[NETFILTER]: ebt_mark: add or/and/xor action support to mark target
[linux-2.6.git] / net / bridge / br_fdb.c
1 /*
2  *      Forwarding database
3  *      Linux ethernet bridge
4  *
5  *      Authors:
6  *      Lennert Buytenhek               <buytenh@gnu.org>
7  *
8  *      $Id: br_fdb.c,v 1.6 2002/01/17 00:57:07 davem Exp $
9  *
10  *      This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/spinlock.h>
19 #include <linux/times.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/jhash.h>
23 #include <asm/atomic.h>
24 #include "br_private.h"
25
26 static kmem_cache_t *br_fdb_cache __read_mostly;
27 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
28                       const unsigned char *addr);
29
30 void __init br_fdb_init(void)
31 {
32         br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
33                                          sizeof(struct net_bridge_fdb_entry),
34                                          0,
35                                          SLAB_HWCACHE_ALIGN, NULL, NULL);
36 }
37
38 void __exit br_fdb_fini(void)
39 {
40         kmem_cache_destroy(br_fdb_cache);
41 }
42
43
44 /* if topology_changing then use forward_delay (default 15 sec)
45  * otherwise keep longer (default 5 minutes)
46  */
47 static __inline__ unsigned long hold_time(const struct net_bridge *br)
48 {
49         return br->topology_change ? br->forward_delay : br->ageing_time;
50 }
51
52 static __inline__ int has_expired(const struct net_bridge *br,
53                                   const struct net_bridge_fdb_entry *fdb)
54 {
55         return !fdb->is_static 
56                 && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
57 }
58
59 static __inline__ int br_mac_hash(const unsigned char *mac)
60 {
61         return jhash(mac, ETH_ALEN, 0) & (BR_HASH_SIZE - 1);
62 }
63
64 static __inline__ void fdb_delete(struct net_bridge_fdb_entry *f)
65 {
66         hlist_del_rcu(&f->hlist);
67         br_fdb_put(f);
68 }
69
70 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
71 {
72         struct net_bridge *br = p->br;
73         int i;
74         
75         spin_lock_bh(&br->hash_lock);
76
77         /* Search all chains since old address/hash is unknown */
78         for (i = 0; i < BR_HASH_SIZE; i++) {
79                 struct hlist_node *h;
80                 hlist_for_each(h, &br->hash[i]) {
81                         struct net_bridge_fdb_entry *f;
82
83                         f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
84                         if (f->dst == p && f->is_local) {
85                                 /* maybe another port has same hw addr? */
86                                 struct net_bridge_port *op;
87                                 list_for_each_entry(op, &br->port_list, list) {
88                                         if (op != p && 
89                                             !compare_ether_addr(op->dev->dev_addr,
90                                                                 f->addr.addr)) {
91                                                 f->dst = op;
92                                                 goto insert;
93                                         }
94                                 }
95
96                                 /* delete old one */
97                                 fdb_delete(f);
98                                 goto insert;
99                         }
100                 }
101         }
102  insert:
103         /* insert new address,  may fail if invalid address or dup. */
104         fdb_insert(br, p, newaddr);
105
106         spin_unlock_bh(&br->hash_lock);
107 }
108
109 void br_fdb_cleanup(unsigned long _data)
110 {
111         struct net_bridge *br = (struct net_bridge *)_data;
112         unsigned long delay = hold_time(br);
113         int i;
114
115         spin_lock_bh(&br->hash_lock);
116         for (i = 0; i < BR_HASH_SIZE; i++) {
117                 struct net_bridge_fdb_entry *f;
118                 struct hlist_node *h, *n;
119
120                 hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
121                         if (!f->is_static && 
122                             time_before_eq(f->ageing_timer + delay, jiffies)) 
123                                 fdb_delete(f);
124                 }
125         }
126         spin_unlock_bh(&br->hash_lock);
127
128         mod_timer(&br->gc_timer, jiffies + HZ/10);
129 }
130
131 void br_fdb_delete_by_port(struct net_bridge *br, struct net_bridge_port *p)
132 {
133         int i;
134
135         spin_lock_bh(&br->hash_lock);
136         for (i = 0; i < BR_HASH_SIZE; i++) {
137                 struct hlist_node *h, *g;
138                 
139                 hlist_for_each_safe(h, g, &br->hash[i]) {
140                         struct net_bridge_fdb_entry *f
141                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
142                         if (f->dst != p) 
143                                 continue;
144
145                         /*
146                          * if multiple ports all have the same device address
147                          * then when one port is deleted, assign
148                          * the local entry to other port
149                          */
150                         if (f->is_local) {
151                                 struct net_bridge_port *op;
152                                 list_for_each_entry(op, &br->port_list, list) {
153                                         if (op != p && 
154                                             !compare_ether_addr(op->dev->dev_addr,
155                                                                 f->addr.addr)) {
156                                                 f->dst = op;
157                                                 goto skip_delete;
158                                         }
159                                 }
160                         }
161
162                         fdb_delete(f);
163                 skip_delete: ;
164                 }
165         }
166         spin_unlock_bh(&br->hash_lock);
167 }
168
169 /* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
170 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
171                                           const unsigned char *addr)
172 {
173         struct hlist_node *h;
174         struct net_bridge_fdb_entry *fdb;
175
176         hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
177                 if (!compare_ether_addr(fdb->addr.addr, addr)) {
178                         if (unlikely(has_expired(br, fdb)))
179                                 break;
180                         return fdb;
181                 }
182         }
183
184         return NULL;
185 }
186
187 /* Interface used by ATM hook that keeps a ref count */
188 struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, 
189                                         unsigned char *addr)
190 {
191         struct net_bridge_fdb_entry *fdb;
192
193         rcu_read_lock();
194         fdb = __br_fdb_get(br, addr);
195         if (fdb) 
196                 atomic_inc(&fdb->use_count);
197         rcu_read_unlock();
198         return fdb;
199 }
200
201 static void fdb_rcu_free(struct rcu_head *head)
202 {
203         struct net_bridge_fdb_entry *ent
204                 = container_of(head, struct net_bridge_fdb_entry, rcu);
205         kmem_cache_free(br_fdb_cache, ent);
206 }
207
208 /* Set entry up for deletion with RCU  */
209 void br_fdb_put(struct net_bridge_fdb_entry *ent)
210 {
211         if (atomic_dec_and_test(&ent->use_count))
212                 call_rcu(&ent->rcu, fdb_rcu_free);
213 }
214
215 /*
216  * Fill buffer with forwarding table records in 
217  * the API format.
