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ipv6: get rid of ipip6_prl_lock
[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / sit.c
1 /*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
8 *
9 * 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 <linux/slab.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_tunnel_init(struct net_device *dev);
67 static void ipip6_tunnel_setup(struct net_device *dev);
68
69 static int sit_net_id __read_mostly;
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 /*
81 * Locking : hash tables are protected by RCU and a spinlock
82 */
83 static DEFINE_SPINLOCK(ipip6_lock);
84
85 #define for_each_ip_tunnel_rcu(start) \
86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
87
88 /*
89 * Must be invoked with rcu_read_lock
90 */
91 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
92 struct net_device *dev, __be32 remote, __be32 local)
93 {
94 unsigned h0 = HASH(remote);
95 unsigned h1 = HASH(local);
96 struct ip_tunnel *t;
97 struct sit_net *sitn = net_generic(net, sit_net_id);
98
99 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
100 if (local == t->parms.iph.saddr &&
101 remote == t->parms.iph.daddr &&
102 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
103 (t->dev->flags & IFF_UP))
104 return t;
105 }
106 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
107 if (remote == t->parms.iph.daddr &&
108 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
109 (t->dev->flags & IFF_UP))
110 return t;
111 }
112 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
113 if (local == t->parms.iph.saddr &&
114 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
115 (t->dev->flags & IFF_UP))
116 return t;
117 }
118 t = rcu_dereference(sitn->tunnels_wc[0]);
119 if ((t != NULL) && (t->dev->flags & IFF_UP))
120 return t;
121 return NULL;
122 }
123
124 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn,
125 struct ip_tunnel_parm *parms)
126 {
127 __be32 remote = parms->iph.daddr;
128 __be32 local = parms->iph.saddr;
129 unsigned h = 0;
130 int prio = 0;
131
132 if (remote) {
133 prio |= 2;
134 h ^= HASH(remote);
135 }
136 if (local) {
137 prio |= 1;
138 h ^= HASH(local);
139 }
140 return &sitn->tunnels[prio][h];
141 }
142
143 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn,
144 struct ip_tunnel *t)
145 {
146 return __ipip6_bucket(sitn, &t->parms);
147 }
148
149 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
150 {
151 struct ip_tunnel **tp;
152
153 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) {
154 if (t == *tp) {
155 spin_lock_bh(&ipip6_lock);
156 *tp = t->next;
157 spin_unlock_bh(&ipip6_lock);
158 break;
159 }
160 }
161 }
162
163 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
164 {
165 struct ip_tunnel **tp = ipip6_bucket(sitn, t);
166
167 spin_lock_bh(&ipip6_lock);
168 t->next = *tp;
169 rcu_assign_pointer(*tp, t);
170 spin_unlock_bh(&ipip6_lock);
171 }
172
173 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
174 {
175 #ifdef CONFIG_IPV6_SIT_6RD
176 struct ip_tunnel *t = netdev_priv(dev);
177
178 if (t->dev == sitn->fb_tunnel_dev) {
179 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
180 t->ip6rd.relay_prefix = 0;
181 t->ip6rd.prefixlen = 16;
182 t->ip6rd.relay_prefixlen = 0;
183 } else {
184 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
185 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
186 }
187 #endif
188 }
189
190 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
