| From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| From: JP Abgrall <jpa@google.com> |
| Date: Tue, 21 Jun 2011 11:14:49 -0700 |
| Subject: ANDROID: netfilter: xt_quota2: add quota2 from xtables-addons |
| |
| 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. |
| |
| Therefore this patch adds xt_quota2, derived from |
| "extensions/xt_quota2.c" from xtables-addons |
| (https://sourceforge.net/projects/xtables-addons) |
| at commit e84391ce665cef046967f796dd91026851d6bbf3. |
| |
| [CPNOTE: 20/07/21] Lee: Poked the bug |
| |
| Bug: 120445421 |
| Change-Id: I19d49858840effee9ecf6cff03c23b45a97efdeb |
| Signed-off-by: JP Abgrall <jpa@google.com> |
| [adelva: Folded 4d33aa305871 ("netfilter: xt_quota2: fixup the quota2, |
| and enable.") into this patch] |
| Signed-off-by: Alistair Delva <adelva@google.com> |
| [maennich: Folded eab894210465 ("ANDROID: fix kernelci build-break") |
| into this patch] |
| Signed-off-by: Matthias Maennich <maennich@google.com> |
| [ebiggers: Folded in the following commits: |
| 8a35207f24f0 ("ANDROID: fix up xt_quota2 for proc_ops changes") |
| 91e5e077d8df ("ANDROID: move up spin_unlock_bh() ahead of remove_proc_entry()"). |
| b20eacd8ddbd ("ANDROID: fix a bug in quota2") |
| Also updated the commit message.] |
| Signed-off-by: Eric Biggers <ebiggers@google.com> |
| --- |
| include/linux/netfilter/xt_quota2.h | 26 ++ |
| net/netfilter/Kconfig | 23 ++ |
| net/netfilter/Makefile | 1 + |
| net/netfilter/xt_quota2.c | 400 ++++++++++++++++++++++++++++ |
| 4 files changed, 450 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 |
| --- /dev/null |
| +++ b/include/linux/netfilter/xt_quota2.h |
| @@ -0,0 +1,26 @@ |
| +#ifndef _XT_QUOTA_H |
| +#define _XT_QUOTA_H |
| +#include <linux/types.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/Kconfig b/net/netfilter/Kconfig |
| --- a/net/netfilter/Kconfig |
| +++ b/net/netfilter/Kconfig |
| @@ -1522,6 +1522,29 @@ config NETFILTER_XT_MATCH_QUOTA |
| If you want to compile it as a module, say M here and read |
| <file:Documentation/kbuild/modules.rst>. If unsure, say `N'. |
| |
| +config NETFILTER_XT_MATCH_QUOTA2 |
| + tristate '"quota2" match support' |
| + depends on NETFILTER_ADVANCED |
| + help |
| + This option adds a `quota2' match, which allows to match on a |
| + byte counter correctly and not per CPU. |
| + It allows naming the quotas. |
| + This is based on http://xtables-addons.git.sourceforge.net |
| + |
| + If you want to compile it as a module, say M here and read |
| + <file:Documentation/kbuild/modules.txt>. If unsure, say `N'. |
| + |
| +config NETFILTER_XT_MATCH_QUOTA2_LOG |
| + bool '"quota2" Netfilter LOG support' |
| + depends on NETFILTER_XT_MATCH_QUOTA2 |
| + default n |
| + help |
| + This option allows `quota2' to log ONCE when a quota limit |
| + is passed. It logs via NETLINK using the NETLINK_NFLOG family. |
| + It logs similarly to how ipt_ULOG would without data. |
| + |
| + If unsure, say `N'. |
| + |
| config NETFILTER_XT_MATCH_RATEEST |
| tristate '"rateest" match support' |
| depends on NETFILTER_ADVANCED |
| diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile |
| --- a/net/netfilter/Makefile |
| +++ b/net/netfilter/Makefile |
| @@ -195,6 +195,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_POLICY) += xt_policy.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_QUOTA) += xt_quota.o |
| +obj-$(CONFIG_NETFILTER_XT_MATCH_QUOTA2) += xt_quota2.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_RATEEST) += xt_rateest.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o |
| obj-$(CONFIG_NETFILTER_XT_MATCH_RECENT) += xt_recent.o |
| diff --git a/net/netfilter/xt_quota2.c b/net/netfilter/xt_quota2.c |
| new file mode 100644 |
| --- /dev/null |
| +++ b/net/netfilter/xt_quota2.c |
| @@ -0,0 +1,400 @@ |
| +/* |
