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Merge git://git.infradead.org/~dedekind/ubi-2.6
[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 * $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 * Changes:
17 * Roger Venning <r.venning@telstra.com>: 6to4 support
18 * Nate Thompson <nate@thebog.net>: 6to4 support
19 * Fred Templin <fred.l.templin@boeing.com>: isatap support
20 */
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 <asm/uaccess.h>
34 #include <linux/init.h>
35 #include <linux/netfilter_ipv4.h>
36 #include <linux/if_ether.h>
37
38 #include <net/sock.h>
39 #include <net/snmp.h>
40
41 #include <net/ipv6.h>
42 #include <net/protocol.h>
43 #include <net/transp_v6.h>
44 #include <net/ip6_fib.h>
45 #include <net/ip6_route.h>
46 #include <net/ndisc.h>
47 #include <net/addrconf.h>
48 #include <net/ip.h>
49 #include <net/udp.h>
50 #include <net/icmp.h>
51 #include <net/ipip.h>
52 #include <net/inet_ecn.h>
53 #include <net/xfrm.h>
54 #include <net/dsfield.h>
55 #include <net/net_namespace.h>
56 #include <net/netns/generic.h>
57
58 /*
59 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
60
61 For comments look at net/ipv4/ip_gre.c --ANK
62 */
63
64 #define HASH_SIZE 16
65 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
66
67 static int ipip6_fb_tunnel_init(struct net_device *dev);
68 static int ipip6_tunnel_init(struct net_device *dev);
69 static void ipip6_tunnel_setup(struct net_device *dev);
70
71 static int sit_net_id;
72 struct sit_net {
73 struct ip_tunnel *tunnels_r_l[HASH_SIZE];
74 struct ip_tunnel *tunnels_r[HASH_SIZE];
75 struct ip_tunnel *tunnels_l[HASH_SIZE];
76 struct ip_tunnel *tunnels_wc[1];
77 struct ip_tunnel **tunnels[4];
78
79 struct net_device *fb_tunnel_dev;
80 };
81
82 static DEFINE_RWLOCK(ipip6_lock);
83
84 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
85 __be32 remote, __be32 local)
86 {
87 unsigned h0 = HASH(remote);
88 unsigned h1 = HASH(local);
89 struct ip_tunnel *t;
90 struct sit_net *sitn = net_generic(net, sit_net_id);
91
92 for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) {
93 if (local == t->parms.iph.saddr &&
94 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
95 return t;
96 }
97 for (t = sitn->tunnels_r[h0]; t; t = t->next) {
98 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
99 return t;
100 }
101 for (t = sitn->tunnels_l[h1]; t; t = t->next) {
102 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
103 return t;
104 }
105 if ((t = sitn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
106 return t;
107 return NULL;
108 }
109
110 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn,
111 struct ip_tunnel_parm *parms)
112 {
113 __be32 remote = parms->iph.daddr;
114 __be32 local = parms->iph.saddr;
115 unsigned h = 0;
116 int prio = 0;
117
118 if (remote) {
119 prio |= 2;
120 h ^= HASH(remote);
121 }
122 if (local) {
123 prio |= 1;
124 h ^= HASH(local);
125 }
126 return &sitn->tunnels[prio][h];
127 }
128
129 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn,
130 struct ip_tunnel *t)
131 {
132 return __ipip6_bucket(sitn, &t->parms);
133 }
134
135 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
136 {
137 struct ip_tunnel **tp;
138
139 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) {
140 if (t == *tp) {
141 write_lock_bh(&ipip6_lock);
142 *tp = t->next;
143 write_unlock_bh(&ipip6_lock);
144 break;
145 }
146 }
147 }
148
149 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
150 {
151 struct ip_tunnel **tp = ipip6_bucket(sitn, t);
152
153 t->next = *tp;
154 write_lock_bh(&ipip6_lock);
155 *tp = t;
156 write_unlock_bh(&ipip6_lock);
157 }
158
159 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
160 struct ip_tunnel_parm *parms, int create)
161 {
162 __be32 remote = parms->iph.daddr;
