Release 4.11 net/ipv6/ip6_tunnel.c

/*
 *      IPv6 tunneling device
 *      Linux INET6 implementation
 *
 *      Authors:
 *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
 *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
 *
 *      Based on:
 *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.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.
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sockios.h>
#include <linux/icmp.h>
#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.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 <linux/slab.h>
#include <linux/hash.h>
#include <linux/etherdevice.h>

#include <linux/uaccess.h>
#include <linux/atomic.h>

#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_tunnels.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>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/dst_metadata.h>

MODULE_AUTHOR("Ville Nuorvala");
MODULE_DESCRIPTION("IPv6 tunneling device");
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("ip6tnl");
MODULE_ALIAS_NETDEV("ip6tnl0");


#define IP6_TUNNEL_HASH_SIZE_SHIFT  5

#define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)


static bool log_ecn_error = true;
module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");



static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
{
	u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);

	return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
35
89.74%
1
33.33%
Ville Nuorvala
3
7.69%
1
33.33%
Jiri Kosina
1
2.56%
1
33.33%
Total
39
100.00%
3
100.00%

static int ip6_tnl_dev_init(struct net_device *dev);
static void ip6_tnl_dev_setup(struct net_device *dev);

static struct rtnl_link_ops ip6_link_ops __read_mostly;


static unsigned int ip6_tnl_net_id __read_mostly;

struct ip6_tnl_net {
	/* the IPv6 tunnel fallback device */
	
struct net_device *fb_tnl_dev;
	/* lists for storing tunnels in use */
	
struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
	
struct ip6_tnl __rcu *tnls_wc[1];
	
struct ip6_tnl __rcu **tnls[2];
	
struct ip6_tnl __rcu *collect_md_tun;
};



static struct net_device_stats *ip6_get_stats(struct net_device *dev)
{
	struct pcpu_sw_netstats tmp, sum = { 0 };
	int i;

	for_each_possible_cpu(i) {
		unsigned int start;
		const struct pcpu_sw_netstats *tstats =
						   per_cpu_ptr(dev->tstats, i);

		do {
			start = u64_stats_fetch_begin_irq(&tstats->syncp);
			tmp.rx_packets = tstats->rx_packets;
			tmp.rx_bytes = tstats->rx_bytes;
			tmp.tx_packets = tstats->tx_packets;
			tmp.tx_bytes =  tstats->tx_bytes;
		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));

		sum.rx_packets += tmp.rx_packets;
		sum.rx_bytes   += tmp.rx_bytes;
		sum.tx_packets += tmp.tx_packets;
		sum.tx_bytes   += tmp.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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
113
60.43%
1
25.00%
Li RongQing
72
38.50%
2
50.00%
Eric W. Biedermann
2
1.07%
1
25.00%
Total
187
100.00%
4
100.00%

/**
 * ip6_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
 **/


#define for_each_ip6_tunnel_rcu(start) \
	for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))


static struct ip6_tnl *

ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
{
	unsigned int hash = HASH(remote, local);
	struct ip6_tnl *t;
	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
	struct in6_addr any;

	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    ipv6_addr_equal(remote, &t->parms.raddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

	memset(&any, 0, sizeof(any));
	hash = HASH(&any, local);
	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    ipv6_addr_any(&t->parms.raddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

	hash = HASH(remote, &any);
	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
		    ipv6_addr_any(&t->parms.laddr) &&
		    (t->dev->flags & IFF_UP))
			return t;
	}

	t = rcu_dereference(ip6n->collect_md_tun);
	if (t)
		return t;

	t = rcu_dereference(ip6n->tnls_wc[0]);
	if (t && (t->dev->flags & IFF_UP))
		return t;

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Steffen Klassert
103
38.29%
1
7.69%
Ville Nuorvala
93
34.57%
1
7.69%
Pavel Emelyanov
19
7.06%
2
15.38%
Vadim Fedorenko
18
6.69%
1
7.69%
Eric Dumazet
16
5.95%
4
30.77%
Alexei Starovoitov
16
5.95%
1
7.69%
Hideaki Yoshifuji / 吉藤英明
3
1.12%
2
15.38%
Yasuyuki Kozakai
1
0.37%
1
7.69%
Total
269
100.00%
13
100.00%

