Esempio n. 1
0
static int ip_tunnel_bind_dev(struct net_device *dev)
{
    struct net_device *tdev = NULL;
    struct ip_tunnel *tunnel = netdev_priv(dev);
    const struct iphdr *iph;
    int hlen = LL_MAX_HEADER;
    int mtu = ETH_DATA_LEN;
    int t_hlen = tunnel->hlen + sizeof(struct iphdr);

    iph = &tunnel->parms.iph;

    /* Guess output device to choose reasonable mtu and needed_headroom */
    if (iph->daddr) {
        struct flowi4 fl4;
        struct rtable *rt;

        init_tunnel_flow(&fl4, iph->protocol, iph->daddr,
                         iph->saddr, tunnel->parms.o_key,
                         RT_TOS(iph->tos), tunnel->parms.link);
        rt = ip_route_output_key(tunnel->net, &fl4);

        if (!IS_ERR(rt)) {
            tdev = rt->dst.dev;
            tunnel_dst_set(tunnel, &rt->dst);
            ip_rt_put(rt);
        }
        if (dev->type != ARPHRD_ETHER)
            dev->flags |= IFF_POINTOPOINT;
    }

    if (!tdev && tunnel->parms.link)
        tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);

    if (tdev) {
        hlen = tdev->hard_header_len + tdev->needed_headroom;
        mtu = tdev->mtu;
    }
    dev->iflink = tunnel->parms.link;

    dev->needed_headroom = t_hlen + hlen;
    mtu -= (dev->hard_header_len + t_hlen);

    if (mtu < 68)
        mtu = 68;

    return mtu;
}
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
		    const struct iphdr *tnl_params, u8 protocol)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	const struct iphdr *inner_iph;
	struct flowi4 fl4;
	u8     tos, ttl;
	__be16 df;
	struct rtable *rt;		/* Route to the other host */
	unsigned int max_headroom;	/* The extra header space needed */
	__be32 dst;
	bool connected;

	inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
	connected = (tunnel->parms.iph.daddr != 0);

	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

	dst = tnl_params->daddr;
	if (dst == 0) {
		/* NBMA tunnel */

		if (!skb_dst(skb)) {
			dev->stats.tx_fifo_errors++;
			goto tx_error;
		}

		if (skb->protocol == htons(ETH_P_IP)) {
			rt = skb_rtable(skb);
			dst = rt_nexthop(rt, inner_iph->daddr);
		}
#if IS_ENABLED(CONFIG_IPV6)
		else if (skb->protocol == htons(ETH_P_IPV6)) {
			const struct in6_addr *addr6;
			struct neighbour *neigh;
			bool do_tx_error_icmp;
			int addr_type;

			neigh = dst_neigh_lookup(skb_dst(skb),
						 &ipv6_hdr(skb)->daddr);
			if (!neigh)
				goto tx_error;

			addr6 = (const 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)
				do_tx_error_icmp = true;
			else {
				do_tx_error_icmp = false;
				dst = addr6->s6_addr32[3];
			}
			neigh_release(neigh);
			if (do_tx_error_icmp)
				goto tx_error_icmp;
		}
#endif
		else
			goto tx_error;

		connected = false;
	}

	tos = tnl_params->tos;
	if (tos & 0x1) {
		tos &= ~0x1;
		if (skb->protocol == htons(ETH_P_IP)) {
			tos = inner_iph->tos;
			connected = false;
		} else if (skb->protocol == htons(ETH_P_IPV6)) {
			tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
			connected = false;
		}
	}

	init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
			 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);

	if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
		goto tx_error;

	rt = connected ? tunnel_rtable_get(tunnel, 0, &fl4.saddr) : NULL;

	if (!rt) {
		rt = ip_route_output_key(tunnel->net, &fl4);

		if (IS_ERR(rt)) {
			dev->stats.tx_carrier_errors++;
			goto tx_error;
		}
		if (connected)
			tunnel_dst_set(tunnel, &rt->dst, fl4.saddr);
	}

