/* 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 * (C) 2003,2004 USAGI/WIDE Project * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NF_CONNTRACK_VERSION "0.5.0" int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct, enum nf_nat_manip_type manip, const struct nlattr *attr) __read_mostly; EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook); DEFINE_SPINLOCK(nf_conntrack_lock); EXPORT_SYMBOL_GPL(nf_conntrack_lock); unsigned int nf_conntrack_htable_size __read_mostly; EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); unsigned int nf_conntrack_max __read_mostly; EXPORT_SYMBOL_GPL(nf_conntrack_max); DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked); EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked); unsigned int nf_conntrack_hash_rnd __read_mostly; static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone) { unsigned int n; /* The direction must be ignored, so we hash everything up to the * destination ports (which is a multiple of 4) and treat the last * three bytes manually. */ n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32); return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^ (((__force __u16)tuple->dst.u.all << 16) | tuple->dst.protonum)); } static u32 __hash_bucket(u32 hash, unsigned int size) { return ((u64)hash * size) >> 32; } static u32 hash_bucket(u32 hash, const struct net *net) { return __hash_bucket(hash, net->ct.htable_size); } static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple, u16 zone, unsigned int size) { return __hash_bucket(hash_conntrack_raw(tuple, zone), size); } static inline u_int32_t hash_conntrack(const struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple) { return __hash_conntrack(tuple, zone, net->ct.htable_size); } bool nf_ct_get_tuple(const struct sk_buff *skb, unsigned int nhoff, unsigned int dataoff, u_int16_t l3num, u_int8_t protonum, struct nf_conntrack_tuple *tuple, const struct nf_conntrack_l3proto *l3proto, const struct nf_conntrack_l4proto *l4proto) { memset(tuple, 0, sizeof(*tuple)); tuple->src.l3num = l3num; if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0) return false; tuple->dst.protonum = protonum; tuple->dst.dir = IP_CT_DIR_ORIGINAL; return l4proto->pkt_to_tuple(skb, dataoff, tuple); } EXPORT_SYMBOL_GPL(nf_ct_get_tuple); bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff, u_int16_t l3num, struct nf_conntrack_tuple *tuple) { struct nf_conntrack_l3proto *l3proto; struct nf_conntrack_l4proto *l4proto; unsigned int protoff; u_int8_t protonum; int ret; rcu_read_lock(); l3proto = __nf_ct_l3proto_find(l3num); ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum); if (ret != NF_ACCEPT) { rcu_read_unlock(); return false; } l4proto = __nf_ct_l4proto_find(l3num, protonum); ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple, l3proto, l4proto); rcu_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr); bool nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse, const struct nf_conntrack_tuple *orig, const struct nf_conntrack_l3proto *l3proto, const struct nf_conntrack_l4proto *l4proto) { memset(inverse, 0, sizeof(*inverse)); inverse->src.l3num = orig->src.l3num; if (l3proto->invert_tuple(inverse, orig) == 0) return false; inverse->dst.dir = !orig->dst.dir; inverse->dst.protonum = orig->dst.protonum; return l4proto->invert_tuple(inverse, orig); } EXPORT_SYMBOL_GPL(nf_ct_invert_tuple); static void clean_from_lists(struct nf_conn *ct) { pr_debug("clean_from_lists(%p)\n", ct); hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode); /* Destroy all pending expectations */ nf_ct_remove_expectations(ct); } static void destroy_conntrack(struct nf_conntrack *nfct) { struct nf_conn *ct = (struct nf_conn *)nfct; struct net *net = nf_ct_net(ct); struct nf_conntrack_l4proto *l4proto; pr_debug("destroy_conntrack(%p)\n", ct); NF_CT_ASSERT(atomic_read(&nfct->use) == 0); NF_CT_ASSERT(!timer_pending(&ct->timeout)); /* To make sure we don't get any weird locking issues here: * destroy_conntrack() MUST NOT be called with a write lock * to nf_conntrack_lock!!! -HW */ rcu_read_lock(); l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct)); if (l4proto && l4proto->destroy) l4proto->destroy(ct); rcu_read_unlock(); spin_lock_bh(&nf_conntrack_lock); /* Expectations will have been removed in clean_from_lists, * except TFTP can create an expectation on the first packet, * before connection is in the list, so we need to clean here, * too. */ nf_ct_remove_expectations(ct); /* We overload first tuple to link into unconfirmed list. */ if (!nf_ct_is_confirmed(ct)) { BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode)); hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); } NF_CT_STAT_INC(net, delete); spin_unlock_bh(&nf_conntrack_lock); if (ct->master) nf_ct_put(ct->master); pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct); nf_conntrack_free(ct); } void nf_ct_delete_from_lists(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); nf_ct_helper_destroy(ct); spin_lock_bh(&nf_conntrack_lock); /* Inside lock so preempt is disabled on module removal path. * Otherwise we can get spurious warnings. */ NF_CT_STAT_INC(net, delete_list); clean_from_lists(ct); spin_unlock_bh(&nf_conntrack_lock); } EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists); static void death_by_event(unsigned long ul_conntrack) { struct nf_conn *ct = (void *)ul_conntrack; struct net *net = nf_ct_net(ct); if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) { /* bad luck, let's retry again */ ct->timeout.expires = jiffies + (random32() % net->ct.sysctl_events_retry_timeout); add_timer(&ct->timeout); return; } /* we've got the event delivered, now it's dying */ set_bit(IPS_DYING_BIT, &ct->status); spin_lock(&nf_conntrack_lock); hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); spin_unlock(&nf_conntrack_lock); nf_ct_put(ct); } void nf_ct_insert_dying_list(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); /* add this conntrack to the dying list */ spin_lock_bh(&nf_conntrack_lock); hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, &net->ct.dying); spin_unlock_bh(&nf_conntrack_lock); /* set a new timer to retry event delivery */ setup_timer(&ct->timeout, death_by_event, (unsigned long)ct); ct->timeout.expires = jiffies + (random32() % net->ct.sysctl_events_retry_timeout); add_timer(&ct->timeout); } EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list); static void death_by_timeout(unsigned long ul_conntrack) { struct nf_conn *ct = (void *)ul_conntrack; if (!test_bit(IPS_DYING_BIT, &ct->status) && unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) { /* destroy event was not delivered */ nf_ct_delete_from_lists(ct); nf_ct_insert_dying_list(ct); return; } set_bit(IPS_DYING_BIT, &ct->status); nf_ct_delete_from_lists(ct); nf_ct_put(ct); } /* * Warning : * - Caller must take a reference on returned object * and recheck nf_ct_tuple_equal(tuple, &h->tuple) * OR * - Caller must lock nf_conntrack_lock before calling this function */ static struct nf_conntrack_tuple_hash * ____nf_conntrack_find(struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple, u32 hash) { struct nf_conntrack_tuple_hash *h; struct hlist_nulls_node *n; unsigned int bucket = hash_bucket(hash, net); /* Disable BHs the entire time since we normally need to disable them * at least once for the stats anyway. */ local_bh_disable(); begin: hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[bucket], hnnode) { if (nf_ct_tuple_equal(tuple, &h->tuple) && nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) { NF_CT_STAT_INC(net, found); local_bh_enable(); return h; } NF_CT_STAT_INC(net, searched); } /* * if the nulls value we got at the end of this lookup is * not the expected one, we must restart lookup. * We probably met an item that was moved to another chain. */ if (get_nulls_value(n) != bucket) { NF_CT_STAT_INC(net, search_restart); goto begin; } local_bh_enable(); return NULL; } struct nf_conntrack_tuple_hash * __nf_conntrack_find(struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple) { return ____nf_conntrack_find(net, zone, tuple, hash_conntrack_raw(tuple, zone)); } EXPORT_SYMBOL_GPL(__nf_conntrack_find); /* Find a connection corresponding to a tuple. */ static struct nf_conntrack_tuple_hash * __nf_conntrack_find_get(struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple, u32 hash) { struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; rcu_read_lock(); begin: h = ____nf_conntrack_find(net, zone, tuple, hash); if (h) { ct = nf_ct_tuplehash_to_ctrack(h); if (unlikely(nf_ct_is_dying(ct) || !atomic_inc_not_zero(&ct->ct_general.use))) h = NULL; else { if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple) || nf_ct_zone(ct) != zone)) { nf_ct_put(ct); goto begin; } } } rcu_read_unlock(); return h; } struct nf_conntrack_tuple_hash * nf_conntrack_find_get(struct net *net, u16 zone, const struct nf_conntrack_tuple *tuple) { return __nf_conntrack_find_get(net, zone, tuple, hash_conntrack_raw(tuple, zone)); } EXPORT_SYMBOL_GPL(nf_conntrack_find_get); static void __nf_conntrack_hash_insert(struct nf_conn *ct, unsigned int hash, unsigned int repl_hash) { struct net *net = nf_ct_net(ct); hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, &net->ct.hash[hash]); hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode, &net->ct.hash[repl_hash]); } void nf_conntrack_hash_insert(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); unsigned