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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/module.h>
23#include <linux/capability.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/in6.h>
30#include <linux/netdevice.h>
31#include <linux/if_arp.h>
32#include <linux/icmp.h>
33#include <linux/slab.h>
34#include <asm/uaccess.h>
35#include <linux/init.h>
36#include <linux/netfilter_ipv4.h>
37#include <linux/if_ether.h>
38
39#include <net/sock.h>
40#include <net/snmp.h>
41
42#include <net/ipv6.h>
43#include <net/protocol.h>
44#include <net/transp_v6.h>
45#include <net/ip6_fib.h>
46#include <net/ip6_route.h>
47#include <net/ndisc.h>
48#include <net/addrconf.h>
49#include <net/ip.h>
50#include <net/udp.h>
51#include <net/icmp.h>
52#include <net/ipip.h>
53#include <net/inet_ecn.h>
54#include <net/xfrm.h>
55#include <net/dsfield.h>
56#include <net/net_namespace.h>
57#include <net/netns/generic.h>
58
59/*
60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
61
62 For comments look at net/ipv4/ip_gre.c --ANK
63 */
64
65#define HASH_SIZE 16
66#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
67
68static int ipip6_tunnel_init(struct net_device *dev);
69static void ipip6_tunnel_setup(struct net_device *dev);
70static void ipip6_dev_free(struct net_device *dev);
71
72static int sit_net_id __read_mostly;
73struct sit_net {
74 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
75 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
76 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
77 struct ip_tunnel __rcu *tunnels_wc[1];
78 struct ip_tunnel __rcu **tunnels[4];
79
80 struct net_device *fb_tunnel_dev;
81};
82
83/*
84 * Locking : hash tables are protected by RCU and RTNL
85 */
86
87#define for_each_ip_tunnel_rcu(start) \
88 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
89
90/* often modified stats are per cpu, other are shared (netdev->stats) */
91struct pcpu_tstats {
92 u64 rx_packets;
93 u64 rx_bytes;
94 u64 tx_packets;
95 u64 tx_bytes;
96 struct u64_stats_sync syncp;
97};
98
99static struct rtnl_link_stats64 *ipip6_get_stats64(struct net_device *dev,
100 struct rtnl_link_stats64 *tot)
101{
102 int i;
103
104 for_each_possible_cpu(i) {
105 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
106 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
107 unsigned int start;
108
109 do {
110 start = u64_stats_fetch_begin_bh(&tstats->syncp);
111 rx_packets = tstats->rx_packets;
112 tx_packets = tstats->tx_packets;
113 rx_bytes = tstats->rx_bytes;
114 tx_bytes = tstats->tx_bytes;
115 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
116
117 tot->rx_packets += rx_packets;
118 tot->tx_packets += tx_packets;
119 tot->rx_bytes += rx_bytes;
120 tot->tx_bytes += tx_bytes;
121 }
122
123 tot->rx_errors = dev->stats.rx_errors;
124 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
125 tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
126 tot->tx_dropped = dev->stats.tx_dropped;
127 tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
128 tot->tx_errors = dev->stats.tx_errors;
129
130 return tot;
131}
132
133/*
134 * Must be invoked with rcu_read_lock
135 */
136static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
137 struct net_device *dev, __be32 remote, __be32 local)
138{
139 unsigned int h0 = HASH(remote);
140 unsigned int h1 = HASH(local);
141 struct ip_tunnel *t;
142 struct sit_net *sitn = net_generic(net, sit_net_id);
143
144 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
145 if (local == t->parms.iph.saddr &&
146 remote == t->parms.iph.daddr &&
147 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
148 (t->dev->flags & IFF_UP))
149 return t;
150 }
151 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
152 if (remote == t->parms.iph.daddr &&
153 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
154 (t->dev->flags & IFF_UP))
155 return t;
156 }
157 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
158 if (local == t->parms.iph.saddr &&
159 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
160 (t->dev->flags & IFF_UP))
161 return t;
162 }
163 t = rcu_dereference(sitn->tunnels_wc[0]);
164 if ((t != NULL) && (t->dev->flags & IFF_UP))
165 return t;
166 return NULL;
167}
168
