| /* Connection state tracking for netfilter. This is separated from, |
| but required by, the NAT layer; it can also be used by an iptables |
| extension. */ |
| |
| /* (C) 1999-2001 Paul `Rusty' Russell |
| * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/netfilter.h> |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/skbuff.h> |
| #include <linux/proc_fs.h> |
| #include <linux/vmalloc.h> |
| #include <linux/stddef.h> |
| #include <linux/slab.h> |
| #include <linux/random.h> |
| #include <linux/jhash.h> |
| #include <linux/err.h> |
| #include <linux/percpu.h> |
| #include <linux/moduleparam.h> |
| #include <linux/notifier.h> |
| #include <linux/kernel.h> |
| #include <linux/netdevice.h> |
| #include <linux/socket.h> |
| #include <linux/mm.h> |
| #include <linux/nsproxy.h> |
| #include <linux/rculist_nulls.h> |
| |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_l3proto.h> |
| #include <net/netfilter/nf_conntrack_l4proto.h> |
| #include <net/netfilter/nf_conntrack_expect.h> |
| #include <net/netfilter/nf_conntrack_helper.h> |
| #include <net/netfilter/nf_conntrack_core.h> |
| #include <net/netfilter/nf_conntrack_extend.h> |
| #include <net/netfilter/nf_conntrack_acct.h> |
| #include <net/netfilter/nf_conntrack_ecache.h> |
| #include <net/netfilter/nf_conntrack_zones.h> |
| #include <net/netfilter/nf_conntrack_timestamp.h> |
| #include <net/netfilter/nf_conntrack_timeout.h> |
| #include <net/netfilter/nf_nat.h> |
| #include <net/netfilter/nf_nat_core.h> |
| |
| #define NF_CONNTRACK_VERSION "0.5.0" |
| |
| int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct, |
| enum nf_nat_manip_type manip, |
| const struct nlattr *attr) __read_mostly; |
| EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook); |
| |
| DEFINE_SPINLOCK(nf_conntrack_lock); |
| EXPORT_SYMBOL_GPL(nf_conntrack_lock); |
| |
| unsigned int nf_conntrack_htable_size __read_mostly; |
| EXPORT_SYMBOL_GPL(nf_conntrack_htable_size); |
| |
| unsigned int nf_conntrack_max __read_mostly; |
| EXPORT_SYMBOL_GPL(nf_conntrack_max); |
| |
| DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked); |
| EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked); |
| |
| unsigned int nf_conntrack_hash_rnd __read_mostly; |
| 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 ((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(%pK)\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(%pK)\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=%pK to slab\n", ct); |
| nf_conntrack_free(ct); |
| } |
| |
| void nf_ct_delete_from_lists(struct nf_conn *ct) |
| { |
| struct net *net = nf_ct_net(ct); |
| |
| nf_ct_helper_destroy(ct); |
| spin_lock_bh(&nf_conntrack_lock); |
| /* Inside lock so preempt is disabled on module removal path. |
| * Otherwise we can get spurious warnings. */ |
| NF_CT_STAT_INC(net, delete_list); |
| clean_from_lists(ct); |
| spin_unlock_bh(&nf_conntrack_lock); |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists); |
| |
| static void death_by_event(unsigned long ul_conntrack) |
| { |
| struct nf_conn *ct = (void *)ul_conntrack; |
| struct net *net = nf_ct_net(ct); |
| struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); |
| |
| BUG_ON(ecache == NULL); |
| |
| if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) { |
| /* bad luck, let's retry again */ |
| ecache->timeout.expires = jiffies + |
| (random32() % net->ct.sysctl_events_retry_timeout); |
| add_timer(&ecache->timeout); |
| return; |
| } |
