1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: IP/IP protocol decoder modified to support
4 * virtual tunnel interface
5 *
6 * Authors:
7 * Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
8 */
9
10/*
11 This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
12
13 For comments look at net/ipv4/ip_gre.c --ANK
14 */
15
16
17#include <linux/capability.h>
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/uaccess.h>
22#include <linux/skbuff.h>
23#include <linux/netdevice.h>
24#include <linux/in.h>
25#include <linux/tcp.h>
26#include <linux/udp.h>
27#include <linux/if_arp.h>
28#include <linux/init.h>
29#include <linux/netfilter_ipv4.h>
30#include <linux/if_ether.h>
31#include <linux/icmpv6.h>
32
33#include <net/sock.h>
34#include <net/ip.h>
35#include <net/icmp.h>
36#include <net/ip_tunnels.h>
37#include <net/inet_ecn.h>
38#include <net/xfrm.h>
39#include <net/net_namespace.h>
40#include <net/netns/generic.h>
41
42static struct rtnl_link_ops vti_link_ops __read_mostly;
43
44static unsigned int vti_net_id __read_mostly;
45static int vti_tunnel_init(struct net_device *dev);
46
47static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
48 int encap_type, bool update_skb_dev)
49{
50 struct ip_tunnel *tunnel;
51 const struct iphdr *iph = ip_hdr(skb);
52 struct net *net = dev_net(dev: skb->dev);
53 struct ip_tunnel_net *itn = net_generic(net, id: vti_net_id);
54
55 tunnel = ip_tunnel_lookup(itn, link: skb->dev->ifindex, TUNNEL_NO_KEY,
56 remote: iph->saddr, local: iph->daddr, key: 0);
57 if (tunnel) {
58 if (!xfrm4_policy_check(NULL, dir: XFRM_POLICY_IN, skb))
59 goto drop;
60
61 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
62
63 if (update_skb_dev)
64 skb->dev = tunnel->dev;
65
66 return xfrm_input(skb, nexthdr, spi, encap_type);
67 }
68
69 return -EINVAL;
70drop:
71 kfree_skb(skb);
72 return 0;
73}
74
75static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
76 int encap_type)
77{
78 return vti_input(skb, nexthdr, spi, encap_type, update_skb_dev: false);
79}
80
81static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev)
82{
83 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
84 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
85
86 return vti_input(skb, nexthdr: ip_hdr(skb)->protocol, spi, encap_type: 0, update_skb_dev);
87}
88
89static int vti_rcv_proto(struct sk_buff *skb)
90{
91 return vti_rcv(skb, spi: 0, update_skb_dev: false);
92}
93
94static int vti_rcv_cb(struct sk_buff *skb, int err)
95{
96 unsigned short family;
97 struct net_device *dev;
98 struct xfrm_state *x;
99 const struct xfrm_mode *inner_mode;
100 struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
101 u32 orig_mark = skb->mark;
102 int ret;
103
104 if (!tunnel)
105 return 1;
106
107 dev = tunnel->dev;
108
109 if (err) {
110 DEV_STATS_INC(dev, rx_errors);
111 DEV_STATS_INC(dev, rx_dropped);
112
113 return 0;
114 }
115
116 x = xfrm_input_state(skb);
117
118 inner_mode = &x->inner_mode;
119
120 if (x->sel.family == AF_UNSPEC) {
121 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
122 if (inner_mode == NULL) {
123 XFRM_INC_STATS(dev_net(skb->dev),
124 LINUX_MIB_XFRMINSTATEMODEERROR);
125 return -EINVAL;
126 }
127 }
128
129 family = inner_mode->family;
130
131 skb->mark = be32_to_cpu(tunnel->parms.i_key);
132 ret = xfrm_policy_check(NULL, dir: XFRM_POLICY_IN, skb, family);
133 skb->mark = orig_mark;
134
135 if (!ret)
136 return -EPERM;
137
138 skb_scrub_packet(skb, xnet: !net_eq(net1: tunnel->net, net2: dev_net(dev: skb->dev)));
139 skb->dev = dev;
140 dev_sw_netstats_rx_add(dev, len: skb->len);
141
142 return 0;
143}
144
145static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
146{
147 xfrm_address_t *daddr = (xfrm_address_t *)&dst;
148 xfrm_address_t *saddr = (xfrm_address_t *)&src;
149
150 /* if there is no transform then this tunnel is not functional.