169static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
170 struct ip_tunnel_parm *parms)
171{
172 __be32 remote = parms->iph.daddr;
173 __be32 local = parms->iph.saddr;
174 unsigned int h = 0;
175 int prio = 0;
176
177 if (remote) {
178 prio |= 2;
179 h ^= HASH(remote);
180 }
181 if (local) {
182 prio |= 1;
183 h ^= HASH(local);
184 }
185 return &sitn->tunnels[prio][h];
186}
187
188static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
189 struct ip_tunnel *t)
190{
191 return __ipip6_bucket(sitn, &t->parms);
192}
193
194static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
195{
196 struct ip_tunnel __rcu **tp;
197 struct ip_tunnel *iter;
198
199 for (tp = ipip6_bucket(sitn, t);
200 (iter = rtnl_dereference(*tp)) != NULL;
201 tp = &iter->next) {
202 if (t == iter) {
203 rcu_assign_pointer(*tp, t->next);
204 break;
205 }
206 }
207}
208
209static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
210{
211 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
212
213 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
214 rcu_assign_pointer(*tp, t);
215}
216
217static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
218{
219#ifdef CONFIG_IPV6_SIT_6RD
220 struct ip_tunnel *t = netdev_priv(dev);
221
222 if (t->dev == sitn->fb_tunnel_dev) {
223 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
224 t->ip6rd.relay_prefix = 0;
225 t->ip6rd.prefixlen = 16;
226 t->ip6rd.relay_prefixlen = 0;
227 } else {
228 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
229 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
230 }
231#endif
232}
233
234static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
235 struct ip_tunnel_parm *parms, int create)
236{
237 __be32 remote = parms->iph.daddr;
238 __be32 local = parms->iph.saddr;
239 struct ip_tunnel *t, *nt;
240 struct ip_tunnel __rcu **tp;
241 struct net_device *dev;
242 char name[IFNAMSIZ];
243 struct sit_net *sitn = net_generic(net, sit_net_id);
244
245 for (tp = __ipip6_bucket(sitn, parms);
246 (t = rtnl_dereference(*tp)) != NULL;
247 tp = &t->next) {
248 if (local == t->parms.iph.saddr &&
249 remote == t->parms.iph.daddr &&
250 parms->link == t->parms.link) {
251 if (create)
252 return NULL;
253 else
254 return t;
255 }
256 }
257 if (!create)
258 goto failed;
259
260 if (parms->name[0])
261 strlcpy(name, parms->name, IFNAMSIZ);
262 else
263 strcpy(name, "sit%d");
264
265 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
266 if (dev == NULL)
267 return NULL;
268
269 dev_net_set(dev, net);
270
271 nt = netdev_priv(dev);
272
273 nt->parms = *parms;
274 if (ipip6_tunnel_init(dev) < 0)
275 goto failed_free;
276 ipip6_tunnel_clone_6rd(dev, sitn);
277
278 if (parms->i_flags & SIT_ISATAP)
279 dev->priv_flags |= IFF_ISATAP;
280
281 if (register_netdevice(dev) < 0)
282 goto failed_free;
283
284 strcpy(nt->parms.name, dev->name);
285
286 dev_hold(dev);
287
288 ipip6_tunnel_link(sitn, nt);
289 return nt;
290
291failed_free:
292 ipip6_dev_free(dev);
293failed:
294 return NULL;
295}
296
297#define for_each_prl_rcu(start) \
298 for (prl = rcu_dereference(start); \
299 prl; \
300 prl = rcu_dereference(prl->next))
301
302static struct ip_tunnel_prl_entry *
303__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
304{
305 struct ip_tunnel_prl_entry *prl;
306
307 for_each_prl_rcu(t->prl)
308 if (prl->addr == addr)
309 break;
310 return prl;
311
312}
313
314static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
315 struct ip_tunnel_prl __user *a)
316{
317 struct ip_tunnel_prl kprl, *kp;
318 struct ip_tunnel_prl_entry *prl;
319 unsigned int cmax, c = 0, ca, len;
320 int ret = 0;
321
322 if (copy_from_user(&kprl, a, sizeof(kprl)))
323 return -EFAULT;
324 cmax = kprl.datalen / sizeof(kprl);
325 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
326 cmax = 1;
327
328 /* For simple GET or for root users,
329 * we try harder to allocate.
330 */
331 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
332 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
333 NULL;
334
335 rcu_read_lock();
336
337 ca = t->prl_count < cmax ? t->prl_count : cmax;
338
339 if (!kp) {
340 /* We don't try hard to allocate much memory for
341 * non-root users.
342 * For root users, retry allocating enough memory for
343 * the answer.
