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Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
[linux/fpc-iii.git] / net / ipv6 / sit.c
blob0ae4f6448187ef288c0692d6eb3b3697a2b6aa25
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 netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
613 struct net_device *dev)
614 {
615 struct ip_tunnel *tunnel = netdev_priv(dev);
616 struct net_device_stats *stats = &tunnel->dev->stats;
617 struct iphdr *tiph = &tunnel->parms.iph;
618 struct ipv6hdr *iph6 = ipv6_hdr(skb);
619 u8 tos = tunnel->parms.iph.tos;
620 struct rtable *rt; /* Route to the other host */
621 struct net_device *tdev; /* Device to other host */
622 struct iphdr *iph; /* Our new IP header */
623 unsigned int max_headroom; /* The extra header space needed */
624 __be32 dst = tiph->daddr;
625 int mtu;
626 struct in6_addr *addr6;
627 int addr_type;
628
629 if (tunnel->recursion++) {
630 stats->collisions++;
631 goto tx_error;
632 }
633
634 if (skb->protocol != htons(ETH_P_IPV6))
635 goto tx_error;
636
637 /* ISATAP (RFC4214) - must come before 6to4 */
638 if (dev->priv_flags & IFF_ISATAP) {
639 struct neighbour *neigh = NULL;
640
641 if (skb_dst(skb))
642 neigh = skb_dst(skb)->neighbour;
643
644 if (neigh == NULL) {
645 if (net_ratelimit())
646 printk(KERN_DEBUG "sit: nexthop == NULL\n");
647 goto tx_error;
648 }
649
650 addr6 = (struct in6_addr*)&neigh->primary_key;
651 addr_type = ipv6_addr_type(addr6);
652
653 if ((addr_type & IPV6_ADDR_UNICAST) &&
654 ipv6_addr_is_isatap(addr6))
655 dst = addr6->s6_addr32[3];
656 else
657 goto tx_error;
658 }
659
660 if (!dst)
661 dst = try_6to4(&iph6->daddr);
662
663 if (!dst) {
664 struct neighbour *neigh = NULL;
665
666 if (skb_dst(skb))
667 neigh = skb_dst(skb)->neighbour;
668
669 if (neigh == NULL) {
670 if (net_ratelimit())
671 printk(KERN_DEBUG "sit: nexthop == NULL\n");
672 goto tx_error;
673 }
674
675 addr6 = (struct in6_addr*)&neigh->primary_key;
676 addr_type = ipv6_addr_type(addr6);
677
678 if (addr_type == IPV6_ADDR_ANY) {
679 addr6 = &ipv6_hdr(skb)->daddr;
680 addr_type = ipv6_addr_type(addr6);
681 }
682
683 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
684 goto tx_error_icmp;
685
686 dst = addr6->s6_addr32[3];
687 }
688
689 {
690 struct flowi fl = { .nl_u = { .ip4_u =
691 { .daddr = dst,
692 .saddr = tiph->saddr,
693 .tos = RT_TOS(tos) } },
694 .oif = tunnel->parms.link,
695 .proto = IPPROTO_IPV6 };
696 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
697 stats->tx_carrier_errors++;
698 goto tx_error_icmp;
699 }
700 }
701 if (rt->rt_type != RTN_UNICAST) {
702 ip_rt_put(rt);
703 stats->tx_carrier_errors++;
704 goto tx_error_icmp;
705 }
706 tdev = rt->u.dst.dev;
707
708 if (tdev == dev) {
709 ip_rt_put(rt);
710 stats->collisions++;
711 goto tx_error;
712 }
713
714 if (tiph->frag_off)
715 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
716 else
717 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
718
719 if (mtu < 68) {
720 stats->collisions++;
721 ip_rt_put(rt);
722 goto tx_error;
723 }
724 if (mtu < IPV6_MIN_MTU)
725 mtu = IPV6_MIN_MTU;
726 if (tunnel->parms.iph.daddr && skb_dst(skb))
727 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
728
729 if (skb->len > mtu) {
730 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
731 ip_rt_put(rt);
732 goto tx_error;
733 }
734
735 if (tunnel->err_count > 0) {
736 if (time_before(jiffies,
737 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
738 tunnel->err_count--;
739 dst_link_failure(skb);
740 } else
741 tunnel->err_count = 0;
742 }
743
744 /*
745 * Okay, now see if we can stuff it in the buffer as-is.
