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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(skb->dev);
53 struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
54
55 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
56 iph->saddr, iph->daddr, 0);
57 if (tunnel) {
58 if (!xfrm4_policy_check(NULL, 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, 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, ip_hdr(skb)->protocol, spi, 0, update_skb_dev);
87}
88
89static int vti_rcv_proto(struct sk_buff *skb)
90{
91 return vti_rcv(skb, 0, false);
92}
93
94static int vti_rcv_tunnel(struct sk_buff *skb)
95{
96 return vti_rcv(skb, ip_hdr(skb)->saddr, true);
97}
98
99static int vti_rcv_cb(struct sk_buff *skb, int err)
100{
101 unsigned short family;
102 struct net_device *dev;
103 struct pcpu_sw_netstats *tstats;
104 struct xfrm_state *x;
105 const struct xfrm_mode *inner_mode;
106 struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
107 u32 orig_mark = skb->mark;
108 int ret;
109
110 if (!tunnel)
111 return 1;
112
113 dev = tunnel->dev;
114
115 if (err) {
116 dev->stats.rx_errors++;
117 dev->stats.rx_dropped++;
118
119 return 0;
120 }
121
122 x = xfrm_input_state(skb);
123
124 inner_mode = &x->inner_mode;
125
126 if (x->sel.family == AF_UNSPEC) {
127 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
128 if (inner_mode == NULL) {
129 XFRM_INC_STATS(dev_net(skb->dev),
130 LINUX_MIB_XFRMINSTATEMODEERROR);
131 return -EINVAL;
132 }
133 }
134
135 family = inner_mode->family;
136
137 skb->mark = be32_to_cpu(tunnel->parms.i_key);
138 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
139 skb->mark = orig_mark;
140
141 if (!ret)
142 return -EPERM;
143
144 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
145 skb->dev = dev;
146
147 tstats = this_cpu_ptr(dev->tstats);
148
149 u64_stats_update_begin(&tstats->syncp);
150 tstats->rx_packets++;
151 tstats->rx_bytes += skb->len;
152 u64_stats_update_end(&tstats->syncp);
153
154 return 0;
155}
156
157static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
158{
159 xfrm_address_t *daddr = (xfrm_address_t *)&dst;
160 xfrm_address_t *saddr = (xfrm_address_t *)&src;
161
162
163
164
165 if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
166 x->props.family != AF_INET)
167 return false;
168
169 if (!dst)
170 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
171
172 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
173 return false;
174
175 return true;
176}
177
178static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
179 struct flowi *fl)
180{
181 struct ip_tunnel *tunnel = netdev_priv(dev);
182 struct ip_tunnel_parm *parms = &tunnel->parms;
183 struct dst_entry *dst = skb_dst(skb);
184 struct net_device *tdev;
185 int pkt_len = skb->len;
186 int err;
187 int mtu;
188
189 if (!dst) {
190 dev->stats.tx_carrier_errors++;
191 goto tx_error_icmp;
192 }
193
194 dst_hold(dst);
195 dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
196 if (IS_ERR(dst)) {
197 dev->stats.tx_carrier_errors++;
198 goto tx_error_icmp;
199 }
200
201 if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
202 dev->stats.tx_carrier_errors++;
203 dst_release(dst);
204 goto tx_error_icmp;
205 }
206
207 tdev = dst->dev;
208
209 if (tdev == dev) {
210 dst_release(dst);
211 dev->stats.collisions++;
212 goto tx_error;
213 }
214
215 mtu = dst_mtu(dst);
216 if (skb->len > mtu) {
217 skb_dst_update_pmtu(skb, mtu);
218 if (skb->protocol == htons(ETH_P_IP)) {
219 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
220 htonl(mtu));
221 } else {
222 if (mtu < IPV6_MIN_MTU)
223 mtu = IPV6_MIN_MTU;
224
225 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
226 }
227
228 dst_release(dst);
229 goto tx_error;
230 }
231
232 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
