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 <[email protected]>
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
__xfrm_transport_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)23 static 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
__xfrm_mode_tunnel_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)35 static 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,
46 skb->mac_len + x->props.header_len - x->props.enc_hdr_len);
47 }
48
__xfrm_mode_beet_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)49 static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
50 unsigned int hsize)
51 {
52 struct xfrm_offload *xo = xfrm_offload(skb);
53 int phlen = 0;
54
55 if (xo->flags & XFRM_GSO_SEGMENT)
56 skb->transport_header = skb->network_header + hsize;
57
58 skb_reset_mac_len(skb);
59 if (x->sel.family != AF_INET6) {
60 phlen = IPV4_BEET_PHMAXLEN;
61 if (x->outer_mode.family == AF_INET6)
62 phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
63 }
64
65 pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
66 }
67
68 /* Adjust pointers into the packet when IPsec is done at layer2 */
xfrm_outer_mode_prep(struct xfrm_state * x,struct sk_buff * skb)69 static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
70 {
71 switch (x->outer_mode.encap) {
72 case XFRM_MODE_IPTFS:
73 case XFRM_MODE_TUNNEL:
74 if (x->outer_mode.family == AF_INET)
75 return __xfrm_mode_tunnel_prep(x, skb,
76 sizeof(struct iphdr));
77 if (x->outer_mode.family == AF_INET6)
78 return __xfrm_mode_tunnel_prep(x, skb,
79 sizeof(struct ipv6hdr));
80 break;
81 case XFRM_MODE_TRANSPORT:
82 if (x->outer_mode.family == AF_INET)
83 return __xfrm_transport_prep(x, skb,
84 sizeof(struct iphdr));
85 if (x->outer_mode.family == AF_INET6)
86 return __xfrm_transport_prep(x, skb,
87 sizeof(struct ipv6hdr));
88 break;
89 case XFRM_MODE_BEET:
90 if (x->outer_mode.family == AF_INET)
91 return __xfrm_mode_beet_prep(x, skb,
92 sizeof(struct iphdr));
93 if (x->outer_mode.family == AF_INET6)
94 return __xfrm_mode_beet_prep(x, skb,
95 sizeof(struct ipv6hdr));
96 break;
97 case XFRM_MODE_ROUTEOPTIMIZATION:
98 case XFRM_MODE_IN_TRIGGER:
99 break;
100 }
101 }
102
xmit_xfrm_check_overflow(struct sk_buff * skb)103 static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb)
104 {
105 struct xfrm_offload *xo = xfrm_offload(skb);
106 __u32 seq = xo->seq.low;
107
108 seq += skb_shinfo(skb)->gso_segs;
109 if (unlikely(seq < xo->seq.low))
110 return true;
111
112 return false;
113 }
114
validate_xmit_xfrm(struct sk_buff * skb,netdev_features_t features,bool * again)115 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
116 {
117 int err;
118 unsigned long flags;
119 struct xfrm_state *x;
120 struct softnet_data *sd;
121 struct sk_buff *skb2, *nskb, *pskb = NULL;
122 netdev_features_t esp_features = features;
123 struct xfrm_offload *xo = xfrm_offload(skb);
124 struct net_device *dev = skb->dev;
125 struct sec_path *sp;
126
127 if (!xo || (xo->flags & XFRM_XMIT))
128 return skb;
129
130 if (!(features & NETIF_F_HW_ESP))
131 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
132
133 sp = skb_sec_path(skb);
134 x = sp->xvec[sp->len - 1];
135 if (xo->flags & XFRM_GRO || x->xso.dir == XFRM_DEV_OFFLOAD_IN)
136 return skb;
137
138 /* The packet was sent to HW IPsec packet offload engine,
139 * but to wrong device. Drop the packet, so it won't skip
140 * XFRM stack.
