FS-8537: Passing nil to various lua functions causes segfault

Various functions exposed via lua do not check their parameters for null
causing freeswitch to segfault.

This change adds checking for null parameters and returns an error
instead of segfaulting.

src/mod/languages/mod_lua/freeswitch_lua.cpp

@@ -88,6 +88,11 @@ void Session::setLUA(lua_State * state)
 
 int Session::originate(CoreSession *a_leg_session, char *dest, int timeout)
 {
+	if (zstr(dest)) {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing destination.\n");
+		return 0;
+	}
+
 	int x = CoreSession::originate(a_leg_session, dest, timeout);
 
 	if (x) {
@@ -356,7 +361,7 @@ Dbh::Dbh(char *dsn, char *user, char *pass)
 		dsn = tmp;
 	}
 
-	if (switch_cache_db_get_db_handle_dsn(&dbh, dsn) == SWITCH_STATUS_SUCCESS) {
+	if (!zstr(dsn) && switch_cache_db_get_db_handle_dsn(&dbh, dsn) == SWITCH_STATUS_SUCCESS) {
 		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "DBH handle %p Connected.\n", (void *) dbh);
 	} else {
 		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Connection failed.  DBH NOT Connected.\n");
@@ -391,8 +396,12 @@ bool Dbh::connected()
 bool Dbh::test_reactive(char *test_sql, char *drop_sql, char *reactive_sql)
 {
   if (dbh) {
-    if (switch_cache_db_test_reactive(dbh, test_sql, drop_sql, reactive_sql) == SWITCH_TRUE) {
-      return true;
+    if (!zstr(test_sql) && !zstr(reactive_sql)) {
+      if (switch_cache_db_test_reactive(dbh, test_sql, drop_sql, reactive_sql) == SWITCH_TRUE) {
+        return true;
+      }
+    } else {
+      switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing parameters.\n");
     }
   } else {
     switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "DBH NOT Connected.\n");
@@ -431,6 +440,11 @@ int Dbh::query_callback(void *pArg, int argc, char **argv, char **cargv)
 
 bool Dbh::query(char *sql, SWIGLUA_FN lua_fun)
 {
+  if (zstr(sql)) {
+    switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing SQL query.\n");
+    return false;
+  }
+
   if (dbh) {
     if (lua_fun.L) {
       if (switch_cache_db_execute_sql_callback(dbh, sql, query_callback, &lua_fun, NULL) == SWITCH_STATUS_SUCCESS) {
@@ -459,6 +473,11 @@ int Dbh::affected_rows()
 
 int Dbh::load_extension(const char *extension)
 {
+  if (zstr(extension)) {
+    switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing extension name.\n");
+    return 0;
+  }
+
   if (dbh) {
     return switch_cache_db_load_extension(dbh, extension);
   }

src/switch_core.c

@@ -392,11 +392,13 @@ SWITCH_DECLARE(char *) switch_core_get_variable_dup(const char *varname)
 {
 	char *val = NULL, *v;
 
-	switch_thread_rwlock_rdlock(runtime.global_var_rwlock);
-	if ((v = (char *) switch_event_get_header(runtime.global_vars, varname))) {
-		val = strdup(v);
+	if (varname) {
+		switch_thread_rwlock_rdlock(runtime.global_var_rwlock);
+		if ((v = (char *) switch_event_get_header(runtime.global_vars, varname))) {
+			val = strdup(v);
+		}
+		switch_thread_rwlock_unlock(runtime.global_var_rwlock);
 	}
-	switch_thread_rwlock_unlock(runtime.global_var_rwlock);
 
 	return val;
 }
@@ -405,11 +407,13 @@ SWITCH_DECLARE(char *) switch_core_get_variable_pdup(const char *varname, switch
 {
 	char *val = NULL, *v;
 
-	switch_thread_rwlock_rdlock(runtime.global_var_rwlock);
-	if ((v = (char *) switch_event_get_header(runtime.global_vars, varname))) {
-		val = switch_core_strdup(pool, v);
+	if (varname) {
+		switch_thread_rwlock_rdlock(runtime.global_var_rwlock);
+		if ((v = (char *) switch_event_get_header(runtime.global_vars, varname))) {
+			val = switch_core_strdup(pool, v);
+		}
+		switch_thread_rwlock_unlock(runtime.global_var_rwlock);
 	}
-	switch_thread_rwlock_unlock(runtime.global_var_rwlock);
 
 	return val;
 }

src/switch_cpp.cpp

@@ -266,17 +266,24 @@ SWITCH_DECLARE(const char *) API::executeString(const char *cmd)
 
 	this_check("");
 
-	mycmd = strdup(cmd);
+	SWITCH_STANDARD_STREAM(stream);
+
+	if (zstr(cmd)) {
+		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "No application specified\n");
+		stream.write_function(&stream, "-ERR No application specified");
+	} else {
+		mycmd = strdup(cmd);
 
-	switch_assert(mycmd);
+		switch_assert(mycmd);
+
+		if ((arg = strchr(mycmd, ' '))) {
+			*arg++ = '\0';
+		}
 
-	if ((arg = strchr(mycmd, ' '))) {
-		*arg++ = '\0';
+		switch_api_execute(mycmd, arg, session, &stream);
+		switch_safe_free(mycmd);
 	}
 
-	SWITCH_STANDARD_STREAM(stream);
-	switch_api_execute(mycmd, arg, session, &stream);
-	switch_safe_free(mycmd);
 	return (char *) stream.data;
 }
 
@@ -425,6 +432,11 @@ SWITCH_DECLARE(const char *)Event::getHeader(const char *header_name)
 {
 	this_check("");
 
+    if (zstr(header_name)) {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Trying to getHeader an invalid header!\n");
+		return NULL;
+    }
+
 	if (event) {
 		return switch_event_get_header(event, header_name);
 	} else {
@@ -450,6 +462,11 @@ SWITCH_DECLARE(bool) Event::delHeader(const char *header_name)
 {
 	this_check(false);
 
+	if (zstr(header_name)) {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Trying to delHeader an invalid header!\n");
+		return false;
+	}
+
 	if (event) {
 		return switch_event_del_header(event, header_name) == SWITCH_STATUS_SUCCESS ? true : false;
 	} else {

src/switch_utils.c

@@ -775,6 +775,11 @@ SWITCH_DECLARE(switch_bool_t) switch_simple_email(const char *to,
 	switch_bool_t rval = SWITCH_FALSE;
 	const char *err = NULL;
 
+	if (zstr(to)) {
+		err = "No to address specified";
+		goto end;
+	}
+
 	if (!zstr(file) && !zstr(convert_cmd) && !zstr(convert_ext)) {
 		if ((ext = strrchr(file, '.'))) {
 			dupfile = strdup(file);