/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.  The following fields
 * in it shall be filled in by x->type->output:
 *      tot_len
 *      check
 *
 * On exit, skb->h will be set to the start of the payload to be processed
 * by x->type->output and skb->nh will be set to the top IP header.
 */
static int xfrm4_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
	struct iphdr *iph, *top_iph;
	int flags;

	iph = skb->nh.iph;
	skb->h.ipiph = iph;

	skb->nh.raw = skb_push(skb, x->props.header_len);
	top_iph = skb->nh.iph;

	top_iph->ihl = 5;
	top_iph->version = 4;

	flags = x->props.flags;

	/* DS disclosed */
	if (xdst->route->ops->family == AF_INET) {
		top_iph->protocol = IPPROTO_IPIP;
		top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
		top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
			0 : (iph->frag_off & htons(IP_DF));
	}
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
	else {
		struct ipv6hdr *ipv6h = (struct ipv6hdr*)iph;
		top_iph->protocol = IPPROTO_IPV6;
		top_iph->tos = INET_ECN_encapsulate(iph->tos, ipv6_get_dsfield(ipv6h));
		top_iph->frag_off = 0;
	}
#endif

	if (flags & XFRM_STATE_NOECN)
		IP_ECN_clear(top_iph);

	if (!top_iph->frag_off)
		__ip_select_ident(top_iph, dst->child, 0);

	top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;

	skb->protocol = htons(ETH_P_IP);

	memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
	return 0;
}
Пример #2
0
/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.  The following fields
 * in it shall be filled in by x->type->output:
 *	payload_len
 *
 * On exit, skb->h will be set to the start of the encapsulation header to be
 * filled in by x->type->output and skb->nh will be set to the nextheader field
 * of the extension header directly preceding the encapsulation header, or in
 * its absence, that of the top IP header.  The value of skb->data will always
 * point to the top IP header.
 */
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct ipv6hdr *iph, *top_iph;
	int dsfield;

	skb_push(skb, x->props.header_len);
	iph = skb->nh.ipv6h;

	skb->nh.raw = skb->data;
	top_iph = skb->nh.ipv6h;
	skb->nh.raw = &top_iph->nexthdr;
	skb->h.ipv6h = top_iph + 1;

	top_iph->version = 6;
	top_iph->priority = iph->priority;
	top_iph->flow_lbl[0] = iph->flow_lbl[0];
	top_iph->flow_lbl[1] = iph->flow_lbl[1];
	top_iph->flow_lbl[2] = iph->flow_lbl[2];
	dsfield = ipv6_get_dsfield(top_iph);
	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	if (x->props.flags & XFRM_STATE_NOECN)
		dsfield &= ~INET_ECN_MASK;
	ipv6_change_dsfield(top_iph, 0, dsfield);
	top_iph->nexthdr = IPPROTO_IPV6; 
	top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
	return 0;
}
/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *top_iph;
	int dsfield;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct ipv6hdr, nexthdr);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ipv6_hdr(skb);

	top_iph->version = 6;

	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	       sizeof(top_iph->flow_lbl));
	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);

	dsfield = XFRM_MODE_SKB_CB(skb)->tos;
	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	if (x->props.flags & XFRM_STATE_NOECN)
		dsfield &= ~INET_ECN_MASK;
	ipv6_change_dsfield(top_iph, 0, dsfield);
	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
	ipv6_addr_copy(&top_iph->saddr, (const struct in6_addr *)&x->props.saddr);
	ipv6_addr_copy(&top_iph->daddr, (const struct in6_addr *)&x->id.daddr);
	return 0;
}
Пример #4
0
static inline u8
ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
{
	u8 inner = 0;
	if (skb->protocol == htons(ETH_P_IP))
		inner = old_iph->tos;
	else if (skb->protocol == htons(ETH_P_IPV6))
		inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
	return INET_ECN_encapsulate(tos, inner);
}
Пример #5
0
static int ipip_output(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	struct iphdr *iph, *top_iph;
	int tos, err;

