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v5.9
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * xfrm_device.c - IPsec device offloading code.
  4 *
  5 * Copyright (c) 2015 secunet Security Networks AG
  6 *
  7 * Author:
  8 * Steffen Klassert <steffen.klassert@secunet.com>
 
 
 
 
 
  9 */
 10
 11#include <linux/errno.h>
 12#include <linux/module.h>
 13#include <linux/netdevice.h>
 14#include <linux/skbuff.h>
 15#include <linux/slab.h>
 16#include <linux/spinlock.h>
 17#include <net/dst.h>
 18#include <net/xfrm.h>
 19#include <linux/notifier.h>
 20
 21#ifdef CONFIG_XFRM_OFFLOAD
 22static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb,
 23				  unsigned int hsize)
 24{
 25	struct xfrm_offload *xo = xfrm_offload(skb);
 26
 27	skb_reset_mac_len(skb);
 28	if (xo->flags & XFRM_GSO_SEGMENT)
 29		skb->transport_header -= x->props.header_len;
 30
 31	pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len);
 32}
 33
 34static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
 35				    unsigned int hsize)
 36
 37{
 38	struct xfrm_offload *xo = xfrm_offload(skb);
 39
 40	if (xo->flags & XFRM_GSO_SEGMENT)
 41		skb->transport_header = skb->network_header + hsize;
 42
 43	skb_reset_mac_len(skb);
 44	pskb_pull(skb, skb->mac_len + x->props.header_len);
 45}
 46
 47static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
 48				  unsigned int hsize)
 49{
 50	struct xfrm_offload *xo = xfrm_offload(skb);
 51	int phlen = 0;
 52
 53	if (xo->flags & XFRM_GSO_SEGMENT)
 54		skb->transport_header = skb->network_header + hsize;
 55
 56	skb_reset_mac_len(skb);
 57	if (x->sel.family != AF_INET6) {
 58		phlen = IPV4_BEET_PHMAXLEN;
 59		if (x->outer_mode.family == AF_INET6)
 60			phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
 61	}
 62
 63	pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
 64}
 65
 66/* Adjust pointers into the packet when IPsec is done at layer2 */
 67static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
 68{
 69	switch (x->outer_mode.encap) {
 70	case XFRM_MODE_TUNNEL:
 71		if (x->outer_mode.family == AF_INET)
 72			return __xfrm_mode_tunnel_prep(x, skb,
 73						       sizeof(struct iphdr));
 74		if (x->outer_mode.family == AF_INET6)
 75			return __xfrm_mode_tunnel_prep(x, skb,
 76						       sizeof(struct ipv6hdr));
 77		break;
 78	case XFRM_MODE_TRANSPORT:
 79		if (x->outer_mode.family == AF_INET)
 80			return __xfrm_transport_prep(x, skb,
 81						     sizeof(struct iphdr));
 82		if (x->outer_mode.family == AF_INET6)
 83			return __xfrm_transport_prep(x, skb,
 84						     sizeof(struct ipv6hdr));
 85		break;
 86	case XFRM_MODE_BEET:
 87		if (x->outer_mode.family == AF_INET)
 88			return __xfrm_mode_beet_prep(x, skb,
 89						     sizeof(struct iphdr));
 90		if (x->outer_mode.family == AF_INET6)
 91			return __xfrm_mode_beet_prep(x, skb,
 92						     sizeof(struct ipv6hdr));
 93		break;
 94	case XFRM_MODE_ROUTEOPTIMIZATION:
 95	case XFRM_MODE_IN_TRIGGER:
 96		break;
 97	}
 98}
 99
100struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
101{
102	int err;
103	unsigned long flags;
104	struct xfrm_state *x;
 
105	struct softnet_data *sd;
106	struct sk_buff *skb2, *nskb, *pskb = NULL;
107	netdev_features_t esp_features = features;
108	struct xfrm_offload *xo = xfrm_offload(skb);
109	struct net_device *dev = skb->dev;
110	struct sec_path *sp;
111
112	if (!xo || (xo->flags & XFRM_XMIT))
113		return skb;
114
115	if (!(features & NETIF_F_HW_ESP))
116		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
117
118	sp = skb_sec_path(skb);
119	x = sp->xvec[sp->len - 1];
120	if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
121		return skb;
122
123	/* This skb was already validated on the upper/virtual dev */
124	if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
125		return skb;
126
127	local_irq_save(flags);
128	sd = this_cpu_ptr(&softnet_data);
129	err = !skb_queue_empty(&sd->xfrm_backlog);
130	local_irq_restore(flags);
131
132	if (err) {
133		*again = true;
134		return skb;
135	}
136
137	xo->flags |= XFRM_XMIT;
138
139	if (skb_is_gso(skb) && unlikely(x->xso.dev != dev)) {
140		struct sk_buff *segs;
141
142		/* Packet got rerouted, fixup features and segment it. */
143		esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP);
144
145		segs = skb_gso_segment(skb, esp_features);
146		if (IS_ERR(segs)) {
147			kfree_skb(skb);
148			atomic_long_inc(&dev->tx_dropped);
149			return NULL;
150		} else {
151			consume_skb(skb);
152			skb = segs;
 
