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22#include <linux/capability.h>
23#include <linux/module.h>
24#include <linux/types.h>
25#include <linux/kernel.h>
26#include <linux/uaccess.h>
27#include <linux/skbuff.h>
28#include <linux/netdevice.h>
29#include <linux/in.h>
30#include <linux/tcp.h>
31#include <linux/udp.h>
32#include <linux/if_arp.h>
33#include <linux/mroute.h>
34#include <linux/init.h>
35#include <linux/netfilter_ipv4.h>
36#include <linux/if_ether.h>
37#include <linux/icmpv6.h>
38
39#include <net/sock.h>
40#include <net/ip.h>
41#include <net/icmp.h>
42#include <net/ip_tunnels.h>
43#include <net/inet_ecn.h>
44#include <net/xfrm.h>
45#include <net/net_namespace.h>
46#include <net/netns/generic.h>
47
48static struct rtnl_link_ops vti_link_ops __read_mostly;
49
50static int vti_net_id __read_mostly;
51static int vti_tunnel_init(struct net_device *dev);
52
53static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
54 int encap_type)
55{
56 struct ip_tunnel *tunnel;
57 const struct iphdr *iph = ip_hdr(skb);
58 struct net *net = dev_net(skb->dev);
59 struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
60
61 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
62 iph->saddr, iph->daddr, 0);
63 if (tunnel) {
64 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
65 goto drop;
66
67 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
68
69 return xfrm_input(skb, nexthdr, spi, encap_type);
70 }
71
72 return -EINVAL;
73drop:
74 kfree_skb(skb);
75 return 0;
76}
77
78static int vti_rcv(struct sk_buff *skb)
79{
80 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
81 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
82
83 return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
84}
85
86static int vti_rcv_cb(struct sk_buff *skb, int err)
87{
88 unsigned short family;
89 struct net_device *dev;
90 struct pcpu_sw_netstats *tstats;
91 struct xfrm_state *x;
92 struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
93 u32 orig_mark = skb->mark;
94 int ret;
95
96 if (!tunnel)
97 return 1;
98
99 dev = tunnel->dev;
100
101 if (err) {
102 dev->stats.rx_errors++;
103 dev->stats.rx_dropped++;
104
105 return 0;
106 }
107
108 x = xfrm_input_state(skb);
109 family = x->inner_mode->afinfo->family;
110
111 skb->mark = be32_to_cpu(tunnel->parms.i_key);
112 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
113 skb->mark = orig_mark;
114
115 if (!ret)
116 return -EPERM;
117
118 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
119 skb->dev = dev;
120
121 tstats = this_cpu_ptr(dev->tstats);
122
123 u64_stats_update_begin(&tstats->syncp);
124 tstats->rx_packets++;
125 tstats->rx_bytes += skb->len;
126 u64_stats_update_end(&tstats->syncp);
127
128 return 0;
129}
130
131static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
132{
133 xfrm_address_t *daddr = (xfrm_address_t *)&dst;
134 xfrm_address_t *saddr = (xfrm_address_t *)&src;
135
136
137
138
139 if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
140 x->props.family != AF_INET)
141 return false;
142
143 if (!dst)
144 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
145
146 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
147 return false;
148
149 return true;
150}
151
152static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
153 struct flowi *fl)
154{
155 struct ip_tunnel *tunnel = netdev_priv(dev);
156 struct ip_tunnel_parm *parms = &tunnel->parms;
157 struct dst_entry *dst = skb_dst(skb);
158 struct net_device *tdev;
159 int err;
160
161 if (!dst) {
162 dev->stats.tx_carrier_errors++;
163 goto tx_error_icmp;
164 }
165
166 dst_hold(dst);
167 dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
168 if (IS_ERR(dst)) {
