The seg6_make_flowlabel() is used by seg6_do_srh_encap() to compute the flowlabel from a given skb. It relies on skb_get_hash() which eventually calls __skb_flow_dissect() to extract the flow_keys struct values from the skb.
In case of IPv4 traffic, calling seg6_make_flowlabel() after skb_push(), skb_reset_network_header(), and skb_mac_header_rebuild() will results in flow_keys struct of all key values set to zero. This patch calls seg6_make_flowlabel() before resetting the headers of skb to get the right key values. Extracted Key values are based on the type inner packet as follows: 1) IPv6 traffic: src_IP, dst_IP, L4 proto, and flowlabel of inner packet. 2) IPv4 traffic: src_IP, dst_IP, L4 proto, src_port, and dst_port 3) L2 traffic: depends on what kind of traffic carried into the L2 frame. IPv6 and IPv4 traffic works as discussed 1) and 2) Signed-off-by: Ahmed Abdelsalam <amsala...@gmail.com> --- net/ipv6/seg6_iptunnel.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 9898926..0df83c0 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -119,6 +119,9 @@ int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto) int hdrlen, tot_len, err; __be32 flowlabel; + inner_hdr = ipv6_hdr(skb); + flowlabel = seg6_make_flowlabel(net, skb, inner_hdr); + hdrlen = (osrh->hdrlen + 1) << 3; tot_len = hdrlen + sizeof(*hdr); @@ -126,8 +129,6 @@ int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto) if (unlikely(err)) return err; - inner_hdr = ipv6_hdr(skb); - skb_push(skb, tot_len); skb_reset_network_header(skb); skb_mac_header_rebuild(skb); @@ -138,7 +139,6 @@ int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto) * decapsulation will overwrite inner hlim with outer hlim */ - flowlabel = seg6_make_flowlabel(net, skb, inner_hdr); if (skb->protocol == htons(ETH_P_IPV6)) { ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)), flowlabel); -- 2.1.4