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, 7 insertions, 0 deletions

diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt
index 70c926ae212d..dfe0b008df74 100644
--- a/Documentation/networking/rxrpc.txt
+++ b/Documentation/networking/rxrpc.txt
@@ -868,6 +868,13 @@ The kernel interface functions are as follows:
      This is used to allocate a null RxRPC key that can be used to indicate
      anonymous security for a particular domain.
 
+ (*) Get the peer address of a call.
+
+        void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
+                                   struct sockaddr_rxrpc *_srx);
+
+     This is used to find the remote peer address of a call.
+
 
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 CONFIGURABLE PARAMETERS