linux/net/ipv6/sit.c
Pavel Emelyanov 74b0b85b88 tunnels: Fix tunnels change rcu protection
After making rcu protection for tunnels (ipip, gre, sit and ip6) a bug
was introduced into the SIOCCHGTUNNEL code.

The tunnel is first unlinked, then addresses change, then it is linked
back probably into another bucket. But while changing the parms, the
hash table is unlocked to readers and they can lookup the improper tunnel.

Respective commits are b7285b79 (ipip: get rid of ipip_lock), 1507850b
(gre: get rid of ipgre_lock), 3a43be3c (sit: get rid of ipip6_lock) and
94767632 (ip6tnl: get rid of ip6_tnl_lock).

The quick fix is to wait for quiescent state to pass after unlinking,
but if it is inappropriate I can invent something better, just let me
know.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27 14:20:08 -07:00

1295 lines
29 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>
*
* 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
* Fred Templin <fred.l.templin@boeing.com>: isatap support
*/
#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmp.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/init.h>
#include <linux/netfilter_ipv4.h>
#include <linux/if_ether.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>
#include <net/net_namespace.h>
#include <net/netns/generic.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) (((__force u32)addr^((__force u32)addr>>4))&0xF)
static int ipip6_tunnel_init(struct net_device *dev);
static void ipip6_tunnel_setup(struct net_device *dev);
static void ipip6_dev_free(struct net_device *dev);
static int sit_net_id __read_mostly;
struct sit_net {
struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
struct ip_tunnel __rcu *tunnels_wc[1];
struct ip_tunnel __rcu **tunnels[4];
struct net_device *fb_tunnel_dev;
};
/*
* Locking : hash tables are protected by RCU and RTNL
*/
#define for_each_ip_tunnel_rcu(start) \
for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
/* often modified stats are per cpu, other are shared (netdev->stats) */
struct pcpu_tstats {
unsigned long rx_packets;
unsigned long rx_bytes;
unsigned long tx_packets;
unsigned long tx_bytes;
};
static struct net_device_stats *ipip6_get_stats(struct net_device *dev)
{
struct pcpu_tstats sum = { 0 };
int i;
for_each_possible_cpu(i) {
const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
sum.rx_packets += tstats->rx_packets;
sum.rx_bytes += tstats->rx_bytes;
sum.tx_packets += tstats->tx_packets;
sum.tx_bytes += tstats->tx_bytes;
}
dev->stats.rx_packets = sum.rx_packets;
dev->stats.rx_bytes = sum.rx_bytes;
dev->stats.tx_packets = sum.tx_packets;
dev->stats.tx_bytes = sum.tx_bytes;
return &dev->stats;
}
/*
* Must be invoked with rcu_read_lock
*/
static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
struct net_device *dev, __be32 remote, __be32 local)
{
unsigned int h0 = HASH(remote);
unsigned int h1 = HASH(local);
struct ip_tunnel *t;
struct sit_net *sitn = net_generic(net, sit_net_id);
for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
if (local == t->parms.iph.saddr &&
remote == t->parms.iph.daddr &&
(!dev || !t->parms.link || dev->iflink == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
if (remote == t->parms.iph.daddr &&
(!dev || !t->parms.link || dev->iflink == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
if (local == t->parms.iph.saddr &&
(!dev || !t->parms.link || dev->iflink == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
t = rcu_dereference(sitn->tunnels_wc[0]);
if ((t != NULL) && (t->dev->flags & IFF_UP))
return t;