| + * 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/module.h> |
| +#include <linux/proc_fs.h> |
| +#include <linux/skbuff.h> |
| +#include <linux/spinlock.h> |
| +#include <asm/atomic.h> |
| +#include <net/netlink.h> |
| + |
| +#include <linux/netfilter/x_tables.h> |
| +#include <linux/netfilter/xt_quota2.h> |
| + |
| +#ifdef CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG |
| +/* For compatibility, these definitions are copied from the |
| + * deprecated header file <linux/netfilter_ipv4/ipt_ULOG.h> */ |
| +#define ULOG_MAC_LEN 80 |
| +#define ULOG_PREFIX_LEN 32 |
| + |
| +/* Format of the ULOG packets passed through netlink */ |
| +typedef struct ulog_packet_msg { |
| + unsigned long mark; |
| + long timestamp_sec; |
| + long timestamp_usec; |
| + unsigned int hook; |
| + char indev_name[IFNAMSIZ]; |
| + char outdev_name[IFNAMSIZ]; |
| + size_t data_len; |
| + char prefix[ULOG_PREFIX_LEN]; |
| + unsigned char mac_len; |
| + unsigned char mac[ULOG_MAC_LEN]; |
| + unsigned char payload[0]; |
| +} ulog_packet_msg_t; |
| +#endif |
| + |
| +/** |
| + * @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; |
| +}; |
| + |
| +#ifdef CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG |
| +/* Harald's favorite number +1 :D From ipt_ULOG.C */ |
| +static int qlog_nl_event = 112; |
| +module_param_named(event_num, qlog_nl_event, uint, S_IRUGO | S_IWUSR); |
| +MODULE_PARM_DESC(event_num, |
| + "Event number for NETLINK_NFLOG message. 0 disables log." |
| + "111 is what ipt_ULOG uses."); |
| +static struct sock *nflognl; |
| +#endif |
| + |
| +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 kuid_t quota_list_uid = KUIDT_INIT(0); |
| +static kgid_t quota_list_gid = KGIDT_INIT(0); |
| +module_param_named(perms, quota_list_perms, uint, S_IRUGO | S_IWUSR); |
| + |
| +#ifdef CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG |
| +static void quota2_log(unsigned int hooknum, |
| + const struct sk_buff *skb, |
| + const struct net_device *in, |
| + const struct net_device *out, |
| + const char *prefix) |
| +{ |
| + ulog_packet_msg_t *pm; |
| + struct sk_buff *log_skb; |
| + size_t size; |
| + struct nlmsghdr *nlh; |
| + |
| + if (!qlog_nl_event) |
| + return; |
| + |
| + size = NLMSG_SPACE(sizeof(*pm)); |
| + size = max(size, (size_t)NLMSG_GOODSIZE); |
| + log_skb = alloc_skb(size, GFP_ATOMIC); |
| + if (!log_skb) { |
| + pr_err("xt_quota2: cannot alloc skb for logging\n"); |
| + return; |
| + } |
| + |
| + nlh = nlmsg_put(log_skb, /*pid*/0, /*seq*/0, qlog_nl_event, |
| + sizeof(*pm), 0); |
| + if (!nlh) { |
| + pr_err("xt_quota2: nlmsg_put failed\n"); |
| + kfree_skb(log_skb); |
| + return; |
| + } |
| + pm = nlmsg_data(nlh); |
| + if (skb->tstamp == 0) |
| + __net_timestamp((struct sk_buff *)skb); |
| + pm->data_len = 0; |
| + pm->hook = hooknum; |
| + if (prefix != NULL) |
| + strlcpy(pm->prefix, prefix, sizeof(pm->prefix)); |
| + else |
| + *(pm->prefix) = '\0'; |
| + if (in) |
| + strlcpy(pm->indev_name, in->name, sizeof(pm->indev_name)); |
| + else |
| + pm->indev_name[0] = '\0'; |
| + |
| + if (out) |
| + strlcpy(pm->outdev_name, out->name, sizeof(pm->outdev_name)); |
| + else |
| + pm->outdev_name[0] = '\0'; |
| + |
| + NETLINK_CB(log_skb).dst_group = 1; |
| + pr_debug("throwing 1 packets to netlink group 1\n"); |
| + netlink_broadcast(nflognl, log_skb, 0, 1, GFP_ATOMIC); |
| +} |
| +#else |
| +static void quota2_log(unsigned int hooknum, |
| + const struct sk_buff *skb, |
| + const struct net_device *in, |
| + const struct net_device *out, |
| + const char *prefix) |
| +{ |
| +} |
| +#endif /* if+else CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG */ |
| + |
| +static ssize_t quota_proc_read(struct file *file, char __user *buf, |
| + size_t size, loff_t *ppos) |
| +{ |
| + struct xt_quota_counter *e = PDE_DATA(file_inode(file)); |
| + char tmp[24]; |
| + size_t tmp_size; |
| + |
| + spin_lock_bh(&e->lock); |
| + tmp_size = scnprintf(tmp, sizeof(tmp), "%llu\n", e->quota); |
| + spin_unlock_bh(&e->lock); |
| + return simple_read_from_buffer(buf, size, ppos, tmp, tmp_size); |
| +} |
| + |
| +static ssize_t quota_proc_write(struct file *file, const char __user *input, |
| + size_t size, loff_t *ppos) |
| +{ |
| + struct xt_quota_counter *e = PDE_DATA(file_inode(file)); |
| + 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 const struct proc_ops q2_counter_fops = { |
| + .proc_read = quota_proc_read, |
| + .proc_write = quota_proc_write, |
| + .proc_lseek = default_llseek, |
| +}; |
| + |
| +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); |
| + strlcpy(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 = NULL; |
| + struct xt_quota_counter *new_e; |
| + |
| + if (*q->name == '\0') |
| + return q2_new_counter(q, true); |
| + |
| + /* No need to hold a lock while getting a new counter */ |
| + new_e = q2_new_counter(q, false); |
| + if (new_e == NULL) |
| + goto out; |
| + |
| + 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); |
| + kfree(new_e); |
| + pr_debug("xt_quota2: old counter name=%s", e->name); |
| + return e; |
| + } |
| + e = new_e; |
| + pr_debug("xt_quota2: new_counter name=%s", e->name); |
| + list_add_tail(&e->list, &counter_list); |
| + /* The entry having a refcount of 1 is not directly destructible. |
| + * This func has not yet returned the new entry, thus iptables |
| + * has not references for destroying this entry. |
| + * For another rule to try to destroy it, it would 1st need for this |
| + * func* to be re-invoked, acquire a new ref for the same named quota. |
| + * Nobody will access the e->procfs_entry either. |
| + * So release the lock. */ |
| + spin_unlock_bh(&counter_list_lock); |
| + |
| + /* create_proc_entry() is not spin_lock happy */ |
| + p = e->procfs_entry = proc_create_data(e->name, quota_list_perms, |
| + proc_xt_quota, &q2_counter_fops, e); |
| + |
| + if (IS_ERR_OR_NULL(p)) { |
| + spin_lock_bh(&counter_list_lock); |
| + list_del(&e->list); |
| + spin_unlock_bh(&counter_list_lock); |
| + goto out; |
| + } |
| + proc_set_user(p, quota_list_uid, quota_list_gid); |
| + return e; |
| + |
| + out: |
| + kfree(e); |
| + return NULL; |
| +} |
| + |
| +static int quota_mt2_check(const struct xt_mtchk_param *par) |
| +{ |
| + struct xt_quota_mtinfo2 *q = par->matchinfo; |
| + |
| + pr_debug("xt_quota2: check() flags=0x%04x", q->flags); |
| + |
| + 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); |
| + spin_unlock_bh(&counter_list_lock); |
| + remove_proc_entry(e->name, proc_xt_quota); |
| + 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; |
| + int charge = (q->flags & XT_QUOTA_PACKET) ? 1 : skb->len; |
| + bool no_change = q->flags & XT_QUOTA_NO_CHANGE; |
| + 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 (!no_change) |
| + e->quota += charge; |
| + ret = true; /* note: does not respect inversion (bug??) */ |
| + } else { |
| + if (e->quota > charge) { |
| + if (!no_change) |
| + e->quota -= charge; |
| + ret = !ret; |
| + } else if (e->quota) { |
| + /* We are transitioning, log that fact. */ |
| + quota2_log(xt_hooknum(par), |
| + skb, |
| + xt_in(par), |
| + xt_out(par), |
| + q->name); |
| + /* we do not allow even small packets from now on */ |
| + e->quota = 0; |
| + } |
| + } |
| + 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; |
| + pr_debug("xt_quota2: init()"); |
| + |
| +#ifdef CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG |
| + nflognl = netlink_kernel_create(&init_net, NETLINK_NFLOG, NULL); |
| + if (!nflognl) |
| + return -ENOMEM; |
| +#endif |
| + |
| + 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); |
| + pr_debug("xt_quota2: init() %d", ret); |
| + 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"); |