blob: 3d3622ac17789334d388b503a33654ceeb05be0d [file] [log] [blame]
/* Connection state tracking for netfilter. This is separated from,
but required by, the NAT layer; it can also be used by an iptables
extension. */
/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/stddef.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/jhash.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/moduleparam.h>
#include <linux/notifier.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/socket.h>
#include <linux/mm.h>
#include <linux/nsproxy.h>
#include <linux/rculist_nulls.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_timestamp.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#define NF_CONNTRACK_VERSION "0.5.0"
int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
enum nf_nat_manip_type manip,
const struct nlattr *attr) __read_mostly;
EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
DEFINE_SPINLOCK(nf_conntrack_lock);
EXPORT_SYMBOL_GPL(nf_conntrack_lock);
unsigned int nf_conntrack_htable_size __read_mostly;
EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
unsigned int nf_conntrack_max __read_mostly;
EXPORT_SYMBOL_GPL(nf_conntrack_max);
DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
unsigned int nf_conntrack_hash_rnd __read_mostly;
static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
{
unsigned int n;
/* The direction must be ignored, so we hash everything up to the
* destination ports (which is a multiple of 4) and treat the last
* three bytes manually.
*/
n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
(((__force __u16)tuple->dst.u.all << 16) |
tuple->dst.protonum));
}
static u32 __hash_bucket(u32 hash, unsigned int size)
{
return ((u64)hash * size) >> 32;
}
static u32 hash_bucket(u32 hash, const struct net *net)
{
return __hash_bucket(hash, net->ct.htable_size);
}
static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
u16 zone, unsigned int size)
{
return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
}
static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
const struct nf_conntrack_tuple *tuple)
{
return __hash_conntrack(tuple, zone, net->ct.htable_size);
}
bool
nf_ct_get_tuple(const struct sk_buff *skb,
unsigned int nhoff,
unsigned int dataoff,
u_int16_t l3num,
u_int8_t protonum,
struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_l3proto *l3proto,
const struct nf_conntrack_l4proto *l4proto)
{
memset(tuple, 0, sizeof(*tuple));
tuple->src.l3num = l3num;
if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
return false;
tuple->dst.protonum = protonum;
tuple->dst.dir = IP_CT_DIR_ORIGINAL;
return l4proto->pkt_to_tuple(skb, dataoff, tuple);
}
EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
u_int16_t l3num, struct nf_conntrack_tuple *tuple)
{
struct nf_conntrack_l3proto *l3proto;
struct nf_conntrack_l4proto *l4proto;
unsigned int protoff;
u_int8_t protonum;
int ret;
rcu_read_lock();
l3proto = __nf_ct_l3proto_find(l3num);
ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
if (ret != NF_ACCEPT) {
rcu_read_unlock();
return false;
}
l4proto = __nf_ct_l4proto_find(l3num, protonum);
ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
l3proto, l4proto);
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
bool
nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_l3proto *l3proto,
const struct nf_conntrack_l4proto *l4proto)
{
memset(inverse, 0, sizeof(*inverse));
inverse->src.l3num = orig->src.l3num;
if (l3proto->invert_tuple(inverse, orig) == 0)
return false;
inverse->dst.dir = !orig->dst.dir;
inverse->dst.protonum = orig->dst.protonum;
return l4proto->invert_tuple(inverse, orig);
}
EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
static void
clean_from_lists(struct nf_conn *ct)
{
pr_debug("clean_from_lists(%p)\n", ct);
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
/* Destroy all pending expectations */
nf_ct_remove_expectations(ct);
}
static void
destroy_conntrack(struct nf_conntrack *nfct)
{
struct nf_conn *ct = (struct nf_conn *)nfct;
struct net *net = nf_ct_net(ct);
struct nf_conntrack_l4proto *l4proto;
pr_debug("destroy_conntrack(%p)\n", ct);
NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
NF_CT_ASSERT(!timer_pending(&ct->timeout));
