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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[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->ifindex == 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->ifindex == 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->ifindex == 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, NET_NAME_UNKNOWN,
254 ipip6_tunnel_setup);
255 if (dev == NULL)
256 return NULL;
257
258 dev_net_set(dev, net);
259
260 nt = netdev_priv(dev);
261
262 nt->parms = *parms;
263 if (ipip6_tunnel_create(dev) < 0)
264 goto failed_free;
265
266 return nt;
267
268 failed_free:
269 ipip6_dev_free(dev);
270 failed:
271 return NULL;
272 }
273
274 #define for_each_prl_rcu(start) \
275 for (prl = rcu_dereference(start); \
276 prl; \
277 prl = rcu_dereference(prl->next))
278
279 static struct ip_tunnel_prl_entry *
280 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
281 {
282 struct ip_tunnel_prl_entry *prl;
283
284 for_each_prl_rcu(t->prl)
285 if (prl->addr == addr)
286 break;
287 return prl;
288
289 }
290
291 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
292 struct ip_tunnel_prl __user *a)
293 {
294 struct ip_tunnel_prl kprl, *kp;
295 struct ip_tunnel_prl_entry *prl;
296 unsigned int cmax, c = 0, ca, len;
297 int ret = 0;
298
299 if (copy_from_user(&kprl, a, sizeof(kprl)))
300 return -EFAULT;
301 cmax = kprl.datalen / sizeof(kprl);
302 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
303 cmax = 1;
304
305 /* For simple GET or for root users,
306 * we try harder to allocate.
307 */
308 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
309 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
310 NULL;
311
312 rcu_read_lock();
313
314 ca = t->prl_count < cmax ? t->prl_count : cmax;
315
316 if (!kp) {
317 /* We don't try hard to allocate much memory for
318 * non-root users.
319 * For root users, retry allocating enough memory for
320 * the answer.
321 */
322 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
323 if (!kp) {
324 ret = -ENOMEM;
325 goto out;
326 }
327 }
328
329 c = 0;
330 for_each_prl_rcu(t->prl) {
331 if (c >= cmax)
332 break;
333 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
334 continue;
335 kp[c].addr = prl->addr;
336 kp[c].flags = prl->flags;
337 c++;
338 if (kprl.addr != htonl(INADDR_ANY))
339 break;
340 }
341 out:
342 rcu_read_unlock();
343
344 len = sizeof(*kp) * c;
345 ret = 0;
346 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
347 ret = -EFAULT;
348
349 kfree(kp);
350
351 return ret;
352 }
353
354 static int
355 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
356 {
357 struct ip_tunnel_prl_entry *p;
358 int err = 0;
359
360 if (a->addr == htonl(INADDR_ANY))
361 return -EINVAL;
362
363 ASSERT_RTNL();
364
365 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
366 if (p->addr == a->addr) {
367 if (chg) {
368 p->flags = a->flags;
369 goto out;
370 }
371 err = -EEXIST;
372 goto out;
373 }
374 }
375
376 if (chg) {
377 err = -ENXIO;
378 goto out;
379 }
380
381 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
382 if (!p) {
383 err = -ENOBUFS;
384 goto out;
385 }
386
387 p->next = t->prl;
388 p->addr = a->addr;
389 p->flags = a->flags;
390 t->prl_count++;
391 rcu_assign_pointer(t->prl, p);
392 out:
393 return err;
394 }
395
396 static void prl_list_destroy_rcu(struct rcu_head *head)
397 {
398 struct ip_tunnel_prl_entry *p, *n;
399
400 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
401 do {
402 n = rcu_dereference_protected(p->next, 1);
403 kfree(p);
404 p = n;
405 } while (p);
406 }
407
408 static int
409 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
410 {
411 struct ip_tunnel_prl_entry *x;
412 struct ip_tunnel_prl_entry __rcu **p;
413 int err = 0;
414
415 ASSERT_RTNL();
416
417 if (a && a->addr != htonl(INADDR_ANY)) {
418 for (p = &t->prl;
419 (x = rtnl_dereference(*p)) != NULL;
420 p = &x->next) {
421 if (x->addr == a->addr) {
422 *p = x->next;
423 kfree_rcu(x, rcu_head);
424 t->prl_count--;
425 goto out;
426 }
427 }
428 err = -ENXIO;
429 } else {
430 x = rtnl_dereference(t->prl);
431 if (x) {
432 t->prl_count = 0;
433 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
434 t->prl = NULL;
435 }
436 }
437 out:
438 return err;
439 }
440
441 static int
442 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
443 {
444 struct ip_tunnel_prl_entry *p;
445 int ok = 1;
446
447 rcu_read_lock();
448 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
449 if (p) {
450 if (p->flags & PRL_DEFAULT)
451 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
452 else
453 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
454 } else {
455 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
456
457 if (ipv6_addr_is_isatap(addr6) &&
458 (addr6->s6_addr32[3] == iph->saddr) &&
459 ipv6_chk_prefix(addr6, t->dev))
460 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
461 else
462 ok = 0;
463 }
464 rcu_read_unlock();
465 return ok;
466 }
467
468 static void ipip6_tunnel_uninit(struct net_device *dev)
469 {
470 struct ip_tunnel *tunnel = netdev_priv(dev);
471 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
472
473 if (dev == sitn->fb_tunnel_dev) {
474 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
475 } else {
476 ipip6_tunnel_unlink(sitn, tunnel);
477 ipip6_tunnel_del_prl(tunnel, NULL);
478 }
479 ip_tunnel_dst_reset_all(tunnel);
480 dev_put(dev);
481 }
482
483 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
484 * if sufficient data bytes are available
485 */
486 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb)
487 {
488 const struct iphdr *iph = (const struct iphdr *) skb->data;
489 struct rt6_info *rt;
490 struct sk_buff *skb2;
491
492 if (!pskb_may_pull(skb, iph->ihl * 4 + sizeof(struct ipv6hdr) + 8))
493 return 1;
494
495 skb2 = skb_clone(skb, GFP_ATOMIC);
496
497 if (!skb2)
498 return 1;
499
500 skb_dst_drop(skb2);
501 skb_pull(skb2, iph->ihl * 4);
502 skb_reset_network_header(skb2);
503
504 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
505
506 if (rt && rt->dst.dev)
507 skb2->dev = rt->dst.dev;
508
509 icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
510
511 if (rt)
512 ip6_rt_put(rt);
513
514 kfree_skb(skb2);
515
516 return 0;
517 }
518
519 static int ipip6_err(struct sk_buff *skb, u32 info)
520 {
521 const struct iphdr *iph = (const struct iphdr *)skb->data;
522 const int type = icmp_hdr(skb)->type;
523 const int code = icmp_hdr(skb)->code;
524 struct ip_tunnel *t;
525 int err;
526
527 switch (type) {
528 default:
529 case ICMP_PARAMETERPROB:
530 return 0;
531
532 case ICMP_DEST_UNREACH:
533 switch (code) {
534 case ICMP_SR_FAILED:
535 /* Impossible event. */
536 return 0;
537 default:
538 /* All others are translated to HOST_UNREACH.