 
 
 
 
153		}
154	}
155
156	if (!skb->next) {
157		esp_features |= skb->dev->gso_partial_features;
158		xfrm_outer_mode_prep(x, skb);
159
160		xo->flags |= XFRM_DEV_RESUME;
161
162		err = x->type_offload->xmit(x, skb, esp_features);
163		if (err) {
164			if (err == -EINPROGRESS)
165				return NULL;
166
167			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
168			kfree_skb(skb);
169			return NULL;
170		}
171
172		skb_push(skb, skb->data - skb_mac_header(skb));
173
174		return skb;
175	}
176
177	skb_list_walk_safe(skb, skb2, nskb) {
178		esp_features |= skb->dev->gso_partial_features;
179		skb_mark_not_on_list(skb2);
 
 
180
181		xo = xfrm_offload(skb2);
182		xo->flags |= XFRM_DEV_RESUME;
183
184		xfrm_outer_mode_prep(x, skb2);
185
186		err = x->type_offload->xmit(x, skb2, esp_features);
187		if (!err) {
188			skb2->next = nskb;
189		} else if (err != -EINPROGRESS) {
190			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
191			skb2->next = nskb;
192			kfree_skb_list(skb2);
193			return NULL;
194		} else {
195			if (skb == skb2)
196				skb = nskb;
197			else
198				pskb->next = nskb;
199
200			continue;
 
 
 
201		}
202
203		skb_push(skb2, skb2->data - skb_mac_header(skb2));
204		pskb = skb2;
205	}
 
 
206
207	return skb;
208}
209EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
210
211int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
212		       struct xfrm_user_offload *xuo)
213{
214	int err;
215	struct dst_entry *dst;
216	struct net_device *dev;
217	struct xfrm_state_offload *xso = &x->xso;
218	xfrm_address_t *saddr;
219	xfrm_address_t *daddr;
220
221	if (!x->type_offload)
222		return -EINVAL;
223
224	/* We don't yet support UDP encapsulation and TFC padding. */
225	if (x->encap || x->tfcpad)
226		return -EINVAL;
227
228	dev = dev_get_by_index(net, xuo->ifindex);
229	if (!dev) {
230		if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
231			saddr = &x->props.saddr;
232			daddr = &x->id.daddr;
233		} else {
234			saddr = &x->id.daddr;
235			daddr = &x->props.saddr;
236		}
237
238		dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr,
239					x->props.family,
240					xfrm_smark_get(0, x));
241		if (IS_ERR(dst))
242			return 0;
243
244		dev = dst->dev;
245
246		dev_hold(dev);
247		dst_release(dst);
248	}
249
250	if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
251		xso->dev = NULL;
252		dev_put(dev);
253		return 0;
254	}
255
256	if (x->props.flags & XFRM_STATE_ESN &&
257	    !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
258		xso->dev = NULL;
259		dev_put(dev);
260		return -EINVAL;
261	}
262
263	xso->dev = dev;
264	xso->real_dev = dev;
265	xso->num_exthdrs = 1;
266	xso->flags = xuo->flags;
267
268	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
269	if (err) {
270		xso->num_exthdrs = 0;
271		xso->flags = 0;
272		xso->dev = NULL;
273		dev_put(dev);
274
275		if (err != -EOPNOTSUPP)
276			return err;
277	}
278
279	return 0;
280}
281EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
282
283bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
284{
285	int mtu;
286	struct dst_entry *dst = skb_dst(skb);
287	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
288	struct net_device *dev = x->xso.dev;
289
290	if (!x->type_offload || x->encap)
291		return false;
292
293	if ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
294	    (!xdst->child->xfrm)) {
295		mtu = xfrm_state_mtu(x, xdst->child_mtu_cached);
 
