netfilter: xt_hashlimit: netns support

Make hashtable per-netns.
Make proc files per-netns.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 98 insertions, 43 deletions

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 944fd11c8989..fb7fcb773a3f 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -26,6 +26,7 @@
 #endif
 
 #include <net/net_namespace.h>
+#include <net/netns/generic.h>
 
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
@@ -40,9 +41,19 @@ MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match");
 MODULE_ALIAS("ipt_hashlimit");
 MODULE_ALIAS("ip6t_hashlimit");
 
+struct hashlimit_net {
+        struct hlist_head       htables;
+        struct proc_dir_entry   *ipt_hashlimit;
+        struct proc_dir_entry   *ip6t_hashlimit;
+};
+
+static int hashlimit_net_id;
+static inline struct hashlimit_net *hashlimit_pernet(struct net *net)
+{
+        return net_generic(net, hashlimit_net_id);
+}
+
 /* need to declare this at the top */
-static struct proc_dir_entry *hashlimit_procdir4;
-static struct proc_dir_entry *hashlimit_procdir6;
 static const struct file_operations dl_file_ops;
 
 /* hash table crap */
@@ -93,13 +104,13 @@ struct xt_hashlimit_htable {
 
         /* seq_file stuff */
         struct proc_dir_entry *pde;
+        struct net *net;
 
         struct hlist_head hash[0];      /* hashtable itself */
 };
 
 static DEFINE_SPINLOCK(hashlimit_lock); /* protects htables list */
 static DEFINE_MUTEX(hlimit_mutex);      /* additional checkentry protection */
-static HLIST_HEAD(hashlimit_htables);
 static struct kmem_cache *hashlimit_cachep __read_mostly;
 
 static inline bool dst_cmp(const struct dsthash_ent *ent,
@@ -185,8 +196,9 @@ dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent)
 }
 static void htable_gc(unsigned long htlong);
 
-static int htable_create_v0(struct xt_hashlimit_info *minfo, u_int8_t family)
+static int htable_create_v0(struct net *net, struct xt_hashlimit_info *minfo, u_int8_t family)
 {
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
         struct xt_hashlimit_htable *hinfo;
         unsigned int size;
         unsigned int i;
@@ -239,26 +251,29 @@ static int htable_create_v0(struct xt_hashlimit_info *minfo, u_int8_t family)
         spin_lock_init(&hinfo->lock);
         hinfo->pde = proc_create_data(minfo->name, 0,
                 (family == NFPROTO_IPV4) ?
-                hashlimit_procdir4 : hashlimit_procdir6,
+                hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
                 &dl_file_ops, hinfo);
         if (!hinfo->pde) {
                 vfree(hinfo);
                 return -1;
         }
+        hinfo->net = net;
 
         setup_timer(&hinfo->timer, htable_gc, (unsigned long )hinfo);
         hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
         add_timer(&hinfo->timer);
 
         spin_lock_bh(&hashlimit_lock);
-        hlist_add_head(&hinfo->node, &hashlimit_htables);
+        hlist_add_head(&hinfo->node, &hashlimit_net->htables);
         spin_unlock_bh(&hashlimit_lock);
 
         return 0;
 }
 
-static int htable_create(struct xt_hashlimit_mtinfo1 *minfo, u_int8_t family)
+static int htable_create(struct net *net, struct xt_hashlimit_mtinfo1 *minfo,
+                         u_int8_t family)
 {
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
         struct xt_hashlimit_htable *hinfo;
         unsigned int size;
         unsigned int i;
@@ -301,19 +316,20 @@ static int htable_create(struct xt_hashlimit_mtinfo1 *minfo, u_int8_t family)
 
         hinfo->pde = proc_create_data(minfo->name, 0,
                 (family == NFPROTO_IPV4) ?
-                hashlimit_procdir4 : hashlimit_procdir6,
+                hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit,
                 &dl_file_ops, hinfo);
         if (hinfo->pde == NULL) {
                 vfree(hinfo);
                 return -1;
         }
+        hinfo->net = net;
 
         setup_timer(&hinfo->timer, htable_gc, (unsigned long)hinfo);
         hinfo->timer.expires = jiffies + msecs_to_jiffies(hinfo->cfg.gc_interval);
         add_timer(&hinfo->timer);
 
         spin_lock_bh(&hashlimit_lock);
-        hlist_add_head(&hinfo->node, &hashlimit_htables);
+        hlist_add_head(&hinfo->node, &hashlimit_net->htables);
         spin_unlock_bh(&hashlimit_lock);
 
         return 0;
@@ -364,24 +380,30 @@ static void htable_gc(unsigned long htlong)
 
 static void htable_destroy(struct xt_hashlimit_htable *hinfo)
 {
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net);
+        struct proc_dir_entry *parent;
+
         del_timer_sync(&hinfo->timer);
 
-        /* remove proc entry */
-        remove_proc_entry(hinfo->pde->name,
-                          hinfo->family == NFPROTO_IPV4 ? hashlimit_procdir4 :
-                                                     hashlimit_procdir6);
+        if (hinfo->family == NFPROTO_IPV4)
+                parent = hashlimit_net->ipt_hashlimit;
+        else
+                parent = hashlimit_net->ip6t_hashlimit;
+        remove_proc_entry(hinfo->pde->name, parent);
         htable_selective_cleanup(hinfo, select_all);
         vfree(hinfo);
 }
 