141 */
142 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET && x->xso.dev != dev) {
143 kfree_skb(skb);
144 dev_core_stats_tx_dropped_inc(dev);
145 return NULL;
146 }
147
148 /* This skb was already validated on the upper/virtual dev */
149 if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
150 return skb;
151
152 local_irq_save(flags);
153 sd = this_cpu_ptr(&softnet_data);
154 err = !skb_queue_empty(&sd->xfrm_backlog);
155 local_irq_restore(flags);
156
157 if (err) {
158 *again = true;
159 return skb;
160 }
161
162 if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) ||
163 unlikely(xmit_xfrm_check_overflow(skb)))) {
164 struct sk_buff *segs;
165
166 /* Packet got rerouted, fixup features and segment it. */
167 esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP);
168
169 segs = skb_gso_segment(skb, esp_features);
170 if (IS_ERR(segs)) {
171 kfree_skb(skb);
172 dev_core_stats_tx_dropped_inc(dev);
173 return NULL;
174 } else {
175 consume_skb(skb);
176 skb = segs;
177 }
178 }
179
180 if (!skb->next) {
181 esp_features |= skb->dev->gso_partial_features;
182 xfrm_outer_mode_prep(x, skb);
183
184 xo->flags |= XFRM_DEV_RESUME;
185
186 err = x->type_offload->xmit(x, skb, esp_features);
187 if (err) {
188 if (err == -EINPROGRESS)
189 return NULL;
190
191 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
192 kfree_skb(skb);
193 return NULL;
194 }
195
196 skb_push(skb, skb->data - skb_mac_header(skb));
197
198 return skb;
199 }
200
201 skb_list_walk_safe(skb, skb2, nskb) {
202 esp_features |= skb->dev->gso_partial_features;
203 skb_mark_not_on_list(skb2);
204
205 xo = xfrm_offload(skb2);
206 xo->flags |= XFRM_DEV_RESUME;
207
208 xfrm_outer_mode_prep(x, skb2);
209
210 err = x->type_offload->xmit(x, skb2, esp_features);
211 if (!err) {
212 skb2->next = nskb;
213 } else if (err != -EINPROGRESS) {
214 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
215 skb2->next = nskb;
216 kfree_skb_list(skb2);
217 return NULL;
218 } else {
219 if (skb == skb2)
220 skb = nskb;
221 else
222 pskb->next = nskb;
223
224 continue;
225 }
226
227 skb_push(skb2, skb2->data - skb_mac_header(skb2));
228 pskb = skb2;
229 }
230
231 return skb;
232 }
233 EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
234
xfrm_dev_state_add(struct net * net,struct xfrm_state * x,struct xfrm_user_offload * xuo,struct netlink_ext_ack * extack)235 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
236 struct xfrm_user_offload *xuo,
237 struct netlink_ext_ack *extack)
238 {
239 int err;
240 struct dst_entry *dst;
241 struct net_device *dev;
242 struct xfrm_dev_offload *xso = &x->xso;
243 xfrm_address_t *saddr;
244 xfrm_address_t *daddr;
245 bool is_packet_offload;
246
247 if (xuo->flags &
248 ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND | XFRM_OFFLOAD_PACKET)) {
249 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
250 return -EINVAL;
251 }
252
253 if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) ||
254 (!(xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN)) {
255 NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction");
256 return -EINVAL;
257 }
258
259 is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET;
260
261 /* We don't yet support TFC padding. */
262 if (x->tfcpad) {
263 NL_SET_ERR_MSG(extack, "TFC padding can't be offloaded");
264 return -EINVAL;
265 }
266
267 dev = dev_get_by_index(net, xuo->ifindex);
268 if (!dev) {
269 struct xfrm_dst_lookup_params params;
270
271 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
272 saddr = &x->props.saddr;
273 daddr = &x->id.daddr;
274 } else {
275 saddr = &x->id.daddr;
276 daddr = &x->props.saddr;
277 }
278
279 memset(¶ms, 0, sizeof(params));
280 params.net = net;
281 params.saddr = saddr;
282 params.daddr = daddr;
283 params.mark = xfrm_smark_get(0, x);