191 struct ip_tunnel_parm *parms, int create)
192 {
193 __be32 remote = parms->iph.daddr;
194 __be32 local = parms->iph.saddr;
195 struct ip_tunnel *t, **tp, *nt;
196 struct net_device *dev;
197 char name[IFNAMSIZ];
198 struct sit_net *sitn = net_generic(net, sit_net_id);
199
200 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) {
201 if (local == t->parms.iph.saddr &&
202 remote == t->parms.iph.daddr &&
203 parms->link == t->parms.link) {
204 if (create)
205 return NULL;
206 else
207 return t;
208 }
209 }
210 if (!create)
211 goto failed;
212
213 if (parms->name[0])
214 strlcpy(name, parms->name, IFNAMSIZ);
215 else
216 sprintf(name, "sit%%d");
217
218 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
219 if (dev == NULL)
220 return NULL;
221
222 dev_net_set(dev, net);
223
224 if (strchr(name, '%')) {
225 if (dev_alloc_name(dev, name) < 0)
226 goto failed_free;
227 }
228
229 nt = netdev_priv(dev);
230
231 nt->parms = *parms;
232 ipip6_tunnel_init(dev);
233 ipip6_tunnel_clone_6rd(dev, sitn);
234
235 if (parms->i_flags & SIT_ISATAP)
236 dev->priv_flags |= IFF_ISATAP;
237
238 if (register_netdevice(dev) < 0)
239 goto failed_free;
240
241 dev_hold(dev);
242
243 ipip6_tunnel_link(sitn, nt);
244 return nt;
245
246 failed_free:
247 free_netdev(dev);
248 failed:
249 return NULL;
250 }
251
252 #define for_each_prl_rcu(start) \
253 for (prl = rcu_dereference(start); \
254 prl; \
255 prl = rcu_dereference(prl->next))
256
257 static struct ip_tunnel_prl_entry *
258 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
259 {
260 struct ip_tunnel_prl_entry *prl;
261
262 for_each_prl_rcu(t->prl)
263 if (prl->addr == addr)
264 break;
265 return prl;
266
267 }
268
269 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
270 struct ip_tunnel_prl __user *a)
271 {
272 struct ip_tunnel_prl kprl, *kp;
273 struct ip_tunnel_prl_entry *prl;
274 unsigned int cmax, c = 0, ca, len;
275 int ret = 0;
276
277 if (copy_from_user(&kprl, a, sizeof(kprl)))
278 return -EFAULT;
279 cmax = kprl.datalen / sizeof(kprl);
280 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
281 cmax = 1;
282
283 /* For simple GET or for root users,
284 * we try harder to allocate.
285 */
286 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
287 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
288 NULL;
289
290 rcu_read_lock();
291
292 ca = t->prl_count < cmax ? t->prl_count : cmax;
293
294 if (!kp) {
295 /* We don't try hard to allocate much memory for
296 * non-root users.
297 * For root users, retry allocating enough memory for
298 * the answer.
299 */
300 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
301 if (!kp) {
302 ret = -ENOMEM;
303 goto out;
304 }
305 }
306
307 c = 0;
308 for_each_prl_rcu(t->prl) {
309 if (c >= cmax)
310 break;
311 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
312 continue;
313 kp[c].addr = prl->addr;
314 kp[c].flags = prl->flags;
315 c++;
316 if (kprl.addr != htonl(INADDR_ANY))
317 break;
318 }
319 out:
320 rcu_read_unlock();
321
322 len = sizeof(*kp) * c;
323 ret = 0;
324 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
325 ret = -EFAULT;
326
327 kfree(kp);
328
329 return ret;
330 }
331
332 static int
333 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
334 {
335 struct ip_tunnel_prl_entry *p;
336 int err = 0;
337
338 if (a->addr == htonl(INADDR_ANY))
339 return -EINVAL;
340
341 ASSERT_RTNL();
342
343 for (p = t->prl; p; p = p->next) {
344 if (p->addr == a->addr) {
