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printk removal, receive reordering bugfix
[cor_2_6_31.git] / net / ipv6 / sit.c
blob98b7327d0949aa993751411f6512ebdf304f326f
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 * Sascha Hlusiak <mail@saschahlusiak.de>: stateless autoconf for isatap
19 */
20
21 #include <linux/module.h>
22 #include <linux/capability.h>
23 #include <linux/errno.h>
24 #include <linux/types.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/icmp.h>
32 #include <asm/uaccess.h>
33 #include <linux/init.h>
34 #include <linux/netfilter_ipv4.h>
35 #include <linux/if_ether.h>
36
37 #include <net/sock.h>
38 #include <net/snmp.h>
39
40 #include <net/ipv6.h>
41 #include <net/protocol.h>
42 #include <net/transp_v6.h>
43 #include <net/ip6_fib.h>
44 #include <net/ip6_route.h>
45 #include <net/ndisc.h>
46 #include <net/addrconf.h>
47 #include <net/ip.h>
48 #include <net/udp.h>
49 #include <net/icmp.h>
50 #include <net/ipip.h>
51 #include <net/inet_ecn.h>
52 #include <net/xfrm.h>
53 #include <net/dsfield.h>
54 #include <net/net_namespace.h>
55 #include <net/netns/generic.h>
56
57 /*
58 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
59
60 For comments look at net/ipv4/ip_gre.c --ANK
61 */
62
63 #define HASH_SIZE 16
64 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
65
66 static void ipip6_fb_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_init(struct net_device *dev);
68 static void ipip6_tunnel_setup(struct net_device *dev);
69
70 static int sit_net_id;
71 struct sit_net {
72 struct ip_tunnel *tunnels_r_l[HASH_SIZE];
73 struct ip_tunnel *tunnels_r[HASH_SIZE];
74 struct ip_tunnel *tunnels_l[HASH_SIZE];
75 struct ip_tunnel *tunnels_wc[1];
76 struct ip_tunnel **tunnels[4];
77
78 struct net_device *fb_tunnel_dev;
79 };
80
81 static DEFINE_RWLOCK(ipip6_lock);
82
83 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
84 struct net_device *dev, __be32 remote, __be32 local)
85 {
86 unsigned h0 = HASH(remote);
87 unsigned h1 = HASH(local);
88 struct ip_tunnel *t;
89 struct sit_net *sitn = net_generic(net, sit_net_id);
90
91 for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) {
92 if (local == t->parms.iph.saddr &&
93 remote == t->parms.iph.daddr &&
94 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
95 (t->dev->flags & IFF_UP))
96 return t;
97 }
98 for (t = sitn->tunnels_r[h0]; t; t = t->next) {
99 if (remote == t->parms.iph.daddr &&
100 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
101 (t->dev->flags & IFF_UP))
102 return t;
103 }
104 for (t = sitn->tunnels_l[h1]; t; t = t->next) {
105 if (local == t->parms.iph.saddr &&
106 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
107 (t->dev->flags & IFF_UP))
108 return t;
109 }
110 t = sitn->tunnels_wc[0];
111 if ((t != NULL) && (t->dev->flags & IFF_UP))
112 return t;
113 return NULL;
114 }
115
116 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn,
117 struct ip_tunnel_parm *parms)
118 {
119 __be32 remote = parms->iph.daddr;
120 __be32 local = parms->iph.saddr;
121 unsigned h = 0;
122 int prio = 0;
123
124 if (remote) {
125 prio |= 2;
126 h ^= HASH(remote);
127 }
128 if (local) {
129 prio |= 1;
130 h ^= HASH(local);
131 }
132 return &sitn->tunnels[prio][h];
133 }
134
135 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn,
136 struct ip_tunnel *t)
137 {
138 return __ipip6_bucket(sitn, &t->parms);
139 }
140
141 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
142 {
143 struct ip_tunnel **tp;
144
145 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) {
146 if (t == *tp) {
147 write_lock_bh(&ipip6_lock);
148 *tp = t->next;
149 write_unlock_bh(&ipip6_lock);
150 break;
151 }
152 }
153 }
154
