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