return NULL;
}
static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
struct ip_tunnel_parm *parms)
{
__be32 remote = parms->iph.daddr;
__be32 local = parms->iph.saddr;
unsigned int h = 0;
int prio = 0;
if (remote) {
prio |= 2;
h ^= HASH(remote);
}
if (local) {
prio |= 1;
h ^= HASH(local);
}
return &sitn->tunnels[prio][h];
}
static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
struct ip_tunnel *t)
{
return __ipip6_bucket(sitn, &t->parms);
}
static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
{
struct ip_tunnel __rcu **tp;
struct ip_tunnel *iter;
for (tp = ipip6_bucket(sitn, t);
(iter = rtnl_dereference(*tp)) != NULL;
tp = &iter->next) {
if (t == iter) {
rcu_assign_pointer(*tp, t->next);
break;
}
}
}
static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
{
struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
rcu_assign_pointer(t->next, rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}
static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
{
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel *t = netdev_priv(dev);
if (t->dev == sitn->fb_tunnel_dev) {
ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
t->ip6rd.relay_prefix = 0;
t->ip6rd.prefixlen = 16;
t->ip6rd.relay_prefixlen = 0;
} else {
struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
}
#endif
}
static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
struct ip_tunnel_parm *parms, int create)
{
__be32 remote = parms->iph.daddr;
__be32 local = parms->iph.saddr;
struct ip_tunnel *t, *nt;
struct ip_tunnel __rcu **tp;
struct net_device *dev;
char name[IFNAMSIZ];
struct sit_net *sitn = net_generic(net, sit_net_id);
for (tp = __ipip6_bucket(sitn, parms);
(t = rtnl_dereference(*tp)) != NULL;
tp = &t->next) {
if (local == t->parms.iph.saddr &&
remote == t->parms.iph.daddr &&
parms->link == t->parms.link) {
if (create)
return NULL;
else
return t;
}
}
if (!create)
goto failed;
if (parms->name[0])
strlcpy(name, parms->name, IFNAMSIZ);
else
strcpy(name, "sit%d");
dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
if (dev == NULL)
return NULL;
dev_net_set(dev, net);
if (strchr(name, '%')) {
if (dev_alloc_name(dev, name) < 0)
goto failed_free;
}
nt = netdev_priv(dev);
nt->parms = *parms;
if (ipip6_tunnel_init(dev) < 0)
goto failed_free;
ipip6_tunnel_clone_6rd(dev, sitn);
if (parms->i_flags & SIT_ISATAP)
dev->priv_flags |= IFF_ISATAP;
if (register_netdevice(dev) < 0)
goto failed_free;
dev_hold(dev);
ipip6_tunnel_link(sitn, nt);
return nt;
failed_free:
ipip6_dev_free(dev);
failed:
return NULL;
}
#define for_each_prl_rcu(start) \
for (prl = rcu_dereference(start); \
prl; \
prl = rcu_dereference(prl->next))
static struct ip_tunnel_prl_entry *
__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
{
struct ip_tunnel_prl_entry *prl;
for_each_prl_rcu(t->prl)
if (prl->addr == addr)
break;
return prl;
}
static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
struct ip_tunnel_prl __user *a)
{
struct ip_tunnel_prl kprl, *kp;
struct ip_tunnel_prl_entry *prl;
unsigned int cmax, c = 0, ca, len;
int ret = 0;
if (copy_from_user(&kprl, a, sizeof(kprl)))
return -EFAULT;
cmax = kprl.datalen / sizeof(kprl);
if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
cmax = 1;
/* For simple GET or for root users,
* we try harder to allocate.
*/
kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
NULL;
rcu_read_lock();
ca = t->prl_count < cmax ? t->prl_count : cmax;
if (!kp) {
/* We don't try hard to allocate much memory for
* non-root users.
* For root users, retry allocating enough memory for
* the answer.