int hash, repl_hash; u16 zone; zone = nf_ct_zone(ct); hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple); __nf_conntrack_hash_insert(ct, hash, repl_hash); } EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert); /* Confirm a connection given skb; places it in hash table */ int __nf_conntrack_confirm(struct sk_buff *skb) { unsigned int hash, repl_hash; struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; struct nf_conn_help *help; struct hlist_nulls_node *n; enum ip_conntrack_info ctinfo; struct net *net; u16 zone; ct = nf_ct_get(skb, &ctinfo); net = nf_ct_net(ct); /* ipt_REJECT uses nf_conntrack_attach to attach related ICMP/TCP RST packets in other direction. Actual packet which created connection will be IP_CT_NEW or for an expected connection, IP_CT_RELATED. */ if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) return NF_ACCEPT; zone = nf_ct_zone(ct); /* reuse the hash saved before */ hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev; hash = hash_bucket(hash, net); repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple); /* We're not in hash table, and we refuse to set up related connections for unconfirmed conns. But packet copies and REJECT will give spurious warnings here. */ /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ /* No external references means noone else could have confirmed us. */ NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); pr_debug("Confirming conntrack %p\n", ct); spin_lock_bh(&nf_conntrack_lock); /* We have to check the DYING flag inside the lock to prevent a race against nf_ct_get_next_corpse() possibly called from user context, else we insert an already 'dead' hash, blocking further use of that particular connection -JM */ if (unlikely(nf_ct_is_dying(ct))) { spin_unlock_bh(&nf_conntrack_lock); return NF_ACCEPT; } /* See if there's one in the list already, including reverse: NAT could have grabbed it without realizing, since we're not in the hash. If there is, we lost race. */ hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode) if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, &h->tuple) && zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) goto out; hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode) if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, &h->tuple) && zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) goto out; /* Remove from unconfirmed list */ hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); /* Timer relative to confirmation time, not original setting time, otherwise we'd get timer wrap in weird delay cases. */ ct->timeout.expires += jiffies; add_timer(&ct->timeout); atomic_inc(&ct->ct_general.use); ct->status |= IPS_CONFIRMED; /* Since the lookup is lockless, hash insertion must be done after * starting the timer and setting the CONFIRMED bit. The RCU barriers * guarantee that no other CPU can find the conntrack before the above * stores are visible. */ __nf_conntrack_hash_insert(ct, hash, repl_hash); NF_CT_STAT_INC(net, insert); spin_unlock_bh(&nf_conntrack_lock); help = nfct_help(ct); if (help && help->helper) nf_conntrack_event_cache(IPCT_HELPER, ct); nf_conntrack_event_cache(master_ct(ct) ? IPCT_RELATED : IPCT_NEW, ct); return NF_ACCEPT; out: NF_CT_STAT_INC(net, insert_failed); spin_unlock_bh(&nf_conntrack_lock); return NF_DROP; } EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); /* Returns true if a connection correspondings to the tuple (required for NAT). */ int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, const struct nf_conn *ignored_conntrack) { struct net *net = nf_ct_net(ignored_conntrack); struct nf_conntrack_tuple_hash *h; struct hlist_nulls_node *n; struct nf_conn *ct; u16 zone = nf_ct_zone(ignored_conntrack); unsigned int hash = hash_conntrack(net, zone, tuple); /* Disable BHs the entire time since we need to disable them at * least once for the stats anyway. */ rcu_read_lock_bh(); hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (ct != ignored_conntrack && nf_ct_tuple_equal(tuple, &h->tuple) && nf_ct_zone(ct) == zone) { NF_CT_STAT_INC(net, found); rcu_read_unlock_bh(); return 1; } NF_CT_STAT_INC(net, searched); } rcu_read_unlock_bh(); return 0; } EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); #define NF_CT_EVICTION_RANGE 8 /* There's a small race here where we may free a just-assured connection. Too bad: we're in trouble anyway. */ static noinline int early_drop(struct net *net, unsigned int hash) { /* Use oldest entry, which is roughly LRU */ struct nf_conntrack_tuple_hash *h; struct nf_conn *ct = NULL, *tmp; struct hlist_nulls_node *n; unsigned int i, cnt = 0; int dropped = 0; rcu_read_lock(); for (i = 