net: Implement read-only protection and COW'ing of metrics.

[deliverable/linux.git] / net / ipv6 / route.c

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 1534508f6c68a3c4f010657e94051e06a7d727c4..45fafa018f12f410850a5a5335f27e590c8fa65d 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -105,6 +105,7 @@ static struct dst_ops ip6_dst_ops_template = {
        .check                  =       ip6_dst_check,
        .default_advmss         =       ip6_default_advmss,
        .default_mtu            =       ip6_default_mtu,
+       .cow_metrics            =       dst_cow_metrics_generic,
        .destroy                =       ip6_dst_destroy,
        .ifdown                 =       ip6_dst_ifdown,
        .negative_advice        =       ip6_negative_advice,
@@ -125,6 +126,10 @@ static struct dst_ops ip6_dst_blackhole_ops = {
        .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
 };
 
+static const u32 ip6_template_metrics[RTAX_MAX] = {
+       [RTAX_HOPLIMIT - 1] = 255,
+};
+
 static struct rt6_info ip6_null_entry_template = {
        .dst = {
                .__refcnt       = ATOMIC_INIT(1),
@@ -193,6 +198,7 @@ static void ip6_dst_destroy(struct dst_entry *dst)
                rt->rt6i_idev = NULL;
                in6_dev_put(idev);
        }
+       dst_destroy_metrics_generic(dst);
        if (peer) {
                BUG_ON(!(rt->rt6i_flags & RTF_CACHE));
                rt->rt6i_peer = NULL;
@@ -2681,7 +2687,8 @@ static int __net_init ip6_route_net_init(struct net *net)
        net->ipv6.ip6_null_entry->dst.path =
                (struct dst_entry *)net->ipv6.ip6_null_entry;
        net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
-       dst_metric_set(&net->ipv6.ip6_null_entry->dst, RTAX_HOPLIMIT, 255);
+       dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
+                        ip6_template_metrics, true);
 
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
        net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
@@ -2692,7 +2699,8 @@ static int __net_init ip6_route_net_init(struct net *net)
        net->ipv6.ip6_prohibit_entry->dst.path =
                (struct dst_entry *)net->ipv6.ip6_prohibit_entry;
        net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
-       dst_metric_set(&net->ipv6.ip6_prohibit_entry->dst, RTAX_HOPLIMIT, 255);
+       dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
+                        ip6_template_metrics, true);
 
        net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
                                               sizeof(*net->ipv6.ip6_blk_hole_entry),
@@ -2702,7 +2710,8 @@ static int __net_init ip6_route_net_init(struct net *net)
        net->ipv6.ip6_blk_hole_entry->dst.path =
                (struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
        net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
-       dst_metric_set(&net->ipv6.ip6_blk_hole_entry->dst, RTAX_HOPLIMIT, 255);
+       dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
+                        ip6_template_metrics, true);
 #endif
 
        net->ipv6.sysctl.flush_delay = 0;