mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-19 09:59:04 +00:00
6636568cf8
Noticed by Pablo Neira <pablo@eurodev.net>. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
1548 lines
43 KiB
C
1548 lines
43 KiB
C
/* 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) 2002-2005 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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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* 23 Apr 2001: Harald Welte <laforge@gnumonks.org>
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* - new API and handling of conntrack/nat helpers
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* - now capable of multiple expectations for one master
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* 16 Jul 2002: Harald Welte <laforge@gnumonks.org>
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* - add usage/reference counts to ip_conntrack_expect
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* - export ip_conntrack[_expect]_{find_get,put} functions
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* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - generalize L3 protocol denendent part.
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* 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - add support various size of conntrack structures.
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*
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* Derived from net/ipv4/netfilter/ip_conntrack_core.c
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*/
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#include <linux/config.h>
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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/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/jhash.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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/* This rwlock protects the main hash table, protocol/helper/expected
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registrations, conntrack timers*/
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#define ASSERT_READ_LOCK(x)
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#define ASSERT_WRITE_LOCK(x)
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_protocol.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 <linux/netfilter_ipv4/listhelp.h>
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#define NF_CONNTRACK_VERSION "0.4.1"
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(format, args...)
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#endif
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DEFINE_RWLOCK(nf_conntrack_lock);
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/* nf_conntrack_standalone needs this */
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atomic_t nf_conntrack_count = ATOMIC_INIT(0);
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void (*nf_conntrack_destroyed)(struct nf_conn *conntrack) = NULL;
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LIST_HEAD(nf_conntrack_expect_list);
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struct nf_conntrack_protocol **nf_ct_protos[PF_MAX];
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struct nf_conntrack_l3proto *nf_ct_l3protos[PF_MAX];
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static LIST_HEAD(helpers);
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unsigned int nf_conntrack_htable_size = 0;
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int nf_conntrack_max;
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struct list_head *nf_conntrack_hash;
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static kmem_cache_t *nf_conntrack_expect_cachep;
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struct nf_conn nf_conntrack_untracked;
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unsigned int nf_ct_log_invalid;
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static LIST_HEAD(unconfirmed);
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static int nf_conntrack_vmalloc;
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#ifdef CONFIG_NF_CONNTRACK_EVENTS
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struct notifier_block *nf_conntrack_chain;
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struct notifier_block *nf_conntrack_expect_chain;
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DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache);
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/* deliver cached events and clear cache entry - must be called with locally
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* disabled softirqs */
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static inline void
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__nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache)
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{
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DEBUGP("ecache: delivering events for %p\n", ecache->ct);
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if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct)
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&& ecache->events)
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notifier_call_chain(&nf_conntrack_chain, ecache->events,
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ecache->ct);
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ecache->events = 0;
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nf_ct_put(ecache->ct);
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ecache->ct = NULL;
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}
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/* Deliver all cached events for a particular conntrack. This is called
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* by code prior to async packet handling for freeing the skb */
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void nf_ct_deliver_cached_events(const struct nf_conn *ct)
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{
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struct nf_conntrack_ecache *ecache;
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local_bh_disable();
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ecache = &__get_cpu_var(nf_conntrack_ecache);
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if (ecache->ct == ct)
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__nf_ct_deliver_cached_events(ecache);
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local_bh_enable();
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}
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/* Deliver cached events for old pending events, if current conntrack != old */
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void __nf_ct_event_cache_init(struct nf_conn *ct)
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{
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struct nf_conntrack_ecache *ecache;
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/* take care of delivering potentially old events */
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ecache = &__get_cpu_var(nf_conntrack_ecache);
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BUG_ON(ecache->ct == ct);
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if (ecache->ct)
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__nf_ct_deliver_cached_events(ecache);
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/* initialize for this conntrack/packet */
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ecache->ct = ct;
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nf_conntrack_get(&ct->ct_general);
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}
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/* flush the event cache - touches other CPU's data and must not be called
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* while packets are still passing through the code */
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static void nf_ct_event_cache_flush(void)
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{
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struct nf_conntrack_ecache *ecache;
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int cpu;
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for_each_cpu(cpu) {
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ecache = &per_cpu(nf_conntrack_ecache, cpu);
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if (ecache->ct)
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nf_ct_put(ecache->ct);
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}
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}
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#else
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static inline void nf_ct_event_cache_flush(void) {}
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#endif /* CONFIG_NF_CONNTRACK_EVENTS */
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DEFINE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
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EXPORT_PER_CPU_SYMBOL(nf_conntrack_stat);
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/*
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* This scheme offers various size of "struct nf_conn" dependent on
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* features(helper, nat, ...)
