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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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155a8e8e22
[ Upstream commit2cdaa3eefe
]e6d57e9ff0
("netfilter: conntrack: fix rmmod double-free race") consolidates IPS_CONFIRMED bit set in nf_conntrack_hash_check_insert(). However, this breaks ctnetlink: # conntrack -I -p tcp --timeout 123 --src 1.2.3.4 --dst 5.6.7.8 --state ESTABLISHED --sport 1 --dport 4 -u SEEN_REPLY conntrack v1.4.6 (conntrack-tools): Operation failed: Device or resource busy This is a partial revert of the aforementioned commit to restore IPS_CONFIRMED. Fixes:e6d57e9ff0
("netfilter: conntrack: fix rmmod double-free race") Reported-by: Stéphane Graber <stgraber@stgraber.org> Tested-by: Stéphane Graber <stgraber@stgraber.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2868 lines
74 KiB
C
2868 lines
74 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Connection state tracking for netfilter. This is separated from,
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but required by, the NAT layer; it can also be used by an iptables
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extension. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
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* (C) 2005-2012 Patrick McHardy <kaber@trash.net>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/skbuff.h>
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#include <linux/proc_fs.h>
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#include <linux/vmalloc.h>
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#include <linux/stddef.h>
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#include <linux/slab.h>
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#include <linux/random.h>
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#include <linux/siphash.h>
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#include <linux/err.h>
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#include <linux/percpu.h>
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#include <linux/moduleparam.h>
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#include <linux/notifier.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/socket.h>
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#include <linux/mm.h>
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#include <linux/nsproxy.h>
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#include <linux/rculist_nulls.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_bpf.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_extend.h>
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#include <net/netfilter/nf_conntrack_acct.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <net/netfilter/nf_conntrack_timestamp.h>
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#include <net/netfilter/nf_conntrack_timeout.h>
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#include <net/netfilter/nf_conntrack_labels.h>
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#include <net/netfilter/nf_conntrack_synproxy.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_helper.h>
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#include <net/netns/hash.h>
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#include <net/ip.h>
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#include "nf_internals.h"
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__cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
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EXPORT_SYMBOL_GPL(nf_conntrack_locks);
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__cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
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EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
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struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_hash);
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struct conntrack_gc_work {
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struct delayed_work dwork;
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u32 next_bucket;
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u32 avg_timeout;
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u32 count;
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u32 start_time;
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bool exiting;
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bool early_drop;
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};
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static __read_mostly struct kmem_cache *nf_conntrack_cachep;
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static DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
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static __read_mostly bool nf_conntrack_locks_all;
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/* serialize hash resizes and nf_ct_iterate_cleanup */
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static DEFINE_MUTEX(nf_conntrack_mutex);
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#define GC_SCAN_INTERVAL_MAX (60ul * HZ)
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#define GC_SCAN_INTERVAL_MIN (1ul * HZ)
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/* clamp timeouts to this value (TCP unacked) */
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#define GC_SCAN_INTERVAL_CLAMP (300ul * HZ)
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/* Initial bias pretending we have 100 entries at the upper bound so we don't
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* wakeup often just because we have three entries with a 1s timeout while still
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* allowing non-idle machines to wakeup more often when needed.
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*/
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#define GC_SCAN_INITIAL_COUNT 100
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#define GC_SCAN_INTERVAL_INIT GC_SCAN_INTERVAL_MAX
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#define GC_SCAN_MAX_DURATION msecs_to_jiffies(10)
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#define GC_SCAN_EXPIRED_MAX (64000u / HZ)
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#define MIN_CHAINLEN 50u
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#define MAX_CHAINLEN (80u - MIN_CHAINLEN)
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static struct conntrack_gc_work conntrack_gc_work;
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void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
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{
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/* 1) Acquire the lock */
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spin_lock(lock);
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/* 2) read nf_conntrack_locks_all, with ACQUIRE semantics
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* It pairs with the smp_store_release() in nf_conntrack_all_unlock()
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*/
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if (likely(smp_load_acquire(&nf_conntrack_locks_all) == false))
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return;
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/* fast path failed, unlock */
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spin_unlock(lock);
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/* Slow path 1) get global lock */
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spin_lock(&nf_conntrack_locks_all_lock);
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/* Slow path 2) get the lock we want */
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spin_lock(lock);
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/* Slow path 3) release the global lock */
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spin_unlock(&nf_conntrack_locks_all_lock);
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_lock);
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static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
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{
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h1 %= CONNTRACK_LOCKS;
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h2 %= CONNTRACK_LOCKS;
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spin_unlock(&nf_conntrack_locks[h1]);
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if (h1 != h2)
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spin_unlock(&nf_conntrack_locks[h2]);
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}
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/* return true if we need to recompute hashes (in case hash table was resized) */
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static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
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unsigned int h2, unsigned int sequence)
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{
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h1 %= CONNTRACK_LOCKS;
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h2 %= CONNTRACK_LOCKS;
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if (h1 <= h2) {
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nf_conntrack_lock(&nf_conntrack_locks[h1]);
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if (h1 != h2)
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spin_lock_nested(&nf_conntrack_locks[h2],
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SINGLE_DEPTH_NESTING);
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} else {
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nf_conntrack_lock(&nf_conntrack_locks[h2]);
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spin_lock_nested(&nf_conntrack_locks[h1],
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SINGLE_DEPTH_NESTING);
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}
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if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
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nf_conntrack_double_unlock(h1, h2);
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return true;
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}
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return false;
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}
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static void nf_conntrack_all_lock(void)
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__acquires(&nf_conntrack_locks_all_lock)
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{
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int i;
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spin_lock(&nf_conntrack_locks_all_lock);
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/* For nf_contrack_locks_all, only the latest time when another
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* CPU will see an update is controlled, by the "release" of the
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* spin_lock below.
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* The earliest time is not controlled, an thus KCSAN could detect
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* a race when nf_conntract_lock() reads the variable.
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* WRITE_ONCE() is used to ensure the compiler will not
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* optimize the write.
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*/
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WRITE_ONCE(nf_conntrack_locks_all, true);
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for (i = 0; i < CONNTRACK_LOCKS; i++) {
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spin_lock(&nf_conntrack_locks[i]);
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/* This spin_unlock provides the "release" to ensure that
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* nf_conntrack_locks_all==true is visible to everyone that
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* acquired spin_lock(&nf_conntrack_locks[]).
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*/
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spin_unlock(&nf_conntrack_locks[i]);
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}
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}
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static void nf_conntrack_all_unlock(void)
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__releases(&nf_conntrack_locks_all_lock)
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{
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/* All prior stores must be complete before we clear
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* 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
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* might observe the false value but not the entire
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* critical section.
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* It pairs with the smp_load_acquire() in nf_conntrack_lock()
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*/
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smp_store_release(&nf_conntrack_locks_all, false);
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spin_unlock(&nf_conntrack_locks_all_lock);
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}
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unsigned int nf_conntrack_htable_size __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
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unsigned int nf_conntrack_max __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_max);
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seqcount_spinlock_t nf_conntrack_generation __read_mostly;
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static siphash_aligned_key_t nf_conntrack_hash_rnd;
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static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
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unsigned int zoneid,
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const struct net *net)
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{
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u64 a, b, c, d;
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get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
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/* The direction must be ignored, handle usable tuplehash members manually */
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a = (u64)tuple->src.u3.all[0] << 32 | tuple->src.u3.all[3];
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b = (u64)tuple->dst.u3.all[0] << 32 | tuple->dst.u3.all[3];
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c = (__force u64)tuple->src.u.all << 32 | (__force u64)tuple->dst.u.all << 16;
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c |= tuple->dst.protonum;
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d = (u64)zoneid << 32 | net_hash_mix(net);
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/* IPv4: u3.all[1,2,3] == 0 */
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c ^= (u64)tuple->src.u3.all[1] << 32 | tuple->src.u3.all[2];
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d += (u64)tuple->dst.u3.all[1] << 32 | tuple->dst.u3.all[2];
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return (u32)siphash_4u64(a, b, c, d, &nf_conntrack_hash_rnd);
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}
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static u32 scale_hash(u32 hash)
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{
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return reciprocal_scale(hash, nf_conntrack_htable_size);
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}
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static u32 __hash_conntrack(const struct net *net,
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const struct nf_conntrack_tuple *tuple,
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unsigned int zoneid,
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unsigned int size)
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{
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return reciprocal_scale(hash_conntrack_raw(tuple, zoneid, net), size);
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}
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static u32 hash_conntrack(const struct net *net,
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const struct nf_conntrack_tuple *tuple,
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unsigned int zoneid)
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{
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return scale_hash(hash_conntrack_raw(tuple, zoneid, net));
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}
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static bool nf_ct_get_tuple_ports(const struct sk_buff *skb,
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unsigned int dataoff,
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struct nf_conntrack_tuple *tuple)
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{ struct {
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__be16 sport;
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__be16 dport;
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} _inet_hdr, *inet_hdr;
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/* Actually only need first 4 bytes to get ports. */
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inet_hdr = skb_header_pointer(skb, dataoff, sizeof(_inet_hdr), &_inet_hdr);
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if (!inet_hdr)
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return false;
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tuple->src.u.udp.port = inet_hdr->sport;
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tuple->dst.u.udp.port = inet_hdr->dport;
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return true;
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}
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static bool
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nf_ct_get_tuple(const struct sk_buff *skb,
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unsigned int nhoff,
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unsigned int dataoff,
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u_int16_t l3num,
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u_int8_t protonum,
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struct net *net,
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struct nf_conntrack_tuple *tuple)
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{
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unsigned int size;
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const __be32 *ap;
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__be32 _addrs[8];
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memset(tuple, 0, sizeof(*tuple));
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tuple->src.l3num = l3num;
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switch (l3num) {
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case NFPROTO_IPV4:
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nhoff += offsetof(struct iphdr, saddr);
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size = 2 * sizeof(__be32);
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break;
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case NFPROTO_IPV6:
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nhoff += offsetof(struct ipv6hdr, saddr);
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size = sizeof(_addrs);
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break;
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default:
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return true;
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}
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ap = skb_header_pointer(skb, nhoff, size, _addrs);
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if (!ap)
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return false;
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switch (l3num) {
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case NFPROTO_IPV4:
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tuple->src.u3.ip = ap[0];
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tuple->dst.u3.ip = ap[1];
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break;
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case NFPROTO_IPV6:
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memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
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memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
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break;
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}
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tuple->dst.protonum = protonum;
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tuple->dst.dir = IP_CT_DIR_ORIGINAL;
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switch (protonum) {
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#if IS_ENABLED(CONFIG_IPV6)
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case IPPROTO_ICMPV6:
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return icmpv6_pkt_to_tuple(skb, dataoff, net, tuple);
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#endif
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case IPPROTO_ICMP:
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return icmp_pkt_to_tuple(skb, dataoff, net, tuple);
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#ifdef CONFIG_NF_CT_PROTO_GRE
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case IPPROTO_GRE:
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return gre_pkt_to_tuple(skb, dataoff, net, tuple);
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#endif
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case IPPROTO_TCP:
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case IPPROTO_UDP:
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#ifdef CONFIG_NF_CT_PROTO_UDPLITE
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case IPPROTO_UDPLITE:
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#endif
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#ifdef CONFIG_NF_CT_PROTO_SCTP
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case IPPROTO_SCTP:
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#endif
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#ifdef CONFIG_NF_CT_PROTO_DCCP
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case IPPROTO_DCCP:
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#endif
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/* fallthrough */
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return nf_ct_get_tuple_ports(skb, dataoff, tuple);
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default:
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break;
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}
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return true;
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}
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static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
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u_int8_t *protonum)
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{
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int dataoff = -1;
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const struct iphdr *iph;
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struct iphdr _iph;
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iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
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if (!iph)
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return -1;
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/* Conntrack defragments packets, we might still see fragments
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* inside ICMP packets though.
