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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: IP/IP protocol decoder.
4 *
5 * Authors:
6 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
7 *
8 * Fixes:
9 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
10 * a module taking up 2 pages).
11 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
12 * to keep ip_forward happy.
13 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
14 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
15 * David Woodhouse : Perform some basic ICMP handling.
16 * IPIP Routing without decapsulation.
17 * Carlos Picoto : GRE over IP support
18 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
19 * I do not want to merge them together.
20 */
21
22/* tunnel.c: an IP tunnel driver
23
24 The purpose of this driver is to provide an IP tunnel through
25 which you can tunnel network traffic transparently across subnets.
26
27 This was written by looking at Nick Holloway's dummy driver
28 Thanks for the great code!
29
30 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
31
32 Minor tweaks:
33 Cleaned up the code a little and added some pre-1.3.0 tweaks.
34 dev->hard_header/hard_header_len changed to use no headers.
35 Comments/bracketing tweaked.
36 Made the tunnels use dev->name not tunnel: when error reporting.
37 Added tx_dropped stat
38
39 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
40
41 Reworked:
42 Changed to tunnel to destination gateway in addition to the
43 tunnel's pointopoint address
44 Almost completely rewritten
45 Note: There is currently no firewall or ICMP handling done.
46
47 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
48
49*/
50
51/* Things I wish I had known when writing the tunnel driver:
52
53 When the tunnel_xmit() function is called, the skb contains the
54 packet to be sent (plus a great deal of extra info), and dev
55 contains the tunnel device that _we_ are.
56
57 When we are passed a packet, we are expected to fill in the
58 source address with our source IP address.
59
60 What is the proper way to allocate, copy and free a buffer?
61 After you allocate it, it is a "0 length" chunk of memory
62 starting at zero. If you want to add headers to the buffer
63 later, you'll have to call "skb_reserve(skb, amount)" with
64 the amount of memory you want reserved. Then, you call
65 "skb_put(skb, amount)" with the amount of space you want in
66 the buffer. skb_put() returns a pointer to the top (#0) of
67 that buffer. skb->len is set to the amount of space you have
68 "allocated" with skb_put(). You can then write up to skb->len
69 bytes to that buffer. If you need more, you can call skb_put()
70 again with the additional amount of space you need. You can
71 find out how much more space you can allocate by calling
72 "skb_tailroom(skb)".
73 Now, to add header space, call "skb_push(skb, header_len)".
74 This creates space at the beginning of the buffer and returns
75 a pointer to this new space. If later you need to strip a
76 header from a buffer, call "skb_pull(skb, header_len)".
77 skb_headroom() will return how much space is left at the top
78 of the buffer (before the main data). Remember, this headroom
79 space must be reserved before the skb_put() function is called.
80 */
81
82/*
83 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
84
85 For comments look at net/ipv4/ip_gre.c --ANK
86 */
87
88
89#include <linux/capability.h>
90#include <linux/module.h>
91#include <linux/types.h>
92#include <linux/kernel.h>
93#include <linux/slab.h>
94#include <linux/uaccess.h>
95#include <linux/skbuff.h>
96#include <linux/netdevice.h>
97#include <linux/in.h>
98#include <linux/tcp.h>
99#include <linux/udp.h>
100#include <linux/if_arp.h>
101#include <linux/init.h>
102#include <linux/netfilter_ipv4.h>
103#include <linux/if_ether.h>
104
105#include <net/sock.h>
106#include <net/ip.h>
107#include <net/icmp.h>
108#include <net/ip_tunnels.h>
109#include <net/inet_ecn.h>
110#include <net/xfrm.h>
111#include <net/net_namespace.h>
112#include <net/netns/generic.h>
113#include <net/dst_metadata.h>
114
115static bool log_ecn_error = true;
116module_param(log_ecn_error, bool, 0644);
117MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118
119static unsigned int ipip_net_id __read_mostly;
120
121static int ipip_tunnel_init(struct net_device *dev);
122static struct rtnl_link_ops ipip_link_ops __read_mostly;
123
124static int ipip_err(struct sk_buff *skb, u32 info)
125{
126 /* All the routers (except for Linux) return only
127 * 8 bytes of packet payload. It means, that precise relaying of
128 * ICMP in the real Internet is absolutely infeasible.
129 */
130 struct net *net = dev_net(skb->dev);
131 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
132 const struct iphdr *iph = (const struct iphdr *)skb->data;
133 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
134 const int type = icmp_hdr(skb)->type;
135 const int code = icmp_hdr(skb)->code;
136 struct ip_tunnel *t;
137 int err = 0;
138
139 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
140
141 t = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->daddr,
142 iph->saddr, 0);
143 if (!t) {
144 err = -ENOENT;
145 goto out;
146 }
147
148 switch (type) {
149 case ICMP_DEST_UNREACH:
150 switch (code) {
151 case ICMP_SR_FAILED:
152 /* Impossible event. */
153 goto out;
154 default:
155 /* All others are translated to HOST_UNREACH.
