Add two masks for conntrack end expectation events to struct nf_conntrack_ecache and use them to filter events. Their default value is "all events" when the event sysctl is on and "no events" when it is off. A following patch will add specific initializations. Expectation events depend on the ecache struct of their master conntrack. Signed-off-by: Patrick McHardy <kaber@trash.net>
1394 lines
38 KiB
C
1394 lines
38 KiB
C
/* Connection state tracking for netfilter. This is separated from,
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but required by, the NAT layer; it can also be used by an iptables
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extension. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/netfilter.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/skbuff.h>
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#include <linux/proc_fs.h>
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#include <linux/vmalloc.h>
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#include <linux/stddef.h>
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#include <linux/slab.h>
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#include <linux/random.h>
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#include <linux/jhash.h>
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#include <linux/err.h>
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#include <linux/percpu.h>
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#include <linux/moduleparam.h>
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#include <linux/notifier.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/socket.h>
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#include <linux/mm.h>
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#include <linux/rculist_nulls.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_l3proto.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/nf_conntrack_extend.h>
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#include <net/netfilter/nf_conntrack_acct.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_core.h>
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#define NF_CONNTRACK_VERSION "0.5.0"
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int (*nfnetlink_parse_nat_setup_hook)(struct nf_conn *ct,
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enum nf_nat_manip_type manip,
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const struct nlattr *attr) __read_mostly;
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EXPORT_SYMBOL_GPL(nfnetlink_parse_nat_setup_hook);
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DEFINE_SPINLOCK(nf_conntrack_lock);
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EXPORT_SYMBOL_GPL(nf_conntrack_lock);
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unsigned int nf_conntrack_htable_size __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_htable_size);
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unsigned int nf_conntrack_max __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_max);
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struct nf_conn nf_conntrack_untracked __read_mostly;
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EXPORT_SYMBOL_GPL(nf_conntrack_untracked);
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static struct kmem_cache *nf_conntrack_cachep __read_mostly;
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static int nf_conntrack_hash_rnd_initted;
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static unsigned int nf_conntrack_hash_rnd;
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static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
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unsigned int size, unsigned int rnd)
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{
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unsigned int n;
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u_int32_t h;
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/* The direction must be ignored, so we hash everything up to the
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* destination ports (which is a multiple of 4) and treat the last
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* three bytes manually.
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*/
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n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
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h = jhash2((u32 *)tuple, n,
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rnd ^ (((__force __u16)tuple->dst.u.all << 16) |
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tuple->dst.protonum));
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return ((u64)h * size) >> 32;
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}
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static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
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{
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return __hash_conntrack(tuple, nf_conntrack_htable_size,
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nf_conntrack_hash_rnd);
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}
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bool
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nf_ct_get_tuple(const struct sk_buff *skb,
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unsigned int nhoff,
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unsigned int dataoff,
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u_int16_t l3num,
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u_int8_t protonum,
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struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_l3proto *l3proto,
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const struct nf_conntrack_l4proto *l4proto)
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{
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memset(tuple, 0, sizeof(*tuple));
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tuple->src.l3num = l3num;
