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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");
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
86static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
87{
88 struct ip_tunnel *t = netdev_priv(dev);
89
90 return net_generic(t->net, sit_net_id);
91}
92
93/*
94 * Must be invoked with rcu_read_lock
95 */
96static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
97 struct net_device *dev,
98 __be32 remote, __be32 local,
99 int sifindex)
100{
101 unsigned int h0 = HASH(remote);
102 unsigned int h1 = HASH(local);
103 struct ip_tunnel *t;
104 struct sit_net *sitn = net_generic(net, sit_net_id);
105 int ifindex = dev ? dev->ifindex : 0;
106
107 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
108 if (local == t->parms.iph.saddr &&
109 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_r[h0]) {
116 if (remote == t->parms.iph.daddr &&
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 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
123 if (local == t->parms.iph.saddr &&
124 (!dev || !t->parms.link || ifindex == t->parms.link ||
125 sifindex == t->parms.link) &&
126 (t->dev->flags & IFF_UP))
127 return t;
128 }
129 t = rcu_dereference(sitn->tunnels_wc[0]);
130 if (t && (t->dev->flags & IFF_UP))
131 return t;
132 return NULL;
133}
134
135static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
136 struct ip_tunnel_parm *parms)
137{
138 __be32 remote = parms->iph.daddr;
139 __be32 local = parms->iph.saddr;
140 unsigned int h = 0;
141 int prio = 0;
142
143 if (remote) {
144 prio |= 2;
145 h ^= HASH(remote);
146 }
147 if (local) {
148 prio |= 1;
149 h ^= HASH(local);
150 }
151 return &sitn->tunnels[prio][h];
152}
153
154static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
155 struct ip_tunnel *t)
156{
157 return __ipip6_bucket(sitn, &t->parms);
158}
159
160static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
161{
162 struct ip_tunnel __rcu **tp;
163 struct ip_tunnel *iter;
164
165 for (tp = ipip6_bucket(sitn, t);
166 (iter = rtnl_dereference(*tp)) != NULL;
167 tp = &iter->next) {
168 if (t == iter) {
169 rcu_assign_pointer(*tp, t->next);
170 break;
171 }
172 }
173}
174
175static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
176{
177 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
178
179 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
180 rcu_assign_pointer(*tp, t);
181}
182
183static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
184{
185#ifdef CONFIG_IPV6_SIT_6RD
186 struct ip_tunnel *t = netdev_priv(dev);
187
188 if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
189 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
190 t->ip6rd.relay_prefix = 0;
191 t->ip6rd.prefixlen = 16;
192 t->ip6rd.relay_prefixlen = 0;
193 } else {
194 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
195 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
196 }
197#endif
198}
199
200static int ipip6_tunnel_create(struct net_device *dev)
201{
202 struct ip_tunnel *t = netdev_priv(dev);
203 struct net *net = dev_net(dev);
204 struct sit_net *sitn = net_generic(net, sit_net_id);
205 int err;
206
207 __dev_addr_set(dev, &t->parms.iph.saddr, 4);
208 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
209
210 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
211 dev->priv_flags |= IFF_ISATAP;
212
213 dev->rtnl_link_ops = &sit_link_ops;
214
215 err = register_netdevice(dev);
216 if (err < 0)
217 goto out;
218
219 ipip6_tunnel_clone_6rd(dev, sitn);
220
221 ipip6_tunnel_link(sitn, t);
222 return 0;
223
224out:
225 return err;
226}
227
228static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
229 struct ip_tunnel_parm *parms, int create)
230{
231 __be32 remote = parms->iph.daddr;
232 __be32 local = parms->iph.saddr;
233 struct ip_tunnel *t, *nt;
234 struct ip_tunnel __rcu **tp;
235 struct net_device *dev;
236 char name[IFNAMSIZ];
237 struct sit_net *sitn = net_generic(net, sit_net_id);
238
239 for (tp = __ipip6_bucket(sitn, parms);
240 (t = rtnl_dereference(*tp)) != NULL;
241 tp = &t->next) {
242 if (local == t->parms.iph.saddr &&
243 remote == t->parms.iph.daddr &&
244 parms->link == t->parms.link) {
245 if (create)
246 return NULL;
247 else
248 return t;
249 }
250 }
251 if (!create)
252 goto failed;
253
254 if (parms->name[0]) {
255 if (!dev_valid_name(parms->name))
256 goto failed;
257 strscpy(name, parms->name, IFNAMSIZ);
258 } else {
259 strcpy(name, "sit%d");
260 }
261 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
262 ipip6_tunnel_setup);
263 if (!dev)
264 return NULL;
265
266 dev_net_set(dev, net);
267
268 nt = netdev_priv(dev);
269
270 nt->parms = *parms;
271 if (ipip6_tunnel_create(dev) < 0)
272 goto failed_free;
273
274 if (!parms->name[0])
275 strcpy(parms->name, dev->name);
276
277 return nt;
278
279failed_free:
280 free_netdev(dev);
281failed:
282 return NULL;
283}
284
285#define for_each_prl_rcu(start) \
286 for (prl = rcu_dereference(start); \
287 prl; \
288 prl = rcu_dereference(prl->next))
289
290static struct ip_tunnel_prl_entry *
291__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
292{
293 struct ip_tunnel_prl_entry *prl;
294
295 for_each_prl_rcu(t->prl)
296 if (prl->addr == addr)
297 break;
298 return prl;
299
300}
301
302static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a)
303{
304 struct ip_tunnel *t = netdev_priv(dev);
305 struct ip_tunnel_prl kprl, *kp;
306 struct ip_tunnel_prl_entry *prl;
307 unsigned int cmax, c = 0, ca, len;
308 int ret = 0;
309
310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
311 return -EINVAL;
312
313 if (copy_from_user(&kprl, a, sizeof(kprl)))
314 return -EFAULT;
315 cmax = kprl.datalen / sizeof(kprl);
316 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
317 cmax = 1;
318
319 /* For simple GET or for root users,
320 * we try harder to allocate.
321 */
322 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
323 kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) :
324 NULL;
325
326 ca = min(t->prl_count, cmax);
327
328 if (!kp) {
329 /* We don't try hard to allocate much memory for
330 * non-root users.
331 * For root users, retry allocating enough memory for
332 * the answer.