218  */
219 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
220                    unsigned long maxnum, unsigned long skip)
221 {
222         struct __fdb_entry *fe = buf;
223         int i, num = 0;
224         struct hlist_node *h;
225         struct net_bridge_fdb_entry *f;
226
227         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
228
229         rcu_read_lock();
230         for (i = 0; i < BR_HASH_SIZE; i++) {
231                 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
232                         if (num >= maxnum)
233                                 goto out;
234
235                         if (has_expired(br, f)) 
236                                 continue;
237
238                         if (skip) {
239                                 --skip;
240                                 continue;
241                         }
242
243                         /* convert from internal format to API */
244                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
245                         fe->port_no = f->dst->port_no;
246                         fe->is_local = f->is_local;
247                         if (!f->is_static)
248                                 fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
249                         ++fe;
250                         ++num;
251                 }
252         }
253
254  out:
255         rcu_read_unlock();
256
257         return num;
258 }
259
260 static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
261                                                     const unsigned char *addr)
262 {
263         struct hlist_node *h;
264         struct net_bridge_fdb_entry *fdb;
265
266         hlist_for_each_entry_rcu(fdb, h, head, hlist) {
267                 if (!compare_ether_addr(fdb->addr.addr, addr))
268                         return fdb;
269         }
270         return NULL;
271 }
272
273 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
274                                                struct net_bridge_port *source,
275                                                const unsigned char *addr, 
276                                                int is_local)
277 {
278         struct net_bridge_fdb_entry *fdb;
279
280         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
281         if (fdb) {
282                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
283                 atomic_set(&fdb->use_count, 1);
284                 hlist_add_head_rcu(&fdb->hlist, head);
285
286                 fdb->dst = source;
287                 fdb->is_local = is_local;
288                 fdb->is_static = is_local;
289                 fdb->ageing_timer = jiffies;
290         }
291         return fdb;
292 }
293
294 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
295                   const unsigned char *addr)
296 {
297         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
298         struct net_bridge_fdb_entry *fdb;
299
300         if (!is_valid_ether_addr(addr))
301                 return -EINVAL;
302
303         fdb = fdb_find(head, addr);
304         if (fdb) {
305                 /* it is okay to have multiple ports with same 
306                  * address, just use the first one.
307                  */
308                 if (fdb->is_local) 
309                         return 0;
310
311                 printk(KERN_WARNING "%s adding interface with same address "
312                        "as a received packet\n",
313                        source->dev->name);
314                 fdb_delete(fdb);
315         }
316
317         if (!fdb_create(head, source, addr, 1))
318                 return -ENOMEM;
319
320         return 0;
321 }
322
323 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
324                   const unsigned char *addr)
325 {
326         int ret;
327
328         spin_lock_bh(&br->hash_lock);
329         ret = fdb_insert(br, source, addr);
330         spin_unlock_bh(&br->hash_lock);
331         return ret;
332 }
333
334 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
335                    const unsigned char *addr)
336 {
337         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
338         struct net_bridge_fdb_entry *fdb;
339
340         /* some users want to always flood. */
341         if (hold_time(br) == 0)
342                 return;
343
344         fdb = fdb_find(head, addr);
345         if (likely(fdb)) {
346                 /* attempt to update an entry for a local interface */
347                 if (unlikely(fdb->is_local)) {
348                         if (net_ratelimit()) 
349                                 printk(KERN_WARNING "%s: received packet with "
350                                        " own address as source address\n",
351                                        source->dev->name);
352                 } else {
353                         /* fastpath: update of existing entry */
354                         fdb->dst = source;
355                         fdb->ageing_timer = jiffies;
356                 }
357         } else {
358                 spin_lock(&br->hash_lock);
359                 if (!fdb_find(head, addr))
360                         fdb_create(head, source, addr, 0);
361                 /* else  we lose race and someone else inserts
362                  * it first, don't bother updating
363                  */
364                 spin_unlock(&br->hash_lock);
365         }
366 }