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 <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 502 insertions, 0 deletions

diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
new file mode 100644
index 00000000000..422c0e4d66b
--- /dev/null
+++ b/net/netfilter/xt_recent.c
@@ -0,0 +1,502 @@
+/*
+ * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
+ *
+ * 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 <sfrost@snowman.net>
+ * Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
+ */
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/moduleparam.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/list.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/bitops.h>
+#include <linux/skbuff.h>
+#include <linux/inet.h>
+#include <net/net_namespace.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_recent.h>
+
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+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);