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[SIT]: Use proper net in hash-lookup functions.
[deliverable/linux.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 };
74
75 static struct net_device *ipip6_fb_tunnel_dev;
76
77 static struct ip_tunnel *tunnels_r_l[HASH_SIZE];
78 static struct ip_tunnel *tunnels_r[HASH_SIZE];
79 static struct ip_tunnel *tunnels_l[HASH_SIZE];
80 static struct ip_tunnel *tunnels_wc[1];
81 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l };
82
83 static DEFINE_RWLOCK(ipip6_lock);
84
85 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
86 __be32 remote, __be32 local)
87 {
88 unsigned h0 = HASH(remote);
89 unsigned h1 = HASH(local);
90 struct ip_tunnel *t;
91
92 for (t = 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 = 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 = 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 = 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 &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 if (strchr(name, '%')) {
186 if (dev_alloc_name(dev, name) < 0)
187 goto failed_free;
188 }
189
190 nt = netdev_priv(dev);
191 dev->init = ipip6_tunnel_init;
192 nt->parms = *parms;
193
194 if (parms->i_flags & SIT_ISATAP)
195 dev->priv_flags |= IFF_ISATAP;
196
197 if (register_netdevice(dev) < 0)
198 goto failed_free;
199
200 dev_hold(dev);
201
202 ipip6_tunnel_link(sitn, nt);
203 return nt;
204
205 failed_free:
206 free_netdev(dev);
207 failed:
208 return NULL;
209 }
210
211 static struct ip_tunnel_prl_entry *
212 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
213 {
214 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL;
215
216 for (p = t->prl; p; p = p->next)
217 if (p->addr == addr)
218 break;
219 return p;
220
221 }
222
223 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
224 {
225 struct ip_tunnel_prl *kp;
226 struct ip_tunnel_prl_entry *prl;
227 unsigned int cmax, c = 0, ca, len;
228 int ret = 0;
229
230 cmax = a->datalen / sizeof(*a);
231 if (cmax > 1 && a->addr != htonl(INADDR_ANY))
232 cmax = 1;
233
234 /* For simple GET or for root users,
235 * we try harder to allocate.
236 */
237 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
238 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
239 NULL;
240
241 read_lock(&ipip6_lock);
242
243 ca = t->prl_count < cmax ? t->prl_count : cmax;
244
245 if (!kp) {
246 /* We don't try hard to allocate much memory for
247 * non-root users.
248 * For root users, retry allocating enough memory for
249 * the answer.
250 */
251 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
252 if (!kp) {
253 ret = -ENOMEM;
254 goto out;
255 }
256 }
257
258 c = 0;
259 for (prl = t->prl; prl; prl = prl->next) {
260 if (c > cmax)
261 break;
262 if (a->addr != htonl(INADDR_ANY) && prl->addr != a->addr)
263 continue;
264 kp[c].addr = prl->addr;
265 kp[c].flags = prl->flags;
266 c++;
267 if (a->addr != htonl(INADDR_ANY))
268 break;
269 }
270 out:
271 read_unlock(&ipip6_lock);
272
273 len = sizeof(*kp) * c;
274 ret = len ? copy_to_user(a->data, kp, len) : 0;
275
276 kfree(kp);
277 if (ret)
278 return -EFAULT;
279
280 a->datalen = len;
281 return 0;
282 }
283
284 static int
285 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
286 {
287 struct ip_tunnel_prl_entry *p;
288 int err = 0;
289
290 if (a->addr == htonl(INADDR_ANY))
291 return -EINVAL;
292
293 write_lock(&ipip6_lock);
294
295 for (p = t->prl; p; p = p->next) {
296 if (p->addr == a->addr) {
297 if (chg)
298 goto update;
299 err = -EEXIST;
300 goto out;
301 }
302 }
303
304 if (chg) {
305 err = -ENXIO;
306 goto out;
307 }
308
309 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
310 if (!p) {
311 err = -ENOBUFS;
312 goto out;
313 }
314
315 p->next = t->prl;
316 t->prl = p;
317 t->prl_count++;
318 update:
319 p->addr = a->addr;
320 p->flags = a->flags;
321 out:
322 write_unlock(&ipip6_lock);
323 return err;
324 }
325
326 static int
327 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
