Staging: hv: remove OnChildDeviceRemove vmbus_driver callback
[zen-stable.git] / net / ipv4 / ipcomp.c
blob629067571f0286316dded32c79a8dbdf70840df6
1 /*
2 * IP Payload Compression Protocol (IPComp) - RFC3173.
4 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
11 * Todo:
12 * - Tunable compression parameters.
13 * - Compression stats.
14 * - Adaptive compression.
16 #include <linux/module.h>
17 #include <linux/err.h>
18 #include <linux/rtnetlink.h>
19 #include <net/ip.h>
20 #include <net/xfrm.h>
21 #include <net/icmp.h>
22 #include <net/ipcomp.h>
23 #include <net/protocol.h>
24 #include <net/sock.h>
26 static void ipcomp4_err(struct sk_buff *skb, u32 info)
28 struct net *net = dev_net(skb->dev);
29 __be32 spi;
30 struct iphdr *iph = (struct iphdr *)skb->data;
31 struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
32 struct xfrm_state *x;
34 if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
35 icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
36 return;
38 spi = htonl(ntohs(ipch->cpi));
39 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr,
40 spi, IPPROTO_COMP, AF_INET);
41 if (!x)
42 return;
43 NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n",
44 spi, &iph->daddr);
45 xfrm_state_put(x);
48 /* We always hold one tunnel user reference to indicate a tunnel */
49 static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
51 struct net *net = xs_net(x);
52 struct xfrm_state *t;
54 t = xfrm_state_alloc(net);
55 if (t == NULL)
56 goto out;
58 t->id.proto = IPPROTO_IPIP;
59 t->id.spi = x->props.saddr.a4;
60 t->id.daddr.a4 = x->id.daddr.a4;
61 memcpy(&t->sel, &x->sel, sizeof(t->sel));
62 t->props.family = AF_INET;
63 t->props.mode = x->props.mode;
64 t->props.saddr.a4 = x->props.saddr.a4;
65 t->props.flags = x->props.flags;
66 memcpy(&t->mark, &x->mark, sizeof(t->mark));
68 if (xfrm_init_state(t))
69 goto error;
71 atomic_set(&t->tunnel_users, 1);
72 out:
73 return t;
75 error:
76 t->km.state = XFRM_STATE_DEAD;
77 xfrm_state_put(t);
78 t = NULL;
79 goto out;
83 * Must be protected by xfrm_cfg_mutex. State and tunnel user references are
84 * always incremented on success.
86 static int ipcomp_tunnel_attach(struct xfrm_state *x)
88 struct net *net = xs_net(x);
89 int err = 0;
90 struct xfrm_state *t;
91 u32 mark = x->mark.v & x->mark.m;
93 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4,
94 x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
95 if (!t) {
96 t = ipcomp_tunnel_create(x);
97 if (!t) {
98 err = -EINVAL;
99 goto out;
101 xfrm_state_insert(t);
102 xfrm_state_hold(t);
104 x->tunnel = t;
105 atomic_inc(&t->tunnel_users);
106 out:
107 return err;
110 static int ipcomp4_init_state(struct xfrm_state *x)
112 int err = -EINVAL;
114 x->props.header_len = 0;
115 switch (x->props.mode) {
116 case XFRM_MODE_TRANSPORT:
117 break;
118 case XFRM_MODE_TUNNEL:
119 x->props.header_len += sizeof(struct iphdr);
120 break;
121 default:
122 goto out;
125 err = ipcomp_init_state(x);
126 if (err)
127 goto out;
129 if (x->props.mode == XFRM_MODE_TUNNEL) {
130 err = ipcomp_tunnel_attach(x);
131 if (err)
132 goto out;
135 err = 0;
136 out:
137 return err;
140 static const struct xfrm_type ipcomp_type = {
141 .description = "IPCOMP4",
142 .owner = THIS_MODULE,
143 .proto = IPPROTO_COMP,
144 .init_state = ipcomp4_init_state,
145 .destructor = ipcomp_destroy,
146 .input = ipcomp_input,
147 .output = ipcomp_output
150 static const struct net_protocol ipcomp4_protocol = {
151 .handler = xfrm4_rcv,
152 .err_handler = ipcomp4_err,
153 .no_policy = 1,
156 static int __init ipcomp4_init(void)
158 if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
159 printk(KERN_INFO "ipcomp init: can't add xfrm type\n");
160 return -EAGAIN;
162 if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
163 printk(KERN_INFO "ipcomp init: can't add protocol\n");
164 xfrm_unregister_type(&ipcomp_type, AF_INET);
165 return -EAGAIN;
167 return 0;
170 static void __exit ipcomp4_fini(void)
172 if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
173 printk(KERN_INFO "ip ipcomp close: can't remove protocol\n");
174 if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
175 printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n");
178 module_init(ipcomp4_init);
179 module_exit(ipcomp4_fini);
181 MODULE_LICENSE("GPL");
182 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
183 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
185 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);