156 * rfc2003 contains "deep thoughts" about NET_UNREACH,
157 * I believe they are just ether pollution. --ANK
158 */
159 break;
160 }
161 break;
162
163 case ICMP_TIME_EXCEEDED:
164 if (code != ICMP_EXC_TTL)
165 goto out;
166 break;
167
168 case ICMP_REDIRECT:
169 break;
170
171 default:
172 goto out;
173 }
174
175 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
176 ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
177 goto out;
178 }
179
180 if (type == ICMP_REDIRECT) {
181 ipv4_redirect(skb, net, t->parms.link, iph->protocol);
182 goto out;
183 }
184
185 if (t->parms.iph.daddr == 0) {
186 err = -ENOENT;
187 goto out;
188 }
189
190 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
191 goto out;
192
193 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
194 t->err_count++;
195 else
196 t->err_count = 1;
197 t->err_time = jiffies;
198
199out:
200 return err;
201}
202
203static const struct tnl_ptk_info ipip_tpi = {
204 /* no tunnel info required for ipip. */
205 .proto = htons(ETH_P_IP),
206};
207
208#if IS_ENABLED(CONFIG_MPLS)
209static const struct tnl_ptk_info mplsip_tpi = {
210 /* no tunnel info required for mplsip. */
211 .proto = htons(ETH_P_MPLS_UC),
212};
213#endif
214
215static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
216{
217 struct net *net = dev_net(skb->dev);
218 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
219 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
220 struct metadata_dst *tun_dst = NULL;
221 struct ip_tunnel *tunnel;
222 const struct iphdr *iph;
223
224 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
225
226 iph = ip_hdr(skb);
227 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->saddr,
228 iph->daddr, 0);
229 if (tunnel) {
230 const struct tnl_ptk_info *tpi;
231
232 if (tunnel->parms.iph.protocol != ipproto &&
233 tunnel->parms.iph.protocol != 0)
234 goto drop;
235
236 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
237 goto drop;
238#if IS_ENABLED(CONFIG_MPLS)
239 if (ipproto == IPPROTO_MPLS)
240 tpi = &mplsip_tpi;
241 else
242#endif
243 tpi = &ipip_tpi;
244 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
245 goto drop;
246 if (tunnel->collect_md) {
247 ip_tunnel_flags_zero(flags);
248
249 tun_dst = ip_tun_rx_dst(skb, flags, 0, 0);
250 if (!tun_dst)
251 return 0;
252 ip_tunnel_md_udp_encap(skb, &tun_dst->u.tun_info);
253 }
254 skb_reset_mac_header(skb);
255
256 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
257 }
258
259 return -1;
260
261drop:
262 kfree_skb(skb);
263 return 0;
264}
265
266static int ipip_rcv(struct sk_buff *skb)
267{
268 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
269}
270
271#if IS_ENABLED(CONFIG_MPLS)
272static int mplsip_rcv(struct sk_buff *skb)
273{
274 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
275}
276#endif
277
278/*
279 * This function assumes it is being called from dev_queue_xmit()
280 * and that skb is filled properly by that function.
281 */
282static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
283 struct net_device *dev)
284{
285 struct ip_tunnel *tunnel = netdev_priv(dev);
286 const struct iphdr *tiph = &tunnel->parms.iph;
287 u8 ipproto;
288
289 if (!pskb_inet_may_pull(skb))
290 goto tx_error;
291
292 switch (skb->protocol) {
293 case htons(ETH_P_IP):
294 ipproto = IPPROTO_IPIP;
295 break;
296#if IS_ENABLED(CONFIG_MPLS)
297 case htons(ETH_P_MPLS_UC):
298 ipproto = IPPROTO_MPLS;
299 break;
300#endif
301 default:
302 goto tx_error;
303 }
304
305 if (tiph->protocol != ipproto && tiph->protocol != 0)
306 goto tx_error;
307
308 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
309 goto tx_error;
310
311 skb_set_inner_ipproto(skb, ipproto);
312
313 if (tunnel->collect_md)
314 ip_md_tunnel_xmit(skb, dev, ipproto, 0);
315 else
316 ip_tunnel_xmit(skb, dev, tiph, ipproto);
317 return NETDEV_TX_OK;
318
319tx_error:
320 kfree_skb(skb);
321
322 DEV_STATS_INC(dev, tx_errors);
323 return NETDEV_TX_OK;
324}
325
326static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
327{
328 switch (ipproto) {
329 case 0:
330 case IPPROTO_IPIP:
331#if IS_ENABLED(CONFIG_MPLS)
332 case IPPROTO_MPLS:
333#endif
334 return true;
335 }
336
337 return false;
338}
339
340static int
341ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p, int cmd)
342{
343 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
344 if (p->iph.version != 4 ||
345 !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||
346 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
347 return -EINVAL;
348 }
349
350 p->i_key = p->o_key = 0;
351 ip_tunnel_flags_zero(p->i_flags);
352 ip_tunnel_flags_zero(p->o_flags);
353 return ip_tunnel_ctl(dev, p, cmd);
354}
355
356static const struct net_device_ops ipip_netdev_ops = {