333 */
334 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT |
335 __GFP_NOWARN);
336 if (!kp) {
337 ret = -ENOMEM;
338 goto out;
339 }
340 }
341
342 rcu_read_lock();
343 for_each_prl_rcu(t->prl) {
344 if (c >= cmax)
345 break;
346 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
347 continue;
348 kp[c].addr = prl->addr;
349 kp[c].flags = prl->flags;
350 c++;
351 if (kprl.addr != htonl(INADDR_ANY))
352 break;
353 }
354
355 rcu_read_unlock();
356
357 len = sizeof(*kp) * c;
358 ret = 0;
359 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
360 ret = -EFAULT;
361
362 kfree(kp);
363out:
364 return ret;
365}
366
367static int
368ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
369{
370 struct ip_tunnel_prl_entry *p;
371 int err = 0;
372
373 if (a->addr == htonl(INADDR_ANY))
374 return -EINVAL;
375
376 ASSERT_RTNL();
377
378 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
379 if (p->addr == a->addr) {
380 if (chg) {
381 p->flags = a->flags;
382 goto out;
383 }
384 err = -EEXIST;
385 goto out;
386 }
387 }
388
389 if (chg) {
390 err = -ENXIO;
391 goto out;
392 }
393
394 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
395 if (!p) {
396 err = -ENOBUFS;
397 goto out;
398 }
399
400 p->next = t->prl;
401 p->addr = a->addr;
402 p->flags = a->flags;
403 t->prl_count++;
404 rcu_assign_pointer(t->prl, p);
405out:
406 return err;
407}
408
409static void prl_list_destroy_rcu(struct rcu_head *head)
410{
411 struct ip_tunnel_prl_entry *p, *n;
412
413 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
414 do {
415 n = rcu_dereference_protected(p->next, 1);
416 kfree(p);
417 p = n;
418 } while (p);
419}
420
421static int
422ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
423{
424 struct ip_tunnel_prl_entry *x;
425 struct ip_tunnel_prl_entry __rcu **p;
426 int err = 0;
427
428 ASSERT_RTNL();
429
430 if (a && a->addr != htonl(INADDR_ANY)) {
431 for (p = &t->prl;
432 (x = rtnl_dereference(*p)) != NULL;
433 p = &x->next) {
434 if (x->addr == a->addr) {
435 *p = x->next;
436 kfree_rcu(x, rcu_head);
437 t->prl_count--;
438 goto out;
439 }
440 }
441 err = -ENXIO;
442 } else {
443 x = rtnl_dereference(t->prl);
444 if (x) {
445 t->prl_count = 0;
446 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
447 t->prl = NULL;
448 }
449 }
450out:
451 return err;
452}
453
454static int ipip6_tunnel_prl_ctl(struct net_device *dev,
455 struct ip_tunnel_prl __user *data, int cmd)
456{
457 struct ip_tunnel *t = netdev_priv(dev);
458 struct ip_tunnel_prl prl;
459 int err;
460
461 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
462 return -EPERM;
463 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
464 return -EINVAL;
465
466 if (copy_from_user(&prl, data, sizeof(prl)))
467 return -EFAULT;
468
469 switch (cmd) {
470 case SIOCDELPRL:
471 err = ipip6_tunnel_del_prl(t, &prl);
472 break;
473 case SIOCADDPRL:
474 case SIOCCHGPRL:
475 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
476 break;
477 }
478 dst_cache_reset(&t->dst_cache);
479 netdev_state_change(dev);
480 return err;
481}
482
483static int
484isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
485{
486 struct ip_tunnel_prl_entry *p;
487 int ok = 1;
488
489 rcu_read_lock();
490 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
491 if (p) {
492 if (p->flags & PRL_DEFAULT)
493 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
494 else
495 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
496 } else {
497 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
498
499 if (ipv6_addr_is_isatap(addr6) &&
500 (addr6->s6_addr32[3] == iph->saddr) &&
501 ipv6_chk_prefix(addr6, t->dev))
502 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
503 else
504 ok = 0;
505 }
506 rcu_read_unlock();
507 return ok;
508}
509
510static void ipip6_tunnel_uninit(struct net_device *dev)
511{
512 struct ip_tunnel *tunnel = netdev_priv(dev);
513 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
514
515 if (dev == sitn->fb_tunnel_dev) {
516 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
517 } else {
518 ipip6_tunnel_unlink(sitn, tunnel);
519 ipip6_tunnel_del_prl(tunnel, NULL);
520 }
521 dst_cache_reset(&tunnel->dst_cache);
522 netdev_put(dev, &tunnel->dev_tracker);
523}
524
525static int ipip6_err(struct sk_buff *skb, u32 info)
526{
527 const struct iphdr *iph = (const struct iphdr *)skb->data;
528 const int type = icmp_hdr(skb)->type;
529 const int code = icmp_hdr(skb)->code;
530 unsigned int data_len = 0;
531 struct ip_tunnel *t;
532 int sifindex;
533 int err;
534
535 switch (type) {
536 default:
537 case ICMP_PARAMETERPROB:
538 return 0;
539
540 case ICMP_DEST_UNREACH:
541 switch (code) {
542 case ICMP_SR_FAILED:
543 /* Impossible event. */
544 return 0;
545 default:
546 /* All others are translated to HOST_UNREACH.
547 rfc2003 contains "deep thoughts" about NET_UNREACH,
548 I believe they are just ether pollution. --ANK
549 */
550 break;
551 }
552 break;
553 case ICMP_TIME_EXCEEDED:
554 if (code != ICMP_EXC_TTL)
555 return 0;
556 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
557 break;
558 case ICMP_REDIRECT:
559 break;
560 }
561
562 err = -ENOENT;
563
564 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
565 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
566 iph->daddr, iph->saddr, sifindex);
567 if (!t)
568 goto out;
569
570 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
571 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
572 t->parms.link, iph->protocol);
573 err = 0;
574 goto out;
575 }
576 if (type == ICMP_REDIRECT) {
577 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
578 iph->protocol);
579 err = 0;
580 goto out;
581 }
582
583 err = 0;
584 if (__in6_dev_get(skb->dev) &&
585 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
586 goto out;
587
588 if (t->parms.iph.daddr == 0)
589 goto out;
590
591 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
592 goto out;
593
594 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
595 t->err_count++;
596 else
597 t->err_count = 1;
598 t->err_time = jiffies;
599out:
600 return err;
601}
602
603static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
604 const struct in6_addr *v6addr)
605{
606 __be32 v4embed = 0;
607 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
608 return true;
609 return false;
610}
611
612/* Checks if an address matches an address on the tunnel interface.
613 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
614 * Long story:
615 * This function is called after we considered the packet as spoofed
616 * in is_spoofed_6rd.
617 * We may have a router that is doing NAT for proto 41 packets
618 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
619 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
620 * function will return true, dropping the packet.
621 * But, we can still check if is spoofed against the IP
622 * addresses associated with the interface.