539 rfc2003 contains "deep thoughts" about NET_UNREACH,
540 I believe they are just ether pollution. --ANK
541 */
542 break;
543 }
544 break;
545 case ICMP_TIME_EXCEEDED:
546 if (code != ICMP_EXC_TTL)
547 return 0;
548 break;
549 case ICMP_REDIRECT:
550 break;
551 }
552
553 err = -ENOENT;
554
555 t = ipip6_tunnel_lookup(dev_net(skb->dev),
556 skb->dev,
557 iph->daddr,
558 iph->saddr);
559 if (t == NULL)
560 goto out;
561
562 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
563 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
564 t->parms.link, 0, IPPROTO_IPV6, 0);
565 err = 0;
566 goto out;
567 }
568 if (type == ICMP_REDIRECT) {
569 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
570 IPPROTO_IPV6, 0);
571 err = 0;
572 goto out;
573 }
574
575 if (t->parms.iph.daddr == 0)
576 goto out;
577
578 err = 0;
579 if (!ipip6_err_gen_icmpv6_unreach(skb))
580 goto out;
581
582 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
583 goto out;
584
585 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
586 t->err_count++;
587 else
588 t->err_count = 1;
589 t->err_time = jiffies;
590 out:
591 return err;
592 }
593
594 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
595 const struct in6_addr *v6addr)
596 {
597 __be32 v4embed = 0;
598 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
599 return true;
600 return false;
601 }
602
603 /* Checks if an address matches an address on the tunnel interface.
604 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
605 * Long story:
606 * This function is called after we considered the packet as spoofed
607 * in is_spoofed_6rd.
608 * We may have a router that is doing NAT for proto 41 packets
609 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
610 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
611 * function will return true, dropping the packet.
612 * But, we can still check if is spoofed against the IP
613 * addresses associated with the interface.
614 */
615 static bool only_dnatted(const struct ip_tunnel *tunnel,
616 const struct in6_addr *v6dst)
617 {
618 int prefix_len;
619
620 #ifdef CONFIG_IPV6_SIT_6RD
621 prefix_len = tunnel->ip6rd.prefixlen + 32
622 - tunnel->ip6rd.relay_prefixlen;
623 #else
624 prefix_len = 48;
625 #endif
626 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
627 }
628
629 /* Returns true if a packet is spoofed */
630 static bool packet_is_spoofed(struct sk_buff *skb,
631 const struct iphdr *iph,
632 struct ip_tunnel *tunnel)
633 {
634 const struct ipv6hdr *ipv6h;
635
636 if (tunnel->dev->priv_flags & IFF_ISATAP) {
637 if (!isatap_chksrc(skb, iph, tunnel))
638 return true;
639
640 return false;
641 }
642
643 if (tunnel->dev->flags & IFF_POINTOPOINT)
644 return false;
645
646 ipv6h = ipv6_hdr(skb);
647
648 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
649 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
650 &iph->saddr, &ipv6h->saddr,
651 &iph->daddr, &ipv6h->daddr);
652 return true;
653 }
654
655 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
656 return false;
657
658 if (only_dnatted(tunnel, &ipv6h->daddr))
659 return false;
660
661 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
662 &iph->saddr, &ipv6h->saddr,
663 &iph->daddr, &ipv6h->daddr);
664 return true;
665 }
666
667 static int ipip6_rcv(struct sk_buff *skb)
668 {
669 const struct iphdr *iph = ip_hdr(skb);
670 struct ip_tunnel *tunnel;
671 int err;
672
673 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
674 iph->saddr, iph->daddr);
675 if (tunnel != NULL) {
676 struct pcpu_sw_netstats *tstats;
677
678 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
679 tunnel->parms.iph.protocol != 0)
680 goto out;
681
682 skb->mac_header = skb->network_header;
683 skb_reset_network_header(skb);
684 IPCB(skb)->flags = 0;
685 skb->protocol = htons(ETH_P_IPV6);
686
687 if (packet_is_spoofed(skb, iph, tunnel)) {
688 tunnel->dev->stats.rx_errors++;
689 goto out;
690 }
691
692 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
693
694 err = IP_ECN_decapsulate(iph, skb);
695 if (unlikely(err)) {
696 if (log_ecn_error)
697 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
698 &iph->saddr, iph->tos);
699 if (err > 1) {
700 ++tunnel->dev->stats.rx_frame_errors;
701 ++tunnel->dev->stats.rx_errors;
702 goto out;
703 }
704 }
705
706 tstats = this_cpu_ptr(tunnel->dev->tstats);
707 u64_stats_update_begin(&tstats->syncp);
708 tstats->rx_packets++;
709 tstats->rx_bytes += skb->len;
710 u64_stats_update_end(&tstats->syncp);
711
712 netif_rx(skb);
713
714 return 0;
715 }
716
717 /* no tunnel matched, let upstream know, ipsec may handle it */
718 return 1;
719 out:
720 kfree_skb(skb);
721 return 0;
722 }
723
724 static const struct tnl_ptk_info tpi = {
725 /* no tunnel info required for ipip. */
726 .proto = htons(ETH_P_IP),
727 };
728
729 static int ipip_rcv(struct sk_buff *skb)
730 {
731 const struct iphdr *iph;
732 struct ip_tunnel *tunnel;
733
734 iph = ip_hdr(skb);
735 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
736 iph->saddr, iph->daddr);
737 if (tunnel != NULL) {
738 if (tunnel->parms.iph.protocol != IPPROTO_IPIP &&
739 tunnel->parms.iph.protocol != 0)
740 goto drop;
741
742 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
743 goto drop;
744 if (iptunnel_pull_header(skb, 0, tpi.proto))
745 goto drop;
746 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
747 }
748
749 return 1;
750
751 drop:
752 kfree_skb(skb);
753 return 0;
754 }
755
756 /*
757 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
758 * stores the embedded IPv4 address in v4dst and returns true.
759 */
760 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
761 __be32 *v4dst)
762 {
763 #ifdef CONFIG_IPV6_SIT_6RD
764 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
765 tunnel->ip6rd.prefixlen)) {
766 unsigned int pbw0, pbi0;
767 int pbi1;
768 u32 d;
769
770 pbw0 = tunnel->ip6rd.prefixlen >> 5;
771 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
772
773 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
774 tunnel->ip6rd.relay_prefixlen;
775
776 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
777 if (pbi1 > 0)
778 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
779 (32 - pbi1);
780
781 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
782 return true;
783 }
784 #else
785 if (v6dst->s6_addr16[0] == htons(0x2002)) {
786 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
787 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
788 return true;
789 }
790 #endif
791 return false;
792 }
793
794 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
795 const struct in6_addr *v6dst)
796 {
797 __be32 dst = 0;
798 check_6rd(tunnel, v6dst, &dst);
799 return dst;
800 }
801
802 /*
803 * This function assumes it is being called from dev_queue_xmit()
804 * and that skb is filled properly by that function.
805 */
806
807 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
808 struct net_device *dev)
809 {
810 struct ip_tunnel *tunnel = netdev_priv(dev);
811 const struct iphdr *tiph = &tunnel->parms.iph;
812 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
813 u8 tos = tunnel->parms.iph.tos;
814 __be16 df = tiph->frag_off;
815 struct rtable *rt; /* Route to the other host */
816 struct net_device *tdev; /* Device to other host */
817 unsigned int max_headroom; /* The extra header space needed */
818 __be32 dst = tiph->daddr;
819 struct flowi4 fl4;
820 int mtu;
821 const struct in6_addr *addr6;
822 int addr_type;
823 u8 ttl;
824 int err;
825
826 if (skb->protocol != htons(ETH_P_IPV6))
827 goto tx_error;
828
829 if (tos == 1)
830 tos = ipv6_get_dsfield(iph6);
831
832 /* ISATAP (RFC4214) - must come before 6to4 */
833 if (dev->priv_flags & IFF_ISATAP) {
834 struct neighbour *neigh = NULL;
835 bool do_tx_error = false;
836
837 if (skb_dst(skb))
838 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
839
840 if (neigh == NULL) {
841 net_dbg_ratelimited("nexthop == NULL\n");
842 goto tx_error;
843 }
844
845 addr6 = (const struct in6_addr *)&neigh->primary_key;
846 addr_type = ipv6_addr_type(addr6);
847
848 if ((addr_type & IPV6_ADDR_UNICAST) &&
849 ipv6_addr_is_isatap(addr6))
850 dst = addr6->s6_addr32[3];
851 else
852 do_tx_error = true;
853
854 neigh_release(neigh);
855 if (do_tx_error)
856 goto tx_error;
857 }
858
859 if (!dst)
860 dst = try_6rd(tunnel, &iph6->daddr);
861
862 if (!dst) {
863 struct neighbour *neigh = NULL;
864 bool do_tx_error = false;
865
866 if (skb_dst(skb))
867 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
868
869 if (neigh == NULL) {
870 net_dbg_ratelimited("nexthop == NULL\n");
871 goto tx_error;
872 }
873
874 addr6 = (const struct in6_addr *)&neigh->primary_key;
875 addr_type = ipv6_addr_type(addr6);
876
877 if (addr_type == IPV6_ADDR_ANY) {
878 addr6 = &ipv6_hdr(skb)->daddr;
879 addr_type = ipv6_addr_type(addr6);
880 }
881
882 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
883 dst = addr6->s6_addr32[3];
884 else
885 do_tx_error = true;
886
887 neigh_release(neigh);
888 if (do_tx_error)
889 goto tx_error;
890 }
891
892 rt = ip_route_output_ports(tunnel->net, &fl4, NULL,
893 dst, tiph->saddr,
894 0, 0,
895 IPPROTO_IPV6, RT_TOS(tos),
896 tunnel->parms.link);
897 if (IS_ERR(rt)) {
898 dev->stats.tx_carrier_errors++;
899 goto tx_error_icmp;
900 }
901 if (rt->rt_type != RTN_UNICAST) {
902 ip_rt_put(rt);
903 dev->stats.tx_carrier_errors++;
904 goto tx_error_icmp;
905 }
906 tdev = rt->dst.dev;
907
908 if (tdev == dev) {
909 ip_rt_put(rt);
910 dev->stats.collisions++;
911 goto tx_error;
912 }
913
914 if (df) {
915 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
916
917 if (mtu < 68) {
918 dev->stats.collisions++;
919 ip_rt_put(rt);
920 goto tx_error;
921 }
922
923 if (mtu < IPV6_MIN_MTU) {
924 mtu = IPV6_MIN_MTU;
925 df = 0;
926 }
927
928 if (tunnel->parms.iph.daddr && skb_dst(skb))
929 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
930
931 if (skb->len > mtu && !skb_is_gso(skb)) {
932 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
933 ip_rt_put(rt);
934 goto tx_error;
935 }
936 }
937
938 if (tunnel->err_count > 0) {
939 if (time_before(jiffies,
940 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
941 tunnel->err_count--;
942 dst_link_failure(skb);
943 } else
944 tunnel->err_count = 0;
945 }
946
947 /*
948 * Okay, now see if we can stuff it in the buffer as-is.
949 */
950 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
951
952 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
953 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
954 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
955 if (!new_skb) {
956 ip_rt_put(rt);
957 dev->stats.tx_dropped++;
958 kfree_skb(skb);
959 return NETDEV_TX_OK;
960 }
961 if (skb->sk)
962 skb_set_owner_w(new_skb, skb->sk);
963 dev_kfree_skb(skb);
964 skb = new_skb;
965 iph6 = ipv6_hdr(skb);
966 }
967 ttl = tiph->ttl;
968 if (ttl == 0)
969 ttl = iph6->hop_limit;
970 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
971
972 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
973 if (IS_ERR(skb)) {
974 ip_rt_put(rt);
975 goto out;
976 }
977
978 err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr,
979 IPPROTO_IPV6, tos, ttl, df,
980 !net_eq(tunnel->net, dev_net(dev)));
981 iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
982 return NETDEV_TX_OK;
983
984 tx_error_icmp:
985 dst_link_failure(skb);
986 tx_error:
987 kfree_skb(skb);
988 out:
989 dev->stats.tx_errors++;
990 return NETDEV_TX_OK;
991 }
992
993 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
994 {
995 struct ip_tunnel *tunnel = netdev_priv(dev);
996 const struct iphdr *tiph = &tunnel->parms.iph;
997
998 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
999 if (IS_ERR(skb))
1000 goto out;
1001
1002 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP);
1003 return NETDEV_TX_OK;
1004 out:
1005 dev->stats.tx_errors++;
1006 return NETDEV_TX_OK;
1007 }
1008
1009 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1010 struct net_device *dev)
1011 {
1012 switch (skb->protocol) {
1013 case htons(ETH_P_IP):
1014 ipip_tunnel_xmit(skb, dev);
1015 break;
1016 case htons(ETH_P_IPV6):
1017 ipip6_tunnel_xmit(skb, dev);
1018 break;
1019 default:
1020 goto tx_err;
1021 }
1022
1023 return NETDEV_TX_OK;
1024
1025 tx_err:
1026 dev->stats.tx_errors++;
1027 kfree_skb(skb);
1028 return NETDEV_TX_OK;
1029
1030 }
1031
1032 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1033 {
1034 struct net_device *tdev = NULL;
1035 struct ip_tunnel *tunnel;
1036 const struct iphdr *iph;
1037 struct flowi4 fl4;
1038
1039 tunnel = netdev_priv(dev);
1040 iph = &tunnel->parms.iph;
1041
1042 if (iph->daddr) {
1043 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1044 NULL,
1045 iph->daddr, iph->saddr,
1046 0, 0,
1047 IPPROTO_IPV6,
1048 RT_TOS(iph->tos),
1049 tunnel->parms.link);
1050
1051 if (!IS_ERR(rt)) {
1052 tdev = rt->dst.dev;
1053 ip_rt_put(rt);
1054 }
1055 dev->flags |= IFF_POINTOPOINT;
1056 }
1057
1058 if (!tdev && tunnel->parms.link)
1059 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1060
1061 if (tdev) {
1062 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1063 dev->mtu = tdev->mtu - sizeof(struct iphdr);
1064 if (dev->mtu < IPV6_MIN_MTU)
1065 dev->mtu = IPV6_MIN_MTU;
1066 }
1067 dev->iflink = tunnel->parms.link;
1068 }
1069
1070 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
1071 {
1072 struct net *net = t->net;
1073 struct sit_net *sitn = net_generic(net, sit_net_id);
1074
1075 ipip6_tunnel_unlink(sitn, t);
1076 synchronize_net();
1077 t->parms.iph.saddr = p->iph.saddr;
1078 t->parms.iph.daddr = p->iph.daddr;
1079 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1080 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1081 ipip6_tunnel_link(sitn, t);
1082 t->parms.iph.ttl = p->iph.ttl;
1083 t->parms.iph.tos = p->iph.tos;
1084 if (t->parms.link != p->link) {
1085 t->parms.link = p->link;
1086 ipip6_tunnel_bind_dev(t->dev);
1087 }
1088 ip_tunnel_dst_reset_all(t);
1089 netdev_state_change(t->dev);
1090 }
1091
1092 #ifdef CONFIG_IPV6_SIT_6RD
1093 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1094 struct ip_tunnel_6rd *ip6rd)
1095 {
1096 struct in6_addr prefix;
1097 __be32 relay_prefix;
1098
1099 if (ip6rd->relay_prefixlen > 32 ||
1100 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1101 return -EINVAL;
1102
1103 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1104 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1105 return -EINVAL;
1106 if (ip6rd->relay_prefixlen)
1107 relay_prefix = ip6rd->relay_prefix &
1108 htonl(0xffffffffUL <<
1109 (32 - ip6rd->relay_prefixlen));
1110 else
1111 relay_prefix = 0;
1112 if (relay_prefix != ip6rd->relay_prefix)
1113 return -EINVAL;
1114
1115 t->ip6rd.prefix = prefix;
1116 t->ip6rd.relay_prefix = relay_prefix;
1117 t->ip6rd.prefixlen = ip6rd->prefixlen;
1118 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1119 ip_tunnel_dst_reset_all(t);
1120 netdev_state_change(t->dev);
1121 return 0;
1122 }
1123 #endif
1124
1125 static int
1126 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1127 {
1128 int err = 0;
1129 struct ip_tunnel_parm p;
1130 struct ip_tunnel_prl prl;
1131 struct ip_tunnel *t = netdev_priv(dev);
1132 struct net *net = t->net;
1133 struct sit_net *sitn = net_generic(net, sit_net_id);
1134 #ifdef CONFIG_IPV6_SIT_6RD
1135 struct ip_tunnel_6rd ip6rd;
1136 #endif
1137
1138 switch (cmd) {
1139 case SIOCGETTUNNEL:
1140 #ifdef CONFIG_IPV6_SIT_6RD
1141 case SIOCGET6RD:
1142 #endif
1143 if (dev == sitn->fb_tunnel_dev) {
1144 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1145 err = -EFAULT;
1146 break;
1147 }
1148 t = ipip6_tunnel_locate(net, &p, 0);
1149 if (t == NULL)
1150 t = netdev_priv(dev);
1151 }
1152
1153 err = -EFAULT;
1154 if (cmd == SIOCGETTUNNEL) {
1155 memcpy(&p, &t->parms, sizeof(p));
1156 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1157 sizeof(p)))
1158 goto done;
1159 #ifdef CONFIG_IPV6_SIT_6RD
1160 } else {
1161 ip6rd.prefix = t->ip6rd.prefix;
1162 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1163 ip6rd.prefixlen = t->ip6rd.prefixlen;
1164 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1165 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1166 sizeof(ip6rd)))
1167 goto done;
1168 #endif
1169 }
1170 err = 0;
1171 break;
1172
1173 case SIOCADDTUNNEL:
1174 case SIOCCHGTUNNEL:
1175 err = -EPERM;
1176 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1177 goto done;
1178
1179 err = -EFAULT;
1180 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1181 goto done;
1182
1183 err = -EINVAL;
1184 if (p.iph.protocol != IPPROTO_IPV6 &&
1185 p.iph.protocol != IPPROTO_IPIP &&
1186 p.iph.protocol != 0)
1187 goto done;
1188 if (p.iph.version != 4 ||
1189 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1190 goto done;
1191 if (p.iph.ttl)
1192 p.iph.frag_off |= htons(IP_DF);
1193
1194 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1195
1196 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1197 if (t != NULL) {
1198 if (t->dev != dev) {
1199 err = -EEXIST;
1200 break;
1201 }
1202 } else {
1203 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1204 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1205 err = -EINVAL;
1206 break;
1207 }
1208 t = netdev_priv(dev);
1209 }
1210
1211 ipip6_tunnel_update(t, &p);
1212 }
1213
1214 if (t) {
1215 err = 0;
1216 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1217 err = -EFAULT;
1218 } else
1219 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1220 break;
1221
1222 case SIOCDELTUNNEL:
1223 err = -EPERM;
1224 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1225 goto done;
1226
1227 if (dev == sitn->fb_tunnel_dev) {
1228 err = -EFAULT;
1229 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1230 goto done;
1231 err = -ENOENT;
1232 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1233 goto done;
1234 err = -EPERM;
1235 if (t == netdev_priv(sitn->fb_tunnel_dev))
1236 goto done;
1237 dev = t->dev;
1238 }
1239 unregister_netdevice(dev);
1240 err = 0;
1241 break;
1242
1243 case SIOCGETPRL:
1244 err = -EINVAL;
1245 if (dev == sitn->fb_tunnel_dev)
1246 goto done;
1247 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1248 break;
1249
1250 case SIOCADDPRL:
1251 case SIOCDELPRL:
1252 case SIOCCHGPRL:
1253 err = -EPERM;
1254 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1255 goto done;
1256 err = -EINVAL;
1257 if (dev == sitn->fb_tunnel_dev)
1258 goto done;
1259 err = -EFAULT;
1260 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1261 goto done;
1262
1263 switch (cmd) {
1264 case SIOCDELPRL:
1265 err = ipip6_tunnel_del_prl(t, &prl);
1266 break;
1267 case SIOCADDPRL:
1268 case SIOCCHGPRL:
1269 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1270 break;
1271 }
1272 ip_tunnel_dst_reset_all(t);
1273 netdev_state_change(dev);
1274 break;
1275
1276 #ifdef CONFIG_IPV6_SIT_6RD
1277 case SIOCADD6RD:
1278 case SIOCCHG6RD:
1279 case SIOCDEL6RD:
1280 err = -EPERM;
1281 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1282 goto done;
1283
1284 err = -EFAULT;
1285 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1286 sizeof(ip6rd)))
1287 goto done;
1288
1289 if (cmd != SIOCDEL6RD) {
1290 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1291 if (err < 0)
1292 goto done;
1293 } else
1294 ipip6_tunnel_clone_6rd(dev, sitn);
1295
1296 err = 0;
1297 break;
1298 #endif
1299
1300 default:
1301 err = -EINVAL;
1302 }
1303
1304 done:
1305 return err;
1306 }
1307
1308 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1309 {
1310 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1311 return -EINVAL;
1312 dev->mtu = new_mtu;
1313 return 0;
1314 }
1315
1316 static const struct net_device_ops ipip6_netdev_ops = {
1317 .ndo_uninit = ipip6_tunnel_uninit,
1318 .ndo_start_xmit = sit_tunnel_xmit,
1319 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1320 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1321 .ndo_get_stats64 = ip_tunnel_get_stats64,
1322 };
1323
1324 static void ipip6_dev_free(struct net_device *dev)
1325 {
1326 struct ip_tunnel *tunnel = netdev_priv(dev);
1327
1328 free_percpu(tunnel->dst_cache);
1329 free_percpu(dev->tstats);
1330 free_netdev(dev);
1331 }
1332
1333 #define SIT_FEATURES (NETIF_F_SG | \
1334 NETIF_F_FRAGLIST | \
1335 NETIF_F_HIGHDMA | \
1336 NETIF_F_GSO_SOFTWARE | \
1337 NETIF_F_HW_CSUM)
1338
1339 static void ipip6_tunnel_setup(struct net_device *dev)
1340 {
1341 dev->netdev_ops = &ipip6_netdev_ops;
1342 dev->destructor = ipip6_dev_free;
1343
1344 dev->type = ARPHRD_SIT;
1345 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1346 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1347 dev->flags = IFF_NOARP;
1348 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1349 dev->iflink = 0;
1350 dev->addr_len = 4;
1351 dev->features |= NETIF_F_LLTX;
1352 dev->features |= SIT_FEATURES;
1353 dev->hw_features |= SIT_FEATURES;
1354 }
1355
1356 static int ipip6_tunnel_init(struct net_device *dev)
1357 {
1358 struct ip_tunnel *tunnel = netdev_priv(dev);
1359
1360 tunnel->dev = dev;
1361 tunnel->net = dev_net(dev);
1362
1363 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1364 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1365
1366 ipip6_tunnel_bind_dev(dev);
1367 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1368 if (!dev->tstats)
1369 return -ENOMEM;
1370
1371 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
1372 if (!tunnel->dst_cache) {
1373 free_percpu(dev->tstats);
1374 return -ENOMEM;
1375 }
1376
1377 return 0;
1378 }
1379
1380 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1381 {
1382 struct ip_tunnel *tunnel = netdev_priv(dev);
1383 struct iphdr *iph = &tunnel->parms.iph;
1384 struct net *net = dev_net(dev);
1385 struct sit_net *sitn = net_generic(net, sit_net_id);
1386
1387 tunnel->dev = dev;
1388 tunnel->net = dev_net(dev);
1389 strcpy(tunnel->parms.name, dev->name);
1390
1391 iph->version = 4;
1392 iph->protocol = IPPROTO_IPV6;
1393 iph->ihl = 5;
1394 iph->ttl = 64;
1395
1396 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1397 if (!dev->tstats)
1398 return -ENOMEM;
1399
1400 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
1401 if (!tunnel->dst_cache) {
1402 free_percpu(dev->tstats);
1403 return -ENOMEM;
1404 }
1405
1406 dev_hold(dev);
1407 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1408 return 0;
1409 }
1410
1411 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1412 {
1413 u8 proto;
1414
1415 if (!data || !data[IFLA_IPTUN_PROTO])
1416 return 0;
1417
1418 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1419 if (proto != IPPROTO_IPV6 &&
1420 proto != IPPROTO_IPIP &&
1421 proto != 0)
1422 return -EINVAL;
1423
1424 return 0;
1425 }
1426
1427 static void ipip6_netlink_parms(struct nlattr *data[],
1428 struct ip_tunnel_parm *parms)
1429 {
1430 memset(parms, 0, sizeof(*parms));
1431
1432 parms->iph.version = 4;
1433 parms->iph.protocol = IPPROTO_IPV6;
1434 parms->iph.ihl = 5;
1435 parms->iph.ttl = 64;
1436
1437 if (!data)
1438 return;
1439
1440 if (data[IFLA_IPTUN_LINK])
1441 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1442
1443 if (data[IFLA_IPTUN_LOCAL])
1444 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1445
1446 if (data[IFLA_IPTUN_REMOTE])
1447 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1448
1449 if (data[IFLA_IPTUN_TTL]) {
1450 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1451 if (parms->iph.ttl)
1452 parms->iph.frag_off = htons(IP_DF);
1453 }
1454
1455 if (data[IFLA_IPTUN_TOS])
1456 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1457
1458 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1459 parms->iph.frag_off = htons(IP_DF);
1460
1461 if (data[IFLA_IPTUN_FLAGS])
1462 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1463
1464 if (data[IFLA_IPTUN_PROTO])
1465 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1466
1467 }
1468
1469 #ifdef CONFIG_IPV6_SIT_6RD
1470 /* This function returns true when 6RD attributes are present in the nl msg */
1471 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1472 struct ip_tunnel_6rd *ip6rd)
1473 {
1474 bool ret = false;
1475 memset(ip6rd, 0, sizeof(*ip6rd));
1476
1477 if (!data)
1478 return ret;
1479
1480 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1481 ret = true;
1482 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX],
1483 sizeof(struct in6_addr));
1484 }
1485
1486 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1487 ret = true;
1488 ip6rd->relay_prefix =
1489 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1490 }
1491
1492 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1493 ret = true;
1494 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1495 }
1496
