1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * IPV6 GSO/GRO offload support
4 * Linux INET implementation
5 *
6 * Copyright (C) 2016 secunet Security Networks AG
7 * Author: Steffen Klassert <steffen.klassert@secunet.com>
8 *
9 * ESP GRO support
10 */
11
12 #include <linux/skbuff.h>
13 #include <linux/init.h>
14 #include <net/protocol.h>
15 #include <crypto/aead.h>
16 #include <crypto/authenc.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <net/gro.h>
20 #include <net/gso.h>
21 #include <net/ip.h>
22 #include <net/xfrm.h>
23 #include <net/esp.h>
24 #include <linux/scatterlist.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <net/ip6_route.h>
29 #include <net/ipv6.h>
30 #include <linux/icmpv6.h>
31
esp6_nexthdr_esp_offset(struct ipv6hdr * ipv6_hdr,int nhlen)32 static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen)
33 {
34 int off = sizeof(struct ipv6hdr);
35 struct ipv6_opt_hdr *exthdr;
36
37 /* ESP or ESPINUDP */
38 if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP ||
39 ipv6_hdr->nexthdr == NEXTHDR_UDP))
40 return offsetof(struct ipv6hdr, nexthdr);
41
42 while (off < nhlen) {
43 exthdr = (void *)ipv6_hdr + off;
44 if (exthdr->nexthdr == NEXTHDR_ESP)
45 return off;
46
47 off += ipv6_optlen(exthdr);
48 }
49
50 return 0;
51 }
52
esp6_gro_receive(struct list_head * head,struct sk_buff * skb)53 static struct sk_buff *esp6_gro_receive(struct list_head *head,
54 struct sk_buff *skb)
55 {
56 int offset = skb_gro_offset(skb);
57 struct xfrm_offload *xo;
58 struct xfrm_state *x;
59 int encap_type = 0;
60 __be32 seq;
61 __be32 spi;
62 int nhoff;
63
64 if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
65 encap_type = UDP_ENCAP_ESPINUDP;
66
67 if (!pskb_pull(skb, offset))
68 return NULL;
69
70 if (xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq) != 0)
71 goto out;
72
73 xo = xfrm_offload(skb);
74 if (!xo || !(xo->flags & CRYPTO_DONE)) {
75 struct sec_path *sp = secpath_set(skb);
76
77 if (!sp)
78 goto out;
79
80 if (sp->len == XFRM_MAX_DEPTH)
81 goto out_reset;
82
83 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
84 (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
85 spi, IPPROTO_ESP, AF_INET6);
86
87 if (unlikely(x && x->dir && x->dir != XFRM_SA_DIR_IN)) {
88 /* non-offload path will record the error and audit log */
89 xfrm_state_put(x);
90 x = NULL;
91 }
92
93 if (!x)
94 goto out_reset;
95
96 skb->mark = xfrm_smark_get(skb->mark, x);
97
98 sp->xvec[sp->len++] = x;
99 sp->olen++;
100
101 xo = xfrm_offload(skb);
102 if (!xo)
103 goto out_reset;
104 }
105
106 xo->flags |= XFRM_GRO;
107
108 nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset);
109 if (!nhoff)
110 goto out;
111
112 IP6CB(skb)->nhoff = nhoff;
113 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
114 XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
115 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
116 XFRM_SPI_SKB_CB(skb)->seq = seq;
117
118 /* We don't need to handle errors from xfrm_input, it does all
119 * the error handling and frees the resources on error. */
120 xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
121
122 return ERR_PTR(-EINPROGRESS);
123 out_reset:
124 secpath_reset(skb);
125 out:
126 skb_push(skb, offset);
127 NAPI_GRO_CB(skb)->same_flow = 0;
128 NAPI_GRO_CB(skb)->flush = 1;
129
130 return NULL;
131 }
132
esp6_gso_encap(struct xfrm_state * x,struct sk_buff * skb)133 static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
134 {
135 struct ip_esp_hdr *esph;
136 struct ipv6hdr *iph = ipv6_hdr(skb);
137 struct xfrm_offload *xo = xfrm_offload(skb);
138 u8 proto = iph->nexthdr;
139
140 skb_push(skb, -skb_network_offset(skb));
141
142 if (x->outer_mode.encap == XFRM_MODE_TRANSPORT) {
143 __be16 frag;
144
145 ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, &frag);
146 }
147
148 esph = ip_esp_hdr(skb);
149 *skb_mac_header(skb) = IPPROTO_ESP;
150
151 esph->spi = x->id.spi;
152 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
153