/**
 * ip6_tnl_bucket - get head of list matching given tunnel parameters
 *   @p: parameters containing tunnel end-points
 *
 * Description:
 *   ip6_tnl_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 __rcu **

ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
{
	const struct in6_addr *remote = &p->raddr;
	const struct in6_addr *local = &p->laddr;
	unsigned int h = 0;
	int prio = 0;

	if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
		prio = 1;
		h = HASH(remote, local);
	}
	return &ip6n->tnls[prio][h];
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
80
84.21%
1
11.11%
Pavel Emelyanov
7
7.37%
2
22.22%
Eric Dumazet
6
6.32%
4
44.44%
Yasuyuki Kozakai
1
1.05%
1
11.11%
Dmitry Kozlov
1
1.05%
1
11.11%
Total
95
100.00%
9
100.00%

/**
 * ip6_tnl_link - add tunnel to hash table
 *   @t: tunnel to be added
 **/


static void

ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
{
	struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);

	if (t->parms.collect_md)
		rcu_assign_pointer(ip6n->collect_md_tun, t);
	rcu_assign_pointer(t->next , rtnl_dereference(*tp));
	rcu_assign_pointer(*tp, t);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
34
47.89%
1
14.29%
Alexei Starovoitov
17
23.94%
1
14.29%
Eric Dumazet
11
15.49%
3
42.86%
Pavel Emelyanov
7
9.86%
1
14.29%
Yasuyuki Kozakai
2
2.82%
1
14.29%
Total
71
100.00%
7
100.00%

/**
 * ip6_tnl_unlink - remove tunnel from hash table
 *   @t: tunnel to be removed
 **/


static void

ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
{
	struct ip6_tnl __rcu **tp;
	struct ip6_tnl *iter;

	if (t->parms.collect_md)
		rcu_assign_pointer(ip6n->collect_md_tun, NULL);

	for (tp = ip6_tnl_bucket(ip6n, &t->parms);
	     (iter = rtnl_dereference(*tp)) != NULL;
	     tp = &iter->next) {
		if (t == iter) {
			rcu_assign_pointer(*tp, t->next);
			break;
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
54
54.55%
1
16.67%
Eric Dumazet
19
19.19%
2
33.33%
Alexei Starovoitov
17
17.17%
1
16.67%
Pavel Emelyanov
7
7.07%
1
16.67%
Yasuyuki Kozakai
2
2.02%
1
16.67%
Total
99
100.00%
6
100.00%



static void ip6_dev_free(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);

	gro_cells_destroy(&t->gro_cells);
	dst_cache_destroy(&t->dst_cache);
	free_percpu(dev->tstats);
	free_netdev(dev);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric Dumazet
23
46.94%
1
25.00%
Martin KaFai Lau
14
28.57%
1
25.00%
Tom Herbert
8
16.33%
1
25.00%
Paolo Abeni
4
8.16%
1
25.00%
Total
49
100.00%
4
100.00%



static int ip6_tnl_create2(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net *net = dev_net(dev);
	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
	int err;

	t = netdev_priv(dev);

	dev->rtnl_link_ops = &ip6_link_ops;
	err = register_netdevice(dev);
	if (err < 0)
		goto out;

	strcpy(t->parms.name, dev->name);

	dev_hold(dev);
	ip6_tnl_link(ip6n, t);
	return 0;

out:
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nicolas Dichtel
102
93.58%
1
50.00%
Thadeu Lima de Souza Cascardo
7
6.42%
1
50.00%
Total
109
100.00%
2
100.00%

/**
 * ip6_tnl_create - create a new tunnel
 *   @p: tunnel parameters
 *   @pt: pointer to new tunnel
 *
 * Description:
 *   Create tunnel matching given parameters.
 *
 * Return:
 *   created tunnel or error pointer
 **/



static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
{
	struct net_device *dev;
	struct ip6_tnl *t;
	char name[IFNAMSIZ];
	int err = -ENOMEM;

	if (p->name[0])
		strlcpy(name, p->name, IFNAMSIZ);
	else
		sprintf(name, "ip6tnl%%d");