| /* we've got the event delivered, now it's dying */ |
| set_bit(IPS_DYING_BIT, &ct->status); |
| spin_lock(&nf_conntrack_lock); |
| hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); |
| spin_unlock(&nf_conntrack_lock); |
| nf_ct_put(ct); |
| } |
| |
| void nf_ct_insert_dying_list(struct nf_conn *ct) |
| { |
| struct net *net = nf_ct_net(ct); |
| struct nf_conntrack_ecache *ecache = nf_ct_ecache_find(ct); |
| |
| BUG_ON(ecache == NULL); |
| |
| /* add this conntrack to the dying list */ |
| spin_lock_bh(&nf_conntrack_lock); |
| hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, |
| &net->ct.dying); |
| spin_unlock_bh(&nf_conntrack_lock); |
| /* set a new timer to retry event delivery */ |
| setup_timer(&ecache->timeout, death_by_event, (unsigned long)ct); |
| ecache->timeout.expires = jiffies + |
| (random32() % net->ct.sysctl_events_retry_timeout); |
| add_timer(&ecache->timeout); |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list); |
| |
| static void death_by_timeout(unsigned long ul_conntrack) |
| { |
| struct nf_conn *ct = (void *)ul_conntrack; |
| struct nf_conn_tstamp *tstamp; |
| |
| tstamp = nf_conn_tstamp_find(ct); |
| if (tstamp && tstamp->stop == 0) |
| tstamp->stop = ktime_to_ns(ktime_get_real()); |
| |
| 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); |
| } |
| |
| 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) |
| * 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_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; |
| } |
| |
| 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_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 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]); |
| } |
| |
| int |
| nf_conntrack_hash_check_insert(struct nf_conn *ct) |
| { |
| struct net *net = nf_ct_net(ct); |
| unsigned int hash, repl_hash; |
| struct nf_conntrack_tuple_hash *h; |
| struct hlist_nulls_node *n; |
| 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); |
| |
| spin_lock_bh(&nf_conntrack_lock); |
| |
| /* 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[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; |
| |
| add_timer(&ct->timeout); |
| nf_conntrack_get(&ct->ct_general); |
| __nf_conntrack_hash_insert(ct, hash, repl_hash); |
| NF_CT_STAT_INC(net, insert); |
| spin_unlock_bh(&nf_conntrack_lock); |
| |
| return 0; |
| |
| out: |
| NF_CT_STAT_INC(net, insert_failed); |
| spin_unlock_bh(&nf_conntrack_lock); |
| 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) |
| { |
| unsigned int hash, repl_hash; |
| struct nf_conntrack_tuple_hash *h; |
| struct nf_conn *ct; |
| struct nf_conn_help *help; |
| struct nf_conn_tstamp *tstamp; |
| struct hlist_nulls_node *n; |
| enum ip_conntrack_info ctinfo; |
| struct net *net; |
| u16 zone; |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| net = nf_ct_net(ct); |
| |
| /* ipt_REJECT uses nf_conntrack_attach to attach related |
| ICMP/TCP RST packets in other direction. Actual packet |
| which created connection will be IP_CT_NEW or for an |
| expected connection, IP_CT_RELATED. */ |
| if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) |
| return NF_ACCEPT; |
| |
| zone = nf_ct_zone(ct); |
| /* reuse the hash saved before */ |
| hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev; |
| hash = hash_bucket(hash, net); |
| repl_hash = hash_conntrack(net, zone, |
| &ct->tuplehash[IP_CT_DIR_REPLY].tuple); |
| |
| /* We're not in hash table, and we refuse to set up related |
| connections for unconfirmed conns. But packet copies and |
