rxrpc: Keep the skb private record of the Rx header in host byte order

Currently, a copy of the Rx packet header is copied into the the sk_buff
private data so that we can advance the pointer into the buffer,
potentially discarding the original.  At the moment, this copy is held in
network byte order, but this means we're doing a lot of unnecessary
translations.

The reasons it was done this way are that we need the values in network
byte order occasionally and we can use the copy, slightly modified, as part
of an iov array when sending an ack or an abort packet.

However, it seems more reasonable on review that it would be better kept in
host byte order and that we make up a new header when we want to send
another packet.

To this end, rename the original header struct to rxrpc_wire_header (with
BE fields) and institute a variant called rxrpc_host_header that has host
order fields.  Change the struct in the sk_buff private data into an
rxrpc_host_header and translate the values when filling it in.

This further allows us to keep values kept in various structures in host
byte order rather than network byte order and allows removal of some fields
that are byteswapped duplicates.

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

1 files changed, 7 insertions, 13 deletions

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 7e2d1057d8bc..7bb5cca0ae32 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -37,7 +37,7 @@ static struct proto rxrpc_proto;
 static const struct proto_ops rxrpc_rpc_ops;
 
 /* local epoch for detecting local-end reset */
-__be32 rxrpc_epoch;
+u32 rxrpc_epoch;
 
 /* current debugging ID */
 atomic_t rxrpc_debug_id;
@@ -125,7 +125,6 @@ static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
 	struct sock *sk = sock->sk;
 	struct rxrpc_local *local;
 	struct rxrpc_sock *rx = rxrpc_sk(sk), *prx;
-	__be16 service_id;
 	int ret;
 
 	_enter("%p,%p,%d", rx, saddr, len);
@@ -152,14 +151,12 @@ static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
 
 	rx->local = local;
 	if (srx->srx_service) {
-		service_id = htons(srx->srx_service);
 		write_lock_bh(&local->services_lock);
 		list_for_each_entry(prx, &local->services, listen_link) {
-			if (prx->service_id == service_id)
+			if (prx->srx.srx_service == srx->srx_service)
 				goto service_in_use;
 		}
 
-		rx->service_id = service_id;
 		list_add_tail(&rx->listen_link, &local->services);
 		write_unlock_bh(&local->services_lock);
 
@@ -276,7 +273,6 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
 	struct rxrpc_transport *trans;
 	struct rxrpc_call *call;
 	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
-	__be16 service_id;
 
 	_enter(",,%x,%lx", key_serial(key), user_call_ID);
 
@@ -299,16 +295,15 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
 		atomic_inc(&trans->usage);
 	}
 
-	service_id = rx->service_id;
-	if (srx)
-		service_id = htons(srx->srx_service);
+	if (!srx)
+		srx = &rx->srx;
 
 	if (!key)
 		key = rx->key;
 	if (key && !key->payload.data[0])
 		key = NULL; /* a no-security key */
 
-	bundle = rxrpc_get_bundle(rx, trans, key, service_id, gfp);
+	bundle = rxrpc_get_bundle(rx, trans, key, srx->srx_service, gfp);
 	if (IS_ERR(bundle)) {
 		call = ERR_CAST(bundle);
 		goto out;
@@ -425,7 +420,6 @@ static int rxrpc_connect(struct socket *sock, struct sockaddr *addr,
 	}
 
 	rx->trans = trans;
-	rx->service_id = htons(srx->srx_service);
 	rx->sk.sk_state = RXRPC_CLIENT_CONNECTED;
 
 	release_sock(&rx->sk);
@@ -778,7 +772,7 @@ static struct proto rxrpc_proto = {
 	.name		= "RXRPC",
 	.owner		= THIS_MODULE,
 	.obj_size	= sizeof(struct rxrpc_sock),
-	.max_header	= sizeof(struct rxrpc_header),
+	.max_header	= sizeof(struct rxrpc_wire_header),
 };
 
 static const struct net_proto_family rxrpc_family_ops = {
@@ -796,7 +790,7 @@ static int __init af_rxrpc_init(void)
 
 	BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct sk_buff, cb));
 
-	rxrpc_epoch = htonl(get_seconds());
+	rxrpc_epoch = get_seconds();
 
 	ret = -ENOMEM;
 	rxrpc_call_jar = kmem_cache_create(