The RCU protected conntrack hash lookup only checks whether the entry has a refcount of zero to decide whether it is stale. This is not sufficient, entries are explicitly removed while there is at least one reference left, possibly more. Explicitly check whether the entry has been marked as dying to fix this. Signed-off-by: Patrick McHardy <kaber@trash.net>
1364 lines
37 KiB
C
1364 lines
37 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/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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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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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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/*
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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)
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* OR
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* - Caller must lock nf_conntrack_lock before calling this function
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*/
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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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{
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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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*/
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local_bh_disable();
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begin:
|
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hlist_nulls_for_each_entry_rcu(h, n, &net->ct.hash[hash], hnnode) {
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if (nf_ct_tuple_equal(tuple, &h->tuple)) {
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NF_CT_STAT_INC(net, found);
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local_bh_enable();
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return h;
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}
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NF_CT_STAT_INC(net, searched);
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}
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/*
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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.
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*/
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if (get_nulls_value(n) != hash)
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goto begin;
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local_bh_enable();
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return NULL;
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}
|
|
EXPORT_SYMBOL_GPL(__nf_conntrack_find);
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|
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/* Find a connection corresponding to a tuple. */
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struct nf_conntrack_tuple_hash *
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nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
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{
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struct nf_conntrack_tuple_hash *h;
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struct nf_conn *ct;
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rcu_read_lock();
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begin:
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h = __nf_conntrack_find(net, tuple);
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if (h) {
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ct = nf_ct_tuplehash_to_ctrack(h);
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if (unlikely(nf_ct_is_dying(ct) ||
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!atomic_inc_not_zero(&ct->ct_general.use)))
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h = NULL;
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else {
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if (unlikely(!nf_ct_tuple_equal(tuple, &h->tuple))) {
|
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nf_ct_put(ct);
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goto begin;
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}
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}
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}
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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,
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unsigned int repl_hash)
|
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{
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struct net *net = nf_ct_net(ct);
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|
|
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hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
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&net->ct.hash[hash]);
|
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hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode,
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&net->ct.hash[repl_hash]);
|
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}
|
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|
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void nf_conntrack_hash_insert(struct nf_conn *ct)
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{
|
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unsigned int hash, repl_hash;
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|
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hash = hash_conntrack(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
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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
|
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__nf_conntrack_confirm(struct sk_buff *skb)
|
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{
|
|
unsigned int hash, repl_hash;
|
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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 && unlikely(nf_ct_is_dying(ct) ||
|
|
!atomic_inc_not_zero(&ct->ct_general.use)))
|
|
ct = NULL;
|
|
if (ct || 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);
|
|
}
|
|
}
|
|
|
|
ct = kmem_cache_zalloc(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);
|
|
}
|
|
|
|
spin_lock_init(&ct->lock);
|
|
atomic_set(&ct->ct_general.use, 1);
|
|
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *repl;
|
|
/* 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
|
|
|
|
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, 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_STATUS, 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(void)
|
|
{
|
|
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, &init_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();
|
|
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
|
|
= (((num_physpages << PAGE_SHIFT) / 16384)
|
|
/ sizeof(struct hlist_head));
|
|
if (num_physpages > (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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
return 0;
|
|
|
|
out_net:
|
|
if (net_eq(net, &init_net))
|
|
nf_conntrack_cleanup_init_net();
|
|
out_init_net:
|
|
return ret;
|
|
}
|