295 lines
7.0 KiB
C
295 lines
7.0 KiB
C
/* 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");
|