/* * 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/dsa.h> #include <net/sock.h> #include <linux/if_vlan.h> #include <net/switchdev.h> #include <net/net_namespace.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_link_ksettings ecmd; if (!__ethtool_get_link_ksettings(dev, &ecmd)) { switch (ecmd.base.speed) { 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, bool *notified) { 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); *notified = false; 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); *notified = true; } } else { if (p->state != BR_STATE_DISABLED) { br_stp_disable_port(p); *notified = true; } } 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->dev)) 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); } } } int nbp_backup_change(struct net_bridge_port *p, struct net_device *backup_dev) { struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port); struct net_bridge_port *backup_p = NULL; ASSERT_RTNL(); if (backup_dev) { if (!br_port_exists(backup_dev)) return -ENOENT; backup_p = br_port_get_rtnl(backup_dev); if (backup_p->br != p->br) return -EINVAL; } if (p == backup_p) return -EINVAL; if (old_backup == backup_p) return 0; /* if the backup link is already set, clear it */ if (old_backup) old_backup->backup_redirected_cnt--; if (backup_p) backup_p->backup_redirected_cnt++; rcu_assign_pointer(p->backup_port, backup_p); return 0; } static void nbp_backup_clear(struct net_bridge_port *p) { nbp_backup_change(p, NULL); if (p->backup_redirected_cnt) { struct net_bridge_port *cur_p; list_for_each_entry(cur_p, &p->br->port_list, list) { struct net_bridge_port *backup_p; backup_p = rtnl_dereference(cur_p->backup_port); if (backup_p == p) nbp_backup_change(cur_p, NULL); } } WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt); } 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 void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid) { struct net_bridge_port *p = kobj_to_brport(kobj); net_ns_get_ownership(dev_net(p->dev), uid, gid); } static struct kobj_type brport_ktype = { #ifdef CONFIG_SYSFS .sysfs_ops = &brport_sysfs_ops, #endif .release = release_nbp, .get_ownership = brport_get_ownership, }; 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); } static unsigned get_max_headroom(struct net_bridge *br) { unsigned max_headroom = 0; struct net_bridge_port *p; list_for_each_entry(p, &br->port_list, list) { unsigned dev_headroom = netdev_get_fwd_headroom(p->dev); if (dev_headroom > max_headroom) max_headroom = dev_headroom; } return max_headroom; } static void update_headroom(struct net_bridge *br, int new_hr) { struct net_bridge_port *p; list_for_each_entry(p, &br->port_list, list) netdev_set_rx_headroom(p->dev, new_hr); br->dev->needed_headroom = new_hr; } /* 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, NULL, p); list_del_rcu(&p->list); if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom) update_headroom(br, get_max_headroom(br)); netdev_reset_rx_headroom(dev); nbp_vlan_flush(p); br_fdb_delete_by_port(br, p, 0, 1); switchdev_deferred_process(); nbp_backup_clear(p); 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_recalculate_neigh_suppress_enabled(br); br_fdb_delete_by_port(br, NULL, 0, 1); cancel_delayed_work_sync(&br->gc_work); 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 = bitmap_zalloc(BR_MAX_PORTS, 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); bitmap_free(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) { struct net_bridge_port *p; int index, err; 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_MCAST_FLOOD | BR_BCAST_FLOOD; br_init_port(p); br_set_state(p, BR_STATE_DISABLED); br_stp_port_timer_init(p); err = br_multicast_add_port(p); if (err) { dev_put(dev); kfree(p); p = ERR_PTR(err); } 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 */ static int br_mtu_min(const struct net_bridge *br) { const struct net_bridge_port *p; int ret_mtu = 0; list_for_each_entry(p, &br->port_list, list) if (!ret_mtu || ret_mtu > p->dev->mtu) ret_mtu = p->dev->mtu; return ret_mtu ? ret_mtu : ETH_DATA_LEN; } void br_mtu_auto_adjust(struct net_bridge *br) { ASSERT_RTNL(); /* if the bridge MTU was manually configured don't mess with it */ if (br_opt_get(br, BROPT_MTU_SET_BY_USER)) return; /* change to the minimum MTU and clear the flag which was set by * the bridge ndo_change_mtu callback */ dev_set_mtu(br->dev, br_mtu_min(br)); br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false); } static void br_set_gso_limits(struct net_bridge *br) { unsigned int gso_max_size = GSO_MAX_SIZE; u16 gso_max_segs = GSO_MAX_SEGS; const struct net_bridge_port *p; list_for_each_entry(p, &br->port_list, list) { gso_max_size = min(gso_max_size, p->dev->gso_max_size); gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs); } br->dev->gso_max_size = gso_max_size; br->dev->gso_max_segs = gso_max_segs; } /* * 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 netlink_ext_ack *extack) { struct net_bridge_port *p; int err = 0; unsigned br_hr, dev_hr; 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) { NL_SET_ERR_MSG(extack, "Can not enslave a bridge to a bridge"); return -ELOOP; } /* Device has master upper dev */ if (netdev_master_upper_dev_get(dev)) return -EBUSY; /* No bridging devices that dislike that (e.g. wireless) */ if (dev->priv_flags & IFF_DONT_BRIDGE) { NL_SET_ERR_MSG(extack, "Device does not allow enslaving to a 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, NULL, NULL, extack); if (err) goto err5; err = nbp_switchdev_mark_set(p); if (err) goto err6; dev_disable_lro(dev); list_add_rcu(&p->list, &br->port_list); nbp_update_port_count(br); netdev_update_features(br->dev); br_hr = br->dev->needed_headroom; dev_hr = netdev_get_fwd_headroom(dev); if (br_hr < dev_hr) update_headroom(br, dev_hr); else netdev_set_rx_headroom(dev, br_hr); if (br_fdb_insert(br, p, dev->dev_addr, 0)) netdev_err(dev, "failed insert local address bridge forwarding table\n"); if (br->dev->addr_assign_type != NET_ADDR_SET) { /* Ask for permission to use this MAC address now, even if we * don't end up choosing it below. */ err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack); if (err) goto err7; } err = nbp_vlan_init(p, extack); if (err) { netdev_err(dev, "failed to initialize vlan filtering on this port\n"); goto err7; } 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, NULL, p); if (changed_addr) call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); br_mtu_auto_adjust(br); br_set_gso_limits(br); kobject_uevent(&p->kobj, KOBJ_ADD); return 0; err7: list_del_rcu(&p->list); br_fdb_delete_by_port(br, p, 0, 1); nbp_update_port_count(br); err6: netdev_upper_dev_unlink(dev, br->dev); 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); br_mtu_auto_adjust(br); br_set_gso_limits(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); if (mask & BR_NEIGH_SUPPRESS) br_recalculate_neigh_suppress_enabled(br); } bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag) { struct net_bridge_port *p; p = br_port_get_rtnl_rcu(dev); if (!p) return false; return p->flags & flag; } EXPORT_SYMBOL_GPL(br_port_flag_is_set);