fs: fix do_mount_root() false positive kmemcheck warning
[GitHub/mt8127/android_kernel_alcatel_ttab.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 * 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 */
19
20 #include <linux/module.h>
21 #include <linux/capability.h>
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/socket.h>
25 #include <linux/sockios.h>
26 #include <linux/net.h>
27 #include <linux/in6.h>
28 #include <linux/netdevice.h>
29 #include <linux/if_arp.h>
30 #include <linux/icmp.h>
31 #include <asm/uaccess.h>
32 #include <linux/init.h>
33 #include <linux/netfilter_ipv4.h>
34 #include <linux/if_ether.h>
35
36 #include <net/sock.h>
37 #include <net/snmp.h>
38
39 #include <net/ipv6.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/ip6_fib.h>
43 #include <net/ip6_route.h>
44 #include <net/ndisc.h>
45 #include <net/addrconf.h>
46 #include <net/ip.h>
47 #include <net/udp.h>
48 #include <net/icmp.h>
49 #include <net/ipip.h>
50 #include <net/inet_ecn.h>
51 #include <net/xfrm.h>
52 #include <net/dsfield.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55
56 /*
57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
58
59 For comments look at net/ipv4/ip_gre.c --ANK
60 */
61
62 #define HASH_SIZE 16
63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
64
65 static void ipip6_fb_tunnel_init(struct net_device *dev);
66 static void ipip6_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_setup(struct net_device *dev);
68
69 static int sit_net_id;
70 struct sit_net {
71 struct ip_tunnel *tunnels_r_l[HASH_SIZE];
72 struct ip_tunnel *tunnels_r[HASH_SIZE];
73 struct ip_tunnel *tunnels_l[HASH_SIZE];
74 struct ip_tunnel *tunnels_wc[1];
75 struct ip_tunnel **tunnels[4];
76
77 struct net_device *fb_tunnel_dev;
78 };
79
80 static DEFINE_RWLOCK(ipip6_lock);
81
82 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
83 __be32 remote, __be32 local)
84 {
85 unsigned h0 = HASH(remote);
86 unsigned h1 = HASH(local);
87 struct ip_tunnel *t;
88 struct sit_net *sitn = net_generic(net, sit_net_id);
89
90 for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) {
91 if (local == t->parms.iph.saddr &&
92 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
93 return t;
94 }
95 for (t = sitn->tunnels_r[h0]; t; t = t->next) {
96 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
97 return t;
98 }
99 for (t = sitn->tunnels_l[h1]; t; t = t->next) {
100 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
101 return t;
102 }
103 if ((t = sitn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
104 return t;
105 return NULL;
106 }
107
108 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn,
109 struct ip_tunnel_parm *parms)
110 {
111 __be32 remote = parms->iph.daddr;
112 __be32 local = parms->iph.saddr;
113 unsigned h = 0;
114 int prio = 0;
115
116 if (remote) {
117 prio |= 2;
118 h ^= HASH(remote);
119 }
120 if (local) {
121 prio |= 1;
122 h ^= HASH(local);
123 }
124 return &sitn->tunnels[prio][h];
125 }
126
127 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn,
128 struct ip_tunnel *t)
129 {
130 return __ipip6_bucket(sitn, &t->parms);
131 }
132
133 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
134 {
135 struct ip_tunnel **tp;
136
137 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) {
138 if (t == *tp) {
139 write_lock_bh(&ipip6_lock);
140 *tp = t->next;
141 write_unlock_bh(&ipip6_lock);
142 break;
143 }
144 }
145 }
146
147 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
148 {
149 struct ip_tunnel **tp = ipip6_bucket(sitn, t);
150
151 t->next = *tp;
152 write_lock_bh(&ipip6_lock);
153 *tp = t;
154 write_unlock_bh(&ipip6_lock);
155 }
156
157 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
158 struct ip_tunnel_parm *parms, int create)
159 {
160 __be32 remote = parms->iph.daddr;
161 __be32 local = parms->iph.saddr;
162 struct ip_tunnel *t, **tp, *nt;
163 struct net_device *dev;
164 char name[IFNAMSIZ];
165 struct sit_net *sitn = net_generic(net, sit_net_id);
166
167 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) {
168 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
169 return t;
170 }
171 if (!create)
172 goto failed;
