nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

ipv6: tcp: send consistent autoflowlabel in TIME_WAIT state

Browse source 
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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2019-06-08 17:58:51 -07:00 committed by David S. Miller
parent 6566cd3690
commit c67b85558f
3 changed files with 12 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
include/net/inet_timewait_sock.h
View file

@ -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;
};

1
net/ipv4/tcp_minisocks.c
View file

@ -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

13
net/ipv6/tcp_ipv6.c
View file

@ -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;