Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 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> |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 19 | #include <linux/kernel.h> |
| 20 | #include <linux/netdevice.h> |
| 21 | |
| 22 | #include <net/netfilter/nf_conntrack.h> |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 23 | #include <net/netfilter/nf_conntrack_core.h> |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 24 | #include <net/netfilter/nf_conntrack_extend.h> |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 25 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 26 | static DEFINE_MUTEX(nf_ct_ecache_mutex); |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 27 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 28 | struct nf_ct_event_notifier *nf_conntrack_event_cb __read_mostly; |
| 29 | EXPORT_SYMBOL_GPL(nf_conntrack_event_cb); |
| 30 | |
| 31 | struct nf_exp_event_notifier *nf_expect_event_cb __read_mostly; |
| 32 | EXPORT_SYMBOL_GPL(nf_expect_event_cb); |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 33 | |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 34 | /* deliver cached events and clear cache entry - must be called with locally |
| 35 | * disabled softirqs */ |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 36 | void nf_ct_deliver_cached_events(struct nf_conn *ct) |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 37 | { |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 38 | unsigned long events; |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 39 | struct nf_ct_event_notifier *notify; |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 40 | struct nf_conntrack_ecache *e; |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 41 | |
| 42 | rcu_read_lock(); |
| 43 | notify = rcu_dereference(nf_conntrack_event_cb); |
| 44 | if (notify == NULL) |
| 45 | goto out_unlock; |
| 46 | |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 47 | e = nf_ct_ecache_find(ct); |
| 48 | if (e == NULL) |
| 49 | goto out_unlock; |
| 50 | |
| 51 | events = xchg(&e->cache, 0); |
| 52 | |
| 53 | if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct) && events) { |
Pablo Neira Ayuso | 19abb7b | 2008-11-18 11:56:20 +0100 | [diff] [blame] | 54 | struct nf_ct_event item = { |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 55 | .ct = ct, |
Pablo Neira Ayuso | 19abb7b | 2008-11-18 11:56:20 +0100 | [diff] [blame] | 56 | .pid = 0, |
| 57 | .report = 0 |
| 58 | }; |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 59 | int ret; |
| 60 | /* We make a copy of the missed event cache without taking |
| 61 | * the lock, thus we may send missed events twice. However, |
| 62 | * this does not harm and it happens very rarely. */ |
| 63 | unsigned long missed = e->missed; |
Pablo Neira Ayuso | 19abb7b | 2008-11-18 11:56:20 +0100 | [diff] [blame] | 64 | |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 65 | ret = notify->fcn(events | missed, &item); |
| 66 | if (unlikely(ret < 0 || missed)) { |
| 67 | spin_lock_bh(&ct->lock); |
| 68 | if (ret < 0) |
| 69 | e->missed |= events; |
| 70 | else |
| 71 | e->missed &= ~missed; |
| 72 | spin_unlock_bh(&ct->lock); |
| 73 | } |
Pablo Neira Ayuso | 19abb7b | 2008-11-18 11:56:20 +0100 | [diff] [blame] | 74 | } |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 75 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 76 | out_unlock: |
| 77 | rcu_read_unlock(); |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 78 | } |
Patrick McHardy | 13b1833 | 2006-12-02 22:11:25 -0800 | [diff] [blame] | 79 | EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); |
