Date:	Thu, 20 Mar 2014 16:42:06 +0100
From:	Jiri Pirko <jiri@...nulli.us>
To:	Nikolay Aleksandrov <nikolay@...hat.com>
Cc:	netdev@...r.kernel.org, davem@...emloft.net, nhorman@...driver.com,
	andy@...yhouse.net, tgraf@...g.ch, dborkman@...hat.com,
	ogerlitz@...lanox.com, jesse@...ira.com, pshelar@...ira.com,
	azhou@...ira.com, ben@...adent.org.uk, stephen@...workplumber.org,
	jeffrey.t.kirsher@...el.com, vyasevic@...hat.com,
	xiyou.wangcong@...il.com, john.r.fastabend@...el.com,
	edumazet@...gle.com
Subject: Re: [patch net-next RFC 2/4] net: introduce switchdev API

Thu, Mar 20, 2014 at 03:43:42PM CET, nikolay@...hat.com wrote:
>On 03/19/2014 04:33 PM, Jiri Pirko wrote:
>> switchdev API is designed to allow kernel support for various switch
>> chips.
>> 
>> Signed-off-by: Jiri Pirko <jiri@...nulli.us>
>> ---
>>  include/linux/switchdev.h |  62 +++++++++
>>  net/Kconfig               |  10 ++
>>  net/core/Makefile         |   1 +
>>  net/core/switchdev.c      | 330 ++++++++++++++++++++++++++++++++++++++++++++++
>>  4 files changed, 403 insertions(+)
>>  create mode 100644 include/linux/switchdev.h
>>  create mode 100644 net/core/switchdev.c
>> 
>> diff --git a/include/linux/switchdev.h b/include/linux/switchdev.h
>> new file mode 100644
>> index 0000000..ac6db2d
>> --- /dev/null
>> +++ b/include/linux/switchdev.h
>> @@ -0,0 +1,62 @@
>> +/*
>> + * include/linux/switchdev.h - Switch device API
>> + * Copyright (c) 2014 Jiri Pirko <jiri@...nulli.us>
>> + *
>> + * 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.
>> + */
>> +#ifndef _LINUX_SWITCHDEV_H_
>> +#define _LINUX_SWITCHDEV_H_
>> +
>> +#include <linux/netdevice.h>
>> +#include <linux/sw_flow.h>
>> +
>> +struct swdev_linked_ops {
>> +};
>> +
>> +bool swdev_dev_check(const struct net_device *dev);
>> +void swdev_link(struct net_device *dev,
>> +		const struct swdev_linked_ops *linked_ops,
>> +		void *linked_priv);
>> +void swdev_unlink(struct net_device *dev);
>> +void *swdev_linked_priv(const struct net_device *dev);
>> +bool swdev_is_linked(const struct net_device *dev);
>> +int swdev_flow_insert(struct net_device *dev, struct sw_flow *flow);
>> +int swdev_flow_remove(struct net_device *dev, struct sw_flow *flow);
>> +int swdev_packet_upcall(struct net_device *dev, struct sk_buff *skb);
>> +
>> +struct swdev_ops {
>> +	const char *kind;
>> +	int (*flow_insert)(struct net_device *dev, struct sw_flow *flow);
>> +	int (*flow_remove)(struct net_device *dev, struct sw_flow *flow);
>> +};
>> +
>> +struct net_device *swdev_create(const struct swdev_ops *ops);
>> +void swdev_destroy(struct net_device *dev);
>> +
>> +struct swportdev_linked_ops {
>> +	void (*skb_upcall)(struct net_device *dev, struct sk_buff *skb,
>> +			   struct sw_flow_key *key, void *linked_priv);
>> +};
>> +
>> +bool swportdev_dev_check(const struct net_device *dev);
>> +void swportdev_link(struct net_device *dev,
>> +		    const struct swportdev_linked_ops *linked_ops,
>> +		    void *linked_priv);
>> +void swportdev_unlink(struct net_device *dev);
>> +void *swportdev_linked_priv(const struct net_device *dev);
>> +bool swportdev_is_linked(const struct net_device *dev);
>> +
>> +struct swportdev_ops {
>> +	const char *kind;
>> +	netdev_tx_t (*skb_xmit)(struct sk_buff *skb,
>> +				struct net_device *port_dev);
>> +};
>> +
>> +struct net_device *swportdev_create(struct net_device *dev,
>> +				    const struct swportdev_ops *ops);
>> +void swportdev_destroy(struct net_device *port_dev);
>> +
>> +#endif /* _LINUX_SWITCHDEV_H_ */
>> diff --git a/net/Kconfig b/net/Kconfig
>> index e411046..e02ab8d 100644
>> --- a/net/Kconfig
>> +++ b/net/Kconfig
>> @@ -285,6 +285,16 @@ config NET_FLOW_LIMIT
>>  	  with many clients some protection against DoS by a single (spoofed)
>>  	  flow that greatly exceeds average workload.