169 dev->stats.tx_carrier_errors++;
170 goto tx_error_icmp;
171 }
172
173 if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
174 dev->stats.tx_carrier_errors++;
175 dst_release(dst);
176 goto tx_error_icmp;
177 }
178
179 tdev = dst->dev;
180
181 if (tdev == dev) {
182 dst_release(dst);
183 dev->stats.collisions++;
184 goto tx_error;
185 }
186
187 if (tunnel->err_count > 0) {
188 if (time_before(jiffies,
189 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
190 tunnel->err_count--;
191 dst_link_failure(skb);
192 } else
193 tunnel->err_count = 0;
194 }
195
196 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
197 skb_dst_set(skb, dst);
198 skb->dev = skb_dst(skb)->dev;
199
200 err = dst_output(tunnel->net, skb->sk, skb);
201 if (net_xmit_eval(err) == 0)
202 err = skb->len;
203 iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
204 return NETDEV_TX_OK;
205
206tx_error_icmp:
207 dst_link_failure(skb);
208tx_error:
209 dev->stats.tx_errors++;
210 kfree_skb(skb);
211 return NETDEV_TX_OK;
212}
213
214
215
216
217static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
218{
219 struct ip_tunnel *tunnel = netdev_priv(dev);
220 struct flowi fl;
221
222 memset(&fl, 0, sizeof(fl));
223
224 switch (skb->protocol) {
225 case htons(ETH_P_IP):
226 xfrm_decode_session(skb, &fl, AF_INET);
227 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
228 break;
229 case htons(ETH_P_IPV6):
230 xfrm_decode_session(skb, &fl, AF_INET6);
231 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
232 break;
233 default:
234 dev->stats.tx_errors++;
235 dev_kfree_skb(skb);
236 return NETDEV_TX_OK;
237 }
238
239
240 fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
241
242 return vti_xmit(skb, dev, &fl);
243}
244
245static int vti4_err(struct sk_buff *skb, u32 info)
246{
247 __be32 spi;
248 __u32 mark;
249 struct xfrm_state *x;
250 struct ip_tunnel *tunnel;
251 struct ip_esp_hdr *esph;
252 struct ip_auth_hdr *ah ;
253 struct ip_comp_hdr *ipch;
254 struct net *net = dev_net(skb->dev);
255 const struct iphdr *iph = (const struct iphdr *)skb->data;
256 int protocol = iph->protocol;
257 struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
258
259 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
260 iph->daddr, iph->saddr, 0);
261 if (!tunnel)
262 return -1;
263
264 mark = be32_to_cpu(tunnel->parms.o_key);
265
266 switch (protocol) {
267 case IPPROTO_ESP:
268 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
269 spi = esph->spi;
270 break;
271 case IPPROTO_AH:
272 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
273 spi = ah->spi;
274 break;
275 case IPPROTO_COMP:
276 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
277 spi = htonl(ntohs(ipch->cpi));
278 break;
279 default:
280 return 0;
281 }
282
283 switch (icmp_hdr(skb)->type) {
284 case ICMP_DEST_UNREACH:
285 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
286 return 0;
287 case ICMP_REDIRECT:
288 break;
289 default:
290 return 0;
291 }
292
293 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
294 spi, protocol, AF_INET);
295 if (!x)
296 return 0;
297
298 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
299 ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
300 else
301 ipv4_redirect(skb, net, 0, 0, protocol, 0);
302 xfrm_state_put(x);
303
304 return 0;
305}
306
307static int
308vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
309{
310 int err = 0;
311 struct ip_tunnel_parm p;
312
313 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
314 return -EFAULT;
315
316 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
317 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
318 p.iph.ihl != 5)
319 return -EINVAL;
320 }
321
