From c67b85558ff20cb1ff20874461d12af456bee5d0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 8 Jun 2019 17:58:51 -0700 Subject: [PATCH] ipv6: tcp: send consistent autoflowlabel in TIME_WAIT state In case autoflowlabel is in action, skb_get_hash_flowi6() derives a non zero skb->hash to the flowlabel. If skb->hash is zero, a flow dissection is performed. Since all TCP skbs sent from ESTABLISH state inherit their skb->hash from sk->sk_txhash, we better keep a copy of sk->sk_txhash into the TIME_WAIT socket. After this patch, ACK or RST packets sent on behalf of a TIME_WAIT socket have the flowlabel that was previously used by the flow. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/inet_timewait_sock.h | 1 + net/ipv4/tcp_minisocks.c | 1 + net/ipv6/tcp_ipv6.c | 13 ++++++++++--- 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h index c2f756aedc54..aef38c140014 100644 --- a/include/net/inet_timewait_sock.h +++ b/include/net/inet_timewait_sock.h @@ -70,6 +70,7 @@ struct inet_timewait_sock { tw_flowlabel : 20, tw_pad : 2, /* 2 bits hole */ tw_tos : 8; + u32 tw_txhash; struct timer_list tw_timer; struct inet_bind_bucket *tw_tb; }; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 7c35731816e2..11011e8386dc 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -283,6 +283,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr; tw->tw_tclass = np->tclass; tw->tw_flowlabel = be32_to_cpu(np->flow_label & IPV6_FLOWLABEL_MASK); + tw->tw_txhash = sk->sk_txhash; tw->tw_ipv6only = sk->sk_ipv6only; } #endif diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index c1da52c7f990..ad7039137a20 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -883,9 +883,16 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 fl6.flowi6_oif = oif; } - if (sk) - mark = (sk->sk_state == TCP_TIME_WAIT) ? - inet_twsk(sk)->tw_mark : sk->sk_mark; + if (sk) { + if (sk->sk_state == TCP_TIME_WAIT) { + mark = inet_twsk(sk)->tw_mark; + /* autoflowlabel relies on buff->hash */ + skb_set_hash(buff, inet_twsk(sk)->tw_txhash, + PKT_HASH_TYPE_L4); + } else { + mark = sk->sk_mark; + } + } fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; fl6.fl6_dport = t1->dest; fl6.fl6_sport = t1->source;