	if ((err = xfrm4_tunnel_check_size(skb)) != 0)
		goto error_nolock;
		
	iph = skb->nh.iph;

	spin_lock_bh(&x->lock);

	tos = iph->tos;

	top_iph = (struct iphdr *) skb_push(skb, x->props.header_len);
	top_iph->ihl = 5;
	top_iph->version = 4;
	top_iph->tos = INET_ECN_encapsulate(tos, iph->tos);
	top_iph->tot_len = htons(skb->len);
	top_iph->frag_off = iph->frag_off & ~htons(IP_MF|IP_OFFSET);
	if (!(iph->frag_off & htons(IP_DF))) {
#ifdef NETIF_F_TSO
		__ip_select_ident(top_iph, dst, 0);
#else
		__ip_select_ident(top_iph, dst);
#endif
	}
	top_iph->ttl = iph->ttl;
	top_iph->protocol = IPPROTO_IPIP;
	top_iph->check = 0;
	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;
	memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
	ip_send_check(top_iph);

	skb->nh.raw = skb->data;
	x->curlft.bytes += skb->len;
	x->curlft.packets++;

	spin_unlock_bh(&x->lock);

	if ((skb->dst = dst_pop(dst)) == NULL) {
		kfree_skb(skb);
		err = -EHOSTUNREACH;
		goto error_nolock;
	}
	return NET_XMIT_BYPASS;

error_nolock:
	kfree_skb(skb);
	return err;
}
Пример #6
0
/* Add encapsulation header.
 *
 * In transport mode, the IP header and mutable extension headers will be moved
 * forward to make space for the encapsulation header.
 *
 * In tunnel mode, the top IP header will be constructed per RFC 2401.
 * The following fields in it shall be filled in by x->type->output:
 *	payload_len
 *
 * On exit, skb->h will be set to the start of the encapsulation header to be
 * filled in by x->type->output and skb->nh will be set to the nextheader field
 * of the extension header directly preceding the encapsulation header, or in
 * its absence, that of the top IP header.  The value of skb->data will always
 * point to the top IP header.
 */
static void xfrm6_encap(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	struct ipv6hdr *iph, *top_iph;
	int dsfield;

	skb_push(skb, x->props.header_len);
	iph = skb->nh.ipv6h;

	if (!x->props.mode) {
		u8 *prevhdr;
		int hdr_len;

#ifdef CONFIG_XFRM_ENHANCEMENT
		hdr_len = xfrm6_place_find(skb, &prevhdr, x->id.proto);
#else
		hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
#endif
		skb->nh.raw = prevhdr - x->props.header_len;
		skb->h.raw = skb->data + hdr_len;
		memmove(skb->data, iph, hdr_len);
		return;
	}

	skb->nh.raw = skb->data;
	top_iph = skb->nh.ipv6h;
	skb->nh.raw = &top_iph->nexthdr;
	skb->h.ipv6h = top_iph + 1;

	top_iph->version = 6;
	top_iph->priority = iph->priority;
	top_iph->flow_lbl[0] = iph->flow_lbl[0];
	top_iph->flow_lbl[1] = iph->flow_lbl[1];
	top_iph->flow_lbl[2] = iph->flow_lbl[2];
	dsfield = ipv6_get_dsfield(top_iph);
	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	if (x->props.flags & XFRM_STATE_NOECN)
		dsfield &= ~INET_ECN_MASK;
	ipv6_change_dsfield(top_iph, 0, dsfield);
	top_iph->nexthdr = IPPROTO_IPV6; 
	top_iph->hop_limit = dst_path_metric(dst, RTAX_HOPLIMIT);
	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
}
/* Add encapsulation header.
 *
 * In transport mode, the IP header will be moved forward to make space
 * for the encapsulation header.
 *
 * In tunnel mode, the top IP header will be constructed per RFC 2401.
 * The following fields in it shall be filled in by x->type->output:
 *	tot_len
 *	check
 *
 * On exit, skb->h will be set to the start of the payload to be processed
 * by x->type->output and skb->nh will be set to the top IP header.
 */
static void xfrm4_encap(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	struct iphdr *iph, *top_iph;
	int flags;

	iph = skb->nh.iph;
	skb->h.ipiph = iph;

	skb->nh.raw = skb_push(skb, x->props.header_len);
	top_iph = skb->nh.iph;

	if (!x->props.mode) {
		skb->h.raw += iph->ihl*4;
		memmove(top_iph, iph, iph->ihl*4);
		return;
	}

	top_iph->ihl = 5;
	top_iph->version = 4;

