[RFC net 2/2] net: tcp_v6_send_reset should set flowlabel

[Shaohua Li]

From: Shaohua Li <s...@fb.com>

Currently tcp_v6_send_reset ignores user defined flowlabel, so the reset
packet doesn't include the flowlabel info.

Signed-off-by: Shaohua Li <s...@fb.com>
---
 net/ipv6/tcp_ipv6.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2e656d2..eaf4b8e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -898,6 +898,8 @@ static void tcp_v6_send_reset(const struct sock *sk, struct 
sk_buff *skb)
        struct sock *sk1 = NULL;
 #endif
        int oif;
+       u8 tclass = 0;
+       __be32 flowlabel = 0;
 
        if (th->rst)
                return;
@@ -946,7 +948,21 @@ static void tcp_v6_send_reset(const struct sock *sk, 
struct sk_buff *skb)
                          (th->doff << 2);
 
        oif = sk ? sk->sk_bound_dev_if : 0;
-       tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
+       if (sk) {
+               if (sk_fullsock(sk)) {
+                       struct ipv6_pinfo *np = inet6_sk(sk);
+
+                       tclass = np->tclass;
+                       flowlabel = np->flow_label & IPV6_FLOWLABEL_MASK;
+               } else {
+                       struct inet_timewait_sock *tw = inet_twsk(sk);
+
+                       tclass = tw->tw_tclass;
+                       flowlabel = cpu_to_be32(tw->tw_flowlabel);
+               }
+       }
+       tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
+               tclass, flowlabel);
 
 #ifdef CONFIG_TCP_MD5SIG
 out:
-- 
2.9.3