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linux/net/ipv6/ip6_tunnel.c
Herbert Xu d2acc3479c [INET]: Introduce tunnel4/tunnel6 
Basically this patch moves the generic tunnel protocol stuff out of
xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c
and tunnel6 respectively.

The reason for this is that the problem that Hugo uncovered is only
the tip of the iceberg.  The real problem is that when we removed the
dependency of ipip on xfrm4_tunnel we didn't really consider the module
case at all.

For instance, as it is it's possible to build both ipip and xfrm4_tunnel
as modules and if the latter is loaded then ipip simply won't load.

After considering the alternatives I've decided that the best way out of
this is to restore the dependency of ipip on the non-xfrm-specific part
of xfrm4_tunnel.  This is acceptable IMHO because the intention of the
removal was really to be able to use ipip without the xfrm subsystem.
This is still preserved by this patch.

So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles
the arbitration between the two.  The order of processing is determined
by a simple integer which ensures that ipip gets processed before
xfrm4_tunnel.

The situation for ICMP handling is a little bit more complicated since
we may not have enough information to determine who it's for.  It's not
a big deal at the moment since the xfrm ICMP handlers are basically
no-ops.  In future we can deal with this when we look at ICMP caching
in general.

The user-visible change to this is the removal of the TUNNEL Kconfig
prompts.  This makes sense because it can only be used through IPCOMP
as it stands.

The addition of the new modules shouldn't introduce any problems since
module dependency will cause them to be loaded.

Oh and I also turned some unnecessary pskb's in IPv6 related to this
patch to skb's.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-28 17:02:46 -08:00

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/*
* IPv6 over IPv6 tunnel device
* Linux INET6 implementation
*
* Authors:
* Ville Nuorvala <vnuorval@tcs.hut.fi>
*
* $Id$
*
* Based on:
* linux/net/ipv6/sit.c
*
* RFC 2473
*
* 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.
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sockios.h>
#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/route.h>
#include <linux/rtnetlink.h>
#include <linux/netfilter_ipv6.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/ip6_tunnel.h>
#include <net/xfrm.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
MODULE_AUTHOR("Ville Nuorvala");
MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel");
MODULE_LICENSE("GPL");
#define IPV6_TLV_TEL_DST_SIZE 8
#ifdef IP6_TNL_DEBUG
#define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__)
#else
#define IP6_TNL_TRACE(x...) do {;} while(0)
#endif
#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
#define HASH_SIZE 32
#define HASH(addr) (((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \
(addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \
(HASH_SIZE - 1))
static int ip6ip6_fb_tnl_dev_init(struct net_device *dev);
static int ip6ip6_tnl_dev_init(struct net_device *dev);
static void ip6ip6_tnl_dev_setup(struct net_device *dev);
/* the IPv6 tunnel fallback device */
static struct net_device *ip6ip6_fb_tnl_dev;
/* lists for storing tunnels in use */
static struct ip6_tnl *tnls_r_l[HASH_SIZE];
static struct ip6_tnl *tnls_wc[1];
static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l };
/* lock for the tunnel lists */
static DEFINE_RWLOCK(ip6ip6_lock);
static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
{
struct dst_entry *dst = t->dst_cache;
if (dst && dst->obsolete &&
dst->ops->check(dst, t->dst_cookie) == NULL) {
t->dst_cache = NULL;
dst_release(dst);
return NULL;
}
return dst;
}
static inline void ip6_tnl_dst_reset(struct ip6_tnl *t)
{
dst_release(t->dst_cache);
t->dst_cache = NULL;
}
static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
{
struct rt6_info *rt = (struct rt6_info *) dst;
t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
dst_release(t->dst_cache);
t->dst_cache = dst;
}
/**
* ip6ip6_tnl_lookup - fetch tunnel matching the end-point addresses
* @remote: the address of the tunnel exit-point
* @local: the address of the tunnel entry-point
*
* Return:
* tunnel matching given end-points if found,
* else fallback tunnel if its device is up,
* else %NULL
**/
static struct ip6_tnl *
ip6ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local)
{
unsigned h0 = HASH(remote);
unsigned h1 = HASH(local);
struct ip6_tnl *t;
for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) {
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_equal(remote, &t->parms.raddr) &&
(t->dev->flags & IFF_UP))
return t;
}
if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP))
return t;
return NULL;
}
/**
* ip6ip6_bucket - get head of list matching given tunnel parameters
* @p: parameters containing tunnel end-points
*
* Description:
* ip6ip6_bucket() returns the head of the list matching the
* &struct in6_addr entries laddr and raddr in @p.