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*/
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#define NF_CT_FEATURES_NAMELEN 256
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static struct {
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/* name of slab cache. printed in /proc/slabinfo */
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char *name;
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/* size of slab cache */
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size_t size;
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/* slab cache pointer */
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kmem_cache_t *cachep;
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/* allocated slab cache + modules which uses this slab cache */
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int use;
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/* Initialization */
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int (*init_conntrack)(struct nf_conn *, u_int32_t);
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} nf_ct_cache[NF_CT_F_NUM];
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/* protect members of nf_ct_cache except of "use" */
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DEFINE_RWLOCK(nf_ct_cache_lock);
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/* This avoids calling kmem_cache_create() with same name simultaneously */
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DECLARE_MUTEX(nf_ct_cache_mutex);
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extern struct nf_conntrack_protocol nf_conntrack_generic_protocol;
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struct nf_conntrack_protocol *
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nf_ct_find_proto(u_int16_t l3proto, u_int8_t protocol)
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{
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if (unlikely(nf_ct_protos[l3proto] == NULL))
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return &nf_conntrack_generic_protocol;
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return nf_ct_protos[l3proto][protocol];
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}
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static int nf_conntrack_hash_rnd_initted;
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static unsigned int nf_conntrack_hash_rnd;
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static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
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unsigned int size, unsigned int rnd)
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{
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unsigned int a, b;
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a = jhash((void *)tuple->src.u3.all, sizeof(tuple->src.u3.all),
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((tuple->src.l3num) << 16) | tuple->dst.protonum);
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b = jhash((void *)tuple->dst.u3.all, sizeof(tuple->dst.u3.all),
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(tuple->src.u.all << 16) | tuple->dst.u.all);
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return jhash_2words(a, b, rnd) % size;
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}
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static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
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{
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return __hash_conntrack(tuple, nf_conntrack_htable_size,
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nf_conntrack_hash_rnd);
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}
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/* Initialize "struct nf_conn" which has spaces for helper */
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static int
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init_conntrack_for_helper(struct nf_conn *conntrack, u_int32_t features)
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{
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conntrack->help = (union nf_conntrack_help *)
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(((unsigned long)conntrack->data
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+ (__alignof__(union nf_conntrack_help) - 1))
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& (~((unsigned long)(__alignof__(union nf_conntrack_help) -1))));
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return 0;
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}
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int nf_conntrack_register_cache(u_int32_t features, const char *name,
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size_t size,
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int (*init)(struct nf_conn *, u_int32_t))
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{
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int ret = 0;
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char *cache_name;
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kmem_cache_t *cachep;
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DEBUGP("nf_conntrack_register_cache: features=0x%x, name=%s, size=%d\n",
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features, name, size);
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if (features < NF_CT_F_BASIC || features >= NF_CT_F_NUM) {
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DEBUGP("nf_conntrack_register_cache: invalid features.: 0x%x\n",
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features);
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return -EINVAL;
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}
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down(&nf_ct_cache_mutex);
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write_lock_bh(&nf_ct_cache_lock);
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/* e.g: multiple helpers are loaded */
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if (nf_ct_cache[features].use > 0) {
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DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
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if ((!strncmp(nf_ct_cache[features].name, name,
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NF_CT_FEATURES_NAMELEN))
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&& nf_ct_cache[features].size == size
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&& nf_ct_cache[features].init_conntrack == init) {
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DEBUGP("nf_conntrack_register_cache: reusing.\n");
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nf_ct_cache[features].use++;
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ret = 0;
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} else
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ret = -EBUSY;
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write_unlock_bh(&nf_ct_cache_lock);
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up(&nf_ct_cache_mutex);
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return ret;
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}
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write_unlock_bh(&nf_ct_cache_lock);
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/*
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* The memory space for name of slab cache must be alive until
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* cache is destroyed.
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*/
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cache_name = kmalloc(sizeof(char)*NF_CT_FEATURES_NAMELEN, GFP_ATOMIC);
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if (cache_name == NULL) {
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DEBUGP("nf_conntrack_register_cache: can't alloc cache_name\n");
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ret = -ENOMEM;
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goto out_up_mutex;
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}
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if (strlcpy(cache_name, name, NF_CT_FEATURES_NAMELEN)
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>= NF_CT_FEATURES_NAMELEN) {
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printk("nf_conntrack_register_cache: name too long\n");
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ret = -EINVAL;
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goto out_free_name;
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}
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cachep = kmem_cache_create(cache_name, size, 0, 0,
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NULL, NULL);
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if (!cachep) {
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printk("nf_conntrack_register_cache: Can't create slab cache "
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"for the features = 0x%x\n", features);
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ret = -ENOMEM;
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goto out_free_name;
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}
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write_lock_bh(&nf_ct_cache_lock);
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nf_ct_cache[features].use = 1;
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nf_ct_cache[features].size = size;
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nf_ct_cache[features].init_conntrack = init;
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nf_ct_cache[features].cachep = cachep;
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nf_ct_cache[features].name = cache_name;
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write_unlock_bh(&nf_ct_cache_lock);
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goto out_up_mutex;
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out_free_name:
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kfree(cache_name);
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out_up_mutex:
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up(&nf_ct_cache_mutex);
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return ret;
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}
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/* FIXME: In the current, only nf_conntrack_cleanup() can call this function. */
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void nf_conntrack_unregister_cache(u_int32_t features)
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{
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kmem_cache_t *cachep;
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char *name;
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/*
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* This assures that kmem_cache_create() isn't called before destroying
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* slab cache.
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*/
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DEBUGP("nf_conntrack_unregister_cache: 0x%04x\n", features);
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down(&nf_ct_cache_mutex);
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write_lock_bh(&nf_ct_cache_lock);
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if (--nf_ct_cache[features].use > 0) {
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write_unlock_bh(&nf_ct_cache_lock);
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up(&nf_ct_cache_mutex);
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return;
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}
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cachep = nf_ct_cache[features].cachep;
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name = nf_ct_cache[features].name;
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nf_ct_cache[features].cachep = NULL;
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nf_ct_cache[features].name = NULL;
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nf_ct_cache[features].init_conntrack = NULL;
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nf_ct_cache[features].size = 0;
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write_unlock_bh(&nf_ct_cache_lock);
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synchronize_net();
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kmem_cache_destroy(cachep);
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kfree(name);
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up(&nf_ct_cache_mutex);
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}
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int
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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 nf_conntrack_tuple *tuple,
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const struct nf_conntrack_l3proto *l3proto,
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const struct nf_conntrack_protocol *protocol)
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{
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NF_CT_TUPLE_U_BLANK(tuple);
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tuple->src.l3num = l3num;
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if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
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return 0;
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tuple->dst.protonum = protonum;
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tuple->dst.dir = IP_CT_DIR_ORIGINAL;
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return protocol->pkt_to_tuple(skb, dataoff, tuple);
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}
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int
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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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const struct nf_conntrack_l3proto *l3proto,
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const struct nf_conntrack_protocol *protocol)
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{
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NF_CT_TUPLE_U_BLANK(inverse);
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inverse->src.l3num = orig->src.l3num;
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if (l3proto->invert_tuple(inverse, orig) == 0)
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return 0;
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inverse->dst.dir = !orig->dst.dir;
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inverse->dst.protonum = orig->dst.protonum;
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return protocol->invert_tuple(inverse, orig);
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}
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/* nf_conntrack_expect helper functions */
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static void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
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{
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ASSERT_WRITE_LOCK(&nf_conntrack_lock);
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NF_CT_ASSERT(!timer_pending(&exp->timeout));
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list_del(&exp->list);
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NF_CT_STAT_INC(expect_delete);
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exp->master->expecting--;
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nf_conntrack_expect_put(exp);
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}
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static void expectation_timed_out(unsigned long ul_expect)
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{
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struct nf_conntrack_expect *exp = (void *)ul_expect;
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write_lock_bh(&nf_conntrack_lock);
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nf_ct_unlink_expect(exp);
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write_unlock_bh(&nf_conntrack_lock);
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nf_conntrack_expect_put(exp);
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}
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/* If an expectation for this connection is found, it gets delete from
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* global list then returned. */
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static struct nf_conntrack_expect *
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find_expectation(const struct nf_conntrack_tuple *tuple)
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{
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struct nf_conntrack_expect *i;
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list_for_each_entry(i, &nf_conntrack_expect_list, list) {
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/* If master is not in hash table yet (ie. packet hasn't left
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this machine yet), how can other end know about expected?