623 */
624static bool only_dnatted(const struct ip_tunnel *tunnel,
625 const struct in6_addr *v6dst)
626{
627 int prefix_len;
628
629#ifdef CONFIG_IPV6_SIT_6RD
630 prefix_len = tunnel->ip6rd.prefixlen + 32
631 - tunnel->ip6rd.relay_prefixlen;
632#else
633 prefix_len = 48;
634#endif
635 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
636}
637
638/* Returns true if a packet is spoofed */
639static bool packet_is_spoofed(struct sk_buff *skb,
640 const struct iphdr *iph,
641 struct ip_tunnel *tunnel)
642{
643 const struct ipv6hdr *ipv6h;
644
645 if (tunnel->dev->priv_flags & IFF_ISATAP) {
646 if (!isatap_chksrc(skb, iph, tunnel))
647 return true;
648
649 return false;
650 }
651
652 if (tunnel->dev->flags & IFF_POINTOPOINT)
653 return false;
654
655 ipv6h = ipv6_hdr(skb);
656
657 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
658 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
659 &iph->saddr, &ipv6h->saddr,
660 &iph->daddr, &ipv6h->daddr);
661 return true;
662 }
663
664 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
665 return false;
666
667 if (only_dnatted(tunnel, &ipv6h->daddr))
668 return false;
669
670 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
671 &iph->saddr, &ipv6h->saddr,
672 &iph->daddr, &ipv6h->daddr);
673 return true;
674}
675
676static int ipip6_rcv(struct sk_buff *skb)
677{
678 const struct iphdr *iph = ip_hdr(skb);
679 struct ip_tunnel *tunnel;
680 int sifindex;
681 int err;
682
683 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
684 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
685 iph->saddr, iph->daddr, sifindex);
686 if (tunnel) {
687 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
688 tunnel->parms.iph.protocol != 0)
689 goto out;
690
691 skb->mac_header = skb->network_header;
692 skb_reset_network_header(skb);
693 IPCB(skb)->flags = 0;
694 skb->dev = tunnel->dev;
695
696 if (packet_is_spoofed(skb, iph, tunnel)) {
697 DEV_STATS_INC(tunnel->dev, rx_errors);
698 goto out;
699 }
700
701 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
702 !net_eq(tunnel->net, dev_net(tunnel->dev))))
703 goto out;
704
705 /* skb can be uncloned in iptunnel_pull_header, so
706 * old iph is no longer valid
707 */
708 iph = (const struct iphdr *)skb_mac_header(skb);
709 skb_reset_mac_header(skb);
710
711 err = IP_ECN_decapsulate(iph, skb);
712 if (unlikely(err)) {
713 if (log_ecn_error)
714 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
715 &iph->saddr, iph->tos);
716 if (err > 1) {
717 DEV_STATS_INC(tunnel->dev, rx_frame_errors);
718 DEV_STATS_INC(tunnel->dev, rx_errors);
719 goto out;
720 }
721 }
722
723 dev_sw_netstats_rx_add(tunnel->dev, skb->len);
724
725 netif_rx(skb);
726
727 return 0;
728 }
729
730 /* no tunnel matched, let upstream know, ipsec may handle it */
731 return 1;
732out:
733 kfree_skb(skb);
734 return 0;
735}
736
737static const struct tnl_ptk_info ipip_tpi = {
738 /* no tunnel info required for ipip. */
739 .proto = htons(ETH_P_IP),
740};
741
742#if IS_ENABLED(CONFIG_MPLS)
743static const struct tnl_ptk_info mplsip_tpi = {
744 /* no tunnel info required for mplsip. */
745 .proto = htons(ETH_P_MPLS_UC),
746};
747#endif
748
749static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
750{
751 const struct iphdr *iph;
752 struct ip_tunnel *tunnel;
753 int sifindex;
754
755 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
756
757 iph = ip_hdr(skb);
758 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
759 iph->saddr, iph->daddr, sifindex);
760 if (tunnel) {
761 const struct tnl_ptk_info *tpi;
762
763 if (tunnel->parms.iph.protocol != ipproto &&
764 tunnel->parms.iph.protocol != 0)
765 goto drop;
766
767 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
768 goto drop;
769#if IS_ENABLED(CONFIG_MPLS)
770 if (ipproto == IPPROTO_MPLS)
771 tpi = &mplsip_tpi;
772 else
773#endif
774 tpi = &ipip_tpi;
775 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
776 goto drop;
777 skb_reset_mac_header(skb);
778
779 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
780 }
781
782 return 1;
783
784drop:
785 kfree_skb(skb);
786 return 0;
787}
788
789static int ipip_rcv(struct sk_buff *skb)
790{
791 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
792}
793
794#if IS_ENABLED(CONFIG_MPLS)
795static int mplsip_rcv(struct sk_buff *skb)
796{
797 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
798}
799#endif
800
801/*
802 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
803 * stores the embedded IPv4 address in v4dst and returns true.
804 */
805static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
806 __be32 *v4dst)
807{
808#ifdef CONFIG_IPV6_SIT_6RD
809 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
810 tunnel->ip6rd.prefixlen)) {
811 unsigned int pbw0, pbi0;
812 int pbi1;
813 u32 d;
814
815 pbw0 = tunnel->ip6rd.prefixlen >> 5;
816 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
817
818 d = tunnel->ip6rd.relay_prefixlen < 32 ?
819 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
820 tunnel->ip6rd.relay_prefixlen : 0;
821
822 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
823 if (pbi1 > 0)
824 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
825 (32 - pbi1);
826
827 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
828 return true;
829 }
830#else
831 if (v6dst->s6_addr16[0] == htons(0x2002)) {
832 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
833 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
834 return true;
835 }
836#endif
837 return false;
838}
839
840static inline __be32 try_6rd(struct ip_tunnel *tunnel,
841 const struct in6_addr *v6dst)
842{
843 __be32 dst = 0;
844 check_6rd(tunnel, v6dst, &dst);
845 return dst;
846}
847
848/*
849 * This function assumes it is being called from dev_queue_xmit()
850 * and that skb is filled properly by that function.