155 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
156 {
157 struct ip_tunnel **tp = ipip6_bucket(sitn, t);
158
159 t->next = *tp;
160 write_lock_bh(&ipip6_lock);
161 *tp = t;
162 write_unlock_bh(&ipip6_lock);
163 }
164
165 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
166 struct ip_tunnel_parm *parms, int create)
167 {
168 __be32 remote = parms->iph.daddr;
169 __be32 local = parms->iph.saddr;
170 struct ip_tunnel *t, **tp, *nt;
171 struct net_device *dev;
172 char name[IFNAMSIZ];
173 struct sit_net *sitn = net_generic(net, sit_net_id);
174
175 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) {
176 if (local == t->parms.iph.saddr &&
177 remote == t->parms.iph.daddr &&
178 parms->link == t->parms.link) {
179 if (create)
180 return NULL;
181 else
182 return t;
183 }
184 }
185 if (!create)
186 goto failed;
187
188 if (parms->name[0])
189 strlcpy(name, parms->name, IFNAMSIZ);
190 else
191 sprintf(name, "sit%%d");
192
193 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
194 if (dev == NULL)
195 return NULL;
196
197 dev_net_set(dev, net);
198
199 if (strchr(name, '%')) {
200 if (dev_alloc_name(dev, name) < 0)
201 goto failed_free;
202 }
203
204 nt = netdev_priv(dev);
205
206 nt->parms = *parms;
207 ipip6_tunnel_init(dev);
208
209 if (parms->i_flags & SIT_ISATAP)
210 dev->priv_flags |= IFF_ISATAP;
211
212 if (register_netdevice(dev) < 0)
213 goto failed_free;
214
215 dev_hold(dev);
216
217 ipip6_tunnel_link(sitn, nt);
218 return nt;
219
220 failed_free:
221 free_netdev(dev);
222 failed:
223 return NULL;
224 }
225
226 static void ipip6_tunnel_rs_timer(unsigned long data)
227 {
228 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *) data;
229 struct inet6_dev *ifp;
230 struct inet6_ifaddr *addr;
231
232 spin_lock(&p->lock);
233 ifp = __in6_dev_get(p->tunnel->dev);
234
235 read_lock_bh(&ifp->lock);
236 for (addr = ifp->addr_list; addr; addr = addr->if_next) {
237 struct in6_addr rtr;
238
239 if (!(ipv6_addr_type(&addr->addr) & IPV6_ADDR_LINKLOCAL))
240 continue;
241
242 /* Send RS to guessed linklocal address of router
243 *
244 * Better: send to ff02::2 encapsuled in unicast directly
245 * to router-v4 instead of guessing the v6 address.
246 *
247 * Cisco/Windows seem to not set the u/l bit correctly,
248 * so we won't guess right.
249 */
250 ipv6_addr_set(&rtr, htonl(0xFE800000), 0, 0, 0);
251 if (!__ipv6_isatap_ifid(rtr.s6_addr + 8,
252 p->addr)) {
253 ndisc_send_rs(p->tunnel->dev, &addr->addr, &rtr);
254 }
255 }
256 read_unlock_bh(&ifp->lock);
257
258 mod_timer(&p->rs_timer, jiffies + HZ * p->rs_delay);
259 spin_unlock(&p->lock);
260
261 return;
262 }
263
264 static struct ip_tunnel_prl_entry *
265 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
266 {
267 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL;
268
269 for (p = t->prl; p; p = p->next)
270 if (p->addr == addr)
271 break;
272 return p;
273
274 }
275
276 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
277 struct ip_tunnel_prl __user *a)
278 {
279 struct ip_tunnel_prl kprl, *kp;
280 struct ip_tunnel_prl_entry *prl;
281 unsigned int cmax, c = 0, ca, len;
282 int ret = 0;
283
284 if (copy_from_user(&kprl, a, sizeof(kprl)))
285 return -EFAULT;
286 cmax = kprl.datalen / sizeof(kprl);
287 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
288 cmax = 1;
289
290 /* For simple GET or for root users,
291 * we try harder to allocate.
292 */
293 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
294 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
295 NULL;
296
297 read_lock(&ipip6_lock);
298
299 ca = t->prl_count < cmax ? t->prl_count : cmax;
300
301 if (!kp) {
302 /* We don't try hard to allocate much memory for
303 * non-root users.
