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, 46 insertions, 3 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 0e28383c096f..9a459be24af7 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -262,7 +262,51 @@ static struct ctl_table xfrm4_policy_table[] = {
         { }
 };
 
-static struct ctl_table_header *sysctl_hdr;
+static int __net_init xfrm4_net_init(struct net *net)
+{
+        struct ctl_table *table;
+        struct ctl_table_header *hdr;
+
+        table = xfrm4_policy_table;
+        if (!net_eq(net, &init_net)) {
+                table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL);
+                if (!table)
+                        goto err_alloc;
+
+                table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;
+        }
+
+        hdr = register_net_sysctl(net, "net/ipv4", table);
+        if (!hdr)
+                goto err_reg;
+
+        net->ipv4.xfrm4_hdr = hdr;
+        return 0;
+
+err_reg:
+        if (!net_eq(net, &init_net))
+                kfree(table);
+err_alloc:
+        return -ENOMEM;
+}
+
+static void __net_exit xfrm4_net_exit(struct net *net)
+{
+        struct ctl_table *table;
+
+        if (net->ipv4.xfrm4_hdr == NULL)
+                return;
+
+        table = net->ipv4.xfrm4_hdr->ctl_table_arg;
+        unregister_net_sysctl_table(net->ipv4.xfrm4_hdr);
+        if (!net_eq(net, &init_net))
+                kfree(table);
+}
+
+static struct pernet_operations __net_initdata xfrm4_net_ops = {
+        .init   = xfrm4_net_init,
+        .exit   = xfrm4_net_exit,
+};
 #endif
 
 static void __init xfrm4_policy_init(void)
@@ -277,8 +321,7 @@ void __init xfrm4_init(void)
         xfrm4_state_init();
         xfrm4_policy_init();
 #ifdef CONFIG_SYSCTL
-        sysctl_hdr = register_net_sysctl(&init_net, "net/ipv4",
-                                         xfrm4_policy_table);
+        register_pernet_subsys(&xfrm4_net_ops);
 #endif
 }