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1/*
2 * Linux NET3: IP/IP protocol decoder.
3 *
4 * Authors:
5 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
6 *
7 * Fixes:
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.
19 *
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.
24 *
25 */
26
27/* tunnel.c: an IP tunnel driver
28
29 The purpose of this driver is to provide an IP tunnel through
30 which you can tunnel network traffic transparently across subnets.
31
32 This was written by looking at Nick Holloway's dummy driver
33 Thanks for the great code!
34
35 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
36
37 Minor tweaks:
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.
42 Added tx_dropped stat
43
44 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
45
46 Reworked:
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.
51
52 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
53
54*/
55
56/* Things I wish I had known when writing the tunnel driver:
57
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.
61
62 When we are passed a packet, we are expected to fill in the
63 source address with our source IP address.
64
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
77 "skb_tailroom(skb)".
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.
85 */
86
87/*
88 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
89
90 For comments look at net/ipv4/ip_gre.c --ANK
91 */
92
93
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>
110
111#include <net/sock.h>
112#include <net/ip.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>
119
120static bool log_ecn_error = true;
121module_param(log_ecn_error, bool, 0644);
122MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
123
124static int ipip_net_id __read_mostly;
125
126static int ipip_tunnel_init(struct net_device *dev);
127static struct rtnl_link_ops ipip_link_ops __read_mostly;
128
129static int ipip_err(struct sk_buff *skb, u32 info)
130{
131
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.
135 */
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;
139 struct ip_tunnel *t;
140 int err;
141 const int type = icmp_hdr(skb)->type;
142 const int code = icmp_hdr(skb)->code;
143
144 err = -ENOENT;
145 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
146 iph->daddr, iph->saddr, 0);
147 if (t == NULL)
148 goto out;
149
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);
153 err = 0;
154 goto out;
155 }
156
157 if (type == ICMP_REDIRECT) {
158 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
159 IPPROTO_IPIP, 0);
160 err = 0;
161 goto out;
162 }
163
164 if (t->parms.iph.daddr == 0)
165 goto out;
166
167 err = 0;
168 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
169 goto out;
170
171 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
172 t->err_count++;
173 else
174 t->err_count = 1;
175 t->err_time = jiffies;
176
177out:
178 return err;
179}
180
181static const struct tnl_ptk_info tpi = {
182 /* no tunnel info required for ipip. */
183 .proto = htons(ETH_P_IP),
184};
185
186static int ipip_rcv(struct sk_buff *skb)
187{
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;
192
193 iph = ip_hdr(skb);
194 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
195 iph->saddr, iph->daddr, 0);
196 if (tunnel) {
197 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
198 goto drop;
199 if (iptunnel_pull_header(skb, 0, tpi.proto))
200 goto drop;
201 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
202 }
203
204 return -1;
205
206drop:
207 kfree_skb(skb);
208 return 0;
209}
210
211/*
212 * This function assumes it is being called from dev_queue_xmit()
213 * and that skb is filled properly by that function.
