When a helper module is unloaded all conntracks refering to it have their helper pointer NULLed out, leading to lots of races. In most places this can be fixed by proper use of RCU (they do already check for != NULL, but in a racy way), additionally nf_conntrack_expect_related needs to bail out when no helper is present. Also remove two paranoid BUG_ONs in nf_conntrack_proto_gre that are racy and not worth fixing. Signed-off-by: Patrick McHarrdy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
1293 lines
35 KiB
C
1293 lines
35 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) 2002-2006 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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*
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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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#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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#include <linux/mm.h>
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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_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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#define NF_CONNTRACK_VERSION "0.5.0"
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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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EXPORT_SYMBOL_GPL(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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EXPORT_SYMBOL_GPL(nf_conntrack_count);
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void (*nf_conntrack_destroyed)(struct nf_conn *conntrack);
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EXPORT_SYMBOL_GPL(nf_conntrack_destroyed);
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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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int nf_conntrack_max __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_max);
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struct list_head *nf_conntrack_hash __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_hash);
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struct nf_conn nf_conntrack_untracked __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
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unsigned int nf_ct_log_invalid __read_mostly;
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LIST_HEAD(unconfirmed);
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static int nf_conntrack_vmalloc __read_mostly;
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static unsigned int nf_conntrack_next_id;
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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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struct kmem_cache *cachep;
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/* allocated slab cache + modules which uses this slab cache */
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int use;
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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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static DEFINE_MUTEX(nf_ct_cache_mutex);
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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 = jhash2(tuple->src.u3.all, ARRAY_SIZE(tuple->src.u3.all),
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(tuple->src.l3num << 16) | tuple->dst.protonum);
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b = jhash2(tuple->dst.u3.all, ARRAY_SIZE(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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int nf_conntrack_register_cache(u_int32_t features, const char *name,
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size_t size)
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{
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int ret = 0;
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char *cache_name;
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struct kmem_cache *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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mutex_lock(&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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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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mutex_unlock(&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].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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mutex_unlock(&nf_ct_cache_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_register_cache);
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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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struct kmem_cache *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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mutex_lock(&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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mutex_unlock(&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].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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mutex_unlock(&nf_ct_cache_mutex);
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_unregister_cache);
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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_l4proto *l4proto)
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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 l4proto->pkt_to_tuple(skb, dataoff, tuple);
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}
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EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
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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_l4proto *l4proto)
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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 l4proto->invert_tuple(inverse, orig);
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}
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EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
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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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DEBUGP("clean_from_lists(%p)\n", ct);
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list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
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list_del(&ct->tuplehash[IP_CT_DIR_REPLY].list);
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/* Destroy all pending expectations */
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nf_ct_remove_expectations(ct);
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}
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static void
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destroy_conntrack(struct nf_conntrack *nfct)
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{
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struct nf_conn *ct = (struct nf_conn *)nfct;
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struct nf_conntrack_l4proto *l4proto;
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typeof(nf_conntrack_destroyed) destroyed;
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DEBUGP("destroy_conntrack(%p)\n", ct);
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NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
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NF_CT_ASSERT(!timer_pending(&ct->timeout));
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nf_conntrack_event(IPCT_DESTROY, ct);
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set_bit(IPS_DYING_BIT, &ct->status);
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/* To make sure we don't get any weird locking issues here:
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* destroy_conntrack() MUST NOT be called with a write lock
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* to nf_conntrack_lock!!! -HW */
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rcu_read_lock();
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l4proto = __nf_ct_l4proto_find(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.l3num,
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ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.protonum);
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if (l4proto && l4proto->destroy)
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l4proto->destroy(ct);
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destroyed = rcu_dereference(nf_conntrack_destroyed);
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if (destroyed)
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destroyed(ct);
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rcu_read_unlock();
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write_lock_bh(&nf_conntrack_lock);
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/* Expectations will have been removed in clean_from_lists,
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* except TFTP can create an expectation on the first packet,
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* before connection is in the list, so we need to clean here,
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* too. */
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nf_ct_remove_expectations(ct);
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/* We overload first tuple to link into unconfirmed list. */
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if (!nf_ct_is_confirmed(ct)) {
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BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
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list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
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}
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NF_CT_STAT_INC(delete);
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write_unlock_bh(&nf_conntrack_lock);
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if (ct->master)
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nf_ct_put(ct->master);
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DEBUGP("destroy_conntrack: returning ct=%p to slab\n", ct);
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nf_conntrack_free(ct);
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}
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static void death_by_timeout(unsigned long ul_conntrack)
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{
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struct nf_conn *ct = (void *)ul_conntrack;
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struct nf_conn_help *help = nfct_help(ct);
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struct nf_conntrack_helper *helper;
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if (help) {
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rcu_read_lock();
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helper = rcu_dereference(help->helper);
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if (helper && helper->destroy)
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helper->destroy(ct);
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rcu_read_unlock();
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}
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write_lock_bh(&nf_conntrack_lock);
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/* Inside lock so preempt is disabled on module removal path.