163 __be32 local = parms->iph.saddr;
164 struct ip_tunnel *t, **tp, *nt;
165 struct net_device *dev;
166 char name[IFNAMSIZ];
167 struct sit_net *sitn = net_generic(net, sit_net_id);
168
169 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) {
170 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
171 return t;
172 }
173 if (!create)
174 goto failed;
175
176 if (parms->name[0])
177 strlcpy(name, parms->name, IFNAMSIZ);
178 else
179 sprintf(name, "sit%%d");
180
181 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
182 if (dev == NULL)
183 return NULL;
184
185 dev_net_set(dev, net);
186
187 if (strchr(name, '%')) {
188 if (dev_alloc_name(dev, name) < 0)
189 goto failed_free;
190 }
191
192 nt = netdev_priv(dev);
193 dev->init = ipip6_tunnel_init;
194 nt->parms = *parms;
195
196 if (parms->i_flags & SIT_ISATAP)
197 dev->priv_flags |= IFF_ISATAP;
198
199 if (register_netdevice(dev) < 0)
200 goto failed_free;
201
202 dev_hold(dev);
203
204 ipip6_tunnel_link(sitn, nt);
205 return nt;
206
207 failed_free:
208 free_netdev(dev);
209 failed:
210 return NULL;
211 }
212
213 static struct ip_tunnel_prl_entry *
214 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
215 {
216 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL;
217
218 for (p = t->prl; p; p = p->next)
219 if (p->addr == addr)
220 break;
221 return p;
222
223 }
224
225 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
226 {
227 struct ip_tunnel_prl *kp;
228 struct ip_tunnel_prl_entry *prl;
229 unsigned int cmax, c = 0, ca, len;
230 int ret = 0;
231
232 cmax = a->datalen / sizeof(*a);
233 if (cmax > 1 && a->addr != htonl(INADDR_ANY))
234 cmax = 1;
235
236 /* For simple GET or for root users,
237 * we try harder to allocate.
238 */
239 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
240 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
241 NULL;
242
243 read_lock(&ipip6_lock);
244
245 ca = t->prl_count < cmax ? t->prl_count : cmax;
246
247 if (!kp) {
248 /* We don't try hard to allocate much memory for
249 * non-root users.
250 * For root users, retry allocating enough memory for
251 * the answer.
252 */
253 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
254 if (!kp) {
255 ret = -ENOMEM;
256 goto out;
257 }
258 }
259
260 c = 0;
261 for (prl = t->prl; prl; prl = prl->next) {
262 if (c > cmax)
263 break;
264 if (a->addr != htonl(INADDR_ANY) && prl->addr != a->addr)
265 continue;
266 kp[c].addr = prl->addr;
267 kp[c].flags = prl->flags;
268 c++;
269 if (a->addr != htonl(INADDR_ANY))
270 break;
271 }
272 out:
273 read_unlock(&ipip6_lock);
274
275 len = sizeof(*kp) * c;
276 ret = len ? copy_to_user(a->data, kp, len) : 0;
277
278 kfree(kp);
279 if (ret)
280 return -EFAULT;
281
282 a->datalen = len;
283 return 0;
284 }
285
286 static int
287 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
288 {
289 struct ip_tunnel_prl_entry *p;
290 int err = 0;
291
292 if (a->addr == htonl(INADDR_ANY))
293 return -EINVAL;
294
295 write_lock(&ipip6_lock);
296
297 for (p = t->prl; p; p = p->next) {
298 if (p->addr == a->addr) {
299 if (chg)
300 goto update;
301 err = -EEXIST;
302 goto out;
303 }
304 }
305
306 if (chg) {
307 err = -ENXIO;
308 goto out;
309 }
310
311 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
312 if (!p) {
313 err = -ENOBUFS;
314 goto out;
315 }
316
317 p->next = t->prl;
318 t->prl = p;
319 t->prl_count++;
320 update:
321 p->addr = a->addr;
322 p->flags = a->flags;
323 out:
324 write_unlock(&ipip6_lock);
325 return err;
326 }
327
328 static int
329 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
330 {
331 struct ip_tunnel_prl_entry *x, **p;
332 int err = 0;
333
334 write_lock(&ipip6_lock);
335
336 if (a && a->addr != htonl(INADDR_ANY)) {
337 for (p = &t->prl; *p; p = &(*p)->next) {
