Commit | Line | Data |
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7785bba2 SK |
1 | /* |
2 | * IPV4 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/udp.h> | |
30 | ||
d4546c25 DM |
31 | static struct sk_buff *esp4_gro_receive(struct list_head *head, |
32 | struct sk_buff *skb) | |
7785bba2 SK |
33 | { |
34 | int offset = skb_gro_offset(skb); | |
35 | struct xfrm_offload *xo; | |
36 | struct xfrm_state *x; | |
37 | __be32 seq; | |
38 | __be32 spi; | |
39 | int err; | |
40 | ||
374d1b5a SK |
41 | if (!pskb_pull(skb, offset)) |
42 | return NULL; | |
7785bba2 SK |
43 | |
44 | if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0) | |
45 | goto out; | |
46 | ||
bcd1f8a4 SK |
47 | xo = xfrm_offload(skb); |
48 | if (!xo || !(xo->flags & CRYPTO_DONE)) { | |
0ca64da1 FW |
49 | struct sec_path *sp = secpath_set(skb); |
50 | ||
51 | if (!sp) | |
bcd1f8a4 | 52 | goto out; |
7785bba2 | 53 | |
0ca64da1 | 54 | if (sp->len == XFRM_MAX_DEPTH) |
bcd1f8a4 | 55 | goto out; |
7785bba2 | 56 | |
bcd1f8a4 SK |
57 | x = xfrm_state_lookup(dev_net(skb->dev), skb->mark, |
58 | (xfrm_address_t *)&ip_hdr(skb)->daddr, | |
59 | spi, IPPROTO_ESP, AF_INET); | |
60 | if (!x) | |
61 | goto out; | |
7785bba2 | 62 | |
0ca64da1 FW |
63 | sp->xvec[sp->len++] = x; |
64 | sp->olen++; | |
7785bba2 | 65 | |
bcd1f8a4 SK |
66 | xo = xfrm_offload(skb); |
67 | if (!xo) { | |
68 | xfrm_state_put(x); | |
69 | goto out; | |
70 | } | |
7785bba2 | 71 | } |
bcd1f8a4 | 72 | |
7785bba2 SK |
73 | xo->flags |= XFRM_GRO; |
74 | ||
75 | XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; | |
76 | XFRM_SPI_SKB_CB(skb)->family = AF_INET; | |
77 | XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr); | |
78 | XFRM_SPI_SKB_CB(skb)->seq = seq; | |
79 | ||
80 | /* We don't need to handle errors from xfrm_input, it does all | |
81 | * the error handling and frees the resources on error. */ | |
82 | xfrm_input(skb, IPPROTO_ESP, spi, -2); | |
83 | ||
84 | return ERR_PTR(-EINPROGRESS); | |
85 | out: | |
86 | skb_push(skb, offset); | |
87 | NAPI_GRO_CB(skb)->same_flow = 0; | |
88 | NAPI_GRO_CB(skb)->flush = 1; | |
89 | ||
90 | return NULL; | |
91 | } | |
92 | ||
7862b405 SK |
93 | static void esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb) |
94 | { | |
95 | struct ip_esp_hdr *esph; | |
96 | struct iphdr *iph = ip_hdr(skb); | |
97 | struct xfrm_offload *xo = xfrm_offload(skb); | |
98 | int proto = iph->protocol; | |
99 | ||
100 | skb_push(skb, -skb_network_offset(skb)); | |
101 | esph = ip_esp_hdr(skb); | |
102 | *skb_mac_header(skb) = IPPROTO_ESP; | |
103 | ||
104 | esph->spi = x->id.spi; | |
105 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); | |
106 | ||
107 | xo->proto = proto; | |
108 | } | |
109 | ||
110 | static struct sk_buff *esp4_gso_segment(struct sk_buff *skb, | |
111 | netdev_features_t features) | |
112 | { | |
7862b405 SK |
113 | struct xfrm_state *x; |
114 | struct ip_esp_hdr *esph; | |
115 | struct crypto_aead *aead; | |
7862b405 SK |
116 | netdev_features_t esp_features = features; |
117 | struct xfrm_offload *xo = xfrm_offload(skb); | |
118 | ||
119 | if (!xo) | |
3dca3f38 | 120 | return ERR_PTR(-EINVAL); |
7862b405 | 121 | |
121d57af | 122 | if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP)) |
5ca11440 | 123 | return ERR_PTR(-EINVAL); |
7862b405 SK |
124 | |
125 | x = skb->sp->xvec[skb->sp->len - 1]; | |
126 | aead = x->data; | |
127 | esph = ip_esp_hdr(skb); | |
128 | ||
129 | if (esph->spi != x->id.spi) | |
3dca3f38 | 130 | return ERR_PTR(-EINVAL); |
7862b405 SK |
131 | |
132 | if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) | |
3dca3f38 | 133 | return ERR_PTR(-EINVAL); |
7862b405 SK |
134 | |
135 | __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)); | |
136 | ||
137 | skb->encap_hdr_csum = 1; | |
138 | ||
fcb662de | 139 | if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) |
7862b405 | 140 | esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); |
5211fcfb SN |
141 | else if (!(features & NETIF_F_HW_ESP_TX_CSUM)) |
142 | esp_features = features & ~NETIF_F_CSUM_MASK; | |
7862b405 | 143 | |
3dca3f38 | 144 | xo->flags |= XFRM_GSO_SEGMENT; |
7862b405 | 145 | |
3dca3f38 | 146 | return x->outer_mode->gso_segment(x, skb, esp_features); |
7862b405 SK |
147 | } |
148 | ||
fca11ebd SK |
149 | static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb) |