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Hence these are not the droids you are looking for (if
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master ct never got confirmed, we'd hold a reference to it
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and weird things would happen to future packets). */
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if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)
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&& nf_ct_is_confirmed(i->master)) {
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if (i->flags & NF_CT_EXPECT_PERMANENT) {
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atomic_inc(&i->use);
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return i;
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} else if (del_timer(&i->timeout)) {
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nf_ct_unlink_expect(i);
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return i;
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}
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}
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}
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return NULL;
|
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}
|
|
|
|
/* delete all expectations for this conntrack */
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|
static void remove_expectations(struct nf_conn *ct)
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{
|
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struct nf_conntrack_expect *i, *tmp;
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|
|
/* Optimization: most connection never expect any others. */
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if (ct->expecting == 0)
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return;
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|
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list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) {
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if (i->master == ct && del_timer(&i->timeout)) {
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nf_ct_unlink_expect(i);
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nf_conntrack_expect_put(i);
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}
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}
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}
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|
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static void
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clean_from_lists(struct nf_conn *ct)
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{
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unsigned int ho, hr;
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DEBUGP("clean_from_lists(%p)\n", ct);
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ASSERT_WRITE_LOCK(&nf_conntrack_lock);
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|
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ho = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
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hr = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
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LIST_DELETE(&nf_conntrack_hash[ho], &ct->tuplehash[IP_CT_DIR_ORIGINAL]);
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LIST_DELETE(&nf_conntrack_hash[hr], &ct->tuplehash[IP_CT_DIR_REPLY]);
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|
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/* Destroy all pending expectations */
|
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remove_expectations(ct);
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}
|
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|
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static void
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destroy_conntrack(struct nf_conntrack *nfct)
|
|
{
|
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struct nf_conn *ct = (struct nf_conn *)nfct;
|
|
struct nf_conntrack_l3proto *l3proto;
|
|
struct nf_conntrack_protocol *proto;
|
|
|
|
DEBUGP("destroy_conntrack(%p)\n", ct);
|
|
NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
|
|
NF_CT_ASSERT(!timer_pending(&ct->timeout));
|
|
|
|
nf_conntrack_event(IPCT_DESTROY, ct);
|
|
set_bit(IPS_DYING_BIT, &ct->status);
|
|
|
|
/* To make sure we don't get any weird locking issues here:
|
|
* destroy_conntrack() MUST NOT be called with a write lock
|
|
* to nf_conntrack_lock!!! -HW */
|
|
l3proto = nf_ct_find_l3proto(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num);
|
|
if (l3proto && l3proto->destroy)
|
|
l3proto->destroy(ct);
|
|
|
|
proto = nf_ct_find_proto(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num,
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
|
|
if (proto && proto->destroy)
|
|
proto->destroy(ct);
|
|
|
|
if (nf_conntrack_destroyed)
|
|
nf_conntrack_destroyed(ct);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
/* 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. */
|
|
remove_expectations(ct);
|
|
|
|
/* We overload first tuple to link into unconfirmed list. */
|
|
if (!nf_ct_is_confirmed(ct)) {
|
|
BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
|
|
list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
|
|
}
|
|
|
|
NF_CT_STAT_INC(delete);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
if (ct->master)
|
|
nf_ct_put(ct->master);
|
|
|
|
DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
|
|
nf_conntrack_free(ct);
|
|
}
|
|
|
|
static void death_by_timeout(unsigned long ul_conntrack)
|
|
{
|
|
struct nf_conn *ct = (void *)ul_conntrack;
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
/* Inside lock so preempt is disabled on module removal path.
|
|
* Otherwise we can get spurious warnings. */
|
|
NF_CT_STAT_INC(delete_list);
|
|
clean_from_lists(ct);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
nf_ct_put(ct);
|
|
}
|
|
|
|
static inline int
|
|
conntrack_tuple_cmp(const struct nf_conntrack_tuple_hash *i,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conn *ignored_conntrack)
|
|
{
|
|
ASSERT_READ_LOCK(&nf_conntrack_lock);
|
|
return nf_ct_tuplehash_to_ctrack(i) != ignored_conntrack
|
|
&& nf_ct_tuple_equal(tuple, &i->tuple);
|
|
}
|
|
|
|
static struct nf_conntrack_tuple_hash *
|
|
__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conn *ignored_conntrack)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
unsigned int hash = hash_conntrack(tuple);
|
|
|
|
ASSERT_READ_LOCK(&nf_conntrack_lock);
|
|
list_for_each_entry(h, &nf_conntrack_hash[hash], list) {
|
|
if (conntrack_tuple_cmp(h, tuple, ignored_conntrack)) {
|
|
NF_CT_STAT_INC(found);
|
|
return h;
|
|
}
|
|
NF_CT_STAT_INC(searched);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Find a connection corresponding to a tuple. */
|
|
struct nf_conntrack_tuple_hash *
|
|
nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conn *ignored_conntrack)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
h = __nf_conntrack_find(tuple, ignored_conntrack);
|
|
if (h)
|
|
atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
|
|
read_unlock_bh(&nf_conntrack_lock);
|
|
|
|
return h;
|
|
}
|
|
|
|
/* Confirm a connection given skb; places it in hash table */
|
|
int
|
|
__nf_conntrack_confirm(struct sk_buff **pskb)
|
|
{
|
|
unsigned int hash, repl_hash;
|
|
struct nf_conn *ct;
|
|
enum ip_conntrack_info ctinfo;
|
|
|
|
ct = nf_ct_get(*pskb, &ctinfo);
|
|
|
|
/* 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;
|
|
|
|
hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
|
|
|
|
/* 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. */
|
|
/* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */
|
|
|
|
/* No external references means noone else could have
|
|
confirmed us. */
|
|
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
|
|
DEBUGP("Confirming conntrack %p\n", ct);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
|
|
/* 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. */
|
|
if (!LIST_FIND(&nf_conntrack_hash[hash],
|
|
conntrack_tuple_cmp,
|
|
struct nf_conntrack_tuple_hash *,
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, NULL)
|
|
&& !LIST_FIND(&nf_conntrack_hash[repl_hash],
|
|
conntrack_tuple_cmp,
|
|
struct nf_conntrack_tuple_hash *,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) {
|
|
/* Remove from unconfirmed list */
|
|
list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
|
|
|
|
list_prepend(&nf_conntrack_hash[hash],
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL]);
|
|
list_prepend(&nf_conntrack_hash[repl_hash],
|
|
&ct->tuplehash[IP_CT_DIR_REPLY]);
|
|
/* Timer relative to confirmation time, not original
|
|
setting time, otherwise we'd get timer wrap in
|
|
weird delay cases. */
|
|
ct->timeout.expires += jiffies;
|
|
add_timer(&ct->timeout);
|
|
atomic_inc(&ct->ct_general.use);
|
|
set_bit(IPS_CONFIRMED_BIT, &ct->status);
|
|
NF_CT_STAT_INC(insert);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
if (ct->helper)
|
|
nf_conntrack_event_cache(IPCT_HELPER, *pskb);
|
|
#ifdef CONFIG_NF_NAT_NEEDED
|
|
if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
|
|
test_bit(IPS_DST_NAT_DONE_BIT, &ct->status))
|
|
nf_conntrack_event_cache(IPCT_NATINFO, *pskb);
|
|
#endif
|
|
nf_conntrack_event_cache(master_ct(ct) ?
