2 * Linux NET3: IP/IP protocol decoder.
5 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
8 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
9 * a module taking up 2 pages).
10 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
11 * to keep ip_forward happy.
12 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
13 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
14 * David Woodhouse : Perform some basic ICMP handling.
15 * IPIP Routing without decapsulation.
16 * Carlos Picoto : GRE over IP support
17 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
18 * I do not want to merge them together.
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
27 /* tunnel.c: an IP tunnel driver
29 The purpose of this driver is to provide an IP tunnel through
30 which you can tunnel network traffic transparently across subnets.
32 This was written by looking at Nick Holloway's dummy driver
33 Thanks for the great code!
35 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
38 Cleaned up the code a little and added some pre-1.3.0 tweaks.
39 dev->hard_header/hard_header_len changed to use no headers.
40 Comments/bracketing tweaked.
41 Made the tunnels use dev->name not tunnel: when error reporting.
44 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
47 Changed to tunnel to destination gateway in addition to the
48 tunnel's pointopoint address
49 Almost completely rewritten
50 Note: There is currently no firewall or ICMP handling done.
52 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
56 /* Things I wish I had known when writing the tunnel driver:
58 When the tunnel_xmit() function is called, the skb contains the
59 packet to be sent (plus a great deal of extra info), and dev
60 contains the tunnel device that _we_ are.
62 When we are passed a packet, we are expected to fill in the
63 source address with our source IP address.
65 What is the proper way to allocate, copy and free a buffer?
66 After you allocate it, it is a "0 length" chunk of memory
67 starting at zero. If you want to add headers to the buffer
68 later, you'll have to call "skb_reserve(skb, amount)" with
69 the amount of memory you want reserved. Then, you call
70 "skb_put(skb, amount)" with the amount of space you want in
71 the buffer. skb_put() returns a pointer to the top (#0) of
72 that buffer. skb->len is set to the amount of space you have
73 "allocated" with skb_put(). You can then write up to skb->len
74 bytes to that buffer. If you need more, you can call skb_put()
75 again with the additional amount of space you need. You can
76 find out how much more space you can allocate by calling
78 Now, to add header space, call "skb_push(skb, header_len)".
79 This creates space at the beginning of the buffer and returns
80 a pointer to this new space. If later you need to strip a
81 header from a buffer, call "skb_pull(skb, header_len)".
82 skb_headroom() will return how much space is left at the top
83 of the buffer (before the main data). Remember, this headroom
84 space must be reserved before the skb_put() function is called.
88 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
90 For comments look at net/ipv4/ip_gre.c --ANK
94 #include <linux/capability.h>
95 #include <linux/module.h>
96 #include <linux/types.h>
97 #include <linux/kernel.h>
98 #include <linux/slab.h>
99 #include <asm/uaccess.h>
100 #include <linux/skbuff.h>
101 #include <linux/netdevice.h>
102 #include <linux/in.h>
103 #include <linux/tcp.h>
104 #include <linux/udp.h>
105 #include <linux/if_arp.h>
106 #include <linux/mroute.h>
107 #include <linux/init.h>
108 #include <linux/netfilter_ipv4.h>
109 #include <linux/if_ether.h>
111 #include <net/sock.h>
113 #include <net/icmp.h>
114 #include <net/ip_tunnels.h>
115 #include <net/inet_ecn.h>
116 #include <net/xfrm.h>
117 #include <net/net_namespace.h>
118 #include <net/netns/generic.h>
120 static bool log_ecn_error
= true;
121 module_param(log_ecn_error
, bool, 0644);
122 MODULE_PARM_DESC(log_ecn_error
, "Log packets received with corrupted ECN");
124 static int ipip_net_id __read_mostly
;
126 static int ipip_tunnel_init(struct net_device
*dev
);
127 static struct rtnl_link_ops ipip_link_ops __read_mostly
;
129 static int ipip_err(struct sk_buff
*skb
, u32 info
)
