blob: 264074f046152caa42480c13d53bce584c9ca3fe [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>
* (C) 2005-2012 Patrick McHardy <kaber@trash.net>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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_l4proto.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_seqadj.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_conntrack_timeout.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_synproxy.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_helper.h>
#include <net/netns/hash.h>
#include <net/ip.h>
#include "nf_internals.h"
__cacheline_aligned_in_smp spinlock_t nf_conntrack_locks[CONNTRACK_LOCKS];
EXPORT_SYMBOL_GPL(nf_conntrack_locks);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(nf_conntrack_expect_lock);
EXPORT_SYMBOL_GPL(nf_conntrack_expect_lock);
struct hlist_nulls_head *nf_conntrack_hash __read_mostly;
EXPORT_SYMBOL_GPL(nf_conntrack_hash);
struct conntrack_gc_work {
struct delayed_work dwork;
u32 last_bucket;
bool exiting;
bool early_drop;
long next_gc_run;
};
static __read_mostly struct kmem_cache *nf_conntrack_cachep;
static __read_mostly spinlock_t nf_conntrack_locks_all_lock;
static __read_mostly DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
static __read_mostly bool nf_conntrack_locks_all;
/* every gc cycle scans at most 1/GC_MAX_BUCKETS_DIV part of table */
#define GC_MAX_BUCKETS_DIV 128u
/* upper bound of full table scan */
#define GC_MAX_SCAN_JIFFIES (16u * HZ)
/* desired ratio of entries found to be expired */
#define GC_EVICT_RATIO 50u
static struct conntrack_gc_work conntrack_gc_work;
void nf_conntrack_lock(spinlock_t *lock) __acquires(lock)
{
/* 1) Acquire the lock */
spin_lock(lock);
/* 2) read nf_conntrack_locks_all, with ACQUIRE semantics
* It pairs with the smp_store_release() in nf_conntrack_all_unlock()
*/
if (likely(smp_load_acquire(&nf_conntrack_locks_all) == false))
return;
/* fast path failed, unlock */
spin_unlock(lock);
/* Slow path 1) get global lock */
spin_lock(&nf_conntrack_locks_all_lock);
/* Slow path 2) get the lock we want */
spin_lock(lock);
/* Slow path 3) release the global lock */
spin_unlock(&nf_conntrack_locks_all_lock);
}
EXPORT_SYMBOL_GPL(nf_conntrack_lock);
static void nf_conntrack_double_unlock(unsigned int h1, unsigned int h2)
{
h1 %= CONNTRACK_LOCKS;
h2 %= CONNTRACK_LOCKS;
spin_unlock(&nf_conntrack_locks[h1]);
if (h1 != h2)
spin_unlock(&nf_conntrack_locks[h2]);
}
/* return true if we need to recompute hashes (in case hash table was resized) */
static bool nf_conntrack_double_lock(struct net *net, unsigned int h1,
unsigned int h2, unsigned int sequence)
{
h1 %= CONNTRACK_LOCKS;
h2 %= CONNTRACK_LOCKS;
if (h1 <= h2) {
nf_conntrack_lock(&nf_conntrack_locks[h1]);
if (h1 != h2)
spin_lock_nested(&nf_conntrack_locks[h2],
SINGLE_DEPTH_NESTING);
} else {
nf_conntrack_lock(&nf_conntrack_locks[h2]);
spin_lock_nested(&nf_conntrack_locks[h1],
SINGLE_DEPTH_NESTING);
}
if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
nf_conntrack_double_unlock(h1, h2);
return true;
}
return false;
}
static void nf_conntrack_all_lock(void)
{
int i;
spin_lock(&nf_conntrack_locks_all_lock);
nf_conntrack_locks_all = true;
for (i = 0; i < CONNTRACK_LOCKS; i++) {
spin_lock(&nf_conntrack_locks[i]);
/* This spin_unlock provides the "release" to ensure that
* nf_conntrack_locks_all==true is visible to everyone that
* acquired spin_lock(&nf_conntrack_locks[]).
*/
spin_unlock(&nf_conntrack_locks[i]);
}
}
static void nf_conntrack_all_unlock(void)
{
/* All prior stores must be complete before we clear
* 'nf_conntrack_locks_all'. Otherwise nf_conntrack_lock()
* might observe the false value but not the entire
* critical section.
* It pairs with the smp_load_acquire() in nf_conntrack_lock()
*/
smp_store_release(&nf_conntrack_locks_all, false);
spin_unlock(&nf_conntrack_locks_all_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);
seqcount_t nf_conntrack_generation __read_mostly;
static unsigned int nf_conntrack_hash_rnd __read_mostly;
static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
const struct net *net)
{
unsigned int n;
u32 seed;
get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
/* 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.
*/
seed = nf_conntrack_hash_rnd ^ net_hash_mix(net);
n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
return jhash2((u32 *)tuple, n, seed ^
(((__force __u16)tuple->dst.u.all << 16) |
tuple->dst.protonum));
}
static u32 scale_hash(u32 hash)
{
return reciprocal_scale(hash, nf_conntrack_htable_size);
}
static u32 __hash_conntrack(const struct net *net,
const struct nf_conntrack_tuple *tuple,
unsigned int size)
{
return reciprocal_scale(hash_conntrack_raw(tuple, net), size);
}
static u32 hash_conntrack(const struct net *net,
const struct nf_conntrack_tuple *tuple)
{
return scale_hash(hash_conntrack_raw(tuple, net));
}
static 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 net *net,
struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_l4proto *l4proto)
{
unsigned int size;
const __be32 *ap;
__be32 _addrs[8];
struct {
__be16 sport;
__be16 dport;
} _inet_hdr, *inet_hdr;
memset(tuple, 0, sizeof(*tuple));
tuple->src.l3num = l3num;
switch (l3num) {
case NFPROTO_IPV4:
nhoff += offsetof(struct iphdr, saddr);
size = 2 * sizeof(__be32);
break;
case NFPROTO_IPV6:
nhoff += offsetof(struct ipv6hdr, saddr);
size = sizeof(_addrs);
break;
default:
return true;
}
ap = skb_header_pointer(skb, nhoff, size, _addrs);
if (!ap)
return false;
switch (l3num) {
case NFPROTO_IPV4:
tuple->src.u3.ip = ap[0];
tuple->dst.u3.ip = ap[1];
break;
case NFPROTO_IPV6:
memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
break;
}
tuple->dst.protonum = protonum;
tuple->dst.dir = IP_CT_DIR_ORIGINAL;
switch (protonum) {
case IPPROTO_ICMPV6:
return icmpv6_pkt_to_tuple(skb, dataoff, net, tuple);
case IPPROTO_ICMP:
return icmp_pkt_to_tuple(skb, dataoff, net, tuple);
#ifdef CONFIG_NF_CT_PROTO_GRE
case IPPROTO_GRE:
return gre_pkt_to_tuple(skb, dataoff, net, tuple);
#endif
}
/* Actually only need first 4 bytes to get ports. */
inet_hdr = skb_header_pointer(skb, dataoff, sizeof(_inet_hdr), &_inet_hdr);
if (!inet_hdr)
return false;
tuple->src.u.udp.port = inet_hdr->sport;
tuple->dst.u.udp.port = inet_hdr->dport;
return true;
}
static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
u_int8_t *protonum)
{
int dataoff = -1;
const struct iphdr *iph;
struct iphdr _iph;
iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
if (!iph)
return -1;
/* Conntrack defragments packets, we might still see fragments
* inside ICMP packets though.