304 * For root users, retry allocating enough memory for
305 * the answer.
306 */
307 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
308 if (!kp) {
309 ret = -ENOMEM;
310 goto out;
311 }
312 }
313
314 c = 0;
315 for (prl = t->prl; prl; prl = prl->next) {
316 if (c > cmax)
317 break;
318 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
319 continue;
320 kp[c].addr = prl->addr;
321 kp[c].flags = prl->flags;
322 kp[c].rs_delay = prl->rs_delay;
323 c++;
324 if (kprl.addr != htonl(INADDR_ANY))
325 break;
326 }
327 out:
328 read_unlock(&ipip6_lock);
329
330 len = sizeof(*kp) * c;
331 ret = 0;
332 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
333 ret = -EFAULT;
334
335 kfree(kp);
336
337 return ret;
338 }
339
340 static int
341 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
342 {
343 struct ip_tunnel_prl_entry *p;
344 int err = 0;
345
346 if (a->addr == htonl(INADDR_ANY))
347 return -EINVAL;
348
349 write_lock(&ipip6_lock);
350
351 for (p = t->prl; p; p = p->next) {
352 if (p->addr == a->addr) {
353 if (chg)
354 goto update;
355 err = -EEXIST;
356 goto out;
357 }
358 }
359
360 if (chg) {
361 err = -ENXIO;
362 goto out;
363 }
364
365 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
366 if (!p) {
367 err = -ENOBUFS;
368 goto out;
369 }
370
371 p->next = t->prl;
372 p->tunnel = t;
373 t->prl = p;
374 t->prl_count++;
375
376 spin_lock_init(&p->lock);
377 setup_timer(&p->rs_timer, ipip6_tunnel_rs_timer, (unsigned long) p);
378 update:
379 p->addr = a->addr;
380 p->flags = a->flags;
381 p->rs_delay = a->rs_delay;
382 if (p->rs_delay == 0)
383 p->rs_delay = IPTUNNEL_RS_DEFAULT_DELAY;
384 spin_lock(&p->lock);
385 del_timer(&p->rs_timer);
386 if (p->flags & PRL_DEFAULT)
387 mod_timer(&p->rs_timer, jiffies + 1);
388 spin_unlock(&p->lock);
389 out:
390 write_unlock(&ipip6_lock);
391 return err;
392 }
393
394 static int
395 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
396 {
397 struct ip_tunnel_prl_entry *x, **p;
398 int err = 0;
399
400 write_lock(&ipip6_lock);
401
402 if (a && a->addr != htonl(INADDR_ANY)) {
403 for (p = &t->prl; *p; p = &(*p)->next) {
404 if ((*p)->addr == a->addr) {
405 x = *p;
406 *p = x->next;
407 spin_lock(&x->lock);
408 del_timer(&x->rs_timer);
409 spin_unlock(&x->lock);
410 kfree(x);
411 t->prl_count--;
412 goto out;
413 }
414 }
415 err = -ENXIO;
416 } else {
417 while (t->prl) {
418 x = t->prl;
419 t->prl = t->prl->next;
420 spin_lock(&x->lock);
421 del_timer(&x->rs_timer);
422 spin_unlock(&x->lock);
423 kfree(x);
424 t->prl_count--;
425 }
426 }
427 out:
428 write_unlock(&ipip6_lock);
429 return err;
430 }
431
432 static int
433 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
434 {
435 struct ip_tunnel_prl_entry *p;
436 int ok = 1;
437
438 read_lock(&ipip6_lock);
439 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
440 if (p) {
441 if (p->flags & PRL_DEFAULT)
442 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
443 else
444 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
445 } else {
446 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
447 if (ipv6_addr_is_isatap(addr6) &&
448 (addr6->s6_addr32[3] == iph->saddr) &&
449 ipv6_chk_prefix(addr6, t->dev))
450 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
451 else
452 ok = 0;
453 }
454 read_unlock(&ipip6_lock);
455 return ok;
456 }
457
458 static void ipip6_tunnel_uninit(struct net_device *dev)
459 {
460 struct net *net = dev_net(dev);
461 struct sit_net *sitn = net_generic(net, sit_net_id);
462
463 if (dev == sitn->fb_tunnel_dev) {
464 write_lock_bh(&ipip6_lock);
465 sitn->tunnels_wc[0] = NULL;
466 write_unlock_bh(&ipip6_lock);
467 dev_put(dev);
468 } else {
469 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
470 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
471 dev_put(dev);
472 }
473 }
474
475
476 static int ipip6_err(struct sk_buff *skb, u32 info)