173
174 if (parms->name[0])
175 strlcpy(name, parms->name, IFNAMSIZ);
176 else
177 sprintf(name, "sit%%d");
178
179 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
180 if (dev == NULL)
181 return NULL;
182
183 dev_net_set(dev, net);
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
192 nt->parms = *parms;
193 ipip6_tunnel_init(dev);
194
195 if (parms->i_flags & SIT_ISATAP)
196 dev->priv_flags |= IFF_ISATAP;
197
198 if (register_netdevice(dev) < 0)
199 goto failed_free;
200
201 dev_hold(dev);
202
203 ipip6_tunnel_link(sitn, nt);
204 return nt;
205
206 failed_free:
207 free_netdev(dev);
208 failed:
209 return NULL;
210 }
211
212 static struct ip_tunnel_prl_entry *
213 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
214 {
215 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL;
216
217 for (p = t->prl; p; p = p->next)
218 if (p->addr == addr)
219 break;
220 return p;
221
222 }
223
224 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
225 struct ip_tunnel_prl __user *a)
226 {
227 struct ip_tunnel_prl kprl, *kp;
228 struct ip_tunnel_prl_entry *prl;
229 unsigned int cmax, c = 0, ca, len;
230 int ret = 0;
231
232 if (copy_from_user(&kprl, a, sizeof(kprl)))
233 return -EFAULT;
234 cmax = kprl.datalen / sizeof(kprl);
235 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
236 cmax = 1;
237
238 /* For simple GET or for root users,
239 * we try harder to allocate.
240 */
241 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
242 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
243 NULL;
244
245 read_lock(&ipip6_lock);
246
247 ca = t->prl_count < cmax ? t->prl_count : cmax;
248
249 if (!kp) {
250 /* We don't try hard to allocate much memory for
251 * non-root users.
252 * For root users, retry allocating enough memory for
253 * the answer.
254 */
255 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
256 if (!kp) {
257 ret = -ENOMEM;
258 goto out;
259 }
260 }
261
262 c = 0;
263 for (prl = t->prl; prl; prl = prl->next) {
264 if (c > cmax)
265 break;
266 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
267 continue;
268 kp[c].addr = prl->addr;
269 kp[c].flags = prl->flags;
270 c++;
271 if (kprl.addr != htonl(INADDR_ANY))
272 break;
273 }
274 out:
275 read_unlock(&ipip6_lock);
276
277 len = sizeof(*kp) * c;
278 ret = 0;
279 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
280 ret = -EFAULT;
281
282 kfree(kp);
283
284 return ret;
285 }
286
287 static int
288 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
289 {
290 struct ip_tunnel_prl_entry *p;
291 int err = 0;
292
293 if (a->addr == htonl(INADDR_ANY))
294 return -EINVAL;
295
296 write_lock(&ipip6_lock);
297
298 for (p = t->prl; p; p = p->next) {
299 if (p->addr == a->addr) {
300 if (chg)
301 goto update;
302 err = -EEXIST;
303 goto out;
304 }
305 }
306
307 if (chg) {
308 err = -ENXIO;
309 goto out;
310 }
311
312 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
313 if (!p) {
314 err = -ENOBUFS;
315 goto out;
316 }
317
318 p->next = t->prl;
319 t->prl = p;
320 t->prl_count++;
321 update:
322 p->addr = a->addr;
323 p->flags = a->flags;
324 out:
325 write_unlock(&ipip6_lock);
326 return err;
327 }
328
329 static int
330 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
331 {
332 struct ip_tunnel_prl_entry *x, **p;
333 int err = 0;
334
335 write_lock(&ipip6_lock);
336
337 if (a && a->addr != htonl(INADDR_ANY)) {
338 for (p = &t->prl; *p; p = &(*p)->next) {
339 if ((*p)->addr == a->addr) {
340 x = *p;
341 *p = x->next;
342 kfree(x);
343 t->prl_count--;
344 goto out;
345 }
346 }
347 err = -ENXIO;
348 } else {
349 while (t->prl) {
350 x = t->prl;
351 t->prl = t->prl->next;
352 kfree(x);
353 t->prl_count--;
354 }
355 }
356 out:
357 write_unlock(&ipip6_lock);
358 return 0;
359 }
360
361 static int
362 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
363 {
364 struct ip_tunnel_prl_entry *p;
365 int ok = 1;
366
367 read_lock(&ipip6_lock);
368 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
369 if (p) {
370 if (p->flags & PRL_DEFAULT)
371 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
372 else
373 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
374 } else {