344 */
345 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
346 if (!kp) {
347 ret = -ENOMEM;
348 goto out;
349 }
350 }
351
352 c = 0;
353 for_each_prl_rcu(t->prl) {
354 if (c >= cmax)
355 break;
356 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
357 continue;
358 kp[c].addr = prl->addr;
359 kp[c].flags = prl->flags;
360 c++;
361 if (kprl.addr != htonl(INADDR_ANY))
362 break;
363 }
364out:
365 rcu_read_unlock();
366
367 len = sizeof(*kp) * c;
368 ret = 0;
369 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
370 ret = -EFAULT;
371
372 kfree(kp);
373
374 return ret;
375}
376
377static int
378ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
379{
380 struct ip_tunnel_prl_entry *p;
381 int err = 0;
382
383 if (a->addr == htonl(INADDR_ANY))
384 return -EINVAL;
385
386 ASSERT_RTNL();
387
388 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
389 if (p->addr == a->addr) {
390 if (chg) {
391 p->flags = a->flags;
392 goto out;
393 }
394 err = -EEXIST;
395 goto out;
396 }
397 }
398
399 if (chg) {
400 err = -ENXIO;
401 goto out;
402 }
403
404 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
405 if (!p) {
406 err = -ENOBUFS;
407 goto out;
408 }
409
410 p->next = t->prl;
411 p->addr = a->addr;
412 p->flags = a->flags;
413 t->prl_count++;
414 rcu_assign_pointer(t->prl, p);
415out:
416 return err;
417}
418
419static void prl_list_destroy_rcu(struct rcu_head *head)
420{
421 struct ip_tunnel_prl_entry *p, *n;
422
423 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
424 do {
425 n = rcu_dereference_protected(p->next, 1);
426 kfree(p);
427 p = n;
428 } while (p);
429}
430
431static int
432ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
433{
434 struct ip_tunnel_prl_entry *x;
435 struct ip_tunnel_prl_entry __rcu **p;
436 int err = 0;
437
438 ASSERT_RTNL();
439
440 if (a && a->addr != htonl(INADDR_ANY)) {
441 for (p = &t->prl;
442 (x = rtnl_dereference(*p)) != NULL;
443 p = &x->next) {
444 if (x->addr == a->addr) {
445 *p = x->next;
446 kfree_rcu(x, rcu_head);
447 t->prl_count--;
448 goto out;
449 }
450 }
451 err = -ENXIO;
452 } else {
453 x = rtnl_dereference(t->prl);
454 if (x) {
455 t->prl_count = 0;
456 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
457 t->prl = NULL;
458 }
459 }
460out:
461 return err;
462}
463
464static int
465isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
466{
467 struct ip_tunnel_prl_entry *p;
468 int ok = 1;
469
470 rcu_read_lock();
471 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
472 if (p) {
473 if (p->flags & PRL_DEFAULT)
474 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
475 else
476 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
477 } else {
478 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
479
480 if (ipv6_addr_is_isatap(addr6) &&
481 (addr6->s6_addr32[3] == iph->saddr) &&
482 ipv6_chk_prefix(addr6, t->dev))
483 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
484 else
485 ok = 0;
486 }
487 rcu_read_unlock();
488 return ok;
489}
490
491static void ipip6_tunnel_uninit(struct net_device *dev)
492{
493 struct net *net = dev_net(dev);
494 struct sit_net *sitn = net_generic(net, sit_net_id);
495
496 if (dev == sitn->fb_tunnel_dev) {
497 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
498 } else {
499 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
500 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
501 }
502 dev_put(dev);
503}
504
505
506static int ipip6_err(struct sk_buff *skb, u32 info)
507{
508
509/* All the routers (except for Linux) return only
510 8 bytes of packet payload. It means, that precise relaying of
511 ICMP in the real Internet is absolutely infeasible.
512 */
513 const struct iphdr *iph = (const struct iphdr *)skb->data;
514 const int type = icmp_hdr(skb)->type;
515 const int code = icmp_hdr(skb)->code;
516 struct ip_tunnel *t;
517 int err;
518
519 switch (type) {
520 default:
521 case ICMP_PARAMETERPROB:
522 return 0;
523
524 case ICMP_DEST_UNREACH:
525 switch (code) {
526 case ICMP_SR_FAILED:
527 case ICMP_PORT_UNREACH:
528 /* Impossible event. */
529 return 0;
530 case ICMP_FRAG_NEEDED:
531 /* Soft state for pmtu is maintained by IP core. */
532 return 0;
533 default:
534 /* All others are translated to HOST_UNREACH.
