[NETNS][IPV6] rt6_info - make rt6_info accessed as a pointer

This patch make mindless changes and prepares the code to use dynamic
allocation for rt6_info structure. The code accesses the rt6_info
structure as a pointer instead of a global static variable.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 75 insertions, 37 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index b37ae421b61b..3192a848a53a 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4301,13 +4301,13 @@ int __init addrconf_init(void)
         if (err)
                 goto errlo;
 
-        ip6_null_entry.u.dst.dev = init_net.loopback_dev;
-        ip6_null_entry.rt6i_idev = in6_dev_get(init_net.loopback_dev);
+        ip6_null_entry->u.dst.dev = init_net.loopback_dev;
+        ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
-        ip6_prohibit_entry.u.dst.dev = init_net.loopback_dev;
-        ip6_prohibit_entry.rt6i_idev = in6_dev_get(init_net.loopback_dev);
-        ip6_blk_hole_entry.u.dst.dev = init_net.loopback_dev;
-        ip6_blk_hole_entry.rt6i_idev = in6_dev_get(init_net.loopback_dev);
+        ip6_prohibit_entry->u.dst.dev = init_net.loopback_dev;
+        ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+        ip6_blk_hole_entry->u.dst.dev = init_net.loopback_dev;
+        ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
 #endif
 
         register_netdevice_notifier(&ipv6_dev_notf);
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 89cb092c9732..c00055f232c4 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -43,8 +43,8 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
         if (arg.result)
                 return arg.result;
 
-        dst_hold(&ip6_null_entry.u.dst);
-        return &ip6_null_entry.u.dst;
+        dst_hold(&ip6_null_entry->u.dst);
+        return &ip6_null_entry->u.dst;
 }
 
 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
@@ -58,14 +58,14 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
         case FR_ACT_TO_TBL:
                 break;
         case FR_ACT_UNREACHABLE:
-                rt = &ip6_null_entry;
+                rt = ip6_null_entry;
                 goto discard_pkt;
         default:
         case FR_ACT_BLACKHOLE:
-                rt = &ip6_blk_hole_entry;
+                rt = ip6_blk_hole_entry;
                 goto discard_pkt;
         case FR_ACT_PROHIBIT:
-                rt = &ip6_prohibit_entry;
+                rt = ip6_prohibit_entry;
                 goto discard_pkt;
         }
 
@@ -73,7 +73,7 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
         if (table)
                 rt = lookup(table, flp, flags);
 
-        if (rt != &ip6_null_entry) {
+        if (rt != ip6_null_entry) {
                 struct fib6_rule *r = (struct fib6_rule *)rule;
 
                 /*
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 1c2566e3d392..f028f7a1a446 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -200,7 +200,7 @@ static struct fib6_table *fib6_alloc_table(u32 id)
         table = kzalloc(sizeof(*table), GFP_ATOMIC);
         if (table != NULL) {
                 table->tb6_id = id;
-                table->tb6_root.leaf = &ip6_null_entry;
+                table->tb6_root.leaf = ip6_null_entry;
                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
         }
 
@@ -717,8 +717,8 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
                         if (sfn == NULL)
                                 goto st_failure;
 
-                        sfn->leaf = &ip6_null_entry;
-                        atomic_inc(&ip6_null_entry.rt6i_ref);
+                        sfn->leaf = ip6_null_entry;
+                        atomic_inc(&ip6_null_entry->rt6i_ref);
                         sfn->fn_flags = RTN_ROOT;
                         sfn->fn_sernum = fib6_new_sernum();
 
@@ -777,7 +777,7 @@ out:
 #if RT6_DEBUG >= 2
                         if (!pn->leaf) {
                                 BUG_TRAP(pn->leaf != NULL);
-                                pn->leaf = &ip6_null_entry;
+                                pn->leaf = ip6_null_entry;
                         }
 #endif
                         atomic_inc(&pn->leaf->rt6i_ref);
@@ -962,7 +962,7 @@ struct fib6_node * fib6_locate(struct fib6_node *root,
 static struct rt6_info * fib6_find_prefix(struct fib6_node *fn)
 {
         if (fn->fn_flags&RTN_ROOT)
-                return &ip6_null_entry;
+                return ip6_null_entry;
 
         while(fn) {
                 if(fn->left)
@@ -1012,7 +1012,7 @@ static struct fib6_node * fib6_repair_tree(struct fib6_node *fn)
 #if RT6_DEBUG >= 2
                         if (fn->leaf==NULL) {
                                 BUG_TRAP(fn->leaf);
-                                fn->leaf = &ip6_null_entry;
+                                fn->leaf = ip6_null_entry;
                         }
 #endif
                         atomic_inc(&fn->leaf->rt6i_ref);
@@ -1154,7 +1154,7 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
                 return -ENOENT;
         }
 #endif
-        if (fn == NULL || rt == &ip6_null_entry)
+        if (fn == NULL || rt == ip6_null_entry)
                 return -ENOENT;
 