338 if ((*p)->addr == a->addr) {
339 x = *p;
340 *p = x->next;
341 kfree(x);
342 t->prl_count--;
343 goto out;
344 }
345 }
346 err = -ENXIO;
347 } else {
348 while (t->prl) {
349 x = t->prl;
350 t->prl = t->prl->next;
351 kfree(x);
352 t->prl_count--;
353 }
354 }
355 out:
356 write_unlock(&ipip6_lock);
357 return 0;
358 }
359
360 static int
361 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
362 {
363 struct ip_tunnel_prl_entry *p;
364 int ok = 1;
365
366 read_lock(&ipip6_lock);
367 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
368 if (p) {
369 if (p->flags & PRL_DEFAULT)
370 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
371 else
372 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
373 } else {
374 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
375 if (ipv6_addr_is_isatap(addr6) &&
376 (addr6->s6_addr32[3] == iph->saddr) &&
377 ipv6_chk_prefix(addr6, t->dev))
378 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
379 else
380 ok = 0;
381 }
382 read_unlock(&ipip6_lock);
383 return ok;
384 }
385
386 static void ipip6_tunnel_uninit(struct net_device *dev)
387 {
388 struct net *net = dev_net(dev);
389 struct sit_net *sitn = net_generic(net, sit_net_id);
390
391 if (dev == sitn->fb_tunnel_dev) {
392 write_lock_bh(&ipip6_lock);
393 sitn->tunnels_wc[0] = NULL;
394 write_unlock_bh(&ipip6_lock);
395 dev_put(dev);
396 } else {
397 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
398 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
399 dev_put(dev);
400 }
401 }
402
403
404 static int ipip6_err(struct sk_buff *skb, u32 info)
405 {
406 #ifndef I_WISH_WORLD_WERE_PERFECT
407
408 /* It is not :-( All the routers (except for Linux) return only
409 8 bytes of packet payload. It means, that precise relaying of
410 ICMP in the real Internet is absolutely infeasible.
411 */
412 struct iphdr *iph = (struct iphdr*)skb->data;
413 const int type = icmp_hdr(skb)->type;
414 const int code = icmp_hdr(skb)->code;
415 struct ip_tunnel *t;
416 int err;
417
418 switch (type) {
419 default:
420 case ICMP_PARAMETERPROB:
421 return 0;
422
423 case ICMP_DEST_UNREACH:
424 switch (code) {
425 case ICMP_SR_FAILED:
426 case ICMP_PORT_UNREACH:
427 /* Impossible event. */
428 return 0;
429 case ICMP_FRAG_NEEDED:
430 /* Soft state for pmtu is maintained by IP core. */
431 return 0;
432 default:
433 /* All others are translated to HOST_UNREACH.
434 rfc2003 contains "deep thoughts" about NET_UNREACH,
435 I believe they are just ether pollution. --ANK
436 */
437 break;
438 }
439 break;
440 case ICMP_TIME_EXCEEDED:
441 if (code != ICMP_EXC_TTL)
442 return 0;
443 break;
444 }
445
446 err = -ENOENT;
447
448 read_lock(&ipip6_lock);
449 t = ipip6_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
450 if (t == NULL || t->parms.iph.daddr == 0)
451 goto out;
452
453 err = 0;
454 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
455 goto out;
456
457 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
458 t->err_count++;
459 else
460 t->err_count = 1;
461 t->err_time = jiffies;
462 out:
463 read_unlock(&ipip6_lock);
464 return err;
465 #else
466 struct iphdr *iph = (struct iphdr*)dp;
467 int hlen = iph->ihl<<2;
468 struct ipv6hdr *iph6;
469 const int type = icmp_hdr(skb)->type;
470 const int code = icmp_hdr(skb)->code;
471 int rel_type = 0;
472 int rel_code = 0;
473 int rel_info = 0;
474 struct sk_buff *skb2;
475 struct rt6_info *rt6i;
476
477 if (len < hlen + sizeof(struct ipv6hdr))
478 return;
479 iph6 = (struct ipv6hdr*)(dp + hlen);
480
481 switch (type) {
482 default:
483 return;
484 case ICMP_PARAMETERPROB:
485 if (icmp_hdr(skb)->un.gateway < hlen)
486 return;
487
488 /* So... This guy found something strange INSIDE encapsulated
489 packet. Well, he is fool, but what can we do ?