-static struct xt_hashlimit_htable *htable_find_get(const char *name,
+static struct xt_hashlimit_htable *htable_find_get(struct net *net,
+                                                   const char *name,
                                                    u_int8_t family)
 {
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
         struct xt_hashlimit_htable *hinfo;
         struct hlist_node *pos;
 
         spin_lock_bh(&hashlimit_lock);
-        hlist_for_each_entry(hinfo, pos, &hashlimit_htables, node) {
+        hlist_for_each_entry(hinfo, pos, &hashlimit_net->htables, node) {
                 if (!strcmp(name, hinfo->pde->name) &&
                     hinfo->family == family) {
                         atomic_inc(&hinfo->use);
@@ -665,6 +687,7 @@ hashlimit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 
 static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
 {
+        struct net *net = par->net;
         struct xt_hashlimit_info *r = par->matchinfo;
 
         /* Check for overflow. */
@@ -694,8 +717,8 @@ static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
          * the list of htable's in htable_create(), since then we would
          * create duplicate proc files. -HW */
         mutex_lock(&hlimit_mutex);
-        r->hinfo = htable_find_get(r->name, par->match->family);
-        if (!r->hinfo && htable_create_v0(r, par->match->family) != 0) {
+        r->hinfo = htable_find_get(net, r->name, par->match->family);
+        if (!r->hinfo && htable_create_v0(net, r, par->match->family) != 0) {
                 mutex_unlock(&hlimit_mutex);
                 return false;
         }
@@ -706,6 +729,7 @@ static bool hashlimit_mt_check_v0(const struct xt_mtchk_param *par)
 
 static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
 {
+        struct net *net = par->net;
         struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
 
         /* Check for overflow. */
@@ -735,8 +759,8 @@ static bool hashlimit_mt_check(const struct xt_mtchk_param *par)
          * the list of htable's in htable_create(), since then we would
          * create duplicate proc files. -HW */
         mutex_lock(&hlimit_mutex);
-        info->hinfo = htable_find_get(info->name, par->match->family);
-        if (!info->hinfo && htable_create(info, par->match->family) != 0) {
+        info->hinfo = htable_find_get(net, info->name, par->match->family);
+        if (!info->hinfo && htable_create(net, info, par->match->family) != 0) {
                 mutex_unlock(&hlimit_mutex);
                 return false;
         }
@@ -953,10 +977,61 @@ static const struct file_operations dl_file_ops = {
         .release = seq_release
 };
 
+static int __net_init hashlimit_proc_net_init(struct net *net)
+{
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+        hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net);
+        if (!hashlimit_net->ipt_hashlimit)
+                return -ENOMEM;
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+        hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net);
+        if (!hashlimit_net->ip6t_hashlimit) {
+                proc_net_remove(net, "ipt_hashlimit");
+                return -ENOMEM;
+        }
+#endif
+        return 0;
+}
+
+static void __net_exit hashlimit_proc_net_exit(struct net *net)
+{
+        proc_net_remove(net, "ipt_hashlimit");
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+        proc_net_remove(net, "ip6t_hashlimit");
+#endif
+}
+
+static int __net_init hashlimit_net_init(struct net *net)
+{
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+        INIT_HLIST_HEAD(&hashlimit_net->htables);
+        return hashlimit_proc_net_init(net);
+}
+
+static void __net_exit hashlimit_net_exit(struct net *net)
+{
+        struct hashlimit_net *hashlimit_net = hashlimit_pernet(net);
+
+        BUG_ON(!hlist_empty(&hashlimit_net->htables));
+        hashlimit_proc_net_exit(net);
+}
+
+static struct pernet_operations hashlimit_net_ops = {
+        .init   = hashlimit_net_init,
+        .exit   = hashlimit_net_exit,
+        .id     = &hashlimit_net_id,
+        .size   = sizeof(struct hashlimit_net),
+};
+
 static int __init hashlimit_mt_init(void)
 {
         int err;
 
+        err = register_pernet_subsys(&hashlimit_net_ops);
+        if (err < 0)
+                return err;
         err = xt_register_matches(hashlimit_mt_reg,
               ARRAY_SIZE(hashlimit_mt_reg));
         if (err < 0)
@@ -970,41 +1045,21 @@ static int __init hashlimit_mt_init(void)
                 printk(KERN_ERR "xt_hashlimit: unable to create slab cache\n");
                 goto err2;
         }
-        hashlimit_procdir4 = proc_mkdir("ipt_hashlimit", init_net.proc_net);
-        if (!hashlimit_procdir4) {
-                printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
-                                "entry\n");
-                goto err3;
-        }
-        err = 0;
-#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
-        hashlimit_procdir6 = proc_mkdir("ip6t_hashlimit", init_net.proc_net);
-        if (!hashlimit_procdir6) {
-                printk(KERN_ERR "xt_hashlimit: unable to create proc dir "
-                                "entry\n");
-                err = -ENOMEM;
-        }
-#endif
-        if (!err)
-                return 0;
-        remove_proc_entry("ipt_hashlimit", init_net.proc_net);
-err3:
-        kmem_cache_destroy(hashlimit_cachep);
+        return 0;
+
 err2:
         xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
 err1:
+        unregister_pernet_subsys(&hashlimit_net_ops);
         return err;
 
 }
 
 static void __exit hashlimit_mt_exit(void)
 {
-        remove_proc_entry("ipt_hashlimit", init_net.proc_net);
-#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
-        remove_proc_entry("ip6t_hashlimit", init_net.proc_net);
-#endif
         kmem_cache_destroy(hashlimit_cachep);
         xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg));
+        unregister_pernet_subsys(&hashlimit_net_ops);
 }
 
 module_init(hashlimit_mt_init);