xfrm: make gc_thresh configurable in all namespaces

The xfrm gc threshold can be configured via xfrm{4,6}_gc_thresh
sysctl but currently only in init_net, other namespaces always
use the default value. This can substantially limit the number
of IPsec tunnels that can be effectively used.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 47 insertions, 5 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 128273744332..4ef7bdb65440 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -320,7 +320,51 @@ static struct ctl_table xfrm6_policy_table[] = {
         { }
 };
 
-static struct ctl_table_header *sysctl_hdr;
+static int __net_init xfrm6_net_init(struct net *net)
+{
+        struct ctl_table *table;
+        struct ctl_table_header *hdr;
+
+        table = xfrm6_policy_table;
+        if (!net_eq(net, &init_net)) {
+                table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
+                if (!table)
+                        goto err_alloc;
+
+                table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
+        }
+
+        hdr = register_net_sysctl(net, "net/ipv6", table);
+        if (!hdr)
+                goto err_reg;
+
+        net->ipv6.sysctl.xfrm6_hdr = hdr;
+        return 0;
+
+err_reg:
+        if (!net_eq(net, &init_net))
+                kfree(table);
+err_alloc:
+        return -ENOMEM;
+}
+
+static void __net_exit xfrm6_net_exit(struct net *net)
+{
+        struct ctl_table *table;
+
+        if (net->ipv6.sysctl.xfrm6_hdr == NULL)
+                return;
+
+        table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
+        unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
+        if (!net_eq(net, &init_net))
+                kfree(table);
+}
+
+static struct pernet_operations xfrm6_net_ops = {
+        .init   = xfrm6_net_init,
+        .exit   = xfrm6_net_exit,
+};
 #endif
 
 int __init xfrm6_init(void)
@@ -339,8 +383,7 @@ int __init xfrm6_init(void)
                 goto out_policy;
 
 #ifdef CONFIG_SYSCTL
-        sysctl_hdr = register_net_sysctl(&init_net, "net/ipv6",
-                                         xfrm6_policy_table);
+        register_pernet_subsys(&xfrm6_net_ops);
 #endif
 out:
         return ret;
@@ -352,8 +395,7 @@ out_policy:
 void xfrm6_fini(void)
 {
 #ifdef CONFIG_SYSCTL
-        if (sysctl_hdr)
-                unregister_net_sysctl_table(sysctl_hdr);
+        unregister_pernet_subsys(&xfrm6_net_ops);
 #endif
         xfrm6_policy_fini();
         xfrm6_state_fini();