[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>

1 files changed, 26 insertions, 9 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_net.c b/drivers/media/dvb/dvb-core/dvb_net.c
index 997199cc5801..6a968c346a36 100644
--- 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);