[PATCH libnetfilter_queue] src: Fix test for IPv6 header

[Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>]

Updated:

 src/extra/ipv6.c: Only test the first 4 bits of the putative IPv6 header to be
                   6, since all the other bits are up for grabs.
                   (I have seen nonzero Flow Control on the local interface and
                   RFC2474 & RFC3168 document Traffic Class use).

Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
 src/extra/ipv6.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/extra/ipv6.c b/src/extra/ipv6.c
index af307d6..f685b3b 100644
--- a/src/extra/ipv6.c
+++ b/src/extra/ipv6.c
@@ -45,7 +45,7 @@ struct ip6_hdr *nfq_ip6_get_hdr(struct pkt_buff *pktb)
 	ip6h = (struct ip6_hdr *)pktb->network_header;
 
 	/* Not IPv6 packet. */
-	if (ip6h->ip6_flow != 0x60)
+	if ((*(uint8_t *)ip6h & 0xf0) != 0x60)
 		return NULL;
 
 	return ip6h;
-- 
2.14.5