*/
if (iph->frag_off & htons(IP_OFFSET))
return -1;
dataoff = nhoff + (iph->ihl << 2);
*protonum = iph->protocol;
/* Check bogus IP headers */
if (dataoff > skb->len) {
pr_debug("bogus IPv4 packet: nhoff %u, ihl %u, skblen %u\n",
nhoff, iph->ihl << 2, skb->len);
return -1;
}
return dataoff;
}
#if IS_ENABLED(CONFIG_IPV6)
static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
u8 *protonum)
{
int protoff = -1;
unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
__be16 frag_off;
u8 nexthdr;
if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
&nexthdr, sizeof(nexthdr)) != 0) {
pr_debug("can't get nexthdr\n");
return -1;
}
protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
/*
* (protoff == skb->len) means the packet has not data, just
* IPv6 and possibly extensions headers, but it is tracked anyway
*/
if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
pr_debug("can't find proto in pkt\n");
return -1;
}
*protonum = nexthdr;
return protoff;
}
#endif
static int get_l4proto(const struct sk_buff *skb,
unsigned int nhoff, u8 pf, u8 *l4num)
{
switch (pf) {
case NFPROTO_IPV4:
return ipv4_get_l4proto(skb, nhoff, l4num);
#if IS_ENABLED(CONFIG_IPV6)
case NFPROTO_IPV6:
return ipv6_get_l4proto(skb, nhoff, l4num);
#endif
default:
*l4num = 0;
break;
}
return -1;
}
bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
u_int16_t l3num,
struct net *net, struct nf_conntrack_tuple *tuple)
{
const struct nf_conntrack_l4proto *l4proto;
u8 protonum;
int protoff;
int ret;
rcu_read_lock();
protoff = get_l4proto(skb, nhoff, l3num, &protonum);
if (protoff <= 0) {
rcu_read_unlock();
return false;
}
l4proto = __nf_ct_l4proto_find(protonum);
ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, net, tuple,
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_l4proto *l4proto)
{
memset(inverse, 0, sizeof(*inverse));
inverse->src.l3num = orig->src.l3num;
switch (orig->src.l3num) {
case NFPROTO_IPV4:
inverse->src.u3.ip = orig->dst.u3.ip;
inverse->dst.u3.ip = orig->src.u3.ip;
break;
case NFPROTO_IPV6:
inverse->src.u3.in6 = orig->dst.u3.in6;
inverse->dst.u3.in6 = orig->src.u3.in6;
break;
default:
break;
}
inverse->dst.dir = !orig->dst.dir;
inverse->dst.protonum = orig->dst.protonum;
switch (orig->dst.protonum) {
case IPPROTO_ICMP:
return nf_conntrack_invert_icmp_tuple(inverse, orig);
case IPPROTO_ICMPV6:
return nf_conntrack_invert_icmpv6_tuple(inverse, orig);
}
inverse->src.u.all = orig->dst.u.all;
inverse->dst.u.all = orig->src.u.all;
return true;
}
EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
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);
}
/* must be called with local_bh_disable */
static void nf_ct_add_to_dying_list(struct nf_conn *ct)
{
struct ct_pcpu *pcpu;
/* add this conntrack to the (per cpu) dying list */
ct->cpu = smp_processor_id();
pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
spin_lock(&pcpu->lock);
hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&pcpu->dying);
spin_unlock(&pcpu->lock);
}
/* must be called with local_bh_disable */
static void nf_ct_add_to_unconfirmed_list(struct nf_conn *ct)
{
struct ct_pcpu *pcpu;
/* add this conntrack to the (per cpu) unconfirmed list */
ct->cpu = smp_processor_id();
pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
spin_lock(&pcpu->lock);
hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&pcpu->unconfirmed);
spin_unlock(&pcpu->lock);
}
/* must be called with local_bh_disable */
static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct)
{
struct ct_pcpu *pcpu;
/* We overload first tuple to link into unconfirmed or dying list.*/
pcpu = per_cpu_ptr(nf_ct_net(ct)->ct.pcpu_lists, ct->cpu);
spin_lock(&pcpu->lock);
BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
spin_unlock(&pcpu->lock);
}
#define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK)
/* Released via destroy_conntrack() */
struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
const struct nf_conntrack_zone *zone,
gfp_t flags)
{
struct nf_conn *tmpl, *p;
if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) {
tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags);
if (!tmpl)
return NULL;
p = tmpl;
tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
if (tmpl != p) {
tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p);
tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p;
}
} else {
tmpl = kzalloc(sizeof(*tmpl), flags);
if (!tmpl)
return NULL;
}
tmpl->status = IPS_TEMPLATE;
write_pnet(&tmpl->ct_net, net);
nf_ct_zone_add(tmpl, zone);
atomic_set(&tmpl->ct_general.use, 0);
return tmpl;
}
EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc);
void nf_ct_tmpl_free(struct nf_conn *tmpl)
{
nf_ct_ext_destroy(tmpl);
nf_ct_ext_free(tmpl);
if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK)
kfree((char *)tmpl - tmpl->proto.tmpl_padto);
else
kfree(tmpl);
}
EXPORT_SYMBOL_GPL(nf_ct_tmpl_free);
static void
destroy_conntrack(struct nf_conntrack *nfct)
{
struct nf_conn *ct = (struct nf_conn *)nfct;
const struct nf_conntrack_l4proto *l4proto;
pr_debug("destroy_conntrack(%p)\n", ct);
WARN_ON(atomic_read(&nfct->use) != 0);
if (unlikely(nf_ct_is_template(ct))) {
nf_ct_tmpl_free(ct);
return;
}
l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
if (l4proto->destroy)
l4proto->destroy(ct);
local_bh_disable();
/* 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);
nf_ct_del_from_dying_or_unconfirmed_list(ct);
local_bh_enable();
if (ct->master)
nf_ct_put(ct->master);
pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
nf_conntrack_free(ct);
}
static void nf_ct_delete_from_lists(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
unsigned int hash, reply_hash;
unsigned int sequence;
nf_ct_helper_destroy(ct);
local_bh_disable();
do {
sequence = read_seqcount_begin(&nf_conntrack_generation);
hash = hash_conntrack(net,
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
reply_hash = hash_conntrack(net,
&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
clean_from_lists(ct);
nf_conntrack_double_unlock(hash, reply_hash);
nf_ct_add_to_dying_list(ct);
local_bh_enable();
}
bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
{
struct nf_conn_tstamp *tstamp;
if (test_and_set_bit(IPS_DYING_BIT, &ct->status))
return false;
tstamp = nf_conn_tstamp_find(ct);
if (tstamp && tstamp->stop == 0)
tstamp->stop = ktime_get_real_ns();
if (nf_conntrack_event_report(IPCT_DESTROY, ct,
portid, report) < 0) {
/* destroy event was not delivered. nf_ct_put will
* be done by event cache worker on redelivery.