296		if (skb->len <= mtu)
297			goto ok;
298
299		if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
300			goto ok;
301	}
302
303	return false;
304
305ok:
306	if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
307		return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
308
309	return true;
310}
311EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
312
313void xfrm_dev_resume(struct sk_buff *skb)
314{
315	struct net_device *dev = skb->dev;
316	int ret = NETDEV_TX_BUSY;
317	struct netdev_queue *txq;
318	struct softnet_data *sd;
319	unsigned long flags;
320
321	rcu_read_lock();
322	txq = netdev_core_pick_tx(dev, skb, NULL);
323
324	HARD_TX_LOCK(dev, txq, smp_processor_id());
325	if (!netif_xmit_frozen_or_stopped(txq))
326		skb = dev_hard_start_xmit(skb, dev, txq, &ret);
327	HARD_TX_UNLOCK(dev, txq);
328
329	if (!dev_xmit_complete(ret)) {
330		local_irq_save(flags);
331		sd = this_cpu_ptr(&softnet_data);
332		skb_queue_tail(&sd->xfrm_backlog, skb);
333		raise_softirq_irqoff(NET_TX_SOFTIRQ);
334		local_irq_restore(flags);
335	}
336	rcu_read_unlock();
337}
338EXPORT_SYMBOL_GPL(xfrm_dev_resume);
339
340void xfrm_dev_backlog(struct softnet_data *sd)
341{
342	struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
343	struct sk_buff_head list;
344	struct sk_buff *skb;
345
346	if (skb_queue_empty(xfrm_backlog))
347		return;
348
349	__skb_queue_head_init(&list);
350
351	spin_lock(&xfrm_backlog->lock);
352	skb_queue_splice_init(xfrm_backlog, &list);
353	spin_unlock(&xfrm_backlog->lock);
354
355	while (!skb_queue_empty(&list)) {
356		skb = __skb_dequeue(&list);
357		xfrm_dev_resume(skb);
358	}
359
360}
361#endif
362
363static int xfrm_api_check(struct net_device *dev)
364{
365#ifdef CONFIG_XFRM_OFFLOAD
366	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
367	    !(dev->features & NETIF_F_HW_ESP))
368		return NOTIFY_BAD;
369
370	if ((dev->features & NETIF_F_HW_ESP) &&
371	    (!(dev->xfrmdev_ops &&
372	       dev->xfrmdev_ops->xdo_dev_state_add &&
373	       dev->xfrmdev_ops->xdo_dev_state_delete)))
374		return NOTIFY_BAD;
375#else
376	if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
377		return NOTIFY_BAD;
378#endif
379
380	return NOTIFY_DONE;
381}
382
383static int xfrm_dev_register(struct net_device *dev)
384{
385	return xfrm_api_check(dev);
386}
387
 
 
 
 
 
 
388static int xfrm_dev_feat_change(struct net_device *dev)
389{
390	return xfrm_api_check(dev);
391}
392
393static int xfrm_dev_down(struct net_device *dev)
394{
395	if (dev->features & NETIF_F_HW_ESP)
396		xfrm_dev_state_flush(dev_net(dev), dev, true);
397
 
398	return NOTIFY_DONE;
399}
400
401static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
402{
403	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
404
405	switch (event) {
406	case NETDEV_REGISTER:
407		return xfrm_dev_register(dev);
408
 
 
 
409	case NETDEV_FEAT_CHANGE:
410		return xfrm_dev_feat_change(dev);
411
412	case NETDEV_DOWN:
413	case NETDEV_UNREGISTER:
414		return xfrm_dev_down(dev);
415	}
416	return NOTIFY_DONE;
417}
418
419static struct notifier_block xfrm_dev_notifier = {
420	.notifier_call	= xfrm_dev_event,
421};
422
423void __init xfrm_dev_init(void)
424{
425	register_netdevice_notifier(&xfrm_dev_notifier);
426}
v4.17
 
  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
 25#ifdef CONFIG_XFRM_OFFLOAD
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 26struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
 27{
 28	int err;
 29	unsigned long flags;
 30	struct xfrm_state *x;
 31	struct sk_buff *skb2;
 32	struct softnet_data *sd;
 
 33	netdev_features_t esp_features = features;
 34	struct xfrm_offload *xo = xfrm_offload(skb);
 
 
 35
 36	if (!xo)
 37		return skb;
 38
 39	if (!(features & NETIF_F_HW_ESP))
 40		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
 41
 42	x = skb->sp->xvec[skb->sp->len - 1];
 
 43	if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
 44		return skb;
 45
 
 
 
 
 46	local_irq_save(flags);
 47	sd = this_cpu_ptr(&softnet_data);
 48	err = !skb_queue_empty(&sd->xfrm_backlog);
 49	local_irq_restore(flags);
 50
 51	if (err) {
 52		*again = true;
 53		return skb;
 54	}
 55
 56	if (skb_is_gso(skb)) {
 57		struct net_device *dev = skb->dev;
 
 
 58
 59		if (unlikely(!x->xso.offload_handle || (x->xso.dev != dev))) {
 60			struct sk_buff *segs;
 61
 62			/* Packet got rerouted, fixup features and segment it. */
 63			esp_features = esp_features & ~(NETIF_F_HW_ESP
 64							| NETIF_F_GSO_ESP);
 65
 66			segs = skb_gso_segment(skb, esp_features);
 67			if (IS_ERR(segs)) {
 68				kfree_skb(skb);
 69				atomic_long_inc(&dev->tx_dropped);
 70				return NULL;
 71			} else {
 72				consume_skb(skb);
 73				skb = segs;
 74			}
 75		}
 76	}
 77
 78	if (!skb->next) {
 79		x->outer_mode->xmit(x, skb);
 
 80
 81		xo->flags |= XFRM_DEV_RESUME;
 82
 83		err = x->type_offload->xmit(x, skb, esp_features);
 84		if (err) {
 85			if (err == -EINPROGRESS)
 86				return NULL;
 87
 88			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
 89			kfree_skb(skb);
 90			return NULL;
 91		}
 92
 93		skb_push(skb, skb->data - skb_mac_header(skb));
 94
 95		return skb;
 96	}
 97
 98	skb2 = skb;
 99
100	do {
101		struct sk_buff *nskb = skb2->next;
102		skb2->next = NULL;
103
104		xo = xfrm_offload(skb2);
105		xo->flags |= XFRM_DEV_RESUME;
106
107		x->outer_mode->xmit(x, skb2);
108
109		err = x->type_offload->xmit(x, skb2, esp_features);
110		if (!err) {
111			skb2->next = nskb;
112		} else if (err != -EINPROGRESS) {
113			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
114			skb2->next = nskb;
115			kfree_skb_list(skb2);
116			return NULL;
117		} else {
118			if (skb == skb2)
119				skb = nskb;
 
 
120
121			if (!skb)
122				return NULL;
123
124			goto skip_push;
125		}
126
127		skb_push(skb2, skb2->data - skb_mac_header(skb2));
128
129skip_push:
130		skb2 = nskb;
131	} while (skb2);
132
133	return skb;
134}
135EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
136
137int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
138		       struct xfrm_user_offload *xuo)
139{
140	int err;
141	struct dst_entry *dst;
142	struct net_device *dev;
143	struct xfrm_state_offload *xso = &x->xso;
144	xfrm_address_t *saddr;
145	xfrm_address_t *daddr;
146
147	if (!x->type_offload)
148		return -EINVAL;
149
150	/* We don't yet support UDP encapsulation and TFC padding. */
151	if (x->encap || x->tfcpad)
152		return -EINVAL;
153
154	dev = dev_get_by_index(net, xuo->ifindex);
155	if (!dev) {
156		if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
157			saddr = &x->props.saddr;
158			daddr = &x->id.daddr;
159		} else {
160			saddr = &x->id.daddr;
161			daddr = &x->props.saddr;
162		}
163
164		dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr,
165					x->props.family, x->props.output_mark);
 
166		if (IS_ERR(dst))
167			return 0;
168
169		dev = dst->dev;
170
171		dev_hold(dev);
172		dst_release(dst);
173	}
174
175	if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
176		xso->dev = NULL;
177		dev_put(dev);
178		return 0;
179	}
180
181	if (x->props.flags & XFRM_STATE_ESN &&
182	    !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
183		xso->dev = NULL;
184		dev_put(dev);
185		return -EINVAL;
186	}
187
188	xso->dev = dev;
 
189	xso->num_exthdrs = 1;
190	xso->flags = xuo->flags;
191
192	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
193	if (err) {
 
 
194		xso->dev = NULL;
195		dev_put(dev);
196		return err;
 
