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
__xfrm_transport_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)22 static 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
__xfrm_mode_tunnel_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)34 static 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
__xfrm_mode_beet_prep(struct xfrm_state * x,struct sk_buff * skb,unsigned int hsize)47 static 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 */
xfrm_outer_mode_prep(struct xfrm_state * x,struct sk_buff * skb)67 static 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
validate_xmit_xfrm(struct sk_buff * skb,netdev_features_t features,bool * again)100 struct 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 }
209 EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
210
xfrm_dev_state_add(struct net * net,struct xfrm_state * x,struct xfrm_user_offload * xuo)211 int 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 }
281 EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
282
xfrm_dev_offload_ok(struct sk_buff * skb,struct xfrm_state * x)283 bool 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
305 ok:
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 }
311 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
312
xfrm_dev_resume(struct sk_buff * skb)313 void 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 }
338 EXPORT_SYMBOL_GPL(xfrm_dev_resume);
339
xfrm_dev_backlog(struct softnet_data * sd)340 void 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
xfrm_api_check(struct net_device * dev)363 static 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
xfrm_dev_register(struct net_device * dev)383 static int xfrm_dev_register(struct net_device *dev)
384 {
385 return xfrm_api_check(dev);
386 }
387
xfrm_dev_feat_change(struct net_device * dev)388 static int xfrm_dev_feat_change(struct net_device *dev)
389 {
390 return xfrm_api_check(dev);
391 }
392
xfrm_dev_down(struct net_device * dev)393 static 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
xfrm_dev_event(struct notifier_block * this,unsigned long event,void * ptr)401 static 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
419 static struct notifier_block xfrm_dev_notifier = {
420 .notifier_call = xfrm_dev_event,
421 };
422
xfrm_dev_init(void)423 void __init xfrm_dev_init(void)
424 {
425 register_netdevice_notifier(&xfrm_dev_notifier);
426 }
427
