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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 <linux/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#include <net/dst_metadata.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 unsigned 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)
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->parms.link, 0, iph->protocol, 0);
153 err = 0;
154 goto out;
155 }
156
157 if (type == ICMP_REDIRECT) {
158 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
159 iph->protocol, 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 ipip_tpi = {
182 /* no tunnel info required for ipip. */
183 .proto = htons(ETH_P_IP),
184};
185
186#if IS_ENABLED(CONFIG_MPLS)
187static const struct tnl_ptk_info mplsip_tpi = {
188 /* no tunnel info required for mplsip. */
189 .proto = htons(ETH_P_MPLS_UC),
190};
191#endif
192
193static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
194{
195 struct net *net = dev_net(skb->dev);
196 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
197 struct metadata_dst *tun_dst = NULL;
198 struct ip_tunnel *tunnel;
199 const struct iphdr *iph;
200
201 iph = ip_hdr(skb);
202 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
203 iph->saddr, iph->daddr, 0);
204 if (tunnel) {
205 const struct tnl_ptk_info *tpi;
206
207 if (tunnel->parms.iph.protocol != ipproto &&
208 tunnel->parms.iph.protocol != 0)
209 goto drop;
210
211 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
212 goto drop;
213#if IS_ENABLED(CONFIG_MPLS)
214 if (ipproto == IPPROTO_MPLS)
215 tpi = &mplsip_tpi;
216 else
217#endif
218 tpi = &ipip_tpi;
219 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
220 goto drop;
221 if (tunnel->collect_md) {
222 tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
223 if (!tun_dst)
224 return 0;
225 }
226 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
227 }
228
229 return -1;
230
231drop:
232 kfree_skb(skb);
233 return 0;
234}
235
236static int ipip_rcv(struct sk_buff *skb)
237{
238 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
239}
240
241#if IS_ENABLED(CONFIG_MPLS)
242static int mplsip_rcv(struct sk_buff *skb)
243{
244 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
245}
246#endif
247
248/*
249 * This function assumes it is being called from dev_queue_xmit()
250 * and that skb is filled properly by that function.
251 */
252static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
253 struct net_device *dev)
254{
255 struct ip_tunnel *tunnel = netdev_priv(dev);
256 const struct iphdr *tiph = &tunnel->parms.iph;
257 u8 ipproto;
258
259 switch (skb->protocol) {
260 case htons(ETH_P_IP):
261 ipproto = IPPROTO_IPIP;
262 break;
263#if IS_ENABLED(CONFIG_MPLS)
264 case htons(ETH_P_MPLS_UC):
265 ipproto = IPPROTO_MPLS;
266 break;
267#endif
268 default:
269 goto tx_error;
270 }
271
272 if (tiph->protocol != ipproto && tiph->protocol != 0)
273 goto tx_error;
274
275 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
276 goto tx_error;
277
278 skb_set_inner_ipproto(skb, ipproto);
279
280 if (tunnel->collect_md)
281 ip_md_tunnel_xmit(skb, dev, ipproto);
282 else
283 ip_tunnel_xmit(skb, dev, tiph, ipproto);
284 return NETDEV_TX_OK;
285
286tx_error:
287 kfree_skb(skb);
288
289 dev->stats.tx_errors++;
290 return NETDEV_TX_OK;
291}
292
293static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
294{
295 switch (ipproto) {
296 case 0:
297 case IPPROTO_IPIP:
298#if IS_ENABLED(CONFIG_MPLS)
299 case IPPROTO_MPLS:
300#endif
301 return true;
302 }
303
304 return false;
305}
306
307static int
308ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
309{
310 int err = 0;
311 struct ip_tunnel_parm p;
312
313 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
314 return -EFAULT;
315
316 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
317 if (p.iph.version != 4 ||
318 !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||
319 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
320 return -EINVAL;
321 }
322
323 p.i_key = p.o_key = 0;
324 p.i_flags = p.o_flags = 0;
325 err = ip_tunnel_ioctl(dev, &p, cmd);
326 if (err)
327 return err;
328
329 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
330 return -EFAULT;
331
332 return 0;
333}
334
335static const struct net_device_ops ipip_netdev_ops = {
336 .ndo_init = ipip_tunnel_init,
337 .ndo_uninit = ip_tunnel_uninit,
338 .ndo_start_xmit = ipip_tunnel_xmit,
339 .ndo_do_ioctl = ipip_tunnel_ioctl,
340 .ndo_change_mtu = ip_tunnel_change_mtu,
341 .ndo_get_stats64 = ip_tunnel_get_stats64,
342 .ndo_get_iflink = ip_tunnel_get_iflink,
343};
344
345#define IPIP_FEATURES (NETIF_F_SG | \
346 NETIF_F_FRAGLIST | \
347 NETIF_F_HIGHDMA | \
348 NETIF_F_GSO_SOFTWARE | \
349 NETIF_F_HW_CSUM)
350
351static void ipip_tunnel_setup(struct net_device *dev)
352{
353 dev->netdev_ops = &ipip_netdev_ops;
354