*/
kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
if (!kp) {
ret = -ENOMEM;
goto out;
}
}
c = 0;
for_each_prl_rcu(t->prl) {
if (c >= cmax)
break;
if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
continue;
kp[c].addr = prl->addr;
kp[c].flags = prl->flags;
c++;
if (kprl.addr != htonl(INADDR_ANY))
break;
}
out:
rcu_read_unlock();
len = sizeof(*kp) * c;
ret = 0;
if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
ret = -EFAULT;
kfree(kp);
return ret;
}
static int
ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
{
struct ip_tunnel_prl_entry *p;
int err = 0;
if (a->addr == htonl(INADDR_ANY))
return -EINVAL;
ASSERT_RTNL();
for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
if (p->addr == a->addr) {
if (chg) {
p->flags = a->flags;
goto out;
}
err = -EEXIST;
goto out;
}
}
if (chg) {
err = -ENXIO;
goto out;
}
p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
if (!p) {
err = -ENOBUFS;
goto out;
}
p->next = t->prl;
p->addr = a->addr;
p->flags = a->flags;
t->prl_count++;
rcu_assign_pointer(t->prl, p);
out:
return err;
}
static void prl_entry_destroy_rcu(struct rcu_head *head)
{
kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head));
}
static void prl_list_destroy_rcu(struct rcu_head *head)
{
struct ip_tunnel_prl_entry *p, *n;
p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
do {
n = p->next;
kfree(p);
p = n;
} while (p);
}
static int
ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
{
struct ip_tunnel_prl_entry *x, **p;
int err = 0;
ASSERT_RTNL();
if (a && a->addr != htonl(INADDR_ANY)) {
for (p = &t->prl; *p; p = &(*p)->next) {
if ((*p)->addr == a->addr) {
x = *p;
*p = x->next;
call_rcu(&x->rcu_head, prl_entry_destroy_rcu);
t->prl_count--;
goto out;
}
}
err = -ENXIO;
} else {
if (t->prl) {
t->prl_count = 0;
x = t->prl;
call_rcu(&x->rcu_head, prl_list_destroy_rcu);
t->prl = NULL;
}
}
out:
return err;
}
static int
isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
{
struct ip_tunnel_prl_entry *p;
int ok = 1;
rcu_read_lock();
p = __ipip6_tunnel_locate_prl(t, iph->saddr);
if (p) {
if (p->flags & PRL_DEFAULT)
skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
else
skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
} else {
struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
if (ipv6_addr_is_isatap(addr6) &&
(addr6->s6_addr32[3] == iph->saddr) &&
ipv6_chk_prefix(addr6, t->dev))
skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
else
ok = 0;
}
rcu_read_unlock();
return ok;
}
static void ipip6_tunnel_uninit(struct net_device *dev)
{
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
if (dev == sitn->fb_tunnel_dev) {
rcu_assign_pointer(sitn->tunnels_wc[0], NULL);
} else {
ipip6_tunnel_unlink(sitn, netdev_priv(dev));
ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
}
dev_put(dev);
}
static int ipip6_err(struct sk_buff *skb, u32 info)
{
/* 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;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
struct ip_tunnel *t;
int err;
switch (type) {
default:
case ICMP_PARAMETERPROB:
return 0;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
return 0;
case ICMP_FRAG_NEEDED:
/* Soft state for pmtu is maintained by IP core. */
return 0;
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 0;
break;
}
err = -ENOENT;
rcu_read_lock();
t = ipip6_tunnel_lookup(dev_net(skb->dev),
skb->dev,
iph->daddr,
iph->saddr);
if (t == NULL || t->parms.iph.daddr == 0)
goto out;
err = 0;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
goto out;
if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
out:
rcu_read_unlock();
return err;
}
static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
{
if (INET_ECN_is_ce(iph->tos))
IP6_ECN_set_ce(ipv6_hdr(skb));
}
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 = ip_hdr(skb);
rcu_read_lock();
tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
iph->saddr, iph->daddr);
if (tunnel != NULL) {
struct pcpu_tstats *tstats;
secpath_reset(skb);
skb->mac_header = skb->network_header;
skb_reset_network_header(skb);
IPCB(skb)->flags = 0;
skb->protocol = htons(ETH_P_IPV6);
skb->pkt_type = PACKET_HOST;
if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
!isatap_chksrc(skb, iph, tunnel)) {
tunnel->dev->stats.rx_errors++;
rcu_read_unlock();
kfree_skb(skb);
return 0;
}
tstats = this_cpu_ptr(tunnel->dev->tstats);
tstats->rx_packets++;
tstats->rx_bytes += skb->len;
__skb_tunnel_rx(skb, tunnel->dev);
ipip6_ecn_decapsulate(iph, skb);
netif_rx(skb);
rcu_read_unlock();
return 0;
}
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
rcu_read_unlock();
out:
kfree_skb(skb);
return 0;
}
/*
* Returns the embedded IPv4 address if the IPv6 address
* comes from 6rd / 6to4 (RFC 3056) addr space.