284 dst = __xfrm_dst_lookup(x->props.family, ¶ms);
285 if (IS_ERR(dst))
286 return (is_packet_offload) ? -EINVAL : 0;
287
288 dev = dst->dev;
289
290 dev_hold(dev);
291 dst_release(dst);
292 }
293
294 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
295 xso->dev = NULL;
296 dev_put(dev);
297 return (is_packet_offload) ? -EINVAL : 0;
298 }
299
300 if (!is_packet_offload && x->props.flags & XFRM_STATE_ESN &&
301 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
302 NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN");
303 xso->dev = NULL;
304 dev_put(dev);
305 return -EINVAL;
306 }
307
308 xfrm_set_type_offload(x);
309 if (!x->type_offload) {
310 NL_SET_ERR_MSG(extack, "Type doesn't support offload");
311 dev_put(dev);
312 return -EINVAL;
313 }
314
315 xso->dev = dev;
316 netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC);
317 xso->real_dev = dev;
318
319 if (xuo->flags & XFRM_OFFLOAD_INBOUND)
320 xso->dir = XFRM_DEV_OFFLOAD_IN;
321 else
322 xso->dir = XFRM_DEV_OFFLOAD_OUT;
323
324 if (is_packet_offload)
325 xso->type = XFRM_DEV_OFFLOAD_PACKET;
326 else
327 xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
328
329 err = dev->xfrmdev_ops->xdo_dev_state_add(x, extack);
330 if (err) {
331 xso->dev = NULL;
332 xso->dir = 0;
333 xso->real_dev = NULL;
334 netdev_put(dev, &xso->dev_tracker);
335 xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
336
337 xfrm_unset_type_offload(x);
338 /* User explicitly requested packet offload mode and configured
339 * policy in addition to the XFRM state. So be civil to users,
340 * and return an error instead of taking fallback path.
341 */
342 if ((err != -EOPNOTSUPP && !is_packet_offload) || is_packet_offload) {
343 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state");
344 return err;
345 }
346 }
347
348 return 0;
349 }
350 EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
351
xfrm_dev_policy_add(struct net * net,struct xfrm_policy * xp,struct xfrm_user_offload * xuo,u8 dir,struct netlink_ext_ack * extack)352 int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp,
353 struct xfrm_user_offload *xuo, u8 dir,
354 struct netlink_ext_ack *extack)
355 {
356 struct xfrm_dev_offload *xdo = &xp->xdo;
357 struct net_device *dev;
358 int err;
359
360 if (!xuo->flags || xuo->flags & ~XFRM_OFFLOAD_PACKET) {
361 /* We support only packet offload mode and it means
362 * that user must set XFRM_OFFLOAD_PACKET bit.
363 */
364 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
365 return -EINVAL;
366 }
367
368 dev = dev_get_by_index(net, xuo->ifindex);
369 if (!dev)
370 return -EINVAL;
371
372 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_policy_add) {
373 xdo->dev = NULL;
374 dev_put(dev);
375 NL_SET_ERR_MSG(extack, "Policy offload is not supported");
376 return -EINVAL;
377 }
378
379 xdo->dev = dev;
380 netdev_tracker_alloc(dev, &xdo->dev_tracker, GFP_ATOMIC);
381 xdo->real_dev = dev;
382 xdo->type = XFRM_DEV_OFFLOAD_PACKET;
383 switch (dir) {
384 case XFRM_POLICY_IN:
385 xdo->dir = XFRM_DEV_OFFLOAD_IN;
386 break;
387 case XFRM_POLICY_OUT:
388 xdo->dir = XFRM_DEV_OFFLOAD_OUT;
389 break;
390 case XFRM_POLICY_FWD:
391 xdo->dir = XFRM_DEV_OFFLOAD_FWD;
392 break;
393 default:
394 xdo->dev = NULL;
395 netdev_put(dev, &xdo->dev_tracker);
396 NL_SET_ERR_MSG(extack, "Unrecognized offload direction");
397 return -EINVAL;
398 }
399
400 err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack);
401 if (err) {
402 xdo->dev = NULL;
403 xdo->real_dev = NULL;
404 xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
405 xdo->dir = 0;
406 netdev_put(dev, &xdo->dev_tracker);
407 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy");
408 return err;
409 }
410
411 return 0;
412 }
413 EXPORT_SYMBOL_GPL(xfrm_dev_policy_add);
414
xfrm_dev_offload_ok(struct sk_buff * skb,struct xfrm_state * x)415 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