345 if (chg) {
346 p->flags = a->flags;
347 goto out;
348 }
349 err = -EEXIST;
350 goto out;
351 }
352 }
353
354 if (chg) {
355 err = -ENXIO;
356 goto out;
357 }
358
359 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
360 if (!p) {
361 err = -ENOBUFS;
362 goto out;
363 }
364
365 p->next = t->prl;
366 p->addr = a->addr;
367 p->flags = a->flags;
368 t->prl_count++;
369 rcu_assign_pointer(t->prl, p);
370 out:
371 return err;
372 }
373
374 static void prl_entry_destroy_rcu(struct rcu_head *head)
375 {
376 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head));
377 }
378
379 static void prl_list_destroy_rcu(struct rcu_head *head)
380 {
381 struct ip_tunnel_prl_entry *p, *n;
382
383 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
384 do {
385 n = p->next;
386 kfree(p);
387 p = n;
388 } while (p);
389 }
390
391 static int
392 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
393 {
394 struct ip_tunnel_prl_entry *x, **p;
395 int err = 0;
396
397 ASSERT_RTNL();
398
399 if (a && a->addr != htonl(INADDR_ANY)) {
400 for (p = &t->prl; *p; p = &(*p)->next) {
401 if ((*p)->addr == a->addr) {
402 x = *p;
403 *p = x->next;
404 call_rcu(&x->rcu_head, prl_entry_destroy_rcu);
405 t->prl_count--;
406 goto out;
407 }
408 }
409 err = -ENXIO;
410 } else {
411 if (t->prl) {
412 t->prl_count = 0;
413 x = t->prl;
414 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
415 t->prl = NULL;
416 }
417 }
418 out:
419 return err;
420 }
421
422 static int
423 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
424 {
425 struct ip_tunnel_prl_entry *p;
426 int ok = 1;
427
428 rcu_read_lock();
429 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
430 if (p) {
431 if (p->flags & PRL_DEFAULT)
432 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
433 else
434 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
435 } else {
436 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
437 if (ipv6_addr_is_isatap(addr6) &&
438 (addr6->s6_addr32[3] == iph->saddr) &&
439 ipv6_chk_prefix(addr6, t->dev))
440 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
441 else
442 ok = 0;
443 }
444 rcu_read_unlock();
445 return ok;
446 }
447
448 static void ipip6_tunnel_uninit(struct net_device *dev)
449 {
450 struct net *net = dev_net(dev);
451 struct sit_net *sitn = net_generic(net, sit_net_id);
452
453 if (dev == sitn->fb_tunnel_dev) {
454 spin_lock_bh(&ipip6_lock);
455 sitn->tunnels_wc[0] = NULL;
456 spin_unlock_bh(&ipip6_lock);
457 dev_put(dev);
458 } else {
459 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
460 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
461 dev_put(dev);
462 }
463 }
464
465
466 static int ipip6_err(struct sk_buff *skb, u32 info)
467 {
468
469 /* All the routers (except for Linux) return only
470 8 bytes of packet payload. It means, that precise relaying of
471 ICMP in the real Internet is absolutely infeasible.
472 */
473 struct iphdr *iph = (struct iphdr*)skb->data;
474 const int type = icmp_hdr(skb)->type;
475 const int code = icmp_hdr(skb)->code;
476 struct ip_tunnel *t;
477 int err;
478
479 switch (type) {
480 default:
481 case ICMP_PARAMETERPROB:
482 return 0;
483
484 case ICMP_DEST_UNREACH:
485 switch (code) {
486 case ICMP_SR_FAILED:
487 case ICMP_PORT_UNREACH:
488 /* Impossible event. */
489 return 0;
490 case ICMP_FRAG_NEEDED:
491 /* Soft state for pmtu is maintained by IP core. */
492 return 0;
493 default:
494 /* All others are translated to HOST_UNREACH.
