--- /dev/null
+/*
+ * Equalizer Load-balancer for serial network interfaces.
+ *
+ * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
+ * NCM: Network and Communications Management, Inc.
+ *
+ * (c) Copyright 2002 David S. Miller (davem@redhat.com)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * The author may be reached as simon@ncm.com, or C/O
+ * NCM
+ * Attn: Simon Janes
+ * 6803 Whittier Ave
+ * McLean VA 22101
+ * Phone: 1-703-847-0040 ext 103
+ */
+
+/*
+ * Sources:
+ * skeleton.c by Donald Becker.
+ * Inspirations:
+ * The Harried and Overworked Alan Cox
+ * Conspiracies:
+ * The Alan Cox and Mike McLagan plot to get someone else to do the code,
+ * which turned out to be me.
+ */
+
+/*
+ * $Log: eql.c,v $
+ * Revision 1.2 1996/04/11 17:51:52 guru
+ * Added one-line eql_remove_slave patch.
+ *
+ * Revision 1.1 1996/04/11 17:44:17 guru
+ * Initial revision
+ *
+ * Revision 3.13 1996/01/21 15:17:18 alan
+ * tx_queue_len changes.
+ * reformatted.
+ *
+ * Revision 3.12 1995/03/22 21:07:51 anarchy
+ * Added capable() checks on configuration.
+ * Moved header file.
+ *
+ * Revision 3.11 1995/01/19 23:14:31 guru
+ * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
+ * (priority_Bps) + bytes_queued * 8;
+ *
+ * Revision 3.10 1995/01/19 23:07:53 guru
+ * back to
+ * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
+ * (priority_Bps) + bytes_queued;
+ *
+ * Revision 3.9 1995/01/19 22:38:20 guru
+ * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
+ * (priority_Bps) + bytes_queued * 4;
+ *
+ * Revision 3.8 1995/01/19 22:30:55 guru
+ * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
+ * (priority_Bps) + bytes_queued * 2;
+ *
+ * Revision 3.7 1995/01/19 21:52:35 guru
+ * printk's trimmed out.
+ *
+ * Revision 3.6 1995/01/19 21:49:56 guru
+ * This is working pretty well. I gained 1 K/s in speed.. now it's just
+ * robustness and printk's to be diked out.
+ *
+ * Revision 3.5 1995/01/18 22:29:59 guru
+ * still crashes the kernel when the lock_wait thing is woken up.
+ *
+ * Revision 3.4 1995/01/18 21:59:47 guru
+ * Broken set-bit locking snapshot
+ *
+ * Revision 3.3 1995/01/17 22:09:18 guru
+ * infinite sleep in a lock somewhere..
+ *
+ * Revision 3.2 1995/01/15 16:46:06 guru
+ * Log trimmed of non-pertinent 1.x branch messages
+ *
+ * Revision 3.1 1995/01/15 14:41:45 guru
+ * New Scheduler and timer stuff...
+ *
+ * Revision 1.15 1995/01/15 14:29:02 guru
+ * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
+ * with the dumber scheduler
+ *
+ * Revision 1.14 1995/01/15 02:37:08 guru
+ * shock.. the kept-new-versions could have zonked working
+ * stuff.. shudder
+ *
+ * Revision 1.13 1995/01/15 02:36:31 guru
+ * big changes
+ *
+ * scheduler was torn out and replaced with something smarter
+ *
+ * global names not prefixed with eql_ were renamed to protect
+ * against namespace collisions
+ *
+ * a few more abstract interfaces were added to facilitate any
+ * potential change of datastructure. the driver is still using
+ * a linked list of slaves. going to a heap would be a bit of
+ * an overkill.
+ *
+ * this compiles fine with no warnings.
