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Commit | Line | Data |
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406ef77c HX |
1 | /* |
2 | * xfrm_output.c - Common IPsec encapsulation code. | |
3 | * | |
4 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/errno.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netdevice.h> | |
862b82c6 | 15 | #include <linux/netfilter.h> |
406ef77c | 16 | #include <linux/skbuff.h> |
5a0e3ad6 | 17 | #include <linux/slab.h> |
406ef77c | 18 | #include <linux/spinlock.h> |
406ef77c HX |
19 | #include <net/dst.h> |
20 | #include <net/xfrm.h> | |
21 | ||
0c4b51f0 | 22 | static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb); |
c6581a45 | 23 | |
26b2072e | 24 | static int xfrm_skb_check_space(struct sk_buff *skb) |
83815dea | 25 | { |
adf30907 | 26 | struct dst_entry *dst = skb_dst(skb); |
550ade84 | 27 | int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev) |
83815dea | 28 | - skb_headroom(skb); |
f5184d26 | 29 | int ntail = dst->dev->needed_tailroom - skb_tailroom(skb); |
83815dea | 30 | |
d01dbeb6 HX |
31 | if (nhead <= 0) { |
32 | if (ntail <= 0) | |
33 | return 0; | |
34 | nhead = 0; | |
35 | } else if (ntail < 0) | |
36 | ntail = 0; | |
37 | ||
38 | return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC); | |
83815dea HX |
39 | } |
40 | ||
9449c3cd YX |
41 | /* Children define the path of the packet through the |
42 | * Linux networking. Thus, destinations are stackable. | |
43 | */ | |
44 | ||
45 | static struct dst_entry *skb_dst_pop(struct sk_buff *skb) | |
46 | { | |
47 | struct dst_entry *child = dst_clone(skb_dst(skb)->child); | |
48 | ||
49 | skb_dst_drop(skb); | |
50 | return child; | |
51 | } | |
52 | ||
c6581a45 | 53 | static int xfrm_output_one(struct sk_buff *skb, int err) |
406ef77c | 54 | { |
adf30907 | 55 | struct dst_entry *dst = skb_dst(skb); |
406ef77c | 56 | struct xfrm_state *x = dst->xfrm; |
a6483b79 | 57 | struct net *net = xs_net(x); |
406ef77c | 58 | |
c6581a45 HX |
59 | if (err <= 0) |
60 | goto resume; | |
406ef77c HX |
61 | |
62 | do { | |
26b2072e | 63 | err = xfrm_skb_check_space(skb); |
b15c4bcd | 64 | if (err) { |
59c9940e | 65 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
910ef70a | 66 | goto error_nolock; |
b15c4bcd | 67 | } |
910ef70a | 68 | |
077fbac4 LC |
69 | if (x->props.output_mark) |
70 | skb->mark = x->props.output_mark; | |
71 | ||
a2deb6d2 | 72 | err = x->outer_mode->output(x, skb); |
b15c4bcd | 73 | if (err) { |
59c9940e | 74 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR); |
910ef70a | 75 | goto error_nolock; |
b15c4bcd | 76 | } |
a2deb6d2 | 77 | |
406ef77c | 78 | spin_lock_bh(&x->lock); |
bb65a9cb LR |
79 | |
80 | if (unlikely(x->km.state != XFRM_STATE_VALID)) { | |
81 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID); | |
497574c7 | 82 | err = -EINVAL; |
fa8599db | 83 | goto error; |
bb65a9cb LR |
84 | } |
85 | ||
910ef70a | 86 | err = xfrm_state_check_expire(x); |
b15c4bcd | 87 | if (err) { |
59c9940e | 88 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED); |
406ef77c | 89 | goto error; |
b15c4bcd | 90 | } |
406ef77c | 91 | |
9fdc4883 SK |
92 | err = x->repl->overflow(x, skb); |
93 | if (err) { | |
94 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR); | |
95 | goto error; | |
436a0a40 HX |
96 | } |
97 | ||
406ef77c HX |
