diff options
Diffstat (limited to '')
| -rw-r--r-- | net/bridge/br_if.c | 793 |
1 files changed, 793 insertions, 0 deletions
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c new file mode 100644 index 000000000..e35488fde --- /dev/null +++ b/net/bridge/br_if.c @@ -0,0 +1,793 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Userspace interface + * Linux ethernet bridge + * + * Authors: + * Lennert Buytenhek <buytenh@gnu.org> + */ + +#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 ((p->dev->priv_flags & IFF_UNICAST_FLT) && + (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 (!netif_is_bridge_port(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_mrp_port_del(br, p); + + 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, fdb_synced = false; + + /* 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; + + /* Also don't allow bridging of net devices that are DSA masters, since + * the bridge layer rx_handler prevents the DSA fake ethertype handler + * to be invoked, so we don't get the chance to strip off and parse the + * DSA switch tag protocol header (the bridge layer just returns + * RX_HANDLER_CONSUMED, stopping RX processing for these frames). + * The only case where that would not be an issue is when bridging can + * already be offloaded, such as when the DSA master is itself a DSA + * or plain switchdev port, and is bridged only with other ports from + * the same hardware device. + */ + if (netdev_uses_dsa(dev)) { + list_for_each_entry(p, &br->port_list, list) { + if (!netdev_port_same_parent_id(dev, p->dev)) { + NL_SET_ERR_MSG(extack, + "Cannot do software bridging with a DSA master"); + 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) { + br_multicast_del_port(p); + kfree(p); /* kobject not yet init'd, manually free */ + goto err1; + } + + err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), + SYSFS_BRIDGE_PORT_ATTR); + if (err) + goto err2; + + 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_get_rx_handler(dev), 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); + if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) { + /* When updating the port count we also update all ports' + * promiscuous mode. + * A port leaving promiscuous mode normally gets the bridge's + * fdb synced to the unicast filter (if supported), however, + * `br_port_clear_promisc` does not distinguish between + * non-promiscuous ports and *new* ports, so we need to + * sync explicitly here. + */ + fdb_synced = br_fdb_sync_static(br, p) == 0; + if (!fdb_synced) + netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n"); + } + + 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: + if (fdb_synced) + br_fdb_unsync_static(br, p); + 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: + br_multicast_del_port(p); + kobject_put(&p->kobj); + dev_set_allmulti(dev, -1); +err1: + dev_put(dev); + 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); |