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, 37 insertions, 36 deletions

diff --git a/net/rxrpc/ar-connevent.c b/net/rxrpc/ar-connevent.c
index 45e81b7e96ae..1bdaaed8cdc4 100644
--- a/net/rxrpc/ar-connevent.c
+++ b/net/rxrpc/ar-connevent.c
@@ -60,11 +60,12 @@ static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 				  u32 error, u32 abort_code)
 {
-	struct rxrpc_header hdr;
+	struct rxrpc_wire_header whdr;
 	struct msghdr msg;
 	struct kvec iov[2];
 	__be32 word;
 	size_t len;
+	u32 serial;
 	int ret;
 
 	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);
@@ -89,28 +90,29 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 	msg.msg_controllen = 0;
 	msg.msg_flags	= 0;
 
-	hdr.epoch	= conn->epoch;
-	hdr.cid		= conn->cid;
-	hdr.callNumber	= 0;
-	hdr.seq		= 0;
-	hdr.type	= RXRPC_PACKET_TYPE_ABORT;
-	hdr.flags	= conn->out_clientflag;
-	hdr.userStatus	= 0;
-	hdr.securityIndex = conn->security_ix;
-	hdr._rsvd	= 0;
-	hdr.serviceId	= conn->service_id;
+	whdr.epoch	= htonl(conn->epoch);
+	whdr.cid	= htonl(conn->cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_ABORT;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
 
 	word = htonl(abort_code);
 
-	iov[0].iov_base	= &hdr;
-	iov[0].iov_len	= sizeof(hdr);
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
 	iov[1].iov_base	= &word;
 	iov[1].iov_len	= sizeof(word);
 
 	len = iov[0].iov_len + iov[1].iov_len;
 
-	hdr.serial = htonl(atomic_inc_return(&conn->serial));
-	_proto("Tx CONN ABORT %%%u { %d }", ntohl(hdr.serial), abort_code);
+	serial = atomic_inc_return(&conn->serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx CONN ABORT %%%u { %d }", serial, abort_code);
 
 	ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
 	if (ret < 0) {
@@ -146,8 +148,8 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
 			       u32 *_abort_code)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	__be32 tmp;
-	u32 serial;
+	__be32 wtmp;
+	u32 abort_code;
 	int loop, ret;
 
 	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
@@ -155,19 +157,18 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
 		return -ECONNABORTED;
 	}
 
-	serial = ntohl(sp->hdr.serial);
-
-	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, serial);
+	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_ABORT:
-		if (skb_copy_bits(skb, 0, &tmp, sizeof(tmp)) < 0)
+		if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
 			return -EPROTO;
-		_proto("Rx ABORT %%%u { ac=%d }", serial, ntohl(tmp));
+		abort_code = ntohl(wtmp);
+		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 
 		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
-				  ntohl(tmp));
+				  abort_code);
 		return -ECONNABORTED;
 
 	case RXRPC_PACKET_TYPE_CHALLENGE:
@@ -335,7 +336,7 @@ void rxrpc_reject_packets(struct work_struct *work)
 		struct sockaddr_in sin;
 	} sa;
 	struct rxrpc_skb_priv *sp;
-	struct rxrpc_header hdr;
+	struct rxrpc_wire_header whdr;
 	struct rxrpc_local *local;
 	struct sk_buff *skb;
 	struct msghdr msg;
@@ -348,11 +349,11 @@ void rxrpc_reject_packets(struct work_struct *work)
 
 	_enter("%d", local->debug_id);
 
-	iov[0].iov_base = &hdr;
-	iov[0].iov_len = sizeof(hdr);
+	iov[0].iov_base = &whdr;
+	iov[0].iov_len = sizeof(whdr);
 	iov[1].iov_base = &code;
 	iov[1].iov_len = sizeof(code);
-	size = sizeof(hdr) + sizeof(code);
+	size = sizeof(whdr) + sizeof(code);
 
 	msg.msg_name = &sa;
 	msg.msg_control = NULL;
@@ -370,8 +371,8 @@ void rxrpc_reject_packets(struct work_struct *work)
 		break;
 	}
 
-	memset(&hdr, 0, sizeof(hdr));
-	hdr.type = RXRPC_PACKET_TYPE_ABORT;
+	memset(&whdr, 0, sizeof(whdr));
+	whdr.type = RXRPC_PACKET_TYPE_ABORT;
 
 	while ((skb = skb_dequeue(&local->reject_queue))) {
 		sp = rxrpc_skb(skb);
@@ -381,13 +382,13 @@ void rxrpc_reject_packets(struct work_struct *work)
 			sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
 			code = htonl(skb->priority);
 
-			hdr.epoch = sp->hdr.epoch;
-			hdr.cid = sp->hdr.cid;
-			hdr.callNumber = sp->hdr.callNumber;
-			hdr.serviceId = sp->hdr.serviceId;
-			hdr.flags = sp->hdr.flags;
-			hdr.flags ^= RXRPC_CLIENT_INITIATED;
-			hdr.flags &= RXRPC_CLIENT_INITIATED;
+			whdr.epoch	= htonl(sp->hdr.epoch);
+			whdr.cid	= htonl(sp->hdr.cid);
+			whdr.callNumber	= htonl(sp->hdr.callNumber);
+			whdr.serviceId	= htons(sp->hdr.serviceId);
+			whdr.flags	= sp->hdr.flags;
+			whdr.flags	^= RXRPC_CLIENT_INITIATED;
+			whdr.flags	&= RXRPC_CLIENT_INITIATED;
 
 			kernel_sendmsg(local->socket, &msg, iov, 2, size);
 			break;