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

	if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off, inner_iph)) {
		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;
	}

	tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
	ttl = tnl_params->ttl;
	if (ttl == 0) {
		if (skb->protocol == htons(ETH_P_IP))
			ttl = inner_iph->ttl;
#if IS_ENABLED(CONFIG_IPV6)
		else if (skb->protocol == htons(ETH_P_IPV6))
			ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
#endif
		else
			ttl = ip4_dst_hoplimit(&rt->dst);
	}

	df = tnl_params->frag_off;
	if (skb->protocol == htons(ETH_P_IP))
		df |= (inner_iph->frag_off&htons(IP_DF));

	max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
			+ rt->dst.header_len + ip_encap_hlen(&tunnel->encap);
	if (max_headroom > dev->needed_headroom)
		dev->needed_headroom = max_headroom;

	if (skb_cow_head(skb, dev->needed_headroom)) {
		ip_rt_put(rt);
		dev->stats.tx_dropped++;
		kfree_skb(skb);
		return;
	}

	iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
		      df, !net_eq(tunnel->net, dev_net(dev)));
	return;

#if IS_ENABLED(CONFIG_IPV6)
tx_error_icmp:
	dst_link_failure(skb);
#endif
tx_error:
	dev->stats.tx_errors++;
	kfree_skb(skb);
}
Esempio n. 3
0
void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, u8 proto)
{
	struct ip_tunnel *tunnel = netdev_priv(dev);
	u32 headroom = sizeof(struct iphdr);
	struct ip_tunnel_info *tun_info;
	const struct ip_tunnel_key *key;
	const struct iphdr *inner_iph;
	struct rtable *rt;
	struct flowi4 fl4;
	__be16 df = 0;
	u8 tos, ttl;

	tun_info = skb_tunnel_info(skb);
	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
		     ip_tunnel_info_af(tun_info) != AF_INET))
		goto tx_error;
	key = &tun_info->key;
	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
	inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
	tos = key->tos;
	if (tos == 1) {
		if (skb->protocol == htons(ETH_P_IP))
			tos = inner_iph->tos;
		else if (skb->protocol == htons(ETH_P_IPV6))
			tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
	}
	init_tunnel_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, 0,
			 RT_TOS(tos), tunnel->parms.link);
	if (tunnel->encap.type != TUNNEL_ENCAP_NONE)
		goto tx_error;
	rt = ip_route_output_key(tunnel->net, &fl4);
	if (IS_ERR(rt)) {
		dev->stats.tx_carrier_errors++;
		goto tx_error;
	}
	if (rt->dst.dev == dev) {
		ip_rt_put(rt);
		dev->stats.collisions++;
		goto tx_error;
	}
	tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
	ttl = key->ttl;
	if (ttl == 0) {
		if (skb->protocol == htons(ETH_P_IP))
			ttl = inner_iph->ttl;
		else if (skb->protocol == htons(ETH_P_IPV6))
			ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
		else
			ttl = ip4_dst_hoplimit(&rt->dst);
	}
	if (key->tun_flags & TUNNEL_DONT_FRAGMENT)
		df = htons(IP_DF);
	else if (skb->protocol == htons(ETH_P_IP))
		df = inner_iph->frag_off & htons(IP_DF);
	headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len;
	if (headroom > dev->needed_headroom)
		dev->needed_headroom = headroom;

	if (skb_cow_head(skb, dev->needed_headroom)) {
		ip_rt_put(rt);
		goto tx_dropped;
	}
	iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, key->tos,
		      key->ttl, df, !net_eq(tunnel->net, dev_net(dev)));
	return;
tx_error:
	dev->stats.tx_errors++;
	goto kfree;
tx_dropped:
	dev->stats.tx_dropped++;
kfree:
	kfree_skb(skb);
}