/* 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 */
rcu_read_lock();
l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
if (l4proto && l4proto->destroy)
l4proto->destroy(ct);
rcu_read_unlock();
spin_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. */
nf_ct_remove_expectations(ct);
#if defined(CONFIG_NETFILTER_XT_MATCH_LAYER7) || defined(CONFIG_NETFILTER_XT_MATCH_LAYER7_MODULE)
if(ct->layer7.app_proto)
kfree(ct->layer7.app_proto);
if(ct->layer7.app_data)
kfree(ct->layer7.app_data);
#endif
/* We overload first tuple to link into unconfirmed list. */
if (!nf_ct_is_confirmed(ct)) {
BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
}
NF_CT_STAT_INC(net, delete);
spin_unlock_bh(&nf_conntrack_lock);
if (ct->master)
nf_ct_put(ct->master);
pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
nf_conntrack_free(ct);
}
void nf_ct_delete_from_lists(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
nf_ct_helper_destroy(ct);
spin_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(net, delete_list);
clean_from_lists(ct);
spin_unlock_bh(&nf_conntrack_lock);
}
EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
static void death_by_event(unsigned long ul_conntrack)
{
struct nf_conn *ct = (void *)ul_conntrack;
struct net *net = nf_ct_net(ct);
struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
BUG_ON(ecache == NULL);
if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
/* bad luck, let's retry again */
ecache->timeout.expires = jiffies +
(random32() % net->ct.sysctl_events_retry_timeout);
add_timer(&ecache->timeout);
return;
}
/* we've got the event delivered, now it's dying */
set_bit(IPS_DYING_BIT, &ct->status);
spin_lock(&nf_conntrack_lock);
hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
spin_unlock(&nf_conntrack_lock);
nf_ct_put(ct);
}
void nf_ct_insert_dying_list(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct);
BUG_ON(ecache == NULL);
/* add this conntrack to the dying list */
spin_lock_bh(&nf_conntrack_lock);
hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&net->ct.dying);
spin_unlock_bh(&nf_conntrack_lock);
/* set a new timer to retry event delivery */
setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct);
ecache->timeout.expires = jiffies +
(random32() % net->ct.sysctl_events_retry_timeout);
add_timer(&ecache->timeout);
}
EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
static void death_by_timeout(unsigned long ul_conntrack)
{
struct nf_conn *ct = (void *)ul_conntrack;
struct nf_conn_tstamp *tstamp;
#ifdef CONFIG_COMCERTO_FP
struct nf_conntrack_l4proto *l4proto;
#endif
tstamp = nf_conn_tstamp_find(ct);
if (tstamp && tstamp->stop == 0)
tstamp->stop = ktime_to_ns(ktime_get_real());
#ifdef CONFIG_COMCERTO_FP
l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
if (test_bit(IPS_DYING_BIT, &ct->status) ||
(!test_bit(IPS_PERMANENT_BIT, &ct->status)) ||
((l4proto->l4proto == IPPROTO_TCP) && (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED))) {
if (!test_bit(IPS_DYING_BIT, &ct->status) &&
unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
/* destroy event was not delivered */
nf_ct_delete_from_lists(ct);
nf_ct_insert_dying_list(ct);
return;
}
set_bit(IPS_DYING_BIT, &ct->status);
nf_ct_delete_from_lists(ct);
nf_ct_put(ct);
} else {
ct->timeout.expires = jiffies + COMCERTO_PERMANENT_TIMEOUT * HZ;
add_timer(&ct->timeout);
}
#else
if (!test_bit(IPS_DYING_BIT, &ct->status) &&
unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
/* destroy event was not delivered */
nf_ct_delete_from_lists(ct);
nf_ct_insert_dying_list(ct);
return;
}
set_bit(IPS_DYING_BIT, &ct->status);
nf_ct_delete_from_lists(ct);
nf_ct_put(ct);
#endif
}
/*
* Warning :
* - Caller must take a reference on returned object
* and recheck nf_ct_tuple_equal(tuple, &h->tuple)
* OR
* - Caller must lock nf_conntrack_lock before calling this function
*/
static struct nf_conntrack_tuple_hash *
____nf_conntrack_find(struct net *net, u16 zone,
const struct nf_conntrack_tuple *tuple, u32 hash)
{
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
unsigned int bucket = hash_bucket(hash, net);
/* Disable BHs the entire time since we normally need to disable them
* at least once for the stats anyway.
