Commit 079aa88f authored by Jan Engelhardt's avatar Jan Engelhardt Committed by Patrick McHardy
Browse files

netfilter: xt_recent: IPv6 support 



This updates xt_recent to support the IPv6 address family.
The new /proc/net/xt_recent directory must be used for this.
The old proc interface can also be configured out.

Signed-off-by: default avatarJan Engelhardt <jengelh@medozas.de>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent e948b20a

Documentation/feature-removal-schedule.txt

+3 −0
Original line number Diff line number Diff line
@@ -250,6 +250,9 @@ What (Why): 
	- xt_mark match revision 0

	  (superseded by xt_mark match revision 1)



	- xt_recent: the old ipt_recent proc dir

	  (superseded by /proc/net/xt_recent)



When:	January 2009 or Linux 2.7.0, whichever comes first

Why:	Superseded by newer revisions or modules

Who:	Jan Engelhardt <jengelh@computergmbh.de>

net/netfilter/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -743,6 +743,13 @@ config NETFILTER_XT_MATCH_RECENT 
	Short options are available by using 'iptables -m recent -h'

	Official Website: <http://snowman.net/projects/ipt_recent/>



config NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

	bool 'Enable obsolete /proc/net/ipt_recent'

	depends on NETFILTER_XT_MATCH_RECENT && PROC_FS

	---help---

	This option enables the old /proc/net/ipt_recent interface,

	which has been obsoleted by /proc/net/xt_recent.



config NETFILTER_XT_MATCH_SCTP

	tristate  '"sctp" protocol match support (EXPERIMENTAL)'

	depends on NETFILTER_XTABLES && EXPERIMENTAL

net/netfilter/xt_recent.c

+246 −54
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>

 * Copyright © CC Computer Consultants GmbH, 2007 - 2008

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as
@@ -13,6 +14,8 @@ 
 */

#include <linux/init.h>

#include <linux/ip.h>

#include <linux/ipv6.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>
@@ -30,9 +33,11 @@ 
#include <linux/netfilter/xt_recent.h>



MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");

MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");

MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4");

MODULE_LICENSE("GPL");

MODULE_ALIAS("ipt_recent");

MODULE_ALIAS("ip6t_recent");



static unsigned int ip_list_tot = 100;

static unsigned int ip_pkt_list_tot = 20;
@@ -49,14 +54,15 @@ module_param(ip_list_gid, uint, 0400); 
MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");

MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP to remember (max. 255)");

MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");

MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/ipt_recent/* files");

MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/ipt_recent/* files");

MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/ipt_recent/* files");

MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");

MODULE_PARM_DESC(ip_list_uid,"owner of /proc/net/xt_recent/* files");

MODULE_PARM_DESC(ip_list_gid,"owning group of /proc/net/xt_recent/* files");



struct recent_entry {

	struct list_head	list;

	struct list_head	lru_list;

	__be32			addr;

	union nf_inet_addr	addr;

	u_int16_t		family;

	u_int8_t		ttl;

	u_int8_t		index;

	u_int16_t		nstamps;
@@ -67,7 +73,7 @@ struct recent_table { 
	struct list_head	list;

	char			name[XT_RECENT_NAME_LEN];

#ifdef CONFIG_PROC_FS

	struct proc_dir_entry	*proc;

	struct proc_dir_entry	*proc_old, *proc;

#endif

	unsigned int		refcnt;

	unsigned int		entries;
@@ -80,31 +86,53 @@ static DEFINE_SPINLOCK(recent_lock); 
static DEFINE_MUTEX(recent_mutex);



#ifdef CONFIG_PROC_FS

static struct proc_dir_entry	*proc_dir;

static const struct file_operations	recent_fops;

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

static struct proc_dir_entry *proc_old_dir;

#endif

static struct proc_dir_entry *recent_proc_dir;

static const struct file_operations recent_old_fops, recent_mt_fops;

#endif



static u_int32_t hash_rnd;

static int hash_rnd_initted;

static bool hash_rnd_initted;



static unsigned int recent_entry_hash4(const union nf_inet_addr *addr)

{

	if (!hash_rnd_initted) {

		get_random_bytes(&hash_rnd, sizeof(hash_rnd));

		hash_rnd_initted = true;

	}

	return jhash_1word((__force u32)addr->ip, hash_rnd) &

	       (ip_list_hash_size - 1);

}



static unsigned int recent_entry_hash(__be32 addr)

static unsigned int recent_entry_hash6(const union nf_inet_addr *addr)

