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1/*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * Changes:
15 * Roger Venning <r.venning@telstra.com>: 6to4 support
16 * Nate Thompson <nate@thebog.net>: 6to4 support
17 * Fred Templin <fred.l.templin@boeing.com>: isatap support
18 */
19
20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/module.h>
23#include <linux/capability.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/in6.h>
30#include <linux/netdevice.h>
31#include <linux/if_arp.h>
32#include <linux/icmp.h>
33#include <linux/slab.h>
34#include <linux/uaccess.h>
35#include <linux/init.h>
36#include <linux/netfilter_ipv4.h>
37#include <linux/if_ether.h>
38
39#include <net/sock.h>
40#include <net/snmp.h>
41
42#include <net/ipv6.h>
43#include <net/protocol.h>
44#include <net/transp_v6.h>
45#include <net/ip6_fib.h>
46#include <net/ip6_route.h>
47#include <net/ndisc.h>
48#include <net/addrconf.h>
49#include <net/ip.h>
50#include <net/udp.h>
51#include <net/icmp.h>
52#include <net/ip_tunnels.h>
53#include <net/inet_ecn.h>
54#include <net/xfrm.h>
55#include <net/dsfield.h>
56#include <net/net_namespace.h>
57#include <net/netns/generic.h>
58
59/*
60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
61
62 For comments look at net/ipv4/ip_gre.c --ANK
63 */
64
65#define IP6_SIT_HASH_SIZE 16
66#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
67
68static bool log_ecn_error = true;
69module_param(log_ecn_error, bool, 0644);
70MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
71
72static int ipip6_tunnel_init(struct net_device *dev);
73static void ipip6_tunnel_setup(struct net_device *dev);
74static void ipip6_dev_free(struct net_device *dev);
75static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
76 __be32 *v4dst);
77static struct rtnl_link_ops sit_link_ops __read_mostly;
78
79static unsigned int sit_net_id __read_mostly;
80struct sit_net {
81 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
82 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
83 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
84 struct ip_tunnel __rcu *tunnels_wc[1];
85 struct ip_tunnel __rcu **tunnels[4];
86
87 struct net_device *fb_tunnel_dev;
88};
89
90/*
91 * Must be invoked with rcu_read_lock
92 */
93static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
94 struct net_device *dev,
95 __be32 remote, __be32 local,
96 int sifindex)
97{
98 unsigned int h0 = HASH(remote);
99 unsigned int h1 = HASH(local);
100 struct ip_tunnel *t;
101 struct sit_net *sitn = net_generic(net, sit_net_id);
102 int ifindex = dev ? dev->ifindex : 0;
103
104 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
105 if (local == t->parms.iph.saddr &&
106 remote == t->parms.iph.daddr &&
107 (!dev || !t->parms.link || ifindex == t->parms.link ||
108 sifindex == t->parms.link) &&
109 (t->dev->flags & IFF_UP))
110 return t;
111 }
112 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
113 if (remote == t->parms.iph.daddr &&
114 (!dev || !t->parms.link || ifindex == t->parms.link ||
115 sifindex == t->parms.link) &&
116 (t->dev->flags & IFF_UP))
117 return t;
118 }
119 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
120 if (local == t->parms.iph.saddr &&
121 (!dev || !t->parms.link || ifindex == t->parms.link ||
122 sifindex == t->parms.link) &&
123 (t->dev->flags & IFF_UP))
124 return t;
125 }
126 t = rcu_dereference(sitn->tunnels_wc[0]);
127 if (t && (t->dev->flags & IFF_UP))
128 return t;
129 return NULL;
130}
131
132static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
133 struct ip_tunnel_parm *parms)
134{
135 __be32 remote = parms->iph.daddr;
136 __be32 local = parms->iph.saddr;
137 unsigned int h = 0;
138 int prio = 0;
139
140 if (remote) {
141 prio |= 2;
142 h ^= HASH(remote);
143 }
144 if (local) {
145 prio |= 1;
146 h ^= HASH(local);
147 }
148 return &sitn->tunnels[prio][h];
149}
150
151static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
152 struct ip_tunnel *t)
153{
154 return __ipip6_bucket(sitn, &t->parms);
155}
156
157static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
158{
159 struct ip_tunnel __rcu **tp;
160 struct ip_tunnel *iter;
161
162 for (tp = ipip6_bucket(sitn, t);
163 (iter = rtnl_dereference(*tp)) != NULL;
164 tp = &iter->next) {
165 if (t == iter) {
166 rcu_assign_pointer(*tp, t->next);
167 break;
168 }
169 }
170}
171
172static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
173{
174 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
175
176 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
177 rcu_assign_pointer(*tp, t);
178}
179
180static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
181{
182#ifdef CONFIG_IPV6_SIT_6RD
183 struct ip_tunnel *t = netdev_priv(dev);
184
185 if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
186 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
187 t->ip6rd.relay_prefix = 0;
188 t->ip6rd.prefixlen = 16;
189 t->ip6rd.relay_prefixlen = 0;
190 } else {
191 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
192 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
193 }
194#endif
195}
196
197static int ipip6_tunnel_create(struct net_device *dev)
198{
199 struct ip_tunnel *t = netdev_priv(dev);
200 struct net *net = dev_net(dev);
201 struct sit_net *sitn = net_generic(net, sit_net_id);
202 int err;
203
204 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
205 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
206
207 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
208 dev->priv_flags |= IFF_ISATAP;
209
210 dev->rtnl_link_ops = &sit_link_ops;
211
212 err = register_netdevice(dev);
213 if (err < 0)
214 goto out;
215
216 ipip6_tunnel_clone_6rd(dev, sitn);
217
218 dev_hold(dev);
219
220 ipip6_tunnel_link(sitn, t);
221 return 0;
222
223out:
224 return err;
225}
226
227static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
228 struct ip_tunnel_parm *parms, int create)
229{
230 __be32 remote = parms->iph.daddr;
231 __be32 local = parms->iph.saddr;
232 struct ip_tunnel *t, *nt;
233 struct ip_tunnel __rcu **tp;
234 struct net_device *dev;
235 char name[IFNAMSIZ];
236 struct sit_net *sitn = net_generic(net, sit_net_id);
237
238 for (tp = __ipip6_bucket(sitn, parms);
239 (t = rtnl_dereference(*tp)) != NULL;
240 tp = &t->next) {
241 if (local == t->parms.iph.saddr &&
242 remote == t->parms.iph.daddr &&
243 parms->link == t->parms.link) {
244 if (create)
245 return NULL;
246 else
247 return t;
248 }
249 }
250 if (!create)
251 goto failed;
252
253 if (parms->name[0]) {
254 if (!dev_valid_name(parms->name))
255 goto failed;
256 strlcpy(name, parms->name, IFNAMSIZ);
257 } else {
258 strcpy(name, "sit%d");
259 }
260 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
261 ipip6_tunnel_setup);
262 if (!dev)
263 return NULL;
264
265 dev_net_set(dev, net);
266
267 nt = netdev_priv(dev);
268
269 nt->parms = *parms;
270 if (ipip6_tunnel_create(dev) < 0)
271 goto failed_free;
272
273 return nt;
274
275failed_free:
276 free_netdev(dev);
277failed:
278 return NULL;
279}
280
281#define for_each_prl_rcu(start) \
282 for (prl = rcu_dereference(start); \
283 prl; \
284 prl = rcu_dereference(prl->next))
285
286static struct ip_tunnel_prl_entry *
287__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
288{
289 struct ip_tunnel_prl_entry *prl;
290
291 for_each_prl_rcu(t->prl)
292 if (prl->addr == addr)
293 break;
294 return prl;
295
296}
297
298static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
299 struct ip_tunnel_prl __user *a)
300{
301 struct ip_tunnel_prl kprl, *kp;
302 struct ip_tunnel_prl_entry *prl;
303 unsigned int cmax, c = 0, ca, len;
304 int ret = 0;
305
306 if (copy_from_user(&kprl, a, sizeof(kprl)))
307 return -EFAULT;
308 cmax = kprl.datalen / sizeof(kprl);
309 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
310 cmax = 1;
311
312 /* For simple GET or for root users,
313 * we try harder to allocate.
314 */
315 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
316 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
317 NULL;
318
319 rcu_read_lock();
320
321 ca = t->prl_count < cmax ? t->prl_count : cmax;
322
323 if (!kp) {
324 /* We don't try hard to allocate much memory for
325 * non-root users.
326 * For root users, retry allocating enough memory for
327 * the answer.
328 */
329 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
330 if (!kp) {
331 ret = -ENOMEM;
332 goto out;
333 }
334 }
335
336 c = 0;
337 for_each_prl_rcu(t->prl) {
338 if (c >= cmax)
339 break;
340 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
341 continue;
342 kp[c].addr = prl->addr;
343 kp[c].flags = prl->flags;
344 c++;
345 if (kprl.addr != htonl(INADDR_ANY))
346 break;
347 }
348out:
349 rcu_read_unlock();
350
351 len = sizeof(*kp) * c;
352 ret = 0;
353 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
354 ret = -EFAULT;
355
356 kfree(kp);
357
358 return ret;
359}
360
361static int
362ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
363{
364 struct ip_tunnel_prl_entry *p;
365 int err = 0;
366
367 if (a->addr == htonl(INADDR_ANY))
368 return -EINVAL;
369
370 ASSERT_RTNL();
371
372 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
373 if (p->addr == a->addr) {
374 if (chg) {
375 p->flags = a->flags;
376 goto out;
377 }
378 err = -EEXIST;
379 goto out;
380 }
381 }
382
383 if (chg) {
384 err = -ENXIO;
385 goto out;
386 }
387
388 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
389 if (!p) {
390 err = -ENOBUFS;
391 goto out;
392 }
393
394 p->next = t->prl;
395 p->addr = a->addr;
396 p->flags = a->flags;
397 t->prl_count++;
398 rcu_assign_pointer(t->prl, p);
399out:
400 return err;
401}
402
403static void prl_list_destroy_rcu(struct rcu_head *head)
404{
405 struct ip_tunnel_prl_entry *p, *n;
406
407 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
408 do {
409 n = rcu_dereference_protected(p->next, 1);
410 kfree(p);
411 p = n;
412 } while (p);
413}
414
415static int
416ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
417{
418 struct ip_tunnel_prl_entry *x;
419 struct ip_tunnel_prl_entry __rcu **p;
420 int err = 0;
421
422 ASSERT_RTNL();
423
424 if (a && a->addr != htonl(INADDR_ANY)) {
425 for (p = &t->prl;
426 (x = rtnl_dereference(*p)) != NULL;
427 p = &x->next) {
428 if (x->addr == a->addr) {
429 *p = x->next;
430 kfree_rcu(x, rcu_head);
431 t->prl_count--;
432 goto out;
433 }
434 }
435 err = -ENXIO;
436 } else {
437 x = rtnl_dereference(t->prl);
438 if (x) {
439 t->prl_count = 0;
440 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
441 t->prl = NULL;
442 }
443 }
444out:
445 return err;
446}
447
448static int
449isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
450{
451 struct ip_tunnel_prl_entry *p;
452 int ok = 1;
453
454 rcu_read_lock();
455 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
456 if (p) {
457 if (p->flags & PRL_DEFAULT)
458 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
459 else
460 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
461 } else {
462 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
463
464 if (ipv6_addr_is_isatap(addr6) &&
465 (addr6->s6_addr32[3] == iph->saddr) &&
466 ipv6_chk_prefix(addr6, t->dev))
467 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
468 else
469 ok = 0;
470 }
471 rcu_read_unlock();
472 return ok;
473}
474
475static void ipip6_tunnel_uninit(struct net_device *dev)
476{
477 struct ip_tunnel *tunnel = netdev_priv(dev);
478 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
479
480 if (dev == sitn->fb_tunnel_dev) {
481 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
482 } else {
483 ipip6_tunnel_unlink(sitn, tunnel);
484 ipip6_tunnel_del_prl(tunnel, NULL);
485 }
486 dst_cache_reset(&tunnel->dst_cache);
487 dev_put(dev);
488}
489
490static int ipip6_err(struct sk_buff *skb, u32 info)
491{
492 const struct iphdr *iph = (const struct iphdr *)skb->data;
493 const int type = icmp_hdr(skb)->type;
494 const int code = icmp_hdr(skb)->code;
495 unsigned int data_len = 0;
496 struct ip_tunnel *t;
497 int sifindex;
498 int err;
499
500 switch (type) {
501 default:
502 case ICMP_PARAMETERPROB:
503 return 0;
504
505 case ICMP_DEST_UNREACH:
506 switch (code) {
507 case ICMP_SR_FAILED:
508 /* Impossible event. */
509 return 0;
510 default:
511 /* All others are translated to HOST_UNREACH.