322 if (!(p.i_flags & GRE_KEY))
323 p.i_key = 0;
324 if (!(p.o_flags & GRE_KEY))
325 p.o_key = 0;
326
327 p.i_flags = VTI_ISVTI;
328
329 err = ip_tunnel_ioctl(dev, &p, cmd);
330 if (err)
331 return err;
332
333 if (cmd != SIOCDELTUNNEL) {
334 p.i_flags |= GRE_KEY;
335 p.o_flags |= GRE_KEY;
336 }
337
338 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
339 return -EFAULT;
340 return 0;
341}
342
343static const struct net_device_ops vti_netdev_ops = {
344 .ndo_init = vti_tunnel_init,
345 .ndo_uninit = ip_tunnel_uninit,
346 .ndo_start_xmit = vti_tunnel_xmit,
347 .ndo_do_ioctl = vti_tunnel_ioctl,
348 .ndo_change_mtu = ip_tunnel_change_mtu,
349 .ndo_get_stats64 = ip_tunnel_get_stats64,
350 .ndo_get_iflink = ip_tunnel_get_iflink,
351};
352
353static void vti_tunnel_setup(struct net_device *dev)
354{
355 dev->netdev_ops = &vti_netdev_ops;
356 dev->type = ARPHRD_TUNNEL;
357 ip_tunnel_setup(dev, vti_net_id);
358}
359
360static int vti_tunnel_init(struct net_device *dev)
361{
362 struct ip_tunnel *tunnel = netdev_priv(dev);
363 struct iphdr *iph = &tunnel->parms.iph;
364
365 memcpy(dev->dev_addr, &iph->saddr, 4);
366 memcpy(dev->broadcast, &iph->daddr, 4);
367
368 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
369 dev->mtu = ETH_DATA_LEN;
370 dev->flags = IFF_NOARP;
371 dev->addr_len = 4;
372 dev->features |= NETIF_F_LLTX;
373 netif_keep_dst(dev);
374
375 return ip_tunnel_init(dev);
376}
377
378static void __net_init vti_fb_tunnel_init(struct net_device *dev)
379{
380 struct ip_tunnel *tunnel = netdev_priv(dev);
381 struct iphdr *iph = &tunnel->parms.iph;
382
383 iph->version = 4;
384 iph->protocol = IPPROTO_IPIP;
385 iph->ihl = 5;
386}
387
388static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
389 .handler = vti_rcv,
390 .input_handler = vti_input,
391 .cb_handler = vti_rcv_cb,
392 .err_handler = vti4_err,
393 .priority = 100,
394};
395
396static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
397 .handler = vti_rcv,
398 .input_handler = vti_input,
399 .cb_handler = vti_rcv_cb,
400 .err_handler = vti4_err,
401 .priority = 100,
402};
403
404static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
405 .handler = vti_rcv,
406 .input_handler = vti_input,
407 .cb_handler = vti_rcv_cb,
408 .err_handler = vti4_err,
409 .priority = 100,
410};
411
412static int __net_init vti_init_net(struct net *net)
413{
414 int err;
415 struct ip_tunnel_net *itn;
416
417 err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
418 if (err)
419 return err;
420 itn = net_generic(net, vti_net_id);
421 vti_fb_tunnel_init(itn->fb_tunnel_dev);
422 return 0;
423}
424
425static void __net_exit vti_exit_net(struct net *net)
426{
427 struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
428 ip_tunnel_delete_net(itn, &vti_link_ops);
429}
430
431static struct pernet_operations vti_net_ops = {
432 .init = vti_init_net,
433 .exit = vti_exit_net,
434 .id = &vti_net_id,
435 .size = sizeof(struct ip_tunnel_net),
436};
437
438static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
439{
440 return 0;
441}
442
443static void vti_netlink_parms(struct nlattr *data[],
444 struct ip_tunnel_parm *parms)
445{
446 memset(parms, 0, sizeof(*parms));
447
448 parms->iph.protocol = IPPROTO_IPIP;
449
450 if (!data)
451 return;
452
453 parms->i_flags = VTI_ISVTI;
454
455 if (data[IFLA_VTI_LINK])
456 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
457
458 if (data[IFLA_VTI_IKEY])
459 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
460
461 if (data[IFLA_VTI_OKEY])
462 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
463
464 if (data[IFLA_VTI_LOCAL])
465 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
466
467 if (data[IFLA_VTI_REMOTE])