*
* Return: head of IPv6 tunnel list
**/
static struct ip6_tnl **
ip6ip6_bucket(struct ip6_tnl_parm *p)
{
struct in6_addr *remote = &p->raddr;
struct in6_addr *local = &p->laddr;
unsigned h = 0;
int prio = 0;
if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
prio = 1;
h = HASH(remote) ^ HASH(local);
}
return &tnls[prio][h];
}
/**
* ip6ip6_tnl_link - add tunnel to hash table
* @t: tunnel to be added
**/
static void
ip6ip6_tnl_link(struct ip6_tnl *t)
{
struct ip6_tnl **tp = ip6ip6_bucket(&t->parms);
t->next = *tp;
write_lock_bh(&ip6ip6_lock);
*tp = t;
write_unlock_bh(&ip6ip6_lock);
}
/**
* ip6ip6_tnl_unlink - remove tunnel from hash table
* @t: tunnel to be removed
**/
static void
ip6ip6_tnl_unlink(struct ip6_tnl *t)
{
struct ip6_tnl **tp;
for (tp = ip6ip6_bucket(&t->parms); *tp; tp = &(*tp)->next) {
if (t == *tp) {
write_lock_bh(&ip6ip6_lock);
*tp = t->next;
write_unlock_bh(&ip6ip6_lock);
break;
}
}
}
/**
* ip6_tnl_create() - create a new tunnel
* @p: tunnel parameters
* @pt: pointer to new tunnel
*
* Description:
* Create tunnel matching given parameters.
*
* Return:
* 0 on success
**/
static int
ip6_tnl_create(struct ip6_tnl_parm *p, struct ip6_tnl **pt)
{
struct net_device *dev;
struct ip6_tnl *t;
char name[IFNAMSIZ];
int err;
if (p->name[0]) {
strlcpy(name, p->name, IFNAMSIZ);
} else {
int i;
for (i = 1; i < IP6_TNL_MAX; i++) {
sprintf(name, "ip6tnl%d", i);
if (__dev_get_by_name(name) == NULL)
break;
}
if (i == IP6_TNL_MAX)
return -ENOBUFS;
}
dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup);
if (dev == NULL)
return -ENOMEM;
t = netdev_priv(dev);
dev->init = ip6ip6_tnl_dev_init;
t->parms = *p;
if ((err = register_netdevice(dev)) < 0) {
free_netdev(dev);
return err;
}
dev_hold(dev);
ip6ip6_tnl_link(t);
*pt = t;
return 0;
}
/**
* ip6ip6_tnl_locate - find or create tunnel matching given parameters
* @p: tunnel parameters
* @create: != 0 if allowed to create new tunnel if no match found
*
* Description:
* ip6ip6_tnl_locate() first tries to locate an existing tunnel
* based on @parms. If this is unsuccessful, but @create is set a new
* tunnel device is created and registered for use.