357 .ndo_init = ipip_tunnel_init,
358 .ndo_uninit = ip_tunnel_uninit,
359 .ndo_start_xmit = ipip_tunnel_xmit,
360 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
361 .ndo_change_mtu = ip_tunnel_change_mtu,
362 .ndo_get_stats64 = dev_get_tstats64,
363 .ndo_get_iflink = ip_tunnel_get_iflink,
364 .ndo_tunnel_ctl = ipip_tunnel_ctl,
365};
366
367#define IPIP_FEATURES (NETIF_F_SG | \
368 NETIF_F_FRAGLIST | \
369 NETIF_F_HIGHDMA | \
370 NETIF_F_GSO_SOFTWARE | \
371 NETIF_F_HW_CSUM)
372
373static void ipip_tunnel_setup(struct net_device *dev)
374{
375 dev->netdev_ops = &ipip_netdev_ops;
376 dev->header_ops = &ip_tunnel_header_ops;
377
378 dev->type = ARPHRD_TUNNEL;
379 dev->flags = IFF_NOARP;
380 dev->addr_len = 4;
381 dev->lltx = true;
382 netif_keep_dst(dev);
383
384 dev->features |= IPIP_FEATURES;
385 dev->hw_features |= IPIP_FEATURES;
386 ip_tunnel_setup(dev, ipip_net_id);
387}
388
389static int ipip_tunnel_init(struct net_device *dev)
390{
391 struct ip_tunnel *tunnel = netdev_priv(dev);
392
393 __dev_addr_set(dev, &tunnel->parms.iph.saddr, 4);
394 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
395
396 tunnel->tun_hlen = 0;
397 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
398 return ip_tunnel_init(dev);
399}
400
401static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
402 struct netlink_ext_ack *extack)
403{
404 u8 proto;
405
406 if (!data || !data[IFLA_IPTUN_PROTO])
407 return 0;
408
409 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
410 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
411 return -EINVAL;
412
413 return 0;
414}
415
416static void ipip_netlink_parms(struct nlattr *data[],
417 struct ip_tunnel_parm_kern *parms,
418 bool *collect_md, __u32 *fwmark)
419{
420 memset(parms, 0, sizeof(*parms));
421
422 parms->iph.version = 4;
423 parms->iph.protocol = IPPROTO_IPIP;
424 parms->iph.ihl = 5;
425 *collect_md = false;
426
427 if (!data)
428 return;
429
430 ip_tunnel_netlink_parms(data, parms);
431
432 if (data[IFLA_IPTUN_COLLECT_METADATA])
433 *collect_md = true;
434
435 if (data[IFLA_IPTUN_FWMARK])
436 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
437}
438
439static int ipip_newlink(struct net *src_net, struct net_device *dev,
440 struct nlattr *tb[], struct nlattr *data[],
441 struct netlink_ext_ack *extack)
442{
443 struct ip_tunnel *t = netdev_priv(dev);
444 struct ip_tunnel_encap ipencap;
445 struct ip_tunnel_parm_kern p;
446 __u32 fwmark = 0;
447
448 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
449 int err = ip_tunnel_encap_setup(t, &ipencap);
450
451 if (err < 0)
452 return err;
453 }
454
455 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
456 return ip_tunnel_newlink(dev, tb, &p, fwmark);
457}
458
459static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
460 struct nlattr *data[],
461 struct netlink_ext_ack *extack)
462{
463 struct ip_tunnel *t = netdev_priv(dev);
464 struct ip_tunnel_encap ipencap;
465 struct ip_tunnel_parm_kern p;
466 bool collect_md;
467 __u32 fwmark = t->fwmark;
468
469 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
470 int err = ip_tunnel_encap_setup(t, &ipencap);
471
472 if (err < 0)
473 return err;
474 }
475
476 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
477 if (collect_md)
478 return -EINVAL;
479
480 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
481 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
482 return -EINVAL;
483
484 return ip_tunnel_changelink(dev, tb, &p, fwmark);
485}
486
487static size_t ipip_get_size(const struct net_device *dev)
488{
489 return
490 /* IFLA_IPTUN_LINK */
491 nla_total_size(4) +
492 /* IFLA_IPTUN_LOCAL */
493 nla_total_size(4) +
494 /* IFLA_IPTUN_REMOTE */
495 nla_total_size(4) +
496 /* IFLA_IPTUN_TTL */
497 nla_total_size(1) +
498 /* IFLA_IPTUN_TOS */
499 nla_total_size(1) +
500 /* IFLA_IPTUN_PROTO */
501 nla_total_size(1) +
502 /* IFLA_IPTUN_PMTUDISC */
503 nla_total_size(1) +
504 /* IFLA_IPTUN_ENCAP_TYPE */
505 nla_total_size(2) +
506 /* IFLA_IPTUN_ENCAP_FLAGS */
507 nla_total_size(2) +
508 /* IFLA_IPTUN_ENCAP_SPORT */
509 nla_total_size(2) +
510 /* IFLA_IPTUN_ENCAP_DPORT */
511 nla_total_size(2) +
512 /* IFLA_IPTUN_COLLECT_METADATA */
513 nla_total_size(0) +
514 /* IFLA_IPTUN_FWMARK */
515 nla_total_size(4) +
516 0;
517}
518
519static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
520{
521 struct ip_tunnel *tunnel = netdev_priv(dev);
522 struct ip_tunnel_parm_kern *parm = &tunnel->parms;
523
524 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
525 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
526 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
527 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