*/
static inline
__be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
{
__be32 dst = 0;
#ifdef CONFIG_IPV6_SIT_6RD
if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
tunnel->ip6rd.prefixlen)) {
unsigned int pbw0, pbi0;
int pbi1;
u32 d;
pbw0 = tunnel->ip6rd.prefixlen >> 5;
pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
tunnel->ip6rd.relay_prefixlen;
pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
if (pbi1 > 0)
d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
(32 - pbi1);
dst = tunnel->ip6rd.relay_prefix | htonl(d);
}
#else
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);
}
#endif
return dst;
}
/*
* This function assumes it is being called from dev_queue_xmit()
* and that skb is filled properly by that function.
*/
static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct pcpu_tstats *tstats;
struct iphdr *tiph = &tunnel->parms.iph;
struct ipv6hdr *iph6 = ipv6_hdr(skb);
u8 tos = tunnel->parms.iph.tos;
__be16 df = tiph->frag_off;
struct rtable *rt; /* Route to the other host */
struct net_device *tdev; /* Device to other host */
struct iphdr *iph; /* Our new IP header */
unsigned int max_headroom; /* The extra header space needed */
__be32 dst = tiph->daddr;
int mtu;
struct in6_addr *addr6;
int addr_type;
if (skb->protocol != htons(ETH_P_IPV6))
goto tx_error;
/* ISATAP (RFC4214) - must come before 6to4 */
if (dev->priv_flags & IFF_ISATAP) {
struct neighbour *neigh = NULL;
if (skb_dst(skb))
neigh = skb_dst(skb)->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_UNICAST) &&
ipv6_addr_is_isatap(addr6))
dst = addr6->s6_addr32[3];
else
goto tx_error;
}
if (!dst)
dst = try_6rd(&iph6->daddr, tunnel);
if (!dst) {
struct neighbour *neigh = NULL;
if (skb_dst(skb))
neigh = skb_dst(skb)->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 = &ipv6_hdr(skb)->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(dev_net(dev), &rt, &fl)) {
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
}
if (rt->rt_type != RTN_UNICAST) {
ip_rt_put(rt);
dev->stats.tx_carrier_errors++;
goto tx_error_icmp;
}
tdev = rt->dst.dev;
if (tdev == dev) {
ip_rt_put(rt);
dev->stats.collisions++;
goto tx_error;
}
if (df) {
mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
if (mtu < 68) {
dev->stats.collisions++;
ip_rt_put(rt);
goto tx_error;
}
if (mtu < IPV6_MIN_MTU) {
mtu = IPV6_MIN_MTU;
df = 0;
}
if (tunnel->parms.iph.daddr && skb_dst(skb))
skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
if (skb->len > mtu) {
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
ip_rt_put(rt);
goto tx_error;
}
}
if (tunnel->err_count > 0) {
if (time_before(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_shared(skb) ||
(skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
if (!new_skb) {
ip_rt_put(rt);
dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
if (skb->sk)
skb_set_owner_w(new_skb, skb->sk);
dev_kfree_skb(skb);
skb = new_skb;
iph6 = ipv6_hdr(skb);
}
skb->transport_header = skb->network_header;
skb_push(skb, sizeof(struct iphdr));
skb_reset_network_header(skb);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
IPCB(skb)->flags = 0;
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
/*
* Push down and install the IPIP header.