512 rfc2003 contains "deep thoughts" about NET_UNREACH,
513 I believe they are just ether pollution. --ANK
514 */
515 break;
516 }
517 break;
518 case ICMP_TIME_EXCEEDED:
519 if (code != ICMP_EXC_TTL)
520 return 0;
521 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
522 break;
523 case ICMP_REDIRECT:
524 break;
525 }
526
527 err = -ENOENT;
528
529 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
530 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
531 iph->daddr, iph->saddr, sifindex);
532 if (!t)
533 goto out;
534
535 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
536 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
537 t->parms.link, 0, iph->protocol, 0);
538 err = 0;
539 goto out;
540 }
541 if (type == ICMP_REDIRECT) {
542 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
543 iph->protocol, 0);
544 err = 0;
545 goto out;
546 }
547
548 err = 0;
549 if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
550 goto out;
551
552 if (t->parms.iph.daddr == 0)
553 goto out;
554
555 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
556 goto out;
557
558 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
559 t->err_count++;
560 else
561 t->err_count = 1;
562 t->err_time = jiffies;
563out:
564 return err;
565}
566
567static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
568 const struct in6_addr *v6addr)
569{
570 __be32 v4embed = 0;
571 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
572 return true;
573 return false;
574}
575
576/* Checks if an address matches an address on the tunnel interface.
577 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
578 * Long story:
579 * This function is called after we considered the packet as spoofed
580 * in is_spoofed_6rd.
581 * We may have a router that is doing NAT for proto 41 packets
582 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
583 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
584 * function will return true, dropping the packet.
585 * But, we can still check if is spoofed against the IP
586 * addresses associated with the interface.
587 */
588static bool only_dnatted(const struct ip_tunnel *tunnel,
589 const struct in6_addr *v6dst)
590{
591 int prefix_len;
592
593#ifdef CONFIG_IPV6_SIT_6RD
594 prefix_len = tunnel->ip6rd.prefixlen + 32
595 - tunnel->ip6rd.relay_prefixlen;
596#else
597 prefix_len = 48;
598#endif
599 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
600}
601
602/* Returns true if a packet is spoofed */
603static bool packet_is_spoofed(struct sk_buff *skb,
604 const struct iphdr *iph,
605 struct ip_tunnel *tunnel)
606{
607 const struct ipv6hdr *ipv6h;
608
609 if (tunnel->dev->priv_flags & IFF_ISATAP) {
610 if (!isatap_chksrc(skb, iph, tunnel))
611 return true;
612
613 return false;
614 }
615
616 if (tunnel->dev->flags & IFF_POINTOPOINT)
617 return false;
618
619 ipv6h = ipv6_hdr(skb);
620
621 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
622 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
623 &iph->saddr, &ipv6h->saddr,
624 &iph->daddr, &ipv6h->daddr);
625 return true;
626 }
627
628 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
629 return false;
630
631 if (only_dnatted(tunnel, &ipv6h->daddr))
632 return false;
633
634 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
635 &iph->saddr, &ipv6h->saddr,
636 &iph->daddr, &ipv6h->daddr);
637 return true;
638}
639
640static int ipip6_rcv(struct sk_buff *skb)
641{
642 const struct iphdr *iph = ip_hdr(skb);
643 struct ip_tunnel *tunnel;
644 int sifindex;
645 int err;
646
647 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
648 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
649 iph->saddr, iph->daddr, sifindex);
650 if (tunnel) {
651 struct pcpu_sw_netstats *tstats;
652
653 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
654 tunnel->parms.iph.protocol != 0)
655 goto out;
656
657 skb->mac_header = skb->network_header;
658 skb_reset_network_header(skb);
659 IPCB(skb)->flags = 0;
660 skb->dev = tunnel->dev;
661
662 if (packet_is_spoofed(skb, iph, tunnel)) {
663 tunnel->dev->stats.rx_errors++;
664 goto out;
665 }
666
667 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
668 !net_eq(tunnel->net, dev_net(tunnel->dev))))
669 goto out;
670
671 err = IP_ECN_decapsulate(iph, skb);
672 if (unlikely(err)) {
673 if (log_ecn_error)
674 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
675 &iph->saddr, iph->tos);
676 if (err > 1) {
677 ++tunnel->dev->stats.rx_frame_errors;
678 ++tunnel->dev->stats.rx_errors;
679 goto out;
680 }
681 }
682
683 tstats = this_cpu_ptr(tunnel->dev->tstats);
684 u64_stats_update_begin(&tstats->syncp);
685 tstats->rx_packets++;
686 tstats->rx_bytes += skb->len;
687 u64_stats_update_end(&tstats->syncp);
688
689 netif_rx(skb);
690
691 return 0;
692 }
693
694 /* no tunnel matched, let upstream know, ipsec may handle it */
695 return 1;
696out:
697 kfree_skb(skb);
698 return 0;
699}
700
701static const struct tnl_ptk_info ipip_tpi = {
702 /* no tunnel info required for ipip. */
703 .proto = htons(ETH_P_IP),
704};
705
706#if IS_ENABLED(CONFIG_MPLS)
707static const struct tnl_ptk_info mplsip_tpi = {
708 /* no tunnel info required for mplsip. */
709 .proto = htons(ETH_P_MPLS_UC),
710};
711#endif
712
713static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
714{
715 const struct iphdr *iph;
716 struct ip_tunnel *tunnel;
717 int sifindex;
718
719 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
720
721 iph = ip_hdr(skb);
722 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
723 iph->saddr, iph->daddr, sifindex);
724 if (tunnel) {
725 const struct tnl_ptk_info *tpi;
726
727 if (tunnel->parms.iph.protocol != ipproto &&
728 tunnel->parms.iph.protocol != 0)
729 goto drop;
730
731 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
732 goto drop;
733#if IS_ENABLED(CONFIG_MPLS)
734 if (ipproto == IPPROTO_MPLS)
735 tpi = &mplsip_tpi;
736 else
737#endif
738 tpi = &ipip_tpi;
739 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
740 goto drop;
741 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
742 }
743
744 return 1;
745
746drop:
747 kfree_skb(skb);
748 return 0;
749}
750
751static int ipip_rcv(struct sk_buff *skb)
752{
753 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
754}
755
756#if IS_ENABLED(CONFIG_MPLS)
757static int mplsip_rcv(struct sk_buff *skb)
758{
759 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
760}
761#endif
762
763/*
764 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
765 * stores the embedded IPv4 address in v4dst and returns true.
766 */
767static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
768 __be32 *v4dst)
769{
770#ifdef CONFIG_IPV6_SIT_6RD
771 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
772 tunnel->ip6rd.prefixlen)) {
773 unsigned int pbw0, pbi0;
774 int pbi1;
775 u32 d;
776
777 pbw0 = tunnel->ip6rd.prefixlen >> 5;
778 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
779
780 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
781 tunnel->ip6rd.relay_prefixlen;
782
783 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
784 if (pbi1 > 0)
785 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
786 (32 - pbi1);
787
788 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
789 return true;
790 }
791#else
792 if (v6dst->s6_addr16[0] == htons(0x2002)) {
793 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
794 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
795 return true;
796 }
797#endif
798 return false;
799}
800
801static inline __be32 try_6rd(struct ip_tunnel *tunnel,
802 const struct in6_addr *v6dst)
803{
804 __be32 dst = 0;
805 check_6rd(tunnel, v6dst, &dst);
806 return dst;
807}
808
809/*
810 * This function assumes it is being called from dev_queue_xmit()
811 * and that skb is filled properly by that function.
812 */
813
814static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
815 struct net_device *dev)
816{
817 struct ip_tunnel *tunnel = netdev_priv(dev);
818 const struct iphdr *tiph = &tunnel->parms.iph;
819 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
820 u8 tos = tunnel->parms.iph.tos;
821 __be16 df = tiph->frag_off;
822 struct rtable *rt; /* Route to the other host */
823 struct net_device *tdev; /* Device to other host */
824 unsigned int max_headroom; /* The extra header space needed */
825 __be32 dst = tiph->daddr;
826 struct flowi4 fl4;
827 int mtu;
828 const struct in6_addr *addr6;
829 int addr_type;
830 u8 ttl;
831 u8 protocol = IPPROTO_IPV6;
832 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
833
834 if (tos == 1)
835 tos = ipv6_get_dsfield(iph6);
836
837 /* ISATAP (RFC4214) - must come before 6to4 */
838 if (dev->priv_flags & IFF_ISATAP) {
839 struct neighbour *neigh = NULL;
840 bool do_tx_error = false;
841
842 if (skb_dst(skb))
843 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
844
845 if (!neigh) {
846 net_dbg_ratelimited("nexthop == NULL\n");
847 goto tx_error;
848 }
849
850 addr6 = (const struct in6_addr *)&neigh->primary_key;
851 addr_type = ipv6_addr_type(addr6);
852
853 if ((addr_type & IPV6_ADDR_UNICAST) &&
854 ipv6_addr_is_isatap(addr6))
855 dst = addr6->s6_addr32[3];
856 else
857 do_tx_error = true;
858
859 neigh_release(neigh);
860 if (do_tx_error)
861 goto tx_error;
862 }
863
864 if (!dst)
865 dst = try_6rd(tunnel, &iph6->daddr);
866
867 if (!dst) {
868 struct neighbour *neigh = NULL;
869 bool do_tx_error = false;
870
871 if (skb_dst(skb))
872 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
873
874 if (!neigh) {
875 net_dbg_ratelimited("nexthop == NULL\n");
876 goto tx_error;
877 }
878
879 addr6 = (const struct in6_addr *)&neigh->primary_key;
880 addr_type = ipv6_addr_type(addr6);
881
882 if (addr_type == IPV6_ADDR_ANY) {
883 addr6 = &ipv6_hdr(skb)->daddr;
884 addr_type = ipv6_addr_type(addr6);
885 }
886
887 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
888 dst = addr6->s6_addr32[3];
889 else
890 do_tx_error = true;
891
892 neigh_release(neigh);
893 if (do_tx_error)
894 goto tx_error;
895 }
896
897 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
898 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
899 0, dst, tiph->saddr, 0, 0,
900 sock_net_uid(tunnel->net, NULL));
901 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
902
903 if (IS_ERR(rt)) {
904 dev->stats.tx_carrier_errors++;
905 goto tx_error_icmp;
906 }
907 if (rt->rt_type != RTN_UNICAST) {
908 ip_rt_put(rt);
909 dev->stats.tx_carrier_errors++;
910 goto tx_error_icmp;
911 }
912 tdev = rt->dst.dev;
913
914 if (tdev == dev) {
915 ip_rt_put(rt);
916 dev->stats.collisions++;
917 goto tx_error;
918 }
919
920 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
921 ip_rt_put(rt);
922 goto tx_error;
923 }
924
925 if (df) {
926 mtu = dst_mtu(&rt->dst) - t_hlen;
927
928 if (mtu < 68) {
929 dev->stats.collisions++;
930 ip_rt_put(rt);
931 goto tx_error;
932 }
933
934 if (mtu < IPV6_MIN_MTU) {
935 mtu = IPV6_MIN_MTU;
936 df = 0;
937 }
938
939 if (tunnel->parms.iph.daddr)
940 skb_dst_update_pmtu(skb, mtu);
941
942 if (skb->len > mtu && !skb_is_gso(skb)) {
943 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
944 ip_rt_put(rt);
945 goto tx_error;
946 }
947 }
948
949 if (tunnel->err_count > 0) {
950 if (time_before(jiffies,
951 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
952 tunnel->err_count--;
953 dst_link_failure(skb);
954 } else
955 tunnel->err_count = 0;
956 }
957
958 /*
959 * Okay, now see if we can stuff it in the buffer as-is.
