[INET]: Make inet_create try to load protocol modules
Syntax is net-pf-PROTOCOL_FAMILY-PROTOCOL-SOCK_TYPE and if this
fails net-pf-PROTOCOL_FAMILY-PROTOCOL.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 52f5ecc..20f52b5 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -228,12 +228,14 @@
struct proto *answer_prot;
unsigned char answer_flags;
char answer_no_check;
- int err;
+ int try_loading_module = 0;
+ int err = -ESOCKTNOSUPPORT;
sock->state = SS_UNCONNECTED;
/* Look for the requested type/protocol pair. */
answer = NULL;
+lookup_protocol:
rcu_read_lock();
list_for_each_rcu(p, &inetsw[sock->type]) {
answer = list_entry(p, struct inet_protosw, list);
@@ -254,9 +256,28 @@
answer = NULL;
}
- err = -ESOCKTNOSUPPORT;
- if (!answer)
- goto out_rcu_unlock;
+ if (unlikely(answer == NULL)) {
+ if (try_loading_module < 2) {
+ rcu_read_unlock();
+ /*
+ * Be more specific, e.g. net-pf-2-proto-132-type-1
+ * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
+ */
+ if (++try_loading_module == 1)
+ request_module("net-pf-%d-proto-%d-type-%d",
+ PF_INET, protocol, sock->type);
+ /*
+ * Fall back to generic, e.g. net-pf-2-proto-132
+ * (net-pf-PF_INET-proto-IPPROTO_SCTP)
+ */
+ else
+ request_module("net-pf-%d-proto-%d",
+ PF_INET, protocol);
+ goto lookup_protocol;
+ } else
+ goto out_rcu_unlock;
+ }
+
err = -EPERM;
if (answer->capability > 0 && !capable(answer->capability))
goto out_rcu_unlock;