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(dev: skb->dev);
131 struct ip_tunnel_net *itn = net_generic(net, id: 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, link: skb->dev->ifindex, flags, remote: iph->daddr,
142 local: iph->saddr, key: 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, mtu: info, oif: t->parms.link, protocol: iph->protocol);
177 goto out;
178 }
179
180 if (type == ICMP_REDIRECT) {
181 ipv4_redirect(skb, net, oif: t->parms.link, protocol: 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(dev: skb->dev);
218 struct ip_tunnel_net *itn = net_generic(net, id: 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, link: skb->dev->ifindex, flags, remote: iph->saddr,
228 local: iph->daddr, key: 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, dir: 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, hdr_len: 0, inner_proto: tpi->proto, xnet: 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, tunnel_id: 0, md_size: 0);
250 if (!tun_dst)
251 return 0;
252 ip_tunnel_md_udp_encap(skb, info: &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, gso_type_mask: 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, proto: ipproto, tunnel_hlen: 0);
315 else
316 ip_tunnel_xmit(skb, dev, tnl_params: tiph, protocol: 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(ipproto: 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 int ipip_fill_forward_path(struct net_device_path_ctx *ctx,
357 struct net_device_path *path)
358{
359 struct ip_tunnel *tunnel = netdev_priv(dev: ctx->dev);
360 const struct iphdr *tiph = &tunnel->parms.iph;
361 struct rtable *rt;
362
363 rt = ip_route_output(net: dev_net(dev: ctx->dev), daddr: tiph->daddr, saddr: 0, dscp: 0, oif: 0,
364 scope: RT_SCOPE_UNIVERSE);
365 if (IS_ERR(ptr: rt))
366 return PTR_ERR(ptr: rt);
367
368 path->type = DEV_PATH_TUN;
369 path->tun.src_v4.s_addr = tiph->saddr;
370 path->tun.dst_v4.s_addr = tiph->daddr;
371 path->tun.l3_proto = IPPROTO_IPIP;
372 path->dev = ctx->dev;
373
374 ctx->dev = rt->dst.dev;
375 ip_rt_put(rt);
376
377 return 0;
378}
379
380static const struct net_device_ops ipip_netdev_ops = {
381 .ndo_init = ipip_tunnel_init,
382 .ndo_uninit = ip_tunnel_uninit,
383 .ndo_start_xmit = ipip_tunnel_xmit,
384 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
385 .ndo_change_mtu = ip_tunnel_change_mtu,
386 .ndo_get_stats64 = dev_get_tstats64,
387 .ndo_get_iflink = ip_tunnel_get_iflink,
388 .ndo_tunnel_ctl = ipip_tunnel_ctl,
389 .ndo_fill_forward_path = ipip_fill_forward_path,
390};
391
392#define IPIP_FEATURES (NETIF_F_SG | \
393 NETIF_F_FRAGLIST | \
394 NETIF_F_HIGHDMA | \
395 NETIF_F_GSO_SOFTWARE | \
396 NETIF_F_HW_CSUM)
397
398static void ipip_tunnel_setup(struct net_device *dev)
399{
400 dev->netdev_ops = &ipip_netdev_ops;
401 dev->header_ops = &ip_tunnel_header_ops;
402
403 dev->type = ARPHRD_TUNNEL;
404 dev->flags = IFF_NOARP;
405 dev->addr_len = 4;
406 dev->lltx = true;
407 netif_keep_dst(dev);
408
409 dev->features |= IPIP_FEATURES;
410 dev->hw_features |= IPIP_FEATURES;
411 ip_tunnel_setup(dev, net_id: ipip_net_id);
412}
413
414static int ipip_tunnel_init(struct net_device *dev)
415{
416 struct ip_tunnel *tunnel = netdev_priv(dev);
417
418 __dev_addr_set(dev, addr: &tunnel->parms.iph.saddr, len: 4);
419 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
420
421 tunnel->tun_hlen = 0;
422 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
423 return ip_tunnel_init(dev);
424}
425
426static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
427 struct netlink_ext_ack *extack)
428{
429 u8 proto;
430
431 if (!data || !data[IFLA_IPTUN_PROTO])
432 return 0;
433
434 proto = nla_get_u8(nla: data[IFLA_IPTUN_PROTO]);
435 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
436 return -EINVAL;
437
438 return 0;
439}
440
441static void ipip_netlink_parms(struct nlattr *data[],
442 struct ip_tunnel_parm_kern *parms,
443 bool *collect_md, __u32 *fwmark)
444{
445 memset(parms, 0, sizeof(*parms));
446
447 parms->iph.version = 4;
448 parms->iph.protocol = IPPROTO_IPIP;