960 */
961 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
962
963 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
964 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
965 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
966 if (!new_skb) {
967 ip_rt_put(rt);
968 dev->stats.tx_dropped++;
969 kfree_skb(skb);
970 return NETDEV_TX_OK;
971 }
972 if (skb->sk)
973 skb_set_owner_w(new_skb, skb->sk);
974 dev_kfree_skb(skb);
975 skb = new_skb;
976 iph6 = ipv6_hdr(skb);
977 }
978 ttl = tiph->ttl;
979 if (ttl == 0)
980 ttl = iph6->hop_limit;
981 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
982
983 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
984 ip_rt_put(rt);
985 goto tx_error;
986 }
987
988 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
989
990 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
991 df, !net_eq(tunnel->net, dev_net(dev)));
992 return NETDEV_TX_OK;
993
994tx_error_icmp:
995 dst_link_failure(skb);
996tx_error:
997 kfree_skb(skb);
998 dev->stats.tx_errors++;
999 return NETDEV_TX_OK;
1000}
1001
1002static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1003 struct net_device *dev, u8 ipproto)
1004{
1005 struct ip_tunnel *tunnel = netdev_priv(dev);
1006 const struct iphdr *tiph = &tunnel->parms.iph;
1007
1008 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1009 goto tx_error;
1010
1011 skb_set_inner_ipproto(skb, ipproto);
1012
1013 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1014 return NETDEV_TX_OK;
1015tx_error:
1016 kfree_skb(skb);
1017 dev->stats.tx_errors++;
1018 return NETDEV_TX_OK;
1019}
1020
1021static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1022 struct net_device *dev)
1023{
1024 switch (skb->protocol) {
1025 case htons(ETH_P_IP):
1026 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1027 break;
1028 case htons(ETH_P_IPV6):
1029 ipip6_tunnel_xmit(skb, dev);
1030 break;
1031#if IS_ENABLED(CONFIG_MPLS)
1032 case htons(ETH_P_MPLS_UC):
1033 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1034 break;
1035#endif
1036 default:
1037 goto tx_err;
1038 }
1039
1040 return NETDEV_TX_OK;
1041
1042tx_err:
1043 dev->stats.tx_errors++;
1044 kfree_skb(skb);
1045 return NETDEV_TX_OK;
1046
1047}
1048
1049static void ipip6_tunnel_bind_dev(struct net_device *dev)
1050{
1051 struct net_device *tdev = NULL;
1052 struct ip_tunnel *tunnel;
1053 const struct iphdr *iph;
1054 struct flowi4 fl4;
1055
1056 tunnel = netdev_priv(dev);
1057 iph = &tunnel->parms.iph;
1058
1059 if (iph->daddr) {
1060 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1061 NULL,
1062 iph->daddr, iph->saddr,
1063 0, 0,
1064 IPPROTO_IPV6,
1065 RT_TOS(iph->tos),
1066 tunnel->parms.link);
1067
1068 if (!IS_ERR(rt)) {
1069 tdev = rt->dst.dev;
1070 ip_rt_put(rt);
1071 }
1072 dev->flags |= IFF_POINTOPOINT;
1073 }
1074
1075 if (!tdev && tunnel->parms.link)
1076 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1077
1078 if (tdev) {
1079 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1080
1081 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1082 dev->mtu = tdev->mtu - t_hlen;
1083 if (dev->mtu < IPV6_MIN_MTU)
1084 dev->mtu = IPV6_MIN_MTU;
1085 }
1086}
1087
1088static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1089 __u32 fwmark)
1090{
1091 struct net *net = t->net;
1092 struct sit_net *sitn = net_generic(net, sit_net_id);
1093
1094 ipip6_tunnel_unlink(sitn, t);
1095 synchronize_net();
1096 t->parms.iph.saddr = p->iph.saddr;
1097 t->parms.iph.daddr = p->iph.daddr;
1098 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1099 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1100 ipip6_tunnel_link(sitn, t);
1101 t->parms.iph.ttl = p->iph.ttl;
1102 t->parms.iph.tos = p->iph.tos;
1103 t->parms.iph.frag_off = p->iph.frag_off;
1104 if (t->parms.link != p->link || t->fwmark != fwmark) {
1105 t->parms.link = p->link;
1106 t->fwmark = fwmark;
1107 ipip6_tunnel_bind_dev(t->dev);
1108 }
1109 dst_cache_reset(&t->dst_cache);
1110 netdev_state_change(t->dev);
1111}
1112
1113#ifdef CONFIG_IPV6_SIT_6RD
1114static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1115 struct ip_tunnel_6rd *ip6rd)
1116{
1117 struct in6_addr prefix;
1118 __be32 relay_prefix;
1119
1120 if (ip6rd->relay_prefixlen > 32 ||
1121 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1122 return -EINVAL;
1123
1124 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1125 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1126 return -EINVAL;
1127 if (ip6rd->relay_prefixlen)
1128 relay_prefix = ip6rd->relay_prefix &
1129 htonl(0xffffffffUL <<
1130 (32 - ip6rd->relay_prefixlen));
1131 else
1132 relay_prefix = 0;
1133 if (relay_prefix != ip6rd->relay_prefix)
1134 return -EINVAL;
1135
1136 t->ip6rd.prefix = prefix;
1137 t->ip6rd.relay_prefix = relay_prefix;
1138 t->ip6rd.prefixlen = ip6rd->prefixlen;
1139 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1140 dst_cache_reset(&t->dst_cache);
1141 netdev_state_change(t->dev);
1142 return 0;
1143}
1144#endif
1145
1146static bool ipip6_valid_ip_proto(u8 ipproto)
1147{
1148 return ipproto == IPPROTO_IPV6 ||
1149 ipproto == IPPROTO_IPIP ||
1150#if IS_ENABLED(CONFIG_MPLS)
1151 ipproto == IPPROTO_MPLS ||
1152#endif
1153 ipproto == 0;
1154}
1155
1156static int
1157ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1158{
1159 int err = 0;
1160 struct ip_tunnel_parm p;
1161 struct ip_tunnel_prl prl;
1162 struct ip_tunnel *t = netdev_priv(dev);
1163 struct net *net = t->net;
1164 struct sit_net *sitn = net_generic(net, sit_net_id);
1165#ifdef CONFIG_IPV6_SIT_6RD
1166 struct ip_tunnel_6rd ip6rd;
1167#endif
1168
1169 switch (cmd) {
1170 case SIOCGETTUNNEL:
1171#ifdef CONFIG_IPV6_SIT_6RD
1172 case SIOCGET6RD:
1173#endif
1174 if (dev == sitn->fb_tunnel_dev) {
1175 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1176 err = -EFAULT;
1177 break;
1178 }
1179 t = ipip6_tunnel_locate(net, &p, 0);
1180 if (!t)
1181 t = netdev_priv(dev);
1182 }
1183
1184 err = -EFAULT;
1185 if (cmd == SIOCGETTUNNEL) {
1186 memcpy(&p, &t->parms, sizeof(p));
1187 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1188 sizeof(p)))
1189 goto done;
1190#ifdef CONFIG_IPV6_SIT_6RD
1191 } else {
1192 ip6rd.prefix = t->ip6rd.prefix;
1193 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1194 ip6rd.prefixlen = t->ip6rd.prefixlen;
1195 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1196 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1197 sizeof(ip6rd)))
1198 goto done;
1199#endif
1200 }
1201 err = 0;
1202 break;
1203
1204 case SIOCADDTUNNEL:
1205 case SIOCCHGTUNNEL:
1206 err = -EPERM;
1207 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1208 goto done;
1209
1210 err = -EFAULT;
1211 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1212 goto done;
1213
1214 err = -EINVAL;
1215 if (!ipip6_valid_ip_proto(p.iph.protocol))
1216 goto done;
1217 if (p.iph.version != 4 ||
1218 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1219 goto done;
1220 if (p.iph.ttl)
1221 p.iph.frag_off |= htons(IP_DF);
1222
1223 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1224
1225 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1226 if (t) {
1227 if (t->dev != dev) {
1228 err = -EEXIST;
1229 break;
1230 }
1231 } else {
1232 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1233 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1234 err = -EINVAL;
1235 break;
1236 }
1237 t = netdev_priv(dev);
1238 }
1239
1240 ipip6_tunnel_update(t, &p, t->fwmark);
1241 }
1242
1243 if (t) {
1244 err = 0;
1245 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1246 err = -EFAULT;
1247 } else
1248 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1249 break;
1250
1251 case SIOCDELTUNNEL:
1252 err = -EPERM;
1253 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1254 goto done;
1255
1256 if (dev == sitn->fb_tunnel_dev) {
1257 err = -EFAULT;
1258 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1259 goto done;
1260 err = -ENOENT;
1261 t = ipip6_tunnel_locate(net, &p, 0);
1262 if (!t)
1263 goto done;
1264 err = -EPERM;
1265 if (t == netdev_priv(sitn->fb_tunnel_dev))
1266 goto done;
1267 dev = t->dev;
1268 }
1269 unregister_netdevice(dev);
1270 err = 0;
1271 break;
1272
1273 case SIOCGETPRL:
1274 err = -EINVAL;
1275 if (dev == sitn->fb_tunnel_dev)
1276 goto done;
1277 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1278 break;
1279
1280 case SIOCADDPRL:
1281 case SIOCDELPRL:
1282 case SIOCCHGPRL:
1283 err = -EPERM;
1284 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1285 goto done;
1286 err = -EINVAL;
1287 if (dev == sitn->fb_tunnel_dev)
1288 goto done;
1289 err = -EFAULT;
1290 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1291 goto done;
1292
1293 switch (cmd) {
1294 case SIOCDELPRL:
1295 err = ipip6_tunnel_del_prl(t, &prl);
1296 break;
1297 case SIOCADDPRL:
1298 case SIOCCHGPRL:
1299 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1300 break;
1301 }
1302 dst_cache_reset(&t->dst_cache);
1303 netdev_state_change(dev);
1304 break;
1305
1306#ifdef CONFIG_IPV6_SIT_6RD
1307 case SIOCADD6RD:
1308 case SIOCCHG6RD:
1309 case SIOCDEL6RD:
1310 err = -EPERM;
1311 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1312 goto done;
1313
1314 err = -EFAULT;
1315 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1316 sizeof(ip6rd)))
1317 goto done;
1318
1319 if (cmd != SIOCDEL6RD) {
1320 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1321 if (err < 0)
1322 goto done;
1323 } else
1324 ipip6_tunnel_clone_6rd(dev, sitn);
1325
1326 err = 0;
1327 break;
1328#endif
1329
1330 default:
1331 err = -EINVAL;
1332 }
1333
1334done:
1335 return err;
1336}
1337
1338static const struct net_device_ops ipip6_netdev_ops = {
1339 .ndo_init = ipip6_tunnel_init,
1340 .ndo_uninit = ipip6_tunnel_uninit,
1341 .ndo_start_xmit = sit_tunnel_xmit,
1342 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1343 .ndo_get_stats64 = ip_tunnel_get_stats64,
1344 .ndo_get_iflink = ip_tunnel_get_iflink,
1345};
1346
1347static void ipip6_dev_free(struct net_device *dev)
1348{
1349 struct ip_tunnel *tunnel = netdev_priv(dev);
1350
1351 dst_cache_destroy(&tunnel->dst_cache);
1352 free_percpu(dev->tstats);
1353}
1354
1355#define SIT_FEATURES (NETIF_F_SG | \
1356 NETIF_F_FRAGLIST | \
1357 NETIF_F_HIGHDMA | \
1358 NETIF_F_GSO_SOFTWARE | \
1359 NETIF_F_HW_CSUM)
1360
1361static void ipip6_tunnel_setup(struct net_device *dev)
1362{
1363 struct ip_tunnel *tunnel = netdev_priv(dev);
1364 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1365
1366 dev->netdev_ops = &ipip6_netdev_ops;
1367 dev->needs_free_netdev = true;
1368 dev->priv_destructor = ipip6_dev_free;
1369
1370 dev->type = ARPHRD_SIT;
1371 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1372 dev->mtu = ETH_DATA_LEN - t_hlen;
1373 dev->min_mtu = IPV6_MIN_MTU;
1374 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1375 dev->flags = IFF_NOARP;
1376 netif_keep_dst(dev);
1377 dev->addr_len = 4;
1378 dev->features |= NETIF_F_LLTX;
1379 dev->features |= SIT_FEATURES;
1380 dev->hw_features |= SIT_FEATURES;
1381}
1382
1383static int ipip6_tunnel_init(struct net_device *dev)
1384{
1385 struct ip_tunnel *tunnel = netdev_priv(dev);
1386 int err;
1387
1388 tunnel->dev = dev;
1389 tunnel->net = dev_net(dev);
1390 strcpy(tunnel->parms.name, dev->name);
1391
1392 ipip6_tunnel_bind_dev(dev);
1393 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1394 if (!dev->tstats)
1395 return -ENOMEM;
1396
1397 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1398 if (err) {
1399 free_percpu(dev->tstats);
1400 dev->tstats = NULL;
1401 return err;
1402 }
1403
1404 return 0;
1405}
1406
1407static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1408{
1409 struct ip_tunnel *tunnel = netdev_priv(dev);
1410 struct iphdr *iph = &tunnel->parms.iph;
1411 struct net *net = dev_net(dev);
1412 struct sit_net *sitn = net_generic(net, sit_net_id);
1413
1414 iph->version = 4;
1415 iph->protocol = IPPROTO_IPV6;
1416 iph->ihl = 5;
1417 iph->ttl = 64;
1418
1419 dev_hold(dev);
1420 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1421}
1422
1423static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1424 struct netlink_ext_ack *extack)
1425{
1426 u8 proto;
1427
1428 if (!data || !data[IFLA_IPTUN_PROTO])
1429 return 0;
1430
1431 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1432 if (!ipip6_valid_ip_proto(proto))
1433 return -EINVAL;
1434
1435 return 0;
1436}
1437
1438static void ipip6_netlink_parms(struct nlattr *data[],
