From 00483690552c5fb6aa30bf3acb75b0ee89b4c0fd Mon Sep 17 00:00:00 2001 From: Jon Maxwell Date: Thu, 10 May 2018 16:53:51 +1000 Subject: tcp: Add mark for TIMEWAIT sockets This version has some suggestions by Eric Dumazet: - Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP races. - Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark" statement. - Factorize code as sk_fullsock() check is not necessary. Aidan McGurn from Openwave Mobility systems reported the following bug: "Marked routing is broken on customer deployment. Its effects are large increase in Uplink retransmissions caused by the client never receiving the final ACK to their FINACK - this ACK misses the mark and routes out of the incorrect route." Currently marks are added to sk_buffs for replies when the "fwmark_reflect" sysctl is enabled. But not for TW sockets that had sk->sk_mark set via setsockopt(SO_MARK..). Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location. Then progate this so that the skb gets sent with the correct mark. Do the same for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that netfilter rules are still honored. Signed-off-by: Jon Maxwell Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index f70586b50838..caf23de88f8a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -621,6 +621,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) struct sock *sk1 = NULL; #endif struct net *net; + struct sock *ctl_sk; /* Never send a reset in response to a reset. */ if (th->rst) @@ -723,11 +724,16 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) arg.tos = ip_hdr(skb)->tos; arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); local_bh_disable(); - ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), + ctl_sk = *this_cpu_ptr(net->ipv4.tcp_sk); + if (sk) + ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_mark : sk->sk_mark; + ip_send_unicast_reply(ctl_sk, skb, &TCP_SKB_CB(skb)->header.h4.opt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); + ctl_sk->sk_mark = 0; __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); local_bh_enable(); @@ -759,6 +765,7 @@ static void tcp_v4_send_ack(const struct sock *sk, } rep; struct net *net = sock_net(sk); struct ip_reply_arg arg; + struct sock *ctl_sk; memset(&rep.th, 0, sizeof(struct tcphdr)); memset(&arg, 0, sizeof(arg)); @@ -809,11 +816,16 @@ static void tcp_v4_send_ack(const struct sock *sk, arg.tos = tos; arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL); local_bh_disable(); - ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), + ctl_sk = *this_cpu_ptr(net->ipv4.tcp_sk); + if (sk) + ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? + inet_twsk(sk)->tw_mark : sk->sk_mark; + ip_send_unicast_reply(ctl_sk, skb, &TCP_SKB_CB(skb)->header.h4.opt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); + ctl_sk->sk_mark = 0; __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); local_bh_enable(); } -- cgit v1.2.3-59-g8ed1b