375 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
376 if (ipv6_addr_is_isatap(addr6) &&
377 (addr6->s6_addr32[3] == iph->saddr) &&
378 ipv6_chk_prefix(addr6, t->dev))
379 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
380 else
381 ok = 0;
382 }
383 read_unlock(&ipip6_lock);
384 return ok;
385 }
386
387 static void ipip6_tunnel_uninit(struct net_device *dev)
388 {
389 struct net *net = dev_net(dev);
390 struct sit_net *sitn = net_generic(net, sit_net_id);
391
392 if (dev == sitn->fb_tunnel_dev) {
393 write_lock_bh(&ipip6_lock);
394 sitn->tunnels_wc[0] = NULL;
395 write_unlock_bh(&ipip6_lock);
396 dev_put(dev);
397 } else {
398 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
399 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
400 dev_put(dev);
401 }
402 }
403
404
405 static int ipip6_err(struct sk_buff *skb, u32 info)
406 {
407
408 /* All the routers (except for Linux) return only
409 8 bytes of packet payload. It means, that precise relaying of
410 ICMP in the real Internet is absolutely infeasible.
411 */
412 struct iphdr *iph = (struct iphdr*)skb->data;
413 const int type = icmp_hdr(skb)->type;
414 const int code = icmp_hdr(skb)->code;
415 struct ip_tunnel *t;
416 int err;
417
418 switch (type) {
419 default:
420 case ICMP_PARAMETERPROB:
421 return 0;
422
423 case ICMP_DEST_UNREACH:
424 switch (code) {
425 case ICMP_SR_FAILED:
426 case ICMP_PORT_UNREACH:
427 /* Impossible event. */
428 return 0;
429 case ICMP_FRAG_NEEDED:
430 /* Soft state for pmtu is maintained by IP core. */
431 return 0;
432 default:
433 /* All others are translated to HOST_UNREACH.
434 rfc2003 contains "deep thoughts" about NET_UNREACH,
435 I believe they are just ether pollution. --ANK
436 */
437 break;
438 }
439 break;
440 case ICMP_TIME_EXCEEDED:
441 if (code != ICMP_EXC_TTL)
442 return 0;
443 break;
444 }
445
446 err = -ENOENT;
447
448 read_lock(&ipip6_lock);
449 t = ipip6_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
450 if (t == NULL || t->parms.iph.daddr == 0)
451 goto out;
452
453 err = 0;
454 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
455 goto out;
456
457 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
458 t->err_count++;
459 else
460 t->err_count = 1;
461 t->err_time = jiffies;
462 out:
463 read_unlock(&ipip6_lock);
464 return err;
465 }
466
467 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
468 {
469 if (INET_ECN_is_ce(iph->tos))
470 IP6_ECN_set_ce(ipv6_hdr(skb));
471 }
472
473 static int ipip6_rcv(struct sk_buff *skb)
474 {
475 struct iphdr *iph;
476 struct ip_tunnel *tunnel;
477
478 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
479 goto out;
480
481 iph = ip_hdr(skb);
482
483 read_lock(&ipip6_lock);
484 if ((tunnel = ipip6_tunnel_lookup(dev_net(skb->dev),
485 iph->saddr, iph->daddr)) != NULL) {
486 secpath_reset(skb);
487 skb->mac_header = skb->network_header;
488 skb_reset_network_header(skb);
489 IPCB(skb)->flags = 0;
490 skb->protocol = htons(ETH_P_IPV6);
491 skb->pkt_type = PACKET_HOST;
492
493 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
494 !isatap_chksrc(skb, iph, tunnel)) {
495 tunnel->dev->stats.rx_errors++;
496 read_unlock(&ipip6_lock);
497 kfree_skb(skb);
498 return 0;
499 }
500 tunnel->dev->stats.rx_packets++;
501 tunnel->dev->stats.rx_bytes += skb->len;
502 skb->dev = tunnel->dev;
503 dst_release(skb->dst);
504 skb->dst = NULL;
505 nf_reset(skb);
506 ipip6_ecn_decapsulate(iph, skb);
507 netif_rx(skb);
508 read_unlock(&ipip6_lock);
509 return 0;
510 }
511
512 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
513 read_unlock(&ipip6_lock);
514 out:
515 kfree_skb(skb);
516 return 0;
517 }
518
519 /* Returns the embedded IPv4 address if the IPv6 address
520 comes from 6to4 (RFC 3056) addr space */
521
522 static inline __be32 try_6to4(struct in6_addr *v6dst)
523 {
524 __be32 dst = 0;
525
526 if (v6dst->s6_addr16[0] == htons(0x2002)) {
527 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
528 memcpy(&dst, &v6dst->s6_addr16[1], 4);
529 }
530 return dst;
531 }
532
533 /*
534 * This function assumes it is being called from dev_queue_xmit()
535 * and that skb is filled properly by that function.