233 skb_dst_set(skb, dst);
234 skb->dev = skb_dst(skb)->dev;
235
236 err = dst_output(tunnel->net, skb->sk, skb);
237 if (net_xmit_eval(err) == 0)
238 err = pkt_len;
239 iptunnel_xmit_stats(dev, err);
240 return NETDEV_TX_OK;
241
242tx_error_icmp:
243 dst_link_failure(skb);
244tx_error:
245 dev->stats.tx_errors++;
246 kfree_skb(skb);
247 return NETDEV_TX_OK;
248}
249
250
251
252
253static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
254{
255 struct ip_tunnel *tunnel = netdev_priv(dev);
256 struct flowi fl;
257
258 if (!pskb_inet_may_pull(skb))
259 goto tx_err;
260
261 memset(&fl, 0, sizeof(fl));
262
263 switch (skb->protocol) {
264 case htons(ETH_P_IP):
265 xfrm_decode_session(skb, &fl, AF_INET);
266 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
267 break;
268 case htons(ETH_P_IPV6):
269 xfrm_decode_session(skb, &fl, AF_INET6);
270 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
271 break;
272 default:
273 goto tx_err;
274 }
275
276
277 fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
278
279 return vti_xmit(skb, dev, &fl);
280
281tx_err:
282 dev->stats.tx_errors++;
283 kfree_skb(skb);
284 return NETDEV_TX_OK;
285}
286
287static int vti4_err(struct sk_buff *skb, u32 info)
288{
289 __be32 spi;
290 __u32 mark;
291 struct xfrm_state *x;
292 struct ip_tunnel *tunnel;
293 struct ip_esp_hdr *esph;
294 struct ip_auth_hdr *ah ;
295 struct ip_comp_hdr *ipch;
296 struct net *net = dev_net(skb->dev);
297 const struct iphdr *iph = (const struct iphdr *)skb->data;
298 int protocol = iph->protocol;
299 struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
300
301 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
302 iph->daddr, iph->saddr, 0);
303 if (!tunnel)
304 return -1;
305
306 mark = be32_to_cpu(tunnel->parms.o_key);
307
308 switch (protocol) {
309 case IPPROTO_ESP:
310 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
311 spi = esph->spi;
312 break;
313 case IPPROTO_AH:
314 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
315 spi = ah->spi;
316 break;
317 case IPPROTO_COMP:
318 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
319 spi = htonl(ntohs(ipch->cpi));
320 break;
321 default:
322 return 0;
323 }
324
325 switch (icmp_hdr(skb)->type) {
326 case ICMP_DEST_UNREACH:
327 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
328 return 0;
329 case ICMP_REDIRECT:
330 break;
331 default:
332 return 0;
333 }
334
335 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
336 spi, protocol, AF_INET);
337 if (!x)
338 return 0;
339
340 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
341 ipv4_update_pmtu(skb, net, info, 0, protocol);
342 else
343 ipv4_redirect(skb, net, 0, protocol);
344 xfrm_state_put(x);
345
346 return 0;
347}
348
349static int
350vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
351{
352 int err = 0;
353 struct ip_tunnel_parm p;
354
355 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
356 return -EFAULT;
357
358 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
359 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
360 p.iph.ihl != 5)
361 return -EINVAL;
362 }
363
364 if (!(p.i_flags & GRE_KEY))
365 p.i_key = 0;
366 if (!(p.o_flags & GRE_KEY))
367 p.o_key = 0;
368
369 p.i_flags = VTI_ISVTI;
370
371 err = ip_tunnel_ioctl(dev, &p, cmd);
372 if (err)
373 return err;
374
375 if (cmd != SIOCDELTUNNEL) {
376 p.i_flags |= GRE_KEY;
377 p.o_flags |= GRE_KEY;
378 }
379
380 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
381 return -EFAULT;
382 return 0;
383}
384
385static const struct net_device_ops vti_netdev_ops = {
386 .ndo_init = vti_tunnel_init,
387 .ndo_uninit = ip_tunnel_uninit,
388 .ndo_start_xmit = vti_tunnel_xmit,
389 .ndo_do_ioctl = vti_tunnel_ioctl,
390 .ndo_change_mtu = ip_tunnel_change_mtu,
391 .ndo_get_stats64 = ip_tunnel_get_stats64,
