* Andi Kleen <ak@muc.de>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
*
- * $Id: exthdrs.c,v 1.13 2001/06/19 15:58:56 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
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/icmpv6.h>
+#include <linux/slab.h>
+#include <net/dst.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
#include <net/xfrm.h>
#endif
bad:
return -1;
}
+EXPORT_SYMBOL_GPL(ipv6_find_tlv);
/*
* Parsing tlv encoded headers.
struct tlvtype_proc {
int type;
- int (*func)(struct sk_buff **skbp, int offset);
+ int (*func)(struct sk_buff *skb, int offset);
};
/*********************
/* An unknown option is detected, decide what to do */
-static int ip6_tlvopt_unknown(struct sk_buff **skbp, int optoff)
+static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
{
- struct sk_buff *skb = *skbp;
-
switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
case 0: /* ignore */
return 1;
case 2: /* send ICMP PARM PROB regardless and drop packet */
icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
return 0;
- };
+ }
kfree_skb(skb);
return 0;
/* Parse tlv encoded option header (hop-by-hop or destination) */
-static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp)
+static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
{
- struct sk_buff *skb = *skbp;
struct tlvtype_proc *curr;
const unsigned char *nh = skb_network_header(skb);
int off = skb_network_header_len(skb);
/* type specific length/alignment
checks will be performed in the
func(). */
- if (curr->func(skbp, off) == 0)
+ if (curr->func(skb, off) == 0)
return 0;
break;
}
}
if (curr->type < 0) {
- if (ip6_tlvopt_unknown(skbp, off) == 0)
+ if (ip6_tlvopt_unknown(skb, off) == 0)
return 0;
}
break;
Destination options header.
*****************************/
-#ifdef CONFIG_IPV6_MIP6
-static int ipv6_dest_hao(struct sk_buff **skbp, int optoff)
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
+static int ipv6_dest_hao(struct sk_buff *skb, int optoff)
{
- struct sk_buff *skb = *skbp;
struct ipv6_destopt_hao *hao;
struct inet6_skb_parm *opt = IP6CB(skb);
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
LIMIT_NETDEBUG(
- KERN_DEBUG "hao is not an unicast addr: " NIP6_FMT "\n", NIP6(hao->addr));
+ KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
goto discard;
}
goto discard;
if (skb_cloned(skb)) {
- struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
- struct inet6_skb_parm *opt2;
-
- if (skb2 == NULL)
+ if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto discard;
- opt2 = IP6CB(skb2);
- memcpy(opt2, opt, sizeof(*opt2));
-
- kfree_skb(skb);
-
/* update all variable using below by copied skbuff */
- *skbp = skb = skb2;
- hao = (struct ipv6_destopt_hao *)(skb_network_header(skb2) +
+ hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
optoff);
- ipv6h = ipv6_hdr(skb2);
+ ipv6h = ipv6_hdr(skb);
}
if (skb->ip_summed == CHECKSUM_COMPLETE)
#endif
static struct tlvtype_proc tlvprocdestopt_lst[] = {
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
{
.type = IPV6_TLV_HAO,
.func = ipv6_dest_hao,
{-1, NULL}
};
-static int ipv6_destopt_rcv(struct sk_buff **skbp)
+static int ipv6_destopt_rcv(struct sk_buff *skb)
{
- struct sk_buff *skb = *skbp;
struct inet6_skb_parm *opt = IP6CB(skb);
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
__u16 dstbuf;
#endif
struct dst_entry *dst;
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
!pskb_may_pull(skb, (skb_transport_offset(skb) +
((skb_transport_header(skb)[1] + 1) << 3)))) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
kfree_skb(skb);
return -1;
}
opt->lastopt = opt->dst1 = skb_network_header_len(skb);
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
dstbuf = opt->dst1;
#endif
- dst = dst_clone(skb->dst);
- if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) {
+ dst = dst_clone(skb_dst(skb));
+ if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
dst_release(dst);
- skb = *skbp;
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
opt = IP6CB(skb);
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
opt->nhoff = dstbuf;
#else
opt->nhoff = opt->dst1;
return 1;
}
- IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
+ IP6_INC_STATS_BH(dev_net(dst->dev),
+ ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
dst_release(dst);
return -1;
}
-static struct inet6_protocol destopt_protocol = {
- .handler = ipv6_destopt_rcv,
- .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
-};
-
-void __init ipv6_destopt_init(void)
-{
- if (inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS) < 0)
- printk(KERN_ERR "ipv6_destopt_init: Could not register protocol\n");
-}
-
-/********************************
- NONE header. No data in packet.
- ********************************/
-
-static int ipv6_nodata_rcv(struct sk_buff **skbp)
-{
- struct sk_buff *skb = *skbp;
-
- kfree_skb(skb);
- return 0;
-}
-
-static struct inet6_protocol nodata_protocol = {
- .handler = ipv6_nodata_rcv,
- .flags = INET6_PROTO_NOPOLICY,
-};
-
-void __init ipv6_nodata_init(void)
-{
- if (inet6_add_protocol(&nodata_protocol, IPPROTO_NONE) < 0)
- printk(KERN_ERR "ipv6_nodata_init: Could not register protocol\n");
-}
-
/********************************
Routing header.
