360 lines
8.4 KiB
C
360 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* drivers/net/ifb.c:
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The purpose of this driver is to provide a device that allows
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for sharing of resources:
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1) qdiscs/policies that are per device as opposed to system wide.
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ifb allows for a device which can be redirected to thus providing
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an impression of sharing.
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2) Allows for queueing incoming traffic for shaping instead of
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dropping.
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The original concept is based on what is known as the IMQ
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driver initially written by Martin Devera, later rewritten
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by Patrick McHardy and then maintained by Andre Correa.
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You need the tc action mirror or redirect to feed this device
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packets.
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Authors: Jamal Hadi Salim (2005)
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/moduleparam.h>
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#include <net/pkt_sched.h>
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#include <net/net_namespace.h>
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#define TX_Q_LIMIT 32
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struct ifb_q_private {
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struct net_device *dev;
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struct tasklet_struct ifb_tasklet;
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int tasklet_pending;
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int txqnum;
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struct sk_buff_head rq;
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u64 rx_packets;
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u64 rx_bytes;
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struct u64_stats_sync rsync;
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struct u64_stats_sync tsync;
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u64 tx_packets;
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u64 tx_bytes;
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struct sk_buff_head tq;
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} ____cacheline_aligned_in_smp;
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struct ifb_dev_private {
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struct ifb_q_private *tx_private;
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};
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static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
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static int ifb_open(struct net_device *dev);
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static int ifb_close(struct net_device *dev);
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static void ifb_ri_tasklet(unsigned long _txp)
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{
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struct ifb_q_private *txp = (struct ifb_q_private *)_txp;
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struct netdev_queue *txq;
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struct sk_buff *skb;
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txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
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skb = skb_peek(&txp->tq);
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if (!skb) {
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if (!__netif_tx_trylock(txq))
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goto resched;
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skb_queue_splice_tail_init(&txp->rq, &txp->tq);
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__netif_tx_unlock(txq);
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}
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while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
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skb->redirected = 0;
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skb->tc_skip_classify = 1;
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u64_stats_update_begin(&txp->tsync);
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txp->tx_packets++;
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txp->tx_bytes += skb->len;
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u64_stats_update_end(&txp->tsync);
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rcu_read_lock();
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skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
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if (!skb->dev) {
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rcu_read_unlock();
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dev_kfree_skb(skb);
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txp->dev->stats.tx_dropped++;
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if (skb_queue_len(&txp->tq) != 0)
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goto resched;
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break;
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}
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rcu_read_unlock();
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skb->skb_iif = txp->dev->ifindex;
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if (!skb->from_ingress) {
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dev_queue_xmit(skb);
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} else {
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skb_pull_rcsum(skb, skb->mac_len);
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netif_receive_skb(skb);
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}
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}
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if (__netif_tx_trylock(txq)) {
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skb = skb_peek(&txp->rq);
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if (!skb) {
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txp->tasklet_pending = 0;
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if (netif_tx_queue_stopped(txq))
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netif_tx_wake_queue(txq);
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} else {
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__netif_tx_unlock(txq);
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goto resched;
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}
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__netif_tx_unlock(txq);
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} else {
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resched:
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txp->tasklet_pending = 1;
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tasklet_schedule(&txp->ifb_tasklet);
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}
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}
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static void ifb_stats64(struct net_device *dev,
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struct rtnl_link_stats64 *stats)
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{
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struct ifb_dev_private *dp = netdev_priv(dev);
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struct ifb_q_private *txp = dp->tx_private;
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unsigned int start;
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u64 packets, bytes;
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int i;
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for (i = 0; i < dev->num_tx_queues; i++,txp++) {
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do {
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start = u64_stats_fetch_begin_irq(&txp->rsync);
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packets = txp->rx_packets;
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bytes = txp->rx_bytes;
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} while (u64_stats_fetch_retry_irq(&txp->rsync, start));
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stats->rx_packets += packets;
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stats->rx_bytes += bytes;
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do {
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start = u64_stats_fetch_begin_irq(&txp->tsync);
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packets = txp->tx_packets;
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bytes = txp->tx_bytes;
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} while (u64_stats_fetch_retry_irq(&txp->tsync, start));
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stats->tx_packets += packets;
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stats->tx_bytes += bytes;
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}
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stats->rx_dropped = dev->stats.rx_dropped;
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stats->tx_dropped = dev->stats.tx_dropped;
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}
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static int ifb_dev_init(struct net_device *dev)
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{
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struct ifb_dev_private *dp = netdev_priv(dev);
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struct ifb_q_private *txp;
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int i;
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txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
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if (!txp)
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return -ENOMEM;
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dp->tx_private = txp;
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for (i = 0; i < dev->num_tx_queues; i++,txp++) {
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txp->txqnum = i;
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txp->dev = dev;
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__skb_queue_head_init(&txp->rq);
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__skb_queue_head_init(&txp->tq);
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u64_stats_init(&txp->rsync);
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u64_stats_init(&txp->tsync);
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tasklet_init(&txp->ifb_tasklet, ifb_ri_tasklet,
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(unsigned long)txp);
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netif_tx_start_queue(netdev_get_tx_queue(dev, i));
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}
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return 0;
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}
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static const struct net_device_ops ifb_netdev_ops = {