| REJECT will give spurious warnings here. */ |
| /* NF_CT_ASSERT(atomic_read(&ct->ct_general.use) == 1); */ |
| |
| /* No external references means no one else could have |
| confirmed us. */ |
| NF_CT_ASSERT(!nf_ct_is_confirmed(ct)); |
| pr_debug("Confirming conntrack %pK\n", ct); |
| |
| spin_lock_bh(&nf_conntrack_lock); |
| |
| /* We have to check the DYING flag inside the lock to prevent |
| a race against nf_ct_get_next_corpse() possibly called from |
| user context, else we insert an already 'dead' hash, blocking |
| further use of that particular connection -JM */ |
| |
| if (unlikely(nf_ct_is_dying(ct))) { |
| spin_unlock_bh(&nf_conntrack_lock); |
| return NF_ACCEPT; |
| } |
| |
| /* See if there's one in the list already, including reverse: |
| NAT could have grabbed it without realizing, since we're |
| not in the hash. If there is, we lost race. */ |
| hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode) |
| if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple, |
| &h->tuple) && |
| zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) |
| goto out; |
| hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode) |
| if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple, |
| &h->tuple) && |
| zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h))) |
| goto out; |
| |
| /* Remove from unconfirmed list */ |
| hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode); |
| |
| /* Timer relative to confirmation time, not original |
| setting time, otherwise we'd get timer wrap in |
| weird delay cases. */ |
| ct->timeout.expires += jiffies; |
| add_timer(&ct->timeout); |
| atomic_inc(&ct->ct_general.use); |
| ct->status |= IPS_CONFIRMED; |
| |
| /* set conntrack timestamp, if enabled. */ |
| tstamp = nf_conn_tstamp_find(ct); |
| if (tstamp) { |
| if (skb->tstamp.tv64 == 0) |
| __net_timestamp((struct sk_buff *)skb); |
| |
| tstamp->start = ktime_to_ns(skb->tstamp); |
| } |
| /* Since the lookup is lockless, hash insertion must be done after |
| * starting the timer and setting the CONFIRMED bit. The RCU barriers |
| * guarantee that no other CPU can find the conntrack before the above |
| * stores are visible. |
| */ |
| __nf_conntrack_hash_insert(ct, hash, repl_hash); |
| NF_CT_STAT_INC(net, insert); |
| spin_unlock_bh(&nf_conntrack_lock); |
| |
| help = nfct_help(ct); |
| if (help && help->helper) |
| nf_conntrack_event_cache(IPCT_HELPER, ct); |
| |
| nf_conntrack_event_cache(master_ct(ct) ? |
| IPCT_RELATED : IPCT_NEW, ct); |
| return NF_ACCEPT; |
| |
| out: |
| NF_CT_STAT_INC(net, insert_failed); |
| spin_unlock_bh(&nf_conntrack_lock); |
| return NF_DROP; |
| } |
| EXPORT_SYMBOL_GPL(__nf_conntrack_confirm); |
| |
| /* Returns true if a connection correspondings to the tuple (required |
| for NAT). */ |
| int |
| nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, |
| const struct nf_conn *ignored_conntrack) |
| { |
| struct net *net = nf_ct_net(ignored_conntrack); |
| struct nf_conntrack_tuple_hash *h; |
| struct hlist_nulls_node *n; |
| struct nf_conn *ct; |
| u16 zone = nf_ct_zone(ignored_conntrack); |
| unsigned int hash = hash_conntrack(net, zone, tuple); |
| |
| /* Disable BHs the entire time since we need to disable them at |
| * least once for the stats anyway. |
| */ |
| rcu_read_lock_bh(); |
| hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) { |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| if (ct != ignored_conntrack && |
| nf_ct_tuple_equal(tuple, &h->tuple) && |
| nf_ct_zone(ct) == zone) { |
| NF_CT_STAT_INC(net, found); |
| rcu_read_unlock_bh(); |
| return 1; |
| } |
| NF_CT_STAT_INC(net, searched); |
| } |
| rcu_read_unlock_bh(); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nf_conntrack_tuple_taken); |
| |
| #define NF_CT_EVICTION_RANGE 8 |
| |
| /* There's a small race here where we may free a just-assured |
| connection. Too bad: we're in trouble anyway. */ |
| static noinline int early_drop(struct net *net, unsigned int hash) |
| { |
| /* Use oldest entry, which is roughly LRU */ |
| struct nf_conntrack_tuple_hash *h; |
| struct nf_conn *ct = NULL, *tmp; |
| struct hlist_nulls_node *n; |
| unsigned int i, cnt = 0; |
| int dropped = 0; |
| |
| rcu_read_lock(); |
| for (i = 0; i < net->ct.htable_size; i++) { |
| hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], |
| hnnode) { |
| tmp = nf_ct_tuplehash_to_ctrack(h); |
| if (!test_bit(IPS_ASSURED_BIT, &tmp->status)) |
| ct = tmp; |
| cnt++; |
| } |
| |
| if (ct != NULL) { |
| if (likely(!nf_ct_is_dying(ct) && |
| atomic_inc_not_zero(&ct->ct_general.use))) |
| break; |
| else |
| ct = NULL; |
| } |
| |
| if (cnt >= NF_CT_EVICTION_RANGE) |
| break; |
| |
| hash = (hash + 1) % net->ct.htable_size; |
| } |
| rcu_read_unlock(); |
| |
| if (!ct) |
| return dropped; |
| |
| if (del_timer(&ct->timeout)) { |
| death_by_timeout((unsigned long)ct); |
| /* Check if we indeed killed this entry. Reliable event |
| delivery may have inserted it into the dying list. */ |
| if (test_bit(IPS_DYING_BIT, &ct->status)) { |
| dropped = 1; |
| NF_CT_STAT_INC_ATOMIC(net, early_drop); |
| } |
| } |
| nf_ct_put(ct); |
| return dropped; |
| } |
| |
| void init_nf_conntrack_hash_rnd(void) |
| { |
| unsigned int rand; |
| |
| /* |
| * Why not initialize nf_conntrack_rnd in a "init()" function ? |
| * Because there isn't enough entropy when system initializing, |
| * and we initialize it as late as possible. |
| */ |
| do { |
| get_random_bytes(&rand, sizeof(rand)); |
| } while (!rand); |
| cmpxchg(&nf_conntrack_hash_rnd, 0, rand); |
| } |
| |
| static struct nf_conn * |
| __nf_conntrack_alloc(struct net *net, u16 zone, |
| const struct nf_conntrack_tuple *orig, |
| const struct nf_conntrack_tuple *repl, |
| gfp_t gfp, u32 hash) |
| { |
| struct nf_conn *ct; |
| |
| if (unlikely(!nf_conntrack_hash_rnd)) { |
| init_nf_conntrack_hash_rnd(); |
| /* recompute the hash as nf_conntrack_hash_rnd is initialized */ |
| hash = hash_conntrack_raw(orig, zone); |
| } |
| |
| /* We don't want any race condition at early drop stage */ |
| atomic_inc(&net->ct.count); |
| |
| if (nf_conntrack_max && |
| unlikely(atomic_read(&net->ct.count) > nf_conntrack_max)) { |
| if (!early_drop(net, hash_bucket(hash, net))) { |
| atomic_dec(&net->ct.count); |
| if (net_ratelimit()) |
| printk(KERN_WARNING |
| "nf_conntrack: table full, dropping" |
| " packet.\n"); |
| return ERR_PTR(-ENOMEM); |
| } |
| } |
| |
| /* |
| * Do not use kmem_cache_zalloc(), as this cache uses |
| * SLAB_DESTROY_BY_RCU. |
| */ |
| ct = kmem_cache_alloc(net->ct.nf_conntrack_cachep, gfp); |
| if (ct == NULL) { |
| atomic_dec(&net->ct.count); |
| return ERR_PTR(-ENOMEM); |
| } |
| /* |
| * Let ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.next |
| * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged. |
| */ |
| memset(&ct->tuplehash[IP_CT_DIR_MAX], 0, |
| offsetof(struct nf_conn, proto) - |
| offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX])); |
