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, 40 insertions, 43 deletions

diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
index 6c71ed1caf16..53df14cb8d25 100644
--- a/net/rxrpc/ar-connection.c
+++ b/net/rxrpc/ar-connection.c
@@ -57,10 +57,10 @@ static struct rxrpc_conn_bundle *rxrpc_alloc_bundle(gfp_t gfp)
  */
 static inline
 int rxrpc_cmp_bundle(const struct rxrpc_conn_bundle *bundle,
-		     struct key *key, __be16 service_id)
+		     struct key *key, u16 service_id)
 {
 	return (bundle->service_id - service_id) ?:
-		((unsigned long) bundle->key - (unsigned long) key);
+		((unsigned long)bundle->key - (unsigned long)key);
 }
 
 /*
@@ -69,14 +69,14 @@ int rxrpc_cmp_bundle(const struct rxrpc_conn_bundle *bundle,
 struct rxrpc_conn_bundle *rxrpc_get_bundle(struct rxrpc_sock *rx,
 					   struct rxrpc_transport *trans,
 					   struct key *key,
-					   __be16 service_id,
+					   u16 service_id,
 					   gfp_t gfp)
 {
 	struct rxrpc_conn_bundle *bundle, *candidate;
 	struct rb_node *p, *parent, **pp;
 
 	_enter("%p{%x},%x,%hx,",
-	       rx, key_serial(key), trans->debug_id, ntohs(service_id));
+	       rx, key_serial(key), trans->debug_id, service_id);
 
 	if (rx->trans == trans && rx->bundle) {
 		atomic_inc(&rx->bundle->usage);
@@ -213,7 +213,7 @@ static struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
 		conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
 		conn->avail_calls = RXRPC_MAXCALLS;
 		conn->size_align = 4;
-		conn->header_size = sizeof(struct rxrpc_header);
+		conn->header_size = sizeof(struct rxrpc_wire_header);
 	}
 
 	_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
@@ -230,7 +230,7 @@ static void rxrpc_assign_connection_id(struct rxrpc_connection *conn)
 	struct rxrpc_connection *xconn;
 	struct rb_node *parent, **p;
 	__be32 epoch;
-	u32 real_conn_id;
+	u32 cid;
 
 	_enter("");
 
@@ -241,7 +241,7 @@ static void rxrpc_assign_connection_id(struct rxrpc_connection *conn)
 	conn->trans->conn_idcounter += RXRPC_CID_INC;
 	if (conn->trans->conn_idcounter < RXRPC_CID_INC)
 		conn->trans->conn_idcounter = RXRPC_CID_INC;
-	real_conn_id = conn->trans->conn_idcounter;
+	cid = conn->trans->conn_idcounter;
 
 attempt_insertion:
 	parent = NULL;
@@ -255,9 +255,9 @@ attempt_insertion:
 			p = &(*p)->rb_left;
 		else if (epoch > xconn->epoch)
 			p = &(*p)->rb_right;
-		else if (real_conn_id < xconn->real_conn_id)
+		else if (cid < xconn->cid)
 			p = &(*p)->rb_left;
-		else if (real_conn_id > xconn->real_conn_id)
+		else if (cid > xconn->cid)
 			p = &(*p)->rb_right;
 		else
 			goto id_exists;
@@ -268,20 +268,19 @@ attempt_insertion:
 	rb_link_node(&conn->node, parent, p);
 	rb_insert_color(&conn->node, &conn->trans->client_conns);
 
-	conn->real_conn_id = real_conn_id;
-	conn->cid = htonl(real_conn_id);
+	conn->cid = cid;
 	write_unlock_bh(&conn->trans->conn_lock);
-	_leave(" [CONNID %x CID %x]", real_conn_id, ntohl(conn->cid));
+	_leave(" [CID %x]", cid);
 	return;
 
 	/* we found a connection with the proposed ID - walk the tree from that
 	 * point looking for the next unused ID */
 id_exists:
 	for (;;) {
-		real_conn_id += RXRPC_CID_INC;
-		if (real_conn_id < RXRPC_CID_INC) {
-			real_conn_id = RXRPC_CID_INC;
-			conn->trans->conn_idcounter = real_conn_id;
+		cid += RXRPC_CID_INC;
+		if (cid < RXRPC_CID_INC) {
+			cid = RXRPC_CID_INC;
+			conn->trans->conn_idcounter = cid;
 			goto attempt_insertion;
 		}
 
@@ -291,7 +290,7 @@ id_exists:
 
 		xconn = rb_entry(parent, struct rxrpc_connection, node);
 		if (epoch < xconn->epoch ||
-		    real_conn_id < xconn->real_conn_id)
+		    cid < xconn->cid)
 			goto attempt_insertion;
 	}
 }
@@ -334,7 +333,7 @@ static void rxrpc_add_call_ID_to_conn(struct rxrpc_connection *conn,
  */
 static int rxrpc_connect_exclusive(struct rxrpc_sock *rx,
 				   struct rxrpc_transport *trans,
-				   __be16 service_id,
+				   u16 service_id,
 				   struct rxrpc_call *call,
 				   gfp_t gfp)
 {
@@ -404,11 +403,11 @@ found_channel:
 	conn->channels[chan] = call;
 	call->conn = conn;
 	call->channel = chan;
-	call->cid = conn->cid | htonl(chan);
-	call->call_id = htonl(++conn->call_counter);
+	call->cid = conn->cid | chan;
+	call->call_id = ++conn->call_counter;
 
