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); 152 153 netdev_upper_dev_unlink(dev, br->dev); 154 155 br_multicast_del_port(p); 156 157 kobject_uevent(&p->kobj, KOBJ_REMOVE); 158 kobject_del(&p->kobj); 159 160 br_netpoll_disable(p); 161 162 call_rcu(&p->rcu, destroy_nbp_rcu); 163 } 164 165 /* Delete bridge device */ 166 void br_dev_delete(struct net_device *dev, struct list_head *head) 167 { 168 struct net_bridge *br = netdev_priv(dev); 169 struct net_bridge_port *p, *n; 170 171 list_for_each_entry_safe(p, n, &br->port_list, list) { 172 del_nbp(p); 173 } 174 175 del_timer_sync(&br->gc_timer); 176 177 br_sysfs_delbr(br->dev); 178 unregister_netdevice_queue(br->dev, head); 179 } 180 181 /* find an available port number */ 182 static int find_portno(struct net_bridge *br) 183 { 184 int index; 185 struct net_bridge_port *p; 186 unsigned long *inuse; 187 188 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 189 GFP_KERNEL); 190 if (!inuse) 191 return -ENOMEM; 192 193 set_bit(0, inuse); /* zero is reserved */ 194 list_for_each_entry(p, &br->port_list, list) { 195 set_bit(p->port_no, inuse); 196 } 197 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 198 kfree(inuse); 199 200 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 201 } 202 203 /* called with RTNL but without bridge lock */ 204 static struct net_bridge_port *new_nbp(struct net_bridge *br, 205 struct net_device *dev) 206 { 207 int index; 208 struct net_bridge_port *p; 209 210 index = find_portno(br); 211 if (index < 0) 212 return ERR_PTR(index); 213 214 p = kzalloc(sizeof(*p), GFP_KERNEL); 215 if (p == NULL) 216 return ERR_PTR(-ENOMEM); 217 218 p->br = br; 219 dev_hold(dev); 220 p->dev = dev; 221 p->path_cost = port_cost(dev); 222 p->priority = 0x8000 >> BR_PORT_BITS; 223 p->port_no = index; 224 p->flags = 0; 225 br_init_port(p); 226 p->state = BR_STATE_DISABLED; 227 br_stp_port_timer_init(p); 228 br_multicast_add_port(p); 229 230 return p; 231 } 232 233 int br_add_bridge(struct net *net, const char *name) 234 { 235 struct net_device *dev; 236 int res; 237 238 dev = alloc_netdev(sizeof(struct net_bridge), name, 239 br_dev_setup); 240 241 if (!dev) 242 return -ENOMEM; 243 244 dev_net_set(dev, net); 245 dev->rtnl_link_ops = &br_link_ops; 246 247 res = register_netdev(dev); 248 if (res) 249 free_netdev(dev); 250 return res; 251 } 252 253 int br_del_bridge(struct net *net, const char *name) 254 { 255 struct net_device *dev; 256 int ret = 0; 257 258 rtnl_lock(); 259 dev = __dev_get_by_name(net, name); 260 if (dev == NULL) 261 ret = -ENXIO; /* Could not find device */ 262 263 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 264 /* Attempt to delete non bridge device! */ 265 ret = -EPERM; 266 } 267 268 else if (dev->flags & IFF_UP) { 269 /* Not shutdown yet. */ 270 ret = -EBUSY; 271 } 272 273 else 274 br_dev_delete(dev, NULL); 275 276 rtnl_unlock(); 277 return ret; 278 } 279 280 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 281 int br_min_mtu(const struct net_bridge *br) 282 { 283 const struct net_bridge_port *p; 284 int mtu = 0; 285 286 ASSERT_RTNL(); 287 288 if (list_empty(&br->port_list)) 289 mtu = ETH_DATA_LEN; 290 else { 291 list_for_each_entry(p, &br->port_list, list) { 292 if (!mtu || p->dev->mtu < mtu) 293 mtu = p->dev->mtu; 294 } 295 } 296 return mtu; 297 } 298 299 /* 300 * Recomputes features using slave's features 301 */ 302 netdev_features_t br_features_recompute(struct net_bridge *br, 303 netdev_features_t features) 304 { 305 struct net_bridge_port *p; 306 netdev_features_t mask; 307 308 if (list_empty(&br->port_list)) 309 return features; 310 311 mask = features; 312 features &= ~NETIF_F_ONE_FOR_ALL; 313 314 