*
* Return:
* 0 if tunnel located or created,
* -EINVAL if parameters incorrect,
* -ENODEV if no matching tunnel available
**/
static int
ip6ip6_tnl_locate(struct ip6_tnl_parm *p, struct ip6_tnl **pt, int create)
{
struct in6_addr *remote = &p->raddr;
struct in6_addr *local = &p->laddr;
struct ip6_tnl *t;
if (p->proto != IPPROTO_IPV6)
return -EINVAL;
for (t = *ip6ip6_bucket(p); t; t = t->next) {
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_equal(remote, &t->parms.raddr)) {
*pt = t;
return (create ? -EEXIST : 0);
}
}
if (!create)
return -ENODEV;
return ip6_tnl_create(p, pt);
}
/**
* ip6ip6_tnl_dev_uninit - tunnel device uninitializer
* @dev: the device to be destroyed
*
* Description:
* ip6ip6_tnl_dev_uninit() removes tunnel from its list
**/
static void
ip6ip6_tnl_dev_uninit(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
if (dev == ip6ip6_fb_tnl_dev) {
write_lock_bh(&ip6ip6_lock);
tnls_wc[0] = NULL;
write_unlock_bh(&ip6ip6_lock);
} else {
ip6ip6_tnl_unlink(t);
}
ip6_tnl_dst_reset(t);
dev_put(dev);
}
/**
* parse_tvl_tnl_enc_lim - handle encapsulation limit option
* @skb: received socket buffer
*
* Return:
* 0 if none was found,
* else index to encapsulation limit
**/
static __u16
parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
{
struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw;
__u8 nexthdr = ipv6h->nexthdr;
__u16 off = sizeof (*ipv6h);
while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
__u16 optlen = 0;
struct ipv6_opt_hdr *hdr;
if (raw + off + sizeof (*hdr) > skb->data &&
!pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
break;
hdr = (struct ipv6_opt_hdr *) (raw + off);
if (nexthdr == NEXTHDR_FRAGMENT) {
struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
if (frag_hdr->frag_off)
break;
optlen = 8;
} else if (nexthdr == NEXTHDR_AUTH) {
optlen = (hdr->hdrlen + 2) << 2;
} else {
optlen = ipv6_optlen(hdr);
}
if (nexthdr == NEXTHDR_DEST) {
__u16 i = off + 2;
while (1) {
struct ipv6_tlv_tnl_enc_lim *tel;
/* No more room for encapsulation limit */
if (i + sizeof (*tel) > off + optlen)
break;
tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
/* return index of option if found and valid */
if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
tel->length == 1)
return i;
/* else jump to next option */
if (tel->type)
i += tel->length + 2;
else
i++;
}
}
nexthdr = hdr->nexthdr;
off += optlen;
}
return 0;
}
/**
* ip6ip6_err - tunnel error handler
*
* Description:
* ip6ip6_err() should handle errors in the tunnel according
* to the specifications in RFC 2473.
**/
static int
ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __u32 info)
{
struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data;
struct ip6_tnl *t;
int rel_msg = 0;
int rel_type = ICMPV6_DEST_UNREACH;
int rel_code = ICMPV6_ADDR_UNREACH;
__u32 rel_info = 0;
__u16 len;
int err = -ENOENT;
/* If the packet doesn't contain the original IPv6 header we are
in trouble since we might need the source address for further
processing of the error. */
read_lock(&ip6ip6_lock);
if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL)
goto out;
err = 0;
switch (type) {
__u32 teli;
struct ipv6_tlv_tnl_enc_lim *tel;
__u32 mtu;
case ICMPV6_DEST_UNREACH:
if (net_ratelimit())
printk(KERN_WARNING
"%s: Path to destination invalid "
"or inactive!\n", t->parms.name);
rel_msg = 1;
break;
case ICMPV6_TIME_EXCEED:
if (code == ICMPV6_EXC_HOPLIMIT) {
if (net_ratelimit())
printk(KERN_WARNING
"%s: Too small hop limit or "
"routing loop in tunnel!\n",
t->parms.name);
rel_msg = 1;
}
break;
case ICMPV6_PARAMPROB:
/* ignore if parameter problem not caused by a tunnel
encapsulation limit sub-option */
if (code != ICMPV6_HDR_FIELD) {
break;
}
teli = parse_tlv_tnl_enc_lim(skb, skb->data);
if (teli && teli == ntohl(info) - 2) {
tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
if (tel->encap_limit == 0) {
if (net_ratelimit())
printk(KERN_WARNING
"%s: Too small encapsulation "
"limit or routing loop in "
"tunnel!\n", t->parms.name);
rel_msg = 1;
}
}
break;
case ICMPV6_PKT_TOOBIG:
mtu = ntohl(info) - offset;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
t->dev->mtu = mtu;
if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
rel_type = ICMPV6_PKT_TOOBIG;
rel_code = 0;
rel_info = mtu;
rel_msg = 1;
}
break;
}
if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) {
struct rt6_info *rt;
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
goto out;
dst_release(skb2->dst);
skb2->dst = NULL;
skb_pull(skb2, offset);
skb2->nh.raw = skb2->data;
/* Try to guess incoming interface */
rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0);
if (rt && rt->rt6i_dev)
skb2->dev = rt->rt6i_dev;
icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
if (rt)
dst_release(&rt->u.dst);
kfree_skb(skb2);
}
out:
read_unlock(&ip6ip6_lock);
return err;
}
static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph,
struct sk_buff *skb)
{
struct ipv6hdr *inner_iph = skb->nh.ipv6h;
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
IP6_ECN_set_ce(inner_iph);
}
/**
* ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally
* @skb: received socket buffer
*
* Return: 0
**/
static int
ip6ip6_rcv(struct sk_buff *skb)
{
struct ipv6hdr *ipv6h;
struct ip6_tnl *t;
if (!pskb_may_pull(skb, sizeof (*ipv6h)))
goto discard;
ipv6h = skb->nh.ipv6h;
read_lock(&ip6ip6_lock);
if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) {
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
read_unlock(&ip6ip6_lock);
kfree_skb(skb);
return 0;
}
if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) {
t->stat.rx_dropped++;
read_unlock(&ip6ip6_lock);
goto discard;
}
secpath_reset(skb);
skb->mac.raw = skb->nh.raw;
skb->nh.raw = skb->data;
skb->protocol = htons(ETH_P_IPV6);
skb->pkt_type = PACKET_HOST;
memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
skb->dev = t->dev;
dst_release(skb->dst);
skb->dst = NULL;
if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
ipv6_copy_dscp(ipv6h, skb->nh.ipv6h);
ip6ip6_ecn_decapsulate(ipv6h, skb);
t->stat.rx_packets++;
t->stat.rx_bytes += skb->len;
netif_rx(skb);
read_unlock(&ip6ip6_lock);
return 0;
}
read_unlock(&ip6ip6_lock);
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev);
discard:
return 1;
}
static inline struct ipv6_txoptions *create_tel(__u8 encap_limit)
{
struct ipv6_tlv_tnl_enc_lim *tel;
struct ipv6_txoptions *opt;
__u8 *raw;
int opt_len = sizeof(*opt) + 8;
if (!(opt = kmalloc(opt_len, GFP_ATOMIC))) {
return NULL;
}
memset(opt, 0, opt_len);
opt->tot_len = opt_len;
opt->dst0opt = (struct ipv6_opt_hdr *) (opt + 1);
opt->opt_nflen = 8;
tel = (struct ipv6_tlv_tnl_enc_lim *) (opt->dst0opt + 1);
tel->type = IPV6_TLV_TNL_ENCAP_LIMIT;
tel->length = 1;
tel->encap_limit = encap_limit;
raw = (__u8 *) opt->dst0opt;
raw[5] = IPV6_TLV_PADN;
raw[6] = 1;
return opt;
}
/**
* ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
* @t: the outgoing tunnel device
* @hdr: IPv6 header from the incoming packet
*
* Description:
* Avoid trivial tunneling loop by checking that tunnel exit-point
* doesn't match source of incoming packet.
*
* Return:
* 1 if conflict,
* 0 else
**/
static inline int
ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr)
{
return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
}
/**
* ip6ip6_tnl_xmit - encapsulate packet and send
* @skb: the outgoing socket buffer
* @dev: the outgoing tunnel device
*
* Description:
* Build new header and do some sanity checks on the packet before sending
* it.
*
* Return:
* 0
**/
static int
ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct net_device_stats *stats = &t->stat;
struct ipv6hdr *ipv6h = skb->nh.ipv6h;
struct ipv6_txoptions *opt = NULL;
int encap_limit = -1;
__u16 offset;
struct flowi fl;
struct dst_entry *dst;
struct net_device *tdev;
int mtu;
int max_headroom = sizeof(struct ipv6hdr);
u8 proto;
int err;
int pkt_len;
int dsfield;
if (t->recursion++) {
stats->collisions++;
goto tx_err;
}
if (skb->protocol != htons(ETH_P_IPV6) ||
!(t->parms.flags & IP6_TNL_F_CAP_XMIT) ||
ip6ip6_tnl_addr_conflict(t, ipv6h)) {
goto tx_err;
}
if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) {
struct ipv6_tlv_tnl_enc_lim *tel;
tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset];
if (tel->encap_limit == 0) {
icmpv6_send(skb, ICMPV6_PARAMPROB,
ICMPV6_HDR_FIELD, offset + 2, skb->dev);
goto tx_err;
}
encap_limit = tel->encap_limit - 1;
} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
encap_limit = t->parms.encap_limit;
}
memcpy(&fl, &t->fl, sizeof (fl));
proto = fl.proto;
dsfield = ipv6_get_dsfield(ipv6h);
if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_TCLASS_MASK);
if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_FLOWLABEL_MASK);
if (encap_limit >= 0 && (opt = create_tel(encap_limit)) == NULL)
goto tx_err;
if ((dst = ip6_tnl_dst_check(t)) != NULL)
dst_hold(dst);
else {
dst = ip6_route_output(NULL, &fl);
if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0)
goto tx_err_link_failure;
}
tdev = dst->dev;
if (tdev == dev) {
stats->collisions++;
if (net_ratelimit())
printk(KERN_WARNING
"%s: Local routing loop detected!\n",
t->parms.name);
goto tx_err_dst_release;
}
mtu = dst_mtu(dst) - sizeof (*ipv6h);
if (opt) {
max_headroom += 8;
mtu -= 8;
}
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb->dst && mtu < dst_mtu(skb->dst)) {
struct rt6_info *rt = (struct rt6_info *) skb->dst;
rt->rt6i_flags |= RTF_MODIFIED;
rt->u.dst.metrics[RTAX_MTU-1] = mtu;
}
if (skb->len > mtu) {
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
goto tx_err_dst_release;
}
/*
* Okay, now see if we can stuff it in the buffer as-is.
*/
max_headroom += LL_RESERVED_SPACE(tdev);
if (skb_headroom(skb) < max_headroom ||
skb_cloned(skb) || skb_shared(skb)) {
struct sk_buff *new_skb;
if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
goto tx_err_dst_release;
if (skb->sk)
skb_set_owner_w(new_skb, skb->sk);
kfree_skb(skb);
skb = new_skb;
}
dst_release(skb->dst);
skb->dst = dst_clone(dst);
skb->h.raw = skb->nh.raw;
if (opt)
ipv6_push_nfrag_opts(skb, opt, &proto, NULL);
skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr));
ipv6h = skb->nh.ipv6h;
*(u32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000);
dsfield = INET_ECN_encapsulate(0, dsfield);
ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
ipv6h->hop_limit = t->parms.hop_limit;
ipv6h->nexthdr = proto;
ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src);
ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst);
nf_reset(skb);
pkt_len = skb->len;
err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL,
skb->dst->dev, dst_output);
if (err == NET_XMIT_SUCCESS || err == NET_XMIT_CN) {
stats->tx_bytes += pkt_len;
stats->tx_packets++;
} else {
stats->tx_errors++;
stats->tx_aborted_errors++;
}
ip6_tnl_dst_store(t, dst);
kfree(opt);
t->recursion--;
return 0;
tx_err_link_failure:
stats->tx_carrier_errors++;
dst_link_failure(skb);
tx_err_dst_release:
dst_release(dst);
kfree(opt);
tx_err:
stats->tx_errors++;
stats->tx_dropped++;
kfree_skb(skb);
t->recursion--;
return 0;
}
static void ip6_tnl_set_cap(struct ip6_tnl *t)
{
struct ip6_tnl_parm *p = &t->parms;
struct in6_addr *laddr = &p->laddr;
struct in6_addr *raddr = &p->raddr;
int ltype = ipv6_addr_type(laddr);
int rtype = ipv6_addr_type(raddr);
p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV);
if (ltype != IPV6_ADDR_ANY && rtype != IPV6_ADDR_ANY &&