851 */
852
853static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
854 struct net_device *dev)
855{
856 struct ip_tunnel *tunnel = netdev_priv(dev);
857 const struct iphdr *tiph = &tunnel->parms.iph;
858 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
859 u8 tos = tunnel->parms.iph.tos;
860 __be16 df = tiph->frag_off;
861 struct rtable *rt; /* Route to the other host */
862 struct net_device *tdev; /* Device to other host */
863 unsigned int max_headroom; /* The extra header space needed */
864 __be32 dst = tiph->daddr;
865 struct flowi4 fl4;
866 int mtu;
867 const struct in6_addr *addr6;
868 int addr_type;
869 u8 ttl;
870 u8 protocol = IPPROTO_IPV6;
871 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
872
873 if (tos == 1)
874 tos = ipv6_get_dsfield(iph6);
875
876 /* ISATAP (RFC4214) - must come before 6to4 */
877 if (dev->priv_flags & IFF_ISATAP) {
878 struct neighbour *neigh = NULL;
879 bool do_tx_error = false;
880
881 if (skb_dst(skb))
882 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
883
884 if (!neigh) {
885 net_dbg_ratelimited("nexthop == NULL\n");
886 goto tx_error;
887 }
888
889 addr6 = (const struct in6_addr *)&neigh->primary_key;
890 addr_type = ipv6_addr_type(addr6);
891
892 if ((addr_type & IPV6_ADDR_UNICAST) &&
893 ipv6_addr_is_isatap(addr6))
894 dst = addr6->s6_addr32[3];
895 else
896 do_tx_error = true;
897
898 neigh_release(neigh);
899 if (do_tx_error)
900 goto tx_error;
901 }
902
903 if (!dst)
904 dst = try_6rd(tunnel, &iph6->daddr);
905
906 if (!dst) {
907 struct neighbour *neigh = NULL;
908 bool do_tx_error = false;
909
910 if (skb_dst(skb))
911 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
912
913 if (!neigh) {
914 net_dbg_ratelimited("nexthop == NULL\n");
915 goto tx_error;
916 }
917
918 addr6 = (const struct in6_addr *)&neigh->primary_key;
919 addr_type = ipv6_addr_type(addr6);
920
921 if (addr_type == IPV6_ADDR_ANY) {
922 addr6 = &ipv6_hdr(skb)->daddr;
923 addr_type = ipv6_addr_type(addr6);
924 }
925
926 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
927 dst = addr6->s6_addr32[3];
928 else
929 do_tx_error = true;
930
931 neigh_release(neigh);
932 if (do_tx_error)
933 goto tx_error;
934 }
935
936 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
937 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
938 0, dst, tiph->saddr, 0, 0,
939 sock_net_uid(tunnel->net, NULL));
940
941 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
942 if (!rt) {
943 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
944 if (IS_ERR(rt)) {
945 DEV_STATS_INC(dev, tx_carrier_errors);
946 goto tx_error_icmp;
947 }
948 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
949 }
950
951 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
952 ip_rt_put(rt);
953 DEV_STATS_INC(dev, tx_carrier_errors);
954 goto tx_error_icmp;
955 }
956 tdev = rt->dst.dev;
957
958 if (tdev == dev) {
959 ip_rt_put(rt);
960 DEV_STATS_INC(dev, collisions);
961 goto tx_error;
962 }
963
964 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
965 ip_rt_put(rt);
966 goto tx_error;
967 }
968
969 if (df) {
970 mtu = dst_mtu(&rt->dst) - t_hlen;
971
972 if (mtu < IPV4_MIN_MTU) {
973 DEV_STATS_INC(dev, collisions);
974 ip_rt_put(rt);
975 goto tx_error;
976 }
977
978 if (mtu < IPV6_MIN_MTU) {
979 mtu = IPV6_MIN_MTU;
980 df = 0;
981 }
982
983 if (tunnel->parms.iph.daddr)
984 skb_dst_update_pmtu_no_confirm(skb, mtu);
985
986 if (skb->len > mtu && !skb_is_gso(skb)) {
987 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
988 ip_rt_put(rt);
989 goto tx_error;
990 }
991 }
992
993 if (tunnel->err_count > 0) {
994 if (time_before(jiffies,
995 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
996 tunnel->err_count--;
997 dst_link_failure(skb);
998 } else
999 tunnel->err_count = 0;
1000 }
1001
1002 /*
1003 * Okay, now see if we can stuff it in the buffer as-is.
1004 */
1005 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1006
1007 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1008 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1009 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1010 if (!new_skb) {
1011 ip_rt_put(rt);
1012 DEV_STATS_INC(dev, tx_dropped);
1013 kfree_skb(skb);
1014 return NETDEV_TX_OK;
1015 }
1016 if (skb->sk)
1017 skb_set_owner_w(new_skb, skb->sk);
1018 dev_kfree_skb(skb);
1019 skb = new_skb;
1020 iph6 = ipv6_hdr(skb);
1021 }
1022 ttl = tiph->ttl;
1023 if (ttl == 0)
1024 ttl = iph6->hop_limit;
1025 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1026
1027 if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0) {
1028 ip_rt_put(rt);
1029 goto tx_error;
1030 }
1031
1032 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1033
1034 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1035 df, !net_eq(tunnel->net, dev_net(dev)));
1036 return NETDEV_TX_OK;
1037
1038tx_error_icmp:
1039 dst_link_failure(skb);
1040tx_error:
1041 kfree_skb(skb);
1042 DEV_STATS_INC(dev, tx_errors);
1043 return NETDEV_TX_OK;
1044}
1045
1046static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1047 struct net_device *dev, u8 ipproto)
1048{
1049 struct ip_tunnel *tunnel = netdev_priv(dev);
1050 const struct iphdr *tiph = &tunnel->parms.iph;
1051
1052 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1053 goto tx_error;
1054
1055 skb_set_inner_ipproto(skb, ipproto);
1056
1057 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1058 return NETDEV_TX_OK;
1059tx_error:
1060 kfree_skb(skb);
1061 DEV_STATS_INC(dev, tx_errors);
1062 return NETDEV_TX_OK;
1063}
1064
1065static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1066 struct net_device *dev)
1067{
1068 if (!pskb_inet_may_pull(skb))
1069 goto tx_err;
1070
1071 switch (skb->protocol) {
1072 case htons(ETH_P_IP):
1073 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1074 break;
1075 case htons(ETH_P_IPV6):
1076 ipip6_tunnel_xmit(skb, dev);
1077 break;
1078#if IS_ENABLED(CONFIG_MPLS)
1079 case htons(ETH_P_MPLS_UC):
1080 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1081 break;
1082#endif
1083 default:
1084 goto tx_err;
1085 }
1086
1087 return NETDEV_TX_OK;
1088
1089tx_err:
1090 DEV_STATS_INC(dev, tx_errors);
1091 kfree_skb(skb);
1092 return NETDEV_TX_OK;
1093
1094}
1095
1096static void ipip6_tunnel_bind_dev(struct net_device *dev)
1097{
1098 struct ip_tunnel *tunnel = netdev_priv(dev);
1099 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1100 struct net_device *tdev = NULL;
1101 int hlen = LL_MAX_HEADER;
1102 const struct iphdr *iph;
1103 struct flowi4 fl4;
1104
1105 iph = &tunnel->parms.iph;
1106
1107 if (iph->daddr) {
1108 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1109 NULL,
1110 iph->daddr, iph->saddr,
1111 0, 0,
1112 IPPROTO_IPV6,
1113 RT_TOS(iph->tos),
1114 tunnel->parms.link);
1115
1116 if (!IS_ERR(rt)) {
1117 tdev = rt->dst.dev;
1118 ip_rt_put(rt);
1119 }
1120 dev->flags |= IFF_POINTOPOINT;
1121 }
1122
1123 if (!tdev && tunnel->parms.link)
1124 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1125
1126 if (tdev && !netif_is_l3_master(tdev)) {
1127 int mtu;
1128
1129 mtu = tdev->mtu - t_hlen;
1130 if (mtu < IPV6_MIN_MTU)
1131 mtu = IPV6_MIN_MTU;
1132 WRITE_ONCE(dev->mtu, mtu);
1133 hlen = tdev->hard_header_len + tdev->needed_headroom;
1134 }
1135 dev->needed_headroom = t_hlen + hlen;
1136}
1137
1138static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1139 __u32 fwmark)
1140{
1141 struct net *net = t->net;
1142 struct sit_net *sitn = net_generic(net, sit_net_id);
1143
1144 ipip6_tunnel_unlink(sitn, t);
1145 synchronize_net();
1146 t->parms.iph.saddr = p->iph.saddr;
1147 t->parms.iph.daddr = p->iph.daddr;
1148 __dev_addr_set(t->dev, &p->iph.saddr, 4);
1149 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1150 ipip6_tunnel_link(sitn, t);
1151 t->parms.iph.ttl = p->iph.ttl;
1152 t->parms.iph.tos = p->iph.tos;
1153 t->parms.iph.frag_off = p->iph.frag_off;
1154 if (t->parms.link != p->link || t->fwmark != fwmark) {
1155 t->parms.link = p->link;
1156 t->fwmark = fwmark;
1157 ipip6_tunnel_bind_dev(t->dev);
1158 }
1159 dst_cache_reset(&t->dst_cache);
1160 netdev_state_change(t->dev);
1161}
1162
1163#ifdef CONFIG_IPV6_SIT_6RD
1164static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1165 struct ip_tunnel_6rd *ip6rd)
1166{
1167 struct in6_addr prefix;
1168 __be32 relay_prefix;
1169
1170 if (ip6rd->relay_prefixlen > 32 ||
1171 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1172 return -EINVAL;
1173
1174 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1175 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1176 return -EINVAL;
1177 if (ip6rd->relay_prefixlen)
1178 relay_prefix = ip6rd->relay_prefix &
1179 htonl(0xffffffffUL <<
1180 (32 - ip6rd->relay_prefixlen));
1181 else
1182 relay_prefix = 0;
1183 if (relay_prefix != ip6rd->relay_prefix)
1184 return -EINVAL;
1185
1186 t->ip6rd.prefix = prefix;
1187 t->ip6rd.relay_prefix = relay_prefix;
1188 t->ip6rd.prefixlen = ip6rd->prefixlen;
1189 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1190 dst_cache_reset(&t->dst_cache);
1191 netdev_state_change(t->dev);
1192 return 0;
1193}
1194
1195static int
1196ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data)
1197{
1198 struct ip_tunnel *t = netdev_priv(dev);
1199 struct ip_tunnel_6rd ip6rd;
1200 struct ip_tunnel_parm p;
1201
1202 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1203 if (copy_from_user(&p, data, sizeof(p)))
1204 return -EFAULT;
1205 t = ipip6_tunnel_locate(t->net, &p, 0);
1206 }
1207 if (!t)
1208 t = netdev_priv(dev);
1209
1210 ip6rd.prefix = t->ip6rd.prefix;
1211 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1212 ip6rd.prefixlen = t->ip6rd.prefixlen;
1213 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1214 if (copy_to_user(data, &ip6rd, sizeof(ip6rd)))
1215 return -EFAULT;
1216 return 0;
1217}
1218
1219static int
1220ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data,
1221 int cmd)
1222{
1223 struct ip_tunnel *t = netdev_priv(dev);
1224 struct ip_tunnel_6rd ip6rd;
1225 int err;
1226
1227 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1228 return -EPERM;
1229 if (copy_from_user(&ip6rd, data, sizeof(ip6rd)))
1230 return -EFAULT;
1231
1232 if (cmd != SIOCDEL6RD) {
1233 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1234 if (err < 0)
1235 return err;
1236 } else
1237 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1238 return 0;
1239}
1240
1241#endif /* CONFIG_IPV6_SIT_6RD */
1242
1243static bool ipip6_valid_ip_proto(u8 ipproto)
1244{
1245 return ipproto == IPPROTO_IPV6 ||
1246 ipproto == IPPROTO_IPIP ||
1247#if IS_ENABLED(CONFIG_MPLS)
1248 ipproto == IPPROTO_MPLS ||
1249#endif
1250 ipproto == 0;
1251}
1252
1253static int
1254__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1255{
1256 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1257 return -EPERM;
1258
1259 if (!ipip6_valid_ip_proto(p->iph.protocol))
1260 return -EINVAL;
1261 if (p->iph.version != 4 ||
1262 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1263 return -EINVAL;
1264
1265 if (p->iph.ttl)
1266 p->iph.frag_off |= htons(IP_DF);
1267 return 0;
1268}
1269
1270static int
1271ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1272{
1273 struct ip_tunnel *t = netdev_priv(dev);
1274
1275 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1276 t = ipip6_tunnel_locate(t->net, p, 0);
1277 if (!t)
1278 t = netdev_priv(dev);
1279 memcpy(p, &t->parms, sizeof(*p));
1280 return 0;
1281}
1282
1283static int
1284ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1285{
1286 struct ip_tunnel *t = netdev_priv(dev);
1287 int err;
1288
1289 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1290 if (err)
1291 return err;
1292
1293 t = ipip6_tunnel_locate(t->net, p, 1);
1294 if (!t)
1295 return -ENOBUFS;
1296 return 0;
1297}
1298
1299static int
1300ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1301{
1302 struct ip_tunnel *t = netdev_priv(dev);
1303 int err;
1304
1305 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1306 if (err)
1307 return err;
1308
1309 t = ipip6_tunnel_locate(t->net, p, 0);
1310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1311 if (!t)
1312 return -ENOENT;
1313 } else {
1314 if (t) {
1315 if (t->dev != dev)
1316 return -EEXIST;
1317 } else {
