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-rw-r--r--drivers/net/ifb.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
new file mode 100644
index 000000000..1c64d5347
--- /dev/null
+++ b/drivers/net/ifb.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* 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.
+
+
+ Authors: Jamal Hadi Salim (2005)
+
+*/
+
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/ethtool.h>
+#include <linux/etherdevice.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+#include <linux/netfilter_netdev.h>
+#include <net/pkt_sched.h>
+#include <net/net_namespace.h>
+
+#define TX_Q_LIMIT 32
+
+struct ifb_q_stats {
+ u64 packets;
+ u64 bytes;
+ struct u64_stats_sync sync;
+};
+
+struct ifb_q_private {
+ struct net_device *dev;
+ struct tasklet_struct ifb_tasklet;
+ int tasklet_pending;
+ int txqnum;
+ struct sk_buff_head rq;
+ struct sk_buff_head tq;
+ struct ifb_q_stats rx_stats;
+ struct ifb_q_stats tx_stats;
+} ____cacheline_aligned_in_smp;
+
+struct ifb_dev_private {
+ struct ifb_q_private *tx_private;
+};
+
+/* For ethtools stats. */
+struct ifb_q_stats_desc {
+ char desc[ETH_GSTRING_LEN];
+ size_t offset;
+};
+
+#define IFB_Q_STAT(m) offsetof(struct ifb_q_stats, m)
+
+static const struct ifb_q_stats_desc ifb_q_stats_desc[] = {
+ { "packets", IFB_Q_STAT(packets) },
+ { "bytes", IFB_Q_STAT(bytes) },
+};
+
+#define IFB_Q_STATS_LEN ARRAY_SIZE(ifb_q_stats_desc)
+
+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 ifb_update_q_stats(struct ifb_q_stats *stats, int len)
+{
+ u64_stats_update_begin(&stats->sync);
+ stats->packets++;
+ stats->bytes += len;
+ u64_stats_update_end(&stats->sync);
+}
+
+static void ifb_ri_tasklet(struct tasklet_struct *t)
+{
+ struct ifb_q_private *txp = from_tasklet(txp, t, ifb_tasklet);
+ struct netdev_queue *txq;
+ struct sk_buff *skb;
+
+ txq = netdev_get_tx_queue(txp->dev, txp->txqnum);
+ skb = skb_peek(&txp->tq);
+ if (!skb) {
+ if (!__netif_tx_trylock(txq))
+ goto resched;
+ skb_queue_splice_tail_init(&txp->rq, &txp->tq);
+ __netif_tx_unlock(txq);
+ }
+
+ while ((skb = __skb_dequeue(&txp->tq)) != NULL) {
+ /* Skip tc and netfilter to prevent redirection loop. */
+ skb->redirected = 0;
+#ifdef CONFIG_NET_CLS_ACT
+ skb->tc_skip_classify = 1;
+#endif
+ nf_skip_egress(skb, true);
+
+ ifb_update_q_stats(&txp->tx_stats, skb->len);
+
+ rcu_read_lock();
+ skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
+ if (!skb->dev) {
+ rcu_read_unlock();
+ dev_kfree_skb(skb);
+ txp->dev->stats.tx_dropped++;
+ if (skb_queue_len(&txp->tq) != 0)
+ goto resched;
+ break;
+ }
+ rcu_read_unlock();
+ skb->skb_iif = txp->dev->ifindex;
+
+ if (!skb->from_ingress) {
+ dev_queue_xmit(skb);
+ } else {
+ skb_pull_rcsum(skb, skb->mac_len);
+ netif_receive_skb(skb);
+ }
+ }
+
+ if (__netif_tx_trylock(txq)) {
+ skb = skb_peek(&txp->rq);
+ if (!skb) {
+ txp->tasklet_pending = 0;
+ if (netif_tx_queue_stopped(txq))
+ netif_tx_wake_queue(txq);
+ } else {
+ __netif_tx_unlock(txq);
+ goto resched;
+ }
+ __netif_tx_unlock(txq);
+ } else {
+resched:
+ txp->tasklet_pending = 1;
+ tasklet_schedule(&txp->ifb_tasklet);