((ltype|rtype) &
(IPV6_ADDR_UNICAST|
IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL|
IPV6_ADDR_MAPPED|IPV6_ADDR_RESERVED)) == IPV6_ADDR_UNICAST) {
struct net_device *ldev = NULL;
int l_ok = 1;
int r_ok = 1;
if (p->link)
ldev = dev_get_by_index(p->link);
if (ltype&IPV6_ADDR_UNICAST && !ipv6_chk_addr(laddr, ldev, 0))
l_ok = 0;
if (rtype&IPV6_ADDR_UNICAST && ipv6_chk_addr(raddr, NULL, 0))
r_ok = 0;
if (l_ok && r_ok) {
if (ltype&IPV6_ADDR_UNICAST)
p->flags |= IP6_TNL_F_CAP_XMIT;
if (rtype&IPV6_ADDR_UNICAST)
p->flags |= IP6_TNL_F_CAP_RCV;
}
if (ldev)
dev_put(ldev);
}
}
static void ip6ip6_tnl_link_config(struct ip6_tnl *t)
{
struct net_device *dev = t->dev;
struct ip6_tnl_parm *p = &t->parms;
struct flowi *fl = &t->fl;
memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr));
/* Set up flowi template */
ipv6_addr_copy(&fl->fl6_src, &p->laddr);
ipv6_addr_copy(&fl->fl6_dst, &p->raddr);
fl->oif = p->link;
fl->fl6_flowlabel = 0;
if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
ip6_tnl_set_cap(t);
if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
dev->flags |= IFF_POINTOPOINT;
else
dev->flags &= ~IFF_POINTOPOINT;
dev->iflink = p->link;
if (p->flags & IP6_TNL_F_CAP_XMIT) {
struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr,
p->link, 0);
if (rt == NULL)
return;
if (rt->rt6i_dev) {
dev->hard_header_len = rt->rt6i_dev->hard_header_len +
sizeof (struct ipv6hdr);
dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr);
if (dev->mtu < IPV6_MIN_MTU)
dev->mtu = IPV6_MIN_MTU;
}
dst_release(&rt->u.dst);
}
}
/**
* ip6ip6_tnl_change - update the tunnel parameters
* @t: tunnel to be changed
* @p: tunnel configuration parameters
* @active: != 0 if tunnel is ready for use
*
* Description:
* ip6ip6_tnl_change() updates the tunnel parameters
**/
static int
ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
{
ipv6_addr_copy(&t->parms.laddr, &p->laddr);
ipv6_addr_copy(&t->parms.raddr, &p->raddr);
t->parms.flags = p->flags;
t->parms.hop_limit = p->hop_limit;
t->parms.encap_limit = p->encap_limit;
t->parms.flowinfo = p->flowinfo;
t->parms.link = p->link;
ip6_tnl_dst_reset(t);
ip6ip6_tnl_link_config(t);
return 0;
}
/**
* ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace
* @dev: virtual device associated with tunnel
* @ifr: parameters passed from userspace
* @cmd: command to be performed
*
* Description:
* ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels
* from userspace.
*
* The possible commands are the following:
* %SIOCGETTUNNEL: get tunnel parameters for device
* %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
* %SIOCCHGTUNNEL: change tunnel parameters to those given
* %SIOCDELTUNNEL: delete tunnel
*
* The fallback device "ip6tnl0", created during module
* initialization, can be used for creating other tunnel devices.
*
* Return:
* 0 on success,
* %-EFAULT if unable to copy data to or from userspace,
* %-EPERM if current process hasn't %CAP_NET_ADMIN set
* %-EINVAL if passed tunnel parameters are invalid,
* %-EEXIST if changing a tunnel's parameters would cause a conflict
* %-ENODEV if attempting to change or delete a nonexisting device
**/
static int
ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
int err = 0;
int create;
struct ip6_tnl_parm p;
struct ip6_tnl *t = NULL;
switch (cmd) {
case SIOCGETTUNNEL:
if (dev == ip6ip6_fb_tnl_dev) {
if (copy_from_user(&p,
ifr->ifr_ifru.ifru_data,
sizeof (p))) {
err = -EFAULT;
break;
}
if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV)
t = netdev_priv(dev);
else if (err)
break;
} else
t = netdev_priv(dev);
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;
create = (cmd == SIOCADDTUNNEL);
if (!capable(CAP_NET_ADMIN))
break;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
err = -EFAULT;
break;
}
if (!create && dev != ip6ip6_fb_tnl_dev) {
t = netdev_priv(dev);
}
if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) {
break;
}
if (cmd == SIOCCHGTUNNEL) {
if (t->dev != dev) {
err = -EEXIST;
break;
}
ip6ip6_tnl_unlink(t);
err = ip6ip6_tnl_change(t, &p);
ip6ip6_tnl_link(t);
netdev_state_change(dev);
}
if (copy_to_user(ifr->ifr_ifru.ifru_data,
&t->parms, sizeof (p))) {
err = -EFAULT;
} else {
err = 0;
}
break;
case SIOCDELTUNNEL:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
break;
if (dev == ip6ip6_fb_tnl_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data,
sizeof (p))) {
err = -EFAULT;
break;
}
err = ip6ip6_tnl_locate(&p, &t, 0);
if (err)
break;
if (t == netdev_priv(ip6ip6_fb_tnl_dev)) {
err = -EPERM;
break;
}
} else {
t = netdev_priv(dev);
}
err = unregister_netdevice(t->dev);
break;
default:
err = -EINVAL;
}
return err;
}
/**
* ip6ip6_tnl_get_stats - return the stats for tunnel device
* @dev: virtual device associated with tunnel
*
* Return: stats for device
**/
static struct net_device_stats *
ip6ip6_tnl_get_stats(struct net_device *dev)
{
return &(((struct ip6_tnl *)netdev_priv(dev))->stat);
}
/**
* ip6ip6_tnl_change_mtu - change mtu manually for tunnel device
* @dev: virtual device associated with tunnel
* @new_mtu: the new mtu
*
* Return:
* 0 on success,
* %-EINVAL if mtu too small
**/
static int
ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
{
if (new_mtu < IPV6_MIN_MTU) {
return -EINVAL;
}
dev->mtu = new_mtu;
return 0;
}
/**
* ip6ip6_tnl_dev_setup - setup virtual tunnel device
* @dev: virtual device associated with tunnel
*
* Description:
* Initialize function pointers and device parameters
**/
static void ip6ip6_tnl_dev_setup(struct net_device *dev)
{
SET_MODULE_OWNER(dev);
dev->uninit = ip6ip6_tnl_dev_uninit;
dev->destructor = free_netdev;
dev->hard_start_xmit = ip6ip6_tnl_xmit;
dev->get_stats = ip6ip6_tnl_get_stats;
dev->do_ioctl = ip6ip6_tnl_ioctl;
dev->change_mtu = ip6ip6_tnl_change_mtu;
dev->type = ARPHRD_TUNNEL6;
dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
}
/**
* ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices
* @dev: virtual device associated with tunnel
**/
static inline void
ip6ip6_tnl_dev_init_gen(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
t->fl.proto = IPPROTO_IPV6;
t->dev = dev;
strcpy(t->parms.name, dev->name);
}
/**
* ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices
* @dev: virtual device associated with tunnel
**/
static int
ip6ip6_tnl_dev_init(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
ip6ip6_tnl_dev_init_gen(dev);
ip6ip6_tnl_link_config(t);
return 0;
}
/**
* ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device
* @dev: fallback device
*
* Return: 0
**/
static int
ip6ip6_fb_tnl_dev_init(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
ip6ip6_tnl_dev_init_gen(dev);
dev_hold(dev);
tnls_wc[0] = t;
return 0;
}
static struct xfrm6_tunnel ip6ip6_handler = {
.handler = ip6ip6_rcv,
.err_handler = ip6ip6_err,
.priority = 1,
};
/**
* ip6_tunnel_init - register protocol and reserve needed resources
*
* Return: 0 on success
**/
static int __init ip6_tunnel_init(void)
{
int err;
if (xfrm6_tunnel_register(&ip6ip6_handler)) {
printk(KERN_ERR "ip6ip6 init: can't register tunnel\n");
return -EAGAIN;
}
ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
ip6ip6_tnl_dev_setup);
if (!ip6ip6_fb_tnl_dev) {
err = -ENOMEM;
goto fail;
}
ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init;
if ((err = register_netdev(ip6ip6_fb_tnl_dev))) {
free_netdev(ip6ip6_fb_tnl_dev);
goto fail;
}
return 0;
fail:
xfrm6_tunnel_deregister(&ip6ip6_handler);
return err;
}
/**
* ip6_tunnel_cleanup - free resources and unregister protocol
**/
static void __exit ip6_tunnel_cleanup(void)
{
if (xfrm6_tunnel_deregister(&ip6ip6_handler))
printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n");
unregister_netdev(ip6ip6_fb_tnl_dev);
}
module_init(ip6_tunnel_init);
module_exit(ip6_tunnel_cleanup);
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