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if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
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return false;
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tuple->dst.protonum = protonum;
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tuple->dst.dir = IP_CT_DIR_ORIGINAL;
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return l4proto->pkt_to_tuple(skb, dataoff, tuple);
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}
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EXPORT_SYMBOL_GPL(nf_ct_get_tuple);
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bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
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u_int16_t l3num, struct nf_conntrack_tuple *tuple)
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{
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struct nf_conntrack_l3proto *l3proto;
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struct nf_conntrack_l4proto *l4proto;
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unsigned int protoff;
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u_int8_t protonum;
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int ret;
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rcu_read_lock();
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l3proto = __nf_ct_l3proto_find(l3num);
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ret = l3proto->get_l4proto(skb, nhoff, &protoff, &protonum);
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if (ret != NF_ACCEPT) {
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rcu_read_unlock();
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return false;
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}
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l4proto = __nf_ct_l4proto_find(l3num, protonum);
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ret = nf_ct_get_tuple(skb, nhoff, protoff, l3num, protonum, tuple,
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l3proto, l4proto);
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rcu_read_unlock();
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return ret;
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}
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EXPORT_SYMBOL_GPL(nf_ct_get_tuplepr);
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bool
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nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
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const struct nf_conntrack_tuple *orig,
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const struct nf_conntrack_l3proto *l3proto,
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const struct nf_conntrack_l4proto *l4proto)
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{
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memset(inverse, 0, sizeof(*inverse));
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inverse->src.l3num = orig->src.l3num;
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if (l3proto->invert_tuple(inverse, orig) == 0)
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return false;
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inverse->dst.dir = !orig->dst.dir;
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inverse->dst.protonum = orig->dst.protonum;
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return l4proto->invert_tuple(inverse, orig);
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}
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EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
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static void
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clean_from_lists(struct nf_conn *ct)
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{
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pr_debug("clean_from_lists(%p)\n", ct);
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hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
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hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
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/* Destroy all pending expectations */
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nf_ct_remove_expectations(ct);
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}
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static void
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destroy_conntrack(struct nf_conntrack *nfct)
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{
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struct nf_conn *ct = (struct nf_conn *)nfct;
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struct net *net = nf_ct_net(ct);
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struct nf_conntrack_l4proto *l4proto;
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pr_debug("destroy_conntrack(%p)\n", ct);
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NF_CT_ASSERT(atomic_read(&nfct->use) == 0);
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NF_CT_ASSERT(!timer_pending(&ct->timeout));
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/* To make sure we don't get any weird locking issues here:
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* destroy_conntrack() MUST NOT be called with a write lock
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* to nf_conntrack_lock!!! -HW */
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rcu_read_lock();
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l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
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if (l4proto && l4proto->destroy)
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l4proto->destroy(ct);
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rcu_read_unlock();
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spin_lock_bh(&nf_conntrack_lock);
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/* Expectations will have been removed in clean_from_lists,
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* except TFTP can create an expectation on the first packet,