535 rfc2003 contains "deep thoughts" about NET_UNREACH,
536 I believe they are just ether pollution. --ANK
537 */
538 break;
539 }
540 break;
541 case ICMP_TIME_EXCEEDED:
542 if (code != ICMP_EXC_TTL)
543 return 0;
544 break;
545 }
546
547 err = -ENOENT;
548
549 rcu_read_lock();
550 t = ipip6_tunnel_lookup(dev_net(skb->dev),
551 skb->dev,
552 iph->daddr,
553 iph->saddr);
554 if (t == NULL || t->parms.iph.daddr == 0)
555 goto out;
556
557 err = 0;
558 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
559 goto out;
560
561 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
562 t->err_count++;
563 else
564 t->err_count = 1;
565 t->err_time = jiffies;
566out:
567 rcu_read_unlock();
568 return err;
569}
570
571static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
572{
573 if (INET_ECN_is_ce(iph->tos))
574 IP6_ECN_set_ce(ipv6_hdr(skb));
575}
576
577static int ipip6_rcv(struct sk_buff *skb)
578{
579 const struct iphdr *iph;
580 struct ip_tunnel *tunnel;
581
582 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
583 goto out;
584
585 iph = ip_hdr(skb);
586
587 rcu_read_lock();
588 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
589 iph->saddr, iph->daddr);
590 if (tunnel != NULL) {
591 struct pcpu_tstats *tstats;
592
593 secpath_reset(skb);
594 skb->mac_header = skb->network_header;
595 skb_reset_network_header(skb);
596 IPCB(skb)->flags = 0;
597 skb->protocol = htons(ETH_P_IPV6);
598 skb->pkt_type = PACKET_HOST;
599
600 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
601 !isatap_chksrc(skb, iph, tunnel)) {
602 tunnel->dev->stats.rx_errors++;
603 rcu_read_unlock();
604 kfree_skb(skb);
605 return 0;
606 }
607
608 tstats = this_cpu_ptr(tunnel->dev->tstats);
609 tstats->rx_packets++;
610 tstats->rx_bytes += skb->len;
611
612 __skb_tunnel_rx(skb, tunnel->dev);
613
614 ipip6_ecn_decapsulate(iph, skb);
615
616 netif_rx(skb);
617
618 rcu_read_unlock();
619 return 0;
620 }
621
622 /* no tunnel matched, let upstream know, ipsec may handle it */
623 rcu_read_unlock();
624 return 1;
625out:
626 kfree_skb(skb);
627 return 0;
628}
629
630/*
631 * Returns the embedded IPv4 address if the IPv6 address
632 * comes from 6rd / 6to4 (RFC 3056) addr space.
633 */
634static inline
635__be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel)
636{
637 __be32 dst = 0;
638
639#ifdef CONFIG_IPV6_SIT_6RD
640 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
641 tunnel->ip6rd.prefixlen)) {
642 unsigned int pbw0, pbi0;
643 int pbi1;
644 u32 d;
645
646 pbw0 = tunnel->ip6rd.prefixlen >> 5;
647 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
648
649 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
650 tunnel->ip6rd.relay_prefixlen;
651
652 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
653 if (pbi1 > 0)
654 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
655 (32 - pbi1);
656
657 dst = tunnel->ip6rd.relay_prefix | htonl(d);
658 }
659#else
660 if (v6dst->s6_addr16[0] == htons(0x2002)) {
661 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
662 memcpy(&dst, &v6dst->s6_addr16[1], 4);
663 }
664#endif
665 return dst;
666}
667
668/*
669 * This function assumes it is being called from dev_queue_xmit()
670 * and that skb is filled properly by that function.
671 */
672
673static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
674 struct net_device *dev)
675{
676 struct ip_tunnel *tunnel = netdev_priv(dev);
677 struct pcpu_tstats *tstats;
678 const struct iphdr *tiph = &tunnel->parms.iph;
679 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
680 u8 tos = tunnel->parms.iph.tos;
681 __be16 df = tiph->frag_off;
682 struct rtable *rt; /* Route to the other host */
683 struct net_device *tdev; /* Device to other host */
684 struct iphdr *iph; /* Our new IP header */
685 unsigned int max_headroom; /* The extra header space needed */
686 __be32 dst = tiph->daddr;
687 struct flowi4 fl4;
688 int mtu;
689 const struct in6_addr *addr6;
690 int addr_type;
691
692 if (skb->protocol != htons(ETH_P_IPV6))
693 goto tx_error;
694
695 if (tos == 1)
696 tos = ipv6_get_dsfield(iph6);
697
698 /* ISATAP (RFC4214) - must come before 6to4 */
699 if (dev->priv_flags & IFF_ISATAP) {
700 struct neighbour *neigh = NULL;
701 bool do_tx_error = false;
702
703 if (skb_dst(skb))
704 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
705
706 if (neigh == NULL) {
707 net_dbg_ratelimited("sit: nexthop == NULL\n");
708 goto tx_error;
709 }
710
711 addr6 = (const struct in6_addr *)&neigh->primary_key;
712 addr_type = ipv6_addr_type(addr6);
713
714 if ((addr_type & IPV6_ADDR_UNICAST) &&
715 ipv6_addr_is_isatap(addr6))
716 dst = addr6->s6_addr32[3];
717 else
718 do_tx_error = true;
719
720 neigh_release(neigh);
721 if (do_tx_error)
722 goto tx_error;
723 }
724
725 if (!dst)
726 dst = try_6rd(&iph6->daddr, tunnel);
727
728 if (!dst) {
729 struct neighbour *neigh = NULL;
730 bool do_tx_error = false;
731
732 if (skb_dst(skb))
733 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
734
735 if (neigh == NULL) {
736 net_dbg_ratelimited("sit: nexthop == NULL\n");
737 goto tx_error;
738 }
739
740 addr6 = (const struct in6_addr *)&neigh->primary_key;
741 addr_type = ipv6_addr_type(addr6);
742
743 if (addr_type == IPV6_ADDR_ANY) {
744 addr6 = &ipv6_hdr(skb)->daddr;
745 addr_type = ipv6_addr_type(addr6);
746 }
747
748 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
749 dst = addr6->s6_addr32[3];
750 else
751 do_tx_error = true;
752
753 neigh_release(neigh);
754 if (do_tx_error)
755 goto tx_error;
756 }
757
758 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
759 dst, tiph->saddr,
760 0, 0,
761 IPPROTO_IPV6, RT_TOS(tos),
762 tunnel->parms.link);
763 if (IS_ERR(rt)) {
764 dev->stats.tx_carrier_errors++;
765 goto tx_error_icmp;
766 }
767 if (rt->rt_type != RTN_UNICAST) {
768 ip_rt_put(rt);
769 dev->stats.tx_carrier_errors++;
770 goto tx_error_icmp;
771 }
772 tdev = rt->dst.dev;
773
774 if (tdev == dev) {
775 ip_rt_put(rt);
776 dev->stats.collisions++;
777 goto tx_error;
778 }
779
780 if (df) {
781 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
782
783 if (mtu < 68) {
784 dev->stats.collisions++;
785 ip_rt_put(rt);
786 goto tx_error;
787 }
788
789 if (mtu < IPV6_MIN_MTU) {
790 mtu = IPV6_MIN_MTU;
791 df = 0;
792 }
793
794 if (tunnel->parms.iph.daddr && skb_dst(skb))
795 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
796
797 if (skb->len > mtu) {
798 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
799 ip_rt_put(rt);
800 goto tx_error;
801 }
802 }
803
804 if (tunnel->err_count > 0) {
805 if (time_before(jiffies,
806 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
807 tunnel->err_count--;
808 dst_link_failure(skb);
809 } else
810 tunnel->err_count = 0;
811 }
812
813 /*
814 * Okay, now see if we can stuff it in the buffer as-is.
815 */
816 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
817
818 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
819 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
820 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
821 if (!new_skb) {
822 ip_rt_put(rt);
823 dev->stats.tx_dropped++;
824 dev_kfree_skb(skb);
825 return NETDEV_TX_OK;
826 }
827 if (skb->sk)
828 skb_set_owner_w(new_skb, skb->sk);
829 dev_kfree_skb(skb);
830 skb = new_skb;
831 iph6 = ipv6_hdr(skb);
832 }
833
834 skb->transport_header = skb->network_header;
835 skb_push(skb, sizeof(struct iphdr));
836 skb_reset_network_header(skb);
837 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
838 IPCB(skb)->flags = 0;
839 skb_dst_drop(skb);
840 skb_dst_set(skb, &rt->dst);
841
842 /*
843 * Push down and install the IPIP header.