0; i < net->ct.htable_size; i++) { hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { tmp = nf_ct_tuplehash_to_ctrack(h); if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) ct = tmp; cnt++; } if (ct != NULL) { if (likely(!nf_ct_is_dying(ct) && atomic_inc_not_zero(&ct->ct_general.use))) break; else ct = NULL; } if (cnt >= NF_CT_EVICTION_RANGE) break; hash = (hash + 1) % net->ct.htable_size; } rcu_read_unlock(); if (!ct) return dropped; if (del_timer(&ct->timeout)) { death_by_timeout((unsigned long)ct); dropped = 1; NF_CT_STAT_INC_ATOMIC(net, early_drop); } nf_ct_put(ct); return dropped; } void init_nf_conntrack_hash_rnd(void) { unsigned int rand; /* * Why not initialize nf_conntrack_rnd in a "init()" function ? * Because there isn't enough entropy when system initializing, * and we initialize it as late as possible. */ do { get_random_bytes(&rand, sizeof(rand)); } while (!rand); cmpxchg(&nf_conntrack_hash_rnd, 0, rand); } static struct nf_conn * __nf_conntrack_alloc(struct net *net, u16 zone, const struct nf_conntrack_tuple *orig, const struct nf_conntrack_tuple *repl, gfp_t gfp, u32 hash) { struct nf_conn *ct; if (unlikely(!nf_conntrack_hash_rnd)) { init_nf_conntrack_hash_rnd(); /* recompute the hash as nf_conntrack_hash_rnd is initialized */ hash = hash_conntrack_raw(orig, zone); } /* We don't want any race condition at early drop stage */ atomic_inc(&net->ct.count); if (nf_conntrack_max && unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) { if (!early_drop(net, hash_bucket(hash, net))) { atomic_dec(&net->ct.count); if (net_ratelimit()) printk(KERN_WARNING "nf_conntrack: table full, dropping" " packet.\n"); return ERR_PTR(-ENOMEM); } } /* * Do not use kmem_cache_zalloc(), as this cache uses * SLAB_DESTROY_BY_RCU. */ ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp); if (ct == NULL) { pr_debug("nf_conntrack_alloc: Can't alloc conntrack.\n"); atomic_dec(&net->ct.count); return ERR_PTR(-ENOMEM); } /* * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged. */ memset(&ct->tuplehash[IP_CT_DIR_MAX], 0, offsetof(struct nf_conn, proto) - offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX])); spin_lock_init(&ct->lock); ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL; ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; /* save hash for reusing when confirming */ *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash; /* Don't set timer yet: wait for confirmation */ setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct); write_pnet(&ct->ct_net, net); #ifdef CONFIG_NF_CONNTRACK_ZONES if (zone) { struct nf_conntrack_zone *nf_ct_zone; nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC); if (!nf_ct_zone) goto out_free; nf_ct_zone->id = zone; } #endif /* * changes to lookup keys must be done before setting refcnt to 1 */ smp_wmb(); atomic_set(&ct->ct_general.use, 1); return ct; #ifdef CONFIG_NF_CONNTRACK_ZONES out_free: kmem_cache_free(net->ct.nf_conntrack_cachep, ct); return ERR_PTR(-ENOMEM); #endif } struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone, const struct nf_conntrack_tuple *orig, const struct nf_conntrack_tuple *repl, gfp_t gfp) { return __nf_conntrack_alloc(net, zone, orig, repl, gfp, 0); } EXPORT_SYMBOL_GPL(nf_conntrack_alloc); void nf_conntrack_free(struct nf_conn *ct) { struct net *net = nf_ct_net(ct); nf_ct_ext_destroy(ct); atomic_dec(&net->ct.count); nf_ct_ext_free(ct); kmem_cache_free(net->ct.nf_conntrack_cachep, ct); } EXPORT_SYMBOL_GPL(nf_conntrack_free); /* Allocate a new conntrack: we return -ENOMEM if classification failed due to stress. Otherwise it really is unclassifiable. */ static struct nf_conntrack_tuple_hash * init_conntrack(struct net *net, struct nf_conn *tmpl, const struct nf_conntrack_tuple *tuple, struct nf_conntrack_l3proto *l3proto, struct nf_conntrack_l4proto *l4proto, struct sk_buff *skb, unsigned int dataoff, u32 hash) { struct nf_conn *ct; struct nf_conn_help *help; struct nf_conntrack_tuple repl_tuple; struct nf_conntrack_ecache *ecache; struct nf_conntrack_expect *exp; u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) { pr_debug("Can't invert tuple.\n"); return NULL; } ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC, hash); if (IS_ERR(ct)) { pr_debug("Can't allocate conntrack.