--- /dev/null
+/* 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/config.h>
+#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>
+
+#define TX_TIMEOUT (2*HZ)
+
+#define TX_Q_LIMIT 32
+struct ifb_private {
+ struct net_device_stats stats;
+ 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 struct net_device_stats *ifb_get_stats(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 = &dp->stats;
+ struct sk_buff *skb;
+
+ dp->st_task_enter++;
+ if ((skb = skb_peek(&dp->tq)) == NULL) {
+ dp->st_txq_refl_try++;
+ if (spin_trylock(&_dev->xmit_lock)) {
+ dp->st_rxq_enter++;
+ while ((skb = skb_dequeue(&dp->rq)) != NULL) {
+ skb_queue_tail(&dp->tq, skb);
+ dp->st_rx2tx_tran++;
+ }
+ spin_unlock(&_dev->xmit_lock);
+ } 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;
+ if (from & AT_EGRESS) {
+ dp->st_rx_frm_egr++;
+ dev_queue_xmit(skb);
+ } else if (from & AT_INGRESS) {
+
+ dp->st_rx_frm_ing++;
+ netif_rx(skb);
+ } else {
+ dev_kfree_skb(skb);
+ stats->tx_dropped++;
+ }
+ }
+
+ if (spin_trylock(&_dev->xmit_lock)) {
+ 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++;
+ spin_unlock(&_dev->xmit_lock);
+ goto resched;
+ }
+ spin_unlock(&_dev->xmit_lock);
+ } else {
+resched:
+ dp->tasklet_pending = 1;
+ tasklet_schedule(&dp->ifb_tasklet);
+ }
+
+}
+
+static void __init ifb_setup(struct net_device *dev)
+{
+ /* Initialize the device structure. */
+ dev->get_stats = ifb_get_stats;
+ dev->hard_start_xmit = ifb_xmit;
+ dev->open = &ifb_open;
+ dev->stop = &ifb_close;
+
+ /* 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;
+ SET_MODULE_OWNER(dev);
+ 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 = &dp->stats;
+ int ret = 0;
+ u32 from = G_TC_FROM(skb->tc_verd);
+
+ stats->tx_packets++;
+ stats->tx_bytes+=skb->len;
+
+ if (!from || !skb->input_dev) {
+dropped:
+ dev_kfree_skb(skb);
+ stats->rx_dropped++;
+ return ret;
+ } else {
+ /*
+ * note we could be going
+ * ingress -> egress or
+ * egress -> ingress
+ */
+ skb->dev = skb->input_dev;
+ skb->input_dev = dev;
+ if (from & AT_INGRESS) {
+ skb_pull(skb, skb->dev->hard_header_len);
+ } else {
+ if (!(from & AT_EGRESS)) {
+ goto dropped;
+ }
+ }
+ }
+
+ 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 struct net_device_stats *ifb_get_stats(struct net_device *dev)
+{
+ struct ifb_private *dp = netdev_priv(dev);
+ struct net_device_stats *stats = &dp->stats;
+
+ pr_debug("tasklets stats %ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld \n",
+ dp->st_task_enter, dp->st_txq_refl_try, dp->st_rxq_enter,
+ dp->st_rx2tx_tran dp->st_rxq_notenter, dp->st_rx_frm_egr,
+ dp->st_rx_frm_ing, dp->st_rxq_check, dp->st_rxq_rsch );
+
+ return stats;
+}
+
+static struct net_device **ifbs;
+
+/* Number of ifb devices to be set up by this module. */
+module_param(numifbs, int, 0);
+MODULE_PARM_DESC(numifbs, "Number of ifb devices");
+
+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 __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;
+
+ if ((err = register_netdev(dev_ifb))) {
+ free_netdev(dev_ifb);
+ dev_ifb = NULL;
+ } else {
+ ifbs[index] = dev_ifb;
+ }
+
+ return err;
+}
+
+static void ifb_free_one(int index)
+{
+ unregister_netdev(ifbs[index]);
+ free_netdev(ifbs[index]);
+}
+
+static int __init ifb_init_module(void)
+{
+ int i, err = 0;
+ ifbs = kmalloc(numifbs * sizeof(void *), GFP_KERNEL);
+ if (!ifbs)
+ return -ENOMEM;
+ for (i = 0; i < numifbs && !err; i++)
+ err = ifb_init_one(i);
+ if (err) {
+ while (--i >= 0)
+ ifb_free_one(i);
+ }
+
+ return err;
+}
+
+static void __exit ifb_cleanup_module(void)
+{
+ int i;
+
+ for (i = 0; i < numifbs; i++)
+ ifb_free_one(i);
+ kfree(ifbs);
+}
+
+module_init(ifb_init_module);
+module_exit(ifb_cleanup_module);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jamal Hadi Salim");
git://git.onelab.eu / linux-2.6.git / blobdiff