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DEFINITIONS
This source file includes following definitions.
- calc_padlen
- mip6_padn
- mip6_param_prob
- mip6_mh_len
- mip6_mh_filter
- mip6_destopt_input
- mip6_destopt_output
- mip6_report_rl_allow
- mip6_destopt_reject
- mip6_destopt_offset
- mip6_destopt_init_state
- mip6_destopt_destroy
- mip6_rthdr_input
- mip6_rthdr_output
- mip6_rthdr_offset
- mip6_rthdr_init_state
- mip6_rthdr_destroy
- mip6_init
- mip6_fini
/*
* Copyright (C)2003-2006 Helsinki University of Technology
* Copyright (C)2003-2006 USAGI/WIDE Project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Authors:
* Noriaki TAKAMIYA @USAGI
* Masahide NAKAMURA @USAGI
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/time.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ip6_checksum.h>
#include <net/rawv6.h>
#include <net/xfrm.h>
#include <net/mip6.h>
static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
{
return (n - len + 16) & 0x7;
}
static inline void *mip6_padn(__u8 *data, __u8 padlen)
{
if (!data)
return NULL;
if (padlen == 1) {
data[0] = IPV6_TLV_PAD0;
} else if (padlen > 1) {
data[0] = IPV6_TLV_PADN;
data[1] = padlen - 2;
if (padlen > 2)
memset(data+2, 0, data[1]);
}
return data + padlen;
}
static inline void mip6_param_prob(struct sk_buff *skb, int code, int pos)
{
icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
}
static int mip6_mh_len(int type)
{
int len = 0;
switch (type) {
case IP6_MH_TYPE_BRR:
len = 0;
break;
case IP6_MH_TYPE_HOTI:
case IP6_MH_TYPE_COTI:
case IP6_MH_TYPE_BU:
case IP6_MH_TYPE_BACK:
len = 1;
break;
case IP6_MH_TYPE_HOT:
case IP6_MH_TYPE_COT:
case IP6_MH_TYPE_BERROR:
len = 2;
break;
}
return len;
}
static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
{
struct ip6_mh *mh;
if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
!pskb_may_pull(skb, (skb_transport_offset(skb) +
((skb_transport_header(skb)[1] + 1) << 3))))
return -1;
mh = (struct ip6_mh *)skb_transport_header(skb);
if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
skb_network_header(skb)));
return -1;
}
if (mh->ip6mh_proto != IPPROTO_NONE) {
LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
mh->ip6mh_proto);
mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
skb_network_header(skb)));
return -1;
}
return 0;
}
struct mip6_report_rate_limiter {
spinlock_t lock;
struct timeval stamp;
int iif;
struct in6_addr src;
struct in6_addr dst;
};
static struct mip6_report_rate_limiter mip6_report_rl = {
.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
};
static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *iph = ipv6_hdr(skb);
struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
int err = destopt->nexthdr;
spin_lock(&x->lock);
if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
!ipv6_addr_any((struct in6_addr *)x->coaddr))
err = -ENOENT;
spin_unlock(&x->lock);
return err;
}
/* Destination Option Header is inserted.
* IP Header's src address is replaced with Home Address Option in
* Destination Option Header.
