[netdevice] Split multicast hashing out into an mc_hash method

Multicast hashing is an ugly overlap between network and link layers.
EFI requires us to provide access to this functionality, so move it
out of ipv4.c and expose it as a method of the link layer.

diff --git a/src/drivers/net/ipoib.c b/src/drivers/net/ipoib.c
index 9c9bc918ac11489a4ba8a82797182ee4072a9ca2..47090bb27aa6f20ca6d9811c1f5011b7297eeb5a 100644 (file)
--- a/src/drivers/net/ipoib.c
+++ b/src/drivers/net/ipoib.c
@@ -222,6 +222,21 @@ const char * ipoib_ntoa ( const void *ll_addr ) {
        return buf;
 }
 
+/**
+ * Hash multicast address
+ *
+ * @v af               Address family
+ * @v net_addr         Network-layer address
+ * @v ll_addr          Link-layer address to fill in
+ * @ret rc             Return status code
+ */
+static int ipoib_mc_hash ( unsigned int af __unused,
+                          const void *net_addr __unused,
+                          void *ll_addr __unused ) {
+
+       return -ENOTSUP;
+}
+
 /** IPoIB protocol */
 struct ll_protocol ipoib_protocol __ll_protocol = {
        .name           = "IPoIB",
@@ -232,6 +247,7 @@ struct ll_protocol ipoib_protocol __ll_protocol = {
        .push           = ipoib_push,
        .pull           = ipoib_pull,
        .ntoa           = ipoib_ntoa,
+       .mc_hash        = ipoib_mc_hash,
 };
 
 /****************************************************************************

diff --git a/src/include/gpxe/netdevice.h b/src/include/gpxe/netdevice.h
index 9f39e0c9157698d566ba7d0a59d2c6202b093f38..3109db838e73dce66d62e1ebd1f1e91d9af73931 100644 (file)
--- a/src/include/gpxe/netdevice.h
+++ b/src/include/gpxe/netdevice.h
@@ -120,6 +120,16 @@ struct ll_protocol {
         * allocated.
         */
        const char * ( * ntoa ) ( const void * ll_addr );
+       /**
+        * Hash multicast address
+        *
+        * @v af        Address family
+        * @v net_addr  Network-layer address
+        * @v ll_addr   Link-layer address to fill in
+        * @ret rc      Return status code
+        */
+       int ( * mc_hash ) ( unsigned int af, const void *net_addr,
+                           void *ll_addr );
        /** Link-layer protocol
         *
         * This is an ARPHRD_XXX constant, in network byte order.

diff --git a/src/net/ethernet.c b/src/net/ethernet.c
index 7b1c496f4078363c02c23ca6a5a4259e3bfbc1f3..ebb551f0540439c63486798c666908a94cfb9311 100644 (file)
--- a/src/net/ethernet.c
+++ b/src/net/ethernet.c
@@ -24,6 +24,7 @@
 #include <assert.h>
 #include <gpxe/if_arp.h>
 #include <gpxe/if_ether.h>
+#include <gpxe/in.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/iobuf.h>
 #include <gpxe/ethernet.h>
@@ -92,8 +93,8 @@ static int eth_pull ( struct io_buffer *iobuf,
 /**
  * Transcribe Ethernet address
  *
- * @v ll_addr  Link-layer address
- * @ret string Link-layer address in human-readable format
+ * @v ll_addr          Link-layer address
+ * @ret string         Link-layer address in human-readable format
  */
 const char * eth_ntoa ( const void *ll_addr ) {
        static char buf[18]; /* "00:00:00:00:00:00" */
@@ -105,6 +106,32 @@ const char * eth_ntoa ( const void *ll_addr ) {
        return buf;
 }
 
+/**
+ * Hash multicast address
+ *
+ * @v af               Address family
+ * @v net_addr         Network-layer address
+ * @v ll_addr          Link-layer address to fill in
+ * @ret rc             Return status code
+ */
+static int eth_mc_hash ( unsigned int af, const void *net_addr,
+                        void *ll_addr ) {
+       const uint8_t *net_addr_bytes = net_addr;
+       uint8_t *ll_addr_bytes = ll_addr;
+
+       switch ( af ) {
+       case AF_INET:
+               ll_addr_bytes[0] = 0x01;
+               ll_addr_bytes[1] = 0x00;
+               ll_addr_bytes[2] = 0x5e;
+               ll_addr_bytes[3] = net_addr_bytes[1] & 0x7f;
+               ll_addr_bytes[4] = net_addr_bytes[2];
+               ll_addr_bytes[5] = net_addr_bytes[3];
+       default:
+               return -ENOTSUP;
+       }
+}
+
 /** Ethernet protocol */
 struct ll_protocol ethernet_protocol __ll_protocol = {
        .name           = "Ethernet",
@@ -115,4 +142,5 @@ struct ll_protocol ethernet_protocol __ll_protocol = {
        .push           = eth_push,
        .pull           = eth_pull,
        .ntoa           = eth_ntoa,
+       .mc_hash        = eth_mc_hash,
 };

diff --git a/src/net/ipv4.c b/src/net/ipv4.c
index 82a13c3341588fee4226e77a7acb5f1c3326a09e..e14ed6a7f1317a55b317b8c23920d0c9ef81f627 100644 (file)
--- a/src/net/ipv4.c
+++ b/src/net/ipv4.c
@@ -266,7 +266,6 @@ static uint16_t ipv4_pshdr_chksum ( struct io_buffer *iobuf, uint16_t csum ) {
 static int ipv4_ll_addr ( struct in_addr dest, struct in_addr src,
                          struct net_device *netdev, uint8_t *ll_dest ) {
        struct ll_protocol *ll_protocol = netdev->ll_protocol;
-       uint8_t *dest_bytes = ( ( uint8_t * ) &dest );
 
        if ( dest.s_addr == INADDR_BROADCAST ) {
                /* Broadcast address */
@@ -274,17 +273,7 @@ static int ipv4_ll_addr ( struct in_addr dest, struct in_addr src,
                         ll_protocol->ll_addr_len );
                return 0;
        } else if ( IN_MULTICAST ( ntohl ( dest.s_addr ) ) ) {
-               /* Special case: IPv4 multicast over Ethernet.  This
-                * code may need to be generalised once we find out
-                * what happens for other link layers.
-                */
-               ll_dest[0] = 0x01;
-               ll_dest[1] = 0x00;
-               ll_dest[2] = 0x5e;
-               ll_dest[3] = dest_bytes[1] & 0x7f;
-               ll_dest[4] = dest_bytes[2];
-               ll_dest[5] = dest_bytes[3];
-               return 0;
+               return ll_protocol->mc_hash ( AF_INET, &dest, ll_dest );
        } else {
                /* Unicast address: resolve via ARP */
                return arp_resolve ( netdev, &ipv4_protocol, &dest,