151 * Or if the xfrm is not mode tunnel.
152 */
153 if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
154 x->props.family != AF_INET)
155 return false;
156
157 if (!dst)
158 return xfrm_addr_equal(a: saddr, b: &x->props.saddr, AF_INET);
159
160 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
161 return false;
162
163 return true;
164}
165
166static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
167 struct flowi *fl)
168{
169 struct ip_tunnel *tunnel = netdev_priv(dev);
170 struct ip_tunnel_parm *parms = &tunnel->parms;
171 struct dst_entry *dst = skb_dst(skb);
172 struct net_device *tdev; /* Device to other host */
173 int pkt_len = skb->len;
174 int err;
175 int mtu;
176
177 if (!dst) {
178 switch (skb->protocol) {
179 case htons(ETH_P_IP): {
180 struct rtable *rt;
181
182 fl->u.ip4.flowi4_oif = dev->ifindex;
183 fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
184 rt = __ip_route_output_key(net: dev_net(dev), flp: &fl->u.ip4);
185 if (IS_ERR(ptr: rt)) {
186 DEV_STATS_INC(dev, tx_carrier_errors);
187 goto tx_error_icmp;
188 }
189 dst = &rt->dst;
190 skb_dst_set(skb, dst);
191 break;
192 }
193#if IS_ENABLED(CONFIG_IPV6)
194 case htons(ETH_P_IPV6):
195 fl->u.ip6.flowi6_oif = dev->ifindex;
196 fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
197 dst = ip6_route_output(net: dev_net(dev), NULL, fl6: &fl->u.ip6);
198 if (dst->error) {
199 dst_release(dst);
200 dst = NULL;
201 DEV_STATS_INC(dev, tx_carrier_errors);
202 goto tx_error_icmp;
203 }
204 skb_dst_set(skb, dst);
205 break;
206#endif
207 default:
208 DEV_STATS_INC(dev, tx_carrier_errors);
209 goto tx_error_icmp;
210 }
211 }
212
213 dst_hold(dst);
214 dst = xfrm_lookup_route(net: tunnel->net, dst_orig: dst, fl, NULL, flags: 0);
215 if (IS_ERR(ptr: dst)) {
216 DEV_STATS_INC(dev, tx_carrier_errors);
217 goto tx_error_icmp;
218 }
219
220 if (dst->flags & DST_XFRM_QUEUE)
221 goto xmit;
222
223 if (!vti_state_check(x: dst->xfrm, dst: parms->iph.daddr, src: parms->iph.saddr)) {
224 DEV_STATS_INC(dev, tx_carrier_errors);
225 dst_release(dst);
226 goto tx_error_icmp;
227 }
228
229 tdev = dst->dev;
230
231 if (tdev == dev) {
232 dst_release(dst);
233 DEV_STATS_INC(dev, collisions);
234 goto tx_error;
235 }
236
237 mtu = dst_mtu(dst);
238 if (skb->len > mtu) {
239 skb_dst_update_pmtu_no_confirm(skb, mtu);
240 if (skb->protocol == htons(ETH_P_IP)) {
241 if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
242 goto xmit;
243 icmp_ndo_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
244 htonl(mtu));
245 } else {
246 if (mtu < IPV6_MIN_MTU)
247 mtu = IPV6_MIN_MTU;
248
249 icmpv6_ndo_send(skb_in: skb, ICMPV6_PKT_TOOBIG, code: 0, info: mtu);
250 }
251
252 dst_release(dst);
253 goto tx_error;
254 }
255
256xmit:
257 skb_scrub_packet(skb, xnet: !net_eq(net1: tunnel->net, net2: dev_net(dev)));
258 skb_dst_set(skb, dst);
259 skb->dev = skb_dst(skb)->dev;
260
261 err = dst_output(net: tunnel->net, sk: skb->sk, skb);
262 if (net_xmit_eval(err) == 0)
263 err = pkt_len;
264 iptunnel_xmit_stats(dev, pkt_len: err);
265 return NETDEV_TX_OK;
266
267tx_error_icmp:
268 dst_link_failure(skb);
269tx_error:
270 DEV_STATS_INC(dev, tx_errors);
271 kfree_skb(skb);
272 return NETDEV_TX_OK;
273}
274
275/* This function assumes it is being called from dev_queue_xmit()
276 * and that skb is filled properly by that function.
