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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/gso.h>
19#include <net/xfrm.h>
20#include <linux/notifier.h>
21
22#ifdef CONFIG_XFRM_OFFLOAD
23static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb,
24 unsigned int hsize)
25{
26 struct xfrm_offload *xo = xfrm_offload(skb);
27
28 skb_reset_mac_len(skb);
29 if (xo->flags & XFRM_GSO_SEGMENT)
30 skb->transport_header -= x->props.header_len;
31
32 pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len);
33}
34
35static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
36 unsigned int hsize)
37
38{
39 struct xfrm_offload *xo = xfrm_offload(skb);
40
41 if (xo->flags & XFRM_GSO_SEGMENT)
42 skb->transport_header = skb->network_header + hsize;
43
44 skb_reset_mac_len(skb);
45 pskb_pull(skb, skb->mac_len + x->props.header_len);
46}
47
48static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
49 unsigned int hsize)
50{
51 struct xfrm_offload *xo = xfrm_offload(skb);
52 int phlen = 0;
53
54 if (xo->flags & XFRM_GSO_SEGMENT)
55 skb->transport_header = skb->network_header + hsize;
56
57 skb_reset_mac_len(skb);
58 if (x->sel.family != AF_INET6) {
59 phlen = IPV4_BEET_PHMAXLEN;
60 if (x->outer_mode.family == AF_INET6)
61 phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
62 }
63
64 pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
65}
66
67/* Adjust pointers into the packet when IPsec is done at layer2 */
68static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
69{
70 switch (x->outer_mode.encap) {
71 case XFRM_MODE_TUNNEL:
72 if (x->outer_mode.family == AF_INET)
73 return __xfrm_mode_tunnel_prep(x, skb,
74 sizeof(struct iphdr));
75 if (x->outer_mode.family == AF_INET6)
76 return __xfrm_mode_tunnel_prep(x, skb,
77 sizeof(struct ipv6hdr));
78 break;
79 case XFRM_MODE_TRANSPORT:
80 if (x->outer_mode.family == AF_INET)
81 return __xfrm_transport_prep(x, skb,
82 sizeof(struct iphdr));
83 if (x->outer_mode.family == AF_INET6)
84 return __xfrm_transport_prep(x, skb,
85 sizeof(struct ipv6hdr));
86 break;
87 case XFRM_MODE_BEET:
88 if (x->outer_mode.family == AF_INET)
89 return __xfrm_mode_beet_prep(x, skb,
90 sizeof(struct iphdr));
91 if (x->outer_mode.family == AF_INET6)
92 return __xfrm_mode_beet_prep(x, skb,
93 sizeof(struct ipv6hdr));
94 break;
95 case XFRM_MODE_ROUTEOPTIMIZATION:
96 case XFRM_MODE_IN_TRIGGER:
97 break;
98 }
99}
100
101static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb)
102{
103 struct xfrm_offload *xo = xfrm_offload(skb);
104 __u32 seq = xo->seq.low;
105
106 seq += skb_shinfo(skb)->gso_segs;
107 if (unlikely(seq < xo->seq.low))
108 return true;
109
110 return false;
111}
112
113struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
114{
115 int err;
116 unsigned long flags;
117 struct xfrm_state *x;
118 struct softnet_data *sd;
119 struct sk_buff *skb2, *nskb, *pskb = NULL;
120 netdev_features_t esp_features = features;
121 struct xfrm_offload *xo = xfrm_offload(skb);
122 struct net_device *dev = skb->dev;
123 struct sec_path *sp;
124
125 if (!xo || (xo->flags & XFRM_XMIT))
126 return skb;
127
128 if (!(features & NETIF_F_HW_ESP))
129 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
130
131 sp = skb_sec_path(skb);
132 x = sp->xvec[sp->len - 1];
133 if (xo->flags & XFRM_GRO || x->xso.dir == XFRM_DEV_OFFLOAD_IN)
134 return skb;
135
136 /* The packet was sent to HW IPsec packet offload engine,
137 * but to wrong device. Drop the packet, so it won't skip
138 * XFRM stack.
