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authorJon Maxwell <jmaxwell37@gmail.com>2018-05-10 16:53:51 +1000
committerDavid S. Miller <davem@davemloft.net>2018-05-10 17:44:52 -0400
commit00483690552c5fb6aa30bf3acb75b0ee89b4c0fd (patch)
tree6946a9497933df7fe6ae0f54729ee84b04e1ca1e /net/ipv4/tcp_ipv4.c
parentnet: ipv4: remove define INET_CSK_DEBUG and unnecessary EXPORT_SYMBOL (diff)
downloadlinux-dev-00483690552c5fb6aa30bf3acb75b0ee89b4c0fd.tar.xz
linux-dev-00483690552c5fb6aa30bf3acb75b0ee89b4c0fd.zip
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 <jmaxwell37@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c16
1 files changed, 14 insertions, 2 deletions
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();
}