477 {
478
479 /* All the routers (except for Linux) return only
480 8 bytes of packet payload. It means, that precise relaying of
481 ICMP in the real Internet is absolutely infeasible.
482 */
483 struct iphdr *iph = (struct iphdr*)skb->data;
484 const int type = icmp_hdr(skb)->type;
485 const int code = icmp_hdr(skb)->code;
486 struct ip_tunnel *t;
487 int err;
488
489 switch (type) {
490 default:
491 case ICMP_PARAMETERPROB:
492 return 0;
493
494 case ICMP_DEST_UNREACH:
495 switch (code) {
496 case ICMP_SR_FAILED:
497 case ICMP_PORT_UNREACH:
498 /* Impossible event. */
499 return 0;
500 case ICMP_FRAG_NEEDED:
501 /* Soft state for pmtu is maintained by IP core. */
502 return 0;
503 default:
504 /* All others are translated to HOST_UNREACH.
505 rfc2003 contains "deep thoughts" about NET_UNREACH,
506 I believe they are just ether pollution. --ANK
507 */
508 break;
509 }
510 break;
511 case ICMP_TIME_EXCEEDED:
512 if (code != ICMP_EXC_TTL)
513 return 0;
514 break;
515 }
516
517 err = -ENOENT;
518
519 read_lock(&ipip6_lock);
520 t = ipip6_tunnel_lookup(dev_net(skb->dev),
521 skb->dev,
522 iph->daddr,
523 iph->saddr);
524 if (t == NULL || t->parms.iph.daddr == 0)
525 goto out;
526
527 err = 0;
528 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
529 goto out;
530
531 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
532 t->err_count++;
533 else
534 t->err_count = 1;
535 t->err_time = jiffies;
536 out:
537 read_unlock(&ipip6_lock);
538 return err;
539 }
540
541 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
542 {
543 if (INET_ECN_is_ce(iph->tos))
544 IP6_ECN_set_ce(ipv6_hdr(skb));
545 }
546
547 static int ipip6_rcv(struct sk_buff *skb)
548 {
549 struct iphdr *iph;
550 struct ip_tunnel *tunnel;
551
552 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
553 goto out;
554
555 iph = ip_hdr(skb);
556
557 read_lock(&ipip6_lock);
558 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
559 iph->saddr, iph->daddr);
560 if (tunnel != NULL) {
561 secpath_reset(skb);
562 skb->mac_header = skb->network_header;
563 skb_reset_network_header(skb);
564 IPCB(skb)->flags = 0;
565 skb->protocol = htons(ETH_P_IPV6);
566 skb->pkt_type = PACKET_HOST;
567
568 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
569 !isatap_chksrc(skb, iph, tunnel)) {
570 tunnel->dev->stats.rx_errors++;
571 read_unlock(&ipip6_lock);
572 kfree_skb(skb);
573 return 0;
574 }
575 tunnel->dev->stats.rx_packets++;
576 tunnel->dev->stats.rx_bytes += skb->len;
577 skb->dev = tunnel->dev;
578 skb_dst_drop(skb);
579 nf_reset(skb);
580 ipip6_ecn_decapsulate(iph, skb);
581 netif_rx(skb);
582 read_unlock(&ipip6_lock);
583 return 0;
584 }
585
586 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
587 read_unlock(&ipip6_lock);
588 out:
589 kfree_skb(skb);
590 return 0;
591 }
592
593 /* Returns the embedded IPv4 address if the IPv6 address
594 comes from 6to4 (RFC 3056) addr space */
595
596 static inline __be32 try_6to4(struct in6_addr *v6dst)
597 {
598 __be32 dst = 0;
599
600 if (v6dst->s6_addr16[0] == htons(0x2002)) {
601 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
602 memcpy(&dst, &v6dst->s6_addr16[1], 4);
603 }
604 return dst;
605 }
606
607 /*
608 * This function assumes it is being called from dev_queue_xmit()
609 * and that skb is filled properly by that function.