277 */
278static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
279{
280 struct ip_tunnel *tunnel = netdev_priv(dev);
281 struct flowi fl;
282
283 if (!pskb_inet_may_pull(skb))
284 goto tx_err;
285
286 memset(&fl, 0, sizeof(fl));
287
288 switch (skb->protocol) {
289 case htons(ETH_P_IP):
290 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
291 xfrm_decode_session(net: dev_net(dev), skb, fl: &fl, AF_INET);
292 break;
293 case htons(ETH_P_IPV6):
294 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
295 xfrm_decode_session(net: dev_net(dev), skb, fl: &fl, AF_INET6);
296 break;
297 default:
298 goto tx_err;
299 }
300
301 /* override mark with tunnel output key */
302 fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
303
304 return vti_xmit(skb, dev, fl: &fl);
305
306tx_err:
307 DEV_STATS_INC(dev, tx_errors);
308 kfree_skb(skb);
309 return NETDEV_TX_OK;
310}
311
312static int vti4_err(struct sk_buff *skb, u32 info)
313{
314 __be32 spi;
315 __u32 mark;
316 struct xfrm_state *x;
317 struct ip_tunnel *tunnel;
318 struct ip_esp_hdr *esph;
319 struct ip_auth_hdr *ah ;
320 struct ip_comp_hdr *ipch;
321 struct net *net = dev_net(dev: skb->dev);
322 const struct iphdr *iph = (const struct iphdr *)skb->data;
323 int protocol = iph->protocol;
324 struct ip_tunnel_net *itn = net_generic(net, id: vti_net_id);
325
326 tunnel = ip_tunnel_lookup(itn, link: skb->dev->ifindex, TUNNEL_NO_KEY,
327 remote: iph->daddr, local: iph->saddr, key: 0);
328 if (!tunnel)
329 return -1;
330
331 mark = be32_to_cpu(tunnel->parms.o_key);
332
333 switch (protocol) {
334 case IPPROTO_ESP:
335 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
336 spi = esph->spi;
337 break;
338 case IPPROTO_AH:
339 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
340 spi = ah->spi;
341 break;
342 case IPPROTO_COMP:
343 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
344 spi = htonl(ntohs(ipch->cpi));
345 break;
346 default:
347 return 0;
348 }
349
350 switch (icmp_hdr(skb)->type) {
351 case ICMP_DEST_UNREACH:
352 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
353 return 0;
354 break;
355 case ICMP_REDIRECT:
356 break;
357 default:
358 return 0;
359 }
360
361 x = xfrm_state_lookup(net, mark, daddr: (const xfrm_address_t *)&iph->daddr,
362 spi, proto: protocol, AF_INET);
363 if (!x)
364 return 0;
365
366 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
367 ipv4_update_pmtu(skb, net, mtu: info, oif: 0, protocol);
368 else
369 ipv4_redirect(skb, net, oif: 0, protocol);
370 xfrm_state_put(x);
371
372 return 0;
373}
374
375static int
376vti_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
377{
378 int err = 0;
379
380 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
381 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_IPIP ||
382 p->iph.ihl != 5)
383 return -EINVAL;
384 }
385
386 if (!(p->i_flags & GRE_KEY))
387 p->i_key = 0;
388 if (!(p->o_flags & GRE_KEY))
389 p->o_key = 0;
390
391 p->i_flags = VTI_ISVTI;
392
393 err = ip_tunnel_ctl(dev, p, cmd);
394 if (err)
395 return err;
396
397 if (cmd != SIOCDELTUNNEL) {
398 p->i_flags |= GRE_KEY;
399 p->o_flags |= GRE_KEY;
400 }
401 return 0;
402}
403
404static const struct net_device_ops vti_netdev_ops = {
405 .ndo_init = vti_tunnel_init,
406 .ndo_uninit = ip_tunnel_uninit,