328 {
329 struct ip_tunnel_prl_entry *x, **p;
330 int err = 0;
331
332 write_lock(&ipip6_lock);
333
334 if (a && a->addr != htonl(INADDR_ANY)) {
335 for (p = &t->prl; *p; p = &(*p)->next) {
336 if ((*p)->addr == a->addr) {
337 x = *p;
338 *p = x->next;
339 kfree(x);
340 t->prl_count--;
341 goto out;
342 }
343 }
344 err = -ENXIO;
345 } else {
346 while (t->prl) {
347 x = t->prl;
348 t->prl = t->prl->next;
349 kfree(x);
350 t->prl_count--;
351 }
352 }
353 out:
354 write_unlock(&ipip6_lock);
355 return 0;
356 }
357
358 static int
359 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
360 {
361 struct ip_tunnel_prl_entry *p;
362 int ok = 1;
363
364 read_lock(&ipip6_lock);
365 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
366 if (p) {
367 if (p->flags & PRL_DEFAULT)
368 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
369 else
370 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
371 } else {
372 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
373 if (ipv6_addr_is_isatap(addr6) &&
374 (addr6->s6_addr32[3] == iph->saddr) &&
375 ipv6_chk_prefix(addr6, t->dev))
376 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
377 else
378 ok = 0;
379 }
380 read_unlock(&ipip6_lock);
381 return ok;
382 }
383
384 static void ipip6_tunnel_uninit(struct net_device *dev)
385 {
386 struct net *net = dev_net(dev);
387 struct sit_net *sitn = net_generic(net, sit_net_id);
388
389 if (dev == ipip6_fb_tunnel_dev) {
390 write_lock_bh(&ipip6_lock);
391 tunnels_wc[0] = NULL;
392 write_unlock_bh(&ipip6_lock);
393 dev_put(dev);
394 } else {
395 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
396 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
397 dev_put(dev);
398 }
399 }
400
401
402 static int ipip6_err(struct sk_buff *skb, u32 info)
403 {
404 #ifndef I_WISH_WORLD_WERE_PERFECT
405
406 /* It is not :-( All the routers (except for Linux) return only
407 8 bytes of packet payload. It means, that precise relaying of
408 ICMP in the real Internet is absolutely infeasible.
409 */
410 struct iphdr *iph = (struct iphdr*)skb->data;
411 const int type = icmp_hdr(skb)->type;
412 const int code = icmp_hdr(skb)->code;
413 struct ip_tunnel *t;
414 int err;
415
416 switch (type) {
417 default:
418 case ICMP_PARAMETERPROB:
419 return 0;
420
421 case ICMP_DEST_UNREACH:
422 switch (code) {
423 case ICMP_SR_FAILED:
424 case ICMP_PORT_UNREACH:
425 /* Impossible event. */
426 return 0;
427 case ICMP_FRAG_NEEDED:
428 /* Soft state for pmtu is maintained by IP core. */
429 return 0;
430 default:
431 /* All others are translated to HOST_UNREACH.
432 rfc2003 contains "deep thoughts" about NET_UNREACH,
433 I believe they are just ether pollution. --ANK
434 */
435 break;
436 }
437 break;
438 case ICMP_TIME_EXCEEDED:
439 if (code != ICMP_EXC_TTL)
440 return 0;
441 break;
442 }
443
444 err = -ENOENT;
445
446 read_lock(&ipip6_lock);
447 t = ipip6_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
448 if (t == NULL || t->parms.iph.daddr == 0)
449 goto out;
450
451 err = 0;
452 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
453 goto out;
454
455 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
456 t->err_count++;
457 else
458 t->err_count = 1;
459 t->err_time = jiffies;
460 out:
461 read_unlock(&ipip6_lock);
462 return err;
463 #else
464 struct iphdr *iph = (struct iphdr*)dp;
465 int hlen = iph->ihl<<2;
466 struct ipv6hdr *iph6;
467 const int type = icmp_hdr(skb)->type;
468 const int code = icmp_hdr(skb)->code;
469 int rel_type = 0;
470 int rel_code = 0;
471 int rel_info = 0;
472 struct sk_buff *skb2;
473 struct rt6_info *rt6i;
474
475 if (len < hlen + sizeof(struct ipv6hdr))
476 return;
477 iph6 = (struct ipv6hdr*)(dp + hlen);
478
479 switch (type) {
480 default:
481 return;
482 case ICMP_PARAMETERPROB:
483 if (icmp_hdr(skb)->un.gateway < hlen)
484 return;
485
486 /* So... This guy found something strange INSIDE encapsulated
487 packet. Well, he is fool, but what can we do ?