>>  
>> +config NET_SWITCHDEV
>> +	tristate "Switch device"
>> +	depends on INET
>> +	---help---
>> +	  This module provides glue for hardware switch chips so they can be
>> +	  accessed from userspace via Open vSwitch Netlink API. 
>> +
>> +	  To compile this code as a module, choose M here: the
>> +	  module will be called pktgen.
>> +
>>  menu "Network testing"
>>  
>>  config NET_PKTGEN
>> diff --git a/net/core/Makefile b/net/core/Makefile
>> index 9628c20..426a619 100644
>> --- a/net/core/Makefile
>> +++ b/net/core/Makefile
>> @@ -23,3 +23,4 @@ obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o
>>  obj-$(CONFIG_NETWORK_PHY_TIMESTAMPING) += timestamping.o
>>  obj-$(CONFIG_CGROUP_NET_PRIO) += netprio_cgroup.o
>>  obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o
>> +obj-$(CONFIG_NET_SWITCHDEV) += switchdev.o
>> diff --git a/net/core/switchdev.c b/net/core/switchdev.c
>> new file mode 100644
>> index 0000000..3b8daaf
>> --- /dev/null
>> +++ b/net/core/switchdev.c
>> @@ -0,0 +1,330 @@
>> +/*
>> + * net/core/switchdev.c - Switch device API
>> + * Copyright (c) 2014 Jiri Pirko <jiri@...nulli.us>
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/types.h>
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/ethtool.h>
>> +#include <linux/switchdev.h>
>> +
>> +#include <net/rtnetlink.h>
>> +#include <net/net_namespace.h>
>> +#include <net/netns/generic.h>
>> +
>> +#include <generated/utsrelease.h>
>> +
>> +struct swdev {
>> +	const struct swdev_ops *ops;
>> +	const struct swdev_linked_ops *linked_ops;
>> +	void *linked_priv;
>> +};
>> +
>> +static netdev_tx_t swdev_ndo_start_xmit(struct sk_buff *skb,
>> +					struct net_device *dev)
>> +{
>> +	dev_kfree_skb(skb);
>> +	return NETDEV_TX_OK;
>> +}
>> +
>> +static const struct net_device_ops swdev_netdev_ops = {
>> +	.ndo_start_xmit = swdev_ndo_start_xmit,
>> +};
>> +
>> +static void swdev_ethtool_get_drvinfo(struct net_device *dev,
>> +				      struct ethtool_drvinfo *drvinfo)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	strlcpy(drvinfo->driver, sw->ops->kind, sizeof(drvinfo->driver));
>> +	strlcpy(drvinfo->version, UTS_RELEASE, sizeof(drvinfo->version));
>> +}
>> +
>> +static const struct ethtool_ops swdev_ethtool_ops = {
>> +	.get_drvinfo		= swdev_ethtool_get_drvinfo,
>> +	.get_link		= ethtool_op_get_link,
>> +};
>> +
>> +static void swdev_setup(struct net_device *dev)
>> +{
>> +	ether_setup(dev);
>> +	dev->netdev_ops = &swdev_netdev_ops;
>> +	dev->ethtool_ops = &swdev_ethtool_ops;
>> +}
>> +
>> +bool swdev_dev_check(const struct net_device *dev)
>> +{
>> +	return dev->netdev_ops == &swdev_netdev_ops;
>> +}
>> +EXPORT_SYMBOL(swdev_dev_check);
>> +
>> +void swdev_link(struct net_device *dev,
>> +		const struct swdev_linked_ops *linked_ops,
>> +		void *linked_priv)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	sw->linked_ops = linked_ops;
>> +	sw->linked_priv = linked_priv;
>> +	netdev_info(dev, "Switch device linked\n");
>> +}
>> +EXPORT_SYMBOL(swdev_link);
>> +
>> +void swdev_unlink(struct net_device *dev)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	sw->linked_ops = NULL;
>> +	sw->linked_priv = NULL;
>> +	netdev_info(dev, "Switch device unlinked\n");
>> +}
>> +EXPORT_SYMBOL(swdev_unlink);
>> +
>> +void *swdev_linked_priv(const struct net_device *dev)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	return sw->linked_priv;
>> +}
>> +EXPORT_SYMBOL(swdev_linked_priv);
>> +
>> +bool swdev_is_linked(const struct net_device *dev)
>> +{
>> +	return swdev_linked_priv(dev);
>> +}
>> +EXPORT_SYMBOL(swdev_is_linked);
>> +
>> +int swdev_flow_insert(struct net_device *dev, struct sw_flow *flow)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	BUG_ON(!swdev_dev_check(dev));
>> +	if (!sw->ops->flow_insert)
>> +		return 0;
>> +	return sw->ops->flow_insert(dev, flow);
>> +}
>> +EXPORT_SYMBOL(swdev_flow_insert);
>> +
>> +int swdev_flow_remove(struct net_device *dev, struct sw_flow *flow)
>> +{
>> +	struct swdev *sw = netdev_priv(dev);
>> +
>> +	BUG_ON(!swdev_dev_check(dev));
>> +	if (!sw->ops->flow_remove)
>> +		return 0;
>> +	return sw->ops->flow_remove(dev, flow);
>> +}
>> +EXPORT_SYMBOL(swdev_flow_remove);
>> +
>> +struct net_device *swdev_create(const struct swdev_ops *ops)
>> +{
>> +	struct net_device *dev;
>> +	struct swdev *sw;
>> +	int err;
>> +
>> +	dev = alloc_netdev(sizeof(struct swdev), "swdev%d", swdev_setup);
>> +	if (!dev)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	err = register_netdevice(dev);
>> +	if (err)
>> +		goto err_register_netdevice;
>> +	sw = netdev_priv(dev);
>> +	sw->ops = ops;
>> +	netif_carrier_off(dev);
>> +	netdev_info(dev, "Switch device created (%s)\n", sw->ops->kind);
>> +	return dev;
>> +
>> +err_register_netdevice:
>> +	free_netdev(dev);
>> +	return ERR_PTR(err);
>> +}
>> +EXPORT_SYMBOL(swdev_create);
>> +
>> +void swdev_destroy(struct net_device *dev)
>> +{
>> +	unregister_netdevice(dev);
>> +	free_netdev(dev);
>> +	netdev_info(dev, "Switch device destroyed\n");
>> +}
>> +EXPORT_SYMBOL(swdev_destroy);
>> +
>> +
>> +struct swportdev {
>> +	const struct swportdev_ops *ops;
>> +	const struct swportdev_linked_ops *linked_ops;
>> +	void *linked_priv;
>> +};
>> +
>> +static netdev_tx_t swportdev_ndo_start_xmit(struct sk_buff *skb,
>> +					    struct net_device *port_dev)
>> +{
>> +	struct swportdev *swp = netdev_priv(port_dev);
>> +
>> +	return swp->ops->skb_xmit(skb, port_dev);
>> +}
>> +
>> +static const struct net_device_ops swportdev_netdev_ops = {
>> +	.ndo_start_xmit = swportdev_ndo_start_xmit,
>> +};
>> +
>> +static void swportdev_ethtool_get_drvinfo(struct net_device *port_dev,
>> +					  struct ethtool_drvinfo *drvinfo)
>> +{
>> +	struct swportdev *swp = netdev_priv(port_dev);
>> +
>> +	strlcpy(drvinfo->driver, swp->ops->kind, sizeof(drvinfo->driver));
>> +	strlcpy(drvinfo->version, UTS_RELEASE, sizeof(drvinfo->version));
>> +}
>> +
>> +static const struct ethtool_ops swportdev_ethtool_ops = {
>> +	.get_drvinfo		= swportdev_ethtool_get_drvinfo,
>> +	.get_link		= ethtool_op_get_link,
>> +};
>> +static void swportdev_setup(struct net_device *port_dev)
>> +{
>> +	ether_setup(port_dev);
>> +	port_dev->netdev_ops = &swportdev_netdev_ops;
>> +	port_dev->ethtool_ops = &swportdev_ethtool_ops;
>> +}
>> +
>> +bool swportdev_dev_check(const struct net_device *port_dev)
>> +{
>> +	return port_dev->netdev_ops == &swportdev_netdev_ops;
>> +}
>> +EXPORT_SYMBOL(swportdev_dev_check);
>> +
>> +void swportdev_link(struct net_device *port_dev,
>> +		    const struct swportdev_linked_ops *linked_ops,
>> +		    void *linked_priv)
>> +{
>> +	struct swportdev *swp = netdev_priv(port_dev);
>> +
>> +	swp->linked_priv = linked_priv;
>> +	netdev_info(port_dev, "Switch port device linked\n");
>> +}
>> +EXPORT_SYMBOL(swportdev_link);
>> +
>> +void swportdev_unlink(struct net_device *port_dev)
>> +{
>> +	struct swportdev *swp = netdev_priv(port_dev);
>> +
>> +	swp->linked_ops = NULL;
>> +	swp->linked_priv = NULL;
>> +	netdev_info(port_dev, "Switch port device unlinked\n");
>> +}
>> +EXPORT_SYMBOL(swportdev_unlink);
>> +
>> +void *swportdev_linked_priv(const struct net_device *port_dev)
>> +{
>> +	struct swportdev *swp = netdev_priv(port_dev);
>> +
>> +	return swp->linked_priv;
>> +}
>> +EXPORT_SYMBOL(swportdev_linked_priv);
>> +
>> +bool swportdev_is_linked(const struct net_device *port_dev)
>> +{
>> +	return swportdev_linked_priv(port_dev);
>> +}
>> +EXPORT_SYMBOL(swportdev_is_linked);
>> +
>> +void swportdev_skb_upcall(struct net_device *dev, struct sk_buff *skb,
>> +			  struct sw_flow_key *key, void *linked_priv)
>> +{
>> +	struct swportdev *swp = netdev_priv(dev);
>> +
>> +	BUG_ON(!swportdev_dev_check(dev));
>> +	if (!swp->linked_ops->skb_upcall)
>> +		return;
>> +	swp->linked_ops->skb_upcall(dev, skb, key, swp->linked_priv);
>> +}
>> +EXPORT_SYMBOL(swportdev_skb_upcall);
>> +
>> +static rx_handler_result_t swportdev_handle_frame(struct sk_buff **pskb)
>> +{
>> +	struct sk_buff *skb = *pskb;
>> +
>> +	/* We don't care what comes from port device into rx path.
