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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/ip.h>
20#include <net/xfrm.h>
21#include <net/esp.h>
22#include <linux/scatterlist.h>
23#include <linux/kernel.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26#include <net/udp.h>
27
28static struct sk_buff *esp4_gro_receive(struct list_head *head,
29 struct sk_buff *skb)
30{
31 int offset = skb_gro_offset(skb);
32 struct xfrm_offload *xo;
33 struct xfrm_state *x;
34 __be32 seq;
35 __be32 spi;
36
37 if (!pskb_pull(skb, offset))
38 return NULL;
39
40 if (xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq) != 0)
41 goto out;
42
43 xo = xfrm_offload(skb);
44 if (!xo || !(xo->flags & CRYPTO_DONE)) {
45 struct sec_path *sp = secpath_set(skb);
46
47 if (!sp)
48 goto out;
49
50 if (sp->len == XFRM_MAX_DEPTH)
51 goto out_reset;
52
53 x = xfrm_state_lookup(dev_net(skb->dev), skb->mark,
54 (xfrm_address_t *)&ip_hdr(skb)->daddr,
55 spi, IPPROTO_ESP, AF_INET);
56 if (!x)
57 goto out_reset;
58
59 skb->mark = xfrm_smark_get(skb->mark, x);
60
61 sp->xvec[sp->len++] = x;
62 sp->olen++;
63
64 xo = xfrm_offload(skb);
65 if (!xo)
66 goto out_reset;
67 }
68
69 xo->flags |= XFRM_GRO;
70
71 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
72 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
73 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
74 XFRM_SPI_SKB_CB(skb)->seq = seq;
75
76
77
78 xfrm_input(skb, IPPROTO_ESP, spi, -2);
79
80 return ERR_PTR(-EINPROGRESS);
81out_reset:
82 secpath_reset(skb);
83out:
84 skb_push(skb, offset);
85 NAPI_GRO_CB(skb)->same_flow = 0;
86 NAPI_GRO_CB(skb)->flush = 1;
87
88 return NULL;
89}
90
91static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
92{
93 struct ip_esp_hdr *esph;
94 struct iphdr *iph = ip_hdr(skb);
95 struct xfrm_offload *xo = xfrm_offload(skb);
96 int proto = iph->protocol;
97
98 skb_push(skb, -skb_network_offset(skb));
99 esph = ip_esp_hdr(skb);
100 *skb_mac_header(skb) = IPPROTO_ESP;
101
102 esph->spi = x->id.spi;
103 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
104
105 xo->proto = proto;
106}
107
108static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x,
109 struct sk_buff *skb,
110 netdev_features_t features)
111{
112 __skb_push(skb, skb->mac_len);
113 return skb_mac_gso_segment(skb, features);
114}
115
116static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
117 struct sk_buff *skb,
118 netdev_features_t features)
119{
120 const struct net_offload *ops;
121 struct sk_buff *segs = ERR_PTR(-EINVAL);
122 struct xfrm_offload *xo = xfrm_offload(skb);
123
124 skb->transport_header += x->props.header_len;
125 ops = rcu_dereference(inet_offloads[xo->proto]);
126 if (likely(ops && ops->callbacks.gso_segment))
127 segs = ops->callbacks.gso_segment(skb, features);
128
129 return segs;
130}
131
132static struct sk_buff *xfrm4_beet_gso_segment(struct xfrm_state *x,
133 struct sk_buff *skb,
134 netdev_features_t features)
135{
136 struct xfrm_offload *xo = xfrm_offload(skb);
137 struct sk_buff *segs = ERR_PTR(-EINVAL);
138 const struct net_offload *ops;
139 u8 proto = xo->proto;
140
141 skb->transport_header += x->props.header_len;
142
143 if (x->sel.family != AF_INET6) {
144 if (proto == IPPROTO_BEETPH) {
145 struct ip_beet_phdr *ph =
146 (struct ip_beet_phdr *)skb->data;
147
148 skb->transport_header += ph->hdrlen * 8;
149 proto = ph->nexthdr;
150 } else {
151 skb->transport_header -= IPV4_BEET_PHMAXLEN;
152 }
153 } else {
154 __be16 frag;
155
156 skb->transport_header +=
157 ipv6_skip_exthdr(skb, 0, &proto, &frag);
158 if (proto == IPPROTO_TCP)
159 skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
160 }
161
162 __skb_pull(skb, skb_transport_offset(skb));
163 ops = rcu_dereference(inet_offloads[proto]);
164 if (likely(ops && ops->callbacks.gso_segment))
165 segs = ops->callbacks.gso_segment(skb, features);
166
167 return segs;
168}
169
170static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x,
171 struct sk_buff *skb,
172 netdev_features_t features)
173{
174 switch (x->outer_mode.encap) {
175 case XFRM_MODE_TUNNEL:
176 return xfrm4_tunnel_gso_segment(x, skb, features);
177 case XFRM_MODE_TRANSPORT:
178 return xfrm4_transport_gso_segment(x, skb, features);
179 case XFRM_MODE_BEET:
180 return xfrm4_beet_gso_segment(x, skb, features);
181 }
182
183 return ERR_PTR(-EOPNOTSUPP);
184}
185
186static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
187 netdev_features_t features)
188{
189 struct xfrm_state *x;
190 struct ip_esp_hdr *esph;
