[netdevice] Change link-layer push() and pull() methods to take raw types

EFI requires us to be able to specify the source address for
individual transmitted packets, and to be able to extract the
destination address on received packets.

Take advantage of this to rationalise the push() and pull() methods so
that push() takes a (dest,source,proto) tuple and pull() returns a
(dest,source,proto) tuple.

src/drivers/net/ipoib.c

@@ -153,21 +153,20 @@ static struct ipoib_mac ipoib_broadcast = {
  * Add IPoIB link-layer header
  *
  * @v iobuf		I/O buffer
- * @v netdev		Network device
- * @v net_protocol	Network-layer protocol
  * @v ll_dest		Link-layer destination address
+ * @v ll_source		Source link-layer address
+ * @v net_proto		Network-layer protocol, in network-byte order
+ * @ret rc		Return status code
  */
-static int ipoib_push ( struct io_buffer *iobuf,
-			struct net_device *netdev __unused,
-			struct net_protocol *net_protocol,
-			const void *ll_dest ) {
+static int ipoib_push ( struct io_buffer *iobuf, const void *ll_dest,
+			const void *ll_source __unused, uint16_t net_proto ) {
 	struct ipoib_hdr *ipoib_hdr =
 		iob_push ( iobuf, sizeof ( *ipoib_hdr ) );
 
 	/* Build IPoIB header */
 	memcpy ( &ipoib_hdr->pseudo.peer, ll_dest,
 		 sizeof ( ipoib_hdr->pseudo.peer ) );
-	ipoib_hdr->real.proto = net_protocol->net_proto;
+	ipoib_hdr->real.proto = net_proto;
 	ipoib_hdr->real.reserved = 0;
 
 	return 0;
@@ -177,14 +176,13 @@ static int ipoib_push ( struct io_buffer *iobuf,
  * Remove IPoIB link-layer header
  *
  * @v iobuf		I/O buffer
- * @v netdev		Network device
- * @v net_proto		Network-layer protocol, in network-byte order
- * @v ll_source		Source link-layer address
+ * @ret ll_dest		Link-layer destination address
+ * @ret ll_source	Source link-layer address
+ * @ret net_proto	Network-layer protocol, in network-byte order
  * @ret rc		Return status code
  */
-static int ipoib_pull ( struct io_buffer *iobuf,
-			struct net_device *netdev __unused,
-			uint16_t *net_proto, const void **ll_source ) {
+static int ipoib_pull ( struct io_buffer *iobuf, const void **ll_dest,
+			const void **ll_source, uint16_t *net_proto ) {
 	struct ipoib_hdr *ipoib_hdr = iobuf->data;
 
 	/* Sanity check */
@@ -198,8 +196,9 @@ static int ipoib_pull ( struct io_buffer *iobuf,
 	iob_pull ( iobuf, sizeof ( *ipoib_hdr ) );
 
 	/* Fill in required fields */
-	*net_proto = ipoib_hdr->real.proto;
+	*ll_dest = &ipoib_broadcast; /* Doesn't really exist in packet */
 	*ll_source = &ipoib_hdr->pseudo.peer;
+	*net_proto = ipoib_hdr->real.proto;
 
 	return 0;
 }

src/include/gpxe/netdevice.h

@@ -79,34 +79,24 @@ struct ll_protocol {
 	 * Add link-layer header
 	 *
 	 * @v iobuf		I/O buffer
-	 * @v netdev		Network device
-	 * @v net_protocol	Network-layer protocol
 	 * @v ll_dest		Link-layer destination address
+	 * @v ll_source		Source link-layer address
+	 * @v net_proto		Network-layer protocol, in network-byte order
 	 * @ret rc		Return status code
-	 *
-	 * This method should prepend in the link-layer header
-	 * (e.g. the Ethernet DIX header).
 	 */
-	int ( * push ) ( struct io_buffer *iobuf, struct net_device *netdev,
-			 struct net_protocol *net_protocol,
-			 const void *ll_dest );
+	int ( * push ) ( struct io_buffer *iobuf, const void *ll_dest,
+			 const void *ll_source, uint16_t net_proto );
 	/**
 	 * Remove link-layer header
 	 *
-	 * @v iobuf	I/O buffer
-	 * @v netdev	Network device
-	 * @v net_proto	Network-layer protocol, in network-byte order
-	 * @v ll_source	Source link-layer address
-	 * @ret rc	Return status code
-	 *
-	 * This method should strip off the link-layer header
-	 * (e.g. the Ethernet DIX header) and return the protocol and
-	 * source link-layer address.  The method must not alter the
-	 * packet content, and may return the link-layer address as a
-	 * pointer to data within the packet.
+	 * @v iobuf		I/O buffer
+	 * @ret ll_dest		Link-layer destination address
+	 * @ret ll_source	Source link-layer address
+	 * @ret net_proto	Network-layer protocol, in network-byte order
+	 * @ret rc		Return status code
 	 */
-	int ( * pull ) ( struct io_buffer *iobuf, struct net_device *netdev,
-			 uint16_t *net_proto, const void **ll_source );
+	int ( * pull ) ( struct io_buffer *iobuf, const void **ll_dest,
+			 const void **ll_source, uint16_t *net_proto );
 	/**
 	 * Transcribe link-layer address
 	 *