>> +	 * If there's something there, it is destined to ETH_P_ALL
>> +	 * handlers. So just consume it.
>> +	 */
>> +	dev_kfree_skb(skb);
>> +	return RX_HANDLER_CONSUMED;
>> +}
>> +
>> +struct net_device *swportdev_create(struct net_device *dev,
>> +				    const struct swportdev_ops *ops)
>> +{
>> +	struct net_device *port_dev;
>> +	char name[IFNAMSIZ];
>> +	struct swportdev *swp;
>> +	int err;
>> +
>> +	err = snprintf(name, IFNAMSIZ, "%sp%%d", dev->name);
>> +	if (err >= IFNAMSIZ)
>> +		return ERR_PTR(-EINVAL);
>> +
>> +	port_dev = alloc_netdev(sizeof(struct swportdev), name, swportdev_setup);
>> +	if (!port_dev)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	err = register_netdevice(port_dev);
>> +	if (err)
>> +		goto err_register_netdevice;
>> +
>> +	err = netdev_master_upper_dev_link(port_dev, dev);
>> +	if (err) {
>> +		netdev_err(dev, "Device %s failed to set upper link\n",
>> +			   port_dev->name);
>> +		goto err_set_upper_link;
>> +	}
>> +	swp = netdev_priv(port_dev);
>> +	err = netdev_rx_handler_register(port_dev, swportdev_handle_frame, swp);
>> +	if (err) {
>> +		netdev_err(dev, "Device %s failed to register rx_handler\n",
>> +			   port_dev->name);
>> +		goto err_handler_register;
>> +	}
>> +
>> +	swp = netdev_priv(port_dev);
>> +	swp->ops = ops;
>> +	netif_carrier_off(port_dev);
>> +	netdev_info(port_dev, "Switch port device created (%s)\n", swp->ops->kind);
>> +	return port_dev;
>> +
>> +err_handler_register:
>> +	netdev_upper_dev_unlink(port_dev, dev);
>> +err_set_upper_link:
>> +	unregister_netdevice(port_dev);
>Hi Jiri,
>Sorry to cut in on the discussion, and I might be missing something but wouldn't
>this trigger a BUG_ON in free_netdev: BUG_ON(dev->reg_state !=
>NETREG_UNREGISTERED); since unregister_netdevice leaves the reg_state in
>NETREG_UNREGISTERING and unless netdev_run_todo is executed, the call to
>free_netdev afterwards will get that BUG_ON triggered.


You are right. I'll fix this. Thanks!

>
>> +err_register_netdevice:
>> +	free_netdev(port_dev);
>> +	return ERR_PTR(err);
>> +}
>> +EXPORT_SYMBOL(swportdev_create);
>> +
>> +void swportdev_destroy(struct net_device *port_dev)
>> +{
>> +	struct net_device *dev;
>> +
>> +	dev = netdev_master_upper_dev_get(port_dev);
>> +	BUG_ON(!dev);
>> +	netdev_rx_handler_unregister(port_dev);
>> +	netdev_upper_dev_unlink(port_dev, dev);
>> +	unregister_netdevice(port_dev);
>> +	free_netdev(port_dev);
>Ditto.
>
>> +	netdev_info(port_dev, "Switch port device destroyed\n");
>> +}
>> +EXPORT_SYMBOL(swportdev_destroy);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("Jiri Pirko <jiri@...nulli.us>");
>> +MODULE_DESCRIPTION("Switch device API");
>> 
>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists