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- /* 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.
- */
- #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_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>
- #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);
- __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);
- 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) {
- spin_lock(&nf_conntrack_locks[h1]);
- if (h1 != h2)
- spin_lock_nested(&nf_conntrack_locks[h2],
- SINGLE_DEPTH_NESTING);
- } else {
- spin_lock(&nf_conntrack_locks[h2]);
- spin_lock_nested(&nf_conntrack_locks[h1],
- SINGLE_DEPTH_NESTING);
- }
- if (read_seqcount_retry(&net->ct.generation, sequence)) {
- nf_conntrack_double_unlock(h1, h2);
- return true;
- }
- return false;
- }
- static void nf_conntrack_all_lock(void)
- {
- int i;
- for (i = 0; i < CONNTRACK_LOCKS; i++)
- spin_lock_nested(&nf_conntrack_locks[i], i);
- }
- static void nf_conntrack_all_unlock(void)
- {
- int i;
- for (i = 0; i < CONNTRACK_LOCKS; i++)
- spin_unlock(&nf_conntrack_locks[i]);
- }
- 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;
- EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
- static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple)
- {
- 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, nf_conntrack_hash_rnd ^
- (((__force __u16)tuple->dst.u.all << 16) |
- tuple->dst.protonum));
- }
- static u32 __hash_bucket(u32 hash, unsigned int size)
- {
- return reciprocal_scale(hash, size);
- }
- 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,
- unsigned int size)
- {
- return __hash_bucket(hash_conntrack_raw(tuple), size);
- }
- static inline u_int32_t hash_conntrack(const struct net *net,
- const struct nf_conntrack_tuple *tuple)
- {
- return __hash_conntrack(tuple, 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 net *net,
- 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, net, 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 net *net, 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, net, 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);
- }
- /* 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);
- }
- /* 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;
- tmpl = kzalloc(sizeof(*tmpl), flags);
- if (tmpl == NULL)
- return NULL;
- tmpl->status = IPS_TEMPLATE;
- write_pnet(&tmpl->ct_net, net);
- if (nf_ct_zone_add(tmpl, flags, zone) < 0)
- goto out_free;
- atomic_set(&tmpl->ct_general.use, 0);
- return tmpl;
- out_free:
- kfree(tmpl);
- return NULL;
- }
- 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);
- 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;
- 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));
- if (unlikely(nf_ct_is_template(ct))) {
- nf_ct_tmpl_free(ct);
- return;
- }
- 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();
- 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);
- NF_CT_STAT_INC(net, delete);
- 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(&net->ct.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);
- NF_CT_STAT_INC(net, delete_list);
- local_bh_enable();
- }
- bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
- {
- struct nf_conn_tstamp *tstamp;
- tstamp = nf_conn_tstamp_find(ct);
- if (tstamp && tstamp->stop == 0)
- tstamp->stop = ktime_get_real_ns();
- if (nf_ct_is_dying(ct))
- goto delete;
- if (nf_conntrack_event_report(IPCT_DESTROY, ct,
- portid, report) < 0) {
- /* destroy event was not delivered */
- 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));
- set_bit(IPS_DYING_BIT, &ct->status);
- delete:
- nf_ct_delete_from_lists(ct);
- nf_ct_put(ct);
- return true;
- }
- EXPORT_SYMBOL_GPL(nf_ct_delete);
- static void death_by_timeout(unsigned long ul_conntrack)
- {
- nf_ct_delete((struct nf_conn *)ul_conntrack, 0, 0);
- }
- 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)
- {
- 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);
- }
- /*
- * 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_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_key_equal(h, tuple, 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;
- }
- /* 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))) {
- 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));
- }
- EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
- static void __nf_conntrack_hash_insert(struct nf_conn *ct,
- unsigned int hash,
- unsigned int reply_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[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(&net->ct.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, &net->ct.hash[hash], hnnode)
- if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
- &h->tuple) &&
- nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
- NF_CT_DIRECTION(h)))
- goto out;
- hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
- if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
- &h->tuple) &&
- nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
- NF_CT_DIRECTION(h)))
- goto out;
- add_timer(&ct->timeout);
- 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);
- /* 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;
- 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(&net->ct.generation);
- /* reuse the hash saved before */
- hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
- hash = hash_bucket(hash, net);
- 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.
