db_sqlite: new param to open some database in read-only

src/modules/db_sqlite/db_sqlite.c

@@ -29,6 +29,7 @@
 #include "../../lib/srdb1/db_query.h"
 #include "../../lib/srdb1/db.h"
 #include "dbase.h"
+#include "db_sqlite.h"
 
 MODULE_VERSION
 
@@ -52,6 +53,82 @@ static int sqlite_bind_api(db_func_t *dbb)
 	return 0;
 }
 
+static db_param_list_t *db_param_list = NULL;
+
+static void db_param_list_add(db_param_list_t *e) {
+	if (!db_param_list) {
+		db_param_list = e;
+		LM_DBG("adding readonly database [%s]\n", e->database.s);
+		clist_init(db_param_list, next, prev);
+	} else {
+		LM_DBG("adding append constraint [%s]\n", e->database.s);
+		clist_append(db_param_list, e, next, prev);
+	}
+}
+
+static void db_param_list_destroy(db_param_list_t *e) {
+	if (!e)
+		return;
+	if (e->database.s)
+		pkg_free(e->database.s);
+	pkg_free(e);
+	e = NULL;
+}
+
+static db_param_list_t *db_param_list_new(const char *db_filename) {
+	db_param_list_t *e = pkg_malloc(sizeof(db_param_list_t));
+	if (!e)
+		return NULL;
+	memset(e, 0, sizeof(db_param_list_t));
+
+	e->database.len = strlen(db_filename);
+	e->database.s = pkg_malloc(e->database.len+1);
+	if (!e->database.s) goto error;
+	strcpy(e->database.s, db_filename);
+
+	db_param_list_add(e);
+	return e;
+error:
+	db_param_list_destroy(e);
+	return NULL;
+}
+
+db_param_list_t *db_param_list_search(char *db_filename) {
+	db_param_list_t *e;
+	if (!db_param_list) {
+		return NULL;
+	}
+	if (strcmp(db_filename, db_param_list->database.s) == 0) {
+		return db_param_list;
+	}
+	clist_foreach(db_param_list, e, next){
+		if (strcmp(db_filename, e->database.s) == 0) {
+			return e;
+		}
+	}
+	return NULL;
+}
+
+int db_set_readonly(modparam_t type, void *val) {
+	if(val==NULL)
+		return -1;
+	db_param_list_t *e = db_param_list_search((char*)val);
+	if (!e)
+		e = db_param_list_new((char *)val);
+	if (!e) {
+		LM_ERR("can't create a new db_param for [%s]\n", (char*) val);
+		return -1;
+	}
+	e->readonly = 1;
+	db_param_list_search((char *)val);
+	return 1;
+}
+
+static param_export_t params[] = {
+	{"db_set_readonly",  PARAM_STRING|USE_FUNC_PARAM, (void*)db_set_readonly},
+	{0,0,0}
+};
+
 static cmd_export_t cmds[] = {
 	{"db_bind_api", (cmd_function)sqlite_bind_api, 0, 0, 0, 0},
 	{0, 0, 0, 0, 0, 0}
@@ -86,7 +163,7 @@ struct module_exports exports = {
 	"db_sqlite",
 	DEFAULT_DLFLAGS,	/* dlopen flags */
 	cmds,			/* module commands */
-	0,			/* module parameters */
+	params,			/* module parameters */
 	0,			/* exported statistics */
 	0,			/* exported MI functions */
 	0,			/* exported pseudo-variables */

src/modules/db_sqlite/db_sqlite.h

@@ -0,0 +1,37 @@
+/*
+ * $Id$
+ *
+ * SQlite module interface
+ *
+ * Copyright (C) 2017 Julien Chavanton, Flowroute
+ *
+ * This file is part of Kamailio, a free SIP server.
+ *
+ * Kamailio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version
+ *
+ * Kamailio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef DBSQLITE_H
+#define DBSQLITE_H
+
+typedef struct db_param_list {
+	struct db_param_list* next;
+	struct db_param_list* prev;
+	str database;
+	int readonly;
+} db_param_list_t;
+
+db_param_list_t *db_param_list_search(char *db_filename);
+
+#endif

src/modules/db_sqlite/dbase.c

@@ -29,6 +29,7 @@
 #include "../../lib/srdb1/db_res.h"
 #include "../../lib/srdb1/db_query.h"
 #include "dbase.h"
+#include "db_sqlite.h"
 
 static time_t sqlite_to_timet(double rT)
 {
@@ -60,8 +61,17 @@ static struct sqlite_connection * db_sqlite_new_connection(const struct db_id* i
 	con->hdr.ref = 1;
 	con->hdr.id = (struct db_id*) id; /* set here - freed on error */
 
-	rc = sqlite3_open_v2(id->database, &con->conn,
-		SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL);
+	int flags = 0;
+	db_param_list_t *db_param = db_param_list_search(id->database);
+	if (db_param && db_param->readonly) {
+		// The database is opened in read-only mode. If the database does not already exist, an error is returned.
+		flags |= SQLITE_OPEN_READONLY;
+		LM_DBG("[%s] opened with [SQLITE_OPEN_READONLY]\n", id->database);
+	} else {
+		flags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
+		LM_DBG("[%s] opened with [SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE]\n", id->database);
+	}
+	rc = sqlite3_open_v2(id->database, &con->conn, flags, NULL);
 	if (rc != SQLITE_OK) {
 		pkg_free(con);
 		LM_ERR("failed to open sqlite database '%s'\n", id->database);

src/modules/db_sqlite/doc/db_sqlite.xml

@@ -32,6 +32,22 @@
 	    <year>2011</year>
 	    <holder>Timo Teräs</holder>
 	</copyright>
+	<authorgroup>
+	    <editor>
+		<firstname>Julien</firstname>
+		<surname>Chavanton</surname>
+		<affiliation><orgname>flowroute.com</orgname></affiliation>
+		<email>jchavanton@gmail.com</email>
+		<address>
+		<otheraddr>
+		<ulink></ulink>
+		</otheraddr>
+		</address>
+	    </editor>
+	</authorgroup>
+	<copyright>
+	    <year>2017</year>
+	</copyright>
     </bookinfo>
     <toc></toc>
 

src/modules/db_sqlite/doc/db_sqlite_admin.xml

@@ -62,9 +62,31 @@
 	</section>
 
 	<section>
-	<title>Parameters</title>
+		<title>Parameters</title>
 		<para>
-		NONE
+		<section id="db_sqlite.p.db_set_readonly">
+		<title><varname>db_set_readonly</varname> (string)</title>
+
+		This will set the db connection to "SQLITE_OPEN_READONLY", useful if another program is writing to the DB.
+		The value is the full path to the sqlite file used for example in any db_url or sqlops/sqlcon
+
+		This parameter may be set multiple times to set many DB connections to readonly in the same configuration file.
+		</para>
+		<para>
+		<emphasis>
+			By default all the db connection are using "SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE"
+		</emphasis>
+		</para>
+		<example>
+		<title>Set <varname>db_set_readonly</varname> parameter</title>
+		<programlisting format="linespecific">
+...
+modparam("db_sqlite","db_set_readonly","/var/mydb.sqlite")
+modparam("sqlops","sqlcon","lrn=>sqlite:////var/mydb.sqlite") # Example if using the sqlops module
+...
+		</programlisting>
+		</example>
+		</section>
 		</para>
 	</section>