[IPV6]: Decentralize EXPORT_SYMBOLs.
[linux-2.6.git] / net / ipv6 / xfrm6_output.c
1 /*
2  * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
3  * Copyright (C) 2002 USAGI/WIDE Project
4  * Copyright (c) 2004 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/compiler.h>
13 #include <linux/skbuff.h>
14 #include <linux/spinlock.h>
15 #include <linux/icmpv6.h>
16 #include <linux/netfilter_ipv6.h>
17 #include <net/ipv6.h>
18 #include <net/xfrm.h>
19
20 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
21                           u8 **prevhdr)
22 {
23         return ip6_find_1stfragopt(skb, prevhdr);
24 }
25
26 EXPORT_SYMBOL(xfrm6_find_1stfragopt);
27
28 static int xfrm6_tunnel_check_size(struct sk_buff *skb)
29 {
30         int mtu, ret = 0;
31         struct dst_entry *dst = skb->dst;
32
33         mtu = dst_mtu(dst);
34         if (mtu < IPV6_MIN_MTU)
35                 mtu = IPV6_MIN_MTU;
36
37         if (skb->len > mtu) {
38                 skb->dev = dst->dev;
39                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
40                 ret = -EMSGSIZE;
41         }
42
43         return ret;
44 }
45
46 static int xfrm6_output_one(struct sk_buff *skb)
47 {
48         struct dst_entry *dst = skb->dst;
49         struct xfrm_state *x = dst->xfrm;
50         int err;
51
52         if (skb->ip_summed == CHECKSUM_PARTIAL) {
53                 err = skb_checksum_help(skb);
54                 if (err)
55                         goto error_nolock;
56         }
57
58         if (x->props.mode == XFRM_MODE_TUNNEL) {
59                 err = xfrm6_tunnel_check_size(skb);
60                 if (err)
61                         goto error_nolock;
62         }
63
64         do {
65                 spin_lock_bh(&x->lock);
66                 err = xfrm_state_check(x, skb);
67                 if (err)
68                         goto error;
69
70                 err = x->mode->output(x, skb);
71                 if (err)
72                         goto error;
73
74                 err = x->type->output(x, skb);
75                 if (err)
76                         goto error;
77
78                 x->curlft.bytes += skb->len;
79                 x->curlft.packets++;
80                 if (x->props.mode == XFRM_MODE_ROUTEOPTIMIZATION)
81                         x->lastused = get_seconds();
82
83                 spin_unlock_bh(&x->lock);
84
85                 skb->nh.raw = skb->data;
86
87                 if (!(skb->dst = dst_pop(dst))) {
88                         err = -EHOSTUNREACH;
89                         goto error_nolock;
90                 }
91                 dst = skb->dst;
92                 x = dst->xfrm;
93         } while (x && (x->props.mode != XFRM_MODE_TUNNEL));
94
95         IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
96         err = 0;
97
98 out_exit:
99         return err;
100 error:
101         spin_unlock_bh(&x->lock);
102 error_nolock:
103         kfree_skb(skb);
104         goto out_exit;
105 }
106
107 static int xfrm6_output_finish2(struct sk_buff *skb)
108 {
109         int err;
110
111         while (likely((err = xfrm6_output_one(skb)) == 0)) {
112                 nf_reset(skb);
113
114                 err = nf_hook(PF_INET6, NF_IP6_LOCAL_OUT, &skb, NULL,
115                               skb->dst->dev, dst_output);
116                 if (unlikely(err != 1))
117                         break;
118
119                 if (!skb->dst->xfrm)
120                         return dst_output(skb);
121
122                 err = nf_hook(PF_INET6, NF_IP6_POST_ROUTING, &skb, NULL,
123                               skb->dst->dev, xfrm6_output_finish2);
124                 if (unlikely(err != 1))
125                         break;
126         }
127
128         return err;
129 }
130
131 static int xfrm6_output_finish(struct sk_buff *skb)
132 {
133         struct sk_buff *segs;
134
135         if (!skb_is_gso(skb))
136                 return xfrm6_output_finish2(skb);
137
138         skb->protocol = htons(ETH_P_IPV6);
139         segs = skb_gso_segment(skb, 0);
140         kfree_skb(skb);
141         if (unlikely(IS_ERR(segs)))
142                 return PTR_ERR(segs);
143
144         do {
145                 struct sk_buff *nskb = segs->next;
146                 int err;
147
148                 segs->next = NULL;
149                 err = xfrm6_output_finish2(segs);
150
151                 if (unlikely(err)) {
152                         while ((segs = nskb)) {
153                                 nskb = segs->next;
154                                 segs->next = NULL;
155                                 kfree_skb(segs);
156                         }
157                         return err;
158                 }
159
160                 segs = nskb;
161         } while (segs);
162
163         return 0;
164 }
165
166 int xfrm6_output(struct sk_buff *skb)
167 {
168         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
169                        xfrm6_output_finish);
170 }