[PATCH 2/9] ipv4: Namespaceify tcp synack retries sysctl knob

From: Nikolay Borisov
Date: Mon Jan 11 2016 - 04:52:11 EST


Signed-off-by: Nikolay Borisov <kernel@xxxxxxxx>
---
include/net/netns/ipv4.h | 1 +
include/net/tcp.h | 1 -
net/ipv4/inet_connection_sock.c | 7 ++-----
net/ipv4/sysctl_net_ipv4.c | 14 +++++++-------
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_timer.c | 3 +--
6 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 59c6155e4896..bca049102441 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -96,6 +96,7 @@ struct netns_ipv4 {
int sysctl_tcp_keepalive_intvl;

int sysctl_tcp_syn_retries;
+ int sysctl_tcp_synack_retries;

struct ping_group_range ping_group_range;

diff --git a/include/net/tcp.h b/include/net/tcp.h
index a7f6f25297d7..5a162875e80c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -240,7 +240,6 @@ extern int sysctl_tcp_timestamps;
extern int sysctl_tcp_window_scaling;
extern int sysctl_tcp_sack;
extern int sysctl_tcp_fin_timeout;
-extern int sysctl_tcp_synack_retries;
extern int sysctl_tcp_retries1;
extern int sysctl_tcp_retries2;
extern int sysctl_tcp_orphan_retries;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 46b9c887bede..9b17c1792dce 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -482,10 +482,6 @@ EXPORT_SYMBOL_GPL(inet_csk_route_child_sock);
#define AF_INET_FAMILY(fam) true
#endif

-/* Only thing we need from tcp.h */
-extern int sysctl_tcp_synack_retries;
-
-
/* Decide when to expire the request and when to resend SYN-ACK */
static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
const int max_retries,
@@ -557,6 +553,7 @@ static void reqsk_timer_handler(unsigned long data)
{
struct request_sock *req = (struct request_sock *)data;
struct sock *sk_listener = req->rsk_listener;
+ struct net *net = sock_net(sk_listener);
struct inet_connection_sock *icsk = inet_csk(sk_listener);
struct request_sock_queue *queue = &icsk->icsk_accept_queue;
int qlen, expire = 0, resend = 0;
@@ -566,7 +563,7 @@ static void reqsk_timer_handler(unsigned long data)
if (sk_state_load(sk_listener) != TCP_LISTEN)
goto drop;

- max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
+ max_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries;
thresh = max_retries;
/* Normally all the openreqs are young and become mature
* (i.e. converted to established socket) for first timeout.
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index db95287d2b94..5dd89de5bf8d 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -293,13 +293,6 @@ static struct ctl_table ipv4_table[] = {
.extra2 = &ip_ttl_max,
},
{
- .procname = "tcp_synack_retries",
- .data = &sysctl_tcp_synack_retries,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = proc_dointvec
- },
- {
.procname = "tcp_max_orphans",
.data = &sysctl_tcp_max_orphans,
.maxlen = sizeof(int),
@@ -950,6 +943,13 @@ static struct ctl_table ipv4_net_table[] = {
.extra1 = &tcp_syn_retries_min,
.extra2 = &tcp_syn_retries_max
},
+ {
+ .procname = "tcp_synack_retries",
+ .data = &init_net.ipv4.sysctl_tcp_synack_retries,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
{ }
};

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c9944e0c48d3..a5268576021c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2383,6 +2383,7 @@ static int __net_init tcp_sk_init(struct net *net)
net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL;

net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES;
+ net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES;

return 0;
fail:
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c5d51f530c65..ca25fdf0c525 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -22,7 +22,6 @@
#include <linux/gfp.h>
#include <net/tcp.h>

-int sysctl_tcp_synack_retries __read_mostly = TCP_SYNACK_RETRIES;
int sysctl_tcp_retries1 __read_mostly = TCP_RETR1;
int sysctl_tcp_retries2 __read_mostly = TCP_RETR2;
int sysctl_tcp_orphan_retries __read_mostly;
@@ -332,7 +331,7 @@ static void tcp_fastopen_synack_timer(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
int max_retries = icsk->icsk_syn_retries ? :
- sysctl_tcp_synack_retries + 1; /* add one more retry for fastopen */
+ sock_net(sk)->ipv4.sysctl_tcp_synack_retries + 1; /* add one more retry for fastopen */
struct request_sock *req;

req = tcp_sk(sk)->fastopen_rsk;
--
2.5.0