490 */
491 rel_type = ICMPV6_PARAMPROB;
492 rel_info = icmp_hdr(skb)->un.gateway - hlen;
493 break;
494
495 case ICMP_DEST_UNREACH:
496 switch (code) {
497 case ICMP_SR_FAILED:
498 case ICMP_PORT_UNREACH:
499 /* Impossible event. */
500 return;
501 case ICMP_FRAG_NEEDED:
502 /* Too complicated case ... */
503 return;
504 default:
505 /* All others are translated to HOST_UNREACH.
506 rfc2003 contains "deep thoughts" about NET_UNREACH,
507 I believe, it is just ether pollution. --ANK
508 */
509 rel_type = ICMPV6_DEST_UNREACH;
510 rel_code = ICMPV6_ADDR_UNREACH;
511 break;
512 }
513 break;
514 case ICMP_TIME_EXCEEDED:
515 if (code != ICMP_EXC_TTL)
516 return;
517 rel_type = ICMPV6_TIME_EXCEED;
518 rel_code = ICMPV6_EXC_HOPLIMIT;
519 break;
520 }
521
522 /* Prepare fake skb to feed it to icmpv6_send */
523 skb2 = skb_clone(skb, GFP_ATOMIC);
524 if (skb2 == NULL)
525 return 0;
526 dst_release(skb2->dst);
527 skb2->dst = NULL;
528 skb_pull(skb2, skb->data - (u8*)iph6);
529 skb_reset_network_header(skb2);
530
531 /* Try to guess incoming interface */
532 rt6i = rt6_lookup(dev_net(skb->dev), &iph6->saddr, NULL, NULL, 0);
533 if (rt6i && rt6i->rt6i_dev) {
534 skb2->dev = rt6i->rt6i_dev;
535
536 rt6i = rt6_lookup(dev_net(skb->dev),
537 &iph6->daddr, &iph6->saddr, NULL, 0);
538
539 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
540 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev);
541 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
542 rel_type = ICMPV6_DEST_UNREACH;
543 rel_code = ICMPV6_ADDR_UNREACH;
544 }
545 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
546 }
547 }
548 kfree_skb(skb2);
549 return 0;
550 #endif
551 }
552
553 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
554 {
555 if (INET_ECN_is_ce(iph->tos))
556 IP6_ECN_set_ce(ipv6_hdr(skb));
557 }
558
559 static int ipip6_rcv(struct sk_buff *skb)
560 {
561 struct iphdr *iph;
562 struct ip_tunnel *tunnel;
563
564 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
565 goto out;
566
567 iph = ip_hdr(skb);
568
569 read_lock(&ipip6_lock);
570 if ((tunnel = ipip6_tunnel_lookup(dev_net(skb->dev),
571 iph->saddr, iph->daddr)) != NULL) {
572 secpath_reset(skb);
573 skb->mac_header = skb->network_header;
574 skb_reset_network_header(skb);
575 IPCB(skb)->flags = 0;
576 skb->protocol = htons(ETH_P_IPV6);
577 skb->pkt_type = PACKET_HOST;
578
579 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
580 !isatap_chksrc(skb, iph, tunnel)) {
581 tunnel->stat.rx_errors++;
582 read_unlock(&ipip6_lock);
583 kfree_skb(skb);
584 return 0;
585 }
586 tunnel->stat.rx_packets++;
587 tunnel->stat.rx_bytes += skb->len;
588 skb->dev = tunnel->dev;
589 dst_release(skb->dst);
590 skb->dst = NULL;
591 nf_reset(skb);
592 ipip6_ecn_decapsulate(iph, skb);
593 netif_rx(skb);
594 read_unlock(&ipip6_lock);
595 return 0;
596 }
597
598 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
599 kfree_skb(skb);
600 read_unlock(&ipip6_lock);
601 out:
602 return 0;
603 }
604
605 /* Returns the embedded IPv4 address if the IPv6 address
606 comes from 6to4 (RFC 3056) addr space */
607
608 static inline __be32 try_6to4(struct in6_addr *v6dst)
609 {
610 __be32 dst = 0;
611
612 if (v6dst->s6_addr16[0] == htons(0x2002)) {
613 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
614 memcpy(&dst, &v6dst->s6_addr16[1], 4);
615 }
616 return dst;
617 }
618
619 /*
620 * This function assumes it is being called from dev_queue_xmit()
621 * and that skb is filled properly by that function.