214 */
215static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
216{
217 struct ip_tunnel *tunnel = netdev_priv(dev);
218 const struct iphdr *tiph = &tunnel->parms.iph;
219
220 if (unlikely(skb->protocol != htons(ETH_P_IP)))
221 goto tx_error;
222
223 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
224 if (IS_ERR(skb))
225 goto out;
226
227 ip_tunnel_xmit(skb, dev, tiph, tiph->protocol);
228 return NETDEV_TX_OK;
229
230tx_error:
231 kfree_skb(skb);
232out:
233 dev->stats.tx_errors++;
234 return NETDEV_TX_OK;
235}
236
237static int
238ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
239{
240 int err = 0;
241 struct ip_tunnel_parm p;
242
243 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
244 return -EFAULT;
245
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)))
249 return -EINVAL;
250 }
251
252 p.i_key = p.o_key = p.i_flags = p.o_flags = 0;
253 if (p.iph.ttl)
254 p.iph.frag_off |= htons(IP_DF);
255
256 err = ip_tunnel_ioctl(dev, &p, cmd);
257 if (err)
258 return err;
259
260 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
261 return -EFAULT;
262
263 return 0;
264}
265
266static 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,
273};
274
275#define IPIP_FEATURES (NETIF_F_SG | \
276 NETIF_F_FRAGLIST | \
277 NETIF_F_HIGHDMA | \
278 NETIF_F_GSO_SOFTWARE | \
279 NETIF_F_HW_CSUM)
280
281static void ipip_tunnel_setup(struct net_device *dev)
282{
283 dev->netdev_ops = &ipip_netdev_ops;
284
285 dev->type = ARPHRD_TUNNEL;
286 dev->flags = IFF_NOARP;
287 dev->iflink = 0;
288 dev->addr_len = 4;
289 dev->features |= NETIF_F_LLTX;
290 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
291
292 dev->features |= IPIP_FEATURES;
293 dev->hw_features |= IPIP_FEATURES;
294 ip_tunnel_setup(dev, ipip_net_id);
295}
296
297static int ipip_tunnel_init(struct net_device *dev)
298{
299 struct ip_tunnel *tunnel = netdev_priv(dev);
300
301 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
302 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
303
304 tunnel->hlen = 0;
305 tunnel->parms.iph.protocol = IPPROTO_IPIP;
306 return ip_tunnel_init(dev);
307}
308
309static void ipip_netlink_parms(struct nlattr *data[],
310 struct ip_tunnel_parm *parms)
311{
312 memset(parms, 0, sizeof(*parms));
313
314 parms->iph.version = 4;
315 parms->iph.protocol = IPPROTO_IPIP;
316 parms->iph.ihl = 5;
317
318 if (!data)
319 return;
320
321 if (data[IFLA_IPTUN_LINK])
322 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
323
324 if (data[IFLA_IPTUN_LOCAL])
325 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
326
327 if (data[IFLA_IPTUN_REMOTE])
328 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
329
330 if (data[IFLA_IPTUN_TTL]) {
331 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
332 if (parms->iph.ttl)
333 parms->iph.frag_off = htons(IP_DF);
334 }
335
336 if (data[IFLA_IPTUN_TOS])
337 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
338
339 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
340 parms->iph.frag_off = htons(IP_DF);
341}
342
343static int ipip_newlink(struct net *src_net, struct net_device *dev,
344 struct nlattr *tb[], struct nlattr *data[])
345{
346 struct ip_tunnel_parm p;
347
348 ipip_netlink_parms(data, &p);
349 return ip_tunnel_newlink(dev, tb, &p);
350}
351
352static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
353 struct nlattr *data[])
354{
355 struct ip_tunnel_parm p;
356
357 ipip_netlink_parms(data, &p);
358
359 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
360 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
361 return -EINVAL;
362
363 return ip_tunnel_changelink(dev, tb, &p);
364}
365
366static size_t ipip_get_size(const struct net_device *dev)
367{
368 return
369 /* IFLA_IPTUN_LINK */
370 nla_total_size(4) +
371 /* IFLA_IPTUN_LOCAL */
372 nla_total_size(4) +
373 /* IFLA_IPTUN_REMOTE */
374 nla_total_size(4) +
375 /* IFLA_IPTUN_TTL */
376 nla_total_size(1) +
377 /* IFLA_IPTUN_TOS */
378 nla_total_size(1) +
379 /* IFLA_IPTUN_PMTUDISC */
380 nla_total_size(1) +
381 0;
382}
383
384static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
385{
