linux/net/ipv6/ipcomp6.c
Sabrina Dubroca 0146dca70b xfrm: add support for UDPv6 encapsulation of ESP
This patch adds support for encapsulation of ESP over UDPv6. The code
is very similar to the IPv4 encapsulation implementation, and allows
to easily add espintcp on IPv6 as a follow-up.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2020-04-28 11:28:36 +02:00

220 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
*
* Copyright (C)2003 USAGI/WIDE Project
*
* Author Mitsuru KANDA <mk@linux-ipv6.org>
*/
/*
* [Memo]
*
* Outbound:
* The compression of IP datagram MUST be done before AH/ESP processing,
* fragmentation, and the addition of Hop-by-Hop/Routing header.
*
* Inbound:
* The decompression of IP datagram MUST be done after the reassembly,
* AH/ESP processing.
*/
#define pr_fmt(fmt) "IPv6: " fmt
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipcomp.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <net/ip6_route.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>
static int ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct net *net = dev_net(skb->dev);
__be32 spi;
const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
struct ip_comp_hdr *ipcomph =
(struct ip_comp_hdr *)(skb->data + offset);
struct xfrm_state *x;
if (type != ICMPV6_PKT_TOOBIG &&
type != NDISC_REDIRECT)
return 0;
spi = htonl(ntohs(ipcomph->cpi));
x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
spi, IPPROTO_COMP, AF_INET6);
if (!x)
return 0;
if (type == NDISC_REDIRECT)
ip6_redirect(skb, net, skb->dev->ifindex, 0,
sock_net_uid(net, NULL));
else
ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
xfrm_state_put(x);
return 0;
}
static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
{
struct net *net = xs_net(x);
struct xfrm_state *t = NULL;
t = xfrm_state_alloc(net);
if (!t)
goto out;
t->id.proto = IPPROTO_IPV6;
t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
if (!t->id.spi)
goto error;
memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
memcpy(&t->sel, &x->sel, sizeof(t->sel));
t->props.family = AF_INET6;
t->props.mode = x->props.mode;
memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
memcpy(&t->mark, &x->mark, sizeof(t->mark));
if (xfrm_init_state(t))
goto error;
atomic_set(&t->tunnel_users, 1);
out:
return t;
error:
t->km.state = XFRM_STATE_DEAD;
xfrm_state_put(t);
t = NULL;
goto out;
}
static int ipcomp6_tunnel_attach(struct xfrm_state *x)
{
struct net *net = xs_net(x);
int err = 0;
struct xfrm_state *t = NULL;
__be32 spi;
u32 mark = x->mark.m & x->mark.v;
spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
if (spi)
t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
spi, IPPROTO_IPV6, AF_INET6);
if (!t) {
t = ipcomp6_tunnel_create(x);
if (!t) {
err = -EINVAL;
goto out;
}
xfrm_state_insert(t);
xfrm_state_hold(t);
}
x->tunnel = t;
atomic_inc(&t->tunnel_users);
out:
return err;
}
static int ipcomp6_init_state(struct xfrm_state *x)
{
int err = -EINVAL;
x->props.header_len = 0;
switch (x->props.mode) {
case XFRM_MODE_TRANSPORT:
break;
case XFRM_MODE_TUNNEL:
x->props.header_len += sizeof(struct ipv6hdr);
break;
default:
goto out;
}
err = ipcomp_init_state(x);
if (err)
goto out;
if (x->props.mode == XFRM_MODE_TUNNEL) {
err = ipcomp6_tunnel_attach(x);
if (err)
goto out;
}
err = 0;
out:
return err;
}
static int ipcomp6_rcv_cb(struct sk_buff *skb, int err)
{
return 0;
}
static const struct xfrm_type ipcomp6_type = {
.description = "IPCOMP6",
.owner = THIS_MODULE,
.proto = IPPROTO_COMP,
.init_state = ipcomp6_init_state,
.destructor = ipcomp_destroy,
.input = ipcomp_input,
.output = ipcomp_output,
.hdr_offset = xfrm6_find_1stfragopt,
};
static struct xfrm6_protocol ipcomp6_protocol = {
.handler = xfrm6_rcv,
.input_handler = xfrm_input,
.cb_handler = ipcomp6_rcv_cb,
.err_handler = ipcomp6_err,
.priority = 0,
};
static int __init ipcomp6_init(void)
{
if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
pr_info("%s: can't add xfrm type\n", __func__);
return -EAGAIN;
}
if (xfrm6_protocol_register(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
pr_info("%s: can't add protocol\n", __func__);
xfrm_unregister_type(&ipcomp6_type, AF_INET6);
return -EAGAIN;
}
return 0;
}
static void __exit ipcomp6_fini(void)
{
if (xfrm6_protocol_deregister(&ipcomp6_protocol, IPPROTO_COMP) < 0)
pr_info("%s: can't remove protocol\n", __func__);
xfrm_unregister_type(&ipcomp6_type, AF_INET6);
}
module_init(ipcomp6_init);
module_exit(ipcomp6_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);