/* * 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 */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/timer.h> #include <linux/netdevice.h> #include <linux/if.h> #include <linux/if_arp.h> #include <linux/if_eql.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 int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev); static struct net_device_stats *eql_get_stats(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_bh(&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_bh(&eql->queue.lock); eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL; add_timer(&eql->timer); } static char version[] __initdata = "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n"; static void __init eql_setup(struct net_device *dev) { equalizer_t *eql = netdev_priv(dev); SET_MODULE_OWNER(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->open = eql_open; dev->stop = eql_close; dev->do_ioctl = eql_ioctl; dev->hard_start_xmit = eql_slave_xmit; dev->get_stats = eql_get_stats; /* * 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 */ } static int eql_open(struct net_device *dev) { equalizer_t *eql = netdev_priv(dev); /* XXX We should force this off automatically for the user. */ printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on " "your slave devices.\n", dev->name); if (!list_empty(&eql->queue.all_slaves)) BUG(); 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 int 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 = 1; slave->bytes_queued += skb->len; dev_queue_xmit(skb); eql->stats.tx_packets++; } else { eql->stats.tx_dropped++; dev_kfree_skb(skb); } spin_unlock(&eql->queue.lock); return 0; } static struct net_device_stats * eql_get_stats(struct net_device *dev) { equalizer_t *eql = netdev_priv(dev); return &eql->stats; } /* * 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 != 0) eql_kill_one_slave(queue, duplicate_slave); 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(srq.slave_name); if (slave_dev) { 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) { dev_put(slave_dev); 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) { dev_put(slave_dev); kfree(s); } spin_unlock_bh(&eql->queue.lock); return ret; } } dev_put(slave_dev); } 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(srq.slave_name); ret = -EINVAL; if (slave_dev) { 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; } } dev_put(slave_dev); 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(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); dev_put(slave_dev); 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(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; 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; printk(version); dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", 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");