1318 if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1319 (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1320 return -EINVAL;
1321 t = netdev_priv(dev);
1322 }
1323
1324 ipip6_tunnel_update(t, p, t->fwmark);
1325 }
1326
1327 return 0;
1328}
1329
1330static int
1331ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1332{
1333 struct ip_tunnel *t = netdev_priv(dev);
1334
1335 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1336 return -EPERM;
1337
1338 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1339 t = ipip6_tunnel_locate(t->net, p, 0);
1340 if (!t)
1341 return -ENOENT;
1342 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1343 return -EPERM;
1344 dev = t->dev;
1345 }
1346 unregister_netdevice(dev);
1347 return 0;
1348}
1349
1350static int
1351ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1352{
1353 switch (cmd) {
1354 case SIOCGETTUNNEL:
1355 return ipip6_tunnel_get(dev, p);
1356 case SIOCADDTUNNEL:
1357 return ipip6_tunnel_add(dev, p);
1358 case SIOCCHGTUNNEL:
1359 return ipip6_tunnel_change(dev, p);
1360 case SIOCDELTUNNEL:
1361 return ipip6_tunnel_del(dev, p);
1362 default:
1363 return -EINVAL;
1364 }
1365}
1366
1367static int
1368ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1369 void __user *data, int cmd)
1370{
1371 switch (cmd) {
1372 case SIOCGETTUNNEL:
1373 case SIOCADDTUNNEL:
1374 case SIOCCHGTUNNEL:
1375 case SIOCDELTUNNEL:
1376 return ip_tunnel_siocdevprivate(dev, ifr, data, cmd);
1377 case SIOCGETPRL:
1378 return ipip6_tunnel_get_prl(dev, data);
1379 case SIOCADDPRL:
1380 case SIOCDELPRL:
1381 case SIOCCHGPRL:
1382 return ipip6_tunnel_prl_ctl(dev, data, cmd);
1383#ifdef CONFIG_IPV6_SIT_6RD
1384 case SIOCGET6RD:
1385 return ipip6_tunnel_get6rd(dev, data);
1386 case SIOCADD6RD:
1387 case SIOCCHG6RD:
1388 case SIOCDEL6RD:
1389 return ipip6_tunnel_6rdctl(dev, data, cmd);
1390#endif
1391 default:
1392 return -EINVAL;
1393 }
1394}
1395
1396static const struct net_device_ops ipip6_netdev_ops = {
1397 .ndo_init = ipip6_tunnel_init,
1398 .ndo_uninit = ipip6_tunnel_uninit,
1399 .ndo_start_xmit = sit_tunnel_xmit,
1400 .ndo_siocdevprivate = ipip6_tunnel_siocdevprivate,
1401 .ndo_get_iflink = ip_tunnel_get_iflink,
1402 .ndo_tunnel_ctl = ipip6_tunnel_ctl,
1403};
1404
1405static void ipip6_dev_free(struct net_device *dev)
1406{
1407 struct ip_tunnel *tunnel = netdev_priv(dev);
1408
1409 dst_cache_destroy(&tunnel->dst_cache);
1410}
1411
1412#define SIT_FEATURES (NETIF_F_SG | \
1413 NETIF_F_FRAGLIST | \
1414 NETIF_F_HIGHDMA | \
1415 NETIF_F_GSO_SOFTWARE | \
1416 NETIF_F_HW_CSUM)
1417
1418static void ipip6_tunnel_setup(struct net_device *dev)
1419{
1420 struct ip_tunnel *tunnel = netdev_priv(dev);
1421 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1422
1423 dev->netdev_ops = &ipip6_netdev_ops;
1424 dev->header_ops = &ip_tunnel_header_ops;
1425 dev->needs_free_netdev = true;
1426 dev->priv_destructor = ipip6_dev_free;
1427
1428 dev->type = ARPHRD_SIT;
1429 dev->mtu = ETH_DATA_LEN - t_hlen;
1430 dev->min_mtu = IPV6_MIN_MTU;
1431 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1432 dev->flags = IFF_NOARP;
1433 netif_keep_dst(dev);
1434 dev->addr_len = 4;
1435 dev->features |= NETIF_F_LLTX;
1436 dev->features |= SIT_FEATURES;
1437 dev->hw_features |= SIT_FEATURES;
1438 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1439
1440}
1441
1442static int ipip6_tunnel_init(struct net_device *dev)
1443{
1444 struct ip_tunnel *tunnel = netdev_priv(dev);
1445 int err;
1446
1447 tunnel->dev = dev;
1448 tunnel->net = dev_net(dev);
1449 strcpy(tunnel->parms.name, dev->name);
1450
1451 ipip6_tunnel_bind_dev(dev);
1452
1453 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1454 if (err)
1455 return err;
1456
1457 netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
1458 netdev_lockdep_set_classes(dev);
1459 return 0;
1460}
1461
1462static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1463{
1464 struct ip_tunnel *tunnel = netdev_priv(dev);
1465 struct iphdr *iph = &tunnel->parms.iph;
1466 struct net *net = dev_net(dev);
1467 struct sit_net *sitn = net_generic(net, sit_net_id);
1468
1469 iph->version = 4;
1470 iph->protocol = IPPROTO_IPV6;
1471 iph->ihl = 5;
1472 iph->ttl = 64;
1473
1474 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1475}
1476
1477static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1478 struct netlink_ext_ack *extack)
1479{
1480 u8 proto;
1481
1482 if (!data || !data[IFLA_IPTUN_PROTO])
1483 return 0;
1484
1485 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1486 if (!ipip6_valid_ip_proto(proto))
1487 return -EINVAL;
1488
1489 return 0;
1490}
1491
1492static void ipip6_netlink_parms(struct nlattr *data[],
1493 struct ip_tunnel_parm *parms,
1494 __u32 *fwmark)
1495{
1496 memset(parms, 0, sizeof(*parms));
1497
1498 parms->iph.version = 4;
1499 parms->iph.protocol = IPPROTO_IPV6;
1500 parms->iph.ihl = 5;
1501 parms->iph.ttl = 64;
1502
1503 if (!data)
1504 return;
1505
1506 ip_tunnel_netlink_parms(data, parms);
1507
1508 if (data[IFLA_IPTUN_FWMARK])
1509 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1510}
1511
1512#ifdef CONFIG_IPV6_SIT_6RD
1513/* This function returns true when 6RD attributes are present in the nl msg */
1514static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1515 struct ip_tunnel_6rd *ip6rd)
1516{
1517 bool ret = false;
1518 memset(ip6rd, 0, sizeof(*ip6rd));
1519
1520 if (!data)
1521 return ret;
1522
1523 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1524 ret = true;
1525 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1526 }
1527
1528 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1529 ret = true;
1530 ip6rd->relay_prefix =
1531 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1532 }
1533
1534 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1535 ret = true;
1536 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1537 }
1538
1539 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1540 ret = true;
1541 ip6rd->relay_prefixlen =
1542 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1543 }
1544
1545 return ret;
1546}
1547#endif
1548
