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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#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
66static int ipip6_tunnel_init(struct net_device *dev);
67static void ipip6_tunnel_setup(struct net_device *dev);
68static void ipip6_dev_free(struct net_device *dev);
69
70static int sit_net_id __read_mostly;
71struct sit_net {
72 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
73 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
74 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
75 struct ip_tunnel __rcu *tunnels_wc[1];
76 struct ip_tunnel __rcu **tunnels[4];
77
78 struct net_device *fb_tunnel_dev;
79};
80
81/*
82 * Locking : hash tables are protected by RCU and RTNL
83 */
84
85#define for_each_ip_tunnel_rcu(start) \
86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
87
88/* often modified stats are per cpu, other are shared (netdev->stats) */
89struct pcpu_tstats {
90 unsigned long rx_packets;
91 unsigned long rx_bytes;
92 unsigned long tx_packets;
93 unsigned long tx_bytes;
94};
95
96static struct net_device_stats *ipip6_get_stats(struct net_device *dev)
97{
98 struct pcpu_tstats sum = { 0 };
99 int i;
100
101 for_each_possible_cpu(i) {
102 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
103
104 sum.rx_packets += tstats->rx_packets;
105 sum.rx_bytes += tstats->rx_bytes;
106 sum.tx_packets += tstats->tx_packets;
107 sum.tx_bytes += tstats->tx_bytes;
108 }
109 dev->stats.rx_packets = sum.rx_packets;
110 dev->stats.rx_bytes = sum.rx_bytes;
111 dev->stats.tx_packets = sum.tx_packets;
112 dev->stats.tx_bytes = sum.tx_bytes;
113 return &dev->stats;
114}
115/*
116 * Must be invoked with rcu_read_lock
117 */
118static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
119 struct net_device *dev, __be32 remote, __be32 local)
120{
121 unsigned int h0 = HASH(remote);
122 unsigned int h1 = HASH(local);
123 struct ip_tunnel *t;
124 struct sit_net *sitn = net_generic(net, sit_net_id);
125
126 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
127 if (local == t->parms.iph.saddr &&
128 remote == t->parms.iph.daddr &&
129 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
130 (t->dev->flags & IFF_UP))
131 return t;
132 }
133 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
134 if (remote == t->parms.iph.daddr &&
135 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
136 (t->dev->flags & IFF_UP))
137 return t;
138 }
139 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
140 if (local == t->parms.iph.saddr &&
141 (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
142 (t->dev->flags & IFF_UP))
143 return t;
144 }
145 t = rcu_dereference(sitn->tunnels_wc[0]);
146 if ((t != NULL) && (t->dev->flags & IFF_UP))
147 return t;
148 return NULL;
149}
150
151static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
152 struct ip_tunnel_parm *parms)
153{
154 __be32 remote = parms->iph.daddr;
155 __be32 local = parms->iph.saddr;
156 unsigned int h = 0;
157 int prio = 0;
158
159 if (remote) {
160 prio |= 2;
161 h ^= HASH(remote);
162 }
163 if (local) {
164 prio |= 1;
165 h ^= HASH(local);
166 }
167 return &sitn->tunnels[prio][h];
168}
169
170static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
171 struct ip_tunnel *t)
172{
173 return __ipip6_bucket(sitn, &t->parms);
174}
175
176static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
177{
178 struct ip_tunnel __rcu **tp;
179 struct ip_tunnel *iter;
180
181 for (tp = ipip6_bucket(sitn, t);
