1 /* 2 * Userspace interface 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/netdevice.h> 16 #include <linux/etherdevice.h> 17 #include <linux/netpoll.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 <linux/if_ether.h> 24 #include <linux/slab.h> 25 #include <net/sock.h> 26 #include <linux/if_vlan.h> 27 28 #include "br_private.h" 29 30 /* 31 * Determine initial path cost based on speed. 32 * using recommendations from 802.1d standard 33 * 34 * Since driver might sleep need to not be holding any locks. 35 */ 36 static int port_cost(struct net_device *dev) 37 { 38 struct ethtool_cmd ecmd; 39 40 if (!__ethtool_get_settings(dev, &ecmd)) { 41 switch (ethtool_cmd_speed(&ecmd)) { 42 case SPEED_10000: 43 return 2; 44 case SPEED_1000: 45 return 4; 46 case SPEED_100: 47 return 19; 48 case SPEED_10: 49 return 100; 50 } 51 } 52 53 /* Old silly heuristics based on name */ 54 if (!strncmp(dev->name, "lec", 3)) 55 return 7; 56 57 if (!strncmp(dev->name, "plip", 4)) 58 return 2500; 59 60 return 100; /* assume old 10Mbps */ 61 } 62 63 64 /* Check for port carrier transistions. */ 65 void br_port_carrier_check(struct net_bridge_port *p) 66 { 67 struct net_device *dev = p->dev; 68 struct net_bridge *br = p->br; 69 70 if (!(p->flags & BR_ADMIN_COST) && 71 netif_running(dev) && netif_oper_up(dev)) 72 p->path_cost = port_cost(dev); 73 74 if (!netif_running(br->dev)) 75 return; 76 77 spin_lock_bh(&br->lock); 78 if (netif_running(dev) && netif_oper_up(dev)) { 79 if (p->state == BR_STATE_DISABLED) 80 br_stp_enable_port(p); 81 } else { 82 if (p->state != BR_STATE_DISABLED) 83 br_stp_disable_port(p); 84 } 85 spin_unlock_bh(&br->lock); 86 } 87 88 static void release_nbp(struct kobject *kobj) 89 { 90 struct net_bridge_port *p 91 = container_of(kobj, struct net_bridge_port, kobj); 92 kfree(p); 93 } 94 95 static struct kobj_type brport_ktype = { 96 #ifdef CONFIG_SYSFS 97 .sysfs_ops = &brport_sysfs_ops, 98 #endif 99 .release = release_nbp, 100 }; 101 102 static void destroy_nbp(struct net_bridge_port *p) 103 { 104 struct net_device *dev = p->dev; 105 106 p->br = NULL; 107 p->dev = NULL; 108 dev_put(dev); 109 110 kobject_put(&p->kobj); 111 } 112 113 static void destroy_nbp_rcu(struct rcu_head *head) 114 { 115 struct net_bridge_port *p = 116 container_of(head, struct net_bridge_port, rcu); 117 destroy_nbp(p); 118 } 119 120 /* Delete port(interface) from bridge is done in two steps. 121 * via RCU. First step, marks device as down. That deletes 122 * all the timers and stops new packets from flowing through. 123 * 124 * Final cleanup doesn't occur until after all CPU's finished 125 * processing packets. 126 * 127 * Protected from multiple admin operations by RTNL mutex 128 */ 129 static void del_nbp(struct net_bridge_port *p) 130 { 131 struct net_bridge *br = p->br; 132 struct net_device *dev = p->dev; 133 134 sysfs_remove_link(br->ifobj, p->dev->name); 135 136 dev_set_promiscuity(dev, -1); 137 138 spin_lock_bh(&br->lock); 139 br_stp_disable_port(p); 140 spin_unlock_bh(&br->lock); 141 142 br_ifinfo_notify(RTM_DELLINK, p); 143 144 nbp_vlan_flush(p); 145 br_fdb_delete_by_port(br, p, 1); 146 147 list_del_rcu(&p->list); 148 149 dev->priv_flags &= ~IFF_BRIDGE_PORT; 150 151 netdev_rx_handler_unregister(dev); 152 synchronize_net(); 153 154 netdev_upper_dev_unlink(dev, br->dev); 155 156 br_multicast_del_port(p); 157 158 kobject_uevent(&p->kobj, KOBJ_REMOVE); 159 kobject_del(&p->kobj); 160 161 br_netpoll_disable(p); 162 163 call_rcu(&p->rcu, destroy_nbp_rcu); 164 } 165 166 /* Delete