[mirror_ubuntu-artful-kernel.git] / net / xfrm / xfrm_device.c

/*
 * xfrm_device.c - IPsec device offloading code.
 *
 * Copyright (c) 2015 secunet Security Networks AG
 *
 * Author:
 * Steffen Klassert <steffen.klassert@secunet.com>
 *
 * 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/errno.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <net/dst.h>
#include <net/xfrm.h>
#include <linux/notifier.h>

#ifdef CONFIG_XFRM_OFFLOAD
int validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features)
{
	int err;
	struct xfrm_state *x;
	struct xfrm_offload *xo = xfrm_offload(skb);

	if (skb_is_gso(skb))
		return 0;

	if (xo) {
		x = skb->sp->xvec[skb->sp->len - 1];
		if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
			return 0;

		x->outer_mode->xmit(x, skb);

		err = x->type_offload->xmit(x, skb, features);
		if (err) {
			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
			return err;
		}

		skb_push(skb, skb->data - skb_mac_header(skb));
	}

	return 0;
}
EXPORT_SYMBOL_GPL(validate_xmit_xfrm);

int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
		       struct xfrm_user_offload *xuo)
{
	int err;
	struct dst_entry *dst;
	struct net_device *dev;
	struct xfrm_state_offload *xso = &x->xso;
	xfrm_address_t *saddr;
	xfrm_address_t *daddr;

	if (!x->type_offload)
		return 0;

	/* We don't yet support UDP encapsulation, TFC padding and ESN. */
	if (x->encap || x->tfcpad || (x->props.flags & XFRM_STATE_ESN))
		return 0;

	dev = dev_get_by_index(net, xuo->ifindex);
	if (!dev) {
		if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
			saddr = &x->props.saddr;
			daddr = &x->id.daddr;
		} else {
			saddr = &x->id.daddr;
			daddr = &x->props.saddr;
		}

		dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, x->props.family);
		if (IS_ERR(dst))
			return 0;

		dev = dst->dev;

		dev_hold(dev);
		dst_release(dst);
	}

	if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
		dev_put(dev);
		return 0;
	}

	xso->dev = dev;
	xso->num_exthdrs = 1;
	xso->flags = xuo->flags;

	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
	if (err) {
		dev_put(dev);
		return err;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(xfrm_dev_state_add);

bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
{
	int mtu;
	struct dst_entry *dst = skb_dst(skb);
	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
	struct net_device *dev = x->xso.dev;

	if (!x->type_offload || x->encap)
		return false;

	if ((x->xso.offload_handle && (dev == dst->path->dev)) &&
	     !dst->child->xfrm && x->type->get_mtu) {
		mtu = x->type->get_mtu(x, xdst->child_mtu_cached);

		if (skb->len <= mtu)
			goto ok;

		if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
			goto ok;
	}

	return false;

ok:
	if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
		return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);

	return true;
}
EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
#endif

int xfrm_dev_register(struct net_device *dev)
{
	if ((dev->features & NETIF_F_HW_ESP) && !dev->xfrmdev_ops)
		return NOTIFY_BAD;
	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
	    !(dev->features & NETIF_F_HW_ESP))
		return NOTIFY_BAD;

	return NOTIFY_DONE;
}

static int xfrm_dev_unregister(struct net_device *dev)
{
	return NOTIFY_DONE;
}

static int xfrm_dev_feat_change(struct net_device *dev)
{
	if ((dev->features & NETIF_F_HW_ESP) && !dev->xfrmdev_ops)
		return NOTIFY_BAD;
	else if (!(dev->features & NETIF_F_HW_ESP))
		dev->xfrmdev_ops = NULL;

	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
	    !(dev->features & NETIF_F_HW_ESP))
		return NOTIFY_BAD;

	return NOTIFY_DONE;
}

static int xfrm_dev_down(struct net_device *dev)
{
	if (dev->features & NETIF_F_HW_ESP)
		xfrm_dev_state_flush(dev_net(dev), dev, true);

	xfrm_garbage_collect(dev_net(dev));

	return NOTIFY_DONE;
}

static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	switch (event) {
	case NETDEV_REGISTER:
		return xfrm_dev_register(dev);

	case NETDEV_UNREGISTER:
		return xfrm_dev_unregister(dev);

	case NETDEV_FEAT_CHANGE:
		return xfrm_dev_feat_change(dev);

	case NETDEV_DOWN:
		return xfrm_dev_down(dev);
	}
	return NOTIFY_DONE;
}

static struct notifier_block xfrm_dev_notifier = {
	.notifier_call	= xfrm_dev_event,
};

void __net_init xfrm_dev_init(void)
{
	register_netdevice_notifier(&xfrm_dev_notifier);
}
Commit	Line	Data
21f42cc9 SK	1	/*
	2	* xfrm_device.c - IPsec device offloading code.
	3	*
	4	* Copyright (c) 2015 secunet Security Networks AG
	5	*
	6	* Author:
	7	* Steffen Klassert <steffen.klassert@secunet.com>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
	15	#include <linux/errno.h>
	16	#include <linux/module.h>
	17	#include <linux/netdevice.h>
	18	#include <linux/skbuff.h>
	19	#include <linux/slab.h>
	20	#include <linux/spinlock.h>
	21	#include <net/dst.h>
	22	#include <net/xfrm.h>
	23	#include <linux/notifier.h>
	24
b81f884a	25	#ifdef CONFIG_XFRM_OFFLOAD
f6e27114 SK	26	int validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features)
	27	{
	28	int err;
	29	struct xfrm_state *x;
	30	struct xfrm_offload *xo = xfrm_offload(skb);
	31
	32	if (skb_is_gso(skb))
	33	return 0;
	34
	35	if (xo) {
	36	x = skb->sp->xvec[skb->sp->len - 1];
	37	if (xo->flags & XFRM_GRO \|\| x->xso.flags & XFRM_OFFLOAD_INBOUND)
	38	return 0;
	39
	40	x->outer_mode->xmit(x, skb);
	41
	42	err = x->type_offload->xmit(x, skb, features);
	43	if (err) {
	44	XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
	45	return err;
	46	}
	47
	48	skb_push(skb, skb->data - skb_mac_header(skb));
	49	}
	50
	51	return 0;
	52	}
	53	EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
	54
d77e38e6 SK	55	int xfrm_dev_state_add(struct net net, struct xfrm_state x,
	56	struct xfrm_user_offload *xuo)
	57	{
	58	int err;
	59	struct dst_entry *dst;
	60	struct net_device *dev;
	61	struct xfrm_state_offload *xso = &x->xso;
	62	xfrm_address_t *saddr;
	63	xfrm_address_t *daddr;
	64
	65	if (!x->type_offload)
	66	return 0;
	67
	68	/* We don't yet support UDP encapsulation, TFC padding and ESN. */
	69	if (x->encap \|\| x->tfcpad \|\| (x->props.flags & XFRM_STATE_ESN))
	70	return 0;
	71
	72	dev = dev_get_by_index(net, xuo->ifindex);
	73	if (!dev) {
	74	if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
	75	saddr = &x->props.saddr;
	76	daddr = &x->id.daddr;
	77	} else {
	78	saddr = &x->id.daddr;
	79	daddr = &x->props.saddr;
	80	}
	81
	82	dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, x->props.family);
	83	if (IS_ERR(dst))
	84	return 0;
	85
	86	dev = dst->dev;
	87
	88	dev_hold(dev);
	89	dst_release(dst);
	90	}
	91
	92	if (!dev->xfrmdev_ops \|\| !dev->xfrmdev_ops->xdo_dev_state_add) {
	93	dev_put(dev);
	94	return 0;
	95	}
	96
	97	xso->dev = dev;
	98	xso->num_exthdrs = 1;
	99	xso->flags = xuo->flags;
	100
	101	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
	102	if (err) {
	103	dev_put(dev);
	104	return err;
	105	}
	106
	107	return 0;
	108	}
	109	EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
	110
	111	bool xfrm_dev_offload_ok(struct sk_buff skb, struct xfrm_state x)
	112	{
	113	int mtu;
	114	struct dst_entry *dst = skb_dst(skb);
	115	struct xfrm_dst xdst = (struct xfrm_dst )dst;
	116	struct net_device *dev = x->xso.dev;
	117
	118	if (!x->type_offload \|\| x->encap)
119	return false;
120
121	if ((x->xso.offload_handle && (dev == dst->path->dev)) &&
122	!dst->child->xfrm && x->type->get_mtu) {
123	mtu = x->type->get_mtu(x, xdst->child_mtu_cached);
124
125	if (skb->len <= mtu)
126	goto ok;
127
128	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
129	goto ok;
130	}
131
132	return false;
133
134	ok:
135	if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
136	return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
137
138	return true;
139	}
140	EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
b81f884a	141	#endif
d77e38e6 SK	142
	143	int xfrm_dev_register(struct net_device *dev)
	144	{
	145	if ((dev->features & NETIF_F_HW_ESP) && !dev->xfrmdev_ops)
	146	return NOTIFY_BAD;
	147	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
	148	!(dev->features & NETIF_F_HW_ESP))
	149	return NOTIFY_BAD;
	150
	151	return NOTIFY_DONE;
	152	}
	153
	154	static int xfrm_dev_unregister(struct net_device *dev)
	155	{
	156	return NOTIFY_DONE;
	157	}
	158
	159	static int xfrm_dev_feat_change(struct net_device *dev)
	160	{
	161	if ((dev->features & NETIF_F_HW_ESP) && !dev->xfrmdev_ops)
	162	return NOTIFY_BAD;
	163	else if (!(dev->features & NETIF_F_HW_ESP))
	164	dev->xfrmdev_ops = NULL;
	165
	166	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
	167	!(dev->features & NETIF_F_HW_ESP))
	168	return NOTIFY_BAD;
	169
	170	return NOTIFY_DONE;
	171	}
	172
	173	static int xfrm_dev_down(struct net_device *dev)
	174	{
2c1497bb	175	if (dev->features & NETIF_F_HW_ESP)
d77e38e6 SK	176	xfrm_dev_state_flush(dev_net(dev), dev, true);
	177
	178	xfrm_garbage_collect(dev_net(dev));
	179
	180	return NOTIFY_DONE;
	181	}
	182
21f42cc9 SK	183	static int xfrm_dev_event(struct notifier_block this, unsigned long event, void ptr)
	184	{
	185	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
	186
	187	switch (event) {
d77e38e6 SK	188	case NETDEV_REGISTER:
	189	return xfrm_dev_register(dev);
	190
	191	case NETDEV_UNREGISTER:
	192	return xfrm_dev_unregister(dev);
	193
	194	case NETDEV_FEAT_CHANGE:
	195	return xfrm_dev_feat_change(dev);
	196
21f42cc9	197	case NETDEV_DOWN:
d77e38e6	198	return xfrm_dev_down(dev);
21f42cc9 SK	199	}
	200	return NOTIFY_DONE;
	201	}
	202
	203	static struct notifier_block xfrm_dev_notifier = {
	204	.notifier_call = xfrm_dev_event,
	205	};
	206
	207	void __net_init xfrm_dev_init(void)
	208	{
	209	register_netdevice_notifier(&xfrm_dev_notifier);
	210	}