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*/
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if (iph->frag_off & htons(IP_OFFSET))
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return -1;
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dataoff = nhoff + (iph->ihl << 2);
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*protonum = iph->protocol;
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/* Check bogus IP headers */
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if (dataoff > skb->len) {
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pr_debug("bogus IPv4 packet: nhoff %u, ihl %u, skblen %u\n",
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nhoff, iph->ihl << 2, skb->len);
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return -1;
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}
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return dataoff;
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}
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#if IS_ENABLED(CONFIG_IPV6)
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static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
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u8 *protonum)
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{
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int protoff = -1;
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unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
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__be16 frag_off;
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u8 nexthdr;
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if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
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&nexthdr, sizeof(nexthdr)) != 0) {
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pr_debug("can't get nexthdr\n");
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return -1;
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}
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protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
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/*
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* (protoff == skb->len) means the packet has not data, just
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* IPv6 and possibly extensions headers, but it is tracked anyway
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*/
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if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
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pr_debug("can't find proto in pkt\n");
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return -1;
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}
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*protonum = nexthdr;
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return protoff;
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}
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#endif
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static int get_l4proto(const struct sk_buff *skb,
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unsigned int nhoff, u8 pf, u8 *l4num)
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{
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switch (pf) {
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case NFPROTO_IPV4:
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return ipv4_get_l4proto(skb, nhoff, l4num);
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#if IS_ENABLED(CONFIG_IPV6)
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case NFPROTO_IPV6:
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return ipv6_get_l4proto(skb, nhoff, l4num);
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#endif
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default:
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*l4num = 0;
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break;
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}
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return -1;
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}
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bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
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u_int16_t l3num,
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struct net *net, struct nf_conntrack_tuple *tuple)
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{
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u8 protonum;
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int protoff;
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protoff = get_l4proto(skb, nhoff, l3num, &protonum);
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if (protoff <= 0)
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return false;
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return nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple);
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}
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EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
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bool
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nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
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const struct nf_conntrack_tuple *orig)
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{
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memset(inverse, 0, sizeof(*inverse));
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inverse->src.l3num = orig->src.l3num;
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switch (orig->src.l3num) {
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case NFPROTO_IPV4:
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inverse->src.u3.ip = orig->dst.u3.ip;
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inverse->dst.u3.ip = orig->src.u3.ip;
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break;
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case NFPROTO_IPV6:
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inverse->src.u3.in6 = orig->dst.u3.in6;
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inverse->dst.u3.in6 = orig->src.u3.in6;
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break;
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default:
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break;
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}
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inverse->dst.dir = !orig->dst.dir;
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|
inverse->dst.protonum = orig->dst.protonum;
|
|
|
|
switch (orig->dst.protonum) {
|
|
case IPPROTO_ICMP:
|
|
return nf_conntrack_invert_icmp_tuple(inverse, orig);
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
case IPPROTO_ICMPV6:
|
|
return nf_conntrack_invert_icmpv6_tuple(inverse, orig);
|
|
#endif
|
|
}
|
|
|
|
inverse->src.u.all = orig->dst.u.all;
|
|
inverse->dst.u.all = orig->src.u.all;
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
|
|
|
|
/* Generate a almost-unique pseudo-id for a given conntrack.
|
|
*
|
|
* intentionally doesn't re-use any of the seeds used for hash
|
|
* table location, we assume id gets exposed to userspace.
|
|
*
|
|
* Following nf_conn items do not change throughout lifetime
|
|
* of the nf_conn:
|
|
*
|
|
* 1. nf_conn address
|
|
* 2. nf_conn->master address (normally NULL)
|
|
* 3. the associated net namespace
|
|
* 4. the original direction tuple
|
|
*/
|
|
u32 nf_ct_get_id(const struct nf_conn *ct)
|
|
{
|
|
static siphash_aligned_key_t ct_id_seed;
|
|
unsigned long a, b, c, d;
|
|
|
|
net_get_random_once(&ct_id_seed, sizeof(ct_id_seed));
|
|
|
|
a = (unsigned long)ct;
|
|
b = (unsigned long)ct->master;
|
|
c = (unsigned long)nf_ct_net(ct);
|
|
d = (unsigned long)siphash(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
sizeof(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple),
|
|
&ct_id_seed);
|
|
#ifdef CONFIG_64BIT
|
|
return siphash_4u64((u64)a, (u64)b, (u64)c, (u64)d, &ct_id_seed);
|
|
#else
|
|
return siphash_4u32((u32)a, (u32)b, (u32)c, (u32)d, &ct_id_seed);
|
|
#endif
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_get_id);
|
|
|
|
static void
|
|
clean_from_lists(struct nf_conn *ct)
|
|
{
|
|
pr_debug("clean_from_lists(%p)\n", ct);
|
|
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
|
|
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
|
|
|
|
/* Destroy all pending expectations */
|
|
nf_ct_remove_expectations(ct);
|
|
}
|
|
|
|
#define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
|
|
|
|
/* Released via nf_ct_destroy() */
|
|
struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
|
|
const struct nf_conntrack_zone *zone,
|
|
gfp_t flags)
|
|
{
|
|
struct nf_conn *tmpl, *p;
|
|
|
|
if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) {
|
|
tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags);
|
|
if (!tmpl)
|
|
return NULL;
|
|
|
|
p = tmpl;
|
|
tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
|
|
if (tmpl != p) {
|
|
tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
|
|
tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p;
|
|
}
|
|
} else {
|
|
tmpl = kzalloc(sizeof(*tmpl), flags);
|
|
if (!tmpl)
|
|
return NULL;
|
|
}
|
|
|
|
tmpl->status = IPS_TEMPLATE;
|
|
write_pnet(&tmpl->ct_net, net);
|
|
nf_ct_zone_add(tmpl, zone);
|
|
refcount_set(&tmpl->ct_general.use, 1);
|
|
|
|
return tmpl;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
|
|
|
|
void nf_ct_tmpl_free(struct nf_conn *tmpl)
|
|
{
|
|
kfree(tmpl->ext);
|
|
|
|
if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK)
|
|
kfree((char *)tmpl - tmpl->proto.tmpl_padto);
|
|
else
|
|
kfree(tmpl);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
|
|
|
|
static void destroy_gre_conntrack(struct nf_conn *ct)
|
|
{
|
|
#ifdef CONFIG_NF_CT_PROTO_GRE
|
|
struct nf_conn *master = ct->master;
|
|
|
|
if (master)
|
|
nf_ct_gre_keymap_destroy(master);
|
|
#endif
|
|
}
|
|
|
|
void nf_ct_destroy(struct nf_conntrack *nfct)
|
|
{
|
|
struct nf_conn *ct = (struct nf_conn *)nfct;
|
|
|
|
pr_debug("%s(%p)\n", __func__, ct);
|
|
WARN_ON(refcount_read(&nfct->use) != 0);
|
|
|
|
if (unlikely(nf_ct_is_template(ct))) {
|
|
nf_ct_tmpl_free(ct);
|
|
return;
|
|
}
|
|
|
|
if (unlikely(nf_ct_protonum(ct) == IPPROTO_GRE))
|
|
destroy_gre_conntrack(ct);
|
|
|
|
/* Expectations will have been removed in clean_from_lists,
|
|
* except TFTP can create an expectation on the first packet,
|
|
* before connection is in the list, so we need to clean here,
|
|
* too.
|
|
*/
|
|
nf_ct_remove_expectations(ct);
|
|
|
|
if (ct->master)
|
|
nf_ct_put(ct->master);
|
|
|
|
pr_debug("%s: returning ct=%p to slab\n", __func__, ct);
|
|
nf_conntrack_free(ct);
|
|
}
|
|
EXPORT_SYMBOL(nf_ct_destroy);
|
|
|
|
static void __nf_ct_delete_from_lists(struct nf_conn *ct)
|
|
{
|
|
struct net *net = nf_ct_net(ct);
|
|
unsigned int hash, reply_hash;
|
|
unsigned int sequence;
|
|
|
|
do {
|
|
sequence = read_seqcount_begin(&nf_conntrack_generation);
|
|
hash = hash_conntrack(net,
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_ORIGINAL));
|
|
reply_hash = hash_conntrack(net,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_REPLY));
|
|
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
|
|
|
|
clean_from_lists(ct);
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
}
|
|
|
|
static void nf_ct_delete_from_lists(struct nf_conn *ct)
|
|
{
|
|
nf_ct_helper_destroy(ct);
|
|
local_bh_disable();
|
|
|
|
__nf_ct_delete_from_lists(ct);
|
|
|
|
local_bh_enable();
|
|
}
|
|
|
|
static void nf_ct_add_to_ecache_list(struct nf_conn *ct)
|
|
{
|
|
#ifdef CONFIG_NF_CONNTRACK_EVENTS
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(nf_ct_net(ct));
|
|
|
|
spin_lock(&cnet->ecache.dying_lock);
|
|
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
|
|
&cnet->ecache.dying_list);
|
|
spin_unlock(&cnet->ecache.dying_lock);
|
|
#endif
|
|
}
|
|
|
|
bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
|
|
{
|
|
struct nf_conn_tstamp *tstamp;
|
|
struct net *net;
|
|
|
|
if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
|
|
return false;
|
|
|
|
tstamp = nf_conn_tstamp_find(ct);
|
|
if (tstamp) {
|
|
s32 timeout = READ_ONCE(ct->timeout) - nfct_time_stamp;
|
|
|
|
tstamp->stop = ktime_get_real_ns();
|
|
if (timeout < 0)
|
|
tstamp->stop -= jiffies_to_nsecs(-timeout);
|
|
}
|
|
|
|
if (nf_conntrack_event_report(IPCT_DESTROY, ct,
|
|
portid, report) < 0) {
|
|
/* destroy event was not delivered. nf_ct_put will
|
|
* be done by event cache worker on redelivery.
|
|
*/
|
|
nf_ct_helper_destroy(ct);
|
|
local_bh_disable();
|
|
__nf_ct_delete_from_lists(ct);
|
|
nf_ct_add_to_ecache_list(ct);
|
|
local_bh_enable();
|
|
|
|
nf_conntrack_ecache_work(nf_ct_net(ct), NFCT_ECACHE_DESTROY_FAIL);
|
|
return false;
|
|
}
|
|
|
|
net = nf_ct_net(ct);
|
|
if (nf_conntrack_ecache_dwork_pending(net))
|
|
nf_conntrack_ecache_work(net, NFCT_ECACHE_DESTROY_SENT);
|
|
nf_ct_delete_from_lists(ct);
|
|
nf_ct_put(ct);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_delete);
|
|
|
|
static inline bool
|
|
nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conntrack_zone *zone,
|
|
const struct net *net)
|
|
{
|
|
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
/* A conntrack can be recreated with the equal tuple,
|
|
* so we need to check that the conntrack is confirmed
|
|
*/
|
|
return nf_ct_tuple_equal(tuple, &h->tuple) &&
|
|
nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
|
|
nf_ct_is_confirmed(ct) &&
|
|
net_eq(net, nf_ct_net(ct));
|
|
}
|
|
|
|
static inline bool
|
|
nf_ct_match(const struct nf_conn *ct1, const struct nf_conn *ct2)
|
|
{
|
|
return nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
&ct2->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
|
|
nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
&ct2->tuplehash[IP_CT_DIR_REPLY].tuple) &&
|
|
nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_ORIGINAL) &&
|
|
nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_REPLY) &&
|
|
net_eq(nf_ct_net(ct1), nf_ct_net(ct2));
|
|
}
|
|
|
|
/* caller must hold rcu readlock and none of the nf_conntrack_locks */
|
|
static void nf_ct_gc_expired(struct nf_conn *ct)
|
|
{
|
|
if (!refcount_inc_not_zero(&ct->ct_general.use))
|
|
return;
|
|
|
|
/* load ->status after refcount increase */
|
|
smp_acquire__after_ctrl_dep();
|
|
|
|
if (nf_ct_should_gc(ct))
|
|
nf_ct_kill(ct);
|
|
|
|
nf_ct_put(ct);
|
|
}
|
|
|
|
/*
|
|
* Warning :
|
|
* - Caller must take a reference on returned object
|
|
* and recheck nf_ct_tuple_equal(tuple, &h->tuple)
|
|
*/
|
|
static struct nf_conntrack_tuple_hash *
|
|
____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
|
|
const struct nf_conntrack_tuple *tuple, u32 hash)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_head *ct_hash;
|
|
struct hlist_nulls_node *n;
|
|
unsigned int bucket, hsize;
|
|
|
|
begin:
|
|
nf_conntrack_get_ht(&ct_hash, &hsize);
|
|
bucket = reciprocal_scale(hash, hsize);
|
|
|
|
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
|
|
struct nf_conn *ct;
|
|
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
if (nf_ct_is_expired(ct)) {
|
|
nf_ct_gc_expired(ct);
|
|
continue;
|
|
}
|
|
|
|
if (nf_ct_key_equal(h, tuple, zone, net))
|
|
return h;
|
|
}
|
|
/*
|
|
* if the nulls value we got at the end of this lookup is
|
|
* not the expected one, we must restart lookup.
