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, 70 insertions, 68 deletions

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index d7a9ab5a9d9c..160480221224 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -132,8 +132,8 @@ static void rxkad_prime_packet_security(struct rxrpc_connection *conn)
 	desc.info = iv.x;
 	desc.flags = 0;
 
-	tmpbuf.x[0] = conn->epoch;
-	tmpbuf.x[1] = conn->cid;
+	tmpbuf.x[0] = htonl(conn->epoch);
+	tmpbuf.x[1] = htonl(conn->cid);
 	tmpbuf.x[2] = 0;
 	tmpbuf.x[3] = htonl(conn->security_ix);
 
@@ -169,8 +169,8 @@ static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
 
 	_enter("");
 
-	check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
-	data_size |= (u32) check << 16;
+	check = sp->hdr.seq ^ sp->hdr.callNumber;
+	data_size |= (u32)check << 16;
 
 	tmpbuf.hdr.data_size = htonl(data_size);
 	memcpy(&tmpbuf.first, sechdr + 4, sizeof(tmpbuf.first));
@@ -215,9 +215,9 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
 
 	_enter("");
 
-	check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
+	check = sp->hdr.seq ^ sp->hdr.callNumber;
 
-	rxkhdr.data_size = htonl(data_size | (u32) check << 16);
+	rxkhdr.data_size = htonl(data_size | (u32)check << 16);
 	rxkhdr.checksum = 0;
 
 	/* encrypt from the session key */
@@ -262,14 +262,13 @@ static int rxkad_secure_packet(const struct rxrpc_call *call,
 	struct {
 		__be32 x[2];
 	} tmpbuf __attribute__((aligned(8))); /* must all be in same page */
-	__be32 x;
-	u32 y;
+	u32 x, y;
 	int ret;
 
 	sp = rxrpc_skb(skb);
 
 	_enter("{%d{%x}},{#%u},%zu,",
-	       call->debug_id, key_serial(call->conn->key), ntohl(sp->hdr.seq),
+	       call->debug_id, key_serial(call->conn->key), sp->hdr.seq,
 	       data_size);
 
 	if (!call->conn->cipher)
@@ -286,10 +285,10 @@ static int rxkad_secure_packet(const struct rxrpc_call *call,
 	desc.flags = 0;
 
 	/* calculate the security checksum */
-	x = htonl(call->channel << (32 - RXRPC_CIDSHIFT));
-	x |= sp->hdr.seq & cpu_to_be32(0x3fffffff);
-	tmpbuf.x[0] = sp->hdr.callNumber;
-	tmpbuf.x[1] = x;
+	x = call->channel << (32 - RXRPC_CIDSHIFT);
+	x |= sp->hdr.seq & 0x3fffffff;
+	tmpbuf.x[0] = htonl(sp->hdr.callNumber);
+	tmpbuf.x[1] = htonl(x);
 
 	sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
 	sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
@@ -299,7 +298,7 @@ static int rxkad_secure_packet(const struct rxrpc_call *call,
 	y = (y >> 16) & 0xffff;
 	if (y == 0)
 		y = 1; /* zero checksums are not permitted */
-	sp->hdr.cksum = htons(y);
+	sp->hdr.cksum = y;
 
 	switch (call->conn->security_level) {
 	case RXRPC_SECURITY_PLAIN:
@@ -368,7 +367,7 @@ static int rxkad_verify_packet_auth(const struct rxrpc_call *call,
 	data_size = buf & 0xffff;
 
 	check = buf >> 16;
-	check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
+	check ^= sp->hdr.seq ^ sp->hdr.callNumber;
 	check &= 0xffff;
 	if (check != 0) {
 		*_abort_code = RXKADSEALEDINCON;
@@ -453,7 +452,7 @@ static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call,
 	data_size = buf & 0xffff;
 
 	check = buf >> 16;
-	check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
+	check ^= sp->hdr.seq ^ sp->hdr.callNumber;
 	check &= 0xffff;
 	if (check != 0) {
 		*_abort_code = RXKADSEALEDINCON;
@@ -494,16 +493,14 @@ static int rxkad_verify_packet(const struct rxrpc_call *call,
 	struct {
 		__be32 x[2];
 	} tmpbuf __attribute__((aligned(8))); /* must all be in same page */
-	__be32 x;
-	__be16 cksum;
-	u32 y;
+	u16 cksum;
+	u32 x, y;
 	int ret;
 
 	sp = rxrpc_skb(skb);
 