622 */
623
624 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
625 {
626 struct ip_tunnel *tunnel = netdev_priv(dev);
627 struct net_device_stats *stats = &tunnel->stat;
628 struct iphdr *tiph = &tunnel->parms.iph;
629 struct ipv6hdr *iph6 = ipv6_hdr(skb);
630 u8 tos = tunnel->parms.iph.tos;
631 struct rtable *rt; /* Route to the other host */
632 struct net_device *tdev; /* Device to other host */
633 struct iphdr *iph; /* Our new IP header */
634 unsigned int max_headroom; /* The extra header space needed */
635 __be32 dst = tiph->daddr;
636 int mtu;
637 struct in6_addr *addr6;
638 int addr_type;
639
640 if (tunnel->recursion++) {
641 tunnel->stat.collisions++;
642 goto tx_error;
643 }
644
645 if (skb->protocol != htons(ETH_P_IPV6))
646 goto tx_error;
647
648 /* ISATAP (RFC4214) - must come before 6to4 */
649 if (dev->priv_flags & IFF_ISATAP) {
650 struct neighbour *neigh = NULL;
651
652 if (skb->dst)
653 neigh = skb->dst->neighbour;
654
655 if (neigh == NULL) {
656 if (net_ratelimit())
657 printk(KERN_DEBUG "sit: nexthop == NULL\n");
658 goto tx_error;
659 }
660
661 addr6 = (struct in6_addr*)&neigh->primary_key;
662 addr_type = ipv6_addr_type(addr6);
663
664 if ((addr_type & IPV6_ADDR_UNICAST) &&
665 ipv6_addr_is_isatap(addr6))
666 dst = addr6->s6_addr32[3];
667 else
668 goto tx_error;
669 }
670
671 if (!dst)
672 dst = try_6to4(&iph6->daddr);
673
674 if (!dst) {
675 struct neighbour *neigh = NULL;
676
677 if (skb->dst)
678 neigh = skb->dst->neighbour;
679
680 if (neigh == NULL) {
681 if (net_ratelimit())
682 printk(KERN_DEBUG "sit: nexthop == NULL\n");
683 goto tx_error;
684 }
685
686 addr6 = (struct in6_addr*)&neigh->primary_key;
687 addr_type = ipv6_addr_type(addr6);
688
689 if (addr_type == IPV6_ADDR_ANY) {
690 addr6 = &ipv6_hdr(skb)->daddr;
691 addr_type = ipv6_addr_type(addr6);
692 }
693
694 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
695 goto tx_error_icmp;
696
697 dst = addr6->s6_addr32[3];
698 }
699
700 {
701 struct flowi fl = { .nl_u = { .ip4_u =
702 { .daddr = dst,
703 .saddr = tiph->saddr,
704 .tos = RT_TOS(tos) } },
705 .oif = tunnel->parms.link,
706 .proto = IPPROTO_IPV6 };
707 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
708 tunnel->stat.tx_carrier_errors++;
709 goto tx_error_icmp;
710 }
711 }
712 if (rt->rt_type != RTN_UNICAST) {
713 ip_rt_put(rt);
714 tunnel->stat.tx_carrier_errors++;
715 goto tx_error_icmp;
716 }
717 tdev = rt->u.dst.dev;
718
719 if (tdev == dev) {
720 ip_rt_put(rt);
721 tunnel->stat.collisions++;
722 goto tx_error;
723 }
724
725 if (tiph->frag_off)
726 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
727 else
728 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
729
730 if (mtu < 68) {
731 tunnel->stat.collisions++;
732 ip_rt_put(rt);
733 goto tx_error;
734 }
735 if (mtu < IPV6_MIN_MTU)
736 mtu = IPV6_MIN_MTU;
737 if (tunnel->parms.iph.daddr && skb->dst)
738 skb->dst->ops->update_pmtu(skb->dst, mtu);
739
740 if (skb->len > mtu) {
741 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
742 ip_rt_put(rt);
743 goto tx_error;
744 }
745
746 if (tunnel->err_count > 0) {
747 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
748 tunnel->err_count--;
749 dst_link_failure(skb);
750 } else
751 tunnel->err_count = 0;
752 }
753
754 /*
755 * Okay, now see if we can stuff it in the buffer as-is.