|
|
* We probably met an item that was moved to another chain.
|
|
*/
|
|
if (get_nulls_value(n) != bucket) {
|
|
NF_CT_STAT_INC_ATOMIC(net, search_restart);
|
|
goto begin;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Find a connection corresponding to a tuple. */
|
|
static struct nf_conntrack_tuple_hash *
|
|
__nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
|
|
const struct nf_conntrack_tuple *tuple, u32 hash)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
|
|
rcu_read_lock();
|
|
|
|
h = ____nf_conntrack_find(net, zone, tuple, hash);
|
|
if (h) {
|
|
/* We have a candidate that matches the tuple we're interested
|
|
* in, try to obtain a reference and re-check tuple
|
|
*/
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
if (likely(refcount_inc_not_zero(&ct->ct_general.use))) {
|
|
/* re-check key after refcount */
|
|
smp_acquire__after_ctrl_dep();
|
|
|
|
if (likely(nf_ct_key_equal(h, tuple, zone, net)))
|
|
goto found;
|
|
|
|
/* TYPESAFE_BY_RCU recycled the candidate */
|
|
nf_ct_put(ct);
|
|
}
|
|
|
|
h = NULL;
|
|
}
|
|
found:
|
|
rcu_read_unlock();
|
|
|
|
return h;
|
|
}
|
|
|
|
struct nf_conntrack_tuple_hash *
|
|
nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
|
|
const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
unsigned int rid, zone_id = nf_ct_zone_id(zone, IP_CT_DIR_ORIGINAL);
|
|
struct nf_conntrack_tuple_hash *thash;
|
|
|
|
thash = __nf_conntrack_find_get(net, zone, tuple,
|
|
hash_conntrack_raw(tuple, zone_id, net));
|
|
|
|
if (thash)
|
|
return thash;
|
|
|
|
rid = nf_ct_zone_id(zone, IP_CT_DIR_REPLY);
|
|
if (rid != zone_id)
|
|
return __nf_conntrack_find_get(net, zone, tuple,
|
|
hash_conntrack_raw(tuple, rid, net));
|
|
return thash;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
|
|
|
|
static void __nf_conntrack_hash_insert(struct nf_conn *ct,
|
|
unsigned int hash,
|
|
unsigned int reply_hash)
|
|
{
|
|
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
|
|
&nf_conntrack_hash[hash]);
|
|
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
|
|
&nf_conntrack_hash[reply_hash]);
|
|
}
|
|
|
|
static bool nf_ct_ext_valid_pre(const struct nf_ct_ext *ext)
|
|
{
|
|
/* if ext->gen_id is not equal to nf_conntrack_ext_genid, some extensions
|
|
* may contain stale pointers to e.g. helper that has been removed.
|
|
*
|
|
* The helper can't clear this because the nf_conn object isn't in
|
|
* any hash and synchronize_rcu() isn't enough because associated skb
|
|
* might sit in a queue.
|
|
*/
|
|
return !ext || ext->gen_id == atomic_read(&nf_conntrack_ext_genid);
|
|
}
|
|
|
|
static bool nf_ct_ext_valid_post(struct nf_ct_ext *ext)
|
|
{
|
|
if (!ext)
|
|
return true;
|
|
|
|
if (ext->gen_id != atomic_read(&nf_conntrack_ext_genid))
|
|
return false;
|
|
|
|
/* inserted into conntrack table, nf_ct_iterate_cleanup()
|
|
* will find it. Disable nf_ct_ext_find() id check.
|
|
*/
|
|
WRITE_ONCE(ext->gen_id, 0);
|
|
return true;
|
|
}
|
|
|
|
int
|
|
nf_conntrack_hash_check_insert(struct nf_conn *ct)
|
|
{
|
|
const struct nf_conntrack_zone *zone;
|
|
struct net *net = nf_ct_net(ct);
|
|
unsigned int hash, reply_hash;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_node *n;
|
|
unsigned int max_chainlen;
|
|
unsigned int chainlen = 0;
|
|
unsigned int sequence;
|
|
int err = -EEXIST;
|
|
|
|
zone = nf_ct_zone(ct);
|
|
|
|
if (!nf_ct_ext_valid_pre(ct->ext))
|
|
return -EAGAIN;
|
|
|
|
local_bh_disable();
|
|
do {
|
|
sequence = read_seqcount_begin(&nf_conntrack_generation);
|
|
hash = hash_conntrack(net,
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_ORIGINAL));
|
|
reply_hash = hash_conntrack(net,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_REPLY));
|
|
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
|
|
|
|
max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
|
|
|
|
/* See if there's one in the list already, including reverse */
|
|
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode) {
|
|
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
zone, net))
|
|
goto out;
|
|
|
|
if (chainlen++ > max_chainlen)
|
|
goto chaintoolong;
|
|
}
|
|
|
|
chainlen = 0;
|
|
|
|
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode) {
|
|
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
zone, net))
|
|
goto out;
|
|
if (chainlen++ > max_chainlen)
|
|
goto chaintoolong;
|
|
}
|
|
|
|
/* If genid has changed, we can't insert anymore because ct
|
|
* extensions could have stale pointers and nf_ct_iterate_destroy
|
|
* might have completed its table scan already.
|
|
*
|
|
* Increment of the ext genid right after this check is fine:
|
|
* nf_ct_iterate_destroy blocks until locks are released.
|
|
*/
|
|
if (!nf_ct_ext_valid_post(ct->ext)) {
|
|
err = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
smp_wmb();
|
|
/* The caller holds a reference to this object */
|
|
refcount_set(&ct->ct_general.use, 2);
|
|
__nf_conntrack_hash_insert(ct, hash, reply_hash);
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
NF_CT_STAT_INC(net, insert);
|
|
local_bh_enable();
|
|
|
|
return 0;
|
|
chaintoolong:
|
|
NF_CT_STAT_INC(net, chaintoolong);
|
|
err = -ENOSPC;
|
|
out:
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
local_bh_enable();
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
|
|
|
|
void nf_ct_acct_add(struct nf_conn *ct, u32 dir, unsigned int packets,
|
|
unsigned int bytes)
|
|
{
|
|
struct nf_conn_acct *acct;
|
|
|
|
acct = nf_conn_acct_find(ct);
|
|
if (acct) {
|
|
struct nf_conn_counter *counter = acct->counter;
|
|
|
|
atomic64_add(packets, &counter[dir].packets);
|
|
atomic64_add(bytes, &counter[dir].bytes);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_acct_add);
|
|
|
|
static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
|
|
const struct nf_conn *loser_ct)
|
|
{
|
|
struct nf_conn_acct *acct;
|
|
|
|
acct = nf_conn_acct_find(loser_ct);
|
|
if (acct) {
|
|
struct nf_conn_counter *counter = acct->counter;
|
|
unsigned int bytes;
|
|
|
|
/* u32 should be fine since we must have seen one packet. */
|
|
bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
|
|
nf_ct_acct_update(ct, CTINFO2DIR(ctinfo), bytes);
|
|
}
|
|
}
|
|
|
|
static void __nf_conntrack_insert_prepare(struct nf_conn *ct)
|
|
{
|
|
struct nf_conn_tstamp *tstamp;
|
|
|
|
refcount_inc(&ct->ct_general.use);
|
|
|
|
/* set conntrack timestamp, if enabled. */
|
|
tstamp = nf_conn_tstamp_find(ct);
|
|
if (tstamp)
|
|
tstamp->start = ktime_get_real_ns();
|
|
}
|
|
|
|
/* caller must hold locks to prevent concurrent changes */
|
|
static int __nf_ct_resolve_clash(struct sk_buff *skb,
|
|
struct nf_conntrack_tuple_hash *h)
|
|
{
|
|
/* This is the conntrack entry already in hashes that won race. */
|
|
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *loser_ct;
|
|
|
|
loser_ct = nf_ct_get(skb, &ctinfo);
|
|
|
|
if (nf_ct_is_dying(ct))
|
|
return NF_DROP;
|
|
|
|
if (((ct->status & IPS_NAT_DONE_MASK) == 0) ||
|
|
nf_ct_match(ct, loser_ct)) {
|
|
struct net *net = nf_ct_net(ct);
|
|
|
|
nf_conntrack_get(&ct->ct_general);
|
|
|
|
nf_ct_acct_merge(ct, ctinfo, loser_ct);
|
|
nf_ct_put(loser_ct);
|
|
nf_ct_set(skb, ct, ctinfo);
|
|
|
|
NF_CT_STAT_INC(net, clash_resolve);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
return NF_DROP;
|
|
}
|
|
|
|
/**
|
|
* nf_ct_resolve_clash_harder - attempt to insert clashing conntrack entry
|
|
*
|
|
* @skb: skb that causes the collision
|
|
* @repl_idx: hash slot for reply direction
|
|
*
|
|
* Called when origin or reply direction had a clash.
|
|
* The skb can be handled without packet drop provided the reply direction
|
|
* is unique or there the existing entry has the identical tuple in both
|
|
* directions.
|
|
*
|
|
* Caller must hold conntrack table locks to prevent concurrent updates.
|
|
*
|
|
* Returns NF_DROP if the clash could not be handled.
|
|
*/
|
|
static int nf_ct_resolve_clash_harder(struct sk_buff *skb, u32 repl_idx)
|
|
{
|
|
struct nf_conn *loser_ct = (struct nf_conn *)skb_nfct(skb);
|
|
const struct nf_conntrack_zone *zone;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_node *n;
|
|
struct net *net;
|
|
|
|
zone = nf_ct_zone(loser_ct);
|
|
net = nf_ct_net(loser_ct);
|
|
|
|
/* Reply direction must never result in a clash, unless both origin
|
|
* and reply tuples are identical.
|
|
*/
|
|
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[repl_idx], hnnode) {
|
|
if (nf_ct_key_equal(h,
|
|
&loser_ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
zone, net))
|
|
return __nf_ct_resolve_clash(skb, h);
|
|
}
|
|
|
|
/* We want the clashing entry to go away real soon: 1 second timeout. */
|
|
WRITE_ONCE(loser_ct->timeout, nfct_time_stamp + HZ);
|
|
|
|
/* IPS_NAT_CLASH removes the entry automatically on the first
|
|
* reply. Also prevents UDP tracker from moving the entry to
|
|
* ASSURED state, i.e. the entry can always be evicted under
|
|
* pressure.
|
|
*/
|
|
loser_ct->status |= IPS_FIXED_TIMEOUT | IPS_NAT_CLASH;
|
|
|
|
__nf_conntrack_insert_prepare(loser_ct);
|
|
|
|
/* fake add for ORIGINAL dir: we want lookups to only find the entry
|
|
* already in the table. This also hides the clashing entry from
|
|
* ctnetlink iteration, i.e. conntrack -L won't show them.