407 .ndo_start_xmit = vti_tunnel_xmit,
408 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
409 .ndo_change_mtu = ip_tunnel_change_mtu,
410 .ndo_get_stats64 = dev_get_tstats64,
411 .ndo_get_iflink = ip_tunnel_get_iflink,
412 .ndo_tunnel_ctl = vti_tunnel_ctl,
413};
414
415static void vti_tunnel_setup(struct net_device *dev)
416{
417 dev->netdev_ops = &vti_netdev_ops;
418 dev->header_ops = &ip_tunnel_header_ops;
419 dev->type = ARPHRD_TUNNEL;
420 ip_tunnel_setup(dev, net_id: vti_net_id);
421}
422
423static int vti_tunnel_init(struct net_device *dev)
424{
425 struct ip_tunnel *tunnel = netdev_priv(dev);
426 struct iphdr *iph = &tunnel->parms.iph;
427
428 __dev_addr_set(dev, addr: &iph->saddr, len: 4);
429 memcpy(dev->broadcast, &iph->daddr, 4);
430
431 dev->flags = IFF_NOARP;
432 dev->addr_len = 4;
433 dev->features |= NETIF_F_LLTX;
434 netif_keep_dst(dev);
435
436 return ip_tunnel_init(dev);
437}
438
439static void __net_init vti_fb_tunnel_init(struct net_device *dev)
440{
441 struct ip_tunnel *tunnel = netdev_priv(dev);
442 struct iphdr *iph = &tunnel->parms.iph;
443
444 iph->version = 4;
445 iph->protocol = IPPROTO_IPIP;
446 iph->ihl = 5;
447}
448
449static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
450 .handler = vti_rcv_proto,
451 .input_handler = vti_input_proto,
452 .cb_handler = vti_rcv_cb,
453 .err_handler = vti4_err,
454 .priority = 100,
455};
456
457static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
458 .handler = vti_rcv_proto,
459 .input_handler = vti_input_proto,
460 .cb_handler = vti_rcv_cb,
461 .err_handler = vti4_err,
462 .priority = 100,
463};
464
465static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
466 .handler = vti_rcv_proto,
467 .input_handler = vti_input_proto,
468 .cb_handler = vti_rcv_cb,
469 .err_handler = vti4_err,
470 .priority = 100,
471};
472
473#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
474static int vti_rcv_tunnel(struct sk_buff *skb)
475{
476 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
477 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
478
479 return vti_input(skb, IPPROTO_IPIP, spi: ip_hdr(skb)->saddr, encap_type: 0, update_skb_dev: false);
480}
481
482static struct xfrm_tunnel vti_ipip_handler __read_mostly = {
483 .handler = vti_rcv_tunnel,
484 .cb_handler = vti_rcv_cb,
485 .err_handler = vti4_err,
486 .priority = 0,
487};
488
489#if IS_ENABLED(CONFIG_IPV6)
490static struct xfrm_tunnel vti_ipip6_handler __read_mostly = {
491 .handler = vti_rcv_tunnel,
492 .cb_handler = vti_rcv_cb,
493 .err_handler = vti4_err,
494 .priority = 0,
495};
496#endif
497#endif
498
499static int __net_init vti_init_net(struct net *net)
500{
501 int err;
502 struct ip_tunnel_net *itn;
503
504 err = ip_tunnel_init_net(net, ip_tnl_net_id: vti_net_id, ops: &vti_link_ops, devname: "ip_vti0");
505 if (err)
506 return err;
507 itn = net_generic(net, id: vti_net_id);
508 if (itn->fb_tunnel_dev)
509 vti_fb_tunnel_init(dev: itn->fb_tunnel_dev);
510 return 0;
511}
512
513static void __net_exit vti_exit_batch_rtnl(struct list_head *list_net,
514 struct list_head *dev_to_kill)
515{
516 ip_tunnel_delete_nets(list_net, id: vti_net_id, ops: &vti_link_ops,
517 dev_to_kill);
518}
519
520static struct pernet_operations vti_net_ops = {
521 .init = vti_init_net,