1439 struct ip_tunnel_parm *parms,
1440 __u32 *fwmark)
1441{
1442 memset(parms, 0, sizeof(*parms));
1443
1444 parms->iph.version = 4;
1445 parms->iph.protocol = IPPROTO_IPV6;
1446 parms->iph.ihl = 5;
1447 parms->iph.ttl = 64;
1448
1449 if (!data)
1450 return;
1451
1452 if (data[IFLA_IPTUN_LINK])
1453 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1454
1455 if (data[IFLA_IPTUN_LOCAL])
1456 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1457
1458 if (data[IFLA_IPTUN_REMOTE])
1459 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1460
1461 if (data[IFLA_IPTUN_TTL]) {
1462 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1463 if (parms->iph.ttl)
1464 parms->iph.frag_off = htons(IP_DF);
1465 }
1466
1467 if (data[IFLA_IPTUN_TOS])
1468 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1469
1470 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1471 parms->iph.frag_off = htons(IP_DF);
1472
1473 if (data[IFLA_IPTUN_FLAGS])
1474 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1475
1476 if (data[IFLA_IPTUN_PROTO])
1477 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1478
1479 if (data[IFLA_IPTUN_FWMARK])
1480 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1481}
1482
1483/* This function returns true when ENCAP attributes are present in the nl msg */
1484static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1485 struct ip_tunnel_encap *ipencap)
1486{
1487 bool ret = false;
1488
1489 memset(ipencap, 0, sizeof(*ipencap));
1490
1491 if (!data)
1492 return ret;
1493
1494 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1495 ret = true;
1496 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1497 }
1498
1499 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1500 ret = true;
1501 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1502 }
1503
1504 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1505 ret = true;
1506 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1507 }
1508
1509 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1510 ret = true;
1511 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1512 }
1513
1514 return ret;
1515}
1516
1517#ifdef CONFIG_IPV6_SIT_6RD
1518/* This function returns true when 6RD attributes are present in the nl msg */
1519static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1520 struct ip_tunnel_6rd *ip6rd)
1521{
1522 bool ret = false;
1523 memset(ip6rd, 0, sizeof(*ip6rd));
1524
1525 if (!data)
1526 return ret;
1527
1528 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1529 ret = true;
1530 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1531 }
1532
1533 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1534 ret = true;
1535 ip6rd->relay_prefix =
1536 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1537 }
1538
1539 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1540 ret = true;
1541 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1542 }
1543
1544 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1545 ret = true;
1546 ip6rd->relay_prefixlen =
1547 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1548 }
1549
1550 return ret;
1551}
1552#endif
1553
1554static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1555 struct nlattr *tb[], struct nlattr *data[],
1556 struct netlink_ext_ack *extack)
1557{
1558 struct net *net = dev_net(dev);
1559 struct ip_tunnel *nt;
1560 struct ip_tunnel_encap ipencap;
1561#ifdef CONFIG_IPV6_SIT_6RD
1562 struct ip_tunnel_6rd ip6rd;
1563#endif
1564 int err;
1565
1566 nt = netdev_priv(dev);
1567
1568 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1569 err = ip_tunnel_encap_setup(nt, &ipencap);
1570 if (err < 0)
1571 return err;
1572 }
1573
1574 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1575
1576 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1577 return -EEXIST;
1578
1579 err = ipip6_tunnel_create(dev);
1580 if (err < 0)
1581 return err;
1582
1583 if (tb[IFLA_MTU]) {
1584 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1585
1586 if (mtu >= IPV6_MIN_MTU &&
1587 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1588 dev->mtu = mtu;
1589 }
1590
1591#ifdef CONFIG_IPV6_SIT_6RD
1592 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1593 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1594#endif
1595
1596 return err;
1597}
1598
1599static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1600 struct nlattr *data[],
1601 struct netlink_ext_ack *extack)
1602{
1603 struct ip_tunnel *t = netdev_priv(dev);
1604 struct ip_tunnel_parm p;
1605 struct ip_tunnel_encap ipencap;
1606 struct net *net = t->net;
1607 struct sit_net *sitn = net_generic(net, sit_net_id);
1608#ifdef CONFIG_IPV6_SIT_6RD
1609 struct ip_tunnel_6rd ip6rd;
1610#endif
1611 __u32 fwmark = t->fwmark;
1612 int err;
1613
1614 if (dev == sitn->fb_tunnel_dev)
1615 return -EINVAL;
1616
1617 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1618 err = ip_tunnel_encap_setup(t, &ipencap);
1619 if (err < 0)
1620 return err;
1621 }
1622
1623 ipip6_netlink_parms(data, &p, &fwmark);
1624
1625 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1626 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1627 return -EINVAL;
1628
1629 t = ipip6_tunnel_locate(net, &p, 0);
1630
1631 if (t) {
1632 if (t->dev != dev)
1633 return -EEXIST;
1634 } else
1635 t = netdev_priv(dev);
1636
1637 ipip6_tunnel_update(t, &p, fwmark);
1638
1639#ifdef CONFIG_IPV6_SIT_6RD
1640 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1641 return ipip6_tunnel_update_6rd(t, &ip6rd);
1642#endif
1643
1644 return 0;
1645}
1646
1647static size_t ipip6_get_size(const struct net_device *dev)
1648{
1649 return
1650 /* IFLA_IPTUN_LINK */
1651 nla_total_size(4) +
1652 /* IFLA_IPTUN_LOCAL */
1653 nla_total_size(4) +
1654 /* IFLA_IPTUN_REMOTE */
1655 nla_total_size(4) +
1656 /* IFLA_IPTUN_TTL */
1657 nla_total_size(1) +
1658 /* IFLA_IPTUN_TOS */
1659 nla_total_size(1) +
1660 /* IFLA_IPTUN_PMTUDISC */
1661 nla_total_size(1) +
1662 /* IFLA_IPTUN_FLAGS */
1663 nla_total_size(2) +
1664 /* IFLA_IPTUN_PROTO */
1665 nla_total_size(1) +
1666#ifdef CONFIG_IPV6_SIT_6RD
1667 /* IFLA_IPTUN_6RD_PREFIX */
1668 nla_total_size(sizeof(struct in6_addr)) +
1669 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1670 nla_total_size(4) +
1671 /* IFLA_IPTUN_6RD_PREFIXLEN */
1672 nla_total_size(2) +
1673 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1674 nla_total_size(2) +
1675#endif
1676 /* IFLA_IPTUN_ENCAP_TYPE */
1677 nla_total_size(2) +
1678 /* IFLA_IPTUN_ENCAP_FLAGS */
1679 nla_total_size(2) +
1680 /* IFLA_IPTUN_ENCAP_SPORT */
1681 nla_total_size(2) +
1682 /* IFLA_IPTUN_ENCAP_DPORT */
1683 nla_total_size(2) +
1684 /* IFLA_IPTUN_FWMARK */
1685 nla_total_size(4) +
1686 0;
1687}
1688
1689static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1690{
1691 struct ip_tunnel *tunnel = netdev_priv(dev);
1692 struct ip_tunnel_parm *parm = &tunnel->parms;
1693
1694 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1695 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1696 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1697 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1698 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1699 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1700 !!(parm->iph.frag_off & htons(IP_DF))) ||
1701 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1702 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1703 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1704 goto nla_put_failure;
1705
1706#ifdef CONFIG_IPV6_SIT_6RD
1707 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1708 &tunnel->ip6rd.prefix) ||
1709 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1710 tunnel->ip6rd.relay_prefix) ||
1711 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1712 tunnel->ip6rd.prefixlen) ||
1713 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1714 tunnel->ip6rd.relay_prefixlen))
1715 goto nla_put_failure;
1716#endif
1717
1718 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1719 tunnel->encap.type) ||
1720 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1721 tunnel->encap.sport) ||
1722 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1723 tunnel->encap.dport) ||
1724 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1725 tunnel->encap.flags))
1726 goto nla_put_failure;
1727
1728 return 0;
1729
1730nla_put_failure:
1731 return -EMSGSIZE;
1732}
1733
1734static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1735 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1736 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1737 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1738 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1739 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1740 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1741 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1742 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1743#ifdef CONFIG_IPV6_SIT_6RD
1744 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1745 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1746 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1747 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1748#endif
1749 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1750 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1751 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1752 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1753 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1754};
1755
1756static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1757{
1758 struct net *net = dev_net(dev);
1759 struct sit_net *sitn = net_generic(net, sit_net_id);
1760
1761 if (dev != sitn->fb_tunnel_dev)
1762 unregister_netdevice_queue(dev, head);
1763}
1764
1765static struct rtnl_link_ops sit_link_ops __read_mostly = {
1766 .kind = "sit",
1767 .maxtype = IFLA_IPTUN_MAX,
1768 .policy = ipip6_policy,
1769 .priv_size = sizeof(struct ip_tunnel),
1770 .setup = ipip6_tunnel_setup,
1771 .validate = ipip6_validate,
1772 .newlink = ipip6_newlink,
1773 .changelink = ipip6_changelink,
1774 .get_size = ipip6_get_size,
1775 .fill_info = ipip6_fill_info,
1776 .dellink = ipip6_dellink,
1777 .get_link_net = ip_tunnel_get_link_net,
1778};
1779
1780static struct xfrm_tunnel sit_handler __read_mostly = {
1781 .handler = ipip6_rcv,
1782 .err_handler = ipip6_err,
1783 .priority = 1,
1784};
1785
1786static struct xfrm_tunnel ipip_handler __read_mostly = {
1787 .handler = ipip_rcv,
1788 .err_handler = ipip6_err,
1789 .priority = 2,
1790};
1791
1792#if IS_ENABLED(CONFIG_MPLS)
1793static struct xfrm_tunnel mplsip_handler __read_mostly = {
1794 .handler = mplsip_rcv,
1795 .err_handler = ipip6_err,
1796 .priority = 2,
1797};
1798#endif
1799
1800static void __net_exit sit_destroy_tunnels(struct net *net,
1801 struct list_head *head)
1802{
1803 struct sit_net *sitn = net_generic(net, sit_net_id);
1804 struct net_device *dev, *aux;
1805 int prio;
1806
1807 for_each_netdev_safe(net, dev, aux)
1808 if (dev->rtnl_link_ops == &sit_link_ops)
1809 unregister_netdevice_queue(dev, head);
1810
1811 for (prio = 1; prio < 4; prio++) {
1812 int h;
1813 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1814 struct ip_tunnel *t;
1815
1816 t = rtnl_dereference(sitn->tunnels[prio][h]);
1817 while (t) {
1818 /* If dev is in the same netns, it has already
1819 * been added to the list by the previous loop.
1820 */
1821 if (!net_eq(dev_net(t->dev), net))
1822 unregister_netdevice_queue(t->dev,
1823 head);
1824 t = rtnl_dereference(t->next);
1825 }
1826 }
1827 }
1828}
1829
1830static int __net_init sit_init_net(struct net *net)
1831{
1832 struct sit_net *sitn = net_generic(net, sit_net_id);
1833 struct ip_tunnel *t;
1834 int err;
1835
1836 sitn->tunnels[0] = sitn->tunnels_wc;
1837 sitn->tunnels[1] = sitn->tunnels_l;
1838 sitn->tunnels[2] = sitn->tunnels_r;
1839 sitn->tunnels[3] = sitn->tunnels_r_l;
1840
1841 if (!net_has_fallback_tunnels(net))
1842 return 0;
1843
1844 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1845 NET_NAME_UNKNOWN,
1846 ipip6_tunnel_setup);
1847 if (!sitn->fb_tunnel_dev) {
1848 err = -ENOMEM;
1849 goto err_alloc_dev;
1850 }
1851 dev_net_set(sitn->fb_tunnel_dev, net);
1852 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1853 /* FB netdevice is special: we have one, and only one per netns.
1854 * Allowing to move it to another netns is clearly unsafe.