|
|
*/
|
|
hlist_nulls_add_fake(&loser_ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
|
|
|
|
hlist_nulls_add_head_rcu(&loser_ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
|
|
&nf_conntrack_hash[repl_idx]);
|
|
|
|
NF_CT_STAT_INC(net, clash_resolve);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/**
|
|
* nf_ct_resolve_clash - attempt to handle clash without packet drop
|
|
*
|
|
* @skb: skb that causes the clash
|
|
* @h: tuplehash of the clashing entry already in table
|
|
* @reply_hash: hash slot for reply direction
|
|
*
|
|
* A conntrack entry can be inserted to the connection tracking table
|
|
* if there is no existing entry with an identical tuple.
|
|
*
|
|
* If there is one, @skb (and the assocated, unconfirmed conntrack) has
|
|
* to be dropped. In case @skb is retransmitted, next conntrack lookup
|
|
* will find the already-existing entry.
|
|
*
|
|
* The major problem with such packet drop is the extra delay added by
|
|
* the packet loss -- it will take some time for a retransmit to occur
|
|
* (or the sender to time out when waiting for a reply).
|
|
*
|
|
* This function attempts to handle the situation without packet drop.
|
|
*
|
|
* If @skb has no NAT transformation or if the colliding entries are
|
|
* exactly the same, only the to-be-confirmed conntrack entry is discarded
|
|
* and @skb is associated with the conntrack entry already in the table.
|
|
*
|
|
* Failing that, the new, unconfirmed conntrack is still added to the table
|
|
* provided that the collision only occurs in the ORIGINAL direction.
|
|
* The new entry will be added only in the non-clashing REPLY direction,
|
|
* so packets in the ORIGINAL direction will continue to match the existing
|
|
* entry. The new entry will also have a fixed timeout so it expires --
|
|
* due to the collision, it will only see reply traffic.
|
|
*
|
|
* Returns NF_DROP if the clash could not be resolved.
|
|
*/
|
|
static __cold noinline int
|
|
nf_ct_resolve_clash(struct sk_buff *skb, struct nf_conntrack_tuple_hash *h,
|
|
u32 reply_hash)
|
|
{
|
|
/* This is the conntrack entry already in hashes that won race. */
|
|
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
|
|
const struct nf_conntrack_l4proto *l4proto;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *loser_ct;
|
|
struct net *net;
|
|
int ret;
|
|
|
|
loser_ct = nf_ct_get(skb, &ctinfo);
|
|
net = nf_ct_net(loser_ct);
|
|
|
|
l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
|
|
if (!l4proto->allow_clash)
|
|
goto drop;
|
|
|
|
ret = __nf_ct_resolve_clash(skb, h);
|
|
if (ret == NF_ACCEPT)
|
|
return ret;
|
|
|
|
ret = nf_ct_resolve_clash_harder(skb, reply_hash);
|
|
if (ret == NF_ACCEPT)
|
|
return ret;
|
|
|
|
drop:
|
|
NF_CT_STAT_INC(net, drop);
|
|
NF_CT_STAT_INC(net, insert_failed);
|
|
return NF_DROP;
|
|
}
|
|
|
|
/* Confirm a connection given skb; places it in hash table */
|
|
int
|
|
__nf_conntrack_confirm(struct sk_buff *skb)
|
|
{
|
|
unsigned int chainlen = 0, sequence, max_chainlen;
|
|
const struct nf_conntrack_zone *zone;
|
|
unsigned int hash, reply_hash;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
struct nf_conn_help *help;
|
|
struct hlist_nulls_node *n;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct net *net;
|
|
int ret = NF_DROP;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
net = nf_ct_net(ct);
|
|
|
|
/* ipt_REJECT uses nf_conntrack_attach to attach related
|
|
ICMP/TCP RST packets in other direction. Actual packet
|
|
which created connection will be IP_CT_NEW or for an
|
|
expected connection, IP_CT_RELATED. */
|
|
if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
|
|
return NF_ACCEPT;
|
|
|
|
zone = nf_ct_zone(ct);
|
|
local_bh_disable();
|
|
|
|
do {
|
|
sequence = read_seqcount_begin(&nf_conntrack_generation);
|
|
/* reuse the hash saved before */
|
|
hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
|
|
hash = scale_hash(hash);
|
|
reply_hash = hash_conntrack(net,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
nf_ct_zone_id(nf_ct_zone(ct), IP_CT_DIR_REPLY));
|
|
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
|
|
|
|
/* We're not in hash table, and we refuse to set up related
|
|
* connections for unconfirmed conns. But packet copies and
|
|
* REJECT will give spurious warnings here.
|
|
*/
|
|
|
|
/* Another skb with the same unconfirmed conntrack may
|
|
* win the race. This may happen for bridge(br_flood)
|
|
* or broadcast/multicast packets do skb_clone with
|
|
* unconfirmed conntrack.
|
|
*/
|
|
if (unlikely(nf_ct_is_confirmed(ct))) {
|
|
WARN_ON_ONCE(1);
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
local_bh_enable();
|
|
return NF_DROP;
|
|
}
|
|
|
|
if (!nf_ct_ext_valid_pre(ct->ext)) {
|
|
NF_CT_STAT_INC(net, insert_failed);
|
|
goto dying;
|
|
}
|
|
|
|
pr_debug("Confirming conntrack %p\n", ct);
|
|
/* We have to check the DYING flag after unlink to prevent
|
|
* a race against nf_ct_get_next_corpse() possibly called from
|
|
* user context, else we insert an already 'dead' hash, blocking
|
|
* further use of that particular connection -JM.
|
|
*/
|
|
ct->status |= IPS_CONFIRMED;
|
|
|
|
if (unlikely(nf_ct_is_dying(ct))) {
|
|
NF_CT_STAT_INC(net, insert_failed);
|
|
goto dying;
|
|
}
|
|
|
|
max_chainlen = MIN_CHAINLEN + get_random_u32_below(MAX_CHAINLEN);
|
|
/* See if there's one in the list already, including reverse:
|
|
NAT could have grabbed it without realizing, since we're
|
|
not in the hash. If there is, we lost race. */
|
|
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode) {
|
|
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
zone, net))
|
|
goto out;
|
|
if (chainlen++ > max_chainlen)
|
|
goto chaintoolong;
|
|
}
|
|
|
|
chainlen = 0;
|
|
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode) {
|
|
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
zone, net))
|
|
goto out;
|
|
if (chainlen++ > max_chainlen) {
|
|
chaintoolong:
|
|
NF_CT_STAT_INC(net, chaintoolong);
|
|
NF_CT_STAT_INC(net, insert_failed);
|
|
ret = NF_DROP;
|
|
goto dying;
|
|
}
|
|
}
|
|
|
|
/* Timer relative to confirmation time, not original
|
|
setting time, otherwise we'd get timer wrap in
|
|
weird delay cases. */
|
|
ct->timeout += nfct_time_stamp;
|
|
|
|
__nf_conntrack_insert_prepare(ct);
|
|
|
|
/* Since the lookup is lockless, hash insertion must be done after
|
|
* starting the timer and setting the CONFIRMED bit. The RCU barriers
|
|
* guarantee that no other CPU can find the conntrack before the above
|
|
* stores are visible.
|
|
*/
|
|
__nf_conntrack_hash_insert(ct, hash, reply_hash);
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
local_bh_enable();
|
|
|
|
/* ext area is still valid (rcu read lock is held,
|
|
* but will go out of scope soon, we need to remove
|
|
* this conntrack again.
|
|
*/
|
|
if (!nf_ct_ext_valid_post(ct->ext)) {
|
|
nf_ct_kill(ct);
|
|
NF_CT_STAT_INC_ATOMIC(net, drop);
|
|
return NF_DROP;
|
|
}
|
|
|
|
help = nfct_help(ct);
|
|
if (help && help->helper)
|
|
nf_conntrack_event_cache(IPCT_HELPER, ct);
|
|
|
|
nf_conntrack_event_cache(master_ct(ct) ?
|
|
IPCT_RELATED : IPCT_NEW, ct);
|
|
return NF_ACCEPT;
|
|
|
|
out:
|
|
ret = nf_ct_resolve_clash(skb, h, reply_hash);
|
|
dying:
|
|
nf_conntrack_double_unlock(hash, reply_hash);
|
|
local_bh_enable();
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
|
|
|
|
/* Returns true if a connection correspondings to the tuple (required
|
|
for NAT). */
|
|
int
|
|
nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conn *ignored_conntrack)
|
|
{
|
|
struct net *net = nf_ct_net(ignored_conntrack);
|
|
const struct nf_conntrack_zone *zone;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_head *ct_hash;
|
|
unsigned int hash, hsize;
|
|
struct hlist_nulls_node *n;
|
|
struct nf_conn *ct;
|
|
|
|
zone = nf_ct_zone(ignored_conntrack);
|
|
|
|
rcu_read_lock();
|
|
begin:
|
|
nf_conntrack_get_ht(&ct_hash, &hsize);
|
|
hash = __hash_conntrack(net, tuple, nf_ct_zone_id(zone, IP_CT_DIR_REPLY), hsize);
|
|
|
|
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
if (ct == ignored_conntrack)
|
|
continue;
|
|
|
|
if (nf_ct_is_expired(ct)) {
|
|
nf_ct_gc_expired(ct);
|
|
continue;
|
|
}
|
|
|
|
if (nf_ct_key_equal(h, tuple, zone, net)) {
|
|
/* Tuple is taken already, so caller will need to find
|
|
* a new source port to use.
|
|
*
|
|
* Only exception:
|
|
* If the *original tuples* are identical, then both
|
|
* conntracks refer to the same flow.
|
|
* This is a rare situation, it can occur e.g. when
|
|
* more than one UDP packet is sent from same socket
|
|
* in different threads.
|
|
*
|
|
* Let nf_ct_resolve_clash() deal with this later.
|
|
*/
|
|
if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
|
|
nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL))
|
|
continue;
|
|
|
|
NF_CT_STAT_INC_ATOMIC(net, found);
|
|
rcu_read_unlock();
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
if (get_nulls_value(n) != hash) {
|
|
NF_CT_STAT_INC_ATOMIC(net, search_restart);
|
|
goto begin;
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
|
|
|
|
#define NF_CT_EVICTION_RANGE 8
|
|
|
|
/* There's a small race here where we may free a just-assured
|
|
connection. Too bad: we're in trouble anyway. */
|
|
static unsigned int early_drop_list(struct net *net,
|
|
struct hlist_nulls_head *head)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_node *n;
|
|
unsigned int drops = 0;
|
|
struct nf_conn *tmp;
|
|
|
|
hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
|
|
tmp = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
if (test_bit(IPS_OFFLOAD_BIT, &tmp->status))
|
|
continue;
|
|
|
|
if (nf_ct_is_expired(tmp)) {
|
|
nf_ct_gc_expired(tmp);
|
|
continue;
|
|
}
|
|
|
|
if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
|
|
!net_eq(nf_ct_net(tmp), net) ||
|
|
nf_ct_is_dying(tmp))
|
|
continue;
|
|
|
|
if (!refcount_inc_not_zero(&tmp->ct_general.use))
|
|
continue;
|
|
|
|
/* load ->ct_net and ->status after refcount increase */
|
|
smp_acquire__after_ctrl_dep();
|
|
|
|
/* kill only if still in same netns -- might have moved due to
|
|
* SLAB_TYPESAFE_BY_RCU rules.
|
|
*
|
|
* We steal the timer reference. If that fails timer has
|
|
* already fired or someone else deleted it. Just drop ref
|
|
* and move to next entry.