154 xo->proto = proto;
155 }
156
xfrm6_tunnel_gso_segment(struct xfrm_state * x,struct sk_buff * skb,netdev_features_t features)157 static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
158 struct sk_buff *skb,
159 netdev_features_t features)
160 {
161 __be16 type = x->inner_mode.family == AF_INET ? htons(ETH_P_IP)
162 : htons(ETH_P_IPV6);
163
164 return skb_eth_gso_segment(skb, features, type);
165 }
166
xfrm6_transport_gso_segment(struct xfrm_state * x,struct sk_buff * skb,netdev_features_t features)167 static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
168 struct sk_buff *skb,
169 netdev_features_t features)
170 {
171 const struct net_offload *ops;
172 struct sk_buff *segs = ERR_PTR(-EINVAL);
173 struct xfrm_offload *xo = xfrm_offload(skb);
174
175 skb->transport_header += x->props.header_len;
176 ops = rcu_dereference(inet6_offloads[xo->proto]);
177 if (likely(ops && ops->callbacks.gso_segment))
178 segs = ops->callbacks.gso_segment(skb, features);
179
180 return segs;
181 }
182
xfrm6_beet_gso_segment(struct xfrm_state * x,struct sk_buff * skb,netdev_features_t features)183 static struct sk_buff *xfrm6_beet_gso_segment(struct xfrm_state *x,
184 struct sk_buff *skb,
185 netdev_features_t features)
186 {
187 struct xfrm_offload *xo = xfrm_offload(skb);
188 struct sk_buff *segs = ERR_PTR(-EINVAL);
189 const struct net_offload *ops;
190 u8 proto = xo->proto;
191
192 skb->transport_header += x->props.header_len;
193
194 if (x->sel.family != AF_INET6) {
195 skb->transport_header -=
196 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
197
198 if (proto == IPPROTO_BEETPH) {
199 struct ip_beet_phdr *ph =
200 (struct ip_beet_phdr *)skb->data;
201
202 skb->transport_header += ph->hdrlen * 8;
203 proto = ph->nexthdr;
204 } else {
205 skb->transport_header -= IPV4_BEET_PHMAXLEN;
206 }
207
208 if (proto == IPPROTO_TCP)
209 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
210 } else {
211 __be16 frag;
212
213 skb->transport_header +=
214 ipv6_skip_exthdr(skb, 0, &proto, &frag);
215 }
216
217 if (proto == IPPROTO_IPIP)
218 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
219
220 __skb_pull(skb, skb_transport_offset(skb));
221 ops = rcu_dereference(inet6_offloads[proto]);
222 if (likely(ops && ops->callbacks.gso_segment))
223 segs = ops->callbacks.gso_segment(skb, features);
224
225 return segs;
226 }
227
xfrm6_outer_mode_gso_segment(struct xfrm_state * x,struct sk_buff * skb,netdev_features_t features)228 static struct sk_buff *xfrm6_outer_mode_gso_segment(struct xfrm_state *x,
229 struct sk_buff *skb,
230 netdev_features_t features)
231 {
232 switch (x->outer_mode.encap) {
233 case XFRM_MODE_TUNNEL:
234 return xfrm6_tunnel_gso_segment(x, skb, features);
235 case XFRM_MODE_TRANSPORT:
236 return xfrm6_transport_gso_segment(x, skb, features);
237 case XFRM_MODE_BEET:
238 return xfrm6_beet_gso_segment(x, skb, features);
239 }
240
241 return ERR_PTR(-EOPNOTSUPP);
242 }
243
esp6_gso_segment(struct sk_buff * skb,netdev_features_t features)244 static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
245 netdev_features_t features)
246 {
247 struct xfrm_state *x;
248 struct ip_esp_hdr *esph;
249 struct crypto_aead *aead;
250 netdev_features_t esp_features = features;
251 struct xfrm_offload *xo = xfrm_offload(skb);
252 struct sec_path *sp;
253
254 if (!xo)
255 return ERR_PTR(-EINVAL);
256
257 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
258 return ERR_PTR(-EINVAL);
259
260 sp = skb_sec_path(skb);
261 x = sp->xvec[sp->len - 1];
262 aead = x->data;
263 esph = ip_esp_hdr(skb);
264
265 if (esph->spi != x->id.spi)
266 return ERR_PTR(-EINVAL);
267
268 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
269 return ERR_PTR(-EINVAL);
270
271 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
272
273 skb->encap_hdr_csum = 1;
274
275 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev)
276 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK |
277 NETIF_F_SCTP_CRC);