746 */
747 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
748
749 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
750 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
751 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
752 if (!new_skb) {
753 ip_rt_put(rt);
754 stats->tx_dropped++;
755 dev_kfree_skb(skb);
756 tunnel->recursion--;
757 return NETDEV_TX_OK;
758 }
759 if (skb->sk)
760 skb_set_owner_w(new_skb, skb->sk);
761 dev_kfree_skb(skb);
762 skb = new_skb;
763 iph6 = ipv6_hdr(skb);
764 }
765
766 skb->transport_header = skb->network_header;
767 skb_push(skb, sizeof(struct iphdr));
768 skb_reset_network_header(skb);
769 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
770 IPCB(skb)->flags = 0;
771 skb_dst_drop(skb);
772 skb_dst_set(skb, &rt->u.dst);
773
774 /*
775 * Push down and install the IPIP header.
776 */
777
778 iph = ip_hdr(skb);
779 iph->version = 4;
780 iph->ihl = sizeof(struct iphdr)>>2;
781 if (mtu > IPV6_MIN_MTU)
782 iph->frag_off = tiph->frag_off;
783 else
784 iph->frag_off = 0;
785
786 iph->protocol = IPPROTO_IPV6;
787 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
788 iph->daddr = rt->rt_dst;
789 iph->saddr = rt->rt_src;
790
791 if ((iph->ttl = tiph->ttl) == 0)
792 iph->ttl = iph6->hop_limit;
793
794 nf_reset(skb);
795
796 IPTUNNEL_XMIT();
797 tunnel->recursion--;
798 return NETDEV_TX_OK;
799
800 tx_error_icmp:
801 dst_link_failure(skb);
802 tx_error:
803 stats->tx_errors++;
804 dev_kfree_skb(skb);
805 tunnel->recursion--;
806 return NETDEV_TX_OK;
807 }
808
809 static void ipip6_tunnel_bind_dev(struct net_device *dev)
810 {
811 struct net_device *tdev = NULL;
812 struct ip_tunnel *tunnel;
813 struct iphdr *iph;
814
815 tunnel = netdev_priv(dev);
816 iph = &tunnel->parms.iph;
817
818 if (iph->daddr) {
819 struct flowi fl = { .nl_u = { .ip4_u =
820 { .daddr = iph->daddr,
821 .saddr = iph->saddr,
822 .tos = RT_TOS(iph->tos) } },
823 .oif = tunnel->parms.link,
824 .proto = IPPROTO_IPV6 };
825 struct rtable *rt;
826 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
827 tdev = rt->u.dst.dev;
828 ip_rt_put(rt);
829 }
830 dev->flags |= IFF_POINTOPOINT;
831 }
832
833 if (!tdev && tunnel->parms.link)
834 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
835
836 if (tdev) {
837 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
838 dev->mtu = tdev->mtu - sizeof(struct iphdr);
839 if (dev->mtu < IPV6_MIN_MTU)
840 dev->mtu = IPV6_MIN_MTU;
841 }
842 dev->iflink = tunnel->parms.link;
843 }
844
845 static int
846 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
847 {
848 int err = 0;
849 struct ip_tunnel_parm p;
850 struct ip_tunnel_prl prl;
851 struct ip_tunnel *t;
852 struct net *net = dev_net(dev);
853 struct sit_net *sitn = net_generic(net, sit_net_id);
854
855 switch (cmd) {
856 case SIOCGETTUNNEL:
857 t = NULL;
858 if (dev == sitn->fb_tunnel_dev) {
859 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
860 err = -EFAULT;
861 break;
862 }
863 t = ipip6_tunnel_locate(net, &p, 0);
864 }
865 if (t == NULL)
866 t = netdev_priv(dev);
867 memcpy(&p, &t->parms, sizeof(p));
868 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
869 err = -EFAULT;
870 break;
871
872 case SIOCADDTUNNEL:
873 case SIOCCHGTUNNEL:
874 err = -EPERM;
875 if (!capable(CAP_NET_ADMIN))
876 goto done;
877
878 err = -EFAULT;
879 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
880 goto done;
881
882 err = -EINVAL;
883 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
