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/*
* IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
*
* $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $
*
* 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.
*
* Changes:
* Roger Venning <r.venning@telstra.com>: 6to4 support
* Nate Thompson <nate@thebog.net>: 6to4 support
*/
#define __NO_VERSION__
#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmp.h>
#include <asm/uaccess.h>
#include <linux/init.h>
#include <linux/netfilter_ipv4.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip.h>
#include <net/udp.h>
#include <net/icmp.h>
#include <net/ipip.h>
#include <net/inet_ecn.h>
/*
This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
For comments look at net/ipv4/ip_gre.c --ANK
*/
#define HASH_SIZE 16
#define HASH(addr) ((addr^(addr>>4))&0xF)
static int ipip6_fb_tunnel_init(struct net_device *dev);
static int ipip6_tunnel_init(struct net_device *dev);
static struct net_device ipip6_fb_tunnel_dev = {
"sit0", 0x0, 0x0, 0x0, 0x0, 0, 0, 0, 0, 0, NULL, ipip6_fb_tunnel_init,
};
static struct ip_tunnel ipip6_fb_tunnel = {
NULL, &ipip6_fb_tunnel_dev, {0, }, 0, 0, 0, 0, 0, 0, 0, {"sit0", }
};
static struct ip_tunnel *tunnels_r_l[HASH_SIZE];
static struct ip_tunnel *tunnels_r[HASH_SIZE];
static struct ip_tunnel *tunnels_l[HASH_SIZE];
static struct ip_tunnel *tunnels_wc[1];
static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l };
static rwlock_t ipip6_lock = RW_LOCK_UNLOCKED;
static struct ip_tunnel * ipip6_tunnel_lookup(u32 remote, u32 local)
{
unsigned h0 = HASH(remote);
unsigned h1 = HASH(local);
struct ip_tunnel *t;
for (t = tunnels_r_l[h0^h1]; t; t = t->next) {
if (local == t->parms.iph.saddr &&
remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
return t;
}
for (t = tunnels_r[h0]; t; t = t->next) {
if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
return t;
}
for (t = tunnels_l[h1]; t; t = t->next) {
if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
return t;
}
if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
return t;
return NULL;
}
static struct ip_tunnel ** ipip6_bucket(struct ip_tunnel *t)
{
u32 remote = t->parms.iph.daddr;
u32 local = t->parms.iph.saddr;
unsigned h = 0;
int prio = 0;
if (remote) {
prio |= 2;
h ^= HASH(remote);
}
if (local) {
prio |= 1;
h ^= HASH(local);
}
return &tunnels[prio][h];
}
static void ipip6_tunnel_unlink(struct ip_tunnel *t)
{
struct ip_tunnel **tp;
for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) {
if (t == *tp) {
write_lock_bh(&ipip6_lock);
*tp = t->next;
write_unlock_bh(&ipip6_lock);
break;
}
}
}
static void ipip6_tunnel_link(struct ip_tunnel *t)
{
struct ip_tunnel **tp = ipip6_bucket(t);
write_lock_bh(&ipip6_lock);
t->next = *tp;
write_unlock_bh(&ipip6_lock);
*tp = t;
}
struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create)
{
u32 remote = parms->iph.daddr;
u32 local = parms->iph.saddr;
struct ip_tunnel *t, **tp, *nt;
struct net_device *dev;
unsigned h = 0;
int prio = 0;
if (remote) {
prio |= 2;
h ^= HASH(remote);