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* Otherwise we can get spurious warnings. */
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NF_CT_STAT_INC(delete_list);
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clean_from_lists(ct);
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write_unlock_bh(&nf_conntrack_lock);
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nf_ct_put(ct);
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}
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struct nf_conntrack_tuple_hash *
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__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
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const struct nf_conn *ignored_conntrack)
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{
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struct nf_conntrack_tuple_hash *h;
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unsigned int hash = hash_conntrack(tuple);
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list_for_each_entry(h, &nf_conntrack_hash[hash], list) {
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if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
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nf_ct_tuple_equal(tuple, &h->tuple)) {
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NF_CT_STAT_INC(found);
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return h;
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}
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NF_CT_STAT_INC(searched);
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(__nf_conntrack_find);
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/* Find a connection corresponding to a tuple. */
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struct nf_conntrack_tuple_hash *
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nf_conntrack_find_get(const struct nf_conntrack_tuple *tuple,
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const struct nf_conn *ignored_conntrack)
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{
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struct nf_conntrack_tuple_hash *h;
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read_lock_bh(&nf_conntrack_lock);
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h = __nf_conntrack_find(tuple, ignored_conntrack);
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if (h)
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atomic_inc(&nf_ct_tuplehash_to_ctrack(h)->ct_general.use);
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read_unlock_bh(&nf_conntrack_lock);
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|
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return h;
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}
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EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
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|
|
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static void __nf_conntrack_hash_insert(struct nf_conn *ct,
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unsigned int hash,
|
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unsigned int repl_hash)
|
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{
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ct->id = ++nf_conntrack_next_id;
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list_add(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list,
|
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&nf_conntrack_hash[hash]);
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list_add(&ct->tuplehash[IP_CT_DIR_REPLY].list,
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&nf_conntrack_hash[repl_hash]);
|
|
}
|
|
|
|
void nf_conntrack_hash_insert(struct nf_conn *ct)
|
|
{
|
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unsigned int hash, repl_hash;
|
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|
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hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
repl_hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
|
|
|
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write_lock_bh(&nf_conntrack_lock);
|
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__nf_conntrack_hash_insert(ct, hash, repl_hash);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
|
|
|
|
/* 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_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
struct nf_conn_help *help;
|
|
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. */
|
|
list_for_each_entry(h, &nf_conntrack_hash[hash], list)
|
|
if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
|
|
&h->tuple))
|
|
goto out;
|
|
list_for_each_entry(h, &nf_conntrack_hash[repl_hash], list)
|
|
if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
|
|
&h->tuple))
|
|
goto out;
|
|
|
|
/* Remove from unconfirmed list */
|
|
list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
|
|
|
|
__nf_conntrack_hash_insert(ct, hash, repl_hash);
|
|
/* 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);
|
|
help = nfct_help(ct);
|
|
if (help && help->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;
|
|
|
|
out:
|
|
NF_CT_STAT_INC(insert_failed);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return NF_DROP;
|
|
}
|
|
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 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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
|
|
|
|
/* There's a small race here where we may free a just-assured
|
|
connection. Too bad: we're in trouble anyway. */
|
|
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, *tmp;
|
|
int dropped = 0;
|
|
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
list_for_each_entry_reverse(h, chain, list) {
|
|
tmp = nf_ct_tuplehash_to_ctrack(h);
|
|
if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) {
|
|
ct = tmp;
|
|
atomic_inc(&ct->ct_general.use);
|
|
break;
|
|
}
|
|
}
|
|
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_ATOMIC(early_drop);
|
|
}
|
|
nf_ct_put(ct);
|
|
return dropped;
|
|
}
|
|
|
|
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,
|
|
u_int32_t features)
|
|
{
|
|
struct nf_conn *conntrack = NULL;
|
|
struct nf_conntrack_helper *helper;
|
|
|
|
if (unlikely(!nf_conntrack_hash_rnd_initted)) {
|
|
get_random_bytes(&nf_conntrack_hash_rnd, 4);
|
|
nf_conntrack_hash_rnd_initted = 1;
|
|
}
|
|
|
|
/* We don't want any race condition at early drop stage */
|
|
atomic_inc(&nf_conntrack_count);
|
|
|
|
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])) {
|
|
atomic_dec(&nf_conntrack_count);
|
|
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);
|
|
|
|
/* FIXME: protect helper list per RCU */
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
helper = __nf_ct_helper_find(repl);
|
|
/* NAT might want to assign a helper later */
|
|
if (helper || features & NF_CT_F_NAT)
|
|
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 (unlikely(!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;
|
|
atomic_set(&conntrack->ct_general.use, 1);
|
|
conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
|
|
conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
|
|
/* Don't set timer yet: wait for confirmation */
|
|
setup_timer(&conntrack->timeout, death_by_timeout,
|
|
(unsigned long)conntrack);
|
|
read_unlock_bh(&nf_ct_cache_lock);
|
|
|
|
return conntrack;
|
|
out:
|
|
read_unlock_bh(&nf_ct_cache_lock);
|
|
atomic_dec(&nf_conntrack_count);
|
|
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;
|
|
struct nf_conn *ct;
|
|
|
|
rcu_read_lock();
|
|
l3proto = __nf_ct_l3proto_find(orig->src.l3num);
|
|
ct = __nf_conntrack_alloc(orig, repl, l3proto, 0);
|
|
rcu_read_unlock();
|
|
|
|
return ct;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
|
|
|
|
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);
|
|
}
|
|
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 struct nf_conntrack_tuple_hash *
|
|
init_conntrack(const struct nf_conntrack_tuple *tuple,
|
|
struct nf_conntrack_l3proto *l3proto,
|
|
struct nf_conntrack_l4proto *l4proto,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff)
|
|
{
|
|
struct nf_conn *conntrack;
|
|
struct nf_conn_help *help;
|
|
struct nf_conntrack_tuple repl_tuple;
|
|
struct nf_conntrack_expect *exp;
|
|
u_int32_t features = 0;
|
|
|
|
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
|
|
DEBUGP("Can't invert tuple.\n");
|
|
return NULL;
|
|
}
|
|
|
|
read_lock_bh(&nf_conntrack_lock);
|
|
exp = __nf_conntrack_expect_find(tuple);
|
|
if (exp && exp->helper)
|
|
features = NF_CT_F_HELP;
|
|
read_unlock_bh(&nf_conntrack_lock);
|
|
|
|
conntrack = __nf_conntrack_alloc(tuple, &repl_tuple, l3proto, features);
|
|
if (conntrack == NULL || IS_ERR(conntrack)) {
|
|
DEBUGP("Can't allocate conntrack.\n");
|
|
return (struct nf_conntrack_tuple_hash *)conntrack;
|
|
}
|
|
|
|
if (!l4proto->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);
|
|
|
|
help = nfct_help(conntrack);
|
|
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;
|
|
if (exp->helper)
|
|
rcu_assign_pointer(help->helper, exp->helper);
|
|
#ifdef CONFIG_NF_CONNTRACK_MARK
|
|
conntrack->mark = exp->master->mark;
|
|
#endif
|
|
#ifdef CONFIG_NF_CONNTRACK_SECMARK
|
|
conntrack->secmark = exp->master->secmark;
|
|
#endif
|
|
