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path: root/drivers/net/ifb.c
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-rw-r--r--drivers/net/ifb.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
new file mode 100644
index 000000000..94570aace
--- /dev/null
+++ b/drivers/net/ifb.c
@@ -0,0 +1,326 @@
+/* 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/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+#include <net/pkt_sched.h>
+#include <net/net_namespace.h>
+
+#define TX_Q_LIMIT 32
+struct ifb_private {
+ struct tasklet_struct ifb_tasklet;
+ int tasklet_pending;
+
+ struct u64_stats_sync rsync;
+ struct sk_buff_head rq;
+ u64 rx_packets;
+ u64 rx_bytes;
+
+ struct u64_stats_sync tsync;
+ struct sk_buff_head tq;
+ u64 tx_packets;
+ u64 tx_bytes;
+};
+
+static int numifbs = 2;
+
+static void ri_tasklet(unsigned long dev);
+static netdev_tx_t ifb_xmit(struct sk_buff *skb, 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 netdev_queue *txq;
+ struct sk_buff *skb;
+
+ txq = netdev_get_tx_queue(_dev, 0);
+ if ((skb = skb_peek(&dp->tq)) == NULL) {
+ if (__netif_tx_trylock(txq)) {
+ skb_queue_splice_tail_init(&dp->rq, &dp->tq);
+ __netif_tx_unlock(txq);
+ } else {
+ /* reschedule */
+ 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);
+
+ u64_stats_update_begin(&dp->tsync);
+ dp->tx_packets++;
+ dp->tx_bytes += skb->len;
+ u64_stats_update_end(&dp->tsync);
+
+ rcu_read_lock();
+ skb->dev = dev_get_by_index_rcu(dev_net(_dev), skb->skb_iif);
+ if (!skb->dev) {
+ rcu_read_unlock();
+ dev_kfree_skb(skb);
+ _dev->stats.tx_dropped++;
+ if (skb_queue_len(&dp->tq) != 0)
+ goto resched;
+ break;
+ }
+ rcu_read_unlock();
+ skb->skb_iif = _dev->ifindex;
+
+ if (from & AT_EGRESS) {
+ dev_queue_xmit(skb);
+ } else if (from & AT_INGRESS) {
+ skb_pull(skb, skb->mac_len);
+ netif_receive_skb(skb);
+ } else
+ BUG();
+ }
+
+ if (__netif_tx_trylock(txq)) {
+ if ((skb = skb_peek(&dp->rq)) == NULL) {
+ dp->tasklet_pending = 0;
+ if (netif_queue_stopped(_dev))
+ netif_wake_queue(_dev);
+ } else {
+ __netif_tx_unlock(txq);
+ goto resched;
+ }
+ __netif_tx_unlock(txq);
+ } else {
+resched:
+ dp->tasklet_pending = 1;
+ tasklet_schedule(&dp->ifb_tasklet);
+ }
+
+}
+
+static struct rtnl_link_stats64 *ifb_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct ifb_private *dp = netdev_priv(dev);
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&dp->rsync);
+ stats->rx_packets = dp->rx_packets;
+ stats->rx_bytes = dp->rx_bytes;
+ } while (u64_stats_fetch_retry_irq(&dp->rsync, start));
+
+ do {
+ start = u64_stats_fetch_begin_irq(&dp->tsync);
+
+ stats->tx_packets = dp->tx_packets;
+ stats->tx_bytes = dp->tx_bytes;
+
+ } while (u64_stats_fetch_retry_irq(&dp->tsync, start));
+
+ stats->rx_dropped = dev->stats.rx_dropped;
+ stats->tx_dropped = dev->stats.tx_dropped;
+
+ return stats;
+}
+
+
+static const struct net_device_ops ifb_netdev_ops = {
+ .ndo_open = ifb_open,
+ .ndo_stop = ifb_close,
+ .ndo_get_stats64 = ifb_stats64,
+ .ndo_start_xmit = ifb_xmit,
+ .ndo_validate_addr = eth_validate_addr,
+};
+
+#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \
+ NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6 | \
+ NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
+ NETIF_F_HW_VLAN_STAG_TX)
+
+static void ifb_setup(struct net_device *dev)
+{
+ /* Initialize the device structure. */
+ dev->destructor = free_netdev;
+ dev->netdev_ops = &ifb_netdev_ops;
+
+ /* Fill in device structure with ethernet-generic values. */
+ ether_setup(dev);
+ dev->tx_queue_len = TX_Q_LIMIT;
+
+ dev->features |= IFB_FEATURES;
+ dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX);
+
+ dev->flags |= IFF_NOARP;
+ dev->flags &= ~IFF_MULTICAST;
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ netif_keep_dst(dev);
+ eth_hw_addr_random(dev);
+}
+
+static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ifb_private *dp = netdev_priv(dev);
+ u32 from = G_TC_FROM(skb->tc_verd);
+
+ u64_stats_update_begin(&dp->rsync);
+ dp->rx_packets++;
+ dp->rx_bytes += skb->len;
+ u64_stats_update_end(&dp->rsync);
+
+ if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
+ dev_kfree_skb(skb);
+ dev->stats.rx_dropped++;
+ return NETDEV_TX_OK;
+ }
+
+ if (skb_queue_len(&dp->rq) >= dev->tx_queue_len) {
+ netif_stop_queue(dev);
+ }
+
+ __skb_queue_tail(&dp->rq, skb);
+ if (!dp->tasklet_pending) {
+ dp->tasklet_pending = 1;
+ tasklet_schedule(&dp->ifb_tasklet);
+ }
+
+ return NETDEV_TX_OK;
+}
+
+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 ifb_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+ return -EINVAL;
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+ return -EADDRNOTAVAIL;
+ }
+ return 0;
+}
+
+static struct rtnl_link_ops ifb_link_ops __read_mostly = {
+ .kind = "ifb",
+ .priv_size = sizeof(struct ifb_private),
+ .setup = ifb_setup,
+ .validate = ifb_validate,
+};
+
+/* 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 __init ifb_init_one(int index)
+{
+ struct net_device *dev_ifb;
+ struct ifb_private *dp;
+ int err;
+
+ dev_ifb = alloc_netdev(sizeof(struct ifb_private), "ifb%d",
+ NET_NAME_UNKNOWN, ifb_setup);
+
+ if (!dev_ifb)
+ return -ENOMEM;
+
+ dp = netdev_priv(dev_ifb);
+ u64_stats_init(&dp->rsync);
+ u64_stats_init(&dp->tsync);
+
+ dev_ifb->rtnl_link_ops = &ifb_link_ops;
+ err = register_netdevice(dev_ifb);
+ if (err < 0)
+ goto err;
+
+ return 0;
+
+err:
+ free_netdev(dev_ifb);
+ return err;
+}
+
+static int __init ifb_init_module(void)
+{
+ int i, err;
+
+ rtnl_lock();
+ err = __rtnl_link_register(&ifb_link_ops);
+ if (err < 0)
+ goto out;
+
+ for (i = 0; i < numifbs && !err; i++) {
+ err = ifb_init_one(i);
+ cond_resched();
+ }
+ if (err)
+ __rtnl_link_unregister(&ifb_link_ops);
+
+out:
+ rtnl_unlock();
+
+ return err;
+}
+
+static void __exit ifb_cleanup_module(void)
+{
+ rtnl_link_unregister(&ifb_link_ops);
+}
+
+module_init(ifb_init_module);
+module_exit(ifb_cleanup_module);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jamal Hadi Salim");
+MODULE_ALIAS_RTNL_LINK("ifb");