}
if (local) {
prio |= 1;
h ^= HASH(local);
}
for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) {
if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
return t;
}
if (!create)
return NULL;
MOD_INC_USE_COUNT;
dev = kmalloc(sizeof(*dev) + sizeof(*t), GFP_KERNEL);
if (dev == NULL) {
MOD_DEC_USE_COUNT;
return NULL;
}
memset(dev, 0, sizeof(*dev) + sizeof(*t));
dev->priv = (void*)(dev+1);
nt = (struct ip_tunnel*)dev->priv;
nt->dev = dev;
dev->init = ipip6_tunnel_init;
dev->features |= NETIF_F_DYNALLOC;
memcpy(&nt->parms, parms, sizeof(*parms));
nt->parms.name[IFNAMSIZ-1] = '\0';
strcpy(dev->name, nt->parms.name);
if (dev->name[0] == 0) {
int i;
for (i=1; i<100; i++) {
sprintf(dev->name, "sit%d", i);
if (__dev_get_by_name(dev->name) == NULL)
break;
}
if (i==100)
goto failed;
memcpy(nt->parms.name, dev->name, IFNAMSIZ);
}
if (register_netdevice(dev) < 0)
goto failed;
dev_hold(dev);
ipip6_tunnel_link(nt);
/* Do not decrement MOD_USE_COUNT here. */
return nt;
failed:
kfree(dev);
MOD_DEC_USE_COUNT;
return NULL;
}
static void ipip6_tunnel_destructor(struct net_device *dev)
{
if (dev != &ipip6_fb_tunnel_dev) {
MOD_DEC_USE_COUNT;
}
}
static void ipip6_tunnel_uninit(struct net_device *dev)
{
if (dev == &ipip6_fb_tunnel_dev) {
write_lock_bh(&ipip6_lock);
tunnels_wc[0] = NULL;
write_unlock_bh(&ipip6_lock);
dev_put(dev);
} else {
ipip6_tunnel_unlink((struct ip_tunnel*)dev->priv);
dev_put(dev);
}
}
void ipip6_err(struct sk_buff *skb, u32 info)
{
#ifndef I_WISH_WORLD_WERE_PERFECT
/* It is not :-( All the routers (except for Linux) return only
8 bytes of packet payload. It means, that precise relaying of
ICMP in the real Internet is absolutely infeasible.
*/
struct iphdr *iph = (struct iphdr*)skb->data;
int type = skb->h.icmph->type;
int code = skb->h.icmph->code;
struct ip_tunnel *t;
switch (type) {
default:
case ICMP_PARAMETERPROB:
return;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
return;
case ICMP_FRAG_NEEDED:
/* Soft state for pmtu is maintained by IP core. */
return;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
I believe they are just ether pollution. --ANK
*/
break;
}
break;
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return;
break;
}
read_lock(&ipip6_lock);
t = ipip6_tunnel_lookup(iph->daddr, iph->saddr);
if (t == NULL || t->parms.iph.daddr == 0)
goto out;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
goto out;
if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
out:
read_unlock(&ipip6_lock);
return;
#else
struct iphdr *iph = (struct iphdr*)dp;
int hlen = iph->ihl<<2;
struct ipv6hdr *iph6;
int type = skb->h.icmph->type;
int code = skb->h.icmph->code;
int rel_type = 0;
int rel_code = 0;
int rel_info = 0;
struct sk_buff *skb2;
struct rt6_info *rt6i;
if (len < hlen + sizeof(struct ipv6hdr))
return;
iph6 = (struct ipv6hdr*)(dp + hlen);
switch (type) {
default:
return;
case ICMP_PARAMETERPROB:
if (skb->h.icmph->un.gateway < hlen)
return;
/* So... This guy found something strange INSIDE encapsulated
packet. Well, he is fool, but what can we do ?