392 .ndo_get_iflink = ip_tunnel_get_iflink,
393};
394
395static void vti_tunnel_setup(struct net_device *dev)
396{
397 dev->netdev_ops = &vti_netdev_ops;
398 dev->type = ARPHRD_TUNNEL;
399 ip_tunnel_setup(dev, vti_net_id);
400}
401
402static int vti_tunnel_init(struct net_device *dev)
403{
404 struct ip_tunnel *tunnel = netdev_priv(dev);
405 struct iphdr *iph = &tunnel->parms.iph;
406
407 memcpy(dev->dev_addr, &iph->saddr, 4);
408 memcpy(dev->broadcast, &iph->daddr, 4);
409
410 dev->flags = IFF_NOARP;
411 dev->addr_len = 4;
412 dev->features |= NETIF_F_LLTX;
413 netif_keep_dst(dev);
414
415 return ip_tunnel_init(dev);
416}
417
418static void __net_init vti_fb_tunnel_init(struct net_device *dev)
419{
420 struct ip_tunnel *tunnel = netdev_priv(dev);
421 struct iphdr *iph = &tunnel->parms.iph;
422
423 iph->version = 4;
424 iph->protocol = IPPROTO_IPIP;
425 iph->ihl = 5;
426}
427
428static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
429 .handler = vti_rcv_proto,
430 .input_handler = vti_input_proto,
431 .cb_handler = vti_rcv_cb,
432 .err_handler = vti4_err,
433 .priority = 100,
434};
435
436static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
437 .handler = vti_rcv_proto,
438 .input_handler = vti_input_proto,
439 .cb_handler = vti_rcv_cb,
440 .err_handler = vti4_err,
441 .priority = 100,
442};
443
444static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
445 .handler = vti_rcv_proto,
446 .input_handler = vti_input_proto,
447 .cb_handler = vti_rcv_cb,
448 .err_handler = vti4_err,
449 .priority = 100,
450};
451
452static struct xfrm_tunnel ipip_handler __read_mostly = {
453 .handler = vti_rcv_tunnel,
454 .err_handler = vti4_err,
455 .priority = 0,
456};
457
458static int __net_init vti_init_net(struct net *net)
459{
460 int err;
461 struct ip_tunnel_net *itn;
462
463 err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
464 if (err)
465 return err;
466 itn = net_generic(net, vti_net_id);
467 if (itn->fb_tunnel_dev)
468 vti_fb_tunnel_init(itn->fb_tunnel_dev);
469 return 0;
470}
471
472static void __net_exit vti_exit_batch_net(struct list_head *list_net)
473{
474 ip_tunnel_delete_nets(list_net, vti_net_id, &vti_link_ops);
475}
476
477static struct pernet_operations vti_net_ops = {
478 .init = vti_init_net,
479 .exit_batch = vti_exit_batch_net,
480 .id = &vti_net_id,
481 .size = sizeof(struct ip_tunnel_net),
482};
483
484static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
485 struct netlink_ext_ack *extack)
486{
487 return 0;
488}
489
490static void vti_netlink_parms(struct nlattr *data[],
491 struct ip_tunnel_parm *parms,
492 __u32 *fwmark)
493{
494 memset(parms, 0, sizeof(*parms));
495
496 parms->iph.protocol = IPPROTO_IPIP;
497
498 if (!data)
499 return;
500
501 parms->i_flags = VTI_ISVTI;
502
503 if (data[IFLA_VTI_LINK])
504 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
505
506 if (data[IFLA_VTI_IKEY])
507 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
508
509 if (data[IFLA_VTI_OKEY])
510 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
511
512 if (data[IFLA_VTI_LOCAL])
513 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
514
515 if (data[IFLA_VTI_REMOTE])
516 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
517
518 if (data[IFLA_VTI_FWMARK])
519 *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
520}
521
522static int vti_newlink(struct net *src_net, struct net_device *dev,
523 struct nlattr *tb[], struct nlattr *data[],
524 struct netlink_ext_ack *extack)
525{
526 struct ip_tunnel_parm parms;
527 __u32 fwmark = 0;
528
529 vti_netlink_parms(data, &parms, &fwmark);
530 return ip_tunnel_newlink(dev, tb, &parms, fwmark);
531}
532
533static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
534 struct nlattr *data[],
535 struct netlink_ext_ack *extack)