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* before connection is in the list, so we need to clean here,
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* too. */
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nf_ct_remove_expectations(ct);
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/* We overload first tuple to link into unconfirmed list. */
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if (!nf_ct_is_confirmed(ct)) {
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BUG_ON(hlist_nulls_unhashed(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode));
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hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
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}
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NF_CT_STAT_INC(net, delete);
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spin_unlock_bh(&nf_conntrack_lock);
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if (ct->master)
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nf_ct_put(ct->master);
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pr_debug("destroy_conntrack: returning ct=%p to slab\n", ct);
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nf_conntrack_free(ct);
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}
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void nf_ct_delete_from_lists(struct nf_conn *ct)
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{
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struct net *net = nf_ct_net(ct);
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nf_ct_helper_destroy(ct);
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spin_lock_bh(&nf_conntrack_lock);
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/* Inside lock so preempt is disabled on module removal path.
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* Otherwise we can get spurious warnings. */
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NF_CT_STAT_INC(net, delete_list);
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clean_from_lists(ct);
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spin_unlock_bh(&nf_conntrack_lock);
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}
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EXPORT_SYMBOL_GPL(nf_ct_delete_from_lists);
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static void death_by_event(unsigned long ul_conntrack)
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{
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struct nf_conn *ct = (void *)ul_conntrack;
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struct net *net = nf_ct_net(ct);
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if (nf_conntrack_event(IPCT_DESTROY, ct) < 0) {
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/* bad luck, let's retry again */
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ct->timeout.expires = jiffies +
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(random32() % net->ct.sysctl_events_retry_timeout);
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add_timer(&ct->timeout);
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return;
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}
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/* we've got the event delivered, now it's dying */
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set_bit(IPS_DYING_BIT, &ct->status);
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spin_lock(&nf_conntrack_lock);
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hlist_nulls_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
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spin_unlock(&nf_conntrack_lock);
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nf_ct_put(ct);
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}
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void nf_ct_insert_dying_list(struct nf_conn *ct)
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{
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struct net *net = nf_ct_net(ct);
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/* add this conntrack to the dying list */
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spin_lock_bh(&nf_conntrack_lock);
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hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
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&net->ct.dying);
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spin_unlock_bh(&nf_conntrack_lock);
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/* set a new timer to retry event delivery */
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setup_timer(&ct->timeout, death_by_event, (unsigned long)ct);
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ct->timeout.expires = jiffies +
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(random32() % net->ct.sysctl_events_retry_timeout);
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add_timer(&ct->timeout);
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}
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EXPORT_SYMBOL_GPL(nf_ct_insert_dying_list);
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static void death_by_timeout(unsigned long ul_conntrack)
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{
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struct nf_conn *ct = (void *)ul_conntrack;
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|
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if (!test_bit(IPS_DYING_BIT, &ct->status) &&
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unlikely(nf_conntrack_event(IPCT_DESTROY, ct) < 0)) {
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/* destroy event was not delivered */
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nf_ct_delete_from_lists(ct);
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nf_ct_insert_dying_list(ct);
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return;
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}