 	_net("CONNECT client on conn %d chan %d as call %x",
-	     conn->debug_id, chan, ntohl(call->call_id));
+	     conn->debug_id, chan, call->call_id);
 
 	spin_unlock(&trans->client_lock);
 
@@ -593,11 +592,11 @@ found_channel:
 	conn->channels[chan] = call;
 	call->conn = conn;
 	call->channel = chan;
-	call->cid = conn->cid | htonl(chan);
-	call->call_id = htonl(++conn->call_counter);
+	call->cid = conn->cid | chan;
+	call->call_id = ++conn->call_counter;
 
 	_net("CONNECT client on conn %d chan %d as call %x",
-	     conn->debug_id, chan, ntohl(call->call_id));
+	     conn->debug_id, chan, call->call_id);
 
 	ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS);
 	spin_unlock(&trans->client_lock);
@@ -620,21 +619,21 @@ interrupted:
  */
 struct rxrpc_connection *
 rxrpc_incoming_connection(struct rxrpc_transport *trans,
-			  struct rxrpc_header *hdr,
+			  struct rxrpc_host_header *hdr,
 			  gfp_t gfp)
 {
 	struct rxrpc_connection *conn, *candidate = NULL;
 	struct rb_node *p, **pp;
 	const char *new = "old";
 	__be32 epoch;
-	u32 conn_id;
+	u32 cid;
 
 	_enter("");
 
 	ASSERT(hdr->flags & RXRPC_CLIENT_INITIATED);
 
 	epoch = hdr->epoch;
-	conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK;
+	cid = hdr->cid & RXRPC_CIDMASK;
 
 	/* search the connection list first */
 	read_lock_bh(&trans->conn_lock);
@@ -643,15 +642,15 @@ rxrpc_incoming_connection(struct rxrpc_transport *trans,
 	while (p) {
 		conn = rb_entry(p, struct rxrpc_connection, node);
 
-		_debug("maybe %x", conn->real_conn_id);
+		_debug("maybe %x", conn->cid);
 
 		if (epoch < conn->epoch)
 			p = p->rb_left;
 		else if (epoch > conn->epoch)
 			p = p->rb_right;
-		else if (conn_id < conn->real_conn_id)
+		else if (cid < conn->cid)
 			p = p->rb_left;
-		else if (conn_id > conn->real_conn_id)
+		else if (cid > conn->cid)
 			p = p->rb_right;
 		else
 			goto found_extant_connection;
@@ -668,12 +667,11 @@ rxrpc_incoming_connection(struct rxrpc_transport *trans,
 
 	candidate->trans = trans;
 	candidate->epoch = hdr->epoch;
-	candidate->cid = hdr->cid & cpu_to_be32(RXRPC_CIDMASK);
+	candidate->cid = hdr->cid & RXRPC_CIDMASK;
 	candidate->service_id = hdr->serviceId;
 	candidate->security_ix = hdr->securityIndex;
 	candidate->in_clientflag = RXRPC_CLIENT_INITIATED;
 	candidate->out_clientflag = 0;
-	candidate->real_conn_id = conn_id;
 	candidate->state = RXRPC_CONN_SERVER;
 	if (candidate->service_id)
 		candidate->state = RXRPC_CONN_SERVER_UNSECURED;
@@ -690,9 +688,9 @@ rxrpc_incoming_connection(struct rxrpc_transport *trans,
 			pp = &(*pp)->rb_left;
 		else if (epoch > conn->epoch)
 			pp = &(*pp)->rb_right;
-		else if (conn_id < conn->real_conn_id)
+		else if (cid < conn->cid)
 			pp = &(*pp)->rb_left;
-		else if (conn_id > conn->real_conn_id)
+		else if (cid > conn->cid)
 			pp = &(*pp)->rb_right;
 		else
 			goto found_extant_second;
@@ -714,7 +712,7 @@ rxrpc_incoming_connection(struct rxrpc_transport *trans,
 	new = "new";
 
 success:
-	_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->real_conn_id);
+	_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->cid);
 
 	_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
 	return conn;
@@ -751,18 +749,17 @@ security_mismatch:
  * packet
  */
 struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *trans,
-					       struct rxrpc_header *hdr)
+					       struct rxrpc_host_header *hdr)
 {
 	struct rxrpc_connection *conn;
 	struct rb_node *p;
-	__be32 epoch;
-	u32 conn_id;
+	u32 epoch, cid;
 
-	_enter(",{%x,%x}", ntohl(hdr->cid), hdr->flags);
+	_enter(",{%x,%x}", hdr->cid, hdr->flags);
 
 	read_lock_bh(&trans->conn_lock);
 
-	conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK;
+	cid = hdr->cid & RXRPC_CIDMASK;
 	epoch = hdr->epoch;
 
 	if (hdr->flags & RXRPC_CLIENT_INITIATED)
@@ -773,15 +770,15 @@ struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *trans,
 	while (p) {
 		conn = rb_entry(p, struct rxrpc_connection, node);
 
-		_debug("maybe %x", conn->real_conn_id);
+		_debug("maybe %x", conn->cid);
 
 		if (epoch < conn->epoch)
 			p = p->rb_left;
 		else if (epoch > conn->epoch)
 			p = p->rb_right;
-		else if (conn_id < conn->real_conn_id)
+		else if (cid < conn->cid)
 			p = p->rb_left;
-		else if (conn_id > conn->real_conn_id)
+		else if (cid > conn->cid)
 			p = p->rb_right;
 		else
 			goto found;