182 (iter = rtnl_dereference(*tp)) != NULL;
183 tp = &iter->next) {
184 if (t == iter) {
185 rcu_assign_pointer(*tp, t->next);
186 break;
187 }
188 }
189}
190
191static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
192{
193 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
194
195 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
196 rcu_assign_pointer(*tp, t);
197}
198
199static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
200{
201#ifdef CONFIG_IPV6_SIT_6RD
202 struct ip_tunnel *t = netdev_priv(dev);
203
204 if (t->dev == sitn->fb_tunnel_dev) {
205 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
206 t->ip6rd.relay_prefix = 0;
207 t->ip6rd.prefixlen = 16;
208 t->ip6rd.relay_prefixlen = 0;
209 } else {
210 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
211 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
212 }
213#endif
214}
215
216static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
217 struct ip_tunnel_parm *parms, int create)
218{
219 __be32 remote = parms->iph.daddr;
220 __be32 local = parms->iph.saddr;
221 struct ip_tunnel *t, *nt;
222 struct ip_tunnel __rcu **tp;
223 struct net_device *dev;
224 char name[IFNAMSIZ];
225 struct sit_net *sitn = net_generic(net, sit_net_id);
226
227 for (tp = __ipip6_bucket(sitn, parms);
228 (t = rtnl_dereference(*tp)) != NULL;
229 tp = &t->next) {
230 if (local == t->parms.iph.saddr &&
231 remote == t->parms.iph.daddr &&
232 parms->link == t->parms.link) {
233 if (create)
234 return NULL;
235 else
236 return t;
237 }
238 }
239 if (!create)
240 goto failed;
241
242 if (parms->name[0])
243 strlcpy(name, parms->name, IFNAMSIZ);
244 else
245 strcpy(name, "sit%d");
246
247 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
248 if (dev == NULL)
249 return NULL;
250
251 dev_net_set(dev, net);
252
253 nt = netdev_priv(dev);
254
255 nt->parms = *parms;
256 if (ipip6_tunnel_init(dev) < 0)
257 goto failed_free;
258 ipip6_tunnel_clone_6rd(dev, sitn);
259
260 if (parms->i_flags & SIT_ISATAP)
261 dev->priv_flags |= IFF_ISATAP;
262
263 if (register_netdevice(dev) < 0)
264 goto failed_free;
265
266 dev_hold(dev);
267
268 ipip6_tunnel_link(sitn, nt);
269 return nt;
270
271failed_free:
272 ipip6_dev_free(dev);
273failed:
274 return NULL;
275}
276
277#define for_each_prl_rcu(start) \
278 for (prl = rcu_dereference(start); \
279 prl; \
280 prl = rcu_dereference(prl->next))
281
282static struct ip_tunnel_prl_entry *
283__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
284{
285 struct ip_tunnel_prl_entry *prl;
286
287 for_each_prl_rcu(t->prl)
288 if (prl->addr == addr)
289 break;
290 return prl;
291
292}
293
294static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
295 struct ip_tunnel_prl __user *a)
296{
297 struct ip_tunnel_prl kprl, *kp;
298 struct ip_tunnel_prl_entry *prl;
299 unsigned int cmax, c = 0, ca, len;
300 int ret = 0;
301
302 if (copy_from_user(&kprl, a, sizeof(kprl)))
303 return -EFAULT;
304 cmax = kprl.datalen / sizeof(kprl);
305 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
306 cmax = 1;
307
308 /* For simple GET or for root users,
309 * we try harder to allocate.
310 */
311 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
312 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
313 NULL;
314
315 rcu_read_lock();
316
317 ca = t->prl_count < cmax ? t->prl_count : cmax;
318
319 if (!kp) {
320 /* We don't try hard to allocate much memory for
321 * non-root users.
322 * For root users, retry allocating enough memory for
323 * the answer.