| spin_lock_init(&ct->lock); |
| ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig; |
| ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL; |
| ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl; |
| /* save hash for reusing when confirming */ |
| *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash; |
| /* Don't set timer yet: wait for confirmation */ |
| setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct); |
| write_pnet(&ct->ct_net, net); |
| #if defined(CONFIG_IP_NF_TARGET_NATTYPE_MODULE) |
| ct->nattype_entry = 0; |
| #endif |
| #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: |
| 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); |
| |
| nf_ct_ext_destroy(ct); |
| nf_ct_ext_free(ct); |
| kmem_cache_free(net->ct.nf_conntrack_cachep, ct); |
| smp_mb__before_atomic_dec(); |
| 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; |
| 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; |
| |
| 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); |
| |
| 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=%pK exp=%pK\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 |
| /* Intialize the NAT type entry. */ |
| #if defined(CONFIG_IP_NF_TARGET_NATTYPE_MODULE) |
| ct->nattype_entry = 0; |
| #endif |
| nf_conntrack_get(&ct->master->ct_general); |
| NF_CT_STAT_INC(net, expect_new); |
| } else { |
| __nf_ct_try_assign_helper(ct, tmpl, GFP_ATOMIC); |
| NF_CT_STAT_INC(net, new); |
| } |
| |
| /* Overload tuple linked list to put us in unconfirmed list. */ |
| hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode, |
| &net->ct.unconfirmed); |
| |
| spin_unlock_bh(&nf_conntrack_lock); |
| |
| if (exp) { |
| if (exp->expectfn) |
| exp->expectfn(ct, exp); |
| nf_ct_expect_put(exp); |
| } |
| |
| return &ct->tuplehash[IP_CT_DIR_ORIGINAL]; |
| } |
| |
| /* On success, returns conntrack ptr, sets skb->nfct and ctinfo */ |
| static inline struct nf_conn * |
| resolve_normal_ct(struct net *net, struct nf_conn *tmpl, |
| struct sk_buff *skb, |
| unsigned int dataoff, |
| u_int16_t l3num, |
| u_int8_t protonum, |
| struct nf_conntrack_l3proto *l3proto, |
| struct nf_conntrack_l4proto *l4proto, |
| int *set_reply, |
| enum ip_conntrack_info *ctinfo) |
| { |
| struct nf_conntrack_tuple tuple; |
| struct nf_conntrack_tuple_hash *h; |
| struct nf_conn *ct; |
| u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE; |
| u32 hash; |
| |
| if (!nf_ct_get_tuple(skb, skb_network_offset(skb), |
| dataoff, l3num, protonum, &tuple, l3proto, |
| l4proto)) { |
| pr_debug("resolve_normal_ct: Can't get tuple\n"); |
| return NULL; |
| } |
| |
| /* look for tuple match */ |
| hash = hash_conntrack_raw(&tuple, zone); |
| h = __nf_conntrack_find_get(net, zone, &tuple, hash); |
| if (!h) { |
| h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto, |
| skb, dataoff, hash); |
| if (!h) |
| return NULL; |
| if (IS_ERR(h)) |
| return (void *)h; |
| } |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| |
| /* It exists; we have (non-exclusive) reference. */ |
| if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) { |
| *ctinfo = IP_CT_ESTABLISHED_REPLY; |
| /* Please set reply bit if this packet OK */ |
| *set_reply = 1; |
| } else { |
| /* Once we've had two way comms, always ESTABLISHED. */ |
| if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { |
| pr_debug("nf_conntrack_in: normal packet for %pK\n", ct); |
| *ctinfo = IP_CT_ESTABLISHED; |
| } else if (test_bit(IPS_EXPECTED_BIT, &ct->status)) { |
