netns: Register net/core/ sysctls at read-only root.

Most of the net/core/xxx sysctls are read-only now, but this
goal is achieved with excessive memory consumption in each
namespace - the whole table is cloned and most of the entries
in it are ~= 0222.

Split it into two parts and register (the largest) one at the
read-only root.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pavel Emelyanov 2008-05-19 13:49:52 -07:00 committed by David S. Miller
parent d62c612ef8
commit d5a4502e9e

View file

@ -124,14 +124,6 @@ static struct ctl_table net_core_table[] = {
},
#endif /* CONFIG_XFRM */
#endif /* CONFIG_NET */
{
.ctl_name = NET_CORE_SOMAXCONN,
.procname = "somaxconn",
.data = &init_net.core.sysctl_somaxconn,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{
.ctl_name = NET_CORE_BUDGET,
.procname = "netdev_budget",
@ -151,6 +143,18 @@ static struct ctl_table net_core_table[] = {
{ .ctl_name = 0 }
};
static struct ctl_table netns_core_table[] = {
{
.ctl_name = NET_CORE_SOMAXCONN,
.procname = "somaxconn",
.data = &init_net.core.sysctl_somaxconn,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec
},
{ .ctl_name = 0 }
};
static __net_initdata struct ctl_path net_core_path[] = {
{ .procname = "net", .ctl_name = CTL_NET, },
{ .procname = "core", .ctl_name = NET_CORE, },
@ -159,23 +163,17 @@ static __net_initdata struct ctl_path net_core_path[] = {
static __net_init int sysctl_core_net_init(struct net *net)
{
struct ctl_table *tbl, *tmp;
struct ctl_table *tbl;
net->core.sysctl_somaxconn = SOMAXCONN;
tbl = net_core_table;
tbl = netns_core_table;
if (net != &init_net) {
tbl = kmemdup(tbl, sizeof(net_core_table), GFP_KERNEL);
tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
if (tbl == NULL)
goto err_dup;
for (tmp = tbl; tmp->procname; tmp++) {
if (tmp->data >= (void *)&init_net &&
tmp->data < (void *)(&init_net + 1))
tmp->data += (char *)net - (char *)&init_net;
else
tmp->mode &= ~0222;
}
tbl[0].data = &net->core.sysctl_somaxconn;
}
net->core.sysctl_hdr = register_net_sysctl_table(net,
@ -186,7 +184,7 @@ static __net_init int sysctl_core_net_init(struct net *net)
return 0;
err_reg:
if (tbl != net_core_table)
if (tbl != netns_core_table)
kfree(tbl);
err_dup:
return -ENOMEM;
@ -198,7 +196,7 @@ static __net_exit void sysctl_core_net_exit(struct net *net)
tbl = net->core.sysctl_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->core.sysctl_hdr);
BUG_ON(tbl == net_core_table);
BUG_ON(tbl == netns_core_table);
kfree(tbl);
}
@ -209,6 +207,7 @@ static __net_initdata struct pernet_operations sysctl_core_ops = {
static __init int sysctl_core_init(void)
{
register_net_sysctl_rotable(net_core_path, net_core_table);
return register_pernet_subsys(&sysctl_core_ops);
}