********************************/
-static int ipv6_rthdr_rcv(struct sk_buff **skbp)
+static int ipv6_rthdr_rcv(struct sk_buff *skb)
{
- struct sk_buff *skb = *skbp;
struct inet6_skb_parm *opt = IP6CB(skb);
struct in6_addr *addr = NULL;
struct in6_addr daddr;
int n, i;
struct ipv6_rt_hdr *hdr;
struct rt0_hdr *rthdr;
- int accept_source_route = ipv6_devconf.accept_source_route;
+ struct net *net = dev_net(skb->dev);
+ int accept_source_route = net->ipv6.devconf_all->accept_source_route;
- if (accept_source_route < 0 ||
- ((idev = in6_dev_get(skb->dev)) == NULL)) {
- kfree_skb(skb);
- return -1;
- }
- if (idev->cnf.accept_source_route < 0) {
+ idev = in6_dev_get(skb->dev);
+ if (idev) {
+ if (accept_source_route > idev->cnf.accept_source_route)
+ accept_source_route = idev->cnf.accept_source_route;
in6_dev_put(idev);
- kfree_skb(skb);
- return -1;
}
- if (accept_source_route > idev->cnf.accept_source_route)
- accept_source_route = idev->cnf.accept_source_route;
-
- in6_dev_put(idev);
-
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
!pskb_may_pull(skb, (skb_transport_offset(skb) +
((skb_transport_header(skb)[1] + 1) << 3)))) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
kfree_skb(skb);
return -1;
hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
- switch (hdr->type) {
-#ifdef CONFIG_IPV6_MIP6
- break;
-#endif
- case IPV6_SRCRT_TYPE_0:
- if (accept_source_route > 0)
- break;
- kfree_skb(skb);
- return -1;
- default:
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
- IPSTATS_MIB_INHDRERRORS);
- icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
- (&hdr->type) - skb_network_header(skb));
- return -1;
- }
-
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
skb->pkt_type != PACKET_HOST) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
looped_back:
if (hdr->segments_left == 0) {
switch (hdr->type) {
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case IPV6_SRCRT_TYPE_2:
/* Silently discard type 2 header unless it was
* processed by own
*/
if (!addr) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
switch (hdr->type) {
- case IPV6_SRCRT_TYPE_0:
- if (hdr->hdrlen & 0x01) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
- IPSTATS_MIB_INHDRERRORS);
- icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
- ((&hdr->hdrlen) -
- skb_network_header(skb)));
- return -1;
- }
- break;
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case IPV6_SRCRT_TYPE_2:
+ if (accept_source_route < 0)
+ goto unknown_rh;
/* Silently discard invalid RTH type 2 */
if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
kfree_skb(skb);
return -1;
}
break;
#endif
+ default:
+ goto unknown_rh;
}
/*
n = hdr->hdrlen >> 1;
if (hdr->segments_left > n) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
((&hdr->segments_left) -
Do not damage packets queued somewhere.
*/
if (skb_cloned(skb)) {
- struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
/* the copy is a forwarded packet */
- if (skb2 == NULL) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_OUTDISCARDS);
kfree_skb(skb);
return -1;
}
- kfree_skb(skb);
- *skbp = skb = skb2;
- opt = IP6CB(skb2);
- hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb2);
+ hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
}
if (skb->ip_summed == CHECKSUM_COMPLETE)
addr += i - 1;
switch (hdr->type) {
-#ifdef CONFIG_IPV6_MIP6
+#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case IPV6_SRCRT_TYPE_2:
if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
(xfrm_address_t *)&ipv6_hdr(skb)->saddr,
IPPROTO_ROUTING) < 0) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
- if (!ipv6_chk_home_addr(addr)) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
if (ipv6_addr_is_multicast(addr)) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr);
ipv6_addr_copy(&ipv6_hdr(skb)->daddr, &daddr);
- dst_release(xchg(&skb->dst, NULL));
+ skb_dst_drop(skb);
ip6_route_input(skb);
- if (skb->dst->error) {
+ if (skb_dst(skb)->error) {
skb_push(skb, skb->data - skb_network_header(skb));
dst_input(skb);
return -1;
}
- if (skb->dst->dev->flags&IFF_LOOPBACK) {
+ if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
if (ipv6_hdr(skb)->hop_limit <= 1) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
- 0, skb->dev);
+ 0);
kfree_skb(skb);
return -1;
}
skb_push(skb, skb->data - skb_network_header(skb));
dst_input(skb);
return -1;
+
+unknown_rh:
+ IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
+ icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
+ (&hdr->type) - skb_network_header(skb));
+ return -1;
}
-static struct inet6_protocol rthdr_protocol = {
+static const struct inet6_protocol rthdr_protocol = {
.handler = ipv6_rthdr_rcv,
.flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
};
-void __init ipv6_rthdr_init(void)
-{
- if (inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING) < 0)
- printk(KERN_ERR "ipv6_rthdr_init: Could not register protocol\n");
+static const struct inet6_protocol destopt_protocol = {
+ .handler = ipv6_destopt_rcv,
+ .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
};
-/*
- This function inverts received rthdr.
- NOTE: specs allow to make it automatically only if
- packet authenticated.
-
- I will not discuss it here (though, I am really pissed off at
- this stupid requirement making rthdr idea useless)
-
- Actually, it creates severe problems for us.
- Embryonic requests has no associated sockets,
- so that user have no control over it and
- cannot not only to set reply options, but
- even to know, that someone wants to connect
- without success. :-(
-
- For now we need to test the engine, so that I created
- temporary (or permanent) backdoor.
- If listening socket set IPV6_RTHDR to 2, then we invert header.
- --ANK (980729)
- */
+static const struct inet6_protocol nodata_protocol = {
+ .handler = dst_discard,
+ .flags = INET6_PROTO_NOPOLICY,
+};
-struct ipv6_txoptions *
-ipv6_invert_rthdr(struct sock *sk, struct ipv6_rt_hdr *hdr)
+int __init ipv6_exthdrs_init(void)
{
- /* Received rthdr:
+ int ret;
- [ H1 -> H2 -> ... H_prev ] daddr=ME
+ ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
+ if (ret)
+ goto out;
- Inverted result:
- [ H_prev -> ... -> H1 ] daddr =sender
+ ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+ if (ret)
+ goto out_rthdr;
- Note, that IP output engine will rewrite this rthdr
- by rotating it left by one addr.
- */
+ ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
+ if (ret)
+ goto out_destopt;
- int n, i;
- struct rt0_hdr *rthdr = (struct rt0_hdr*)hdr;
- struct rt0_hdr *irthdr;
- struct ipv6_txoptions *opt;
- int hdrlen = ipv6_optlen(hdr);
-
- if (hdr->segments_left ||
- hdr->type != IPV6_SRCRT_TYPE_0 ||
- hdr->hdrlen & 0x01)
- return NULL;
+out:
+ return ret;
+out_rthdr:
+ inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
+out_destopt:
+ inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+ goto out;
+};
- n = hdr->hdrlen >> 1;
- opt = sock_kmalloc(sk, sizeof(*opt) + hdrlen, GFP_ATOMIC);
- if (opt == NULL)
- return NULL;
- memset(opt, 0, sizeof(*opt));
- opt->tot_len = sizeof(*opt) + hdrlen;
- opt->srcrt = (void*)(opt+1);
- opt->opt_nflen = hdrlen;
-
- memcpy(opt->srcrt, hdr, sizeof(*hdr));
- irthdr = (struct rt0_hdr*)opt->srcrt;
- irthdr->reserved = 0;
- opt->srcrt->segments_left = n;
- for (i=0; i<n; i++)
- memcpy(irthdr->addr+i, rthdr->addr+(n-1-i), 16);
- return opt;
+void ipv6_exthdrs_exit(void)
+{
+ inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
+ inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
+ inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
}
-EXPORT_SYMBOL_GPL(ipv6_invert_rthdr);
-
/**********************************
Hop-by-hop options.
**********************************/
+/*
+ * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
+ */
+static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
+{
+ return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
+}
+
+static inline struct net *ipv6_skb_net(struct sk_buff *skb)
+{
+ return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
+}
+
/* Router Alert as of RFC 2711 */
-static int ipv6_hop_ra(struct sk_buff **skbp, int optoff)
+static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
{
- struct sk_buff *skb = *skbp;
const unsigned char *nh = skb_network_header(skb);
if (nh[optoff + 1] == 2) {
/* Jumbo payload */
-static int ipv6_hop_jumbo(struct sk_buff **skbp, int optoff)
+static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
{
- struct sk_buff *skb = *skbp;
const unsigned char *nh = skb_network_header(skb);
+ struct net *net = ipv6_skb_net(skb);
u32 pkt_len;
if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
nh[optoff+1]);
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
+ IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
IPSTATS_MIB_INHDRERRORS);
goto drop;
}
pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
if (pkt_len <= IPV6_MAXPLEN) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
+ IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
+ IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
return 0;
}
if (ipv6_hdr(skb)->payload_len) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
+ IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
+ IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
return 0;
}
if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
- IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INTRUNCATEDPKTS);
+ IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
+ IPSTATS_MIB_INTRUNCATEDPKTS);
goto drop;
}
{ -1, }
};
-int ipv6_parse_hopopts(struct sk_buff **skbp)
+int ipv6_parse_hopopts(struct sk_buff *skb)
{
- struct sk_buff *skb = *skbp;
struct inet6_skb_parm *opt = IP6CB(skb);
/*
}
opt->hop = sizeof(struct ipv6hdr);
- if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) {
- skb = *skbp;
+ if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
opt = IP6CB(skb);
opt->nhoff = sizeof(struct ipv6hdr);