Martin Josefsson | f618012 | 2006-11-29 02:35:01 +0100 | [diff] [blame] | 80 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 81 | int nf_conntrack_register_notifier(struct nf_ct_event_notifier *new) |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 82 | { |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 83 | int ret = 0; |
| 84 | struct nf_ct_event_notifier *notify; |
| 85 | |
| 86 | mutex_lock(&nf_ct_ecache_mutex); |
| 87 | notify = rcu_dereference(nf_conntrack_event_cb); |
| 88 | if (notify != NULL) { |
| 89 | ret = -EBUSY; |
| 90 | goto out_unlock; |
| 91 | } |
| 92 | rcu_assign_pointer(nf_conntrack_event_cb, new); |
| 93 | mutex_unlock(&nf_ct_ecache_mutex); |
| 94 | return ret; |
| 95 | |
| 96 | out_unlock: |
| 97 | mutex_unlock(&nf_ct_ecache_mutex); |
| 98 | return ret; |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 99 | } |
| 100 | EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier); |
| 101 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 102 | void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *new) |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 103 | { |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 104 | struct nf_ct_event_notifier *notify; |
| 105 | |
| 106 | mutex_lock(&nf_ct_ecache_mutex); |
| 107 | notify = rcu_dereference(nf_conntrack_event_cb); |
| 108 | BUG_ON(notify != new); |
| 109 | rcu_assign_pointer(nf_conntrack_event_cb, NULL); |
| 110 | mutex_unlock(&nf_ct_ecache_mutex); |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 111 | } |
| 112 | EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier); |
| 113 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 114 | int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *new) |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 115 | { |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 116 | int ret = 0; |
| 117 | struct nf_exp_event_notifier *notify; |
| 118 | |
| 119 | mutex_lock(&nf_ct_ecache_mutex); |
| 120 | notify = rcu_dereference(nf_expect_event_cb); |
| 121 | if (notify != NULL) { |
| 122 | ret = -EBUSY; |
| 123 | goto out_unlock; |
| 124 | } |
| 125 | rcu_assign_pointer(nf_expect_event_cb, new); |
| 126 | mutex_unlock(&nf_ct_ecache_mutex); |
| 127 | return ret; |
| 128 | |
| 129 | out_unlock: |
| 130 | mutex_unlock(&nf_ct_ecache_mutex); |
| 131 | return ret; |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 132 | } |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 133 | EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier); |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 134 | |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 135 | void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *new) |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 136 | { |
Pablo Neira Ayuso | e34d5c1 | 2009-06-03 10:32:06 +0200 | [diff] [blame] | 137 | struct nf_exp_event_notifier *notify; |
| 138 | |
| 139 | mutex_lock(&nf_ct_ecache_mutex); |
| 140 | notify = rcu_dereference(nf_expect_event_cb); |
| 141 | BUG_ON(notify != new); |
| 142 | rcu_assign_pointer(nf_expect_event_cb, NULL); |
| 143 | mutex_unlock(&nf_ct_ecache_mutex); |
Patrick McHardy | 010c7d6 | 2007-03-14 16:40:10 -0700 | [diff] [blame] | 144 | } |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 145 | EXPORT_SYMBOL_GPL(nf_ct_expect_unregister_notifier); |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 146 | |
| 147 | #define NF_CT_EVENTS_DEFAULT 1 |
| 148 | static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT; |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 149 | static int nf_ct_events_retry_timeout __read_mostly = 15*HZ; |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 150 | |
| 151 | #ifdef CONFIG_SYSCTL |
| 152 | static struct ctl_table event_sysctl_table[] = { |