 	_enter("{%d{%x}},{#%u}",
-	       call->debug_id, key_serial(call->conn->key),
-	       ntohl(sp->hdr.seq));
+	       call->debug_id, key_serial(call->conn->key), sp->hdr.seq);
 
 	if (!call->conn->cipher)
 		return 0;
@@ -521,21 +518,20 @@ static int rxkad_verify_packet(const struct rxrpc_call *call,
 	desc.flags = 0;
 
 	/* validate the security checksum */
-	x = htonl(call->channel << (32 - RXRPC_CIDSHIFT));
-	x |= sp->hdr.seq & cpu_to_be32(0x3fffffff);
-	tmpbuf.x[0] = call->call_id;
-	tmpbuf.x[1] = x;
+	x = call->channel << (32 - RXRPC_CIDSHIFT);
+	x |= sp->hdr.seq & 0x3fffffff;
+	tmpbuf.x[0] = htonl(call->call_id);
+	tmpbuf.x[1] = htonl(x);
 
 	sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
 	sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
 	crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
 
 	y = ntohl(tmpbuf.x[1]);
-	y = (y >> 16) & 0xffff;
-	if (y == 0)
-		y = 1; /* zero checksums are not permitted */
+	cksum = (y >> 16) & 0xffff;
+	if (cksum == 0)
+		cksum = 1; /* zero checksums are not permitted */
 
-	cksum = htons(y);
 	if (sp->hdr.cksum != cksum) {
 		*_abort_code = RXKADSEALEDINCON;
 		_leave(" = -EPROTO [csum failed]");
@@ -567,10 +563,11 @@ static int rxkad_verify_packet(const struct rxrpc_call *call,
 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
 {
 	struct rxkad_challenge challenge;
-	struct rxrpc_header hdr;
+	struct rxrpc_wire_header whdr;
 	struct msghdr msg;
 	struct kvec iov[2];
 	size_t len;
+	u32 serial;
 	int ret;
 
 	_enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
@@ -592,26 +589,27 @@ static int rxkad_issue_challenge(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_CHALLENGE;
-	hdr.flags	= conn->out_clientflag;
-	hdr.userStatus	= 0;
-	hdr.securityIndex = conn->security_ix;
-	hdr._rsvd	= 0;
-	hdr.serviceId	= conn->service_id;
-
-	iov[0].iov_base	= &hdr;
-	iov[0].iov_len	= sizeof(hdr);
+	whdr.epoch	= htonl(conn->epoch);
+	whdr.cid	= htonl(conn->cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_CHALLENGE;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
 	iov[1].iov_base	= &challenge;
 	iov[1].iov_len	= sizeof(challenge);
 
 	len = iov[0].iov_len + iov[1].iov_len;
 
-	hdr.serial = htonl(atomic_inc_return(&conn->serial));
-	_proto("Tx CHALLENGE %%%u", ntohl(hdr.serial));
+	serial = atomic_inc_return(&conn->serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx CHALLENGE %%%u", serial);
 
 	ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
 	if (ret < 0) {
@@ -627,13 +625,15 @@ static int rxkad_issue_challenge(struct rxrpc_connection *conn)
  * send a Kerberos security response
  */
 static int rxkad_send_response(struct rxrpc_connection *conn,
-			       struct rxrpc_header *hdr,
+			       struct rxrpc_host_header *hdr,
 			       struct rxkad_response *resp,
 			       const struct rxkad_key *s2)
 {
+	struct rxrpc_wire_header whdr;
 	struct msghdr msg;
 	struct kvec iov[3];
 	size_t len;
+	u32 serial;
 	int ret;
 
 	_enter("");
@@ -644,24 +644,26 @@ static int rxkad_send_response(struct rxrpc_connection *conn,
 	msg.msg_controllen = 0;
 	msg.msg_flags	= 0;
 