         BUG_TRAP(fn->fn_flags&RTN_RTINFO);
@@ -1501,7 +1501,7 @@ static int fib6_net_init(struct net *net)
                 goto out_fib_table_hash;
 
         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
-        net->ipv6.fib6_main_tbl->tb6_root.leaf = &ip6_null_entry;
+        net->ipv6.fib6_main_tbl->tb6_root.leaf = ip6_null_entry;
         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 
@@ -1511,7 +1511,7 @@ static int fib6_net_init(struct net *net)
         if (!net->ipv6.fib6_local_tbl)
                 goto out_fib6_main_tbl;
         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
-        net->ipv6.fib6_local_tbl->tb6_root.leaf = &ip6_null_entry;
+        net->ipv6.fib6_local_tbl->tb6_root.leaf = ip6_null_entry;
         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 #endif
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b3ac4901af86..8f954c1e961f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -127,7 +127,7 @@ static struct dst_ops ip6_dst_blackhole_ops = {
         .entries                =       ATOMIC_INIT(0),
 };
 
-struct rt6_info ip6_null_entry = {
+static struct rt6_info ip6_null_entry_template = {
         .u = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
@@ -138,7 +138,6 @@ struct rt6_info ip6_null_entry = {
                         .input          = ip6_pkt_discard,
                         .output         = ip6_pkt_discard_out,
                         .ops            = &ip6_dst_ops,
-                        .path           = (struct dst_entry*)&ip6_null_entry,
                 }
         },
         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
@@ -146,12 +145,14 @@ struct rt6_info ip6_null_entry = {
         .rt6i_ref       = ATOMIC_INIT(1),
 };
 
+struct rt6_info *ip6_null_entry;
+
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 
 static int ip6_pkt_prohibit(struct sk_buff *skb);
 static int ip6_pkt_prohibit_out(struct sk_buff *skb);
 
-struct rt6_info ip6_prohibit_entry = {
+struct rt6_info ip6_prohibit_entry_template = {
         .u = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
@@ -162,7 +163,6 @@ struct rt6_info ip6_prohibit_entry = {
                         .input          = ip6_pkt_prohibit,
                         .output         = ip6_pkt_prohibit_out,
                         .ops            = &ip6_dst_ops,
-                        .path           = (struct dst_entry*)&ip6_prohibit_entry,
                 }
         },
         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
@@ -170,7 +170,9 @@ struct rt6_info ip6_prohibit_entry = {
         .rt6i_ref       = ATOMIC_INIT(1),
 };
 
-struct rt6_info ip6_blk_hole_entry = {
+struct rt6_info *ip6_prohibit_entry;
+
+static struct rt6_info ip6_blk_hole_entry_template = {
         .u = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
@@ -181,7 +183,6 @@ struct rt6_info ip6_blk_hole_entry = {
                         .input          = dst_discard,
                         .output         = dst_discard,
                         .ops            = &ip6_dst_ops,
-                        .path           = (struct dst_entry*)&ip6_blk_hole_entry,
                 }
         },
         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
@@ -189,6 +190,8 @@ struct rt6_info ip6_blk_hole_entry = {
         .rt6i_ref       = ATOMIC_INIT(1),
 };
 
+struct rt6_info *ip6_blk_hole_entry;
+
 #endif
 
 /* allocate dst with ip6_dst_ops */
@@ -271,7 +274,7 @@ static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt,
                         return local;
 
                 if (strict)
-                        return &ip6_null_entry;
+                        return ip6_null_entry;
         }
         return rt;
 }
@@ -437,7 +440,7 @@ static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
         RT6_TRACE("%s() => %p\n",
                   __FUNCTION__, match);
 
-        return (match ? match : &ip6_null_entry);
+        return (match ? match : ip6_null_entry);
 }
 