|
|
*/
|
|
if (net_eq(nf_ct_net(tmp), net) &&
|
|
nf_ct_is_confirmed(tmp) &&
|
|
nf_ct_delete(tmp, 0, 0))
|
|
drops++;
|
|
|
|
nf_ct_put(tmp);
|
|
}
|
|
|
|
return drops;
|
|
}
|
|
|
|
static noinline int early_drop(struct net *net, unsigned int hash)
|
|
{
|
|
unsigned int i, bucket;
|
|
|
|
for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
|
|
struct hlist_nulls_head *ct_hash;
|
|
unsigned int hsize, drops;
|
|
|
|
rcu_read_lock();
|
|
nf_conntrack_get_ht(&ct_hash, &hsize);
|
|
if (!i)
|
|
bucket = reciprocal_scale(hash, hsize);
|
|
else
|
|
bucket = (bucket + 1) % hsize;
|
|
|
|
drops = early_drop_list(net, &ct_hash[bucket]);
|
|
rcu_read_unlock();
|
|
|
|
if (drops) {
|
|
NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool gc_worker_skip_ct(const struct nf_conn *ct)
|
|
{
|
|
return !nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct);
|
|
}
|
|
|
|
static bool gc_worker_can_early_drop(const struct nf_conn *ct)
|
|
{
|
|
const struct nf_conntrack_l4proto *l4proto;
|
|
|
|
if (!test_bit(IPS_ASSURED_BIT, &ct->status))
|
|
return true;
|
|
|
|
l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
|
|
if (l4proto->can_early_drop && l4proto->can_early_drop(ct))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static void gc_worker(struct work_struct *work)
|
|
{
|
|
unsigned int i, hashsz, nf_conntrack_max95 = 0;
|
|
u32 end_time, start_time = nfct_time_stamp;
|
|
struct conntrack_gc_work *gc_work;
|
|
unsigned int expired_count = 0;
|
|
unsigned long next_run;
|
|
s32 delta_time;
|
|
long count;
|
|
|
|
gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
|
|
|
|
i = gc_work->next_bucket;
|
|
if (gc_work->early_drop)
|
|
nf_conntrack_max95 = nf_conntrack_max / 100u * 95u;
|
|
|
|
if (i == 0) {
|
|
gc_work->avg_timeout = GC_SCAN_INTERVAL_INIT;
|
|
gc_work->count = GC_SCAN_INITIAL_COUNT;
|
|
gc_work->start_time = start_time;
|
|
}
|
|
|
|
next_run = gc_work->avg_timeout;
|
|
count = gc_work->count;
|
|
|
|
end_time = start_time + GC_SCAN_MAX_DURATION;
|
|
|
|
do {
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct hlist_nulls_head *ct_hash;
|
|
struct hlist_nulls_node *n;
|
|
struct nf_conn *tmp;
|
|
|
|
rcu_read_lock();
|
|
|
|
nf_conntrack_get_ht(&ct_hash, &hashsz);
|
|
if (i >= hashsz) {
|
|
rcu_read_unlock();
|
|
break;
|
|
}
|
|
|
|
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
|
|
struct nf_conntrack_net *cnet;
|
|
struct net *net;
|
|
long expires;
|
|
|
|
tmp = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
if (test_bit(IPS_OFFLOAD_BIT, &tmp->status)) {
|
|
nf_ct_offload_timeout(tmp);
|
|
continue;
|
|
}
|
|
|
|
if (expired_count > GC_SCAN_EXPIRED_MAX) {
|
|
rcu_read_unlock();
|
|
|
|
gc_work->next_bucket = i;
|
|
gc_work->avg_timeout = next_run;
|
|
gc_work->count = count;
|
|
|
|
delta_time = nfct_time_stamp - gc_work->start_time;
|
|
|
|
/* re-sched immediately if total cycle time is exceeded */
|
|
next_run = delta_time < (s32)GC_SCAN_INTERVAL_MAX;
|
|
goto early_exit;
|
|
}
|
|
|
|
if (nf_ct_is_expired(tmp)) {
|
|
nf_ct_gc_expired(tmp);
|
|
expired_count++;
|
|
continue;
|
|
}
|
|
|
|
expires = clamp(nf_ct_expires(tmp), GC_SCAN_INTERVAL_MIN, GC_SCAN_INTERVAL_CLAMP);
|
|
expires = (expires - (long)next_run) / ++count;
|
|
next_run += expires;
|
|
|
|
if (nf_conntrack_max95 == 0 || gc_worker_skip_ct(tmp))
|
|
continue;
|
|
|
|
net = nf_ct_net(tmp);
|
|
cnet = nf_ct_pernet(net);
|
|
if (atomic_read(&cnet->count) < nf_conntrack_max95)
|
|
continue;
|
|
|
|
/* need to take reference to avoid possible races */
|
|
if (!refcount_inc_not_zero(&tmp->ct_general.use))
|
|
continue;
|
|
|
|
/* load ->status after refcount increase */
|
|
smp_acquire__after_ctrl_dep();
|
|
|
|
if (gc_worker_skip_ct(tmp)) {
|
|
nf_ct_put(tmp);
|
|
continue;
|
|
}
|
|
|
|
if (gc_worker_can_early_drop(tmp)) {
|
|
nf_ct_kill(tmp);
|
|
expired_count++;
|
|
}
|
|
|
|
nf_ct_put(tmp);
|
|
}
|
|
|
|
/* could check get_nulls_value() here and restart if ct
|
|
* was moved to another chain. But given gc is best-effort
|
|
* we will just continue with next hash slot.
|
|
*/
|
|
rcu_read_unlock();
|
|
cond_resched();
|
|
i++;
|
|
|
|
delta_time = nfct_time_stamp - end_time;
|
|
if (delta_time > 0 && i < hashsz) {
|
|
gc_work->avg_timeout = next_run;
|
|
gc_work->count = count;
|
|
gc_work->next_bucket = i;
|
|
next_run = 0;
|
|
goto early_exit;
|
|
}
|
|
} while (i < hashsz);
|
|
|
|
gc_work->next_bucket = 0;
|
|
|
|
next_run = clamp(next_run, GC_SCAN_INTERVAL_MIN, GC_SCAN_INTERVAL_MAX);
|
|
|
|
delta_time = max_t(s32, nfct_time_stamp - gc_work->start_time, 1);
|
|
if (next_run > (unsigned long)delta_time)
|
|
next_run -= delta_time;
|
|
else
|
|
next_run = 1;
|
|
|
|
early_exit:
|
|
if (gc_work->exiting)
|
|
return;
|
|
|
|
if (next_run)
|
|
gc_work->early_drop = false;
|
|
|
|
queue_delayed_work(system_power_efficient_wq, &gc_work->dwork, next_run);
|
|
}
|
|
|
|
static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
|
|
{
|
|
INIT_DELAYED_WORK(&gc_work->dwork, gc_worker);
|
|
gc_work->exiting = false;
|
|
}
|
|
|
|
static struct nf_conn *
|
|
__nf_conntrack_alloc(struct net *net,
|
|
const struct nf_conntrack_zone *zone,
|
|
const struct nf_conntrack_tuple *orig,
|
|
const struct nf_conntrack_tuple *repl,
|
|
gfp_t gfp, u32 hash)
|
|
{
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(net);
|
|
unsigned int ct_count;
|
|
struct nf_conn *ct;
|
|
|
|
/* We don't want any race condition at early drop stage */
|
|
ct_count = atomic_inc_return(&cnet->count);
|
|
|
|
if (nf_conntrack_max && unlikely(ct_count > nf_conntrack_max)) {
|
|
if (!early_drop(net, hash)) {
|
|
if (!conntrack_gc_work.early_drop)
|
|
conntrack_gc_work.early_drop = true;
|
|
atomic_dec(&cnet->count);
|
|
net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Do not use kmem_cache_zalloc(), as this cache uses
|
|
* SLAB_TYPESAFE_BY_RCU.
|
|
*/
|
|
ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
|
|
if (ct == NULL)
|
|
goto out;
|
|
|
|
spin_lock_init(&ct->lock);
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
|
|
/* save hash for reusing when confirming */
|
|
*(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
|
|
ct->status = 0;
|
|
WRITE_ONCE(ct->timeout, 0);
|
|
write_pnet(&ct->ct_net, net);
|
|
memset_after(ct, 0, __nfct_init_offset);
|
|
|
|
nf_ct_zone_add(ct, zone);
|
|
|
|
/* Because we use RCU lookups, we set ct_general.use to zero before
|
|
* this is inserted in any list.
|
|
*/
|
|
refcount_set(&ct->ct_general.use, 0);
|
|
return ct;
|
|
out:
|
|
atomic_dec(&cnet->count);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
struct nf_conn *nf_conntrack_alloc(struct net *net,
|
|
const struct nf_conntrack_zone *zone,
|
|
const struct nf_conntrack_tuple *orig,
|
|
const struct nf_conntrack_tuple *repl,
|
|
gfp_t gfp)
|
|
{
|
|
return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
|
|
|
|
void nf_conntrack_free(struct nf_conn *ct)
|
|
{
|
|
struct net *net = nf_ct_net(ct);
|
|
struct nf_conntrack_net *cnet;
|
|
|
|
/* A freed object has refcnt == 0, that's
|
|
* the golden rule for SLAB_TYPESAFE_BY_RCU
|
|
*/
|
|
WARN_ON(refcount_read(&ct->ct_general.use) != 0);
|
|
|
|
if (ct->status & IPS_SRC_NAT_DONE) {
|
|
const struct nf_nat_hook *nat_hook;
|
|
|
|
rcu_read_lock();
|
|
nat_hook = rcu_dereference(nf_nat_hook);
|
|
if (nat_hook)
|
|
nat_hook->remove_nat_bysrc(ct);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
kfree(ct->ext);
|
|
kmem_cache_free(nf_conntrack_cachep, ct);
|
|
cnet = nf_ct_pernet(net);
|
|
|
|
smp_mb__before_atomic();
|
|
atomic_dec(&cnet->count);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_free);
|
|
|
|
|
|
/* Allocate a new conntrack: we return -ENOMEM if classification
|
|
failed due to stress. Otherwise it really is unclassifiable. */
|
|
static noinline struct nf_conntrack_tuple_hash *
|
|
init_conntrack(struct net *net, struct nf_conn *tmpl,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff, u32 hash)
|
|
{
|
|
struct nf_conn *ct;
|
|
struct nf_conn_help *help;
|
|
struct nf_conntrack_tuple repl_tuple;
|
|
#ifdef CONFIG_NF_CONNTRACK_EVENTS
|
|
struct nf_conntrack_ecache *ecache;
|
|
#endif
|
|
struct nf_conntrack_expect *exp = NULL;
|
|
const struct nf_conntrack_zone *zone;
|
|
struct nf_conn_timeout *timeout_ext;
|
|
struct nf_conntrack_zone tmp;
|
|
struct nf_conntrack_net *cnet;
|
|
|
|
if (!nf_ct_invert_tuple(&repl_tuple, tuple)) {
|
|
pr_debug("Can't invert tuple.\n");
|
|
return NULL;
|
|
}
|
|
|
|
zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
|
|
ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
|
|
hash);
|
|
if (IS_ERR(ct))
|
|
return (struct nf_conntrack_tuple_hash *)ct;
|
|
|
|
if (!nf_ct_add_synproxy(ct, tmpl)) {
|
|
nf_conntrack_free(ct);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
|
|
|
|
if (timeout_ext)
|
|
nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
|
|
GFP_ATOMIC);
|
|
|
|
nf_ct_acct_ext_add(ct, GFP_ATOMIC);
|
|
nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
|
|
nf_ct_labels_ext_add(ct);
|
|
|
|
#ifdef CONFIG_NF_CONNTRACK_EVENTS
|
|
ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
|
|
|
|
if ((ecache || net->ct.sysctl_events) &&
|
|
!nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
|
|
ecache ? ecache->expmask : 0,
|
|
GFP_ATOMIC)) {
|
|
nf_conntrack_free(ct);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
#endif
|
|
|
|
cnet = nf_ct_pernet(net);
|
|
if (cnet->expect_count) {
|
|
spin_lock_bh(&nf_conntrack_expect_lock);
|
|
exp = nf_ct_find_expectation(net, zone, tuple);
|
|
if (exp) {
|
|
pr_debug("expectation arrives ct=%p exp=%p\n",
|
|
ct, exp);
|
|
/* Welcome, Mr. Bond. We've been expecting you... */
|
|
__set_bit(IPS_EXPECTED_BIT, &ct->status);
|
|
/* exp->master safe, refcnt bumped in nf_ct_find_expectation */
|
|
ct->master = exp->master;
|
|
if (exp->helper) {
|
|
help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
|
|
if (help)
|
|
rcu_assign_pointer(help->helper, exp->helper);
|
|
}
|
|
|
|
#ifdef CONFIG_NF_CONNTRACK_MARK
|
|
ct->mark = READ_ONCE(exp->master->mark);
|
|
#endif
|
|
#ifdef CONFIG_NF_CONNTRACK_SECMARK
|
|
ct->secmark = exp->master->secmark;
|
|
#endif
|
|
NF_CT_STAT_INC(net, expect_new);
|
|
}
|
|
spin_unlock_bh(&nf_conntrack_expect_lock);
|
|
}
|
|
if (!exp && tmpl)
|
|
__nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
|
|
|
|
/* Other CPU might have obtained a pointer to this object before it was
|
|
* released. Because refcount is 0, refcount_inc_not_zero() will fail.
