1 files changed, 38 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 3a3c677bc0f2..8ec3d45cd1d9 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -306,9 +306,26 @@ static void xfrm6_policy_fini(void)
         xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
 }
 
+#ifdef CONFIG_SYSCTL
+static struct ctl_table xfrm6_policy_table[] = {
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "xfrm6_gc_thresh",
+                .data           = &xfrm6_dst_ops.gc_thresh,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = proc_dointvec,
+        },
+        { }
+};
+
+static struct ctl_table_header *sysctl_hdr;
+#endif
+
 int __init xfrm6_init(void)
 {
         int ret;
+        unsigned int gc_thresh;
 
         ret = xfrm6_policy_init();
         if (ret)
@@ -317,6 +334,23 @@ int __init xfrm6_init(void)
         ret = xfrm6_state_init();
         if (ret)
                 goto out_policy;
+        /*
+         * We need a good default value for the xfrm6 gc threshold.
+         * In ipv4 we set it to the route hash table size * 8, which
+         * is half the size of the maximaum route cache for ipv4.  It
+         * would be good to do the same thing for v6, except the table is
+         * constructed differently here.  Here each table for a net namespace
+         * can have FIB_TABLE_HASHSZ entries, so lets go with the same
+         * computation that we used for ipv4 here.  Also, lets keep the initial
+         * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults
+         * to that as a minimum as well
+         */
+        gc_thresh = FIB6_TABLE_HASHSZ * 8;
+        xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
+#ifdef CONFIG_SYSCTL
+        sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path,
+                                                xfrm6_policy_table);
+#endif
 out:
         return ret;
 out_policy:
@@ -326,6 +360,10 @@ out_policy:
 
 void xfrm6_fini(void)
 {
+#ifdef CONFIG_SYSCTL
+        if (sysctl_hdr)
+                unregister_net_sysctl_table(sysctl_hdr);
+#endif
         //xfrm6_input_fini();
         xfrm6_policy_fini();
         xfrm6_state_fini();