*/
static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *iph;
struct ipv6_destopt_hdr *dstopt;
struct ipv6_destopt_hao *hao;
u8 nexthdr;
int len;
skb_push(skb, -skb_network_offset(skb));
iph = ipv6_hdr(skb);
nexthdr = *skb_mac_header(skb);
*skb_mac_header(skb) = IPPROTO_DSTOPTS;
dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
dstopt->nexthdr = nexthdr;
hao = mip6_padn((char *)(dstopt + 1),
calc_padlen(sizeof(*dstopt), 6));
hao->type = IPV6_TLV_HAO;
BUILD_BUG_ON(sizeof(*hao) != 18);
hao->length = sizeof(*hao) - 2;
len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
spin_lock_bh(&x->lock);
memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
spin_unlock_bh(&x->lock);
WARN_ON(len != x->props.header_len);
dstopt->hdrlen = (x->props.header_len >> 3) - 1;
return 0;
}
static inline int mip6_report_rl_allow(struct timeval *stamp,
struct in6_addr *dst,
struct in6_addr *src, int iif)
{
int allow = 0;
spin_lock_bh(&mip6_report_rl.lock);
if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
mip6_report_rl.iif != iif ||
!ipv6_addr_equal(&mip6_report_rl.src, src) ||
!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
mip6_report_rl.iif = iif;
ipv6_addr_copy(&mip6_report_rl.src, src);
ipv6_addr_copy(&mip6_report_rl.dst, dst);
allow = 1;
}
spin_unlock_bh(&mip6_report_rl.lock);
return allow;
}
static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl)
{
struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
struct ipv6_destopt_hao *hao = NULL;
struct xfrm_selector sel;
int offset;
struct timeval stamp;
int err = 0;
if (unlikely(fl->proto == IPPROTO_MH &&
fl->fl_mh_type <= IP6_MH_TYPE_MAX))
goto out;
if (likely(opt->dsthao)) {
offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
if (likely(offset >= 0))
hao = (struct ipv6_destopt_hao *)
(skb_network_header(skb) + offset);
}
skb_get_timestamp(skb, &stamp);
if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
opt->iif))
goto out;
memset(&sel, 0, sizeof(sel));
memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
sizeof(sel.daddr));
sel.prefixlen_d = 128;
memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
sizeof(sel.saddr));
sel.prefixlen_s = 128;
sel.family = AF_INET6;
sel.proto = fl->proto;
sel.dport = xfrm_flowi_dport(fl);
if (sel.dport)
sel.dport_mask = htons(~0);
sel.sport = xfrm_flowi_sport(fl);
if (sel.sport)
sel.sport_mask = htons(~0);
sel.ifindex = fl->oif;
err = km_report(IPPROTO_DSTOPTS, &sel,
(hao ? (xfrm_address_t *)&hao->addr : NULL));
out:
return err;
}
static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
u8 **nexthdr)
{
u16 offset = sizeof(struct ipv6hdr);
struct ipv6_opt_hdr *exthdr =
(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
const unsigned char *nh = skb_network_header(skb);
unsigned int packet_len = skb->tail - skb->network_header;
int found_rhdr = 0;
*nexthdr = &ipv6_hdr(skb)->nexthdr;
while (offset + 1 <= packet_len) {
switch (**nexthdr) {
case NEXTHDR_HOP:
break;
case NEXTHDR_ROUTING:
found_rhdr = 1;
break;
case NEXTHDR_DEST:
/*
* HAO MUST NOT appear more than once.
* XXX: It is better to try to find by the end of
* XXX: packet if HAO exists.
*/
if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
return offset;
}
if (found_rhdr)
return offset;
break;
default:
return offset;
}
offset += ipv6_optlen(exthdr);
*nexthdr = &exthdr->nexthdr;
exthdr = (struct ipv6_opt_hdr *)(nh + offset);
}
return offset;
}
static int mip6_destopt_init_state(struct xfrm_state *x)
{
if (x->id.spi) {
printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
x->id.spi);
return -EINVAL;
}
if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
printk(KERN_INFO "%s: state's mode is not %u: %u\n",
__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
return -EINVAL;
}
x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
sizeof(struct ipv6_destopt_hao);
WARN_ON(x->props.header_len != 24);
return 0;
}
/*
* Do nothing about destroying since it has no specific operation for
* destination options header unlike IPsec protocols.
