[IPSEC]: Handle GSO packets
[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 static int xfrm6_tunnel_check_size(struct sk_buff *skb)
21 {
22         int mtu, ret = 0;
23         struct dst_entry *dst = skb->dst;
24
25         mtu = dst_mtu(dst);
26         if (mtu < IPV6_MIN_MTU)
27                 mtu = IPV6_MIN_MTU;
28
29         if (skb->len > mtu) {
30                 skb->dev = dst->dev;
31                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
32                 ret = -EMSGSIZE;
33         }
34
35         return ret;
36 }
37
38 static int xfrm6_output_one(struct sk_buff *skb)
39 {
40         struct dst_entry *dst = skb->dst;
41         struct xfrm_state *x = dst->xfrm;
42         int err;
43         
44         if (skb->ip_summed == CHECKSUM_HW) {
45                 err = skb_checksum_help(skb, 0);
46                 if (err)
47                         goto error_nolock;
48         }
49
50         if (x->props.mode) {
51                 err = xfrm6_tunnel_check_size(skb);
52                 if (err)
53                         goto error_nolock;
54         }
55
56         do {
57                 spin_lock_bh(&x->lock);
58                 err = xfrm_state_check(x, skb);
59                 if (err)
60                         goto error;
61
62                 err = x->mode->output(skb);
63                 if (err)
64                         goto error;
65
66                 err = x->type->output(x, skb);
67                 if (err)
68                         goto error;
69
70                 x->curlft.bytes += skb->len;
71                 x->curlft.packets++;
72
73                 spin_unlock_bh(&x->lock);
74
75                 skb->nh.raw = skb->data;
76                 
77                 if (!(skb->dst = dst_pop(dst))) {
78                         err = -EHOSTUNREACH;
79                         goto error_nolock;
80                 }
81                 dst = skb->dst;
82                 x = dst->xfrm;
83         } while (x && !x->props.mode);
84
85         IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
86         err = 0;
87
88 out_exit:
89         return err;
90 error:
91         spin_unlock_bh(&x->lock);
92 error_nolock:
93         kfree_skb(skb);
94         goto out_exit;
95 }
96
97 static int xfrm6_output_finish2(struct sk_buff *skb)
98 {
99         int err;
100
101         while (likely((err = xfrm6_output_one(skb)) == 0)) {
102                 nf_reset(skb);
103         
104                 err = nf_hook(PF_INET6, NF_IP6_LOCAL_OUT, &skb, NULL,
105                               skb->dst->dev, dst_output);
106                 if (unlikely(err != 1))
107                         break;
108
109                 if (!skb->dst->xfrm)
110                         return dst_output(skb);
111
112                 err = nf_hook(PF_INET6, NF_IP6_POST_ROUTING, &skb, NULL,
113                               skb->dst->dev, xfrm6_output_finish2);
114                 if (unlikely(err != 1))
115                         break;
116         }
117
118         return err;
119 }
120
121 static int xfrm6_output_finish(struct sk_buff *skb)
122 {
123         struct sk_buff *segs;
124
125         if (!skb_shinfo(skb)->gso_size)
126                 return xfrm6_output_finish2(skb);
127
128         skb->protocol = htons(ETH_P_IP);
129         segs = skb_gso_segment(skb, 0);
130         kfree_skb(skb);
131         if (unlikely(IS_ERR(segs)))
132                 return PTR_ERR(segs);
133
134         do {
135                 struct sk_buff *nskb = segs->next;
136                 int err;
137
138                 segs->next = NULL;
139                 err = xfrm6_output_finish2(segs);
140
141                 if (unlikely(err)) {
142                         while ((segs = nskb)) {
143                                 nskb = segs->next;
144                                 segs->next = NULL;
145                                 kfree_skb(segs);
146                         }
147                         return err;
148                 }
149
150                 segs = nskb;
151         } while (segs);
152
153         return 0;
154 }
155
156 int xfrm6_output(struct sk_buff *skb)
157 {
158         return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
159                        xfrm6_output_finish);
160 }