1 /* 2 * Userspace interface 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * $Id: br_if.c,v 1.7 2001/12/24 00:59:55 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/netdevice.h> 18 #include <linux/ethtool.h> 19 #include <linux/if_arp.h> 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/rtnetlink.h> 23 #include <net/sock.h> 24 25 #include "br_private.h" 26 27 /* 28 * Determine initial path cost based on speed. 29 * using recommendations from 802.1d standard 30 * 31 * Need to simulate user ioctl because not all device's that support 32 * ethtool, use ethtool_ops. Also, since driver might sleep need to 33 * not be holding any locks. 34 */ 35 static int br_initial_port_cost(struct net_device *dev) 36 { 37 38 struct ethtool_cmd ecmd = { ETHTOOL_GSET }; 39 struct ifreq ifr; 40 mm_segment_t old_fs; 41 int err; 42 43 strncpy(ifr.ifr_name, dev->name, IFNAMSIZ); 44 ifr.ifr_data = (void __user *) &ecmd; 45 46 old_fs = get_fs(); 47 set_fs(KERNEL_DS); 48 err = dev_ethtool(&ifr); 49 set_fs(old_fs); 50 51 if (!err) { 52 switch(ecmd.speed) { 53 case SPEED_100: 54 return 19; 55 case SPEED_1000: 56 return 4; 57 case SPEED_10000: 58 return 2; 59 case SPEED_10: 60 return 100; 61 default: 62 pr_info("bridge: can't decode speed from %s: %d\n", 63 dev->name, ecmd.speed); 64 return 100; 65 } 66 } 67 68 /* Old silly heuristics based on name */ 69 if (!strncmp(dev->name, "lec", 3)) 70 return 7; 71 72 if (!strncmp(dev->name, "plip", 4)) 73 return 2500; 74 75 return 100; /* assume old 10Mbps */ 76 } 77 78 static void destroy_nbp(struct net_bridge_port *p) 79 { 80 struct net_device *dev = p->dev; 81 82 p->br = NULL; 83 p->dev = NULL; 84 dev_put(dev); 85 86 br_sysfs_freeif(p); 87 } 88 89 static void destroy_nbp_rcu(struct rcu_head *head) 90 { 91 struct net_bridge_port *p = 92 container_of(head, struct net_bridge_port, rcu); 93 destroy_nbp(p); 94 } 95 96 /* called with RTNL */ 97 static void del_nbp(struct net_bridge_port *p) 98 { 99 struct net_bridge *br = p->br; 100 struct net_device *dev = p->dev; 101 102 dev->br_port = NULL; 103 dev_set_promiscuity(dev, -1); 104 105 spin_lock_bh(&br->lock); 106 br_stp_disable_port(p); 107 spin_unlock_bh(&br->lock); 108 109 br_fdb_delete_by_port(br, p); 110 111 list_del_rcu(&p->list); 112 113 del_timer_sync(&p->message_age_timer); 114 del_timer_sync(&p->forward_delay_timer); 115 del_timer_sync(&p->hold_timer); 116 117 call_rcu(&p->rcu, destroy_nbp_rcu); 118 } 119 120 /* called with RTNL */ 121 static void del_br(struct net_bridge *br) 122 { 123 struct net_bridge_port *p, *n; 124 125 list_for_each_entry_safe(p, n, &br->port_list, list) { 126 br_sysfs_removeif(p); 127 del_nbp(p); 128 } 129 130 del_timer_sync(&br->gc_timer); 131 132 br_sysfs_delbr(br->dev); 133 unregister_netdevice(br->dev); 134 } 135 136 static struct net_device *new_bridge_dev(const char *name) 137 { 138 struct net_bridge *br; 139 struct net_device *dev; 140 141 dev = alloc_netdev(sizeof(struct net_bridge), name, 142 br_dev_setup); 143 144 if (!dev) 145 return NULL; 146 147 br = netdev_priv(dev); 148 br->dev = dev; 149 150 spin_lock_init(&br->lock); 151 INIT_LIST_HEAD(&br->port_list); 152 spin_lock_init(&br->hash_lock); 153 154 br->bridge_id.prio[0] = 0x80; 155 br->bridge_id.prio[1] = 0x00; 156 memset(br->bridge_id.addr, 0, ETH_ALEN); 157 158 br->stp_enabled = 0; 159 br->designated_root = br->bridge_id; 160 br->root_path_cost = 0; 161 br->root_port = 0; 162 br->bridge_max_age = br->max_age = 20 * HZ; 163 br->bridge_hello_time = br->hello_time = 2 * HZ; 164 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 165 br->topology_change = 0; 166 br->topology_change_detected = 0; 167 br->ageing_time = 300 * HZ; 168 INIT_LIST_HEAD(&br->age_list); 169 170 br_stp_timer_init(br); 171 172 return dev; 173 } 174 175 /* find an available port number */ 176 static int find_portno(struct net_bridge *br) 177 { 178 int index; 179 struct net_bridge_port *p; 180 unsigned long *inuse; 181 182 inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long), 183 GFP_KERNEL); 184 if (!inuse) 185 return -ENOMEM; 186 187 memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long)); 188 set_bit(0, inuse); /* zero is reserved */ 189 list_for_each_entry(p, &br->port_list, list) { 190 set_bit(p->port_no, inuse); 191 } 192 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 193 kfree(inuse); 194 195 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 196 } 197 198 /* called with RTNL */ 199 static struct net_bridge_port *new_nbp(struct net_bridge *br, 200 struct net_device *dev, 