summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--net/netlink/af_netlink.c100
1 files changed, 35 insertions, 65 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7b7b45a..c41a881 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -73,8 +73,12 @@ struct netlink_sock {
struct netlink_callback *cb;
spinlock_t cb_lock;
void (*data_ready)(struct sock *sk, int bytes);
+ struct module *module;
+ u32 flags;
};
+#define NETLINK_KERNEL_SOCKET 0x1
+
static inline struct netlink_sock *nlk_sk(struct sock *sk)
{
return (struct netlink_sock *)sk;
@@ -97,7 +101,7 @@ struct netlink_table {
struct nl_pid_hash hash;
struct hlist_head mc_list;
unsigned int nl_nonroot;
- struct proto_ops *p_ops;
+ struct module *module;
};
static struct netlink_table *nl_table;
@@ -338,6 +342,7 @@ static int netlink_create(struct socket *sock, int protocol)
{
struct sock *sk;
struct netlink_sock *nlk;
+ struct module *module;
sock->state = SS_UNCONNECTED;
@@ -347,30 +352,36 @@ static int netlink_create(struct socket *sock, int protocol)
if (protocol<0 || protocol >= MAX_LINKS)
return -EPROTONOSUPPORT;
- netlink_table_grab();
+ 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
*/
- netlink_table_ungrab();
+ netlink_unlock_table();
request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
- netlink_table_grab();
+ netlink_lock_table();
#endif
}
- netlink_table_ungrab();
+ module = nl_table[protocol].module;
+ if (!try_module_get(module))
+ module = NULL;
+ netlink_unlock_table();
- sock->ops = nl_table[protocol].p_ops;
+ sock->ops = &netlink_ops;
sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
- if (!sk)
+ if (!sk) {
+ module_put(module);
return -ENOMEM;
+ }
sock_init_data(sock, sk);
nlk = nlk_sk(sk);
+ nlk->module = module;
spin_lock_init(&nlk->cb_lock);
init_waitqueue_head(&nlk->wait);
sk->sk_destruct = netlink_sock_destruct;
@@ -415,22 +426,15 @@ static int netlink_release(struct socket *sock)
notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
}
- /* When this is a kernel socket, we need to remove the owner pointer,
- * since we don't know whether the module will be dying at any given
- * point - HW
- */
- if (!nlk->pid) {
- struct proto_ops *p_tmp;
+ if (nlk->module)
+ module_put(nlk->module);
+ if (nlk->flags & NETLINK_KERNEL_SOCKET) {
netlink_table_grab();
- p_tmp = nl_table[sk->sk_protocol].p_ops;
- if (p_tmp != &netlink_ops) {
- nl_table[sk->sk_protocol].p_ops = &netlink_ops;
- kfree(p_tmp);
- }
+ nl_table[sk->sk_protocol].module = NULL;
netlink_table_ungrab();
}
-
+
sock_put(sk);
return 0;
}
@@ -1060,9 +1064,9 @@ static void netlink_data_ready(struct sock *sk, int len)
struct sock *
netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct module *module)
{
- struct proto_ops *p_ops;
struct socket *sock;
struct sock *sk;
+ struct netlink_sock *nlk;
if (!nl_table)
return NULL;
@@ -1070,64 +1074,32 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
if (unit<0 || unit>=MAX_LINKS)
return NULL;
- /* Do a quick check, to make us not go down to netlink_insert()
- * if protocol already has kernel socket.
- */
- sk = netlink_lookup(unit, 0);
- if (unlikely(sk)) {
- sock_put(sk);
- return NULL;
- }
-
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
return NULL;
- sk = NULL;
- if (module) {
- /* Every registering protocol implemented in a module needs
- * it's own p_ops, since the socket code cannot deal with
- * module refcounting otherwise. -HW
- */
- p_ops = kmalloc(sizeof(*p_ops), GFP_KERNEL);
- if (!p_ops)
- goto out_sock_release;
-
- memcpy(p_ops, &netlink_ops, sizeof(*p_ops));
- p_ops->owner = module;
- } else
- p_ops = &netlink_ops;
-
- netlink_table_grab();
- nl_table[unit].p_ops = p_ops;
- netlink_table_ungrab();
-
- if (netlink_create(sock, unit) < 0) {
- sk = NULL;
- goto out_kfree_p_ops;
- }
+ if (netlink_create(sock, unit) < 0)
+ goto out_sock_release;
sk = sock->sk;
sk->sk_data_ready = netlink_data_ready;
if (input)
nlk_sk(sk)->data_ready = input;
- if (netlink_insert(sk, 0)) {
- sk = NULL;
- goto out_kfree_p_ops;
- }
+ if (netlink_insert(sk, 0))
+ goto out_sock_release;
- return sk;
+ nlk = nlk_sk(sk);
+ nlk->flags |= NETLINK_KERNEL_SOCKET;
-out_kfree_p_ops:
netlink_table_grab();
- if (nl_table[unit].p_ops != &netlink_ops) {
- kfree(nl_table[unit].p_ops);
- nl_table[unit].p_ops = &netlink_ops;
- }
+ nl_table[unit].module = module;
netlink_table_ungrab();
+
+ return sk;
+
out_sock_release:
sock_release(sock);
- return sk;
+ return NULL;
}
void netlink_set_nonroot(int protocol, unsigned int flags)
@@ -1490,8 +1462,6 @@ enomem:
for (i = 0; i < MAX_LINKS; i++) {
struct nl_pid_hash *hash = &nl_table[i].hash;
- nl_table[i].p_ops = &netlink_ops;
-
hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
if (!hash->table) {
while (i-- > 0)
OpenPOWER on IntegriCloud