528 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
529 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
530 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
531 !!(parm->iph.frag_off & htons(IP_DF))) ||
532 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
533 goto nla_put_failure;
534
535 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
536 tunnel->encap.type) ||
537 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
538 tunnel->encap.sport) ||
539 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
540 tunnel->encap.dport) ||
541 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
542 tunnel->encap.flags))
543 goto nla_put_failure;
544
545 if (tunnel->collect_md)
546 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
547 goto nla_put_failure;
548 return 0;
549
550nla_put_failure:
551 return -EMSGSIZE;
552}
553
554static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
555 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
556 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
557 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
558 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
559 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
560 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
561 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
562 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
563 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
564 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
565 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
566 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
567 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
568};
569
570static struct rtnl_link_ops ipip_link_ops __read_mostly = {
571 .kind = "ipip",
572 .maxtype = IFLA_IPTUN_MAX,
573 .policy = ipip_policy,
574 .priv_size = sizeof(struct ip_tunnel),
575 .setup = ipip_tunnel_setup,
576 .validate = ipip_tunnel_validate,
577 .newlink = ipip_newlink,
578 .changelink = ipip_changelink,
579 .dellink = ip_tunnel_dellink,
580 .get_size = ipip_get_size,
581 .fill_info = ipip_fill_info,
582 .get_link_net = ip_tunnel_get_link_net,
583};
584
585static struct xfrm_tunnel ipip_handler __read_mostly = {
586 .handler = ipip_rcv,
587 .err_handler = ipip_err,
588 .priority = 1,
589};
590
591#if IS_ENABLED(CONFIG_MPLS)
592static struct xfrm_tunnel mplsip_handler __read_mostly = {
593 .handler = mplsip_rcv,
594 .err_handler = ipip_err,
595 .priority = 1,
596};
597#endif
598
599static int __net_init ipip_init_net(struct net *net)
600{
601 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
602}
603
604static void __net_exit ipip_exit_batch_rtnl(struct list_head *list_net,
605 struct list_head *dev_to_kill)
606{
607 ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops,
608 dev_to_kill);
609}
610
611static struct pernet_operations ipip_net_ops = {
612 .init = ipip_init_net,
613 .exit_batch_rtnl = ipip_exit_batch_rtnl,
614 .id = &ipip_net_id,
615 .size = sizeof(struct ip_tunnel_net),
616};
617
618static int __init ipip_init(void)
619{
620 int err;
621
622 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
623
624 err = register_pernet_device(&ipip_net_ops);
625 if (err < 0)
626 return err;
627 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
628 if (err < 0) {
629 pr_info("%s: can't register tunnel\n", __func__);
630 goto xfrm_tunnel_ipip_failed;
631 }
632#if IS_ENABLED(CONFIG_MPLS)
633 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
634 if (err < 0) {
635 pr_info("%s: can't register tunnel\n", __func__);
636 goto xfrm_tunnel_mplsip_failed;
637 }
638#endif
639 err = rtnl_link_register(&ipip_link_ops);
640 if (err < 0)
641 goto rtnl_link_failed;
642
643out:
644 return err;
645
646rtnl_link_failed:
647#if IS_ENABLED(CONFIG_MPLS)
648 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
649xfrm_tunnel_mplsip_failed:
650
651#endif
652 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
653xfrm_tunnel_ipip_failed:
654 unregister_pernet_device(&ipip_net_ops);
655 goto out;
656}
657
658static void __exit ipip_fini(void)
659{
660 rtnl_link_unregister(&ipip_link_ops);
661 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
662 pr_info("%s: can't deregister tunnel\n", __func__);
663#if IS_ENABLED(CONFIG_MPLS)
664 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
665 pr_info("%s: can't deregister tunnel\n", __func__);
666#endif
667 unregister_pernet_device(&ipip_net_ops);
668}
669
670module_init(ipip_init);
671module_exit(ipip_fini);
672MODULE_DESCRIPTION("IP/IP protocol decoder library");
673MODULE_LICENSE("GPL");
674MODULE_ALIAS_RTNL_LINK("ipip");
675MODULE_ALIAS_NETDEV("tunl0");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: IP/IP protocol decoder.