139 */
140 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET && x->xso.dev != dev) {
141 kfree_skb(skb);
142 dev_core_stats_tx_dropped_inc(dev);
143 return NULL;
144 }
145
146 /* This skb was already validated on the upper/virtual dev */
147 if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
148 return skb;
149
150 local_irq_save(flags);
151 sd = this_cpu_ptr(&softnet_data);
152 err = !skb_queue_empty(&sd->xfrm_backlog);
153 local_irq_restore(flags);
154
155 if (err) {
156 *again = true;
157 return skb;
158 }
159
160 if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) ||
161 unlikely(xmit_xfrm_check_overflow(skb)))) {
162 struct sk_buff *segs;
163
164 /* Packet got rerouted, fixup features and segment it. */
165 esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP);
166
167 segs = skb_gso_segment(skb, esp_features);
168 if (IS_ERR(segs)) {
169 kfree_skb(skb);
170 dev_core_stats_tx_dropped_inc(dev);
171 return NULL;
172 } else {
173 consume_skb(skb);
174 skb = segs;
175 }
176 }
177
178 if (!skb->next) {
179 esp_features |= skb->dev->gso_partial_features;
180 xfrm_outer_mode_prep(x, skb);
181
182 xo->flags |= XFRM_DEV_RESUME;
183
184 err = x->type_offload->xmit(x, skb, esp_features);
185 if (err) {
186 if (err == -EINPROGRESS)
187 return NULL;
188
189 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
190 kfree_skb(skb);
191 return NULL;
192 }
193
194 skb_push(skb, skb->data - skb_mac_header(skb));
195
196 return skb;
197 }
198
199 skb_list_walk_safe(skb, skb2, nskb) {
200 esp_features |= skb->dev->gso_partial_features;
201 skb_mark_not_on_list(skb2);
202
203 xo = xfrm_offload(skb2);
204 xo->flags |= XFRM_DEV_RESUME;
205
206 xfrm_outer_mode_prep(x, skb2);
207
208 err = x->type_offload->xmit(x, skb2, esp_features);
209 if (!err) {
210 skb2->next = nskb;
211 } else if (err != -EINPROGRESS) {
212 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
213 skb2->next = nskb;
214 kfree_skb_list(skb2);
215 return NULL;
216 } else {
217 if (skb == skb2)
218 skb = nskb;
219 else
220 pskb->next = nskb;
221
222 continue;
223 }
224
225 skb_push(skb2, skb2->data - skb_mac_header(skb2));
226 pskb = skb2;
227 }
228
229 return skb;
230}
231EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
232
233int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
234 struct xfrm_user_offload *xuo,
235 struct netlink_ext_ack *extack)
236{
237 int err;
238 struct dst_entry *dst;
239 struct net_device *dev;
240 struct xfrm_dev_offload *xso = &x->xso;
241 xfrm_address_t *saddr;
242 xfrm_address_t *daddr;
243 bool is_packet_offload;
244
245 if (!x->type_offload) {
246 NL_SET_ERR_MSG(extack, "Type doesn't support offload");
247 return -EINVAL;
248 }
249
250 if (xuo->flags &
251 ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND | XFRM_OFFLOAD_PACKET)) {
252 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
253 return -EINVAL;
254 }
255
256 if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) ||
257 (!(xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN)) {
258 NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction");
259 return -EINVAL;
260 }
261
262 is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET;
263
264 /* We don't yet support TFC padding. */
265 if (x->tfcpad) {
266 NL_SET_ERR_MSG(extack, "TFC padding can't be offloaded");
267 return -EINVAL;
268 }
269
270 dev = dev_get_by_index(net, xuo->ifindex);
271 if (!dev) {
272 struct xfrm_dst_lookup_params params;
273
274 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
275 saddr = &x->props.saddr;
276 daddr = &x->id.daddr;
277 } else {
