[PATCH net-next 2/2] flow_dissector: add support for dst, hop-by-hop and routing ext hdrs

[Tom Herbert <tom@herbertland.com>]

If dst, hop-by-hop or routing extension headers are present determine
length of the options and skip over them in flow dissection.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 net/core/flow_dissector.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 1818cdc..22e4dff 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -327,6 +327,7 @@ mpls:
 		return false;
 	}
 
+ip_proto_again:
 	switch (ip_proto) {
 	case IPPROTO_GRE: {
 		struct gre_hdr {
@@ -383,6 +384,22 @@ mpls:
 		}
 		goto again;
 	}
+	case NEXTHDR_HOP:
+	case NEXTHDR_ROUTING:
+	case NEXTHDR_DEST: {
+		u8 _opthdr[2], *opthdr;
+
+		if (proto != htons(ETH_P_IPV6))
+			break;
+
+		opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
+					      data, hlen, &_opthdr);
+
+		ip_proto = _opthdr[0];
+		nhoff += (_opthdr[1] + 1) << 3;
+
+		goto ip_proto_again;
+	}
 	case IPPROTO_IPIP:
 		proto = htons(ETH_P_IP);
 		goto ip;
-- 
1.8.1