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 HX |
16 | #include <linux/skbuff.h> |
17 | #include <linux/spinlock.h> | |
406ef77c HX |
18 | #include <net/dst.h> |
19 | #include <net/xfrm.h> | |
20 | ||
c6581a45 HX |
21 | static int xfrm_output2(struct sk_buff *skb); |
22 | ||
83815dea HX |
23 | static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb) |
24 | { | |
adf30907 | 25 | struct dst_entry *dst = skb_dst(skb); |
550ade84 | 26 | int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev) |
83815dea | 27 | - skb_headroom(skb); |
f5184d26 | 28 | int ntail = dst->dev->needed_tailroom - skb_tailroom(skb); |
83815dea | 29 | |
d01dbeb6 HX |
30 | if (nhead <= 0) { |
31 | if (ntail <= 0) | |
32 | return 0; | |
33 | nhead = 0; | |
34 | } else if (ntail < 0) | |
35 | ntail = 0; | |
36 | ||
37 | return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC); | |
83815dea HX |
38 | } |
39 | ||
c6581a45 | 40 | static int xfrm_output_one(struct sk_buff *skb, int err) |
406ef77c | 41 | { |
adf30907 | 42 | struct dst_entry *dst = skb_dst(skb); |
406ef77c | 43 | struct xfrm_state *x = dst->xfrm; |
a6483b79 | 44 | struct net *net = xs_net(x); |
406ef77c | 45 | |
c6581a45 HX |
46 | if (err <= 0) |
47 | goto resume; | |
406ef77c HX |
48 | |
49 | do { | |
910ef70a | 50 | err = xfrm_state_check_space(x, skb); |
b15c4bcd | 51 | if (err) { |
59c9940e | 52 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
910ef70a | 53 | goto error_nolock; |
b15c4bcd | 54 | } |
910ef70a | 55 | |
a2deb6d2 | 56 | err = x->outer_mode->output(x, skb); |
b15c4bcd | 57 | if (err) { |
59c9940e | 58 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR); |
910ef70a | 59 | goto error_nolock; |
b15c4bcd | 60 | } |
a2deb6d2 | 61 | |
406ef77c | 62 | spin_lock_bh(&x->lock); |
910ef70a | 63 | err = xfrm_state_check_expire(x); |
b15c4bcd | 64 | if (err) { |
59c9940e | 65 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED); |
406ef77c | 66 | goto error; |
b15c4bcd | 67 | } |
406ef77c | 68 | |
436a0a40 | 69 | if (x->type->flags & XFRM_TYPE_REPLAY_PROT) { |
b318e0e4 | 70 | XFRM_SKB_CB(skb)->seq.output = ++x->replay.oseq; |
e1af9f27 | 71 | if (unlikely(x->replay.oseq == 0)) { |
59c9940e | 72 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR); |
e1af9f27 | 73 | x->replay.oseq--; |
afeb14b4 | 74 | xfrm_audit_state_replay_overflow(x, skb); |
dbb1db8b | 75 | err = -EOVERFLOW; |
e1af9f27 PM |
76 | goto error; |
77 | } | |
a6483b79 | 78 | if (xfrm_aevent_is_on(net)) |
cdf7e668 | 79 | xfrm_replay_notify(x, XFRM_REPLAY_UPDATE); |
436a0a40 HX |
80 | } |
81 | ||
406ef77c HX |
82 | x->curlft.bytes += skb->len; |
83 | x->curlft.packets++; | |
84 | ||
406ef77c HX |
85 | spin_unlock_bh(&x->lock); |
86 | ||
b7c6538c | 87 | err = x->type->output(x, skb); |
fcb8c156 HX |
88 | if (err == -EINPROGRESS) |
89 | goto out_exit; | |
c6581a45 HX |
90 | |
91 | resume: | |
0aa64774 | 92 | if (err) { |
59c9940e | 93 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR); |
b7c6538c | 94 | goto error_nolock; |
0aa64774 | 95 | } |
b7c6538c | 96 | |
adf30907 ED |
97 | dst = dst_pop(dst); |
98 | if (!dst) { | |
59c9940e | 99 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
406ef77c HX |
100 | err = -EHOSTUNREACH; |
101 | goto error_nolock; | |
102 | } | |
adf30907 | 103 | skb_dst_set(skb, dst); |
406ef77c | 104 | x = dst->xfrm; |
13996378 | 105 | } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL)); |