- */
- /* 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);
- /* 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)))
- goto out;
- /* 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) &&
- nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
- NF_CT_DIRECTION(h)))
- goto out;
- hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
- if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
- &h->tuple) &&
- nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
- NF_CT_DIRECTION(h)))
- goto out;
- /* 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(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);
- NF_CT_STAT_INC(net, insert);
- 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);
- nf_conntrack_double_unlock(hash, reply_hash);
- NF_CT_STAT_INC(net, insert_failed);
- local_bh_enable();
- 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);
- const struct nf_conntrack_zone *zone;
- struct nf_conntrack_tuple_hash *h;
- struct hlist_nulls_node *n;
- struct nf_conn *ct;
- unsigned int hash;
- zone = nf_ct_zone(ignored_conntrack);
- hash = hash_conntrack(net, tuple);
- /* Disable BHs the entire time since we need to disable them at
- * least once for the stats anyway.
- */
- rcu_read_lock_bh();
- begin:
- 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_equal(ct, zone, NF_CT_DIRECTION(h))) {
- NF_CT_STAT_INC(net, found);
- rcu_read_unlock_bh();
- return 1;
- }
- NF_CT_STAT_INC(net, searched);
- }
- if (get_nulls_value(n) != hash) {
- NF_CT_STAT_INC(net, search_restart);
- goto begin;
- }
- 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 = 0, cnt = 0;
- int dropped = 0;
- unsigned int hash, sequence;
- spinlock_t *lockp;
- local_bh_disable();
- restart:
- sequence = read_seqcount_begin(&net->ct.generation);
- hash = hash_bucket(_hash, net);
- for (; i < net->ct.htable_size; i++) {
- lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
- spin_lock(lockp);
- if (read_seqcount_retry(&net->ct.generation, sequence)) {
- spin_unlock(lockp);
- goto restart;
- }
- 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) &&
- !nf_ct_is_dying(tmp) &&
- atomic_inc_not_zero(&tmp->ct_general.use)) {
- ct = tmp;
- break;
- }
- cnt++;
- }
- hash = (hash + 1) % net->ct.htable_size;
- spin_unlock(lockp);
- if (ct || cnt >= NF_CT_EVICTION_RANGE)
- break;
- }
- local_bh_enable();
- if (!ct)
- return dropped;
- if (del_timer(&ct->timeout)) {
- if (nf_ct_delete(ct, 0, 0)) {
- 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,
- 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;
- 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);
- }
- /* 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)) {
- 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_DESTROY_BY_RCU.
