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-rw-r--r--net/netlink/af_netlink.c72
1 files changed, 44 insertions, 28 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 3c56b96b4a4..444ed223ee4 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -102,6 +102,7 @@ struct netlink_table {
struct hlist_head mc_list;
unsigned int nl_nonroot;
struct module *module;
+ int registered;
};
static struct netlink_table *nl_table;
@@ -343,11 +344,32 @@ static struct proto netlink_proto = {
.obj_size = sizeof(struct netlink_sock),
};
-static int netlink_create(struct socket *sock, int protocol)
+static int __netlink_create(struct socket *sock, int protocol)
{
struct sock *sk;
struct netlink_sock *nlk;
- struct module *module;
+
+ sock->ops = &netlink_ops;
+
+ sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
+ if (!sk)
+ return -ENOMEM;
+
+ sock_init_data(sock, sk);
+
+ nlk = nlk_sk(sk);
+ spin_lock_init(&nlk->cb_lock);
+ init_waitqueue_head(&nlk->wait);
+
+ sk->sk_destruct = netlink_sock_destruct;
+ sk->sk_protocol = protocol;
+ return 0;
+}
+
+static int netlink_create(struct socket *sock, int protocol)
+{
+ struct module *module = NULL;
+ int err = 0;
sock->state = SS_UNCONNECTED;
@@ -358,41 +380,33 @@ static int netlink_create(struct socket *sock, int protocol)
return -EPROTONOSUPPORT;
netlink_lock_table();
- if (!nl_table[protocol].hash.entries) {
#ifdef CONFIG_KMOD
- /* We do 'best effort'. If we find a matching module,
- * it is loaded. If not, we don't return an error to
- * allow pure userspace<->userspace communication. -HW
- */
+ if (!nl_table[protocol].registered) {
netlink_unlock_table();
request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
netlink_lock_table();
-#endif
}
- module = nl_table[protocol].module;
- if (!try_module_get(module))
- module = NULL;
+#endif
+ if (nl_table[protocol].registered &&
+ try_module_get(nl_table[protocol].module))
+ module = nl_table[protocol].module;
+ else
+ err = -EPROTONOSUPPORT;
netlink_unlock_table();
- sock->ops = &netlink_ops;
-
- sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
- if (!sk) {
- module_put(module);
- return -ENOMEM;
- }
-
- sock_init_data(sock, sk);
+ if (err)
+ goto out;
- nlk = nlk_sk(sk);
+ if ((err = __netlink_create(sock, protocol) < 0))
+ goto out_module;
- nlk->module = module;
- spin_lock_init(&nlk->cb_lock);
- init_waitqueue_head(&nlk->wait);
- sk->sk_destruct = netlink_sock_destruct;
+ nlk_sk(sock->sk)->module = module;
+out:
+ return err;
- sk->sk_protocol = protocol;
- return 0;
+out_module:
+ module_put(module);
+ goto out;
}
static int netlink_release(struct socket *sock)
@@ -437,6 +451,7 @@ static int netlink_release(struct socket *sock)
if (nlk->flags & NETLINK_KERNEL_SOCKET) {
netlink_table_grab();
nl_table[sk->sk_protocol].module = NULL;
+ nl_table[sk->sk_protocol].registered = 0;
netlink_table_ungrab();
}
@@ -1082,7 +1097,7 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
return NULL;
- if (netlink_create(sock, unit) < 0)
+ if (__netlink_create(sock, unit) < 0)
goto out_sock_release;
sk = sock->sk;
@@ -1098,6 +1113,7 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
netlink_table_grab();
nl_table[unit].module = module;
+ nl_table[unit].registered = 1;
netlink_table_ungrab();
return sk;