+ }
+
+}
+
+static void ifb_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct ifb_dev_private *dp = netdev_priv(dev);
+ struct ifb_q_private *txp = dp->tx_private;
+ unsigned int start;
+ u64 packets, bytes;
+ int i;
+
+ for (i = 0; i < dev->num_tx_queues; i++,txp++) {
+ do {
+ start = u64_stats_fetch_begin_irq(&txp->rx_stats.sync);
+ packets = txp->rx_stats.packets;
+ bytes = txp->rx_stats.bytes;
+ } while (u64_stats_fetch_retry_irq(&txp->rx_stats.sync, start));
+ stats->rx_packets += packets;
+ stats->rx_bytes += bytes;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&txp->tx_stats.sync);
+ packets = txp->tx_stats.packets;
+ bytes = txp->tx_stats.bytes;
+ } while (u64_stats_fetch_retry_irq(&txp->tx_stats.sync, start));
+ stats->tx_packets += packets;
+ stats->tx_bytes += bytes;
+ }
+ stats->rx_dropped = dev->stats.rx_dropped;
+ stats->tx_dropped = dev->stats.tx_dropped;
+}
+
+static int ifb_dev_init(struct net_device *dev)
+{
+ struct ifb_dev_private *dp = netdev_priv(dev);
+ struct ifb_q_private *txp;
+ int i;
+
+ txp = kcalloc(dev->num_tx_queues, sizeof(*txp), GFP_KERNEL);
+ if (!txp)
+ return -ENOMEM;
+ dp->tx_private = txp;
+ for (i = 0; i < dev->num_tx_queues; i++,txp++) {
+ txp->txqnum = i;
+ txp->dev = dev;
+ __skb_queue_head_init(&txp->rq);
+ __skb_queue_head_init(&txp->tq);
+ u64_stats_init(&txp->rx_stats.sync);
+ u64_stats_init(&txp->tx_stats.sync);
+ tasklet_setup(&txp->ifb_tasklet, ifb_ri_tasklet);
+ netif_tx_start_queue(netdev_get_tx_queue(dev, i));
+ }
+ return 0;
+}
+
+static void ifb_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+ u8 *p = buf;
+ int i, j;
+
+ switch (stringset) {
+ case ETH_SS_STATS:
+ for (i = 0; i < dev->real_num_rx_queues; i++)
+ for (j = 0; j < IFB_Q_STATS_LEN; j++)
+ ethtool_sprintf(&p, "rx_queue_%u_%.18s",
+ i, ifb_q_stats_desc[j].desc);
+
+ for (i = 0; i < dev->real_num_tx_queues; i++)
+ for (j = 0; j < IFB_Q_STATS_LEN; j++)
+ ethtool_sprintf(&p, "tx_queue_%u_%.18s",
+ i, ifb_q_stats_desc[j].desc);
+
+ break;
+ }
+}
+
+static int ifb_get_sset_count(struct net_device *dev, int sset)
+{
+ switch (sset) {
+ case ETH_SS_STATS:
+ return IFB_Q_STATS_LEN * (dev->real_num_rx_queues +
+ dev->real_num_tx_queues);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static void ifb_fill_stats_data(u64 **data,
+ struct ifb_q_stats *q_stats)
+{
+ void *stats_base = (void *)q_stats;
+ unsigned int start;
+ size_t offset;
+ int j;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&q_stats->sync);
+ for (j = 0; j < IFB_Q_STATS_LEN; j++) {
+ offset = ifb_q_stats_desc[j].offset;
+ (*data)[j] = *(u64 *)(stats_base + offset);
+ }
+ } while (u64_stats_fetch_retry_irq(&q_stats->sync, start));
+
+ *data += IFB_Q_STATS_LEN;
+}
+
+static void ifb_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *stats, u64 *data)
+{
+ struct ifb_dev_private *dp = netdev_priv(dev);
+ struct ifb_q_private *txp;
+ int i;
+
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ txp = dp->tx_private + i;
+ ifb_fill_stats_data(&data, &txp->rx_stats);
+ }
+
+ for (i = 0; i < dev->real_num_tx_queues; i++) {
