[PATCH] dvb: dvb_net: handle IPv6 and LLC/SNAP

handle IPv6 and LLC/SNAP (Bertrand Mazieres, Matthieu Castet, Johannes
Stezenbach)

Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/media/dvb/dvb-core/dvb_net.c b/drivers/media/dvb/dvb-core/dvb_net.c
index 997199c..6a968c3 100644 (file)
--- a/drivers/media/dvb/dvb-core/dvb_net.c
+++ b/drivers/media/dvb/dvb-core/dvb_net.c
@@ -727,6 +727,7 @@ static void dvb_net_sec(struct net_device *dev, u8 *pkt, int pkt_len)
         u8 *eth;
         struct sk_buff *skb;
        struct net_device_stats *stats = &(((struct dvb_net_priv *) dev->priv)->stats);
+       int snap = 0;
 
        /* note: pkt_len includes a 32bit checksum */
        if (pkt_len < 16) {
@@ -750,9 +751,12 @@ static void dvb_net_sec(struct net_device *dev, u8 *pkt, int pkt_len)
                return;
        }
        if (pkt[5] & 0x02) {
-               //FIXME: handle LLC/SNAP
-                stats->rx_dropped++;
-                return;
+               /* handle LLC/SNAP, see rfc-1042 */
+               if (pkt_len < 24 || memcmp(&pkt[12], "\xaa\xaa\x03\0\0\0", 6)) {
+                       stats->rx_dropped++;
+                       return;
+               }
+               snap = 8;
         }
        if (pkt[7]) {
                /* FIXME: assemble datagram from multiple sections */
@@ -762,9 +766,9 @@ static void dvb_net_sec(struct net_device *dev, u8 *pkt, int pkt_len)
        }
 
        /* we have 14 byte ethernet header (ip header follows);
-        * 12 byte MPE header; 4 byte checksum; + 2 byte alignment
+        * 12 byte MPE header; 4 byte checksum; + 2 byte alignment, 8 byte LLC/SNAP
         */
-       if (!(skb = dev_alloc_skb(pkt_len - 4 - 12 + 14 + 2))) {
+       if (!(skb = dev_alloc_skb(pkt_len - 4 - 12 + 14 + 2 - snap))) {
                //printk(KERN_NOTICE "%s: Memory squeeze, dropping packet.\n", dev->name);
                stats->rx_dropped++;
                return;
@@ -773,8 +777,8 @@ static void dvb_net_sec(struct net_device *dev, u8 *pkt, int pkt_len)
        skb->dev = dev;
 
        /* copy L3 payload */
-       eth = (u8 *) skb_put(skb, pkt_len - 12 - 4 + 14);
-       memcpy(eth + 14, pkt + 12, pkt_len - 12 - 4);
+       eth = (u8 *) skb_put(skb, pkt_len - 12 - 4 + 14 - snap);
+       memcpy(eth + 14, pkt + 12 + snap, pkt_len - 12 - 4 - snap);
 
        /* create ethernet header: */
         eth[0]=pkt[0x0b];
@@ -786,8 +790,21 @@ static void dvb_net_sec(struct net_device *dev, u8 *pkt, int pkt_len)
 
         eth[6]=eth[7]=eth[8]=eth[9]=eth[10]=eth[11]=0;
 
-       eth[12] = 0x08; /* ETH_P_IP */
-       eth[13] = 0x00;
+       if (snap) {
+               eth[12] = pkt[18];
+               eth[13] = pkt[19];
+       } else {
+               /* protocol numbers are from rfc-1700 or
+                * http://www.iana.org/assignments/ethernet-numbers
+                */
+               if (pkt[12] >> 4 == 6) { /* version field from IP header */
+                       eth[12] = 0x86; /* IPv6 */
+                       eth[13] = 0xdd;
+               } else {
+                       eth[12] = 0x08; /* IPv4 */
+                       eth[13] = 0x00;
+               }
+       }
 
        skb->protocol = dvb_net_eth_type_trans(skb, dev);