From 8577f158df19072bcc9bea7bdb2dfce333927205 Mon Sep 17 00:00:00 2001 From: JP Abgrall Date: Tue, 21 Jun 2011 11:14:49 -0700 Subject: [PATCH] netfilter: adding the original quota2 from xtables-addons The original xt_quota in the kernel is plain broken: - counts quota at a per CPU level (was written back when ubiquitous SMP was just a dream) - provides no way to count across IPV4/IPV6. This patch is the original unaltered code from: http://sourceforge.net/projects/xtables-addons at commit e84391ce665cef046967f796dd91026851d6bbf3 Change-Id: I19d49858840effee9ecf6cff03c23b45a97efdeb Signed-off-by: JP Abgrall --- include/linux/netfilter/xt_quota2.h | 25 +++ net/netfilter/xt_quota2.c | 274 ++++++++++++++++++++++++++++ 2 files changed, 299 insertions(+) create mode 100644 include/linux/netfilter/xt_quota2.h create mode 100644 net/netfilter/xt_quota2.c diff --git a/include/linux/netfilter/xt_quota2.h b/include/linux/netfilter/xt_quota2.h new file mode 100644 index 000000000000..eadc6903314e --- /dev/null +++ b/include/linux/netfilter/xt_quota2.h @@ -0,0 +1,25 @@ +#ifndef _XT_QUOTA_H +#define _XT_QUOTA_H + +enum xt_quota_flags { + XT_QUOTA_INVERT = 1 << 0, + XT_QUOTA_GROW = 1 << 1, + XT_QUOTA_PACKET = 1 << 2, + XT_QUOTA_NO_CHANGE = 1 << 3, + XT_QUOTA_MASK = 0x0F, +}; + +struct xt_quota_counter; + +struct xt_quota_mtinfo2 { + char name[15]; + u_int8_t flags; + + /* Comparison-invariant */ + aligned_u64 quota; + + /* Used internally by the kernel */ + struct xt_quota_counter *master __attribute__((aligned(8))); +}; + +#endif /* _XT_QUOTA_H */ diff --git a/net/netfilter/xt_quota2.c b/net/netfilter/xt_quota2.c new file mode 100644 index 000000000000..4857008f1eb0 --- /dev/null +++ b/net/netfilter/xt_quota2.c @@ -0,0 +1,274 @@ +/* + * xt_quota2 - enhanced xt_quota that can count upwards and in packets + * as a minimal accounting match. + * by Jan Engelhardt , 2008 + * + * Originally based on xt_quota.c: + * netfilter module to enforce network quotas + * Sam Johnston + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License; either + * version 2 of the License, as published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#include +#include "xt_quota2.h" +#include "compat_xtables.h" + +/** + * @lock: lock to protect quota writers from each other + */ +struct xt_quota_counter { + u_int64_t quota; + spinlock_t lock; + struct list_head list; + atomic_t ref; + char name[sizeof(((struct xt_quota_mtinfo2 *)NULL)->name)]; + struct proc_dir_entry *procfs_entry; +}; + +static LIST_HEAD(counter_list); +static DEFINE_SPINLOCK(counter_list_lock); + +static struct proc_dir_entry *proc_xt_quota; +static unsigned int quota_list_perms = S_IRUGO | S_IWUSR; +static unsigned int quota_list_uid = 0; +static unsigned int quota_list_gid = 0; +module_param_named(perms, quota_list_perms, uint, S_IRUGO | S_IWUSR); +module_param_named(uid, quota_list_uid, uint, S_IRUGO | S_IWUSR); +module_param_named(gid, quota_list_gid, uint, S_IRUGO | S_IWUSR); + +static int quota_proc_read(char *page, char **start, off_t offset, + int count, int *eof, void *data) +{ + struct xt_quota_counter *e = data; + int ret; + + spin_lock_bh(&e->lock); + ret = snprintf(page, PAGE_SIZE, "%llu\n", e->quota); + spin_unlock_bh(&e->lock); + return ret; +} + +static int quota_proc_write(struct file *file, const char __user *input, + unsigned long size, void *data) +{ + struct xt_quota_counter *e = data; + char buf[sizeof("18446744073709551616")]; + + if (size > sizeof(buf)) + size = sizeof(buf); + if (copy_from_user(buf, input, size) != 0) + return -EFAULT; + buf[sizeof(buf)-1] = '\0'; + + spin_lock_bh(&e->lock); + e->quota = simple_strtoull(buf, NULL, 0); + spin_unlock_bh(&e->lock); + return size; +} + +static struct xt_quota_counter * +q2_new_counter(const struct xt_quota_mtinfo2 *q, bool anon) +{ + struct xt_quota_counter *e; + unsigned int size; + + /* Do not need all the procfs things for anonymous counters. */ + size = anon ? offsetof(typeof(*e), list) : sizeof(*e); + e = kmalloc(size, GFP_KERNEL); + if (e == NULL) + return NULL; + + e->quota = q->quota; + spin_lock_init(&e->lock); + if (!anon) { + INIT_LIST_HEAD(&e->list); + atomic_set(&e->ref, 1); + strncpy(e->name, q->name, sizeof(e->name)); + } + return