495 rfc2003 contains "deep thoughts" about NET_UNREACH,
496 I believe they are just ether pollution. --ANK
497 */
498 break;
499 }
500 break;
501 case ICMP_TIME_EXCEEDED:
502 if (code != ICMP_EXC_TTL)
503 return 0;
504 break;
505 }
506
507 err = -ENOENT;
508
509 rcu_read_lock();
510 t = ipip6_tunnel_lookup(dev_net(skb->dev),
511 skb->dev,
512 iph->daddr,
513 iph->saddr);
514 if (t == NULL || t->parms.iph.daddr == 0)
515 goto out;
516
517 err = 0;
518 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
519 goto out;
520
521 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
522 t->err_count++;
523 else
524 t->err_count = 1;
525 t->err_time = jiffies;
526 out:
527 rcu_read_unlock();
528 return err;
529 }
530
531 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
532 {
533 if (INET_ECN_is_ce(iph->tos))
534 IP6_ECN_set_ce(ipv6_hdr(skb));
535 }
536
537 static int ipip6_rcv(struct sk_buff *skb)
538 {
539 struct iphdr *iph;
540 struct ip_tunnel *tunnel;
541
542 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
543 goto out;
544
545 iph = ip_hdr(skb);
546
547 rcu_read_lock();
548 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
549 iph->saddr, iph->daddr);
550 if (tunnel != NULL) {
551 secpath_reset(skb);
552 skb->mac_header = skb->network_header;
553 skb_reset_network_header(skb);
554 IPCB(skb)->flags = 0;
555 skb->protocol = htons(ETH_P_IPV6);
556 skb->pkt_type = PACKET_HOST;
557
558 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
559 !isatap_chksrc(skb, iph, tunnel)) {
560 tunnel->dev->stats.rx_errors++;
561 rcu_read_unlock();
562 kfree_skb(skb);
563 return 0;
564 }
565
566 skb_tunnel_rx(skb, tunnel->dev);
567
568 ipip6_ecn_decapsulate(iph, skb);
569 netif_rx(skb);
570 rcu_read_unlock();
571 return 0;
572 }
573
574 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
575 rcu_read_unlock();
576 out:
577 kfree_skb(skb);
578 return 0;
579 }
580
581 /*
582 * Returns the embedded IPv4 address if the IPv6 address
583 * comes from 6rd / 6to4 (RFC 3056) addr space.
584 */
585 static inline
586 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
587 {
588 __be32 dst = 0;
589
590 #ifdef CONFIG_IPV6_SIT_6RD
591 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
592 tunnel->ip6rd.prefixlen)) {
593 unsigned pbw0, pbi0;
594 int pbi1;
595 u32 d;
596
597 pbw0 = tunnel->ip6rd.prefixlen >> 5;
598 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
599
600 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
601 tunnel->ip6rd.relay_prefixlen;
602
603 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
604 if (pbi1 > 0)
605 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
606 (32 - pbi1);
607
608 dst = tunnel->ip6rd.relay_prefix | htonl(d);
609 }
610 #else
611 if (v6dst->s6_addr16[0] == htons(0x2002)) {
612 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
613 memcpy(&dst, &v6dst->s6_addr16[1], 4);
614 }
615 #endif
616 return dst;
617 }
618
619 /*
620 * This function assumes it is being called from dev_queue_xmit()
621 * and that skb is filled properly by that function.
622 */
623
624 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
625 struct net_device *dev)
626 {
627 struct ip_tunnel *tunnel = netdev_priv(dev);
628 struct net_device_stats *stats = &dev->stats;
629 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
630 struct iphdr *tiph = &tunnel->parms.iph;
631 struct ipv6hdr *iph6 = ipv6_hdr(skb);
632 u8 tos = tunnel->parms.iph.tos;
633 __be16 df = tiph->frag_off;
634 struct rtable *rt; /* Route to the other host */
635 struct net_device *tdev; /* Device to other host */
636 struct iphdr *iph; /* Our new IP header */