150 | { | |
151 | struct crypto_aead *aead = x->data; | |
ec9567a9 | 152 | struct xfrm_offload *xo = xfrm_offload(skb); |
fca11ebd SK |
153 | |
154 | if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead))) | |
155 | return -EINVAL; | |
156 | ||
ec9567a9 IT |
157 | if (!(xo->flags & CRYPTO_DONE)) |
158 | skb->ip_summed = CHECKSUM_NONE; | |
fca11ebd SK |
159 | |
160 | return esp_input_done2(skb, 0); | |
161 | } | |
162 | ||
163 | static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) | |
164 | { | |
165 | int err; | |
166 | int alen; | |
167 | int blksize; | |
168 | struct xfrm_offload *xo; | |
169 | struct ip_esp_hdr *esph; | |
170 | struct crypto_aead *aead; | |
171 | struct esp_info esp; | |
172 | bool hw_offload = true; | |
3dca3f38 | 173 | __u32 seq; |
fca11ebd SK |
174 | |
175 | esp.inplace = true; | |
176 | ||
177 | xo = xfrm_offload(skb); | |
178 | ||
179 | if (!xo) | |
180 | return -EINVAL; | |
181 | ||
fcb662de | 182 | if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) { |
fca11ebd SK |
183 | xo->flags |= CRYPTO_FALLBACK; |
184 | hw_offload = false; | |
185 | } | |
186 | ||
187 | esp.proto = xo->proto; | |
188 | ||
189 | /* skb is pure payload to encrypt */ | |
190 | ||
191 | aead = x->data; | |
192 | alen = crypto_aead_authsize(aead); | |
193 | ||
194 | esp.tfclen = 0; | |
195 | /* XXX: Add support for tfc padding here. */ | |
196 | ||
197 | blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
198 | esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); | |
199 | esp.plen = esp.clen - skb->len - esp.tfclen; | |
200 | esp.tailen = esp.tfclen + esp.plen + alen; | |
201 | ||
202 | esp.esph = ip_esp_hdr(skb); | |
203 | ||
204 | ||
205 | if (!hw_offload || (hw_offload && !skb_is_gso(skb))) { | |
206 | esp.nfrags = esp_output_head(x, skb, &esp); | |
207 | if (esp.nfrags < 0) | |
208 | return esp.nfrags; | |
209 | } | |
210 | ||
3dca3f38 SK |
211 | seq = xo->seq.low; |
212 | ||
fca11ebd SK |
213 | esph = esp.esph; |
214 | esph->spi = x->id.spi; | |
215 | ||
216 | skb_push(skb, -skb_network_offset(skb)); | |
217 | ||
218 | if (xo->flags & XFRM_GSO_SEGMENT) { | |
3dca3f38 SK |
219 | esph->seq_no = htonl(seq); |
220 | ||
221 | if (!skb_is_gso(skb)) | |
222 | xo->seq.low++; | |
223 | else | |
224 | xo->seq.low += skb_shinfo(skb)->gso_segs; | |
fca11ebd SK |
225 | } |
226 | ||
3dca3f38 SK |
227 | esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32)); |
228 | ||
229 | ip_hdr(skb)->tot_len = htons(skb->len); | |
230 | ip_send_check(ip_hdr(skb)); | |
231 | ||
fca11ebd SK |
232 | if (hw_offload) |
233 | return 0; | |
234 | ||
fca11ebd | 235 | err = esp_output_tail(x, skb, &esp); |
4ff0308f | 236 | if (err) |
fca11ebd SK |
237 | return err; |
238 | ||
239 | secpath_reset(skb); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
7785bba2 SK |
244 | static const struct net_offload esp4_offload = { |
245 | .callbacks = { | |
246 | .gro_receive = esp4_gro_receive, | |
7862b405 | 247 | .gso_segment = esp4_gso_segment, |
7785bba2 SK |
248 | }, |
249 | }; | |
250 | ||
fca11ebd SK |
251 | static const struct xfrm_type_offload esp_type_offload = { |
252 | .description = "ESP4 OFFLOAD", | |
253 | .owner = THIS_MODULE, | |
254 | .proto = IPPROTO_ESP, | |
255 | .input_tail = esp_input_tail, | |
256 | .xmit = esp_xmit, | |
7862b405 | 257 | .encap = esp4_gso_encap, |
fca11ebd SK |
258 | }; |
259 | ||
7785bba2 SK |
260 | static int __init esp4_offload_init(void) |
261 | { | |
fca11ebd SK |
262 | if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) { |
263 | pr_info("%s: can't add xfrm type offload\n", __func__); | |
264 | return -EAGAIN; | |
265 | } | |
266 | ||
7785bba2 SK |
267 | return inet_add_offload(&esp4_offload, IPPROTO_ESP); |
268 | } | |
269 | ||
270 | static void __exit esp4_offload_exit(void) | |
271 | { | |
fca11ebd SK |
272 | if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0) |
273 | pr_info("%s: can't remove xfrm type offload\n", __func__); | |
274 | ||
7785bba2 SK |
275 | inet_del_offload(&esp4_offload, IPPROTO_ESP); |
276 | } | |
277 | ||
278 | module_init(esp4_offload_init); | |
279 | module_exit(esp4_offload_exit); | |
280 | MODULE_LICENSE("GPL"); | |
281 | MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); | |
ffdb5211 | 282 | MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP); |