*/
static void mip6_destopt_destroy(struct xfrm_state *x)
{
}
static const struct xfrm_type mip6_destopt_type =
{
.description = "MIP6DESTOPT",
.owner = THIS_MODULE,
.proto = IPPROTO_DSTOPTS,
.flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
.init_state = mip6_destopt_init_state,
.destructor = mip6_destopt_destroy,
.input = mip6_destopt_input,
.output = mip6_destopt_output,
.reject = mip6_destopt_reject,
.hdr_offset = mip6_destopt_offset,
};
static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
int err = rt2->rt_hdr.nexthdr;
spin_lock(&x->lock);
if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
!ipv6_addr_any((struct in6_addr *)x->coaddr))
err = -ENOENT;
spin_unlock(&x->lock);
return err;
}
/* Routing Header type 2 is inserted.
* IP Header's dst address is replaced with Routing Header's Home Address.
*/
static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *iph;
struct rt2_hdr *rt2;
u8 nexthdr;
skb_push(skb, -skb_network_offset(skb));
iph = ipv6_hdr(skb);
nexthdr = *skb_mac_header(skb);
*skb_mac_header(skb) = IPPROTO_ROUTING;
rt2 = (struct rt2_hdr *)skb_transport_header(skb);
rt2->rt_hdr.nexthdr = nexthdr;
rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
rt2->rt_hdr.segments_left = 1;
memset(&rt2->reserved, 0, sizeof(rt2->reserved));
WARN_ON(rt2->rt_hdr.hdrlen != 2);
memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
spin_lock_bh(&x->lock);
memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
spin_unlock_bh(&x->lock);
return 0;
}
static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
u8 **nexthdr)
{
u16 offset = sizeof(struct ipv6hdr);
struct ipv6_opt_hdr *exthdr =
(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
const unsigned char *nh = skb_network_header(skb);
unsigned int packet_len = skb->tail - skb->network_header;
int found_rhdr = 0;
*nexthdr = &ipv6_hdr(skb)->nexthdr;
while (offset + 1 <= packet_len) {
switch (**nexthdr) {
case NEXTHDR_HOP:
break;
case NEXTHDR_ROUTING:
if (offset + 3 <= packet_len) {
struct ipv6_rt_hdr *rt;
rt = (struct ipv6_rt_hdr *)(nh + offset);
if (rt->type != 0)
return offset;
}
found_rhdr = 1;
break;
case NEXTHDR_DEST:
if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
return offset;
if (found_rhdr)
return offset;
break;
default:
return offset;
}
offset += ipv6_optlen(exthdr);
*nexthdr = &exthdr->nexthdr;
exthdr = (struct ipv6_opt_hdr *)(nh + offset);
}
return offset;
}
static int mip6_rthdr_init_state(struct xfrm_state *x)
{
if (x->id.spi) {
printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
x->id.spi);
return -EINVAL;
}
if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
printk(KERN_INFO "%s: state's mode is not %u: %u\n",
__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
return -EINVAL;
}
x->props.header_len = sizeof(struct rt2_hdr);
return 0;
}
/*
* Do nothing about destroying since it has no specific operation for routing
* header type 2 unlike IPsec protocols.
*/
static void mip6_rthdr_destroy(struct xfrm_state *x)
{
}
static const struct xfrm_type mip6_rthdr_type =
{
.description = "MIP6RT",
.owner = THIS_MODULE,
.proto = IPPROTO_ROUTING,
.flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
.init_state = mip6_rthdr_init_state,
.destructor = mip6_rthdr_destroy,
.input = mip6_rthdr_input,
.output = mip6_rthdr_output,
.hdr_offset = mip6_rthdr_offset,
};
static int __init mip6_init(void)
{
printk(KERN_INFO "Mobile IPv6\n");
if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __func__);
goto mip6_destopt_xfrm_fail;
}
if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __func__);
goto mip6_rthdr_xfrm_fail;
}
if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __func__);
goto mip6_rawv6_mh_fail;
}
return 0;
mip6_rawv6_mh_fail:
xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
mip6_rthdr_xfrm_fail:
xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
mip6_destopt_xfrm_fail:
return -EAGAIN;
}
static void __exit mip6_fini(void)
{
if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
}
module_init(mip6_init);
module_exit(mip6_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);