[NET]: Replace CHECKSUM_HW by CHECKSUM_PARTIAL/CHECKSUM_COMPLETE
[linux-2.6.git] / net / ipv4 / xfrm4_output.c
1 /*
2  * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
3  * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
4  * 
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version
8  * 2 of the License, or (at your option) any later version.
9  */
10
11 #include <linux/compiler.h>
12 #include <linux/if_ether.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/spinlock.h>
16 #include <linux/netfilter_ipv4.h>
17 #include <net/ip.h>
18 #include <net/xfrm.h>
19 #include <net/icmp.h>
20
21 static int xfrm4_tunnel_check_size(struct sk_buff *skb)
22 {
23         int mtu, ret = 0;
24         struct dst_entry *dst;
25         struct iphdr *iph = skb->nh.iph;
26
27         if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
28                 goto out;
29
30         IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
31         
32         if (!(iph->frag_off & htons(IP_DF)) || skb->local_df)
33                 goto out;
34
35         dst = skb->dst;
36         mtu = dst_mtu(dst);
37         if (skb->len > mtu) {
38                 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
39                 ret = -EMSGSIZE;
40         }
41 out:
42         return ret;
43 }
44
45 static int xfrm4_output_one(struct sk_buff *skb)
46 {
47         struct dst_entry *dst = skb->dst;
48         struct xfrm_state *x = dst->xfrm;
49         int err;
50         
51         if (skb->ip_summed == CHECKSUM_PARTIAL) {
52                 err = skb_checksum_help(skb);
53                 if (err)
54                         goto error_nolock;
55         }
56
57         if (x->props.mode) {
58                 err = xfrm4_tunnel_check_size(skb);
59                 if (err)
60                         goto error_nolock;
61         }
62
63         do {
64                 spin_lock_bh(&x->lock);
65                 err = xfrm_state_check(x, skb);
66                 if (err)
67                         goto error;
68
69                 err = x->mode->output(skb);
70                 if (err)
71                         goto error;
72
73                 err = x->type->output(x, skb);
74                 if (err)
75                         goto error;
76
77                 x->curlft.bytes += skb->len;
78                 x->curlft.packets++;
79
80                 spin_unlock_bh(&x->lock);
81         
82                 if (!(skb->dst = dst_pop(dst))) {
83                         err = -EHOSTUNREACH;
84                         goto error_nolock;
85                 }
86                 dst = skb->dst;
87                 x = dst->xfrm;
88         } while (x && !x->props.mode);
89
90         IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
91         err = 0;
92
93 out_exit:
94         return err;
95 error:
96         spin_unlock_bh(&x->lock);
97 error_nolock:
98         kfree_skb(skb);
99         goto out_exit;
100 }
101
102 static int xfrm4_output_finish2(struct sk_buff *skb)
103 {
104         int err;
105
106         while (likely((err = xfrm4_output_one(skb)) == 0)) {
107                 nf_reset(skb);
108
109                 err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
110                               skb->dst->dev, dst_output);
111                 if (unlikely(err != 1))
112                         break;
113
114                 if (!skb->dst->xfrm)
115                         return dst_output(skb);
116
117                 err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL,
118                               skb->dst->dev, xfrm4_output_finish2);
119                 if (unlikely(err != 1))
120                         break;
121         }
122
123         return err;
124 }
125
126 static int xfrm4_output_finish(struct sk_buff *skb)
127 {
128         struct sk_buff *segs;
129
130 #ifdef CONFIG_NETFILTER
131         if (!skb->dst->xfrm) {
132                 IPCB(skb)->flags |= IPSKB_REROUTED;
133                 return dst_output(skb);
134         }
135 #endif
136
137         if (!skb_is_gso(skb))
138                 return xfrm4_output_finish2(skb);
139
140         skb->protocol = htons(ETH_P_IP);
141         segs = skb_gso_segment(skb, 0);
142         kfree_skb(skb);
143         if (unlikely(IS_ERR(segs)))
144                 return PTR_ERR(segs);
145
146         do {
147                 struct sk_buff *nskb = segs->next;
148                 int err;
149
150                 segs->next = NULL;
151                 err = xfrm4_output_finish2(segs);
152
153                 if (unlikely(err)) {
154                         while ((segs = nskb)) {
155                                 nskb = segs->next;
156                                 segs->next = NULL;
157                                 kfree_skb(segs);
158                         }
159                         return err;
160                 }
161
162                 segs = nskb;
163         } while (segs);
164
165         return 0;
166 }
167
168 int xfrm4_output(struct sk_buff *skb)
169 {
170         return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
171                             xfrm4_output_finish,
172                             !(IPCB(skb)->flags & IPSKB_REROUTED));
173 }