	/* DS disclosed */
	top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);

	flags = x->props.flags;
	if (flags & XFRM_STATE_NOECN)
		IP_ECN_clear(top_iph);

	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
		0 : (iph->frag_off & htons(IP_DF));
	if (!top_iph->frag_off)
		__ip_select_ident(top_iph, dst, 0);

	top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;
	top_iph->protocol = IPPROTO_IPIP;

	memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
}
Пример #8
0
/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct iphdr *top_iph;
	int flags;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct iphdr, protocol);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ip_hdr(skb);

	top_iph->ihl = 5;
	top_iph->version = 4;

	top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);

	/* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
	if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
		top_iph->tos = 0;
	else
		top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
	top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
					    XFRM_MODE_SKB_CB(skb)->tos);

	flags = x->props.flags;
	if (flags & XFRM_STATE_NOECN)
		IP_ECN_clear(top_iph);

	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));

	top_iph->ttl = ip4_dst_hoplimit(dst->child);

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;
	ip_select_ident(dev_net(dst->dev), skb, NULL);

	return 0;
}
/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct iphdr *top_iph;
	int flags;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct iphdr, protocol);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ip_hdr(skb);

	top_iph->ihl = 5;
	top_iph->version = 4;

	top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);

	/* DS disclosed */
	top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos,
					    XFRM_MODE_SKB_CB(skb)->tos);

	flags = x->props.flags;
	if (flags & XFRM_STATE_NOECN)
		IP_ECN_clear(top_iph);

	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
	ip_select_ident(top_iph, dst->child, NULL);

	top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;

	return 0;
}
Пример #10
0
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
        };
        if (ip_route_output_key(&rt, &fl)) {
            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;
    }

    if (tiph->frag_off)
        mtu = dst_pmtu(&rt->u.dst) - sizeof(struct iphdr);
    else
        mtu = skb->dst ? dst_pmtu(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;
    }

    skb->h.raw = skb->nh.raw;

    /*
     * 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->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, 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;
}
Пример #11
0
static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct net_device_stats *stats = &tunnel->stat;
	struct iphdr  *tiph = &tunnel->parms.iph;
	struct ipv6hdr *iph6 = ipv6_hdr(skb);
	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 */
	unsigned int max_headroom;		/* The extra header space needed */
	__be32 dst = tiph->daddr;
	int    mtu;

	if (tunnel->recursion++) {
		tunnel->stat.collisions++;
		goto tx_error;
	}

	if (skb->protocol != htons(ETH_P_IPV6))
		goto tx_error;

	if (extract_ipv4_endpoint(&iph6->daddr, &dst) < 0)
		goto tx_error_icmp;

	{
		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_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);
			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 = 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;
	dst_release(skb->dst);
	skb->dst = &rt->u.dst;

	/*
	 *	Push down and install the IPIP header.
	 */

	iph 			=	ip_hdr(skb);
	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;
}
Пример #12
0
static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
				     struct net_device *dev)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	struct net_device_stats *stats = &tunnel->dev->stats;
	struct iphdr  *tiph = &tunnel->parms.iph;
	struct ipv6hdr *iph6 = ipv6_hdr(skb);
	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 */
	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_6to4(&iph6->daddr);

	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)) {
			stats->tx_carrier_errors++;
			goto tx_error_icmp;
		}
	}
	if (rt->rt_type != RTN_UNICAST) {
		ip_rt_put(rt);
		stats->tx_carrier_errors++;
		goto tx_error_icmp;
	}
	tdev = rt->u.dst.dev;

	if (tdev == dev) {
		ip_rt_put(rt);
		stats->collisions++;
		goto tx_error;
	}

	if (tiph->frag_off)
		mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
	else
		mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;

	if (mtu < 68) {
		stats->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))
		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), 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 (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);
			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->u.dst);

	/*
	 *	Push down and install the IPIP header.
	 */

	iph 			=	ip_hdr(skb);
	iph->version		=	4;
	iph->ihl		=	sizeof(struct iphdr)>>2;
	if (mtu > IPV6_MIN_MTU)
		iph->frag_off	=	tiph->frag_off;
	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();
	return NETDEV_TX_OK;

tx_error_icmp:
	dst_link_failure(skb);
tx_error:
	stats->tx_errors++;
	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
}
Пример #13
0
static int ipip_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;
	u8     tos = tunnel->parms.iph.tos;
	u16    df = tiph->frag_off;
	struct rtable *rt;     			/* Route to the other host */
	struct net_device *tdev;			/* Device to other host */
	struct iphdr  *old_iph = skb->nh.iph;
	struct iphdr  *iph;			/* Our new IP header */
	int    max_headroom;			/* The extra header space needed */
	u32    dst = tiph->daddr;
	int    mtu;

	if (tunnel->recursion++) {
		tunnel->stat.collisions++;
		goto tx_error;
	}

	if (skb->protocol != htons(ETH_P_IP))
		goto tx_error;

	if (tos&1)
		tos = old_iph->tos;

	if (!dst) {
		/* NBMA tunnel */
		if ((rt = (struct rtable*)skb->dst) == NULL) {
			tunnel->stat.tx_fifo_errors++;
			goto tx_error;
		}
		if ((dst = rt->rt_gateway) == 0)
			goto tx_error_icmp;
	}

	if (ip_route_output(&rt, dst, tiph->saddr, RT_TOS(tos), tunnel->parms.link)) {
		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 = rt->u.dst.pmtu - sizeof(struct iphdr);
	else
		mtu = skb->dst ? skb->dst->pmtu : dev->mtu;

	if (mtu < 68) {
		tunnel->stat.collisions++;
		ip_rt_put(rt);
		goto tx_error;
	}
	if (skb->dst && mtu < skb->dst->pmtu)
		skb->dst->pmtu = mtu;

	df |= (old_iph->frag_off&htons(IP_DF));

	if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) {
		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
		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;
	iph->frag_off		=	df;
	iph->protocol		=	IPPROTO_IPIP;
	iph->tos		=	INET_ECN_encapsulate(tos, old_iph->tos);
	iph->daddr		=	rt->rt_dst;
	iph->saddr		=	rt->rt_src;

	if ((iph->ttl = tiph->ttl) == 0)
		iph->ttl	=	old_iph->ttl;

#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
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;
	int encap_limit = -1;
	struct ipv6_tel_txoption opt;
	__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) ||
	    !ip6_tnl_xmit_ctl(t) || 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 |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
	if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
		fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);

	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 (encap_limit >= 0) {
		max_headroom += 8;
		mtu -= 8;
	}
	if (mtu < IPV6_MIN_MTU)
		mtu = IPV6_MIN_MTU;
	if (skb->dst)
		skb->dst->ops->update_pmtu(skb->dst, 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 (encap_limit >= 0) {
		init_tel_txopt(&opt, encap_limit);
		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
	}
	skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr));
	ipv6h = skb->nh.ipv6h;
	*(__be32*)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 (net_xmit_eval(err) == 0) {
		stats->tx_bytes += pkt_len;
		stats->tx_packets++;
	} else {
		stats->tx_errors++;
		stats->tx_aborted_errors++;
	}
	ip6_tnl_dst_store(t, dst);
	t->recursion--;
	return 0;
tx_err_link_failure:
	stats->tx_carrier_errors++;
	dst_link_failure(skb);
tx_err_dst_release:
	dst_release(dst);
tx_err:
	stats->tx_errors++;
	stats->tx_dropped++;
	kfree_skb(skb);
	t->recursion--;
	return 0;
}
Пример #15
0
static int ip6_tnl_xmit2(struct sk_buff *skb,
			 struct net_device *dev,
			 __u8 dsfield,
			 struct flowi *fl,
			 int encap_limit,
			 __u32 *pmtu)
{
	struct net *net = dev_net(dev);
	struct ip6_tnl *t = netdev_priv(dev);
	struct net_device_stats *stats = &t->dev->stats;
	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
	struct ipv6_tel_txoption opt;
	struct dst_entry *dst;
	struct net_device *tdev;
	int mtu;
	unsigned int max_headroom = sizeof(struct ipv6hdr);
	u8 proto;
	int err = -1;
	int pkt_len;