844 */
845
846 iph = ip_hdr(skb);
847 iph->version = 4;
848 iph->ihl = sizeof(struct iphdr)>>2;
849 iph->frag_off = df;
850 iph->protocol = IPPROTO_IPV6;
851 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
852 iph->daddr = fl4.daddr;
853 iph->saddr = fl4.saddr;
854
855 if ((iph->ttl = tiph->ttl) == 0)
856 iph->ttl = iph6->hop_limit;
857
858 nf_reset(skb);
859 tstats = this_cpu_ptr(dev->tstats);
860 __IPTUNNEL_XMIT(tstats, &dev->stats);
861 return NETDEV_TX_OK;
862
863tx_error_icmp:
864 dst_link_failure(skb);
865tx_error:
866 dev->stats.tx_errors++;
867 dev_kfree_skb(skb);
868 return NETDEV_TX_OK;
869}
870
871static void ipip6_tunnel_bind_dev(struct net_device *dev)
872{
873 struct net_device *tdev = NULL;
874 struct ip_tunnel *tunnel;
875 const struct iphdr *iph;
876 struct flowi4 fl4;
877
878 tunnel = netdev_priv(dev);
879 iph = &tunnel->parms.iph;
880
881 if (iph->daddr) {
882 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
883 iph->daddr, iph->saddr,
884 0, 0,
885 IPPROTO_IPV6,
886 RT_TOS(iph->tos),
887 tunnel->parms.link);
888
889 if (!IS_ERR(rt)) {
890 tdev = rt->dst.dev;
891 ip_rt_put(rt);
892 }
893 dev->flags |= IFF_POINTOPOINT;
894 }
895
896 if (!tdev && tunnel->parms.link)
897 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
898
899 if (tdev) {
900 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
901 dev->mtu = tdev->mtu - sizeof(struct iphdr);
902 if (dev->mtu < IPV6_MIN_MTU)
903 dev->mtu = IPV6_MIN_MTU;
904 }
905 dev->iflink = tunnel->parms.link;
906}
907
908static int
909ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
910{
911 int err = 0;
912 struct ip_tunnel_parm p;
913 struct ip_tunnel_prl prl;
914 struct ip_tunnel *t;
915 struct net *net = dev_net(dev);
916 struct sit_net *sitn = net_generic(net, sit_net_id);
917#ifdef CONFIG_IPV6_SIT_6RD
918 struct ip_tunnel_6rd ip6rd;
919#endif
920
921 switch (cmd) {
922 case SIOCGETTUNNEL:
923#ifdef CONFIG_IPV6_SIT_6RD
924 case SIOCGET6RD:
925#endif
926 t = NULL;
927 if (dev == sitn->fb_tunnel_dev) {
928 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
929 err = -EFAULT;
930 break;
931 }
932 t = ipip6_tunnel_locate(net, &p, 0);
933 }
934 if (t == NULL)
935 t = netdev_priv(dev);
936
937 err = -EFAULT;
938 if (cmd == SIOCGETTUNNEL) {
939 memcpy(&p, &t->parms, sizeof(p));
940 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
941 sizeof(p)))
942 goto done;
943#ifdef CONFIG_IPV6_SIT_6RD
944 } else {
945 ip6rd.prefix = t->ip6rd.prefix;
946 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
947 ip6rd.prefixlen = t->ip6rd.prefixlen;
948 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
949 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
950 sizeof(ip6rd)))
951 goto done;
952#endif
953 }
954 err = 0;
955 break;
956
957 case SIOCADDTUNNEL:
958 case SIOCCHGTUNNEL:
959 err = -EPERM;
960 if (!capable(CAP_NET_ADMIN))
961 goto done;
962
963 err = -EFAULT;
964 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
965 goto done;
966
967 err = -EINVAL;
968 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
969 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
970 goto done;
971 if (p.iph.ttl)
972 p.iph.frag_off |= htons(IP_DF);
973
974 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
975
976 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
977 if (t != NULL) {
978 if (t->dev != dev) {
979 err = -EEXIST;
980 break;
981 }
982 } else {
983 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
984 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
985 err = -EINVAL;
986 break;
987 }
988 t = netdev_priv(dev);
989 ipip6_tunnel_unlink(sitn, t);
990 synchronize_net();
991 t->parms.iph.saddr = p.iph.saddr;
992 t->parms.iph.daddr = p.iph.daddr;
993 memcpy(dev->dev_addr, &p.iph.saddr, 4);
994 memcpy(dev->broadcast, &p.iph.daddr, 4);
995 ipip6_tunnel_link(sitn, t);
996 netdev_state_change(dev);
997 }
998 }
999
1000 if (t) {
1001 err = 0;
1002 if (cmd == SIOCCHGTUNNEL) {
1003 t->parms.iph.ttl = p.iph.ttl;
1004 t->parms.iph.tos = p.iph.tos;
1005 if (t->parms.link != p.link) {