*/
local_bh_disable();
begin:
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) {
if (nf_ct_tuple_equal(tuple, &h->tuple) &&
nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
NF_CT_STAT_INC(net, found);
local_bh_enable();
return h;
}
NF_CT_STAT_INC(net, searched);
}
/*
* if the nulls value we got at the end of this lookup is
* not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(n) != bucket) {
NF_CT_STAT_INC(net, search_restart);
goto begin;
}
local_bh_enable();
return NULL;
}
struct nf_conntrack_tuple_hash *
__nf_conntrack_find(struct net *net, u16 zone,
const struct nf_conntrack_tuple *tuple)
{
return ____nf_conntrack_find(net, zone, tuple,
hash_conntrack_raw(tuple, zone));
}
EXPORT_SYMBOL_GPL(__nf_conntrack_find);
/* Find a connection corresponding to a tuple. */
static struct nf_conntrack_tuple_hash *
__nf_conntrack_find_get(struct net *net, u16 zone,
const struct nf_conntrack_tuple *tuple, u32 hash)
{
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
rcu_read_lock();
begin:
h = ____nf_conntrack_find(net, zone, tuple, hash);
if (h) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (unlikely(nf_ct_is_dying(ct) ||
!atomic_inc_not_zero(&ct->ct_general.use)))
h = NULL;
else {
if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) ||
nf_ct_zone(ct) != zone)) {
nf_ct_put(ct);
goto begin;
}
}
}
rcu_read_unlock();
return h;
}
struct nf_conntrack_tuple_hash *
nf_conntrack_find_get(struct net *net, u16 zone,
const struct nf_conntrack_tuple *tuple)
{
return __nf_conntrack_find_get(net, zone, tuple,
hash_conntrack_raw(tuple, zone));
}
EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
static void __nf_conntrack_hash_insert(struct nf_conn *ct,
unsigned int hash,
unsigned int repl_hash)
{
struct net *net = nf_ct_net(ct);
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&net->ct.hash[hash]);
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
&net->ct.hash[repl_hash]);
}
void nf_conntrack_hash_insert(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
unsigned int hash, repl_hash;
u16 zone;
zone = nf_ct_zone(ct);
hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
__nf_conntrack_hash_insert(ct, hash, repl_hash);
}
EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
/* Confirm a connection given skb; places it in hash table */
int
__nf_conntrack_confirm(struct sk_buff *skb)
{
unsigned int hash, repl_hash;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
struct nf_conn_help *help;
struct nf_conn_tstamp *tstamp;
struct hlist_nulls_node *n;
enum ip_conntrack_info ctinfo;
struct net *net;
u16 zone;
ct = nf_ct_get(skb, &ctinfo);
net = nf_ct_net(ct);
/* ipt_REJECT uses nf_conntrack_attach to attach related
ICMP/TCP RST packets in other direction. Actual packet
which created connection will be IP_CT_NEW or for an
expected connection, IP_CT_RELATED. */
if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
return NF_ACCEPT;
zone = nf_ct_zone(ct);
/* reuse the hash saved before */
hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
hash = hash_bucket(hash, net);
repl_hash = hash_conntrack(net, zone,
&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 no one else could have
confirmed us. */
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
pr_debug("Confirming conntrack %p\n", ct);
spin_lock_bh(&nf_conntrack_lock);
/* We have to check the DYING flag inside the lock to prevent
a race against nf_ct_get_next_corpse() possibly called from
user context, else we insert an already 'dead' hash, blocking
further use of that particular connection -JM */
if (unlikely(nf_ct_is_dying(ct))) {
spin_unlock_bh(&nf_conntrack_lock);
return NF_ACCEPT;
}
/* See if there's one in the list already, including reverse:
NAT could have grabbed it without realizing, since we're
not in the hash. If there is, we lost race. */
hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
&h->tuple) &&
zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
goto out;
hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
&h->tuple) &&
zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
goto out;
/* Remove from unconfirmed list */
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
/* 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);
ct->status |= IPS_CONFIRMED;
/* set conntrack timestamp, if enabled. */
tstamp = nf_conn_tstamp_find(ct);
if (tstamp) {
if (skb->tstamp.tv64 == 0)
__net_timestamp((struct sk_buff *)skb);
tstamp->start = ktime_to_ns(skb->tstamp);
}
/* Since the lookup is lockless, hash insertion must be done after
* starting the timer and setting the CONFIRMED bit. The RCU barriers
* guarantee that no other CPU can find the conntrack before the above
* stores are visible.
*/
__nf_conntrack_hash_insert(ct, hash, repl_hash);
NF_CT_STAT_INC(net, insert);
spin_unlock_bh(&nf_conntrack_lock);
help = nfct_help(ct);
if (help && help->helper)
nf_conntrack_event_cache(IPCT_HELPER, ct);
nf_conntrack_event_cache(master_ct(ct) ?
IPCT_RELATED : IPCT_NEW, ct);
return NF_ACCEPT;
out:
NF_CT_STAT_INC(net, insert_failed);
spin_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 net *net = nf_ct_net(ignored_conntrack);
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
struct nf_conn *ct;
u16 zone = nf_ct_zone(ignored_conntrack);
unsigned int hash = hash_conntrack(net, zone, tuple);
/* Disable BHs the entire time since we need to disable them at
* least once for the stats anyway.