nf_conntrack_get(&conntrack->master->ct_general);
|
|
NF_CT_STAT_INC(expect_new);
|
|
} else {
|
|
if (help) {
|
|
/* not in hash table yet, so not strictly necessary */
|
|
rcu_assign_pointer(help->helper,
|
|
__nf_ct_helper_find(&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_l4proto *l4proto,
|
|
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, skb_network_offset(skb),
|
|
dataoff, l3num, protonum, &tuple, l3proto,
|
|
l4proto)) {
|
|
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, l4proto, 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_l4proto *l4proto;
|
|
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_ATOMIC(ignore);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/* rcu_read_lock()ed by nf_hook_slow */
|
|
l3proto = __nf_ct_l3proto_find((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;
|
|
}
|
|
|
|
l4proto = __nf_ct_l4proto_find((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 (l4proto->error != NULL &&
|
|
(ret = l4proto->error(*pskb, dataoff, &ctinfo, pf, hooknum)) <= 0) {
|
|
NF_CT_STAT_INC_ATOMIC(error);
|
|
NF_CT_STAT_INC_ATOMIC(invalid);
|
|
return -ret;
|
|
}
|
|
|
|
ct = resolve_normal_ct(*pskb, dataoff, pf, protonum, l3proto, l4proto,
|
|
&set_reply, &ctinfo);
|
|
if (!ct) {
|
|
/* Not valid part of a connection */
|
|
NF_CT_STAT_INC_ATOMIC(invalid);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
if (IS_ERR(ct)) {
|
|
/* Too stressed to deal. */
|
|
NF_CT_STAT_INC_ATOMIC(drop);
|
|
return NF_DROP;
|
|
}
|
|
|
|
NF_CT_ASSERT((*pskb)->nfct);
|
|
|
|
ret = l4proto->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_ATOMIC(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;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_in);
|
|
|
|
int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
|
|
const struct nf_conntrack_tuple *orig)
|
|
{
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
ret = nf_ct_invert_tuple(inverse, orig,
|
|
__nf_ct_l3proto_find(orig->src.l3num),
|
|
__nf_ct_l4proto_find(orig->src.l3num,
|
|
orig->dst.protonum));
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr);
|
|
|
|
/* 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);
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
/* Should be unconfirmed, so not in hash table yet */
|
|
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
|
|
|
|
DEBUGP("Altering reply tuple of %p to ", ct);
|
|
NF_CT_DUMP_TUPLE(newreply);
|
|
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
|
|
if (!ct->master && help && help->expecting == 0) {
|
|
struct nf_conntrack_helper *helper;
|
|
helper = __nf_ct_helper_find(newreply);
|
|
if (helper)
|
|
memset(&help->help, 0, sizeof(help->help));
|
|
/* not in hash table yet, so not strictly necessary */
|
|
rcu_assign_pointer(help->helper, helper);
|
|
}
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
}
|
|
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,
|
|
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);
|
|
|
|
/* Only update if this is not a fixed timeout */
|
|
if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) {
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return;
|
|
}
|
|
|
|
/* 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 {
|
|
unsigned long newtime = jiffies + extra_jiffies;
|
|
|
|
/* Only update the timeout if the new timeout is at least
|
|
HZ jiffies from the old timeout. Need del_timer for race
|
|
avoidance (may already be dying). */
|
|
if (newtime - ct->timeout.expires >= HZ
|
|
&& del_timer(&ct->timeout)) {
|
|
ct->timeout.expires = newtime;
|
|
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 - skb_network_offset(skb);
|
|
|
|
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);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
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|
|
|
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
|
|
|
|
#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_conntrack.h>
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#include <linux/mutex.h>
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|
|
|
|
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/* Generic function for tcp/udp/sctp/dccp and alike. This needs to be
|
|
* in ip_conntrack_core, since we don't want the protocols to autoload
|
|
* or depend on ctnetlink */
|
|
int nf_ct_port_tuple_to_nfattr(struct sk_buff *skb,
|
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const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
NFA_PUT(skb, CTA_PROTO_SRC_PORT, sizeof(u_int16_t),
|
|
&tuple->src.u.tcp.port);
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NFA_PUT(skb, CTA_PROTO_DST_PORT, sizeof(u_int16_t),