	if ((dst = ip6_tnl_dst_check(t)) != NULL)
		dst_hold(dst);
	else {
		dst = ip6_route_output(net, NULL, fl);

		if (dst->error || xfrm_lookup(net, &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 (encap_limit >= 0) {
		max_headroom += 8;
		mtu -= 8;
	}
	if (mtu < IPV6_MIN_MTU)
		mtu = IPV6_MIN_MTU;
	if (skb_dst(skb))
		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
	if (skb->len > mtu) {
		*pmtu = mtu;
		err = -EMSGSIZE;
		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_shared(skb) ||
	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
		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;
	}
	skb_dst_drop(skb);
	skb_dst_set(skb, dst_clone(dst));

	skb->transport_header = skb->network_header;

	proto = fl->proto;
	if (encap_limit >= 0) {
		init_tel_txopt(&opt, encap_limit);
		ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
	}
	skb_push(skb, sizeof(struct ipv6hdr));
	skb_reset_network_header(skb);
	ipv6h = ipv6_hdr(skb);
	*(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000);
	dsfield = INET_ECN_encapsulate(0, dsfield);
	ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
	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 = ip6_local_out(skb);

	if (net_xmit_eval(err) == 0) {
		stats->tx_bytes += pkt_len;
		stats->tx_packets++;
	} else {
		stats->tx_errors++;
		stats->tx_aborted_errors++;
	}
	ip6_tnl_dst_store(t, dst);
	return 0;
tx_err_link_failure:
	stats->tx_carrier_errors++;
	dst_link_failure(skb);
tx_err_dst_release:
	dst_release(dst);
	return err;
}
Пример #16
0
static int ipip_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;
	u8     tos = tunnel->parms.iph.tos;
	u16    df = tiph->frag_off;
	struct rtable *rt;     			/* Route to the other host */
	struct net_device *tdev;			/* Device to other host */
	struct iphdr  *old_iph = skb->nh.iph;
#ifdef CONFIG_NET_IPIP_IPV6
	struct ipv6hdr *iph6 = skb->nh.ipv6h;
#endif
	struct iphdr  *iph;			/* Our new IP header */
	int    max_headroom;			/* The extra header space needed */
	u32    dst = tiph->daddr;
	int    mtu;
	u8 protocol = 0; 

	switch (skb->protocol) {
	case __constant_htons(ETH_P_IP):
		protocol = IPPROTO_IPIP;
		break;
#ifdef CONFIG_NET_IPIP_IPV6
	case __constant_htons(ETH_P_IPV6):
		protocol = IPPROTO_IPV6;
		break;
#endif
	}

	if (tunnel->recursion++) {
		tunnel->stat.collisions++;
		goto tx_error;
	}

	switch(skb->protocol) {
	case __constant_htons(ETH_P_IP):
		if (tunnel->parms.iph.protocol &&
		    tunnel->parms.iph.protocol != IPPROTO_IPIP)
			goto tx_error;
		if (tos&1)
			tos = old_iph->tos;
		break;
#ifdef CONFIG_NET_IPIP_IPV6
	case __constant_htons(ETH_P_IPV6):
		if (tunnel->parms.iph.protocol &&
		    tunnel->parms.iph.protocol != IPPROTO_IPV6)
			goto tx_error;
		break;
#endif
	default:
		goto tx_error;
	}