132 /* All the routers (except for Linux) return only
133 8 bytes of packet payload. It means, that precise relaying of
134 ICMP in the real Internet is absolutely infeasible.
136 struct net
*net
= dev_net(skb
->dev
);
137 struct ip_tunnel_net
*itn
= net_generic(net
, ipip_net_id
);
138 const struct iphdr
*iph
= (const struct iphdr
*)skb
->data
;
141 const int type
= icmp_hdr(skb
)->type
;
142 const int code
= icmp_hdr(skb
)->code
;
145 t
= ip_tunnel_lookup(itn
, skb
->dev
->ifindex
, TUNNEL_NO_KEY
,
146 iph
->daddr
, iph
->saddr
, 0);
150 if (type
== ICMP_DEST_UNREACH
&& code
== ICMP_FRAG_NEEDED
) {
151 ipv4_update_pmtu(skb
, dev_net(skb
->dev
), info
,
152 t
->dev
->ifindex
, 0, IPPROTO_IPIP
, 0);
157 if (type
== ICMP_REDIRECT
) {
158 ipv4_redirect(skb
, dev_net(skb
->dev
), t
->dev
->ifindex
, 0,
164 if (t
->parms
.iph
.daddr
== 0)
168 if (t
->parms
.iph
.ttl
== 0 && type
== ICMP_TIME_EXCEEDED
)
171 if (time_before(jiffies
, t
->err_time
+ IPTUNNEL_ERR_TIMEO
))
175 t
->err_time
= jiffies
;
181 static const struct tnl_ptk_info tpi
= {
182 /* no tunnel info required for ipip. */
183 .proto
= htons(ETH_P_IP
),
186 static int ipip_rcv(struct sk_buff
*skb
)
188 struct net
*net
= dev_net(skb
->dev
);
189 struct ip_tunnel_net
*itn
= net_generic(net
, ipip_net_id
);
190 struct ip_tunnel
*tunnel
;
191 const struct iphdr
*iph
;
194 tunnel
= ip_tunnel_lookup(itn
, skb
->dev
->ifindex
, TUNNEL_NO_KEY
,
195 iph
->saddr
, iph
->daddr
, 0);
197 if (!xfrm4_policy_check(NULL
, XFRM_POLICY_IN
, skb
))
199 if (iptunnel_pull_header(skb
, 0, tpi
.proto
))
201 return ip_tunnel_rcv(tunnel
, skb
, &tpi
, log_ecn_error
);
212 * This function assumes it is being called from dev_queue_xmit()
213 * and that skb is filled properly by that function.
215 static netdev_tx_t
ipip_tunnel_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
217 struct ip_tunnel
*tunnel
= netdev_priv(dev
);
218 const struct iphdr
*tiph
= &tunnel
->parms
.iph
;
220 if (unlikely(skb
->protocol
!= htons(ETH_P_IP
)))
223 skb
= iptunnel_handle_offloads(skb
, false, SKB_GSO_IPIP
);
227 ip_tunnel_xmit(skb
, dev
, tiph
, tiph
->protocol
);
233 dev
->stats
.tx_errors
++;
238 ipip_tunnel_ioctl(struct net_device
*dev
, struct ifreq
*ifr
, int cmd
)
241 struct ip_tunnel_parm p
;
243 if (copy_from_user(&p
, ifr
->ifr_ifru
.ifru_data
, sizeof(p
)))
246 if (cmd
== SIOCADDTUNNEL
|| cmd
== SIOCCHGTUNNEL
) {
247 if (p
.iph
.version
!= 4 || p
.iph
.protocol
!= IPPROTO_IPIP
||
248 p
.iph
.ihl
!= 5 || (p
.iph
.frag_off
&htons(~IP_DF
)))
252 p
.i_key
= p
.o_key
= p
.i_flags
= p
.o_flags
= 0;
254 p
.iph
.frag_off
|= htons(IP_DF
);
256 err
= ip_tunnel_ioctl(dev
, &p
, cmd
);
260 if (copy_to_user(ifr
->ifr_ifru
.ifru_data