4 *
5 * Authors:
6 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
7 *
8 * Fixes:
9 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
10 * a module taking up 2 pages).
11 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
12 * to keep ip_forward happy.
13 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
14 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
15 * David Woodhouse : Perform some basic ICMP handling.
16 * IPIP Routing without decapsulation.
17 * Carlos Picoto : GRE over IP support
18 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
19 * I do not want to merge them together.
20 */
21
22/* tunnel.c: an IP tunnel driver
23
24 The purpose of this driver is to provide an IP tunnel through
25 which you can tunnel network traffic transparently across subnets.
26
27 This was written by looking at Nick Holloway's dummy driver
28 Thanks for the great code!
29
30 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
31
32 Minor tweaks:
33 Cleaned up the code a little and added some pre-1.3.0 tweaks.
34 dev->hard_header/hard_header_len changed to use no headers.
35 Comments/bracketing tweaked.
36 Made the tunnels use dev->name not tunnel: when error reporting.
37 Added tx_dropped stat
38
39 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
40
41 Reworked:
42 Changed to tunnel to destination gateway in addition to the
43 tunnel's pointopoint address
44 Almost completely rewritten
45 Note: There is currently no firewall or ICMP handling done.
46
47 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
48
49*/
50
51/* Things I wish I had known when writing the tunnel driver:
52
53 When the tunnel_xmit() function is called, the skb contains the
54 packet to be sent (plus a great deal of extra info), and dev
55 contains the tunnel device that _we_ are.
56
57 When we are passed a packet, we are expected to fill in the
58 source address with our source IP address.
59
60 What is the proper way to allocate, copy and free a buffer?
61 After you allocate it, it is a "0 length" chunk of memory
62 starting at zero. If you want to add headers to the buffer
63 later, you'll have to call "skb_reserve(skb, amount)" with
64 the amount of memory you want reserved. Then, you call
65 "skb_put(skb, amount)" with the amount of space you want in
66 the buffer. skb_put() returns a pointer to the top (#0) of
67 that buffer. skb->len is set to the amount of space you have
68 "allocated" with skb_put(). You can then write up to skb->len
69 bytes to that buffer. If you need more, you can call skb_put()
70 again with the additional amount of space you need. You can
71 find out how much more space you can allocate by calling
72 "skb_tailroom(skb)".
73 Now, to add header space, call "skb_push(skb, header_len)".
74 This creates space at the beginning of the buffer and returns
75 a pointer to this new space. If later you need to strip a
76 header from a buffer, call "skb_pull(skb, header_len)".
77 skb_headroom() will return how much space is left at the top
78 of the buffer (before the main data). Remember, this headroom
79 space must be reserved before the skb_put() function is called.
80 */
81
82/*
83 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
84
85 For comments look at net/ipv4/ip_gre.c --ANK
86 */
87
88
89#include <linux/capability.h>
90#include <linux/module.h>
91#include <linux/types.h>
92#include <linux/kernel.h>
93#include <linux/slab.h>
94#include <linux/uaccess.h>
95#include <linux/skbuff.h>
96#include <linux/netdevice.h>
97#include <linux/in.h>
98#include <linux/tcp.h>
99#include <linux/udp.h>
100#include <linux/if_arp.h>
101#include <linux/init.h>
102#include <linux/netfilter_ipv4.h>
103#include <linux/if_ether.h>
104
105#include <net/sock.h>
106#include <net/ip.h>
107#include <net/icmp.h>
108#include <net/ip_tunnels.h>
109#include <net/inet_ecn.h>
110#include <net/xfrm.h>
111#include <net/net_namespace.h>
112#include <net/netns/generic.h>
113#include <net/dst_metadata.h>
114
115static bool log_ecn_error = true;
116module_param(log_ecn_error, bool, 0644);
117MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118
119static unsigned int ipip_net_id __read_mostly;
120
121static int ipip_tunnel_init(struct net_device *dev);
122static struct rtnl_link_ops ipip_link_ops __read_mostly;
123
124static int ipip_err(struct sk_buff *skb, u32 info)
125{
126 /* All the routers (except for Linux) return only
127 * 8 bytes of packet payload. It means, that precise relaying of
128 * ICMP in the real Internet is absolutely infeasible.
