM_CRIT("database not bound\n");

modules_k/pua/pua.c

@@ -247,6 +247,9 @@ static int mod_init(void)
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (pua_dbf.init==0)
 	{
 		LM_CRIT("database not bound\n");

modules_k/rls/rls.c

@@ -453,6 +453,9 @@ static int mod_init(void)
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	LM_DBG("child [%d]  pid [%d]\n", rank, getpid());
 	if (rls_dbf.init==0)
 	{

modules_k/siptrace/siptrace.c

@@ -321,6 +321,9 @@ static int mod_init(void)
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	db_con = db_funcs.init(&db_url);
 	if (!db_con) {
 		LM_ERR("unable to connect to database. Please check configuration.\n");

modules_k/speeddial/speeddial.c

@@ -113,6 +113,9 @@ struct module_exports exports = {
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	db_handle = db_funcs.init(&db_url);
 	if (!db_handle)
 	{

modules_k/sqlops/sqlops.c

@@ -89,7 +89,7 @@ struct module_exports exports= {
 
 static int child_init(int rank)
 {
-	if (rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
 		return 0;
 	return sql_connect();
 }

modules_k/uri_db/uridb_mod.c

@@ -141,6 +141,9 @@ struct module_exports exports = {
  */
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (db_url.len)
 		return uridb_db_init(&db_url);
 	else

modules_k/userblacklist/userblacklist.c

@@ -567,6 +567,9 @@ static int mod_init(void)
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if (userblacklist_db_open() != 0) return -1;
 	dtrie_root=dtrie_init(10);
 	if (dtrie_root == NULL) {

modules_k/xcap_client/xcap_client.c

@@ -169,6 +169,9 @@ static int mod_init(void)
 
 static int child_init(int rank)
 {
+	if (rank==PROC_INIT || rank==PROC_MAIN || rank==PROC_TCP_MAIN)
+		return 0; /* do nothing for the main process */
+
 	if((xcap_db = xcap_dbf.init(&xcap_db_url))==NULL)
 	{
 		LM_ERR("cannot connect to db\n");