610 */
611
612 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
613 {
614 struct ip_tunnel *tunnel = netdev_priv(dev);
615 struct net_device_stats *stats = &tunnel->dev->stats;
616 struct iphdr *tiph = &tunnel->parms.iph;
617 struct ipv6hdr *iph6 = ipv6_hdr(skb);
618 u8 tos = tunnel->parms.iph.tos;
619 struct rtable *rt; /* Route to the other host */
620 struct net_device *tdev; /* Device to other host */
621 struct iphdr *iph; /* Our new IP header */
622 unsigned int max_headroom; /* The extra header space needed */
623 __be32 dst = tiph->daddr;
624 int mtu;
625 struct in6_addr *addr6;
626 int addr_type;
627
628 if (tunnel->recursion++) {
629 stats->collisions++;
630 goto tx_error;
631 }
632
633 if (skb->protocol != htons(ETH_P_IPV6))
634 goto tx_error;
635
636 /* ISATAP (RFC4214) - must come before 6to4 */
637 if (dev->priv_flags & IFF_ISATAP) {
638 struct neighbour *neigh = NULL;
639
640 if (skb_dst(skb))
641 neigh = skb_dst(skb)->neighbour;
642
643 if (neigh == NULL) {
644 if (net_ratelimit())
645 printk(KERN_DEBUG "sit: nexthop == NULL\n");
646 goto tx_error;
647 }
648
649 addr6 = (struct in6_addr*)&neigh->primary_key;
650 addr_type = ipv6_addr_type(addr6);
651
652 if ((addr_type & IPV6_ADDR_UNICAST) &&
653 ipv6_addr_is_isatap(addr6))
654 dst = addr6->s6_addr32[3];
655 else
656 goto tx_error;
657 }
658
659 if (!dst)
660 dst = try_6to4(&iph6->daddr);
661
662 if (!dst) {
663 struct neighbour *neigh = NULL;
664
665 if (skb_dst(skb))
666 neigh = skb_dst(skb)->neighbour;
667
668 if (neigh == NULL) {
669 if (net_ratelimit())
670 printk(KERN_DEBUG "sit: nexthop == NULL\n");
671 goto tx_error;
672 }
673
674 addr6 = (struct in6_addr*)&neigh->primary_key;
675 addr_type = ipv6_addr_type(addr6);
676
677 if (addr_type == IPV6_ADDR_ANY) {
678 addr6 = &ipv6_hdr(skb)->daddr;
679 addr_type = ipv6_addr_type(addr6);
680 }
681
682 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
683 goto tx_error_icmp;
684
685 dst = addr6->s6_addr32[3];
686 }
687
688 {
689 struct flowi fl = { .nl_u = { .ip4_u =
690 { .daddr = dst,
691 .saddr = tiph->saddr,
692 .tos = RT_TOS(tos) } },
693 .oif = tunnel->parms.link,
694 .proto = IPPROTO_IPV6 };
695 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
696 stats->tx_carrier_errors++;
697 goto tx_error_icmp;
698 }
699 }
700 if (rt->rt_type != RTN_UNICAST) {
701 ip_rt_put(rt);
702 stats->tx_carrier_errors++;
703 goto tx_error_icmp;
704 }
705 tdev = rt->u.dst.dev;
706
707 if (tdev == dev) {
708 ip_rt_put(rt);
709 stats->collisions++;
710 goto tx_error;
711 }
712
713 if (tiph->frag_off)
714 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
715 else
716 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
717
718 if (mtu < 68) {
719 stats->collisions++;
720 ip_rt_put(rt);
721 goto tx_error;
722 }
723 if (mtu < IPV6_MIN_MTU)
724 mtu = IPV6_MIN_MTU;
725 if (tunnel->parms.iph.daddr && skb_dst(skb))
726 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
727
728 if (skb->len > mtu) {
729 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
730 ip_rt_put(rt);
731 goto tx_error;
732 }
733
734 if (tunnel->err_count > 0) {
735 if (time_before(jiffies,
736 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
737 tunnel->err_count--;
738 dst_link_failure(skb);
739 } else
740 tunnel->err_count = 0;
741 }
742
743 /*
744 * Okay, now see if we can stuff it in the buffer as-is.
745 */
746 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
747
748 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
749 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
750 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
751 if (!new_skb) {
752 ip_rt_put(rt);
753 stats->tx_dropped++;
754 dev_kfree_skb(skb);
755 tunnel->recursion--;
756 return 0;
757 }
758 if (skb->sk)
759 skb_set_owner_w(new_skb, skb->sk);
760 dev_kfree_skb(skb);
761 skb = new_skb;
762 iph6 = ipv6_hdr(skb);
763 }
764
765 skb->transport_header = skb->network_header;
766 skb_push(skb, sizeof(struct iphdr));
767 skb_reset_network_header(skb);
768 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
769 IPCB(skb)->flags = 0;
770 skb_dst_drop(skb);
771 skb_dst_set(skb, &rt->u.dst);
772
773 /*
774 * Push down and install the IPIP header.
775 */
776
777 iph = ip_hdr(skb);
778 iph->version = 4;
779 iph->ihl = sizeof(struct iphdr)>>2;
780 if (mtu > IPV6_MIN_MTU)
781 iph->frag_off = htons(IP_DF);
782 else
783 iph->frag_off = 0;
784
785 iph->protocol = IPPROTO_IPV6;
786 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
787 iph->daddr = rt->rt_dst;
788 iph->saddr = rt->rt_src;
789
790 if ((iph->ttl = tiph->ttl) == 0)
791 iph->ttl = iph6->hop_limit;
792
793 nf_reset(skb);
794
795 IPTUNNEL_XMIT();
796 tunnel->recursion--;
797 return 0;
798
799 tx_error_icmp:
800 dst_link_failure(skb);
801 tx_error:
802 stats->tx_errors++;
803 dev_kfree_skb(skb);
804 tunnel->recursion--;
805 return 0;
806 }
807
808 static void ipip6_tunnel_bind_dev(struct net_device *dev)
809 {
810 struct net_device *tdev = NULL;
811 struct ip_tunnel *tunnel;
812 struct iphdr *iph;
813
814 tunnel = netdev_priv(dev);
815 iph = &tunnel->parms.iph;
816
817 if (iph->daddr) {
818 struct flowi fl = { .nl_u = { .ip4_u =
819 { .daddr = iph->daddr,
820 .saddr = iph->saddr,
821 .tos = RT_TOS(iph->tos) } },
822 .oif = tunnel->parms.link,
823 .proto = IPPROTO_IPV6 };
824 struct rtable *rt;
825 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
826 tdev = rt->u.dst.dev;
827 ip_rt_put(rt);
828 }
829 dev->flags |= IFF_POINTOPOINT;
830 }
831
832 if (!tdev && tunnel->parms.link)
833 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
834
835 if (tdev) {
836 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
837 dev->mtu = tdev->mtu - sizeof(struct iphdr);
838 if (dev->mtu < IPV6_MIN_MTU)
839 dev->mtu = IPV6_MIN_MTU;
840 }
841 dev->iflink = tunnel->parms.link;
842 }
843
844 static int
845 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
846 {
847 int err = 0;
848 struct ip_tunnel_parm p;
849 struct ip_tunnel_prl prl;
850 struct ip_tunnel *t;
851 struct net *net = dev_net(dev);
852 struct sit_net *sitn = net_generic(net, sit_net_id);
853
854 switch (cmd) {
855 case SIOCGETTUNNEL:
856 t = NULL;
857 if (dev == sitn->fb_tunnel_dev) {
858 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
859 err = -EFAULT;
860 break;
861 }
862 t = ipip6_tunnel_locate(net, &p, 0);
863 }
864 if (t == NULL)
865 t = netdev_priv(dev);
866 memcpy(&p, &t->parms, sizeof(p));
867 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
868 err = -EFAULT;
869 break;
870
871 case SIOCADDTUNNEL:
872 case SIOCCHGTUNNEL:
873 err = -EPERM;
874 if (!capable(CAP_NET_ADMIN))
875 goto done;
876
877 err = -EFAULT;
878 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
879 goto done;
880
881 err = -EINVAL;
882 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
883 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
884 goto done;
885 if (p.iph.ttl)
886 p.iph.frag_off |= htons(IP_DF);
