This updates xt_recent to support IPv6 handling. It is sort of a flag
day, as the new control directory is /proc/net/xt_recent with a new,
more strict protocol (the string you ought to write into
/proc/net/xt_recent/LIST). But on the other hand, I kept the binary
interface towards iptables (which is quite memory consuming I must
say) to keep the patch small.
Signed-off-by: Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx>
---
net/netfilter/xt_recent.c | 207 +++++++++++++++++++++++++------------
1 files changed, 143 insertions(+), 64 deletions(-)
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index cc5472d..a614b34 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2006 Patrick McHardy <kaber@xxxxxxxxx>
+ * 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@xxxxxxxxx>");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx>");
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;
@@ -87,24 +93,43 @@ static const struct file_operations recent_fops;
static u_int32_t hash_rnd;
static int hash_rnd_initted;
-static unsigned int recent_entry_hash(__be32 addr)
+static unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
{
if (!hash_rnd_initted) {
- get_random_bytes(&hash_rnd, 4);
+ get_random_bytes(&hash_rnd, sizeof(hash_rnd));
hash_rnd_initted = 1;
}
- return jhash_1word((__force u32)addr, hash_rnd) & (ip_list_hash_size - 1);
+ return jhash_1word((__force u32)addr->ip, hash_rnd) &
+ (ip_list_hash_size - 1);
+}
+
+static unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
+{
+ if (!hash_rnd_initted) {
+ get_random_bytes(&hash_rnd, sizeof(hash_rnd));
+ hash_rnd_initted = 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 +143,8 @@ 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 +156,16 @@ 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 +209,42 @@ 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 (info->side == XT_RECENT_DEST)
- addr = ip_hdr(skb)->daddr;
- else
- addr = ip_hdr(skb)->saddr;
+ if (match->family == AF_INET) {
+ const struct iphdr *iph = ip_hdr(skb);
+
+ if (info->side == XT_RECENT_DEST)
+ addr.ip = iph->daddr;
+ else
+ 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,
+ 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;
@@ -318,7 +362,7 @@ 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;
};
@@ -343,8 +387,8 @@ 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)
@@ -367,8 +411,14 @@ 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");
@@ -401,45 +451,59 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input,
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("+255.255.255.255")], *c = buf;
- __be32 addr;
- int add;
+ char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")], *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))
+ if (copy_from_user(buf, input, size) != 0)
return -EFAULT;
- while (isspace(*c))
- c++;
- if (size - (c - buf) < 5)
- return c - buf;
- if (!strncmp(c, "clear", 5)) {
- c += 5;
+ /* 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 c - buf;
- }
-
- switch (*c) {
- case '-':
- add = 0;
- c++;
+ return size;
+ case '-': /* remove address */
+ add = false;
break;
- case '+':
- c++;
- default:
- add = 1;
+ 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;
}
- addr = in_aton(c);
spin_lock_bh(&recent_lock);
- e = recent_entry_lookup(t, addr, 0);
+ e = recent_entry_lookup(t, &addr, family, 0);
if (e == NULL) {
if (add)
- recent_entry_init(t, addr, 0);
+ recent_entry_init(t, &addr, family, 0);
} else {
if (add)
recent_entry_update(t, e);
@@ -447,7 +511,9 @@ static ssize_t recent_proc_write(struct file *file, const char __user *input,
recent_entry_remove(t, e);
}
spin_unlock_bh(&recent_lock);
- return size;
+ /* Note we removed one above */
+ *loff += size + 1;
+ return size + 1;
}
static const struct file_operations recent_fops = {
@@ -459,14 +525,27 @@ static const struct file_operations recent_fops = {
};
#endif /* CONFIG_PROC_FS */
-static struct xt_match recent_mt_reg __read_mostly = {
- .name = "recent",
- .family = AF_INET,
- .match = recent_mt,
- .matchsize = sizeof(struct xt_recent_mtinfo),
- .checkentry = recent_mt_check,
- .destroy = recent_mt_destroy,
- .me = THIS_MODULE,
+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)
@@ -477,13 +556,13 @@ 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);
+ proc_dir = proc_mkdir("xt_recent", init_net.proc_net);
if (proc_dir == NULL) {
- xt_unregister_match(&recent_mt_reg);
+ xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
err = -ENOMEM;
}
#endif
@@ -493,9 +572,9 @@ 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
- remove_proc_entry("ipt_recent", init_net.proc_net);
+ remove_proc_entry("xt_recent", init_net.proc_net);
#endif
}
--
1.5.4.4
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