\n"); return (struct nf_conntrack_tuple_hash *)ct; } if (!l4proto->new(ct, skb, dataoff)) { nf_conntrack_free(ct); pr_debug("init conntrack: can't track with proto module\n"); return NULL; } nf_ct_acct_ext_add(ct, GFP_ATOMIC); ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL; nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0, ecache ? ecache->expmask : 0, GFP_ATOMIC); spin_lock_bh(&nf_conntrack_lock); exp = nf_ct_find_expectation(net, zone, tuple); if (exp) { pr_debug("conntrack: expectation arrives ct=%p exp=%p\n", ct, exp); /* Welcome, Mr. Bond. We've been expecting you... */ __set_bit(IPS_EXPECTED_BIT, &ct->status); ct->master = exp->master; if (exp->helper) { help = nf_ct_helper_ext_add(ct, GFP_ATOMIC); if (help) rcu_assign_pointer(help->helper, exp->helper); } #ifdef CONFIG_NF_CONNTRACK_MARK ct->mark = exp->master->mark; #endif #ifdef CONFIG_NF_CONNTRACK_SECMARK ct->secmark = exp->master->secmark; #endif nf_conntrack_get(&ct->master->ct_general); NF_CT_STAT_INC(net, expect_new); } else { __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC); NF_CT_STAT_INC(net, new); } /* Overload tuple linked list to put us in unconfirmed list. */ hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, &net->ct.unconfirmed); spin_unlock_bh(&nf_conntrack_lock); if (exp) { if (exp->expectfn) exp->expectfn(ct, exp); nf_ct_expect_put(exp); } return &ct->tuplehash[IP_CT_DIR_ORIGINAL]; } /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ static inline struct nf_conn * resolve_normal_ct(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, unsigned int dataoff, u_int16_t l3num, u_int8_t protonum, struct nf_conntrack_l3proto *l3proto, struct nf_conntrack_l4proto *l4proto, int *set_reply, enum ip_conntrack_info *ctinfo) { struct nf_conntrack_tuple tuple; struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; u32 hash; if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num, protonum, &tuple, l3proto, l4proto)) { pr_debug("resolve_normal_ct: Can't get tuple\n"); return NULL; } /* look for tuple match */ hash = hash_conntrack_raw(&tuple, zone); h = __nf_conntrack_find_get(net, zone, &tuple, hash); if (!h) { h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto, skb, dataoff, hash); if (!h) return NULL; if (IS_ERR(h)) return (void *)h; } ct = nf_ct_tuplehash_to_ctrack(h); /* It exists; we have (non-exclusive) reference. */ if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { *ctinfo = IP_CT_ESTABLISHED + IP_CT_IS_REPLY; /* Please set reply bit if this packet OK */ *set_reply = 1; } else { /* Once we've had two way comms, always ESTABLISHED. */ if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { pr_debug("nf_conntrack_in: normal packet for %p\n", ct); *ctinfo = IP_CT_ESTABLISHED; } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { pr_debug("nf_conntrack_in: related packet for %p\n", ct); *ctinfo = IP_CT_RELATED; } else { pr_debug("nf_conntrack_in: new packet for %p\n", ct); *ctinfo = IP_CT_NEW; } *set_reply = 0; } skb->nfct = &ct->ct_general; skb->nfctinfo = *ctinfo; return ct; } unsigned int nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum, struct sk_buff *skb) { struct nf_conn *ct, *tmpl = NULL; enum ip_conntrack_info ctinfo; struct nf_conntrack_l3proto *l3proto; struct nf_conntrack_l4proto *l4proto; unsigned int dataoff; u_int8_t protonum; int set_reply = 0; int ret; if (skb->nfct) { /* Previously seen (loopback or untracked)? Ignore. */ tmpl = (struct nf_conn *)skb->nfct; if (!nf_ct_is_template(tmpl)) { NF_CT_STAT_INC_ATOMIC(net, ignore); return NF_ACCEPT; } skb->nfct = NULL; } /* rcu_read_lock()ed by nf_hook_slow */ l3proto = __nf_ct_l3proto_find(pf); ret = l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff, &protonum); if (ret <= 0) { pr_debug("not prepared to track yet or error occured\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; } } ct = resolve_normal_ct(net, tmpl, skb, dataoff, pf, protonum, l3proto, l4proto, &set_reply, &ctinfo); if (!ct) { /* Not valid part of a connection */ NF_CT_STAT_INC_ATOMIC(net, invalid); ret = NF_ACCEPT; goto out; } if (IS_ERR(ct)) { /* Too stressed to deal. */ NF_CT_STAT_INC_ATOMIC(net, drop); ret = NF_DROP; goto out; } NF_CT_ASSERT(skb->nfct); ret = l4proto->packet(ct, skb, dataoff, ctinfo, pf, hooknum); if (ret <= 0) { /* Invalid: inverse of the return code tells * the netfilter core what to do */ pr_debug("nf_conntrack_in: Can't track with proto module\n"); nf_conntrack_put(skb->nfct); skb->nfct = NULL; NF_CT_STAT_INC_ATOMIC(net, invalid); if (ret == -NF_DROP) NF_CT_STAT_INC_ATOMIC(net, drop); ret = -ret; goto out; } if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status)) nf_conntrack_event_cache(IPCT_REPLY, ct); out: if (tmpl) nf_ct_put(tmpl); return ret; } EXPORT_SYMBOL_GPL(nf_conntrack_in); bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, const struct nf_conntrack_tuple *orig) { bool ret; rcu_read_lock(); ret = nf_ct_invert_tuple(inverse, orig, __nf_ct_l3proto_find(orig->src.l3num), __nf_ct_l4proto_find(orig->src.l3num, orig->dst.protonum)); rcu_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(nf_ct_invert_tuplepr); /* Alter reply tuple (maybe alter