536 */
537
538 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
539 {
540 struct ip_tunnel *tunnel = netdev_priv(dev);
541 struct net_device_stats *stats = &tunnel->dev->stats;
542 struct iphdr *tiph = &tunnel->parms.iph;
543 struct ipv6hdr *iph6 = ipv6_hdr(skb);
544 u8 tos = tunnel->parms.iph.tos;
545 struct rtable *rt; /* Route to the other host */
546 struct net_device *tdev; /* Device to other host */
547 struct iphdr *iph; /* Our new IP header */
548 unsigned int max_headroom; /* The extra header space needed */
549 __be32 dst = tiph->daddr;
550 int mtu;
551 struct in6_addr *addr6;
552 int addr_type;
553
554 if (tunnel->recursion++) {
555 stats->collisions++;
556 goto tx_error;
557 }
558
559 if (skb->protocol != htons(ETH_P_IPV6))
560 goto tx_error;
561
562 /* ISATAP (RFC4214) - must come before 6to4 */
563 if (dev->priv_flags & IFF_ISATAP) {
564 struct neighbour *neigh = NULL;
565
566 if (skb->dst)
567 neigh = skb->dst->neighbour;
568
569 if (neigh == NULL) {
570 if (net_ratelimit())
571 printk(KERN_DEBUG "sit: nexthop == NULL\n");
572 goto tx_error;
573 }
574
575 addr6 = (struct in6_addr*)&neigh->primary_key;
576 addr_type = ipv6_addr_type(addr6);
577
578 if ((addr_type & IPV6_ADDR_UNICAST) &&
579 ipv6_addr_is_isatap(addr6))
580 dst = addr6->s6_addr32[3];
581 else
582 goto tx_error;
583 }
584
585 if (!dst)
586 dst = try_6to4(&iph6->daddr);
587
588 if (!dst) {
589 struct neighbour *neigh = NULL;
590
591 if (skb->dst)
592 neigh = skb->dst->neighbour;
593
594 if (neigh == NULL) {
595 if (net_ratelimit())
596 printk(KERN_DEBUG "sit: nexthop == NULL\n");
597 goto tx_error;
598 }
599
600 addr6 = (struct in6_addr*)&neigh->primary_key;
601 addr_type = ipv6_addr_type(addr6);
602
603 if (addr_type == IPV6_ADDR_ANY) {
604 addr6 = &ipv6_hdr(skb)->daddr;
605 addr_type = ipv6_addr_type(addr6);
606 }
607
608 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
609 goto tx_error_icmp;
610
611 dst = addr6->s6_addr32[3];
612 }
613
614 {
615 struct flowi fl = { .nl_u = { .ip4_u =
616 { .daddr = dst,
617 .saddr = tiph->saddr,
618 .tos = RT_TOS(tos) } },
619 .oif = tunnel->parms.link,
620 .proto = IPPROTO_IPV6 };
621 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
622 stats->tx_carrier_errors++;
623 goto tx_error_icmp;
624 }
625 }
626 if (rt->rt_type != RTN_UNICAST) {
627 ip_rt_put(rt);
628 stats->tx_carrier_errors++;
629 goto tx_error_icmp;
630 }
631 tdev = rt->u.dst.dev;
632
633 if (tdev == dev) {
634 ip_rt_put(rt);
635 stats->collisions++;
636 goto tx_error;
637 }
638
639 if (tiph->frag_off)
640 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
641 else
642 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
643
644 if (mtu < 68) {
645 stats->collisions++;
646 ip_rt_put(rt);
647 goto tx_error;
648 }
649 if (mtu < IPV6_MIN_MTU)
650 mtu = IPV6_MIN_MTU;
651 if (tunnel->parms.iph.daddr && skb->dst)
652 skb->dst->ops->update_pmtu(skb->dst, mtu);
653
654 if (skb->len > mtu) {
655 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
656 ip_rt_put(rt);
657 goto tx_error;
658 }
659
660 if (tunnel->err_count > 0) {
661 if (time_before(jiffies,
662 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
663 tunnel->err_count--;
664 dst_link_failure(skb);
665 } else
666 tunnel->err_count = 0;
667 }
668
669 /*
670 * Okay, now see if we can stuff it in the buffer as-is.