756 */
757 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
758
759 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
760 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
761 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
762 if (!new_skb) {
763 ip_rt_put(rt);
764 stats->tx_dropped++;
765 dev_kfree_skb(skb);
766 tunnel->recursion--;
767 return 0;
768 }
769 if (skb->sk)
770 skb_set_owner_w(new_skb, skb->sk);
771 dev_kfree_skb(skb);
772 skb = new_skb;
773 iph6 = ipv6_hdr(skb);
774 }
775
776 skb->transport_header = skb->network_header;
777 skb_push(skb, sizeof(struct iphdr));
778 skb_reset_network_header(skb);
779 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
780 IPCB(skb)->flags = 0;
781 dst_release(skb->dst);
782 skb->dst = &rt->u.dst;
783
784 /*
785 * Push down and install the IPIP header.
786 */
787
788 iph = ip_hdr(skb);
789 iph->version = 4;
790 iph->ihl = sizeof(struct iphdr)>>2;
791 if (mtu > IPV6_MIN_MTU)
792 iph->frag_off = htons(IP_DF);
793 else
794 iph->frag_off = 0;
795
796 iph->protocol = IPPROTO_IPV6;
797 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
798 iph->daddr = rt->rt_dst;
799 iph->saddr = rt->rt_src;
800
801 if ((iph->ttl = tiph->ttl) == 0)
802 iph->ttl = iph6->hop_limit;
803
804 nf_reset(skb);
805
806 IPTUNNEL_XMIT();
807 tunnel->recursion--;
808 return 0;
809
810 tx_error_icmp:
811 dst_link_failure(skb);
812 tx_error:
813 stats->tx_errors++;
814 dev_kfree_skb(skb);
815 tunnel->recursion--;
816 return 0;
817 }
818
819 static void ipip6_tunnel_bind_dev(struct net_device *dev)
820 {
821 struct net_device *tdev = NULL;
822 struct ip_tunnel *tunnel;
823 struct iphdr *iph;
824
825 tunnel = netdev_priv(dev);
826 iph = &tunnel->parms.iph;
827
828 if (iph->daddr) {
829 struct flowi fl = { .nl_u = { .ip4_u =
830 { .daddr = iph->daddr,
831 .saddr = iph->saddr,
832 .tos = RT_TOS(iph->tos) } },
833 .oif = tunnel->parms.link,
834 .proto = IPPROTO_IPV6 };
835 struct rtable *rt;
836 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
837 tdev = rt->u.dst.dev;
838 ip_rt_put(rt);
839 }
840 dev->flags |= IFF_POINTOPOINT;
841 }
842
843 if (!tdev && tunnel->parms.link)
844 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
845
846 if (tdev) {
847 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
848 dev->mtu = tdev->mtu - sizeof(struct iphdr);
849 if (dev->mtu < IPV6_MIN_MTU)
850 dev->mtu = IPV6_MIN_MTU;
851 }
852 dev->iflink = tunnel->parms.link;
853 }
854
855 static int
856 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
857 {
858 int err = 0;
859 struct ip_tunnel_parm p;
860 struct ip_tunnel_prl prl;
861 struct ip_tunnel *t;
862 struct net *net = dev_net(dev);
863 struct sit_net *sitn = net_generic(net, sit_net_id);
864
865 switch (cmd) {
866 case SIOCGETTUNNEL:
867 t = NULL;
868 if (dev == sitn->fb_tunnel_dev) {
869 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
870 err = -EFAULT;
871 break;
872 }
873 t = ipip6_tunnel_locate(net, &p, 0);
874 }
875 if (t == NULL)
876 t = netdev_priv(dev);
877 memcpy(&p, &t->parms, sizeof(p));
878 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
879 err = -EFAULT;
880 break;
881
882 case SIOCADDTUNNEL:
883 case SIOCCHGTUNNEL:
884 err = -EPERM;
885 if (!capable(CAP_NET_ADMIN))
886 goto done;
887
888 err = -EFAULT;
889 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
890 goto done;
891
892 err = -EINVAL;
893 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
894 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
895 goto done;
896 if (p.iph.ttl)
897 p.iph.frag_off |= htons(IP_DF);