884 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
885 goto done;
886 if (p.iph.ttl)
887 p.iph.frag_off |= htons(IP_DF);
888
889 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
890
891 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
892 if (t != NULL) {
893 if (t->dev != dev) {
894 err = -EEXIST;
895 break;
896 }
897 } else {
898 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
899 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
900 err = -EINVAL;
901 break;
902 }
903 t = netdev_priv(dev);
904 ipip6_tunnel_unlink(sitn, t);
905 t->parms.iph.saddr = p.iph.saddr;
906 t->parms.iph.daddr = p.iph.daddr;
907 memcpy(dev->dev_addr, &p.iph.saddr, 4);
908 memcpy(dev->broadcast, &p.iph.daddr, 4);
909 ipip6_tunnel_link(sitn, t);
910 netdev_state_change(dev);
911 }
912 }
913
914 if (t) {
915 err = 0;
916 if (cmd == SIOCCHGTUNNEL) {
917 t->parms.iph.ttl = p.iph.ttl;
918 t->parms.iph.tos = p.iph.tos;
919 if (t->parms.link != p.link) {
920 t->parms.link = p.link;
921 ipip6_tunnel_bind_dev(dev);
922 netdev_state_change(dev);
923 }
924 }
925 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
926 err = -EFAULT;
927 } else
928 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
929 break;
930
931 case SIOCDELTUNNEL:
932 err = -EPERM;
933 if (!capable(CAP_NET_ADMIN))
934 goto done;
935
936 if (dev == sitn->fb_tunnel_dev) {
937 err = -EFAULT;
938 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
939 goto done;
940 err = -ENOENT;
941 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
942 goto done;
943 err = -EPERM;
944 if (t == netdev_priv(sitn->fb_tunnel_dev))
945 goto done;
946 dev = t->dev;
947 }
948 unregister_netdevice(dev);
949 err = 0;
950 break;
951
952 case SIOCGETPRL:
953 err = -EINVAL;
954 if (dev == sitn->fb_tunnel_dev)
955 goto done;
956 err = -ENOENT;
957 if (!(t = netdev_priv(dev)))
958 goto done;
959 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
960 break;
961
962 case SIOCADDPRL:
963 case SIOCDELPRL:
964 case SIOCCHGPRL:
965 err = -EPERM;
966 if (!capable(CAP_NET_ADMIN))
967 goto done;
968 err = -EINVAL;
969 if (dev == sitn->fb_tunnel_dev)
970 goto done;
971 err = -EFAULT;
972 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
973 goto done;
974 err = -ENOENT;
975 if (!(t = netdev_priv(dev)))
976 goto done;
977
978 switch (cmd) {
979 case SIOCDELPRL:
980 err = ipip6_tunnel_del_prl(t, &prl);
981 break;
982 case SIOCADDPRL:
983 case SIOCCHGPRL:
984 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
985 break;
986 }
987 netdev_state_change(dev);
988 break;
989
990 default:
991 err = -EINVAL;
992 }
993
994 done:
995 return err;
996 }
997
998 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
999 {
1000 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1001 return -EINVAL;
1002 dev->mtu = new_mtu;
1003 return 0;
1004 }
1005
1006 static const struct net_device_ops ipip6_netdev_ops = {
1007 .ndo_uninit = ipip6_tunnel_uninit,
1008 .ndo_start_xmit = ipip6_tunnel_xmit,
1009 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1010 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1011 };
1012
1013 static void ipip6_tunnel_setup(struct net_device *dev)
1014 {
1015 dev->netdev_ops = &ipip6_netdev_ops;
1016 dev->destructor = free_netdev;
1017
1018 dev->type = ARPHRD_SIT;
1019 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1020 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1021 dev->flags = IFF_NOARP;
