Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Eric Dumazet | ba89966 | 2005-08-26 12:05:31 -0700 | [diff] [blame] | 26 | static kmem_cache_t *br_fdb_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 && |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame^] | 89 | !compare_ether_addr(op->dev->dev_addr, |
| 90 | f->addr.addr)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 && |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame^] | 154 | !compare_ether_addr(op->dev->dev_addr, |
| 155 | f->addr.addr)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) { |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame^] | 177 | if (!compare_ether_addr(fdb->addr.addr, addr)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) { |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame^] | 267 | if (!compare_ether_addr(fdb->addr.addr, addr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | rcu_read_lock(); |
| 345 | fdb = fdb_find(head, addr); |
| 346 | if (likely(fdb)) { |
| 347 | /* attempt to update an entry for a local interface */ |
| 348 | if (unlikely(fdb->is_local)) { |
| 349 | if (net_ratelimit()) |
| 350 | printk(KERN_WARNING "%s: received packet with " |
| 351 | " own address as source address\n", |
| 352 | source->dev->name); |
| 353 | } else { |
| 354 | /* fastpath: update of existing entry */ |
| 355 | fdb->dst = source; |
| 356 | fdb->ageing_timer = jiffies; |
| 357 | } |
| 358 | } else { |
| 359 | spin_lock_bh(&br->hash_lock); |
| 360 | if (!fdb_find(head, addr)) |
| 361 | fdb_create(head, source, addr, 0); |
| 362 | /* else we lose race and someone else inserts |
| 363 | * it first, don't bother updating |
| 364 | */ |
| 365 | spin_unlock_bh(&br->hash_lock); |
| 366 | } |
| 367 | rcu_read_unlock(); |
| 368 | } |