468 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
469
470}
471
472static int vti_newlink(struct net *src_net, struct net_device *dev,
473 struct nlattr *tb[], struct nlattr *data[])
474{
475 struct ip_tunnel_parm parms;
476
477 vti_netlink_parms(data, &parms);
478 return ip_tunnel_newlink(dev, tb, &parms);
479}
480
481static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
482 struct nlattr *data[])
483{
484 struct ip_tunnel_parm p;
485
486 vti_netlink_parms(data, &p);
487 return ip_tunnel_changelink(dev, tb, &p);
488}
489
490static size_t vti_get_size(const struct net_device *dev)
491{
492 return
493
494 nla_total_size(4) +
495
496 nla_total_size(4) +
497
498 nla_total_size(4) +
499
500 nla_total_size(4) +
501
502 nla_total_size(4) +
503 0;
504}
505
506static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
507{
508 struct ip_tunnel *t = netdev_priv(dev);
509 struct ip_tunnel_parm *p = &t->parms;
510
511 nla_put_u32(skb, IFLA_VTI_LINK, p->link);
512 nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key);
513 nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key);
514 nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr);
515 nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr);
516
517 return 0;
518}
519
520static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
521 [IFLA_VTI_LINK] = { .type = NLA_U32 },
522 [IFLA_VTI_IKEY] = { .type = NLA_U32 },
523 [IFLA_VTI_OKEY] = { .type = NLA_U32 },
524 [IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
525 [IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
526};
527
528static struct rtnl_link_ops vti_link_ops __read_mostly = {
529 .kind = "vti",
530 .maxtype = IFLA_VTI_MAX,
531 .policy = vti_policy,
532 .priv_size = sizeof(struct ip_tunnel),
533 .setup = vti_tunnel_setup,
534 .validate = vti_tunnel_validate,
535 .newlink = vti_newlink,
536 .changelink = vti_changelink,
537 .dellink = ip_tunnel_dellink,
538 .get_size = vti_get_size,
539 .fill_info = vti_fill_info,
540 .get_link_net = ip_tunnel_get_link_net,
541};
542
543static int __init vti_init(void)
544{
545 const char *msg;
546 int err;
547
548 pr_info("IPv4 over IPsec tunneling driver\n");
549
550 msg = "tunnel device";
551 err = register_pernet_device(&vti_net_ops);
552 if (err < 0)
553 goto pernet_dev_failed;
554
555 msg = "tunnel protocols";
556 err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
557 if (err < 0)
558 goto xfrm_proto_esp_failed;
559 err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
560 if (err < 0)
561 goto xfrm_proto_ah_failed;
562 err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
563 if (err < 0)
564 goto xfrm_proto_comp_failed;
565
566 msg = "netlink interface";
567 err = rtnl_link_register(&vti_link_ops);
568 if (err < 0)
569 goto rtnl_link_failed;
570
571 return err;
572
573rtnl_link_failed:
574 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
575xfrm_proto_comp_failed:
576 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
577xfrm_proto_ah_failed:
578 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
579xfrm_proto_esp_failed:
580 unregister_pernet_device(&vti_net_ops);
581pernet_dev_failed:
582 pr_err("vti init: failed to register %s\n", msg);
583 return err;
584}
585
586static void __exit vti_fini(void)
587{
588 rtnl_link_unregister(&vti_link_ops);
589 xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
590 xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
591 xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
592 unregister_pernet_device(&vti_net_ops);
593}
594
595module_init(vti_init);
596module_exit(vti_fini);
597MODULE_LICENSE("GPL");
598MODULE_ALIAS_RTNL_LINK("vti");
599MODULE_ALIAS_NETDEV("ip_vti0");
600
