These changes are the raw update to qemu-2.6.

[kvmfornfv.git] / qemu / roms / ipxe / src / net / ethernet.c

diff --git a/qemu/roms/ipxe/src/net/ethernet.c b/qemu/roms/ipxe/src/net/ethernet.c
index 03978c2..6ddf053 100644 (file)
--- a/qemu/roms/ipxe/src/net/ethernet.c
+++ b/qemu/roms/ipxe/src/net/ethernet.c
@@ -15,9 +15,13 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
  */
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stdint.h>
 #include <stdlib.h>
@@ -42,6 +46,24 @@ FILE_LICENCE ( GPL2_OR_LATER );
 /** Ethernet broadcast MAC address */
 uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
+/**
+ * Check if Ethernet packet has an 802.3 LLC header
+ *
+ * @v ethhdr           Ethernet header
+ * @ret is_llc         Packet has 802.3 LLC header
+ */
+static inline int eth_is_llc_packet ( struct ethhdr *ethhdr ) {
+       uint8_t len_msb;
+
+       /* Check if the protocol field contains a value short enough
+        * to be a frame length.  The slightly convoluted form of the
+        * comparison is designed to reduce to a single x86
+        * instruction.
+        */
+       len_msb = *( ( uint8_t * ) &ethhdr->h_protocol );
+       return ( len_msb < 0x06 );
+}
+
 /**
  * Add Ethernet link-layer header
  *
@@ -80,9 +102,14 @@ int eth_pull ( struct net_device *netdev __unused, struct io_buffer *iobuf,
               const void **ll_dest, const void **ll_source,
               uint16_t *net_proto, unsigned int *flags ) {
        struct ethhdr *ethhdr = iobuf->data;
+       uint16_t *llc_proto;
 
-       /* Sanity check */
-       if ( iob_len ( iobuf ) < sizeof ( *ethhdr ) ) {
+       /* Sanity check.  While in theory we could receive a one-byte
+        * packet, this will never happen in practice and performing
+        * the combined length check here avoids the need for an
+        * additional comparison if we detect an LLC frame.
+        */
+       if ( iob_len ( iobuf ) < ( sizeof ( *ethhdr ) + sizeof ( *llc_proto ))){
                DBG ( "Ethernet packet too short (%zd bytes)\n",
                      iob_len ( iobuf ) );
                return -EINVAL;
@@ -100,6 +127,17 @@ int eth_pull ( struct net_device *netdev __unused, struct io_buffer *iobuf,
                   ( is_broadcast_ether_addr ( ethhdr->h_dest ) ?
                     LL_BROADCAST : 0 ) );
 
+       /* If this is an LLC frame (with a length in place of the
+        * protocol field), then use the next two bytes (which happen
+        * to be the LLC DSAP and SSAP) as the protocol.  This allows
+        * for minimal-overhead support for receiving (rare) LLC
+        * frames, without requiring a full LLC protocol layer.
+        */
+       if ( eth_is_llc_packet ( ethhdr ) ) {
+               llc_proto = ( &ethhdr->h_protocol + 1 );
+               *net_proto = *llc_proto;
+       }
+
        return 0;
 }
 
@@ -235,5 +273,11 @@ struct net_device * alloc_etherdev ( size_t priv_size ) {
        return netdev;
 }
 
+/* Drag in objects via ethernet_protocol */
+REQUIRING_SYMBOL ( ethernet_protocol );
+
+/* Drag in Ethernet configuration */
+REQUIRE_OBJECT ( config_ethernet );
+
 /* Drag in Ethernet slow protocols */
 REQUIRE_OBJECT ( eth_slow );