android_kernel_xiaomi_sm8350/net/ipv6/tunnel6.c
Colin 8283637231 [IPV6] TUNNEL6: Fix incoming packet length check for inter-protocol tunnel.
I discover a strange behavior in [ipv4 in ipv6] tunnel. When IPv6 tunnel
payload is less than 40(0x28), packet can be sent to network, received in
physical interface, but not seen in IP tunnel interface. No counter increase
in tunnel interface.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
2008-06-05 04:02:32 +09:00

173 lines
4.3 KiB
C

/*
* Copyright (C)2003,2004 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 Mitsuru KANDA <mk@linux-ipv6.org>
* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
*/
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/xfrm.h>
static struct xfrm6_tunnel *tunnel6_handlers;
static struct xfrm6_tunnel *tunnel46_handlers;
static DEFINE_MUTEX(tunnel6_mutex);
int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
{
struct xfrm6_tunnel **pprev;
int ret = -EEXIST;
int priority = handler->priority;
mutex_lock(&tunnel6_mutex);
for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
*pprev; pprev = &(*pprev)->next) {
if ((*pprev)->priority > priority)
break;
if ((*pprev)->priority == priority)
goto err;
}
handler->next = *pprev;
*pprev = handler;
ret = 0;
err:
mutex_unlock(&tunnel6_mutex);
return ret;
}
EXPORT_SYMBOL(xfrm6_tunnel_register);
int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
{
struct xfrm6_tunnel **pprev;
int ret = -ENOENT;
mutex_lock(&tunnel6_mutex);
for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
*pprev; pprev = &(*pprev)->next) {
if (*pprev == handler) {
*pprev = handler->next;
ret = 0;
break;
}
}
mutex_unlock(&tunnel6_mutex);
synchronize_net();
return ret;
}
EXPORT_SYMBOL(xfrm6_tunnel_deregister);
static int tunnel6_rcv(struct sk_buff *skb)
{
struct xfrm6_tunnel *handler;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
for (handler = tunnel6_handlers; handler; handler = handler->next)
if (!handler->handler(skb))
return 0;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev);
drop:
kfree_skb(skb);
return 0;
}
static int tunnel46_rcv(struct sk_buff *skb)
{
struct xfrm6_tunnel *handler;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
for (handler = tunnel46_handlers; handler; handler = handler->next)
if (!handler->handler(skb))
return 0;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev);
drop:
kfree_skb(skb);
return 0;
}
static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __be32 info)
{
struct xfrm6_tunnel *handler;
for (handler = tunnel6_handlers; handler; handler = handler->next)
if (!handler->err_handler(skb, opt, type, code, offset, info))
break;
}
static struct inet6_protocol tunnel6_protocol = {
.handler = tunnel6_rcv,
.err_handler = tunnel6_err,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};
static struct inet6_protocol tunnel46_protocol = {
.handler = tunnel46_rcv,
.err_handler = tunnel6_err,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};
static int __init tunnel6_init(void)
{
if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) {
printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
return -EAGAIN;
}
if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) {
printk(KERN_ERR "tunnel6 init(): can't add protocol\n");
inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6);
return -EAGAIN;
}
return 0;
}
static void __exit tunnel6_fini(void)
{
if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP))
printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6))
printk(KERN_ERR "tunnel6 close: can't remove protocol\n");
}
module_init(tunnel6_init);
module_exit(tunnel6_fini);
MODULE_LICENSE("GPL");