1855 */
1856 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1857
1858 err = register_netdev(sitn->fb_tunnel_dev);
1859 if (err)
1860 goto err_reg_dev;
1861
1862 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1863 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1864
1865 t = netdev_priv(sitn->fb_tunnel_dev);
1866
1867 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1868 return 0;
1869
1870err_reg_dev:
1871 ipip6_dev_free(sitn->fb_tunnel_dev);
1872err_alloc_dev:
1873 return err;
1874}
1875
1876static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1877{
1878 LIST_HEAD(list);
1879 struct net *net;
1880
1881 rtnl_lock();
1882 list_for_each_entry(net, net_list, exit_list)
1883 sit_destroy_tunnels(net, &list);
1884
1885 unregister_netdevice_many(&list);
1886 rtnl_unlock();
1887}
1888
1889static struct pernet_operations sit_net_ops = {
1890 .init = sit_init_net,
1891 .exit_batch = sit_exit_batch_net,
1892 .id = &sit_net_id,
1893 .size = sizeof(struct sit_net),
1894};
1895
1896static void __exit sit_cleanup(void)
1897{
1898 rtnl_link_unregister(&sit_link_ops);
1899 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1900 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1901#if IS_ENABLED(CONFIG_MPLS)
1902 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1903#endif
1904
1905 unregister_pernet_device(&sit_net_ops);
1906 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1907}
1908
1909static int __init sit_init(void)
1910{
1911 int err;
1912
1913 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1914
1915 err = register_pernet_device(&sit_net_ops);
1916 if (err < 0)
1917 return err;
1918 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1919 if (err < 0) {
1920 pr_info("%s: can't register ip6ip4\n", __func__);
1921 goto xfrm_tunnel_failed;
1922 }
1923 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1924 if (err < 0) {
1925 pr_info("%s: can't register ip4ip4\n", __func__);
1926 goto xfrm_tunnel4_failed;
1927 }
1928#if IS_ENABLED(CONFIG_MPLS)
1929 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1930 if (err < 0) {
1931 pr_info("%s: can't register mplsip\n", __func__);
1932 goto xfrm_tunnel_mpls_failed;
1933 }
1934#endif
1935 err = rtnl_link_register(&sit_link_ops);
1936 if (err < 0)
1937 goto rtnl_link_failed;
1938
1939out:
1940 return err;
1941
1942rtnl_link_failed:
1943#if IS_ENABLED(CONFIG_MPLS)
1944 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1945xfrm_tunnel_mpls_failed:
1946#endif
1947 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1948xfrm_tunnel4_failed:
1949 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1950xfrm_tunnel_failed:
1951 unregister_pernet_device(&sit_net_ops);
1952 goto out;
1953}
1954
1955module_init(sit_init);
1956module_exit(sit_cleanup);
1957MODULE_LICENSE("GPL");
1958MODULE_ALIAS_RTNL_LINK("sit");
1959MODULE_ALIAS_NETDEV("sit0");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
9 *
10 * Changes:
11 * Roger Venning <r.venning@telstra.com>: 6to4 support
12 * Nate Thompson <nate@thebog.net>: 6to4 support
13 * Fred Templin <fred.l.templin@boeing.com>: isatap support
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/capability.h>
20#include <linux/errno.h>
21#include <linux/types.h>
22#include <linux/socket.h>
23#include <linux/sockios.h>
24#include <linux/net.h>
25#include <linux/in6.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/icmp.h>
29#include <linux/slab.h>
30#include <linux/uaccess.h>
31#include <linux/init.h>
32#include <linux/netfilter_ipv4.h>
33#include <linux/if_ether.h>
34
35#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/transp_v6.h>
41#include <net/ip6_fib.h>
42#include <net/ip6_route.h>
43#include <net/ndisc.h>
44#include <net/addrconf.h>
45#include <net/ip.h>
46#include <net/udp.h>
47#include <net/icmp.h>
48#include <net/ip_tunnels.h>
49#include <net/inet_ecn.h>
50#include <net/xfrm.h>
51#include <net/dsfield.h>
52#include <net/net_namespace.h>
53#include <net/netns/generic.h>
54
55/*
56 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
57
58 For comments look at net/ipv4/ip_gre.c --ANK
59 */
60
61#define IP6_SIT_HASH_SIZE 16
62#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
63
64static bool log_ecn_error = true;
65module_param(log_ecn_error, bool, 0644);
66MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
67
68static int ipip6_tunnel_init(struct net_device *dev);
69static void ipip6_tunnel_setup(struct net_device *dev);
70static void ipip6_dev_free(struct net_device *dev);
71static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
72 __be32 *v4dst);
73static struct rtnl_link_ops sit_link_ops __read_mostly;
74
75static unsigned int sit_net_id __read_mostly;
76struct sit_net {
77 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
78 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
79 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
80 struct ip_tunnel __rcu *tunnels_wc[1];
81 struct ip_tunnel __rcu **tunnels[4];
82
83 struct net_device *fb_tunnel_dev;
84};
85
86/*
87 * Must be invoked with rcu_read_lock
88 */
89static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
90 struct net_device *dev,
91 __be32 remote, __be32 local,
92 int sifindex)
93{
94 unsigned int h0 = HASH(remote);
95 unsigned int h1 = HASH(local);
96 struct ip_tunnel *t;
97 struct sit_net *sitn = net_generic(net, sit_net_id);
98 int ifindex = dev ? dev->ifindex : 0;
99
100 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
101 if (local == t->parms.iph.saddr &&
102 remote == t->parms.iph.daddr &&
103 (!dev || !t->parms.link || ifindex == t->parms.link ||
104 sifindex == t->parms.link) &&
105 (t->dev->flags & IFF_UP))
106 return t;
107 }
108 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
109 if (remote == t->parms.iph.daddr &&
110 (!dev || !t->parms.link || ifindex == t->parms.link ||
111 sifindex == t->parms.link) &&
112 (t->dev->flags & IFF_UP))
113 return t;
114 }
115 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
116 if (local == t->parms.iph.saddr &&
117 (!dev || !t->parms.link || ifindex == t->parms.link ||
118 sifindex == t->parms.link) &&
119 (t->dev->flags & IFF_UP))
120 return t;
121 }
122 t = rcu_dereference(sitn->tunnels_wc[0]);
123 if (t && (t->dev->flags & IFF_UP))
124 return t;
125 return NULL;
126}
127
128static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
129 struct ip_tunnel_parm *parms)
130{
131 __be32 remote = parms->iph.daddr;
132 __be32 local = parms->iph.saddr;
133 unsigned int h = 0;
134 int prio = 0;
135
136 if (remote) {
137 prio |= 2;
138 h ^= HASH(remote);
139 }
140 if (local) {
141 prio |= 1;
142 h ^= HASH(local);
143 }
144 return &sitn->tunnels[prio][h];
145}
146
147static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
148 struct ip_tunnel *t)
149{
150 return __ipip6_bucket(sitn, &t->parms);
151}
152
153static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
154{
155 struct ip_tunnel __rcu **tp;
156 struct ip_tunnel *iter;
157
158 for (tp = ipip6_bucket(sitn, t);
159 (iter = rtnl_dereference(*tp)) != NULL;
160 tp = &iter->next) {
161 if (t == iter) {
162 rcu_assign_pointer(*tp, t->next);
163 break;
164 }
165 }
166}
167
168static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
169{
170 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
171
172 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
173 rcu_assign_pointer(*tp, t);
174}
175
176static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
177{
178#ifdef CONFIG_IPV6_SIT_6RD
179 struct ip_tunnel *t = netdev_priv(dev);
180
181 if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
182 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
183 t->ip6rd.relay_prefix = 0;
184 t->ip6rd.prefixlen = 16;
185 t->ip6rd.relay_prefixlen = 0;
186 } else {
187 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
188 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
189 }
190#endif
191}
192
193static int ipip6_tunnel_create(struct net_device *dev)
194{
195 struct ip_tunnel *t = netdev_priv(dev);
196 struct net *net = dev_net(dev);
197 struct sit_net *sitn = net_generic(net, sit_net_id);
198 int err;
199
200 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
201 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
202
203 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
204 dev->priv_flags |= IFF_ISATAP;
205
206 dev->rtnl_link_ops = &sit_link_ops;
207
208 err = register_netdevice(dev);
209 if (err < 0)
210 goto out;
211
212 ipip6_tunnel_clone_6rd(dev, sitn);
213
214 dev_hold(dev);
215
216 ipip6_tunnel_link(sitn, t);
217 return 0;
218
219out:
220 return err;
221}
222
223static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
224 struct ip_tunnel_parm *parms, int create)
225{
226 __be32 remote = parms->iph.daddr;
227 __be32 local = parms->iph.saddr;
228 struct ip_tunnel *t, *nt;
229 struct ip_tunnel __rcu **tp;
230 struct net_device *dev;
231 char name[IFNAMSIZ];
232 struct sit_net *sitn = net_generic(net, sit_net_id);
233
234 for (tp = __ipip6_bucket(sitn, parms);
235 (t = rtnl_dereference(*tp)) != NULL;
236 tp = &t->next) {
237 if (local == t->parms.iph.saddr &&
238 remote == t->parms.iph.daddr &&
239 parms->link == t->parms.link) {
240 if (create)
241 return NULL;
242 else
243 return t;
244 }
245 }
246 if (!create)
247 goto failed;
248
249 if (parms->name[0]) {
250 if (!dev_valid_name(parms->name))
251 goto failed;
252 strlcpy(name, parms->name, IFNAMSIZ);
253 } else {
254 strcpy(name, "sit%d");
255 }
256 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
257 ipip6_tunnel_setup);
258 if (!dev)
259 return NULL;
260
261 dev_net_set(dev, net);
262
263 nt = netdev_priv(dev);
264
265 nt->parms = *parms;
266 if (ipip6_tunnel_create(dev) < 0)
267 goto failed_free;
268
269 return nt;
270
271failed_free:
272 free_netdev(dev);
273failed:
274 return NULL;
275}
276
277#define for_each_prl_rcu(start) \
278 for (prl = rcu_dereference(start); \
279 prl; \
280 prl = rcu_dereference(prl->next))
281
282static struct ip_tunnel_prl_entry *
283__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
284{
285 struct ip_tunnel_prl_entry *prl;
286
287 for_each_prl_rcu(t->prl)
288 if (prl->addr == addr)
289 break;
290 return prl;
291
292}
293
294static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
295 struct ip_tunnel_prl __user *a)
296{
297 struct ip_tunnel_prl kprl, *kp;
298 struct ip_tunnel_prl_entry *prl;
299 unsigned int cmax, c = 0, ca, len;
300 int ret = 0;
301
302 if (copy_from_user(&kprl, a, sizeof(kprl)))
303 return -EFAULT;
304 cmax = kprl.datalen / sizeof(kprl);
305 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
306 cmax = 1;
307
308 /* For simple GET or for root users,
309 * we try harder to allocate.
310 */
311 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
312 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
313 NULL;
314
315 rcu_read_lock();
316
317 ca = t->prl_count < cmax ? t->prl_count : cmax;
318
319 if (!kp) {
320 /* We don't try hard to allocate much memory for
321 * non-root users.
322 * For root users, retry allocating enough memory for
323 * the answer.
324 */
325 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
326 if (!kp) {
327 ret = -ENOMEM;
328 goto out;
329 }
330 }
331
332 c = 0;
333 for_each_prl_rcu(t->prl) {
334 if (c >= cmax)
335 break;
336 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
337 continue;
338 kp[c].addr = prl->addr;
339 kp[c].flags = prl->flags;
340 c++;
341 if (kprl.addr != htonl(INADDR_ANY))
342 break;
343 }
344out:
345 rcu_read_unlock();
346
347 len = sizeof(*kp) * c;
348 ret = 0;
349 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
350 ret = -EFAULT;
351
352 kfree(kp);
353
354 return ret;
355}
356
357static int
358ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
359{
360 struct ip_tunnel_prl_entry *p;
361 int err = 0;
362
363 if (a->addr == htonl(INADDR_ANY))
364 return -EINVAL;
365
366 ASSERT_RTNL();
367
368 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
369 if (p->addr == a->addr) {
370 if (chg) {
371 p->flags = a->flags;
372 goto out;
373 }
374 err = -EEXIST;
375 goto out;
376 }
377 }
378
379 if (chg) {
380 err = -ENXIO;
381 goto out;
382 }
383
384 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
385 if (!p) {
386 err = -ENOBUFS;
387 goto out;
388 }
389
390 p->next = t->prl;
391 p->addr = a->addr;
392 p->flags = a->flags;
393 t->prl_count++;
394 rcu_assign_pointer(t->prl, p);
395out:
396 return err;
397}
398
399static void prl_list_destroy_rcu(struct rcu_head *head)
400{
401 struct ip_tunnel_prl_entry *p, *n;
402
403 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
404 do {
405 n = rcu_dereference_protected(p->next, 1);
406 kfree(p);
407 p = n;
408 } while (p);
409}
410
411static int
412ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
413{
414 struct ip_tunnel_prl_entry *x;
415 struct ip_tunnel_prl_entry __rcu **p;
416 int err = 0;
417
418 ASSERT_RTNL();
419
420 if (a && a->addr != htonl(INADDR_ANY)) {
421 for (p = &t->prl;
422 (x = rtnl_dereference(*p)) != NULL;
423 p = &x->next) {
424 if (x->addr == a->addr) {
425 *p = x->next;
426 kfree_rcu(x, rcu_head);
427 t->prl_count--;
428 goto out;
429 }
430 }
431 err = -ENXIO;
432 } else {
433 x = rtnl_dereference(t->prl);
434 if (x) {
435 t->prl_count = 0;
436 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
437 t->prl = NULL;
438 }
439 }
440out:
441 return err;
442}
443
444static int
445isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
446{
447 struct ip_tunnel_prl_entry *p;
448 int ok = 1;
449
450 rcu_read_lock();
451 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
452 if (p) {
453 if (p->flags & PRL_DEFAULT)
454 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
455 else
456 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
457 } else {
458 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
459
460 if (ipv6_addr_is_isatap(addr6) &&
461 (addr6->s6_addr32[3] == iph->saddr) &&
462 ipv6_chk_prefix(addr6, t->dev))
463 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
464 else
465 ok = 0;
466 }
467 rcu_read_unlock();
468 return ok;
469}
470
471static void ipip6_tunnel_uninit(struct net_device *dev)
472{
473 struct ip_tunnel *tunnel = netdev_priv(dev);
474 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
475
476 if (dev == sitn->fb_tunnel_dev) {
477 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
478 } else {
479 ipip6_tunnel_unlink(sitn, tunnel);
480 ipip6_tunnel_del_prl(tunnel, NULL);
481 }
482 dst_cache_reset(&tunnel->dst_cache);
483 dev_put(dev);
484}
485
486static int ipip6_err(struct sk_buff *skb, u32 info)
487{
488 const struct iphdr *iph = (const struct iphdr *)skb->data;
489 const int type = icmp_hdr(skb)->type;
490 const int code = icmp_hdr(skb)->code;
491 unsigned int data_len = 0;
492 struct ip_tunnel *t;
493 int sifindex;
494 int err;
495
496 switch (type) {
497 default:
498 case ICMP_PARAMETERPROB:
499 return 0;
500
501 case ICMP_DEST_UNREACH:
502 switch (code) {
503 case ICMP_SR_FAILED:
504 /* Impossible event. */
505 return 0;
506 default:
507 /* All others are translated to HOST_UNREACH.
508 rfc2003 contains "deep thoughts" about NET_UNREACH,
509 I believe they are just ether pollution. --ANK
510 */
511 break;
512 }
513 break;
514 case ICMP_TIME_EXCEEDED:
515 if (code != ICMP_EXC_TTL)
516 return 0;
517 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
518 break;
519 case ICMP_REDIRECT:
520 break;
521 }
522
523 err = -ENOENT;
524
525 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
526 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
527 iph->daddr, iph->saddr, sifindex);
528 if (!t)
529 goto out;
530
531 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
532 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
533 t->parms.link, iph->protocol);
534 err = 0;
535 goto out;
536 }
537 if (type == ICMP_REDIRECT) {
538 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
539 iph->protocol);
540 err = 0;
541 goto out;
542 }
543
544 err = 0;
545 if (__in6_dev_get(skb->dev) &&
546 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
547 goto out;
548
549 if (t->parms.iph.daddr == 0)
550 goto out;
551
552 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
553 goto out;
554
555 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
556 t->err_count++;
557 else
558 t->err_count = 1;
559 t->err_time = jiffies;
560out:
561 return err;
562}
563
564static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
565 const struct in6_addr *v6addr)
566{
567 __be32 v4embed = 0;
568 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
569 return true;
570 return false;
571}
572
573/* Checks if an address matches an address on the tunnel interface.