helper). This is for NAT, and is implicitly racy: see __nf_conntrack_confirm */ void nf_conntrack_alter_reply(struct nf_conn *ct, const struct nf_conntrack_tuple *newreply) { struct nf_conn_help *help = nfct_help(ct); /* Should be unconfirmed, so not in hash table yet */ NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); pr_debug("Altering reply tuple of %p to ", ct); nf_ct_dump_tuple(newreply); ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply; if (ct->master || (help && !hlist_empty(&help->expectations))) return; rcu_read_lock(); __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC); rcu_read_unlock(); } EXPORT_SYMBOL_GPL(nf_conntrack_alter_reply); /* Refresh conntrack for this many jiffies and do accounting if do_acct is 1 */ void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo, const struct sk_buff *skb, unsigned long extra_jiffies, int do_acct) { NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct); NF_CT_ASSERT(skb); /* Only update if this is not a fixed timeout */ if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status)) goto acct; /* If not in hash table, timer will not be active yet */ if (!nf_ct_is_confirmed(ct)) { ct->timeout.expires = extra_jiffies; } else { unsigned long newtime = jiffies + extra_jiffies; /* Only update the timeout if the new timeout is at least HZ jiffies from the old timeout. Need del_timer for race avoidance (may already be dying). */ if (newtime - ct->timeout.expires >= HZ) mod_timer_pending(&ct->timeout, newtime); } acct: if (do_acct) { struct nf_conn_counter *acct; acct = nf_conn_acct_find(ct); if (acct) { spin_lock_bh(&ct->lock); acct[CTINFO2DIR(ctinfo)].packets++; acct[CTINFO2DIR(ctinfo)].bytes += skb->len; spin_unlock_bh(&ct->lock); } } } EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct); bool __nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo, const struct sk_buff *skb, int do_acct) { if (do_acct) { struct nf_conn_counter *acct; acct = nf_conn_acct_find(ct); if (acct) { spin_lock_bh(&ct->lock); acct[CTINFO2DIR(ctinfo)].packets++; acct[CTINFO2DIR(ctinfo)].bytes += skb->len - skb_network_offset(skb); spin_unlock_bh(&ct->lock); } } 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 defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) #include #include #include /* Generic function for tcp/udp/sctp/dccp and alike. This needs to be * in ip_conntrack_core, since we don't want the protocols to autoload * or depend on ctnetlink */ int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb, const struct nf_conntrack_tuple *tuple) { NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port); NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port); return 0; nla_put_failure: return -1; } EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr); const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = { [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 }, [CTA_PROTO_DST_PORT] = { .type = NLA_U16 }, }; EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy); int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[], struct nf_conntrack_tuple *t) { if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT]) return -EINVAL; t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]); t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]); return 0; } EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple); int nf_ct_port_nlattr_tuple_size(void) { return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1); } EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size); #endif /* Used by ipt_REJECT and ip6t_REJECT. */ static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) { struct nf_conn *ct; enum ip_conntrack_info ctinfo; /* This ICMP is in reverse direction to the packet which caused it */ ct = nf_ct_get(skb, &ctinfo); if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ctinfo = IP_CT_RELATED + IP_CT_IS_REPLY; else ctinfo = IP_CT_RELATED; /* Attach to new skbuff, and increment count */ nskb->nfct = &ct->ct_general; nskb->nfctinfo = ctinfo; nf_conntrack_get(nskb->nfct); } /* Bring out ya dead! */ static struct nf_conn * get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data, unsigned int *bucket) { struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; struct hlist_nulls_node *n; spin_lock_bh(&nf_conntrack_lock); for (; *bucket < net->ct.htable_size; (*bucket)++) { hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (iter(ct, data)) goto found; } } hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); if (iter(ct, data)) set_bit(IPS_DYING_BIT, &ct->status); } spin_unlock_bh(&nf_conntrack_lock); return NULL; found: atomic_inc(&ct->ct_general.use); spin_unlock_bh(&nf_conntrack_lock); return ct; } void nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data) { struct nf_conn *ct; unsigned int bucket = 0; while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) { /* Time to push up daises... */ if (del_timer(&ct->timeout)) death_by_timeout((unsigned long)ct); /* ... else the timer will get him soon. */ nf_ct_put(ct); } } EXPORT_SYMBOL_GPL(nf_ct_iterate_cleanup); struct __nf_ct_flush_report { u32 pid; int report; }; static int kill_report(struct nf_conn *i, void *data) { struct __nf_ct_flush_report *fr = (struct __nf_ct_flush_report *)data; /* If we fail to deliver the event, death_by_timeout() will retry */ if (nf_conntrack_event_report(IPCT_DESTROY, i, fr->pid, fr->report) < 0) return 1; /* Avoid the delivery of the destroy event in death_by_timeout(). */ set_bit(IPS_DYING_BIT, &i->status); return 1; } static int kill_all(struct nf_conn *i, void *data) { return 1; } void nf_ct_free_hashtable(void *hash, unsigned int size) { if (is_vmalloc_addr(hash)) vfree(hash); else free_pages((unsigned long)hash, get_order(sizeof(struct hlist_head) * size)); } EXPORT_SYMBOL_GPL(nf_ct_free_hashtable); void nf_conntrack_flush_report(struct net *net, u32 pid, int report) { struct __nf_ct_flush_report fr = { .pid = pid, .report = report, }; nf_ct_iterate_cleanup(net, kill_report, &fr); } EXPORT_SYMBOL_GPL(nf_conntrack_flush_report); static void nf_ct_release_dying_list(struct net *net) { struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; struct hlist_nulls_node *n; spin_lock_bh(&nf_conntrack_lock); hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) { ct = nf_ct_tuplehash_to_ctrack(h); /* never fails to remove them, no listeners at this point */ nf_ct_kill(ct); } spin_unlock_bh(&nf_conntrack_lock); } static int untrack_refs(void) { int cnt = 0, cpu; for_each_possible_cpu(cpu) { struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu); cnt += atomic_read(&ct->ct_general.use) - 1; } return cnt; } static void nf_conntrack_cleanup_init_net(void) { while (untrack_refs() > 0) schedule(); nf_conntrack_helper_fini(); nf_conntrack_proto_fini(); #ifdef CONFIG_NF_CONNTRACK_ZONES nf_ct_extend_unregister(&nf_ct_zone_extend); #endif } static void nf_conntrack_cleanup_net(struct net *net) { i_see_dead_people: nf_ct_iterate_cleanup(net, kill_all, NULL); nf_ct_release_dying_list(net); if (atomic_read(&net->ct.count) != 0) { schedule(); goto i_see_dead_people; } nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); nf_conntrack_ecache_fini(net); nf_conntrack_acct_fini(net); nf_conntrack_expect_fini(net); kmem_cache_destroy(net->ct.nf_conntrack_cachep); kfree(net->ct.slabname); free_percpu(net->ct.stat); } /* Mishearing the voices in his head, our hero wonders how he's supposed to kill the mall. */ void nf_conntrack_cleanup(struct net *net) { if (net_eq(net, &init_net)) rcu_assign_pointer(ip_ct_attach, NULL); /* This makes sure all current packets have passed through netfilter framework. Roll on, two-stage module delete... */ synchronize_net(); nf_conntrack_cleanup_net(net); if (net_eq(net, &init_net)) { rcu_assign_pointer(nf_ct_destroy, NULL); nf_conntrack_cleanup_init_net(); } } void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) { struct hlist_nulls_head *hash; unsigned int nr_slots, i; size_t sz; BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); sz = nr_slots * sizeof(struct hlist_nulls_head); hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, get_order(sz)); if (!hash) { printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); hash = __vmalloc(sz, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); } if (hash && nulls) for (i = 0; i < nr_slots; i++) INIT_HLIST_NULLS_HEAD(&hash[i], i); return hash; } EXPORT_SYMBOL_GPL(nf_ct_alloc_hashtable); int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp) { int i, bucket; unsigned int hashsize, old_size; struct hlist_nulls_head *hash, *old_hash; struct nf_conntrack_tuple_hash *h; struct nf_conn *ct; if (current->nsproxy->net_ns != &init_net) return -EOPNOTSUPP; /* On boot, we can set this without any fancy locking. */ if (!nf_conntrack_htable_size) return param_set_uint(val, kp); hashsize = simple_strtoul(val, NULL, 0); if (!hashsize) return -EINVAL; hash = nf_ct_alloc_hashtable(&hashsize, 1); if (!hash) return -ENOMEM; /* Lookups in the old hash might happen in parallel, which means we * might get false negatives during connection lookup. New connections * created because of a false negative won't make it into the hash * though since that required taking the lock. */ spin_lock_bh(&nf_conntrack_lock); for (i = 0; i < init_net.ct.htable_size; i++) { while (!hlist_nulls_empty(&init_net.ct.hash[i])) { h = hlist_nulls_entry(init_net.ct.hash[i].first, struct