3 The purpose of this driver is to provide a device that allows
4 for sharing of resources:
6 1) qdiscs/policies that are per device as opposed to system wide.
7 ifb allows for a device which can be redirected to thus providing
8 an impression of sharing.
10 2) Allows for queueing incoming traffic for shaping instead of
13 The original concept is based on what is known as the IMQ
14 driver initially written by Martin Devera, later rewritten
15 by Patrick McHardy and then maintained by Andre Correa.
17 You need the tc action mirror or redirect to feed this device
20 This program is free software; you can redistribute it and/or
21 modify it under the terms of the GNU General Public License
22 as published by the Free Software Foundation; either version
23 2 of the License, or (at your option) any later version.
25 Authors: Jamal Hadi Salim (2005)
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/netdevice.h>
33 #include <linux/etherdevice.h>
34 #include <linux/init.h>
35 #include <linux/moduleparam.h>
36 #include <net/pkt_sched.h>
37 #include <net/net_namespace.h>
39 #define TX_TIMEOUT (2*HZ)
43 struct net_device_stats stats;
44 struct tasklet_struct ifb_tasklet;
46 /* mostly debug stats leave in for now */
47 unsigned long st_task_enter; /* tasklet entered */
48 unsigned long st_txq_refl_try; /* transmit queue refill attempt */
49 unsigned long st_rxq_enter; /* receive queue entered */
50 unsigned long st_rx2tx_tran; /* receive to trasmit transfers */
51 unsigned long st_rxq_notenter; /*receiveQ not entered, resched */
52 unsigned long st_rx_frm_egr; /* received from egress path */
53 unsigned long st_rx_frm_ing; /* received from ingress path */
54 unsigned long st_rxq_check;
55 unsigned long st_rxq_rsch;
56 struct sk_buff_head rq;
57 struct sk_buff_head tq;
60 static int numifbs = 2;
62 static void ri_tasklet(unsigned long dev);
63 static int ifb_xmit(struct sk_buff *skb, struct net_device *dev);
64 static struct net_device_stats *ifb_get_stats(struct net_device *dev);
65 static int ifb_open(struct net_device *dev);
66 static int ifb_close(struct net_device *dev);
68 static void ri_tasklet(unsigned long dev)
71 struct net_device *_dev = (struct net_device *)dev;
72 struct ifb_private *dp = netdev_priv(_dev);
73 struct net_device_stats *stats = &dp->stats;
77 if ((skb = skb_peek(&dp->tq)) == NULL) {
78 dp->st_txq_refl_try++;
79 if (netif_tx_trylock(_dev)) {
81 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
82 skb_queue_tail(&dp->tq, skb);
85 netif_tx_unlock(_dev);
88 dp->st_rxq_notenter++;
93 while ((skb = skb_dequeue(&dp->tq)) != NULL) {
94 u32 from = G_TC_FROM(skb->tc_verd);
97 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
99 stats->tx_bytes +=skb->len;
101 skb->dev = __dev_get_by_index(&init_net, skb->iif);
107 skb->iif = _dev->ifindex;
109 if (from & AT_EGRESS) {
112 } else if (from & AT_INGRESS) {
114 skb_pull(skb, skb->dev->hard_header_len);
120 if (netif_tx_trylock(_dev)) {
122 if ((skb = skb_peek(&dp->rq)) == NULL) {
123 dp->tasklet_pending = 0;
124 if (netif_queue_stopped(_dev))
125 netif_wake_queue(_dev);
128 netif_tx_unlock(_dev);
131 netif_tx_unlock(_dev);
134 dp->tasklet_pending = 1;
135 tasklet_schedule(&dp->ifb_tasklet);
140 static void ifb_setup(struct net_device *dev)
142 /* Initialize the device structure. */
143 dev->get_stats = ifb_get_stats;
144 dev->hard_start_xmit = ifb_xmit;
145 dev->open = &ifb_open;
146 dev->stop = &ifb_close;
147 dev->destructor = free_netdev;
149 /* Fill in device structure with ethernet-generic values. */
151 dev->tx_queue_len = TX_Q_LIMIT;
152 dev->change_mtu = NULL;
153 dev->flags |= IFF_NOARP;
154 dev->flags &= ~IFF_MULTICAST;
155 SET_MODULE_OWNER(dev);
156 random_ether_addr(dev->dev_addr);
159 static int ifb_xmit(struct sk_buff *skb, struct net_device *dev)
161 struct ifb_private *dp = netdev_priv(dev);
162 struct net_device_stats *stats = &dp->stats;
164 u32 from = G_TC_FROM(skb->tc_verd);
167 stats->rx_bytes+=skb->len;
169 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->iif) {
175 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
176 netif_stop_queue(dev);
179 dev->trans_start = jiffies;
180 skb_queue_tail(&dp->rq, skb);
181 if (!dp->tasklet_pending) {
182 dp->tasklet_pending = 1;
183 tasklet_schedule(&dp->ifb_tasklet);
189 static struct net_device_stats *ifb_get_stats(struct net_device *dev)
191 struct ifb_private *dp = netdev_priv(dev);
192 struct net_device_stats *stats = &dp->stats;
194 pr_debug("tasklets stats %ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld:%ld \n",
195 dp->st_task_enter, dp->st_txq_refl_try, dp->st_rxq_enter,
196 dp->st_rx2tx_tran, dp->st_rxq_notenter, dp->st_rx_frm_egr,
197 dp->st_rx_frm_ing, dp->st_rxq_check, dp->st_rxq_rsch);
202 static int ifb_close(struct net_device *dev)
204 struct ifb_private *dp = netdev_priv(dev);
206 tasklet_kill(&dp->ifb_tasklet);
207 netif_stop_queue(dev);
208 skb_queue_purge(&dp->rq);
209 skb_queue_purge(&dp->tq);
213 static int ifb_open(struct net_device *dev)
215 struct ifb_private *dp = netdev_priv(dev);
217 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
218 skb_queue_head_init(&dp->rq);
219 skb_queue_head_init(&dp->tq);
220 netif_start_queue(dev);
225 static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
227 if (tb[IFLA_ADDRESS]) {
228 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
230 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
231 return -EADDRNOTAVAIL;
236 static struct rtnl_link_ops ifb_link_ops __read_mostly = {
238 .priv_size = sizeof(struct ifb_private),
240 .validate = ifb_validate,
243 /* Number of ifb devices to be set up by this module. */
244 module_param(numifbs, int, 0);
245 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
247 static int __init ifb_init_one(int index)
249 struct net_device *dev_ifb;
252 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
258 err = dev_alloc_name(dev_ifb, dev_ifb->name);
262 dev_ifb->rtnl_link_ops = &ifb_link_ops;
263 err = register_netdevice(dev_ifb);
269 free_netdev(dev_ifb);
273 static int __init ifb_init_module(void)
278 err = __rtnl_link_register(&ifb_link_ops);
280 for (i = 0; i < numifbs && !err; i++)
281 err = ifb_init_one(i);
283 __rtnl_link_unregister(&ifb_link_ops);
289 static void __exit ifb_cleanup_module(void)
291 rtnl_link_unregister(&ifb_link_ops);
294 module_init(ifb_init_module);
295 module_exit(ifb_cleanup_module);
296 MODULE_LICENSE("GPL");
297 MODULE_AUTHOR("Jamal Hadi Salim");
298 MODULE_ALIAS_RTNL_LINK("ifb");