{

	if (!hash_rnd_initted) {

		get_random_bytes(&hash_rnd, 4);

		hash_rnd_initted = 1;

		get_random_bytes(&hash_rnd, sizeof(hash_rnd));

		hash_rnd_initted = true;

	}

	return jhash_1word((__force u32)addr, hash_rnd) & (ip_list_hash_size - 1);

	return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &

	       (ip_list_hash_size - 1);

}



static struct recent_entry *

recent_entry_lookup(const struct recent_table *table, __be32 addr, u_int8_t ttl)

recent_entry_lookup(const struct recent_table *table,

		    const union nf_inet_addr *addrp, u_int16_t family,

		    u_int8_t ttl)

{

	struct recent_entry *e;

	unsigned int h;



	h = recent_entry_hash(addr);

	if (family == AF_INET)

		h = recent_entry_hash4(addrp);

	else

		h = recent_entry_hash6(addrp);



	list_for_each_entry(e, &table->iphash[h], list)

		if (e->addr == addr && (ttl == e->ttl || !ttl || !e->ttl))

		if (e->family == family &&

		    memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&

		    (ttl == e->ttl || ttl == 0 || e->ttl == 0))

			return e;

	return NULL;

}
@@ -118,7 +146,8 @@ static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) 
}



static struct recent_entry *

recent_entry_init(struct recent_table *t, __be32 addr, u_int8_t ttl)

recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,

		  u_int16_t family, u_int8_t ttl)

{

	struct recent_entry *e;
@@ -130,12 +159,16 @@ recent_entry_init(struct recent_table *t, __be32 addr, u_int8_t ttl) 
		    GFP_ATOMIC);

	if (e == NULL)

		return NULL;

	e->addr      = addr;

	memcpy(&e->addr, addr, sizeof(e->addr));

	e->ttl       = ttl;

	e->stamps[0] = jiffies;

	e->nstamps   = 1;

	e->index     = 1;

	list_add_tail(&e->list, &t->iphash[recent_entry_hash(addr)]);

	e->family    = family;

	if (family == AF_INET)

		list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);

	else

		list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);

	list_add_tail(&e->lru_list, &t->lru_list);

	t->entries++;

	return e;
@@ -179,28 +212,42 @@ recent_mt(const struct sk_buff *skb, const struct net_device *in, 
	const struct xt_recent_mtinfo *info = matchinfo;

	struct recent_table *t;

	struct recent_entry *e;

	__be32 addr;

	union nf_inet_addr addr = {};

	u_int8_t ttl;

	bool ret = info->invert;



	if (match->family == AF_INET) {

		const struct iphdr *iph = ip_hdr(skb);



		if (info->side == XT_RECENT_DEST)

		addr = ip_hdr(skb)->daddr;

			addr.ip = iph->daddr;

		else

		addr = ip_hdr(skb)->saddr;

			addr.ip = iph->saddr;



		ttl = iph->ttl;

	} else {

		const struct ipv6hdr *iph = ipv6_hdr(skb);



		if (info->side == XT_RECENT_DEST)

			memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));

		else

			memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));



		ttl = iph->hop_limit;

	}



	ttl = ip_hdr(skb)->ttl;

	/* use TTL as seen before forwarding */

	if (out && !skb->sk)

		ttl++;



	spin_lock_bh(&recent_lock);

	t = recent_table_lookup(info->name);

	e = recent_entry_lookup(t, addr,

				info->check_set & XT_RECENT_TTL ? ttl : 0);

	e = recent_entry_lookup(t, &addr, match->family,

				(info->check_set & XT_RECENT_TTL) ? ttl : 0);

	if (e == NULL) {

		if (!(info->check_set & XT_RECENT_SET))

			goto out;

		e = recent_entry_init(t, addr, ttl);

		e = recent_entry_init(t, &addr, match->family, ttl);

		if (e == NULL)

			*hotdrop = true;

		ret = !ret;
@@ -277,11 +324,24 @@ recent_mt_check(const char *tablename, const void *ip, 
	for (i = 0; i < ip_list_hash_size; i++)

		INIT_LIST_HEAD(&t->iphash[i]);

#ifdef CONFIG_PROC_FS

	t->proc = proc_create(t->name, ip_list_perms, proc_dir, &recent_fops);

	t->proc = proc_create(t->name, ip_list_perms, recent_proc_dir,

		  &recent_mt_fops);

	if (t->proc == NULL) {

		kfree(t);

		goto out;

	}

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

	t->proc_old = proc_create(t->name, ip_list_perms, proc_old_dir,

		      &recent_old_fops);

	if (t->proc_old == NULL) {

		remove_proc_entry(t->name, proc_old_dir);

		kfree(t);

		goto out;

	}

	t->proc_old->uid   = ip_list_uid;

	t->proc_old->gid   = ip_list_gid;

	t->proc_old->data  = t;

#endif

	t->proc->uid       = ip_list_uid;

	t->proc->gid       = ip_list_gid;

	t->proc->data      = t;
@@ -307,7 +367,10 @@ static void recent_mt_destroy(const struct xt_match *match, void *matchinfo) 
		list_del(&t->list);

		spin_unlock_bh(&recent_lock);

#ifdef CONFIG_PROC_FS

		remove_proc_entry(t->name, proc_dir);

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

		remove_proc_entry(t->name, proc_old_dir);

#endif

		remove_proc_entry(t->name, recent_proc_dir);

#endif

		recent_table_flush(t);

		kfree(t);
@@ -317,7 +380,7 @@ static void recent_mt_destroy(const struct xt_match *match, void *matchinfo) 


#ifdef CONFIG_PROC_FS

struct recent_iter_state {

	struct recent_table	*table;

	const struct recent_table *table;

	unsigned int		bucket;

};
@@ -342,8 +405,8 @@ static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
{

	struct recent_iter_state *st = seq->private;

	const struct recent_table *t = st->table;

	struct recent_entry *e = v;

	struct list_head *head = e->list.next;

	const struct recent_entry *e = v;

	const struct list_head *head = e->list.next;



	while (head == &t->iphash[st->bucket]) {

		if (++st->bucket >= ip_list_hash_size)
@@ -366,8 +429,14 @@ static int recent_seq_show(struct seq_file *seq, void *v) 
	unsigned int i;



	i = (e->index - 1) % ip_pkt_list_tot;

	seq_printf(seq, "src=%u.%u.%u.%u ttl: %u last_seen: %lu oldest_pkt: %u",

		   NIPQUAD(e->addr), e->ttl, e->stamps[i], e->index);

	if (e->family == AF_INET)

		seq_printf(seq, "src=" NIPQUAD_FMT " ttl: %u last_seen: %lu "

			   "oldest_pkt: %u", NIPQUAD(e->addr.ip), e->ttl,

			   e->stamps[i], e->index);

	else

		seq_printf(seq, "src=" NIP6_FMT " ttl: %u last_seen: %lu "

			   "oldest_pkt: %u", NIP6(e->addr.in6), e->ttl,

			   e->stamps[i], e->index);

	for (i = 0; i < e->nstamps; i++)

		seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);

	seq_printf(seq, "\n");
@@ -394,7 +463,21 @@ static int recent_seq_open(struct inode *inode, struct file *file) 
	return 0;

}



static ssize_t recent_proc_write(struct file *file, const char __user *input,

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

static int recent_old_seq_open(struct inode *inode, struct file *filp)

{

	static bool warned_of_old;



	if (unlikely(!warned_of_old)) {

		printk(KERN_INFO KBUILD_MODNAME ": Use of /proc/net/ipt_recent"

		       " is deprecated; use /proc/net/xt_recent.\n");

		warned_of_old = true;

	}

	return recent_seq_open(inode, filp);

}



static ssize_t recent_old_proc_write(struct file *file,

				     const char __user *input,

				     size_t size, loff_t *loff)

{

	const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
@@ -408,6 +491,7 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, 
		size = sizeof(buf);

	if (copy_from_user(buf, input, size))

		return -EFAULT;



	while (isspace(*c))

		c++;
@@ -435,10 +519,10 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, 
	addr = in_aton(c);



	spin_lock_bh(&recent_lock);

	e = recent_entry_lookup(t, addr, 0);

	e = recent_entry_lookup(t, (const void *)&addr, PF_INET, 0);

	if (e == NULL) {

		if (add)

			recent_entry_init(t, addr, 0);

			recent_entry_init(t, (const void *)&addr, PF_INET, 0);

	} else {

		if (add)

			recent_entry_update(t, e);
@@ -449,23 +533,118 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input, 
	return size;

}



static const struct file_operations recent_fops = {

static const struct file_operations recent_old_fops = {

	.open		= recent_old_seq_open,

	.read		= seq_read,

	.write		= recent_old_proc_write,

	.release	= seq_release_private,

	.owner		= THIS_MODULE,

};

#endif



static ssize_t

recent_mt_proc_write(struct file *file, const char __user *input,

		     size_t size, loff_t *loff)

