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Jeff Garzik6aa20a22006-09-13 13:24:59 -04001/* drivers/net/ifb.c:
Jamal Hadi Salim253af422006-01-08 22:34:25 -08002
3 The purpose of this driver is to provide a device that allows
4 for sharing of resources:
5
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.
9
10 2) Allows for queueing incoming traffic for shaping instead of
Jeff Garzik6aa20a22006-09-13 13:24:59 -040011 dropping.
12
Jamal Hadi Salim253af422006-01-08 22:34:25 -080013 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.
16
17 You need the tc action mirror or redirect to feed this device
18 packets.
19
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.
Jeff Garzik6aa20a22006-09-13 13:24:59 -040024
Jamal Hadi Salim253af422006-01-08 22:34:25 -080025 Authors: Jamal Hadi Salim (2005)
Jeff Garzik6aa20a22006-09-13 13:24:59 -040026
Jamal Hadi Salim253af422006-01-08 22:34:25 -080027*/
28
29
Jamal Hadi Salim253af422006-01-08 22:34:25 -080030#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>
Jeff Garzik6aa20a22006-09-13 13:24:59 -040036#include <net/pkt_sched.h>
Eric W. Biederman881d9662007-09-17 11:56:21 -070037#include <net/net_namespace.h>
Jamal Hadi Salim253af422006-01-08 22:34:25 -080038
39#define TX_TIMEOUT (2*HZ)
Jeff Garzik6aa20a22006-09-13 13:24:59 -040040
Jamal Hadi Salim253af422006-01-08 22:34:25 -080041#define TX_Q_LIMIT 32
42struct ifb_private {
Jamal Hadi Salim253af422006-01-08 22:34:25 -080043 struct tasklet_struct ifb_tasklet;
44 int tasklet_pending;
45 /* mostly debug stats leave in for now */
46 unsigned long st_task_enter; /* tasklet entered */
47 unsigned long st_txq_refl_try; /* transmit queue refill attempt */
48 unsigned long st_rxq_enter; /* receive queue entered */
49 unsigned long st_rx2tx_tran; /* receive to trasmit transfers */
50 unsigned long st_rxq_notenter; /*receiveQ not entered, resched */
51 unsigned long st_rx_frm_egr; /* received from egress path */
52 unsigned long st_rx_frm_ing; /* received from ingress path */
53 unsigned long st_rxq_check;
54 unsigned long st_rxq_rsch;
55 struct sk_buff_head rq;
56 struct sk_buff_head tq;
57};
58
Richard Lucassen35eaa312006-02-23 16:23:51 -080059static int numifbs = 2;
Jamal Hadi Salim253af422006-01-08 22:34:25 -080060
61static void ri_tasklet(unsigned long dev);
Stephen Hemminger424efe92009-08-31 19:50:51 +000062static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
Jamal Hadi Salim253af422006-01-08 22:34:25 -080063static int ifb_open(struct net_device *dev);
64static int ifb_close(struct net_device *dev);
65
Jeff Garzik6aa20a22006-09-13 13:24:59 -040066static void ri_tasklet(unsigned long dev)
Jamal Hadi Salim253af422006-01-08 22:34:25 -080067{
68
69 struct net_device *_dev = (struct net_device *)dev;
70 struct ifb_private *dp = netdev_priv(_dev);
Jeff Garzik09f75cd2007-10-03 17:41:50 -070071 struct net_device_stats *stats = &_dev->stats;
David S. Millerc3f26a22008-07-31 16:58:50 -070072 struct netdev_queue *txq;
Jamal Hadi Salim253af422006-01-08 22:34:25 -080073 struct sk_buff *skb;
74
David S. Millerc3f26a22008-07-31 16:58:50 -070075 txq = netdev_get_tx_queue(_dev, 0);
Jamal Hadi Salim253af422006-01-08 22:34:25 -080076 dp->st_task_enter++;
77 if ((skb = skb_peek(&dp->tq)) == NULL) {
78 dp->st_txq_refl_try++;
David S. Millerc3f26a22008-07-31 16:58:50 -070079 if (__netif_tx_trylock(txq)) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -080080 dp->st_rxq_enter++;
81 while ((skb = skb_dequeue(&dp->rq)) != NULL) {
82 skb_queue_tail(&dp->tq, skb);
83 dp->st_rx2tx_tran++;
84 }
David S. Millerc3f26a22008-07-31 16:58:50 -070085 __netif_tx_unlock(txq);
Jamal Hadi Salim253af422006-01-08 22:34:25 -080086 } else {
87 /* reschedule */
88 dp->st_rxq_notenter++;
89 goto resched;
90 }
91 }
92
93 while ((skb = skb_dequeue(&dp->tq)) != NULL) {
94 u32 from = G_TC_FROM(skb->tc_verd);
95
96 skb->tc_verd = 0;
97 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
98 stats->tx_packets++;
99 stats->tx_bytes +=skb->len;
Patrick McHardyc01003c2007-03-29 11:46:52 -0700100
Eric Dumazet05e86892009-11-01 19:45:16 +0000101 rcu_read_lock();
Eric Dumazet8964be42009-11-20 15:35:04 -0800102 skb->dev = dev_get_by_index_rcu(&init_net, skb->skb_iif);
Patrick McHardyc01003c2007-03-29 11:46:52 -0700103 if (!skb->dev) {
Eric Dumazet05e86892009-11-01 19:45:16 +0000104 rcu_read_unlock();
Patrick McHardyc01003c2007-03-29 11:46:52 -0700105 dev_kfree_skb(skb);
106 stats->tx_dropped++;
107 break;
108 }
Eric Dumazet05e86892009-11-01 19:45:16 +0000109 rcu_read_unlock();
Eric Dumazet8964be42009-11-20 15:35:04 -0800110 skb->skb_iif = _dev->ifindex;
Patrick McHardyc01003c2007-03-29 11:46:52 -0700111
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800112 if (from & AT_EGRESS) {
113 dp->st_rx_frm_egr++;
114 dev_queue_xmit(skb);
115 } else if (from & AT_INGRESS) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800116 dp->st_rx_frm_ing++;
Patrick McHardyc01003c2007-03-29 11:46:52 -0700117 skb_pull(skb, skb->dev->hard_header_len);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800118 netif_rx(skb);
Patrick McHardyc01003c2007-03-29 11:46:52 -0700119 } else
120 BUG();
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800121 }
122
David S. Millerc3f26a22008-07-31 16:58:50 -0700123 if (__netif_tx_trylock(txq)) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800124 dp->st_rxq_check++;
125 if ((skb = skb_peek(&dp->rq)) == NULL) {
126 dp->tasklet_pending = 0;
127 if (netif_queue_stopped(_dev))
128 netif_wake_queue(_dev);
129 } else {
130 dp->st_rxq_rsch++;
David S. Millerc3f26a22008-07-31 16:58:50 -0700131 __netif_tx_unlock(txq);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800132 goto resched;
133 }
David S. Millerc3f26a22008-07-31 16:58:50 -0700134 __netif_tx_unlock(txq);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800135 } else {
136resched:
137 dp->tasklet_pending = 1;
138 tasklet_schedule(&dp->ifb_tasklet);
139 }
140
141}
142
Stephen Hemminger8dfcdf32008-11-19 21:47:07 -0800143static const struct net_device_ops ifb_netdev_ops = {
Stephen Hemminger8dfcdf32008-11-19 21:47:07 -0800144 .ndo_open = ifb_open,
145 .ndo_stop = ifb_close,
Stephen Hemminger00829822008-11-20 20:14:53 -0800146 .ndo_start_xmit = ifb_xmit,
147 .ndo_validate_addr = eth_validate_addr,
Stephen Hemminger8dfcdf32008-11-19 21:47:07 -0800148};
149
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700150static void ifb_setup(struct net_device *dev)
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800151{
152 /* Initialize the device structure. */
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700153 dev->destructor = free_netdev;
Stephen Hemminger8dfcdf32008-11-19 21:47:07 -0800154 dev->netdev_ops = &ifb_netdev_ops;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800155
156 /* Fill in device structure with ethernet-generic values. */
157 ether_setup(dev);
158 dev->tx_queue_len = TX_Q_LIMIT;
Stephen Hemminger8dfcdf32008-11-19 21:47:07 -0800159
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800160 dev->flags |= IFF_NOARP;
161 dev->flags &= ~IFF_MULTICAST;
Eric Dumazet93f154b2009-05-18 22:19:19 -0700162 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800163 random_ether_addr(dev->dev_addr);
164}
165
Stephen Hemminger424efe92009-08-31 19:50:51 +0000166static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800167{
168 struct ifb_private *dp = netdev_priv(dev);
Jeff Garzik09f75cd2007-10-03 17:41:50 -0700169 struct net_device_stats *stats = &dev->stats;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800170 u32 from = G_TC_FROM(skb->tc_verd);
171
dean gaudet3136dcb2007-01-01 19:39:09 -0800172 stats->rx_packets++;
173 stats->rx_bytes+=skb->len;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800174
Eric Dumazet8964be42009-11-20 15:35:04 -0800175 if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800176 dev_kfree_skb(skb);
177 stats->rx_dropped++;
Stephen Hemminger424efe92009-08-31 19:50:51 +0000178 return NETDEV_TX_OK;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800179 }
180
181 if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
182 netif_stop_queue(dev);
183 }
