From e948b20a71a06a740c925d6ea22b59b4e17cfa0c Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Wed, 8 Oct 2008 11:35:00 +0200 Subject: netfilter: rename ipt_recent to xt_recent Like with other modules (such as ipt_state), ipt_recent.h is changed to forward definitions to (IOW include) xt_recent.h, and xt_recent.c is changed to use the new constant names. Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy --- net/netfilter/xt_recent.c | 502 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 502 insertions(+) create mode 100644 net/netfilter/xt_recent.c (limited to 'net/netfilter/xt_recent.c') diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c new file mode 100644 index 000000000000..422c0e4d66b7 --- /dev/null +++ b/net/netfilter/xt_recent.c @@ -0,0 +1,502 @@ +/* + * Copyright (c) 2006 Patrick McHardy + * + * 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 + * published by the Free Software Foundation. + * + * This is a replacement of the old ipt_recent module, which carried the + * following copyright notice: + * + * Author: Stephen Frost + * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +MODULE_AUTHOR("Patrick McHardy "); +MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching for IPv4"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("ipt_recent"); + +static unsigned int ip_list_tot = 100; +static unsigned int ip_pkt_list_tot = 20; +static unsigned int ip_list_hash_size = 0; +static unsigned int ip_list_perms = 0644; +static unsigned int ip_list_uid = 0; +static unsigned int ip_list_gid = 0; +module_param(ip_list_tot, uint, 0400); +module_param(ip_pkt_list_tot, uint, 0400); +module_param(ip_list_hash_size, uint, 0400); +module_param(ip_list_perms, uint, 0400); +module_param(ip_list_uid, uint, 0400); +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"); + +struct recent_entry { + struct list_head list; + struct list_head lru_list; + __be32 addr; + u_int8_t ttl; + u_int8_t index; + u_int16_t nstamps; + unsigned long stamps[0]; +}; + +struct recent_table { + struct list_head list; + char name[XT_RECENT_NAME_LEN]; +#ifdef CONFIG_PROC_FS + struct proc_dir_entry *proc; +#endif + unsigned int refcnt; + unsigned int entries; + struct list_head lru_list; + struct list_head iphash[0]; +}; + +static LIST_HEAD(tables); +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; +#endif + +static u_int32_t hash_rnd; +static int hash_rnd_initted; + +static unsigned int recent_entry_hash(__be32 addr) +{ + if (!hash_rnd_initted) { + get_random_bytes(&hash_rnd, 4); + hash_rnd_initted = 1; + } + return jhash_1word((__force u32)addr, 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) +{ + struct recent_entry *e; + unsigned int h; + + h = recent_entry_hash(addr); + list_for_each_entry(e, &table->iphash[h], list) + if (e->addr == addr && (ttl == e->ttl || !ttl || !e->ttl)) + return e; + return NULL; +} + +static void recent_entry_remove(struct recent_table *t, struct recent_entry *e) +{ + list_del(&e->list); + list_del(&e->lru_list); + kfree(e); + t->entries--; +} + +static struct recent_entry * +recent_entry_init(struct recent_table *t, __be32 addr, u_int8_t ttl) +{ + struct recent_entry *e; + + if (t->entries >= ip_list_tot) { + e = list_entry(t->lru_list.next, struct recent_entry, lru_list); + recent_entry_remove(t, e); + } + e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot, + GFP_ATOMIC); + if (e == NULL) + return NULL; + e->addr = 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)]); + list_add_tail(&e->lru_list, &t->lru_list); + t->entries++; + return e; +} + +static void recent_entry_update(struct recent_table *t, struct recent_entry *e) +{ + e->stamps[e->index++] = jiffies; + if (e->index > e->nstamps) + e->nstamps = e->index; + e->index %= ip_pkt_list_tot; + list_move_tail(&e->lru_list, &t->lru_list); +} + +static struct recent_table *recent_table_lookup(const char *name) +{ + struct recent_table *t; + + list_for_each_entry(t, &tables, list) + if (!strcmp(t->name, name)) + return t; + return NULL; +} + +static void recent_table_flush(struct recent_table *t) +{ + struct recent_entry *e, *next; + unsigned int i; + + for (i = 0; i < ip_list_hash_size; i++) + list_for_each_entry_safe(e, next, &t->iphash[i], list) + recent_entry_remove(t, e); +} + +static bool +recent_mt(const struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, const struct xt_match *match, + const void *matchinfo, int offset, unsigned int protoff, + bool *hotdrop) +{ + const struct xt_recent_mtinfo *info = matchinfo; + struct recent_table *t; + struct recent_entry *e; + __be32 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; + + 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); + if (e == NULL) { + if (!