129 */
130 struct net *net = dev_net(skb->dev);
131 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
132 const struct iphdr *iph = (const struct iphdr *)skb->data;
133 const int type = icmp_hdr(skb)->type;
134 const int code = icmp_hdr(skb)->code;
135 struct ip_tunnel *t;
136 int err = 0;
137
138 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
139 iph->daddr, iph->saddr, 0);
140 if (!t) {
141 err = -ENOENT;
142 goto out;
143 }
144
145 switch (type) {
146 case ICMP_DEST_UNREACH:
147 switch (code) {
148 case ICMP_SR_FAILED:
149 /* Impossible event. */
150 goto out;
151 default:
152 /* All others are translated to HOST_UNREACH.
153 * rfc2003 contains "deep thoughts" about NET_UNREACH,
154 * I believe they are just ether pollution. --ANK
155 */
156 break;
157 }
158 break;
159
160 case ICMP_TIME_EXCEEDED:
161 if (code != ICMP_EXC_TTL)
162 goto out;
163 break;
164
165 case ICMP_REDIRECT:
166 break;
167
168 default:
169 goto out;
170 }
171
172 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
173 ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
174 goto out;
175 }
176
177 if (type == ICMP_REDIRECT) {
178 ipv4_redirect(skb, net, t->parms.link, iph->protocol);
179 goto out;
180 }
181
182 if (t->parms.iph.daddr == 0) {
183 err = -ENOENT;
184 goto out;
185 }
186
187 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
188 goto out;
189
190 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
191 t->err_count++;
192 else
193 t->err_count = 1;
194 t->err_time = jiffies;
195
196out:
197 return err;
198}
199
200static const struct tnl_ptk_info ipip_tpi = {
201 /* no tunnel info required for ipip. */
202 .proto = htons(ETH_P_IP),
203};
204
205#if IS_ENABLED(CONFIG_MPLS)
206static const struct tnl_ptk_info mplsip_tpi = {
207 /* no tunnel info required for mplsip. */
208 .proto = htons(ETH_P_MPLS_UC),
209};
210#endif
211
212static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
213{
214 struct net *net = dev_net(skb->dev);
215 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
216 struct metadata_dst *tun_dst = NULL;
217 struct ip_tunnel *tunnel;
218 const struct iphdr *iph;
219
220 iph = ip_hdr(skb);
221 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
222 iph->saddr, iph->daddr, 0);
223 if (tunnel) {
224 const struct tnl_ptk_info *tpi;
225
226 if (tunnel->parms.iph.protocol != ipproto &&
227 tunnel->parms.iph.protocol != 0)
228 goto drop;
229
230 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
231 goto drop;
232#if IS_ENABLED(CONFIG_MPLS)
233 if (ipproto == IPPROTO_MPLS)
234 tpi = &mplsip_tpi;
235 else
236#endif
237 tpi = &ipip_tpi;
238 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
239 goto drop;
240 if (tunnel->collect_md) {
241 tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
242 if (!tun_dst)
243 return 0;
244 }
245 skb_reset_mac_header(skb);
246
247 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
248 }
249
250 return -1;
251
252drop:
253 kfree_skb(skb);
254 return 0;
255}
256
257static int ipip_rcv(struct sk_buff *skb)
258{
259 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
260}
261
262#if IS_ENABLED(CONFIG_MPLS)
263static int mplsip_rcv(struct sk_buff *skb)
264{
265 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
266}
267#endif
268
269/*
270 * This function assumes it is being called from dev_queue_xmit()
271 * and that skb is filled properly by that function.
272 */
273static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
274 struct net_device *dev)
275{
276 struct ip_tunnel *tunnel = netdev_priv(dev);
277 const struct iphdr *tiph = &tunnel->parms.iph;
278 u8 ipproto;
279
280 if (!pskb_inet_may_pull(skb))
281 goto tx_error;
282
283 switch (skb->protocol) {
284 case htons(ETH_P_IP):
285 ipproto = IPPROTO_IPIP;
286 break;
287#if IS_ENABLED(CONFIG_MPLS)
288 case htons(ETH_P_MPLS_UC):
289 ipproto = IPPROTO_MPLS;
290 break;
291#endif
292 default:
293 goto tx_error;
294 }
295
296 if (tiph->protocol != ipproto && tiph->protocol != 0)
297 goto tx_error;
298
299 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
300 goto tx_error;
301
302 skb_set_inner_ipproto(skb, ipproto);
303
304 if (tunnel->collect_md)
305 ip_md_tunnel_xmit(skb, dev, ipproto, 0);
306 else
307 ip_tunnel_xmit(skb, dev, tiph, ipproto);
308 return NETDEV_TX_OK;
309
310tx_error:
311 kfree_skb(skb);
312
313 DEV_STATS_INC(dev, tx_errors);
314 return NETDEV_TX_OK;
315}
316
317static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
318{
319 switch (ipproto) {
320 case 0:
321 case IPPROTO_IPIP:
322#if IS_ENABLED(CONFIG_MPLS)
323 case IPPROTO_MPLS:
324#endif
325 return true;
326 }
327
328 return false;
329}
330
331static int
332ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
333{
334 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
