From: Guillaume Nault gnault@redhat.com
commit 8230680f36fd1525303d1117768c8852314c488c upstream.
Take into account the IPV6_TCLASS socket option (DSCP) in tcp_v6_connect(). Otherwise fib6_rule_match() can't properly match the DSCP value, resulting in invalid route lookup.
For example:
ip route add unreachable table main 2001:db8::10/124
ip route add table 100 2001:db8::10/124 dev eth0 ip -6 rule add dsfield 0x04 table 100
echo test | socat - TCP6:[2001:db8::11]:54321,ipv6-tclass=0x04
Without this patch, socat fails at connect() time ("No route to host") because the fib-rule doesn't jump to table 100 and the lookup ends up being done in the main table.
Fixes: 2cc67cc731d9 ("[IPV6] ROUTE: Routing by Traffic Class.") Signed-off-by: Guillaume Nault gnault@redhat.com Reviewed-by: Eric Dumazet edumazet@google.com Reviewed-by: David Ahern dsahern@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/tcp_ipv6.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -241,6 +241,7 @@ static int tcp_v6_connect(struct sock *s fl6.flowi6_proto = IPPROTO_TCP; fl6.daddr = sk->sk_v6_daddr; fl6.saddr = saddr ? *saddr : np->saddr; + fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label); fl6.flowi6_oif = sk->sk_bound_dev_if; fl6.flowi6_mark = sk->sk_mark; fl6.fl6_dport = usin->sin6_port;