Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh64-2.6
[linux-2.6] / 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/if_ether.h>
13 #include <linux/compiler.h>
14 #include <linux/skbuff.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 inline int xfrm6_output_one(struct sk_buff *skb)
47 {
48         struct dst_entry *dst = skb->dst;
49         struct xfrm_state *x = dst->xfrm;
50         struct ipv6hdr *iph;
51         int err;
52
53         if (x->props.mode == XFRM_MODE_TUNNEL) {
54                 err = xfrm6_tunnel_check_size(skb);
55                 if (err)
56                         goto error_nolock;
57         }
58
59         err = xfrm_output(skb);
60         if (err)
61                 goto error_nolock;
62
63         iph = ipv6_hdr(skb);
64         iph->payload_len = htons(skb->len - sizeof(*iph));
65
66         IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
67         err = 0;
68
69 out_exit:
70         return err;
71 error_nolock:
72         kfree_skb(skb);
73         goto out_exit;
74 }
75
76 static int xfrm6_output_finish2(struct sk_buff *skb)
77 {
78         int err;
79
80         while (likely((err = xfrm6_output_one(skb)) == 0)) {
81                 nf_reset(skb);
82
83                 err = nf_hook(PF_INET6, NF_IP6_LOCAL_OUT, &skb, NULL,
84                               skb->dst->dev, dst_output);
85                 if (unlikely(err != 1))
86                         break;
87
88                 if (!skb->dst->xfrm)
89                         return dst_output(skb);
90
91                 err = nf_hook(PF_INET6, NF_IP6_POST_ROUTING, &skb, NULL,
92                               skb->dst->dev, xfrm6_output_finish2);
93                 if (unlikely(err != 1))
94                         break;
95         }
96
97         return err;
98 }
99
100 static int xfrm6_output_finish(struct sk_buff *skb)
101 {
102         struct sk_buff *segs;
103
104         if (!skb_is_gso(skb))
105                 return xfrm6_output_finish2(skb);
106
107         skb->protocol = htons(ETH_P_IPV6);
108         segs = skb_gso_segment(skb, 0);
109         kfree_skb(skb);
110         if (unlikely(IS_ERR(segs)))
111                 return PTR_ERR(segs);
112
113         do {
114                 struct sk_buff *nskb = segs->next;
115                 int err;
116
117                 segs->next = NULL;
118                 err = xfrm6_output_finish2(segs);
119
120                 if (unlikely(err)) {
121                         while ((segs = nskb)) {
122                                 nskb = segs->next;
123                                 segs->next = NULL;
124                                 kfree_skb(segs);
125                         }
126                         return err;
127                 }
128
129                 segs = nskb;
130         } while (segs);
131
132         return 0;
133 }
134
135 int xfrm6_output(struct sk_buff *skb)
136 {
137         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
138                        xfrm6_output_finish);
139 }