/* * Userspace interface * Linux ethernet bridge * * Authors: * Lennert Buytenhek <buytenh@gnu.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/netpoll.h> #include <linux/ethtool.h> #include <linux/if_arp.h> #include <linux/module.h> #include <linux/init.h> #include <linux/rtnetlink.h> #include <linux/if_ether.h> #include <linux/slab.h> #include <net/sock.h> #include "br_private.h" /* * Determine initial path cost based on speed. * using recommendations from 802.1d standard * * Since driver might sleep need to not be holding any locks. */ static int port_cost(struct net_device *dev) { struct ethtool_cmd ecmd; if (!__ethtool_get_settings(dev, &ecmd)) { switch (ethtool_cmd_speed(&ecmd)) { case SPEED_10000: return 2; case SPEED_1000: return 4; case SPEED_100: return 19; case SPEED_10: return 100; } } /* Old silly heuristics based on name */ if (!strncmp(dev->name, "lec", 3)) return 7; if (!strncmp(dev->name, "plip", 4)) return 2500; return 100; /* assume old 10Mbps */ } /* Check for port carrier transistions. */ void br_port_carrier_check(struct net_bridge_port *p) { struct net_device *dev = p->dev; struct net_bridge *br = p->br; if (netif_running(dev) && netif_carrier_ok(dev)) p->path_cost = port_cost(dev); if (!netif_running(br->dev)) return; spin_lock_bh(&br->lock); if (netif_running(dev) && netif_carrier_ok(dev)) { if (p->state == BR_STATE_DISABLED) br_stp_enable_port(p); } else { if (p->state != BR_STATE_DISABLED) br_stp_disable_port(p); } spin_unlock_bh(&br->lock); } static void release_nbp(struct kobject *kobj) { struct net_bridge_port *p = container_of(kobj, struct net_bridge_port, kobj); kfree(p); } static struct kobj_type brport_ktype = { #ifdef CONFIG_SYSFS .sysfs_ops = &brport_sysfs_ops, #endif .release = release_nbp, }; static void destroy_nbp(struct net_bridge_port *p) { struct net_device *dev = p->dev; p->br = NULL; p->dev = NULL; dev_put(dev); kobject_put(&p->kobj); } static void destroy_nbp_rcu(struct rcu_head *head) { struct net_bridge_port *p = container_of(head, struct net_bridge_port, rcu); destroy_nbp(p); } /* Delete port(interface) from bridge is done in two steps. * via RCU. First step, marks device as down. That deletes * all the timers and stops new packets from flowing through. * * Final cleanup doesn't occur until after all CPU's finished * processing packets. * * Protected from multiple admin operations by RTNL mutex */ static void del_nbp(struct net_bridge_port *p) { struct net_bridge *br = p->br; struct net_device *dev = p->dev; sysfs_remove_link(br->ifobj, p->dev->name); dev_set_promiscuity(dev, -1); spin_lock_bh(&br->lock); br_stp_disable_port(p); spin_unlock_bh(&br->lock); br_ifinfo_notify(RTM_DELLINK, p); br_fdb_delete_by_port(br, p, 1); list_del_rcu(&p->list); dev->priv_flags &= ~IFF_BRIDGE_PORT; netdev_rx_handler_unregister(dev); synchronize_net(); netdev_set_master(dev, NULL); br_multicast_del_port(p); kobject_uevent(&p->kobj, KOBJ_REMOVE); kobject_del(&p->kobj); br_netpoll_disable(p); call_rcu(&p->rcu, destroy_nbp_rcu); } /* Delete bridge device */ void br_dev_delete(struct net_device *dev, struct list_head *head) { struct net_bridge *br = netdev_priv(dev); struct net_bridge_port *p, *n; list_for_each_entry_safe(p, n, &br->port_list, list) { del_nbp(p); } del_timer_sync(&br->gc_timer); br_sysfs_delbr(br->dev); unregister_netdevice_queue(br->dev, head); } /* find an available port number */ static int find_portno(struct net_bridge *br) { int index; struct net_bridge_port *p; unsigned long *inuse; inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), GFP_KERNEL); if (!inuse) return -ENOMEM; set_bit(0, inuse); /* zero is reserved */ list_for_each_entry(p, &br->port_list, list) { set_bit(p->port_no, inuse); } index = find_first_zero_bit(inuse, BR_MAX_PORTS); kfree(inuse); return (index >= BR_MAX_PORTS) ? -EXFULL : index; } /* called with RTNL but without bridge lock */ static struct net_bridge_port *new_nbp(struct net_bridge *br, struct net_device *dev) { int index; struct net_bridge_port *p; index = find_portno(br); if (index < 0) return ERR_PTR(index); p = kzalloc(sizeof(*p), GFP_KERNEL); if (p == NULL) return ERR_PTR(-ENOMEM); p->br = br; dev_hold(dev); p->dev = dev; p->path_cost = port_cost(dev); p->priority = 0x8000 >> BR_PORT_BITS; p->port_no = index; p->flags = 0; br_init_port(p); p->state = BR_STATE_DISABLED; br_stp_port_timer_init(p); br_multicast_add_port(p); return p; } int br_add_bridge(struct net *net, const char *name) { struct net_device *dev; int res; dev = alloc_netdev(sizeof(struct net_bridge), name, br_dev_setup); if (!dev) return -ENOMEM; dev_net_set(dev, net); res = register_netdev(dev); if (res) free_netdev(dev); return res; } int br_del_bridge(struct net *net, const char *name) { struct net_device *dev; int ret = 0; rtnl_lock(); dev = __dev_get_by_name(net, name); if (dev == NULL) ret = -ENXIO; /* Could not find device */ else if (!(dev->priv_flags & IFF_EBRIDGE)) { /* Attempt to delete non bridge device! */ ret = -EPERM; } else if (dev->flags & IFF_UP) { /* Not shutdown yet. */ ret = -EBUSY; } else br_dev_delete(dev, NULL); rtnl_unlock(); return ret; } /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ int br_min_mtu(const struct net_bridge *br) { const struct net_bridge_port *p; int mtu = 0; ASSERT_RTNL(); if (list_empty(&br->port_list)) mtu = ETH_DATA_LEN; else { list_for_each_entry(p, &br->port_list, list) { if (!mtu || p->dev->mtu < mtu) mtu = p->dev->mtu; } } return mtu; } /* * Recomputes features using slave's features */ netdev_features_t br_features_recompute(struct net_bridge *br, netdev_features_t features) { struct net_bridge_port *p; netdev_features_t mask; if (list_empty(&br->port_list)) return features; mask = features; features &= ~NETIF_F_ONE_FOR_ALL; list_for_each_entry(p, &br->port_list, list) { features = netdev_increment_features(features, p->dev->features, mask); } return features; } /* called with RTNL */ int br_add_if(struct net_bridge *br, struct net_device *dev) { struct net_bridge_port *p; int err = 0; bool changed_addr; /* Don't allow bridging non-ethernet like devices */ if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr)) return -EINVAL; /* No bridging of bridges */ if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) return -ELOOP; /* Device is already being bridged */ if (br_port_exists(dev)) return -EBUSY; /* No bridging devices that dislike that (e.g. wireless) */ if (dev->priv_flags & IFF_DONT_BRIDGE) return -EOPNOTSUPP; p = new_nbp(br, dev); if (IS_ERR(p)) return PTR_ERR(p); call_netdevice_notifiers(NETDEV_JOIN, dev); err = dev_set_promiscuity(dev, 1); if (err) goto put_back; err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), SYSFS_BRIDGE_PORT_ATTR); if (err) goto err1; err = br_sysfs_addif(p); if (err) goto err2; if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) goto err3; err = netdev_set_master(dev, br->dev); if (err) goto err3; err = netdev_rx_handler_register(dev, br_handle_frame, p); if (err) goto err4; dev->priv_flags |= IFF_BRIDGE_PORT; dev_disable_lro(dev); list_add_rcu(&p->list, &br->port_list); netdev_update_features(br->dev); spin_lock_bh(&br->lock); changed_addr = br_stp_recalculate_bridge_id(br); if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) br_stp_enable_port(p); spin_unlock_bh(&br->lock); br_ifinfo_notify(RTM_NEWLINK, p); if (changed_addr) call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); dev_set_mtu(br->dev, br_min_mtu(br)); if (br_fdb_insert(br, p, dev->dev_addr)) netdev_err(dev, "failed insert local address bridge forwarding table\n"); kobject_uevent(&p->kobj, KOBJ_ADD); return 0; err4: netdev_set_master(dev, NULL); err3: sysfs_remove_link(br->ifobj, p->dev->name); err2: kobject_put(&p->kobj); p = NULL; /* kobject_put frees */ err1: dev_set_promiscuity(dev, -1); put_back: dev_put(dev); kfree(p); return err; } /* called with RTNL */ int br_del_if(struct net_bridge *br, struct net_device *dev) { struct net_bridge_port *p; bool changed_addr; p = br_port_get_rtnl(dev); if (!p || p->br != br) return -EINVAL; del_nbp(p); spin_lock_bh(&br->lock); changed_addr = br_stp_recalculate_bridge_id(br); spin_unlock_bh(&br->lock); if (changed_addr) call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); netdev_update_features(br->dev); return 0; } void __net_exit br_net_exit(struct net *net) { struct net_device *dev; LIST_HEAD(list); rtnl_lock(); for_each_netdev(net, dev) if (dev->priv_flags & IFF_EBRIDGE) br_dev_delete(dev, &list); unregister_netdevice_many(&list); rtnl_unlock(); }