bridge device */ 167 void br_dev_delete(struct net_device *dev, struct list_head *head) 168 { 169 struct net_bridge *br = netdev_priv(dev); 170 struct net_bridge_port *p, *n; 171 172 list_for_each_entry_safe(p, n, &br->port_list, list) { 173 del_nbp(p); 174 } 175 176 del_timer_sync(&br->gc_timer); 177 178 br_sysfs_delbr(br->dev); 179 unregister_netdevice_queue(br->dev, head); 180 } 181 182 /* find an available port number */ 183 static int find_portno(struct net_bridge *br) 184 { 185 int index; 186 struct net_bridge_port *p; 187 unsigned long *inuse; 188 189 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 190 GFP_KERNEL); 191 if (!inuse) 192 return -ENOMEM; 193 194 set_bit(0, inuse); /* zero is reserved */ 195 list_for_each_entry(p, &br->port_list, list) { 196 set_bit(p->port_no, inuse); 197 } 198 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 199 kfree(inuse); 200 201 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 202 } 203 204 /* called with RTNL but without bridge lock */ 205 static struct net_bridge_port *new_nbp(struct net_bridge *br, 206 struct net_device *dev) 207 { 208 int index; 209 struct net_bridge_port *p; 210 211 index = find_portno(br); 212 if (index < 0) 213 return ERR_PTR(index); 214 215 p = kzalloc(sizeof(*p), GFP_KERNEL); 216 if (p == NULL) 217 return ERR_PTR(-ENOMEM); 218 219 p->br = br; 220 dev_hold(dev); 221 p->dev = dev; 222 p->path_cost = port_cost(dev); 223 p->priority = 0x8000 >> BR_PORT_BITS; 224 p->port_no = index; 225 p->flags = 0; 226 br_init_port(p); 227 p->state = BR_STATE_DISABLED; 228 br_stp_port_timer_init(p); 229 br_multicast_add_port(p); 230 231 return p; 232 } 233 234 int br_add_bridge(struct net *net, const char *name) 235 { 236 struct net_device *dev; 237 int res; 238 239 dev = alloc_netdev(sizeof(struct net_bridge), name, 240 br_dev_setup); 241 242 if (!dev) 243 return -ENOMEM; 244 245 dev_net_set(dev, net); 246 dev->rtnl_link_ops = &br_link_ops; 247 248 res = register_netdev(dev); 249 if (res) 250 free_netdev(dev); 251 return res; 252 } 253 254 int br_del_bridge(struct net *net, const char *name) 255 { 256 struct net_device *dev; 257 int ret = 0; 258 259 rtnl_lock(); 260 dev = __dev_get_by_name(net, name); 261 if (dev == NULL) 262 ret = -ENXIO; /* Could not find device */ 263 264 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 265 /* Attempt to delete non bridge device! */ 266 ret = -EPERM; 267 } 268 269 else if (dev->flags & IFF_UP) { 270 /* Not shutdown yet. */ 271 ret = -EBUSY; 272 } 273 274 else 275 br_dev_delete(dev, NULL); 276 277 rtnl_unlock(); 278 return ret; 279 } 280 281 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 282 int br_min_mtu(const struct net_bridge *br) 283 { 284 const struct net_bridge_port *p; 285 int mtu = 0; 286 287 ASSERT_RTNL(); 288 289 if (list_empty(&br->port_list)) 290 mtu = ETH_DATA_LEN; 291 else { 292 list_for_each_entry(p, &br->port_list, list) { 293 if (!mtu || p->dev->mtu < mtu) 294 mtu = p->dev->mtu; 295 } 296 } 297 return mtu; 298 } 299 300 /* 301 * Recomputes features using slave's features 302 */ 303 netdev_features_t br_features_recompute(struct net_bridge *br, 304 netdev_features_t features) 305 { 306 struct net_bridge_port *p; 307 netdev_features_t mask; 308 309 if (list_empty(&br->port_list)) 310 return features; 311 312 mask = features; 313 features &= ~NETIF_F_ONE_FOR_ALL; 314 315 list_for_each_entry(p, &br->port_list, list) { 316 features = netdev_increment_features(features, 317 p->dev->features, mask); 318 } 319 320 return features; 