671 */
672 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
673
674 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
675 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
676 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
677 if (!new_skb) {
678 ip_rt_put(rt);
679 stats->tx_dropped++;
680 dev_kfree_skb(skb);
681 tunnel->recursion--;
682 return 0;
683 }
684 if (skb->sk)
685 skb_set_owner_w(new_skb, skb->sk);
686 dev_kfree_skb(skb);
687 skb = new_skb;
688 iph6 = ipv6_hdr(skb);
689 }
690
691 skb->transport_header = skb->network_header;
692 skb_push(skb, sizeof(struct iphdr));
693 skb_reset_network_header(skb);
694 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
695 IPCB(skb)->flags = 0;
696 dst_release(skb->dst);
697 skb->dst = &rt->u.dst;
698
699 /*
700 * Push down and install the IPIP header.
701 */
702
703 iph = ip_hdr(skb);
704 iph->version = 4;
705 iph->ihl = sizeof(struct iphdr)>>2;
706 if (mtu > IPV6_MIN_MTU)
707 iph->frag_off = htons(IP_DF);
708 else
709 iph->frag_off = 0;
710
711 iph->protocol = IPPROTO_IPV6;
712 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
713 iph->daddr = rt->rt_dst;
714 iph->saddr = rt->rt_src;
715
716 if ((iph->ttl = tiph->ttl) == 0)
717 iph->ttl = iph6->hop_limit;
718
719 nf_reset(skb);
720
721 IPTUNNEL_XMIT();
722 tunnel->recursion--;
723 return 0;
724
725 tx_error_icmp:
726 dst_link_failure(skb);
727 tx_error:
728 stats->tx_errors++;
729 dev_kfree_skb(skb);
730 tunnel->recursion--;
731 return 0;
732 }
733
734 static void ipip6_tunnel_bind_dev(struct net_device *dev)
735 {
736 struct net_device *tdev = NULL;
737 struct ip_tunnel *tunnel;
738 struct iphdr *iph;
739
740 tunnel = netdev_priv(dev);
741 iph = &tunnel->parms.iph;
742
743 if (iph->daddr) {
744 struct flowi fl = { .nl_u = { .ip4_u =
745 { .daddr = iph->daddr,
746 .saddr = iph->saddr,
747 .tos = RT_TOS(iph->tos) } },
748 .oif = tunnel->parms.link,
749 .proto = IPPROTO_IPV6 };
750 struct rtable *rt;
751 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
752 tdev = rt->u.dst.dev;
753 ip_rt_put(rt);
754 }
755 dev->flags |= IFF_POINTOPOINT;
756 }
757
758 if (!tdev && tunnel->parms.link)
759 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
760
761 if (tdev) {
762 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
763 dev->mtu = tdev->mtu - sizeof(struct iphdr);
764 if (dev->mtu < IPV6_MIN_MTU)
765 dev->mtu = IPV6_MIN_MTU;
766 }
767 dev->iflink = tunnel->parms.link;
768 }
769
770 static int
771 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
772 {
773 int err = 0;
774 struct ip_tunnel_parm p;
775 struct ip_tunnel_prl prl;
776 struct ip_tunnel *t;
777 struct net *net = dev_net(dev);
778 struct sit_net *sitn = net_generic(net, sit_net_id);
779
780 switch (cmd) {
781 case SIOCGETTUNNEL:
782 t = NULL;
783 if (dev == sitn->fb_tunnel_dev) {
784 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
785 err = -EFAULT;
786 break;
787 }
788 t = ipip6_tunnel_locate(net, &p, 0);
789 }
790 if (t == NULL)
791 t = netdev_priv(dev);
792 memcpy(&p, &t->parms, sizeof(p));
793 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
794 err = -EFAULT;
795 break;
796
797 case SIOCADDTUNNEL:
798 case SIOCCHGTUNNEL:
799 err = -EPERM;
800 if (!capable(CAP_NET_ADMIN))
801 goto done;
802
803 err = -EFAULT;
804 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
805 goto done;
806
807 err = -EINVAL;
808 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
809 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
