rxrpc: Provide a way for AFS to ask for the peer address of a call

Provide a function so that kernel users, such as AFS, can ask for the peer
address of a call:

   void rxrpc_kernel_get_peer(struct rxrpc_call *call,
			      struct sockaddr_rxrpc *_srx);

In the future the kernel service won't get sk_buffs to look inside.
Further, this allows us to hide any canonicalisation inside AF_RXRPC for
when IPv6 support is added.

Also propagate this through to afs_find_server() and issue a warning if we
can't handle the address family yet.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index 538e9831c699..aebc73ac16dc 100644
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -313,3 +313,18 @@ void __rxrpc_put_peer(struct rxrpc_peer *peer)
 
 	kfree_rcu(peer, rcu);
 }
+
+/**
+ * rxrpc_kernel_get_peer - Get the peer address of a call
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ * @_srx: Where to place the result
+ *
+ * Get the address of the remote peer in a call.
+ */
+void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
+			   struct sockaddr_rxrpc *_srx)
+{
+	*_srx = call->peer->srx;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer);