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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/xfrm4_output.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv4/xfrm4_output.c')
-rw-r--r--net/ipv4/xfrm4_output.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
new file mode 100644
index 000000000000..af2392ae5769
--- /dev/null
+++ b/net/ipv4/xfrm4_output.c
@@ -0,0 +1,141 @@
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/skbuff.h>
12#include <linux/spinlock.h>
13#include <net/inet_ecn.h>
14#include <net/ip.h>
15#include <net/xfrm.h>
16#include <net/icmp.h>
17
18/* Add encapsulation header.
19 *
20 * In transport mode, the IP header will be moved forward to make space
21 * for the encapsulation header.
22 *
23 * In tunnel mode, the top IP header will be constructed per RFC 2401.
24 * The following fields in it shall be filled in by x->type->output:
25 * tot_len
26 * check
27 *
28 * On exit, skb->h will be set to the start of the payload to be processed
29 * by x->type->output and skb->nh will be set to the top IP header.
30 */
31static void xfrm4_encap(struct sk_buff *skb)
32{
33 struct dst_entry *dst = skb->dst;
34 struct xfrm_state *x = dst->xfrm;
35 struct iphdr *iph, *top_iph;
36
37 iph = skb->nh.iph;
38 skb->h.ipiph = iph;
39
40 skb->nh.raw = skb_push(skb, x->props.header_len);
41 top_iph = skb->nh.iph;
42
43 if (!x->props.mode) {
44 skb->h.raw += iph->ihl*4;
45 memmove(top_iph, iph, iph->ihl*4);
46 return;
47 }
48
49 top_iph->ihl = 5;
50 top_iph->version = 4;
51
52 /* DS disclosed */
53 top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
54 if (x->props.flags & XFRM_STATE_NOECN)
55 IP_ECN_clear(top_iph);
56
57 top_iph->frag_off = iph->frag_off & htons(IP_DF);
58 if (!top_iph->frag_off)
59 __ip_select_ident(top_iph, dst, 0);
60
61 top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);
62
63 top_iph->saddr = x->props.saddr.a4;
64 top_iph->daddr = x->id.daddr.a4;
65 top_iph->protocol = IPPROTO_IPIP;
66
67 memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
68}
69
70static int xfrm4_tunnel_check_size(struct sk_buff *skb)
71{
72 int mtu, ret = 0;
73 struct dst_entry *dst;
74 struct iphdr *iph = skb->nh.iph;
75
76 if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
77 goto out;
78
79 IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
80
81 if (!(iph->frag_off & htons(IP_DF)) || skb->local_df)
82 goto out;
83
84 dst = skb->dst;
85 mtu = dst_mtu(dst);
86 if (skb->len > mtu) {
87 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
88 ret = -EMSGSIZE;
89 }
90out:
91 return ret;
92}
93
94int xfrm4_output(struct sk_buff *skb)
95{
96 struct dst_entry *dst = skb->dst;
97 struct xfrm_state *x = dst->xfrm;
98 int err;
99
100 if (skb->ip_summed == CHECKSUM_HW) {
101 err = skb_checksum_help(skb, 0);
102 if (err)
103 goto error_nolock;
104 }
105
106 if (x->props.mode) {
107 err = xfrm4_tunnel_check_size(skb);
108 if (err)
109 goto error_nolock;
110 }
111
112 spin_lock_bh(&x->lock);
113 err = xfrm_state_check(x, skb);
114 if (err)
115 goto error;
116
117 xfrm4_encap(skb);
118
119 err = x->type->output(x, skb);
120 if (err)
121 goto error;
122
123 x->curlft.bytes += skb->len;
124 x->curlft.packets++;
125
126 spin_unlock_bh(&x->lock);
127
128 if (!(skb->dst = dst_pop(dst))) {
129 err = -EHOSTUNREACH;
130 goto error_nolock;
131 }
132 err = NET_XMIT_BYPASS;
133
134out_exit:
135 return err;
136error:
137 spin_unlock_bh(&x->lock);
138error_nolock:
139 kfree_skb(skb);
140 goto out_exit;
141}