 #ifdef CONFIG_IPV6_ROUTE_INFO
@@ -522,7 +525,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 
 #define BACKTRACK(saddr) \
 do { \
-        if (rt == &ip6_null_entry) { \
+        if (rt == ip6_null_entry) { \
                 struct fib6_node *pn; \
                 while (1) { \
                         if (fn->fn_flags & RTN_TL_ROOT) \
@@ -686,7 +689,7 @@ restart_2:
 restart:
         rt = rt6_select(fn, oif, strict | reachable);
         BACKTRACK(&fl->fl6_src);
-        if (rt == &ip6_null_entry ||
+        if (rt == ip6_null_entry ||
             rt->rt6i_flags & RTF_CACHE)
                 goto out;
 
@@ -704,7 +707,7 @@ restart:
         }
 
         dst_release(&rt->u.dst);
-        rt = nrt ? : &ip6_null_entry;
+        rt = nrt ? : ip6_null_entry;
 
         dst_hold(&rt->u.dst);
         if (nrt) {
@@ -1257,7 +1260,7 @@ static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
         int err;
         struct fib6_table *table;
 
-        if (rt == &ip6_null_entry)
+        if (rt == ip6_null_entry)
                 return -ENOENT;
 
         table = rt->rt6i_table;
@@ -1369,7 +1372,7 @@ restart:
         }
 
         if (!rt)
-                rt = &ip6_null_entry;
+                rt = ip6_null_entry;
         BACKTRACK(&fl->fl6_src);
 out:
         dst_hold(&rt->u.dst);
@@ -1415,7 +1418,7 @@ void rt6_redirect(struct in6_addr *dest, struct in6_addr *src,
 
         rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
 
-        if (rt == &ip6_null_entry) {
+        if (rt == ip6_null_entry) {
                 if (net_ratelimit())
                         printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop "
                                "for redirect target\n");
@@ -1886,7 +1889,7 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 static int fib6_ifdown(struct rt6_info *rt, void *arg)
 {
         if (((void*)rt->rt6i_dev == arg || arg == NULL) &&
-            rt != &ip6_null_entry) {
+            rt != ip6_null_entry) {
                 RT6_TRACE("deleted by ifdown %p\n", rt);
                 return -1;
         }
@@ -2565,9 +2568,30 @@ int __init ip6_route_init(void)
 
         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops.kmem_cachep;
 
+        ret = -ENOMEM;
+        ip6_null_entry = kmemdup(&ip6_null_entry_template,
+                                 sizeof(*ip6_null_entry), GFP_KERNEL);
+        if (!ip6_null_entry)
+                goto out_kmem_cache;
+        ip6_null_entry->u.dst.path = (struct dst_entry *)ip6_null_entry;
+
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+        ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
+                                     sizeof(*ip6_prohibit_entry), GFP_KERNEL);
+        if (!ip6_prohibit_entry)
+                goto out_ip6_null_entry;
+        ip6_prohibit_entry->u.dst.path = (struct dst_entry *)ip6_prohibit_entry;
+
+        ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
+                                     sizeof(*ip6_blk_hole_entry), GFP_KERNEL);
+        if (!ip6_blk_hole_entry)
+                goto out_ip6_prohibit_entry;
+        ip6_blk_hole_entry->u.dst.path = (struct dst_entry *)ip6_blk_hole_entry;
+#endif
+
         ret = fib6_init();
         if (ret)
-                goto out_kmem_cache;
+                goto out_ip6_blk_hole_entry;
 
         ret = xfrm6_init();
         if (ret)
@@ -2595,6 +2619,14 @@ xfrm6_init:
         xfrm6_fini();
 out_fib6_init:
         fib6_gc_cleanup();
+out_ip6_blk_hole_entry:
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+        kfree(ip6_blk_hole_entry);
+out_ip6_prohibit_entry:
+        kfree(ip6_prohibit_entry);
+out_ip6_null_entry:
+#endif
+        kfree(ip6_null_entry);
 out_kmem_cache:
         kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
         goto out;
@@ -2607,4 +2639,10 @@ void ip6_route_cleanup(void)
         xfrm6_fini();
         fib6_gc_cleanup();
         kmem_cache_destroy(ip6_dst_ops.kmem_cachep);
+
+        kfree(ip6_null_entry);
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+        kfree(ip6_prohibit_entry);
+        kfree(ip6_blk_hole_entry);
+#endif
 }