324 */
325 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
326 if (!kp) {
327 ret = -ENOMEM;
328 goto out;
329 }
330 }
331
332 c = 0;
333 for_each_prl_rcu(t->prl) {
334 if (c >= cmax)
335 break;
336 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
337 continue;
338 kp[c].addr = prl->addr;
339 kp[c].flags = prl->flags;
340 c++;
341 if (kprl.addr != htonl(INADDR_ANY))
342 break;
343 }
344out:
345 rcu_read_unlock();
346
347 len = sizeof(*kp) * c;
348 ret = 0;
349 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
350 ret = -EFAULT;
351
352 kfree(kp);
353
354 return ret;
355}
356
357static int
358ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
359{
360 struct ip_tunnel_prl_entry *p;
361 int err = 0;
362
363 if (a->addr == htonl(INADDR_ANY))
364 return -EINVAL;
365
366 ASSERT_RTNL();
367
368 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
369 if (p->addr == a->addr) {
370 if (chg) {
371 p->flags = a->flags;
372 goto out;
373 }
374 err = -EEXIST;
375 goto out;
376 }
377 }
378
379 if (chg) {
380 err = -ENXIO;
381 goto out;
382 }
383
384 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
385 if (!p) {
386 err = -ENOBUFS;
387 goto out;
388 }
389
390 p->next = t->prl;
391 p->addr = a->addr;
392 p->flags = a->flags;
393 t->prl_count++;
394 rcu_assign_pointer(t->prl, p);
395out:
396 return err;
397}
398
399static void prl_list_destroy_rcu(struct rcu_head *head)
400{
401 struct ip_tunnel_prl_entry *p, *n;
402
403 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
404 do {
405 n = rcu_dereference_protected(p->next, 1);
406 kfree(p);
407 p = n;
408 } while (p);
409}
410
411static int
412ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
413{
414 struct ip_tunnel_prl_entry *x;
415 struct ip_tunnel_prl_entry __rcu **p;
416 int err = 0;
417
418 ASSERT_RTNL();
419
420 if (a && a->addr != htonl(INADDR_ANY)) {
421 for (p = &t->prl;
422 (x = rtnl_dereference(*p)) != NULL;
423 p = &x->next) {
424 if (x->addr == a->addr) {
425 *p = x->next;
426 kfree_rcu(x, rcu_head);
427 t->prl_count--;
428 goto out;
429 }
430 }
431 err = -ENXIO;
432 } else {
433 x = rtnl_dereference(t->prl);
434 if (x) {
435 t->prl_count = 0;
436 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
437 t->prl = NULL;
438 }
439 }
440out:
441 return err;
442}
443
444static int
445isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
446{
447 struct ip_tunnel_prl_entry *p;
448 int ok = 1;
449
450 rcu_read_lock();
451 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
452 if (p) {
453 if (p->flags & PRL_DEFAULT)
454 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
455 else
456 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
457 } else {
458 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
459
460 if (ipv6_addr_is_isatap(addr6) &&
461 (addr6->s6_addr32[3] == iph->saddr) &&
462 ipv6_chk_prefix(addr6, t->dev))
463 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
464 else
465 ok = 0;
466 }
467 rcu_read_unlock();
468 return ok;
469}
470
471static void ipip6_tunnel_uninit(struct net_device *dev)
472{
473 struct net *net = dev_net(dev);
474 struct sit_net *sitn = net_generic(net, sit_net_id);
475
476 if (dev == sitn->fb_tunnel_dev) {
477 rcu_assign_pointer(sitn->tunnels_wc[0], NULL);
478 } else {
479 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
480 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
481 }
482 dev_put(dev);
483}
484
485
486static int ipip6_err(struct sk_buff *skb, u32 info)
487{
488
489/* All the routers (except for Linux) return only
490 8 bytes of packet payload. It means, that precise relaying of
491 ICMP in the real Internet is absolutely infeasible.
492 */
493 const struct iphdr *iph = (const struct iphdr *)skb->data;
494 const int type = icmp_hdr(skb)->type;
495 const int code = icmp_hdr(skb)->code;
496 struct ip_tunnel *t;
497 int err;
498
499 switch (type) {
500 default:
501 case ICMP_PARAMETERPROB:
502 return 0;
503
504 case ICMP_DEST_UNREACH:
505 switch (code) {
506 case ICMP_SR_FAILED:
507 case ICMP_PORT_UNREACH:
508 /* Impossible event. */
509 return 0;
510 case ICMP_FRAG_NEEDED:
511 /* Soft state for pmtu is maintained by IP core. */
512 return 0;
513 default:
514 /* All others are translated to HOST_UNREACH.