, &p
, sizeof(p
)))
266 static const struct net_device_ops ipip_netdev_ops
= {
267 .ndo_init
= ipip_tunnel_init
,
268 .ndo_uninit
= ip_tunnel_uninit
,
269 .ndo_start_xmit
= ipip_tunnel_xmit
,
270 .ndo_do_ioctl
= ipip_tunnel_ioctl
,
271 .ndo_change_mtu
= ip_tunnel_change_mtu
,
272 .ndo_get_stats64
= ip_tunnel_get_stats64
,
275 #define IPIP_FEATURES (NETIF_F_SG | \
278 NETIF_F_GSO_SOFTWARE | \
281 static void ipip_tunnel_setup(struct net_device
*dev
)
283 dev
->netdev_ops
= &ipip_netdev_ops
;
285 dev
->type
= ARPHRD_TUNNEL
;
286 dev
->flags
= IFF_NOARP
;
289 dev
->features
|= NETIF_F_LLTX
;
290 dev
->priv_flags
&= ~IFF_XMIT_DST_RELEASE
;
292 dev
->features
|= IPIP_FEATURES
;
293 dev
->hw_features
|= IPIP_FEATURES
;
294 ip_tunnel_setup(dev
, ipip_net_id
);
297 static int ipip_tunnel_init(struct net_device
*dev
)
299 struct ip_tunnel
*tunnel
= netdev_priv(dev
);
301 memcpy(dev
->dev_addr
, &tunnel
->parms
.iph
.saddr
, 4);
302 memcpy(dev
->broadcast
, &tunnel
->parms
.iph
.daddr
, 4);
305 tunnel
->parms
.iph
.protocol
= IPPROTO_IPIP
;
306 return ip_tunnel_init(dev
);
309 static void ipip_netlink_parms(struct nlattr
*data
[],
310 struct ip_tunnel_parm
*parms
)
312 memset(parms
, 0, sizeof(*parms
));
314 parms
->iph
.version
= 4;
315 parms
->iph
.protocol
= IPPROTO_IPIP
;
321 if (data
[IFLA_IPTUN_LINK
])
322 parms
->link
= nla_get_u32(data
[IFLA_IPTUN_LINK
]);
324 if (data
[IFLA_IPTUN_LOCAL
])
325 parms
->iph
.saddr
= nla_get_be32(data
[IFLA_IPTUN_LOCAL
]);
327 if (data
[IFLA_IPTUN_REMOTE
])
328 parms
->iph
.daddr
= nla_get_be32(data
[IFLA_IPTUN_REMOTE
]);
330 if (data
[IFLA_IPTUN_TTL
]) {
331 parms
->iph
.ttl
= nla_get_u8(data
[IFLA_IPTUN_TTL
]);
333 parms
->iph
.frag_off
= htons(IP_DF
);
336 if (data
[IFLA_IPTUN_TOS
])
337 parms
->iph
.tos
= nla_get_u8(data
[IFLA_IPTUN_TOS
]);
339 if (!data
[IFLA_IPTUN_PMTUDISC
] || nla_get_u8(data
[IFLA_IPTUN_PMTUDISC
]))
340 parms
->iph
.frag_off
= htons(IP_DF
);
343 static int ipip_newlink(struct net
*src_net
, struct net_device
*dev
,
344 struct nlattr
*tb
[], struct nlattr
*data
[])
346 struct ip_tunnel_parm p
;
348 ipip_netlink_parms(data
, &p
);
349 return ip_tunnel_newlink(dev
, tb
, &p
);
352 static int ipip_changelink(struct net_device
*dev
, struct nlattr
*tb
[],
353 struct nlattr
*data
[])
355 struct ip_tunnel_parm p
;
357 ipip_netlink_parms(data
, &p
);
359 if (((dev
->flags
& IFF_POINTOPOINT
) && !p
.iph
.daddr
) ||
360 (!(dev
->flags
& IFF_POINTOPOINT
) && p
.iph
.daddr
))
363 return ip_tunnel_changelink(dev
, tb
, &p
);
366 static size_t ipip_get_size(const struct net_device
*dev
)
369 /* IFLA_IPTUN_LINK */
371 /* IFLA_IPTUN_LOCAL */
373 /* IFLA_IPTUN_REMOTE */
379 /* IFLA_IPTUN_PMTUDISC */