416 {
417 int mtu;
418 struct dst_entry *dst = skb_dst(skb);
419 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
420 struct net_device *dev = x->xso.dev;
421
422 if (!x->type_offload ||
423 (x->xso.type == XFRM_DEV_OFFLOAD_UNSPECIFIED && x->encap))
424 return false;
425
426 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET ||
427 ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
428 !xdst->child->xfrm)) {
429 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached);
430 if (skb->len <= mtu)
431 goto ok;
432
433 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
434 goto ok;
435 }
436
437 return false;
438
439 ok:
440 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
441 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
442
443 return true;
444 }
445 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
446
xfrm_dev_resume(struct sk_buff * skb)447 void xfrm_dev_resume(struct sk_buff *skb)
448 {
449 struct net_device *dev = skb->dev;
450 int ret = NETDEV_TX_BUSY;
451 struct netdev_queue *txq;
452 struct softnet_data *sd;
453 unsigned long flags;
454
455 rcu_read_lock();
456 txq = netdev_core_pick_tx(dev, skb, NULL);
457
458 HARD_TX_LOCK(dev, txq, smp_processor_id());
459 if (!netif_xmit_frozen_or_stopped(txq))
460 skb = dev_hard_start_xmit(skb, dev, txq, &ret);
461 HARD_TX_UNLOCK(dev, txq);
462
463 if (!dev_xmit_complete(ret)) {
464 local_irq_save(flags);
465 sd = this_cpu_ptr(&softnet_data);
466 skb_queue_tail(&sd->xfrm_backlog, skb);
467 raise_softirq_irqoff(NET_TX_SOFTIRQ);
468 local_irq_restore(flags);
469 }
470 rcu_read_unlock();
471 }
472 EXPORT_SYMBOL_GPL(xfrm_dev_resume);
473
xfrm_dev_backlog(struct softnet_data * sd)474 void xfrm_dev_backlog(struct softnet_data *sd)
475 {
476 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
477 struct sk_buff_head list;
478 struct sk_buff *skb;
479
480 if (skb_queue_empty(xfrm_backlog))
481 return;
482
483 __skb_queue_head_init(&list);
484
485 spin_lock(&xfrm_backlog->lock);
486 skb_queue_splice_init(xfrm_backlog, &list);
487 spin_unlock(&xfrm_backlog->lock);
488
489 while (!skb_queue_empty(&list)) {
490 skb = __skb_dequeue(&list);
491 xfrm_dev_resume(skb);
492 }
493
494 }
495 #endif
496
xfrm_api_check(struct net_device * dev)497 static int xfrm_api_check(struct net_device *dev)
498 {
499 #ifdef CONFIG_XFRM_OFFLOAD
500 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
501 !(dev->features & NETIF_F_HW_ESP))
502 return NOTIFY_BAD;
503
504 if ((dev->features & NETIF_F_HW_ESP) &&
505 (!(dev->xfrmdev_ops &&
506 dev->xfrmdev_ops->xdo_dev_state_add &&
507 dev->xfrmdev_ops->xdo_dev_state_delete)))
508 return NOTIFY_BAD;
509 #else
510 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
511 return NOTIFY_BAD;
512 #endif
513
514 return NOTIFY_DONE;
515 }
516
xfrm_dev_down(struct net_device * dev)517 static int xfrm_dev_down(struct net_device *dev)
518 {
519 if (dev->features & NETIF_F_HW_ESP) {
520 xfrm_dev_state_flush(dev_net(dev), dev, true);
521 xfrm_dev_policy_flush(dev_net(dev), dev, true);
522 }
523
524 return NOTIFY_DONE;
525 }
526
xfrm_dev_event(struct notifier_block * this,unsigned long event,void * ptr)527 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
528 {
529 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
530
531 switch (event) {
532 case NETDEV_REGISTER:
533 return xfrm_api_check(dev);
534
535 case NETDEV_FEAT_CHANGE:
536 return xfrm_api_check(dev);
537
538 case NETDEV_DOWN:
539 case NETDEV_UNREGISTER:
540 return xfrm_dev_down(dev);
541 }
542 return NOTIFY_DONE;
543 }
544
545 static struct notifier_block xfrm_dev_notifier = {
546 .notifier_call = xfrm_dev_event,
547 };
548
xfrm_dev_init(void)549 void __init xfrm_dev_init(void)
550 {
551 register_netdevice_notifier(&xfrm_dev_notifier);
552 }
553