321 } 322 323 /* called with RTNL */ 324 int br_add_if(struct net_bridge *br, struct net_device *dev) 325 { 326 struct net_bridge_port *p; 327 int err = 0; 328 bool changed_addr; 329 330 /* Don't allow bridging non-ethernet like devices */ 331 if ((dev->flags & IFF_LOOPBACK) || 332 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 333 !is_valid_ether_addr(dev->dev_addr)) 334 return -EINVAL; 335 336 /* No bridging of bridges */ 337 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 338 return -ELOOP; 339 340 /* Device is already being bridged */ 341 if (br_port_exists(dev)) 342 return -EBUSY; 343 344 /* No bridging devices that dislike that (e.g. wireless) */ 345 if (dev->priv_flags & IFF_DONT_BRIDGE) 346 return -EOPNOTSUPP; 347 348 p = new_nbp(br, dev); 349 if (IS_ERR(p)) 350 return PTR_ERR(p); 351 352 call_netdevice_notifiers(NETDEV_JOIN, dev); 353 354 err = dev_set_promiscuity(dev, 1); 355 if (err) 356 goto put_back; 357 358 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 359 SYSFS_BRIDGE_PORT_ATTR); 360 if (err) 361 goto err1; 362 363 err = br_sysfs_addif(p); 364 if (err) 365 goto err2; 366 367 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p, GFP_KERNEL)))) 368 goto err3; 369 370 err = netdev_master_upper_dev_link(dev, br->dev); 371 if (err) 372 goto err4; 373 374 err = netdev_rx_handler_register(dev, br_handle_frame, p); 375 if (err) 376 goto err5; 377 378 dev->priv_flags |= IFF_BRIDGE_PORT; 379 380 dev_disable_lro(dev); 381 382 list_add_rcu(&p->list, &br->port_list); 383 384 netdev_update_features(br->dev); 385 386 spin_lock_bh(&br->lock); 387 changed_addr = br_stp_recalculate_bridge_id(br); 388 389 if (netif_running(dev) && netif_oper_up(dev) && 390 (br->dev->flags & IFF_UP)) 391 br_stp_enable_port(p); 392 spin_unlock_bh(&br->lock); 393 394 br_ifinfo_notify(RTM_NEWLINK, p); 395 396 if (changed_addr) 397 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 398 399 dev_set_mtu(br->dev, br_min_mtu(br)); 400 401 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 402 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 403 404 kobject_uevent(&p->kobj, KOBJ_ADD); 405 406 return 0; 407 408 err5: 409 netdev_upper_dev_unlink(dev, br->dev); 410 err4: 411 br_netpoll_disable(p); 412 err3: 413 sysfs_remove_link(br->ifobj, p->dev->name); 414 err2: 415 kobject_put(&p->kobj); 416 p = NULL; /* kobject_put frees */ 417 err1: 418 dev_set_promiscuity(dev, -1); 419 put_back: 420 dev_put(dev); 421 kfree(p); 422 return err; 423 } 424 425 /* called with RTNL */ 426 int br_del_if(struct net_bridge *br, struct net_device *dev) 427 { 428 struct net_bridge_port *p; 429 bool changed_addr; 430 431 p = br_port_get_rtnl(dev); 432 if (!p || p->br != br) 433 return -EINVAL; 434 435 /* Since more than one interface can be attached to a bridge, 436 * there still maybe an alternate path for netconsole to use; 437 * therefore there is no reason for a NETDEV_RELEASE event. 438 */ 439 del_nbp(p); 440 441 spin_lock_bh(&br->lock); 442 changed_addr = br_stp_recalculate_bridge_id(br); 443 spin_unlock_bh(&br->lock); 444 445 if (changed_addr) 446 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 447 448 netdev_update_features(br->dev); 449 450 return 0; 451 } 452 453 void __net_exit br_net_exit(struct net *net) 454 { 455 struct net_device *dev; 456 LIST_HEAD(list); 457 458 rtnl_lock(); 459 for_each_netdev(net, dev) 460 if (dev->priv_flags & IFF_EBRIDGE) 461 br_dev_delete(dev, &list); 462 463 unregister_netdevice_many(&list); 464 rtnl_unlock(); 465 466 } 467