355 dev->type = ARPHRD_TUNNEL;
356 dev->flags = IFF_NOARP;
357 dev->addr_len = 4;
358 dev->features |= NETIF_F_LLTX;
359 netif_keep_dst(dev);
360
361 dev->features |= IPIP_FEATURES;
362 dev->hw_features |= IPIP_FEATURES;
363 ip_tunnel_setup(dev, ipip_net_id);
364}
365
366static int ipip_tunnel_init(struct net_device *dev)
367{
368 struct ip_tunnel *tunnel = netdev_priv(dev);
369
370 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
371 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
372
373 tunnel->tun_hlen = 0;
374 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
375 return ip_tunnel_init(dev);
376}
377
378static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
379{
380 u8 proto;
381
382 if (!data || !data[IFLA_IPTUN_PROTO])
383 return 0;
384
385 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
386 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
387 return -EINVAL;
388
389 return 0;
390}
391
392static void ipip_netlink_parms(struct nlattr *data[],
393 struct ip_tunnel_parm *parms, bool *collect_md)
394{
395 memset(parms, 0, sizeof(*parms));
396
397 parms->iph.version = 4;
398 parms->iph.protocol = IPPROTO_IPIP;
399 parms->iph.ihl = 5;
400 *collect_md = false;
401
402 if (!data)
403 return;
404
405 if (data[IFLA_IPTUN_LINK])
406 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
407
408 if (data[IFLA_IPTUN_LOCAL])
409 parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
410
411 if (data[IFLA_IPTUN_REMOTE])
412 parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
413
414 if (data[IFLA_IPTUN_TTL]) {
415 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
416 if (parms->iph.ttl)
417 parms->iph.frag_off = htons(IP_DF);
418 }
419
420 if (data[IFLA_IPTUN_TOS])
421 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
422
423 if (data[IFLA_IPTUN_PROTO])
424 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
425
426 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
427 parms->iph.frag_off = htons(IP_DF);
428
429 if (data[IFLA_IPTUN_COLLECT_METADATA])
430 *collect_md = true;
431}
432
433/* This function returns true when ENCAP attributes are present in the nl msg */
434static bool ipip_netlink_encap_parms(struct nlattr *data[],
435 struct ip_tunnel_encap *ipencap)
436{
437 bool ret = false;
438
439 memset(ipencap, 0, sizeof(*ipencap));
440
441 if (!data)
442 return ret;
443
444 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
445 ret = true;
446 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
447 }
448
449 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
450 ret = true;
451 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
452 }
453
454 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
455 ret = true;
456 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
457 }
458
459 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
460 ret = true;
461 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
462 }
463
464 return ret;
465}
466
467static int ipip_newlink(struct net *src_net, struct net_device *dev,
468 struct nlattr *tb[], struct nlattr *data[])
469{
470 struct ip_tunnel *t = netdev_priv(dev);
471 struct ip_tunnel_parm p;
472 struct ip_tunnel_encap ipencap;
473
474 if (ipip_netlink_encap_parms(data, &ipencap)) {
475 int err = ip_tunnel_encap_setup(t, &ipencap);
476
477 if (err < 0)
478 return err;
479 }
480
481 ipip_netlink_parms(data, &p, &t->collect_md);
482 return ip_tunnel_newlink(dev, tb, &p);
483}
484
485static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
486 struct nlattr *data[])
487{
488 struct ip_tunnel_parm p;
489 struct ip_tunnel_encap ipencap;
490 bool collect_md;
491
492 if (ipip_netlink_encap_parms(data, &ipencap)) {
493 struct ip_tunnel *t = netdev_priv(dev);
494 int err = ip_tunnel_encap_setup(t, &ipencap);
495
496 if (err < 0)
497 return err;
498 }
499
500 ipip_netlink_parms(data, &p, &collect_md);
501 if (collect_md)
502 return -EINVAL;
503
504 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
505 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
506 return -EINVAL;
507
508 return ip_tunnel_changelink(dev, tb, &p);
509}
510
511static size_t ipip_get_size(const struct net_device *dev)
512{
513 return
514 /* IFLA_IPTUN_LINK */
515 nla_total_size(4) +
516 /* IFLA_IPTUN_LOCAL */
517 nla_total_size(4) +
518 /* IFLA_IPTUN_REMOTE */
519 nla_total_size(4) +
520 /* IFLA_IPTUN_TTL */
521 nla_total_size(1) +
522 /* IFLA_IPTUN_TOS */
523 nla_total_size(1) +
524 /* IFLA_IPTUN_PROTO */
525 nla_total_size(1) +
526 /* IFLA_IPTUN_PMTUDISC */
527 nla_total_size(1) +
528 /* IFLA_IPTUN_ENCAP_TYPE */
529 nla_total_size(2) +
530 /* IFLA_IPTUN_ENCAP_FLAGS */
531 nla_total_size(2) +
532 /* IFLA_IPTUN_ENCAP_SPORT */
533 nla_total_size(2) +
534 /* IFLA_IPTUN_ENCAP_DPORT */
535 nla_total_size(2) +
536 /* IFLA_IPTUN_COLLECT_METADATA */
537 nla_total_size(0) +
538 0;
539}