+ *
+ * the locking mechanism and timer stuff must be written however,
+ * this version will not work otherwise
+ *
+ * Sorry, I had to rewrite most of this for 2.5.x -DaveM
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/netdevice.h>
+#include <net/net_namespace.h>
+
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/if_eql.h>
+#include <linux/pkt_sched.h>
+
+#include <asm/uaccess.h>
+
+static int eql_open(struct net_device *dev);
+static int eql_close(struct net_device *dev);
+static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
+static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
+
+#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
+#define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
+
+static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
+
+static void eql_timer(unsigned long param)
+{
+ equalizer_t *eql = (equalizer_t *) param;
+ struct list_head *this, *tmp, *head;
+
+ spin_lock(&eql->queue.lock);
+ head = &eql->queue.all_slaves;
+ list_for_each_safe(this, tmp, head) {
+ slave_t *slave = list_entry(this, slave_t, list);
+
+ if ((slave->dev->flags & IFF_UP) == IFF_UP) {
+ slave->bytes_queued -= slave->priority_Bps;
+ if (slave->bytes_queued < 0)
+ slave->bytes_queued = 0;
+ } else {
+ eql_kill_one_slave(&eql->queue, slave);
+ }
+
+ }
+ spin_unlock(&eql->queue.lock);
+
+ eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
+ add_timer(&eql->timer);
+}
+
+static const char version[] __initconst =
+ "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";
+
+static const struct net_device_ops eql_netdev_ops = {
+ .ndo_open = eql_open,
+ .ndo_stop = eql_close,
+ .ndo_do_ioctl = eql_ioctl,
+ .ndo_start_xmit = eql_slave_xmit,
+};
+
+static void __init eql_setup(struct net_device *dev)
+{
+ equalizer_t *eql = netdev_priv(dev);
+
+ init_timer(&eql->timer);
+ eql->timer.data = (unsigned long) eql;
+ eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
+ eql->timer.function = eql_timer;
+
+ spin_lock_init(&eql->queue.lock);
+ INIT_LIST_HEAD(&eql->queue.all_slaves);
+ eql->queue.master_dev = dev;
+
+ dev->netdev_ops = &eql_netdev_ops;
+
+ /*
+ * Now we undo some of the things that eth_setup does
+ * that we don't like
+ */
+
+ dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
+ dev->flags = IFF_MASTER;
+
+ dev->type = ARPHRD_SLIP;
+ dev->tx_queue_len = 5; /* Hands them off fast */
+ netif_keep_dst(dev);
+}
+
+static int eql_open(struct net_device *dev)
+{
+ equalizer_t *eql = netdev_priv(dev);
+
+ /* XXX We should force this off automatically for the user. */
+ netdev_info(dev,
+ "remember to turn off Van-Jacobson compression on your slave devices\n");
+
+ BUG_ON(!list_empty(&eql->queue.all_slaves));
+
+ eql->min_slaves = 1;
+ eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
+
+ add_timer(&eql->timer);
+
+ return 0;
+}
+
+static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
+{
+ list_del(&slave->list);
+ queue->num_slaves--;
+ slave->dev->flags &= ~IFF_SLAVE;
+ dev_put(slave->dev);
+ kfree(slave);
+}
+
+static void eql_kill_slave_queue(slave_queue_t *queue)
+{
+ struct list_head *head, *tmp, *this;
+
+ spin_lock_bh(&queue->lock);
+
+ head = &queue->all_slaves;
+ list_for_each_safe(this, tmp, head) {
+ slave_t *s = list_entry(this, slave_t, list);
+
+ eql_kill_one_slave(queue, s);
+ }
+
+ spin_unlock_bh(&queue->lock);
+}
+
+static int eql_close(struct net_device *dev)
+{
+ equalizer_t *eql = netdev_priv(dev);
+
+ /*
+ * The timer has to be stopped first before we start hacking away
+ * at the data structure it scans every so often...
