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Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[mirror_ubuntu-artful-kernel.git] / net / ipv6 / sit.c
1 /*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * Changes:
15 * Roger Venning <r.venning@telstra.com>: 6to4 support
16 * Nate Thompson <nate@thebog.net>: 6to4 support
17 * Fred Templin <fred.l.templin@boeing.com>: isatap support
18 */
19
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22 #include <linux/module.h>
23 #include <linux/capability.h>
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/icmp.h>
33 #include <linux/slab.h>
34 #include <asm/uaccess.h>
35 #include <linux/init.h>
36 #include <linux/netfilter_ipv4.h>
37 #include <linux/if_ether.h>
38
39 #include <net/sock.h>
40 #include <net/snmp.h>
41
42 #include <net/ipv6.h>
43 #include <net/protocol.h>
44 #include <net/transp_v6.h>
45 #include <net/ip6_fib.h>
46 #include <net/ip6_route.h>
47 #include <net/ndisc.h>
48 #include <net/addrconf.h>
49 #include <net/ip.h>
50 #include <net/udp.h>
51 #include <net/icmp.h>
52 #include <net/ip_tunnels.h>
53 #include <net/inet_ecn.h>
54 #include <net/xfrm.h>
55 #include <net/dsfield.h>
56 #include <net/net_namespace.h>
57 #include <net/netns/generic.h>
58
59 /*
60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
61
62 For comments look at net/ipv4/ip_gre.c --ANK
63 */
64
65 #define HASH_SIZE 16
66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
67
68 static bool log_ecn_error = true;
69 module_param(log_ecn_error, bool, 0644);
70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
71
72 static int ipip6_tunnel_init(struct net_device *dev);
73 static void ipip6_tunnel_setup(struct net_device *dev);
74 static void ipip6_dev_free(struct net_device *dev);
75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
76 __be32 *v4dst);
77 static struct rtnl_link_ops sit_link_ops __read_mostly;
78
79 static int sit_net_id __read_mostly;
80 struct sit_net {
81 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
82 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
83 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
84 struct ip_tunnel __rcu *tunnels_wc[1];
85 struct ip_tunnel __rcu **tunnels[4];
86
87 struct net_device *fb_tunnel_dev;
88 };
89
90 /*
91 * Must be invoked with rcu_read_lock
92 */
93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
94 struct net_device *dev, __be32 remote, __be32 local)
95 {
96 unsigned int h0 = HASH(remote);
97 unsigned int h1 = HASH(local);
98 struct ip_tunnel *t;
99 struct sit_net *sitn = net_generic(net, sit_net_id);
100
101 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
102 if (local == t->parms.iph.saddr &&
103 remote == t->parms.iph.daddr &&
104 (!dev || !t->parms.link || dev->iflink == 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 || dev->iflink == t->parms.link) &&
111 (t->dev->flags & IFF_UP))
112 return t;
113 }
114 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
115 if (local == t->parms.iph.saddr &&
116 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
117 (t->dev->flags & IFF_UP))
118 return t;
119 }
120 t = rcu_dereference(sitn->tunnels_wc[0]);
121 if ((t != NULL) && (t->dev->flags & IFF_UP))
122 return t;
123 return NULL;
124 }
125
126 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
127 struct ip_tunnel_parm *parms)
128 {
129 __be32 remote = parms->iph.daddr;
130 __be32 local = parms->iph.saddr;
131 unsigned int h = 0;
132 int prio = 0;
133
134 if (remote) {
135 prio |= 2;
136 h ^= HASH(remote);
137 }
138 if (local) {
139 prio |= 1;
140 h ^= HASH(local);
141 }
142 return &sitn->tunnels[prio][h];
143 }
144
145 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
146 struct ip_tunnel *t)
147 {
148 return __ipip6_bucket(sitn, &t->parms);
149 }
150
151 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
152 {
153 struct ip_tunnel __rcu **tp;
154 struct ip_tunnel *iter;
155
156 for (tp = ipip6_bucket(sitn, t);
157 (iter = rtnl_dereference(*tp)) != NULL;
158 tp = &iter->next) {
159 if (t == iter) {
160 rcu_assign_pointer(*tp, t->next);
161 break;
162 }
163 }
164 }
165
166 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
167 {
168 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
169
170 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
171 rcu_assign_pointer(*tp, t);
172 }
173
174 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
175 {
176 #ifdef CONFIG_IPV6_SIT_6RD
177 struct ip_tunnel *t = netdev_priv(dev);
178
179 if (t->dev == sitn->fb_tunnel_dev) {
180 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
181 t->ip6rd.relay_prefix = 0;
182 t->ip6rd.prefixlen = 16;
183 t->ip6rd.relay_prefixlen = 0;
184 } else {
185 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
186 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
187 }
188 #endif
189 }
190
191 static int ipip6_tunnel_create(struct net_device *dev)
192 {
193 struct ip_tunnel *t = netdev_priv(dev);
194 struct net *net = dev_net(dev);
195 struct sit_net *sitn = net_generic(net, sit_net_id);
196 int err;
197
198 err = ipip6_tunnel_init(dev);
199 if (err < 0)
200 goto out;
201 ipip6_tunnel_clone_6rd(dev, sitn);
202
203 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
204 dev->priv_flags |= IFF_ISATAP;
205
206 err = register_netdevice(dev);
207 if (err < 0)
208 goto out;
209
210 strcpy(t->parms.name, dev->name);
211 dev->rtnl_link_ops = &sit_link_ops;
212
213 dev_hold(dev);
214
215 ipip6_tunnel_link(sitn, t);
216 return 0;
217
218 out:
219 return err;
220 }
221
222 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
223 struct ip_tunnel_parm *parms, int create)
224 {
225 __be32 remote = parms->iph.daddr;
226 __be32 local = parms->iph.saddr;
227 struct ip_tunnel *t, *nt;
228 struct ip_tunnel __rcu **tp;
229 struct net_device *dev;
230 char name[IFNAMSIZ];
231 struct sit_net *sitn = net_generic(net, sit_net_id);
232
233 for (tp = __ipip6_bucket(sitn, parms);
234 (t = rtnl_dereference(*tp)) != NULL;
235 tp = &t->next) {
236 if (local == t->parms.iph.saddr &&
237 remote == t->parms.iph.daddr &&
238 parms->link == t->parms.link) {
239 if (create)
240 return NULL;
241 else
242 return t;
243 }
244 }
245 if (!create)
246 goto failed;
247
248 if (parms->name[0])
249 strlcpy(name, parms->name, IFNAMSIZ);
250 else
251 strcpy(name, "sit%d");
252
253 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
254 if (dev == NULL)
255 return NULL;
256
257 dev_net_set(dev, net);
258
259 nt = netdev_priv(dev);
260
261 nt->parms = *parms;
262 if (ipip6_tunnel_create(dev) < 0)
263 goto failed_free;
264
265 return nt;
266
267 failed_free:
268 ipip6_dev_free(dev);
269 failed:
270 return NULL;
271 }
272
273 #define for_each_prl_rcu(start) \
274 for (prl = rcu_dereference(start); \
275 prl; \
276 prl = rcu_dereference(prl->next))
277
278 static struct ip_tunnel_prl_entry *
279 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
280 {
281 struct ip_tunnel_prl_entry *prl;
282
283 for_each_prl_rcu(t->prl)
284 if (prl->addr == addr)
285 break;
286 return prl;
287
288 }
289
290 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
291 struct ip_tunnel_prl __user *a)
292 {
293 struct ip_tunnel_prl kprl, *kp;
294 struct ip_tunnel_prl_entry *prl;
295 unsigned int cmax, c = 0, ca, len;
296 int ret = 0;
297
298 if (copy_from_user(&kprl, a, sizeof(kprl)))
299 return -EFAULT;
300 cmax = kprl.datalen / sizeof(kprl);
301 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
302 cmax = 1;
303
304 /* For simple GET or for root users,
305 * we try harder to allocate.
306 */
307 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
308 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
309 NULL;
310
311 rcu_read_lock();
312
313 ca = t->prl_count < cmax ? t->prl_count : cmax;
314
315 if (!kp) {
316 /* We don't try hard to allocate much memory for
317 * non-root users.
318 * For root users, retry allocating enough memory for
319 * the answer.
320 */
321 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
322 if (!kp) {
323 ret = -ENOMEM;
324 goto out;
325 }
326 }
327
328 c = 0;
329 for_each_prl_rcu(t->prl) {
330 if (c >= cmax)
331 break;
332 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
333 continue;
334 kp[c].addr = prl->addr;
335 kp[c].flags = prl->flags;
336 c++;
337 if (kprl.addr != htonl(INADDR_ANY))
338 break;
339 }
340 out:
341 rcu_read_unlock();
342
343 len = sizeof(*kp) * c;
344 ret = 0;
345 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
346 ret = -EFAULT;
347
348 kfree(kp);
349
350 return ret;
351 }
352
353 static int
354 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
355 {
356 struct ip_tunnel_prl_entry *p;
357 int err = 0;
358
359 if (a->addr == htonl(INADDR_ANY))
360 return -EINVAL;
361
362 ASSERT_RTNL();
363
364 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
365 if (p->addr == a->addr) {
366 if (chg) {
367 p->flags = a->flags;
368 goto out;
369 }
370 err = -EEXIST;
371 goto out;
372 }
373 }
374
375 if (chg) {
376 err = -ENXIO;
377 goto out;
378 }
379
380 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
381 if (!p) {
382 err = -ENOBUFS;
383 goto out;
384 }
385
386 p->next = t->prl;
387 p->addr = a->addr;
388 p->flags = a->flags;
389 t->prl_count++;
390 rcu_assign_pointer(t->prl, p);
391 out:
392 return err;
393 }
394
395 static void prl_list_destroy_rcu(struct rcu_head *head)
396 {
397 struct ip_tunnel_prl_entry *p, *n;
398
399 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
400 do {
401 n = rcu_dereference_protected(p->next, 1);
402 kfree(p);
403 p = n;
404 } while (p);
405 }
406
407 static int
408 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
409 {
410 struct ip_tunnel_prl_entry *x;
411 struct ip_tunnel_prl_entry __rcu **p;
412 int err = 0;
413
414 ASSERT_RTNL();
415
416 if (a && a->addr != htonl(INADDR_ANY)) {
417 for (p = &t->prl;
418 (x = rtnl_dereference(*p)) != NULL;
419 p = &x->next) {
420 if (x->addr == a->addr) {
421 *p = x->next;
422 kfree_rcu(x, rcu_head);
423 t->prl_count--;
424 goto out;
425 }
426 }
427 err = -ENXIO;
428 } else {
429 x = rtnl_dereference(t->prl);
430 if (x) {
431 t->prl_count = 0;
432 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
433 t->prl = NULL;
434 }
435 }
436 out:
437 return err;
438 }
439
440 static int
441 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
442 {
443 struct ip_tunnel_prl_entry *p;
444 int ok = 1;
445
446 rcu_read_lock();
447 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
448 if (p) {
449 if (p->flags & PRL_DEFAULT)
450 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
451 else
452 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
453 } else {
454 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
455
456 if (ipv6_addr_is_isatap(addr6) &&
457 (addr6->s6_addr32[3] == iph->saddr) &&
458 ipv6_chk_prefix(addr6, t->dev))
459 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
460 else
461 ok = 0;
462 }
463 rcu_read_unlock();
464 return ok;
465 }
466
467 static void ipip6_tunnel_uninit(struct net_device *dev)
468 {
469 struct ip_tunnel *tunnel = netdev_priv(dev);
470 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
471
472 if (dev == sitn->fb_tunnel_dev) {
473 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
474 } else {
475 ipip6_tunnel_unlink(sitn, tunnel);
476 ipip6_tunnel_del_prl(tunnel, NULL);
477 }
478 dev_put(dev);
479 }
480
481
482 static int ipip6_err(struct sk_buff *skb, u32 info)
483 {
484
485 /* All the routers (except for Linux) return only
486 8 bytes of packet payload. It means, that precise relaying of
487 ICMP in the real Internet is absolutely infeasible.
488 */
489 const struct iphdr *iph = (const struct iphdr *)skb->data;
490 const int type = icmp_hdr(skb)->type;
491 const int code = icmp_hdr(skb)->code;
492 struct ip_tunnel *t;
493 int err;
494
495 switch (type) {
496 default:
497 case ICMP_PARAMETERPROB:
498 return 0;
499
500 case ICMP_DEST_UNREACH:
501 switch (code) {
502 case ICMP_SR_FAILED:
503 case ICMP_PORT_UNREACH:
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 break;
518 case ICMP_REDIRECT:
519 break;
520 }
521
522 err = -ENOENT;
523
524 t = ipip6_tunnel_lookup(dev_net(skb->dev),
525 skb->dev,
526 iph->daddr,
527 iph->saddr);
528 if (t == NULL)
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->dev->ifindex, 0, IPPROTO_IPV6, 0);
534 err = 0;
535 goto out;
536 }
537 if (type == ICMP_REDIRECT) {
538 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
539 IPPROTO_IPV6, 0);
540 err = 0;
541 goto out;
542 }
543
544 if (t->parms.iph.daddr == 0)
545 goto out;
546
547 err = 0;
548 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
549 goto out;
550
551 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
552 t->err_count++;
553 else
554 t->err_count = 1;
555 t->err_time = jiffies;
556 out:
557 return err;
558 }
559
560 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
561 const struct in6_addr *v6addr)
562 {
563 __be32 v4embed = 0;
564 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
565 return true;
566 return false;
567 }
568
569 /* Checks if an address matches an address on the tunnel interface.
570 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
571 * Long story:
572 * This function is called after we considered the packet as spoofed
573 * in is_spoofed_6rd.
574 * We may have a router that is doing NAT for proto 41 packets
575 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
576 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
577 * function will return true, dropping the packet.
578 * But, we can still check if is spoofed against the IP
579 * addresses associated with the interface.
580 */
581 static bool only_dnatted(const struct ip_tunnel *tunnel,
582 const struct in6_addr *v6dst)
583 {
584 int prefix_len;
585
586 #ifdef CONFIG_IPV6_SIT_6RD
587 prefix_len = tunnel->ip6rd.prefixlen + 32
588 - tunnel->ip6rd.relay_prefixlen;
589 #else
590 prefix_len = 48;
591 #endif
592 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
593 }
594
595 /* Returns true if a packet is spoofed */
596 static bool packet_is_spoofed(struct sk_buff *skb,
597 const struct iphdr *iph,
598 struct ip_tunnel *tunnel)
599 {
600 const struct ipv6hdr *ipv6h;
601
602 if (tunnel->dev->priv_flags & IFF_ISATAP) {
603 if (!isatap_chksrc(skb, iph, tunnel))
604 return true;
605
606 return false;
607 }
608
609 if (tunnel->dev->flags & IFF_POINTOPOINT)
610 return false;
611
612 ipv6h = ipv6_hdr(skb);
613
614 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
615 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
616 &iph->saddr, &ipv6h->saddr,
617 &iph->daddr, &ipv6h->daddr);
618 return true;
619 }
620
621 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
622 return false;
623
624 if (only_dnatted(tunnel, &ipv6h->daddr))
625 return false;
626
627 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
628 &iph->saddr, &ipv6h->saddr,
629 &iph->daddr, &ipv6h->daddr);
630 return true;
631 }
632
633 static int ipip6_rcv(struct sk_buff *skb)
634 {
635 const struct iphdr *iph = ip_hdr(skb);
636 struct ip_tunnel *tunnel;
637 int err;
638
639 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
640 iph->saddr, iph->daddr);
641 if (tunnel != NULL) {
642 struct pcpu_tstats *tstats;
643
644 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
645 tunnel->parms.iph.protocol != 0)
646 goto out;
647
648 skb->mac_header = skb->network_header;
649 skb_reset_network_header(skb);
650 IPCB(skb)->flags = 0;
651 skb->protocol = htons(ETH_P_IPV6);
652
653 if (packet_is_spoofed(skb, iph, tunnel)) {
654 tunnel->dev->stats.rx_errors++;
655 goto out;
656 }
657
658 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
659
660 err = IP_ECN_decapsulate(iph, skb);
661 if (unlikely(err)) {
662 if (log_ecn_error)
663 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
664 &iph->saddr, iph->tos);
665 if (err > 1) {
666 ++tunnel->dev->stats.rx_frame_errors;
667 ++tunnel->dev->stats.rx_errors;
668 goto out;
669 }
670 }
671
672 tstats = this_cpu_ptr(tunnel->dev->tstats);
673 tstats->rx_packets++;
674 tstats->rx_bytes += skb->len;
675
676 netif_rx(skb);
677
678 return 0;
679 }
680
681 /* no tunnel matched, let upstream know, ipsec may handle it */
682 return 1;
683 out:
684 kfree_skb(skb);
685 return 0;
686 }
687
688 static const struct tnl_ptk_info tpi = {
689 /* no tunnel info required for ipip. */
690 .proto = htons(ETH_P_IP),
691 };
692
693 static int ipip_rcv(struct sk_buff *skb)
694 {
695 const struct iphdr *iph;
696 struct ip_tunnel *tunnel;
697
698 iph = ip_hdr(skb);
699 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
700 iph->saddr, iph->daddr);
701 if (tunnel != NULL) {
702 if (tunnel->parms.iph.protocol != IPPROTO_IPIP &&
703 tunnel->parms.iph.protocol != 0)
704 goto drop;
705
706 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
707 goto drop;
708 if (iptunnel_pull_header(skb, 0, tpi.proto))
709 goto drop;
710 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
711 }
712
713 return 1;
714
715 drop:
716 kfree_skb(skb);
717 return 0;
718 }
719
720 /*
721 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
722 * stores the embedded IPv4 address in v4dst and returns true.
723 */
724 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
725 __be32 *v4dst)
726 {
727 #ifdef CONFIG_IPV6_SIT_6RD
728 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
729 tunnel->ip6rd.prefixlen)) {
730 unsigned int pbw0, pbi0;
731 int pbi1;
732 u32 d;
733
734 pbw0 = tunnel->ip6rd.prefixlen >> 5;
735 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
736
737 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
738 tunnel->ip6rd.relay_prefixlen;
739
740 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
741 if (pbi1 > 0)
742 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
743 (32 - pbi1);
744
745 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
746 return true;
747 }
748 #else
749 if (v6dst->s6_addr16[0] == htons(0x2002)) {
750 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
751 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
752 return true;
753 }
754 #endif
755 return false;
756 }
757
758 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
759 const struct in6_addr *v6dst)
760 {
761 __be32 dst = 0;
762 check_6rd(tunnel, v6dst, &dst);
763 return dst;
764 }
765
766 /*
767 * This function assumes it is being called from dev_queue_xmit()
768 * and that skb is filled properly by that function.
769 */
770
771 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
772 struct net_device *dev)
773 {
774 struct ip_tunnel *tunnel = netdev_priv(dev);
775 const struct iphdr *tiph = &tunnel->parms.iph;
776 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
777 u8 tos = tunnel->parms.iph.tos;
778 __be16 df = tiph->frag_off;
779 struct rtable *rt; /* Route to the other host */
780 struct net_device *tdev; /* Device to other host */
781 unsigned int max_headroom; /* The extra header space needed */
782 __be32 dst = tiph->daddr;
783 struct flowi4 fl4;
784 int mtu;
785 const struct in6_addr *addr6;
786 int addr_type;
787 u8 ttl;
788 int err;
789
790 if (skb->protocol != htons(ETH_P_IPV6))
791 goto tx_error;
792
793 if (tos == 1)
794 tos = ipv6_get_dsfield(iph6);
795
796 /* ISATAP (RFC4214) - must come before 6to4 */
797 if (dev->priv_flags & IFF_ISATAP) {
798 struct neighbour *neigh = NULL;
799 bool do_tx_error = false;
800
801 if (skb_dst(skb))
802 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
803
804 if (neigh == NULL) {
805 net_dbg_ratelimited("nexthop == NULL\n");
806 goto tx_error;
807 }
808
809 addr6 = (const struct in6_addr *)&neigh->primary_key;
810 addr_type = ipv6_addr_type(addr6);
811
812 if ((addr_type & IPV6_ADDR_UNICAST) &&
813 ipv6_addr_is_isatap(addr6))
814 dst = addr6->s6_addr32[3];
815 else
816 do_tx_error = true;
817
818 neigh_release(neigh);
819 if (do_tx_error)
820 goto tx_error;
821 }
822
823 if (!dst)
824 dst = try_6rd(tunnel, &iph6->daddr);
825
826 if (!dst) {
827 struct neighbour *neigh = NULL;
828 bool do_tx_error = false;
829
830 if (skb_dst(skb))
831 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
832
833 if (neigh == NULL) {
834 net_dbg_ratelimited("nexthop == NULL\n");
835 goto tx_error;
836 }
837
838 addr6 = (const struct in6_addr *)&neigh->primary_key;
839 addr_type = ipv6_addr_type(addr6);
840
841 if (addr_type == IPV6_ADDR_ANY) {
842 addr6 = &ipv6_hdr(skb)->daddr;
843 addr_type = ipv6_addr_type(addr6);
844 }
845
846 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
847 dst = addr6->s6_addr32[3];
848 else
849 do_tx_error = true;
850
851 neigh_release(neigh);
852 if (do_tx_error)
853 goto tx_error;
854 }
855
856 rt = ip_route_output_ports(tunnel->net, &fl4, NULL,
857 dst, tiph->saddr,
858 0, 0,
859 IPPROTO_IPV6, RT_TOS(tos),
860 tunnel->parms.link);
861 if (IS_ERR(rt)) {
862 dev->stats.tx_carrier_errors++;
863 goto tx_error_icmp;
864 }
865 if (rt->rt_type != RTN_UNICAST) {
866 ip_rt_put(rt);
867 dev->stats.tx_carrier_errors++;
868 goto tx_error_icmp;
869 }
870 tdev = rt->dst.dev;
871
872 if (tdev == dev) {
873 ip_rt_put(rt);
874 dev->stats.collisions++;
875 goto tx_error;
876 }
877
878 if (df) {
879 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
880
881 if (mtu < 68) {
882 dev->stats.collisions++;
883 ip_rt_put(rt);
884 goto tx_error;
885 }
886
887 if (mtu < IPV6_MIN_MTU) {
888 mtu = IPV6_MIN_MTU;
889 df = 0;
890 }
891
892 if (tunnel->parms.iph.daddr && skb_dst(skb))
893 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
894
895 if (skb->len > mtu) {
896 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
897 ip_rt_put(rt);
898 goto tx_error;
899 }
900 }
901
902 if (tunnel->err_count > 0) {
903 if (time_before(jiffies,
904 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
905 tunnel->err_count--;
906 dst_link_failure(skb);
907 } else
908 tunnel->err_count = 0;
909 }
910
911 /*
912 * Okay, now see if we can stuff it in the buffer as-is.
913 */
914 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
915
916 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
917 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
918 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
919 if (!new_skb) {
920 ip_rt_put(rt);
921 dev->stats.tx_dropped++;
922 dev_kfree_skb(skb);
923 return NETDEV_TX_OK;
924 }
925 if (skb->sk)
926 skb_set_owner_w(new_skb, skb->sk);
927 dev_kfree_skb(skb);
928 skb = new_skb;
929 iph6 = ipv6_hdr(skb);
930 }
931 ttl = tiph->ttl;
932 if (ttl == 0)
933 ttl = iph6->hop_limit;
934 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
935
936 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
937 if (IS_ERR(skb))
938 goto out;
939
940 err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos,
941 ttl, df, !net_eq(tunnel->net, dev_net(dev)));
942 iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
943 return NETDEV_TX_OK;
944
945 tx_error_icmp:
946 dst_link_failure(skb);
947 tx_error:
948 dev_kfree_skb(skb);
949 out:
950 dev->stats.tx_errors++;
951 return NETDEV_TX_OK;
952 }
953
954 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
955 {
956 struct ip_tunnel *tunnel = netdev_priv(dev);
957 const struct iphdr *tiph = &tunnel->parms.iph;
958
959 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
960 if (IS_ERR(skb))
961 goto out;
962
963 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP);
964 return NETDEV_TX_OK;
965 out:
966 dev->stats.tx_errors++;
967 return NETDEV_TX_OK;
968 }
969
970 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
971 struct net_device *dev)
972 {
973 switch (skb->protocol) {
974 case htons(ETH_P_IP):
975 ipip_tunnel_xmit(skb, dev);
976 break;
977 case htons(ETH_P_IPV6):
978 ipip6_tunnel_xmit(skb, dev);
979 break;
980 default:
981 goto tx_err;
982 }
983
984 return NETDEV_TX_OK;
985
986 tx_err:
987 dev->stats.tx_errors++;
988 dev_kfree_skb(skb);
989 return NETDEV_TX_OK;
990
991 }
992
993 static void ipip6_tunnel_bind_dev(struct net_device *dev)
994 {
995 struct net_device *tdev = NULL;
996 struct ip_tunnel *tunnel;
997 const struct iphdr *iph;
998 struct flowi4 fl4;
999
1000 tunnel = netdev_priv(dev);
1001 iph = &tunnel->parms.iph;
1002
1003 if (iph->daddr) {
1004 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1005 NULL,
1006 iph->daddr, iph->saddr,
1007 0, 0,
1008 IPPROTO_IPV6,
1009 RT_TOS(iph->tos),
1010 tunnel->parms.link);
1011
1012 if (!IS_ERR(rt)) {
1013 tdev = rt->dst.dev;
1014 ip_rt_put(rt);
1015 }
1016 dev->flags |= IFF_POINTOPOINT;
1017 }
1018
1019 if (!tdev && tunnel->parms.link)
1020 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1021
1022 if (tdev) {
1023 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1024 dev->mtu = tdev->mtu - sizeof(struct iphdr);
1025 if (dev->mtu < IPV6_MIN_MTU)
1026 dev->mtu = IPV6_MIN_MTU;
1027 }
1028 dev->iflink = tunnel->parms.link;
1029 }
1030
1031 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
1032 {
1033 struct net *net = t->net;
1034 struct sit_net *sitn = net_generic(net, sit_net_id);
1035
1036 ipip6_tunnel_unlink(sitn, t);
1037 synchronize_net();
1038 t->parms.iph.saddr = p->iph.saddr;
1039 t->parms.iph.daddr = p->iph.daddr;
1040 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1041 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1042 ipip6_tunnel_link(sitn, t);
1043 t->parms.iph.ttl = p->iph.ttl;
1044 t->parms.iph.tos = p->iph.tos;
1045 if (t->parms.link != p->link) {
1046 t->parms.link = p->link;
1047 ipip6_tunnel_bind_dev(t->dev);
1048 }
1049 netdev_state_change(t->dev);
1050 }
1051
1052 #ifdef CONFIG_IPV6_SIT_6RD
1053 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1054 struct ip_tunnel_6rd *ip6rd)
1055 {
1056 struct in6_addr prefix;
1057 __be32 relay_prefix;
1058
1059 if (ip6rd->relay_prefixlen > 32 ||
1060 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1061 return -EINVAL;
1062
1063 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1064 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1065 return -EINVAL;
1066 if (ip6rd->relay_prefixlen)
1067 relay_prefix = ip6rd->relay_prefix &
1068 htonl(0xffffffffUL <<
1069 (32 - ip6rd->relay_prefixlen));
1070 else
1071 relay_prefix = 0;
1072 if (relay_prefix != ip6rd->relay_prefix)
1073 return -EINVAL;
1074
1075 t->ip6rd.prefix = prefix;
1076 t->ip6rd.relay_prefix = relay_prefix;
1077 t->ip6rd.prefixlen = ip6rd->prefixlen;
1078 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1079 netdev_state_change(t->dev);
1080 return 0;
1081 }
1082 #endif
1083
1084 static int
1085 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1086 {
1087 int err = 0;
1088 struct ip_tunnel_parm p;
1089 struct ip_tunnel_prl prl;
1090 struct ip_tunnel *t;
1091 struct net *net = dev_net(dev);
1092 struct sit_net *sitn = net_generic(net, sit_net_id);
1093 #ifdef CONFIG_IPV6_SIT_6RD
1094 struct ip_tunnel_6rd ip6rd;
1095 #endif
1096
1097 switch (cmd) {
1098 case SIOCGETTUNNEL:
1099 #ifdef CONFIG_IPV6_SIT_6RD
1100 case SIOCGET6RD:
1101 #endif
1102 t = NULL;
1103 if (dev == sitn->fb_tunnel_dev) {
1104 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1105 err = -EFAULT;
1106 break;
1107 }
1108 t = ipip6_tunnel_locate(net, &p, 0);
1109 }
1110 if (t == NULL)
1111 t = netdev_priv(dev);
1112
1113 err = -EFAULT;
1114 if (cmd == SIOCGETTUNNEL) {
1115 memcpy(&p, &t->parms, sizeof(p));
1116 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1117 sizeof(p)))
1118 goto done;
1119 #ifdef CONFIG_IPV6_SIT_6RD
1120 } else {
1121 ip6rd.prefix = t->ip6rd.prefix;
1122 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1123 ip6rd.prefixlen = t->ip6rd.prefixlen;
1124 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1125 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1126 sizeof(ip6rd)))
1127 goto done;
1128 #endif
1129 }
1130 err = 0;
1131 break;
1132
1133 case SIOCADDTUNNEL:
1134 case SIOCCHGTUNNEL:
1135 err = -EPERM;
1136 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1137 goto done;
1138
1139 err = -EFAULT;
1140 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1141 goto done;
1142
1143 err = -EINVAL;
1144 if (p.iph.protocol != IPPROTO_IPV6 &&
1145 p.iph.protocol != IPPROTO_IPIP &&
1146 p.iph.protocol != 0)
1147 goto done;
1148 if (p.iph.version != 4 ||
1149 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1150 goto done;
1151 if (p.iph.ttl)
1152 p.iph.frag_off |= htons(IP_DF);
1153
1154 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1155
1156 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1157 if (t != NULL) {
1158 if (t->dev != dev) {
1159 err = -EEXIST;
1160 break;
1161 }
1162 } else {
1163 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1164 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1165 err = -EINVAL;
1166 break;
1167 }
1168 t = netdev_priv(dev);
1169 }
1170
1171 ipip6_tunnel_update(t, &p);
1172 }
1173
1174 if (t) {
1175 err = 0;
1176 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1177 err = -EFAULT;
1178 } else
1179 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1180 break;
1181
1182 case SIOCDELTUNNEL:
1183 err = -EPERM;
1184 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1185 goto done;
1186
1187 if (dev == sitn->fb_tunnel_dev) {
1188 err = -EFAULT;
1189 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1190 goto done;
1191 err = -ENOENT;
1192 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1193 goto done;
1194 err = -EPERM;
1195 if (t == netdev_priv(sitn->fb_tunnel_dev))
1196 goto done;
1197 dev = t->dev;
1198 }
1199 unregister_netdevice(dev);
1200 err = 0;
1201 break;
1202
1203 case SIOCGETPRL:
1204 err = -EINVAL;
1205 if (dev == sitn->fb_tunnel_dev)
1206 goto done;
1207 err = -ENOENT;
1208 if (!(t = netdev_priv(dev)))
1209 goto done;
1210 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1211 break;
1212
1213 case SIOCADDPRL:
1214 case SIOCDELPRL:
1215 case SIOCCHGPRL:
1216 err = -EPERM;
1217 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1218 goto done;
1219 err = -EINVAL;
1220 if (dev == sitn->fb_tunnel_dev)
1221 goto done;
1222 err = -EFAULT;
1223 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1224 goto done;
1225 err = -ENOENT;
1226 if (!(t = netdev_priv(dev)))
1227 goto done;
1228
1229 switch (cmd) {
1230 case SIOCDELPRL:
1231 err = ipip6_tunnel_del_prl(t, &prl);
1232 break;
1233 case SIOCADDPRL:
1234 case SIOCCHGPRL:
1235 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1236 break;
1237 }
1238 netdev_state_change(dev);
1239 break;
1240
1241 #ifdef CONFIG_IPV6_SIT_6RD
1242 case SIOCADD6RD:
1243 case SIOCCHG6RD:
1244 case SIOCDEL6RD:
1245 err = -EPERM;
1246 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1247 goto done;
1248
1249 err = -EFAULT;
1250 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1251 sizeof(ip6rd)))
1252 goto done;
1253
1254 t = netdev_priv(dev);
1255
1256 if (cmd != SIOCDEL6RD) {
1257 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1258 if (err < 0)
1259 goto done;
1260 } else
1261 ipip6_tunnel_clone_6rd(dev, sitn);
1262
1263 err = 0;
1264 break;
1265 #endif
1266
1267 default:
1268 err = -EINVAL;
1269 }
1270
1271 done:
1272 return err;
1273 }
1274
1275 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1276 {
1277 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1278 return -EINVAL;
1279 dev->mtu = new_mtu;
1280 return 0;
1281 }
1282
1283 static const struct net_device_ops ipip6_netdev_ops = {
1284 .ndo_uninit = ipip6_tunnel_uninit,
1285 .ndo_start_xmit = sit_tunnel_xmit,
1286 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1287 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1288 .ndo_get_stats64 = ip_tunnel_get_stats64,
1289 };
1290
1291 static void ipip6_dev_free(struct net_device *dev)
1292 {
1293 free_percpu(dev->tstats);
1294 free_netdev(dev);
1295 }
1296
1297 #define SIT_FEATURES (NETIF_F_SG | \
1298 NETIF_F_FRAGLIST | \
1299 NETIF_F_HIGHDMA | \
1300 NETIF_F_GSO_SOFTWARE | \
1301 NETIF_F_HW_CSUM)
1302
1303 static void ipip6_tunnel_setup(struct net_device *dev)
1304 {
1305 dev->netdev_ops = &ipip6_netdev_ops;
1306 dev->destructor = ipip6_dev_free;
1307
1308 dev->type = ARPHRD_SIT;
1309 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1310 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1311 dev->flags = IFF_NOARP;
1312 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1313 dev->iflink = 0;
1314 dev->addr_len = 4;
1315 dev->features |= NETIF_F_LLTX;
1316 dev->features |= SIT_FEATURES;
1317 dev->hw_features |= SIT_FEATURES;
1318 }
1319
1320 static int ipip6_tunnel_init(struct net_device *dev)
1321 {
1322 struct ip_tunnel *tunnel = netdev_priv(dev);
1323 int i;
1324
1325 tunnel->dev = dev;
1326 tunnel->net = dev_net(dev);
1327
1328 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1329 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1330
1331 ipip6_tunnel_bind_dev(dev);
1332 dev->tstats = alloc_percpu(struct pcpu_tstats);
1333 if (!dev->tstats)
1334 return -ENOMEM;
1335
1336 for_each_possible_cpu(i) {
1337 struct pcpu_tstats *ipip6_tunnel_stats;
1338 ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i);
1339 u64_stats_init(&ipip6_tunnel_stats->syncp);
1340 }
1341
1342 return 0;
1343 }
1344
1345 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1346 {
1347 struct ip_tunnel *tunnel = netdev_priv(dev);
1348 struct iphdr *iph = &tunnel->parms.iph;
1349 struct net *net = dev_net(dev);
1350 struct sit_net *sitn = net_generic(net, sit_net_id);
1351 int i;
1352
1353 tunnel->dev = dev;
1354 tunnel->net = dev_net(dev);
1355 strcpy(tunnel->parms.name, dev->name);
1356
1357 iph->version = 4;
1358 iph->protocol = IPPROTO_IPV6;
1359 iph->ihl = 5;
1360 iph->ttl = 64;
1361
1362 dev->tstats = alloc_percpu(struct pcpu_tstats);
1363 if (!dev->tstats)
1364 return -ENOMEM;
1365
1366 for_each_possible_cpu(i) {
1367 struct pcpu_tstats *ipip6_fb_stats;
1368 ipip6_fb_stats = per_cpu_ptr(dev->tstats, i);
1369 u64_stats_init(&ipip6_fb_stats->syncp);
1370 }
1371
1372 dev_hold(dev);
1373 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1374 return 0;
1375 }
1376
1377 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1378 {
1379 u8 proto;
1380
1381 if (!data || !data[IFLA_IPTUN_PROTO])
1382 return 0;
1383
1384 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1385 if (proto != IPPROTO_IPV6 &&
1386 proto != IPPROTO_IPIP &&
1387 proto != 0)
1388 return -EINVAL;
1389
1390 return 0;
1391 }
1392
1393 static void ipip6_netlink_parms(struct nlattr *data[],
1394 struct ip_tunnel_parm *parms)
1395 {
1396 memset(parms, 0, sizeof(*parms));
1397
1398 parms->iph.version = 4;
1399 parms->iph.protocol = IPPROTO_IPV6;
1400 parms->iph.ihl = 5;
1401 parms->iph.ttl = 64;
1402
1403 if (!data)
1404 return;
1405
1406 if (data[IFLA_IPTUN_LINK])
1407 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1408
1409 if (data[IFLA_IPTUN_LOCAL])
1410 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1411
1412 if (data[IFLA_IPTUN_REMOTE])
1413 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1414
1415 if (data[IFLA_IPTUN_TTL]) {
1416 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1417 if (parms->iph.ttl)
1418 parms->iph.frag_off = htons(IP_DF);
1419 }
1420
1421 if (data[IFLA_IPTUN_TOS])
1422 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1423
1424 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1425 parms->iph.frag_off = htons(IP_DF);
1426
1427 if (data[IFLA_IPTUN_FLAGS])
1428 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1429
1430 if (data[IFLA_IPTUN_PROTO])
1431 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1432
1433 }
1434
1435 #ifdef CONFIG_IPV6_SIT_6RD
1436 /* This function returns true when 6RD attributes are present in the nl msg */
1437 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1438 struct ip_tunnel_6rd *ip6rd)
1439 {
1440 bool ret = false;
1441 memset(ip6rd, 0, sizeof(*ip6rd));
1442
1443 if (!data)
1444 return ret;
1445
1446 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1447 ret = true;
1448 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX],
1449 sizeof(struct in6_addr));
1450 }
1451
1452 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1453 ret = true;
1454 ip6rd->relay_prefix =
1455 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1456 }
1457
1458 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1459 ret = true;
1460 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1461 }
1462
1463 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1464 ret = true;
1465 ip6rd->relay_prefixlen =
1466 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1467 }
1468
1469 return ret;
1470 }
1471 #endif
1472
1473 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1474 struct nlattr *tb[], struct nlattr *data[])
1475 {
1476 struct net *net = dev_net(dev);
1477 struct ip_tunnel *nt;
1478 #ifdef CONFIG_IPV6_SIT_6RD
1479 struct ip_tunnel_6rd ip6rd;
1480 #endif
1481 int err;
1482
1483 nt = netdev_priv(dev);
1484 ipip6_netlink_parms(data, &nt->parms);
1485
1486 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1487 return -EEXIST;
1488
1489 err = ipip6_tunnel_create(dev);
1490 if (err < 0)
1491 return err;
1492
1493 #ifdef CONFIG_IPV6_SIT_6RD
1494 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1495 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1496 #endif
1497
1498 return err;
1499 }
1500
1501 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1502 struct nlattr *data[])
1503 {
1504 struct ip_tunnel *t = netdev_priv(dev);
1505 struct ip_tunnel_parm p;
1506 struct net *net = t->net;
1507 struct sit_net *sitn = net_generic(net, sit_net_id);
1508 #ifdef CONFIG_IPV6_SIT_6RD
1509 struct ip_tunnel_6rd ip6rd;
1510 #endif
1511
1512 if (dev == sitn->fb_tunnel_dev)
1513 return -EINVAL;
1514
1515 ipip6_netlink_parms(data, &p);
1516
1517 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1518 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1519 return -EINVAL;
1520
1521 t = ipip6_tunnel_locate(net, &p, 0);
1522
1523 if (t) {
1524 if (t->dev != dev)
1525 return -EEXIST;
1526 } else
1527 t = netdev_priv(dev);
1528
1529 ipip6_tunnel_update(t, &p);
1530
1531 #ifdef CONFIG_IPV6_SIT_6RD
1532 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1533 return ipip6_tunnel_update_6rd(t, &ip6rd);
1534 #endif
1535
1536 return 0;
1537 }
1538
1539 static size_t ipip6_get_size(const struct net_device *dev)
1540 {
1541 return
1542 /* IFLA_IPTUN_LINK */
1543 nla_total_size(4) +
1544 /* IFLA_IPTUN_LOCAL */
1545 nla_total_size(4) +
1546 /* IFLA_IPTUN_REMOTE */
1547 nla_total_size(4) +
1548 /* IFLA_IPTUN_TTL */
1549 nla_total_size(1) +
1550 /* IFLA_IPTUN_TOS */
1551 nla_total_size(1) +
1552 /* IFLA_IPTUN_PMTUDISC */
1553 nla_total_size(1) +
1554 /* IFLA_IPTUN_FLAGS */
1555 nla_total_size(2) +
1556 /* IFLA_IPTUN_PROTO */
1557 nla_total_size(1) +
1558 #ifdef CONFIG_IPV6_SIT_6RD
1559 /* IFLA_IPTUN_6RD_PREFIX */
1560 nla_total_size(sizeof(struct in6_addr)) +
1561 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1562 nla_total_size(4) +
1563 /* IFLA_IPTUN_6RD_PREFIXLEN */
1564 nla_total_size(2) +
1565 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1566 nla_total_size(2) +
1567 #endif
1568 0;
1569 }
1570
1571 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1572 {
1573 struct ip_tunnel *tunnel = netdev_priv(dev);
1574 struct ip_tunnel_parm *parm = &tunnel->parms;
1575
1576 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1577 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1578 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1579 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1580 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1581 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1582 !!(parm->iph.frag_off & htons(IP_DF))) ||
1583 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1584 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1585 goto nla_put_failure;
1586
1587 #ifdef CONFIG_IPV6_SIT_6RD
1588 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr),
1589 &tunnel->ip6rd.prefix) ||
1590 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1591 tunnel->ip6rd.relay_prefix) ||
1592 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1593 tunnel->ip6rd.prefixlen) ||
1594 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1595 tunnel->ip6rd.relay_prefixlen))
1596 goto nla_put_failure;
1597 #endif
1598
1599 return 0;
1600
1601 nla_put_failure:
1602 return -EMSGSIZE;
1603 }
1604
1605 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1606 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1607 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1608 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1609 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1610 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1611 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1612 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1613 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1614 #ifdef CONFIG_IPV6_SIT_6RD
1615 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1616 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1617 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1618 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1619 #endif
1620 };
1621
1622 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1623 .kind = "sit",
1624 .maxtype = IFLA_IPTUN_MAX,
1625 .policy = ipip6_policy,
1626 .priv_size = sizeof(struct ip_tunnel),
1627 .setup = ipip6_tunnel_setup,
1628 .validate = ipip6_validate,
1629 .newlink = ipip6_newlink,
1630 .changelink = ipip6_changelink,
1631 .get_size = ipip6_get_size,
1632 .fill_info = ipip6_fill_info,
1633 };
1634
1635 static struct xfrm_tunnel sit_handler __read_mostly = {
1636 .handler = ipip6_rcv,
1637 .err_handler = ipip6_err,
1638 .priority = 1,
1639 };
1640
1641 static struct xfrm_tunnel ipip_handler __read_mostly = {
1642 .handler = ipip_rcv,
1643 .err_handler = ipip6_err,
1644 .priority = 2,
1645 };
1646
1647 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1648 {
1649 struct net *net = dev_net(sitn->fb_tunnel_dev);
1650 struct net_device *dev, *aux;
1651 int prio;
1652
1653 for_each_netdev_safe(net, dev, aux)
1654 if (dev->rtnl_link_ops == &sit_link_ops)
1655 unregister_netdevice_queue(dev, head);
1656
1657 for (prio = 1; prio < 4; prio++) {
1658 int h;
1659 for (h = 0; h < HASH_SIZE; h++) {
1660 struct ip_tunnel *t;
1661
1662 t = rtnl_dereference(sitn->tunnels[prio][h]);
1663 while (t != NULL) {
1664 /* If dev is in the same netns, it has already
1665 * been added to the list by the previous loop.
1666 */
1667 if (!net_eq(dev_net(t->dev), net))
1668 unregister_netdevice_queue(t->dev,
1669 head);
1670 t = rtnl_dereference(t->next);
1671 }
1672 }
1673 }
1674 }
1675
1676 static int __net_init sit_init_net(struct net *net)
1677 {
1678 struct sit_net *sitn = net_generic(net, sit_net_id);
1679 struct ip_tunnel *t;
1680 int err;
1681
1682 sitn->tunnels[0] = sitn->tunnels_wc;
1683 sitn->tunnels[1] = sitn->tunnels_l;
1684 sitn->tunnels[2] = sitn->tunnels_r;
1685 sitn->tunnels[3] = sitn->tunnels_r_l;
1686
1687 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1688 ipip6_tunnel_setup);
1689 if (!sitn->fb_tunnel_dev) {
1690 err = -ENOMEM;
1691 goto err_alloc_dev;
1692 }
1693 dev_net_set(sitn->fb_tunnel_dev, net);
1694 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1695 /* FB netdevice is special: we have one, and only one per netns.
1696 * Allowing to move it to another netns is clearly unsafe.
1697 */
1698 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1699
1700 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1701 if (err)
1702 goto err_dev_free;
1703
1704 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1705
1706 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1707 goto err_reg_dev;
1708
1709 t = netdev_priv(sitn->fb_tunnel_dev);
1710
1711 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1712 return 0;
1713
1714 err_reg_dev:
1715 dev_put(sitn->fb_tunnel_dev);
1716 err_dev_free:
1717 ipip6_dev_free(sitn->fb_tunnel_dev);
1718 err_alloc_dev:
1719 return err;
1720 }
1721
1722 static void __net_exit sit_exit_net(struct net *net)
1723 {
1724 struct sit_net *sitn = net_generic(net, sit_net_id);
1725 LIST_HEAD(list);
1726
1727 rtnl_lock();
1728 sit_destroy_tunnels(sitn, &list);
1729 unregister_netdevice_many(&list);
1730 rtnl_unlock();
1731 }
1732
1733 static struct pernet_operations sit_net_ops = {
1734 .init = sit_init_net,
1735 .exit = sit_exit_net,
1736 .id = &sit_net_id,
1737 .size = sizeof(struct sit_net),
1738 };
1739
1740 static void __exit sit_cleanup(void)
1741 {
1742 rtnl_link_unregister(&sit_link_ops);
1743 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1744 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1745
1746 unregister_pernet_device(&sit_net_ops);
1747 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1748 }
1749
1750 static int __init sit_init(void)
1751 {
1752 int err;
1753
1754 pr_info("IPv6 over IPv4 tunneling driver\n");
1755
1756 err = register_pernet_device(&sit_net_ops);
1757 if (err < 0)
1758 return err;
1759 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1760 if (err < 0) {
1761 pr_info("%s: can't register ip6ip4\n", __func__);
1762 goto xfrm_tunnel_failed;
1763 }
1764 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1765 if (err < 0) {
1766 pr_info("%s: can't register ip4ip4\n", __func__);
1767 goto xfrm_tunnel4_failed;
1768 }
1769 err = rtnl_link_register(&sit_link_ops);
1770 if (err < 0)
1771 goto rtnl_link_failed;
1772
1773 out:
1774 return err;
1775
1776 rtnl_link_failed:
1777 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1778 xfrm_tunnel4_failed:
1779 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1780 xfrm_tunnel_failed:
1781 unregister_pernet_device(&sit_net_ops);
1782 goto out;
1783 }
1784
1785 module_init(sit_init);
1786 module_exit(sit_cleanup);
1787 MODULE_LICENSE("GPL");
1788 MODULE_ALIAS_NETDEV("sit0");
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