| pr_debug("nf_conntrack_in: related packet for %pK\n", |
| ct); |
| *ctinfo = IP_CT_RELATED; |
| } else { |
| pr_debug("nf_conntrack_in: new packet for %pK\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; |
| struct nf_conn_timeout *timeout_ext; |
| 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. */ |
| timeout_ext = nf_ct_timeout_find(ct); |
| if (timeout_ext) |
| timeouts = NF_CT_TIMEOUT_EXT_DATA(timeout_ext); |
| else |
| timeouts = l4proto->get_timeouts(net); |
| |
| 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 %pK 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); |
| } |
| |
| /* Refresh the NAT type entry. */ |
| #if defined(CONFIG_IP_NF_TARGET_NATTYPE_MODULE) |
| (void)nattype_refresh_timer(ct->nattype_entry, ct->timeout.expires); |
| #endif |
| |
| acct: |
| if (do_acct) { |
| struct nf_conn_counter *acct; |
| |
| acct = nf_conn_acct_find(ct); |
| if (acct) { |
| atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets); |
| atomic64_add(skb->len, &acct[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_counter *acct; |
| |
| acct = nf_conn_acct_find(ct); |
| if (acct) { |
| atomic64_inc(&acct[CTINFO2DIR(ctinfo)].packets); |
| atomic64_add(skb->len - skb_network_offset(skb), |
| &acct[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) |
| { |
| NLA_PUT_BE16(skb, CTA_PROTO_SRC_PORT, tuple->src.u.tcp.port); |
| NLA_PUT_BE16(skb, CTA_PROTO_DST_PORT, tuple->dst.u.tcp.port); |
| return 0; |
| |
| nla_put_failure: |
| return -1; |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_port_tuple_to_nlattr); |
| |
| const struct nla_policy nf_ct_port_nla_policy[CTA_PROTO_MAX+1] = { |
| [CTA_PROTO_SRC_PORT] = { .type = NLA_U16 }, |
| [CTA_PROTO_DST_PORT] = { .type = NLA_U16 }, |
| }; |
| EXPORT_SYMBOL_GPL(nf_ct_port_nla_policy); |
| |
| int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[], |
| struct nf_conntrack_tuple *t) |
| { |
| if (!tb[CTA_PROTO_SRC_PORT] || !tb[CTA_PROTO_DST_PORT]) |
| return -EINVAL; |
| |
| t->src.u.tcp.port = nla_get_be16(tb[CTA_PROTO_SRC_PORT]); |
| t->dst.u.tcp.port = nla_get_be16(tb[CTA_PROTO_DST_PORT]); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_to_tuple); |
| |
| int nf_ct_port_nlattr_tuple_size(void) |
| { |
| return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1); |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_port_nlattr_tuple_size); |
| #endif |
| |
| /* Used by ipt_REJECT and ip6t_REJECT. */ |
| static void nf_conntrack_attach(struct sk_buff *nskb, struct sk_buff *skb) |
| { |
| struct nf_conn *ct; |
| enum ip_conntrack_info ctinfo; |
| |
| /* This ICMP is in reverse direction to the packet which caused it */ |
| ct = nf_ct_get(skb, &ctinfo); |
| if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) |
| ctinfo = IP_CT_RELATED_REPLY; |
| else |
| ctinfo = IP_CT_RELATED; |
| |
| /* Attach to new skbuff, and increment count */ |
| nskb->nfct = &ct->ct_general; |
| nskb->nfctinfo = ctinfo; |
| nf_conntrack_get(nskb->nfct); |
| } |
| |
| /* Bring out ya dead! */ |
| static struct nf_conn * |
| get_next_corpse(struct net *net, int (*iter)(struct nf_conn *i, void *data), |
| void *data, unsigned int *bucket) |
| { |
| struct nf_conntrack_tuple_hash *h; |
| struct nf_conn *ct; |
| struct hlist_nulls_node *n; |
| |
| spin_lock_bh(&nf_conntrack_lock); |
| for (; *bucket < net->ct.htable_size; (*bucket)++) { |
| hlist_nulls_for_each_entry(h, n, &net->ct.hash[*bucket], hnnode) { |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| if (iter(ct, data)) |
