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34#define pr_fmt(fmt) "IPv6: " fmt
35
36#include <linux/module.h>
37#include <net/ip.h>
38#include <net/xfrm.h>
39#include <net/ipcomp.h>
40#include <linux/crypto.h>
41#include <linux/err.h>
42#include <linux/pfkeyv2.h>
43#include <linux/random.h>
44#include <linux/percpu.h>
45#include <linux/smp.h>
46#include <linux/list.h>
47#include <linux/vmalloc.h>
48#include <linux/rtnetlink.h>
49#include <net/ip6_route.h>
50#include <net/icmp.h>
51#include <net/ipv6.h>
52#include <net/protocol.h>
53#include <linux/ipv6.h>
54#include <linux/icmpv6.h>
55#include <linux/mutex.h>
56
57static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
58 u8 type, u8 code, int offset, __be32 info)
59{
60 struct net *net = dev_net(skb->dev);
61 __be32 spi;
62 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
63 struct ip_comp_hdr *ipcomph =
64 (struct ip_comp_hdr *)(skb->data + offset);
65 struct xfrm_state *x;
66
67 if (type != ICMPV6_PKT_TOOBIG &&
68 type != NDISC_REDIRECT)
69 return;
70
71 spi = htonl(ntohs(ipcomph->cpi));
72 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
73 spi, IPPROTO_COMP, AF_INET6);
74 if (!x)
75 return;
76
77 if (type == NDISC_REDIRECT)
78 ip6_redirect(skb, net, skb->dev->ifindex, 0);
79 else
80 ip6_update_pmtu(skb, net, info, 0, 0);
81 xfrm_state_put(x);
82}
83
84static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
85{
86 struct net *net = xs_net(x);
87 struct xfrm_state *t = NULL;
88
89 t = xfrm_state_alloc(net);
90 if (!t)
91 goto out;
92
93 t->id.proto = IPPROTO_IPV6;
94 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
95 if (!t->id.spi)
96 goto error;
97
98 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
99 memcpy(&t->sel, &x->sel, sizeof(t->sel));
100 t->props.family = AF_INET6;
101 t->props.mode = x->props.mode;
102 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
103 memcpy(&t->mark, &x->mark, sizeof(t->mark));
104
105 if (xfrm_init_state(t))
106 goto error;
107
108 atomic_set(&t->tunnel_users, 1);
109
110out:
111 return t;
112
113error:
114 t->km.state = XFRM_STATE_DEAD;
115 xfrm_state_put(t);
116 t = NULL;
117 goto out;
118}
119
120static int ipcomp6_tunnel_attach(struct xfrm_state *x)
121{
122 struct net *net = xs_net(x);
123 int err = 0;
124 struct xfrm_state *t = NULL;
125 __be32 spi;
126 u32 mark = x->mark.m & x->mark.v;
127
128 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
129 if (spi)
130 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
131 spi, IPPROTO_IPV6, AF_INET6);
132 if (!t) {
133 t = ipcomp6_tunnel_create(x);
134 if (!t) {
135 err = -EINVAL;
136 goto out;
137 }
138 xfrm_state_insert(t);
139 xfrm_state_hold(t);
140 }
141 x->tunnel = t;
142 atomic_inc(&t->tunnel_users);
143
144out:
145 return err;
146}
147
148static int ipcomp6_init_state(struct xfrm_state *x)
149{
150 int err = -EINVAL;
151
152 x->props.header_len = 0;
153 switch (x->props.mode) {
154 case XFRM_MODE_TRANSPORT:
155 break;
156 case XFRM_MODE_TUNNEL:
157 x->props.header_len += sizeof(struct ipv6hdr);
158 break;
159 default:
160 goto out;
161 }
162
163 err = ipcomp_init_state(x);
164 if (err)
165 goto out;
166
167 if (x->props.mode == XFRM_MODE_TUNNEL) {
168 err = ipcomp6_tunnel_attach(x);
169 if (err)
170 goto out;
171 }
172
173 err = 0;
174out:
175 return err;
176}
177
178static const struct xfrm_type ipcomp6_type =
179{
180 .description = "IPCOMP6",
181 .owner = THIS_MODULE,
182 .proto = IPPROTO_COMP,
183 .init_state = ipcomp6_init_state,
184 .destructor = ipcomp_destroy,
185 .input = ipcomp_input,
186 .output = ipcomp_output,
187 .hdr_offset = xfrm6_find_1stfragopt,
188};
189
190static const struct inet6_protocol ipcomp6_protocol =
191{
192 .handler = xfrm6_rcv,
193 .err_handler = ipcomp6_err,
194 .flags = INET6_PROTO_NOPOLICY,
195};
196
197static int __init ipcomp6_init(void)
198{
199 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
200 pr_info("%s: can't add xfrm type\n", __func__);
201 return -EAGAIN;
202 }
203 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
204 pr_info("%s: can't add protocol\n", __func__);
205 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
206 return -EAGAIN;
207 }
208 return 0;
209}
210
211static void __exit ipcomp6_fini(void)
212{
213 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
214 pr_info("%s: can't remove protocol\n", __func__);
215 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
216 pr_info("%s: can't remove xfrm type\n", __func__);
217}
218
219module_init(ipcomp6_init);
220module_exit(ipcomp6_fini);
221MODULE_LICENSE("GPL");
222MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
223MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
224
225MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);
226