898
899 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
900
901 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
902 if (t != NULL) {
903 if (t->dev != dev) {
904 err = -EEXIST;
905 break;
906 }
907 } else {
908 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
909 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
910 err = -EINVAL;
911 break;
912 }
913 t = netdev_priv(dev);
914 ipip6_tunnel_unlink(sitn, t);
915 t->parms.iph.saddr = p.iph.saddr;
916 t->parms.iph.daddr = p.iph.daddr;
917 memcpy(dev->dev_addr, &p.iph.saddr, 4);
918 memcpy(dev->broadcast, &p.iph.daddr, 4);
919 ipip6_tunnel_link(sitn, t);
920 netdev_state_change(dev);
921 }
922 }
923
924 if (t) {
925 err = 0;
926 if (cmd == SIOCCHGTUNNEL) {
927 t->parms.iph.ttl = p.iph.ttl;
928 t->parms.iph.tos = p.iph.tos;
929 if (t->parms.link != p.link) {
930 t->parms.link = p.link;
931 ipip6_tunnel_bind_dev(dev);
932 netdev_state_change(dev);
933 }
934 }
935 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
936 err = -EFAULT;
937 } else
938 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
939 break;
940
941 case SIOCDELTUNNEL:
942 err = -EPERM;
943 if (!capable(CAP_NET_ADMIN))
944 goto done;
945
946 if (dev == sitn->fb_tunnel_dev) {
947 err = -EFAULT;
948 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
949 goto done;
950 err = -ENOENT;
951 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
952 goto done;
953 err = -EPERM;
954 if (t == netdev_priv(sitn->fb_tunnel_dev))
955 goto done;
956 dev = t->dev;
957 }
958 unregister_netdevice(dev);
959 err = 0;
960 break;
961
962 case SIOCGETPRL:
963 case SIOCADDPRL:
964 case SIOCDELPRL:
965 case SIOCCHGPRL:
966 err = -EPERM;
967 if (cmd != SIOCGETPRL && !capable(CAP_NET_ADMIN))
968 goto done;
969 err = -EINVAL;
970 if (dev == sitn->fb_tunnel_dev)
971 goto done;
972 err = -EFAULT;
973 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
974 goto done;
975 err = -ENOENT;
976 if (!(t = netdev_priv(dev)))
977 goto done;
978
979 switch (cmd) {
980 case SIOCGETPRL:
981 err = ipip6_tunnel_get_prl(t, &prl);
982 if (!err && copy_to_user(ifr->ifr_ifru.ifru_data,
983 &prl, sizeof(prl)))
984 err = -EFAULT;
985 break;
986 case SIOCDELPRL:
987 err = ipip6_tunnel_del_prl(t, &prl);
988 break;
989 case SIOCADDPRL:
990 case SIOCCHGPRL:
991 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
992 break;
993 }
994 if (cmd != SIOCGETPRL)
995 netdev_state_change(dev);
996 break;
997
998 default:
999 err = -EINVAL;
1000 }
1001
1002 done:
1003 return err;
1004 }
1005
1006 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev)
1007 {
1008 return &(((struct ip_tunnel*)netdev_priv(dev))->stat);
1009 }
1010
1011 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1012 {
1013 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1014 return -EINVAL;
1015 dev->mtu = new_mtu;
1016 return 0;
1017 }
1018
1019 static void ipip6_tunnel_setup(struct net_device *dev)
1020 {
1021 dev->uninit = ipip6_tunnel_uninit;
1022 dev->destructor = free_netdev;
1023 dev->hard_start_xmit = ipip6_tunnel_xmit;
1024 dev->get_stats = ipip6_tunnel_get_stats;
1025 dev->do_ioctl = ipip6_tunnel_ioctl;
1026 dev->change_mtu = ipip6_tunnel_change_mtu;
1027
1028 dev->type = ARPHRD_SIT;
1029 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1030 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1031 dev->flags = IFF_NOARP;
1032 dev->iflink = 0;
1033 dev->addr_len = 4;
1034 dev->features |= NETIF_F_NETNS_LOCAL;
1035 }
1036
1037 static int ipip6_tunnel_init(struct net_device *dev)
1038 {
1039 struct ip_tunnel *tunnel;