e; +} + +/** + * q2_get_counter - get ref to counter or create new + * @name: name of counter + */ +static struct xt_quota_counter * +q2_get_counter(const struct xt_quota_mtinfo2 *q) +{ + struct proc_dir_entry *p; + struct xt_quota_counter *e; + + if (*q->name == '\0') + return q2_new_counter(q, true); + + spin_lock_bh(&counter_list_lock); + list_for_each_entry(e, &counter_list, list) + if (strcmp(e->name, q->name) == 0) { + atomic_inc(&e->ref); + spin_unlock_bh(&counter_list_lock); + return e; + } + + e = q2_new_counter(q, false); + if (e == NULL) + goto out; + + p = e->procfs_entry = create_proc_entry(e->name, quota_list_perms, + proc_xt_quota); + if (p == NULL || IS_ERR(p)) + goto out; + +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 29) + p->owner = THIS_MODULE; +#endif + p->data = e; + p->read_proc = quota_proc_read; + p->write_proc = quota_proc_write; + p->uid = quota_list_uid; + p->gid = quota_list_gid; + list_add_tail(&e->list, &counter_list); + spin_unlock_bh(&counter_list_lock); + return e; + + out: + spin_unlock_bh(&counter_list_lock); + kfree(e); + return NULL; +} + +static int quota_mt2_check(const struct xt_mtchk_param *par) +{ + struct xt_quota_mtinfo2 *q = par->matchinfo; + + if (q->flags & ~XT_QUOTA_MASK) + return -EINVAL; + + q->name[sizeof(q->name)-1] = '\0'; + if (*q->name == '.' || strchr(q->name, '/') != NULL) { + printk(KERN_ERR "xt_quota.3: illegal name\n"); + return -EINVAL; + } + + q->master = q2_get_counter(q); + if (q->master == NULL) { + printk(KERN_ERR "xt_quota.3: memory alloc failure\n"); + return -ENOMEM; + } + + return 0; +} + +static void quota_mt2_destroy(const struct xt_mtdtor_param *par) +{ + struct xt_quota_mtinfo2 *q = par->matchinfo; + struct xt_quota_counter *e = q->master; + + if (*q->name == '\0') { + kfree(e); + return; + } + + spin_lock_bh(&counter_list_lock); + if (!atomic_dec_and_test(&e->ref)) { + spin_unlock_bh(&counter_list_lock); + return; + } + + list_del(&e->list); + remove_proc_entry(e->name, proc_xt_quota); + spin_unlock_bh(&counter_list_lock); + kfree(e); +} + +static bool +quota_mt2(const struct sk_buff *skb, struct xt_action_param *par) +{ + struct xt_quota_mtinfo2 *q = (void *)par->matchinfo; + struct xt_quota_counter *e = q->master; + bool ret = q->flags & XT_QUOTA_INVERT; + + spin_lock_bh(&e->lock); + if (q->flags & XT_QUOTA_GROW) { + /* + * While no_change is pointless in "grow" mode, we will + * implement it here simply to have a consistent behavior. + */ + if (!(q->flags & XT_QUOTA_NO_CHANGE)) { + e->quota += (q->flags & XT_QUOTA_PACKET) ? 1 : skb->len; + q->quota = e->quota; + } + ret = true; + } else { + if (e->quota >= skb->len) { + if (!(q->flags & XT_QUOTA_NO_CHANGE)) + e->quota -= (q->flags & XT_QUOTA_PACKET) ? 1 : skb->len; + ret = !ret; + } else { + /* we do not allow even small packets from now on */ + e->quota = 0; + } + q->quota = e->quota; + } + spin_unlock_bh(&e->lock); + return ret; +} + +static struct xt_match quota_mt2_reg[] __read_mostly = { + { + .name = "quota2", + .revision = 3, + .family = NFPROTO_IPV4, + .checkentry = quota_mt2_check, + .match = quota_mt2, + .destroy = quota_mt2_destroy, + .matchsize = sizeof(struct xt_quota_mtinfo2), + .me = THIS_MODULE, + }, + { + .name = "quota2", + .revision = 3, + .family = NFPROTO_IPV6, + .checkentry = quota_mt2_check, + .match = quota_mt2, + .destroy = quota_mt2_destroy, + .matchsize = sizeof(struct xt_quota_mtinfo2), + .me = THIS_MODULE, + }, +}; + +static int __init quota_mt2_init(void) +{ + int ret; + + proc_xt_quota = proc_mkdir("xt_quota", init_net__proc_net); + if (proc_xt_quota == NULL) + return -EACCES; + + ret = xt_register_matches(quota_mt2_reg, ARRAY_SIZE(quota_mt2_reg)); + if (ret < 0) + remove_proc_entry("xt_quota", init_net__proc_net); + return ret; +} + +static void __exit quota_mt2_exit(void) +{ + xt_unregister_matches(quota_mt2_reg, ARRAY_SIZE(quota_mt2_reg)); + remove_proc_entry("xt_quota", init_net__proc_net); +} + +module_init(quota_mt2_init); +module_exit(quota_mt2_exit); +MODULE_DESCRIPTION("Xtables: countdown quota match; up counter"); +MODULE_AUTHOR("Sam Johnston "); +MODULE_AUTHOR("Jan Engelhardt "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("ipt_quota2"); +MODULE_ALIAS("ip6t_quota2"); -- 2.20.1