| /* drivers/net/ifb.c: |
| |
| The purpose of this driver is to provide a device that allows |
| for sharing of resources: |
| |
| 1) qdiscs/policies that are per device as opposed to system wide. |
| ifb allows for a device which can be redirected to thus providing |
| an impression of sharing. |
| |
| 2) Allows for queueing incoming traffic for shaping instead of |
| dropping. |
| |
| The original concept is based on what is known as the IMQ |
| driver initially written by Martin Devera, later rewritten |
| by Patrick McHardy and then maintained by Andre Correa. |
| |
| You need the tc action mirror or redirect to feed this device |
| packets. |
| |
| 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. |
| |
| Authors: Jamal Hadi Salim (2005) |
| |
| */ |
| |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/netdevice.h> |
| #include <linux/etherdevice.h> |
| #include <linux/init.h> |
| #include <linux/moduleparam.h> |
| #include <net/pkt_sched.h> |
| #include <net/net_namespace.h> |
| #include <linux/lockdep.h> |
| |
| #define TX_TIMEOUT (2*HZ) |
| |
| #define TX_Q_LIMIT 32 |
| struct ifb_private { |
| struct tasklet_struct ifb_tasklet; |
| int tasklet_pending; |
| /* mostly debug stats leave in for now */ |
| unsigned long st_task_enter; /* tasklet entered */ |
| unsigned long st_txq_refl_try; /* transmit queue refill attempt */ |
| unsigned long st_rxq_enter; /* receive queue entered */ |
| unsigned long st_rx2tx_tran; /* receive to trasmit transfers */ |
| unsigned long st_rxq_notenter; /*receiveQ not entered, resched */ |
| unsigned long st_rx_frm_egr; /* received from egress path */ |
| unsigned long st_rx_frm_ing; /* received from ingress path */ |
| unsigned long st_rxq_check; |
| unsigned long st_rxq_rsch; |
| struct sk_buff_head rq; |
| struct sk_buff_head tq; |
| }; |
| |
| static int numifbs = 2; |
| |
| static void ri_tasklet(unsigned long dev); |
| static int ifb_xmit(struct sk_buff *skb, struct net_device *dev); |
| static int ifb_open(struct net_device *dev); |
| static int ifb_close(struct net_device *dev); |
| |
| static void ri_tasklet(unsigned long dev) |
| { |
| |
| struct net_device *_dev = (struct net_device *)dev; |
| struct ifb_private *dp = netdev_priv(_dev); |
| struct net_device_stats *stats = &_dev->stats; |
| struct sk_buff *skb; |
| |
| dp->st_task_enter++; |
| if ((skb = skb_peek(&dp->tq)) == NULL) { |
| dp->st_txq_refl_try++; |
| if (netif_tx_trylock(_dev)) { |
| dp->st_rxq_enter++; |
| while ((skb = skb_dequeue(&dp->rq)) != NULL) { |
| skb_queue_tail(&dp->tq, skb); |
| dp->st_rx2tx_tran++; |
| } |
| netif_tx_unlock(_dev); |
| } else { |
| /* reschedule */ |
| dp->st_rxq_notenter++; |
| goto resched; |
| } |
| } |
| |
| while ((skb = skb_dequeue(&dp->tq)) != NULL) { |
| u32 from = G_TC_FROM(skb->tc_verd); |
| |
| skb->tc_verd = 0; |
| skb->tc_verd = SET_TC_NCLS(skb->tc_verd); |
| stats->tx_packets++; |
| stats->tx_bytes +=skb->len; |
| |
| skb->dev = __dev_get_by_index(&init_net, skb->iif); |
| if (!skb->dev) { |
| dev_kfree_skb(skb); |
| stats->tx_dropped++; |
| break; |
| } |
| skb->iif = _dev->ifindex; |
| |
| if (from & AT_EGRESS) { |
| dp->st_rx_frm_egr++; |
| dev_queue_xmit(skb); |
| } else if (from & AT_INGRESS) { |
| dp->st_rx_frm_ing++; |
| skb_pull(skb, skb->dev->hard_header_len); |
| netif_rx(skb); |
| } else |
| BUG(); |
| } |
| |
| if (netif_tx_trylock(_dev)) { |
| dp->st_rxq_check++; |
| if ((skb = skb_peek(&dp->rq)) == NULL) { |
| dp->tasklet_pending = 0; |
| if (netif_queue_stopped(_dev)) |
| netif_wake_queue(_dev); |
| } else { |
| dp->st_rxq_rsch++; |
| netif_tx_unlock(_dev); |
| goto resched; |
| } |
| netif_tx_unlock(_dev); |
| } else { |
| resched: |
| dp->tasklet_pending = 1; |
| tasklet_schedule(&dp->ifb_tasklet); |
| } |
| |
| } |
| |
| static void ifb_setup(struct net_device *dev) |
| { |
| /* Initialize the device structure. */ |
| dev->hard_start_xmit = ifb_xmit; |
| dev->open = &ifb_open; |
| dev->stop = &ifb_close; |
| dev->destructor = free_netdev; |
| |