|
|
*
|
|
* After refcount_set(1) it will succeed; ensure that zeroing of
|
|
* ct->status and the correct ct->net pointer are visible; else other
|
|
* core might observe CONFIRMED bit which means the entry is valid and
|
|
* in the hash table, but its not (anymore).
|
|
*/
|
|
smp_wmb();
|
|
|
|
/* Now it is going to be associated with an sk_buff, set refcount to 1. */
|
|
refcount_set(&ct->ct_general.use, 1);
|
|
|
|
if (exp) {
|
|
if (exp->expectfn)
|
|
exp->expectfn(ct, exp);
|
|
nf_ct_expect_put(exp);
|
|
}
|
|
|
|
return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
|
|
}
|
|
|
|
/* On success, returns 0, sets skb->_nfct | ctinfo */
|
|
static int
|
|
resolve_normal_ct(struct nf_conn *tmpl,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff,
|
|
u_int8_t protonum,
|
|
const struct nf_hook_state *state)
|
|
{
|
|
const struct nf_conntrack_zone *zone;
|
|
struct nf_conntrack_tuple tuple;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conntrack_zone tmp;
|
|
u32 hash, zone_id, rid;
|
|
struct nf_conn *ct;
|
|
|
|
if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
|
|
dataoff, state->pf, protonum, state->net,
|
|
&tuple)) {
|
|
pr_debug("Can't get tuple\n");
|
|
return 0;
|
|
}
|
|
|
|
/* look for tuple match */
|
|
zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
|
|
|
|
zone_id = nf_ct_zone_id(zone, IP_CT_DIR_ORIGINAL);
|
|
hash = hash_conntrack_raw(&tuple, zone_id, state->net);
|
|
h = __nf_conntrack_find_get(state->net, zone, &tuple, hash);
|
|
|
|
if (!h) {
|
|
rid = nf_ct_zone_id(zone, IP_CT_DIR_REPLY);
|
|
if (zone_id != rid) {
|
|
u32 tmp = hash_conntrack_raw(&tuple, rid, state->net);
|
|
|
|
h = __nf_conntrack_find_get(state->net, zone, &tuple, tmp);
|
|
}
|
|
}
|
|
|
|
if (!h) {
|
|
h = init_conntrack(state->net, tmpl, &tuple,
|
|
skb, dataoff, hash);
|
|
if (!h)
|
|
return 0;
|
|
if (IS_ERR(h))
|
|
return PTR_ERR(h);
|
|
}
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
/* It exists; we have (non-exclusive) reference. */
|
|
if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
|
|
ctinfo = IP_CT_ESTABLISHED_REPLY;
|
|
} else {
|
|
/* Once we've had two way comms, always ESTABLISHED. */
|
|
if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
|
|
pr_debug("normal packet for %p\n", ct);
|
|
ctinfo = IP_CT_ESTABLISHED;
|
|
} else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
|
|
pr_debug("related packet for %p\n", ct);
|
|
ctinfo = IP_CT_RELATED;
|
|
} else {
|
|
pr_debug("new packet for %p\n", ct);
|
|
ctinfo = IP_CT_NEW;
|
|
}
|
|
}
|
|
nf_ct_set(skb, ct, ctinfo);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* icmp packets need special treatment to handle error messages that are
|
|
* related to a connection.
|
|
*
|
|
* Callers need to check if skb has a conntrack assigned when this
|
|
* helper returns; in such case skb belongs to an already known connection.
|
|
*/
|
|
static unsigned int __cold
|
|
nf_conntrack_handle_icmp(struct nf_conn *tmpl,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff,
|
|
u8 protonum,
|
|
const struct nf_hook_state *state)
|
|
{
|
|
int ret;
|
|
|
|
if (state->pf == NFPROTO_IPV4 && protonum == IPPROTO_ICMP)
|
|
ret = nf_conntrack_icmpv4_error(tmpl, skb, dataoff, state);
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
else if (state->pf == NFPROTO_IPV6 && protonum == IPPROTO_ICMPV6)
|
|
ret = nf_conntrack_icmpv6_error(tmpl, skb, dataoff, state);
|
|
#endif
|
|
else
|
|
return NF_ACCEPT;
|
|
|
|
if (ret <= 0)
|
|
NF_CT_STAT_INC_ATOMIC(state->net, error);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int generic_packet(struct nf_conn *ct, struct sk_buff *skb,
|
|
enum ip_conntrack_info ctinfo)
|
|
{
|
|
const unsigned int *timeout = nf_ct_timeout_lookup(ct);
|
|
|
|
if (!timeout)
|
|
timeout = &nf_generic_pernet(nf_ct_net(ct))->timeout;
|
|
|
|
nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/* Returns verdict for packet, or -1 for invalid. */
|
|
static int nf_conntrack_handle_packet(struct nf_conn *ct,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff,
|
|
enum ip_conntrack_info ctinfo,
|
|
const struct nf_hook_state *state)
|
|
{
|
|
switch (nf_ct_protonum(ct)) {
|
|
case IPPROTO_TCP:
|
|
return nf_conntrack_tcp_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
case IPPROTO_UDP:
|
|
return nf_conntrack_udp_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
case IPPROTO_ICMP:
|
|
return nf_conntrack_icmp_packet(ct, skb, ctinfo, state);
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
case IPPROTO_ICMPV6:
|
|
return nf_conntrack_icmpv6_packet(ct, skb, ctinfo, state);
|
|
#endif
|
|
#ifdef CONFIG_NF_CT_PROTO_UDPLITE
|
|
case IPPROTO_UDPLITE:
|
|
return nf_conntrack_udplite_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
#endif
|
|
#ifdef CONFIG_NF_CT_PROTO_SCTP
|
|
case IPPROTO_SCTP:
|
|
return nf_conntrack_sctp_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
#endif
|
|
#ifdef CONFIG_NF_CT_PROTO_DCCP
|
|
case IPPROTO_DCCP:
|
|
return nf_conntrack_dccp_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
#endif
|
|
#ifdef CONFIG_NF_CT_PROTO_GRE
|
|
case IPPROTO_GRE:
|
|
return nf_conntrack_gre_packet(ct, skb, dataoff,
|
|
ctinfo, state);
|
|
#endif
|
|
}
|
|
|
|
return generic_packet(ct, skb, ctinfo);
|
|
}
|
|
|
|
unsigned int
|
|
nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
|
|
{
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *ct, *tmpl;
|
|
u_int8_t protonum;
|
|
int dataoff, ret;
|
|
|
|
tmpl = nf_ct_get(skb, &ctinfo);
|
|
if (tmpl || ctinfo == IP_CT_UNTRACKED) {
|
|
/* Previously seen (loopback or untracked)? Ignore. */
|
|
if ((tmpl && !nf_ct_is_template(tmpl)) ||
|
|
ctinfo == IP_CT_UNTRACKED)
|
|
return NF_ACCEPT;
|
|
skb->_nfct = 0;
|
|
}
|
|
|
|
/* rcu_read_lock()ed by nf_hook_thresh */
|
|
dataoff = get_l4proto(skb, skb_network_offset(skb), state->pf, &protonum);
|
|
if (dataoff <= 0) {
|
|
pr_debug("not prepared to track yet or error occurred\n");
|
|
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
|
|
ret = NF_ACCEPT;
|
|
goto out;
|
|
}
|
|
|
|
if (protonum == IPPROTO_ICMP || protonum == IPPROTO_ICMPV6) {
|
|
ret = nf_conntrack_handle_icmp(tmpl, skb, dataoff,
|
|
protonum, state);
|
|
if (ret <= 0) {
|
|
ret = -ret;
|
|
goto out;
|
|
}
|
|
/* ICMP[v6] protocol trackers may assign one conntrack. */
|
|
if (skb->_nfct)
|
|
goto out;
|
|
}
|
|
repeat:
|
|
ret = resolve_normal_ct(tmpl, skb, dataoff,
|
|
protonum, state);
|
|
if (ret < 0) {
|
|
/* Too stressed to deal. */
|
|
NF_CT_STAT_INC_ATOMIC(state->net, drop);
|
|
ret = NF_DROP;
|
|
goto out;
|
|
}
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (!ct) {
|
|
/* Not valid part of a connection */
|
|
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
|
|
ret = NF_ACCEPT;
|
|
goto out;
|
|
}
|
|
|
|
ret = nf_conntrack_handle_packet(ct, skb, dataoff, ctinfo, state);
|
|
if (ret <= 0) {
|
|
/* Invalid: inverse of the return code tells
|
|
* the netfilter core what to do */
|
|
pr_debug("nf_conntrack_in: Can't track with proto module\n");
|
|
nf_ct_put(ct);
|
|
skb->_nfct = 0;
|
|
/* Special case: TCP tracker reports an attempt to reopen a
|
|
* closed/aborted connection. We have to go back and create a
|
|
* fresh conntrack.
|
|
*/
|
|
if (ret == -NF_REPEAT)
|
|
goto repeat;
|
|
|
|
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
|
|
if (ret == -NF_DROP)
|
|
NF_CT_STAT_INC_ATOMIC(state->net, drop);
|
|
|
|
ret = -ret;
|
|
goto out;
|
|
}
|
|
|
|
if (ctinfo == IP_CT_ESTABLISHED_REPLY &&
|
|
!test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
|
|
nf_conntrack_event_cache(IPCT_REPLY, ct);
|
|
out:
|
|
if (tmpl)
|
|
nf_ct_put(tmpl);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_in);
|
|
|
|
/* Alter reply tuple (maybe alter helper). This is for NAT, and is
|
|
implicitly racy: see __nf_conntrack_confirm */
|
|
void nf_conntrack_alter_reply(struct nf_conn *ct,
|
|
const struct nf_conntrack_tuple *newreply)
|
|
{
|
|
struct nf_conn_help *help = nfct_help(ct);
|
|
|
|
/* Should be unconfirmed, so not in hash table yet */
|
|
WARN_ON(nf_ct_is_confirmed(ct));
|
|
|
|
pr_debug("Altering reply tuple of %p to ", ct);
|
|
nf_ct_dump_tuple(newreply);
|
|
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
|
|
if (ct->master || (help && !hlist_empty(&help->expectations)))
|
|
return;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply);
|
|
|
|
/* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */
|
|
void __nf_ct_refresh_acct(struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo,
|
|
const struct sk_buff *skb,
|
|
u32 extra_jiffies,
|
|
bool do_acct)
|
|
{
|
|
/* Only update if this is not a fixed timeout */
|
|
if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
|
|
goto acct;
|
|
|
|
/* If not in hash table, timer will not be active yet */
|
|
if (nf_ct_is_confirmed(ct))
|
|
extra_jiffies += nfct_time_stamp;
|
|
|
|
if (READ_ONCE(ct->timeout) != extra_jiffies)
|
|
WRITE_ONCE(ct->timeout, extra_jiffies);
|
|
acct:
|
|
if (do_acct)
|
|
nf_ct_acct_update(ct, CTINFO2DIR(ctinfo), skb->len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
|
|
|
|
bool nf_ct_kill_acct(struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo,
|
|
const struct sk_buff *skb)
|
|
{
|
|
nf_ct_acct_update(ct, CTINFO2DIR(ctinfo), skb->len);
|
|
|
|
return nf_ct_delete(ct, 0, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_kill_acct);
|
|
|
|
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
|
|
|
|
#include <linux/netfilter/nfnetlink.h>
|
|
#include <linux/netfilter/nfnetlink_conntrack.h>
|
|
#include <linux/mutex.h>
|
|
|
|
/* Generic function for tcp/udp/sctp/dccp and alike. */
|
|
int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
|
|
const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
|
|
nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
|
|
goto nla_put_failure;
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
|
|
|
|
const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
|
|
[CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
|
|
[CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
|
|
};
|
|
EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
|
|
|
|
int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
|
|
struct nf_conntrack_tuple *t,
|
|
u_int32_t flags)
|
|
{
|
|
if (flags & CTA_FILTER_FLAG(CTA_PROTO_SRC_PORT)) {
|
|
if (!tb[CTA_PROTO_SRC_PORT])
|
|
return -EINVAL;
|
|
|
|
t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
|
|
}
|
|
|
|
if (flags & CTA_FILTER_FLAG(CTA_PROTO_DST_PORT)) {
|
|
if (!tb[CTA_PROTO_DST_PORT])
|
|
return -EINVAL;
|
|
|
|
t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
|
|
|
|
unsigned int nf_ct_port_nlattr_tuple_size(void)
|
|
{
|
|
static unsigned int size __read_mostly;
|
|
|
|
if (!size)
|
|
size = nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
|
|
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
|
|
#endif
|
|
|
|
/* Used by ipt_REJECT and ip6t_REJECT. */
|
|
static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
|
|
{
|
|
struct nf_conn *ct;
|
|
enum ip_conntrack_info ctinfo;
|
|
|
|
/* This ICMP is in reverse direction to the packet which caused it */
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
|
|
ctinfo = IP_CT_RELATED_REPLY;
|
|
else
|
|
ctinfo = IP_CT_RELATED;
|
|
|
|
/* Attach to new skbuff, and increment count */
|
|
nf_ct_set(nskb, ct, ctinfo);
|
|
nf_conntrack_get(skb_nfct(nskb));
|
|
}
|
|
|
|
static int __nf_conntrack_update(struct net *net, struct sk_buff *skb,
|
|
struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo)
|
|
{
|
|
const struct nf_nat_hook *nat_hook;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conntrack_tuple tuple;
|
|
unsigned int status;
|
|
int dataoff;
|
|
u16 l3num;
|
|
u8 l4num;
|
|
|
|
l3num = nf_ct_l3num(ct);
|
|
|
|
dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num);
|
|
if (dataoff <= 0)
|
|
return -1;
|
|
|
|
if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
|
|
l4num, net, &tuple))
|
|
return -1;
|
|
|
|
if (ct->status & IPS_SRC_NAT) {
|
|
memcpy(tuple.src.u3.all,
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.all,
|
|
sizeof(tuple.src.u3.all));
|
|
tuple.src.u.all =
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all;
|
|
}
|
|
|
|
if (ct->status & IPS_DST_NAT) {
|
|
memcpy(tuple.dst.u3.all,
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.all,
|
|
sizeof(tuple.dst.u3.all));
|
|
tuple.dst.u.all =
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all;
|
|
}
|
|
|
|
h = nf_conntrack_find_get(net, nf_ct_zone(ct), &tuple);
|
|
if (!h)
|
|
return 0;
|
|
|
|
/* Store status bits of the conntrack that is clashing to re-do NAT
|
|
* mangling according to what it has been done already to this packet.
|
|
*/
|
|
status = ct->status;
|
|
|
|
nf_ct_put(ct);
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
nf_ct_set(skb, ct, ctinfo);
|
|
|
|
nat_hook = rcu_dereference(nf_nat_hook);
|
|
if (!nat_hook)
|
|
return 0;
|
|
|
|
if (status & IPS_SRC_NAT &&
|
|
nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_SRC,
|
|
IP_CT_DIR_ORIGINAL) == NF_DROP)
|
|
return -1;
|
|
|
|
if (status & IPS_DST_NAT &&
|
|
nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_DST,
|
|
IP_CT_DIR_ORIGINAL) == NF_DROP)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* This packet is coming from userspace via nf_queue, complete the packet
|
|
* processing after the helper invocation in nf_confirm().
|
|
*/
|
|
static int nf_confirm_cthelper(struct sk_buff *skb, struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo)
|
|
{
|
|
const struct nf_conntrack_helper *helper;
|
|
const struct nf_conn_help *help;
|
|
int protoff;
|
|
|
|
help = nfct_help(ct);
|
|
if (!help)
|
|
return 0;
|
|
|
|
helper = rcu_dereference(help->helper);
|
|
if (!(helper->flags & NF_CT_HELPER_F_USERSPACE))
|
|
return 0;
|
|
|
|
switch (nf_ct_l3num(ct)) {
|
|
case NFPROTO_IPV4:
|
|
protoff = skb_network_offset(skb) + ip_hdrlen(skb);
|
|
break;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
case NFPROTO_IPV6: {
|
|
__be16 frag_off;
|
|
u8 pnum;
|
|
|
|
pnum = ipv6_hdr(skb)->nexthdr;
|
|
protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
|
|
&frag_off);
|
|
if (protoff < 0 || (frag_off & htons(~0x7)) != 0)
|
|
return 0;
|
|
break;
|
|
}
|
|
#endif
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
|
|
!nf_is_loopback_packet(skb)) {
|
|
if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
|
|
NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* We've seen it coming out the other side: confirm it */
|
|
return nf_conntrack_confirm(skb) == NF_DROP ? - 1 : 0;
|
|
}
|
|
|
|
static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
|
|
{
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *ct;
|
|
int err;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (!ct)
|
|
return 0;
|
|
|
|
if (!nf_ct_is_confirmed(ct)) {
|
|
err = __nf_conntrack_update(net, skb, ct, ctinfo);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
}
|
|
|
|
return nf_confirm_cthelper(skb, ct, ctinfo);
|
|
}
|
|
|
|
static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
|
|
const struct sk_buff *skb)
|
|
{
|
|
const struct nf_conntrack_tuple *src_tuple;
|
|
const struct nf_conntrack_tuple_hash *hash;
|
|
struct nf_conntrack_tuple srctuple;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conn *ct;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (ct) {
|
|
src_tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
|
|
memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
|
|
return true;
|
|
}
|
|
|
|
if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
|
|
NFPROTO_IPV4, dev_net(skb->dev),
|
|
&srctuple))
|
|
return false;
|
|
|
|
hash = nf_conntrack_find_get(dev_net(skb->dev),
|
|
&nf_ct_zone_dflt,
|
|
&srctuple);
|
|
if (!hash)
|
|
return false;
|
|
|
|
ct = nf_ct_tuplehash_to_ctrack(hash);
|
|
src_tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
|
|
memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
|
|
nf_ct_put(ct);
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Bring out ya dead! */
|
|
static struct nf_conn *
|
|
get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
|
|
const struct nf_ct_iter_data *iter_data, unsigned int *bucket)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
struct hlist_nulls_node *n;
|
|
spinlock_t *lockp;
|
|
|
|
for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
|
|
struct hlist_nulls_head *hslot = &nf_conntrack_hash[*bucket];
|
|
|
|
if (hlist_nulls_empty(hslot))
|
|
continue;
|
|
|
|
lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
|
|
local_bh_disable();
|
|
nf_conntrack_lock(lockp);
|
|
hlist_nulls_for_each_entry(h, n, hslot, hnnode) {
|
|
if (NF_CT_DIRECTION(h) != IP_CT_DIR_REPLY)
|
|
continue;
|
|
/* All nf_conn objects are added to hash table twice, one
|
|
* for original direction tuple, once for the reply tuple.
|
|
*
|
|
* Exception: In the IPS_NAT_CLASH case, only the reply
|
|
* tuple is added (the original tuple already existed for
|
|
* a different object).
|
|
*
|
|
* We only need to call the iterator once for each
|
|
* conntrack, so we just use the 'reply' direction
|
|
* tuple while iterating.
|
|
*/
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
|
|
if (iter_data->net &&
|
|
!net_eq(iter_data->net, nf_ct_net(ct)))
|
|
continue;
|
|
|
|
if (iter(ct, iter_data->data))
|
|
goto found;
|
|
}
|
|
spin_unlock(lockp);
|
|
local_bh_enable();
|
|
cond_resched();
|
|
}
|
|
|
|
return NULL;
|
|
found:
|
|
refcount_inc(&ct->ct_general.use);
|
|
spin_unlock(lockp);
|
|
local_bh_enable();
|
|
return ct;
|
|
}
|
|
|
|
static void nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data),
|
|
const struct nf_ct_iter_data *iter_data)
|
|
{
|
|
unsigned int bucket = 0;
|
|
struct nf_conn *ct;
|
|
|
|
might_sleep();
|
|
|
|
mutex_lock(&nf_conntrack_mutex);
|
|
while ((ct = get_next_corpse(iter, iter_data, &bucket)) != NULL) {
|
|
/* Time to push up daises... */
|
|
|
|
nf_ct_delete(ct, iter_data->portid, iter_data->report);
|
|
nf_ct_put(ct);
|
|
cond_resched();
|
|
}
|
|
mutex_unlock(&nf_conntrack_mutex);
|
|
}
|
|
|
|
void nf_ct_iterate_cleanup_net(int (*iter)(struct nf_conn *i, void *data),
|
|
const struct nf_ct_iter_data *iter_data)
|
|
{
|
|
struct net *net = iter_data->net;
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(net);
|
|
|
|
might_sleep();
|
|
|
|
if (atomic_read(&cnet->count) == 0)
|
|
return;
|
|
|
|
nf_ct_iterate_cleanup(iter, iter_data);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup_net);
|
|
|
|
/**
|
|
* nf_ct_iterate_destroy - destroy unconfirmed conntracks and iterate table
|
|
* @iter: callback to invoke for each conntrack
|
|
* @data: data to pass to @iter
|
|
*
|
|
* Like nf_ct_iterate_cleanup, but first marks conntracks on the
|
|
* unconfirmed list as dying (so they will not be inserted into
|
|
* main table).
|
|
*
|
|
* Can only be called in module exit path.
|
|
*/
|
|
void
|
|
nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)
|
|
{
|
|
struct nf_ct_iter_data iter_data = {};
|
|
struct net *net;
|
|
|
|
down_read(&net_rwsem);
|
|
for_each_net(net) {
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(net);
|
|
|
|
if (atomic_read(&cnet->count) == 0)
|
|
continue;
|
|
nf_queue_nf_hook_drop(net);
|
|
}
|
|
up_read(&net_rwsem);
|
|
|
|
/* Need to wait for netns cleanup worker to finish, if its
|
|
* running -- it might have deleted a net namespace from
|
|
* the global list, so hook drop above might not have
|
|
* affected all namespaces.
|
|
*/
|
|
net_ns_barrier();
|
|
|
|
/* a skb w. unconfirmed conntrack could have been reinjected just
|
|
* before we called nf_queue_nf_hook_drop().
|
|
*
|
|
* This makes sure its inserted into conntrack table.
|
|
*/
|
|
synchronize_net();
|
|
|
|
nf_ct_ext_bump_genid();
|
|
iter_data.data = data;
|
|
nf_ct_iterate_cleanup(iter, &iter_data);
|
|
|
|
/* Another cpu might be in a rcu read section with
|
|
* rcu protected pointer cleared in iter callback
|
|
* or hidden via nf_ct_ext_bump_genid() above.
|
|
*
|
|
* Wait until those are done.