278 else if (!(features & NETIF_F_HW_ESP_TX_CSUM))
279 esp_features = features & ~(NETIF_F_CSUM_MASK |
280 NETIF_F_SCTP_CRC);
281
282 xo->flags |= XFRM_GSO_SEGMENT;
283
284 return xfrm6_outer_mode_gso_segment(x, skb, esp_features);
285 }
286
esp6_input_tail(struct xfrm_state * x,struct sk_buff * skb)287 static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
288 {
289 struct crypto_aead *aead = x->data;
290 struct xfrm_offload *xo = xfrm_offload(skb);
291
292 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
293 return -EINVAL;
294
295 if (!(xo->flags & CRYPTO_DONE))
296 skb->ip_summed = CHECKSUM_NONE;
297
298 return esp6_input_done2(skb, 0);
299 }
300
esp6_xmit(struct xfrm_state * x,struct sk_buff * skb,netdev_features_t features)301 static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
302 {
303 int len;
304 int err;
305 int alen;
306 int blksize;
307 struct xfrm_offload *xo;
308 struct crypto_aead *aead;
309 struct esp_info esp;
310 bool hw_offload = true;
311 __u32 seq;
312
313 esp.inplace = true;
314
315 xo = xfrm_offload(skb);
316
317 if (!xo)
318 return -EINVAL;
319
320 if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) {
321 xo->flags |= CRYPTO_FALLBACK;
322 hw_offload = false;
323 }
324
325 esp.proto = xo->proto;
326
327 /* skb is pure payload to encrypt */
328
329 aead = x->data;
330 alen = crypto_aead_authsize(aead);
331
332 esp.tfclen = 0;
333 /* XXX: Add support for tfc padding here. */
334
335 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
336 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
337 esp.plen = esp.clen - skb->len - esp.tfclen;
338 esp.tailen = esp.tfclen + esp.plen + alen;
339
340 if (!hw_offload || !skb_is_gso(skb)) {
341 esp.nfrags = esp6_output_head(x, skb, &esp);
342 if (esp.nfrags < 0)
343 return esp.nfrags;
344 }
345
346 seq = xo->seq.low;
347
348 esp.esph = ip_esp_hdr(skb);
349 esp.esph->spi = x->id.spi;
350
351 skb_push(skb, -skb_network_offset(skb));
352
353 if (xo->flags & XFRM_GSO_SEGMENT) {
354 esp.esph->seq_no = htonl(seq);
355
356 if (!skb_is_gso(skb))
357 xo->seq.low++;
358 else
359 xo->seq.low += skb_shinfo(skb)->gso_segs;
360 }
361
362 if (xo->seq.low < seq)
363 xo->seq.hi++;
364
365 esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
366
367 len = skb->len - sizeof(struct ipv6hdr);
368 if (len > IPV6_MAXPLEN)
369 len = 0;
370
371 ipv6_hdr(skb)->payload_len = htons(len);
372
373 if (hw_offload) {
374 if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
375 return -ENOMEM;
376
377 xo = xfrm_offload(skb);
378 if (!xo)
379 return -EINVAL;
380
381 xo->flags |= XFRM_XMIT;
382 return 0;
383 }
384
385 err = esp6_output_tail(x, skb, &esp);
386 if (err)
387 return err;
388
389 secpath_reset(skb);
390
391 if (skb_needs_linearize(skb, skb->dev->features) &&
392 __skb_linearize(skb))
393 return -ENOMEM;
394 return 0;
395 }
396
397 static const struct net_offload esp6_offload = {
398 .callbacks = {
399 .gro_receive = esp6_gro_receive,
400 .gso_segment = esp6_gso_segment,
401 },
402 };
403
404 static const struct xfrm_type_offload esp6_type_offload = {
405 .owner = THIS_MODULE,
406 .proto = IPPROTO_ESP,
407 .input_tail = esp6_input_tail,
408 .xmit = esp6_xmit,
409 .encap = esp6_gso_encap,
410 };
411
esp6_offload_init(void)412 static int __init esp6_offload_init(void)
413 {
414 if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) {
415 pr_info("%s: can't add xfrm type offload\n", __func__);
416 return -EAGAIN;
417 }
418
419 return inet6_add_offload(&esp6_offload, IPPROTO_ESP);
420 }
421
esp6_offload_exit(void)422 static void __exit esp6_offload_exit(void)
423 {
424 xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6);
425 inet6_del_offload(&esp6_offload, IPPROTO_ESP);
426 }
427
428 module_init(esp6_offload_init);
429 module_exit(esp6_offload_exit);
430 MODULE_LICENSE("GPL");
431 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
432 MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP);
433 MODULE_DESCRIPTION("IPV6 GSO/GRO offload support");
434