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>
41 struct tasklet_struct ifb_tasklet;
43 struct sk_buff_head rq;
44 struct sk_buff_head tq;
47 static int numifbs = 2;
49 static void ri_tasklet(unsigned long dev);
50 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
51 static int ifb_open(struct net_device *dev);
52 static int ifb_close(struct net_device *dev);
54 static void ri_tasklet(unsigned long dev)
57 struct net_device *_dev = (struct net_device *)dev;
58 struct ifb_private *dp = netdev_priv(_dev);
59 struct net_device_stats *stats = &_dev->stats;
60 struct netdev_queue *txq;
63 txq = netdev_get_tx_queue(_dev, 0);
64 if ((skb = skb_peek(&dp->tq)) == NULL) {
65 if (__netif_tx_trylock(txq)) {
66 skb_queue_splice_tail_init(&dp->rq, &dp->tq);
67 __netif_tx_unlock(txq);
74 while ((skb = __skb_dequeue(&dp->tq)) != NULL) {
75 u32 from = G_TC_FROM(skb->tc_verd);
78 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
80 stats->tx_bytes +=skb->len;
83 skb->dev = dev_get_by_index_rcu(&init_net, skb->skb_iif);
88 if (skb_queue_len(&dp->tq) != 0)
93 skb->skb_iif = _dev->ifindex;
95 if (from & AT_EGRESS) {
97 } else if (from & AT_INGRESS) {
98 skb_pull(skb, skb->dev->hard_header_len);
99 netif_receive_skb(skb);
104 if (__netif_tx_trylock(txq)) {
105 if ((skb = skb_peek(&dp->rq)) == NULL) {
106 dp->tasklet_pending = 0;
107 if (netif_queue_stopped(_dev))
108 netif_wake_queue(_dev);
110 __netif_tx_unlock(txq);
113 __netif_tx_unlock(txq);
116 dp->tasklet_pending = 1;
117 tasklet_schedule(&dp->ifb_tasklet);
122 static const struct net_device_ops ifb_netdev_ops = {
123 .ndo_open = ifb_open,
124 .ndo_stop = ifb_close,
125 .ndo_start_xmit = ifb_xmit,
126 .ndo_validate_addr = eth_validate_addr,
129 static void ifb_setup(struct net_device *dev)
131 /* Initialize the device structure. */
132 dev->destructor = free_netdev;
133 dev->netdev_ops = &ifb_netdev_ops;
135 /* Fill in device structure with ethernet-generic values. */
137 dev->tx_queue_len = TX_Q_LIMIT;
139 dev->flags |= IFF_NOARP;
140 dev->flags &= ~IFF_MULTICAST;
141 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
142 random_ether_addr(dev->dev_addr);
145 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
147 struct ifb_private *dp = netdev_priv(dev);
148 struct net_device_stats *stats = &dev->stats;
149 u32 from = G_TC_FROM(skb->tc_verd);
152 stats->rx_bytes+=skb->len;
154 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
160 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
161 netif_stop_queue(dev);
164 __skb_queue_tail(&dp->rq, skb);
165 if (!dp->tasklet_pending) {
166 dp->tasklet_pending = 1;
167 tasklet_schedule(&dp->ifb_tasklet);
173 static int ifb_close(struct net_device *dev)
175 struct ifb_private *dp = netdev_priv(dev);
177 tasklet_kill(&dp->ifb_tasklet);
178 netif_stop_queue(dev);
179 __skb_queue_purge(&dp->rq);
180 __skb_queue_purge(&dp->tq);
184 static int ifb_open(struct net_device *dev)
186 struct ifb_private *dp = netdev_priv(dev);
188 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
189 __skb_queue_head_init(&dp->rq);
190 __skb_queue_head_init(&dp->tq);
191 netif_start_queue(dev);
196 static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
198 if (tb[IFLA_ADDRESS]) {
199 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
201 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
202 return -EADDRNOTAVAIL;
207 static struct rtnl_link_ops ifb_link_ops __read_mostly = {
209 .priv_size = sizeof(struct ifb_private),
211 .validate = ifb_validate,
214 /* Number of ifb devices to be set up by this module. */
215 module_param(numifbs, int, 0);
216 MODULE_PARM_DESC(numifbs, "Number of ifb devices");
218 static int __init ifb_init_one(int index)
220 struct net_device *dev_ifb;
223 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
229 err = dev_alloc_name(dev_ifb, dev_ifb->name);
233 dev_ifb->rtnl_link_ops = &ifb_link_ops;
234 err = register_netdevice(dev_ifb);
241 free_netdev(dev_ifb);
245 static int __init ifb_init_module(void)
250 err = __rtnl_link_register(&ifb_link_ops);
252 for (i = 0; i < numifbs && !err; i++)
253 err = ifb_init_one(i);
255 __rtnl_link_unregister(&ifb_link_ops);
261 static void __exit ifb_cleanup_module(void)
263 rtnl_link_unregister(&ifb_link_ops);
266 module_init(ifb_init_module);
267 module_exit(ifb_cleanup_module);
268 MODULE_LICENSE("GPL");
269 MODULE_AUTHOR("Jamal Hadi Salim");
270 MODULE_ALIAS_RTNL_LINK("ifb");