| 153 | { |
| 154 | .ctl_name = CTL_UNNUMBERED, |
| 155 | .procname = "nf_conntrack_events", |
| 156 | .data = &init_net.ct.sysctl_events, |
| 157 | .maxlen = sizeof(unsigned int), |
| 158 | .mode = 0644, |
| 159 | .proc_handler = proc_dointvec, |
| 160 | }, |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 161 | { |
| 162 | .ctl_name = CTL_UNNUMBERED, |
| 163 | .procname = "nf_conntrack_events_retry_timeout", |
| 164 | .data = &init_net.ct.sysctl_events_retry_timeout, |
| 165 | .maxlen = sizeof(unsigned int), |
| 166 | .mode = 0644, |
| 167 | .proc_handler = proc_dointvec_jiffies, |
| 168 | }, |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 169 | {} |
| 170 | }; |
| 171 | #endif /* CONFIG_SYSCTL */ |
| 172 | |
| 173 | static struct nf_ct_ext_type event_extend __read_mostly = { |
| 174 | .len = sizeof(struct nf_conntrack_ecache), |
| 175 | .align = __alignof__(struct nf_conntrack_ecache), |
| 176 | .id = NF_CT_EXT_ECACHE, |
| 177 | }; |
| 178 | |
| 179 | #ifdef CONFIG_SYSCTL |
| 180 | static int nf_conntrack_event_init_sysctl(struct net *net) |
| 181 | { |
| 182 | struct ctl_table *table; |
| 183 | |
| 184 | table = kmemdup(event_sysctl_table, sizeof(event_sysctl_table), |
| 185 | GFP_KERNEL); |
| 186 | if (!table) |
| 187 | goto out; |
| 188 | |
| 189 | table[0].data = &net->ct.sysctl_events; |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 190 | table[1].data = &net->ct.sysctl_events_retry_timeout; |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 191 | |
| 192 | net->ct.event_sysctl_header = |
| 193 | register_net_sysctl_table(net, |
| 194 | nf_net_netfilter_sysctl_path, table); |
| 195 | if (!net->ct.event_sysctl_header) { |
| 196 | printk(KERN_ERR "nf_ct_event: can't register to sysctl.\n"); |
| 197 | goto out_register; |
| 198 | } |
| 199 | return 0; |
| 200 | |
| 201 | out_register: |
| 202 | kfree(table); |
| 203 | out: |
| 204 | return -ENOMEM; |
| 205 | } |
| 206 | |
| 207 | static void nf_conntrack_event_fini_sysctl(struct net *net) |
| 208 | { |
| 209 | struct ctl_table *table; |
| 210 | |
| 211 | table = net->ct.event_sysctl_header->ctl_table_arg; |
| 212 | unregister_net_sysctl_table(net->ct.event_sysctl_header); |
| 213 | kfree(table); |
| 214 | } |
| 215 | #else |
| 216 | static int nf_conntrack_event_init_sysctl(struct net *net) |
| 217 | { |
| 218 | return 0; |
| 219 | } |
| 220 | |
| 221 | static void nf_conntrack_event_fini_sysctl(struct net *net) |
| 222 | { |
| 223 | } |
| 224 | #endif /* CONFIG_SYSCTL */ |
| 225 | |
| 226 | int nf_conntrack_ecache_init(struct net *net) |
| 227 | { |
| 228 | int ret; |
| 229 | |
| 230 | net->ct.sysctl_events = nf_ct_events; |
Pablo Neira Ayuso | dd7669a | 2009-06-13 12:30:52 +0200 | [diff] [blame] | 231 | net->ct.sysctl_events_retry_timeout = nf_ct_events_retry_timeout; |
Pablo Neira Ayuso | a0891aa | 2009-06-13 12:26:29 +0200 | [diff] [blame] | 232 | |
| 233 | if (net_eq(net, &init_net)) { |
| 234 | ret = nf_ct_extend_register(&event_extend); |
| 235 | if (ret < 0) { |
| 236 | printk(KERN_ERR "nf_ct_event: Unable to register " |
| 237 | "event extension.\n"); |
| 238 | goto out_extend_register; |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | ret = nf_conntrack_event_init_sysctl(net); |
| 243 | if (ret < 0) |
| 244 | goto out_sysctl; |
| 245 | |
| 246 | return 0; |
| 247 | |
| 248 | out_sysctl: |
| 249 | if (net_eq(net, &init_net)) |
| 250 | nf_ct_extend_unregister(&event_extend); |
| 251 | out_extend_register: |
| 252 | return ret; |
| 253 | } |
| 254 | |
| 255 | void nf_conntrack_ecache_fini(struct net *net) |
| 256 | { |
| 257 | nf_conntrack_event_fini_sysctl(net); |
| 258 | if (net_eq(net, &init_net)) |
| 259 | nf_ct_extend_unregister(&event_extend); |
| 260 | } |