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-rw-r--r--kernel/net/bridge/br_if.c586
1 files changed, 586 insertions, 0 deletions
diff --git a/kernel/net/bridge/br_if.c b/kernel/net/bridge/br_if.c
new file mode 100644
index 000000000..1849d96b3
--- /dev/null
+++ b/kernel/net/bridge/br_if.c
@@ -0,0 +1,586 @@
+/*
+ * 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);
+}