Commit 83c9e13a authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Daniel Borkmann
Browse files

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: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarSimon Horman <simon.horman@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent bd0b2e7f

MAINTAINERS

+5 −0
Original line number Diff line number Diff line
@@ -9599,6 +9599,11 @@ NETWORKING [WIRELESS] 
L:	linux-wireless@vger.kernel.org

Q:	http://patchwork.kernel.org/project/linux-wireless/list/



NETDEVSIM

M:	Jakub Kicinski <jakub.kicinski@netronome.com>

S:	Maintained

F:	drivers/net/netdevsim/*



NETXEN (1/10) GbE SUPPORT

M:	Manish Chopra <manish.chopra@cavium.com>

M:	Rahul Verma <rahul.verma@cavium.com>

drivers/net/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -497,4 +497,15 @@ config THUNDERBOLT_NET 


source "drivers/net/hyperv/Kconfig"



config NETDEVSIM

	tristate "Simulated networking device"

	depends on DEBUG_FS

	help

	  This driver is a developer testing tool and software model that can

	  be used to test various control path networking APIs, especially

	  HW-offload related.



	  To compile this driver as a module, choose M here: the module

	  will be called netdevsim.



endif # NETDEVICES

drivers/net/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -78,3 +78,4 @@ obj-$(CONFIG_FUJITSU_ES) += fjes/ 


thunderbolt-net-y += thunderbolt.o

obj-$(CONFIG_THUNDERBOLT_NET) += thunderbolt-net.o

obj-$(CONFIG_NETDEVSIM) += netdevsim/

drivers/net/netdevsim/Makefile

0 → 100644
+6 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



obj-$(CONFIG_NETDEVSIM) += netdevsim.o



netdevsim-objs := \

	netdev.o \

drivers/net/netdevsim/netdev.c

0 → 100644
+118 −0
Original line number Diff line number Diff line 
/*

 * 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);

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