src/interface/pxe/pxe_undi.c

@@ -199,9 +199,10 @@ PXENV_EXIT_t pxenv_undi_transmit ( struct s_PXENV_UNDI_TRANSMIT
 	struct DataBlk *datablk;
 	struct io_buffer *iobuf;
 	struct net_protocol *net_protocol;
+	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;
 	char destaddr[MAX_LL_ADDR_LEN];
 	const void *ll_dest;
-	size_t ll_hlen = pxe_netdev->ll_protocol->ll_header_len;
+	size_t ll_hlen = ll_protocol->ll_header_len;
 	size_t len;
 	unsigned int i;
 	int rc;
@@ -259,17 +260,17 @@ PXENV_EXIT_t pxenv_undi_transmit ( struct s_PXENV_UNDI_TRANSMIT
 			copy_from_real ( destaddr,
 					 undi_transmit->DestAddr.segment,
 					 undi_transmit->DestAddr.offset,
-					 pxe_netdev->ll_protocol->ll_addr_len );
+					 ll_protocol->ll_addr_len );
 			ll_dest = destaddr;
 		} else {
 			DBG ( " BCAST" );
-			ll_dest = pxe_netdev->ll_protocol->ll_broadcast;
+			ll_dest = ll_protocol->ll_broadcast;
 		}
 
 		/* Add link-layer header */
-		if ( ( rc = pxe_netdev->ll_protocol->push ( iobuf, pxe_netdev,
-							    net_protocol,
-							    ll_dest )) != 0 ){
+		if ( ( rc = ll_protocol->push ( iobuf, ll_dest,
+						pxe_netdev->ll_addr,
+						net_protocol->net_proto ))!=0){
 			free_iob ( iobuf );
 			undi_transmit->Status = PXENV_STATUS ( rc );
 			return PXENV_EXIT_FAILURE;
@@ -545,6 +546,7 @@ PXENV_EXIT_t pxenv_undi_isr ( struct s_PXENV_UNDI_ISR *undi_isr ) {
 	struct io_buffer *iobuf;
 	size_t len;
 	struct ll_protocol *ll_protocol;
+	const void *ll_dest;
 	const void *ll_source;
 	uint16_t net_proto;
 	size_t ll_hlen;
@@ -625,9 +627,8 @@ PXENV_EXIT_t pxenv_undi_isr ( struct s_PXENV_UNDI_ISR *undi_isr ) {
 
 		/* Strip link-layer header */
 		ll_protocol = pxe_netdev->ll_protocol;
-		if ( ( rc = ll_protocol->pull ( iobuf, pxe_netdev,
-						&net_proto,
-						&ll_source ) ) != 0 ) {
+		if ( ( rc = ll_protocol->pull ( iobuf, &ll_dest, &ll_source,
+						&net_proto ) ) != 0 ) {
 			/* Assume unknown net_proto and no ll_source */
 			net_proto = 0;
 			ll_source = NULL;

src/net/ethernet.c

@@ -42,19 +42,19 @@ static uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  * Add Ethernet link-layer header
  *
  * @v iobuf		I/O buffer
- * @v netdev		Network device
- * @v net_protocol	Network-layer protocol
  * @v ll_dest		Link-layer destination address
+ * @v ll_source		Source link-layer address
+ * @v net_proto		Network-layer protocol, in network-byte order
+ * @ret rc		Return status code
  */
-static int eth_push ( struct io_buffer *iobuf, struct net_device *netdev,
-		      struct net_protocol *net_protocol,
-		      const void *ll_dest ) {
+static int eth_push ( struct io_buffer *iobuf, const void *ll_dest,
+		      const void *ll_source, uint16_t net_proto ) {
 	struct ethhdr *ethhdr = iob_push ( iobuf, sizeof ( *ethhdr ) );
 