| goto found; |
| } |
| } |
| hlist_nulls_for_each_entry(h, n, &net->ct.unconfirmed, hnnode) { |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| if (iter(ct, data)) |
| set_bit(IPS_DYING_BIT, &ct->status); |
| } |
| spin_unlock_bh(&nf_conntrack_lock); |
| return NULL; |
| found: |
| atomic_inc(&ct->ct_general.use); |
| spin_unlock_bh(&nf_conntrack_lock); |
| return ct; |
| } |
| |
| void nf_ct_iterate_cleanup(struct net *net, |
| int (*iter)(struct nf_conn *i, void *data), |
| void *data) |
| { |
| struct nf_conn *ct; |
| unsigned int bucket = 0; |
| |
| while ((ct = get_next_corpse(net, iter, data, &bucket)) != NULL) { |
| /* Time to push up daises... */ |
| 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; |
| struct nf_conn_tstamp *tstamp; |
| |
| tstamp = nf_conn_tstamp_find(i); |
| if (tstamp && tstamp->stop == 0) |
| tstamp->stop = ktime_to_ns(ktime_get_real()); |
| |
| /* If we fail to deliver the event, death_by_timeout() will retry */ |
| if (nf_conntrack_event_report(IPCT_DESTROY, i, |
| fr->pid, fr->report) < 0) |
| return 1; |
| |
| /* Avoid the delivery of the destroy event in death_by_timeout(). */ |
| set_bit(IPS_DYING_BIT, &i->status); |
| return 1; |
| } |
| |
| static int kill_all(struct nf_conn *i, void *data) |
| { |
| return 1; |
| } |
| |
| void nf_ct_free_hashtable(void *hash, unsigned int size) |
| { |
| if (is_vmalloc_addr(hash)) |
| vfree(hash); |
| else |
| free_pages((unsigned long)hash, |
| get_order(sizeof(struct hlist_head) * size)); |
| } |
| EXPORT_SYMBOL_GPL(nf_ct_free_hashtable); |
| |
| void nf_conntrack_flush_report(struct net *net, u32 pid, int report) |
| { |
| struct __nf_ct_flush_report fr = { |
| .pid = pid, |
| .report = report, |
| }; |
| nf_ct_iterate_cleanup(net, kill_report, &fr); |
| } |
| EXPORT_SYMBOL_GPL(nf_conntrack_flush_report); |
| |
| static void nf_ct_release_dying_list(struct net *net) |
| { |
| struct nf_conntrack_tuple_hash *h; |
| struct nf_conn *ct; |
| struct hlist_nulls_node *n; |
| |
| spin_lock_bh(&nf_conntrack_lock); |
| hlist_nulls_for_each_entry(h, n, &net->ct.dying, hnnode) { |
| ct = nf_ct_tuplehash_to_ctrack(h); |
| /* never fails to remove them, no listeners at this point */ |
| nf_ct_kill(ct); |
| } |
| spin_unlock_bh(&nf_conntrack_lock); |
| } |
| |
| static int untrack_refs(void) |
| { |
| int cnt = 0, cpu; |
| |
| for_each_possible_cpu(cpu) { |
| struct nf_conn *ct = &per_cpu(nf_conntrack_untracked, cpu); |
| |
| cnt += atomic_read(&ct->ct_general.use) - 1; |
| } |
| return cnt; |
| } |
| |
| static void nf_conntrack_cleanup_init_net(void) |
| { |
| while (untrack_refs() > 0) |
| schedule(); |
| |
| nf_conntrack_helper_fini(); |
| nf_conntrack_proto_fini(); |
| #ifdef CONFIG_NF_CONNTRACK_ZONES |
| nf_ct_extend_unregister(&nf_ct_zone_extend); |
| #endif |
| } |
| |
| static void nf_conntrack_cleanup_net(struct net *net) |
| { |
| i_see_dead_people: |
| nf_ct_iterate_cleanup(net, kill_all, NULL); |
| nf_ct_release_dying_list(net); |
| if (atomic_read(&net->ct.count) != 0) { |
| schedule(); |
| goto i_see_dead_people; |
| } |
| |
| nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); |
| nf_conntrack_timeout_fini(net); |
| nf_conntrack_ecache_fini(net); |
| nf_conntrack_tstamp_fini(net); |
| nf_conntrack_acct_fini(net); |
| nf_conntrack_expect_fini(net); |
| kmem_cache_destroy(net->ct.nf_conntrack_cachep); |
| kfree(net->ct.slabname); |
| free_percpu(net->ct.stat); |
| } |
| |