*/
nf_ct_delete_from_lists(ct);
nf_conntrack_ecache_delayed_work(nf_ct_net(ct));
return false;
}
nf_conntrack_ecache_work(nf_ct_net(ct));
nf_ct_delete_from_lists(ct);
nf_ct_put(ct);
return true;
}
EXPORT_SYMBOL_GPL(nf_ct_delete);
static inline bool
nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone,
const struct net *net)
{
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
/* A conntrack can be recreated with the equal tuple,
* so we need to check that the conntrack is confirmed
*/
return nf_ct_tuple_equal(tuple, &h->tuple) &&
nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
nf_ct_is_confirmed(ct) &&
net_eq(net, nf_ct_net(ct));
}
static inline bool
nf_ct_match(const struct nf_conn *ct1, const struct nf_conn *ct2)
{
return nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
&ct2->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
nf_ct_tuple_equal(&ct1->tuplehash[IP_CT_DIR_REPLY].tuple,
&ct2->tuplehash[IP_CT_DIR_REPLY].tuple) &&
nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_ORIGINAL) &&
nf_ct_zone_equal(ct1, nf_ct_zone(ct2), IP_CT_DIR_REPLY) &&
net_eq(nf_ct_net(ct1), nf_ct_net(ct2));
}
/* caller must hold rcu readlock and none of the nf_conntrack_locks */
static void nf_ct_gc_expired(struct nf_conn *ct)
{
if (!atomic_inc_not_zero(&ct->ct_general.use))
return;
if (nf_ct_should_gc(ct))
nf_ct_kill(ct);
nf_ct_put(ct);
}
/*
* Warning :
* - Caller must take a reference on returned object
* and recheck nf_ct_tuple_equal(tuple, &h->tuple)
*/
static struct nf_conntrack_tuple_hash *
____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *tuple, u32 hash)
{
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_head *ct_hash;
struct hlist_nulls_node *n;
unsigned int bucket, hsize;
begin:
nf_conntrack_get_ht(&ct_hash, &hsize);
bucket = reciprocal_scale(hash, hsize);
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
struct nf_conn *ct;
ct = nf_ct_tuplehash_to_ctrack(h);
if (nf_ct_is_expired(ct)) {
nf_ct_gc_expired(ct);
continue;
}
if (nf_ct_is_dying(ct))
continue;
if (nf_ct_key_equal(h, tuple, zone, net))
return h;
}
/*
* if the nulls value we got at the end of this lookup is
* not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain.
*/
if (get_nulls_value(n) != bucket) {
NF_CT_STAT_INC_ATOMIC(net, search_restart);
goto begin;
}
return NULL;
}
/* Find a connection corresponding to a tuple. */
static struct nf_conntrack_tuple_hash *
__nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *tuple, u32 hash)
{
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
rcu_read_lock();
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_key_equal(h, tuple, zone, net))) {
nf_ct_put(ct);
goto begin;
}
}
}
rcu_read_unlock();
return h;
}
struct nf_conntrack_tuple_hash *
nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *tuple)
{
return __nf_conntrack_find_get(net, zone, tuple,
hash_conntrack_raw(tuple, net));
}
EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
static void __nf_conntrack_hash_insert(struct nf_conn *ct,
unsigned int hash,
unsigned int reply_hash)
{
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&nf_conntrack_hash[hash]);
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
&nf_conntrack_hash[reply_hash]);
}
int
nf_conntrack_hash_check_insert(struct nf_conn *ct)
{
const struct nf_conntrack_zone *zone;
struct net *net = nf_ct_net(ct);
unsigned int hash, reply_hash;
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
unsigned int sequence;
zone = nf_ct_zone(ct);
local_bh_disable();
do {
sequence = read_seqcount_begin(&nf_conntrack_generation);
hash = hash_conntrack(net,
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
reply_hash = hash_conntrack(net,
&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
/* See if there's one in the list already, including reverse */
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
zone, net))
goto out;
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
zone, net))
goto out;
smp_wmb();
/* The caller holds a reference to this object */
atomic_set(&ct->ct_general.use, 2);
__nf_conntrack_hash_insert(ct, hash, reply_hash);
nf_conntrack_double_unlock(hash, reply_hash);
NF_CT_STAT_INC(net, insert);
local_bh_enable();
return 0;
out:
nf_conntrack_double_unlock(hash, reply_hash);
NF_CT_STAT_INC(net, insert_failed);
local_bh_enable();
return -EEXIST;
}
EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
static inline void nf_ct_acct_update(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
unsigned int len)
{
struct nf_conn_acct *acct;
acct = nf_conn_acct_find(ct);
if (acct) {
struct nf_conn_counter *counter = acct->counter;
atomic64_inc(&counter[CTINFO2DIR(ctinfo)].packets);
atomic64_add(len, &counter[CTINFO2DIR(ctinfo)].bytes);
}
}
static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
const struct nf_conn *loser_ct)
{
struct nf_conn_acct *acct;
acct = nf_conn_acct_find(loser_ct);
if (acct) {
struct nf_conn_counter *counter = acct->counter;
unsigned int bytes;
/* u32 should be fine since we must have seen one packet. */
bytes = atomic64_read(&counter[CTINFO2DIR(ctinfo)].bytes);
nf_ct_acct_update(ct, ctinfo, bytes);
}
}
/* Resolve race on insertion if this protocol allows this. */
static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
enum ip_conntrack_info ctinfo,
struct nf_conntrack_tuple_hash *h)
{
/* This is the conntrack entry already in hashes that won race. */
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
const struct nf_conntrack_l4proto *l4proto;
enum ip_conntrack_info oldinfo;
struct nf_conn *loser_ct = nf_ct_get(skb, &oldinfo);
l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
if (l4proto->allow_clash &&
!nf_ct_is_dying(ct) &&
atomic_inc_not_zero(&ct->ct_general.use)) {
if (((ct->status & IPS_NAT_DONE_MASK) == 0) ||
nf_ct_match(ct, loser_ct)) {
nf_ct_acct_merge(ct, ctinfo, loser_ct);
nf_conntrack_put(&loser_ct->ct_general);
nf_ct_set(skb, ct, oldinfo);
return NF_ACCEPT;
}
nf_ct_put(ct);
}
NF_CT_STAT_INC(net, drop);
return NF_DROP;
}
/* Confirm a connection given skb; places it in hash table */
int
__nf_conntrack_confirm(struct sk_buff *skb)
{
const struct nf_conntrack_zone *zone;
unsigned int hash, reply_hash;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
struct nf_conn_help *help;
struct nf_conn_tstamp *tstamp;
struct hlist_nulls_node *n;
enum ip_conntrack_info ctinfo;
struct net *net;
unsigned int sequence;
int ret = NF_DROP;
ct = nf_ct_get(skb, &ctinfo);
net = nf_ct_net(ct);
/* ipt_REJECT uses nf_conntrack_attach to attach related
ICMP/TCP RST packets in other direction. Actual packet
which created connection will be IP_CT_NEW or for an
expected connection, IP_CT_RELATED. */
if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
return NF_ACCEPT;
zone = nf_ct_zone(ct);
local_bh_disable();
do {
sequence = read_seqcount_begin(&nf_conntrack_generation);
/* reuse the hash saved before */
hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
hash = scale_hash(hash);
reply_hash = hash_conntrack(net,
&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
/* We're not in hash table, and we refuse to set up related
* connections for unconfirmed conns. But packet copies and
* REJECT will give spurious warnings here.
*/
/* No external references means no one else could have
* confirmed us.
*/
WARN_ON(nf_ct_is_confirmed(ct));
pr_debug("Confirming conntrack %p\n", ct);
/* We have to check the DYING flag after unlink to prevent
* a race against nf_ct_get_next_corpse() possibly called from
* user context, else we insert an already 'dead' hash, blocking
* further use of that particular connection -JM.