	if (!dst) {
		switch(skb->protocol){
		case __constant_htons(ETH_P_IP):
			/* NBMA tunnel */
			if ((rt = (struct rtable*)skb->dst) == NULL) {
				tunnel->stat.tx_fifo_errors++;
				goto tx_error;
			}
			dst = rt->rt_gateway;
			break;
#ifdef CONFIG_NET_IPIP_IPV6
		case __constant_htons(ETH_P_IPV6):
		    {
			struct in6_addr *addr6 = &iph6->daddr;
			if (addr6->s6_addr16[0] == htons(0x2002)) {
				memcpy(&dst, &addr6->s6_addr16[1], 4);
			} else {
				/* dst is zero */
				struct neighbour *neigh = NULL;
				if (skb->dst)
					neigh = skb->dst->neighbour;
				if (neigh == NULL) {
					printk(KERN_DEBUG "tunl: nexthop == NULL\n");
					goto tx_error;
				}
				addr6 = (struct in6_addr*)&neigh->primary_key;
				if (IN6_IS_ADDR_UNSPECIFIED(addr6))
					addr6 = &skb->nh.ipv6h->daddr;
				if (IN6_IS_ADDR_V4COMPAT(addr6))
					dst = addr6->s6_addr32[3];
#ifdef CONFIG_IPV6_6TO4_NEXTHOP
				else if (addr6->s6_addr16[0] == htons(0x2002)) 
					memcpy(&dst, &addr6->s6_addr16[1], 4);
#endif
				else
					goto tx_error_icmp;
			}
			break;
		    }
#endif
		}
		if (!dst)
			goto tx_error_icmp;
	}

	if (ip_route_output(&rt, dst, tiph->saddr, RT_TOS(tos), tunnel->parms.link)) {
		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 = rt->u.dst.pmtu - sizeof(struct iphdr);
	else
		mtu = skb->dst ? skb->dst->pmtu : dev->mtu;

	if (mtu < 68) {
		tunnel->stat.collisions++;
		ip_rt_put(rt);
		goto tx_error;
	}

	switch(skb->protocol){
	case __constant_htons(ETH_P_IP):
		if (skb->dst && mtu < skb->dst->pmtu)
			skb->dst->pmtu = mtu;

		df |= (old_iph->frag_off&htons(IP_DF));

		if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) {
			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
			ip_rt_put(rt);
			goto tx_error;
		}
		break;

#ifdef CONFIG_NET_IPIP_IPV6
	case __constant_htons(ETH_P_IPV6):
#if 0
		if (mtu < IPV6_MIN_MTU) {
			/* XXX: too small; we should fragment this packet? */
			tunnel->stat.tx_carrier_errors++;
			goto tx_error_icmp;
		}
#endif
		if (skb->len > mtu && mtu > IPV6_MIN_MTU) {
			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
			ip_rt_put(rt);
			goto tx_error;
		}
		df = mtu > IPV6_MIN_MTU ? htons(IP_DF) : 0;
		break;
#endif
	}
	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 = (((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;
		old_iph = skb->nh.iph;
	}

	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;
	iph->daddr		=	rt->rt_dst;
	iph->saddr		=	rt->rt_src;

	iph->ttl		=	tiph->ttl;
	iph->frag_off		=	df;

	switch(skb->protocol){
	case __constant_htons(ETH_P_IP):
		iph->protocol	=	protocol;
		iph->tos	=	INET_ECN_encapsulate(tos, old_iph->tos);
		if (iph->ttl == 0)
			iph->ttl =	old_iph->ttl;
		break;
#ifdef CONFIG_NET_IPIP_IPV6
	case __constant_htons(ETH_P_IPV6):
		iph->protocol	=	protocol;
		iph->tos	=	INET_ECN_encapsulate(tos, ip6_get_dsfield(iph6));
		if (iph->ttl == 0)
			iph->ttl =	iph6->hop_limit;
		break;
#endif
	}

	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;
}