1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * IPV4 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/udp.h>
29
30static struct sk_buff *esp4_gro_receive(struct list_head *head,
31 struct sk_buff *skb)
32{
33 int offset = skb_gro_offset(skb);
34 struct xfrm_offload *xo;
35 struct xfrm_state *x;
36 int encap_type = 0;
37 __be32 seq;
38 __be32 spi;
39
40 if (!pskb_pull(skb, len: offset))
41 return NULL;
42
43 if (xfrm_parse_spi(skb, IPPROTO_ESP, spi: &spi, seq: &seq) != 0)
44 goto out;
45
46 xo = xfrm_offload(skb);
47 if (!xo || !(xo->flags & CRYPTO_DONE)) {
48 struct sec_path *sp = secpath_set(skb);
49
50 if (!sp)
51 goto out;
52
53 if (sp->len == XFRM_MAX_DEPTH)
54 goto out_reset;
55
56 x = xfrm_state_lookup(net: dev_net(dev: skb->dev), mark: skb->mark,
57 daddr: (xfrm_address_t *)&ip_hdr(skb)->daddr,
58 spi, IPPROTO_ESP, AF_INET);
59 if (!x)
60 goto out_reset;
61
62 skb->mark = xfrm_smark_get(mark: skb->mark, x);
63
64 sp->xvec[sp->len++] = x;
65 sp->olen++;
66
67 xo = xfrm_offload(skb);
68 if (!xo)
69 goto out_reset;
70 }
71
72 xo->flags |= XFRM_GRO;
73
74 if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
75 encap_type = UDP_ENCAP_ESPINUDP;
76
77 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
78 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
79 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
80 XFRM_SPI_SKB_CB(skb)->seq = seq;
81
82 /* We don't need to handle errors from xfrm_input, it does all
83 * the error handling and frees the resources on error. */
84 xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
85
86 return ERR_PTR(error: -EINPROGRESS);
87out_reset:
88 secpath_reset(skb);
89out:
90 skb_push(skb, len: offset);
91 NAPI_GRO_CB(skb)->same_flow = 0;
92 NAPI_GRO_CB(skb)->flush = 1;
93
94 return NULL;
95}
96
97static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
98{
99 struct ip_esp_hdr *esph;
100 struct iphdr *iph = ip_hdr(skb);
101 struct xfrm_offload *xo = xfrm_offload(skb);
102 int proto = iph->protocol;
103
104 skb_push(skb, len: -skb_network_offset(skb));
105 esph = ip_esp_hdr(skb);
106 *skb_mac_header(skb) = IPPROTO_ESP;
107
108 esph->spi = x->id.spi;
109 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
110
111 xo->proto = proto;
112}
113
114static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x,
115 struct sk_buff *skb,
116 netdev_features_t features)
117{
118 __be16 type = x->inner_mode.family == AF_INET6 ? htons(ETH_P_IPV6)
119 : htons(ETH_P_IP);
120
121 return skb_eth_gso_segment(skb, features, type);
122}
123
124static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
125 struct sk_buff *skb,
126 netdev_features_t features)
127{
128 const struct net_offload *ops;
129 struct sk_buff *segs = ERR_PTR(error: -EINVAL);
130 struct xfrm_offload *xo = xfrm_offload(skb);
131
132 skb->transport_header += x->props.header_len;
133 ops = rcu_dereference(inet_offloads[xo->proto]);
134 if (likely(ops && ops->callbacks.gso_segment))
135 segs = ops->callbacks.gso_segment(skb, features);
136
137 return segs;
138}
139
140static struct sk_buff *xfrm4_beet_gso_segment(struct xfrm_state *x,
141 struct sk_buff *skb,
142 netdev_features_t features)
143{
144 struct xfrm_offload *xo = xfrm_offload(skb);
145 struct sk_buff *segs = ERR_PTR(error: -EINVAL);