515 rfc2003 contains "deep thoughts" about NET_UNREACH,
516 I believe they are just ether pollution. --ANK
517 */
518 break;
519 }
520 break;
521 case ICMP_TIME_EXCEEDED:
522 if (code != ICMP_EXC_TTL)
523 return 0;
524 break;
525 }
526
527 err = -ENOENT;
528
529 rcu_read_lock();
530 t = ipip6_tunnel_lookup(dev_net(skb->dev),
531 skb->dev,
532 iph->daddr,
533 iph->saddr);
534 if (t == NULL || t->parms.iph.daddr == 0)
535 goto out;
536
537 err = 0;
538 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
539 goto out;
540
541 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
542 t->err_count++;
543 else
544 t->err_count = 1;
545 t->err_time = jiffies;
546out:
547 rcu_read_unlock();
548 return err;
549}
550
551static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
552{
553 if (INET_ECN_is_ce(iph->tos))
554 IP6_ECN_set_ce(ipv6_hdr(skb));
555}
556
557static int ipip6_rcv(struct sk_buff *skb)
558{
559 const struct iphdr *iph;
560 struct ip_tunnel *tunnel;
561
562 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
563 goto out;
564
565 iph = ip_hdr(skb);
566
567 rcu_read_lock();
568 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
569 iph->saddr, iph->daddr);
570 if (tunnel != NULL) {
571 struct pcpu_tstats *tstats;
572
573 secpath_reset(skb);
574 skb->mac_header = skb->network_header;
575 skb_reset_network_header(skb);
576 IPCB(skb)->flags = 0;
577 skb->protocol = htons(ETH_P_IPV6);
578 skb->pkt_type = PACKET_HOST;
579
580 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
581 !isatap_chksrc(skb, iph, tunnel)) {
582 tunnel->dev->stats.rx_errors++;
583 rcu_read_unlock();
584 kfree_skb(skb);
585 return 0;
586 }
587
588 tstats = this_cpu_ptr(tunnel->dev->tstats);
589 tstats->rx_packets++;
590 tstats->rx_bytes += skb->len;
591
592 __skb_tunnel_rx(skb, tunnel->dev);
593
594 ipip6_ecn_decapsulate(iph, skb);
595
596 netif_rx(skb);
597
598 rcu_read_unlock();
599 return 0;
600 }
601
602 /* no tunnel matched, let upstream know, ipsec may handle it */
603 rcu_read_unlock();
604 return 1;
605out:
606 kfree_skb(skb);
607 return 0;
608}
609
610/*
611 * Returns the embedded IPv4 address if the IPv6 address
612 * comes from 6rd / 6to4 (RFC 3056) addr space.
613 */
614static inline
615__be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel)
616{
617 __be32 dst = 0;
618
619#ifdef CONFIG_IPV6_SIT_6RD
620 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
621 tunnel->ip6rd.prefixlen)) {
622 unsigned int pbw0, pbi0;
623 int pbi1;
624 u32 d;
625
626 pbw0 = tunnel->ip6rd.prefixlen >> 5;
627 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
628
629 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
630 tunnel->ip6rd.relay_prefixlen;
631
632 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
633 if (pbi1 > 0)
634 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
635 (32 - pbi1);
636
637 dst = tunnel->ip6rd.relay_prefix | htonl(d);
638 }
639#else
640 if (v6dst->s6_addr16[0] == htons(0x2002)) {
641 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
642 memcpy(&dst, &v6dst->s6_addr16[1], 4);
643 }
644#endif
645 return dst;
646}
647
648/*
649 * This function assumes it is being called from dev_queue_xmit()
650 * and that skb is filled properly by that function.
651 */
652
653static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
654 struct net_device *dev)
655{
656 struct ip_tunnel *tunnel = netdev_priv(dev);
657 struct pcpu_tstats *tstats;
658 const struct iphdr *tiph = &tunnel->parms.iph;
659 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
660 u8 tos = tunnel->parms.iph.tos;
661 __be16 df = tiph->frag_off;
662 struct rtable *rt; /* Route to the other host */
663 struct net_device *tdev; /* Device to other host */