98 | x->curlft.bytes += skb->len; |
99 | x->curlft.packets++; | |
100 | ||
406ef77c HX |
101 | spin_unlock_bh(&x->lock); |
102 | ||
3bc07321 | 103 | skb_dst_force(skb); |
0d4169ed SK |
104 | if (!skb_dst(skb)) { |
105 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); | |
106 | goto error_nolock; | |
107 | } | |
3bc07321 | 108 | |
d77e38e6 SK |
109 | if (xfrm_offload(skb)) { |
110 | x->type_offload->encap(x, skb); | |
111 | } else { | |
73b9fc49 SK |
112 | /* Inner headers are invalid now. */ |
113 | skb->encapsulation = 0; | |
114 | ||
d77e38e6 SK |
115 | err = x->type->output(x, skb); |
116 | if (err == -EINPROGRESS) | |
117 | goto out; | |
118 | } | |
c6581a45 HX |
119 | |
120 | resume: | |
0aa64774 | 121 | if (err) { |
59c9940e | 122 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR); |
b7c6538c | 123 | goto error_nolock; |
0aa64774 | 124 | } |
b7c6538c | 125 | |
8764ab2c | 126 | dst = skb_dst_pop(skb); |
adf30907 | 127 | if (!dst) { |
59c9940e | 128 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
406ef77c HX |
129 | err = -EHOSTUNREACH; |
130 | goto error_nolock; | |
131 | } | |
e433430a | 132 | skb_dst_set(skb, dst); |
406ef77c | 133 | x = dst->xfrm; |
13996378 | 134 | } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL)); |
406ef77c | 135 | |
ebd4687a | 136 | return 0; |
406ef77c | 137 | |
406ef77c HX |
138 | error: |
139 | spin_unlock_bh(&x->lock); | |
862b82c6 HX |
140 | error_nolock: |
141 | kfree_skb(skb); | |
ebd4687a JS |
142 | out: |
143 | return err; | |
862b82c6 HX |
144 | } |
145 | ||
c6581a45 | 146 | int xfrm_output_resume(struct sk_buff *skb, int err) |
862b82c6 | 147 | { |
29a26a56 | 148 | struct net *net = xs_net(skb_dst(skb)->xfrm); |
be10de0a | 149 | |
c6581a45 | 150 | while (likely((err = xfrm_output_one(skb, err)) == 0)) { |
862b82c6 HX |
151 | nf_reset(skb); |
152 | ||
cf91a99d | 153 | err = skb_dst(skb)->ops->local_out(net, skb->sk, skb); |
862b82c6 | 154 | if (unlikely(err != 1)) |
c6581a45 | 155 | goto out; |
862b82c6 | 156 | |
adf30907 | 157 | if (!skb_dst(skb)->xfrm) |
13206b6b | 158 | return dst_output(net, skb->sk, skb); |
862b82c6 | 159 | |
adf30907 | 160 | err = nf_hook(skb_dst(skb)->ops->family, |
29a26a56 | 161 | NF_INET_POST_ROUTING, net, skb->sk, skb, |
adf30907 | 162 | NULL, skb_dst(skb)->dev, xfrm_output2); |
862b82c6 | 163 | if (unlikely(err != 1)) |
c6581a45 | 164 | goto out; |
862b82c6 HX |
165 | } |
166 | ||
c6581a45 HX |
167 | if (err == -EINPROGRESS) |
168 | err = 0; | |
169 | ||
170 | out: | |
862b82c6 HX |
171 | return err; |
172 | } | |
c6581a45 | 173 | EXPORT_SYMBOL_GPL(xfrm_output_resume); |
862b82c6 | 174 | |
0c4b51f0 | 175 | static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb) |
862b82c6 | 176 | { |
c6581a45 HX |
177 | return xfrm_output_resume(skb, 1); |
178 | } | |
862b82c6 | 179 | |
0c4b51f0 | 180 | static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb) |
c6581a45 HX |
181 | { |
182 | struct sk_buff *segs; | |
862b82c6 | 183 | |
9207f9d4 KK |
184 | BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET); |
185 | BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET); | |
862b82c6 HX |
186 | segs = skb_gso_segment(skb, 0); |
187 | kfree_skb(skb); | |
801678c5 | 188 | if (IS_ERR(segs)) |
862b82c6 | 189 | return PTR_ERR(segs); |
330966e5 FW |
190 | if (segs == NULL) |
191 | return -EINVAL; | |
862b82c6 HX |
