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authorJP Abgrall <jpa@google.com>2011-06-21 11:14:49 -0700
committerPraneeth Bajjuri <praneeth@ti.com>2011-09-20 16:52:24 -0700
commit36a5aee729d8be7efbc85d5cd49d182cff616b33 (patch)
tree80b0337a74e8d2708eee6fe8afe3698568ebe9fd
parentc66e94c705a6ca4c6eff495d1ac7e64b1a2afaaa (diff)
downloadlinux-linaro-36a5aee729d8be7efbc85d5cd49d182cff616b33.tar.gz
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 <jpa@google.com>
-rw-r--r--include/linux/netfilter/xt_quota2.h25
-rw-r--r--net/netfilter/xt_quota2.c274
2 files changed, 299 insertions, 0 deletions
diff --git a/include/linux/netfilter/xt_quota2.h b/include/linux/netfilter/xt_quota2.h
new file mode 100644
index 00000000000..eadc6903314
--- /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 00000000000..4857008f1eb
--- /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 <jengelh@medozas.de>, 2008
+ *
+ * Originally based on xt_quota.c:
+ * netfilter module to enforce network quotas
+ * Sam Johnston <samj@samj.net>
+ *
+ * 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 <linux/list.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+
+#include <linux/netfilter/x_tables.h>
+#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 <samj@samj.net>");
+MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_quota2");
+MODULE_ALIAS("ip6t_quota2");