*/
nf_ct_del_from_dying_or_unconfirmed_list(ct);
if (unlikely(nf_ct_is_dying(ct))) {
nf_ct_add_to_dying_list(ct);
goto dying;
}
/* See if there's one in the list already, including reverse:
NAT could have grabbed it without realizing, since we're
not in the hash. If there is, we lost race. */
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
zone, net))
goto out;
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[reply_hash], hnnode)
if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
zone, net))
goto out;
/* Timer relative to confirmation time, not original
setting time, otherwise we'd get timer wrap in
weird delay cases. */
ct->timeout += nfct_time_stamp;
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 == 0)
__net_timestamp(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, reply_hash);
nf_conntrack_double_unlock(hash, reply_hash);
local_bh_enable();
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_add_to_dying_list(ct);
ret = nf_ct_resolve_clash(net, skb, ctinfo, h);
dying:
nf_conntrack_double_unlock(hash, reply_hash);
NF_CT_STAT_INC(net, insert_failed);
local_bh_enable();
return ret;
}
EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
/* Returns true if a connection correspondings to the tuple (required
for NAT). */
int
nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack)
{
struct net *net = nf_ct_net(ignored_conntrack);
const struct nf_conntrack_zone *zone;
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_head *ct_hash;
unsigned int hash, hsize;
struct hlist_nulls_node *n;
struct nf_conn *ct;
zone = nf_ct_zone(ignored_conntrack);
rcu_read_lock();
begin:
nf_conntrack_get_ht(&ct_hash, &hsize);
hash = __hash_conntrack(net, tuple, hsize);
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
ct = nf_ct_tuplehash_to_ctrack(h);
if (ct == ignored_conntrack)
continue;
if (nf_ct_is_expired(ct)) {
nf_ct_gc_expired(ct);
continue;
}
if (nf_ct_key_equal(h, tuple, zone, net)) {
NF_CT_STAT_INC_ATOMIC(net, found);
rcu_read_unlock();
return 1;
}
}
if (get_nulls_value(n) != hash) {
NF_CT_STAT_INC_ATOMIC(net, search_restart);
goto begin;
}
rcu_read_unlock();
return 0;
}
EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken);
#define NF_CT_EVICTION_RANGE 8
/* There's a small race here where we may free a just-assured
connection. Too bad: we're in trouble anyway. */
static unsigned int early_drop_list(struct net *net,
struct hlist_nulls_head *head)
{
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
unsigned int drops = 0;
struct nf_conn *tmp;
hlist_nulls_for_each_entry_rcu(h, n, head, hnnode) {
tmp = nf_ct_tuplehash_to_ctrack(h);
if (test_bit(IPS_OFFLOAD_BIT, &tmp->status))
continue;
if (nf_ct_is_expired(tmp)) {
nf_ct_gc_expired(tmp);
continue;
}
if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
!net_eq(nf_ct_net(tmp), net) ||
nf_ct_is_dying(tmp))
continue;
if (!atomic_inc_not_zero(&tmp->ct_general.use))
continue;
/* kill only if still in same netns -- might have moved due to
* SLAB_TYPESAFE_BY_RCU rules.
*
* We steal the timer reference. If that fails timer has
* already fired or someone else deleted it. Just drop ref
* and move to next entry.
*/
if (net_eq(nf_ct_net(tmp), net) &&
nf_ct_is_confirmed(tmp) &&
nf_ct_delete(tmp, 0, 0))
drops++;
nf_ct_put(tmp);
}
return drops;
}
static noinline int early_drop(struct net *net, unsigned int hash)
{
unsigned int i, bucket;
for (i = 0; i < NF_CT_EVICTION_RANGE; i++) {
struct hlist_nulls_head *ct_hash;
unsigned int hsize, drops;
rcu_read_lock();
nf_conntrack_get_ht(&ct_hash, &hsize);
if (!i)
bucket = reciprocal_scale(hash, hsize);
else
bucket = (bucket + 1) % hsize;
drops = early_drop_list(net, &ct_hash[bucket]);
rcu_read_unlock();
if (drops) {
NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
return true;
}
}
return false;
}
static bool gc_worker_skip_ct(const struct nf_conn *ct)
{
return !nf_ct_is_confirmed(ct) || nf_ct_is_dying(ct);
}
static bool gc_worker_can_early_drop(const struct nf_conn *ct)
{
const struct nf_conntrack_l4proto *l4proto;
if (!test_bit(IPS_ASSURED_BIT, &ct->status))
return true;
l4proto = __nf_ct_l4proto_find(nf_ct_protonum(ct));
if (l4proto->can_early_drop && l4proto->can_early_drop(ct))
return true;
return false;
}
#define DAY (86400 * HZ)
/* Set an arbitrary timeout large enough not to ever expire, this save
* us a check for the IPS_OFFLOAD_BIT from the packet path via
* nf_ct_is_expired().
*/
static void nf_ct_offload_timeout(struct nf_conn *ct)
{
if (nf_ct_expires(ct) < DAY / 2)
ct->timeout = nfct_time_stamp + DAY;
}
static void gc_worker(struct work_struct *work)
{
unsigned int min_interval = max(HZ / GC_MAX_BUCKETS_DIV, 1u);
unsigned int i, goal, buckets = 0, expired_count = 0;
unsigned int nf_conntrack_max95 = 0;
struct conntrack_gc_work *gc_work;
unsigned int ratio, scanned = 0;
unsigned long next_run;
gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
goal = nf_conntrack_htable_size / GC_MAX_BUCKETS_DIV;
i = gc_work->last_bucket;
if (gc_work->early_drop)
nf_conntrack_max95 = nf_conntrack_max / 100u * 95u;
do {
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_head *ct_hash;
struct hlist_nulls_node *n;
unsigned int hashsz;
struct nf_conn *tmp;
i++;
rcu_read_lock();
nf_conntrack_get_ht(&ct_hash, &hashsz);
if (i >= hashsz)
i = 0;
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
struct net *net;
tmp = nf_ct_tuplehash_to_ctrack(h);
scanned++;
if (test_bit(IPS_OFFLOAD_BIT, &tmp->status)) {
nf_ct_offload_timeout(tmp);
continue;
}
if (nf_ct_is_expired(tmp)) {
nf_ct_gc_expired(tmp);
expired_count++;
continue;
}
if (nf_conntrack_max95 == 0 || gc_worker_skip_ct(tmp))
continue;
net = nf_ct_net(tmp);
if (atomic_read(&net->ct.count) < nf_conntrack_max95)
continue;
/* need to take reference to avoid possible races */
if (!atomic_inc_not_zero(&tmp->ct_general.use))
continue;
if (gc_worker_skip_ct(tmp)) {
nf_ct_put(tmp);
continue;
}
if (gc_worker_can_early_drop(tmp))
nf_ct_kill(tmp);
nf_ct_put(tmp);
}
/* could check get_nulls_value() here and restart if ct
* was moved to another chain. But given gc is best-effort
* we will just continue with next hash slot.
*/
rcu_read_unlock();
cond_resched();
} while (++buckets < goal);
if (gc_work->exiting)
return;
/*
* Eviction will normally happen from the packet path, and not
* from this gc worker.
*
* This worker is only here to reap expired entries when system went
* idle after a busy period.
*
* The heuristics below are supposed to balance conflicting goals:
*
* 1. Minimize time until we notice a stale entry
* 2. Maximize scan intervals to not waste cycles
*
* Normally, expire ratio will be close to 0.
*
* As soon as a sizeable fraction of the entries have expired
* increase scan frequency.
*/
ratio = scanned ? expired_count * 100 / scanned : 0;
if (ratio > GC_EVICT_RATIO) {
gc_work->next_gc_run = min_interval;
} else {
unsigned int max = GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV;
BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV) == 0);
gc_work->next_gc_run += min_interval;
if (gc_work->next_gc_run > max)
gc_work->next_gc_run = max;
}
next_run = gc_work->next_gc_run;
gc_work->last_bucket = i;
gc_work->early_drop = false;
queue_delayed_work(system_power_efficient_wq, &gc_work->dwork, next_run);
}
static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
{
INIT_DEFERRABLE_WORK(&gc_work->dwork, gc_worker);
gc_work->next_gc_run = HZ;
gc_work->exiting = false;
}
static struct nf_conn *
__nf_conntrack_alloc(struct net *net,
const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
gfp_t gfp, u32 hash)
{
struct nf_conn *ct;
/* 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)) {
if (!conntrack_gc_work.early_drop)
conntrack_gc_work.early_drop = true;
atomic_dec(&net->ct.count);
net_warn_ratelimited("nf_conntrack: table full, dropping packet\n");
return ERR_PTR(-ENOMEM);
}
}
/*
* Do not use kmem_cache_zalloc(), as this cache uses
* SLAB_TYPESAFE_BY_RCU.