201 unsigned long cost) 202 { 203 int index; 204 struct net_bridge_port *p; 205 206 index = find_portno(br); 207 if (index < 0) 208 return ERR_PTR(index); 209 210 p = kmalloc(sizeof(*p), GFP_KERNEL); 211 if (p == NULL) 212 return ERR_PTR(-ENOMEM); 213 214 memset(p, 0, sizeof(*p)); 215 p->br = br; 216 dev_hold(dev); 217 p->dev = dev; 218 p->path_cost = cost; 219 p->priority = 0x8000 >> BR_PORT_BITS; 220 dev->br_port = p; 221 p->port_no = index; 222 br_init_port(p); 223 p->state = BR_STATE_DISABLED; 224 kobject_init(&p->kobj); 225 226 return p; 227 } 228 229 int br_add_bridge(const char *name) 230 { 231 struct net_device *dev; 232 int ret; 233 234 dev = new_bridge_dev(name); 235 if (!dev) 236 return -ENOMEM; 237 238 rtnl_lock(); 239 if (strchr(dev->name, '%')) { 240 ret = dev_alloc_name(dev, dev->name); 241 if (ret < 0) 242 goto err1; 243 } 244 245 ret = register_netdevice(dev); 246 if (ret) 247 goto err2; 248 249 /* network device kobject is not setup until 250 * after rtnl_unlock does it's hotplug magic. 251 * so hold reference to avoid race. 252 */ 253 dev_hold(dev); 254 rtnl_unlock(); 255 256 ret = br_sysfs_addbr(dev); 257 dev_put(dev); 258 259 if (ret) 260 unregister_netdev(dev); 261 out: 262 return ret; 263 264 err2: 265 free_netdev(dev); 266 err1: 267 rtnl_unlock(); 268 goto out; 269 } 270 271 int br_del_bridge(const char *name) 272 { 273 struct net_device *dev; 274 int ret = 0; 275 276 rtnl_lock(); 277 dev = __dev_get_by_name(name); 278 if (dev == NULL) 279 ret = -ENXIO; /* Could not find device */ 280 281 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 282 /* Attempt to delete non bridge device! */ 283 ret = -EPERM; 284 } 285 286 else if (dev->flags & IFF_UP) { 287 /* Not shutdown yet. */ 288 ret = -EBUSY; 289 } 290 291 else 292 del_br(netdev_priv(dev)); 293 294 rtnl_unlock(); 295 return ret; 296 } 297 298 /* Mtu of the bridge pseudo-device 1500 or the minimum of the ports */ 299 int br_min_mtu(const struct net_bridge *br) 300 { 301 const struct net_bridge_port *p; 302 int mtu = 0; 303 304 ASSERT_RTNL(); 305 306 if (list_empty(&br->port_list)) 307 mtu = 1500; 308 else { 309 list_for_each_entry(p, &br->port_list, list) { 310 if (!mtu || p->dev->mtu < mtu) 311 mtu = p->dev->mtu; 312 } 313 } 314 return mtu; 315 } 316 317 /* 318 * Recomputes features using slave's features 319 */ 320 void br_features_recompute(struct net_bridge *br) 321 { 322 struct net_bridge_port *p; 323 unsigned long features, checksum; 324 325 features = NETIF_F_SG | NETIF_F_FRAGLIST 326 | NETIF_F_HIGHDMA | NETIF_F_TSO; 327 checksum = NETIF_F_IP_CSUM; /* least commmon subset */ 328 329 list_for_each_entry(p, &br->port_list, list) { 330 if (!(p->dev->features 331 & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM))) 332 checksum = 0; 333 features &= p->dev->features; 334 } 335 336 br->dev->features = features | checksum | NETIF_F_LLTX; 337 } 338 339 /* called with RTNL */ 340 int br_add_if(struct net_bridge *br, struct net_device *dev) 341 { 342 struct net_bridge_port *p; 343 int err = 0; 344 345 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 346 return -EINVAL; 347 348 if (dev->hard_start_xmit == br_dev_xmit) 349 return -ELOOP; 350 351 if (dev->br_port != NULL) 352 return -EBUSY; 353 354 if (IS_ERR(p = new_nbp(br, dev, br_initial_port_cost(dev)))) 355 return PTR_ERR(p); 356 357 if ((err = br_fdb_insert(br, p, dev->dev_addr))) 358 destroy_nbp(p); 359 360 else if ((err = br_sysfs_addif(p))) 361 del_nbp(p); 362 else { 363 dev_set_promiscuity(dev, 1); 364 365 list_add_rcu(&p->list, &br->port_list); 366 367 spin_lock_bh(&br->lock); 368 br_stp_recalculate_bridge_id(br); 369 if ((br->dev->flags & IFF_UP) 370 && (dev->flags & IFF_UP) && netif_carrier_ok(dev)) 371 br_stp_enable_port(p); 372 spin_unlock_bh(&br->lock); 373 374 dev_set_mtu(br->dev, br_min_mtu(br)); 375 } 376 377 return err; 378 } 379 380 /* called with RTNL */ 381 int br_del_if(struct net_bridge *br, struct net_device *dev) 382 { 383 struct net_bridge_port *p = dev->br_port; 384 385 if (!p || p->br != br) 386 return -EINVAL; 387 388 br_sysfs_removeif(p); 389 del_nbp(p); 390 391 spin_lock_bh(&br->lock); 392 br_stp_recalculate_bridge_id(br); 393 br_features_recompute(br); 394 spin_unlock_bh(&br->lock); 395 396 return 0; 397 } 398 399 void __exit br_cleanup_bridges(void) 400 { 401 struct net_device *dev, *nxt; 402 403 rtnl_lock(); 404 for (dev = dev_base; dev; dev = nxt) { 405 nxt = dev->next; 406 if (dev->priv_flags & IFF_EBRIDGE) 407 del_br(dev->priv); 408 } 409 rtnl_unlock(); 410 411 } 412