ipv4: process socket-level control messages in IPv4

Process socket-level control messages by invoking
__sock_cmsg_send in ip_cmsg_send for control messages on
the SOL_SOCKET layer.

This makes sure whenever ip_cmsg_send is called in udp, icmp,
and raw, we also process socket-level control messages.

Note that this commit interprets new control messages that
were ignored before. As such, this commit does not change
the behavior of IPv4 control messages.

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index fad74d3..93725e5 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -56,6 +56,7 @@
 }
 
 struct ipcm_cookie {
+	struct sockcm_cookie	sockc;
 	__be32			addr;
 	int			oif;
 	struct ip_options_rcu	*opt;
@@ -550,7 +551,7 @@
 
 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
 void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset);
-int ip_cmsg_send(struct net *net, struct msghdr *msg,
+int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
 		 struct ipcm_cookie *ipc, bool allow_ipv6);
 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
 		  unsigned int optlen);