536{
537 struct ip_tunnel *t = netdev_priv(dev);
538 __u32 fwmark = t->fwmark;
539 struct ip_tunnel_parm p;
540
541 vti_netlink_parms(data, &p, &fwmark);
542 return ip_tunnel_changelink(dev, tb, &p, fwmark);
543}
544
545static size_t vti_get_size(const struct net_device *dev)
546{
547 return
548
549 nla_total_size(4) +
550
551 nla_total_size(4) +
552
553 nla_total_size(4) +
554
555 nla_total_size(4) +
556
557 nla_total_size(4) +
558
559 nla_total_size(4) +
560 0;
561}
562
563static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
564{
565 struct ip_tunnel *t = netdev_priv(dev);
566 struct ip_tunnel_parm *p = &t->parms;
567
568 if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
569 nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
570 nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
571 nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
572 nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
573 nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
574 return -EMSGSIZE;
575
576 return 0;
577}
578
579static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
580 [IFLA_VTI_LINK] = { .type = NLA_U32 },
581 [IFLA_VTI_IKEY] = { .type = NLA_U32 },
582 [IFLA_VTI_OKEY] = { .type = NLA_U32 },
583 [IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
584 [IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
585 [IFLA_VTI_FWMARK] = { .type = NLA_U32 },
586};
587
588static struct rtnl_link_ops vti_link_ops __read_mostly = {
589 .kind = "vti",
590 .maxtype = IFLA_VTI_MAX,
591 .policy = vti_policy,
592 .priv_size = sizeof(struct ip_tunnel),
593 .setup = vti_tunnel_setup,
594 .validate = vti_tunnel_validate,
595 .newlink = vti_newlink,
596 .changelink = vti_changelink,
597 .dellink = ip_tunnel_dellink,
598 .get_size = vti_get_size,
599 .fill_info = vti_fill_info,
600 .get_link_net = ip_tunnel_get_link_net,
601};
602
603static int __init vti_init(void)
604{
605 const char *msg;
606 int err;
607
608 pr_info("IPv4 over IPsec tunneling driver\n");
609
610 msg = "tunnel device";
611 err = register_pernet_device(&vti_net_ops);
612 if (err < 0)
613 goto pernet_dev_failed;
614
615 msg = "tunnel protocols";
616 err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
617 if (err < 0)
618 goto xfrm_proto_esp_failed;
619 err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
620 if (err < 0)
621 goto xfrm_proto_ah_failed;
622 err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
623 if (err < 0)
624 goto xfrm_proto_comp_failed;
625
626 msg = "ipip tunnel";
627 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
628 if (err < 0)
629 goto xfrm_tunnel_failed;
630
631 msg = "netlink interface";
632 err = rtnl_link_register(&vti_link_ops);
633 if (err < 0)
634 goto rtnl_link_failed;
635
636 return err;
637
638rtnl_link_failed:
639 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
640xfrm_tunnel_failed:
641 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
642xfrm_proto_comp_failed:
643 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
644xfrm_proto_ah_failed:
645 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
646xfrm_proto_esp_failed:
647 unregister_pernet_device(&vti_net_ops);
648pernet_dev_failed:
649 pr_err("vti init: failed to register %s\n", msg);
650 return err;
651}
652
653static void __exit vti_fini(void)
654{
655 rtnl_link_unregister(&vti_link_ops);
656 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
657 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
658 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
659 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
660 unregister_pernet_device(&vti_net_ops);
661}
662
663module_init(vti_init);
664module_exit(vti_fini);
665MODULE_LICENSE("GPL");
666MODULE_ALIAS_RTNL_LINK("vti");
667MODULE_ALIAS_NETDEV("ip_vti0");
668