1549static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1550 struct nlattr *tb[], struct nlattr *data[],
1551 struct netlink_ext_ack *extack)
1552{
1553 struct net *net = dev_net(dev);
1554 struct ip_tunnel *nt;
1555 struct ip_tunnel_encap ipencap;
1556#ifdef CONFIG_IPV6_SIT_6RD
1557 struct ip_tunnel_6rd ip6rd;
1558#endif
1559 int err;
1560
1561 nt = netdev_priv(dev);
1562
1563 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1564 err = ip_tunnel_encap_setup(nt, &ipencap);
1565 if (err < 0)
1566 return err;
1567 }
1568
1569 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1570
1571 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1572 return -EEXIST;
1573
1574 err = ipip6_tunnel_create(dev);
1575 if (err < 0)
1576 return err;
1577
1578 if (tb[IFLA_MTU]) {
1579 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1580
1581 if (mtu >= IPV6_MIN_MTU &&
1582 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1583 dev->mtu = mtu;
1584 }
1585
1586#ifdef CONFIG_IPV6_SIT_6RD
1587 if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
1588 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1589 if (err < 0)
1590 unregister_netdevice_queue(dev, NULL);
1591 }
1592#endif
1593
1594 return err;
1595}
1596
1597static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1598 struct nlattr *data[],
1599 struct netlink_ext_ack *extack)
1600{
1601 struct ip_tunnel *t = netdev_priv(dev);
1602 struct ip_tunnel_parm p;
1603 struct ip_tunnel_encap ipencap;
1604 struct net *net = t->net;
1605 struct sit_net *sitn = net_generic(net, sit_net_id);
1606#ifdef CONFIG_IPV6_SIT_6RD
1607 struct ip_tunnel_6rd ip6rd;
1608#endif
1609 __u32 fwmark = t->fwmark;
1610 int err;
1611
1612 if (dev == sitn->fb_tunnel_dev)
1613 return -EINVAL;
1614
1615 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1616 err = ip_tunnel_encap_setup(t, &ipencap);
1617 if (err < 0)
1618 return err;
1619 }
1620
1621 ipip6_netlink_parms(data, &p, &fwmark);
1622
1623 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1624 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1625 return -EINVAL;
1626
1627 t = ipip6_tunnel_locate(net, &p, 0);
1628
1629 if (t) {
1630 if (t->dev != dev)
1631 return -EEXIST;
1632 } else
1633 t = netdev_priv(dev);
1634
1635 ipip6_tunnel_update(t, &p, fwmark);
1636
1637#ifdef CONFIG_IPV6_SIT_6RD
1638 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1639 return ipip6_tunnel_update_6rd(t, &ip6rd);
1640#endif
1641
1642 return 0;
1643}
1644
1645static size_t ipip6_get_size(const struct net_device *dev)
1646{
1647 return
1648 /* IFLA_IPTUN_LINK */
1649 nla_total_size(4) +
1650 /* IFLA_IPTUN_LOCAL */
1651 nla_total_size(4) +
1652 /* IFLA_IPTUN_REMOTE */
1653 nla_total_size(4) +
1654 /* IFLA_IPTUN_TTL */
1655 nla_total_size(1) +
1656 /* IFLA_IPTUN_TOS */
1657 nla_total_size(1) +
1658 /* IFLA_IPTUN_PMTUDISC */
1659 nla_total_size(1) +
1660 /* IFLA_IPTUN_FLAGS */
1661 nla_total_size(2) +
1662 /* IFLA_IPTUN_PROTO */
1663 nla_total_size(1) +
1664#ifdef CONFIG_IPV6_SIT_6RD
1665 /* IFLA_IPTUN_6RD_PREFIX */
1666 nla_total_size(sizeof(struct in6_addr)) +
1667 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1668 nla_total_size(4) +
1669 /* IFLA_IPTUN_6RD_PREFIXLEN */
1670 nla_total_size(2) +
1671 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1672 nla_total_size(2) +
1673#endif
1674 /* IFLA_IPTUN_ENCAP_TYPE */
1675 nla_total_size(2) +
1676 /* IFLA_IPTUN_ENCAP_FLAGS */
1677 nla_total_size(2) +
1678 /* IFLA_IPTUN_ENCAP_SPORT */
1679 nla_total_size(2) +
1680 /* IFLA_IPTUN_ENCAP_DPORT */
1681 nla_total_size(2) +
1682 /* IFLA_IPTUN_FWMARK */
1683 nla_total_size(4) +
1684 0;
1685}
1686
1687static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1688{
1689 struct ip_tunnel *tunnel = netdev_priv(dev);
1690 struct ip_tunnel_parm *parm = &tunnel->parms;
1691
1692 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1693 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1694 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1695 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1696 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1697 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1698 !!(parm->iph.frag_off & htons(IP_DF))) ||
1699 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1700 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1701 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1702 goto nla_put_failure;
1703
1704#ifdef CONFIG_IPV6_SIT_6RD
1705 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1706 &tunnel->ip6rd.prefix) ||
1707 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1708 tunnel->ip6rd.relay_prefix) ||
1709 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1710 tunnel->ip6rd.prefixlen) ||
1711 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1712 tunnel->ip6rd.relay_prefixlen))
1713 goto nla_put_failure;
1714#endif
1715
1716 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1717 tunnel->encap.type) ||
1718 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1719 tunnel->encap.sport) ||
1720 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1721 tunnel->encap.dport) ||
1722 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1723 tunnel->encap.flags))
1724 goto nla_put_failure;
1725
1726 return 0;
1727
1728nla_put_failure:
1729 return -EMSGSIZE;
1730}
1731
1732static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1733 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1734 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1735 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1736 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1737 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1738 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1739 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1740 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1741#ifdef CONFIG_IPV6_SIT_6RD
1742 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1743 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1744 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1745 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1746#endif