list_for_each_entry(p, &br->port_list, list) { 315 features = netdev_increment_features(features, 316 p->dev->features, mask); 317 } 318 319 return features; 320 } 321 322 /* called with RTNL */ 323 int br_add_if(struct net_bridge *br, struct net_device *dev) 324 { 325 struct net_bridge_port *p; 326 int err = 0; 327 bool changed_addr; 328 329 /* Don't allow bridging non-ethernet like devices */ 330 if ((dev->flags & IFF_LOOPBACK) || 331 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || 332 !is_valid_ether_addr(dev->dev_addr)) 333 return -EINVAL; 334 335 /* No bridging of bridges */ 336 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 337 return -ELOOP; 338 339 /* Device is already being bridged */ 340 if (br_port_exists(dev)) 341 return -EBUSY; 342 343 /* No bridging devices that dislike that (e.g. wireless) */ 344 if (dev->priv_flags & IFF_DONT_BRIDGE) 345 return -EOPNOTSUPP; 346 347 p = new_nbp(br, dev); 348 if (IS_ERR(p)) 349 return PTR_ERR(p); 350 351 call_netdevice_notifiers(NETDEV_JOIN, dev); 352 353 err = dev_set_promiscuity(dev, 1); 354 if (err) 355 goto put_back; 356 357 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 358 SYSFS_BRIDGE_PORT_ATTR); 359 if (err) 360 goto err1; 361 362 err = br_sysfs_addif(p); 363 if (err) 364 goto err2; 365 366 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p, GFP_KERNEL)))) 367 goto err3; 368 369 err = netdev_master_upper_dev_link(dev, br->dev); 370 if (err) 371 goto err4; 372 373 err = netdev_rx_handler_register(dev, br_handle_frame, p); 374 if (err) 375 goto err5; 376 377 dev->priv_flags |= IFF_BRIDGE_PORT; 378 379 dev_disable_lro(dev); 380 381 list_add_rcu(&p->list, &br->port_list); 382 383 netdev_update_features(br->dev); 384 385 spin_lock_bh(&br->lock); 386 changed_addr = br_stp_recalculate_bridge_id(br); 387 388 if (netif_running(dev) && netif_oper_up(dev) && 389 (br->dev->flags & IFF_UP)) 390 br_stp_enable_port(p); 391 spin_unlock_bh(&br->lock); 392 393 br_ifinfo_notify(RTM_NEWLINK, p); 394 395 if (changed_addr) 396 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 397 398 dev_set_mtu(br->dev, br_min_mtu(br)); 399 400 if (br_fdb_insert(br, p, dev->dev_addr, 0)) 401 netdev_err(dev, "failed insert local address bridge forwarding table\n"); 402 403 kobject_uevent(&p->kobj, KOBJ_ADD); 404 405 return 0; 406 407 err5: 408 netdev_upper_dev_unlink(dev, br->dev); 409 err4: 410 br_netpoll_disable(p); 411 err3: 412 sysfs_remove_link(br->ifobj, p->dev->name); 413 err2: 414 kobject_put(&p->kobj); 415 p = NULL; /* kobject_put frees */ 416 err1: 417 dev_set_promiscuity(dev, -1); 418 put_back: 419 dev_put(dev); 420 kfree(p); 421 return err; 422 } 423 424 /* called with RTNL */ 425 int br_del_if(struct net_bridge *br, struct net_device *dev) 426 { 427 struct net_bridge_port *p; 428 bool changed_addr; 429 430 p = br_port_get_rtnl(dev); 431 if (!p || p->br != br) 432 return -EINVAL; 433 434 /* Since more than one interface can be attached to a bridge, 435 * there still maybe an alternate path for netconsole to use; 436 * therefore there is no reason for a NETDEV_RELEASE event. 437 */ 438 del_nbp(p); 439 440 spin_lock_bh(&br->lock); 441 changed_addr = br_stp_recalculate_bridge_id(br); 442 spin_unlock_bh(&br->lock); 443 444 if (changed_addr) 445 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 446 447 netdev_update_features(br->dev); 448 449 return 0; 450 } 451 452 void __net_exit br_net_exit(struct net *net) 453 { 454 struct net_device *dev; 455 LIST_HEAD(list); 456 457 rtnl_lock(); 458 for_each_netdev(net, dev) 459 if (dev->priv_flags & IFF_EBRIDGE) 460 br_dev_delete(dev, &list); 461 462 unregister_netdevice_many(&list); 463 rtnl_unlock(); 464 465 } 466