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7785bba2 SK |
1 | /* |
2 | * IPV6 GSO/GRO offload support | |
3 | * Linux INET implementation | |
4 | * | |
5 | * Copyright (C) 2016 secunet Security Networks AG | |
6 | * Author: Steffen Klassert <steffen.klassert@secunet.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms and conditions of the GNU General Public License, | |
10 | * version 2, as published by the Free Software Foundation. | |
11 | * | |
12 | * ESP GRO support | |
13 | */ | |
14 | ||
15 | #include <linux/skbuff.h> | |
16 | #include <linux/init.h> | |
17 | #include <net/protocol.h> | |
18 | #include <crypto/aead.h> | |
19 | #include <crypto/authenc.h> | |
20 | #include <linux/err.h> | |
21 | #include <linux/module.h> | |
22 | #include <net/ip.h> | |
23 | #include <net/xfrm.h> | |
24 | #include <net/esp.h> | |
25 | #include <linux/scatterlist.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/spinlock.h> | |
29 | #include <net/ip6_route.h> | |
30 | #include <net/ipv6.h> | |
31 | #include <linux/icmpv6.h> | |
32 | ||
ca3a1b85 YK |
33 | static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen) |
34 | { | |
35 | int off = sizeof(struct ipv6hdr); | |
36 | struct ipv6_opt_hdr *exthdr; | |
37 | ||
38 | if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP)) | |
39 | return offsetof(struct ipv6hdr, nexthdr); | |
40 | ||
41 | while (off < nhlen) { | |
42 | exthdr = (void *)ipv6_hdr + off; | |
43 | if (exthdr->nexthdr == NEXTHDR_ESP) | |
44 | return off; | |
45 | ||
46 | off += ipv6_optlen(exthdr); | |
47 | } | |
48 | ||
49 | return 0; | |
50 | } | |
51 | ||
7785bba2 SK |
52 | static struct sk_buff **esp6_gro_receive(struct sk_buff **head, |
53 | struct sk_buff *skb) | |
54 | { | |
55 | int offset = skb_gro_offset(skb); | |
56 | struct xfrm_offload *xo; | |
57 | struct xfrm_state *x; | |
58 | __be32 seq; | |
59 | __be32 spi; | |
ca3a1b85 | 60 | int nhoff; |
7785bba2 SK |
61 | int err; |
62 | ||
374d1b5a SK |
63 | if (!pskb_pull(skb, offset)) |
64 | return NULL; | |
7785bba2 SK |
65 | |
66 | if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0) | |
67 | goto out; | |
68 | ||
bcd1f8a4 SK |
69 | xo = xfrm_offload(skb); |
70 | if (!xo || !(xo->flags & CRYPTO_DONE)) { | |
71 | err = secpath_set(skb); | |
72 | if (err) | |
73 | goto out; | |
7785bba2 | 74 | |
bcd1f8a4 SK |
75 | if (skb->sp->len == XFRM_MAX_DEPTH) |
76 | goto out; | |
7785bba2 | 77 | |
bcd1f8a4 SK |
78 | x = xfrm_state_lookup(dev_net(skb->dev), skb->mark, |
79 | (xfrm_address_t *)&ipv6_hdr(skb)->daddr, | |
80 | spi, IPPROTO_ESP, AF_INET6); | |
81 | if (!x) | |
82 | goto out; | |
7785bba2 | 83 | |
bcd1f8a4 SK |
84 | skb->sp->xvec[skb->sp->len++] = x; |
85 | skb->sp->olen++; | |
7785bba2 | 86 | |
bcd1f8a4 SK |
87 | xo = xfrm_offload(skb); |
88 | if (!xo) { | |
89 | xfrm_state_put(x); | |
90 | goto out; | |
91 | } | |
7785bba2 | 92 | } |
bcd1f8a4 | 93 | |
7785bba2 SK |
94 | xo->flags |= XFRM_GRO; |
95 | ||
ca3a1b85 YK |
96 | nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset); |
97 | if (!nhoff) | |
98 | goto out; | |
99 | ||
100 | IP6CB(skb)->nhoff = nhoff; | |
7785bba2 SK |
101 | XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL; |
102 | XFRM_SPI_SKB_CB(skb)->family = AF_INET6; | |
103 | XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); | |