+ */
+
+ del_timer_sync(&eql->timer);
+
+ eql_kill_slave_queue(&eql->queue);
+
+ return 0;
+}
+
+static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
+static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
+
+static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
+static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
+
+static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
+static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
+
+static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
+ !capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case EQL_ENSLAVE:
+ return eql_enslave(dev, ifr->ifr_data);
+ case EQL_EMANCIPATE:
+ return eql_emancipate(dev, ifr->ifr_data);
+ case EQL_GETSLAVECFG:
+ return eql_g_slave_cfg(dev, ifr->ifr_data);
+ case EQL_SETSLAVECFG:
+ return eql_s_slave_cfg(dev, ifr->ifr_data);
+ case EQL_GETMASTRCFG:
+ return eql_g_master_cfg(dev, ifr->ifr_data);
+ case EQL_SETMASTRCFG:
+ return eql_s_master_cfg(dev, ifr->ifr_data);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+/* queue->lock must be held */
+static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
+{
+ unsigned long best_load = ~0UL;
+ struct list_head *this, *tmp, *head;
+ slave_t *best_slave;
+
+ best_slave = NULL;
+
+ /* Make a pass to set the best slave. */
+ head = &queue->all_slaves;
+ list_for_each_safe(this, tmp, head) {
+ slave_t *slave = list_entry(this, slave_t, list);
+ unsigned long slave_load, bytes_queued, priority_Bps;
+
+ /* Go through the slave list once, updating best_slave
+ * whenever a new best_load is found.
+ */
+ bytes_queued = slave->bytes_queued;
+ priority_Bps = slave->priority_Bps;
+ if ((slave->dev->flags & IFF_UP) == IFF_UP) {
+ slave_load = (~0UL - (~0UL / 2)) -
+ (priority_Bps) + bytes_queued * 8;
+
+ if (slave_load < best_load) {
+ best_load = slave_load;
+ best_slave = slave;
+ }
+ } else {
+ /* We found a dead slave, kill it. */
+ eql_kill_one_slave(queue, slave);
+ }
+ }
+ return best_slave;
+}
+
+static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ equalizer_t *eql = netdev_priv(dev);
+ slave_t *slave;
+
+ spin_lock(&eql->queue.lock);
+
+ slave = __eql_schedule_slaves(&eql->queue);
+ if (slave) {
+ struct net_device *slave_dev = slave->dev;
+
+ skb->dev = slave_dev;
+ skb->priority = TC_PRIO_FILLER;
+ slave->bytes_queued += skb->len;
+ dev_queue_xmit(skb);
+ dev->stats.tx_packets++;
+ } else {
+ dev->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ }
+
+ spin_unlock(&eql->queue.lock);
+
+ return NETDEV_TX_OK;
+}
+
+/*
+ * Private ioctl functions
+ */
+
+/* queue->lock must be held */
+static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
+{
+ struct list_head *this, *head;
+
+ head = &queue->all_slaves;
+ list_for_each(this, head) {
+ slave_t *slave = list_entry(this, slave_t, list);
+
+ if (slave->dev == dev)
+ return slave;
+ }
+
+ return NULL;
+}
+
+static inline int eql_is_full(slave_queue_t *queue)
+{
+ equalizer_t *eql = netdev_priv(queue->master_dev);
+
+ if (queue->num_slaves >= eql->max_slaves)
+ return 1;
+ return 0;
+}
+
+/* queue->lock must be held */
+static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
+{
+ if (!eql_is_full(queue)) {
+ slave_t *duplicate_slave = NULL;
+
+ duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
+ if (duplicate_slave)
+ eql_kill_one_slave(queue, duplicate_slave);
+
+ dev_hold(slave->dev);
+ list_add(&slave->list, &queue->all_slaves);
+ queue->num_slaves++;
+ slave->dev->flags |= IFF_SLAVE;
+
+ return 0;
+ }
+
+ return -ENOSPC;
+}
+
+static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
+{
+ struct net_device *slave_dev;
+ slaving_request_t srq;
+
+ if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
+ return -EFAULT;
+
+ slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
+