*/
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = sizeof(struct iphdr)>>2;
iph->frag_off = df;
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);
tstats = this_cpu_ptr(dev->tstats);
__IPTUNNEL_XMIT(tstats, &dev->stats);
return NETDEV_TX_OK;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
dev->stats.tx_errors++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static void ipip6_tunnel_bind_dev(struct net_device *dev)
{
struct net_device *tdev = NULL;
struct ip_tunnel *tunnel;
struct iphdr *iph;
tunnel = netdev_priv(dev);
iph = &tunnel->parms.iph;
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(dev_net(dev), &rt, &fl)) {
tdev = rt->dst.dev;
ip_rt_put(rt);
}
dev->flags |= IFF_POINTOPOINT;
}
if (!tdev && tunnel->parms.link)
tdev = __dev_get_by_index(dev_net(dev), 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;
}
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_prl prl;
struct ip_tunnel *t;
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd ip6rd;
#endif
switch (cmd) {
case SIOCGETTUNNEL:
#ifdef CONFIG_IPV6_SIT_6RD
case SIOCGET6RD:
#endif
t = NULL;
if (dev == sitn->fb_tunnel_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
err = -EFAULT;
break;
}
t = ipip6_tunnel_locate(net, &p, 0);
}
if (t == NULL)
t = netdev_priv(dev);
err = -EFAULT;
if (cmd == SIOCGETTUNNEL) {
memcpy(&p, &t->parms, sizeof(p));
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
sizeof(p)))
goto done;
#ifdef CONFIG_IPV6_SIT_6RD
} else {
ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
ip6rd.relay_prefix = t->ip6rd.relay_prefix;
ip6rd.prefixlen = t->ip6rd.prefixlen;
ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
sizeof(ip6rd)))
goto done;
#endif
}
err = 0;
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(net, &p, cmd == SIOCADDTUNNEL);
if (dev != sitn->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 = netdev_priv(dev);
ipip6_tunnel_unlink(sitn, t);
synchronize_net();
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(sitn, 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 (t->parms.link != p.link) {
t->parms.link = p.link;
ipip6_tunnel_bind_dev(dev);
netdev_state_change(dev);
}
}
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 == sitn->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(net, &p, 0)) == NULL)
goto done;
err = -EPERM;
if (t == netdev_priv(sitn->fb_tunnel_dev))
goto done;
dev = t->dev;
}
unregister_netdevice(dev);
err = 0;
break;
case SIOCGETPRL:
err = -EINVAL;
if (dev == sitn->fb_tunnel_dev)
goto done;
err = -ENOENT;
if (!(t = netdev_priv(dev)))
goto done;
err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
break;
case SIOCADDPRL:
case SIOCDELPRL:
case SIOCCHGPRL:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
goto done;
err = -EINVAL;
if (dev == sitn->fb_tunnel_dev)
goto done;
err = -EFAULT;
if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
goto done;
err = -ENOENT;
if (!(t = netdev_priv(dev)))
goto done;
switch (cmd) {
case SIOCDELPRL:
err = ipip6_tunnel_del_prl(t, &prl);
break;
case SIOCADDPRL:
case SIOCCHGPRL:
err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
break;
}
netdev_state_change(dev);
break;
#ifdef CONFIG_IPV6_SIT_6RD
case SIOCADD6RD:
case SIOCCHG6RD:
case SIOCDEL6RD:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
goto done;
err = -EFAULT;
if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
sizeof(ip6rd)))
goto done;
t = netdev_priv(dev);
if (cmd != SIOCDEL6RD) {
struct in6_addr prefix;
__be32 relay_prefix;
err = -EINVAL;
if (ip6rd.relay_prefixlen > 32 ||
ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
goto done;
ipv6_addr_prefix(&prefix, &ip6rd.prefix,
ip6rd.prefixlen);
if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
goto done;
if (ip6rd.relay_prefixlen)
relay_prefix = ip6rd.relay_prefix &
htonl(0xffffffffUL <<
(32 - ip6rd.relay_prefixlen));
else
relay_prefix = 0;
if (relay_prefix != ip6rd.relay_prefix)
goto done;
ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