1006 t->parms.link = p.link;
1007 ipip6_tunnel_bind_dev(dev);
1008 netdev_state_change(dev);
1009 }
1010 }
1011 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1012 err = -EFAULT;
1013 } else
1014 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1015 break;
1016
1017 case SIOCDELTUNNEL:
1018 err = -EPERM;
1019 if (!capable(CAP_NET_ADMIN))
1020 goto done;
1021
1022 if (dev == sitn->fb_tunnel_dev) {
1023 err = -EFAULT;
1024 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1025 goto done;
1026 err = -ENOENT;
1027 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1028 goto done;
1029 err = -EPERM;
1030 if (t == netdev_priv(sitn->fb_tunnel_dev))
1031 goto done;
1032 dev = t->dev;
1033 }
1034 unregister_netdevice(dev);
1035 err = 0;
1036 break;
1037
1038 case SIOCGETPRL:
1039 err = -EINVAL;
1040 if (dev == sitn->fb_tunnel_dev)
1041 goto done;
1042 err = -ENOENT;
1043 if (!(t = netdev_priv(dev)))
1044 goto done;
1045 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1046 break;
1047
1048 case SIOCADDPRL:
1049 case SIOCDELPRL:
1050 case SIOCCHGPRL:
1051 err = -EPERM;
1052 if (!capable(CAP_NET_ADMIN))
1053 goto done;
1054 err = -EINVAL;
1055 if (dev == sitn->fb_tunnel_dev)
1056 goto done;
1057 err = -EFAULT;
1058 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1059 goto done;
1060 err = -ENOENT;
1061 if (!(t = netdev_priv(dev)))
1062 goto done;
1063
1064 switch (cmd) {
1065 case SIOCDELPRL:
1066 err = ipip6_tunnel_del_prl(t, &prl);
1067 break;
1068 case SIOCADDPRL:
1069 case SIOCCHGPRL:
1070 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1071 break;
1072 }
1073 netdev_state_change(dev);
1074 break;
1075
1076#ifdef CONFIG_IPV6_SIT_6RD
1077 case SIOCADD6RD:
1078 case SIOCCHG6RD:
1079 case SIOCDEL6RD:
1080 err = -EPERM;
1081 if (!capable(CAP_NET_ADMIN))
1082 goto done;
1083
1084 err = -EFAULT;
1085 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1086 sizeof(ip6rd)))
1087 goto done;
1088
1089 t = netdev_priv(dev);
1090
1091 if (cmd != SIOCDEL6RD) {
1092 struct in6_addr prefix;
1093 __be32 relay_prefix;
1094
1095 err = -EINVAL;
1096 if (ip6rd.relay_prefixlen > 32 ||
1097 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1098 goto done;
1099
1100 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1101 ip6rd.prefixlen);
1102 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1103 goto done;
1104 if (ip6rd.relay_prefixlen)
1105 relay_prefix = ip6rd.relay_prefix &
1106 htonl(0xffffffffUL <<
1107 (32 - ip6rd.relay_prefixlen));
1108 else
1109 relay_prefix = 0;
1110 if (relay_prefix != ip6rd.relay_prefix)
1111 goto done;
1112
1113 t->ip6rd.prefix = prefix;
1114 t->ip6rd.relay_prefix = relay_prefix;
1115 t->ip6rd.prefixlen = ip6rd.prefixlen;
1116 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1117 } else
1118 ipip6_tunnel_clone_6rd(dev, sitn);
1119
1120 err = 0;
1121 break;
1122#endif
1123
1124 default:
1125 err = -EINVAL;
1126 }
1127
1128done:
1129 return err;
1130}
1131
1132static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1133{
1134 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1135 return -EINVAL;
1136 dev->mtu = new_mtu;
1137 return 0;
1138}
1139
1140static const struct net_device_ops ipip6_netdev_ops = {
1141 .ndo_uninit = ipip6_tunnel_uninit,
1142 .ndo_start_xmit = ipip6_tunnel_xmit,
1143 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1144 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1145 .ndo_get_stats64= ipip6_get_stats64,
1146};
1147
1148static void ipip6_dev_free(struct net_device *dev)
1149{
1150 free_percpu(dev->tstats);
1151 free_netdev(dev);
1152}
1153
1154static void ipip6_tunnel_setup(struct net_device *dev)
1155{
1156 dev->netdev_ops = &ipip6_netdev_ops;
1157 dev->destructor = ipip6_dev_free;
1158
1159 dev->type = ARPHRD_SIT;
1160 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1161 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1162 dev->flags = IFF_NOARP;
1163 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1164 dev->iflink = 0;
1165 dev->addr_len = 4;
1166 dev->features |= NETIF_F_NETNS_LOCAL;