386 struct ip_tunnel *tunnel = netdev_priv(dev);
387 struct ip_tunnel_parm *parm = &tunnel->parms;
388
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;
397 return 0;
398
399nla_put_failure:
400 return -EMSGSIZE;
401}
402
403static 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 },
410};
411
412static struct rtnl_link_ops ipip_link_ops __read_mostly = {
413 .kind = "ipip",
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,
423};
424
425static struct xfrm_tunnel ipip_handler __read_mostly = {
426 .handler = ipip_rcv,
427 .err_handler = ipip_err,
428 .priority = 1,
429};
430
431static int __net_init ipip_init_net(struct net *net)
432{
433 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
434}
435
436static void __net_exit ipip_exit_net(struct net *net)
437{
438 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
439 ip_tunnel_delete_net(itn, &ipip_link_ops);
440}
441
442static struct pernet_operations ipip_net_ops = {
443 .init = ipip_init_net,
444 .exit = ipip_exit_net,
445 .id = &ipip_net_id,
446 .size = sizeof(struct ip_tunnel_net),
447};
448
449static int __init ipip_init(void)
450{
451 int err;
452
453 pr_info("ipip: IPv4 over IPv4 tunneling driver\n");
454
455 err = register_pernet_device(&ipip_net_ops);
456 if (err < 0)
457 return err;
458 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
459 if (err < 0) {
460 pr_info("%s: can't register tunnel\n", __func__);
461 goto xfrm_tunnel_failed;
462 }
463 err = rtnl_link_register(&ipip_link_ops);
464 if (err < 0)
465 goto rtnl_link_failed;
466
467out:
468 return err;
469
470rtnl_link_failed:
471 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
472xfrm_tunnel_failed:
473 unregister_pernet_device(&ipip_net_ops);
474 goto out;
475}
476
477static void __exit ipip_fini(void)
478{
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__);
482
483 unregister_pernet_device(&ipip_net_ops);
484}
485
486module_init(ipip_init);
487module_exit(ipip_fini);
488MODULE_LICENSE("GPL");
489MODULE_ALIAS_NETDEV("tunl0");
1/*
2 * Linux NET3: IP/IP protocol decoder.
3 *
4 * Authors:
5 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
6 *
7 * Fixes:
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.
19 *
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.
24 *
25 */
26
27/* tunnel.c: an IP tunnel driver
28
29 The purpose of this driver is to provide an IP tunnel through
30 which you can tunnel network traffic transparently across subnets.
31
32 This was written by looking at Nick Holloway's dummy driver
33 Thanks for the great code!
34
35 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
36
37 Minor tweaks:
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.
42 Added tx_dropped stat
43
44 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
45
46 Reworked:
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.
51
52 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
53
54*/
55
56/* Things I wish I had known when writing the tunnel driver:
57
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.
61
62 When we are passed a packet, we are expected to fill in the
63 source address with our source IP address.
64
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
77 "skb_tailroom(skb)".
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.
85 */
86
87/*
88 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
89
90 For comments look at net/ipv4/ip_gre.c --ANK
91 */
92
93
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/init.h>
107#include <linux/netfilter_ipv4.h>
108#include <linux/if_ether.h>
109
110#include <net/sock.h>
111#include <net/ip.h>
112#include <net/icmp.h>
113#include <net/ip_tunnels.h>
114#include <net/inet_ecn.h>
115#include <net/xfrm.h>
116#include <net/net_namespace.h>
117#include <net/netns/generic.h>
118
119static bool log_ecn_error = true;
120module_param(log_ecn_error, bool, 0644);
121MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
122
123static int ipip_net_id __read_mostly;
124
125static int ipip_tunnel_init(struct net_device *dev);
126static struct rtnl_link_ops ipip_link_ops __read_mostly;
127
128static int ipip_err(struct sk_buff *skb, u32 info)
