[IPV6]: Load protocol module dynamically.

[ Modified to match inet_create() bug fix by Herbert Xu -DaveM ]

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 14 deletions

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index c63b8ce0e1b5..d9546380fa04 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -92,10 +92,13 @@ static int inet6_create(struct socket *sock, int protocol)
         struct proto *answer_prot;
         unsigned char answer_flags;
         char answer_no_check;
-        int rc;
+        int try_loading_module = 0;
+        int err;
 
         /* Look for the requested type/protocol pair. */
         answer = NULL;
+lookup_protocol:
+        err = -ESOCKTNOSUPPORT;
         rcu_read_lock();
         list_for_each_rcu(p, &inetsw6[sock->type]) {
                 answer = list_entry(p, struct inet_protosw, list);
@@ -113,21 +116,37 @@ static int inet6_create(struct socket *sock, int protocol)
                         if (IPPROTO_IP == answer->protocol)
                                 break;
                 }
+                err = -EPROTONOSUPPORT;
                 answer = NULL;
         }
 
-        rc = -ESOCKTNOSUPPORT;
-        if (!answer)
-                goto out_rcu_unlock;
-        rc = -EPERM;
+        if (!answer) {
+                if (try_loading_module < 2) {
+                        rcu_read_unlock();
+                        /*
+                         * Be more specific, e.g. net-pf-10-proto-132-type-1
+                         * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
+                         */
+                        if (++try_loading_module == 1)
+                                request_module("net-pf-%d-proto-%d-type-%d",
+                                                PF_INET6, protocol, sock->type);
+                        /*
+                         * Fall back to generic, e.g. net-pf-10-proto-132
+                         * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
+                         */
+                        else
+                                request_module("net-pf-%d-proto-%d",
+                                                PF_INET6, protocol);
+                        goto lookup_protocol;
+                } else
+                        goto out_rcu_unlock;
+        }
+
+        err = -EPERM;
         if (answer->capability > 0 && !capable(answer->capability))
                 goto out_rcu_unlock;
-        rc = -EPROTONOSUPPORT;
-        if (!protocol)
-                goto out_rcu_unlock;
 
         sock->ops = answer->ops;
-
         answer_prot = answer->prot;
         answer_no_check = answer->no_check;
         answer_flags = answer->flags;
@@ -135,14 +154,14 @@ static int inet6_create(struct socket *sock, int protocol)
 
         BUG_TRAP(answer_prot->slab != NULL);
 
-        rc = -ENOBUFS;
+        err = -ENOBUFS;
         sk = sk_alloc(PF_INET6, GFP_KERNEL, answer_prot, 1);
         if (sk == NULL)
                 goto out;
 
         sock_init_data(sock, sk);
 
-        rc = 0;
+        err = 0;
         sk->sk_no_check = answer_no_check;
         if (INET_PROTOSW_REUSE & answer_flags)
                 sk->sk_reuse = 1;
@@ -202,14 +221,14 @@ static int inet6_create(struct socket *sock, int protocol)
                 sk->sk_prot->hash(sk);
         }
         if (sk->sk_prot->init) {
-                rc = sk->sk_prot->init(sk);
-                if (rc) {
+                err = sk->sk_prot->init(sk);
+                if (err) {
                         sk_common_release(sk);
                         goto out;
                 }
         }
 out:
-        return rc;
+        return err;
 out_rcu_unlock:
         rcu_read_unlock();
         goto out;