*/
ct = kmem_cache_alloc(nf_conntrack_cachep, gfp);
if (ct == NULL)
goto out;
spin_lock_init(&ct->lock);
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
/* save hash for reusing when confirming */
*(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash;
ct->status = 0;
write_pnet(&ct->ct_net, net);
memset(&ct->__nfct_init_offset[0], 0,
offsetof(struct nf_conn, proto) -
offsetof(struct nf_conn, __nfct_init_offset[0]));
nf_ct_zone_add(ct, zone);
/* Because we use RCU lookups, we set ct_general.use to zero before
* this is inserted in any list.
*/
atomic_set(&ct->ct_general.use, 0);
return ct;
out:
atomic_dec(&net->ct.count);
return ERR_PTR(-ENOMEM);
}
struct nf_conn *nf_conntrack_alloc(struct net *net,
const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
gfp_t gfp)
{
return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0);
}
EXPORT_SYMBOL_GPL(nf_conntrack_alloc);
void nf_conntrack_free(struct nf_conn *ct)
{
struct net *net = nf_ct_net(ct);
/* A freed object has refcnt == 0, that's
* the golden rule for SLAB_TYPESAFE_BY_RCU
*/
WARN_ON(atomic_read(&ct->ct_general.use) != 0);
nf_ct_ext_destroy(ct);
nf_ct_ext_free(ct);
kmem_cache_free(nf_conntrack_cachep, ct);
smp_mb__before_atomic();
atomic_dec(&net->ct.count);
}
EXPORT_SYMBOL_GPL(nf_conntrack_free);
/* Allocate a new conntrack: we return -ENOMEM if classification
failed due to stress. Otherwise it really is unclassifiable. */
static noinline struct nf_conntrack_tuple_hash *
init_conntrack(struct net *net, struct nf_conn *tmpl,
const struct nf_conntrack_tuple *tuple,
const 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 = NULL;
const struct nf_conntrack_zone *zone;
struct nf_conn_timeout *timeout_ext;
struct nf_conntrack_zone tmp;
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l4proto)) {
pr_debug("Can't invert tuple.\n");
return NULL;
}
zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
hash);
if (IS_ERR(ct))
return (struct nf_conntrack_tuple_hash *)ct;
if (!nf_ct_add_synproxy(ct, tmpl)) {
nf_conntrack_free(ct);
return ERR_PTR(-ENOMEM);
}
timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
if (timeout_ext)
nf_ct_timeout_ext_add(ct, rcu_dereference(timeout_ext->timeout),
GFP_ATOMIC);
nf_ct_acct_ext_add(ct, GFP_ATOMIC);
nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
nf_ct_labels_ext_add(ct);
ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
ecache ? ecache->expmask : 0,
GFP_ATOMIC);
local_bh_disable();
if (net->ct.expect_count) {
spin_lock(&nf_conntrack_expect_lock);
exp = nf_ct_find_expectation(net, zone, tuple);
if (exp) {
pr_debug("expectation arrives ct=%p exp=%p\n",
ct, exp);
/* Welcome, Mr. Bond. We've been expecting you... */
__set_bit(IPS_EXPECTED_BIT, &ct->status);
/* exp->master safe, refcnt bumped in nf_ct_find_expectation */
ct->master = exp->master;
if (exp->helper) {
help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
if (help)
rcu_assign_pointer(help->helper, exp->helper);
}
#ifdef CONFIG_NF_CONNTRACK_MARK
ct->mark = exp->master->mark;
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
ct->secmark = exp->master->secmark;
#endif
NF_CT_STAT_INC(net, expect_new);
}
spin_unlock(&nf_conntrack_expect_lock);
}
if (!exp)
__nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC);
/* Now it is inserted into the unconfirmed list, bump refcount */
nf_conntrack_get(&ct->ct_general);
nf_ct_add_to_unconfirmed_list(ct);
local_bh_enable();
if (exp) {
if (exp->expectfn)
exp->expectfn(ct, exp);
nf_ct_expect_put(exp);
}
return &ct->tuplehash[IP_CT_DIR_ORIGINAL];
}
/* On success, returns 0, sets skb->_nfct | ctinfo */
static int
resolve_normal_ct(struct nf_conn *tmpl,
struct sk_buff *skb,
unsigned int dataoff,
u_int8_t protonum,
const struct nf_conntrack_l4proto *l4proto,
const struct nf_hook_state *state)
{
const struct nf_conntrack_zone *zone;
struct nf_conntrack_tuple tuple;
struct nf_conntrack_tuple_hash *h;
enum ip_conntrack_info ctinfo;
struct nf_conntrack_zone tmp;
struct nf_conn *ct;
u32 hash;
if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
dataoff, state->pf, protonum, state->net,
&tuple, l4proto)) {
pr_debug("Can't get tuple\n");
return 0;
}
/* look for tuple match */
zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
hash = hash_conntrack_raw(&tuple, state->net);
h = __nf_conntrack_find_get(state->net, zone, &tuple, hash);
if (!h) {
h = init_conntrack(state->net, tmpl, &tuple, l4proto,
skb, dataoff, hash);
if (!h)
return 0;
if (IS_ERR(h))
return PTR_ERR(h);
}
ct = nf_ct_tuplehash_to_ctrack(h);
/* It exists; we have (non-exclusive) reference. */
if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) {
ctinfo = IP_CT_ESTABLISHED_REPLY;
} else {
/* Once we've had two way comms, always ESTABLISHED. */
if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
pr_debug("normal packet for %p\n", ct);
ctinfo = IP_CT_ESTABLISHED;
} else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) {
pr_debug("related packet for %p\n", ct);
ctinfo = IP_CT_RELATED;
} else {
pr_debug("new packet for %p\n", ct);
ctinfo = IP_CT_NEW;
}
}
nf_ct_set(skb, ct, ctinfo);
return 0;
}
/*
* icmp packets need special treatment to handle error messages that are
* related to a connection.
*
* Callers need to check if skb has a conntrack assigned when this
* helper returns; in such case skb belongs to an already known connection.
