[PATCH] slab: remove kmem_cache_t
[linux-3.10.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 struct kmem_cache *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
132 void br_fdb_delete_by_port(struct net_bridge *br,
133                            const struct net_bridge_port *p,
134                            int do_all)
135 {
136         int i;
137
138         spin_lock_bh(&br->hash_lock);
139         for (i = 0; i < BR_HASH_SIZE; i++) {
140                 struct hlist_node *h, *g;
141                 
142                 hlist_for_each_safe(h, g, &br->hash[i]) {
143                         struct net_bridge_fdb_entry *f
144                                 = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
145                         if (f->dst != p) 
146                                 continue;
147
148                         if (f->is_static && !do_all)
149                                 continue;
150                         /*
151                          * if multiple ports all have the same device address
152                          * then when one port is deleted, assign
153                          * the local entry to other port
154                          */
155                         if (f->is_local) {
156                                 struct net_bridge_port *op;
157                                 list_for_each_entry(op, &br->port_list, list) {
158                                         if (op != p && 
159                                             !compare_ether_addr(op->dev->dev_addr,
160                                                                 f->addr.addr)) {
161                                                 f->dst = op;
162                                                 goto skip_delete;
163                                         }
164                                 }
165                         }
166
167                         fdb_delete(f);
168                 skip_delete: ;
169                 }
170         }
171         spin_unlock_bh(&br->hash_lock);
172 }
173
174 /* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
175 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
176                                           const unsigned char *addr)
177 {
178         struct hlist_node *h;
179         struct net_bridge_fdb_entry *fdb;
180
181         hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
182                 if (!compare_ether_addr(fdb->addr.addr, addr)) {
183                         if (unlikely(has_expired(br, fdb)))
184                                 break;
185                         return fdb;
186                 }
187         }
188
189         return NULL;
190 }
191
192 /* Interface used by ATM hook that keeps a ref count */
193 struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, 
194                                         unsigned char *addr)
195 {
196         struct net_bridge_fdb_entry *fdb;
197
198         rcu_read_lock();
199         fdb = __br_fdb_get(br, addr);
200         if (fdb) 
201                 atomic_inc(&fdb->use_count);
202         rcu_read_unlock();
203         return fdb;
204 }
205
206 static void fdb_rcu_free(struct rcu_head *head)
207 {
208         struct net_bridge_fdb_entry *ent
209                 = container_of(head, struct net_bridge_fdb_entry, rcu);
210         kmem_cache_free(br_fdb_cache, ent);
211 }
212
213 /* Set entry up for deletion with RCU  */
214 void br_fdb_put(struct net_bridge_fdb_entry *ent)
215 {
216         if (atomic_dec_and_test(&ent->use_count))
217                 call_rcu(&ent->rcu, fdb_rcu_free);
218 }
219
220 /*
221  * Fill buffer with forwarding table records in 
222  * the API format.
223  */
224 int br_fdb_fillbuf(struct net_bridge *br, void *buf,
225                    unsigned long maxnum, unsigned long skip)
226 {
227         struct __fdb_entry *fe = buf;
228         int i, num = 0;
229         struct hlist_node *h;
230         struct net_bridge_fdb_entry *f;
231
232         memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
233
234         rcu_read_lock();
235         for (i = 0; i < BR_HASH_SIZE; i++) {
236                 hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
237                         if (num >= maxnum)
238                                 goto out;
239
240                         if (has_expired(br, f)) 
241                                 continue;
242
243                         if (skip) {
244                                 --skip;
245                                 continue;
246                         }
247
248                         /* convert from internal format to API */
249                         memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
250                         fe->port_no = f->dst->port_no;
251                         fe->is_local = f->is_local;
252                         if (!f->is_static)
253                                 fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
254                         ++fe;
255                         ++num;
256                 }
257         }
258
259  out:
260         rcu_read_unlock();
261
262         return num;
263 }
264
265 static inline struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
266                                                     const unsigned char *addr)
267 {
268         struct hlist_node *h;
269         struct net_bridge_fdb_entry *fdb;
270
271         hlist_for_each_entry_rcu(fdb, h, head, hlist) {
272                 if (!compare_ether_addr(fdb->addr.addr, addr))
273                         return fdb;
274         }
275         return NULL;
276 }
277
278 static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
279                                                struct net_bridge_port *source,
280                                                const unsigned char *addr, 
281                                                int is_local)
282 {
283         struct net_bridge_fdb_entry *fdb;
284
285         fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
286         if (fdb) {
287                 memcpy(fdb->addr.addr, addr, ETH_ALEN);
288                 atomic_set(&fdb->use_count, 1);
289                 hlist_add_head_rcu(&fdb->hlist, head);
290
291                 fdb->dst = source;
292                 fdb->is_local = is_local;
293                 fdb->is_static = is_local;
294                 fdb->ageing_timer = jiffies;
295         }
296         return fdb;
297 }
298
299 static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
300                   const unsigned char *addr)
301 {
302         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
303         struct net_bridge_fdb_entry *fdb;
304
305         if (!is_valid_ether_addr(addr))
306                 return -EINVAL;
307
308         fdb = fdb_find(head, addr);
309         if (fdb) {
310                 /* it is okay to have multiple ports with same 
311                  * address, just use the first one.
312                  */
313                 if (fdb->is_local) 
314                         return 0;
315
316                 printk(KERN_WARNING "%s adding interface with same address "
317                        "as a received packet\n",
318                        source->dev->name);
319                 fdb_delete(fdb);
320         }
321
322         if (!fdb_create(head, source, addr, 1))
323                 return -ENOMEM;
324
325         return 0;
326 }
327
328 int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
329                   const unsigned char *addr)
330 {
331         int ret;
332
333         spin_lock_bh(&br->hash_lock);
334         ret = fdb_insert(br, source, addr);
335         spin_unlock_bh(&br->hash_lock);
336         return ret;
337 }
338
339 void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
340                    const unsigned char *addr)
341 {
342         struct hlist_head *head = &br->hash[br_mac_hash(addr)];
343         struct net_bridge_fdb_entry *fdb;
344
345         /* some users want to always flood. */
346         if (hold_time(br) == 0)
347                 return;
348
349         fdb = fdb_find(head, addr);
350         if (likely(fdb)) {
351                 /* attempt to update an entry for a local interface */
352                 if (unlikely(fdb->is_local)) {
353                         if (net_ratelimit()) 
354                                 printk(KERN_WARNING "%s: received packet with "
355                                        " own address as source address\n",
356                                        source->dev->name);
357                 } else {
358                         /* fastpath: update of existing entry */
359                         fdb->dst = source;
360                         fdb->ageing_timer = jiffies;
361                 }
362         } else {
363                 spin_lock(&br->hash_lock);
364                 if (!fdb_find(head, addr))
365                         fdb_create(head, source, addr, 0);
366                 /* else  we lose race and someone else inserts
367                  * it first, don't bother updating
368                  */
369                 spin_unlock(&br->hash_lock);
370         }
371 }