/* * 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 <linux/if_vlan.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 transitions. */ void br_port_carrier_check(struct net_bridge_port *p) { struct net_device *dev = p->dev; struct net_bridge *br = p->br; if (!(p->flags & BR_ADMIN_COST) && netif_running(dev) && netif_oper_up(dev)) p->path_cost = port_cost(dev); if (!netif_running(br->dev)) return; spin_lock_bh(&br->lock); if (netif_running(dev) && netif_oper_up(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 br_port_set_promisc(struct net_bridge_port *p) { int err = 0; if (br_promisc_port(p)) return; err = dev_set_promiscuity(p->dev, 1); if (err) return; br_fdb_unsync_static(p->br, p); p->flags |= BR_PROMISC; } static void br_port_clear_promisc(struct net_bridge_port *p) { int err; /* Check if the port is already non-promisc or if it doesn't * support UNICAST filtering. Without unicast filtering support * we'll end up re-enabling promisc mode anyway, so just check for * it here. */ if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT)) return; /* Since we'll be clearing the promisc mode, program the port * first so that we don't have interruption in traffic. */ err = br_fdb_sync_static(p->br, p); if (err) return; dev_set_promiscuity(p->dev, -1); p->flags &= ~BR_PROMISC; } /* When a port is added or removed or when certain port flags * change, this function is called to automatically manage * promiscuity setting of all the bridge ports. We are always called * under RTNL so can skip using rcu primitives. */ void br_manage_promisc(struct net_bridge *br) { struct net_bridge_port *p; bool set_all = false; /* If vlan filtering is disabled or bridge interface is placed * into promiscuous mode, place all ports in promiscuous mode. */ if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br)) set_all = true; list_for_each_entry(p, &br->port_list, list) { if (set_all) { br_port_set_promisc(p); } else { /* If the number of auto-ports is <= 1, then all other * ports will have their output configuration * statically specified through fdbs. Since ingress * on the auto-port becomes forwarding/egress to other * ports and egress configuration is statically known, * we can say that ingress configuration of the * auto-port is also statically known. * This lets us disable promiscuous mode and write * this config to hw. */ if (br->auto_cnt == 0 || (br->auto_cnt == 1 && br_auto_port(p))) br_port_clear_promisc(p); else br_port_set_promisc(p); } } } static void nbp_update_port_count(struct net_bridge *br) { struct net_bridge_port *p; u32 cnt = 0; list_for_each_entry(p, &br->port_list, list) { if (br_auto_port(p)) cnt++; } if (br->auto_cnt != cnt) { br->auto_cnt = cnt; br_manage_promisc(br); } } static void nbp_delete_promisc(struct net_bridge_port *p) { /* If port is currently promiscuous, unset promiscuity. * Otherwise, it is a static port so remove all addresses * from it. */ dev_set_allmulti(p->dev, -1); if (br_promisc_port(p)) dev_set_promiscuity(p->dev, -1); else br_fdb_unsync_static(p->br, p); } 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); nbp_delete_promisc(p); spin_lock_bh(&br->lock); br_stp_disable_port(p); spin_unlock_bh(&br->lock); br_ifinfo_notify(RTM_DELLINK, p); list_del_rcu(&p->list); nbp_vlan_flush(p); br_fdb_delete_by_port(br, p, 1); nbp_update_port_count(br); netdev_upper_dev_unlink(dev, br->dev); dev->priv_flags &= ~IFF_BRIDGE_PORT; netdev_rx_handler_unregister(dev); 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); } br_fdb_delete_by_port(br, NULL, 1); br_vlan_flush(br); 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 = BR_LEARNING | BR_FLOOD; br_init_port(p); br_set_state(p, 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, NET_NAME_UNKNOWN, br_dev_setup); if (!dev) return -ENOMEM; dev_net_set(dev, net); dev->rtnl_link_ops = &br_link_ops; 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); } features = netdev_add_tso_features(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, or DSA-enabled * master network devices since the bridge layer rx_handler prevents * the DSA fake ethertype handler to be invoked, so we do not strip off * the DSA switch tag protocol header and the bridge layer just return * RX_HANDLER_CONSUMED, stopping RX processing for these frames. */ if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr) || netdev_uses_dsa(dev)) 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_allmulti(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; err = br_netpoll_enable(p); if (err) goto err3; err = netdev_rx_handler_register(dev, br_handle_frame, p); if (err) goto err4; dev->priv_flags |= IFF_BRIDGE_PORT; err = netdev_master_upper_dev_link(dev, br->dev); if (err) goto err5; dev_disable_lro(dev); list_add_rcu(&p->list, &br->port_list); nbp_update_port_count(br); netdev_update_features(br->dev); if (br->dev->needed_headroom < dev->needed_headroom) br->dev->needed_headroom = dev->needed_headroom; if (br_fdb_insert(br, p, dev->dev_addr, 0)) netdev_err(dev, "failed insert local address bridge forwarding table\n"); if (nbp_vlan_init(p)) netdev_err(dev, "failed to initialize vlan filtering on this port\n"); spin_lock_bh(&br->lock); changed_addr = br_stp_recalculate_bridge_id(br); if (netif_running(dev) && netif_oper_up(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)); kobject_uevent(&p->kobj, KOBJ_ADD); return 0; err5: dev->priv_flags &= ~IFF_BRIDGE_PORT; netdev_rx_handler_unregister(dev); err4: br_netpoll_disable(p); err3: sysfs_remove_link(br->ifobj, p->dev->name); err2: kobject_put(&p->kobj); p = NULL; /* kobject_put frees */ err1: dev_set_allmulti(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; /* Since more than one interface can be attached to a bridge, * there still maybe an alternate path for netconsole to use; * therefore there is no reason for a NETDEV_RELEASE event. */ del_nbp(p); dev_set_mtu(br->dev, br_min_mtu(br)); 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 br_port_flags_change(struct net_bridge_port *p, unsigned long mask) { struct net_bridge *br = p->br; if (mask & BR_AUTO_MASK) nbp_update_port_count(br); }