1497 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1498 ret = true;
1499 ip6rd->relay_prefixlen =
1500 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1501 }
1502
1503 return ret;
1504 }
1505 #endif
1506
1507 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1508 struct nlattr *tb[], struct nlattr *data[])
1509 {
1510 struct net *net = dev_net(dev);
1511 struct ip_tunnel *nt;
1512 #ifdef CONFIG_IPV6_SIT_6RD
1513 struct ip_tunnel_6rd ip6rd;
1514 #endif
1515 int err;
1516
1517 nt = netdev_priv(dev);
1518 ipip6_netlink_parms(data, &nt->parms);
1519
1520 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1521 return -EEXIST;
1522
1523 err = ipip6_tunnel_create(dev);
1524 if (err < 0)
1525 return err;
1526
1527 #ifdef CONFIG_IPV6_SIT_6RD
1528 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1529 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1530 #endif
1531
1532 return err;
1533 }
1534
1535 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1536 struct nlattr *data[])
1537 {
1538 struct ip_tunnel *t = netdev_priv(dev);
1539 struct ip_tunnel_parm p;
1540 struct net *net = t->net;
1541 struct sit_net *sitn = net_generic(net, sit_net_id);
1542 #ifdef CONFIG_IPV6_SIT_6RD
1543 struct ip_tunnel_6rd ip6rd;
1544 #endif
1545
1546 if (dev == sitn->fb_tunnel_dev)
1547 return -EINVAL;
1548
1549 ipip6_netlink_parms(data, &p);
1550
1551 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1552 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1553 return -EINVAL;
1554
1555 t = ipip6_tunnel_locate(net, &p, 0);
1556
1557 if (t) {
1558 if (t->dev != dev)
1559 return -EEXIST;
1560 } else
1561 t = netdev_priv(dev);
1562
1563 ipip6_tunnel_update(t, &p);
1564
1565 #ifdef CONFIG_IPV6_SIT_6RD
1566 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1567 return ipip6_tunnel_update_6rd(t, &ip6rd);
1568 #endif
1569
1570 return 0;
1571 }
1572
1573 static size_t ipip6_get_size(const struct net_device *dev)
1574 {
1575 return
1576 /* IFLA_IPTUN_LINK */
1577 nla_total_size(4) +
1578 /* IFLA_IPTUN_LOCAL */
1579 nla_total_size(4) +
1580 /* IFLA_IPTUN_REMOTE */
1581 nla_total_size(4) +
1582 /* IFLA_IPTUN_TTL */
1583 nla_total_size(1) +
1584 /* IFLA_IPTUN_TOS */
1585 nla_total_size(1) +
1586 /* IFLA_IPTUN_PMTUDISC */
1587 nla_total_size(1) +
1588 /* IFLA_IPTUN_FLAGS */
1589 nla_total_size(2) +
1590 /* IFLA_IPTUN_PROTO */
1591 nla_total_size(1) +
1592 #ifdef CONFIG_IPV6_SIT_6RD
1593 /* IFLA_IPTUN_6RD_PREFIX */
1594 nla_total_size(sizeof(struct in6_addr)) +
1595 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1596 nla_total_size(4) +
1597 /* IFLA_IPTUN_6RD_PREFIXLEN */
1598 nla_total_size(2) +
1599 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1600 nla_total_size(2) +
1601 #endif
1602 0;
1603 }
1604
1605 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1606 {
1607 struct ip_tunnel *tunnel = netdev_priv(dev);
1608 struct ip_tunnel_parm *parm = &tunnel->parms;
1609
1610 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1611 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1612 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1613 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1614 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1615 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1616 !!(parm->iph.frag_off & htons(IP_DF))) ||
1617 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1618 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1619 goto nla_put_failure;
1620
1621 #ifdef CONFIG_IPV6_SIT_6RD
1622 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr),
1623 &tunnel->ip6rd.prefix) ||
1624 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1625 tunnel->ip6rd.relay_prefix) ||
1626 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1627 tunnel->ip6rd.prefixlen) ||
1628 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1629 tunnel->ip6rd.relay_prefixlen))
1630 goto nla_put_failure;
1631 #endif
1632
1633 return 0;
1634
1635 nla_put_failure:
1636 return -EMSGSIZE;
1637 }
1638
1639 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1640 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1641 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1642 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1643 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1644 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1645 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1646 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1647 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1648 #ifdef CONFIG_IPV6_SIT_6RD
1649 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1650 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1651 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1652 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1653 #endif
1654 };
1655
1656 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1657 {
1658 struct net *net = dev_net(dev);
1659 struct sit_net *sitn = net_generic(net, sit_net_id);