| /* Fill in device structure with ethernet-generic values. */ |
| ether_setup(dev); |
| dev->tx_queue_len = TX_Q_LIMIT; |
| dev->change_mtu = NULL; |
| dev->flags |= IFF_NOARP; |
| dev->flags &= ~IFF_MULTICAST; |
| random_ether_addr(dev->dev_addr); |
| } |
| |
| static int ifb_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct ifb_private *dp = netdev_priv(dev); |
| struct net_device_stats *stats = &dev->stats; |
| int ret = 0; |
| u32 from = G_TC_FROM(skb->tc_verd); |
| |
| stats->rx_packets++; |
| stats->rx_bytes+=skb->len; |
| |
| if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) { |
| dev_kfree_skb(skb); |
| stats->rx_dropped++; |
| return ret; |
| } |
| |
| if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) { |
| netif_stop_queue(dev); |
| } |
| |
| dev->trans_start = jiffies; |
| skb_queue_tail(&dp->rq, skb); |
| if (!dp->tasklet_pending) { |
| dp->tasklet_pending = 1; |
| tasklet_schedule(&dp->ifb_tasklet); |
| } |
| |
| return ret; |
| } |
| |
| static int ifb_close(struct net_device *dev) |
| { |
| struct ifb_private *dp = netdev_priv(dev); |
| |
| tasklet_kill(&dp->ifb_tasklet); |
| netif_stop_queue(dev); |
| skb_queue_purge(&dp->rq); |
| skb_queue_purge(&dp->tq); |
| return 0; |
| } |
| |
| static int ifb_open(struct net_device *dev) |
| { |
| struct ifb_private *dp = netdev_priv(dev); |
| |
| tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev); |
| skb_queue_head_init(&dp->rq); |
| skb_queue_head_init(&dp->tq); |
| netif_start_queue(dev); |
| |
| return 0; |
| } |
| |
| static int ifb_validate(struct nlattr *tb[], struct nlattr *data[]) |
| { |
| if (tb[IFLA_ADDRESS]) { |
| if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) |
| return -EINVAL; |
| if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) |
| return -EADDRNOTAVAIL; |
| } |
| return 0; |
| } |
| |
| static struct rtnl_link_ops ifb_link_ops __read_mostly = { |
| .kind = "ifb", |
| .priv_size = sizeof(struct ifb_private), |
| .setup = ifb_setup, |
| .validate = ifb_validate, |
| }; |
| |
| /* Number of ifb devices to be set up by this module. */ |
| module_param(numifbs, int, 0); |
| MODULE_PARM_DESC(numifbs, "Number of ifb devices"); |
| |
| /* |
| * dev_ifb's TX queue lock is usually taken after dev->rx_queue.lock, |
| * reversely to e.g. qdisc_lock_tree(). It should be safe until |
| * ifb doesn't take dev's TX queue lock with dev_ifb->rx_queue.lock. |
| * But lockdep should know that ifb has different locks from dev. |
| */ |
| static struct lock_class_key ifb_tx_queue_lock_key; |
| static struct lock_class_key ifb_rx_queue_lock_key; |
| |
| static void set_tx_lockdep_key(struct net_device *dev, |
| struct netdev_queue *txq, |
| void *_unused) |
| { |
| lockdep_set_class(&txq->lock, &ifb_tx_queue_lock_key); |
| } |
| |
| static int __init ifb_init_one(int index) |
| { |
| struct net_device *dev_ifb; |
| int err; |
| |
| dev_ifb = alloc_netdev(sizeof(struct ifb_private), |
| "ifb%d", ifb_setup); |
| |
| if (!dev_ifb) |
| return -ENOMEM; |
| |
| err = dev_alloc_name(dev_ifb, dev_ifb->name); |
| if (err < 0) |
| goto err; |
| |
| dev_ifb->rtnl_link_ops = &ifb_link_ops; |
| err = register_netdevice(dev_ifb); |
| if (err < 0) |
| goto err; |
| |
| netdev_for_each_tx_queue(dev_ifb, set_tx_lockdep_key, NULL); |
| lockdep_set_class(&dev_ifb->rx_queue.lock, &ifb_rx_queue_lock_key); |
| |
| return 0; |
| |
| err: |
| free_netdev(dev_ifb); |
| return err; |
| } |
| |
| static int __init ifb_init_module(void) |
| { |
| int i, err; |
| |
| rtnl_lock(); |
| err = __rtnl_link_register(&ifb_link_ops); |
| |
| for (i = 0; i < numifbs && !err; i++) |
| err = ifb_init_one(i); |
| if (err) |
| __rtnl_link_unregister(&ifb_link_ops); |
| rtnl_unlock(); |
| |
| return err; |
| } |
| |
| static void __exit ifb_cleanup_module(void) |
| { |
| rtnl_link_unregister(&ifb_link_ops); |
| } |
| |
| module_init(ifb_init_module); |
| module_exit(ifb_cleanup_module); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Jamal Hadi Salim"); |
| MODULE_ALIAS_RTNL_LINK("ifb"); |