+ txp = dp->tx_private + i;
+ ifb_fill_stats_data(&data, &txp->tx_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,
+ .ndo_init = ifb_dev_init,
+};
+
+static const struct ethtool_ops ifb_ethtool_ops = {
+ .get_strings = ifb_get_strings,
+ .get_sset_count = ifb_get_sset_count,
+ .get_ethtool_stats = ifb_get_ethtool_stats,
+};
+
+#define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_FRAGLIST | \
+ NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
+ NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX | \
+ NETIF_F_HW_VLAN_STAG_TX)
+
+static void ifb_dev_free(struct net_device *dev)
+{
+ struct ifb_dev_private *dp = netdev_priv(dev);
+ struct ifb_q_private *txp = dp->tx_private;
+ int i;
+
+ for (i = 0; i < dev->num_tx_queues; i++,txp++) {
+ tasklet_kill(&txp->ifb_tasklet);
+ __skb_queue_purge(&txp->rq);
+ __skb_queue_purge(&txp->tq);
+ }
+ kfree(dp->tx_private);
+}
+
+static void ifb_setup(struct net_device *dev)
+{
+ /* Initialize the device structure. */
+ dev->netdev_ops = &ifb_netdev_ops;
+ dev->ethtool_ops = &ifb_ethtool_ops;
+
+ /* Fill in device structure with ethernet-generic values. */
+ ether_setup(dev);
+ dev->tx_queue_len = TX_Q_LIMIT;
+
+ dev->features |= IFB_FEATURES;
+ dev->hw_features |= dev->features;
+ dev->hw_enc_features |= dev->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);
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = ifb_dev_free;
+
+ dev->min_mtu = 0;
+ dev->max_mtu = 0;
+}
+
+static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ifb_dev_private *dp = netdev_priv(dev);
+ struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
+
+ ifb_update_q_stats(&txp->rx_stats, skb->len);
+
+ if (!skb->redirected || !skb->skb_iif) {
+ dev_kfree_skb(skb);
+ dev->stats.rx_dropped++;
+ return NETDEV_TX_OK;
+ }
+
+ if (skb_queue_len(&txp->rq) >= dev->tx_queue_len)
+ netif_tx_stop_queue(netdev_get_tx_queue(dev, txp->txqnum));
+
+ __skb_queue_tail(&txp->rq, skb);
+ if (!txp->tasklet_pending) {
+ txp->tasklet_pending = 1;
+ tasklet_schedule(&txp->ifb_tasklet);
+ }
+
+ return NETDEV_TX_OK;
+}
+
+static int ifb_close(struct net_device *dev)
+{
+ netif_tx_stop_all_queues(dev);
+ return 0;
+}
+
+static int ifb_open(struct net_device *dev)
+{
+ netif_tx_start_all_queues(dev);
+ return 0;
+}
+
+static int ifb_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ 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_dev_private),
+ .setup = ifb_setup,
+ .validate = ifb_validate,
+};
+
+/* Number of ifb devices to be set up by this module.
+ * Note that these legacy devices have one queue.
+ * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb
+ */
+static int numifbs = 2;
+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;
+ int err;
+
+ dev_ifb = alloc_netdev(sizeof(struct ifb_dev_private), "ifb%d",
+ NET_NAME_UNKNOWN, ifb_setup);
+
+ if (!dev_ifb)
+ return -ENOMEM;
+
+ 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;
+
+ down_write(&pernet_ops_rwsem);
+ 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();
+ up_write(&pernet_ops_rwsem);
+
+ 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");