1660
1661 if (dev != sitn->fb_tunnel_dev)
1662 unregister_netdevice_queue(dev, head);
1663 }
1664
1665 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1666 .kind = "sit",
1667 .maxtype = IFLA_IPTUN_MAX,
1668 .policy = ipip6_policy,
1669 .priv_size = sizeof(struct ip_tunnel),
1670 .setup = ipip6_tunnel_setup,
1671 .validate = ipip6_validate,
1672 .newlink = ipip6_newlink,
1673 .changelink = ipip6_changelink,
1674 .get_size = ipip6_get_size,
1675 .fill_info = ipip6_fill_info,
1676 .dellink = ipip6_dellink,
1677 };
1678
1679 static struct xfrm_tunnel sit_handler __read_mostly = {
1680 .handler = ipip6_rcv,
1681 .err_handler = ipip6_err,
1682 .priority = 1,
1683 };
1684
1685 static struct xfrm_tunnel ipip_handler __read_mostly = {
1686 .handler = ipip_rcv,
1687 .err_handler = ipip6_err,
1688 .priority = 2,
1689 };
1690
1691 static void __net_exit sit_destroy_tunnels(struct net *net,
1692 struct list_head *head)
1693 {
1694 struct sit_net *sitn = net_generic(net, sit_net_id);
1695 struct net_device *dev, *aux;
1696 int prio;
1697
1698 for_each_netdev_safe(net, dev, aux)
1699 if (dev->rtnl_link_ops == &sit_link_ops)
1700 unregister_netdevice_queue(dev, head);
1701
1702 for (prio = 1; prio < 4; prio++) {
1703 int h;
1704 for (h = 0; h < HASH_SIZE; h++) {
1705 struct ip_tunnel *t;
1706
1707 t = rtnl_dereference(sitn->tunnels[prio][h]);
1708 while (t != NULL) {
1709 /* If dev is in the same netns, it has already
1710 * been added to the list by the previous loop.
1711 */
1712 if (!net_eq(dev_net(t->dev), net))
1713 unregister_netdevice_queue(t->dev,
1714 head);
1715 t = rtnl_dereference(t->next);
1716 }
1717 }
1718 }
1719 }
1720
1721 static int __net_init sit_init_net(struct net *net)
1722 {
1723 struct sit_net *sitn = net_generic(net, sit_net_id);
1724 struct ip_tunnel *t;
1725 int err;
1726
1727 sitn->tunnels[0] = sitn->tunnels_wc;
1728 sitn->tunnels[1] = sitn->tunnels_l;
1729 sitn->tunnels[2] = sitn->tunnels_r;
1730 sitn->tunnels[3] = sitn->tunnels_r_l;
1731
1732 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1733 NET_NAME_UNKNOWN,
1734 ipip6_tunnel_setup);
1735 if (!sitn->fb_tunnel_dev) {
1736 err = -ENOMEM;
1737 goto err_alloc_dev;
1738 }
1739 dev_net_set(sitn->fb_tunnel_dev, net);
1740 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1741 /* FB netdevice is special: we have one, and only one per netns.
1742 * Allowing to move it to another netns is clearly unsafe.
1743 */
1744 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1745
1746 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1747 if (err)
1748 goto err_dev_free;
1749
1750 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1751
1752 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1753 goto err_reg_dev;
1754
1755 t = netdev_priv(sitn->fb_tunnel_dev);
1756
1757 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1758 return 0;
1759
1760 err_reg_dev:
1761 dev_put(sitn->fb_tunnel_dev);
1762 err_dev_free:
1763 ipip6_dev_free(sitn->fb_tunnel_dev);
1764 err_alloc_dev:
1765 return err;
1766 }
1767
1768 static void __net_exit sit_exit_net(struct net *net)
1769 {
1770 LIST_HEAD(list);
1771
1772 rtnl_lock();
1773 sit_destroy_tunnels(net, &list);
1774 unregister_netdevice_many(&list);
1775 rtnl_unlock();
1776 }
1777
1778 static struct pernet_operations sit_net_ops = {
1779 .init = sit_init_net,
1780 .exit = sit_exit_net,
1781 .id = &sit_net_id,
1782 .size = sizeof(struct sit_net),
1783 };
1784
1785 static void __exit sit_cleanup(void)
1786 {
1787 rtnl_link_unregister(&sit_link_ops);
1788 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1789 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1790
1791 unregister_pernet_device(&sit_net_ops);
1792 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1793 }
1794
1795 static int __init sit_init(void)
1796 {
1797 int err;
1798
1799 pr_info("IPv6 over IPv4 tunneling driver\n");
1800
1801 err = register_pernet_device(&sit_net_ops);
1802 if (err < 0)
1803 return err;
1804 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1805 if (err < 0) {
1806 pr_info("%s: can't register ip6ip4\n", __func__);
1807 goto xfrm_tunnel_failed;
1808 }
1809 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1810 if (err < 0) {
1811 pr_info("%s: can't register ip4ip4\n", __func__);
1812 goto xfrm_tunnel4_failed;
1813 }
1814 err = rtnl_link_register(&sit_link_ops);
1815 if (err < 0)
1816 goto rtnl_link_failed;
1817
1818 out:
1819 return err;
1820
1821 rtnl_link_failed:
1822 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1823 xfrm_tunnel4_failed:
1824 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1825 xfrm_tunnel_failed:
1826 unregister_pernet_device(&sit_net_ops);
1827 goto out;
1828 }
1829
1830 module_init(sit_init);
1831 module_exit(sit_cleanup);
1832 MODULE_LICENSE("GPL");
1833 MODULE_ALIAS_RTNL_LINK("sit");
1834 MODULE_ALIAS_NETDEV("sit0");
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