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); 150 151 netdev_set_master(dev, NULL); 152 153 br_multicast_del_port(p); 154 155 kobject_uevent(&p->kobj, KOBJ_REMOVE); 156 kobject_del(&p->kobj); 157 158 br_netpoll_disable(p); 159 160 call_rcu(&p->rcu, destroy_nbp_rcu); 161 } 162 163 /* called with RTNL */ 164 static void del_br(struct net_bridge *br, struct list_head *head) 165 { 166 struct net_bridge_port *p, *n; 167 168 list_for_each_entry_safe(p, n, &br->port_list, list) { 169 del_nbp(p); 170 } 171 172 del_timer_sync(&br->gc_timer); 173 174 br_sysfs_delbr(br->dev); 175 unregister_netdevice_queue(br->dev, head); 176 } 177 178 /* find an available port number */ 179 static int find_portno(struct net_bridge *br) 180 { 181 int index; 182 struct net_bridge_port *p; 183 unsigned long *inuse; 184 185 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 186 GFP_KERNEL); 187 if (!inuse) 188 return -ENOMEM; 189 190 set_bit(0, inuse); /* zero is reserved */ 191 list_for_each_entry(p, &br->port_list, list) { 192 set_bit(p->port_no, inuse); 193 } 194 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 195 kfree(inuse); 196 197 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 198 } 199 200 /* called with RTNL but without bridge lock */ 201 static struct net_bridge_port *new_nbp(struct net_bridge *br, 202 struct net_device *dev) 203 { 204 int index; 205 struct net_bridge_port *p; 206 207 index = find_portno(br); 208 if (index < 0) 209 return ERR_PTR(index); 210 211 p = kzalloc(sizeof(*p), GFP_KERNEL); 212 if (p == NULL) 213 return ERR_PTR(-ENOMEM); 214 215 p->br = br; 216 dev_hold(dev); 217 p->dev = dev; 218 p->path_cost = port_cost(dev); 219 p->priority = 0x8000 >> BR_PORT_BITS; 220 p->port_no = index; 221 p->flags = 0; 222 br_init_port(p); 223 p->state = BR_STATE_DISABLED; 224 br_stp_port_timer_init(p); 225 br_multicast_add_port(p); 226 227 return p; 228 } 229 230 int br_add_bridge(struct net *net, const char *name) 231 { 232 struct net_device *dev; 233 234 dev = alloc_netdev(sizeof(struct net_bridge), name, 235 br_dev_setup); 236 237 if (!dev) 238 return -ENOMEM; 239 240 dev_net_set(dev, net); 241 242 return register_netdev(dev); 243 } 244 245 int br_del_bridge(struct net *net, const char *name) 246 { 247 struct net_device *dev; 248 int ret = 0; 249 250 rtnl_lock(); 251 dev = __dev_get_by_name(net, name); 252 if (dev == NULL) 253 ret = -ENXIO; /* Could not find device */ 254 255 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 256 /* Attempt to delete non bridge device! */ 257 ret = -EPERM; 258 } 259 260 else if (dev->flags & IFF_UP) { 261 /* Not shutdown yet. */ 262 ret = -EBUSY; 263 } 264 265 else 266 del_br(netdev_priv(dev), NULL); 267 268 rtnl_unlock(); 269 return ret; 270 } 271 272 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 273 int br_min_mtu(const struct net_bridge *br) 274 { 275 const struct net_bridge_port *p; 276 int mtu = 0; 277 278 ASSERT_RTNL(); 279 280 if (list_empty(&br->port_list)) 281 mtu = ETH_DATA_LEN; 282 else { 283 list_for_each_entry(p, &br->port_list, list) { 284 if (!mtu || p->dev->mtu < mtu) 285 mtu = p->dev->mtu; 286 } 287 } 288 return mtu; 289 } 290 291 /* 292 * Recomputes features using slave's features 293 */ 294 u32 br_features_recompute(struct net_bridge *br, u32 features) 295 { 296 struct net_bridge_port *p; 297 u32 mask; 298 299 if (list_empty(&br->port_list)) 300 return features; 301 302 mask = features; 303 features &= ~NETIF_F_ONE_FOR_ALL; 304 305 list_for_each_entry(p, &br->port_list, list) { 306 features = netdev_increment_features(features, 307 p->dev->features, mask); 308 } 309 310 return features; 311 } 312 313 /* called with RTNL */ 314 int br_add_if(struct net_bridge *br, struct net_device *dev) 315 { 316 struct net_bridge_port *p; 317 int err = 0; 318 bool changed_addr; 319 320 /* Don't allow bridging non-ethernet like devices */ 321 if ((dev->flags & IFF_LOOPBACK) || 322 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN) 323 return -EINVAL; 324 325 /* No bridging of bridges */ 326 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 327 return -ELOOP; 328 329 /* Device is already being bridged */ 330 if (br_port_exists(dev)) 331 return -EBUSY; 332 333 /* No bridging devices that dislike that (e.g. wireless) */ 334 if (dev->priv_flags & IFF_DONT_BRIDGE) 335 return -EOPNOTSUPP; 336 337 p = new_nbp(br, dev); 338 if (IS_ERR(p)) 339 return PTR_ERR(p); 340 341 err = dev_set_promiscuity(dev, 1); 342 if (err) 343 goto put_back; 344 345 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 346 SYSFS_BRIDGE_PORT_ATTR); 347 if (err) 348 goto err0; 349 350 err = br_fdb_insert(br, p, dev->dev_addr); 351 if (err) 352 goto err1; 353 354 err = br_sysfs_addif(p); 355 if (err) 356 goto err2; 357 358 if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) 359 goto err3; 360 361 err = netdev_set_master(dev, br->dev); 362 if (err) 363 goto err3; 364 365 err = netdev_rx_handler_register(dev, br_handle_frame, p); 366 if (err) 367 goto err4; 368 369 dev->priv_flags |= IFF_BRIDGE_PORT; 370 371 dev_disable_lro(dev); 372 373 list_add_rcu(&p->list, &br->port_list); 374 375 netdev_update_features(br->dev); 376 377 spin_lock_bh(&br->lock); 378 changed_addr = br_stp_recalculate_bridge_id(br); 379 380 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 381 (br->dev->flags & IFF_UP)) 382 br_stp_enable_port(p); 383 spin_unlock_bh(&br->lock); 384 385 br_ifinfo_notify(RTM_NEWLINK, p); 386 387 if (changed_addr) 388 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev); 389 390 dev_set_mtu(br->dev, br_min_mtu(br)); 391 392 kobject_uevent(&p->kobj, KOBJ_ADD); 393 394 return 0; 395 396 err4: 397 netdev_set_master(dev, NULL); 398 err3: 399 sysfs_remove_link(br->ifobj, p->dev->name); 400 err2: 401 br_fdb_delete_by_port(br, p, 1); 402 err1: 403 kobject_put(&p->kobj); 404 p = NULL; /* kobject_put frees */ 405 err0: 406 dev_set_promiscuity(dev, -1); 407 put_back: 408 dev_put(dev); 409 kfree(p); 410 return err; 411 } 412 413 /* called with RTNL */ 414 int br_del_if(struct net_bridge *br, struct net_device *dev) 415 { 416 struct net_bridge_port *p; 417 418 p = br_port_get_rtnl(dev); 419 if (!p || p->br != br) 420 return -EINVAL; 421 422 del_nbp(p); 423 424 spin_lock_bh(&br->lock); 425 br_stp_recalculate_bridge_id(br); 426 spin_unlock_bh(&br->lock); 427 428 netdev_update_features(br->dev); 429 430 return 0; 431 } 432 433 void __net_exit br_net_exit(struct net *net) 434 { 435 struct net_device *dev; 436 LIST_HEAD(list); 437 438 rtnl_lock(); 439 for_each_netdev(net, dev) 440 if (dev->priv_flags & IFF_EBRIDGE) 441 del_br(netdev_priv(dev), &list); 442 443 unregister_netdevice_many(&list); 444 rtnl_unlock(); 445 446 } 447