384 static int ipip_fill_info(struct sk_buff
*skb
, const struct net_device
*dev
)
386 struct ip_tunnel
*tunnel
= netdev_priv(dev
);
387 struct ip_tunnel_parm
*parm
= &tunnel
->parms
;
389 if (nla_put_u32(skb
, IFLA_IPTUN_LINK
, parm
->link
) ||
390 nla_put_be32(skb
, IFLA_IPTUN_LOCAL
, parm
->iph
.saddr
) ||
391 nla_put_be32(skb
, IFLA_IPTUN_REMOTE
, parm
->iph
.daddr
) ||
392 nla_put_u8(skb
, IFLA_IPTUN_TTL
, parm
->iph
.ttl
) ||
393 nla_put_u8(skb
, IFLA_IPTUN_TOS
, parm
->iph
.tos
) ||
394 nla_put_u8(skb
, IFLA_IPTUN_PMTUDISC
,
395 !!(parm
->iph
.frag_off
& htons(IP_DF
))))
396 goto nla_put_failure
;
403 static const struct nla_policy ipip_policy
[IFLA_IPTUN_MAX
+ 1] = {
404 [IFLA_IPTUN_LINK
] = { .type
= NLA_U32
},
405 [IFLA_IPTUN_LOCAL
] = { .type
= NLA_U32
},
406 [IFLA_IPTUN_REMOTE
] = { .type
= NLA_U32
},
407 [IFLA_IPTUN_TTL
] = { .type
= NLA_U8
},
408 [IFLA_IPTUN_TOS
] = { .type
= NLA_U8
},
409 [IFLA_IPTUN_PMTUDISC
] = { .type
= NLA_U8
},
412 static struct rtnl_link_ops ipip_link_ops __read_mostly
= {
414 .maxtype
= IFLA_IPTUN_MAX
,
415 .policy
= ipip_policy
,
416 .priv_size
= sizeof(struct ip_tunnel
),
417 .setup
= ipip_tunnel_setup
,
418 .newlink
= ipip_newlink
,
419 .changelink
= ipip_changelink
,
420 .dellink
= ip_tunnel_dellink
,
421 .get_size
= ipip_get_size
,
422 .fill_info
= ipip_fill_info
,
425 static struct xfrm_tunnel ipip_handler __read_mostly
= {
427 .err_handler
= ipip_err
,
431 static int __net_init
ipip_init_net(struct net
*net
)
433 return ip_tunnel_init_net(net
, ipip_net_id
, &ipip_link_ops
, "tunl0");
436 static void __net_exit
ipip_exit_net(struct net
*net
)
438 struct ip_tunnel_net
*itn
= net_generic(net
, ipip_net_id
);
439 ip_tunnel_delete_net(itn
, &ipip_link_ops
);
442 static struct pernet_operations ipip_net_ops
= {
443 .init
= ipip_init_net
,
444 .exit
= ipip_exit_net
,
446 .size
= sizeof(struct ip_tunnel_net
),
449 static int __init
ipip_init(void)
453 pr_info("ipip: IPv4 over IPv4 tunneling driver\n");
455 err
= register_pernet_device(&ipip_net_ops
);
458 err
= xfrm4_tunnel_register(&ipip_handler
, AF_INET
);
460 pr_info("%s: can't register tunnel\n", __func__
);
461 goto xfrm_tunnel_failed
;
463 err
= rtnl_link_register(&ipip_link_ops
);
465 goto rtnl_link_failed
;
471 xfrm4_tunnel_deregister(&ipip_handler
, AF_INET
);
473 unregister_pernet_device(&ipip_net_ops
);
477 static void __exit
ipip_fini(void)
479 rtnl_link_unregister(&ipip_link_ops
);
480 if (xfrm4_tunnel_deregister(&ipip_handler
, AF_INET
))
481 pr_info("%s: can't deregister tunnel\n", __func__
);
483 unregister_pernet_device(&ipip_net_ops
);
486 module_init(ipip_init
);
487 module_exit(ipip_fini
);
488 MODULE_LICENSE("GPL");
489 MODULE_ALIAS_NETDEV("tunl0");