887
888 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
889
890 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
891 if (t != NULL) {
892 if (t->dev != dev) {
893 err = -EEXIST;
894 break;
895 }
896 } else {
897 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
898 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
899 err = -EINVAL;
900 break;
901 }
902 t = netdev_priv(dev);
903 ipip6_tunnel_unlink(sitn, t);
904 t->parms.iph.saddr = p.iph.saddr;
905 t->parms.iph.daddr = p.iph.daddr;
906 memcpy(dev->dev_addr, &p.iph.saddr, 4);
907 memcpy(dev->broadcast, &p.iph.daddr, 4);
908 ipip6_tunnel_link(sitn, t);
909 netdev_state_change(dev);
910 }
911 }
912
913 if (t) {
914 err = 0;
915 if (cmd == SIOCCHGTUNNEL) {
916 t->parms.iph.ttl = p.iph.ttl;
917 t->parms.iph.tos = p.iph.tos;
918 if (t->parms.link != p.link) {
919 t->parms.link = p.link;
920 ipip6_tunnel_bind_dev(dev);
921 netdev_state_change(dev);
922 }
923 }
924 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
925 err = -EFAULT;
926 } else
927 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
928 break;
929
930 case SIOCDELTUNNEL:
931 err = -EPERM;
932 if (!capable(CAP_NET_ADMIN))
933 goto done;
934
935 if (dev == sitn->fb_tunnel_dev) {
936 err = -EFAULT;
937 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
938 goto done;
939 err = -ENOENT;
940 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
941 goto done;
942 err = -EPERM;
943 if (t == netdev_priv(sitn->fb_tunnel_dev))
944 goto done;
945 dev = t->dev;
946 }
947 unregister_netdevice(dev);
948 err = 0;
949 break;
950
951 case SIOCGETPRL:
952 err = -EINVAL;
953 if (dev == sitn->fb_tunnel_dev)
954 goto done;
955 err = -ENOENT;
956 if (!(t = netdev_priv(dev)))
957 goto done;
958 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
959 break;
960
961 case SIOCADDPRL:
962 case SIOCDELPRL:
963 case SIOCCHGPRL:
964 err = -EPERM;
965 if (!capable(CAP_NET_ADMIN))
966 goto done;
967 err = -EINVAL;
968 if (dev == sitn->fb_tunnel_dev)
969 goto done;
970 err = -EFAULT;
971 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
972 goto done;
973 err = -ENOENT;
974 if (!(t = netdev_priv(dev)))
975 goto done;
976
977 switch (cmd) {
978 case SIOCDELPRL:
979 err = ipip6_tunnel_del_prl(t, &prl);
980 break;
981 case SIOCADDPRL:
982 case SIOCCHGPRL:
983 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
984 break;
985 }
986 netdev_state_change(dev);
987 break;
988
989 default:
990 err = -EINVAL;
991 }
992
993 done:
994 return err;
995 }
996
997 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
998 {
999 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1000 return -EINVAL;
1001 dev->mtu = new_mtu;
1002 return 0;
1003 }
1004
1005 static const struct net_device_ops ipip6_netdev_ops = {
1006 .ndo_uninit = ipip6_tunnel_uninit,
1007 .ndo_start_xmit = ipip6_tunnel_xmit,
1008 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1009 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1010 };
1011
1012 static void ipip6_tunnel_setup(struct net_device *dev)
1013 {
1014 dev->netdev_ops = &ipip6_netdev_ops;
1015 dev->destructor = free_netdev;
1016
1017 dev->type = ARPHRD_SIT;
1018 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1019 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1020 dev->flags = IFF_NOARP;
1021 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1022 dev->iflink = 0;
1023 dev->addr_len = 4;
1024 dev->features |= NETIF_F_NETNS_LOCAL;
1025 }
1026
1027 static void ipip6_tunnel_init(struct net_device *dev)
1028 {