574 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
575 * Long story:
576 * This function is called after we considered the packet as spoofed
577 * in is_spoofed_6rd.
578 * We may have a router that is doing NAT for proto 41 packets
579 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
580 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
581 * function will return true, dropping the packet.
582 * But, we can still check if is spoofed against the IP
583 * addresses associated with the interface.
584 */
585static bool only_dnatted(const struct ip_tunnel *tunnel,
586 const struct in6_addr *v6dst)
587{
588 int prefix_len;
589
590#ifdef CONFIG_IPV6_SIT_6RD
591 prefix_len = tunnel->ip6rd.prefixlen + 32
592 - tunnel->ip6rd.relay_prefixlen;
593#else
594 prefix_len = 48;
595#endif
596 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
597}
598
599/* Returns true if a packet is spoofed */
600static bool packet_is_spoofed(struct sk_buff *skb,
601 const struct iphdr *iph,
602 struct ip_tunnel *tunnel)
603{
604 const struct ipv6hdr *ipv6h;
605
606 if (tunnel->dev->priv_flags & IFF_ISATAP) {
607 if (!isatap_chksrc(skb, iph, tunnel))
608 return true;
609
610 return false;
611 }
612
613 if (tunnel->dev->flags & IFF_POINTOPOINT)
614 return false;
615
616 ipv6h = ipv6_hdr(skb);
617
618 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
619 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
620 &iph->saddr, &ipv6h->saddr,
621 &iph->daddr, &ipv6h->daddr);
622 return true;
623 }
624
625 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
626 return false;
627
628 if (only_dnatted(tunnel, &ipv6h->daddr))
629 return false;
630
631 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
632 &iph->saddr, &ipv6h->saddr,
633 &iph->daddr, &ipv6h->daddr);
634 return true;
635}
636
637static int ipip6_rcv(struct sk_buff *skb)
638{
639 const struct iphdr *iph = ip_hdr(skb);
640 struct ip_tunnel *tunnel;
641 int sifindex;
642 int err;
643
644 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
645 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
646 iph->saddr, iph->daddr, sifindex);
647 if (tunnel) {
648 struct pcpu_sw_netstats *tstats;
649
650 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
651 tunnel->parms.iph.protocol != 0)
652 goto out;
653
654 skb->mac_header = skb->network_header;
655 skb_reset_network_header(skb);
656 IPCB(skb)->flags = 0;
657 skb->dev = tunnel->dev;
658
659 if (packet_is_spoofed(skb, iph, tunnel)) {
660 tunnel->dev->stats.rx_errors++;
661 goto out;
662 }
663
664 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
665 !net_eq(tunnel->net, dev_net(tunnel->dev))))
666 goto out;
667
668 /* skb can be uncloned in iptunnel_pull_header, so
669 * old iph is no longer valid
670 */
671 iph = (const struct iphdr *)skb_mac_header(skb);
672 err = IP_ECN_decapsulate(iph, skb);
673 if (unlikely(err)) {
674 if (log_ecn_error)
675 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
676 &iph->saddr, iph->tos);
677 if (err > 1) {
678 ++tunnel->dev->stats.rx_frame_errors;
679 ++tunnel->dev->stats.rx_errors;
680 goto out;
681 }
682 }
683
684 tstats = this_cpu_ptr(tunnel->dev->tstats);
685 u64_stats_update_begin(&tstats->syncp);
686 tstats->rx_packets++;
687 tstats->rx_bytes += skb->len;
688 u64_stats_update_end(&tstats->syncp);
689
690 netif_rx(skb);
691
692 return 0;
693 }
694
695 /* no tunnel matched, let upstream know, ipsec may handle it */
696 return 1;
697out:
698 kfree_skb(skb);
699 return 0;
700}
701
702static const struct tnl_ptk_info ipip_tpi = {
703 /* no tunnel info required for ipip. */
704 .proto = htons(ETH_P_IP),
705};
706
707#if IS_ENABLED(CONFIG_MPLS)
708static const struct tnl_ptk_info mplsip_tpi = {
709 /* no tunnel info required for mplsip. */
710 .proto = htons(ETH_P_MPLS_UC),
711};
712#endif
713
714static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
715{
716 const struct iphdr *iph;
717 struct ip_tunnel *tunnel;
718 int sifindex;
719
720 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
721
722 iph = ip_hdr(skb);
723 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
724 iph->saddr, iph->daddr, sifindex);
725 if (tunnel) {
726 const struct tnl_ptk_info *tpi;
727
728 if (tunnel->parms.iph.protocol != ipproto &&
729 tunnel->parms.iph.protocol != 0)
730 goto drop;
731
732 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
733 goto drop;
734#if IS_ENABLED(CONFIG_MPLS)
735 if (ipproto == IPPROTO_MPLS)
736 tpi = &mplsip_tpi;
737 else
738#endif
739 tpi = &ipip_tpi;
740 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
741 goto drop;
742 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
743 }
744
745 return 1;
746
747drop:
748 kfree_skb(skb);
749 return 0;
750}
751
752static int ipip_rcv(struct sk_buff *skb)
753{
754 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
755}
756
757#if IS_ENABLED(CONFIG_MPLS)
758static int mplsip_rcv(struct sk_buff *skb)
759{
760 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
761}
762#endif
763
764/*
765 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
766 * stores the embedded IPv4 address in v4dst and returns true.
767 */
768static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
769 __be32 *v4dst)
770{
771#ifdef CONFIG_IPV6_SIT_6RD
772 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
773 tunnel->ip6rd.prefixlen)) {
774 unsigned int pbw0, pbi0;
775 int pbi1;
776 u32 d;
777
778 pbw0 = tunnel->ip6rd.prefixlen >> 5;
779 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
780
781 d = tunnel->ip6rd.relay_prefixlen < 32 ?
782 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
783 tunnel->ip6rd.relay_prefixlen : 0;
784
785 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
786 if (pbi1 > 0)
787 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
788 (32 - pbi1);
789
790 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
791 return true;
792 }
793#else
794 if (v6dst->s6_addr16[0] == htons(0x2002)) {
795 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
796 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
797 return true;
798 }
799#endif
800 return false;
801}
802
803static inline __be32 try_6rd(struct ip_tunnel *tunnel,
804 const struct in6_addr *v6dst)
805{
806 __be32 dst = 0;
807 check_6rd(tunnel, v6dst, &dst);
808 return dst;
809}
810
811/*
812 * This function assumes it is being called from dev_queue_xmit()
813 * and that skb is filled properly by that function.
814 */
815
816static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
817 struct net_device *dev)
818{
819 struct ip_tunnel *tunnel = netdev_priv(dev);
820 const struct iphdr *tiph = &tunnel->parms.iph;
821 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
822 u8 tos = tunnel->parms.iph.tos;
823 __be16 df = tiph->frag_off;
824 struct rtable *rt; /* Route to the other host */
825 struct net_device *tdev; /* Device to other host */
826 unsigned int max_headroom; /* The extra header space needed */
827 __be32 dst = tiph->daddr;
828 struct flowi4 fl4;
829 int mtu;
830 const struct in6_addr *addr6;
831 int addr_type;
832 u8 ttl;
833 u8 protocol = IPPROTO_IPV6;
834 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
835
836 if (tos == 1)
837 tos = ipv6_get_dsfield(iph6);
838
839 /* ISATAP (RFC4214) - must come before 6to4 */
840 if (dev->priv_flags & IFF_ISATAP) {
841 struct neighbour *neigh = NULL;
842 bool do_tx_error = false;
843
844 if (skb_dst(skb))
845 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
846
847 if (!neigh) {
848 net_dbg_ratelimited("nexthop == NULL\n");
849 goto tx_error;
850 }
851
852 addr6 = (const struct in6_addr *)&neigh->primary_key;
853 addr_type = ipv6_addr_type(addr6);
854
855 if ((addr_type & IPV6_ADDR_UNICAST) &&
856 ipv6_addr_is_isatap(addr6))
857 dst = addr6->s6_addr32[3];
858 else
859 do_tx_error = true;
860
861 neigh_release(neigh);
862 if (do_tx_error)
863 goto tx_error;
864 }
865
866 if (!dst)
867 dst = try_6rd(tunnel, &iph6->daddr);
868
869 if (!dst) {
870 struct neighbour *neigh = NULL;
871 bool do_tx_error = false;
872
873 if (skb_dst(skb))
874 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
875
876 if (!neigh) {
877 net_dbg_ratelimited("nexthop == NULL\n");
878 goto tx_error;
879 }
880
881 addr6 = (const struct in6_addr *)&neigh->primary_key;
882 addr_type = ipv6_addr_type(addr6);
883
884 if (addr_type == IPV6_ADDR_ANY) {
885 addr6 = &ipv6_hdr(skb)->daddr;
886 addr_type = ipv6_addr_type(addr6);
887 }
888
889 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
890 dst = addr6->s6_addr32[3];
891 else
892 do_tx_error = true;
893
894 neigh_release(neigh);
895 if (do_tx_error)
896 goto tx_error;
897 }
898
899 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
900 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
901 0, dst, tiph->saddr, 0, 0,
902 sock_net_uid(tunnel->net, NULL));
903
904 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
905 if (!rt) {
906 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
907 if (IS_ERR(rt)) {
908 dev->stats.tx_carrier_errors++;
909 goto tx_error_icmp;
910 }
911 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
912 }
913
914 if (rt->rt_type != RTN_UNICAST) {
915 ip_rt_put(rt);
916 dev->stats.tx_carrier_errors++;
917 goto tx_error_icmp;
918 }
919 tdev = rt->dst.dev;
920
921 if (tdev == dev) {
922 ip_rt_put(rt);
923 dev->stats.collisions++;
924 goto tx_error;
925 }
926
927 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
928 ip_rt_put(rt);
929 goto tx_error;
930 }
931
932 if (df) {
933 mtu = dst_mtu(&rt->dst) - t_hlen;
934
935 if (mtu < 68) {
936 dev->stats.collisions++;
937 ip_rt_put(rt);
938 goto tx_error;
939 }
940
941 if (mtu < IPV6_MIN_MTU) {
942 mtu = IPV6_MIN_MTU;
943 df = 0;
944 }
945
946 if (tunnel->parms.iph.daddr)
947 skb_dst_update_pmtu(skb, mtu);
948
949 if (skb->len > mtu && !skb_is_gso(skb)) {
950 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
951 ip_rt_put(rt);
952 goto tx_error;
953 }
954 }
955
956 if (tunnel->err_count > 0) {
957 if (time_before(jiffies,
958 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
959 tunnel->err_count--;
960 dst_link_failure(skb);
961 } else
962 tunnel->err_count = 0;
963 }
964
965 /*
966 * Okay, now see if we can stuff it in the buffer as-is.