- */
- ct = kmem_cache_alloc(net->ct.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;
- /* Don't set timer yet: wait for confirmation */
- setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
- 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]));
- if (zone && nf_ct_zone_add(ct, GFP_ATOMIC, zone) < 0)
- goto out_free;
- /* 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_free:
- kmem_cache_free(net->ct.nf_conntrack_cachep, 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_DESTROY_BY_RCU
- */
- NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 0);
- nf_ct_ext_destroy(ct);
- nf_ct_ext_free(ct);
- kmem_cache_free(net->ct.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 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 = NULL;
- const struct nf_conntrack_zone *zone;
- struct nf_conn_timeout *timeout_ext;
- struct nf_conntrack_zone tmp;
- unsigned int *timeouts;
- if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, 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 (tmpl && nfct_synproxy(tmpl)) {
- nfct_seqadj_ext_add(ct);
- nfct_synproxy_ext_add(ct);
- }
- timeout_ext = tmpl ? nf_ct_timeout_find(tmpl) : NULL;
- if (timeout_ext) {
- timeouts = nf_ct_timeout_data(timeout_ext);
- if (unlikely(!timeouts))
- timeouts = l4proto->get_timeouts(net);
- } else {
- timeouts = l4proto->get_timeouts(net);
- }
- if (!l4proto->new(ct, skb, dataoff, timeouts)) {
- nf_conntrack_free(ct);
- pr_debug("init conntrack: can't track with proto module\n");
- return 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("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);
- /* exp->master safe, refcnt bumped in nf_ct_find_expectation */
- ct->master = exp->master;
- if (exp->helper) {
- help = nf_ct_helper_ext_add(ct, exp->helper,
- 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);
- NF_CT_STAT_INC(net, new);
- }
- /* 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 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)
- {
- const struct nf_conntrack_zone *zone;
- struct nf_conntrack_tuple tuple;
- struct nf_conntrack_tuple_hash *h;
- struct nf_conntrack_zone tmp;
- struct nf_conn *ct;
- u32 hash;
- if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
- dataoff, l3num, protonum, net, &tuple, l3proto,
- l4proto)) {
- pr_debug("resolve_normal_ct: Can't get tuple\n");
- return NULL;
- }
- /* look for tuple match */
- zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
- hash = hash_conntrack_raw(&tuple);
- 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 *timeouts;
- 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);
- /* Decide what timeout policy we want to apply to this flow. */
- timeouts = nf_ct_timeout_lookup(net, ct, l4proto);
- ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum, timeouts);
- 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_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(skb->len, &counter[CTINFO2DIR(ctinfo)].bytes);
- }
- }
- }
- 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_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(skb->len - skb_network_offset(skb),
- &counter[CTINFO2DIR(ctinfo)].bytes);
- }
- }
- if (del_timer(&ct->timeout)) {
- 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 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);
- 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, 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 */
- 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;
- int cpu;
- spinlock_t *lockp;
- for (; *bucket < net->ct.htable_size; (*bucket)++) {
- lockp = &nf_conntrack_locks[*bucket % CONNTRACK_LOCKS];
- local_bh_disable();
- spin_lock(lockp);
- if (*bucket < net->ct.htable_size) {
- hlist_nulls_for_each_entry(h, n, &net->ct.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();
- }
- for_each_possible_cpu(cpu) {
- struct ct_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) {
- ct = nf_ct_tuplehash_to_ctrack(h);
- if (iter(ct, data))
- set_bit(IPS_DYING_BIT, &ct->status);
- }
- spin_unlock_bh(&pcpu->lock);
- }
- return NULL;
- found:
- atomic_inc(&ct->ct_general.use);
- spin_unlock(lockp);
- local_bh_enable();
- return ct;
- }
- void nf_ct_iterate_cleanup(struct net *net,
- int (*iter)(struct nf_conn *i, void *data),
- void *data, u32 portid, int report)
- {
- struct nf_conn *ct;
- unsigned int bucket = 0;
- while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) {
- /* Time to push up daises... */
- if (del_timer(&ct->timeout))
- nf_ct_delete(ct, portid, report);
- /* ... else the timer will get him soon. */