522 .exit_batch_rtnl = vti_exit_batch_rtnl,
523 .id = &vti_net_id,
524 .size = sizeof(struct ip_tunnel_net),
525};
526
527static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
528 struct netlink_ext_ack *extack)
529{
530 return 0;
531}
532
533static void vti_netlink_parms(struct nlattr *data[],
534 struct ip_tunnel_parm *parms,
535 __u32 *fwmark)
536{
537 memset(parms, 0, sizeof(*parms));
538
539 parms->iph.protocol = IPPROTO_IPIP;
540
541 if (!data)
542 return;
543
544 parms->i_flags = VTI_ISVTI;
545
546 if (data[IFLA_VTI_LINK])
547 parms->link = nla_get_u32(nla: data[IFLA_VTI_LINK]);
548
549 if (data[IFLA_VTI_IKEY])
550 parms->i_key = nla_get_be32(nla: data[IFLA_VTI_IKEY]);
551
552 if (data[IFLA_VTI_OKEY])
553 parms->o_key = nla_get_be32(nla: data[IFLA_VTI_OKEY]);
554
555 if (data[IFLA_VTI_LOCAL])
556 parms->iph.saddr = nla_get_in_addr(nla: data[IFLA_VTI_LOCAL]);
557
558 if (data[IFLA_VTI_REMOTE])
559 parms->iph.daddr = nla_get_in_addr(nla: data[IFLA_VTI_REMOTE]);
560
561 if (data[IFLA_VTI_FWMARK])
562 *fwmark = nla_get_u32(nla: data[IFLA_VTI_FWMARK]);
563}
564
565static int vti_newlink(struct net *src_net, struct net_device *dev,
566 struct nlattr *tb[], struct nlattr *data[],
567 struct netlink_ext_ack *extack)
568{
569 struct ip_tunnel_parm parms;
570 __u32 fwmark = 0;
571
572 vti_netlink_parms(data, parms: &parms, fwmark: &fwmark);
573 return ip_tunnel_newlink(dev, tb, p: &parms, fwmark);
574}
575
576static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
577 struct nlattr *data[],
578 struct netlink_ext_ack *extack)
579{
580 struct ip_tunnel *t = netdev_priv(dev);
581 __u32 fwmark = t->fwmark;
582 struct ip_tunnel_parm p;
583
584 vti_netlink_parms(data, parms: &p, fwmark: &fwmark);
585 return ip_tunnel_changelink(dev, tb, p: &p, fwmark);
586}
587
588static size_t vti_get_size(const struct net_device *dev)
589{
590 return
591 /* IFLA_VTI_LINK */
592 nla_total_size(payload: 4) +
593 /* IFLA_VTI_IKEY */
594 nla_total_size(payload: 4) +
595 /* IFLA_VTI_OKEY */
596 nla_total_size(payload: 4) +
597 /* IFLA_VTI_LOCAL */
598 nla_total_size(payload: 4) +
599 /* IFLA_VTI_REMOTE */
600 nla_total_size(payload: 4) +
601 /* IFLA_VTI_FWMARK */
602 nla_total_size(payload: 4) +
603 0;
604}
605
606static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
607{
608 struct ip_tunnel *t = netdev_priv(dev);
609 struct ip_tunnel_parm *p = &t->parms;
610
611 if (nla_put_u32(skb, attrtype: IFLA_VTI_LINK, value: p->link) ||
612 nla_put_be32(skb, attrtype: IFLA_VTI_IKEY, value: p->i_key) ||
613 nla_put_be32(skb, attrtype: IFLA_VTI_OKEY, value: p->o_key) ||
614 nla_put_in_addr(skb, attrtype: IFLA_VTI_LOCAL, addr: p->iph.saddr) ||
615 nla_put_in_addr(skb, attrtype: IFLA_VTI_REMOTE, addr: p->iph.daddr) ||
616 nla_put_u32(skb, attrtype: IFLA_VTI_FWMARK, value: t->fwmark))
617 return -EMSGSIZE;
618
619 return 0;
620}
621
622static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
623 [IFLA_VTI_LINK] = { .type = NLA_U32 },
624 [IFLA_VTI_IKEY] = { .type = NLA_U32 },
625 [IFLA_VTI_OKEY] = { .type = NLA_U32 },
626 [IFLA_VTI_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
627 [IFLA_VTI_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
628 [IFLA_VTI_FWMARK] = { .type = NLA_U32 },
629};
630