*/
rel_type = ICMPV6_PARAMPROB;
rel_info = skb->h.icmph->un.gateway - hlen;
break;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
return;
case ICMP_FRAG_NEEDED:
/* Too complicated case ... */
return;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
I believe, it is just ether pollution. --ANK
*/
rel_type = ICMPV6_DEST_UNREACH;
rel_code = ICMPV6_ADDR_UNREACH;
break;
}
break;
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return;
rel_type = ICMPV6_TIME_EXCEED;
rel_code = ICMPV6_EXC_HOPLIMIT;
break;
}
/* Prepare fake skb to feed it to icmpv6_send */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
return;
dst_release(skb2->dst);
skb2->dst = NULL;
skb_pull(skb2, skb->data - (u8*)iph6);
skb2->nh.raw = skb2->data;
/* Try to guess incoming interface */
rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0);
if (rt6i && rt6i->rt6i_dev) {
skb2->dev = rt6i->rt6i_dev;
rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0);
if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
struct ip_tunnel * t = (struct ip_tunnel*)rt6i->rt6i_dev->priv;
if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
rel_type = ICMPV6_DEST_UNREACH;
rel_code = ICMPV6_ADDR_UNREACH;
}
icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
}
}
kfree_skb(skb2);
return;
#endif
}
static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
{
if (INET_ECN_is_ce(iph->tos) &&
INET_ECN_is_not_ce(ip6_get_dsfield(skb->nh.ipv6h)))
IP6_ECN_set_ce(skb->nh.ipv6h);
}
int ipip6_rcv(struct sk_buff *skb)
{
struct iphdr *iph;
struct ip_tunnel *tunnel;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
iph = skb->nh.iph;
read_lock(&ipip6_lock);
if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) {
skb->mac.raw = skb->nh.raw;
skb->nh.raw = skb->data;
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
skb->protocol = __constant_htons(ETH_P_IPV6);
skb->pkt_type = PACKET_HOST;
tunnel->stat.rx_packets++;
tunnel->stat.rx_bytes += skb->len;
skb->dev = tunnel->dev;
dst_release(skb->dst);
skb->dst = NULL;
#ifdef CONFIG_NETFILTER
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug = 0;
#endif
#endif
ipip6_ecn_decapsulate(iph, skb);
netif_rx(skb);
read_unlock(&ipip6_lock);
return 0;
}
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0);
kfree_skb(skb);
read_unlock(&ipip6_lock);
out:
return 0;
}
/* Need this wrapper because NF_HOOK takes the function address */
static inline int do_ip_send(struct sk_buff *skb)
{
return ip_send(skb);
}
/* Returns the embedded IPv4 address if the IPv6 address
comes from 6to4 (draft-ietf-ngtrans-6to4-04) addr space */
static inline u32 try_6to4(struct in6_addr *v6dst)
{
u32 dst = 0;
if (v6dst->s6_addr16[0] == htons(0x2002)) {
/* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
memcpy(&dst, &v6dst->s6_addr16[1], 4);
}
return dst;
}
/*
* This function assumes it is being called from dev_queue_xmit()
* and that skb is filled properly by that function.
*/
static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv;
struct net_device_stats *stats = &tunnel->stat;
struct iphdr *tiph = &tunnel->parms.iph;
struct ipv6hdr *iph6 = skb->nh.ipv6h;
u8 tos = tunnel->parms.iph.tos;
struct rtable *rt; /* Route to the other host */
struct net_device *tdev; /* Device to other host */
struct iphdr *iph; /* Our new IP header */
int max_headroom; /* The extra header space needed */
u32 dst = tiph->daddr;
int mtu;
struct in6_addr *addr6;
int addr_type;
if (tunnel->recursion++) {
tunnel->stat.collisions++;
goto tx_error;
}
if (skb->protocol != __constant_htons(ETH_P_IPV6))
goto tx_error;
if (!dst)
dst = try_6to4(&iph6->daddr);
if (!dst) {
struct neighbour *neigh = NULL;
if (skb->dst)
neigh = skb->dst->neighbour;
if (neigh == NULL) {
if (net_ratelimit())
printk(KERN_DEBUG "sit: nexthop == NULL\n");
goto tx_error;
}
addr6 = (struct in6_addr*)&neigh->primary_key;
addr_type = ipv6_addr_type(addr6);
if (addr_type == IPV6_ADDR_ANY) {
addr6 = &skb->nh.ipv6h->daddr;
addr_type = ipv6_addr_type(addr6);
}
if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
goto tx_error_icmp;
dst = addr6->s6_addr32[3];
}
if (ip_route_output(&rt, dst, tiph->saddr, RT_TOS(tos), tunnel->parms.link)) {
tunnel->stat.tx_carrier_errors++;
goto tx_error_icmp;
}
if (rt->rt_type != RTN_UNICAST) {
tunnel->stat.tx_carrier_errors++;
goto tx_error_icmp;
}
tdev = rt->u.dst.dev;
if (tdev == dev) {
ip_rt_put(rt);
tunnel->stat.collisions++;
goto tx_error;
}
mtu = rt->u.dst.pmtu - sizeof(struct iphdr);
if (mtu < 68) {
tunnel->stat.collisions++;
ip_rt_put(rt);
goto tx_error;
}
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb->dst && mtu < skb->dst->pmtu) {
struct rt6_info *rt6 = (struct rt6_info*)skb->dst;
if (mtu < rt6->u.dst.pmtu) {
if (tunnel->parms.iph.daddr || rt6->rt6i_dst.plen == 128) {
rt6->rt6i_flags |= RTF_MODIFIED;
rt6->u.dst.pmtu = mtu;
}
}
}
if (skb->len > mtu) {
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
ip_rt_put(rt);
goto tx_error;
}
if (tunnel->err_count > 0) {
if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
tunnel->err_count--;
dst_link_failure(skb);
} else
tunnel->err_count = 0;
}
skb->h.raw = skb->nh.raw;
/*
* Okay, now see if we can stuff it in the buffer as-is.
