netfilter 17/62: xt_hashlimit: netns support

Patrick McHardy
2010-02-16T14:55:43Z

commit e89fc3f1b06d9241f65e580b002789abaa6d11ac
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon Jan 18 08:33:28 2010 +0100

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>

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 944fd11..fb7fcb7 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);