diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /net/netfilter/nf_conntrack_core.c |
Initial import
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 1821 |
1 files changed, 1821 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c new file mode 100644 index 000000000..13fad8668 --- /dev/null +++ b/net/netfilter/nf_conntrack_core.c @@ -0,0 +1,1821 @@ +/* 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, u16 zone) +{ + unsigned int n; + + /* The direction must be ignored, so we hash everything up to the + * destination ports (which is a multiple of 4) and treat the last + * three bytes manually. + */ + n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32); + return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^ + (((__force __u16)tuple->dst.u.all << 16) | + tuple->dst.protonum)); +} + +static u32 __hash_bucket(u32 hash, unsigned int size) +{ + return 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, + u16 zone, unsigned int size) +{ + return __hash_bucket(hash_conntrack_raw(tuple, zone), size); +} + +static inline u_int32_t hash_conntrack(const struct net *net, u16 zone, + const struct nf_conntrack_tuple *tuple) +{ + return __hash_conntrack(tuple, zone, net->ct.htable_size); +} + +bool +nf_ct_get_tuple(const struct sk_buff *skb, + unsigned int nhoff, + unsigned int dataoff, + u_int16_t l3num, + u_int8_t protonum, + struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_l3proto *l3proto, + const struct nf_conntrack_l4proto *l4proto) +{ + memset(tuple, 0, sizeof(*tuple)); + + tuple->src.l3num = l3num; + if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) + return false; + + tuple->dst.protonum = protonum; + tuple->dst.dir = IP_CT_DIR_ORIGINAL; + + return l4proto->pkt_to_tuple(skb, dataoff, tuple); +} +EXPORT_SYMBOL_GPL(nf_ct_get_tuple); + +bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff, + u_int16_t l3num, struct nf_conntrack_tuple *tuple) +{ + struct nf_conntrack_l3proto *l3proto; + struct nf_conntrack_l4proto *l4proto; + unsigned int protoff; + u_int8_t protonum; + int ret; + + rcu_read_lock(); + + l3proto = __nf_ct_l3proto_find(l3num); + ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum); + if (ret != NF_ACCEPT) { + rcu_read_unlock(); + return false; + } + + l4proto = __nf_ct_l4proto_find(l3num, protonum); + + ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple, + l3proto, l4proto); + + rcu_read_unlock(); + return ret; +} +EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr); + +bool +nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, + const struct nf_conntrack_tuple *orig, + const struct nf_conntrack_l3proto *l3proto, + const struct nf_conntrack_l4proto *l4proto) +{ + memset(inverse, 0, sizeof(*inverse)); + + inverse->src.l3num = orig->src.l3num; + if (l3proto->invert_tuple(inverse, orig) == 0) + return false; + + inverse->dst.dir = !orig->dst.dir; + + inverse->dst.protonum = orig->dst.protonum; + return l4proto->invert_tuple(inverse, orig); +} +EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); + +static void +clean_from_lists(struct nf_conn *ct) +{ + pr_debug("clean_from_lists(%p)\n", ct); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); + hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode); + + /* Destroy all pending expectations */ + nf_ct_remove_expectations(ct); +} + +/* 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); +} + +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)); + + 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; + u16 zone = nf_ct_zone(ct); + unsigned int sequence; + + nf_ct_helper_destroy(ct); + + local_bh_disable(); + do { + sequence = read_seqcount_begin(&net->ct.generation); + hash = hash_conntrack(net, zone, + &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); + reply_hash = hash_conntrack(net, zone, + &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, + u16 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(ct) == zone && + 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, u16 zone, + const struct nf_conntrack_tuple *tuple, u32 hash) +{ + struct nf_conntrack_tuple_hash *h; + struct hlist_nulls_node *n; + unsigned int bucket = hash_bucket(hash, net); + + /* Disable BHs the entire time since we normally need to disable them + * at least once for the stats anyway. + */ + local_bh_disable(); +begin: + hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) { + if (nf_ct_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, u16 zone, + const struct nf_conntrack_tuple *tuple, u32 hash) +{ + struct nf_conntrack_tuple_hash *h; + struct nf_conn *ct; + + rcu_read_lock(); +begin: + h = ____nf_conntrack_find(net, zone, tuple, hash); + if (h) { + ct = nf_ct_tuplehash_to_ctrack(h); + if (unlikely(nf_ct_is_dying(ct) || + !atomic_inc_not_zero(&ct->ct_general.use))) + h = NULL; + else { + if (unlikely(!nf_ct_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, u16 zone, + const struct nf_conntrack_tuple *tuple) +{ + return __nf_conntrack_find_get(net, zone, tuple, + hash_conntrack_raw(tuple, zone)); +} +EXPORT_SYMBOL_GPL(nf_conntrack_find_get); + +static void __nf_conntrack_hash_insert(struct nf_conn *ct, + unsigned int hash, + unsigned int 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) +{ + struct net *net = nf_ct_net(ct); + unsigned int hash, reply_hash; + struct nf_conntrack_tuple_hash *h; + struct hlist_nulls_node *n; + u16 zone; + unsigned int sequence; + + zone = nf_ct_zone(ct); + + local_bh_disable(); + do { + sequence = read_seqcount_begin(&net->ct.generation); + hash = hash_conntrack(net, zone, + &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); + reply_hash = hash_conntrack(net, zone, + &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) && + zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(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) && + zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(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); + +/* deletion from this larval template list happens via nf_ct_put() */ +void nf_conntrack_tmpl_insert(struct net *net, struct nf_conn *tmpl) +{ + struct ct_pcpu *pcpu; + + __set_bit(IPS_TEMPLATE_BIT, &tmpl->status); + __set_bit(IPS_CONFIRMED_BIT, &tmpl->status); + nf_conntrack_get(&tmpl->ct_general); + + /* add this conntrack to the (per cpu) tmpl list */ + local_bh_disable(); + tmpl->cpu = smp_processor_id(); + pcpu = per_cpu_ptr(nf_ct_net(tmpl)->ct.pcpu_lists, tmpl->cpu); + + spin_lock(&pcpu->lock); + /* Overload tuple linked list to put us in template list. */ + hlist_nulls_add_head_rcu(&tmpl->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, + &pcpu->tmpl); + spin_unlock_bh(&pcpu->lock); +} +EXPORT_SYMBOL_GPL(nf_conntrack_tmpl_insert); + +/* Confirm a connection given skb; places it in hash table */ +int +__nf_conntrack_confirm(struct sk_buff *skb) +{ + 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; + u16 zone; + 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, zone, + &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) && + zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(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) && + zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(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); + struct nf_conntrack_tuple_hash *h; + struct hlist_nulls_node *n; + struct nf_conn *ct; + u16 zone = nf_ct_zone(ignored_conntrack); + unsigned int hash = hash_conntrack(net, zone, tuple); + + /* Disable BHs the entire time since we need to disable them at + * least once for the stats anyway. + */ + rcu_read_lock_bh(); + hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { + ct = nf_ct_tuplehash_to_ctrack(h); + if (ct != ignored_conntrack && + nf_ct_tuple_equal(tuple, &h->tuple) && + nf_ct_zone(ct) == zone) { + NF_CT_STAT_INC(net, found); + rcu_read_unlock_bh(); + return 1; + } + NF_CT_STAT_INC(net, searched); + } + rcu_read_unlock_bh(); + + return 0; +} +EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); + +#define NF_CT_EVICTION_RANGE 8 + +/* There's a small race here where we may free a just-assured + connection. Too bad: we're in trouble anyway. */ +static noinline int early_drop(struct net *net, unsigned int _hash) +{ + /* Use oldest entry, which is roughly LRU */ + struct nf_conntrack_tuple_hash *h; + struct nf_conn *ct = NULL, *tmp; + struct hlist_nulls_node *n; + unsigned int i = 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, u16 zone, + const struct nf_conntrack_tuple *orig, + const struct nf_conntrack_tuple *repl, + gfp_t gfp, u32 hash) +{ + struct nf_conn *ct; + + if (unlikely(!nf_conntrack_hash_rnd)) { + init_nf_conntrack_hash_rnd(); + /* recompute the hash as nf_conntrack_hash_rnd is