191 struct crypto_aead *aead;
192 netdev_features_t esp_features = features;
193 struct xfrm_offload *xo = xfrm_offload(skb);
194 struct sec_path *sp;
195
196 if (!xo)
197 return ERR_PTR(-EINVAL);
198
199 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
200 return ERR_PTR(-EINVAL);
201
202 sp = skb_sec_path(skb);
203 x = sp->xvec[sp->len - 1];
204 aead = x->data;
205 esph = ip_esp_hdr(skb);
206
207 if (esph->spi != x->id.spi)
208 return ERR_PTR(-EINVAL);
209
210 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
211 return ERR_PTR(-EINVAL);
212
213 __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
214
215 skb->encap_hdr_csum = 1;
216
217 if ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) &&
218 !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev)
219 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK |
220 NETIF_F_SCTP_CRC);
221 else if (!(features & NETIF_F_HW_ESP_TX_CSUM) &&
222 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM))
223 esp_features = features & ~(NETIF_F_CSUM_MASK |
224 NETIF_F_SCTP_CRC);
225
226 xo->flags |= XFRM_GSO_SEGMENT;
227
228 return xfrm4_outer_mode_gso_segment(x, skb, esp_features);
229}
230
231static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb)
232{
233 struct crypto_aead *aead = x->data;
234 struct xfrm_offload *xo = xfrm_offload(skb);
235
236 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
237 return -EINVAL;
238
239 if (!(xo->flags & CRYPTO_DONE))
240 skb->ip_summed = CHECKSUM_NONE;
241
242 return esp_input_done2(skb, 0);
243}
244
245static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
246{
247 int err;
248 int alen;
249 int blksize;
250 struct xfrm_offload *xo;
251 struct ip_esp_hdr *esph;
252 struct crypto_aead *aead;
253 struct esp_info esp;
254 bool hw_offload = true;
255 __u32 seq;
256
257 esp.inplace = true;
258
259 xo = xfrm_offload(skb);
260
261 if (!xo)
262 return -EINVAL;
263
264 if ((!(features & NETIF_F_HW_ESP) &&
265 !(skb->dev->gso_partial_features & NETIF_F_HW_ESP)) ||
266 x->xso.dev != skb->dev) {
267 xo->flags |= CRYPTO_FALLBACK;
268 hw_offload = false;
269 }
270
271 esp.proto = xo->proto;
272
273
274
275 aead = x->data;
276 alen = crypto_aead_authsize(aead);
277
278 esp.tfclen = 0;
279
280
281 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
282 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
283 esp.plen = esp.clen - skb->len - esp.tfclen;
284 esp.tailen = esp.tfclen + esp.plen + alen;
285
286 esp.esph = ip_esp_hdr(skb);
287
288
289 if (!hw_offload || !skb_is_gso(skb)) {
290 esp.nfrags = esp_output_head(x, skb, &esp);
291 if (esp.nfrags < 0)
292 return esp.nfrags;
293 }
294
295 seq = xo->seq.low;
296
297 esph = esp.esph;
298 esph->spi = x->id.spi;
299
300 skb_push(skb, -skb_network_offset(skb));
301
302 if (xo->flags & XFRM_GSO_SEGMENT) {
303 esph->seq_no = htonl(seq);
304
305 if (!skb_is_gso(skb))
306 xo->seq.low++;
307 else
308 xo->seq.low += skb_shinfo(skb)->gso_segs;
309 }
310
311 esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
312
313 ip_hdr(skb)->tot_len = htons(skb->len);
314 ip_send_check(ip_hdr(skb));
315
316 if (hw_offload) {
317 if (!skb_ext_add(skb, SKB_EXT_SEC_PATH))
318 return -ENOMEM;
319
320 xo = xfrm_offload(skb);
321 if (!xo)
322 return -EINVAL;
323
324 xo->flags |= XFRM_XMIT;
325 return 0;
326 }
327
328 err = esp_output_tail(x, skb, &esp);
329 if (err)
330 return err;
331
332 secpath_reset(skb);
333
334 return 0;
335}
336
337static const struct net_offload esp4_offload = {
338 .callbacks = {
339 .gro_receive = esp4_gro_receive,
340 .gso_segment = esp4_gso_segment,
341 },
342};
343
344static const struct xfrm_type_offload esp_type_offload = {
345 .owner = THIS_MODULE,
346 .proto = IPPROTO_ESP,
347 .input_tail = esp_input_tail,
348 .xmit = esp_xmit,
349 .encap = esp4_gso_encap,
350};
351
352static int __init esp4_offload_init(void)
353{
354 if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
355 pr_info("%s: can't add xfrm type offload\n", __func__);
356 return -EAGAIN;
357 }
358
359 return inet_add_offload(&esp4_offload, IPPROTO_ESP);
360}
361
362static void __exit esp4_offload_exit(void)
363{
364 xfrm_unregister_type_offload(&esp_type_offload, AF_INET);
365 inet_del_offload(&esp4_offload, IPPROTO_ESP);
366}
367
368module_init(esp4_offload_init);
369module_exit(esp4_offload_exit);
370MODULE_LICENSE("GPL");
371MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
372MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP);
373MODULE_DESCRIPTION("IPV4 GSO/GRO offload support");
374