637 unsigned int max_headroom; /* The extra header space needed */
638 __be32 dst = tiph->daddr;
639 int mtu;
640 struct in6_addr *addr6;
641 int addr_type;
642
643 if (skb->protocol != htons(ETH_P_IPV6))
644 goto tx_error;
645
646 /* ISATAP (RFC4214) - must come before 6to4 */
647 if (dev->priv_flags & IFF_ISATAP) {
648 struct neighbour *neigh = NULL;
649
650 if (skb_dst(skb))
651 neigh = skb_dst(skb)->neighbour;
652
653 if (neigh == NULL) {
654 if (net_ratelimit())
655 printk(KERN_DEBUG "sit: nexthop == NULL\n");
656 goto tx_error;
657 }
658
659 addr6 = (struct in6_addr*)&neigh->primary_key;
660 addr_type = ipv6_addr_type(addr6);
661
662 if ((addr_type & IPV6_ADDR_UNICAST) &&
663 ipv6_addr_is_isatap(addr6))
664 dst = addr6->s6_addr32[3];
665 else
666 goto tx_error;
667 }
668
669 if (!dst)
670 dst = try_6rd(&iph6->daddr, tunnel);
671
672 if (!dst) {
673 struct neighbour *neigh = NULL;
674
675 if (skb_dst(skb))
676 neigh = skb_dst(skb)->neighbour;
677
678 if (neigh == NULL) {
679 if (net_ratelimit())
680 printk(KERN_DEBUG "sit: nexthop == NULL\n");
681 goto tx_error;
682 }
683
684 addr6 = (struct in6_addr*)&neigh->primary_key;
685 addr_type = ipv6_addr_type(addr6);
686
687 if (addr_type == IPV6_ADDR_ANY) {
688 addr6 = &ipv6_hdr(skb)->daddr;
689 addr_type = ipv6_addr_type(addr6);
690 }
691
692 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
693 goto tx_error_icmp;
694
695 dst = addr6->s6_addr32[3];
696 }
697
698 {
699 struct flowi fl = { .nl_u = { .ip4_u =
700 { .daddr = dst,
701 .saddr = tiph->saddr,
702 .tos = RT_TOS(tos) } },
703 .oif = tunnel->parms.link,
704 .proto = IPPROTO_IPV6 };
705 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
706 stats->tx_carrier_errors++;
707 goto tx_error_icmp;
708 }
709 }
710 if (rt->rt_type != RTN_UNICAST) {
711 ip_rt_put(rt);
712 stats->tx_carrier_errors++;
713 goto tx_error_icmp;
714 }
715 tdev = rt->u.dst.dev;
716
717 if (tdev == dev) {
718 ip_rt_put(rt);
719 stats->collisions++;
720 goto tx_error;
721 }
722
723 if (df) {
724 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
725
726 if (mtu < 68) {
727 stats->collisions++;
728 ip_rt_put(rt);
729 goto tx_error;
730 }
731
732 if (mtu < IPV6_MIN_MTU) {
733 mtu = IPV6_MIN_MTU;
734 df = 0;
735 }
736
737 if (tunnel->parms.iph.daddr && skb_dst(skb))
738 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
739
740 if (skb->len > mtu) {
741 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
742 ip_rt_put(rt);
743 goto tx_error;
744 }
745 }
746
747 if (tunnel->err_count > 0) {
748 if (time_before(jiffies,
749 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
750 tunnel->err_count--;
751 dst_link_failure(skb);
752 } else
753 tunnel->err_count = 0;
754 }
755
756 /*
757 * Okay, now see if we can stuff it in the buffer as-is.
758 */
759 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
760
761 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
762 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
763 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
764 if (!new_skb) {
765 ip_rt_put(rt);
766 txq->tx_dropped++;
767 dev_kfree_skb(skb);
768 return NETDEV_TX_OK;
769 }
770 if (skb->sk)
771 skb_set_owner_w(new_skb, skb->sk);
772 dev_kfree_skb(skb);
773 skb = new_skb;
774 iph6 = ipv6_hdr(skb);
775 }
776
777 skb->transport_header = skb->network_header;
778 skb_push(skb, sizeof(struct iphdr));
779 skb_reset_network_header(skb);
780 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
781 IPCB(skb)->flags = 0;
782 skb_dst_drop(skb);
783 skb_dst_set(skb, &rt->u.dst);
784
785 /*
786 * Push down and install the IPIP header.