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set_bit(IPS_DYING_BIT, &ct->status);
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nf_ct_delete_from_lists(ct);
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nf_ct_put(ct);
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}
|
|
|
|
/*
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* Warning :
|
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* - Caller must take a reference on returned object
|
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* and recheck nf_ct_tuple_equal(tuple, &h->tuple)
|
|
* OR
|
|
* - Caller must lock nf_conntrack_lock before calling this function
|
|
*/
|
|
struct nf_conntrack_tuple_hash *
|
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__nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple)
|
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{
|
|
struct nf_conntrack_tuple_hash *h;
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struct hlist_nulls_node *n;
|
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unsigned int hash = hash_conntrack(tuple);
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|
|
|
/* Disable BHs the entire time since we normally need to disable them
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* at least once for the stats anyway.
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|
*/
|
|
local_bh_disable();
|
|
begin:
|
|
hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
|
|
if (nf_ct_tuple_equal(tuple, &h->tuple)) {
|
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NF_CT_STAT_INC(net, found);
|
|
local_bh_enable();
|
|
return h;
|
|
}
|
|
NF_CT_STAT_INC(net, searched);
|
|
}
|
|
/*
|
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* if the nulls value we got at the end of this lookup is
|
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* not the expected one, we must restart lookup.
|
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* We probably met an item that was moved to another chain.
|
|
*/
|
|
if (get_nulls_value(n) != hash)
|
|
goto begin;
|
|
local_bh_enable();
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_conntrack_find);
|
|
|
|
/* Find a connection corresponding to a tuple. */
|
|
struct nf_conntrack_tuple_hash *
|
|
nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
struct nf_conntrack_tuple_hash *h;
|
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struct nf_conn *ct;
|
|
|
|
rcu_read_lock();
|
|
begin:
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|
h = __nf_conntrack_find(net, tuple);
|
|
if (h) {
|
|
ct = nf_ct_tuplehash_to_ctrack(h);
|
|
if (unlikely(nf_ct_is_dying(ct) ||
|
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!atomic_inc_not_zero(&ct->ct_general.use)))
|
|
h = NULL;
|
|
else {
|
|
if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple))) {
|
|
nf_ct_put(ct);
|
|
goto begin;
|
|
}
|
|
}
|
|
}
|
|
rcu_read_unlock();
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|
|
|
return h;
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}
|
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EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
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|
|
|
static void __nf_conntrack_hash_insert(struct nf_conn *ct,
|
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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,
|
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&net->ct.hash[repl_hash]);
|
|
}
|
|
|
|
void nf_conntrack_hash_insert(struct nf_conn *ct)
|
|
{
|
|
unsigned int hash, repl_hash;
|
|
|
|
hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
repl_hash = hash_conntrack(&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;
|
|
|
|
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;
|
|
|
|
hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
repl_hash = hash_conntrack(&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);
|
|
|
|
/* 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))
|
|
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))
|
|
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);
|
|
set_bit(IPS_CONFIRMED_BIT, &ct->status);
|
|
|
|
/* 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;
|
|
unsigned int hash = hash_conntrack(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) {
|
|
if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack &&
|
|
nf_ct_tuple_equal(tuple, &h->tuple)) {
|
|
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 < nf_conntrack_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) % nf_conntrack_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;
|
|
}
|
|
|
|
struct nf_conn *nf_conntrack_alloc(struct net *net,
|
|
const struct nf_conntrack_tuple *orig,
|
|
const struct nf_conntrack_tuple *repl,
|
|
gfp_t gfp)
|
|
{
|
|
struct nf_conn *ct;
|
|
|
|
if (unlikely(!nf_conntrack_hash_rnd_initted)) {
|
|
get_random_bytes(&nf_conntrack_hash_rnd,
|
|
sizeof(nf_conntrack_hash_rnd));
|
|
nf_conntrack_hash_rnd_initted = 1;
|
|
}
|
|
|
|
/* 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)) {
|
|
unsigned int hash = hash_conntrack(orig);
|
|
if (!early_drop(net, hash)) {
|
|
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(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,
|
|
sizeof(*ct) - 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;
|
|
ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev = NULL;
|
|
/* Don't set timer yet: wait for confirmation */
|
|
setup_timer(&ct->timeout, death_by_timeout, (unsigned long)ct);
|
|
#ifdef CONFIG_NET_NS
|
|
ct->ct_net = net;
|
|
#endif
|
|
|
|
/*
|
|
* changes to lookup keys must be done before setting refcnt to 1
|
|
*/
|
|
smp_wmb();
|
|
atomic_set(&ct->ct_general.use, 1);
|
|
return ct;
|
|
}
|
|
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(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,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
struct nf_conntrack_l3proto *l3proto,
|
|
struct nf_conntrack_l4proto *l4proto,
|
|
struct sk_buff *skb,
|
|
unsigned int dataoff)
|
|
{
|
|
struct nf_conn *ct;
|
|
struct nf_conn_help *help;
|
|
struct nf_conntrack_tuple repl_tuple;
|
|
struct nf_conntrack_expect *exp;
|
|
|
|