 
197	}
198
199	return 0;
200}
201EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
202
203bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
204{
205	int mtu;
206	struct dst_entry *dst = skb_dst(skb);
207	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
208	struct net_device *dev = x->xso.dev;
209
210	if (!x->type_offload || x->encap)
211		return false;
212
213	if ((!dev || (x->xso.offload_handle && (dev == xfrm_dst_path(dst)->dev))) &&
214	     (!xdst->child->xfrm && x->type->get_mtu)) {
215		mtu = x->type->get_mtu(x, xdst->child_mtu_cached);
216
217		if (skb->len <= mtu)
218			goto ok;
219
220		if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
221			goto ok;
222	}
223
224	return false;
225
226ok:
227	if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
228		return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
229
230	return true;
231}
232EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
233
234void xfrm_dev_resume(struct sk_buff *skb)
235{
236	struct net_device *dev = skb->dev;
237	int ret = NETDEV_TX_BUSY;
238	struct netdev_queue *txq;
239	struct softnet_data *sd;
240	unsigned long flags;
241
242	rcu_read_lock();
243	txq = netdev_pick_tx(dev, skb, NULL);
244
245	HARD_TX_LOCK(dev, txq, smp_processor_id());
246	if (!netif_xmit_frozen_or_stopped(txq))
247		skb = dev_hard_start_xmit(skb, dev, txq, &ret);
248	HARD_TX_UNLOCK(dev, txq);
249
250	if (!dev_xmit_complete(ret)) {
251		local_irq_save(flags);
252		sd = this_cpu_ptr(&softnet_data);
253		skb_queue_tail(&sd->xfrm_backlog, skb);
254		raise_softirq_irqoff(NET_TX_SOFTIRQ);
255		local_irq_restore(flags);
256	}
257	rcu_read_unlock();
258}
259EXPORT_SYMBOL_GPL(xfrm_dev_resume);
260
261void xfrm_dev_backlog(struct softnet_data *sd)
262{
263	struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
264	struct sk_buff_head list;
265	struct sk_buff *skb;
266
267	if (skb_queue_empty(xfrm_backlog))
268		return;
269
270	__skb_queue_head_init(&list);
271
272	spin_lock(&xfrm_backlog->lock);
273	skb_queue_splice_init(xfrm_backlog, &list);
274	spin_unlock(&xfrm_backlog->lock);
275
276	while (!skb_queue_empty(&list)) {
277		skb = __skb_dequeue(&list);
278		xfrm_dev_resume(skb);
279	}
280
281}
282#endif
283
284static int xfrm_api_check(struct net_device *dev)
285{
286#ifdef CONFIG_XFRM_OFFLOAD
287	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
288	    !(dev->features & NETIF_F_HW_ESP))
289		return NOTIFY_BAD;
290
291	if ((dev->features & NETIF_F_HW_ESP) &&
292	    (!(dev->xfrmdev_ops &&
293	       dev->xfrmdev_ops->xdo_dev_state_add &&
294	       dev->xfrmdev_ops->xdo_dev_state_delete)))
295		return NOTIFY_BAD;
296#else
297	if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
298		return NOTIFY_BAD;
299#endif
300
301	return NOTIFY_DONE;
302}
303
304static int xfrm_dev_register(struct net_device *dev)
305{
306	return xfrm_api_check(dev);
307}
308
309static int xfrm_dev_unregister(struct net_device *dev)
310{
311	xfrm_policy_cache_flush();
312	return NOTIFY_DONE;
313}
314
315static int xfrm_dev_feat_change(struct net_device *dev)
316{
317	return xfrm_api_check(dev);
318}
319
320static int xfrm_dev_down(struct net_device *dev)
321{
322	if (dev->features & NETIF_F_HW_ESP)
323		xfrm_dev_state_flush(dev_net(dev), dev, true);
324
325	xfrm_policy_cache_flush();
326	return NOTIFY_DONE;
327}
328
329static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
330{
331	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
332
333	switch (event) {
334	case NETDEV_REGISTER:
335		return xfrm_dev_register(dev);
336
337	case NETDEV_UNREGISTER:
338		return xfrm_dev_unregister(dev);
339
340	case NETDEV_FEAT_CHANGE:
341		return xfrm_dev_feat_change(dev);
342
343	case NETDEV_DOWN:
 
344		return xfrm_dev_down(dev);
345	}
346	return NOTIFY_DONE;
347}
348
349static struct notifier_block xfrm_dev_notifier = {
350	.notifier_call	= xfrm_dev_event,
351};
352
353void __init xfrm_dev_init(void)
354{
355	register_netdevice_notifier(&xfrm_dev_notifier);
356}