*/
rcu_read_lock_bh();
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (ct != ignored_conntrack &&
nf_ct_tuple_equal(tuple, &h->tuple) &&
nf_ct_zone(ct) == zone) {
NF_CT_STAT_INC(net, found);
rcu_read_unlock_bh();
return 1;
}
NF_CT_STAT_INC(net, searched);
}
rcu_read_unlock_bh();
return 0;
}
EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
#define NF_CT_EVICTION_RANGE 8
/* There's a small race here where we may free a just-assured
connection. Too bad: we're in trouble anyway. */
static noinline int early_drop(struct net *net, unsigned int hash)
{
/* Use oldest entry, which is roughly LRU */
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct = NULL, *tmp;
struct hlist_nulls_node *n;
unsigned int i, cnt = 0;
int dropped = 0;
rcu_read_lock();
for (i = 0; i < net->ct.htable_size; i++) {
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash],
hnnode) {
tmp = nf_ct_tuplehash_to_ctrack(h);
if (!test_bit(IPS_ASSURED_BIT, &tmp->status))
ct = tmp;
cnt++;
}
if (ct != NULL) {
if (likely(!nf_ct_is_dying(ct) &&
atomic_inc_not_zero(&ct->ct_general.use)))
break;
else
ct = NULL;
}
if (cnt >= NF_CT_EVICTION_RANGE)
break;
hash = (hash + 1) % net->ct.htable_size;
}
rcu_read_unlock();
if (!ct)
return dropped;
#ifdef CONFIG_COMCERTO_FP
clear_bit(IPS_PERMANENT_BIT, &ct->status);
/* Avoid race with timer expiration */
if (del_timer_sync(&ct->timeout)) {
#else
if (del_timer(&ct->timeout)) {
#endif
death_by_timeout((unsigned long)ct);
/* Check if we indeed killed this entry. Reliable event
delivery may have inserted it into the dying list. */
if (test_bit(IPS_DYING_BIT, &ct->status)) {
dropped = 1;
NF_CT_STAT_INC_ATOMIC(net, early_drop);
}
}
nf_ct_put(ct);
return dropped;
}
void init_nf_conntrack_hash_rnd(void)
{
unsigned int rand;
/*
* Why not initialize nf_conntrack_rnd in a "init()" function ?
* Because there isn't enough entropy when system initializing,
* and we initialize it as late as possible.
*/
do {
get_random_bytes(&rand, sizeof(rand));
} while (!rand);
cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
}
static struct nf_conn *
__nf_conntrack_alloc(struct net *net, u16 zone,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
gfp_t gfp, u32 hash)
{
struct nf_conn *ct;
if (unlikely(!nf_conntrack_hash_rnd)) {
init_nf_conntrack_hash_rnd();
/* recompute the hash as nf_conntrack_hash_rnd is initialized */
hash = hash_conntrack_raw(orig, zone);
}
/* We don't want any race condition at early drop stage */
atomic_inc(&net->ct.count);
if (nf_conntrack_max &&
unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) {
if (!early_drop(net, hash_bucket(hash, net))) {
atomic_dec(&net->ct.count);
if (net_ratelimit())
printk(KERN_WARNING
"nf_conntrack: table full, dropping"
" packet.\n");
return ERR_PTR(-ENOMEM);
}
}
/*
* Do not use kmem_cache_zalloc(), as this cache uses
* SLAB_DESTROY_BY_RCU.
*/
ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp);
if (ct == NULL) {
atomic_dec(&net->ct.count);
return ERR_PTR(-ENOMEM);
}
/*
* Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next
* and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
*/
memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
offsetof(struct nf_conn, proto) -
offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
spin_lock_init(&ct->lock);
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
/* save hash for reusing when confirming */
*(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
/* Don't set timer yet: wait for confirmation */
setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
write_pnet(&ct->ct_net, net);
#ifdef CONFIG_NF_CONNTRACK_ZONES
if (zone) {
struct nf_conntrack_zone *nf_ct_zone;
nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
if (!nf_ct_zone)
goto out_free;
nf_ct_zone->id = zone;
}
#endif
/*
* changes to lookup keys must be done before setting refcnt to 1
*/
smp_wmb();
atomic_set(&ct->ct_general.use, 1);
return ct;
#ifdef CONFIG_NF_CONNTRACK_ZONES
out_free:
kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
return ERR_PTR(-ENOMEM);
#endif
}
struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
gfp_t gfp)
{
return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
}
EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
void nf_conntrack_free(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
nf_ct_ext_destroy(ct);
atomic_dec(&net->ct.count);
nf_ct_ext_free(ct);
kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
}
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(struct net *net, struct nf_conn *tmpl,
const struct nf_conntrack_tuple *tuple,
struct nf_conntrack_l3proto *l3proto,
struct nf_conntrack_l4proto *l4proto,
struct sk_buff *skb,
unsigned int dataoff, u32 hash)
{
struct nf_conn *ct;
struct nf_conn_help *help;
struct nf_conntrack_tuple repl_tuple;
struct nf_conntrack_ecache *ecache;
struct nf_conntrack_expect *exp;
u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
