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 | ||
c6581a45 HX |
22 | static int xfrm_output2(struct sk_buff *skb); |
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 | ||
c6581a45 | 41 | static int xfrm_output_one(struct sk_buff *skb, int err) |
406ef77c | 42 | { |
adf30907 | 43 | struct dst_entry *dst = skb_dst(skb); |
406ef77c | 44 | struct xfrm_state *x = dst->xfrm; |
a6483b79 | 45 | struct net *net = xs_net(x); |
406ef77c | 46 | |
c6581a45 HX |
47 | if (err <= 0) |
48 | goto resume; | |
406ef77c HX |
49 | |
50 | do { | |
26b2072e | 51 | err = xfrm_skb_check_space(skb); |
b15c4bcd | 52 | if (err) { |
59c9940e | 53 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
910ef70a | 54 | goto error_nolock; |
b15c4bcd | 55 | } |
910ef70a | 56 | |
a2deb6d2 | 57 | err = x->outer_mode->output(x, skb); |
b15c4bcd | 58 | if (err) { |
59c9940e | 59 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR); |
910ef70a | 60 | goto error_nolock; |
b15c4bcd | 61 | } |
a2deb6d2 | 62 | |
406ef77c | 63 | spin_lock_bh(&x->lock); |
910ef70a | 64 | err = xfrm_state_check_expire(x); |
b15c4bcd | 65 | if (err) { |
59c9940e | 66 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED); |
406ef77c | 67 | goto error; |
b15c4bcd | 68 | } |
406ef77c | 69 | |
9fdc4883 SK |
70 | err = x->repl->overflow(x, skb); |
71 | if (err) { | |
72 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR); | |
73 | goto error; | |
436a0a40 HX |
74 | } |
75 | ||
406ef77c HX |
76 | x->curlft.bytes += skb->len; |
77 | x->curlft.packets++; | |
78 | ||
406ef77c HX |
79 | spin_unlock_bh(&x->lock); |
80 | ||
3bc07321 SK |
81 | skb_dst_force(skb); |
82 | ||
b7c6538c | 83 | err = x->type->output(x, skb); |
fcb8c156 HX |
84 | if (err == -EINPROGRESS) |
85 | goto out_exit; | |
c6581a45 HX |
86 | |
87 | resume: | |
0aa64774 | 88 | if (err) { |
59c9940e | 89 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR); |
b7c6538c | 90 | goto error_nolock; |
0aa64774 | 91 | } |
b7c6538c | 92 | |
8764ab2c | 93 | dst = skb_dst_pop(skb); |
adf30907 | 94 | if (!dst) { |
59c9940e | 95 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
406ef77c HX |
96 | err = -EHOSTUNREACH; |
97 | goto error_nolock; | |
98 | } | |
e433430a | 99 | skb_dst_set(skb, dst); |
406ef77c | 100 | x = dst->xfrm; |
13996378 | 101 | } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL)); |
406ef77c HX |
102 | |
103 | err = 0; | |
104 | ||
862b82c6 | 105 | out_exit: |
406ef77c HX |
106 | return err; |
107 | error: | |
108 | spin_unlock_bh(&x->lock); | |
862b82c6 HX |
109 | error_nolock: |
110 | kfree_skb(skb); | |
111 | goto out_exit; | |
112 | } | |
113 | ||
c6581a45 | 114 | int xfrm_output_resume(struct sk_buff *skb, int err) |
862b82c6 | 115 | { |
c6581a45 | 116 | while (likely((err = xfrm_output_one(skb, err)) == 0)) { |
862b82c6 HX |
117 | nf_reset(skb); |
118 | ||
adf30907 | 119 | err = skb_dst(skb)->ops->local_out(skb); |
862b82c6 | 120 | if (unlikely(err != 1)) |
c6581a45 | 121 | goto out; |
862b82c6 | 122 | |
adf30907 | 123 | if (!skb_dst(skb)->xfrm) |
862b82c6 HX |
124 | return dst_output(skb); |
125 | ||
adf30907 | 126 | err = nf_hook(skb_dst(skb)->ops->family, |
294b4baf | 127 | NF_INET_POST_ROUTING, skb, |
adf30907 | 128 | NULL, skb_dst(skb)->dev, xfrm_output2); |
862b82c6 | 129 | if (unlikely(err != 1)) |
c6581a45 | 130 | goto out; |
862b82c6 HX |
131 | } |
132 | ||
c6581a45 HX |
133 | if (err == -EINPROGRESS) |
134 | err = 0; | |
135 | ||
136 | out: | |
862b82c6 HX |
137 | return err; |
138 | } | |
c6581a45 | 139 | EXPORT_SYMBOL_GPL(xfrm_output_resume); |
862b82c6 | 140 | |
c6581a45 | 141 | static int xfrm_output2(struct sk_buff *skb) |
862b82c6 | 142 | { |
c6581a45 HX |
143 | return xfrm_output_resume(skb, 1); |
144 | } | |
862b82c6 | 145 | |
c6581a45 HX |
146 | static int xfrm_output_gso(struct sk_buff *skb) |
147 | { | |
148 | struct sk_buff *segs; | |
862b82c6 HX |
149 | |
150 | segs = skb_gso_segment(skb, 0); | |
151 | kfree_skb(skb); | |
801678c5 | 152 | if (IS_ERR(segs)) |
862b82c6 HX |
153 | return PTR_ERR(segs); |
154 | ||
155 | do { | |
156 | struct sk_buff *nskb = segs->next; | |
157 | int err; | |
158 | ||
159 | segs->next = NULL; | |
160 | err = xfrm_output2(segs); | |
161 | ||
162 | if (unlikely(err)) { | |
163 | while ((segs = nskb)) { | |
164 | nskb = segs->next; | |
165 | segs->next = NULL; | |
166 | kfree_skb(segs); | |
167 | } | |
168 | return err; | |
169 | } | |
170 | ||
171 | segs = nskb; | |
172 | } while (segs); | |
173 | ||
174 | return 0; | |
406ef77c | 175 | } |
c6581a45 HX |
176 | |
177 | int xfrm_output(struct sk_buff *skb) | |
178 | { | |
adf30907 | 179 | struct net *net = dev_net(skb_dst(skb)->dev); |
c6581a45 HX |
180 | int err; |
181 | ||
182 | if (skb_is_gso(skb)) | |
183 | return xfrm_output_gso(skb); | |
184 | ||
185 | if (skb->ip_summed == CHECKSUM_PARTIAL) { | |
186 | err = skb_checksum_help(skb); | |
187 | if (err) { | |
59c9940e | 188 | XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR); |
c6581a45 HX |
189 | kfree_skb(skb); |
190 | return err; | |
191 | } | |
192 | } | |
193 | ||
194 | return xfrm_output2(skb); | |
195 | } | |
df9dcb45 KM |
196 | |
197 | int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb) | |
198 | { | |
199 | struct xfrm_mode *inner_mode; | |
200 | if (x->sel.family == AF_UNSPEC) | |
201 | inner_mode = xfrm_ip2inner_mode(x, | |
adf30907 | 202 | xfrm_af2proto(skb_dst(skb)->ops->family)); |
df9dcb45 KM |
203 | else |
204 | inner_mode = x->inner_mode; | |
205 | ||
206 | if (inner_mode == NULL) | |
207 | return -EAFNOSUPPORT; | |
208 | return inner_mode->afinfo->extract_output(x, skb); | |
209 | } | |
210 | ||
406ef77c | 211 | EXPORT_SYMBOL_GPL(xfrm_output); |
df9dcb45 | 212 | EXPORT_SYMBOL_GPL(xfrm_inner_extract_output); |