1167 dev->features |= NETIF_F_LLTX;
1168}
1169
1170static int ipip6_tunnel_init(struct net_device *dev)
1171{
1172 struct ip_tunnel *tunnel = netdev_priv(dev);
1173
1174 tunnel->dev = dev;
1175
1176 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1177 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1178
1179 ipip6_tunnel_bind_dev(dev);
1180 dev->tstats = alloc_percpu(struct pcpu_tstats);
1181 if (!dev->tstats)
1182 return -ENOMEM;
1183
1184 return 0;
1185}
1186
1187static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1188{
1189 struct ip_tunnel *tunnel = netdev_priv(dev);
1190 struct iphdr *iph = &tunnel->parms.iph;
1191 struct net *net = dev_net(dev);
1192 struct sit_net *sitn = net_generic(net, sit_net_id);
1193
1194 tunnel->dev = dev;
1195 strcpy(tunnel->parms.name, dev->name);
1196
1197 iph->version = 4;
1198 iph->protocol = IPPROTO_IPV6;
1199 iph->ihl = 5;
1200 iph->ttl = 64;
1201
1202 dev->tstats = alloc_percpu(struct pcpu_tstats);
1203 if (!dev->tstats)
1204 return -ENOMEM;
1205 dev_hold(dev);
1206 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1207 return 0;
1208}
1209
1210static struct xfrm_tunnel sit_handler __read_mostly = {
1211 .handler = ipip6_rcv,
1212 .err_handler = ipip6_err,
1213 .priority = 1,
1214};
1215
1216static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1217{
1218 int prio;
1219
1220 for (prio = 1; prio < 4; prio++) {
1221 int h;
1222 for (h = 0; h < HASH_SIZE; h++) {
1223 struct ip_tunnel *t;
1224
1225 t = rtnl_dereference(sitn->tunnels[prio][h]);
1226 while (t != NULL) {
1227 unregister_netdevice_queue(t->dev, head);
1228 t = rtnl_dereference(t->next);
1229 }
1230 }
1231 }
1232}
1233
1234static int __net_init sit_init_net(struct net *net)
1235{
1236 struct sit_net *sitn = net_generic(net, sit_net_id);
1237 struct ip_tunnel *t;
1238 int err;
1239
1240 sitn->tunnels[0] = sitn->tunnels_wc;
1241 sitn->tunnels[1] = sitn->tunnels_l;
1242 sitn->tunnels[2] = sitn->tunnels_r;
1243 sitn->tunnels[3] = sitn->tunnels_r_l;
1244
1245 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1246 ipip6_tunnel_setup);
1247 if (!sitn->fb_tunnel_dev) {
1248 err = -ENOMEM;
1249 goto err_alloc_dev;
1250 }
1251 dev_net_set(sitn->fb_tunnel_dev, net);
1252
1253 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1254 if (err)
1255 goto err_dev_free;
1256
1257 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1258
1259 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1260 goto err_reg_dev;
1261
1262 t = netdev_priv(sitn->fb_tunnel_dev);
1263
1264 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1265 return 0;
1266
1267err_reg_dev:
1268 dev_put(sitn->fb_tunnel_dev);
1269err_dev_free:
1270 ipip6_dev_free(sitn->fb_tunnel_dev);
1271err_alloc_dev:
1272 return err;
1273}
1274
1275static void __net_exit sit_exit_net(struct net *net)
1276{
1277 struct sit_net *sitn = net_generic(net, sit_net_id);
1278 LIST_HEAD(list);
1279
1280 rtnl_lock();
1281 sit_destroy_tunnels(sitn, &list);
1282 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1283 unregister_netdevice_many(&list);
1284 rtnl_unlock();
1285}
1286
1287static struct pernet_operations sit_net_ops = {
1288 .init = sit_init_net,
1289 .exit = sit_exit_net,
1290 .id = &sit_net_id,
1291 .size = sizeof(struct sit_net),
1292};
1293
1294static void __exit sit_cleanup(void)
1295{
1296 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1297
1298 unregister_pernet_device(&sit_net_ops);
1299 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1300}
1301
1302static int __init sit_init(void)
1303{
1304 int err;
1305
1306 pr_info("IPv6 over IPv4 tunneling driver\n");
1307
1308 err = register_pernet_device(&sit_net_ops);
1309 if (err < 0)
1310 return err;
1311 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1312 if (err < 0) {
1313 unregister_pernet_device(&sit_net_ops);
1314 pr_info("%s: can't add protocol\n", __func__);
1315 }
1316 return err;
1317}
1318
1319module_init(sit_init);
1320module_exit(sit_cleanup);
1321MODULE_LICENSE("GPL");
1322MODULE_ALIAS_NETDEV("sit0");