pr_debug("Can't invert tuple.\n");
return NULL;
}
ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
hash);
if (IS_ERR(ct))
return (struct nf_conntrack_tuple_hash *)ct;
if (!l4proto->new(ct, skb, dataoff)) {
nf_conntrack_free(ct);
pr_debug("init conntrack: can't track with proto module\n");
return NULL;
}
nf_ct_acct_ext_add(ct, GFP_ATOMIC);
nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
ecache ? ecache->expmask : 0,
GFP_ATOMIC);
spin_lock_bh(&nf_conntrack_lock);
exp = nf_ct_find_expectation(net, zone, tuple);
if (exp) {
pr_debug("conntrack: expectation arrives ct=%p exp=%p\n",
ct, exp);
/* Welcome, Mr. Bond. We've been expecting you... */
__set_bit(IPS_EXPECTED_BIT, &ct->status);
ct->master = exp->master;
if (exp->helper) {
help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
if (help)
rcu_assign_pointer(help->helper, exp->helper);
}
#ifdef CONFIG_NF_CONNTRACK_MARK
ct->mark = exp->master->mark;
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
ct->secmark = exp->master->secmark;
#endif
nf_conntrack_get(&ct->master->ct_general);
NF_CT_STAT_INC(net, expect_new);
} else {
__nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
NF_CT_STAT_INC(net, new);
}
/* Overload tuple linked list to put us in unconfirmed list. */
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&net->ct.unconfirmed);
spin_unlock_bh(&nf_conntrack_lock);
if (exp) {
if (exp->expectfn)
exp->expectfn(ct, exp);
nf_ct_expect_put(exp);
}
return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
}
/* On success, returns conntrack ptr, sets skb->nfct and ctinfo */
static inline struct nf_conn *
resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
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;
u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
u32 hash;
if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
dataoff, l3num, protonum, &tuple, l3proto,
l4proto)) {
pr_debug("resolve_normal_ct: Can't get tuple\n");
return NULL;
}
/* look for tuple match */
hash = hash_conntrack_raw(&tuple, zone);
h = __nf_conntrack_find_get(net, zone, &tuple, hash);
if (!h) {
h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
skb, dataoff, hash);
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_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)) {
pr_debug("nf_conntrack_in: normal packet for %p\n", ct);
*ctinfo = IP_CT_ESTABLISHED;
} else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
pr_debug("nf_conntrack_in: related packet for %p\n",
ct);
*ctinfo = IP_CT_RELATED;
} else {
pr_debug("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(struct net *net, u_int8_t pf, unsigned int hooknum,
struct sk_buff *skb)
{
struct nf_conn *ct, *tmpl = NULL;
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;
if (skb->nfct) {
/* Previously seen (loopback or untracked)? Ignore. */
tmpl = (struct nf_conn *)skb->nfct;
if (!nf_ct_is_template(tmpl)) {
NF_CT_STAT_INC_ATOMIC(net, ignore);
return NF_ACCEPT;
}
skb->nfct = NULL;
}
/* rcu_read_lock()ed by nf_hook_slow */
l3proto = __nf_ct_l3proto_find(pf);
ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
&dataoff, &protonum);
if (ret <= 0) {
pr_debug("not prepared to track yet or error occurred\n");
NF_CT_STAT_INC_ATOMIC(net, error);
NF_CT_STAT_INC_ATOMIC(net, invalid);
ret = -ret;
goto out;
}
l4proto = __nf_ct_l4proto_find(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(net, tmpl, skb, dataoff, &ctinfo,
pf, hooknum);
if (ret <= 0) {
NF_CT_STAT_INC_ATOMIC(net, error);
NF_CT_STAT_INC_ATOMIC(net, invalid);
ret = -ret;
goto out;
}
/* ICMP[v6] protocol trackers may assign one conntrack. */
if (skb->nfct)
goto out;
}
ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum,
l3proto, l4proto, &set_reply, &ctinfo);
if (!ct) {
/* Not valid part of a connection */
NF_CT_STAT_INC_ATOMIC(net, invalid);
ret = NF_ACCEPT;
goto out;
}
if (IS_ERR(ct)) {
/* Too stressed to deal. */
NF_CT_STAT_INC_ATOMIC(net, drop);
ret = NF_DROP;
goto out;
}
NF_CT_ASSERT(skb->nfct);
ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum);
if (ret <= 0) {
/* Invalid: inverse of the return code tells
* the netfilter core what to do */
pr_debug("nf_conntrack_in: Can't track with proto module\n");
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
NF_CT_STAT_INC_ATOMIC(net, invalid);
if (ret == -NF_DROP)
NF_CT_STAT_INC_ATOMIC(net, drop);
ret = -ret;
goto out;
}
if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
nf_conntrack_event_cache(IPCT_REPLY, ct);
out:
if (tmpl) {
/* Special case: we have to repeat this hook, assign the
* template again to this packet. We assume that this packet
* has no conntrack assigned. This is used by nf_ct_tcp. */
if (ret == NF_REPEAT)
skb->nfct = (struct nf_conntrack *)tmpl;
else
nf_ct_put(tmpl);
}
return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_in);
bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
const struct nf_conntrack_tuple *orig)
{
bool 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);
/* Should be unconfirmed, so not in hash table yet */
NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
pr_debug("Altering reply tuple of %p to ", ct);
nf_ct_dump_tuple(newreply);
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
if (ct->master || (help && !hlist_empty(&help->expectations)))
return;
rcu_read_lock();
__nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
rcu_read_unlock();
}
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)
{
NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
NF_CT_ASSERT(skb);
/* Only update if this is not a fixed timeout */
if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
goto acct;
/* If not in hash table, timer will not be active yet */
if (!nf_ct_is_confirmed(ct)) {
ct->timeout.expires = extra_jiffies;
} 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)
mod_timer_pending(&ct->timeout, newtime);
}
acct:
if (do_acct) {
struct nf_conn_counter *acct;
acct = nf_conn_acct_find(ct);
if (acct) {
spin_lock_bh(&ct->lock);
acct[CTINFO2DIR(ctinfo)].packets++;
acct[CTINFO2DIR(ctinfo)].bytes += skb->len;
spin_unlock_bh(&ct->lock);
}
}
}
EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
bool __nf_ct_kill_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
int do_acct)
{
if (do_acct) {
struct nf_conn_counter *acct;
acct = nf_conn_acct_find(ct);
if (acct) {
spin_lock_bh(&ct->lock);
acct[CTINFO2DIR(ctinfo)].packets++;
acct[CTINFO2DIR(ctinfo)].bytes +=
skb->len - skb_network_offset(skb);
spin_unlock_bh(&ct->lock);
}
}
#ifdef CONFIG_COMCERTO_FP
clear_bit(IPS_PERMANENT_BIT, &ct->status);
/* Avoid race with timer expiration */
if (del_timer_sync(&ct->timeout)) {
#else
if (del_timer(&ct->timeout)) {
#endif
ct->timeout.function((unsigned long)ct);
return true;
}
return false;
}
EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
#ifdef CONFIG_NF_CONNTRACK_ZONES
static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
.len = sizeof(struct nf_conntrack_zone),
.align = __alignof__(struct nf_conntrack_zone),
.id = NF_CT_EXT_ZONE,
};
#endif
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <linux/mutex.h>
/* 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_nlattr(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple)
{
NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port);
NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port);
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
[CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
[CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
};
EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
struct nf_conntrack_tuple *t)
{
if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT])
return -EINVAL;
t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]);
t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]);
return 0;
}
EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple);
int nf_ct_port_nlattr_tuple_size(void)
{
return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
}
EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
#endif
/* Used by ipt_REJECT and ip6t_REJECT. */
static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb)
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
/* This ICMP is in reverse direction to the packet which caused it */
ct = nf_ct_get(skb, &ctinfo);
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
ctinfo = IP_CT_RELATED_REPLY;
else
ctinfo = IP_CT_RELATED;
/* Attach to new skbuff, and increment count */
nskb->nfct = &ct->ct_general;
nskb->nfctinfo = ctinfo;
nf_conntrack_get(nskb->nfct);
}
/* Bring out ya dead! */
static struct nf_conn *
get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data),
void *data, unsigned int *bucket)
{
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
struct hlist_nulls_node *n;
spin_lock_bh(&nf_conntrack_lock);
for (; *bucket < net->ct.htable_size; (*bucket)++) {
hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (iter(ct, data))
goto found;
}
}
hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (iter(ct, data))
set_bit(IPS_DYING_BIT, &ct->status);
}
spin_unlock_bh(&nf_conntrack_lock);
return NULL;
found:
atomic_inc(&ct->ct_general.use);
spin_unlock_bh(&nf_conntrack_lock);
return ct;
}
void nf_ct_iterate_cleanup(struct net *net,
int (*iter)(struct nf_conn *i, void *data),
void *data)
{
struct nf_conn *ct;
unsigned int bucket = 0;
while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
/* Time to push up daises... */
#ifdef CONFIG_COMCERTO_FP
clear_bit(IPS_PERMANENT_BIT, &ct->status);
/* Avoid race with timer expiration */
if (del_timer_sync(&ct->timeout))
#else
if (del_timer(&ct->timeout))
#endif
death_by_timeout((unsigned long)ct);
/* ... else the timer will get him soon. */
nf_ct_put(ct);
}
}
EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
struct __nf_ct_flush_report {
u32 pid;
int report;
};
static int kill_report(struct nf_conn *i, void *data)
{
struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data;
struct nf_conn_tstamp *tstamp;
tstamp = nf_conn_tstamp_find(i);
if (tstamp && tstamp->stop == 0)
tstamp->stop = ktime_to_ns(ktime_get_real());
/* If we fail to deliver the event, death_by_timeout() will retry */
if (nf_conntrack_event_report(IPCT_DESTROY, i,
fr->pid, fr->report) < 0)
return 1;
/* Avoid the delivery of the destroy event in death_by_timeout(). */
set_bit(IPS_DYING_BIT, &i->status);
return 1;
}
static int kill_all(struct nf_conn *i, void *data)
{
return 1;
}
void nf_ct_free_hashtable(void *hash, unsigned int size)
{
if (is_vmalloc_addr(hash))
vfree(hash);
else
free_pages((unsigned long)hash,
get_order(sizeof(struct hlist_head) * size));
}
EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
void nf_conntrack_flush_report(struct net *net, u32 pid, int report)
{
struct __nf_ct_flush_report fr = {
.pid = pid,
.report = report,
};
nf_ct_iterate_cleanup(net, kill_report, &fr);
}
EXPORT_SYMBOL_GPL(nf_conntrack_flush_report);
static void nf_ct_release_dying_list(struct net *net)
{
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
struct hlist_nulls_node *n;
spin_lock_bh(&nf_conntrack_lock);
hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
/* never fails to remove them, no listeners at this point */
nf_ct_kill(ct);
}
spin_unlock_bh(&nf_conntrack_lock);
}
static int untrack_refs(void)
{
int cnt = 0, cpu;
for_each_possible_cpu(cpu) {
struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
cnt += atomic_read(&ct->ct_general.use) - 1;
}
return cnt;
}
static void nf_conntrack_cleanup_init_net(void)
{
while (untrack_refs() > 0)
schedule();
nf_conntrack_helper_fini();
nf_conntrack_proto_fini();
#ifdef CONFIG_NF_CONNTRACK_ZONES
nf_ct_extend_unregister(&nf_ct_zone_extend);
#endif
}
static void nf_conntrack_cleanup_net(struct net *net)
{
i_see_dead_people:
nf_ct_iterate_cleanup(net, kill_all, NULL);
nf_ct_release_dying_list(net);
if (atomic_read(&net->ct.count) != 0) {
schedule();
goto i_see_dead_people;
}
nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
nf_conntrack_ecache_fini(net);
nf_conntrack_tstamp_fini(net);
nf_conntrack_acct_fini(net);
nf_conntrack_expect_fini(net);
kmem_cache_destroy(net->ct.nf_conntrack_cachep);
kfree(net->ct.slabname);
free_percpu(net->ct.stat);
}
/* Mishearing the voices in his head, our hero wonders how he's
supposed to kill the mall. */
void nf_conntrack_cleanup(struct net *net)
{
if (net_eq(net, &init_net))
RCU_INIT_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_conntrack_cleanup_net(net);
if (net_eq(net, &init_net)) {
RCU_INIT_POINTER(nf_ct_destroy, NULL);
nf_conntrack_cleanup_init_net();
}
}
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
{
struct hlist_nulls_head *hash;
unsigned int nr_slots, i;
size_t sz;
BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
sz = nr_slots * sizeof(struct hlist_nulls_head);
hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
get_order(sz));
if (!hash) {
printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
hash = __vmalloc(sz, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
PAGE_KERNEL);
}
if (hash && nulls)
for (i = 0; i < nr_slots; i++)
INIT_HLIST_NULLS_HEAD(&hash[i], i);
return hash;
}
EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
#ifdef CONFIG_COMCERTO_FP
int nf_conntrack_set_dpi_allow_report(struct sk_buff *skb)
{
int err = 0;
struct nf_conn *ct = (struct nf_conn *)skb->nfct;
nf_conntrack_get(skb->nfct);
set_bit(IPS_DPI_ALLOWED_BIT, &ct->status);
nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
nf_conntrack_put(skb->nfct);
return err;
}
EXPORT_SYMBOL(nf_conntrack_set_dpi_allow_report);
int nf_conntrack_set_dpi_allow_and_mark(struct sk_buff *skb, int mark)
{
int err = 0;
struct nf_conn *ct = (struct nf_conn *)skb->nfct;
nf_conntrack_get(skb->nfct);
set_bit(IPS_DPI_ALLOWED_BIT, &ct->status);
#ifdef CONFIG_NF_CONNTRACK_MARK
ct->mark = mark;
#endif
nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
nf_conntrack_put(skb->nfct);
return err;
}
EXPORT_SYMBOL(nf_conntrack_set_dpi_allow_and_mark);
#endif
int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
{
int i, bucket;
unsigned int hashsize, old_size;
struct hlist_nulls_head *hash, *old_hash;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
if (current->nsproxy->net_ns != &init_net)
return -EOPNOTSUPP;
/* On boot, we can set this without any fancy locking. */
if (!nf_conntrack_htable_size)
return param_set_uint(val, kp);
hashsize = simple_strtoul(val, NULL, 0);
if (!hashsize)
return -EINVAL;
hash = nf_ct_alloc_hashtable(&hashsize, 1);
if (!hash)
return -ENOMEM;
/* Lookups in the old hash might happen in parallel, which means we
* might get false negatives during connection lookup. New connections
* created because of a false negative won't make it into the hash
* though since that required taking the lock.