810 goto done;
811 if (p.iph.ttl)
812 p.iph.frag_off |= htons(IP_DF);
813
814 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
815
816 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
817 if (t != NULL) {
818 if (t->dev != dev) {
819 err = -EEXIST;
820 break;
821 }
822 } else {
823 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
824 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
825 err = -EINVAL;
826 break;
827 }
828 t = netdev_priv(dev);
829 ipip6_tunnel_unlink(sitn, t);
830 t->parms.iph.saddr = p.iph.saddr;
831 t->parms.iph.daddr = p.iph.daddr;
832 memcpy(dev->dev_addr, &p.iph.saddr, 4);
833 memcpy(dev->broadcast, &p.iph.daddr, 4);
834 ipip6_tunnel_link(sitn, t);
835 netdev_state_change(dev);
836 }
837 }
838
839 if (t) {
840 err = 0;
841 if (cmd == SIOCCHGTUNNEL) {
842 t->parms.iph.ttl = p.iph.ttl;
843 t->parms.iph.tos = p.iph.tos;
844 if (t->parms.link != p.link) {
845 t->parms.link = p.link;
846 ipip6_tunnel_bind_dev(dev);
847 netdev_state_change(dev);
848 }
849 }
850 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
851 err = -EFAULT;
852 } else
853 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
854 break;
855
856 case SIOCDELTUNNEL:
857 err = -EPERM;
858 if (!capable(CAP_NET_ADMIN))
859 goto done;
860
861 if (dev == sitn->fb_tunnel_dev) {
862 err = -EFAULT;
863 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
864 goto done;
865 err = -ENOENT;
866 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
867 goto done;
868 err = -EPERM;
869 if (t == netdev_priv(sitn->fb_tunnel_dev))
870 goto done;
871 dev = t->dev;
872 }
873 unregister_netdevice(dev);
874 err = 0;
875 break;
876
877 case SIOCGETPRL:
878 err = -EINVAL;
879 if (dev == sitn->fb_tunnel_dev)
880 goto done;
881 err = -ENOENT;
882 if (!(t = netdev_priv(dev)))
883 goto done;
884 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
885 break;
886
887 case SIOCADDPRL:
888 case SIOCDELPRL:
889 case SIOCCHGPRL:
890 err = -EPERM;
891 if (!capable(CAP_NET_ADMIN))
892 goto done;
893 err = -EINVAL;
894 if (dev == sitn->fb_tunnel_dev)
895 goto done;
896 err = -EFAULT;
897 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
898 goto done;
899 err = -ENOENT;
900 if (!(t = netdev_priv(dev)))
901 goto done;
902
903 switch (cmd) {
904 case SIOCDELPRL:
905 err = ipip6_tunnel_del_prl(t, &prl);
906 break;
907 case SIOCADDPRL:
908 case SIOCCHGPRL:
909 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
910 break;
911 }
912 netdev_state_change(dev);
913 break;
914
915 default:
916 err = -EINVAL;
917 }
918
919 done:
920 return err;
921 }
922
923 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
924 {
925 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
926 return -EINVAL;
927 dev->mtu = new_mtu;
928 return 0;
929 }
930
931 static const struct net_device_ops ipip6_netdev_ops = {
932 .ndo_uninit = ipip6_tunnel_uninit,
933 .ndo_start_xmit = ipip6_tunnel_xmit,
934 .ndo_do_ioctl = ipip6_tunnel_ioctl,
935 .ndo_change_mtu = ipip6_tunnel_change_mtu,
936 };
937
938 static void ipip6_tunnel_setup(struct net_device *dev)
939 {
940 dev->netdev_ops = &ipip6_netdev_ops;
941 dev->destructor = free_netdev;
942
943 dev->type = ARPHRD_SIT;
944 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
945 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
946 dev->flags = IFF_NOARP;
947 dev->iflink = 0;
948 dev->addr_len = 4;
949 dev->features |= NETIF_F_NETNS_LOCAL;
950 }
951
952 static void ipip6_tunnel_init(struct net_device *dev)
