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