129{
130
131/* All the routers (except for Linux) return only
132 8 bytes of packet payload. It means, that precise relaying of
133 ICMP in the real Internet is absolutely infeasible.
134 */
135 struct net *net = dev_net(skb->dev);
136 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
137 const struct iphdr *iph = (const struct iphdr *)skb->data;
138 struct ip_tunnel *t;
139 int err;
140 const int type = icmp_hdr(skb)->type;
141 const int code = icmp_hdr(skb)->code;
142
143 err = -ENOENT;
144 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
145 iph->daddr, iph->saddr, 0);
146 if (!t)
147 goto out;
148
149 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
150 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
151 t->parms.link, 0, IPPROTO_IPIP, 0);
152 err = 0;
153 goto out;
154 }
155
156 if (type == ICMP_REDIRECT) {
157 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
158 IPPROTO_IPIP, 0);
159 err = 0;
160 goto out;
161 }
162
163 if (t->parms.iph.daddr == 0)
164 goto out;
165
166 err = 0;
167 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
168 goto out;
169
170 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
171 t->err_count++;
172 else
173 t->err_count = 1;
174 t->err_time = jiffies;
175
176out:
177 return err;
178}
179
180static const struct tnl_ptk_info tpi = {
181 /* no tunnel info required for ipip. */
182 .proto = htons(ETH_P_IP),
183};
184
185static int ipip_rcv(struct sk_buff *skb)
186{
187 struct net *net = dev_net(skb->dev);
188 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
189 struct ip_tunnel *tunnel;
190 const struct iphdr *iph;
191
192 iph = ip_hdr(skb);
193 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
194 iph->saddr, iph->daddr, 0);
195 if (tunnel) {
196 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
197 goto drop;
198 if (iptunnel_pull_header(skb, 0, tpi.proto, false))
199 goto drop;
200 return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error);
201 }
202
203 return -1;
204
205drop:
206 kfree_skb(skb);
207 return 0;
208}
209
210/*
211 * This function assumes it is being called from dev_queue_xmit()
212 * and that skb is filled properly by that function.
213 */
214static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
215{
216 struct ip_tunnel *tunnel = netdev_priv(dev);
217 const struct iphdr *tiph = &tunnel->parms.iph;
218
219 if (unlikely(skb->protocol != htons(ETH_P_IP)))
220 goto tx_error;
221
222 skb = iptunnel_handle_offloads(skb, SKB_GSO_IPIP);
223 if (IS_ERR(skb))
224 goto out;
225
226 skb_set_inner_ipproto(skb, IPPROTO_IPIP);
227
228 ip_tunnel_xmit(skb, dev, tiph, tiph->protocol);
229 return NETDEV_TX_OK;
230
231tx_error:
232 kfree_skb(skb);
233out:
234 dev->stats.tx_errors++;
235 return NETDEV_TX_OK;
236}
237
238static int
239ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
240{
241 int err = 0;
242 struct ip_tunnel_parm p;
243
244 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
245 return -EFAULT;
246
247 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
248 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
249 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
250 return -EINVAL;
251 }
252
253 p.i_key = p.o_key = 0;
254 p.i_flags = p.o_flags = 0;
255 err = ip_tunnel_ioctl(dev, &p, cmd);
256 if (err)
257 return err;
258
259 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
260 return -EFAULT;
261
262 return 0;
263}
264
265static const struct net_device_ops ipip_netdev_ops = {
266 .ndo_init = ipip_tunnel_init,
267 .ndo_uninit = ip_tunnel_uninit,
268 .ndo_start_xmit = ipip_tunnel_xmit,
269 .ndo_do_ioctl = ipip_tunnel_ioctl,
270 .ndo_change_mtu = ip_tunnel_change_mtu,
271 .ndo_get_stats64 = ip_tunnel_get_stats64,
272 .ndo_get_iflink = ip_tunnel_get_iflink,
273};
274
275#define IPIP_FEATURES (NETIF_F_SG | \
276 NETIF_F_FRAGLIST | \
277 NETIF_F_HIGHDMA | \
278 NETIF_F_GSO_SOFTWARE | \
279 NETIF_F_HW_CSUM)
280
281static void ipip_tunnel_setup(struct net_device *dev)
282{
283 dev->netdev_ops = &ipip_netdev_ops;