t->ip6rd.relay_prefix = relay_prefix;
t->ip6rd.prefixlen = ip6rd.prefixlen;
t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
} else
ipip6_tunnel_clone_6rd(dev, sitn);
err = 0;
break;
#endif
default:
err = -EINVAL;
}
done:
return err;
}
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 const struct net_device_ops ipip6_netdev_ops = {
.ndo_uninit = ipip6_tunnel_uninit,
.ndo_start_xmit = ipip6_tunnel_xmit,
.ndo_do_ioctl = ipip6_tunnel_ioctl,
.ndo_change_mtu = ipip6_tunnel_change_mtu,
.ndo_get_stats = ipip6_get_stats,
};
static void ipip6_dev_free(struct net_device *dev)
{
free_percpu(dev->tstats);
free_netdev(dev);
}
static void ipip6_tunnel_setup(struct net_device *dev)
{
dev->netdev_ops = &ipip6_netdev_ops;
dev->destructor = ipip6_dev_free;
dev->type = ARPHRD_SIT;
dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
dev->flags = IFF_NOARP;
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
dev->iflink = 0;
dev->addr_len = 4;
dev->features |= NETIF_F_NETNS_LOCAL;
dev->features |= NETIF_F_LLTX;
}
static int ipip6_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
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);
ipip6_tunnel_bind_dev(dev);
dev->tstats = alloc_percpu(struct pcpu_tstats);
if (!dev->tstats)
return -ENOMEM;
return 0;
}
static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct iphdr *iph = &tunnel->parms.iph;
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
tunnel->dev = dev;
strcpy(tunnel->parms.name, dev->name);
iph->version = 4;
iph->protocol = IPPROTO_IPV6;
iph->ihl = 5;
iph->ttl = 64;
dev->tstats = alloc_percpu(struct pcpu_tstats);
if (!dev->tstats)
return -ENOMEM;
dev_hold(dev);
sitn->tunnels_wc[0] = tunnel;
return 0;
}
static struct xfrm_tunnel sit_handler __read_mostly = {
.handler = ipip6_rcv,
.err_handler = ipip6_err,
.priority = 1,
};
static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
{
int prio;
for (prio = 1; prio < 4; prio++) {
int h;
for (h = 0; h < HASH_SIZE; h++) {
struct ip_tunnel *t = sitn->tunnels[prio][h];
while (t != NULL) {
unregister_netdevice_queue(t->dev, head);
t = t->next;
}
}
}
}
static int __net_init sit_init_net(struct net *net)
{
struct sit_net *sitn = net_generic(net, sit_net_id);
int err;
sitn->tunnels[0] = sitn->tunnels_wc;
sitn->tunnels[1] = sitn->tunnels_l;
sitn->tunnels[2] = sitn->tunnels_r;
sitn->tunnels[3] = sitn->tunnels_r_l;
sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
ipip6_tunnel_setup);
if (!sitn->fb_tunnel_dev) {
err = -ENOMEM;
goto err_alloc_dev;
}
dev_net_set(sitn->fb_tunnel_dev, net);
err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
if (err)
goto err_dev_free;
ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
if ((err = register_netdev(sitn->fb_tunnel_dev)))
goto err_reg_dev;
return 0;
err_reg_dev:
dev_put(sitn->fb_tunnel_dev);
err_dev_free:
ipip6_dev_free(sitn->fb_tunnel_dev);
err_alloc_dev:
return err;
}
static void __net_exit sit_exit_net(struct net *net)
{
struct sit_net *sitn = net_generic(net, sit_net_id);
LIST_HEAD(list);
rtnl_lock();
sit_destroy_tunnels(sitn, &list);
unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
unregister_netdevice_many(&list);
rtnl_unlock();
}
static struct pernet_operations sit_net_ops = {
.init = sit_init_net,
.exit = sit_exit_net,
.id = &sit_net_id,
.size = sizeof(struct sit_net),
};
static void __exit sit_cleanup(void)
{
xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
unregister_pernet_device(&sit_net_ops);
rcu_barrier(); /* Wait for completion of call_rcu()'s */
}
static int __init sit_init(void)
{
int err;
printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
err = register_pernet_device(&sit_net_ops);
if (err < 0)
return err;
err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
if (err < 0) {
unregister_pernet_device(&sit_net_ops);
printk(KERN_INFO "sit init: Can't add protocol\n");
}
return err;
}
module_init(sit_init);
module_exit(sit_cleanup);
MODULE_LICENSE("GPL");
MODULE_ALIAS("sit0");