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."
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.k...@sysgo.com>
---
net/core/net_namespace.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 1934efd..4f3bbff 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -37,6 +37,9 @@ EXPORT_SYMBOL_GPL(net_namespace_list);
struct net init_net = {
.count = ATOMIC_INIT(1),
.dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head),
+ .core = {
+ .sysctl_somaxconn = SOMAXCONN,
+ },
};
EXPORT_SYMBOL(init_net);
--
2.10.1