146 const struct net_offload *ops;
147 u8 proto = xo->proto;
148
149 skb->transport_header += x->props.header_len;
150
151 if (x->sel.family != AF_INET6) {
152 if (proto == IPPROTO_BEETPH) {
153 struct ip_beet_phdr *ph =
154 (struct ip_beet_phdr *)skb->data;
155
156 skb->transport_header += ph->hdrlen * 8;
157 proto = ph->nexthdr;
158 } else {
159 skb->transport_header -= IPV4_BEET_PHMAXLEN;
160 }
161 } else {
162 __be16 frag;
163
164 skb->transport_header +=
165 ipv6_skip_exthdr(skb, start: 0, nexthdrp: &proto, frag_offp: &frag);
166 if (proto == IPPROTO_TCP)
167 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
168 }
169
170 if (proto == IPPROTO_IPV6)
171 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
172
173 __skb_pull(skb, len: skb_transport_offset(skb));
174 ops = rcu_dereference(inet_offloads[proto]);
175 if (likely(ops && ops->callbacks.gso_segment))
176 segs = ops->callbacks.gso_segment(skb, features);
177
178 return segs;
179}
180
181static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x,
182 struct sk_buff *skb,
183 netdev_features_t features)
184{
185 switch (x->outer_mode.encap) {
186 case XFRM_MODE_TUNNEL:
187 return xfrm4_tunnel_gso_segment(x, skb, features);
188 case XFRM_MODE_TRANSPORT:
189 return xfrm4_transport_gso_segment(x, skb, features);
190 case XFRM_MODE_BEET:
191 return xfrm4_beet_gso_segment(x, skb, features);
192 }
193
194 return ERR_PTR(error: -EOPNOTSUPP);
195}
196
197static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
198 netdev_features_t features)
199{
200 struct xfrm_state *x;
201 struct ip_esp_hdr *esph;
202 struct crypto_aead *aead;
203 netdev_features_t esp_features = features;
204 struct xfrm_offload *xo = xfrm_offload(skb);
205 struct sec_path *sp;
206
207 if (!xo)
208 return ERR_PTR(error: -EINVAL);
209
210 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
211 return ERR_PTR(error: -EINVAL);
212
213 sp = skb_sec_path(skb);
214 x = sp->xvec[sp->len - 1];
215 aead = x->data;
216 esph = ip_esp_hdr(skb);
217
218 if (esph->spi != x->id.spi)
219 return ERR_PTR(error: -EINVAL);
220
221 if (!pskb_may_pull(skb, len: sizeof(*esph) + crypto_aead_ivsize(tfm: aead)))
222 return ERR_PTR(error: -EINVAL);
223
224 __skb_pull(skb, len: sizeof(*esph) + crypto_aead_ivsize(tfm: aead));
225
226 skb->encap_hdr_csum = 1;
227
228 if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
229 !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev)
230 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK |
231 NETIF_F_SCTP_CRC);
232 else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
233 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
234 esp_features = features & ~(NETIF_F_CSUM_MASK |
235 NETIF_F_SCTP_CRC);
236
237 xo->flags |= XFRM_GSO_SEGMENT;
238
239 return xfrm4_outer_mode_gso_segment(x, skb, features: esp_features);
240}
241
242static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb)
243{
244 struct crypto_aead *aead = x->data;
245 struct xfrm_offload *xo = xfrm_offload(skb);
246
247 if (!pskb_may_pull(skb, len: sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(tfm: aead)))
248 return -EINVAL;
249
250 if (!(xo->flags & CRYPTO_DONE))
251 skb->ip_summed = CHECKSUM_NONE;
252
253 return esp_input_done2(skb, err: 0);
254}
255
256static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