967 */
968 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
969
970 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
971 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
972 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
973 if (!new_skb) {
974 ip_rt_put(rt);
975 dev->stats.tx_dropped++;
976 kfree_skb(skb);
977 return NETDEV_TX_OK;
978 }
979 if (skb->sk)
980 skb_set_owner_w(new_skb, skb->sk);
981 dev_kfree_skb(skb);
982 skb = new_skb;
983 iph6 = ipv6_hdr(skb);
984 }
985 ttl = tiph->ttl;
986 if (ttl == 0)
987 ttl = iph6->hop_limit;
988 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
989
990 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
991 ip_rt_put(rt);
992 goto tx_error;
993 }
994
995 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
996
997 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
998 df, !net_eq(tunnel->net, dev_net(dev)));
999 return NETDEV_TX_OK;
1000
1001tx_error_icmp:
1002 dst_link_failure(skb);
1003tx_error:
1004 kfree_skb(skb);
1005 dev->stats.tx_errors++;
1006 return NETDEV_TX_OK;
1007}
1008
1009static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1010 struct net_device *dev, u8 ipproto)
1011{
1012 struct ip_tunnel *tunnel = netdev_priv(dev);
1013 const struct iphdr *tiph = &tunnel->parms.iph;
1014
1015 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1016 goto tx_error;
1017
1018 skb_set_inner_ipproto(skb, ipproto);
1019
1020 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1021 return NETDEV_TX_OK;
1022tx_error:
1023 kfree_skb(skb);
1024 dev->stats.tx_errors++;
1025 return NETDEV_TX_OK;
1026}
1027
1028static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1029 struct net_device *dev)
1030{
1031 if (!pskb_inet_may_pull(skb))
1032 goto tx_err;
1033
1034 switch (skb->protocol) {
1035 case htons(ETH_P_IP):
1036 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1037 break;
1038 case htons(ETH_P_IPV6):
1039 ipip6_tunnel_xmit(skb, dev);
1040 break;
1041#if IS_ENABLED(CONFIG_MPLS)
1042 case htons(ETH_P_MPLS_UC):
1043 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1044 break;
1045#endif
1046 default:
1047 goto tx_err;
1048 }
1049
1050 return NETDEV_TX_OK;
1051
1052tx_err:
1053 dev->stats.tx_errors++;
1054 kfree_skb(skb);
1055 return NETDEV_TX_OK;
1056
1057}
1058
1059static void ipip6_tunnel_bind_dev(struct net_device *dev)
1060{
1061 struct net_device *tdev = NULL;
1062 struct ip_tunnel *tunnel;
1063 const struct iphdr *iph;
1064 struct flowi4 fl4;
1065
1066 tunnel = netdev_priv(dev);
1067 iph = &tunnel->parms.iph;
1068
1069 if (iph->daddr) {
1070 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1071 NULL,
1072 iph->daddr, iph->saddr,
1073 0, 0,
1074 IPPROTO_IPV6,
1075 RT_TOS(iph->tos),
1076 tunnel->parms.link);
1077
1078 if (!IS_ERR(rt)) {
1079 tdev = rt->dst.dev;
1080 ip_rt_put(rt);
1081 }
1082 dev->flags |= IFF_POINTOPOINT;
1083 }
1084
1085 if (!tdev && tunnel->parms.link)
1086 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1087
1088 if (tdev && !netif_is_l3_master(tdev)) {
1089 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1090
1091 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1092 dev->mtu = tdev->mtu - t_hlen;
1093 if (dev->mtu < IPV6_MIN_MTU)
1094 dev->mtu = IPV6_MIN_MTU;
1095 }
1096}
1097
1098static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1099 __u32 fwmark)
1100{
1101 struct net *net = t->net;
1102 struct sit_net *sitn = net_generic(net, sit_net_id);
1103
1104 ipip6_tunnel_unlink(sitn, t);
1105 synchronize_net();
1106 t->parms.iph.saddr = p->iph.saddr;
1107 t->parms.iph.daddr = p->iph.daddr;
1108 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1109 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1110 ipip6_tunnel_link(sitn, t);
1111 t->parms.iph.ttl = p->iph.ttl;
1112 t->parms.iph.tos = p->iph.tos;
1113 t->parms.iph.frag_off = p->iph.frag_off;
1114 if (t->parms.link != p->link || t->fwmark != fwmark) {
1115 t->parms.link = p->link;
1116 t->fwmark = fwmark;
1117 ipip6_tunnel_bind_dev(t->dev);
1118 }
1119 dst_cache_reset(&t->dst_cache);
1120 netdev_state_change(t->dev);
1121}
1122
1123#ifdef CONFIG_IPV6_SIT_6RD
1124static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1125 struct ip_tunnel_6rd *ip6rd)
1126{
1127 struct in6_addr prefix;
1128 __be32 relay_prefix;
1129
1130 if (ip6rd->relay_prefixlen > 32 ||
1131 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1132 return -EINVAL;
1133
1134 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1135 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1136 return -EINVAL;
1137 if (ip6rd->relay_prefixlen)
1138 relay_prefix = ip6rd->relay_prefix &
1139 htonl(0xffffffffUL <<
1140 (32 - ip6rd->relay_prefixlen));
1141 else
1142 relay_prefix = 0;
1143 if (relay_prefix != ip6rd->relay_prefix)
1144 return -EINVAL;
1145
1146 t->ip6rd.prefix = prefix;
1147 t->ip6rd.relay_prefix = relay_prefix;
1148 t->ip6rd.prefixlen = ip6rd->prefixlen;
1149 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1150 dst_cache_reset(&t->dst_cache);
1151 netdev_state_change(t->dev);
1152 return 0;
1153}
1154#endif
1155
1156static bool ipip6_valid_ip_proto(u8 ipproto)
1157{
1158 return ipproto == IPPROTO_IPV6 ||
1159 ipproto == IPPROTO_IPIP ||
1160#if IS_ENABLED(CONFIG_MPLS)
1161 ipproto == IPPROTO_MPLS ||
1162#endif
1163 ipproto == 0;
1164}
1165
1166static int
1167ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1168{
1169 int err = 0;
1170 struct ip_tunnel_parm p;
1171 struct ip_tunnel_prl prl;
1172 struct ip_tunnel *t = netdev_priv(dev);
1173 struct net *net = t->net;
1174 struct sit_net *sitn = net_generic(net, sit_net_id);
1175#ifdef CONFIG_IPV6_SIT_6RD
1176 struct ip_tunnel_6rd ip6rd;
1177#endif
1178
1179 switch (cmd) {
1180 case SIOCGETTUNNEL:
1181#ifdef CONFIG_IPV6_SIT_6RD
1182 case SIOCGET6RD:
1183#endif
1184 if (dev == sitn->fb_tunnel_dev) {
1185 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1186 err = -EFAULT;
1187 break;
1188 }
1189 t = ipip6_tunnel_locate(net, &p, 0);
1190 if (!t)
1191 t = netdev_priv(dev);
1192 }
1193
1194 err = -EFAULT;
1195 if (cmd == SIOCGETTUNNEL) {
1196 memcpy(&p, &t->parms, sizeof(p));
1197 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1198 sizeof(p)))
1199 goto done;
1200#ifdef CONFIG_IPV6_SIT_6RD
1201 } else {
1202 ip6rd.prefix = t->ip6rd.prefix;
1203 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1204 ip6rd.prefixlen = t->ip6rd.prefixlen;
1205 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1206 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1207 sizeof(ip6rd)))
1208 goto done;
1209#endif
1210 }
1211 err = 0;
1212 break;
1213
1214 case SIOCADDTUNNEL:
1215 case SIOCCHGTUNNEL:
1216 err = -EPERM;
1217 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1218 goto done;
1219
1220 err = -EFAULT;
1221 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1222 goto done;
1223
1224 err = -EINVAL;
1225 if (!ipip6_valid_ip_proto(p.iph.protocol))
1226 goto done;
1227 if (p.iph.version != 4 ||
1228 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1229 goto done;
1230 if (p.iph.ttl)
1231 p.iph.frag_off |= htons(IP_DF);
1232
1233 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1234
1235 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1236 if (t) {
1237 if (t->dev != dev) {
1238 err = -EEXIST;
1239 break;
1240 }
1241 } else {
1242 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1243 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1244 err = -EINVAL;
1245 break;
1246 }
1247 t = netdev_priv(dev);
1248 }
1249
1250 ipip6_tunnel_update(t, &p, t->fwmark);
1251 }
1252
1253 if (t) {
1254 err = 0;
1255 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1256 err = -EFAULT;
1257 } else
1258 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1259 break;
1260
1261 case SIOCDELTUNNEL:
1262 err = -EPERM;
1263 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264 goto done;
1265
1266 if (dev == sitn->fb_tunnel_dev) {
1267 err = -EFAULT;
1268 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1269 goto done;
1270 err = -ENOENT;
1271 t = ipip6_tunnel_locate(net, &p, 0);
1272 if (!t)
1273 goto done;
1274 err = -EPERM;
1275 if (t == netdev_priv(sitn->fb_tunnel_dev))
1276 goto done;
1277 dev = t->dev;
1278 }
1279 unregister_netdevice(dev);
1280 err = 0;
1281 break;
1282
1283 case SIOCGETPRL:
1284 err = -EINVAL;
1285 if (dev == sitn->fb_tunnel_dev)
1286 goto done;
1287 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1288 break;
1289
1290 case SIOCADDPRL:
1291 case SIOCDELPRL:
1292 case SIOCCHGPRL:
1293 err = -EPERM;
1294 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295 goto done;
1296 err = -EINVAL;
1297 if (dev == sitn->fb_tunnel_dev)
1298 goto done;
1299 err = -EFAULT;
1300 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1301 goto done;
1302
1303 switch (cmd) {
1304 case SIOCDELPRL:
1305 err = ipip6_tunnel_del_prl(t, &prl);
1306 break;
1307 case SIOCADDPRL:
1308 case SIOCCHGPRL:
1309 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1310 break;
1311 }
1312 dst_cache_reset(&t->dst_cache);
1313 netdev_state_change(dev);
1314 break;
1315
1316#ifdef CONFIG_IPV6_SIT_6RD
1317 case SIOCADD6RD:
1318 case SIOCCHG6RD:
1319 case SIOCDEL6RD:
1320 err = -EPERM;
1321 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1322 goto done;
1323
1324 err = -EFAULT;
1325 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1326 sizeof(ip6rd)))
1327 goto done;
1328
1329 if (cmd != SIOCDEL6RD) {
1330 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1331 if (err < 0)
1332 goto done;
1333 } else
1334 ipip6_tunnel_clone_6rd(dev, sitn);
1335
1336 err = 0;
1337 break;
1338#endif
1339
1340 default:
1341 err = -EINVAL;
1342 }
1343
1344done:
1345 return err;
1346}
1347
1348static const struct net_device_ops ipip6_netdev_ops = {
1349 .ndo_init = ipip6_tunnel_init,
1350 .ndo_uninit = ipip6_tunnel_uninit,
1351 .ndo_start_xmit = sit_tunnel_xmit,
1352 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1353 .ndo_get_stats64 = ip_tunnel_get_stats64,
1354 .ndo_get_iflink = ip_tunnel_get_iflink,
1355};
1356
1357static void ipip6_dev_free(struct net_device *dev)
1358{
1359 struct ip_tunnel *tunnel = netdev_priv(dev);
1360
1361 dst_cache_destroy(&tunnel->dst_cache);
1362 free_percpu(dev->tstats);
1363}
1364
1365#define SIT_FEATURES (NETIF_F_SG | \
1366 NETIF_F_FRAGLIST | \
1367 NETIF_F_HIGHDMA | \
1368 NETIF_F_GSO_SOFTWARE | \
1369 NETIF_F_HW_CSUM)
1370
1371static void ipip6_tunnel_setup(struct net_device *dev)
1372{
1373 struct ip_tunnel *tunnel = netdev_priv(dev);
1374 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1375
1376 dev->netdev_ops = &ipip6_netdev_ops;
1377 dev->needs_free_netdev = true;
1378 dev->priv_destructor = ipip6_dev_free;
1379
1380 dev->type = ARPHRD_SIT;
1381 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1382 dev->mtu = ETH_DATA_LEN - t_hlen;
1383 dev->min_mtu = IPV6_MIN_MTU;
1384 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1385 dev->flags = IFF_NOARP;
1386 netif_keep_dst(dev);
1387 dev->addr_len = 4;
1388 dev->features |= NETIF_F_LLTX;
1389 dev->features |= SIT_FEATURES;
1390 dev->hw_features |= SIT_FEATURES;
1391}
1392
1393static int ipip6_tunnel_init(struct net_device *dev)
1394{
1395 struct ip_tunnel *tunnel = netdev_priv(dev);
1396 int err;
1397
1398 tunnel->dev = dev;
1399 tunnel->net = dev_net(dev);
1400 strcpy(tunnel->parms.name, dev->name);
1401
1402 ipip6_tunnel_bind_dev(dev);
1403 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1404 if (!dev->tstats)
1405 return -ENOMEM;
1406
1407 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1408 if (err) {
1409 free_percpu(dev->tstats);
1410 dev->tstats = NULL;
1411 return err;
1412 }
1413
1414 return 0;
1415}
1416
1417static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1418{
1419 struct ip_tunnel *tunnel = netdev_priv(dev);
1420 struct iphdr *iph = &tunnel->parms.iph;
1421 struct net *net = dev_net(dev);
1422 struct sit_net *sitn = net_generic(net, sit_net_id);
1423
1424 iph->version = 4;
1425 iph->protocol = IPPROTO_IPV6;
1426 iph->ihl = 5;
1427 iph->ttl = 64;
1428
1429 dev_hold(dev);
1430 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1431}
1432
1433static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1434 struct netlink_ext_ack *extack)
1435{
1436 u8 proto;
1437
1438 if (!data || !data[IFLA_IPTUN_PROTO])
1439 return 0;
1440
1441 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1442 if (!ipip6_valid_ip_proto(proto))
1443 return -EINVAL;
1444
1445 return 0;
1446}
1447
1448static void ipip6_netlink_parms(struct nlattr *data[],
1449 struct ip_tunnel_parm *parms,
1450 __u32 *fwmark)
1451{
1452 memset(parms, 0, sizeof(*parms));
1453
1454 parms->iph.version = 4;
1455 parms->iph.protocol = IPPROTO_IPV6;
1456 parms->iph.ihl = 5;
1457 parms->iph.ttl = 64;
1458
1459 if (!data)
1460 return;
1461
1462 if (data[IFLA_IPTUN_LINK])
1463 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1464
1465 if (data[IFLA_IPTUN_LOCAL])
1466 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1467
1468 if (data[IFLA_IPTUN_REMOTE])
1469 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1470
1471 if (data[IFLA_IPTUN_TTL]) {
1472 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1473 if (parms->iph.ttl)
1474 parms->iph.frag_off = htons(IP_DF);
1475 }
1476
1477 if (data[IFLA_IPTUN_TOS])
1478 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1479
1480 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1481 parms->iph.frag_off = htons(IP_DF);
1482
1483 if (data[IFLA_IPTUN_FLAGS])
1484 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1485
1486 if (data[IFLA_IPTUN_PROTO])
1487 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1488
1489 if (data[IFLA_IPTUN_FWMARK])
1490 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1491}
1492
1493/* This function returns true when ENCAP attributes are present in the nl msg */
1494static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1495 struct ip_tunnel_encap *ipencap)