|
|
*/
|
|
synchronize_rcu();
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_iterate_destroy);
|
|
|
|
static int kill_all(struct nf_conn *i, void *data)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
void nf_conntrack_cleanup_start(void)
|
|
{
|
|
cleanup_nf_conntrack_bpf();
|
|
conntrack_gc_work.exiting = true;
|
|
}
|
|
|
|
void nf_conntrack_cleanup_end(void)
|
|
{
|
|
RCU_INIT_POINTER(nf_ct_hook, NULL);
|
|
cancel_delayed_work_sync(&conntrack_gc_work.dwork);
|
|
kvfree(nf_conntrack_hash);
|
|
|
|
nf_conntrack_proto_fini();
|
|
nf_conntrack_helper_fini();
|
|
nf_conntrack_expect_fini();
|
|
|
|
kmem_cache_destroy(nf_conntrack_cachep);
|
|
}
|
|
|
|
/*
|
|
* Mishearing the voices in his head, our hero wonders how he's
|
|
* supposed to kill the mall.
|
|
*/
|
|
void nf_conntrack_cleanup_net(struct net *net)
|
|
{
|
|
LIST_HEAD(single);
|
|
|
|
list_add(&net->exit_list, &single);
|
|
nf_conntrack_cleanup_net_list(&single);
|
|
}
|
|
|
|
void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
|
|
{
|
|
struct nf_ct_iter_data iter_data = {};
|
|
struct net *net;
|
|
int busy;
|
|
|
|
/*
|
|
* This makes sure all current packets have passed through
|
|
* netfilter framework. Roll on, two-stage module
|
|
* delete...
|
|
*/
|
|
synchronize_net();
|
|
i_see_dead_people:
|
|
busy = 0;
|
|
list_for_each_entry(net, net_exit_list, exit_list) {
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(net);
|
|
|
|
iter_data.net = net;
|
|
nf_ct_iterate_cleanup_net(kill_all, &iter_data);
|
|
if (atomic_read(&cnet->count) != 0)
|
|
busy = 1;
|
|
}
|
|
if (busy) {
|
|
schedule();
|
|
goto i_see_dead_people;
|
|
}
|
|
|
|
list_for_each_entry(net, net_exit_list, exit_list) {
|
|
nf_conntrack_ecache_pernet_fini(net);
|
|
nf_conntrack_expect_pernet_fini(net);
|
|
free_percpu(net->ct.stat);
|
|
}
|
|
}
|
|
|
|
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
|
|
{
|
|
struct hlist_nulls_head *hash;
|
|
unsigned int nr_slots, i;
|
|
|
|
if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
|
|
return NULL;
|
|
|
|
BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
|
|
nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
|
|
|
|
hash = kvcalloc(nr_slots, sizeof(struct hlist_nulls_head), GFP_KERNEL);
|
|
|
|
if (hash && nulls)
|
|
for (i = 0; i < nr_slots; i++)
|
|
INIT_HLIST_NULLS_HEAD(&hash[i], i);
|
|
|
|
return hash;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
|
|
|
|
int nf_conntrack_hash_resize(unsigned int hashsize)
|
|
{
|
|
int i, bucket;
|
|
unsigned int old_size;
|
|
struct hlist_nulls_head *hash, *old_hash;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
|
|
if (!hashsize)
|
|
return -EINVAL;
|
|
|
|
hash = nf_ct_alloc_hashtable(&hashsize, 1);
|
|
if (!hash)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&nf_conntrack_mutex);
|
|
old_size = nf_conntrack_htable_size;
|
|
if (old_size == hashsize) {
|
|
mutex_unlock(&nf_conntrack_mutex);
|
|
kvfree(hash);
|
|
return 0;
|
|
}
|
|
|
|
local_bh_disable();
|
|
nf_conntrack_all_lock();
|
|
write_seqcount_begin(&nf_conntrack_generation);
|
|
|
|
/* Lookups in the old hash might happen in parallel, which means we
|
|
* might get false negatives during connection lookup. New connections
|
|
* created because of a false negative won't make it into the hash
|
|
* though since that required taking the locks.
|
|
*/
|
|
|
|
for (i = 0; i < nf_conntrack_htable_size; i++) {
|
|
while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
|
|
unsigned int zone_id;
|
|
|
|
h = hlist_nulls_entry(nf_conntrack_hash[i].first,
|
|
struct nf_conntrack_tuple_hash, hnnode);
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
hlist_nulls_del_rcu(&h->hnnode);
|
|
|
|
zone_id = nf_ct_zone_id(nf_ct_zone(ct), NF_CT_DIRECTION(h));
|
|
bucket = __hash_conntrack(nf_ct_net(ct),
|
|
&h->tuple, zone_id, hashsize);
|
|
hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
|
|
}
|
|
}
|
|
old_hash = nf_conntrack_hash;
|
|
|
|
nf_conntrack_hash = hash;
|
|
nf_conntrack_htable_size = hashsize;
|
|
|
|
write_seqcount_end(&nf_conntrack_generation);
|
|
nf_conntrack_all_unlock();
|
|
local_bh_enable();
|
|
|
|
mutex_unlock(&nf_conntrack_mutex);
|
|
|
|
synchronize_net();
|
|
kvfree(old_hash);
|
|
return 0;
|
|
}
|
|
|
|
int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp)
|
|
{
|
|
unsigned int hashsize;
|
|
int rc;
|
|
|
|
if (current->nsproxy->net_ns != &init_net)
|
|
return -EOPNOTSUPP;
|
|
|
|
/* On boot, we can set this without any fancy locking. */
|
|
if (!nf_conntrack_hash)
|
|
return param_set_uint(val, kp);
|
|
|
|
rc = kstrtouint(val, 0, &hashsize);
|
|
if (rc)
|
|
return rc;
|
|
|
|
return nf_conntrack_hash_resize(hashsize);
|
|
}
|
|
|
|
int nf_conntrack_init_start(void)
|
|
{
|
|
unsigned long nr_pages = totalram_pages();
|
|
int max_factor = 8;
|
|
int ret = -ENOMEM;
|
|
int i;
|
|
|
|
seqcount_spinlock_init(&nf_conntrack_generation,
|
|
&nf_conntrack_locks_all_lock);
|
|
|
|
for (i = 0; i < CONNTRACK_LOCKS; i++)
|
|
spin_lock_init(&nf_conntrack_locks[i]);
|
|
|
|
if (!nf_conntrack_htable_size) {
|
|
nf_conntrack_htable_size
|
|
= (((nr_pages << PAGE_SHIFT) / 16384)
|
|
/ sizeof(struct hlist_head));
|
|
if (BITS_PER_LONG >= 64 &&
|
|
nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
|
|
nf_conntrack_htable_size = 262144;
|
|
else if (nr_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
|
|
nf_conntrack_htable_size = 65536;
|
|
|
|
if (nf_conntrack_htable_size < 1024)
|
|
nf_conntrack_htable_size = 1024;
|
|
/* Use a max. factor of one by default to keep the average
|
|
* hash chain length at 2 entries. Each entry has to be added
|
|
* twice (once for original direction, once for reply).
|
|
* When a table size is given we use the old value of 8 to
|
|
* avoid implicit reduction of the max entries setting.
|
|
*/
|
|
max_factor = 1;
|
|
}
|
|
|
|
nf_conntrack_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
|
|
if (!nf_conntrack_hash)
|
|
return -ENOMEM;
|
|
|
|
nf_conntrack_max = max_factor * nf_conntrack_htable_size;
|
|
|
|
nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
|
|
sizeof(struct nf_conn),
|
|
NFCT_INFOMASK + 1,
|
|
SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
|
|
if (!nf_conntrack_cachep)
|
|
goto err_cachep;
|
|
|
|
ret = nf_conntrack_expect_init();
|
|
if (ret < 0)
|
|
goto err_expect;
|
|
|
|
ret = nf_conntrack_helper_init();
|
|
if (ret < 0)
|
|
goto err_helper;
|
|
|
|
ret = nf_conntrack_proto_init();
|
|
if (ret < 0)
|
|
goto err_proto;
|
|
|
|
conntrack_gc_work_init(&conntrack_gc_work);
|
|
queue_delayed_work(system_power_efficient_wq, &conntrack_gc_work.dwork, HZ);
|
|
|
|
ret = register_nf_conntrack_bpf();
|
|
if (ret < 0)
|
|
goto err_kfunc;
|
|
|
|
return 0;
|
|
|
|
err_kfunc:
|
|
cancel_delayed_work_sync(&conntrack_gc_work.dwork);
|
|
nf_conntrack_proto_fini();
|
|
err_proto:
|
|
nf_conntrack_helper_fini();
|
|
err_helper:
|
|
nf_conntrack_expect_fini();
|
|
err_expect:
|
|
kmem_cache_destroy(nf_conntrack_cachep);
|
|
err_cachep:
|
|
kvfree(nf_conntrack_hash);
|
|
return ret;
|
|
}
|
|
|
|
static const struct nf_ct_hook nf_conntrack_hook = {
|
|
.update = nf_conntrack_update,
|
|
.destroy = nf_ct_destroy,
|
|
.get_tuple_skb = nf_conntrack_get_tuple_skb,
|
|
.attach = nf_conntrack_attach,
|
|
};
|
|
|
|
void nf_conntrack_init_end(void)
|
|
{
|
|
RCU_INIT_POINTER(nf_ct_hook, &nf_conntrack_hook);
|
|
}
|
|
|
|
/*
|
|
* We need to use special "null" values, not used in hash table
|
|
*/
|
|
#define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
|
|
|
|
int nf_conntrack_init_net(struct net *net)
|
|
{
|
|
struct nf_conntrack_net *cnet = nf_ct_pernet(net);
|
|
int ret = -ENOMEM;
|
|
|
|
BUILD_BUG_ON(IP_CT_UNTRACKED == IP_CT_NUMBER);
|
|
BUILD_BUG_ON_NOT_POWER_OF_2(CONNTRACK_LOCKS);
|
|
atomic_set(&cnet->count, 0);
|
|
|
|
net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
|
|
if (!net->ct.stat)
|
|
return ret;
|
|
|
|
ret = nf_conntrack_expect_pernet_init(net);
|
|
if (ret < 0)
|
|
goto err_expect;
|
|
|
|
nf_conntrack_acct_pernet_init(net);
|
|
nf_conntrack_tstamp_pernet_init(net);
|
|
nf_conntrack_ecache_pernet_init(net);
|
|
nf_conntrack_proto_pernet_init(net);
|
|
|
|
return 0;
|
|
|
|
err_expect:
|
|
free_percpu(net->ct.stat);
|
|
return ret;
|
|
}
|
|
|
|
/* ctnetlink code shared by both ctnetlink and nf_conntrack_bpf */
|
|
|
|
int __nf_ct_change_timeout(struct nf_conn *ct, u64 timeout)
|
|
{
|
|
if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
|
|
return -EPERM;
|
|
|
|
__nf_ct_set_timeout(ct, timeout);
|
|
|
|
if (test_bit(IPS_DYING_BIT, &ct->status))
|
|
return -ETIME;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_ct_change_timeout);
|
|
|
|
void __nf_ct_change_status(struct nf_conn *ct, unsigned long on, unsigned long off)
|
|
{
|
|
unsigned int bit;
|
|
|
|
/* Ignore these unchangable bits */
|
|
on &= ~IPS_UNCHANGEABLE_MASK;
|
|
off &= ~IPS_UNCHANGEABLE_MASK;
|
|
|
|
for (bit = 0; bit < __IPS_MAX_BIT; bit++) {
|
|
if (on & (1 << bit))
|
|
set_bit(bit, &ct->status);
|
|
else if (off & (1 << bit))
|
|
clear_bit(bit, &ct->status);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_ct_change_status);
|
|
|
|
int nf_ct_change_status_common(struct nf_conn *ct, unsigned int status)
|
|
{
|
|
unsigned long d;
|
|
|
|
d = ct->status ^ status;
|
|
|
|
if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING))
|
|
/* unchangeable */
|
|
return -EBUSY;
|
|
|
|
if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
|
|
/* SEEN_REPLY bit can only be set */
|
|
return -EBUSY;
|
|
|
|
if (d & IPS_ASSURED && !(status & IPS_ASSURED))
|
|
/* ASSURED bit can only be set */
|
|
return -EBUSY;
|
|
|
|
__nf_ct_change_status(ct, status, 0);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_change_status_common);
|