104 | XFRM_SPI_SKB_CB(skb)->seq = seq; | |
105 | ||
106 | /* We don't need to handle errors from xfrm_input, it does all | |
107 | * the error handling and frees the resources on error. */ | |
108 | xfrm_input(skb, IPPROTO_ESP, spi, -2); | |
109 | ||
110 | return ERR_PTR(-EINPROGRESS); | |
111 | out: | |
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 | ||
7862b405 SK |
119 | static 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 | int proto = iph->nexthdr; | |
125 | ||
126 | skb_push(skb, -skb_network_offset(skb)); | |
127 | esph = ip_esp_hdr(skb); | |
128 | *skb_mac_header(skb) = IPPROTO_ESP; | |
129 | ||
130 | esph->spi = x->id.spi; | |
131 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); | |
132 | ||
133 | xo->proto = proto; | |
134 | } | |
135 | ||
136 | static struct sk_buff *esp6_gso_segment(struct sk_buff *skb, | |
137 | netdev_features_t features) | |
138 | { | |
7862b405 SK |
139 | struct xfrm_state *x; |
140 | struct ip_esp_hdr *esph; | |
141 | struct crypto_aead *aead; | |
7862b405 SK |
142 | netdev_features_t esp_features = features; |
143 | struct xfrm_offload *xo = xfrm_offload(skb); | |
144 | ||
ffa6f571 | 145 | if (!xo) |
3dca3f38 | 146 | return ERR_PTR(-EINVAL); |
7862b405 SK |
147 | |
148 | x = skb->sp->xvec[skb->sp->len - 1]; | |
149 | aead = x->data; | |
150 | esph = ip_esp_hdr(skb); | |
151 | ||
152 | if (esph->spi != x->id.spi) | |
3dca3f38 | 153 | return ERR_PTR(-EINVAL); |
7862b405 SK |
154 | |
155 | if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) | |
3dca3f38 | 156 | return ERR_PTR(-EINVAL); |
7862b405 SK |
157 | |
158 | __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)); | |
159 | ||
160 | skb->encap_hdr_csum = 1; | |
161 | ||
3dca3f38 SK |
162 | if (!(features & NETIF_F_HW_ESP) || !x->xso.offload_handle || |
163 | (x->xso.dev != skb->dev)) | |
7862b405 SK |
164 | esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); |
165 | ||
3dca3f38 | 166 | xo->flags |= XFRM_GSO_SEGMENT; |
7862b405 | 167 | |
3dca3f38 | 168 | return x->outer_mode->gso_segment(x, skb, esp_features); |
7862b405 SK |
169 | } |
170 | ||
383d0350 SK |
171 | static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb) |
172 | { | |
173 | struct crypto_aead *aead = x->data; | |
e51a6472 | 174 | struct xfrm_offload *xo = xfrm_offload(skb); |
383d0350 SK |
175 | |
176 | if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead))) | |
177 | return -EINVAL; | |
178 | ||
e51a6472 IT |
179 | if (!(xo->flags & CRYPTO_DONE)) |
180 | skb->ip_summed = CHECKSUM_NONE; | |
383d0350 SK |
181 | |
182 | return esp6_input_done2(skb, 0); | |
183 | } | |
184 | ||
185 | static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) | |
186 | { | |
3dca3f38 | 187 | int len; |
383d0350 SK |
188 | int err; |
189 | int alen; | |
190 | int blksize; | |
191 | struct xfrm_offload *xo; | |
192 | struct ip_esp_hdr *esph; | |
193 | struct crypto_aead *aead; | |
194 | struct esp_info esp; | |
195 | bool hw_offload = true; | |
3dca3f38 | 196 | __u32 seq; |
383d0350 SK |
197 | |
198 | esp.inplace = true; | |
199 | ||
200 | xo = xfrm_offload(skb); | |
201 | ||
202 | if (!xo) | |
203 | return -EINVAL; | |
204 | ||
8f92e03e IT |
205 | if (!(features & NETIF_F_HW_ESP) || !x->xso.offload_handle || |
206 | (x->xso.dev != skb->dev)) { | |
383d0350 | 207 | xo->flags |= CRYPTO_FALLBACK; |
8f92e03e | 208 | hw_offload = false; |
383d0350 SK |
209 | } |
210 | ||
211 | esp.proto = xo->proto; | |
212 | ||
213 | /* skb is pure payload to encrypt */ | |
214 | ||
215 | aead = x->data; | |
216 | alen = crypto_aead_authsize(aead); | |
217 | ||
218 | esp.tfclen = 0; | |
219 | /* XXX: Add support for tfc padding here. */ | |
220 | ||
221 | blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
222 | esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); | |
223 | esp.plen = esp.clen - skb->len - esp.tfclen; | |
224 | esp.tailen = esp.tfclen + esp.plen + alen; | |
225 | ||
226 | if (!hw_offload || (hw_offload && !skb_is_gso(skb))) { | |
227 | esp.nfrags = esp6_output_head(x, skb, &esp); | |
228 | if (esp.nfrags < 0) | |
229 | return esp.nfrags; | |
230 | } | |
231 | ||
3dca3f38 SK |
232 | seq = xo->seq.low; |
233 | ||
383d0350 SK |
234 | esph = ip_esp_hdr(skb); |
235 | esph->spi = x->id.spi; | |
236 | ||
237 | skb_push(skb, -skb_network_offset(skb)); | |
238 | ||
239 | if (xo->flags & XFRM_GSO_SEGMENT) { | |
3dca3f38 | 240 | esph->seq_no = htonl(seq); |
383d0350 | 241 | |
3dca3f38 SK |
242 | if (!skb_is_gso(skb)) |
243 | xo->seq.low++; | |
244 | else | |
245 | xo->seq.low += skb_shinfo(skb)->gso_segs; | |
383d0350 SK |
246 | } |
247 | ||
3dca3f38 SK |
248 | esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32)); |
249 | ||
250 | len = skb->len - sizeof(struct ipv6hdr); | |
251 | if (len > IPV6_MAXPLEN) | |
252 | len = 0; | |
253 | ||
254 | ipv6_hdr(skb)->payload_len = htons(len); | |
255 | ||
8f92e03e | 256 | if (hw_offload) |
383d0350 SK |
257 | return 0; |
258 | ||
383d0350 | 259 | err = esp6_output_tail(x, skb, &esp); |
4ff0308f | 260 | if (err) |
383d0350 SK |
261 | return err; |
262 | ||
263 | secpath_reset(skb); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
7785bba2 SK |
268 | static const struct net_offload esp6_offload = { |
269 | .callbacks = { | |
270 | .gro_receive = esp6_gro_receive, | |
7862b405 | 271 | .gso_segment = esp6_gso_segment, |
7785bba2 SK |
272 | }, |
273 | }; | |
274 | ||
383d0350 SK |
275 | static const struct xfrm_type_offload esp6_type_offload = { |
276 | .description = "ESP6 OFFLOAD", | |
277 | .owner = THIS_MODULE, | |
278 | .proto = IPPROTO_ESP, | |
279 | .input_tail = esp6_input_tail, | |
280 | .xmit = esp6_xmit, | |
7862b405 | 281 | .encap = esp6_gso_encap, |
383d0350 SK |
282 | }; |
283 | ||
7785bba2 SK |
284 | static int __init esp6_offload_init(void) |
285 | { | |
383d0350 SK |
286 | if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) { |
287 | pr_info("%s: can't add xfrm type offload\n", __func__); | |
288 | return -EAGAIN; | |
289 | } | |
290 | ||
7785bba2 SK |
291 | return inet6_add_offload(&esp6_offload, IPPROTO_ESP); |
292 | } | |
293 | ||
294 | static void __exit esp6_offload_exit(void) | |
295 | { | |
383d0350 SK |
296 | if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0) |
297 | pr_info("%s: can't remove xfrm type offload\n", __func__); | |
298 | ||
7785bba2 SK |
299 | inet6_del_offload(&esp6_offload, IPPROTO_ESP); |
300 | } | |
301 | ||
302 | module_init(esp6_offload_init); | |
303 | module_exit(esp6_offload_exit); | |
304 | MODULE_LICENSE("GPL"); | |
305 | MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); | |
ffdb5211 | 306 | MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP); |