953 {
954 struct ip_tunnel *tunnel = netdev_priv(dev);
955
956 tunnel->dev = dev;
957 strcpy(tunnel->parms.name, dev->name);
958
959 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
960 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
961
962 ipip6_tunnel_bind_dev(dev);
963 }
964
965 static void ipip6_fb_tunnel_init(struct net_device *dev)
966 {
967 struct ip_tunnel *tunnel = netdev_priv(dev);
968 struct iphdr *iph = &tunnel->parms.iph;
969 struct net *net = dev_net(dev);
970 struct sit_net *sitn = net_generic(net, sit_net_id);
971
972 tunnel->dev = dev;
973 strcpy(tunnel->parms.name, dev->name);
974
975 iph->version = 4;
976 iph->protocol = IPPROTO_IPV6;
977 iph->ihl = 5;
978 iph->ttl = 64;
979
980 dev_hold(dev);
981 sitn->tunnels_wc[0] = tunnel;
982 }
983
984 static struct xfrm_tunnel sit_handler = {
985 .handler = ipip6_rcv,
986 .err_handler = ipip6_err,
987 .priority = 1,
988 };
989
990 static void sit_destroy_tunnels(struct sit_net *sitn)
991 {
992 int prio;
993
994 for (prio = 1; prio < 4; prio++) {
995 int h;
996 for (h = 0; h < HASH_SIZE; h++) {
997 struct ip_tunnel *t;
998 while ((t = sitn->tunnels[prio][h]) != NULL)
999 unregister_netdevice(t->dev);
1000 }
1001 }
1002 }
1003
1004 static int sit_init_net(struct net *net)
1005 {
1006 int err;
1007 struct sit_net *sitn;
1008
1009 err = -ENOMEM;
1010 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL);
1011 if (sitn == NULL)
1012 goto err_alloc;
1013
1014 err = net_assign_generic(net, sit_net_id, sitn);
1015 if (err < 0)
1016 goto err_assign;
1017
1018 sitn->tunnels[0] = sitn->tunnels_wc;
1019 sitn->tunnels[1] = sitn->tunnels_l;
1020 sitn->tunnels[2] = sitn->tunnels_r;
1021 sitn->tunnels[3] = sitn->tunnels_r_l;
1022
1023 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1024 ipip6_tunnel_setup);
1025 if (!sitn->fb_tunnel_dev) {
1026 err = -ENOMEM;
1027 goto err_alloc_dev;
1028 }
1029 dev_net_set(sitn->fb_tunnel_dev, net);
1030
1031 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1032
1033 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1034 goto err_reg_dev;
1035
1036 return 0;
1037
1038 err_reg_dev:
1039 dev_put(sitn->fb_tunnel_dev);
1040 free_netdev(sitn->fb_tunnel_dev);
1041 err_alloc_dev:
1042 /* nothing */
1043 err_assign:
1044 kfree(sitn);
1045 err_alloc:
1046 return err;
1047 }
1048
1049 static void sit_exit_net(struct net *net)
1050 {
1051 struct sit_net *sitn;
1052
1053 sitn = net_generic(net, sit_net_id);
1054 rtnl_lock();
1055 sit_destroy_tunnels(sitn);
1056 unregister_netdevice(sitn->fb_tunnel_dev);
1057 rtnl_unlock();
1058 kfree(sitn);
1059 }
1060
1061 static struct pernet_operations sit_net_ops = {
1062 .init = sit_init_net,
1063 .exit = sit_exit_net,
1064 };
1065
1066 static void __exit sit_cleanup(void)
1067 {
1068 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1069
1070 unregister_pernet_gen_device(sit_net_id, &sit_net_ops);
1071 }
1072
1073 static int __init sit_init(void)
1074 {
1075 int err;
1076
1077 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1078
1079 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) {
1080 printk(KERN_INFO "sit init: Can't add protocol\n");
1081 return -EAGAIN;
1082 }
1083
1084 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops);
1085 if (err < 0)
1086 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1087
1088 return err;
1089 }
1090
1091 module_init(sit_init);
1092 module_exit(sit_cleanup);
1093 MODULE_LICENSE("GPL");
1094 MODULE_ALIAS("sit0");