*/
static unsigned int __cold
nf_conntrack_handle_icmp(struct nf_conn *tmpl,
struct sk_buff *skb,
unsigned int dataoff,
u8 protonum,
const struct nf_hook_state *state)
{
int ret;
if (state->pf == NFPROTO_IPV4 && protonum == IPPROTO_ICMP)
ret = nf_conntrack_icmpv4_error(tmpl, skb, dataoff, state);
#if IS_ENABLED(CONFIG_IPV6)
else if (state->pf == NFPROTO_IPV6 && protonum == IPPROTO_ICMPV6)
ret = nf_conntrack_icmpv6_error(tmpl, skb, dataoff, state);
#endif
else
return NF_ACCEPT;
if (ret <= 0) {
NF_CT_STAT_INC_ATOMIC(state->net, error);
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
}
return ret;
}
static int generic_packet(struct nf_conn *ct, struct sk_buff *skb,
enum ip_conntrack_info ctinfo)
{
const unsigned int *timeout = nf_ct_timeout_lookup(ct);
if (!timeout)
timeout = &nf_generic_pernet(nf_ct_net(ct))->timeout;
nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
return NF_ACCEPT;
}
/* Returns verdict for packet, or -1 for invalid. */
static int nf_conntrack_handle_packet(struct nf_conn *ct,
struct sk_buff *skb,
unsigned int dataoff,
enum ip_conntrack_info ctinfo,
const struct nf_hook_state *state)
{
switch (nf_ct_protonum(ct)) {
case IPPROTO_TCP:
return nf_conntrack_tcp_packet(ct, skb, dataoff,
ctinfo, state);
case IPPROTO_UDP:
return nf_conntrack_udp_packet(ct, skb, dataoff,
ctinfo, state);
case IPPROTO_ICMP:
return nf_conntrack_icmp_packet(ct, skb, ctinfo, state);
case IPPROTO_ICMPV6:
return nf_conntrack_icmpv6_packet(ct, skb, ctinfo, state);
#ifdef CONFIG_NF_CT_PROTO_UDPLITE
case IPPROTO_UDPLITE:
return nf_conntrack_udplite_packet(ct, skb, dataoff,
ctinfo, state);
#endif
#ifdef CONFIG_NF_CT_PROTO_SCTP
case IPPROTO_SCTP:
return nf_conntrack_sctp_packet(ct, skb, dataoff,
ctinfo, state);
#endif
#ifdef CONFIG_NF_CT_PROTO_DCCP
case IPPROTO_DCCP:
return nf_conntrack_dccp_packet(ct, skb, dataoff,
ctinfo, state);
#endif
#ifdef CONFIG_NF_CT_PROTO_GRE
case IPPROTO_GRE:
return nf_conntrack_gre_packet(ct, skb, dataoff,
ctinfo, state);
#endif
}
return generic_packet(ct, skb, ctinfo);
}
unsigned int
nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
{
const struct nf_conntrack_l4proto *l4proto;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct, *tmpl;
u_int8_t protonum;
int dataoff, ret;
tmpl = nf_ct_get(skb, &ctinfo);
if (tmpl || ctinfo == IP_CT_UNTRACKED) {
/* Previously seen (loopback or untracked)? Ignore. */
if ((tmpl && !nf_ct_is_template(tmpl)) ||
ctinfo == IP_CT_UNTRACKED) {
NF_CT_STAT_INC_ATOMIC(state->net, ignore);
return NF_ACCEPT;
}
skb->_nfct = 0;
}
/* rcu_read_lock()ed by nf_hook_thresh */
dataoff = get_l4proto(skb, skb_network_offset(skb), state->pf, &protonum);
if (dataoff <= 0) {
pr_debug("not prepared to track yet or error occurred\n");
NF_CT_STAT_INC_ATOMIC(state->net, error);
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
ret = NF_ACCEPT;
goto out;
}
l4proto = __nf_ct_l4proto_find(protonum);
if (protonum == IPPROTO_ICMP || protonum == IPPROTO_ICMPV6) {
ret = nf_conntrack_handle_icmp(tmpl, skb, dataoff,
protonum, state);
if (ret <= 0) {
ret = -ret;
goto out;
}
/* ICMP[v6] protocol trackers may assign one conntrack. */
if (skb->_nfct)
goto out;
}
repeat:
ret = resolve_normal_ct(tmpl, skb, dataoff,
protonum, l4proto, state);
if (ret < 0) {
/* Too stressed to deal. */
NF_CT_STAT_INC_ATOMIC(state->net, drop);
ret = NF_DROP;
goto out;
}
ct = nf_ct_get(skb, &ctinfo);
if (!ct) {
/* Not valid part of a connection */
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
ret = NF_ACCEPT;
goto out;
}
ret = nf_conntrack_handle_packet(ct, skb, dataoff, ctinfo, state);
if (ret <= 0) {
/* Invalid: inverse of the return code tells
* the netfilter core what to do */
pr_debug("nf_conntrack_in: Can't track with proto module\n");
nf_conntrack_put(&ct->ct_general);
skb->_nfct = 0;
NF_CT_STAT_INC_ATOMIC(state->net, invalid);
if (ret == -NF_DROP)
NF_CT_STAT_INC_ATOMIC(state->net, drop);
/* Special case: TCP tracker reports an attempt to reopen a
* closed/aborted connection. We have to go back and create a
* fresh conntrack.
*/
if (ret == -NF_REPEAT)
goto repeat;
ret = -ret;
goto out;
}
if (ctinfo == IP_CT_ESTABLISHED_REPLY &&
!test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
nf_conntrack_event_cache(IPCT_REPLY, ct);
out:
if (tmpl)
nf_ct_put(tmpl);
return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_in);
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_l4proto_find(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 */
WARN_ON(nf_ct_is_confirmed(ct));
pr_debug("Altering reply tuple of %p to ", ct);
nf_ct_dump_tuple(newreply);
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
if (ct->master || (help && !hlist_empty(&help->expectations)))
return;
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)
{
WARN_ON(!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))
extra_jiffies += nfct_time_stamp;
ct->timeout = extra_jiffies;
acct:
if (do_acct)
nf_ct_acct_update(ct, ctinfo, skb->len);
}
EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
bool nf_ct_kill_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb)
{
nf_ct_acct_update(ct, ctinfo, skb->len);
return nf_ct_delete(ct, 0, 0);
}
EXPORT_SYMBOL_GPL(nf_ct_kill_acct);
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <linux/mutex.h>
/* Generic function for tcp/udp/sctp/dccp and alike. 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)
{
if (nla_put_be16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port) ||
nla_put_be16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr);
const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = {
[CTA_PROTO_SRC_PORT] = { .type = NLA_U16 },
[CTA_PROTO_DST_PORT] = { .type = NLA_U16 },
};
EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy);
int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
struct nf_conntrack_tuple *t)
{
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);
unsigned int nf_ct_port_nlattr_tuple_size(void)
{
static unsigned int size __read_mostly;
if (!size)
size = nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
return size;
}
EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size);
#endif
/* Used by ipt_REJECT and ip6t_REJECT. */
static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
/* This ICMP is in reverse direction to the packet which caused it */
ct = nf_ct_get(skb, &ctinfo);
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
ctinfo = IP_CT_RELATED_REPLY;
else
ctinfo = IP_CT_RELATED;
/* Attach to new skbuff, and increment count */
nf_ct_set(nskb, ct, ctinfo);
nf_conntrack_get(skb_nfct(nskb));
}
static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
{
const struct nf_conntrack_l4proto *l4proto;
struct nf_conntrack_tuple_hash *h;
struct nf_conntrack_tuple tuple;
enum ip_conntrack_info ctinfo;
struct nf_nat_hook *nat_hook;
unsigned int status;
struct nf_conn *ct;
int dataoff;
u16 l3num;
u8 l4num;
ct = nf_ct_get(skb, &ctinfo);
if (!ct || nf_ct_is_confirmed(ct))
return 0;
l3num = nf_ct_l3num(ct);
dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num);
if (dataoff <= 0)
return -1;
l4proto = nf_ct_l4proto_find_get(l4num);
if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
l4num, net, &tuple, l4proto))
return -1;
if (ct->status & IPS_SRC_NAT) {
memcpy(tuple.src.u3.all,
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.all,
sizeof(tuple.src.u3.all));
tuple.src.u.all =
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.all;
}
if (ct->status & IPS_DST_NAT) {
memcpy(tuple.dst.u3.all,
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.all,
sizeof(tuple.dst.u3.all));
tuple.dst.u.all =
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.all;
}
h = nf_conntrack_find_get(net, nf_ct_zone(ct), &tuple);
if (!h)
return 0;
/* Store status bits of the conntrack that is clashing to re-do NAT
* mangling according to what it has been done already to this packet.