1022 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1023 dev->iflink = 0;
1024 dev->addr_len = 4;
1025 dev->features |= NETIF_F_NETNS_LOCAL;
1026 }
1027
1028 static void ipip6_tunnel_init(struct net_device *dev)
1029 {
1030 struct ip_tunnel *tunnel = netdev_priv(dev);
1031
1032 tunnel->dev = dev;
1033 strcpy(tunnel->parms.name, dev->name);
1034
1035 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1036 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1037
1038 ipip6_tunnel_bind_dev(dev);
1039 }
1040
1041 static void ipip6_fb_tunnel_init(struct net_device *dev)
1042 {
1043 struct ip_tunnel *tunnel = netdev_priv(dev);
1044 struct iphdr *iph = &tunnel->parms.iph;
1045 struct net *net = dev_net(dev);
1046 struct sit_net *sitn = net_generic(net, sit_net_id);
1047
1048 tunnel->dev = dev;
1049 strcpy(tunnel->parms.name, dev->name);
1050
1051 iph->version = 4;
1052 iph->protocol = IPPROTO_IPV6;
1053 iph->ihl = 5;
1054 iph->ttl = 64;
1055
1056 dev_hold(dev);
1057 sitn->tunnels_wc[0] = tunnel;
1058 }
1059
1060 static struct xfrm_tunnel sit_handler = {
1061 .handler = ipip6_rcv,
1062 .err_handler = ipip6_err,
1063 .priority = 1,
1064 };
1065
1066 static void sit_destroy_tunnels(struct sit_net *sitn)
1067 {
1068 int prio;
1069
1070 for (prio = 1; prio < 4; prio++) {
1071 int h;
1072 for (h = 0; h < HASH_SIZE; h++) {
1073 struct ip_tunnel *t;
1074 while ((t = sitn->tunnels[prio][h]) != NULL)
1075 unregister_netdevice(t->dev);
1076 }
1077 }
1078 }
1079
1080 static int sit_init_net(struct net *net)
1081 {
1082 int err;
1083 struct sit_net *sitn;
1084
1085 err = -ENOMEM;
1086 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL);
1087 if (sitn == NULL)
1088 goto err_alloc;
1089
1090 err = net_assign_generic(net, sit_net_id, sitn);
1091 if (err < 0)
1092 goto err_assign;
1093
1094 sitn->tunnels[0] = sitn->tunnels_wc;
1095 sitn->tunnels[1] = sitn->tunnels_l;
1096 sitn->tunnels[2] = sitn->tunnels_r;
1097 sitn->tunnels[3] = sitn->tunnels_r_l;
1098
1099 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1100 ipip6_tunnel_setup);
1101 if (!sitn->fb_tunnel_dev) {
1102 err = -ENOMEM;
1103 goto err_alloc_dev;
1104 }
1105 dev_net_set(sitn->fb_tunnel_dev, net);
1106
1107 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1108
1109 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1110 goto err_reg_dev;
1111
1112 return 0;
1113
1114 err_reg_dev:
1115 dev_put(sitn->fb_tunnel_dev);
1116 free_netdev(sitn->fb_tunnel_dev);
1117 err_alloc_dev:
1118 /* nothing */
1119 err_assign:
1120 kfree(sitn);
1121 err_alloc:
1122 return err;
1123 }
1124
1125 static void sit_exit_net(struct net *net)
1126 {
1127 struct sit_net *sitn;
1128
1129 sitn = net_generic(net, sit_net_id);
1130 rtnl_lock();
1131 sit_destroy_tunnels(sitn);
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 unregister_pernet_gen_device(sit_net_id, &sit_net_ops);
1147 }
1148
1149 static int __init sit_init(void)
1150 {
1151 int err;
1152
1153 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1154
1155 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1156 printk(KERN_INFO "sit init: Can't add protocol\n");
1157 return -EAGAIN;
1158 }
1159
1160 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops);
1161 if (err < 0)
1162 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1163
1164 return err;
1165 }
1166
1167 module_init(sit_init);
1168 module_exit(sit_cleanup);
1169 MODULE_LICENSE("GPL");
1170 MODULE_ALIAS("sit0");
Linux with added FPC-III support