488 */
489 rel_type = ICMPV6_PARAMPROB;
490 rel_info = icmp_hdr(skb)->un.gateway - hlen;
491 break;
492
493 case ICMP_DEST_UNREACH:
494 switch (code) {
495 case ICMP_SR_FAILED:
496 case ICMP_PORT_UNREACH:
497 /* Impossible event. */
498 return;
499 case ICMP_FRAG_NEEDED:
500 /* Too complicated case ... */
501 return;
502 default:
503 /* All others are translated to HOST_UNREACH.
504 rfc2003 contains "deep thoughts" about NET_UNREACH,
505 I believe, it is just ether pollution. --ANK
506 */
507 rel_type = ICMPV6_DEST_UNREACH;
508 rel_code = ICMPV6_ADDR_UNREACH;
509 break;
510 }
511 break;
512 case ICMP_TIME_EXCEEDED:
513 if (code != ICMP_EXC_TTL)
514 return;
515 rel_type = ICMPV6_TIME_EXCEED;
516 rel_code = ICMPV6_EXC_HOPLIMIT;
517 break;
518 }
519
520 /* Prepare fake skb to feed it to icmpv6_send */
521 skb2 = skb_clone(skb, GFP_ATOMIC);
522 if (skb2 == NULL)
523 return 0;
524 dst_release(skb2->dst);
525 skb2->dst = NULL;
526 skb_pull(skb2, skb->data - (u8*)iph6);
527 skb_reset_network_header(skb2);
528
529 /* Try to guess incoming interface */
530 rt6i = rt6_lookup(&init_net, &iph6->saddr, NULL, NULL, 0);
531 if (rt6i && rt6i->rt6i_dev) {
532 skb2->dev = rt6i->rt6i_dev;
533
534 rt6i = rt6_lookup(&init_net, &iph6->daddr, &iph6->saddr, NULL, 0);
535
536 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
537 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev);
538 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
539 rel_type = ICMPV6_DEST_UNREACH;
540 rel_code = ICMPV6_ADDR_UNREACH;
541 }
542 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
543 }
544 }
545 kfree_skb(skb2);
546 return 0;
547 #endif
548 }
549
550 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
551 {
552 if (INET_ECN_is_ce(iph->tos))
553 IP6_ECN_set_ce(ipv6_hdr(skb));
554 }
555
556 static int ipip6_rcv(struct sk_buff *skb)
557 {
558 struct iphdr *iph;
559 struct ip_tunnel *tunnel;
560
561 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
562 goto out;
563
564 iph = ip_hdr(skb);
565
566 read_lock(&ipip6_lock);
567 if ((tunnel = ipip6_tunnel_lookup(dev_net(skb->dev),
568 iph->saddr, iph->daddr)) != NULL) {
569 secpath_reset(skb);
570 skb->mac_header = skb->network_header;
571 skb_reset_network_header(skb);
572 IPCB(skb)->flags = 0;
573 skb->protocol = htons(ETH_P_IPV6);
574 skb->pkt_type = PACKET_HOST;
575
576 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
577 !isatap_chksrc(skb, iph, tunnel)) {
578 tunnel->stat.rx_errors++;
579 read_unlock(&ipip6_lock);
580 kfree_skb(skb);
581 return 0;
582 }
583 tunnel->stat.rx_packets++;
584 tunnel->stat.rx_bytes += skb->len;
585 skb->dev = tunnel->dev;
586 dst_release(skb->dst);
587 skb->dst = NULL;
588 nf_reset(skb);
589 ipip6_ecn_decapsulate(iph, skb);
590 netif_rx(skb);
591 read_unlock(&ipip6_lock);
592 return 0;
593 }
594
595 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
596 kfree_skb(skb);
597 read_unlock(&ipip6_lock);
598 out:
599 return 0;
600 }
601
602 /* Returns the embedded IPv4 address if the IPv6 address
603 comes from 6to4 (RFC 3056) addr space */
604
605 static inline __be32 try_6to4(struct in6_addr *v6dst)
606 {
607 __be32 dst = 0;
608
609 if (v6dst->s6_addr16[0] == htons(0x2002)) {
610 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
611 memcpy(&dst, &v6dst->s6_addr16[1], 4);
612 }
613 return dst;
614 }
615
616 /*
617 * This function assumes it is being called from dev_queue_xmit()
618 * and that skb is filled properly by that function.
619 */
620
621 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
622 {
623 struct ip_tunnel *tunnel = netdev_priv(dev);
624 struct net_device_stats *stats = &tunnel->stat;
625 struct iphdr *tiph = &tunnel->parms.iph;
626 struct ipv6hdr *iph6 = ipv6_hdr(skb);
627 u8 tos = tunnel->parms.iph.tos;
628 struct rtable *rt; /* Route to the other host */
629 struct net_device *tdev; /* Device to other host */
630 struct iphdr *iph; /* Our new IP header */
631 unsigned int max_headroom; /* The extra header space needed */
632 __be32 dst = tiph->daddr;
633 int mtu;
634 struct in6_addr *addr6;
635 int addr_type;
636
637 if (tunnel->recursion++) {
638 tunnel->stat.collisions++;
639 goto tx_error;
640 }
641
642 if (skb->protocol != htons(ETH_P_IPV6))
643 goto tx_error;
644
645 /* ISATAP (RFC4214) - must come before 6to4 */
646 if (dev->priv_flags & IFF_ISATAP) {
647 struct neighbour *neigh = NULL;
648
649 if (skb->dst)
650 neigh = skb->dst->neighbour;
651
652 if (neigh == NULL) {
653 if (net_ratelimit())
654 printk(KERN_DEBUG "sit: nexthop == NULL\n");
655 goto tx_error;
656 }
657
658 addr6 = (struct in6_addr*)&neigh->primary_key;
659 addr_type = ipv6_addr_type(addr6);
660
661 if ((addr_type & IPV6_ADDR_UNICAST) &&
662 ipv6_addr_is_isatap(addr6))
663 dst = addr6->s6_addr32[3];
664 else
665 goto tx_error;
666 }
667
668 if (!dst)
669 dst = try_6to4(&iph6->daddr);
670
671 if (!dst) {
672 struct neighbour *neigh = NULL;
673
674 if (skb->dst)
675 neigh = skb->dst->neighbour;
676
677 if (neigh == NULL) {
678 if (net_ratelimit())
679 printk(KERN_DEBUG "sit: nexthop == NULL\n");
680 goto tx_error;
681 }
682
683 addr6 = (struct in6_addr*)&neigh->primary_key;
684 addr_type = ipv6_addr_type(addr6);
685
686 if (addr_type == IPV6_ADDR_ANY) {
687 addr6 = &ipv6_hdr(skb)->daddr;
688 addr_type = ipv6_addr_type(addr6);
689 }
690
691 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
692 goto tx_error_icmp;
693
694 dst = addr6->s6_addr32[3];
695 }
696
697 {
698 struct flowi fl = { .nl_u = { .ip4_u =
699 { .daddr = dst,
700 .saddr = tiph->saddr,
701 .tos = RT_TOS(tos) } },
702 .oif = tunnel->parms.link,
703 .proto = IPPROTO_IPV6 };
704 if (ip_route_output_key(&init_net, &rt, &fl)) {
705 tunnel->stat.tx_carrier_errors++;
706 goto tx_error_icmp;
707 }
708 }
709 if (rt->rt_type != RTN_UNICAST) {
710 ip_rt_put(rt);
711 tunnel->stat.tx_carrier_errors++;
712 goto tx_error_icmp;
713 }
714 tdev = rt->u.dst.dev;
715
716 if (tdev == dev) {
717 ip_rt_put(rt);
718 tunnel->stat.collisions++;
719 goto tx_error;
720 }
721
722 if (tiph->frag_off)
723 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
724 else
725 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
726
727 if (mtu < 68) {
728 tunnel->stat.collisions++;
729 ip_rt_put(rt);
730 goto tx_error;
731 }
732 if (mtu < IPV6_MIN_MTU)
733 mtu = IPV6_MIN_MTU;
734 if (tunnel->parms.iph.daddr && skb->dst)
735 skb->dst->ops->update_pmtu(skb->dst, mtu);
736
737 if (skb->len > mtu) {
738 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
739 ip_rt_put(rt);
740 goto tx_error;
741 }
742
743 if (tunnel->err_count > 0) {
744 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
745 tunnel->err_count--;
746 dst_link_failure(skb);
747 } else
748 tunnel->err_count = 0;
749 }
750
751 /*
752 * Okay, now see if we can stuff it in the buffer as-is.
753 */
754 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
755
756 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
757 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
758 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
759 if (!new_skb) {
760 ip_rt_put(rt);
761 stats->tx_dropped++;
762 dev_kfree_skb(skb);
763 tunnel->recursion--;
764 return 0;
765 }
766 if (skb->sk)
767 skb_set_owner_w(new_skb, skb->sk);
768 dev_kfree_skb(skb);
769 skb = new_skb;
770 iph6 = ipv6_hdr(skb);
771 }
772
773 skb->transport_header = skb->network_header;
774 skb_push(skb, sizeof(struct iphdr));
775 skb_reset_network_header(skb);
776 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
777 IPCB(skb)->flags = 0;
778 dst_release(skb->dst);
779 skb->dst = &rt->u.dst;
780
781 /*
782 * Push down and install the IPIP header.
783 */
784
785 iph = ip_hdr(skb);
786 iph->version = 4;
787 iph->ihl = sizeof(struct iphdr)>>2;
788 if (mtu > IPV6_MIN_MTU)
789 iph->frag_off = htons(IP_DF);
790 else
791 iph->frag_off = 0;
792
793 iph->protocol = IPPROTO_IPV6;
794 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
795 iph->daddr = rt->rt_dst;
796 iph->saddr = rt->rt_src;
797
798 if ((iph->ttl = tiph->ttl) == 0)
799 iph->ttl = iph6->hop_limit;
800
801 nf_reset(skb);
802
803 IPTUNNEL_XMIT();
804 tunnel->recursion--;
805 return 0;
806
807 tx_error_icmp:
808 dst_link_failure(skb);
809 tx_error:
810 stats->tx_errors++;
811 dev_kfree_skb(skb);
812 tunnel->recursion--;
813 return 0;
814 }
815
816 static void ipip6_tunnel_bind_dev(struct net_device *dev)
817 {
818 struct net_device *tdev = NULL;
819 struct ip_tunnel *tunnel;
820 struct iphdr *iph;
821
822 tunnel = netdev_priv(dev);
823 iph = &tunnel->parms.iph;
824
825 if (iph->daddr) {
826 struct flowi fl = { .nl_u = { .ip4_u =
827 { .daddr = iph->daddr,
828 .saddr = iph->saddr,
829 .tos = RT_TOS(iph->tos) } },
830 .oif = tunnel->parms.link,
831 .proto = IPPROTO_IPV6 };
832 struct rtable *rt;
833 if (!ip_route_output_key(&init_net, &rt, &fl)) {
834 tdev = rt->u.dst.dev;
835 ip_rt_put(rt);
836 }
837 dev->flags |= IFF_POINTOPOINT;
838 }
839
840 if (!tdev && tunnel->parms.link)
841 tdev = __dev_get_by_index(&init_net, tunnel->parms.link);
842
843 if (tdev) {
844 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
845 dev->mtu = tdev->mtu - sizeof(struct iphdr);
846 if (dev->mtu < IPV6_MIN_MTU)
847 dev->mtu = IPV6_MIN_MTU;
848 }
849 dev->iflink = tunnel->parms.link;
850 }
851
852 static int
853 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
854 {
855 int err = 0;
856 struct ip_tunnel_parm p;
857 struct ip_tunnel_prl prl;
858 struct ip_tunnel *t;
859 struct net *net = dev_net(dev);
860 struct sit_net *sitn = net_generic(net, sit_net_id);
861
862 switch (cmd) {
863 case SIOCGETTUNNEL:
864 t = NULL;
865 if (dev == ipip6_fb_tunnel_dev) {
866 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
867 err = -EFAULT;
868 break;
869 }
870 t = ipip6_tunnel_locate(net, &p, 0);
871 }
872 if (t == NULL)
873 t = netdev_priv(dev);
874 memcpy(&p, &t->parms, sizeof(p));
875 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
876 err = -EFAULT;
877 break;
878
879 case SIOCADDTUNNEL:
880 case SIOCCHGTUNNEL:
881 err = -EPERM;
882 if (!capable(CAP_NET_ADMIN))
883 goto done;
884
885 err = -EFAULT;
886 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
887 goto done;
888
889 err = -EINVAL;
890 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
891 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
