Merge tag 'rxrpc-rewrite-20170607-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Tx length parameter

Here's a set of patches that allows someone initiating a client call with
AF_RXRPC to indicate upfront the total amount of data that will be
transmitted.  This will allow AF_RXRPC to encrypt directly from source
buffer to packet rather than having to copy into the buffer and only
encrypt when it's full (the encrypted portion of the packet starts with a
length and so we can't encrypt until we know what the length will be).

The three patches are:

 (1) Provide a means of finding out what control message types are actually
     supported.  EINVAL is reported if an unsupported cmsg type is seen, so
     we don't want to set the new cmsg unless we know it will be accepted.

 (2) Consolidate some stuff into a struct to reduce the parameter count on
     the function that parses the cmsg buffer.

 (3) Introduce the RXRPC_TX_LENGTH cmsg.  This can be provided on the first
     sendmsg() that contributes data to a client call request or a service
     call reply.  If provided, the user must provide exactly that amount of
     data or an error will be incurred.

Changes in version 2:

 (*) struct rxrpc_send_params::tx_total_len should be s64 not u64.  Thanks to
     Julia Lawall for reporting this.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 17 insertions, 10 deletions

diff --git a/include/linux/rxrpc.h b/include/linux/rxrpc.h
index 707910c6c6c5..7343f71783dc 100644
--- a/include/linux/rxrpc.h
+++ b/include/linux/rxrpc.h
@@ -38,6 +38,7 @@ struct sockaddr_rxrpc {
 #define RXRPC_EXCLUSIVE_CONNECTION	3	/* Deprecated; use RXRPC_EXCLUSIVE_CALL instead */
 #define RXRPC_MIN_SECURITY_LEVEL	4	/* minimum security level */
 #define RXRPC_UPGRADEABLE_SERVICE	5	/* Upgrade service[0] -> service[1] */
+#define RXRPC_SUPPORTED_CMSG		6	/* Get highest supported control message type */
 
 /*
  * RxRPC control messages
@@ -45,16 +46,20 @@ struct sockaddr_rxrpc {
  * - terminal messages mean that a user call ID tag can be recycled
  * - s/r/- indicate whether these are applicable to sendmsg() and/or recvmsg()
  */
-#define RXRPC_USER_CALL_ID	1	/* sr: user call ID specifier */
-#define RXRPC_ABORT		2	/* sr: abort request / notification [terminal] */
-#define RXRPC_ACK		3	/* -r: [Service] RPC op final ACK received [terminal] */
-#define RXRPC_NET_ERROR		5	/* -r: network error received [terminal] */
-#define RXRPC_BUSY		6	/* -r: server busy received [terminal] */
-#define RXRPC_LOCAL_ERROR	7	/* -r: local error generated [terminal] */
-#define RXRPC_NEW_CALL		8	/* -r: [Service] new incoming call notification */
-#define RXRPC_ACCEPT		9	/* s-: [Service] accept request */
-#define RXRPC_EXCLUSIVE_CALL	10	/* s-: Call should be on exclusive connection */
-#define RXRPC_UPGRADE_SERVICE	11	/* s-: Request service upgrade for client call */
+enum rxrpc_cmsg_type {
+	RXRPC_USER_CALL_ID	= 1,	/* sr: user call ID specifier */
+	RXRPC_ABORT		= 2,	/* sr: abort request / notification [terminal] */
+	RXRPC_ACK		= 3,	/* -r: [Service] RPC op final ACK received [terminal] */
+	RXRPC_NET_ERROR		= 5,	/* -r: network error received [terminal] */
+	RXRPC_BUSY		= 6,	/* -r: server busy received [terminal] */
+	RXRPC_LOCAL_ERROR	= 7,	/* -r: local error generated [terminal] */
+	RXRPC_NEW_CALL		= 8,	/* -r: [Service] new incoming call notification */
+	RXRPC_ACCEPT		= 9,	/* s-: [Service] accept request */
+	RXRPC_EXCLUSIVE_CALL	= 10,	/* s-: Call should be on exclusive connection */
+	RXRPC_UPGRADE_SERVICE	= 11,	/* s-: Request service upgrade for client call */
+	RXRPC_TX_LENGTH		= 12,	/* s-: Total length of Tx data */
+	RXRPC__SUPPORTED
+};
 
 /*
  * RxRPC security levels
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index b5f5187f488c..c172709787af 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 */