-	hdr->epoch	= conn->epoch;
-	hdr->seq	= 0;
-	hdr->type	= RXRPC_PACKET_TYPE_RESPONSE;
-	hdr->flags	= conn->out_clientflag;
-	hdr->userStatus	= 0;
-	hdr->_rsvd	= 0;
+	memset(&whdr, 0, sizeof(whdr));
+	whdr.epoch	= htonl(hdr->epoch);
+	whdr.cid	= htonl(hdr->cid);
+	whdr.type	= RXRPC_PACKET_TYPE_RESPONSE;
+	whdr.flags	= conn->out_clientflag;
+	whdr.securityIndex = hdr->securityIndex;
+	whdr.serviceId	= htons(hdr->serviceId);
 
-	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	= resp;
 	iov[1].iov_len	= sizeof(*resp);
-	iov[2].iov_base	= (void *) s2->ticket;
+	iov[2].iov_base	= (void *)s2->ticket;
 	iov[2].iov_len	= s2->ticket_len;
 
 	len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
 
-	hdr->serial = htonl(atomic_inc_return(&conn->serial));
-	_proto("Tx RESPONSE %%%u", ntohl(hdr->serial));
+	serial = atomic_inc_return(&conn->serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx RESPONSE %%%u", serial);
 
 	ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 3, len);
 	if (ret < 0) {
@@ -770,7 +772,7 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 	min_level = ntohl(challenge.min_level);
 
 	_proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
-	       ntohl(sp->hdr.serial), version, nonce, min_level);
+	       sp->hdr.serial, version, nonce, min_level);
 
 	abort_code = RXKADINCONSISTENCY;
 	if (version != RXKAD_VERSION)
@@ -786,17 +788,17 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
 	memset(&resp, 0, sizeof(resp));
 
 	resp.version = RXKAD_VERSION;
-	resp.encrypted.epoch = conn->epoch;
-	resp.encrypted.cid = conn->cid;
+	resp.encrypted.epoch = htonl(conn->epoch);
+	resp.encrypted.cid = htonl(conn->cid);
 	resp.encrypted.securityIndex = htonl(conn->security_ix);
 	resp.encrypted.call_id[0] =
-		(conn->channels[0] ? conn->channels[0]->call_id : 0);
+		htonl(conn->channels[0] ? conn->channels[0]->call_id : 0);
 	resp.encrypted.call_id[1] =
-		(conn->channels[1] ? conn->channels[1]->call_id : 0);
+		htonl(conn->channels[1] ? conn->channels[1]->call_id : 0);
 	resp.encrypted.call_id[2] =
-		(conn->channels[2] ? conn->channels[2]->call_id : 0);
+		htonl(conn->channels[2] ? conn->channels[2]->call_id : 0);
 	resp.encrypted.call_id[3] =
-		(conn->channels[3] ? conn->channels[3]->call_id : 0);
+		htonl(conn->channels[3] ? conn->channels[3]->call_id : 0);
 	resp.encrypted.inc_nonce = htonl(nonce + 1);
 	resp.encrypted.level = htonl(conn->security_level);
 	resp.kvno = htonl(token->kad->kvno);
@@ -1022,7 +1024,7 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
 	kvno = ntohl(response.kvno);
 	sp = rxrpc_skb(skb);
 	_proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
-	       ntohl(sp->hdr.serial), version, kvno, ticket_len);
+	       sp->hdr.serial, version, kvno, ticket_len);
 
 	abort_code = RXKADINCONSISTENCY;
 	if (version != RXKAD_VERSION)
@@ -1058,9 +1060,9 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
 	rxkad_decrypt_response(conn, &response, &session_key);
 
 	abort_code = RXKADSEALEDINCON;
-	if (response.encrypted.epoch != conn->epoch)
+	if (ntohl(response.encrypted.epoch) != conn->epoch)
 		goto protocol_error_free;
-	if (response.encrypted.cid != conn->cid)
+	if (ntohl(response.encrypted.cid) != conn->cid)
 		goto protocol_error_free;
 	if (ntohl(response.encrypted.securityIndex) != conn->security_ix)
 		goto protocol_error_free;
@@ -1077,7 +1079,7 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
 		goto protocol_error_free;
 
 	abort_code = RXKADOUTOFSEQUENCE;
-	if (response.encrypted.inc_nonce != htonl(conn->security_nonce + 1))
+	if (ntohl(response.encrypted.inc_nonce) != conn->security_nonce + 1)
 		goto protocol_error_free;
 
 	abort_code = RXKADLEVELFAIL;