449 parms->iph.ihl = 5;
450 *collect_md = false;
451
452 if (!data)
453 return;
454
455 ip_tunnel_netlink_parms(data, parms);
456
457 if (data[IFLA_IPTUN_COLLECT_METADATA])
458 *collect_md = true;
459
460 if (data[IFLA_IPTUN_FWMARK])
461 *fwmark = nla_get_u32(nla: data[IFLA_IPTUN_FWMARK]);
462}
463
464static int ipip_newlink(struct net_device *dev,
465 struct rtnl_newlink_params *params,
466 struct netlink_ext_ack *extack)
467{
468 struct ip_tunnel *t = netdev_priv(dev);
469 struct nlattr **data = params->data;
470 struct nlattr **tb = params->tb;
471 struct ip_tunnel_encap ipencap;
472 struct ip_tunnel_parm_kern p;
473 __u32 fwmark = 0;
474
475 if (ip_tunnel_netlink_encap_parms(data, encap: &ipencap)) {
476 int err = ip_tunnel_encap_setup(t, ipencap: &ipencap);
477
478 if (err < 0)
479 return err;
480 }
481
482 ipip_netlink_parms(data, parms: &p, collect_md: &t->collect_md, fwmark: &fwmark);
483 return ip_tunnel_newlink(net: params->link_net ? : dev_net(dev), dev, tb, p: &p,
484 fwmark);
485}
486
487static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
488 struct nlattr *data[],
489 struct netlink_ext_ack *extack)
490{
491 struct ip_tunnel *t = netdev_priv(dev);
492 struct ip_tunnel_encap ipencap;
493 struct ip_tunnel_parm_kern p;
494 bool collect_md;
495 __u32 fwmark = t->fwmark;
496
497 if (ip_tunnel_netlink_encap_parms(data, encap: &ipencap)) {
498 int err = ip_tunnel_encap_setup(t, ipencap: &ipencap);
499
500 if (err < 0)
501 return err;
502 }
503
504 ipip_netlink_parms(data, parms: &p, collect_md: &collect_md, fwmark: &fwmark);
505 if (collect_md)
506 return -EINVAL;
507
508 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
509 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
510 return -EINVAL;
511
512 return ip_tunnel_changelink(dev, tb, p: &p, fwmark);
513}
514
515static size_t ipip_get_size(const struct net_device *dev)
516{
517 return
518 /* IFLA_IPTUN_LINK */
519 nla_total_size(payload: 4) +
520 /* IFLA_IPTUN_LOCAL */
521 nla_total_size(payload: 4) +
522 /* IFLA_IPTUN_REMOTE */
523 nla_total_size(payload: 4) +
524 /* IFLA_IPTUN_TTL */
525 nla_total_size(payload: 1) +
526 /* IFLA_IPTUN_TOS */
527 nla_total_size(payload: 1) +
528 /* IFLA_IPTUN_PROTO */
529 nla_total_size(payload: 1) +
530 /* IFLA_IPTUN_PMTUDISC */
531 nla_total_size(payload: 1) +
532 /* IFLA_IPTUN_ENCAP_TYPE */
533 nla_total_size(payload: 2) +
534 /* IFLA_IPTUN_ENCAP_FLAGS */
535 nla_total_size(payload: 2) +
536 /* IFLA_IPTUN_ENCAP_SPORT */
537 nla_total_size(payload: 2) +
538 /* IFLA_IPTUN_ENCAP_DPORT */
539 nla_total_size(payload: 2) +
540 /* IFLA_IPTUN_COLLECT_METADATA */
541 nla_total_size(payload: 0) +
542 /* IFLA_IPTUN_FWMARK */
543 nla_total_size(payload: 4) +
544 0;
545}
546
547static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
548{
549 struct ip_tunnel *tunnel = netdev_priv(dev);
550 struct ip_tunnel_parm_kern *parm = &tunnel->parms;
551
552 if (nla_put_u32(skb, attrtype: IFLA_IPTUN_LINK, value: parm->link) ||
553 nla_put_in_addr(skb, attrtype: IFLA_IPTUN_LOCAL, addr: parm->iph.saddr) ||
554 nla_put_in_addr(skb, attrtype: IFLA_IPTUN_REMOTE, addr: parm->iph.daddr) ||
555 nla_put_u8(skb, attrtype: IFLA_IPTUN_TTL, value: parm->iph.ttl) ||
556 nla_put_u8(skb, attrtype: IFLA_IPTUN_TOS, value: parm->iph.tos) ||
557 nla_put_u8(skb, attrtype: IFLA_IPTUN_PROTO, value: parm->iph.protocol) ||
558 nla_put_u8(skb, attrtype: IFLA_IPTUN_PMTUDISC,
559 value: !!(parm->iph.frag_off & htons(IP_DF))) ||
560 nla_put_u32(skb, attrtype: IFLA_IPTUN_FWMARK, value: tunnel->fwmark))
561 goto nla_put_failure;
562
563 if (nla_put_u16(skb, attrtype: IFLA_IPTUN_ENCAP_TYPE,
564 value: tunnel->encap.type) ||
565 nla_put_be16(skb, attrtype: IFLA_IPTUN_ENCAP_SPORT,
566 value: tunnel->encap.sport) ||
567 nla_put_be16(skb, attrtype: IFLA_IPTUN_ENCAP_DPORT,
568 value: tunnel->encap.dport) ||
569 nla_put_u16(skb, attrtype: IFLA_IPTUN_ENCAP_FLAGS,
570 value: tunnel->encap.flags))
571 goto nla_put_failure;
572
573 if (tunnel->collect_md)
574 if (nla_put_flag(skb, attrtype: IFLA_IPTUN_COLLECT_METADATA))