|
|
IPCT_RELATED : IPCT_NEW, *pskb);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
NF_CT_STAT_INC(insert_failed);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return NF_DROP;
|
|
}
|
|
|
|
/* 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 nf_conntrack_tuple_hash *h;
|
|
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
h = __nf_conntrack_find(tuple, ignored_conntrack);
|
|
read_unlock_bh(&nf_conntrack_lock);
|
|
|
|
return h != NULL;
|
|
}
|
|
|
|
/* There's a small race here where we may free a just-assured
|
|
connection. Too bad: we're in trouble anyway. */
|
|
static inline int unreplied(const struct nf_conntrack_tuple_hash *i)
|
|
{
|
|
return !(test_bit(IPS_ASSURED_BIT,
|
|
&nf_ct_tuplehash_to_ctrack(i)->status));
|
|
}
|
|
|
|
static int early_drop(struct list_head *chain)
|
|
{
|
|
/* Traverse backwards: gives us oldest, which is roughly LRU */
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct = NULL;
|
|
int dropped = 0;
|
|
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
h = LIST_FIND_B(chain, unreplied, struct nf_conntrack_tuple_hash *);
|
|
if (h) {
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
atomic_inc(&ct->ct_general.use);
|
|
}
|
|
read_unlock_bh(&nf_conntrack_lock);
|
|
|
|
if (!ct)
|
|
return dropped;
|
|
|
|
if (del_timer(&ct->timeout)) {
|
|
death_by_timeout((unsigned long)ct);
|
|
dropped = 1;
|
|
NF_CT_STAT_INC(early_drop);
|
|
}
|
|
nf_ct_put(ct);
|
|
return dropped;
|
|
}
|
|
|
|
static inline int helper_cmp(const struct nf_conntrack_helper *i,
|
|
const struct nf_conntrack_tuple *rtuple)
|
|
{
|
|
return nf_ct_tuple_mask_cmp(rtuple, &i->tuple, &i->mask);
|
|
}
|
|
|
|
static struct nf_conntrack_helper *
|
|
nf_ct_find_helper(const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
return LIST_FIND(&helpers, helper_cmp,
|
|
struct nf_conntrack_helper *,
|
|
tuple);
|
|
}
|
|
|
|
static struct nf_conn *
|
|
__nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
|
|
const struct nf_conntrack_tuple *repl,
|
|
const struct nf_conntrack_l3proto *l3proto)
|
|
{
|
|
struct nf_conn *conntrack = NULL;
|
|
u_int32_t features = 0;
|
|
|
|
if (!nf_conntrack_hash_rnd_initted) {
|
|
get_random_bytes(&nf_conntrack_hash_rnd, 4);
|
|
nf_conntrack_hash_rnd_initted = 1;
|
|
}
|
|
|
|
if (nf_conntrack_max
|
|
&& atomic_read(&nf_conntrack_count) >= nf_conntrack_max) {
|
|
unsigned int hash = hash_conntrack(orig);
|
|
/* Try dropping from this hash chain. */
|
|
if (!early_drop(&nf_conntrack_hash[hash])) {
|
|
if (net_ratelimit())
|
|
printk(KERN_WARNING
|
|
"nf_conntrack: table full, dropping"
|
|
" packet.\n");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
}
|
|
|
|
/* find features needed by this conntrack. */
|
|
features = l3proto->get_features(orig);
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
if (nf_ct_find_helper(repl) != NULL)
|
|
features |= NF_CT_F_HELP;
|
|
read_unlock_bh(&nf_conntrack_lock);
|
|
|
|
DEBUGP("nf_conntrack_alloc: features=0x%x\n", features);
|
|
|
|
read_lock_bh(&nf_ct_cache_lock);
|
|
|
|
if (!nf_ct_cache[features].use) {
|
|
DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
|
|
features);
|
|
goto out;
|
|
}
|
|
|
|
conntrack = kmem_cache_alloc(nf_ct_cache[features].cachep, GFP_ATOMIC);
|
|
if (conntrack == NULL) {
|
|
DEBUGP("nf_conntrack_alloc: Can't alloc conntrack from cache\n");
|
|
goto out;
|
|
}
|
|
|
|
memset(conntrack, 0, nf_ct_cache[features].size);
|
|
conntrack->features = features;
|
|
if (nf_ct_cache[features].init_conntrack &&
|
|
nf_ct_cache[features].init_conntrack(conntrack, features) < 0) {
|
|
DEBUGP("nf_conntrack_alloc: failed to init\n");
|
|
kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
|
|
conntrack = NULL;
|
|
goto out;
|
|
}
|
|
|
|
atomic_set(&conntrack->ct_general.use, 1);
|
|
conntrack->ct_general.destroy = destroy_conntrack;
|
|
conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
|
|
conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
|
|
/* Don't set timer yet: wait for confirmation */
|
|
init_timer(&conntrack->timeout);
|
|
conntrack->timeout.data = (unsigned long)conntrack;
|
|
conntrack->timeout.function = death_by_timeout;
|
|
|
|
atomic_inc(&nf_conntrack_count);
|
|
out:
|
|
read_unlock_bh(&nf_ct_cache_lock);
|
|
return conntrack;
|
|
}
|
|
|
|
struct nf_conn *nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
|
|
const struct nf_conntrack_tuple *repl)
|
|
{
|
|
struct nf_conntrack_l3proto *l3proto;
|
|
|
|
l3proto = nf_ct_find_l3proto(orig->src.l3num);
|
|
return __nf_conntrack_alloc(orig, repl, l3proto);
|
|
}
|
|
|
|
void nf_conntrack_free(struct nf_conn *conntrack)
|
|
{
|
|
u_int32_t features = conntrack->features;
|
|
NF_CT_ASSERT(features >= NF_CT_F_BASIC && features < NF_CT_F_NUM);
|
|
DEBUGP("nf_conntrack_free: features = 0x%x, conntrack=%p\n", features,
|
|
conntrack);
|
|
kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
|
|
atomic_dec(&nf_conntrack_count);
|
|
}
|
|
|
|
/* Allocate a new conntrack: we return -ENOMEM if classification
|
|
failed due to stress. Otherwise it really is unclassifiable. */
|
|
static struct nf_conntrack_tuple_hash *
|
|
init_conntrack(const struct nf_conntrack_tuple *tuple,
|
|
struct nf_conntrack_l3proto *l3proto,
|
|
struct nf_conntrack_protocol *protocol,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff)
|
|
{
|
|
struct nf_conn *conntrack;
|
|
struct nf_conntrack_tuple repl_tuple;
|
|
struct nf_conntrack_expect *exp;
|
|
|
|
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, protocol)) {
|
|
DEBUGP("Can't invert tuple.\n");
|
|
return NULL;
|
|
}
|
|
|
|
conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto);
|
|
if (conntrack == NULL || IS_ERR(conntrack)) {
|
|
DEBUGP("Can't allocate conntrack.\n");
|
|
return (struct nf_conntrack_tuple_hash *)conntrack;
|
|
}
|
|
|
|
if (!protocol->new(conntrack, skb, dataoff)) {
|
|
nf_conntrack_free(conntrack);
|
|
DEBUGP("init conntrack: can't track with proto module\n");
|
|
return NULL;
|
|
}
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
exp = find_expectation(tuple);
|
|
|
|
if (exp) {
|
|
DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n",
|
|
conntrack, exp);
|
|
/* Welcome, Mr. Bond. We've been expecting you... */
|
|
__set_bit(IPS_EXPECTED_BIT, &conntrack->status);
|
|
conntrack->master = exp->master;
|
|
#ifdef CONFIG_NF_CONNTRACK_MARK
|
|
conntrack->mark = exp->master->mark;
|
|
#endif
|
|
nf_conntrack_get(&conntrack->master->ct_general);
|
|
NF_CT_STAT_INC(expect_new);
|
|
} else {
|
|
conntrack->helper = nf_ct_find_helper(&repl_tuple);
|
|
|
|
NF_CT_STAT_INC(new);
|
|
}
|
|
|
|
/* Overload tuple linked list to put us in unconfirmed list. */
|
|
list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
|
|
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
if (exp) {
|
|
if (exp->expectfn)
|
|
exp->expectfn(conntrack, exp);
|
|
nf_conntrack_expect_put(exp);
|
|
}
|
|
|
|
return &conntrack->tuplehash[IP_CT_DIR_ORIGINAL];
|
|
}
|
|
|
|
/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
|
|
static inline struct nf_conn *
|
|
resolve_normal_ct(struct sk_buff *skb,
|
|
unsigned int dataoff,
|
|
u_int16_t l3num,
|
|
u_int8_t protonum,
|
|
struct nf_conntrack_l3proto *l3proto,
|
|
struct nf_conntrack_protocol *proto,
|
|
int *set_reply,
|
|
enum ip_conntrack_info *ctinfo)
|
|
{
|
|
struct nf_conntrack_tuple tuple;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
|
|
if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data),
|
|
dataoff, l3num, protonum, &tuple, l3proto,
|
|
proto)) {
|
|
DEBUGP("resolve_normal_ct: Can't get tuple\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* look for tuple match */
|
|
h = nf_conntrack_find_get(&tuple, NULL);
|
|
if (!h) {
|
|
h = init_conntrack(&tuple, l3proto, proto, skb, dataoff);
|
|
if (!h)
|
|
return NULL;
|
|
if (IS_ERR(h))
|
|
return (void *)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 + IP_CT_IS_REPLY;
|
|
/* Please set reply bit if this packet OK */
|
|
*set_reply = 1;
|
|
} else {
|
|
/* Once we've had two way comms, always ESTABLISHED. */
|
|
if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
|
|
DEBUGP("nf_conntrack_in: normal packet for %p\n", ct);
|
|
*ctinfo = IP_CT_ESTABLISHED;
|
|
} else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
|
|
DEBUGP("nf_conntrack_in: related packet for %p\n", ct);
|
|
*ctinfo = IP_CT_RELATED;
|
|
} else {
|
|
DEBUGP("nf_conntrack_in: new packet for %p\n", ct);
|
|
*ctinfo = IP_CT_NEW;
|
|
}
|
|
*set_reply = 0;
|
|
}
|
|
skb->nfct = &ct->ct_general;
|
|
skb->nfctinfo = *ctinfo;
|
|
return ct;
|
|
}
|
|
|
|
unsigned int
|
|
nf_conntrack_in(int pf, unsigned int hooknum, struct sk_buff **pskb)
|
|
{
|
|
struct nf_conn *ct;
|
|
enum ip_conntrack_info ctinfo;
|
|
struct nf_conntrack_l3proto *l3proto;
|
|
struct nf_conntrack_protocol *proto;
|
|
unsigned int dataoff;
|
|
u_int8_t protonum;
|
|
int set_reply = 0;
|
|
int ret;
|
|
|
|
/* Previously seen (loopback or untracked)? Ignore. */
|
|
if ((*pskb)->nfct) {
|
|
NF_CT_STAT_INC(ignore);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
l3proto = nf_ct_find_l3proto((u_int16_t)pf);
|
|
if ((ret = l3proto->prepare(pskb, hooknum, &dataoff, &protonum)) <= 0) {
|
|
DEBUGP("not prepared to track yet or error occured\n");
|
|
return -ret;
|
|
}
|
|
|
|
proto = nf_ct_find_proto((u_int16_t)pf, protonum);
|
|
|
|
/* It may be an special packet, error, unclean...
|
|
* inverse of the return code tells to the netfilter
|
|
* core what to do with the packet. */
|
|
if (proto->error != NULL &&
|
|
(ret = proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
|
|
NF_CT_STAT_INC(error);
|
|
NF_CT_STAT_INC(invalid);
|
|
return -ret;
|
|
}
|
|
|
|
ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, proto,
|
|
&set_reply, &ctinfo);
|
|
if (!ct) {
|
|
/* Not valid part of a connection */
|
|
NF_CT_STAT_INC(invalid);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
if (IS_ERR(ct)) {
|
|
/* Too stressed to deal. */
|
|
NF_CT_STAT_INC(drop);
|
|
return NF_DROP;
|
|
}
|
|
|
|
NF_CT_ASSERT((*pskb)->nfct);
|
|
|
|
ret = proto->packet(ct, *pskb, dataoff, ctinfo, pf, hooknum);
|
|
if (ret < 0) {
|
|
/* Invalid: inverse of the return code tells
|
|
* the netfilter core what to do */
|
|
DEBUGP("nf_conntrack_in: Can't track with proto module\n");
|
|
nf_conntrack_put((*pskb)->nfct);
|
|
(*pskb)->nfct = NULL;
|
|
NF_CT_STAT_INC(invalid);
|
|
return -ret;
|
|
}
|
|
|
|
if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
|
|
nf_conntrack_event_cache(IPCT_STATUS, *pskb);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
|
|
const struct nf_conntrack_tuple *orig)
|
|
{
|
|
return nf_ct_invert_tuple(inverse, orig,
|
|
nf_ct_find_l3proto(orig->src.l3num),
|
|
nf_ct_find_proto(orig->src.l3num,
|
|
orig->dst.protonum));
|
|
}
|
|
|
|
/* Would two expected things clash? */
|
|
static inline int expect_clash(const struct nf_conntrack_expect *a,
|
|
const struct nf_conntrack_expect *b)
|
|
{
|
|
/* Part covered by intersection of masks must be unequal,
|
|
otherwise they clash */
|
|
struct nf_conntrack_tuple intersect_mask;
|
|
int count;
|
|
|
|
intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num;
|
|
intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all;
|
|
intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all;
|
|
intersect_mask.dst.protonum = a->mask.dst.protonum
|
|
& b->mask.dst.protonum;
|
|
|
|
for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
|
|
intersect_mask.src.u3.all[count] =
|
|
a->mask.src.u3.all[count] & b->mask.src.u3.all[count];
|
|
}
|
|
|
|
for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
|
|
intersect_mask.dst.u3.all[count] =
|
|
a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count];
|
|
}
|
|
|
|
return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
|
|
}
|
|
|
|
static inline int expect_matches(const struct nf_conntrack_expect *a,
|
|
const struct nf_conntrack_expect *b)
|
|
{
|
|
return a->master == b->master
|
|
&& nf_ct_tuple_equal(&a->tuple, &b->tuple)
|
|
&& nf_ct_tuple_equal(&a->mask, &b->mask);
|
|
}
|
|
|
|
/* Generally a bad idea to call this: could have matched already. */
|
|
void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp)
|
|
{
|
|
struct nf_conntrack_expect *i;
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
/* choose the the oldest expectation to evict */
|
|
list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
|
|
if (expect_matches(i, exp) && del_timer(&i->timeout)) {
|
|
nf_ct_unlink_expect(i);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
nf_conntrack_expect_put(i);
|
|
return;
|
|
}
|
|
}
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
}
|
|
|
|
/* We don't increase the master conntrack refcount for non-fulfilled
|
|
* conntracks. During the conntrack destruction, the expectations are
|
|
* always killed before the conntrack itself */
|
|
struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me)
|
|
{
|
|
struct nf_conntrack_expect *new;
|
|
|
|
new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC);
|
|
if (!new) {
|
|
DEBUGP("expect_related: OOM allocating expect\n");
|
|
return NULL;
|
|
}
|
|
new->master = me;
|
|
atomic_set(&new->use, 1);
|
|
return new;
|
|
}
|
|
|
|
void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
|
|
{
|
|
if (atomic_dec_and_test(&exp->use))
|
|
kmem_cache_free(nf_conntrack_expect_cachep, exp);
|
|
}
|
|
|
|
static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp)
|
|
{
|
|
atomic_inc(&exp->use);
|
|
exp->master->expecting++;
|
|
list_add(&exp->list, &nf_conntrack_expect_list);
|
|
|
|
init_timer(&exp->timeout);
|
|
exp->timeout.data = (unsigned long)exp;
|
|
exp->timeout.function = expectation_timed_out;
|
|
exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ;
|
|
add_timer(&exp->timeout);
|
|
|
|
atomic_inc(&exp->use);
|
|
NF_CT_STAT_INC(expect_create);
|
|
}
|
|
|
|
/* Race with expectations being used means we could have none to find; OK. */
|
|
static void evict_oldest_expect(struct nf_conn *master)
|
|
{
|
|
struct nf_conntrack_expect *i;
|
|
|
|
list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
|
|
if (i->master == master) {
|
|
if (del_timer(&i->timeout)) {
|
|
nf_ct_unlink_expect(i);
|
|
nf_conntrack_expect_put(i);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline int refresh_timer(struct nf_conntrack_expect *i)
|
|
{
|
|
if (!del_timer(&i->timeout))
|
|
return 0;
|
|
|
|
i->timeout.expires = jiffies + i->master->helper->timeout*HZ;
|
|
add_timer(&i->timeout);
|
|
return 1;
|
|
}
|
|
|
|
int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
|
|
{
|
|
struct nf_conntrack_expect *i;
|
|
int ret;
|
|
|
|
DEBUGP("nf_conntrack_expect_related %p\n", related_to);
|
|
DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple);
|
|
DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
list_for_each_entry(i, &nf_conntrack_expect_list, list) {
|
|
if (expect_matches(i, expect)) {
|
|
/* Refresh timer: if it's dying, ignore.. */
|
|
if (refresh_timer(i)) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
} else if (expect_clash(i, expect)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
}
|
|
/* Will be over limit? */
|
|
if (expect->master->helper->max_expected &&
|
|
expect->master->expecting >= expect->master->helper->max_expected)
|
|
evict_oldest_expect(expect->master);
|
|
|
|
nf_conntrack_expect_insert(expect);
|
|
nf_conntrack_expect_event(IPEXP_NEW, expect);
|
|
ret = 0;
|
|
out:
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return ret;
|
|
}
|
|
|
|
/* 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 *conntrack,
|
|
const struct nf_conntrack_tuple *newreply)
|
|
{
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
/* Should be unconfirmed, so not in hash table yet */
|
|
NF_CT_ASSERT(!nf_ct_is_confirmed(conntrack));
|
|
|
|
DEBUGP("Altering reply tuple of %p to ", conntrack);
|
|
NF_CT_DUMP_TUPLE(newreply);
|
|
|
|
conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
|
|
if (!conntrack->master && conntrack->expecting == 0)
|
|
conntrack->helper = nf_ct_find_helper(newreply);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
}
|
|
|
|
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
|
|
{
|
|
int ret;
|
|
BUG_ON(me->timeout == 0);
|
|
|
|
ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help",
|
|
sizeof(struct nf_conn)
|
|
+ sizeof(union nf_conntrack_help)
|
|
+ __alignof__(union nf_conntrack_help),
|
|
init_conntrack_for_helper);
|
|
if (ret < 0) {
|
|
printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n");
|
|
return ret;
|
|
}
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
list_prepend(&helpers, me);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int unhelp(struct nf_conntrack_tuple_hash *i,
|
|
const struct nf_conntrack_helper *me)
|
|
{
|
|
if (nf_ct_tuplehash_to_ctrack(i)->helper == me) {
|
|
nf_conntrack_event(IPCT_HELPER, nf_ct_tuplehash_to_ctrack(i));
|
|
nf_ct_tuplehash_to_ctrack(i)->helper = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
|
|
{
|
|
unsigned int i;
|
|
struct nf_conntrack_expect *exp, *tmp;
|
|
|
|
/* Need write lock here, to delete helper. */
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
LIST_DELETE(&helpers, me);
|
|
|
|
/* Get rid of expectations */
|
|
list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) {
|
|
if (exp->master->helper == me && del_timer(&exp->timeout)) {
|
|
nf_ct_unlink_expect(exp);
|
|
nf_conntrack_expect_put(exp);
|
|
}
|
|
}
|
|
|
|
/* Get rid of expecteds, set helpers to NULL. */
|
|
LIST_FIND_W(&unconfirmed, unhelp, struct nf_conntrack_tuple_hash*, me);
|
|
for (i = 0; i < nf_conntrack_htable_size; i++)
|
|
LIST_FIND_W(&nf_conntrack_hash[i], unhelp,
|
|
struct nf_conntrack_tuple_hash *, me);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
/* Someone could be still looking at the helper in a bh. */
|
|
synchronize_net();
|
|
}
|
|
|
|
/* 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,
|
|
unsigned long extra_jiffies,
|
|
int do_acct)
|
|
{
|
|
int event = 0;
|
|
|
|
NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
|
|
NF_CT_ASSERT(skb);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
|
|
/* If not in hash table, timer will not be active yet */
|
|
if (!nf_ct_is_confirmed(ct)) {
|
|
ct->timeout.expires = extra_jiffies;
|
|
event = IPCT_REFRESH;
|
|
} else {
|
|
/* Need del_timer for race avoidance (may already be dying). */
|
|
if (del_timer(&ct->timeout)) {
|
|
ct->timeout.expires = jiffies + extra_jiffies;
|
|
add_timer(&ct->timeout);
|
|
event = IPCT_REFRESH;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_NF_CT_ACCT
|
|
if (do_acct) {
|
|
ct->counters[CTINFO2DIR(ctinfo)].packets++;
|
|
ct->counters[CTINFO2DIR(ctinfo)].bytes +=
|
|
skb->len - (unsigned int)(skb->nh.raw - skb->data);
|
|
if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
|
|
|| (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))
|
|
event |= IPCT_COUNTER_FILLING;
|
|
}
|
|
#endif
|
|
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
/* must be unlocked when calling event cache */
|
|
if (event)
|
|
nf_conntrack_event_cache(event, skb);
|
|
}
|
|
|
|
/* Used by ipt_REJECT and ip6t_REJECT. */
|
|
void __nf_conntrack_attach(struct sk_buff *nskb, 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 + IP_CT_IS_REPLY;
|
|
else
|
|
ctinfo = IP_CT_RELATED;
|
|
|
|
/* Attach to new skbuff, and increment count */
|
|
nskb->nfct = &ct->ct_general;
|
|
nskb->nfctinfo = ctinfo;
|
|
nf_conntrack_get(nskb->nfct);
|
|
}
|
|
|
|
static inline int
|
|
do_iter(const struct nf_conntrack_tuple_hash *i,
|
|
int (*iter)(struct nf_conn *i, void *data),
|
|
void *data)
|
|
{
|
|
return iter(nf_ct_tuplehash_to_ctrack(i), data);
|
|
}
|
|
|
|
/* Bring out ya dead! */
|
|
static struct nf_conntrack_tuple_hash *
|
|
get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
|
|
void *data, unsigned int *bucket)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h = NULL;
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
|
|
h = LIST_FIND_W(&nf_conntrack_hash[*bucket], do_iter,
|
|
struct nf_conntrack_tuple_hash *, iter, data);
|
|
if (h)
|
|
break;
|
|
}
|
|
if (!h)
|
|
h = LIST_FIND_W(&unconfirmed, do_iter,
|
|
struct nf_conntrack_tuple_hash *, iter, data);
|
|
if (h)
|
|
atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
return h;
|
|
}
|
|
|
|
void
|
|
nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
unsigned int bucket = 0;
|
|
|
|
while ((h = get_next_corpse(iter, data, &bucket)) != NULL) {
|
|
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
|
|
/* Time to push up daises... */
|
|
if (del_timer(&ct->timeout))
|
|
death_by_timeout((unsigned long)ct);
|
|
/* ... else the timer will get him soon. */
|
|
|
|
nf_ct_put(ct);
|
|
}
|
|
}
|
|
|
|
static int kill_all(struct nf_conn *i, void *data)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static void free_conntrack_hash(struct list_head *hash, int vmalloced, int size)
|
|
{
|
|
if (vmalloced)
|
|
vfree(hash);
|
|
else
|
|
free_pages((unsigned long)hash,
|
|
get_order(sizeof(struct list_head) * size));
|
|
}
|
|
|
|
/* Mishearing the voices in his head, our hero wonders how he's
|
|
supposed to kill the mall. */
|
|
void nf_conntrack_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
/* This makes sure all current packets have passed through
|
|
netfilter framework. Roll on, two-stage module
|
|
delete... */
|
|
synchronize_net();
|
|
|
|
nf_ct_event_cache_flush();
|
|
i_see_dead_people:
|
|
nf_ct_iterate_cleanup(kill_all, NULL);
|
|
if (atomic_read(&nf_conntrack_count) != 0) {
|
|
schedule();
|
|
goto i_see_dead_people;
|
|
}
|
|
/* wait until all references to nf_conntrack_untracked are dropped */
|
|
while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
|
|
schedule();
|
|
|
|
for (i = 0; i < NF_CT_F_NUM; i++) {
|
|
if (nf_ct_cache[i].use == 0)
|
|
continue;
|
|
|
|
NF_CT_ASSERT(nf_ct_cache[i].use == 1);
|
|
nf_ct_cache[i].use = 1;
|
|
nf_conntrack_unregister_cache(i);
|
|
}
|
|
kmem_cache_destroy(nf_conntrack_expect_cachep);
|
|
free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
|
|
nf_conntrack_htable_size);
|
|
|
|
/* free l3proto protocol tables */
|
|
for (i = 0; i < PF_MAX; i++)
|
|
if (nf_ct_protos[i]) {
|
|
kfree(nf_ct_protos[i]);
|
|
nf_ct_protos[i] = NULL;
|
|
}
|
|
}
|
|
|
|
static struct list_head *alloc_hashtable(int size, int *vmalloced)
|
|
{
|
|
struct list_head *hash;
|
|
unsigned int i;
|
|
|
|
*vmalloced = 0;
|
|
hash = (void*)__get_free_pages(GFP_KERNEL,
|
|
get_order(sizeof(struct list_head)
|
|
* size));
|
|
if (!hash) {
|
|
*vmalloced = 1;
|
|
printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
|
|
hash = vmalloc(sizeof(struct list_head) * size);
|
|
}
|
|
|
|
if (hash)
|
|
for (i = 0; i < size; i++)
|
|
INIT_LIST_HEAD(&hash[i]);
|
|
|
|
return hash;
|
|
}
|
|
|
|
int set_hashsize(const char *val, struct kernel_param *kp)
|
|
{
|
|
int i, bucket, hashsize, vmalloced;
|
|
int old_vmalloced, old_size;
|
|
int rnd;
|
|
struct list_head *hash, *old_hash;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
|
|
/* On boot, we can set this without any fancy locking. */
|
|
if (!nf_conntrack_htable_size)
|
|
return param_set_uint(val, kp);
|
|
|
|
hashsize = simple_strtol(val, NULL, 0);
|
|
if (!hashsize)
|
|
return -EINVAL;
|
|
|
|
hash = alloc_hashtable(hashsize, &vmalloced);
|
|
if (!hash)
|
|
return -ENOMEM;
|
|
|
|
/* We have to rehahs for the new table anyway, so we also can
|
|
* use a newrandom seed */
|
|
get_random_bytes(&rnd, 4);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
for (i = 0; i < nf_conntrack_htable_size; i++) {
|
|
while (!list_empty(&nf_conntrack_hash[i])) {
|
|
h = list_entry(nf_conntrack_hash[i].next,
|
|
struct nf_conntrack_tuple_hash, list);
|
|
list_del(&h->list);
|
|
bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
|
|
list_add_tail(&h->list, &hash[bucket]);
|
|
}
|
|
}
|
|
old_size = nf_conntrack_htable_size;
|
|
old_vmalloced = nf_conntrack_vmalloc;
|
|
old_hash = nf_conntrack_hash;
|
|
|
|
nf_conntrack_htable_size = hashsize;
|
|
nf_conntrack_vmalloc = vmalloced;
|
|
nf_conntrack_hash = hash;
|
|
nf_conntrack_hash_rnd = rnd;
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
free_conntrack_hash(old_hash, old_vmalloced, old_size);
|
|
return 0;
|
|
}
|
|
|
|
module_param_call(hashsize, set_hashsize, param_get_uint,
|
|
&nf_conntrack_htable_size, 0600);
|
|
|
|
int __init nf_conntrack_init(void)
|
|
{
|
|
unsigned int i;
|
|
int ret;
|
|
|
|
/* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
|
|
* machine has 256 buckets. >= 1GB machines have 8192 buckets. */
|
|
if (!nf_conntrack_htable_size) {
|
|
nf_conntrack_htable_size
|
|
= (((num_physpages << PAGE_SHIFT) / 16384)
|
|
/ sizeof(struct list_head));
|
|
if (num_physpages > (1024 * 1024 * 1024 / PAGE_SIZE))
|
|
nf_conntrack_htable_size = 8192;
|
|
if (nf_conntrack_htable_size < 16)
|
|
nf_conntrack_htable_size = 16;
|
|
}
|
|
nf_conntrack_max = 8 * nf_conntrack_htable_size;
|
|
|
|
printk("nf_conntrack version %s (%u buckets, %d max)\n",
|
|
NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
|
|
nf_conntrack_max);
|
|
|
|
nf_conntrack_hash = alloc_hashtable(nf_conntrack_htable_size,
|
|
&nf_conntrack_vmalloc);
|
|
if (!nf_conntrack_hash) {
|
|
printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
|
|
goto err_out;
|
|
}
|
|
|
|
ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic",
|
|
sizeof(struct nf_conn), NULL);
|
|
if (ret < 0) {
|
|
printk(KERN_ERR "Unable to create nf_conn slab cache\n");
|
|
goto err_free_hash;
|
|
}
|
|
|
|
nf_conntrack_expect_cachep = kmem_cache_create("nf_conntrack_expect",
|
|
sizeof(struct nf_conntrack_expect),
|
|
0, 0, NULL, NULL);
|
|
if (!nf_conntrack_expect_cachep) {
|
|
printk(KERN_ERR "Unable to create nf_expect slab cache\n");
|
|
goto err_free_conntrack_slab;
|
|
}
|
|
|
|
/* Don't NEED lock here, but good form anyway. */
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
for (i = 0; i < PF_MAX; i++)
|
|
nf_ct_l3protos[i] = &nf_conntrack_generic_l3proto;
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
|
|
/* Set up fake conntrack:
|
|
- to never be deleted, not in any hashes */
|
|
atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
|
|
/* - and look it like as a confirmed connection */
|
|
set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
|
|
|
|
return ret;
|
|
|
|
err_free_conntrack_slab:
|
|
nf_conntrack_unregister_cache(NF_CT_F_BASIC);
|
|
err_free_hash:
|
|
free_conntrack_hash(nf_conntrack_hash, nf_conntrack_vmalloc,
|
|
nf_conntrack_htable_size);
|
|
err_out:
|
|
return -ENOMEM;
|
|
}
|