netdevsim: add software driver for testing offloads
To be able to run selftests without any hardware required we
need a software model. The model can also serve as an example
implementation for those implementing actual HW offloads.
The dummy driver have previously been extended to test SR-IOV,
but the general consensus seems to be against adding further
features to it.
Add a new driver for purposes of software modelling only.
eBPF and SR-IOV will be added here shortly, others are invited
to further extend the driver with their offload models.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
new file mode 100644
index 0000000..7599c72
--- /dev/null
+++ b/drivers/net/netdevsim/netdev.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2017 Netronome Systems, Inc.
+ *
+ * This software is licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <net/netlink.h>
+#include <net/rtnetlink.h>
+
+#include "netdevsim.h"
+
+static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct netdevsim *ns = netdev_priv(dev);
+
+ u64_stats_update_begin(&ns->syncp);
+ ns->tx_packets++;
+ ns->tx_bytes += skb->len;
+ u64_stats_update_end(&ns->syncp);
+
+ dev_kfree_skb(skb);
+
+ return NETDEV_TX_OK;
+}
+
+static void nsim_set_rx_mode(struct net_device *dev)
+{
+}
+
+static void
+nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
+{
+ struct netdevsim *ns = netdev_priv(dev);
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin(&ns->syncp);
+ stats->tx_bytes = ns->tx_bytes;
+ stats->tx_packets = ns->tx_packets;
+ } while (u64_stats_fetch_retry(&ns->syncp, start));
+}
+
+static const struct net_device_ops nsim_netdev_ops = {
+ .ndo_start_xmit = nsim_start_xmit,
+ .ndo_set_rx_mode = nsim_set_rx_mode,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_get_stats64 = nsim_get_stats64,
+};
+
+static void nsim_setup(struct net_device *dev)
+{
+ ether_setup(dev);
+ eth_hw_addr_random(dev);
+
+ dev->netdev_ops = &nsim_netdev_ops;
+ dev->needs_free_netdev = true;
+
+ dev->tx_queue_len = 0;
+ dev->flags |= IFF_NOARP;
+ dev->flags &= ~IFF_MULTICAST;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE |
+ IFF_NO_QUEUE;
+ dev->features |= NETIF_F_HIGHDMA |
+ NETIF_F_SG |
+ NETIF_F_FRAGLIST |
+ NETIF_F_HW_CSUM |
+ NETIF_F_TSO;
+ dev->max_mtu = ETH_MAX_MTU;
+}
+
+static int nsim_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 nsim_link_ops __read_mostly = {
+ .kind = DRV_NAME,
+ .priv_size = sizeof(struct netdevsim),
+ .setup = nsim_setup,
+ .validate = nsim_validate,
+};
+
+static int __init nsim_module_init(void)
+{
+ return rtnl_link_register(&nsim_link_ops);
+}
+
+static void __exit nsim_module_exit(void)
+{
+ rtnl_link_unregister(&nsim_link_ops);
+}
+
+module_init(nsim_module_init);
+module_exit(nsim_module_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);