*/
status = ct->status;
nf_ct_put(ct);
ct = nf_ct_tuplehash_to_ctrack(h);
nf_ct_set(skb, ct, ctinfo);
nat_hook = rcu_dereference(nf_nat_hook);
if (!nat_hook)
return 0;
if (status & IPS_SRC_NAT &&
nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_SRC,
IP_CT_DIR_ORIGINAL) == NF_DROP)
return -1;
if (status & IPS_DST_NAT &&
nat_hook->manip_pkt(skb, ct, NF_NAT_MANIP_DST,
IP_CT_DIR_ORIGINAL) == NF_DROP)
return -1;
return 0;
}
static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
const struct sk_buff *skb)
{
const struct nf_conntrack_tuple *src_tuple;
const struct nf_conntrack_tuple_hash *hash;
struct nf_conntrack_tuple srctuple;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
ct = nf_ct_get(skb, &ctinfo);
if (ct) {
src_tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
return true;
}
if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
NFPROTO_IPV4, dev_net(skb->dev),
&srctuple))
return false;
hash = nf_conntrack_find_get(dev_net(skb->dev),
&nf_ct_zone_dflt,
&srctuple);
if (!hash)
return false;
ct = nf_ct_tuplehash_to_ctrack(hash);
src_tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
memcpy(dst_tuple, src_tuple, sizeof(*dst_tuple));
nf_ct_put(ct);
return true;
}
/* Bring out ya dead! */
static struct nf_conn *
get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
void *data, unsigned int *bucket)
{
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
struct hlist_nulls_node *n;
spinlock_t *lockp;
for (; *bucket < nf_conntrack_htable_size; (*bucket)++) {
lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
local_bh_disable();
nf_conntrack_lock(lockp);
if (*bucket < nf_conntrack_htable_size) {
hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
continue;
ct = nf_ct_tuplehash_to_ctrack(h);
if (iter(ct, data))
goto found;
}
}
spin_unlock(lockp);
local_bh_enable();
cond_resched();
}
return NULL;
found:
atomic_inc(&ct->ct_general.use);
spin_unlock(lockp);
local_bh_enable();
return ct;
}
static void nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data),
void *data, u32 portid, int report)
{
unsigned int bucket = 0, sequence;
struct nf_conn *ct;
might_sleep();
for (;;) {
sequence = read_seqcount_begin(&nf_conntrack_generation);
while ((ct = get_next_corpse(iter, data, &bucket)) != NULL) {
/* Time to push up daises... */
nf_ct_delete(ct, portid, report);
nf_ct_put(ct);
cond_resched();
}
if (!read_seqcount_retry(&nf_conntrack_generation, sequence))
break;
bucket = 0;
}
}
struct iter_data {
int (*iter)(struct nf_conn *i, void *data);
void *data;
struct net *net;
};
static int iter_net_only(struct nf_conn *i, void *data)
{
struct iter_data *d = data;
if (!net_eq(d->net, nf_ct_net(i)))
return 0;
return d->iter(i, d->data);
}
static void
__nf_ct_unconfirmed_destroy(struct net *net)
{
int cpu;
for_each_possible_cpu(cpu) {
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
struct ct_pcpu *pcpu;
pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
spin_lock_bh(&pcpu->lock);
hlist_nulls_for_each_entry(h, n, &pcpu->unconfirmed, hnnode) {
struct nf_conn *ct;
ct = nf_ct_tuplehash_to_ctrack(h);
/* we cannot call iter() on unconfirmed list, the
* owning cpu can reallocate ct->ext at any time.
*/
set_bit(IPS_DYING_BIT, &ct->status);
}
spin_unlock_bh(&pcpu->lock);
cond_resched();
}
}
void nf_ct_unconfirmed_destroy(struct net *net)
{
might_sleep();
if (atomic_read(&net->ct.count) > 0) {
__nf_ct_unconfirmed_destroy(net);
nf_queue_nf_hook_drop(net);
synchronize_net();
}
}
EXPORT_SYMBOL_GPL(nf_ct_unconfirmed_destroy);
void nf_ct_iterate_cleanup_net(struct net *net,
int (*iter)(struct nf_conn *i, void *data),
void *data, u32 portid, int report)
{
struct iter_data d;
might_sleep();
if (atomic_read(&net->ct.count) == 0)
return;
d.iter = iter;
d.data = data;
d.net = net;
nf_ct_iterate_cleanup(iter_net_only, &d, portid, report);
}
EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup_net);
/**
* nf_ct_iterate_destroy - destroy unconfirmed conntracks and iterate table
* @iter: callback to invoke for each conntrack
* @data: data to pass to @iter
*
* Like nf_ct_iterate_cleanup, but first marks conntracks on the
* unconfirmed list as dying (so they will not be inserted into
* main table).
*
* Can only be called in module exit path.
*/
void
nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)
{
struct net *net;
down_read(&net_rwsem);
for_each_net(net) {
if (atomic_read(&net->ct.count) == 0)
continue;
__nf_ct_unconfirmed_destroy(net);
nf_queue_nf_hook_drop(net);
}
up_read(&net_rwsem);
/* Need to wait for netns cleanup worker to finish, if its
* running -- it might have deleted a net namespace from
* the global list, so our __nf_ct_unconfirmed_destroy() might
* not have affected all namespaces.
*/
net_ns_barrier();
/* a conntrack could have been unlinked from unconfirmed list
* before we grabbed pcpu lock in __nf_ct_unconfirmed_destroy().
* This makes sure its inserted into conntrack table.
*/
synchronize_net();
nf_ct_iterate_cleanup(iter, data, 0, 0);
}
EXPORT_SYMBOL_GPL(nf_ct_iterate_destroy);
static int kill_all(struct nf_conn *i, void *data)
{
return net_eq(nf_ct_net(i), data);
}
void nf_conntrack_cleanup_start(void)
{
conntrack_gc_work.exiting = true;
RCU_INIT_POINTER(ip_ct_attach, NULL);
}
void nf_conntrack_cleanup_end(void)
{
RCU_INIT_POINTER(nf_ct_hook, NULL);
cancel_delayed_work_sync(&conntrack_gc_work.dwork);
kvfree(nf_conntrack_hash);
nf_conntrack_proto_fini();
nf_conntrack_seqadj_fini();
nf_conntrack_labels_fini();
nf_conntrack_helper_fini();
nf_conntrack_timeout_fini();
nf_conntrack_ecache_fini();
nf_conntrack_tstamp_fini();
nf_conntrack_acct_fini();
nf_conntrack_expect_fini();
kmem_cache_destroy(nf_conntrack_cachep);
}
/*
* Mishearing the voices in his head, our hero wonders how he's
* supposed to kill the mall.
*/
void nf_conntrack_cleanup_net(struct net *net)
{
LIST_HEAD(single);
list_add(&net->exit_list, &single);
nf_conntrack_cleanup_net_list(&single);
}
void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list)
{
int busy;
struct net *net;
/*
* This makes sure all current packets have passed through
* netfilter framework. Roll on, two-stage module
* delete...
*/
synchronize_net();
i_see_dead_people:
busy = 0;
list_for_each_entry(net, net_exit_list, exit_list) {
nf_ct_iterate_cleanup(kill_all, net, 0, 0);
if (atomic_read(&net->ct.count) != 0)
busy = 1;
}
if (busy) {
schedule();
goto i_see_dead_people;
}
list_for_each_entry(net, net_exit_list, exit_list) {
nf_conntrack_proto_pernet_fini(net);
nf_conntrack_ecache_pernet_fini(net);
nf_conntrack_expect_pernet_fini(net);
free_percpu(net->ct.stat);
free_percpu(net->ct.pcpu_lists);
}
}
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
{
struct hlist_nulls_head *hash;
unsigned int nr_slots, i;
if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
return NULL;
BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
hash = kvmalloc_array(nr_slots, sizeof(struct hlist_nulls_head),
GFP_KERNEL | __GFP_ZERO);
if (hash && nulls)
for (i = 0; i < nr_slots; i++)
INIT_HLIST_NULLS_HEAD(&hash[i], i);
return hash;
}
EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable);
int nf_conntrack_hash_resize(unsigned int hashsize)
{
int i, bucket;
unsigned int old_size;
struct hlist_nulls_head *hash, *old_hash;
struct nf_conntrack_tuple_hash *h;
struct nf_conn *ct;
if (!hashsize)
return -EINVAL;
hash = nf_ct_alloc_hashtable(&hashsize, 1);
if (!hash)
return -ENOMEM;
old_size = nf_conntrack_htable_size;
if (old_size == hashsize) {
kvfree(hash);
return 0;
}
local_bh_disable();
nf_conntrack_all_lock();
write_seqcount_begin(&nf_conntrack_generation);
/* Lookups in the old hash might happen in parallel, which means we
* might get false negatives during connection lookup. New connections
* created because of a false negative won't make it into the hash
* though since that required taking the locks.