nf_conntrack_tuple_hash, hnnode); ct = nf_ct_tuplehash_to_ctrack(h); hlist_nulls_del_rcu(&h->hnnode); bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct), hashsize); hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]); } } old_size = init_net.ct.htable_size; old_hash = init_net.ct.hash; init_net.ct.htable_size = nf_conntrack_htable_size = hashsize; init_net.ct.hash = hash; spin_unlock_bh(&nf_conntrack_lock); nf_ct_free_hashtable(old_hash, old_size); return 0; } EXPORT_SYMBOL_GPL(nf_conntrack_set_hashsize); module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint, &nf_conntrack_htable_size, 0600); void nf_ct_untracked_status_or(unsigned long bits) { int cpu; for_each_possible_cpu(cpu) per_cpu(nf_conntrack_untracked, cpu).status |= bits; } EXPORT_SYMBOL_GPL(nf_ct_untracked_status_or); static int nf_conntrack_init_init_net(void) { int max_factor = 8; int ret, cpu; /* Idea from tcp.c: use 1/16384 of memory. On i386: 32MB * machine has 512 buckets. >= 1GB machines have 16384 buckets. */ if (!nf_conntrack_htable_size) { nf_conntrack_htable_size = (((totalram_pages << PAGE_SHIFT) / 16384) / sizeof(struct hlist_head)); if (totalram_pages > (1024 * 1024 * 1024 / PAGE_SIZE)) nf_conntrack_htable_size = 16384; if (nf_conntrack_htable_size < 32) nf_conntrack_htable_size = 32; /* Use a max. factor of four by default to get the same max as * with the old struct list_heads. When a table size is given * we use the old value of 8 to avoid reducing the max. * entries. */ max_factor = 4; } nf_conntrack_max = max_factor * nf_conntrack_htable_size; printk(KERN_INFO "nf_conntrack version %s (%u buckets, %d max)\n", NF_CONNTRACK_VERSION, nf_conntrack_htable_size, nf_conntrack_max); ret = nf_conntrack_proto_init(); if (ret < 0) goto err_proto; ret = nf_conntrack_helper_init(); if (ret < 0) goto err_helper; #ifdef CONFIG_NF_CONNTRACK_ZONES ret = nf_ct_extend_register(&nf_ct_zone_extend); if (ret < 0) goto err_extend; #endif /* Set up fake conntrack: to never be deleted, not in any hashes */ for_each_possible_cpu(cpu) { struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu); write_pnet(&ct->ct_net, &init_net); atomic_set(&ct->ct_general.use, 1); } /* - and look it like as a confirmed connection */ nf_ct_untracked_status_or(IPS_CONFIRMED | IPS_UNTRACKED); return 0; #ifdef CONFIG_NF_CONNTRACK_ZONES err_extend: nf_conntrack_helper_fini(); #endif err_helper: nf_conntrack_proto_fini(); err_proto: return ret; } /* * We need to use special "null" values, not used in hash table */ #define UNCONFIRMED_NULLS_VAL ((1<<30)+0) #define DYING_NULLS_VAL ((1<<30)+1) static int nf_conntrack_init_net(struct net *net) { int ret; atomic_set(&net->ct.count, 0); INIT_HLIST_NULLS_HEAD(&net->ct.unconfirmed, UNCONFIRMED_NULLS_VAL); INIT_HLIST_NULLS_HEAD(&net->ct.dying, DYING_NULLS_VAL); net->ct.stat = alloc_percpu(struct ip_conntrack_stat); if (!net->ct.stat) { ret = -ENOMEM; goto err_stat; } net->ct.slabname = kasprintf(GFP_KERNEL, "nf_conntrack_%p", net); if (!net->ct.slabname) { ret = -ENOMEM; goto err_slabname; } net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname, sizeof(struct nf_conn), 0, SLAB_DESTROY_BY_RCU, NULL); if (!net->ct.nf_conntrack_cachep) { printk(KERN_ERR "Unable to create nf_conn slab cache\n"); ret = -ENOMEM; goto err_cache; } net->ct.htable_size = nf_conntrack_htable_size; net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1); if (!net->ct.hash) { ret = -ENOMEM; printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); goto err_hash; } ret = nf_conntrack_expect_init(net); if (ret < 0) goto err_expect; ret = nf_conntrack_acct_init(net); if (ret < 0) goto err_acct; ret = nf_conntrack_ecache_init(net); if (ret < 0) goto err_ecache; return 0; err_ecache: nf_conntrack_acct_fini(net); err_acct: nf_conntrack_expect_fini(net); err_expect: nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); err_hash: kmem_cache_destroy(net->ct.nf_conntrack_cachep); err_cache: kfree(net->ct.slabname); err_slabname: free_percpu(net->ct.stat); err_stat: return ret; } s16 (*nf_ct_nat_offset)(const struct nf_conn *ct, enum ip_conntrack_dir dir, u32 seq); EXPORT_SYMBOL_GPL(nf_ct_nat_offset); int nf_conntrack_init(struct net *net) { int ret; if (net_eq(net, &init_net)) { ret = nf_conntrack_init_init_net(); if (ret < 0) goto out_init_net; } ret = nf_conntrack_init_net(net); if (ret < 0) goto out_net; if (net_eq(net, &init_net)) { /* For use by REJECT target */ rcu_assign_pointer(ip_ct_attach, nf_conntrack_attach); rcu_assign_pointer(nf_ct_destroy, destroy_conntrack); /* Howto get NAT offsets */ rcu_assign_pointer(nf_ct_nat_offset, NULL); } return 0; out_net: if (net_eq(net, &init_net)) nf_conntrack_cleanup_init_net(); out_init_net: return ret; }