{

	const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);

	struct recent_table *t = pde->data;

	struct recent_entry *e;

	char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];

	const char *c = buf;

	union nf_inet_addr addr;

	u_int16_t family;

	bool add, succ;



	if (size == 0)

		return 0;

	if (size > sizeof(buf))

		size = sizeof(buf);

	if (copy_from_user(buf, input, size) != 0)

		return -EFAULT;



	/* Strict protocol! */

	if (*loff != 0)

		return -ESPIPE;

	switch (*c) {

	case '/': /* flush table */

		spin_lock_bh(&recent_lock);

		recent_table_flush(t);

		spin_unlock_bh(&recent_lock);

		return size;

	case '-': /* remove address */

		add = false;

		break;

	case '+': /* add address */

		add = true;

		break;

	default:

		printk(KERN_INFO KBUILD_MODNAME ": Need +ip, -ip or /\n");

		return -EINVAL;

	}



	++c;

	--size;

	if (strnchr(c, size, ':') != NULL) {

		family = AF_INET6;

		succ   = in6_pton(c, size, (void *)&addr, '\n', NULL);

	} else {

		family = AF_INET;

		succ   = in4_pton(c, size, (void *)&addr, '\n', NULL);

	}



	if (!succ) {

		printk(KERN_INFO KBUILD_MODNAME ": illegal address written "

		       "to procfs\n");

		return -EINVAL;

	}



	spin_lock_bh(&recent_lock);

	e = recent_entry_lookup(t, &addr, family, 0);

	if (e == NULL) {

		if (add)

			recent_entry_init(t, &addr, family, 0);

	} else {

		if (add)

			recent_entry_update(t, e);

		else

			recent_entry_remove(t, e);

	}

	spin_unlock_bh(&recent_lock);

	/* Note we removed one above */

	*loff += size + 1;

	return size + 1;

}



static const struct file_operations recent_mt_fops = {

	.open    = recent_seq_open,

	.read    = seq_read,

	.write		= recent_proc_write,

	.write   = recent_mt_proc_write,

	.release = seq_release_private,

	.owner   = THIS_MODULE,

};

#endif /* CONFIG_PROC_FS */



static struct xt_match recent_mt_reg __read_mostly = {

static struct xt_match recent_mt_reg[] __read_mostly = {

	{

		.name       = "recent",

		.revision   = 0,

		.family     = AF_INET,

		.match      = recent_mt,

		.matchsize  = sizeof(struct xt_recent_mtinfo),

		.checkentry = recent_mt_check,

		.destroy    = recent_mt_destroy,

		.me         = THIS_MODULE,

	},

	{

		.name       = "recent",

		.revision   = 0,

		.family     = AF_INET6,

		.match      = recent_mt,

		.matchsize  = sizeof(struct xt_recent_mtinfo),

		.checkentry = recent_mt_check,

		.destroy    = recent_mt_destroy,

		.me         = THIS_MODULE,

	},

};



static int __init recent_mt_init(void)
@@ -476,15 +655,25 @@ static int __init recent_mt_init(void) 
		return -EINVAL;

	ip_list_hash_size = 1 << fls(ip_list_tot);



	err = xt_register_match(&recent_mt_reg);

	err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));

#ifdef CONFIG_PROC_FS

	if (err)

		return err;

	proc_dir = proc_mkdir("ipt_recent", init_net.proc_net);

	if (proc_dir == NULL) {

		xt_unregister_match(&recent_mt_reg);

	recent_proc_dir = proc_mkdir("xt_recent", init_net.proc_net);

	if (recent_proc_dir == NULL) {

		xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));

		err = -ENOMEM;

	}

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

	if (err < 0)

		return err;

	proc_old_dir = proc_mkdir("ipt_recent", init_net.proc_net);

	if (proc_old_dir == NULL) {

		remove_proc_entry("xt_recent", init_net.proc_net);

		xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));

		err = -ENOMEM;

	}

#endif

#endif

	return err;

}
@@ -492,9 +681,12 @@ static int __init recent_mt_init(void) 
static void __exit recent_mt_exit(void)

{

	BUG_ON(!list_empty(&tables));

	xt_unregister_match(&recent_mt_reg);

	xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));

#ifdef CONFIG_PROC_FS

#ifdef CONFIG_NETFILTER_XT_MATCH_RECENT_PROC_COMPAT

	remove_proc_entry("ipt_recent", init_net.proc_net);

#endif

	remove_proc_entry("xt_recent", init_net.proc_net);

#endif

}

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