1496{
1497 bool ret = false;
1498
1499 memset(ipencap, 0, sizeof(*ipencap));
1500
1501 if (!data)
1502 return ret;
1503
1504 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1505 ret = true;
1506 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1507 }
1508
1509 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1510 ret = true;
1511 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1512 }
1513
1514 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1515 ret = true;
1516 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1517 }
1518
1519 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1520 ret = true;
1521 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1522 }
1523
1524 return ret;
1525}
1526
1527#ifdef CONFIG_IPV6_SIT_6RD
1528/* This function returns true when 6RD attributes are present in the nl msg */
1529static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1530 struct ip_tunnel_6rd *ip6rd)
1531{
1532 bool ret = false;
1533 memset(ip6rd, 0, sizeof(*ip6rd));
1534
1535 if (!data)
1536 return ret;
1537
1538 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1539 ret = true;
1540 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1541 }
1542
1543 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1544 ret = true;
1545 ip6rd->relay_prefix =
1546 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1547 }
1548
1549 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1550 ret = true;
1551 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1552 }
1553
1554 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1555 ret = true;
1556 ip6rd->relay_prefixlen =
1557 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1558 }
1559
1560 return ret;
1561}
1562#endif
1563
1564static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1565 struct nlattr *tb[], struct nlattr *data[],
1566 struct netlink_ext_ack *extack)
1567{
1568 struct net *net = dev_net(dev);
1569 struct ip_tunnel *nt;
1570 struct ip_tunnel_encap ipencap;
1571#ifdef CONFIG_IPV6_SIT_6RD
1572 struct ip_tunnel_6rd ip6rd;
1573#endif
1574 int err;
1575
1576 nt = netdev_priv(dev);
1577
1578 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1579 err = ip_tunnel_encap_setup(nt, &ipencap);
1580 if (err < 0)
1581 return err;
1582 }
1583
1584 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1585
1586 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1587 return -EEXIST;
1588
1589 err = ipip6_tunnel_create(dev);
1590 if (err < 0)
1591 return err;
1592
1593 if (tb[IFLA_MTU]) {
1594 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1595
1596 if (mtu >= IPV6_MIN_MTU &&
1597 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1598 dev->mtu = mtu;
1599 }
1600
1601#ifdef CONFIG_IPV6_SIT_6RD
1602 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1603 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1604#endif
1605
1606 return err;
1607}
1608
1609static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1610 struct nlattr *data[],
1611 struct netlink_ext_ack *extack)
1612{
1613 struct ip_tunnel *t = netdev_priv(dev);
1614 struct ip_tunnel_parm p;
1615 struct ip_tunnel_encap ipencap;
1616 struct net *net = t->net;
1617 struct sit_net *sitn = net_generic(net, sit_net_id);
1618#ifdef CONFIG_IPV6_SIT_6RD
1619 struct ip_tunnel_6rd ip6rd;
1620#endif
1621 __u32 fwmark = t->fwmark;
1622 int err;
1623
1624 if (dev == sitn->fb_tunnel_dev)
1625 return -EINVAL;
1626
1627 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1628 err = ip_tunnel_encap_setup(t, &ipencap);
1629 if (err < 0)
1630 return err;
1631 }
1632
1633 ipip6_netlink_parms(data, &p, &fwmark);
1634
1635 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1636 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1637 return -EINVAL;
1638
1639 t = ipip6_tunnel_locate(net, &p, 0);
1640
1641 if (t) {
1642 if (t->dev != dev)
1643 return -EEXIST;
1644 } else
1645 t = netdev_priv(dev);
1646
1647 ipip6_tunnel_update(t, &p, fwmark);
1648
1649#ifdef CONFIG_IPV6_SIT_6RD
1650 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1651 return ipip6_tunnel_update_6rd(t, &ip6rd);
1652#endif
1653
1654 return 0;
1655}
1656
1657static size_t ipip6_get_size(const struct net_device *dev)
1658{
1659 return
1660 /* IFLA_IPTUN_LINK */
1661 nla_total_size(4) +
1662 /* IFLA_IPTUN_LOCAL */
1663 nla_total_size(4) +
1664 /* IFLA_IPTUN_REMOTE */
1665 nla_total_size(4) +
1666 /* IFLA_IPTUN_TTL */
1667 nla_total_size(1) +
1668 /* IFLA_IPTUN_TOS */
1669 nla_total_size(1) +
1670 /* IFLA_IPTUN_PMTUDISC */
1671 nla_total_size(1) +
1672 /* IFLA_IPTUN_FLAGS */
1673 nla_total_size(2) +
1674 /* IFLA_IPTUN_PROTO */
1675 nla_total_size(1) +
1676#ifdef CONFIG_IPV6_SIT_6RD
1677 /* IFLA_IPTUN_6RD_PREFIX */
1678 nla_total_size(sizeof(struct in6_addr)) +
1679 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1680 nla_total_size(4) +
1681 /* IFLA_IPTUN_6RD_PREFIXLEN */
1682 nla_total_size(2) +
1683 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1684 nla_total_size(2) +
1685#endif
1686 /* IFLA_IPTUN_ENCAP_TYPE */
1687 nla_total_size(2) +
1688 /* IFLA_IPTUN_ENCAP_FLAGS */
1689 nla_total_size(2) +
1690 /* IFLA_IPTUN_ENCAP_SPORT */
1691 nla_total_size(2) +
1692 /* IFLA_IPTUN_ENCAP_DPORT */
1693 nla_total_size(2) +
1694 /* IFLA_IPTUN_FWMARK */
1695 nla_total_size(4) +
1696 0;
1697}
1698
1699static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1700{
1701 struct ip_tunnel *tunnel = netdev_priv(dev);
1702 struct ip_tunnel_parm *parm = &tunnel->parms;
1703
1704 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1705 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1706 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1707 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1708 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1709 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1710 !!(parm->iph.frag_off & htons(IP_DF))) ||
1711 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1712 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1713 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1714 goto nla_put_failure;
1715
1716#ifdef CONFIG_IPV6_SIT_6RD
1717 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1718 &tunnel->ip6rd.prefix) ||
1719 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1720 tunnel->ip6rd.relay_prefix) ||
1721 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1722 tunnel->ip6rd.prefixlen) ||
1723 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1724 tunnel->ip6rd.relay_prefixlen))
1725 goto nla_put_failure;
1726#endif
1727
1728 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1729 tunnel->encap.type) ||
1730 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1731 tunnel->encap.sport) ||
1732 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1733 tunnel->encap.dport) ||
1734 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1735 tunnel->encap.flags))
1736 goto nla_put_failure;
1737
1738 return 0;
1739
1740nla_put_failure:
1741 return -EMSGSIZE;
1742}
1743
1744static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1745 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1746 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1747 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1748 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1749 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1750 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1751 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1752 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1753#ifdef CONFIG_IPV6_SIT_6RD
1754 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1755 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1756 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1757 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1758#endif
1759 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1760 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1761 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1762 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1763 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1764};
1765
1766static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1767{
1768 struct net *net = dev_net(dev);
1769 struct sit_net *sitn = net_generic(net, sit_net_id);
1770
1771 if (dev != sitn->fb_tunnel_dev)
1772 unregister_netdevice_queue(dev, head);
1773}
1774
1775static struct rtnl_link_ops sit_link_ops __read_mostly = {
1776 .kind = "sit",
1777 .maxtype = IFLA_IPTUN_MAX,
1778 .policy = ipip6_policy,
1779 .priv_size = sizeof(struct ip_tunnel),
1780 .setup = ipip6_tunnel_setup,
1781 .validate = ipip6_validate,
1782 .newlink = ipip6_newlink,
1783 .changelink = ipip6_changelink,
1784 .get_size = ipip6_get_size,
1785 .fill_info = ipip6_fill_info,
1786 .dellink = ipip6_dellink,
1787 .get_link_net = ip_tunnel_get_link_net,
1788};
1789
1790static struct xfrm_tunnel sit_handler __read_mostly = {
1791 .handler = ipip6_rcv,
1792 .err_handler = ipip6_err,
1793 .priority = 1,
1794};
1795
1796static struct xfrm_tunnel ipip_handler __read_mostly = {
1797 .handler = ipip_rcv,
1798 .err_handler = ipip6_err,
1799 .priority = 2,
1800};
1801
1802#if IS_ENABLED(CONFIG_MPLS)
1803static struct xfrm_tunnel mplsip_handler __read_mostly = {
1804 .handler = mplsip_rcv,
1805 .err_handler = ipip6_err,
1806 .priority = 2,
1807};
1808#endif
1809
1810static void __net_exit sit_destroy_tunnels(struct net *net,
1811 struct list_head *head)
1812{
1813 struct sit_net *sitn = net_generic(net, sit_net_id);
1814 struct net_device *dev, *aux;
1815 int prio;
1816
1817 for_each_netdev_safe(net, dev, aux)
1818 if (dev->rtnl_link_ops == &sit_link_ops)
1819 unregister_netdevice_queue(dev, head);
1820
1821 for (prio = 1; prio < 4; prio++) {
1822 int h;
1823 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1824 struct ip_tunnel *t;
1825
1826 t = rtnl_dereference(sitn->tunnels[prio][h]);
1827 while (t) {
1828 /* If dev is in the same netns, it has already
1829 * been added to the list by the previous loop.
1830 */
1831 if (!net_eq(dev_net(t->dev), net))
1832 unregister_netdevice_queue(t->dev,
1833 head);
1834 t = rtnl_dereference(t->next);
1835 }
1836 }
1837 }
1838}
1839
1840static int __net_init sit_init_net(struct net *net)
1841{
1842 struct sit_net *sitn = net_generic(net, sit_net_id);
1843 struct ip_tunnel *t;
1844 int err;
1845
1846 sitn->tunnels[0] = sitn->tunnels_wc;
1847 sitn->tunnels[1] = sitn->tunnels_l;
1848 sitn->tunnels[2] = sitn->tunnels_r;
1849 sitn->tunnels[3] = sitn->tunnels_r_l;
1850
1851 if (!net_has_fallback_tunnels(net))
1852 return 0;
1853
1854 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1855 NET_NAME_UNKNOWN,
1856 ipip6_tunnel_setup);
1857 if (!sitn->fb_tunnel_dev) {
1858 err = -ENOMEM;
1859 goto err_alloc_dev;
1860 }
1861 dev_net_set(sitn->fb_tunnel_dev, net);
1862 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1863 /* FB netdevice is special: we have one, and only one per netns.
1864 * Allowing to move it to another netns is clearly unsafe.
1865 */
1866 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1867
1868 err = register_netdev(sitn->fb_tunnel_dev);
1869 if (err)
1870 goto err_reg_dev;
1871
1872 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1873 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1874
1875 t = netdev_priv(sitn->fb_tunnel_dev);
1876
1877 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1878 return 0;
1879
1880err_reg_dev:
1881 ipip6_dev_free(sitn->fb_tunnel_dev);
1882 free_netdev(sitn->fb_tunnel_dev);
1883err_alloc_dev:
1884 return err;
1885}
1886
1887static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1888{
1889 LIST_HEAD(list);
1890 struct net *net;
1891
1892 rtnl_lock();
1893 list_for_each_entry(net, net_list, exit_list)
1894 sit_destroy_tunnels(net, &list);
1895
1896 unregister_netdevice_many(&list);
1897 rtnl_unlock();
1898}
1899
1900static struct pernet_operations sit_net_ops = {
1901 .init = sit_init_net,
1902 .exit_batch = sit_exit_batch_net,
1903 .id = &sit_net_id,
1904 .size = sizeof(struct sit_net),
1905};
1906
1907static void __exit sit_cleanup(void)
1908{
1909 rtnl_link_unregister(&sit_link_ops);
1910 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1911 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1912#if IS_ENABLED(CONFIG_MPLS)
1913 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1914#endif
1915
1916 unregister_pernet_device(&sit_net_ops);
1917 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1918}
1919
1920static int __init sit_init(void)
1921{
1922 int err;
1923
1924 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1925
1926 err = register_pernet_device(&sit_net_ops);
1927 if (err < 0)
1928 return err;
1929 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1930 if (err < 0) {
1931 pr_info("%s: can't register ip6ip4\n", __func__);
1932 goto xfrm_tunnel_failed;
1933 }
1934 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1935 if (err < 0) {
1936 pr_info("%s: can't register ip4ip4\n", __func__);
1937 goto xfrm_tunnel4_failed;
1938 }
1939#if IS_ENABLED(CONFIG_MPLS)
1940 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1941 if (err < 0) {
1942 pr_info("%s: can't register mplsip\n", __func__);
1943 goto xfrm_tunnel_mpls_failed;
1944 }
1945#endif
1946 err = rtnl_link_register(&sit_link_ops);
1947 if (err < 0)
1948 goto rtnl_link_failed;
1949
1950out:
1951 return err;
1952
1953rtnl_link_failed:
1954#if IS_ENABLED(CONFIG_MPLS)
1955 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1956xfrm_tunnel_mpls_failed:
1957#endif
1958 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1959xfrm_tunnel4_failed:
1960 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1961xfrm_tunnel_failed:
1962 unregister_pernet_device(&sit_net_ops);
1963 goto out;
1964}
1965
1966module_init(sit_init);
1967module_exit(sit_cleanup);
1968MODULE_LICENSE("GPL");
1969MODULE_ALIAS_RTNL_LINK("sit");
1970MODULE_ALIAS_NETDEV("sit0");