335 if (p->iph.version != 4 ||
336 !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||
337 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
338 return -EINVAL;
339 }
340
341 p->i_key = p->o_key = 0;
342 p->i_flags = p->o_flags = 0;
343 return ip_tunnel_ctl(dev, p, cmd);
344}
345
346static const struct net_device_ops ipip_netdev_ops = {
347 .ndo_init = ipip_tunnel_init,
348 .ndo_uninit = ip_tunnel_uninit,
349 .ndo_start_xmit = ipip_tunnel_xmit,
350 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
351 .ndo_change_mtu = ip_tunnel_change_mtu,
352 .ndo_get_stats64 = dev_get_tstats64,
353 .ndo_get_iflink = ip_tunnel_get_iflink,
354 .ndo_tunnel_ctl = ipip_tunnel_ctl,
355};
356
357#define IPIP_FEATURES (NETIF_F_SG | \
358 NETIF_F_FRAGLIST | \
359 NETIF_F_HIGHDMA | \
360 NETIF_F_GSO_SOFTWARE | \
361 NETIF_F_HW_CSUM)
362
363static void ipip_tunnel_setup(struct net_device *dev)
364{
365 dev->netdev_ops = &ipip_netdev_ops;
366 dev->header_ops = &ip_tunnel_header_ops;
367
368 dev->type = ARPHRD_TUNNEL;
369 dev->flags = IFF_NOARP;
370 dev->addr_len = 4;
371 dev->features |= NETIF_F_LLTX;
372 netif_keep_dst(dev);
373
374 dev->features |= IPIP_FEATURES;
375 dev->hw_features |= IPIP_FEATURES;
376 ip_tunnel_setup(dev, ipip_net_id);
377}
378
379static int ipip_tunnel_init(struct net_device *dev)
380{
381 struct ip_tunnel *tunnel = netdev_priv(dev);
382
383 __dev_addr_set(dev, &tunnel->parms.iph.saddr, 4);
384 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
385
386 tunnel->tun_hlen = 0;
387 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
388 return ip_tunnel_init(dev);
389}
390
391static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
392 struct netlink_ext_ack *extack)
393{
394 u8 proto;
395
396 if (!data || !data[IFLA_IPTUN_PROTO])
397 return 0;
398
399 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
400 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
401 return -EINVAL;
402
403 return 0;
404}
405
406static void ipip_netlink_parms(struct nlattr *data[],
407 struct ip_tunnel_parm *parms, bool *collect_md,
408 __u32 *fwmark)
409{
410 memset(parms, 0, sizeof(*parms));
411
412 parms->iph.version = 4;
413 parms->iph.protocol = IPPROTO_IPIP;
414 parms->iph.ihl = 5;
415 *collect_md = false;
416
417 if (!data)
418 return;
419
420 ip_tunnel_netlink_parms(data, parms);
421
422 if (data[IFLA_IPTUN_COLLECT_METADATA])
423 *collect_md = true;
424
425 if (data[IFLA_IPTUN_FWMARK])
426 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
427}
428
429static int ipip_newlink(struct net *src_net, struct net_device *dev,
430 struct nlattr *tb[], struct nlattr *data[],
431 struct netlink_ext_ack *extack)
432{
433 struct ip_tunnel *t = netdev_priv(dev);
434 struct ip_tunnel_parm p;
435 struct ip_tunnel_encap ipencap;
436 __u32 fwmark = 0;
437
438 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
439 int err = ip_tunnel_encap_setup(t, &ipencap);
440
441 if (err < 0)
442 return err;
443 }
444
445 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
446 return ip_tunnel_newlink(dev, tb, &p, fwmark);
447}
448
449static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
450 struct nlattr *data[],
451 struct netlink_ext_ack *extack)
452{
453 struct ip_tunnel *t = netdev_priv(dev);
454 struct ip_tunnel_parm p;
455 struct ip_tunnel_encap ipencap;
456 bool collect_md;
457 __u32 fwmark = t->fwmark;
458
459 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
460 int err = ip_tunnel_encap_setup(t, &ipencap);
461
462 if (err < 0)
463 return err;
464 }
465
466 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
467 if (collect_md)
468 return -EINVAL;
469
470 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
471 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
472 return -EINVAL;
473
474 return ip_tunnel_changelink(dev, tb, &p, fwmark);
475}
476
477static size_t ipip_get_size(const struct net_device *dev)
478{
479 return
480 /* IFLA_IPTUN_LINK */
481 nla_total_size(4) +
482 /* IFLA_IPTUN_LOCAL */
483 nla_total_size(4) +
484 /* IFLA_IPTUN_REMOTE */
485 nla_total_size(4) +
486 /* IFLA_IPTUN_TTL */
487 nla_total_size(1) +
488 /* IFLA_IPTUN_TOS */
489 nla_total_size(1) +
490 /* IFLA_IPTUN_PROTO */
491 nla_total_size(1) +
492 /* IFLA_IPTUN_PMTUDISC */
493 nla_total_size(1) +
494 /* IFLA_IPTUN_ENCAP_TYPE */
495 nla_total_size(2) +
496 /* IFLA_IPTUN_ENCAP_FLAGS */
497 nla_total_size(2) +
498 /* IFLA_IPTUN_ENCAP_SPORT */
499 nla_total_size(2) +
500 /* IFLA_IPTUN_ENCAP_DPORT */
501 nla_total_size(2) +
502 /* IFLA_IPTUN_COLLECT_METADATA */
503 nla_total_size(0) +
504 /* IFLA_IPTUN_FWMARK */
505 nla_total_size(4) +
506 0;
507}
508
509static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
510{
511 struct ip_tunnel *tunnel = netdev_priv(dev);
512 struct ip_tunnel_parm *parm = &tunnel->parms;