892 goto done;
893 if (p.iph.ttl)
894 p.iph.frag_off |= htons(IP_DF);
895
896 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
897
898 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
899 if (t != NULL) {
900 if (t->dev != dev) {
901 err = -EEXIST;
902 break;
903 }
904 } else {
905 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
906 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
907 err = -EINVAL;
908 break;
909 }
910 t = netdev_priv(dev);
911 ipip6_tunnel_unlink(sitn, t);
912 t->parms.iph.saddr = p.iph.saddr;
913 t->parms.iph.daddr = p.iph.daddr;
914 memcpy(dev->dev_addr, &p.iph.saddr, 4);
915 memcpy(dev->broadcast, &p.iph.daddr, 4);
916 ipip6_tunnel_link(sitn, t);
917 netdev_state_change(dev);
918 }
919 }
920
921 if (t) {
922 err = 0;
923 if (cmd == SIOCCHGTUNNEL) {
924 t->parms.iph.ttl = p.iph.ttl;
925 t->parms.iph.tos = p.iph.tos;
926 if (t->parms.link != p.link) {
927 t->parms.link = p.link;
928 ipip6_tunnel_bind_dev(dev);
929 netdev_state_change(dev);
930 }
931 }
932 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
933 err = -EFAULT;
934 } else
935 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
936 break;
937
938 case SIOCDELTUNNEL:
939 err = -EPERM;
940 if (!capable(CAP_NET_ADMIN))
941 goto done;
942
943 if (dev == ipip6_fb_tunnel_dev) {
944 err = -EFAULT;
945 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
946 goto done;
947 err = -ENOENT;
948 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
949 goto done;
950 err = -EPERM;
951 if (t == netdev_priv(ipip6_fb_tunnel_dev))
952 goto done;
953 dev = t->dev;
954 }
955 unregister_netdevice(dev);
956 err = 0;
957 break;
958
959 case SIOCGETPRL:
960 case SIOCADDPRL:
961 case SIOCDELPRL:
962 case SIOCCHGPRL:
963 err = -EPERM;
964 if (cmd != SIOCGETPRL && !capable(CAP_NET_ADMIN))
965 goto done;
966 err = -EINVAL;
967 if (dev == ipip6_fb_tunnel_dev)
968 goto done;
969 err = -EFAULT;
970 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
971 goto done;
972 err = -ENOENT;
973 if (!(t = netdev_priv(dev)))
974 goto done;
975
976 switch (cmd) {
977 case SIOCGETPRL:
978 err = ipip6_tunnel_get_prl(t, &prl);
979 if (!err && copy_to_user(ifr->ifr_ifru.ifru_data,
980 &prl, sizeof(prl)))
981 err = -EFAULT;
982 break;
983 case SIOCDELPRL:
984 err = ipip6_tunnel_del_prl(t, &prl);
985 break;
986 case SIOCADDPRL:
987 case SIOCCHGPRL:
988 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
989 break;
990 }
991 if (cmd != SIOCGETPRL)
992 netdev_state_change(dev);
993 break;
994
995 default:
996 err = -EINVAL;
997 }
998
999 done:
1000 return err;
1001 }
1002
1003 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev)
1004 {
1005 return &(((struct ip_tunnel*)netdev_priv(dev))->stat);
1006 }
1007
1008 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1009 {
1010 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1011 return -EINVAL;
1012 dev->mtu = new_mtu;
1013 return 0;
1014 }
1015
1016 static void ipip6_tunnel_setup(struct net_device *dev)
1017 {
1018 dev->uninit = ipip6_tunnel_uninit;
1019 dev->destructor = free_netdev;
1020 dev->hard_start_xmit = ipip6_tunnel_xmit;
1021 dev->get_stats = ipip6_tunnel_get_stats;
1022 dev->do_ioctl = ipip6_tunnel_ioctl;
1023 dev->change_mtu = ipip6_tunnel_change_mtu;
1024
1025 dev->type = ARPHRD_SIT;
1026 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1027 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1028 dev->flags = IFF_NOARP;