	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
			   ip6_tnl_dev_setup);
	if (!dev)
		goto failed;

	dev_net_set(dev, net);

	t = netdev_priv(dev);
	t->parms = *p;
	t->net = dev_net(dev);
	err = ip6_tnl_create2(dev);
	if (err < 0)
		goto failed_free;

	return t;

failed_free:
	ip6_dev_free(dev);
failed:
	return ERR_PTR(err);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
99
63.06%
3
17.65%
Pavel Emelyanov
19
12.10%
4
23.53%
Nicolas Dichtel
17
10.83%
3
17.65%
Eric Dumazet
10
6.37%
1
5.88%
Noriaki Takamiya
4
2.55%
1
5.88%
Patrick McHardy
3
1.91%
1
5.88%
Tom Gundersen
2
1.27%
1
5.88%
Dmitry Kozlov
1
0.64%
1
5.88%
Yasuyuki Kozakai
1
0.64%
1
5.88%
Ian Morris
1
0.64%
1
5.88%
Total
157
100.00%
17
100.00%

/**
 * ip6_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:
 *   ip6_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:
 *   matching tunnel or error pointer
 **/



static struct ip6_tnl *ip6_tnl_locate(struct net *net,
		struct __ip6_tnl_parm *p, int create)
{
	const struct in6_addr *remote = &p->raddr;
	const struct in6_addr *local = &p->laddr;
	struct ip6_tnl __rcu **tp;
	struct ip6_tnl *t;
	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);

	for (tp = ip6_tnl_bucket(ip6n, p);
	     (t = rtnl_dereference(*tp)) != NULL;
	     tp = &t->next) {
		if (ipv6_addr_equal(local, &t->parms.laddr) &&
		    ipv6_addr_equal(remote, &t->parms.raddr)) {
			if (create)
				return ERR_PTR(-EEXIST);

			return t;
		}
	}
	if (!create)
		return ERR_PTR(-ENODEV);
	return ip6_tnl_create(net, p);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
95
59.01%
2
20.00%
Eric Dumazet
22
13.66%
2
20.00%
Pavel Emelyanov
21
13.04%
1
10.00%
Nicolas Dichtel
10
6.21%
1
10.00%
Steffen Klassert
8
4.97%
1
10.00%
Hideaki Yoshifuji / 吉藤英明
2
1.24%
1
10.00%
Yasuyuki Kozakai
2
1.24%
1
10.00%
Dmitry Kozlov
1
0.62%
1
10.00%
Total
161
100.00%
10
100.00%

/**
 * ip6_tnl_dev_uninit - tunnel device uninitializer
 *   @dev: the device to be destroyed
 *
 * Description:
 *   ip6_tnl_dev_uninit() removes tunnel from its list
 **/


static void

ip6_tnl_dev_uninit(struct net_device *dev)
{
	struct ip6_tnl *t = netdev_priv(dev);
	struct net *net = t->net;
	struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);

	if (dev == ip6n->fb_tnl_dev)
		RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
	else
		ip6_tnl_unlink(ip6n, t);
	dst_cache_reset(&t->dst_cache);
	dev_put(dev);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
44
53.01%
3
25.00%
Pavel Emelyanov
25
30.12%
3
25.00%
Paolo Abeni
4
4.82%
1
8.33%
Patrick McHardy
3
3.61%
1
8.33%
Nicolas Dichtel
3
3.61%
1
8.33%
Yasuyuki Kozakai
2
2.41%
1
8.33%
Stephen Hemminger
1
1.20%
1
8.33%
Eric Dumazet
1
1.20%
1
8.33%
Total
83
100.00%
12
100.00%

/**
 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 *   @skb: received socket buffer
 *
 * Return:
 *   0 if none was found,
 *   else index to encapsulation limit
 **/