1029 struct ip_tunnel *tunnel = netdev_priv(dev);
1030
1031 tunnel->dev = dev;
1032 strcpy(tunnel->parms.name, dev->name);
1033
1034 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1035 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1036
1037 ipip6_tunnel_bind_dev(dev);
1038 }
1039
1040 static void ipip6_fb_tunnel_init(struct net_device *dev)
1041 {
1042 struct ip_tunnel *tunnel = netdev_priv(dev);
1043 struct iphdr *iph = &tunnel->parms.iph;
1044 struct net *net = dev_net(dev);
1045 struct sit_net *sitn = net_generic(net, sit_net_id);
1046
1047 tunnel->dev = dev;
1048 strcpy(tunnel->parms.name, dev->name);
1049
1050 iph->version = 4;
1051 iph->protocol = IPPROTO_IPV6;
1052 iph->ihl = 5;
1053 iph->ttl = 64;
1054
1055 dev_hold(dev);
1056 sitn->tunnels_wc[0] = tunnel;
1057 }
1058
1059 static struct xfrm_tunnel sit_handler = {
1060 .handler = ipip6_rcv,
1061 .err_handler = ipip6_err,
1062 .priority = 1,
1063 };
1064
1065 static void sit_destroy_tunnels(struct sit_net *sitn)
1066 {
1067 int prio;
1068
1069 for (prio = 1; prio < 4; prio++) {
1070 int h;
1071 for (h = 0; h < HASH_SIZE; h++) {
1072 struct ip_tunnel *t;
1073 while ((t = sitn->tunnels[prio][h]) != NULL)
1074 unregister_netdevice(t->dev);
1075 }
1076 }
1077 }
1078
1079 static int sit_init_net(struct net *net)
1080 {
1081 int err;
1082 struct sit_net *sitn;
1083
1084 err = -ENOMEM;
1085 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL);
1086 if (sitn == NULL)
1087 goto err_alloc;
1088
1089 err = net_assign_generic(net, sit_net_id, sitn);
1090 if (err < 0)
1091 goto err_assign;
1092
1093 sitn->tunnels[0] = sitn->tunnels_wc;
1094 sitn->tunnels[1] = sitn->tunnels_l;
1095 sitn->tunnels[2] = sitn->tunnels_r;
1096 sitn->tunnels[3] = sitn->tunnels_r_l;
1097
1098 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1099 ipip6_tunnel_setup);
1100 if (!sitn->fb_tunnel_dev) {
1101 err = -ENOMEM;
1102 goto err_alloc_dev;
1103 }
1104 dev_net_set(sitn->fb_tunnel_dev, net);
1105
1106 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1107
1108 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1109 goto err_reg_dev;
1110
1111 return 0;
1112
1113 err_reg_dev:
1114 dev_put(sitn->fb_tunnel_dev);
1115 free_netdev(sitn->fb_tunnel_dev);
1116 err_alloc_dev:
1117 /* nothing */
1118 err_assign:
1119 kfree(sitn);
1120 err_alloc:
1121 return err;
1122 }
1123
1124 static void sit_exit_net(struct net *net)
1125 {
1126 struct sit_net *sitn;
1127
1128 sitn = net_generic(net, sit_net_id);
1129 rtnl_lock();
1130 sit_destroy_tunnels(sitn);
1131 unregister_netdevice(sitn->fb_tunnel_dev);
1132 rtnl_unlock();
1133 kfree(sitn);
1134 }
1135
1136 static struct pernet_operations sit_net_ops = {
1137 .init = sit_init_net,
1138 .exit = sit_exit_net,
1139 };
1140
1141 static void __exit sit_cleanup(void)
1142 {
1143 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1144
1145 unregister_pernet_gen_device(sit_net_id, &sit_net_ops);
1146 }
1147
1148 static int __init sit_init(void)
1149 {
1150 int err;
1151
1152 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1153
1154 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1155 printk(KERN_INFO "sit init: Can't add protocol\n");
1156 return -EAGAIN;
1157 }
1158
1159 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops);
1160 if (err < 0)
1161 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1162
1163 return err;
1164 }
1165
1166 module_init(sit_init);
1167 module_exit(sit_cleanup);
1168 MODULE_LICENSE("GPL");
1169 MODULE_ALIAS("sit0");
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