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");