initialized */ + hash = hash_conntrack_raw(orig, zone); + } + + /* We don't want any race condition at early drop stage */ + atomic_inc(&net->ct.count); + + if (nf_conntrack_max && + unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) { + if (!early_drop(net, hash)) { + 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) { + atomic_dec(&net->ct.count); + return ERR_PTR(-ENOMEM); + } + 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])); +#ifdef CONFIG_NF_CONNTRACK_ZONES + if (zone) { + struct nf_conntrack_zone *nf_ct_zone; + + nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC); + if (!nf_ct_zone) + goto out_free; + nf_ct_zone->id = zone; + } +#endif + /* 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; + +#ifdef CONFIG_NF_CONNTRACK_ZONES +out_free: + atomic_dec(&net->ct.count); + kmem_cache_free(net->ct.nf_conntrack_cachep, ct); + return ERR_PTR(-ENOMEM); +#endif +} + +struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone, + const struct nf_conntrack_tuple *orig, + const struct nf_conntrack_tuple *repl, + gfp_t gfp) +{ + return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0); +} +EXPORT_SYMBOL_GPL(nf_conntrack_alloc); + +void nf_conntrack_free(struct nf_conn *ct) +{ + struct net *net = nf_ct_net(ct); + + /* 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; + u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; + struct nf_conn_timeout *timeout_ext; + unsigned int *timeouts; + + if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { + pr_debug("Can't invert tuple.\n"); + return NULL; + } + + ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC, + hash); + if (IS_ERR(ct)) + return (struct nf_conntrack_tuple_hash *)ct; + + if (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_EXT_DATA(timeout_ext); + 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, 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) +{ + struct nf_conntrack_tuple tuple; + struct nf_conntrack_tuple_hash *h; + struct nf_conn *ct; + u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; + u32 hash; + + if (!nf_ct_get_tuple(skb, skb_network_offset(skb), + dataoff, l3num, protonum, &tuple, l3proto, + l4proto)) { + pr_debug("resolve_normal_ct: Can't get tuple\n"); + return NULL; + } + + /* look for tuple match */ + hash = hash_conntrack_raw(&tuple, zone); + h = __nf_conntrack_find_get(net, zone, &tuple, hash); + if (!h) { + h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto, + skb, dataoff, hash); + if (!h) + return NULL; + if (IS_ERR(h)) + return (void *)h; + } + ct = nf_ct_tuplehash_to_ctrack(h); + + /* It exists; we have (non-exclusive) reference. */ + if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { + *ctinfo = IP_CT_ESTABLISHED_REPLY; + /* Please set reply bit if this packet OK */ + *set_reply = 1; + } else { + /* Once we've had two way comms, always ESTABLISHED. */ + if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { + pr_debug("nf_conntrack_in: normal packet for %p\n", ct); + *ctinfo = IP_CT_ESTABLISHED; + } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { + pr_debug("nf_conntrack_in: related packet for %p\n", + ct); + *ctinfo = IP_CT_RELATED; + } else { + pr_debug("nf_conntrack_in: new packet for %p\n", ct); + *ctinfo = IP_CT_NEW; + } + *set_reply = 0; + } + skb->nfct = &ct->ct_general; + skb->nfctinfo = *ctinfo; + return ct; +} + +unsigned int +nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum, + struct sk_buff *skb) +{ + struct nf_conn *ct, *tmpl = NULL; + enum ip_conntrack_info ctinfo; + struct nf_conntrack_l3proto *l3proto; + struct nf_conntrack_l4proto *l4proto; + unsigned int *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) { + printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); + 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, nf_ct_zone(ct), + hashsize); + hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]); + } + } + old_size = init_net.ct.htable_size; + old_hash = init_net.ct.hash; + + init_net.ct.htable_size = nf_conntrack_htable_size = hashsize; + init_net.ct.hash = hash; + + 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) +{ + 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); + INIT_HLIST_NULLS_HEAD(&pcpu->tmpl, TEMPLATE_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_%p", net); + 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; +} |