406ef77c HX |
106 | |
107 | err = 0; | |
108 | ||
862b82c6 | 109 | out_exit: |
406ef77c HX |
110 | return err; |
111 | error: | |
112 | spin_unlock_bh(&x->lock); | |
862b82c6 HX |
113 | error_nolock: |
114 | kfree_skb(skb); | |
115 | goto out_exit; | |
116 | } | |
117 | ||
c6581a45 | 118 | int xfrm_output_resume(struct sk_buff *skb, int err) |
862b82c6 | 119 | { |
c6581a45 | 120 | while (likely((err = xfrm_output_one(skb, err)) == 0)) { |
862b82c6 HX |
121 | nf_reset(skb); |
122 | ||
adf30907 | 123 | err = skb_dst(skb)->ops->local_out(skb); |
862b82c6 | 124 | if (unlikely(err != 1)) |
c6581a45 | 125 | goto out; |
862b82c6 | 126 | |
adf30907 | 127 | if (!skb_dst(skb)->xfrm) |
862b82c6 HX |
128 | return dst_output(skb); |
129 | ||
adf30907 | 130 | err = nf_hook(skb_dst(skb)->ops->family, |
294b4baf | 131 | NF_INET_POST_ROUTING, skb, |
adf30907 | 132 | NULL, skb_dst(skb)->dev, xfrm_output2); |
862b82c6 | 133 | if (unlikely(err != 1)) |
c6581a45 | 134 | goto out; |
862b82c6 HX |
135 | } |
136 | ||
c6581a45 HX |
137 | if (err == -EINPROGRESS) |
138 | err = 0; | |
139 | ||
140 | out: | |
862b82c6 HX |
141 | return err; |
142 | } | |
c6581a45 | 143 | EXPORT_SYMBOL_GPL(xfrm_output_resume); |
862b82c6 | 144 | |
c6581a45 | 145 | static int xfrm_output2(struct sk_buff *skb) |
862b82c6 | 146 | { |
c6581a45 HX |
147 | return xfrm_output_resume(skb, 1); |
148 | } | |
862b82c6 | 149 | |
c6581a45 HX |
150 | static int xfrm_output_gso(struct sk_buff *skb) |
151 | { | |
152 | struct sk_buff *segs; | |
862b82c6 HX |
153 | |
154 | segs = skb_gso_segment(skb, 0); | |
155 | kfree_skb(skb); | |
801678c5 | 156 | if (IS_ERR(segs)) |
862b82c6 HX |
157 | return PTR_ERR(segs); |
158 | ||
159 | do { | |
160 | struct sk_buff *nskb = segs->next; | |
161 | int err; | |
162 | ||
163 | segs->next = NULL; | |
164 | err = xfrm_output2(segs); | |
165 | ||
166 | if (unlikely(err)) { | |
167 | while ((segs = nskb)) { | |
168 | nskb = segs->next; | |
169 | segs->next = NULL; | |
170 | kfree_skb(segs); | |
171 | } | |
172 | return err; | |
173 | } | |
174 | ||
175 | segs = nskb; | |
176 | } while (segs); | |
177 | ||
178 | return 0; | |
406ef77c | 179 | } |
c6581a45 HX |
180 | |
181 | int xfrm_output(struct sk_buff *skb) | |
182 | { | |
adf30907 | 183 | struct net *net = dev_net(skb_dst(skb)->dev); |
c6581a45 HX |
184 | int err; |
185 | ||
186 | if (skb_is_gso(skb)) | |
187 | return xfrm_output_gso(skb); | |
188 | ||
189 | if (skb->ip_summed == CHECKSUM_PARTIAL) { | |
190 | err = skb_checksum_help(skb); | |
191 | if (err) { | |
59c9940e | 192 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
c6581a45 HX |
193 | kfree_skb(skb); |
194 | return err; | |
195 | } | |
196 | } | |
197 | ||
198 | return xfrm_output2(skb); | |
199 | } | |
df9dcb45 KM |
200 | |
201 | int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb) | |
202 | { | |
203 | struct xfrm_mode *inner_mode; | |
204 | if (x->sel.family == AF_UNSPEC) | |
205 | inner_mode = xfrm_ip2inner_mode(x, | |
adf30907 | 206 | xfrm_af2proto(skb_dst(skb)->ops->family)); |
df9dcb45 KM |
207 | else |
208 | inner_mode = x->inner_mode; | |
209 | ||
210 | if (inner_mode == NULL) | |
211 | return -EAFNOSUPPORT; | |
212 | return inner_mode->afinfo->extract_output(x, skb); | |
213 | } | |
214 | ||
406ef77c | 215 | EXPORT_SYMBOL_GPL(xfrm_output); |
df9dcb45 | 216 | EXPORT_SYMBOL_GPL(xfrm_inner_extract_output); |