631static struct rtnl_link_ops vti_link_ops __read_mostly = {
632 .kind = "vti",
633 .maxtype = IFLA_VTI_MAX,
634 .policy = vti_policy,
635 .priv_size = sizeof(struct ip_tunnel),
636 .setup = vti_tunnel_setup,
637 .validate = vti_tunnel_validate,
638 .newlink = vti_newlink,
639 .changelink = vti_changelink,
640 .dellink = ip_tunnel_dellink,
641 .get_size = vti_get_size,
642 .fill_info = vti_fill_info,
643 .get_link_net = ip_tunnel_get_link_net,
644};
645
646static int __init vti_init(void)
647{
648 const char *msg;
649 int err;
650
651 pr_info("IPv4 over IPsec tunneling driver\n");
652
653 msg = "tunnel device";
654 err = register_pernet_device(&vti_net_ops);
655 if (err < 0)
656 goto pernet_dev_failed;
657
658 msg = "tunnel protocols";
659 err = xfrm4_protocol_register(handler: &vti_esp4_protocol, IPPROTO_ESP);
660 if (err < 0)
661 goto xfrm_proto_esp_failed;
662 err = xfrm4_protocol_register(handler: &vti_ah4_protocol, IPPROTO_AH);
663 if (err < 0)
664 goto xfrm_proto_ah_failed;
665 err = xfrm4_protocol_register(handler: &vti_ipcomp4_protocol, IPPROTO_COMP);
666 if (err < 0)
667 goto xfrm_proto_comp_failed;
668
669#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
670 msg = "ipip tunnel";
671 err = xfrm4_tunnel_register(handler: &vti_ipip_handler, AF_INET);
672 if (err < 0)
673 goto xfrm_tunnel_ipip_failed;
674#if IS_ENABLED(CONFIG_IPV6)
675 err = xfrm4_tunnel_register(handler: &vti_ipip6_handler, AF_INET6);
676 if (err < 0)
677 goto xfrm_tunnel_ipip6_failed;
678#endif
679#endif
680
681 msg = "netlink interface";
682 err = rtnl_link_register(ops: &vti_link_ops);
683 if (err < 0)
684 goto rtnl_link_failed;
685
686 return err;
687
688rtnl_link_failed:
689#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
690#if IS_ENABLED(CONFIG_IPV6)
691 xfrm4_tunnel_deregister(handler: &vti_ipip6_handler, AF_INET6);
692xfrm_tunnel_ipip6_failed:
693#endif
694 xfrm4_tunnel_deregister(handler: &vti_ipip_handler, AF_INET);
695xfrm_tunnel_ipip_failed:
696#endif
697 xfrm4_protocol_deregister(handler: &vti_ipcomp4_protocol, IPPROTO_COMP);
698xfrm_proto_comp_failed:
699 xfrm4_protocol_deregister(handler: &vti_ah4_protocol, IPPROTO_AH);
700xfrm_proto_ah_failed:
701 xfrm4_protocol_deregister(handler: &vti_esp4_protocol, IPPROTO_ESP);
702xfrm_proto_esp_failed:
703 unregister_pernet_device(&vti_net_ops);
704pernet_dev_failed:
705 pr_err("vti init: failed to register %s\n", msg);
706 return err;
707}
708
709static void __exit vti_fini(void)
710{
711 rtnl_link_unregister(ops: &vti_link_ops);
712#if IS_ENABLED(CONFIG_INET_XFRM_TUNNEL)
713#if IS_ENABLED(CONFIG_IPV6)
714 xfrm4_tunnel_deregister(handler: &vti_ipip6_handler, AF_INET6);
715#endif
716 xfrm4_tunnel_deregister(handler: &vti_ipip_handler, AF_INET);
717#endif
718 xfrm4_protocol_deregister(handler: &vti_ipcomp4_protocol, IPPROTO_COMP);
719 xfrm4_protocol_deregister(handler: &vti_ah4_protocol, IPPROTO_AH);
720 xfrm4_protocol_deregister(handler: &vti_esp4_protocol, IPPROTO_ESP);
721 unregister_pernet_device(&vti_net_ops);
722}
723
724module_init(vti_init);
725module_exit(vti_fini);
726MODULE_DESCRIPTION("Virtual (secure) IP tunneling library");
727MODULE_LICENSE("GPL");
728MODULE_ALIAS_RTNL_LINK("vti");
729MODULE_ALIAS_NETDEV("ip_vti0");
730

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