*/
spin_lock_bh(&nf_conntrack_lock);
for (i = 0; i < init_net.ct.htable_size; i++) {
while (!hlist_nulls_empty(&init_net.ct.hash[i])) {
h = hlist_nulls_entry(init_net.ct.hash[i].first,
struct nf_conntrack_tuple_hash, hnnode);
ct = nf_ct_tuplehash_to_ctrack(h);
hlist_nulls_del_rcu(&h->hnnode);
bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
hashsize);
hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
}
}
old_size = init_net.ct.htable_size;
old_hash = init_net.ct.hash;
init_net.ct.htable_size = nf_conntrack_htable_size = hashsize;
init_net.ct.hash = hash;
spin_unlock_bh(&nf_conntrack_lock);
nf_ct_free_hashtable(old_hash, old_size);
return 0;
}
EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
&nf_conntrack_htable_size, 0600);
void nf_ct_untracked_status_or(unsigned long bits)
{
int cpu;
for_each_possible_cpu(cpu)
per_cpu(nf_conntrack_untracked, cpu).status |= bits;
}
EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or);
static int nf_conntrack_init_init_net(void)
{
int max_factor = 8;
int ret, cpu;
/* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB
* machine has 512 buckets. >= 1GB machines have 16384 buckets. */
if (!nf_conntrack_htable_size) {
nf_conntrack_htable_size
= (((totalram_pages << PAGE_SHIFT) / 16384)
/ sizeof(struct hlist_head));
if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE))
nf_conntrack_htable_size = 16384;
if (nf_conntrack_htable_size < 32)
nf_conntrack_htable_size = 32;
/* Use a max. factor of four by default to get the same max as
* with the old struct list_heads. When a table size is given
* we use the old value of 8 to avoid reducing the max.
* entries. */
max_factor = 4;
}
nf_conntrack_max = max_factor * nf_conntrack_htable_size;
printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n",
NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
nf_conntrack_max);
ret = nf_conntrack_proto_init();
if (ret < 0)
goto err_proto;
ret = nf_conntrack_helper_init();
if (ret < 0)
goto err_helper;
#ifdef CONFIG_NF_CONNTRACK_ZONES
ret = nf_ct_extend_register(&nf_ct_zone_extend);
if (ret < 0)
goto err_extend;
#endif
/* Set up fake conntrack: to never be deleted, not in any hashes */
for_each_possible_cpu(cpu) {
struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu);
write_pnet(&ct->ct_net, &init_net);
atomic_set(&ct->ct_general.use, 1);
}
/* - and look it like as a confirmed connection */
nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED);
return 0;
#ifdef CONFIG_NF_CONNTRACK_ZONES
err_extend:
nf_conntrack_helper_fini();
#endif
err_helper:
nf_conntrack_proto_fini();
err_proto:
return ret;
}
/*
* We need to use special "null" values, not used in hash table
*/
#define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
#define DYING_NULLS_VAL ((1<<30)+1)
static int nf_conntrack_init_net(struct net *net)
{
int ret;
atomic_set(&net->ct.count, 0);
INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL);
INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL);
net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
if (!net->ct.stat) {
ret = -ENOMEM;
goto err_stat;
}
net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net);
if (!net->ct.slabname) {
ret = -ENOMEM;
goto err_slabname;
}
net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname,
sizeof(struct nf_conn), 0,
SLAB_DESTROY_BY_RCU, NULL);
if (!net->ct.nf_conntrack_cachep) {
printk(KERN_ERR "Unable to create nf_conn slab cache\n");
ret = -ENOMEM;
goto err_cache;
}
net->ct.htable_size = nf_conntrack_htable_size;
net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1);
if (!net->ct.hash) {
ret = -ENOMEM;
printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
goto err_hash;
}
ret = nf_conntrack_expect_init(net);
if (ret < 0)
goto err_expect;
ret = nf_conntrack_acct_init(net);
if (ret < 0)
goto err_acct;
ret = nf_conntrack_tstamp_init(net);
if (ret < 0)
goto err_tstamp;
ret = nf_conntrack_ecache_init(net);
if (ret < 0)
goto err_ecache;
return 0;
err_ecache:
nf_conntrack_tstamp_fini(net);
err_tstamp:
nf_conntrack_acct_fini(net);
err_acct:
nf_conntrack_expect_fini(net);
err_expect:
nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
err_hash:
kmem_cache_destroy(net->ct.nf_conntrack_cachep);
err_cache:
kfree(net->ct.slabname);
err_slabname:
free_percpu(net->ct.stat);
err_stat:
return ret;
}
s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
enum ip_conntrack_dir dir,
u32 seq);
EXPORT_SYMBOL_GPL(nf_ct_nat_offset);
int nf_conntrack_init(struct net *net)
{
int ret;
if (net_eq(net, &init_net)) {
ret = nf_conntrack_init_init_net();
if (ret < 0)
goto out_init_net;
}
ret = nf_conntrack_init_net(net);
if (ret < 0)
goto out_net;
if (net_eq(net, &init_net)) {
/* For use by REJECT target */
RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack);
/* Howto get NAT offsets */
RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
}
return 0;
out_net:
if (net_eq(net, &init_net))
nf_conntrack_cleanup_init_net();
out_init_net:
return ret;
}