284
285 dev->type = ARPHRD_TUNNEL;
286 dev->flags = IFF_NOARP;
287 dev->addr_len = 4;
288 dev->features |= NETIF_F_LLTX;
289 netif_keep_dst(dev);
290
291 dev->features |= IPIP_FEATURES;
292 dev->hw_features |= IPIP_FEATURES;
293 ip_tunnel_setup(dev, ipip_net_id);
294}
295
296static int ipip_tunnel_init(struct net_device *dev)
297{
298 struct ip_tunnel *tunnel = netdev_priv(dev);
299
300 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
301 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
302
303 tunnel->tun_hlen = 0;
304 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
305 tunnel->parms.iph.protocol = IPPROTO_IPIP;
306 return ip_tunnel_init(dev);
307}
308
309static void ipip_netlink_parms(struct nlattr *data[],
310 struct ip_tunnel_parm *parms)
311{
312 memset(parms, 0, sizeof(*parms));
313
314 parms->iph.version = 4;
315 parms->iph.protocol = IPPROTO_IPIP;
316 parms->iph.ihl = 5;
317
318 if (!data)
319 return;
320
321 if (data[IFLA_IPTUN_LINK])
322 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
323
324 if (data[IFLA_IPTUN_LOCAL])
325 parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
326
327 if (data[IFLA_IPTUN_REMOTE])
328 parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
329
330 if (data[IFLA_IPTUN_TTL]) {
331 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
332 if (parms->iph.ttl)
333 parms->iph.frag_off = htons(IP_DF);
334 }
335
336 if (data[IFLA_IPTUN_TOS])
337 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
338
339 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
340 parms->iph.frag_off = htons(IP_DF);
341}
342
343/* This function returns true when ENCAP attributes are present in the nl msg */
344static bool ipip_netlink_encap_parms(struct nlattr *data[],
345 struct ip_tunnel_encap *ipencap)
346{
347 bool ret = false;
348
349 memset(ipencap, 0, sizeof(*ipencap));
350
351 if (!data)
352 return ret;
353
354 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
355 ret = true;
356 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
357 }
358
359 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
360 ret = true;
361 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
362 }
363
364 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
365 ret = true;
366 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
367 }
368
369 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
370 ret = true;
371 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
372 }
373
374 return ret;
375}
376
377static int ipip_newlink(struct net *src_net, struct net_device *dev,
378 struct nlattr *tb[], struct nlattr *data[])
379{
380 struct ip_tunnel_parm p;
381 struct ip_tunnel_encap ipencap;
382
383 if (ipip_netlink_encap_parms(data, &ipencap)) {
384 struct ip_tunnel *t = netdev_priv(dev);
385 int err = ip_tunnel_encap_setup(t, &ipencap);
386
387 if (err < 0)
388 return err;
389 }
390
391 ipip_netlink_parms(data, &p);
392 return ip_tunnel_newlink(dev, tb, &p);
393}
394
395static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
396 struct nlattr *data[])
397{
398 struct ip_tunnel_parm p;
399 struct ip_tunnel_encap ipencap;
400
401 if (ipip_netlink_encap_parms(data, &ipencap)) {
402 struct ip_tunnel *t = netdev_priv(dev);
403 int err = ip_tunnel_encap_setup(t, &ipencap);
404
405 if (err < 0)
406 return err;
407 }
408
409 ipip_netlink_parms(data, &p);
410
411 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
412 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
413 return -EINVAL;
414
415 return ip_tunnel_changelink(dev, tb, &p);
416}
417
418static size_t ipip_get_size(const struct net_device *dev)
419{
420 return
421 /* IFLA_IPTUN_LINK */
422 nla_total_size(4) +
423 /* IFLA_IPTUN_LOCAL */
424 nla_total_size(4) +
425 /* IFLA_IPTUN_REMOTE */
426 nla_total_size(4) +
427 /* IFLA_IPTUN_TTL */
428 nla_total_size(1) +
429 /* IFLA_IPTUN_TOS */
430 nla_total_size(1) +
431 /* IFLA_IPTUN_PMTUDISC */
432 nla_total_size(1) +
433 /* IFLA_IPTUN_ENCAP_TYPE */
434 nla_total_size(2) +
