When I was playing around with TPACKET_V2, I think I ran
into a bug in ixgbe_atr(): if I get here with an
sk_buff that has, e.g., just 14 bytes in the header, then
the skb_network_header is invalid. I found my kernel sometimes
wandering off into ipv6_find_hdr() in an attempt to get the
l4_proto, and then complaining that "IPv6 header not found\n"
(this was an ipv4 packet).
I think we want to use skb_header_pointer in ixgbe_atr to get
the network header itself.. I tried the patch below, and it
works for simple (non-vlan, basic) ethernet header, but probably
needs more refinement to work for more complex encapsulations?
And other drivers may need a similar fix too, I've not checked yet.
--Sowmini
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index a244d9a..be453c6 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7627,6 +7627,10 @@ static void ixgbe_atr(struct ixgbe_ring *ring,
struct iphdr *ipv4;
struct ipv6hdr *ipv6;
} hdr;
+ union {
+ struct iphdr ipv4;
+ struct ipv6hdr ipv6;
+ } ip_hdr;
struct tcphdr *th;
unsigned int hlen;
struct sk_buff *skb;
@@ -7667,13 +7671,15 @@ static void ixgbe_atr(struct ixgbe_ring *ring,
}
/* Currently only IPv4/IPv6 with TCP is supported */
- switch (hdr.ipv4->version) {
- case IPVERSION:
+ switch (ntohs(first->protocol)) {
+ case ETH_P_IP:
+ skb_header_pointer(skb, ETH_HLEN, sizeof (struct iphdr),
+ &ip_hdr);
/* access ihl as u8 to avoid unaligned access on ia64 */
- hlen = (hdr.network[0] & 0x0F) << 2;
- l4_proto = hdr.ipv4->protocol;
+ hlen = ip_hdr.ipv4.ihl << 2;
+ l4_proto = ip_hdr.ipv4.protocol;
break;
- case 6:
+ case ETH_P_IPV6:
hlen = hdr.network - skb->data;
l4_proto = ipv6_find_hdr(skb, &hlen, IPPROTO_TCP, NULL, NULL);
hlen -= hdr.network - skb->data;
