2016-12-25 06:33:33

by Haishuang Yan

Subject: [PATCH v2] ipv4: Namespaceify tcp_tw_reuse knob

Different namespaces might have different requirements to reuse
TIME-WAIT sockets for new connections. This might be required in
cases where different namespace applications are in place which
require TIME_WAIT socket connections to be reduced independently
of the host.

Signed-off-by: Haishuang Yan <[email protected]>

---
Changes in v2:
- Make the commit message more clearer.
---
include/net/netns/ipv4.h | 1 +
include/net/tcp.h | 1 -
net/ipv4/sysctl_net_ipv4.c | 14 +++++++-------
net/ipv4/tcp_ipv4.c | 4 ++--
4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index f0cf5a1..0378e88 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -110,6 +110,7 @@ struct netns_ipv4 {
int sysctl_tcp_orphan_retries;
int sysctl_tcp_fin_timeout;
unsigned int sysctl_tcp_notsent_lowat;
+ int sysctl_tcp_tw_reuse;

int sysctl_igmp_max_memberships;
int sysctl_igmp_max_msf;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 207147b..6061963 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -252,7 +252,6 @@
extern int sysctl_tcp_rmem[3];
extern int sysctl_tcp_app_win;
extern int sysctl_tcp_adv_win_scale;
-extern int sysctl_tcp_tw_reuse;
extern int sysctl_tcp_frto;
extern int sysctl_tcp_low_latency;
extern int sysctl_tcp_nometrics_save;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 80bc36b..22cbd61 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -433,13 +433,6 @@ static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write,
.extra2 = &tcp_adv_win_scale_max,
},
{
- .procname = "tcp_tw_reuse",
- .data = &sysctl_tcp_tw_reuse,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec
- },
- {
.procname = "tcp_frto",
.data = &sysctl_tcp_frto,
.maxlen = sizeof(int),
@@ -960,6 +953,13 @@ static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write,
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "tcp_tw_reuse",
+ .data = &init_net.ipv4.sysctl_tcp_tw_reuse,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
#ifdef CONFIG_IP_ROUTE_MULTIPATH
{
.procname = "fib_multipath_use_neigh",
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 30d81f5..fe9da4f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -84,7 +84,6 @@
#include <crypto/hash.h>
#include <linux/scatterlist.h>

-int sysctl_tcp_tw_reuse __read_mostly;
int sysctl_tcp_low_latency __read_mostly;

#ifdef CONFIG_TCP_MD5SIG
@@ -120,7 +119,7 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
and use initial timestamp retrieved from peer table.
*/
if (tcptw->tw_ts_recent_stamp &&
- (!twp || (sysctl_tcp_tw_reuse &&
+ (!twp || (sock_net(sk)->ipv4.sysctl_tcp_tw_reuse &&
get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
if (tp->write_seq == 0)
@@ -2456,6 +2455,7 @@ static int __net_init tcp_sk_init(struct net *net)
net->ipv4.sysctl_tcp_orphan_retries = 0;
net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;
net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX;
+ net->ipv4.sysctl_tcp_tw_reuse = 0;

return 0;
fail:
--
1.8.3.1

2016-12-27 17:29:56

by David Miller

Subject: Re: [PATCH v2] ipv4: Namespaceify tcp_tw_reuse knob

From: Haishuang Yan <[email protected]>
Date: Sun, 25 Dec 2016 14:33:16 +0800

> Different namespaces might have different requirements to reuse
> TIME-WAIT sockets for new connections. This might be required in
> cases where different namespace applications are in place which
> require TIME_WAIT socket connections to be reduced independently
> of the host.
>
> Signed-off-by: Haishuang Yan <[email protected]>
>
> ---
> Changes in v2:
> - Make the commit message more clearer.

Applied.