git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| f6180121 MJ |
1 | /* Event cache for netfilter. */ |
| 2 | ||
| 3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
| 4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> | |
| 5 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/types.h> | |
| 13 | #include <linux/netfilter.h> | |
| 14 | #include <linux/skbuff.h> | |
| 15 | #include <linux/vmalloc.h> | |
| 16 | #include <linux/stddef.h> | |
| 17 | #include <linux/err.h> | |
| 18 | #include <linux/percpu.h> | |
| 19 | #include <linux/notifier.h> | |
| 20 | #include <linux/kernel.h> | |
| 21 | #include <linux/netdevice.h> | |
| 22 | ||
| 23 | #include <net/netfilter/nf_conntrack.h> | |
| 24 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
| 605dcad6 | 25 | #include <net/netfilter/nf_conntrack_l4proto.h> |
| f6180121 MJ |
26 | #include <net/netfilter/nf_conntrack_expect.h> |
| 27 | #include <net/netfilter/nf_conntrack_helper.h> | |
| 28 | #include <net/netfilter/nf_conntrack_core.h> | |
| 29 | ||
| 30 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_chain); | |
| 31 | ATOMIC_NOTIFIER_HEAD(nf_conntrack_expect_chain); | |
| 32 | ||
| 33 | DEFINE_PER_CPU(struct nf_conntrack_ecache, nf_conntrack_ecache); | |
| 34 | ||
| 35 | /* deliver cached events and clear cache entry - must be called with locally | |
| 36 | * disabled softirqs */ | |
| 37 | static inline void | |
| 38 | __nf_ct_deliver_cached_events(struct nf_conntrack_ecache *ecache) | |
| 39 | { | |
| 40 | if (nf_ct_is_confirmed(ecache->ct) && !nf_ct_is_dying(ecache->ct) | |
| 41 | && ecache->events) | |
| 42 | atomic_notifier_call_chain(&nf_conntrack_chain, ecache->events, | |
| 43 | ecache->ct); | |
| 44 | ||
| 45 | ecache->events = 0; | |
| 46 | nf_ct_put(ecache->ct); | |
| 47 | ecache->ct = NULL; | |
| 48 | } | |
| 49 | ||
| 50 | /* Deliver all cached events for a particular conntrack. This is called | |
| 51 | * by code prior to async packet handling for freeing the skb */ | |
| 52 | void nf_ct_deliver_cached_events(const struct nf_conn *ct) | |
| 53 | { | |
| 54 | struct nf_conntrack_ecache *ecache; | |
| 55 | ||
| 56 | local_bh_disable(); | |
| 57 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
| 58 | if (ecache->ct == ct) | |
| 59 | __nf_ct_deliver_cached_events(ecache); | |
| 60 | local_bh_enable(); | |
| 61 | } | |
| 62 | ||
| 63 | /* Deliver cached events for old pending events, if current conntrack != old */ | |
| 64 | void __nf_ct_event_cache_init(struct nf_conn *ct) | |
| 65 | { | |
| 66 | struct nf_conntrack_ecache *ecache; | |
| 67 | ||
| 68 | /* take care of delivering potentially old events */ | |
| 69 | ecache = &__get_cpu_var(nf_conntrack_ecache); | |
| 70 | BUG_ON(ecache->ct == ct); | |
| 71 | if (ecache->ct) | |
| 72 | __nf_ct_deliver_cached_events(ecache); | |
| 73 | /* initialize for this conntrack/packet */ | |
| 74 | ecache->ct = ct; | |
| 75 | nf_conntrack_get(&ct->ct_general); | |
| 76 | } | |
| 77 | ||
| 78 | /* flush the event cache - touches other CPU's data and must not be called | |
| 79 | * while packets are still passing through the code */ | |
| 80 | void nf_ct_event_cache_flush(void) | |
| 81 | { | |
| 82 | struct nf_conntrack_ecache *ecache; | |
| 83 | int cpu; | |
| 84 | ||
| 85 | for_each_possible_cpu(cpu) { | |
| 86 | ecache = &per_cpu(nf_conntrack_ecache, cpu); | |
| 87 | if (ecache->ct) | |
| 88 | nf_ct_put(ecache->ct); | |
| 89 | } | |
| 90 | } | |
| 91 |