flow: flow_extract() improperly parses IPv6 TOS bits.

This problem could cause userspace to automatically evict IPv6
flows from the datapath which had TOS bits set.

Bug #8323.

diff --git a/lib/flow.c b/lib/flow.c
index 06cc822..8ab2792 100644 (file)
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -148,7 +148,7 @@ parse_ipv6(struct ofpbuf *packet, struct flow *flow)
     flow->ipv6_dst = nh->ip6_dst;
 
     tc_flow = get_unaligned_be32(&nh->ip6_flow);
-    flow->tos_frag = (ntohl(tc_flow) >> 4) & IP_DSCP_MASK;
+    flow->tos_frag = (ntohl(tc_flow) >> 20) & IP_DSCP_MASK;
     flow->nw_proto = IPPROTO_NONE;
 
     while (1) {