rxrpc: Provide a cmsg to specify the amount of Tx data for a call
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.
Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.
By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).
An error will be returned if too little or too much data is presented in
the Tx phase.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index b5f5187..c172709 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -33,6 +33,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *,
struct sockaddr_rxrpc *,
struct key *,
unsigned long,
+ s64,
gfp_t,
rxrpc_notify_rx_t);
int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
@@ -46,5 +47,6 @@ void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *,
struct sockaddr_rxrpc *);
int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
rxrpc_user_attach_call_t, unsigned long, gfp_t);
+void rxrpc_kernel_set_tx_length(struct socket *, struct rxrpc_call *, s64);
#endif /* _NET_RXRPC_H */