*/
for (i = 0; i < nf_conntrack_htable_size; i++) {
while (!hlist_nulls_empty(&nf_conntrack_hash[i])) {
h = hlist_nulls_entry(nf_conntrack_hash[i].first,
struct nf_conntrack_tuple_hash, hnnode);
ct = nf_ct_tuplehash_to_ctrack(h);
hlist_nulls_del_rcu(&h->hnnode);
bucket = __hash_conntrack(nf_ct_net(ct),
&h->tuple, hashsize);
hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
}
}
old_size = nf_conntrack_htable_size;
old_hash = nf_conntrack_hash;
nf_conntrack_hash = hash;
nf_conntrack_htable_size = hashsize;
write_seqcount_end(&nf_conntrack_generation);
nf_conntrack_all_unlock();
local_bh_enable();
synchronize_net();
kvfree(old_hash);
return 0;
}
int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp)
{
unsigned int hashsize;
int rc;
if (current->nsproxy->net_ns != &init_net)
return -EOPNOTSUPP;
/* On boot, we can set this without any fancy locking. */
if (!nf_conntrack_hash)
return param_set_uint(val, kp);
rc = kstrtouint(val, 0, &hashsize);
if (rc)
return rc;
return nf_conntrack_hash_resize(hashsize);
}
EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize);
static __always_inline unsigned int total_extension_size(void)
{
/* remember to add new extensions below */
BUILD_BUG_ON(NF_CT_EXT_NUM > 9);
return sizeof(struct nf_ct_ext) +
sizeof(struct nf_conn_help)
#if IS_ENABLED(CONFIG_NF_NAT)
+ sizeof(struct nf_conn_nat)
#endif
+ sizeof(struct nf_conn_seqadj)
+ sizeof(struct nf_conn_acct)
#ifdef CONFIG_NF_CONNTRACK_EVENTS
+ sizeof(struct nf_conntrack_ecache)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
+ sizeof(struct nf_conn_tstamp)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+ sizeof(struct nf_conn_timeout)
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
+ sizeof(struct nf_conn_labels)
#endif
#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+ sizeof(struct nf_conn_synproxy)
#endif
;
};
int nf_conntrack_init_start(void)
{
unsigned long nr_pages = totalram_pages();
int max_factor = 8;
int ret = -ENOMEM;
int i;
/* struct nf_ct_ext uses u8 to store offsets/size */
BUILD_BUG_ON(total_extension_size() > 255u);
seqcount_init(&nf_conntrack_generation);
for (i = 0; i < CONNTRACK_LOCKS; i++)
spin_lock_init(&nf_conntrack_locks[i]);
if (!nf_conntrack_htable_size) {
/* Idea from tcp.c: use 1/16384 of memory.
* On i386: 32MB machine has 512 buckets.
* >= 1GB machines have 16384 buckets.
* >= 4GB machines have 65536 buckets.
*/
nf_conntrack_htable_size
= (((nr_pages << PAGE_SHIFT) / 16384)
/ sizeof(struct hlist_head));
if (nr_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
nf_conntrack_htable_size = 65536;
else if (nr_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_hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size, 1);
if (!nf_conntrack_hash)
return -ENOMEM;
nf_conntrack_max = max_factor * nf_conntrack_htable_size;
nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
sizeof(struct nf_conn),
NFCT_INFOMASK + 1,
SLAB_TYPESAFE_BY_RCU | SLAB_HWCACHE_ALIGN, NULL);
if (!nf_conntrack_cachep)
goto err_cachep;
ret = nf_conntrack_expect_init();
if (ret < 0)
goto err_expect;
ret = nf_conntrack_acct_init();
if (ret < 0)
goto err_acct;
ret = nf_conntrack_tstamp_init();
if (ret < 0)
goto err_tstamp;
ret = nf_conntrack_ecache_init();
if (ret < 0)
goto err_ecache;
ret = nf_conntrack_timeout_init();
if (ret < 0)
goto err_timeout;
ret = nf_conntrack_helper_init();
if (ret < 0)
goto err_helper;
ret = nf_conntrack_labels_init();
if (ret < 0)
goto err_labels;
ret = nf_conntrack_seqadj_init();
if (ret < 0)
goto err_seqadj;
ret = nf_conntrack_proto_init();
if (ret < 0)
goto err_proto;
conntrack_gc_work_init(&conntrack_gc_work);
queue_delayed_work(system_power_efficient_wq, &conntrack_gc_work.dwork, HZ);
return 0;
err_proto:
nf_conntrack_seqadj_fini();
err_seqadj:
nf_conntrack_labels_fini();
err_labels:
nf_conntrack_helper_fini();
err_helper:
nf_conntrack_timeout_fini();
err_timeout:
nf_conntrack_ecache_fini();
err_ecache:
nf_conntrack_tstamp_fini();
err_tstamp:
nf_conntrack_acct_fini();
err_acct:
nf_conntrack_expect_fini();
err_expect:
kmem_cache_destroy(nf_conntrack_cachep);
err_cachep:
kvfree(nf_conntrack_hash);
return ret;
}
static struct nf_ct_hook nf_conntrack_hook = {
.update = nf_conntrack_update,
.destroy = destroy_conntrack,
.get_tuple_skb = nf_conntrack_get_tuple_skb,
};
void nf_conntrack_init_end(void)
{
/* For use by REJECT target */
RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach);
RCU_INIT_POINTER(nf_ct_hook, &nf_conntrack_hook);
}
/*
* We need to use special "null" values, not used in hash table
*/
#define UNCONFIRMED_NULLS_VAL ((1<<30)+0)
#define DYING_NULLS_VAL ((1<<30)+1)
#define TEMPLATE_NULLS_VAL ((1<<30)+2)
int nf_conntrack_init_net(struct net *net)
{
int ret = -ENOMEM;
int cpu;
BUILD_BUG_ON(IP_CT_UNTRACKED == IP_CT_NUMBER);
atomic_set(&net->ct.count, 0);
net->ct.pcpu_lists = alloc_percpu(struct ct_pcpu);
if (!net->ct.pcpu_lists)
goto err_stat;
for_each_possible_cpu(cpu) {
struct ct_pcpu *pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
spin_lock_init(&pcpu->lock);
INIT_HLIST_NULLS_HEAD(&pcpu->unconfirmed, UNCONFIRMED_NULLS_VAL);
INIT_HLIST_NULLS_HEAD(&pcpu->dying, DYING_NULLS_VAL);
}
net->ct.stat = alloc_percpu(struct ip_conntrack_stat);
if (!net->ct.stat)
goto err_pcpu_lists;
ret = nf_conntrack_expect_pernet_init(net);
if (ret < 0)
goto err_expect;
nf_conntrack_acct_pernet_init(net);
nf_conntrack_tstamp_pernet_init(net);
nf_conntrack_ecache_pernet_init(net);
nf_conntrack_helper_pernet_init(net);
ret = nf_conntrack_proto_pernet_init(net);
if (ret < 0)
goto err_proto;
return 0;
err_proto:
nf_conntrack_ecache_pernet_fini(net);
nf_conntrack_expect_pernet_fini(net);
err_expect:
free_percpu(net->ct.stat);
err_pcpu_lists:
free_percpu(net->ct.pcpu_lists);
err_stat:
return ret;
}