513
514 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
515 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
516 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
517 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
518 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
519 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
520 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
521 !!(parm->iph.frag_off & htons(IP_DF))) ||
522 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
523 goto nla_put_failure;
524
525 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
526 tunnel->encap.type) ||
527 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
528 tunnel->encap.sport) ||
529 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
530 tunnel->encap.dport) ||
531 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
532 tunnel->encap.flags))
533 goto nla_put_failure;
534
535 if (tunnel->collect_md)
536 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
537 goto nla_put_failure;
538 return 0;
539
540nla_put_failure:
541 return -EMSGSIZE;
542}
543
544static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
545 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
546 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
547 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
548 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
549 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
550 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
551 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
552 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
553 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
554 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
555 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
556 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
557 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
558};
559
560static struct rtnl_link_ops ipip_link_ops __read_mostly = {
561 .kind = "ipip",
562 .maxtype = IFLA_IPTUN_MAX,
563 .policy = ipip_policy,
564 .priv_size = sizeof(struct ip_tunnel),
565 .setup = ipip_tunnel_setup,
566 .validate = ipip_tunnel_validate,
567 .newlink = ipip_newlink,
568 .changelink = ipip_changelink,
569 .dellink = ip_tunnel_dellink,
570 .get_size = ipip_get_size,
571 .fill_info = ipip_fill_info,
572 .get_link_net = ip_tunnel_get_link_net,
573};
574
575static struct xfrm_tunnel ipip_handler __read_mostly = {
576 .handler = ipip_rcv,
577 .err_handler = ipip_err,
578 .priority = 1,
579};
580
581#if IS_ENABLED(CONFIG_MPLS)
582static struct xfrm_tunnel mplsip_handler __read_mostly = {
583 .handler = mplsip_rcv,
584 .err_handler = ipip_err,
585 .priority = 1,
586};
587#endif
588
589static int __net_init ipip_init_net(struct net *net)
590{
591 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
592}
593
594static void __net_exit ipip_exit_batch_net(struct list_head *list_net)
595{
596 ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops);
597}
598
599static struct pernet_operations ipip_net_ops = {
600 .init = ipip_init_net,
601 .exit_batch = ipip_exit_batch_net,
602 .id = &ipip_net_id,
603 .size = sizeof(struct ip_tunnel_net),
604};
605
606static int __init ipip_init(void)
607{
608 int err;
609
610 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
611
612 err = register_pernet_device(&ipip_net_ops);
613 if (err < 0)
614 return err;
615 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
616 if (err < 0) {
617 pr_info("%s: can't register tunnel\n", __func__);
618 goto xfrm_tunnel_ipip_failed;
619 }
620#if IS_ENABLED(CONFIG_MPLS)
621 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
622 if (err < 0) {
623 pr_info("%s: can't register tunnel\n", __func__);
624 goto xfrm_tunnel_mplsip_failed;
625 }
626#endif
627 err = rtnl_link_register(&ipip_link_ops);
628 if (err < 0)
629 goto rtnl_link_failed;
630
631out:
632 return err;
633
634rtnl_link_failed:
635#if IS_ENABLED(CONFIG_MPLS)
636 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
637xfrm_tunnel_mplsip_failed:
638
639#endif
640 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
641xfrm_tunnel_ipip_failed:
642 unregister_pernet_device(&ipip_net_ops);
643 goto out;
644}
645
646static void __exit ipip_fini(void)
647{
648 rtnl_link_unregister(&ipip_link_ops);
649 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
650 pr_info("%s: can't deregister tunnel\n", __func__);
651#if IS_ENABLED(CONFIG_MPLS)
652 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
653 pr_info("%s: can't deregister tunnel\n", __func__);
654#endif
655 unregister_pernet_device(&ipip_net_ops);
656}
657
658module_init(ipip_init);
659module_exit(ipip_fini);
660MODULE_LICENSE("GPL");
661MODULE_ALIAS_RTNL_LINK("ipip");
662MODULE_ALIAS_NETDEV("tunl0");