*/
max_headroom = (((tdev->hard_header_len+15)&~15)+sizeof(struct iphdr));
if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
if (!new_skb) {
ip_rt_put(rt);
stats->tx_dropped++;
dev_kfree_skb(skb);
tunnel->recursion--;
return 0;
}
if (skb->sk)
skb_set_owner_w(new_skb, skb->sk);
dev_kfree_skb(skb);
skb = new_skb;
}
skb->nh.raw = skb_push(skb, sizeof(struct iphdr));
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
dst_release(skb->dst);
skb->dst = &rt->u.dst;
/*
* Push down and install the IPIP header.
*/
iph = skb->nh.iph;
iph->version = 4;
iph->ihl = sizeof(struct iphdr)>>2;
if (mtu > IPV6_MIN_MTU)
iph->frag_off = __constant_htons(IP_DF);
else
iph->frag_off = 0;
iph->protocol = IPPROTO_IPV6;
iph->tos = INET_ECN_encapsulate(tos, ip6_get_dsfield(iph6));
iph->daddr = rt->rt_dst;
iph->saddr = rt->rt_src;
if ((iph->ttl = tiph->ttl) == 0)
iph->ttl = iph6->hop_limit;
#ifdef CONFIG_NETFILTER
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
#ifdef CONFIG_NETFILTER_DEBUG
skb->nf_debug = 0;
#endif
#endif
IPTUNNEL_XMIT();
tunnel->recursion--;
return 0;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
stats->tx_errors++;
dev_kfree_skb(skb);
tunnel->recursion--;
return 0;
}
static int
ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
{
int err = 0;
struct ip_tunnel_parm p;
struct ip_tunnel *t;
MOD_INC_USE_COUNT;
switch (cmd) {
case SIOCGETTUNNEL:
t = NULL;
if (dev == &ipip6_fb_tunnel_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
err = -EFAULT;
break;
}
t = ipip6_tunnel_locate(&p, 0);
}
if (t == NULL)
t = (struct ip_tunnel*)dev->priv;
memcpy(&p, &t->parms, sizeof(p));
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
err = -EFAULT;
break;
case SIOCADDTUNNEL:
case SIOCCHGTUNNEL:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
goto done;
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
goto done;
err = -EINVAL;
if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
p.iph.ihl != 5 || (p.iph.frag_off&__constant_htons(~IP_DF)))
goto done;
if (p.iph.ttl)
p.iph.frag_off |= __constant_htons(IP_DF);
t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL);
if (dev != &ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL &&
t != &ipip6_fb_tunnel) {
if (t != NULL) {
if (t->dev != dev) {
err = -EEXIST;
break;
}
} else {
if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
(!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
err = -EINVAL;
break;
}
t = (struct ip_tunnel*)dev->priv;
ipip6_tunnel_unlink(t);
t->parms.iph.saddr = p.iph.saddr;
t->parms.iph.daddr = p.iph.daddr;
memcpy(dev->dev_addr, &p.iph.saddr, 4);
memcpy(dev->broadcast, &p.iph.daddr, 4);
ipip6_tunnel_link(t);
netdev_state_change(dev);
}
}
if (t) {
err = 0;
if (cmd == SIOCCHGTUNNEL) {
t->parms.iph.ttl = p.iph.ttl;
t->parms.iph.tos = p.iph.tos;
}
if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
err = -EFAULT;
} else
err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
break;
case SIOCDELTUNNEL:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
goto done;
if (dev == &ipip6_fb_tunnel_dev) {
