socket: introduce mnl_socket_open2()

Define mnl_socket_open2() so that user can pass a set of SOCK_* flags
at socket creation time.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 33 insertions, 9 deletions

diff --git a/src/libmnl.map b/src/libmnl.map
index 3c147a7..e5920e5 100644
--- a/src/libmnl.map
+++ b/src/libmnl.map
@@ -74,5 +74,6 @@ LIBMNL_1.1 {
 } LIBMNL_1.0;
 
 LIBMNL_1.2 {
+  mnl_socket_open2;
   mnl_socket_fdopen;
 } LIBMNL_1.1;
diff --git a/src/socket.c b/src/socket.c
index 86657d4..d63ab87 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -103,14 +103,7 @@ unsigned int mnl_socket_get_portid(const struct mnl_socket *nl)
 }
 EXPORT_SYMBOL(mnl_socket_get_portid);
 
-/**
- * mnl_socket_open - open a netlink socket
- * \param bus the netlink socket bus ID (see NETLINK_* constants)
- *
- * On error, it returns NULL and errno is appropriately set. Otherwise, it
- * returns a valid pointer to the mnl_socket structure.
- */
-struct mnl_socket *mnl_socket_open(int bus)
+static struct mnl_socket *__mnl_socket_open(int bus, int flags)
 {
 	struct mnl_socket *nl;
 
@@ -118,7 +111,7 @@ struct mnl_socket *mnl_socket_open(int bus)
 	if (nl == NULL)
 		return NULL;
 
-	nl->fd = socket(AF_NETLINK, SOCK_RAW, bus);
+	nl->fd = socket(AF_NETLINK, SOCK_RAW | flags, bus);
 	if (nl->fd == -1) {
 		free(nl);
 		return NULL;
@@ -126,9 +119,39 @@ struct mnl_socket *mnl_socket_open(int bus)
 
 	return nl;
 }
+
+/**
+ * mnl_socket_open - open a netlink socket
+ * \param bus the netlink socket bus ID (see NETLINK_* constants)
+ *
+ * On error, it returns NULL and errno is appropriately set. Otherwise, it
+ * returns a valid pointer to the mnl_socket structure.
+ */
+struct mnl_socket *mnl_socket_open(int bus)
+{
+	return __mnl_socket_open(bus, 0);
+}
 EXPORT_SYMBOL(mnl_socket_open);
 
 /**
+ * mnl_socket_open2 - open a netlink socket with appropriate flags
+ * \param bus the netlink socket bus ID (see NETLINK_* constants)
+ * \param flags the netlink socket flags (see SOCK_* constants in socket(2))
+ *
+ * This is similar to mnl_socket_open(), but allows to set flags like
+ * SOCK_CLOEXEC at socket creation time (useful for multi-threaded programs
+ * performing exec calls).
+ *
+ * On error, it returns NULL and errno is appropriately set. Otherwise, it
+ * returns a valid pointer to the mnl_socket structure.
+ */
+struct mnl_socket *mnl_socket_open2(int bus, int flags)
+{
+	return __mnl_socket_open(bus, flags);
+}
+EXPORT_SYMBOL(mnl_socket_open2);
+
+/**
  * mnl_socket_fdopen - associates a mnl_socket object with pre-existing socket.
  * \param fd pre-existing socket descriptor.
  *