575 goto nla_put_failure;
576 return 0;
577
578nla_put_failure:
579 return -EMSGSIZE;
580}
581
582static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
583 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
584 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
585 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
586 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
587 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
588 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
589 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
590 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
591 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
592 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
593 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
594 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
595 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
596};
597
598static struct rtnl_link_ops ipip_link_ops __read_mostly = {
599 .kind = "ipip",
600 .maxtype = IFLA_IPTUN_MAX,
601 .policy = ipip_policy,
602 .priv_size = sizeof(struct ip_tunnel),
603 .setup = ipip_tunnel_setup,
604 .validate = ipip_tunnel_validate,
605 .newlink = ipip_newlink,
606 .changelink = ipip_changelink,
607 .dellink = ip_tunnel_dellink,
608 .get_size = ipip_get_size,
609 .fill_info = ipip_fill_info,
610 .get_link_net = ip_tunnel_get_link_net,
611};
612
613static struct xfrm_tunnel ipip_handler __read_mostly = {
614 .handler = ipip_rcv,
615 .err_handler = ipip_err,
616 .priority = 1,
617};
618
619#if IS_ENABLED(CONFIG_MPLS)
620static struct xfrm_tunnel mplsip_handler __read_mostly = {
621 .handler = mplsip_rcv,
622 .err_handler = ipip_err,
623 .priority = 1,
624};
625#endif
626
627static int __net_init ipip_init_net(struct net *net)
628{
629 return ip_tunnel_init_net(net, ip_tnl_net_id: ipip_net_id, ops: &ipip_link_ops, devname: "tunl0");
630}
631
632static void __net_exit ipip_exit_rtnl(struct net *net,
633 struct list_head *dev_to_kill)
634{
635 ip_tunnel_delete_net(net, id: ipip_net_id, ops: &ipip_link_ops, dev_to_kill);
636}
637
638static struct pernet_operations ipip_net_ops = {
639 .init = ipip_init_net,
640 .exit_rtnl = ipip_exit_rtnl,
641 .id = &ipip_net_id,
642 .size = sizeof(struct ip_tunnel_net),
643};
644
645static int __init ipip_init(void)
646{
647 int err;
648
649 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
650
651 err = register_pernet_device(&ipip_net_ops);
652 if (err < 0)
653 return err;
654 err = xfrm4_tunnel_register(handler: &ipip_handler, AF_INET);
655 if (err < 0) {
656 pr_info("%s: can't register tunnel\n", __func__);
657 goto xfrm_tunnel_ipip_failed;
658 }
659#if IS_ENABLED(CONFIG_MPLS)
660 err = xfrm4_tunnel_register(handler: &mplsip_handler, AF_MPLS);
661 if (err < 0) {
662 pr_info("%s: can't register tunnel\n", __func__);
663 goto xfrm_tunnel_mplsip_failed;
664 }
665#endif
666 err = rtnl_link_register(ops: &ipip_link_ops);
667 if (err < 0)
668 goto rtnl_link_failed;
669
670out:
671 return err;
672
673rtnl_link_failed:
674#if IS_ENABLED(CONFIG_MPLS)
675 xfrm4_tunnel_deregister(handler: &mplsip_handler, AF_MPLS);
676xfrm_tunnel_mplsip_failed:
677
678#endif
679 xfrm4_tunnel_deregister(handler: &ipip_handler, AF_INET);
680xfrm_tunnel_ipip_failed:
681 unregister_pernet_device(&ipip_net_ops);
682 goto out;
683}
684
685static void __exit ipip_fini(void)
686{
687 rtnl_link_unregister(ops: &ipip_link_ops);
688 if (xfrm4_tunnel_deregister(handler: &ipip_handler, AF_INET))
689 pr_info("%s: can't deregister tunnel\n", __func__);
690#if IS_ENABLED(CONFIG_MPLS)
691 if (xfrm4_tunnel_deregister(handler: &mplsip_handler, AF_MPLS))
692 pr_info("%s: can't deregister tunnel\n", __func__);
693#endif
694 unregister_pernet_device(&ipip_net_ops);
695}
696
697module_init(ipip_init);
698module_exit(ipip_fini);
699MODULE_DESCRIPTION("IP/IP protocol decoder library");
700MODULE_LICENSE("GPL");
701MODULE_ALIAS_RTNL_LINK("ipip");
702MODULE_ALIAS_NETDEV("tunl0");
703

source code of linux/net/ipv4/ipip.c