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/netpoll.h> 17 #include <linux/ethtool.h> 18 #include <linux/if_arp.h> 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/rtnetlink.h> 22 #include <linux/if_ether.h> 23 #include <linux/slab.h> 24 #include <net/sock.h> 25 26 #include "br_private.h" 27 28 /* 29 * Determine initial path cost based on speed. 30 * using recommendations from 802.1d standard 31 * 32 * Since driver might sleep need to not be holding any locks. 33 */ 34 static int port_cost(struct net_device *dev) 35 { 36 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { 37 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; 38 39 if (!dev_ethtool_get_settings(dev, &ecmd)) { 40 switch (ethtool_cmd_speed(&ecmd)) { 41 case SPEED_10000: 42 return 2; 43 case SPEED_1000: 44 return 4; 45 case SPEED_100: 46 return 19; 47 case SPEED_10: 48 return 100; 49 } 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 (netif_running(dev) && netif_carrier_ok(dev)) 71 p->path_cost = port_cost(dev); 72 73 if (!netif_running(br->dev)) 74 return; 75 76 spin_lock_bh(&br->lock); 77 if (netif_running(dev) && netif_carrier_ok(dev)) { 78 if (p->state == BR_STATE_DISABLED) 79 br_stp_enable_port(p); 80 } else { 81 if (p->state != BR_STATE_DISABLED) 82 br_stp_disable_port(p); 83 } 84 spin_unlock_bh(&br->lock); 85 } 86 87 static void release_nbp(struct kobject *kobj) 88 { 89 struct net_bridge_port *p 90 = container_of(kobj, struct net_bridge_port, kobj); 91 kfree(p); 92 } 93 94 static struct kobj_type brport_ktype = { 95 #ifdef CONFIG_SYSFS 96 .sysfs_ops = &brport_sysfs_ops, 97 #endif 98 .release = release_nbp, 99 }; 100 101 static void destroy_nbp(struct net_bridge_port *p) 102 { 103 struct net_device *dev = p->dev; 104 105 p->br = NULL; 106 p->dev = NULL; 107 dev_put(dev); 108 109 kobject_put(&p->kobj); 110 } 111 112 static void destroy_nbp_rcu(struct rcu_head *head) 113 { 114 struct net_bridge_port *p = 115 container_of(head, struct net_bridge_port, rcu); 116 destroy_nbp(p); 117 } 118 119 /* Delete port(interface) from bridge is done in two steps. 120 * via RCU. First step, marks device as down. That deletes 121 * all the timers and stops new packets from flowing through. 122 * 123 * Final cleanup doesn't occur until after all CPU's finished 124 * processing packets. 125 * 126 * Protected from multiple admin operations by RTNL mutex 127 */ 128 static void del_nbp(struct net_bridge_port *p) 129 { 130 struct net_bridge *br = p->br; 131 struct net_device *dev = p->dev; 132 133 sysfs_remove_link(br->ifobj, p->dev->name); 134 135 dev_set_promiscuity(dev, -1); 136 137 spin_lock_bh(&br->lock); 138 br_stp_disable_port(p); 139 spin_unlock_bh(&br->lock); 140 141 br_ifinfo_notify(RTM_DELLINK, p); 142 143 br_fdb_delete_by_port(br, p, 1); 144 145 list_del_rcu(&p->list); 146 147 dev->priv_flags &= ~IFF_BRIDGE_PORT; 148 149 netdev_rx_handler_unregister(dev); 150 synchronize_net(); 151 152 netdev_set_master(dev, NULL); 153 154 br_multicast_del_port(p); 155 156 kobject_uevent(&p->kobj, KOBJ_REMOVE); 157 kobject_del(&p->kobj); 158 159 br_netpoll_disable(p); 160 161 call_rcu(&p->rcu, destroy_nbp_rcu); 162 } 163 164 /* called with RTNL */ 165 static void del_br(struct net_bridge *br, struct list_head *head) 166 { 167 struct net_bridge_port *p, *n; 168 169 list_for_each_entry_safe(p, n, &br->port_list, list) { 170 del_nbp(p); 171 } 172 173 del_timer_sync(&br->gc_timer); 174 175 br_sysfs_delbr(br->dev); 176 unregister_netdevice_queue(br->dev, head); 177 } 178 179 /* find an available port number */ 180 static int find_portno(struct net_bridge *br) 181 { 182 int index; 183 struct net_bridge_port *p; 184 unsigned long *inuse; 185 186 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 187 GFP_KERNEL); 188 if (!inuse) 189 return -ENOMEM; 190 191 set_bit(0, inuse); /* zero is reserved */ 192 list_for_each_entry(p, &br->port_list, list) { 193 set_bit(p->port_no, inuse); 194 } 195 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 196 kfree(inuse); 197 198 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 199 } 200 201 /* called with RTNL but without bridge lock */ 202 static struct net_bridge_port *new_nbp(struct net_bridge *br, 203 struct net_device *dev) 204 { 205 int index; 206 struct net_bridge_port *p; 207 208 index = find_portno(br); 209 if (index < 0) 210 return ERR_PTR(index); 211 212 p = kzalloc(sizeof(*p), GFP_KERNEL); 213 if (p == NULL) 214 return ERR_PTR(-ENOMEM); 215 216 p->br = br; 217 dev_hold(dev); 218 p->dev = dev; 219 p->path_cost = port_cost(dev); 220 p->priority = 0x8000 >> BR_PORT_BITS; 221 p->port_no = index; 222 p->flags = 0; 223 br_init_port(p); 224 p->state = BR_STATE_DISABLED; 225 br_stp_port_timer_init(p); 226 br_multicast_add_port(p); 227 228 return p; 229 } 230 231 int br_add_bridge(struct net *net, const char *name) 232 { 233 struct net_device *dev; 234 235 dev = alloc_netdev(sizeof(struct net_bridge), name, 236 br_dev_setup); 237 238 if (!dev) 239 return -ENOMEM; 240 241 dev_net_set(dev, net); 242 243 return register_netdev(dev); 244 } 245 246 int br_del_bridge(struct net *net, const char *name) 247 { 248 struct net_device *dev; 249 int ret = 0; 250 251 rtnl_lock(); 252 dev = __dev_get_by_name(net, name); 253 if (dev == NULL) 254 ret = -ENXIO; /* Could not find device */ 255 256 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 257 /* Attempt to delete non bridge device! */ 258 ret = -EPERM; 259 } 260 261 else if (dev->flags & IFF_UP) { 262 /* Not shutdown yet. */ 263 ret = -EBUSY; 264 } 265 266 else 267 del_br(netdev_priv(dev), NULL); 268 269 rtnl_unlock(); 270 return ret; 271 } 272 273 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 274 int br_min_mtu(const struct net_bridge *br) 275 { 276 const struct net_bridge_port *p; 277 int mtu = 0; 278 279 ASSERT_RTNL(); 280 281 if (list_empty(&br->port_list)) 282 mtu = ETH_DATA_LEN; 283 else { 284 list_for_each_entry(p, &br->port_list, list) { 285 if (!mtu || p->dev->mtu < mtu) 286 mtu = p->dev->mtu; 287 } 288 } 289 return mtu; 290 } 291 292 /* 293 * Recomputes features using slave's features 294 */ 295 u32 br_features_recompute(struct net_bridge *br, u32 features) 296 { 297 struct net_bridge_port *p; 298 u32 mask; 299 300 if (list_empty(&br->port_list)) 301 return features; 302 303 mask = features; 304 features &= ~NETIF_F_ONE_FOR_ALL; 305 306 list_for_each_entry(p, &br->port_list, list) { 307 features = netdev_increment_features(features, 308 p->dev->features, mask); 309 } 310 311 return features; 312 } 313 314 /* called with RTNL */ 315 int br_add_if(struct net_bridge *br, struct net_device *dev) 316 { 317 struct net_bridge_port *p; 318 int err = 0; 319 bool changed_addr; 320 321 /* Don't allow bridging non-ethernet like devices */ 322 if ((dev->flags & IFF_LOOPBACK) || 323 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN) 324 return -EINVAL; 325 326 /* No bridging of bridges */ 327 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 328 return -ELOOP; 329 330 /* Device is already being bridged */ 331 if (br_port_exists(dev)) 332 return -EBUSY; 333 334 /* No bridging devices that dislike that (e.g. wireless) */ 335 if (dev->priv_flags & IFF_DONT_BRIDGE) 336 return -EOPNOTSUPP; 337 338 p = new_nbp(br, dev); 339 if (IS_ERR(p)) 340 return PTR_ERR(p); 341 342 call_netdevice_notifiers(NETDEV_JOIN, dev); 343 344 err = dev_set_promiscuity(dev, 1); 345 if (err) 346 goto put_back; 347 348 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 349 SYSFS_BRIDGE_PORT_ATTR); 350 if (err) 351 goto err0; 352 353 err = br_fdb_insert(br, p, dev->dev_addr); 354 if (err) 355 goto err1; 356 357 err = br_sysfs_addif(p); 358 if (err) 359 goto err2; 360 361 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) 362 goto err3; 363 364 err = netdev_set_master(dev, br->dev); 365 if (err) 366 goto err3; 367 368 err = netdev_rx_handler_register(dev, br_handle_frame, p); 369 if (err) 370 goto err4; 371 372 dev->priv_flags |= IFF_BRIDGE_PORT; 373 374 dev_disable_lro(dev); 375 376 list_add_rcu(&p->list, &br->port_list); 377 378 netdev_update_features(br->dev); 379 380 spin_lock_bh(&br->lock); 381 changed_addr = br_stp_recalculate_bridge_id(br); 382 383 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 384 (br->dev->flags & IFF_UP)) 385 br_stp_enable_port(p); 386 spin_unlock_bh(&br->lock); 387 388 br_ifinfo_notify(RTM_NEWLINK, p); 389 390 if (changed_addr) 391 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev); 392 393 dev_set_mtu(br->dev, br_min_mtu(br)); 394 395 kobject_uevent(&p->kobj, KOBJ_ADD); 396 397 return 0; 398 399 err4: 400 netdev_set_master(dev, NULL); 401 err3: 402 sysfs_remove_link(br->ifobj, p->dev->name); 403 err2: 404 br_fdb_delete_by_port(br, p, 1); 405 err1: 406 kobject_put(&p->kobj); 407 p = NULL; /* kobject_put frees */ 408 err0: 409 dev_set_promiscuity(dev, -1); 410 put_back: 411 dev_put(dev); 412 kfree(p); 413 return err; 414 } 415 416 /* called with RTNL */ 417 int br_del_if(struct net_bridge *br, struct net_device *dev) 418 { 419 struct net_bridge_port *p; 420 421 p = br_port_get_rtnl(dev); 422 if (!p || p->br != br) 423 return -EINVAL; 424 425 del_nbp(p); 426 427 spin_lock_bh(&br->lock); 428 br_stp_recalculate_bridge_id(br); 429 spin_unlock_bh(&br->lock); 430 431 netdev_update_features(br->dev); 432 433 return 0; 434 } 435 436 void __net_exit br_net_exit(struct net *net) 437 { 438 struct net_device *dev; 439 LIST_HEAD(list); 440 441 rtnl_lock(); 442 for_each_netdev(net, dev) 443 if (dev->priv_flags & IFF_EBRIDGE) 444 del_br(netdev_priv(dev), &list); 445 446 unregister_netdevice_many(&list); 447 rtnl_unlock(); 448 449 } 450