__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
{
	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
	unsigned int nhoff = raw - skb->data;
	unsigned int off = nhoff + sizeof(*ipv6h);
	u8 next, nexthdr = ipv6h->nexthdr;

	while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
		struct ipv6_opt_hdr *hdr;
		u16 optlen;

		if (!pskb_may_pull(skb, off + sizeof(*hdr)))
			break;

		hdr = (struct ipv6_opt_hdr *)(skb->data + 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);
		}
		/* cache hdr->nexthdr, since pskb_may_pull() might
                 * invalidate hdr
                 */
		next = hdr->nexthdr;
		if (nexthdr == NEXTHDR_DEST) {
			u16 i = 2;

			/* Remember : hdr is no longer valid at this point. */
			if (!pskb_may_pull(skb, off + optlen))
				break;

			while (1) {
				struct ipv6_tlv_tnl_enc_lim *tel;

				/* No more room for encapsulation limit */
				if (i + sizeof(*tel) > optlen)
					break;

				tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
				/* return index of option if found and valid */
				if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
				    tel->length == 1)
					return i + off - nhoff;
				/* else jump to next option */
				if (tel->type)
					i += tel->length + 2;
				else
					i++;
			}
		}
		nexthdr = next;
		off += optlen;
	}
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
238
78.81%
1
20.00%
Eric Dumazet
61
20.20%
2
40.00%
Dan Carpenter
2
0.66%
1
20.00%
Dmitry Kozlov
1
0.33%
1
20.00%
Total
302
100.00%
5
100.00%


EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);

/**
 * ip6_tnl_err - tunnel error handler
 *
 * Description:
 *   ip6_tnl_err() should handle errors in the tunnel according
 *   to the specifications in RFC 2473.
 **/


static int

ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
	    u8 *type, u8 *code, int *msg, __u32 *info, int offset)
{
	const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
	struct ip6_tnl *t;
	int rel_msg = 0;
	u8 rel_type = ICMPV6_DEST_UNREACH;
	u8 rel_code = ICMPV6_ADDR_UNREACH;
	u8 tproto;
	__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. */

	rcu_read_lock();
	t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
	if (!t)
		goto out;

	tproto = ACCESS_ONCE(t->parms.proto);
	if (tproto != ipproto && tproto != 0)
		goto out;

	err = 0;

	switch (*type) {
		__u32 teli;
		struct ipv6_tlv_tnl_enc_lim *tel;
		__u32 mtu;
	case ICMPV6_DEST_UNREACH:
		net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
				    t->parms.name);
		rel_msg = 1;
		break;
	case ICMPV6_TIME_EXCEED:
		if ((*code) == ICMPV6_EXC_HOPLIMIT) {
			net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
					    t->parms.name);
			rel_msg = 1;
		}
		break;
	case ICMPV6_PARAMPROB:
		teli = 0;
		if ((*code) == ICMPV6_HDR_FIELD)
			teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);

		if (teli && teli == *info - 2) {
			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
			if (tel->encap_limit == 0) {
				net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
						    t->parms.name);
				rel_msg = 1;
			}
		} else {
			net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
					    t->parms.name);
		}
		break;
	case ICMPV6_PKT_TOOBIG:
		mtu = *info - offset;
		if (mtu < IPV6_MIN_MTU)
			mtu = IPV6_MIN_MTU;
		t->dev->mtu = mtu;

		len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
		if (len > mtu) {
			rel_type = ICMPV6_PKT_TOOBIG;
			rel_code = 0;
			rel_info = mtu;
			rel_msg = 1;
		}
		break;
	}

	*type = rel_type;
	*code = rel_code;
	*info = rel_info;
	*msg = rel_msg;

out:
	rcu_read_unlock();
	return err;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Ville Nuorvala
281
68.37%
4
17.39%
Yasuyuki Kozakai
63
15.33%
3
13.04%
Alexey Andriyanov
13
3.16%
1
4.35%
Herbert Xu
11
2.68%
1
4.35%
Ian Morris
9
2.19%
2
8.70%
Pavel Emelyanov
8
1.95%
2
8.70%
Eric Dumazet
6
1.46%
2
8.70%
Joe Perches
5
1.22%
1
4.35%
Brian Haley
4
0.97%
1
4.35%
Matt Bennett
4
0.97%
1
4.35%
Al Viro
4
0.97%
2
8.70%
Hideaki Yoshifuji / 吉藤英明
2
0.49%
2
8.70%
Dmitry Kozlov
1
0.24%
1
4.35%
Total
411
100.00%
23
100.00%


static int

ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
	   u8 type, u8 code, int offset, __be32 info)
{
	int rel_msg = 0;
	u8 rel_type = type;
	u8 rel_code = code;
	__u32 rel_info = ntohl(info);
	int err;
	struct sk_buff *skb2;
	const struct iphdr *eiph;
	struct rtable *rt;
	struct flowi4 fl4;

	err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
			  &rel_msg, &rel_info, offset);
	if (err < 0)
		return err;

	if (rel_msg == 0)
		return 0;

	switch (rel_type) {
	case ICMPV6_DEST_UNREACH:
		if (rel_code != ICMPV6_ADDR_UNREACH)
			return 0;
		rel_type = ICMP_DEST_UNREACH;
		rel_code = ICMP_HOST_UNREACH;
		break;
	case ICMPV6_PKT_TOOBIG:
		if (rel_code != 0)
			return 0;
		rel_type = ICMP_DEST_UNREACH;
		rel_code = ICMP_FRAG_NEEDED;
		break;
	case NDISC_REDIRECT:
		rel_type = ICMP_REDIRECT;
		rel_code = ICMP_REDIR_HOST;
	default:
		return 0;
	}

	if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
		return 0;

	skb2 = skb_clone(skb, GFP_ATOMIC);
	if (!skb2)
		return 0;

	skb_dst_drop(skb2);

	skb_pull(skb2, offset);
	skb_reset_network_header(skb2);
	eiph = ip_hdr(skb2);

	/* Try to guess incoming interface */
	rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
				   eiph->saddr, 0,
				   0, 0,
				   IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
	if (IS_ERR(rt))
		goto out;

	skb2->dev = rt->dst.dev;

	/* route "incoming" packet */
	if (rt->rt_flags & RTCF_LOCAL) {
		ip_rt_put(rt);
		rt = NULL;
		rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
					   eiph->daddr, eiph->saddr,
					   0, 0,
					   IPPROTO_IPIP,
					   RT_TOS(eiph->tos), 0);
		if (IS_ERR(rt) ||
		    rt->dst.dev->type != ARPHRD_TUNNEL) {
			if (!IS_ERR(rt))
				ip_rt_put(rt);
			goto out;
		}
		skb_dst_set(skb2, &rt->dst);
	} else {
		ip_rt_put(rt);
		if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
				   skb2->dev) ||
		    skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
			goto out;
	}

	/* change mtu on this route */
	if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
		if (rel_info > dst_mtu(skb_dst(skb2)))
			goto out;

		skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
	}
	if (rel_type == ICMP_REDIRECT)
		skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);

	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));

out:
	kfree_skb(skb2);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Yasuyuki Kozakai
338
61.79%
4
20.00%
David S. Miller
118
21.57%
5
25.00%
Ville Nuorvala
49
8.96%
1
5.00%
Eric Dumazet
18
3.29%
2
10.00%
Al Viro
7
1.28%
1
5.00%
Arnaldo Carvalho de Melo
6
1.10%
2
10.00%
Denis V. Lunev
5
0.91%
2
10.00%
Brian Haley
4
0.73%
1
5.00%
Herbert Xu
1
0.18%
1
5.00%
Pavel Emelyanov
1
0.18%
1
5.00%
Total
547
100.00%
20
100.00%


static int

ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
	   u8 type, u8 code, int offset, __be32 info)
{
	int rel_msg = 0;
	u8 rel_type = type;
	u8 rel_code = code;
	__u32 rel_info = ntohl(info);
	int err;

	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
			  &rel_msg, &rel_info, offset);
	if (err < 0)
		return err;

	if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
		struct rt6_info *rt;
		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);

		if (!skb2)
			return 0;

		skb_dst_drop(skb2);
		skb_pull(skb2, offset);
		skb_reset_network_header(skb2);

		/* Try to guess incoming interface */