[SCTP] Add support for ip_nonlocal_bind sysctl & IP_FREEBIND socket option

Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index 3f63992..32360bb 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -163,6 +163,7 @@
 
 extern int sysctl_local_port_range[2];
 extern int sysctl_ip_default_ttl;
+extern int sysctl_ip_nonlocal_bind;
 
 #ifdef CONFIG_INET
 /* The function in 2.2 was invalid, producing wrong result for
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index b3cb49c..03942f1 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1181,6 +1181,7 @@
 EXPORT_SYMBOL(inet_stream_ops);
 EXPORT_SYMBOL(inet_unregister_protosw);
 EXPORT_SYMBOL(net_statistics);
+EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
 
 #ifdef INET_REFCNT_DEBUG
 EXPORT_SYMBOL(inet_sock_nr);
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 2e1f9c3..5135e1a 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -378,10 +378,13 @@
 {
 	int ret = inet_addr_type(addr->v4.sin_addr.s_addr);
 
-	/* FIXME: ip_nonlocal_bind sysctl support. */
 
-	if (addr->v4.sin_addr.s_addr != INADDR_ANY && ret != RTN_LOCAL)
+	if (addr->v4.sin_addr.s_addr != INADDR_ANY &&
+	   ret != RTN_LOCAL &&
+	   !sp->inet.freebind &&
+	   !sysctl_ip_nonlocal_bind)
 		return 0;
+
 	return 1;
 }