- nf_ct_put(ct);
- }
- }
- EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup);
- static int kill_all(struct nf_conn *i, void *data)
- {
- return 1;
- }
- 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);
- 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;
- }
- void nf_conntrack_cleanup_start(void)
- {
- RCU_INIT_POINTER(ip_ct_attach, NULL);
- }
- void nf_conntrack_cleanup_end(void)
- {
- RCU_INIT_POINTER(nf_ct_destroy, NULL);
- while (untrack_refs() > 0)
- schedule();
- #ifdef CONFIG_NF_CONNTRACK_ZONES
- nf_ct_extend_unregister(&nf_ct_zone_extend);
- #endif
- 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();
- }
- /*
- * 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(net, kill_all, NULL, 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_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
- nf_conntrack_proto_pernet_fini(net);
- nf_conntrack_helper_pernet_fini(net);
- nf_conntrack_ecache_pernet_fini(net);
- nf_conntrack_tstamp_pernet_fini(net);
- nf_conntrack_acct_pernet_fini(net);
- nf_conntrack_expect_pernet_fini(net);
- kmem_cache_destroy(net->ct.nf_conntrack_cachep);
- kfree(net->ct.slabname);
- 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;
- 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)
- hash = vzalloc(sz);
- 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_set_hashsize(const char *val, struct kernel_param *kp)
- {
- int i, bucket, rc;
- 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);
- rc = kstrtouint(val, 0, &hashsize);
- if (rc)
- return rc;
- if (!hashsize)
- return -EINVAL;
- hash = nf_ct_alloc_hashtable(&hashsize, 1);
- if (!hash)
- return -ENOMEM;
- local_bh_disable();
- nf_conntrack_all_lock();
- write_seqcount_begin(&init_net.ct.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 < 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, 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;
- write_seqcount_end(&init_net.ct.generation);
- nf_conntrack_all_unlock();
- local_bh_enable();
- 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);
- int nf_conntrack_init_start(void)
- {
- int max_factor = 8;
- int i, ret, cpu;
- 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
- = (((totalram_pages << PAGE_SHIFT) / 16384)
- / sizeof(struct hlist_head));
- if (totalram_pages > (4 * (1024 * 1024 * 1024 / PAGE_SIZE)))
- nf_conntrack_htable_size = 65536;
- else 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_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;
- #ifdef CONFIG_NF_CONNTRACK_ZONES
- ret = nf_ct_extend_register(&nf_ct_zone_extend);
- if (ret < 0)
- goto err_extend;
- #endif
- ret = nf_conntrack_proto_init();
- if (ret < 0)
- goto err_proto;
- /* 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;
- err_proto:
- #ifdef CONFIG_NF_CONNTRACK_ZONES
- nf_ct_extend_unregister(&nf_ct_zone_extend);
- err_extend:
- #endif
- 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:
- return ret;
- }
- 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_destroy, destroy_conntrack);
- }
- /*
- * 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)
- {
- static atomic64_t unique_id;
- int ret = -ENOMEM;
- int cpu;
- atomic_set(&net->ct.count, 0);
- seqcount_init(&net->ct.generation);
- 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;
- net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%llu",
- (u64)atomic64_inc_return(&unique_id));
- if (!net->ct.slabname)
- 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");
- 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) {
- printk(KERN_ERR "Unable to create nf_conntrack_hash\n");
- goto err_hash;
- }
- ret = nf_conntrack_expect_pernet_init(net);
- if (ret < 0)
- goto err_expect;
- ret = nf_conntrack_acct_pernet_init(net);
- if (ret < 0)
- goto err_acct;
- ret = nf_conntrack_tstamp_pernet_init(net);
- if (ret < 0)
- goto err_tstamp;
- ret = nf_conntrack_ecache_pernet_init(net);
- if (ret < 0)
- goto err_ecache;
- ret = nf_conntrack_helper_pernet_init(net);
- if (ret < 0)
- goto err_helper;
- ret = nf_conntrack_proto_pernet_init(net);
- if (ret < 0)
- goto err_proto;
- return 0;
- err_proto:
- nf_conntrack_helper_pernet_fini(net);
- err_helper:
- nf_conntrack_ecache_pernet_fini(net);
- err_ecache:
- nf_conntrack_tstamp_pernet_fini(net);
- err_tstamp:
- nf_conntrack_acct_pernet_fini(net);
- err_acct:
- nf_conntrack_expect_pernet_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_pcpu_lists:
- free_percpu(net->ct.pcpu_lists);
- err_stat:
- return ret;
- }
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