1747 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1748 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1749 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1750 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1751 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1752};
1753
1754static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1755{
1756 struct net *net = dev_net(dev);
1757 struct sit_net *sitn = net_generic(net, sit_net_id);
1758
1759 if (dev != sitn->fb_tunnel_dev)
1760 unregister_netdevice_queue(dev, head);
1761}
1762
1763static struct rtnl_link_ops sit_link_ops __read_mostly = {
1764 .kind = "sit",
1765 .maxtype = IFLA_IPTUN_MAX,
1766 .policy = ipip6_policy,
1767 .priv_size = sizeof(struct ip_tunnel),
1768 .setup = ipip6_tunnel_setup,
1769 .validate = ipip6_validate,
1770 .newlink = ipip6_newlink,
1771 .changelink = ipip6_changelink,
1772 .get_size = ipip6_get_size,
1773 .fill_info = ipip6_fill_info,
1774 .dellink = ipip6_dellink,
1775 .get_link_net = ip_tunnel_get_link_net,
1776};
1777
1778static struct xfrm_tunnel sit_handler __read_mostly = {
1779 .handler = ipip6_rcv,
1780 .err_handler = ipip6_err,
1781 .priority = 1,
1782};
1783
1784static struct xfrm_tunnel ipip_handler __read_mostly = {
1785 .handler = ipip_rcv,
1786 .err_handler = ipip6_err,
1787 .priority = 2,
1788};
1789
1790#if IS_ENABLED(CONFIG_MPLS)
1791static struct xfrm_tunnel mplsip_handler __read_mostly = {
1792 .handler = mplsip_rcv,
1793 .err_handler = ipip6_err,
1794 .priority = 2,
1795};
1796#endif
1797
1798static void __net_exit sit_destroy_tunnels(struct net *net,
1799 struct list_head *head)
1800{
1801 struct sit_net *sitn = net_generic(net, sit_net_id);
1802 struct net_device *dev, *aux;
1803 int prio;
1804
1805 for_each_netdev_safe(net, dev, aux)
1806 if (dev->rtnl_link_ops == &sit_link_ops)
1807 unregister_netdevice_queue(dev, head);
1808
1809 for (prio = 0; prio < 4; prio++) {
1810 int h;
1811 for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
1812 struct ip_tunnel *t;
1813
1814 t = rtnl_dereference(sitn->tunnels[prio][h]);
1815 while (t) {
1816 /* If dev is in the same netns, it has already
1817 * been added to the list by the previous loop.
1818 */
1819 if (!net_eq(dev_net(t->dev), net))
1820 unregister_netdevice_queue(t->dev,
1821 head);
1822 t = rtnl_dereference(t->next);
1823 }
1824 }
1825 }
1826}
1827
1828static int __net_init sit_init_net(struct net *net)
1829{
1830 struct sit_net *sitn = net_generic(net, sit_net_id);
1831 struct ip_tunnel *t;
1832 int err;
1833
1834 sitn->tunnels[0] = sitn->tunnels_wc;
1835 sitn->tunnels[1] = sitn->tunnels_l;
1836 sitn->tunnels[2] = sitn->tunnels_r;
1837 sitn->tunnels[3] = sitn->tunnels_r_l;
1838
1839 if (!net_has_fallback_tunnels(net))
1840 return 0;
1841
1842 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1843 NET_NAME_UNKNOWN,
1844 ipip6_tunnel_setup);
1845 if (!sitn->fb_tunnel_dev) {
1846 err = -ENOMEM;
1847 goto err_alloc_dev;
1848 }
1849 dev_net_set(sitn->fb_tunnel_dev, net);
1850 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1851 /* FB netdevice is special: we have one, and only one per netns.
1852 * Allowing to move it to another netns is clearly unsafe.
1853 */
1854 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1855
1856 err = register_netdev(sitn->fb_tunnel_dev);
1857 if (err)
1858 goto err_reg_dev;
1859
1860 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1861 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1862
1863 t = netdev_priv(sitn->fb_tunnel_dev);
1864
1865 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1866 return 0;
1867
1868err_reg_dev:
1869 free_netdev(sitn->fb_tunnel_dev);
1870err_alloc_dev:
1871 return err;
1872}
1873
1874static void __net_exit sit_exit_batch_rtnl(struct list_head *net_list,
1875 struct list_head *dev_to_kill)
1876{
1877 struct net *net;
1878
1879 ASSERT_RTNL();
1880 list_for_each_entry(net, net_list, exit_list)
1881 sit_destroy_tunnels(net, dev_to_kill);
1882}
1883
1884static struct pernet_operations sit_net_ops = {
1885 .init = sit_init_net,
1886 .exit_batch_rtnl = sit_exit_batch_rtnl,
1887 .id = &sit_net_id,
1888 .size = sizeof(struct sit_net),
1889};
1890
1891static void __exit sit_cleanup(void)
1892{
1893 rtnl_link_unregister(&sit_link_ops);
1894 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1895 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1896#if IS_ENABLED(CONFIG_MPLS)
1897 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1898#endif
1899
1900 unregister_pernet_device(&sit_net_ops);
1901 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1902}
1903
1904static int __init sit_init(void)
1905{
1906 int err;
1907
1908 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1909
1910 err = register_pernet_device(&sit_net_ops);
1911 if (err < 0)
1912 return err;
1913 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1914 if (err < 0) {
1915 pr_info("%s: can't register ip6ip4\n", __func__);
1916 goto xfrm_tunnel_failed;
1917 }
1918 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1919 if (err < 0) {
1920 pr_info("%s: can't register ip4ip4\n", __func__);
1921 goto xfrm_tunnel4_failed;
1922 }
1923#if IS_ENABLED(CONFIG_MPLS)
1924 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1925 if (err < 0) {
1926 pr_info("%s: can't register mplsip\n", __func__);
1927 goto xfrm_tunnel_mpls_failed;
1928 }
1929#endif
1930 err = rtnl_link_register(&sit_link_ops);
1931 if (err < 0)
1932 goto rtnl_link_failed;
1933
1934out:
1935 return err;
1936
1937rtnl_link_failed:
1938#if IS_ENABLED(CONFIG_MPLS)
1939 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1940xfrm_tunnel_mpls_failed:
1941#endif
1942 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1943xfrm_tunnel4_failed:
1944 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1945xfrm_tunnel_failed:
1946 unregister_pernet_device(&sit_net_ops);
1947 goto out;
1948}
1949
1950module_init(sit_init);
1951module_exit(sit_cleanup);
1952MODULE_DESCRIPTION("IPv6-in-IPv4 tunnel SIT driver");
1953MODULE_LICENSE("GPL");
1954MODULE_ALIAS_RTNL_LINK("sit");
1955MODULE_ALIAS_NETDEV("sit0");