540
541static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
542{
543 struct ip_tunnel *tunnel = netdev_priv(dev);
544 struct ip_tunnel_parm *parm = &tunnel->parms;
545
546 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
547 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
548 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
549 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
550 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
551 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
552 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
553 !!(parm->iph.frag_off & htons(IP_DF))))
554 goto nla_put_failure;
555
556 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
557 tunnel->encap.type) ||
558 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
559 tunnel->encap.sport) ||
560 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
561 tunnel->encap.dport) ||
562 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
563 tunnel->encap.flags))
564 goto nla_put_failure;
565
566 if (tunnel->collect_md)
567 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
568 goto nla_put_failure;
569 return 0;
570
571nla_put_failure:
572 return -EMSGSIZE;
573}
574
575static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
576 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
577 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
578 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
579 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
580 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
581 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
582 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
583 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
584 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
585 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
586 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
587 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
588};
589
590static struct rtnl_link_ops ipip_link_ops __read_mostly = {
591 .kind = "ipip",
592 .maxtype = IFLA_IPTUN_MAX,
593 .policy = ipip_policy,
594 .priv_size = sizeof(struct ip_tunnel),
595 .setup = ipip_tunnel_setup,
596 .validate = ipip_tunnel_validate,
597 .newlink = ipip_newlink,
598 .changelink = ipip_changelink,
599 .dellink = ip_tunnel_dellink,
600 .get_size = ipip_get_size,
601 .fill_info = ipip_fill_info,
602 .get_link_net = ip_tunnel_get_link_net,
603};
604
605static struct xfrm_tunnel ipip_handler __read_mostly = {
606 .handler = ipip_rcv,
607 .err_handler = ipip_err,
608 .priority = 1,
609};
610
611#if IS_ENABLED(CONFIG_MPLS)
612static struct xfrm_tunnel mplsip_handler __read_mostly = {
613 .handler = mplsip_rcv,
614 .err_handler = ipip_err,
615 .priority = 1,
616};
617#endif
618
619static int __net_init ipip_init_net(struct net *net)
620{
621 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
622}
623
624static void __net_exit ipip_exit_net(struct net *net)
625{
626 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
627 ip_tunnel_delete_net(itn, &ipip_link_ops);
628}
629
630static struct pernet_operations ipip_net_ops = {
631 .init = ipip_init_net,
632 .exit = ipip_exit_net,
633 .id = &ipip_net_id,
634 .size = sizeof(struct ip_tunnel_net),
635};
636
637static int __init ipip_init(void)
638{
639 int err;
640
641 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
642
643 err = register_pernet_device(&ipip_net_ops);
644 if (err < 0)
645 return err;
646 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
647 if (err < 0) {
648 pr_info("%s: can't register tunnel\n", __func__);
649 goto xfrm_tunnel_ipip_failed;
650 }
651#if IS_ENABLED(CONFIG_MPLS)
652 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
653 if (err < 0) {
654 pr_info("%s: can't register tunnel\n", __func__);
655 goto xfrm_tunnel_mplsip_failed;
656 }
657#endif
658 err = rtnl_link_register(&ipip_link_ops);
659 if (err < 0)
660 goto rtnl_link_failed;
661
662out:
663 return err;
664
665rtnl_link_failed:
666#if IS_ENABLED(CONFIG_MPLS)
667 xfrm4_tunnel_deregister(&mplsip_handler, AF_INET);
668xfrm_tunnel_mplsip_failed:
669
670#endif
671 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
672xfrm_tunnel_ipip_failed:
673 unregister_pernet_device(&ipip_net_ops);
674 goto out;
675}
676
677static void __exit ipip_fini(void)
678{
679 rtnl_link_unregister(&ipip_link_ops);
680 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
681 pr_info("%s: can't deregister tunnel\n", __func__);
682#if IS_ENABLED(CONFIG_MPLS)
683 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
684 pr_info("%s: can't deregister tunnel\n", __func__);
685#endif
686 unregister_pernet_device(&ipip_net_ops);
687}
688
689module_init(ipip_init);
690module_exit(ipip_fini);
691MODULE_LICENSE("GPL");
692MODULE_ALIAS_RTNL_LINK("ipip");
693MODULE_ALIAS_NETDEV("tunl0");