1040
1041 tunnel = netdev_priv(dev);
1042
1043 tunnel->dev = dev;
1044 strcpy(tunnel->parms.name, dev->name);
1045
1046 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1047 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1048
1049 ipip6_tunnel_bind_dev(dev);
1050
1051 return 0;
1052 }
1053
1054 static int ipip6_fb_tunnel_init(struct net_device *dev)
1055 {
1056 struct ip_tunnel *tunnel = netdev_priv(dev);
1057 struct iphdr *iph = &tunnel->parms.iph;
1058 struct net *net = dev_net(dev);
1059 struct sit_net *sitn = net_generic(net, sit_net_id);
1060
1061 tunnel->dev = dev;
1062 strcpy(tunnel->parms.name, dev->name);
1063
1064 iph->version = 4;
1065 iph->protocol = IPPROTO_IPV6;
1066 iph->ihl = 5;
1067 iph->ttl = 64;
1068
1069 dev_hold(dev);
1070 sitn->tunnels_wc[0] = tunnel;
1071 return 0;
1072 }
1073
1074 static struct xfrm_tunnel sit_handler = {
1075 .handler = ipip6_rcv,
1076 .err_handler = ipip6_err,
1077 .priority = 1,
1078 };
1079
1080 static void sit_destroy_tunnels(struct sit_net *sitn)
1081 {
1082 int prio;
1083
1084 for (prio = 1; prio < 4; prio++) {
1085 int h;
1086 for (h = 0; h < HASH_SIZE; h++) {
1087 struct ip_tunnel *t;
1088 while ((t = sitn->tunnels[prio][h]) != NULL)
1089 unregister_netdevice(t->dev);
1090 }
1091 }
1092 }
1093
1094 static int sit_init_net(struct net *net)
1095 {
1096 int err;
1097 struct sit_net *sitn;
1098
1099 err = -ENOMEM;
1100 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL);
1101 if (sitn == NULL)
1102 goto err_alloc;
1103
1104 err = net_assign_generic(net, sit_net_id, sitn);
1105 if (err < 0)
1106 goto err_assign;
1107
1108 sitn->tunnels[0] = sitn->tunnels_wc;
1109 sitn->tunnels[1] = sitn->tunnels_l;
1110 sitn->tunnels[2] = sitn->tunnels_r;
1111 sitn->tunnels[3] = sitn->tunnels_r_l;
1112
1113 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1114 ipip6_tunnel_setup);
1115 if (!sitn->fb_tunnel_dev) {
1116 err = -ENOMEM;
1117 goto err_alloc_dev;
1118 }
1119
1120 sitn->fb_tunnel_dev->init = ipip6_fb_tunnel_init;
1121 dev_net_set(sitn->fb_tunnel_dev, net);
1122
1123 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1124 goto err_reg_dev;
1125
1126 return 0;
1127
1128 err_reg_dev:
1129 free_netdev(sitn->fb_tunnel_dev);
1130 err_alloc_dev:
1131 /* nothing */
1132 err_assign:
1133 kfree(sitn);
1134 err_alloc:
1135 return err;
1136 }
1137
1138 static void sit_exit_net(struct net *net)
1139 {
1140 struct sit_net *sitn;
1141
1142 sitn = net_generic(net, sit_net_id);
1143 rtnl_lock();
1144 sit_destroy_tunnels(sitn);
1145 unregister_netdevice(sitn->fb_tunnel_dev);
1146 rtnl_unlock();
1147 kfree(sitn);
1148 }
1149
1150 static struct pernet_operations sit_net_ops = {
1151 .init = sit_init_net,
1152 .exit = sit_exit_net,
1153 };
1154
1155 static void __exit sit_cleanup(void)
1156 {
1157 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1158
1159 unregister_pernet_gen_device(sit_net_id, &sit_net_ops);
1160 }
1161
1162 static int __init sit_init(void)
1163 {
1164 int err;
1165
1166 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1167
1168 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1169 printk(KERN_INFO "sit init: Can't add protocol\n");
1170 return -EAGAIN;
1171 }
1172
1173 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops);
1174 if (err < 0)
1175 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1176
1177 return err;
1178 }
1179
1180 module_init(sit_init);
1181 module_exit(sit_cleanup);
1182 MODULE_LICENSE("GPL");
1183 MODULE_ALIAS("sit0");
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