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, 32 insertions, 36 deletions

diff --git a/net/rxrpc/ar-call.c b/net/rxrpc/ar-call.c
index 3468a0705ab7..4a499e0100f1 100644
--- a/net/rxrpc/ar-call.c
+++ b/net/rxrpc/ar-call.c
@@ -64,11 +64,11 @@ static DEFINE_HASHTABLE(rxrpc_call_hash, 10);
  * Hash function for rxrpc_call_hash
  */
 static unsigned long rxrpc_call_hashfunc(
-	u8		clientflag,
-	__be32		cid,
-	__be32		call_id,
-	__be32		epoch,
-	__be16		service_id,
+	u8		in_clientflag,
+	u32		cid,
+	u32		call_id,
+	u32		epoch,
+	u16		service_id,
 	sa_family_t	proto,
 	void		*localptr,
 	unsigned int	addr_size,
@@ -77,7 +77,6 @@ static unsigned long rxrpc_call_hashfunc(
 	const u16 *p;
 	unsigned int i;
 	unsigned long key;
-	u32 hcid = ntohl(cid);
 
 	_enter("");
 
@@ -85,12 +84,12 @@ static unsigned long rxrpc_call_hashfunc(
 	/* We just want to add up the __be32 values, so forcing the
 	 * cast should be okay.
 	 */
-	key += (__force u32)epoch;
-	key += (__force u16)service_id;
-	key += (__force u32)call_id;
-	key += (hcid & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT;
-	key += hcid & RXRPC_CHANNELMASK;
-	key += clientflag;
+	key += epoch;
+	key += service_id;
+	key += call_id;
+	key += (cid & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT;
+	key += cid & RXRPC_CHANNELMASK;
+	key += in_clientflag;
 	key += proto;
 	/* Step through the peer address in 16-bit portions for speed */
 	for (i = 0, p = (const u16 *)peer_addr; i < addr_size >> 1; i++, p++)
@@ -148,19 +147,16 @@ static void rxrpc_call_hash_del(struct rxrpc_call *call)
  * isn't there.
  */
 struct rxrpc_call *rxrpc_find_call_hash(
-	u8		clientflag,
-	__be32		cid,
-	__be32		call_id,
-	__be32		epoch,
-	__be16		service_id,
+	struct rxrpc_host_header *hdr,
 	void		*localptr,
 	sa_family_t	proto,
-	const u8	*peer_addr)
+	const void	*peer_addr)
 {
 	unsigned long key;
 	unsigned int addr_size = 0;
 	struct rxrpc_call *call = NULL;
 	struct rxrpc_call *ret = NULL;
+	u8 in_clientflag = hdr->flags & RXRPC_CLIENT_INITIATED;
 
 	_enter("");
 	switch (proto) {
@@ -174,20 +170,21 @@ struct rxrpc_call *rxrpc_find_call_hash(
 		break;
 	}
 
-	key = rxrpc_call_hashfunc(clientflag, cid, call_id, epoch,
-				  service_id, proto, localptr, addr_size,
+	key = rxrpc_call_hashfunc(in_clientflag, hdr->cid, hdr->callNumber,
+				  hdr->epoch, hdr->serviceId,
+				  proto, localptr, addr_size,
 				  peer_addr);
 	hash_for_each_possible_rcu(rxrpc_call_hash, call, hash_node, key) {
 		if (call->hash_key == key &&
-		    call->call_id == call_id &&
-		    call->cid == cid &&
-		    call->in_clientflag == clientflag &&
-		    call->service_id == service_id &&
+		    call->call_id == hdr->callNumber &&
+		    call->cid == hdr->cid &&
+		    call->in_clientflag == in_clientflag &&
+		    call->service_id == hdr->serviceId &&
 		    call->proto == proto &&
 		    call->local == localptr &&
 		    memcmp(call->peer_ip.ipv6_addr, peer_addr,
-			      addr_size) == 0 &&
-		    call->epoch == epoch) {
+			   addr_size) == 0 &&
+		    call->epoch == hdr->epoch) {
 			ret = call;
 			break;
 		}
@@ -414,12 +411,12 @@ found_extant_second:
  */
 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 				       struct rxrpc_connection *conn,
-				       struct rxrpc_header *hdr,
+				       struct rxrpc_host_header *hdr,
 				       gfp_t gfp)
 {
 	struct rxrpc_call *call, *candidate;
 	struct rb_node **p, *parent;
-	__be32 call_id;
+	u32 call_id;
 
 	_enter(",%d,,%x", conn->debug_id, gfp);
 
@@ -433,7 +430,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 	candidate->conn = conn;
 	candidate->cid = hdr->cid;
 	candidate->call_id = hdr->callNumber;
-	candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK;
+	candidate->channel = hdr->cid & RXRPC_CHANNELMASK;
 	candidate->rx_data_post = 0;
 	candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
 	if (conn->security_ix > 0)
@@ -492,9 +489,9 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 		/* The tree is sorted in order of the __be32 value without
 		 * turning it into host order.
 		 */
-		if ((__force u32)call_id < (__force u32)call->call_id)
+		if (call_id < call->call_id)
 			p = &(*p)->rb_left;
-		else if ((__force u32)call_id > (__force u32)call->call_id)
+		else if (call_id > call->call_id)
 			p = &(*p)->rb_right;
 		else
 			goto old_call;
@@ -714,8 +711,7 @@ void rxrpc_release_call(struct rxrpc_call *call)
 
 			_debug("- zap %s %%%u #%u",
 			       rxrpc_pkts[sp->hdr.type],
-			       ntohl(sp->hdr.serial),
-			       ntohl(sp->hdr.seq));
+			       sp->hdr.serial, sp->hdr.seq);
 			rxrpc_free_skb(skb);
 			spin_lock_bh(&call->lock);
 		}
@@ -873,9 +869,9 @@ static void rxrpc_cleanup_call(struct rxrpc_call *call)
 			unsigned long _skb;
 
 			_skb = call->acks_window[call->acks_tail] & ~1;
-			sp = rxrpc_skb((struct sk_buff *) _skb);
-			_debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
-			rxrpc_free_skb((struct sk_buff *) _skb);
+			sp = rxrpc_skb((struct sk_buff *)_skb);
+			_debug("+++ clear Tx %u", sp->hdr.seq);
+			rxrpc_free_skb((struct sk_buff *)_skb);
 			call->acks_tail =
 				(call->acks_tail + 1) & (call->acks_winsz - 1);
 		}