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.ndo_open = ifb_open,
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.ndo_stop = ifb_close,
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.ndo_get_stats64 = ifb_stats64,
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.ndo_start_xmit = ifb_xmit,
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.ndo_validate_addr = eth_validate_addr,
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.ndo_init = ifb_dev_init,
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};
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#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \
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NETIF_F_TSO_ECN | NETIF_F_TSO | NETIF_F_TSO6 | \
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NETIF_F_GSO_ENCAP_ALL | \
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NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
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NETIF_F_HW_VLAN_STAG_TX)
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static void ifb_dev_free(struct net_device *dev)
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{
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struct ifb_dev_private *dp = netdev_priv(dev);
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struct ifb_q_private *txp = dp->tx_private;
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int i;
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for (i = 0; i < dev->num_tx_queues; i++,txp++) {
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tasklet_kill(&txp->ifb_tasklet);
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__skb_queue_purge(&txp->rq);
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__skb_queue_purge(&txp->tq);
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}
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kfree(dp->tx_private);
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}
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static void ifb_setup(struct net_device *dev)
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{
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/* Initialize the device structure. */
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dev->netdev_ops = &ifb_netdev_ops;
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/* Fill in device structure with ethernet-generic values. */
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ether_setup(dev);
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dev->tx_queue_len = TX_Q_LIMIT;
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dev->features |= IFB_FEATURES;
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dev->hw_features |= dev->features;
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dev->hw_enc_features |= dev->features;
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dev->vlan_features |= IFB_FEATURES & ~(NETIF_F_HW_VLAN_CTAG_TX |
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NETIF_F_HW_VLAN_STAG_TX);
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dev->flags |= IFF_NOARP;
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dev->flags &= ~IFF_MULTICAST;
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dev->priv_flags &= ~IFF_TX_SKB_SHARING;
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netif_keep_dst(dev);
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eth_hw_addr_random(dev);
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dev->needs_free_netdev = true;
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dev->priv_destructor = ifb_dev_free;
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dev->min_mtu = 0;
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dev->max_mtu = 0;
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}
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static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct ifb_dev_private *dp = netdev_priv(dev);
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struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
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u64_stats_update_begin(&txp->rsync);
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txp->rx_packets++;
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txp->rx_bytes += skb->len;
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u64_stats_update_end(&txp->rsync);
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if (!skb->redirected || !skb->skb_iif) {
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dev_kfree_skb(skb);
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dev->stats.rx_dropped++;
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return NETDEV_TX_OK;
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}
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if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
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netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
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__skb_queue_tail(&txp->rq, skb);
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if (!txp->tasklet_pending) {
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txp->tasklet_pending = 1;
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tasklet_schedule(&txp->ifb_tasklet);
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}
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return NETDEV_TX_OK;
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}
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static int ifb_close(struct net_device *dev)
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{
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netif_tx_stop_all_queues(dev);
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return 0;
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}
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static int ifb_open(struct net_device *dev)
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{
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netif_tx_start_all_queues(dev);
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return 0;
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}
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static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
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struct netlink_ext_ack *extack)
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{
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if (tb[IFLA_ADDRESS]) {
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if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
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return -EINVAL;
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if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
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return -EADDRNOTAVAIL;
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}
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return 0;
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}
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static struct rtnl_link_ops ifb_link_ops __read_mostly = {
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.kind = "ifb",
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.priv_size = sizeof(struct ifb_dev_private),
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.setup = ifb_setup,
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.validate = ifb_validate,
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};
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/* Number of ifb devices to be set up by this module.
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* Note that these legacy devices have one queue.
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* Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
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*/
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static int numifbs = 2;
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module_param(numifbs, int, 0);
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MODULE_PARM_DESC(numifbs, "Number of ifb devices");
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static int __init ifb_init_one(int index)
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{
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struct net_device *dev_ifb;
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int err;
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dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
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NET_NAME_UNKNOWN, ifb_setup);
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if (!dev_ifb)
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return -ENOMEM;
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dev_ifb->rtnl_link_ops = &ifb_link_ops;
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err = register_netdevice(dev_ifb);
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if (err < 0)
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goto err;
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return 0;
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err:
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free_netdev(dev_ifb);
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return err;
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}
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static int __init ifb_init_module(void)
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{
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int i, err;
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down_write(&pernet_ops_rwsem);
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rtnl_lock();
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err = __rtnl_link_register(&ifb_link_ops);
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if (err < 0)
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goto out;
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for (i = 0; i < numifbs && !err; i++) {
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err = ifb_init_one(i);
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cond_resched();
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}
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if (err)
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__rtnl_link_unregister(&ifb_link_ops);
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out:
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rtnl_unlock();
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up_write(&pernet_ops_rwsem);
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return err;
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}
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static void __exit ifb_cleanup_module(void)
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{
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rtnl_link_unregister(&ifb_link_ops);
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}
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module_init(ifb_init_module);
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module_exit(ifb_cleanup_module);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Jamal Hadi Salim");
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MODULE_ALIAS_RTNL_LINK("ifb");
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