1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
5 * Copyright (C)2003 USAGI/WIDE Project
7 * Author Mitsuru KANDA <mk@linux-ipv6.org>
13 * The compression of IP datagram MUST be done before AH/ESP processing,
14 * fragmentation, and the addition of Hop-by-Hop/Routing header.
17 * The decompression of IP datagram MUST be done after the reassembly,
21 #define pr_fmt(fmt) "IPv6: " fmt
23 #include <linux/module.h>
26 #include <net/ipcomp.h>
27 #include <linux/crypto.h>
28 #include <linux/err.h>
29 #include <linux/pfkeyv2.h>
30 #include <linux/random.h>
31 #include <linux/percpu.h>
32 #include <linux/smp.h>
33 #include <linux/list.h>
34 #include <linux/vmalloc.h>
35 #include <linux/rtnetlink.h>
36 #include <net/ip6_route.h>
39 #include <net/protocol.h>
40 #include <linux/ipv6.h>
41 #include <linux/icmpv6.h>
42 #include <linux/mutex.h>
44 static int ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
45 u8 type, u8 code, int offset, __be32 info)
47 struct net *net = dev_net(skb->dev);
49 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
50 struct ip_comp_hdr *ipcomph =
51 (struct ip_comp_hdr *)(skb->data + offset);
54 if (type != ICMPV6_PKT_TOOBIG &&
55 type != NDISC_REDIRECT)
58 spi = htonl(ntohs(ipcomph->cpi));
59 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
60 spi, IPPROTO_COMP, AF_INET6);
64 if (type == NDISC_REDIRECT)
65 ip6_redirect(skb, net, skb->dev->ifindex, 0,
66 sock_net_uid(net, NULL));
68 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
74 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
76 struct net *net = xs_net(x);
77 struct xfrm_state *t = NULL;
79 t = xfrm_state_alloc(net);
83 t->id.proto = IPPROTO_IPV6;
84 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
88 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
89 memcpy(&t->sel, &x->sel, sizeof(t->sel));
90 t->props.family = AF_INET6;
91 t->props.mode = x->props.mode;
92 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
93 memcpy(&t->mark, &x->mark, sizeof(t->mark));
96 if (xfrm_init_state(t))
99 atomic_set(&t->tunnel_users, 1);
105 t->km.state = XFRM_STATE_DEAD;
111 static int ipcomp6_tunnel_attach(struct xfrm_state *x)
113 struct net *net = xs_net(x);
115 struct xfrm_state *t = NULL;
117 u32 mark = x->mark.m & x->mark.v;
119 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
121 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
122 spi, IPPROTO_IPV6, AF_INET6);
124 t = ipcomp6_tunnel_create(x);
129 xfrm_state_insert(t);
133 atomic_inc(&t->tunnel_users);
139 static int ipcomp6_init_state(struct xfrm_state *x)
143 x->props.header_len = 0;
144 switch (x->props.mode) {
145 case XFRM_MODE_TRANSPORT:
147 case XFRM_MODE_TUNNEL:
148 x->props.header_len += sizeof(struct ipv6hdr);
154 err = ipcomp_init_state(x);
158 if (x->props.mode == XFRM_MODE_TUNNEL) {
159 err = ipcomp6_tunnel_attach(x);
169 static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
174 static const struct xfrm_type ipcomp6_type = {
175 .description = "IPCOMP6",
176 .owner = THIS_MODULE,
177 .proto = IPPROTO_COMP,
178 .init_state = ipcomp6_init_state,
179 .destructor = ipcomp_destroy,
180 .input = ipcomp_input,
181 .output = ipcomp_output,
182 .hdr_offset = xfrm6_find_1stfragopt,
185 static struct xfrm6_protocol ipcomp6_protocol = {
186 .handler = xfrm6_rcv,
187 .input_handler = xfrm_input,
188 .cb_handler = ipcomp6_rcv_cb,
189 .err_handler = ipcomp6_err,
193 static int __init ipcomp6_init(void)
195 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
196 pr_info("%s: can't add xfrm type\n", __func__);
199 if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
200 pr_info("%s: can't add protocol\n", __func__);
201 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
207 static void __exit ipcomp6_fini(void)
209 if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
210 pr_info("%s: can't remove protocol\n", __func__);
211 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
214 module_init(ipcomp6_init);
215 module_exit(ipcomp6_fini);
216 MODULE_LICENSE("GPL");
217 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
218 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
220 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);