278 saddr = &x->id.daddr;
279 daddr = &x->props.saddr;
280 }
281
282 memset(¶ms, 0, sizeof(params));
283 params.net = net;
284 params.saddr = saddr;
285 params.daddr = daddr;
286 params.mark = xfrm_smark_get(0, x);
287 dst = __xfrm_dst_lookup(x->props.family, ¶ms);
288 if (IS_ERR(dst))
289 return (is_packet_offload) ? -EINVAL : 0;
290
291 dev = dst->dev;
292
293 dev_hold(dev);
294 dst_release(dst);
295 }
296
297 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
298 xso->dev = NULL;
299 dev_put(dev);
300 return (is_packet_offload) ? -EINVAL : 0;
301 }
302
303 if (!is_packet_offload && x->props.flags & XFRM_STATE_ESN &&
304 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
305 NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN");
306 xso->dev = NULL;
307 dev_put(dev);
308 return -EINVAL;
309 }
310
311 xso->dev = dev;
312 netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC);
313 xso->real_dev = dev;
314
315 if (xuo->flags & XFRM_OFFLOAD_INBOUND)
316 xso->dir = XFRM_DEV_OFFLOAD_IN;
317 else
318 xso->dir = XFRM_DEV_OFFLOAD_OUT;
319
320 if (is_packet_offload)
321 xso->type = XFRM_DEV_OFFLOAD_PACKET;
322 else
323 xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
324
325 err = dev->xfrmdev_ops->xdo_dev_state_add(x, extack);
326 if (err) {
327 xso->dev = NULL;
328 xso->dir = 0;
329 xso->real_dev = NULL;
330 netdev_put(dev, &xso->dev_tracker);
331 xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
332
333 /* User explicitly requested packet offload mode and configured
334 * policy in addition to the XFRM state. So be civil to users,
335 * and return an error instead of taking fallback path.
336 */
337 if ((err != -EOPNOTSUPP && !is_packet_offload) || is_packet_offload) {
338 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state");
339 return err;
340 }
341 }
342
343 return 0;
344}
345EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
346
347int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp,
348 struct xfrm_user_offload *xuo, u8 dir,
349 struct netlink_ext_ack *extack)
350{
351 struct xfrm_dev_offload *xdo = &xp->xdo;
352 struct net_device *dev;
353 int err;
354
355 if (!xuo->flags || xuo->flags & ~XFRM_OFFLOAD_PACKET) {
356 /* We support only packet offload mode and it means
357 * that user must set XFRM_OFFLOAD_PACKET bit.
358 */
359 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
360 return -EINVAL;
361 }
362
363 dev = dev_get_by_index(net, xuo->ifindex);
364 if (!dev)
365 return -EINVAL;
366
367 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_policy_add) {
368 xdo->dev = NULL;
369 dev_put(dev);
370 NL_SET_ERR_MSG(extack, "Policy offload is not supported");
371 return -EINVAL;
372 }
373
374 xdo->dev = dev;
375 netdev_tracker_alloc(dev, &xdo->dev_tracker, GFP_ATOMIC);
376 xdo->real_dev = dev;
377 xdo->type = XFRM_DEV_OFFLOAD_PACKET;
378 switch (dir) {
379 case XFRM_POLICY_IN:
380 xdo->dir = XFRM_DEV_OFFLOAD_IN;
381 break;
382 case XFRM_POLICY_OUT:
383 xdo->dir = XFRM_DEV_OFFLOAD_OUT;
384 break;
385 case XFRM_POLICY_FWD:
386 xdo->dir = XFRM_DEV_OFFLOAD_FWD;
387 break;
388 default:
389 xdo->dev = NULL;
390 netdev_put(dev, &xdo->dev_tracker);
391 NL_SET_ERR_MSG(extack, "Unrecognized offload direction");
392 return -EINVAL;
393 }
394
395 err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack);
396 if (err) {
397 xdo->dev = NULL;
398 xdo->real_dev = NULL;
399 xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
400 xdo->dir = 0;
401 netdev_put(dev, &xdo->dev_tracker);
402 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy");
403 return err;
404 }
405
406 return 0;
407}