435 /* IFLA_IPTUN_ENCAP_FLAGS */
436 nla_total_size(2) +
437 /* IFLA_IPTUN_ENCAP_SPORT */
438 nla_total_size(2) +
439 /* IFLA_IPTUN_ENCAP_DPORT */
440 nla_total_size(2) +
441 0;
442}
443
444static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
445{
446 struct ip_tunnel *tunnel = netdev_priv(dev);
447 struct ip_tunnel_parm *parm = &tunnel->parms;
448
449 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
450 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
451 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
452 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
453 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
454 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
455 !!(parm->iph.frag_off & htons(IP_DF))))
456 goto nla_put_failure;
457
458 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
459 tunnel->encap.type) ||
460 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
461 tunnel->encap.sport) ||
462 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
463 tunnel->encap.dport) ||
464 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
465 tunnel->encap.flags))
466 goto nla_put_failure;
467
468 return 0;
469
470nla_put_failure:
471 return -EMSGSIZE;
472}
473
474static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
475 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
476 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
477 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
478 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
479 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
480 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
481 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
482 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
483 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
484 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
485};
486
487static struct rtnl_link_ops ipip_link_ops __read_mostly = {
488 .kind = "ipip",
489 .maxtype = IFLA_IPTUN_MAX,
490 .policy = ipip_policy,
491 .priv_size = sizeof(struct ip_tunnel),
492 .setup = ipip_tunnel_setup,
493 .newlink = ipip_newlink,
494 .changelink = ipip_changelink,
495 .dellink = ip_tunnel_dellink,
496 .get_size = ipip_get_size,
497 .fill_info = ipip_fill_info,
498 .get_link_net = ip_tunnel_get_link_net,
499};
500
501static struct xfrm_tunnel ipip_handler __read_mostly = {
502 .handler = ipip_rcv,
503 .err_handler = ipip_err,
504 .priority = 1,
505};
506
507static int __net_init ipip_init_net(struct net *net)
508{
509 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
510}
511
512static void __net_exit ipip_exit_net(struct net *net)
513{
514 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
515 ip_tunnel_delete_net(itn, &ipip_link_ops);
516}
517
518static struct pernet_operations ipip_net_ops = {
519 .init = ipip_init_net,
520 .exit = ipip_exit_net,
521 .id = &ipip_net_id,
522 .size = sizeof(struct ip_tunnel_net),
523};
524
525static int __init ipip_init(void)
526{
527 int err;
528
529 pr_info("ipip: IPv4 over IPv4 tunneling driver\n");
530
531 err = register_pernet_device(&ipip_net_ops);
532 if (err < 0)
533 return err;
534 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
535 if (err < 0) {
536 pr_info("%s: can't register tunnel\n", __func__);
537 goto xfrm_tunnel_failed;
538 }
539 err = rtnl_link_register(&ipip_link_ops);
540 if (err < 0)
541 goto rtnl_link_failed;
542
543out:
544 return err;
545
546rtnl_link_failed:
547 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
548xfrm_tunnel_failed:
549 unregister_pernet_device(&ipip_net_ops);
550 goto out;
551}
552
553static void __exit ipip_fini(void)
554{
555 rtnl_link_unregister(&ipip_link_ops);
556 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
557 pr_info("%s: can't deregister tunnel\n", __func__);
558
559 unregister_pernet_device(&ipip_net_ops);
560}
561
562module_init(ipip_init);
563module_exit(ipip_fini);
564MODULE_LICENSE("GPL");
565MODULE_ALIAS_RTNL_LINK("ipip");
566MODULE_ALIAS_NETDEV("tunl0");