787 */
788
789 iph = ip_hdr(skb);
790 iph->version = 4;
791 iph->ihl = sizeof(struct iphdr)>>2;
792 iph->frag_off = df;
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 return NETDEV_TX_OK;
805
806 tx_error_icmp:
807 dst_link_failure(skb);
808 tx_error:
809 stats->tx_errors++;
810 dev_kfree_skb(skb);
811 return NETDEV_TX_OK;
812 }
813
814 static void ipip6_tunnel_bind_dev(struct net_device *dev)
815 {
816 struct net_device *tdev = NULL;
817 struct ip_tunnel *tunnel;
818 struct iphdr *iph;
819
820 tunnel = netdev_priv(dev);
821 iph = &tunnel->parms.iph;
822
823 if (iph->daddr) {
824 struct flowi fl = { .nl_u = { .ip4_u =
825 { .daddr = iph->daddr,
826 .saddr = iph->saddr,
827 .tos = RT_TOS(iph->tos) } },
828 .oif = tunnel->parms.link,
829 .proto = IPPROTO_IPV6 };
830 struct rtable *rt;
831 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
832 tdev = rt->u.dst.dev;
833 ip_rt_put(rt);
834 }
835 dev->flags |= IFF_POINTOPOINT;
836 }
837
838 if (!tdev && tunnel->parms.link)
839 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
840
841 if (tdev) {
842 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
843 dev->mtu = tdev->mtu - sizeof(struct iphdr);
844 if (dev->mtu < IPV6_MIN_MTU)
845 dev->mtu = IPV6_MIN_MTU;
846 }
847 dev->iflink = tunnel->parms.link;
848 }
849
850 static int
851 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
852 {
853 int err = 0;
854 struct ip_tunnel_parm p;
855 struct ip_tunnel_prl prl;
856 struct ip_tunnel *t;
857 struct net *net = dev_net(dev);
858 struct sit_net *sitn = net_generic(net, sit_net_id);
859 #ifdef CONFIG_IPV6_SIT_6RD
860 struct ip_tunnel_6rd ip6rd;
861 #endif
862
863 switch (cmd) {
864 case SIOCGETTUNNEL:
865 #ifdef CONFIG_IPV6_SIT_6RD
866 case SIOCGET6RD:
867 #endif
868 t = NULL;
869 if (dev == sitn->fb_tunnel_dev) {
870 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
871 err = -EFAULT;
872 break;
873 }
874 t = ipip6_tunnel_locate(net, &p, 0);
875 }
876 if (t == NULL)
877 t = netdev_priv(dev);
878
879 err = -EFAULT;
880 if (cmd == SIOCGETTUNNEL) {
881 memcpy(&p, &t->parms, sizeof(p));
882 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
883 sizeof(p)))
884 goto done;
885 #ifdef CONFIG_IPV6_SIT_6RD
886 } else {
887 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
888 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
889 ip6rd.prefixlen = t->ip6rd.prefixlen;
890 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
891 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
892 sizeof(ip6rd)))
893 goto done;
894 #endif
895 }
896 err = 0;
897 break;
898
899 case SIOCADDTUNNEL:
900 case SIOCCHGTUNNEL:
901 err = -EPERM;
902 if (!capable(CAP_NET_ADMIN))
903 goto done;
904
905 err = -EFAULT;
906 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
907 goto done;
908
909 err = -EINVAL;
910 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
911 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
912 goto done;
913 if (p.iph.ttl)
914 p.iph.frag_off |= htons(IP_DF);
915
916 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
917
918 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
919 if (t != NULL) {
920 if (t->dev != dev) {
921 err = -EEXIST;
922 break;
923 }
924 } else {
925 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
926 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
927 err = -EINVAL;
928 break;
929 }
930 t = netdev_priv(dev);
931 ipip6_tunnel_unlink(sitn, t);
932 t->parms.iph.saddr = p.iph.saddr;
933 t->parms.iph.daddr = p.iph.daddr;
934 memcpy(dev->dev_addr, &p.iph.saddr, 4);
935 memcpy(dev->broadcast, &p.iph.daddr, 4);
936 ipip6_tunnel_link(sitn, t);
937 netdev_state_change(dev);
938 }
939 }
940
941 if (t) {
942 err = 0;
943 if (cmd == SIOCCHGTUNNEL) {
944 t->parms.iph.ttl = p.iph.ttl;
