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| author | Roman Kapl <roman.kapl@sysgo.com> | 2017-05-24 10:22:22 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-25 13:12:17 -0400 |
| commit | 7c3f1875c66fbc19762760097cabc91849ea0bbb (patch) | |
| tree | 3254c77f3f02b5436ab02632a5cbfa81367b6f9a | |
| parent | 65d786c21bf8140dac83563306f46fe0b13a9aaa (diff) | |
| download | linux-7c3f1875c66fbc19762760097cabc91849ea0bbb.tar.gz linux-7c3f1875c66fbc19762760097cabc91849ea0bbb.tar.bz2 linux-7c3f1875c66fbc19762760097cabc91849ea0bbb.zip | |
net: move somaxconn init from sysctl code
The default value for somaxconn is set in sysctl_core_net_init(), but this
function is not called when kernel is configured without CONFIG_SYSCTL.
This results in the kernel not being able to accept TCP connections,
because the backlog has zero size. Usually, the user ends up with:
"TCP: request_sock_TCP: Possible SYN flooding on port 7. Dropping request. Check SNMP counters."
If SYN cookies are not enabled the connection is rejected.
Before ef547f2ac16 (tcp: remove max_qlen_log), the effects were less
severe, because the backlog was always at least eight slots long.
Signed-off-by: Roman Kapl <roman.kapl@sysgo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/net_namespace.c | 19 | ||||
| -rw-r--r-- | net/core/sysctl_net_core.c | 2 |
2 files changed, 19 insertions, 2 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 1934efd4a9d4..26bbfababff2 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -315,6 +315,25 @@ out_undo: goto out; } +static int __net_init net_defaults_init_net(struct net *net) +{ + net->core.sysctl_somaxconn = SOMAXCONN; + return 0; +} + +static struct pernet_operations net_defaults_ops = { + .init = net_defaults_init_net, +}; + +static __init int net_defaults_init(void) +{ + if (register_pernet_subsys(&net_defaults_ops)) + panic("Cannot initialize net default settings"); + + return 0; +} + +core_initcall(net_defaults_init); #ifdef CONFIG_NET_NS static struct ucounts *inc_net_namespaces(struct user_namespace *ns) diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index ea23254b2457..b7cd9aafe99e 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -479,8 +479,6 @@ static __net_init int sysctl_core_net_init(struct net *net) { struct ctl_table *tbl; - net->core.sysctl_somaxconn = SOMAXCONN; - tbl = netns_core_table; if (!net_eq(net, &init_net)) { tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL); |