(info->check_set & XT_RECENT_SET)) + goto out; + e = recent_entry_init(t, addr, ttl); + if (e == NULL) + *hotdrop = true; + ret = !ret; + goto out; + } + + if (info->check_set & XT_RECENT_SET) + ret = !ret; + else if (info->check_set & XT_RECENT_REMOVE) { + recent_entry_remove(t, e); + ret = !ret; + } else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) { + unsigned long time = jiffies - info->seconds * HZ; + unsigned int i, hits = 0; + + for (i = 0; i < e->nstamps; i++) { + if (info->seconds && time_after(time, e->stamps[i])) + continue; + if (++hits >= info->hit_count) { + ret = !ret; + break; + } + } + } + + if (info->check_set & XT_RECENT_SET || + (info->check_set & XT_RECENT_UPDATE && ret)) { + recent_entry_update(t, e); + e->ttl = ttl; + } +out: + spin_unlock_bh(&recent_lock); + return ret; +} + +static bool +recent_mt_check(const char *tablename, const void *ip, + const struct xt_match *match, void *matchinfo, + unsigned int hook_mask) +{ + const struct xt_recent_mtinfo *info = matchinfo; + struct recent_table *t; + unsigned i; + bool ret = false; + + if (hweight8(info->check_set & + (XT_RECENT_SET | XT_RECENT_REMOVE | + XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1) + return false; + if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) && + (info->seconds || info->hit_count)) + return false; + if (info->hit_count > ip_pkt_list_tot) + return false; + if (info->name[0] == '\0' || + strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN) + return false; + + mutex_lock(&recent_mutex); + t = recent_table_lookup(info->name); + if (t != NULL) { + t->refcnt++; + ret = true; + goto out; + } + + t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size, + GFP_KERNEL); + if (t == NULL) + goto out; + t->refcnt = 1; + strcpy(t->name, info->name); + INIT_LIST_HEAD(&t->lru_list); + 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); + if (t->proc == NULL) { + kfree(t); + goto out; + } + t->proc->uid = ip_list_uid; + t->proc->gid = ip_list_gid; + t->proc->data = t; +#endif + spin_lock_bh(&recent_lock); + list_add_tail(&t->list, &tables); + spin_unlock_bh(&recent_lock); + ret = true; +out: + mutex_unlock(&recent_mutex); + return ret; +} + +static void recent_mt_destroy(const struct xt_match *match, void *matchinfo) +{ + const struct xt_recent_mtinfo *info = matchinfo; + struct recent_table *t; + + mutex_lock(&recent_mutex); + t = recent_table_lookup(info->name); + if (--t->refcnt == 0) { + spin_lock_bh(&recent_lock); + list_del(&t->list); + spin_unlock_bh(&recent_lock); +#ifdef CONFIG_PROC_FS + remove_proc_entry(t->name, proc_dir); +#endif + recent_table_flush(t); + kfree(t); + } + mutex_unlock(&recent_mutex); +} + +#ifdef CONFIG_PROC_FS +struct recent_iter_state { + struct recent_table *table; + unsigned int bucket; +}; + +static void *recent_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(recent_lock) +{ + struct recent_iter_state *st = seq->private; + const struct recent_table *t = st->table; + struct recent_entry *e; + loff_t p = *pos; + + spin_lock_bh(&recent_lock); + + for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++) + list_for_each_entry(e, &t->iphash[st->bucket], list) + if (p-- == 0) + return e; + return NULL; +} + +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; + + while (head == &t->iphash[st->bucket]) { + if (++st->bucket >= ip_list_hash_size) + return NULL; + head = t->iphash[st->bucket].next; + } + (*pos)++; + return list_entry(head, struct recent_entry, list); +} + +static void recent_seq_stop(struct seq_file *s, void *v) + __releases(recent_lock) +{ + spin_unlock_bh(&recent_lock); +} + +static int recent_seq_show(struct seq_file *seq, void *v) +{ + const struct recent_entry *e = 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); + for (i = 0; i < e->nstamps; i++) + seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]); + seq_printf(seq, "\n"); + return 0; +} + +static const struct seq_operations recent_seq_ops = { + .start = recent_seq_start, + .next = recent_seq_next, + .stop = recent_seq_stop, + .show = recent_seq_show, +}; + +static int recent_seq_open(struct inode *inode, struct file *file) +{ + struct proc_dir_entry *pde = PDE(inode); + struct recent_iter_state *st; + + st = __seq_open_private(file, &recent_seq_ops, sizeof(*st)); + if (st == NULL) + return -ENOMEM; + + st->table = pde->data; + return 0; +} + +static ssize_t recent_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("+255.255.255.255")], *c = buf; + __be32 addr; + int add; + + if (size > sizeof(buf)) + size = sizeof(buf); + if (copy_from_user(buf, input, size)) + return -EFAULT; + while (isspace(*c)) + c++; + + if (size - (c - buf) < 5) + return c - buf; + if (!strncmp(c, "clear", 5)) { + c += 5; + spin_lock_bh(&recent_lock); + recent_table_flush(t); + spin_unlock_bh(&recent_lock); + return c - buf; + } + + switch (*c) { + case '-': + add = 0; + c++; + break; + case '+': + c++; + default: + add = 1; + break; + } + addr = in_aton(c); + + spin_lock_bh(&recent_lock); + e = recent_entry_lookup(t, addr, 0); + if (e == NULL) { + if (add) + recent_entry_init(t, addr, 0); + } else { + if (add) + recent_entry_update(t, e); + else + recent_entry_remove(t, e); + } + spin_unlock_bh(&recent_lock); + return size; +} + +static const struct file_operations recent_fops = { + .open = recent_seq_open, + .read = seq_read, + .write = recent_proc_write, + .release = seq_release_private, + .owner = THIS_MODULE, +}; +#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 int __init recent_mt_init(void) +{ + int err; + + if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255) + return -EINVAL; + ip_list_hash_size = 1 << fls(ip_list_tot); + + err = xt_register_match(&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); + err = -ENOMEM; + } +#endif + return err; +} + +static void __exit recent_mt_exit(void) +{ + BUG_ON(!list_empty(&tables)); + xt_unregister_match(&recent_mt_reg); +#ifdef CONFIG_PROC_FS + remove_proc_entry("ipt_recent", init_net.proc_net); +#endif +} + +module_init(recent_mt_init); +module_exit(recent_mt_exit); -- cgit v1.2.3