945 t->parms.iph.tos = p.iph.tos;
946 if (t->parms.link != p.link) {
947 t->parms.link = p.link;
948 ipip6_tunnel_bind_dev(dev);
949 netdev_state_change(dev);
950 }
951 }
952 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
953 err = -EFAULT;
954 } else
955 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
956 break;
957
958 case SIOCDELTUNNEL:
959 err = -EPERM;
960 if (!capable(CAP_NET_ADMIN))
961 goto done;
962
963 if (dev == sitn->fb_tunnel_dev) {
964 err = -EFAULT;
965 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
966 goto done;
967 err = -ENOENT;
968 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
969 goto done;
970 err = -EPERM;
971 if (t == netdev_priv(sitn->fb_tunnel_dev))
972 goto done;
973 dev = t->dev;
974 }
975 unregister_netdevice(dev);
976 err = 0;
977 break;
978
979 case SIOCGETPRL:
980 err = -EINVAL;
981 if (dev == sitn->fb_tunnel_dev)
982 goto done;
983 err = -ENOENT;
984 if (!(t = netdev_priv(dev)))
985 goto done;
986 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
987 break;
988
989 case SIOCADDPRL:
990 case SIOCDELPRL:
991 case SIOCCHGPRL:
992 err = -EPERM;
993 if (!capable(CAP_NET_ADMIN))
994 goto done;
995 err = -EINVAL;
996 if (dev == sitn->fb_tunnel_dev)
997 goto done;
998 err = -EFAULT;
999 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1000 goto done;
1001 err = -ENOENT;
1002 if (!(t = netdev_priv(dev)))
1003 goto done;
1004
1005 switch (cmd) {
1006 case SIOCDELPRL:
1007 err = ipip6_tunnel_del_prl(t, &prl);
1008 break;
1009 case SIOCADDPRL:
1010 case SIOCCHGPRL:
1011 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1012 break;
1013 }
1014 netdev_state_change(dev);
1015 break;
1016
1017 #ifdef CONFIG_IPV6_SIT_6RD
1018 case SIOCADD6RD:
1019 case SIOCCHG6RD:
1020 case SIOCDEL6RD:
1021 err = -EPERM;
1022 if (!capable(CAP_NET_ADMIN))
1023 goto done;
1024
1025 err = -EFAULT;
1026 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1027 sizeof(ip6rd)))
1028 goto done;
1029
1030 t = netdev_priv(dev);
1031
1032 if (cmd != SIOCDEL6RD) {
1033 struct in6_addr prefix;
1034 __be32 relay_prefix;
1035
1036 err = -EINVAL;
1037 if (ip6rd.relay_prefixlen > 32 ||
1038 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1039 goto done;
1040
1041 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1042 ip6rd.prefixlen);
1043 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1044 goto done;
1045 if (ip6rd.relay_prefixlen)
1046 relay_prefix = ip6rd.relay_prefix &
1047 htonl(0xffffffffUL <<
1048 (32 - ip6rd.relay_prefixlen));
1049 else
1050 relay_prefix = 0;
1051 if (relay_prefix != ip6rd.relay_prefix)
1052 goto done;
1053
1054 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1055 t->ip6rd.relay_prefix = relay_prefix;
1056 t->ip6rd.prefixlen = ip6rd.prefixlen;
1057 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1058 } else
1059 ipip6_tunnel_clone_6rd(dev, sitn);
1060
1061 err = 0;
1062 break;
1063 #endif
1064
1065 default:
1066 err = -EINVAL;
1067 }
1068
1069 done:
1070 return err;
1071 }
1072
1073 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1074 {
1075 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1076 return -EINVAL;
1077 dev->mtu = new_mtu;
1078 return 0;
1079 }
1080
1081 static const struct net_device_ops ipip6_netdev_ops = {
1082 .ndo_uninit = ipip6_tunnel_uninit,
1083 .ndo_start_xmit = ipip6_tunnel_xmit,
1084 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1085 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1086 };
1087
1088 static void ipip6_tunnel_setup(struct net_device *dev)
1089 {
1090 dev->netdev_ops = &ipip6_netdev_ops;
1091 dev->destructor = free_netdev;
1092
1093 dev->type = ARPHRD_SIT;
1094 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1095 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1096 dev->flags = IFF_NOARP;