 	/* Build Ethernet header */
 	memcpy ( ethhdr->h_dest, ll_dest, ETH_ALEN );
-	memcpy ( ethhdr->h_source, netdev->ll_addr, ETH_ALEN );
-	ethhdr->h_protocol = net_protocol->net_proto;
+	memcpy ( ethhdr->h_source, ll_source, ETH_ALEN );
+	ethhdr->h_protocol = net_proto;
 
 	return 0;
 }
@@ -63,14 +63,13 @@ static int eth_push ( struct io_buffer *iobuf, struct net_device *netdev,
  * Remove Ethernet link-layer header
  *
  * @v iobuf		I/O buffer
- * @v netdev		Network device
- * @v net_proto		Network-layer protocol, in network-byte order
- * @v ll_source		Source link-layer address
+ * @ret ll_dest		Link-layer destination address
+ * @ret ll_source	Source link-layer address
+ * @ret net_proto	Network-layer protocol, in network-byte order
  * @ret rc		Return status code
  */
-static int eth_pull ( struct io_buffer *iobuf,
-		      struct net_device *netdev __unused,
-		      uint16_t *net_proto, const void **ll_source ) {
+static int eth_pull ( struct io_buffer *iobuf, const void **ll_dest,
+		      const void **ll_source, uint16_t *net_proto ) {
 	struct ethhdr *ethhdr = iobuf->data;
 
 	/* Sanity check */
@@ -84,8 +83,9 @@ static int eth_pull ( struct io_buffer *iobuf,
 	iob_pull ( iobuf, sizeof ( *ethhdr ) );
 
 	/* Fill in required fields */
-	*net_proto = ethhdr->h_protocol;
+	*ll_dest = ethhdr->h_dest;
 	*ll_source = ethhdr->h_source;
+	*net_proto = ethhdr->h_protocol;
 
 	return 0;
 }

src/net/netdevice.c

@@ -439,6 +439,7 @@ struct net_device * find_netdev_by_location ( unsigned int bus_type,
  */
 int net_tx ( struct io_buffer *iobuf, struct net_device *netdev,
 	     struct net_protocol *net_protocol, const void *ll_dest ) {
+	struct ll_protocol *ll_protocol = netdev->ll_protocol;
 	int rc;
 
 	/* Force a poll on the netdevice to (potentially) clear any
@@ -449,8 +450,8 @@ int net_tx ( struct io_buffer *iobuf, struct net_device *netdev,
 	netdev_poll ( netdev );
 
 	/* Add link-layer header */
-	if ( ( rc = netdev->ll_protocol->push ( iobuf, netdev, net_protocol,
-						ll_dest ) ) != 0 ) {
+	if ( ( rc = ll_protocol->push ( iobuf, ll_dest, netdev->ll_addr,
+					net_protocol->net_proto ) ) != 0 ) {
 		free_iob ( iobuf );
 		return rc;
 	}
@@ -495,8 +496,9 @@ static void net_step ( struct process *process __unused ) {
 	struct net_device *netdev;
 	struct io_buffer *iobuf;
 	struct ll_protocol *ll_protocol;
-	uint16_t net_proto;
+	const void *ll_dest;
 	const void *ll_source;
+	uint16_t net_proto;
 	int rc;
 
 	/* Poll and process each network device */
@@ -519,9 +521,9 @@ static void net_step ( struct process *process __unused ) {
 
 			/* Remove link-layer header */
 			ll_protocol = netdev->ll_protocol;
-			if ( ( rc = ll_protocol->pull ( iobuf, netdev,
-							&net_proto,
-							&ll_source ) ) != 0 ) {
+			if ( ( rc = ll_protocol->pull ( iobuf, &ll_dest,
+							&ll_source,
+							&net_proto ) ) != 0 ) {
 				free_iob ( iobuf );
 				continue;
 			}