+ if ((master_dev->flags & IFF_UP) == IFF_UP) {
+ /* slave is not a master & not already a slave: */
+ if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) {
+ slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
+ equalizer_t *eql = netdev_priv(master_dev);
+ int ret;
+
+ if (!s)
+ return -ENOMEM;
+
+ memset(s, 0, sizeof(*s));
+ s->dev = slave_dev;
+ s->priority = srq.priority;
+ s->priority_bps = srq.priority;
+ s->priority_Bps = srq.priority / 8;
+
+ spin_lock_bh(&eql->queue.lock);
+ ret = __eql_insert_slave(&eql->queue, s);
+ if (ret)
+ kfree(s);
+
+ spin_unlock_bh(&eql->queue.lock);
+
+ return ret;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
+{
+ equalizer_t *eql = netdev_priv(master_dev);
+ struct net_device *slave_dev;
+ slaving_request_t srq;
+ int ret;
+
+ if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
+ return -EFAULT;
+
+ slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
+
+ ret = -EINVAL;
+ spin_lock_bh(&eql->queue.lock);
+ if (eql_is_slave(slave_dev)) {
+ slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev);
+ if (slave) {
+ eql_kill_one_slave(&eql->queue, slave);
+ ret = 0;
+ }
+ }
+ spin_unlock_bh(&eql->queue.lock);
+
+ return ret;
+}
+
+static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
+{
+ equalizer_t *eql = netdev_priv(dev);
+ slave_t *slave;
+ struct net_device *slave_dev;
+ slave_config_t sc;
+ int ret;
+
+ if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
+ return -EFAULT;
+
+ slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
+
+ ret = -EINVAL;
+
+ spin_lock_bh(&eql->queue.lock);
+ if (eql_is_slave(slave_dev)) {
+ slave = __eql_find_slave_dev(&eql->queue, slave_dev);
+ if (slave) {
+ sc.priority = slave->priority;
+ ret = 0;
+ }
+ }
+ spin_unlock_bh(&eql->queue.lock);
+
+ if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
+ ret = -EFAULT;
+
+ return ret;
+}
+
+static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
+{
+ slave_t *slave;
+ equalizer_t *eql;
+ struct net_device *slave_dev;
+ slave_config_t sc;
+ int ret;
+
+ if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
+ return -EFAULT;
+
+ slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
+
+ ret = -EINVAL;
+
+ eql = netdev_priv(dev);
+ spin_lock_bh(&eql->queue.lock);
+ if (eql_is_slave(slave_dev)) {
+ slave = __eql_find_slave_dev(&eql->queue, slave_dev);
+ if (slave) {
+ slave->priority = sc.priority;
+ slave->priority_bps = sc.priority;
+ slave->priority_Bps = sc.priority / 8;
+ ret = 0;
+ }
+ }
+ spin_unlock_bh(&eql->queue.lock);
+
+ return ret;
+}
+
+static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
+{
+ equalizer_t *eql;
+ master_config_t mc;
+
+ memset(&mc, 0, sizeof(master_config_t));
+
+ if (eql_is_master(dev)) {
+ eql = netdev_priv(dev);
+ mc.max_slaves = eql->max_slaves;
+ mc.min_slaves = eql->min_slaves;
+ if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
+ return -EFAULT;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
+{
+ equalizer_t *eql;
+ master_config_t mc;
+
+ if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
+ return -EFAULT;
+
+ if (eql_is_master(dev)) {
+ eql = netdev_priv(dev);
+ eql->max_slaves = mc.max_slaves;
+ eql->min_slaves = mc.min_slaves;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static struct net_device *dev_eql;
+
+static int __init eql_init_module(void)
+{
+ int err;
+
+ pr_info("%s\n", version);
+
+ dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN,
+ eql_setup);
+ if (!dev_eql)
+ return -ENOMEM;
+
+ err = register_netdev(dev_eql);
+ if (err)
+ free_netdev(dev_eql);
+ return err;
+}
+
+static void __exit eql_cleanup_module(void)
+{
+ unregister_netdev(dev_eql);
+ free_netdev(dev_eql);
+}
+
+module_init(eql_init_module);
+module_exit(eql_cleanup_module);
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff