1 files changed, 454 insertions, 0 deletions
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
new file mode 100644
index 00000000..44908737
--- /dev/null
+++ b/net/bridge/br_if.c
@@ -0,0 +1,454 @@
+/*
+ *	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/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)
+{
+	if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
+		struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
+
+		if (!dev_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
+ */
+u32 br_features_recompute(struct net_bridge *br, u32 features)
+{
+	struct net_bridge_port *p;
+	u32 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)
+		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 err0;
+
+	err = br_fdb_insert(br, p, dev->dev_addr);
+	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, dev);
+
+	dev_set_mtu(br->dev, br_min_mtu(br));
+
+	kobject_uevent(&p->kobj, KOBJ_ADD);
+
+	return 0;
+
+err4:
+	netdev_set_master(dev, NULL);
+err3:
+	sysfs_remove_link(br->ifobj, p->dev->name);
+err2:
+	br_fdb_delete_by_port(br, p, 1);
+err1:
+	kobject_put(&p->kobj);
+	p = NULL; /* kobject_put frees */
+err0:
+	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;
+
+	p = br_port_get_rtnl(dev);
+	if (!p || p->br != br)
+		return -EINVAL;
+
+	del_nbp(p);
+
+	spin_lock_bh(&br->lock);
+	br_stp_recalculate_bridge_id(br);
+	spin_unlock_bh(&br->lock);
+
+	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();
+
+}