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
goto done;
err = -ENOENT;
if ((t = ipip6_tunnel_locate(&p, 0)) == NULL)
goto done;
err = -EPERM;
if (t == &ipip6_fb_tunnel)
goto done;
dev = t->dev;
}
err = unregister_netdevice(dev);
break;
default:
err = -EINVAL;
}
done:
MOD_DEC_USE_COUNT;
return err;
}
static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev)
{
return &(((struct ip_tunnel*)dev->priv)->stat);
}
static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
{
if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
return -EINVAL;
dev->mtu = new_mtu;
return 0;
}
static void ipip6_tunnel_init_gen(struct net_device *dev)
{
struct ip_tunnel *t = (struct ip_tunnel*)dev->priv;
dev->destructor = ipip6_tunnel_destructor;
dev->uninit = ipip6_tunnel_uninit;
dev->hard_start_xmit = ipip6_tunnel_xmit;
dev->get_stats = ipip6_tunnel_get_stats;
dev->do_ioctl = ipip6_tunnel_ioctl;
dev->change_mtu = ipip6_tunnel_change_mtu;
dev->type = ARPHRD_SIT;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
dev->mtu = 1500 - sizeof(struct iphdr);
dev->flags = IFF_NOARP;
dev->iflink = 0;
dev->addr_len = 4;
memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
}
static int ipip6_tunnel_init(struct net_device *dev)
{
struct net_device *tdev = NULL;
struct ip_tunnel *tunnel;
struct iphdr *iph;
tunnel = (struct ip_tunnel*)dev->priv;
iph = &tunnel->parms.iph;
ipip6_tunnel_init_gen(dev);
if (iph->daddr) {
struct rtable *rt;
if (!ip_route_output(&rt, iph->daddr, iph->saddr, RT_TOS(iph->tos), tunnel->parms.link)) {
tdev = rt->u.dst.dev;
ip_rt_put(rt);
}
dev->flags |= IFF_POINTOPOINT;
}
if (!tdev && tunnel->parms.link)
tdev = __dev_get_by_index(tunnel->parms.link);
if (tdev) {
dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
dev->mtu = tdev->mtu - sizeof(struct iphdr);
if (dev->mtu < IPV6_MIN_MTU)
dev->mtu = IPV6_MIN_MTU;
}
dev->iflink = tunnel->parms.link;
return 0;
}
#ifdef MODULE
static int ipip6_fb_tunnel_open(struct net_device *dev)
{
MOD_INC_USE_COUNT;
return 0;
}
static int ipip6_fb_tunnel_close(struct net_device *dev)
{
MOD_DEC_USE_COUNT;
return 0;
}
#endif
int __init ipip6_fb_tunnel_init(struct net_device *dev)
{
struct iphdr *iph;
ipip6_tunnel_init_gen(dev);
#ifdef MODULE
dev->open = ipip6_fb_tunnel_open;
dev->stop = ipip6_fb_tunnel_close;
#endif
iph = &ipip6_fb_tunnel.parms.iph;
iph->version = 4;
iph->protocol = IPPROTO_IPV6;
iph->ihl = 5;
iph->ttl = 64;
dev_hold(dev);
tunnels_wc[0] = &ipip6_fb_tunnel;
return 0;
}
static struct inet_protocol sit_protocol = {
ipip6_rcv,
ipip6_err,
0,
IPPROTO_IPV6,
0,
NULL,
"IPv6"
};
#ifdef MODULE
void sit_cleanup(void)
{
inet_del_protocol(&sit_protocol);
unregister_netdev(&ipip6_fb_tunnel_dev);
}
#endif
int __init sit_init(void)
{
printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
ipip6_fb_tunnel_dev.priv = (void*)&ipip6_fb_tunnel;
strcpy(ipip6_fb_tunnel_dev.name, ipip6_fb_tunnel.parms.name);
register_netdev(&ipip6_fb_tunnel_dev);
inet_add_protocol(&sit_protocol);
return 0;
}
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