408EXPORT_SYMBOL_GPL(xfrm_dev_policy_add);
409
410bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
411{
412 int mtu;
413 struct dst_entry *dst = skb_dst(skb);
414 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
415 struct net_device *dev = x->xso.dev;
416
417 if (!x->type_offload ||
418 (x->xso.type == XFRM_DEV_OFFLOAD_UNSPECIFIED && x->encap))
419 return false;
420
421 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET ||
422 ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
423 !xdst->child->xfrm)) {
424 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached);
425 if (skb->len <= mtu)
426 goto ok;
427
428 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
429 goto ok;
430 }
431
432 return false;
433
434ok:
435 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
436 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
437
438 return true;
439}
440EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
441
442void xfrm_dev_resume(struct sk_buff *skb)
443{
444 struct net_device *dev = skb->dev;
445 int ret = NETDEV_TX_BUSY;
446 struct netdev_queue *txq;
447 struct softnet_data *sd;
448 unsigned long flags;
449
450 rcu_read_lock();
451 txq = netdev_core_pick_tx(dev, skb, NULL);
452
453 HARD_TX_LOCK(dev, txq, smp_processor_id());
454 if (!netif_xmit_frozen_or_stopped(txq))
455 skb = dev_hard_start_xmit(skb, dev, txq, &ret);
456 HARD_TX_UNLOCK(dev, txq);
457
458 if (!dev_xmit_complete(ret)) {
459 local_irq_save(flags);
460 sd = this_cpu_ptr(&softnet_data);
461 skb_queue_tail(&sd->xfrm_backlog, skb);
462 raise_softirq_irqoff(NET_TX_SOFTIRQ);
463 local_irq_restore(flags);
464 }
465 rcu_read_unlock();
466}
467EXPORT_SYMBOL_GPL(xfrm_dev_resume);
468
469void xfrm_dev_backlog(struct softnet_data *sd)
470{
471 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
472 struct sk_buff_head list;
473 struct sk_buff *skb;
474
475 if (skb_queue_empty(xfrm_backlog))
476 return;
477
478 __skb_queue_head_init(&list);
479
480 spin_lock(&xfrm_backlog->lock);
481 skb_queue_splice_init(xfrm_backlog, &list);
482 spin_unlock(&xfrm_backlog->lock);
483
484 while (!skb_queue_empty(&list)) {
485 skb = __skb_dequeue(&list);
486 xfrm_dev_resume(skb);
487 }
488
489}
490#endif
491
492static int xfrm_api_check(struct net_device *dev)
493{
494#ifdef CONFIG_XFRM_OFFLOAD
495 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
496 !(dev->features & NETIF_F_HW_ESP))
497 return NOTIFY_BAD;
498
499 if ((dev->features & NETIF_F_HW_ESP) &&
500 (!(dev->xfrmdev_ops &&
501 dev->xfrmdev_ops->xdo_dev_state_add &&
502 dev->xfrmdev_ops->xdo_dev_state_delete)))
503 return NOTIFY_BAD;
504#else
505 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
506 return NOTIFY_BAD;
507#endif
508
509 return NOTIFY_DONE;
510}
511
512static int xfrm_dev_down(struct net_device *dev)
513{
514 if (dev->features & NETIF_F_HW_ESP) {
515 xfrm_dev_state_flush(dev_net(dev), dev, true);
516 xfrm_dev_policy_flush(dev_net(dev), dev, true);
517 }
518
519 return NOTIFY_DONE;
520}
521
522static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
523{
524 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
525
526 switch (event) {
527 case NETDEV_REGISTER:
528 return xfrm_api_check(dev);
529
530 case NETDEV_FEAT_CHANGE:
531 return xfrm_api_check(dev);
532
533 case NETDEV_DOWN:
534 case NETDEV_UNREGISTER:
535 return xfrm_dev_down(dev);
536 }
537 return NOTIFY_DONE;
538}
539
540static struct notifier_block xfrm_dev_notifier = {
541 .notifier_call = xfrm_dev_event,
542};
543
544void __init xfrm_dev_init(void)
545{
546 register_netdevice_notifier(&xfrm_dev_notifier);
547}