192 | |
193 | do { | |
194 | struct sk_buff *nskb = segs->next; | |
195 | int err; | |
196 | ||
197 | segs->next = NULL; | |
0c4b51f0 | 198 | err = xfrm_output2(net, sk, segs); |
862b82c6 HX |
199 | |
200 | if (unlikely(err)) { | |
46cfd725 | 201 | kfree_skb_list(nskb); |
862b82c6 HX |
202 | return err; |
203 | } | |
204 | ||
205 | segs = nskb; | |
206 | } while (segs); | |
207 | ||
208 | return 0; | |
406ef77c | 209 | } |
c6581a45 | 210 | |
7026b1dd | 211 | int xfrm_output(struct sock *sk, struct sk_buff *skb) |
c6581a45 | 212 | { |
adf30907 | 213 | struct net *net = dev_net(skb_dst(skb)->dev); |
d77e38e6 | 214 | struct xfrm_state *x = skb_dst(skb)->xfrm; |
c6581a45 HX |
215 | int err; |
216 | ||
d77e38e6 SK |
217 | secpath_reset(skb); |
218 | ||
219 | if (xfrm_dev_offload_ok(skb, x)) { | |
220 | struct sec_path *sp; | |
221 | ||
222 | sp = secpath_dup(skb->sp); | |
223 | if (!sp) { | |
224 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); | |
225 | kfree_skb(skb); | |
226 | return -ENOMEM; | |
227 | } | |
228 | if (skb->sp) | |
229 | secpath_put(skb->sp); | |
230 | skb->sp = sp; | |
f1bd7d65 | 231 | skb->encapsulation = 1; |
d77e38e6 SK |
232 | |
233 | sp->olen++; | |
234 | sp->xvec[skb->sp->len++] = x; | |
235 | xfrm_state_hold(x); | |
236 | ||
237 | if (skb_is_gso(skb)) { | |
238 | skb_shinfo(skb)->gso_type |= SKB_GSO_ESP; | |
239 | ||
240 | return xfrm_output2(net, sk, skb); | |
241 | } | |
242 | ||
243 | if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM) | |
244 | goto out; | |
245 | } | |
246 | ||
c6581a45 | 247 | if (skb_is_gso(skb)) |
0c4b51f0 | 248 | return xfrm_output_gso(net, sk, skb); |
c6581a45 HX |
249 | |
250 | if (skb->ip_summed == CHECKSUM_PARTIAL) { | |
251 | err = skb_checksum_help(skb); | |
252 | if (err) { | |
59c9940e | 253 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
c6581a45 HX |
254 | kfree_skb(skb); |
255 | return err; | |
256 | } | |
257 | } | |
258 | ||
d77e38e6 | 259 | out: |
0c4b51f0 | 260 | return xfrm_output2(net, sk, skb); |
c6581a45 | 261 | } |
fc68086c | 262 | EXPORT_SYMBOL_GPL(xfrm_output); |
df9dcb45 KM |
263 | |
264 | int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb) | |
265 | { | |
266 | struct xfrm_mode *inner_mode; | |
267 | if (x->sel.family == AF_UNSPEC) | |
268 | inner_mode = xfrm_ip2inner_mode(x, | |
adf30907 | 269 | xfrm_af2proto(skb_dst(skb)->ops->family)); |
df9dcb45 KM |
270 | else |
271 | inner_mode = x->inner_mode; | |
272 | ||
273 | if (inner_mode == NULL) | |
274 | return -EAFNOSUPPORT; | |
275 | return inner_mode->afinfo->extract_output(x, skb); | |
276 | } | |
fc68086c | 277 | EXPORT_SYMBOL_GPL(xfrm_inner_extract_output); |
df9dcb45 | 278 | |
628e341f HFS |
279 | void xfrm_local_error(struct sk_buff *skb, int mtu) |
280 | { | |
844d4874 | 281 | unsigned int proto; |
628e341f HFS |
282 | struct xfrm_state_afinfo *afinfo; |
283 | ||
844d4874 HFS |
284 | if (skb->protocol == htons(ETH_P_IP)) |
285 | proto = AF_INET; | |
286 | else if (skb->protocol == htons(ETH_P_IPV6)) | |
287 | proto = AF_INET6; | |
288 | else | |
289 | return; | |
290 | ||
291 | afinfo = xfrm_state_get_afinfo(proto); | |
36dbb90a | 292 | if (afinfo) { |
af5d27c4 | 293 | afinfo->local_error(skb, mtu); |
36dbb90a TY |
294 | rcu_read_unlock(); |
295 | } | |
628e341f | 296 | } |
628e341f | 297 | EXPORT_SYMBOL_GPL(xfrm_local_error); |