664 struct iphdr *iph; /* Our new IP header */
665 unsigned int max_headroom; /* The extra header space needed */
666 __be32 dst = tiph->daddr;
667 struct flowi4 fl4;
668 int mtu;
669 const struct in6_addr *addr6;
670 int addr_type;
671
672 if (skb->protocol != htons(ETH_P_IPV6))
673 goto tx_error;
674
675 if (tos == 1)
676 tos = ipv6_get_dsfield(iph6);
677
678 /* ISATAP (RFC4214) - must come before 6to4 */
679 if (dev->priv_flags & IFF_ISATAP) {
680 struct neighbour *neigh = NULL;
681
682 if (skb_dst(skb))
683 neigh = dst_get_neighbour(skb_dst(skb));
684
685 if (neigh == NULL) {
686 if (net_ratelimit())
687 printk(KERN_DEBUG "sit: nexthop == NULL\n");
688 goto tx_error;
689 }
690
691 addr6 = (const struct in6_addr*)&neigh->primary_key;
692 addr_type = ipv6_addr_type(addr6);
693
694 if ((addr_type & IPV6_ADDR_UNICAST) &&
695 ipv6_addr_is_isatap(addr6))
696 dst = addr6->s6_addr32[3];
697 else
698 goto tx_error;
699 }
700
701 if (!dst)
702 dst = try_6rd(&iph6->daddr, tunnel);
703
704 if (!dst) {
705 struct neighbour *neigh = NULL;
706
707 if (skb_dst(skb))
708 neigh = dst_get_neighbour(skb_dst(skb));
709
710 if (neigh == NULL) {
711 if (net_ratelimit())
712 printk(KERN_DEBUG "sit: nexthop == NULL\n");
713 goto tx_error;
714 }
715
716 addr6 = (const struct in6_addr*)&neigh->primary_key;
717 addr_type = ipv6_addr_type(addr6);
718
719 if (addr_type == IPV6_ADDR_ANY) {
720 addr6 = &ipv6_hdr(skb)->daddr;
721 addr_type = ipv6_addr_type(addr6);
722 }
723
724 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
725 goto tx_error_icmp;
726
727 dst = addr6->s6_addr32[3];
728 }
729
730 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
731 dst, tiph->saddr,
732 0, 0,
733 IPPROTO_IPV6, RT_TOS(tos),
734 tunnel->parms.link);
735 if (IS_ERR(rt)) {
736 dev->stats.tx_carrier_errors++;
737 goto tx_error_icmp;
738 }
739 if (rt->rt_type != RTN_UNICAST) {
740 ip_rt_put(rt);
741 dev->stats.tx_carrier_errors++;
742 goto tx_error_icmp;
743 }
744 tdev = rt->dst.dev;
745
746 if (tdev == dev) {
747 ip_rt_put(rt);
748 dev->stats.collisions++;
749 goto tx_error;
750 }
751
752 if (df) {
753 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
754
755 if (mtu < 68) {
756 dev->stats.collisions++;
757 ip_rt_put(rt);
758 goto tx_error;
759 }
760
761 if (mtu < IPV6_MIN_MTU) {
762 mtu = IPV6_MIN_MTU;
763 df = 0;
764 }
765
766 if (tunnel->parms.iph.daddr && skb_dst(skb))
767 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
768
769 if (skb->len > mtu) {
770 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
771 ip_rt_put(rt);
772 goto tx_error;
773 }
774 }
775
776 if (tunnel->err_count > 0) {
777 if (time_before(jiffies,
778 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
779 tunnel->err_count--;
780 dst_link_failure(skb);
781 } else
782 tunnel->err_count = 0;
783 }
784
785 /*
786 * Okay, now see if we can stuff it in the buffer as-is.
787 */
788 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
789
790 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
791 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
792 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
793 if (!new_skb) {
794 ip_rt_put(rt);
795 dev->stats.tx_dropped++;
796 dev_kfree_skb(skb);
797 return NETDEV_TX_OK;
798 }
799 if (skb->sk)
800 skb_set_owner_w(new_skb, skb->sk);
801 dev_kfree_skb(skb);
802 skb = new_skb;
803 iph6 = ipv6_hdr(skb);
804 }
805
806 skb->transport_header = skb->network_header;
807 skb_push(skb, sizeof(struct iphdr));
808 skb_reset_network_header(skb);
809 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
810 IPCB(skb)->flags = 0;
811 skb_dst_drop(skb);
812 skb_dst_set(skb, &rt->dst);
813
814 /*
815 * Push down and install the IPIP header.