| /* Mishearing the voices in his head, our hero wonders how he's |
| supposed to kill the mall. */ |
| void nf_conntrack_cleanup(struct net *net) |
| { |
| if (net_eq(net, &init_net)) |
| RCU_INIT_POINTER(ip_ct_attach, NULL); |
| |
| /* This makes sure all current packets have passed through |
| netfilter framework. Roll on, two-stage module |
| delete... */ |
| synchronize_net(); |
| |
| nf_conntrack_cleanup_net(net); |
| |
| if (net_eq(net, &init_net)) { |
| RCU_INIT_POINTER(nf_ct_destroy, NULL); |
| nf_conntrack_cleanup_init_net(); |
| } |
| } |
| |
| void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) |
| { |
| struct hlist_nulls_head *hash; |
| unsigned int nr_slots, i; |
| size_t sz; |
| |
| BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); |
| nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); |
| sz = nr_slots * sizeof(struct hlist_nulls_head); |
| hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, |
| get_order(sz)); |
| if (!hash) { |
| printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n"); |
| hash = 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; |
| 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_%pK", net); |
| if (!net->ct.slabname) { |
| ret = -ENOMEM; |
| goto err_slabname; |
| } |
| |
| net->ct.nf_conntrack_cachep = kmem_cache_create(net->ct.slabname, |
| sizeof(struct nf_conn), 0, |
| SLAB_DESTROY_BY_RCU, NULL); |
| if (!net->ct.nf_conntrack_cachep) { |
| printk(KERN_ERR "Unable to create nf_conn slab cache\n"); |
| ret = -ENOMEM; |
| goto err_cache; |
| } |
| |
| net->ct.htable_size = nf_conntrack_htable_size; |
| net->ct.hash = nf_ct_alloc_hashtable(&net->ct.htable_size, 1); |
| if (!net->ct.hash) { |
| ret = -ENOMEM; |
| printk(KERN_ERR "Unable to create nf_conntrack_hash\n"); |
| goto err_hash; |
| } |
| ret = nf_conntrack_expect_init(net); |
| if (ret < 0) |
| goto err_expect; |
| ret = nf_conntrack_acct_init(net); |
| if (ret < 0) |
| goto err_acct; |
| ret = nf_conntrack_tstamp_init(net); |
| if (ret < 0) |
| goto err_tstamp; |
| ret = nf_conntrack_ecache_init(net); |
| if (ret < 0) |
| goto err_ecache; |
| ret = nf_conntrack_timeout_init(net); |
| if (ret < 0) |
| goto err_timeout; |
| |
| return 0; |
| |
| err_timeout: |
| nf_conntrack_ecache_fini(net); |
| err_ecache: |
| nf_conntrack_tstamp_fini(net); |
| err_tstamp: |
| nf_conntrack_acct_fini(net); |
| err_acct: |
| nf_conntrack_expect_fini(net); |
| err_expect: |
| nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); |
| err_hash: |
| kmem_cache_destroy(net->ct.nf_conntrack_cachep); |
| err_cache: |
| kfree(net->ct.slabname); |
| err_slabname: |
| free_percpu(net->ct.stat); |
| err_stat: |
| return ret; |
| } |
| |
| s16 (*nf_ct_nat_offset)(const struct nf_conn *ct, |
| enum ip_conntrack_dir dir, |
| u32 seq); |
| EXPORT_SYMBOL_GPL(nf_ct_nat_offset); |
| |
| int nf_conntrack_init(struct net *net) |
| { |
| int ret; |
| |
| if (net_eq(net, &init_net)) { |
| ret = nf_conntrack_init_init_net(); |
| if (ret < 0) |
| goto out_init_net; |
| } |
| ret = nf_conntrack_init_net(net); |
| if (ret < 0) |
| goto out_net; |
| |
| if (net_eq(net, &init_net)) { |
| /* For use by REJECT target */ |
| RCU_INIT_POINTER(ip_ct_attach, nf_conntrack_attach); |
| RCU_INIT_POINTER(nf_ct_destroy, destroy_conntrack); |
| |
| /* Howto get NAT offsets */ |
| RCU_INIT_POINTER(nf_ct_nat_offset, NULL); |
| } |
| return 0; |
| |
| out_net: |
| if (net_eq(net, &init_net)) |
| nf_conntrack_cleanup_init_net(); |
| out_init_net: |
| return ret; |
| } |