257{
258 int err;
259 int alen;
260 int blksize;
261 struct xfrm_offload *xo;
262 struct ip_esp_hdr *esph;
263 struct crypto_aead *aead;
264 struct esp_info esp;
265 bool hw_offload = true;
266 __u32 seq;
267
268 esp.inplace = true;
269
270 xo = xfrm_offload(skb);
271
272 if (!xo)
273 return -EINVAL;
274
275 if ((!(features & NETIF_F_HW_ESP) &&
276 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) ||
277 x->xso.dev != skb->dev) {
278 xo->flags |= CRYPTO_FALLBACK;
279 hw_offload = false;
280 }
281
282 esp.proto = xo->proto;
283
284 /* skb is pure payload to encrypt */
285
286 aead = x->data;
287 alen = crypto_aead_authsize(tfm: aead);
288
289 esp.tfclen = 0;
290 /* XXX: Add support for tfc padding here. */
291
292 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
293 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
294 esp.plen = esp.clen - skb->len - esp.tfclen;
295 esp.tailen = esp.tfclen + esp.plen + alen;
296
297 esp.esph = ip_esp_hdr(skb);
298
299
300 if (!hw_offload || !skb_is_gso(skb)) {
301 esp.nfrags = esp_output_head(x, skb, esp: &esp);
302 if (esp.nfrags < 0)
303 return esp.nfrags;
304 }
305
306 seq = xo->seq.low;
307
308 esph = esp.esph;
309 esph->spi = x->id.spi;
310
311 skb_push(skb, len: -skb_network_offset(skb));
312
313 if (xo->flags & XFRM_GSO_SEGMENT) {
314 esph->seq_no = htonl(seq);
315
316 if (!skb_is_gso(skb))
317 xo->seq.low++;
318 else
319 xo->seq.low += skb_shinfo(skb)->gso_segs;
320 }
321
322 if (xo->seq.low < seq)
323 xo->seq.hi++;
324
325 esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
326
327 ip_hdr(skb)->tot_len = htons(skb->len);
328 ip_send_check(ip: ip_hdr(skb));
329
330 if (hw_offload) {
331 if (!skb_ext_add(skb, id: SKB_EXT_SEC_PATH))
332 return -ENOMEM;
333
334 xo = xfrm_offload(skb);
335 if (!xo)
336 return -EINVAL;
337
338 xo->flags |= XFRM_XMIT;
339 return 0;
340 }
341
342 err = esp_output_tail(x, skb, esp: &esp);
343 if (err)
344 return err;
345
346 secpath_reset(skb);
347
348 if (skb_needs_linearize(skb, features: skb->dev->features) &&
349 __skb_linearize(skb))
350 return -ENOMEM;
351 return 0;
352}
353
354static const struct net_offload esp4_offload = {
355 .callbacks = {
356 .gro_receive = esp4_gro_receive,
357 .gso_segment = esp4_gso_segment,
358 },
359};
360
361static const struct xfrm_type_offload esp_type_offload = {
362 .owner = THIS_MODULE,
363 .proto = IPPROTO_ESP,
364 .input_tail = esp_input_tail,
365 .xmit = esp_xmit,
366 .encap = esp4_gso_encap,
367};
368
369static int __init esp4_offload_init(void)
370{
371 if (xfrm_register_type_offload(type: &esp_type_offload, AF_INET) < 0) {
372 pr_info("%s: can't add xfrm type offload\n", __func__);
373 return -EAGAIN;
374 }
375
376 return inet_add_offload(prot: &esp4_offload, IPPROTO_ESP);
377}
378
379static void __exit esp4_offload_exit(void)
380{
381 xfrm_unregister_type_offload(type: &esp_type_offload, AF_INET);
382 inet_del_offload(prot: &esp4_offload, IPPROTO_ESP);
383}
384
385module_init(esp4_offload_init);
386module_exit(esp4_offload_exit);
387MODULE_LICENSE("GPL");
388MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
389MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);
390MODULE_DESCRIPTION("IPV4 GSO/GRO offload support");
391

source code of linux/net/ipv4/esp4_offload.c