1097 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1098 dev->iflink = 0;
1099 dev->addr_len = 4;
1100 dev->features |= NETIF_F_NETNS_LOCAL;
1101 }
1102
1103 static void ipip6_tunnel_init(struct net_device *dev)
1104 {
1105 struct ip_tunnel *tunnel = netdev_priv(dev);
1106
1107 tunnel->dev = dev;
1108 strcpy(tunnel->parms.name, dev->name);
1109
1110 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1111 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1112
1113 ipip6_tunnel_bind_dev(dev);
1114 }
1115
1116 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1117 {
1118 struct ip_tunnel *tunnel = netdev_priv(dev);
1119 struct iphdr *iph = &tunnel->parms.iph;
1120 struct net *net = dev_net(dev);
1121 struct sit_net *sitn = net_generic(net, sit_net_id);
1122
1123 tunnel->dev = dev;
1124 strcpy(tunnel->parms.name, dev->name);
1125
1126 iph->version = 4;
1127 iph->protocol = IPPROTO_IPV6;
1128 iph->ihl = 5;
1129 iph->ttl = 64;
1130
1131 dev_hold(dev);
1132 sitn->tunnels_wc[0] = tunnel;
1133 }
1134
1135 static struct xfrm_tunnel sit_handler = {
1136 .handler = ipip6_rcv,
1137 .err_handler = ipip6_err,
1138 .priority = 1,
1139 };
1140
1141 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1142 {
1143 int prio;
1144
1145 for (prio = 1; prio < 4; prio++) {
1146 int h;
1147 for (h = 0; h < HASH_SIZE; h++) {
1148 struct ip_tunnel *t = sitn->tunnels[prio][h];
1149
1150 while (t != NULL) {
1151 unregister_netdevice_queue(t->dev, head);
1152 t = t->next;
1153 }
1154 }
1155 }
1156 }
1157
1158 static int __net_init sit_init_net(struct net *net)
1159 {
1160 struct sit_net *sitn = net_generic(net, sit_net_id);
1161 int err;
1162
1163 sitn->tunnels[0] = sitn->tunnels_wc;
1164 sitn->tunnels[1] = sitn->tunnels_l;
1165 sitn->tunnels[2] = sitn->tunnels_r;
1166 sitn->tunnels[3] = sitn->tunnels_r_l;
1167
1168 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1169 ipip6_tunnel_setup);
1170 if (!sitn->fb_tunnel_dev) {
1171 err = -ENOMEM;
1172 goto err_alloc_dev;
1173 }
1174 dev_net_set(sitn->fb_tunnel_dev, net);
1175
1176 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1177 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1178
1179 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1180 goto err_reg_dev;
1181
1182 return 0;
1183
1184 err_reg_dev:
1185 dev_put(sitn->fb_tunnel_dev);
1186 free_netdev(sitn->fb_tunnel_dev);
1187 err_alloc_dev:
1188 return err;
1189 }
1190
1191 static void __net_exit sit_exit_net(struct net *net)
1192 {
1193 struct sit_net *sitn = net_generic(net, sit_net_id);
1194 LIST_HEAD(list);
1195
1196 rtnl_lock();
1197 sit_destroy_tunnels(sitn, &list);
1198 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1199 unregister_netdevice_many(&list);
1200 rtnl_unlock();
1201 }
1202
1203 static struct pernet_operations sit_net_ops = {
1204 .init = sit_init_net,
1205 .exit = sit_exit_net,
1206 .id = &sit_net_id,
1207 .size = sizeof(struct sit_net),
1208 };
1209
1210 static void __exit sit_cleanup(void)
1211 {
1212 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1213
1214 unregister_pernet_device(&sit_net_ops);
1215 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1216 }
1217
1218 static int __init sit_init(void)
1219 {
1220 int err;
1221
1222 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1223
1224 err = register_pernet_device(&sit_net_ops);
1225 if (err < 0)
1226 return err;
1227 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1228 if (err < 0) {
1229 unregister_pernet_device(&sit_net_ops);
1230 printk(KERN_INFO "sit init: Can't add protocol\n");
1231 }
1232 return err;
1233 }
1234
1235 module_init(sit_init);
1236 module_exit(sit_cleanup);
1237 MODULE_LICENSE("GPL");
1238 MODULE_ALIAS("sit0");
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