1029 dev->iflink = 0;
1030 dev->addr_len = 4;
1031 }
1032
1033 static int ipip6_tunnel_init(struct net_device *dev)
1034 {
1035 struct ip_tunnel *tunnel;
1036
1037 tunnel = netdev_priv(dev);
1038
1039 tunnel->dev = dev;
1040 strcpy(tunnel->parms.name, dev->name);
1041
1042 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1043 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1044
1045 ipip6_tunnel_bind_dev(dev);
1046
1047 return 0;
1048 }
1049
1050 static int __init ipip6_fb_tunnel_init(struct net_device *dev)
1051 {
1052 struct ip_tunnel *tunnel = netdev_priv(dev);
1053 struct iphdr *iph = &tunnel->parms.iph;
1054
1055 tunnel->dev = dev;
1056 strcpy(tunnel->parms.name, dev->name);
1057
1058 iph->version = 4;
1059 iph->protocol = IPPROTO_IPV6;
1060 iph->ihl = 5;
1061 iph->ttl = 64;
1062
1063 dev_hold(dev);
1064 tunnels_wc[0] = tunnel;
1065 return 0;
1066 }
1067
1068 static struct xfrm_tunnel sit_handler = {
1069 .handler = ipip6_rcv,
1070 .err_handler = ipip6_err,
1071 .priority = 1,
1072 };
1073
1074 static void __exit sit_destroy_tunnels(void)
1075 {
1076 int prio;
1077
1078 for (prio = 1; prio < 4; prio++) {
1079 int h;
1080 for (h = 0; h < HASH_SIZE; h++) {
1081 struct ip_tunnel *t;
1082 while ((t = tunnels[prio][h]) != NULL)
1083 unregister_netdevice(t->dev);
1084 }
1085 }
1086 }
1087
1088 static int sit_init_net(struct net *net)
1089 {
1090 int err;
1091 struct sit_net *sitn;
1092
1093 err = -ENOMEM;
1094 sitn = kmalloc(sizeof(struct sit_net), GFP_KERNEL);
1095 if (sitn == NULL)
1096 goto err_alloc;
1097
1098 err = net_assign_generic(net, sit_net_id, sitn);
1099 if (err < 0)
1100 goto err_assign;
1101
1102 return 0;
1103
1104 err_assign:
1105 kfree(sitn);
1106 err_alloc:
1107 return err;
1108 }
1109
1110 static void sit_exit_net(struct net *net)
1111 {
1112 struct sit_net *sitn;
1113
1114 sitn = net_generic(net, sit_net_id);
1115 kfree(sitn);
1116 }
1117
1118 static struct pernet_operations sit_net_ops = {
1119 .init = sit_init_net,
1120 .exit = sit_exit_net,
1121 };
1122
1123 static void __exit sit_cleanup(void)
1124 {
1125 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1126
1127 rtnl_lock();
1128 sit_destroy_tunnels();
1129 unregister_netdevice(ipip6_fb_tunnel_dev);
1130 rtnl_unlock();
1131
1132 unregister_pernet_gen_device(sit_net_id, &sit_net_ops);
1133 }
1134
1135 static int __init sit_init(void)
1136 {
1137 int err;
1138
1139 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1140
1141 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1142 printk(KERN_INFO "sit init: Can't add protocol\n");
1143 return -EAGAIN;
1144 }
1145
1146 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1147 ipip6_tunnel_setup);
1148 if (!ipip6_fb_tunnel_dev) {
1149 err = -ENOMEM;
1150 goto err1;
1151 }
1152
1153 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init;
1154
1155 if ((err = register_netdev(ipip6_fb_tunnel_dev)))
1156 goto err2;
1157
1158 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops);
1159 if (err < 0)
1160 goto err3;
1161
1162 out:
1163 return err;
1164 err2:
1165 free_netdev(ipip6_fb_tunnel_dev);
1166 err1:
1167 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1168 goto out;
1169 err3:
1170 unregister_netdevice(ipip6_fb_tunnel_dev);
1171 goto err1;
1172 }
1173
1174 module_init(sit_init);
1175 module_exit(sit_cleanup);
1176 MODULE_LICENSE("GPL");
1177 MODULE_ALIAS("sit0");
Linux kernel - Deliverables
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