linux/net/ipv6/sit.c
Alexey Kuznetsov db44575f6f [NET]: fix oops after tunnel module unload
Tunnel modules used to obtain module refcount each time when
some tunnel was created, which meaned that tunnel could be unloaded
only after all the tunnels are deleted.

Since killing old MOD_*_USE_COUNT macros this protection has gone.
It is possible to return it back as module_get/put, but it looks
more natural and practically useful to force destruction of all
the child tunnels on module unload.

Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-30 17:46:44 -07:00

851 lines
19 KiB
C

/*
* 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
*/
#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>
#include <net/xfrm.h>
#include <net/dsfield.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 void ipip6_tunnel_setup(struct net_device *dev);
static struct net_device *ipip6_fb_tunnel_dev;
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 DEFINE_RWLOCK(ipip6_lock);
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);
t->next = *tp;
write_lock_bh(&ipip6_lock);
*tp = t;
write_unlock_bh(&ipip6_lock);
}
static 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;
char name[IFNAMSIZ];
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)
goto failed;
if (parms->name[0])
strlcpy(name, parms->name, IFNAMSIZ);
else {
int i;
for (i=1; i<100; i++) {
sprintf(name, "sit%d", i);
if (__dev_get_by_name(name) == NULL)
break;
}
if (i==100)
goto failed;
}
dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
if (dev == NULL)
return NULL;
nt = dev->priv;
dev->init = ipip6_tunnel_init;
nt->parms = *parms;
if (register_netdevice(dev) < 0) {
free_netdev(dev);
goto failed;
}
dev_hold(dev);
ipip6_tunnel_link(nt);
return nt;
failed:
return NULL;
}
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);
}
}
static 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))
IP6_ECN_set_ce(skb->nh.ipv6h);
}
static 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) {
secpath_reset(skb);
skb->mac.raw = skb->nh.raw;
skb->nh.raw = skb->data;
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
skb->protocol = 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;
nf_reset(skb);
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;
}
/* Returns the embedded IPv4 address if the IPv6 address
comes from 6to4 (RFC 3056) 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 != 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];
}
{
struct flowi fl = { .nl_u = { .ip4_u =
{ .daddr = dst,
.saddr = tiph->saddr,
.tos = RT_TOS(tos) } },
.oif = tunnel->parms.link,
.proto = IPPROTO_IPV6 };
if (ip_route_output_key(&rt, &fl)) {
tunnel->stat.tx_carrier_errors++;
goto tx_error_icmp;
}
}
if (rt->rt_type != RTN_UNICAST) {
ip_rt_put(rt);
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;
}
if (tiph->frag_off)
mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
else
mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
if (mtu < 68) {
tunnel->stat.collisions++;
ip_rt_put(rt);
goto tx_error;
}
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (tunnel->parms.iph.daddr && skb->dst)
skb->dst->ops->update_pmtu(skb->dst, 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;
}
/*
* Okay, now see if we can stuff it in the buffer as-is.
*/
max_headroom = LL_RESERVED_SPACE(tdev)+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;
iph6 = skb->nh.ipv6h;
}
skb->h.raw = skb->nh.raw;
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 = htons(IP_DF);
else
iph->frag_off = 0;
iph->protocol = IPPROTO_IPV6;
iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
iph->daddr = rt->rt_dst;
iph->saddr = rt->rt_src;
if ((iph->ttl = tiph->ttl) == 0)
iph->ttl = iph6->hop_limit;
nf_reset(skb);
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;
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&htons(~IP_DF)))
goto done;
if (p.iph.ttl)
p.iph.frag_off |= htons(IP_DF);
t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL);
if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
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_dev->priv)
goto done;
dev = t->dev;
}
err = unregister_netdevice(dev);
break;
default:
err = -EINVAL;
}
done:
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_setup(struct net_device *dev)
{
SET_MODULE_OWNER(dev);
dev->uninit = ipip6_tunnel_uninit;
dev->destructor = free_netdev;
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;
}
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;
tunnel->dev = dev;
strcpy(tunnel->parms.name, dev->name);
memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
if (iph->daddr) {
struct flowi fl = { .nl_u = { .ip4_u =
{ .daddr = iph->daddr,
.saddr = iph->saddr,
.tos = RT_TOS(iph->tos) } },
.oif = tunnel->parms.link,
.proto = IPPROTO_IPV6 };
struct rtable *rt;
if (!ip_route_output_key(&rt, &fl)) {
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;
}
int __init ipip6_fb_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = dev->priv;
struct iphdr *iph = &tunnel->parms.iph;
tunnel->dev = dev;
strcpy(tunnel->parms.name, dev->name);
iph->version = 4;
iph->protocol = IPPROTO_IPV6;
iph->ihl = 5;
iph->ttl = 64;
dev_hold(dev);
tunnels_wc[0] = tunnel;
return 0;
}
static struct net_protocol sit_protocol = {
.handler = ipip6_rcv,
.err_handler = ipip6_err,
};
static void __exit sit_destroy_tunnels(void)
{
int prio;
for (prio = 1; prio < 4; prio++) {
int h;
for (h = 0; h < HASH_SIZE; h++) {
struct ip_tunnel *t;
while ((t = tunnels[prio][h]) != NULL)
unregister_netdevice(t->dev);
}
}
}
void __exit sit_cleanup(void)
{
inet_del_protocol(&sit_protocol, IPPROTO_IPV6);
rtnl_lock();
sit_destroy_tunnels();
unregister_netdevice(ipip6_fb_tunnel_dev);
rtnl_unlock();
}
int __init sit_init(void)
{
int err;
printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
if (inet_add_protocol(&sit_protocol, IPPROTO_IPV6) < 0) {
printk(KERN_INFO "sit init: Can't add protocol\n");
return -EAGAIN;
}
ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
ipip6_tunnel_setup);
if (!ipip6_fb_tunnel_dev) {
err = -ENOMEM;
goto err1;
}
ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init;
if ((err = register_netdev(ipip6_fb_tunnel_dev)))
goto err2;
out:
return err;
err2:
free_netdev(ipip6_fb_tunnel_dev);
err1:
inet_del_protocol(&sit_protocol, IPPROTO_IPV6);
goto out;
}