184
185 dev->trans_start = jiffies;
186 skb_queue_tail(&dp->rq, skb);
187 if (!dp->tasklet_pending) {
188 dp->tasklet_pending = 1;
189 tasklet_schedule(&dp->ifb_tasklet);
190 }
191
Stephen Hemminger424efe92009-08-31 19:50:51 +0000192 return NETDEV_TX_OK;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800193}
194
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800195static int ifb_close(struct net_device *dev)
196{
197 struct ifb_private *dp = netdev_priv(dev);
198
199 tasklet_kill(&dp->ifb_tasklet);
200 netif_stop_queue(dev);
201 skb_queue_purge(&dp->rq);
202 skb_queue_purge(&dp->tq);
203 return 0;
204}
205
206static int ifb_open(struct net_device *dev)
207{
208 struct ifb_private *dp = netdev_priv(dev);
209
210 tasklet_init(&dp->ifb_tasklet, ri_tasklet, (unsigned long)dev);
211 skb_queue_head_init(&dp->rq);
212 skb_queue_head_init(&dp->tq);
213 netif_start_queue(dev);
214
215 return 0;
216}
217
Patrick McHardy0e068772007-07-11 19:42:31 -0700218static int ifb_validate(struct nlattr *tb[], struct nlattr *data[])
219{
220 if (tb[IFLA_ADDRESS]) {
221 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
222 return -EINVAL;
223 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
224 return -EADDRNOTAVAIL;
225 }
226 return 0;
227}
228
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700229static struct rtnl_link_ops ifb_link_ops __read_mostly = {
230 .kind = "ifb",
231 .priv_size = sizeof(struct ifb_private),
232 .setup = ifb_setup,
Patrick McHardy0e068772007-07-11 19:42:31 -0700233 .validate = ifb_validate,
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700234};
235
Patrick McHardy2d85cba2007-07-11 19:42:13 -0700236/* Number of ifb devices to be set up by this module. */
237module_param(numifbs, int, 0);
238MODULE_PARM_DESC(numifbs, "Number of ifb devices");
239
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800240static int __init ifb_init_one(int index)
241{
242 struct net_device *dev_ifb;
243 int err;
244
245 dev_ifb = alloc_netdev(sizeof(struct ifb_private),
246 "ifb%d", ifb_setup);
247
248 if (!dev_ifb)
249 return -ENOMEM;
250
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700251 err = dev_alloc_name(dev_ifb, dev_ifb->name);
252 if (err < 0)
253 goto err;
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800254
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700255 dev_ifb->rtnl_link_ops = &ifb_link_ops;
256 err = register_netdevice(dev_ifb);
257 if (err < 0)
258 goto err;
Jarek Poplawski94833df2008-03-20 17:05:13 -0700259
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700260 return 0;
261
262err:
263 free_netdev(dev_ifb);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800264 return err;
265}
266
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800267static int __init ifb_init_module(void)
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400268{
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700269 int i, err;
270
271 rtnl_lock();
272 err = __rtnl_link_register(&ifb_link_ops);
Patrick McHardy62b7ffc2007-06-13 12:04:51 -0700273
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800274 for (i = 0; i < numifbs && !err; i++)
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400275 err = ifb_init_one(i);
Patrick McHardy2d85cba2007-07-11 19:42:13 -0700276 if (err)
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700277 __rtnl_link_unregister(&ifb_link_ops);
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700278 rtnl_unlock();
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800279
280 return err;
Jeff Garzik6aa20a22006-09-13 13:24:59 -0400281}
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800282
283static void __exit ifb_cleanup_module(void)
284{
Patrick McHardy2d85cba2007-07-11 19:42:13 -0700285 rtnl_link_unregister(&ifb_link_ops);
Jamal Hadi Salim253af422006-01-08 22:34:25 -0800286}
287
288module_init(ifb_init_module);
289module_exit(ifb_cleanup_module);
290MODULE_LICENSE("GPL");
291MODULE_AUTHOR("Jamal Hadi Salim");
Patrick McHardy9ba2cd62007-06-13 12:05:06 -0700292MODULE_ALIAS_RTNL_LINK("ifb");