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&tuple->dst.u.tcp.port);
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return 0;
|
|
|
|
nfattr_failure:
|
|
return -1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nfattr);
|
|
|
|
static const size_t cta_min_proto[CTA_PROTO_MAX] = {
|
|
[CTA_PROTO_SRC_PORT-1] = sizeof(u_int16_t),
|
|
[CTA_PROTO_DST_PORT-1] = sizeof(u_int16_t)
|
|
};
|
|
|
|
int nf_ct_port_nfattr_to_tuple(struct nfattr *tb[],
|
|
struct nf_conntrack_tuple *t)
|
|
{
|
|
if (!tb[CTA_PROTO_SRC_PORT-1] || !tb[CTA_PROTO_DST_PORT-1])
|
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return -EINVAL;
|
|
|
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if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
|
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return -EINVAL;
|
|
|
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t->src.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_SRC_PORT-1]);
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t->dst.u.tcp.port = *(__be16 *)NFA_DATA(tb[CTA_PROTO_DST_PORT-1]);
|
|
|
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return 0;
|
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}
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EXPORT_SYMBOL_GPL(nf_ct_port_nfattr_to_tuple);
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|
#endif
|
|
|
|
/* Used by ipt_REJECT and ip6t_REJECT. */
|
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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 */
|
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ct = nf_ct_get(skb, &ctinfo);
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if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
|
|
ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY;
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|
else
|
|
ctinfo = IP_CT_RELATED;
|
|
|
|
/* Attach to new skbuff, and increment count */
|
|
nskb->nfct = &ct->ct_general;
|
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nskb->nfctinfo = ctinfo;
|
|
nf_conntrack_get(nskb->nfct);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_conntrack_attach);
|
|
|
|
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_conn *
|
|
get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
|
|
void *data, unsigned int *bucket)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
|
struct nf_conn *ct;
|
|
|
|
write_lock_bh(&nf_conntrack_lock);
|
|
for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
|
|
list_for_each_entry(h, &nf_conntrack_hash[*bucket], list) {
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
if (iter(ct, data))
|
|
goto found;
|
|
}
|
|
}
|
|
list_for_each_entry(h, &unconfirmed, list) {
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
if (iter(ct, data))
|
|
set_bit(IPS_DYING_BIT, &ct->status);
|
|
}
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return NULL;
|
|
found:
|
|
atomic_inc(&ct->ct_general.use);
|
|
write_unlock_bh(&nf_conntrack_lock);
|
|
return ct;
|
|
}
|
|
|
|
void
|
|
nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data)
|
|
{
|
|
struct nf_conn *ct;
|
|
unsigned int bucket = 0;
|
|
|
|
while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
|
|
/* 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);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
|
|
|
|
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));
|
|
}
|
|
|
|
void nf_conntrack_flush(void)
|
|
{
|
|
nf_ct_iterate_cleanup(kill_all, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_conntrack_flush);
|
|
|
|
/* Mishearing the voices in his head, our hero wonders how he's
|
|
supposed to kill the mall. */
|
|
void nf_conntrack_cleanup(void)
|
|
{
|
|
int i;
|
|
|
|
rcu_assign_pointer(ip_ct_attach, NULL);
|
|
|
|
/* 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_conntrack_flush();
|
|
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();
|
|
|
|
rcu_assign_pointer(nf_ct_destroy, NULL);
|
|
|
|
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);
|
|
|
|
nf_conntrack_proto_fini();
|
|
}
|
|
|
|
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)
|
|
{
|
|
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));
|
|
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;
|
|
}
|
|
|
|
ret = nf_conntrack_proto_init();
|
|
if (ret < 0)
|
|
goto out_free_expect_slab;
|
|
|
|
/* For use by REJECT target */
|
|
rcu_assign_pointer(ip_ct_attach, __nf_conntrack_attach);
|
|
rcu_assign_pointer(nf_ct_destroy, destroy_conntrack);
|
|
|
|
/* 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;
|
|
|
|
out_free_expect_slab:
|
|
kmem_cache_destroy(nf_conntrack_expect_cachep);
|
|
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;
|
|
}
|