if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
|
|
pr_debug("Can't invert tuple.\n");
|
|
return NULL;
|
|
}
|
|
|
|
ct = nf_conntrack_alloc(net, tuple, &repl_tuple, GFP_ATOMIC);
|
|
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);
|
|
nf_ct_ecache_ext_add(ct, 0, 0, GFP_ATOMIC);
|
|
|
|
spin_lock_bh(&nf_conntrack_lock);
|
|
exp = nf_ct_find_expectation(net, 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, 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 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;
|
|
|
|
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 */
|
|
h = nf_conntrack_find_get(net, &tuple);
|
|
if (!h) {
|
|
h = init_conntrack(net, &tuple, l3proto, l4proto, skb, dataoff);
|
|
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;
|
|
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;
|
|
|
|
/* Previously seen (loopback or untracked)? Ignore. */
|
|
if (skb->nfct) {
|
|
NF_CT_STAT_INC_ATOMIC(net, ignore);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
/* 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);
|
|
return -ret;
|
|
}
|
|
|
|
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, skb, dataoff, &ctinfo, pf, hooknum);
|
|
if (ret <= 0) {
|
|
NF_CT_STAT_INC_ATOMIC(net, error);
|
|
NF_CT_STAT_INC_ATOMIC(net, invalid);
|
|
return -ret;
|
|
}
|
|
}
|
|
|
|
ct = resolve_normal_ct(net, skb, dataoff, pf, protonum,
|
|
l3proto, l4proto, &set_reply, &ctinfo);
|
|
if (!ct) {
|
|
/* Not valid part of a connection */
|
|
NF_CT_STAT_INC_ATOMIC(net, invalid);
|
|
return NF_ACCEPT;
|
|
}
|
|
|
|
if (IS_ERR(ct)) {
|
|
/* Too stressed to deal. */
|
|
NF_CT_STAT_INC_ATOMIC(net, drop);
|
|
return NF_DROP;
|
|
}
|
|
|
|
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);
|
|
return -ret;
|
|
}
|
|
|
|
if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
|
|
nf_conntrack_event_cache(IPCT_REPLY, ct);
|
|
|
|
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, 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 - skb_network_offset(skb);
|
|
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);
|
|
|
|
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
|
|
|
|
#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 + 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 < nf_conntrack_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, int vmalloced, unsigned int size)
|
|
{
|
|
if (vmalloced)
|
|
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 void nf_conntrack_cleanup_init_net(void)
|
|
{
|
|
nf_conntrack_helper_fini();
|
|
nf_conntrack_proto_fini();
|
|
kmem_cache_destroy(nf_conntrack_cachep);
|
|
}
|
|
|
|
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;
|
|
}
|
|
/* wait until all references to nf_conntrack_untracked are dropped */
|
|
while (atomic_read(&nf_conntrack_untracked.ct_general.use) > 1)
|
|
schedule();
|
|
|
|
nf_ct_free_hashtable(net->ct.hash, net->ct.hash_vmalloc,
|
|
nf_conntrack_htable_size);
|
|
nf_conntrack_ecache_fini(net);
|
|
nf_conntrack_acct_fini(net);
|
|
nf_conntrack_expect_fini(net);
|
|
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 *vmalloced, int nulls)
|
|
{
|
|
struct hlist_nulls_head *hash;
|
|
unsigned int nr_slots, i;
|
|
size_t sz;
|
|
|
|
*vmalloced = 0;
|
|
|
|
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) {
|
|
*vmalloced = 1;
|
|
printk(KERN_WARNING "nf_conntrack: falling back to vmalloc.\n");
|
|
hash = __vmalloc(sz, GFP_KERNEL | __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, vmalloced, old_vmalloced;
|
|
unsigned int hashsize, old_size;
|
|
int rnd;
|
|
struct hlist_nulls_head *hash, *old_hash;
|
|
struct nf_conntrack_tuple_hash *h;
|
|
|
|
/* 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, &vmalloced, 1);
|
|
if (!hash)
|
|
return -ENOMEM;
|
|
|
|
/* We have to rehahs for the new table anyway, so we also can
|
|
* use a newrandom seed */
|
|
get_random_bytes(&rnd, sizeof(rnd));
|
|
|
|
/* 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 < nf_conntrack_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);
|
|
hlist_nulls_del_rcu(&h->hnnode);
|
|
bucket = __hash_conntrack(&h->tuple, hashsize, rnd);
|
|
hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
|
|
}
|
|
}
|
|
old_size = nf_conntrack_htable_size;
|
|
old_vmalloced = init_net.ct.hash_vmalloc;
|
|
old_hash = init_net.ct.hash;
|
|
|
|
nf_conntrack_htable_size = hashsize;
|
|
init_net.ct.hash_vmalloc = vmalloced;
|
|
init_net.ct.hash = hash;
|
|
nf_conntrack_hash_rnd = rnd;
|
|
spin_unlock_bh(&nf_conntrack_lock);
|
|
|
|
nf_ct_free_hashtable(old_hash, old_vmalloced, 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);
|
|
|
|
static int nf_conntrack_init_init_net(void)
|
|
{
|
|
int max_factor = 8;
|
|
int ret;
|
|
|
|
/* 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("nf_conntrack version %s (%u buckets, %d max)\n",
|
|
NF_CONNTRACK_VERSION, nf_conntrack_htable_size,
|
|
nf_conntrack_max);
|
|
|
|
nf_conntrack_cachep = kmem_cache_create("nf_conntrack",
|
|
sizeof(struct nf_conn),
|
|
0, SLAB_DESTROY_BY_RCU, NULL);
|
|
if (!nf_conntrack_cachep) {
|
|
printk(KERN_ERR "Unable to create nf_conn slab cache\n");
|
|
ret = -ENOMEM;
|
|
goto err_cache;
|
|
}
|
|
|
|
ret = nf_conntrack_proto_init();
|
|
if (ret < 0)
|
|
goto err_proto;
|
|
|
|
ret = nf_conntrack_helper_init();
|
|
if (ret < 0)
|
|
goto err_helper;
|
|
|
|
return 0;
|
|
|
|
err_helper:
|
|
nf_conntrack_proto_fini();
|
|
err_proto:
|
|
kmem_cache_destroy(nf_conntrack_cachep);
|
|
err_cache:
|
|
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.hash = nf_ct_alloc_hashtable(&nf_conntrack_htable_size,
|
|
&net->ct.hash_vmalloc, 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;
|
|
|
|
/* Set up fake conntrack:
|
|
- to never be deleted, not in any hashes */
|
|
#ifdef CONFIG_NET_NS
|
|
nf_conntrack_untracked.ct_net = &init_net;
|
|
#endif
|
|
atomic_set(&nf_conntrack_untracked.ct_general.use, 1);
|
|
/* - and look it like as a confirmed connection */
|
|
set_bit(IPS_CONFIRMED_BIT, &nf_conntrack_untracked.status);
|
|
|
|
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.hash_vmalloc,
|
|
nf_conntrack_htable_size);
|
|
err_hash:
|
|
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;
|
|
}
|