816 */
817
818 iph = ip_hdr(skb);
819 iph->version = 4;
820 iph->ihl = sizeof(struct iphdr)>>2;
821 iph->frag_off = df;
822 iph->protocol = IPPROTO_IPV6;
823 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
824 iph->daddr = fl4.daddr;
825 iph->saddr = fl4.saddr;
826
827 if ((iph->ttl = tiph->ttl) == 0)
828 iph->ttl = iph6->hop_limit;
829
830 nf_reset(skb);
831 tstats = this_cpu_ptr(dev->tstats);
832 __IPTUNNEL_XMIT(tstats, &dev->stats);
833 return NETDEV_TX_OK;
834
835tx_error_icmp:
836 dst_link_failure(skb);
837tx_error:
838 dev->stats.tx_errors++;
839 dev_kfree_skb(skb);
840 return NETDEV_TX_OK;
841}
842
843static void ipip6_tunnel_bind_dev(struct net_device *dev)
844{
845 struct net_device *tdev = NULL;
846 struct ip_tunnel *tunnel;
847 const struct iphdr *iph;
848 struct flowi4 fl4;
849
850 tunnel = netdev_priv(dev);
851 iph = &tunnel->parms.iph;
852
853 if (iph->daddr) {
854 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
855 iph->daddr, iph->saddr,
856 0, 0,
857 IPPROTO_IPV6,
858 RT_TOS(iph->tos),
859 tunnel->parms.link);
860
861 if (!IS_ERR(rt)) {
862 tdev = rt->dst.dev;
863 ip_rt_put(rt);
864 }
865 dev->flags |= IFF_POINTOPOINT;
866 }
867
868 if (!tdev && tunnel->parms.link)
869 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
870
871 if (tdev) {
872 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
873 dev->mtu = tdev->mtu - sizeof(struct iphdr);
874 if (dev->mtu < IPV6_MIN_MTU)
875 dev->mtu = IPV6_MIN_MTU;
876 }
877 dev->iflink = tunnel->parms.link;
878}
879
880static int
881ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
882{
883 int err = 0;
884 struct ip_tunnel_parm p;
885 struct ip_tunnel_prl prl;
886 struct ip_tunnel *t;
887 struct net *net = dev_net(dev);
888 struct sit_net *sitn = net_generic(net, sit_net_id);
889#ifdef CONFIG_IPV6_SIT_6RD
890 struct ip_tunnel_6rd ip6rd;
891#endif
892
893 switch (cmd) {
894 case SIOCGETTUNNEL:
895#ifdef CONFIG_IPV6_SIT_6RD
896 case SIOCGET6RD:
897#endif
898 t = NULL;
899 if (dev == sitn->fb_tunnel_dev) {
900 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
901 err = -EFAULT;
902 break;
903 }
904 t = ipip6_tunnel_locate(net, &p, 0);
905 }
906 if (t == NULL)
907 t = netdev_priv(dev);
908
909 err = -EFAULT;
910 if (cmd == SIOCGETTUNNEL) {
911 memcpy(&p, &t->parms, sizeof(p));
912 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
913 sizeof(p)))
914 goto done;
915#ifdef CONFIG_IPV6_SIT_6RD
916 } else {
917 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
918 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
919 ip6rd.prefixlen = t->ip6rd.prefixlen;
920 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
921 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
922 sizeof(ip6rd)))
923 goto done;
924#endif
925 }
926 err = 0;
927 break;
928
929 case SIOCADDTUNNEL:
930 case SIOCCHGTUNNEL:
931 err = -EPERM;
932 if (!capable(CAP_NET_ADMIN))
933 goto done;
934
935 err = -EFAULT;
936 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
937 goto done;
938
939 err = -EINVAL;
940 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
941 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
942 goto done;
943 if (p.iph.ttl)
944 p.iph.frag_off |= htons(IP_DF);
945
946 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
947
948 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
949 if (t != NULL) {
950 if (t->dev != dev) {
951 err = -EEXIST;
952 break;
953 }
954 } else {
955 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
956 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
957 err = -EINVAL;
958 break;
959 }
960 t = netdev_priv(dev);
961 ipip6_tunnel_unlink(sitn, t);
962 synchronize_net();
963 t->parms.iph.saddr = p.iph.saddr;
964 t->parms.iph.daddr = p.iph.daddr;
965 memcpy(dev->dev_addr, &p.iph.saddr, 4);
966 memcpy(dev->broadcast, &p.iph.daddr, 4);
967 ipip6_tunnel_link(sitn, t);
968 netdev_state_change(dev);
969 }
970 }
971
972 if (t) {
973 err = 0;
974 if (cmd == SIOCCHGTUNNEL) {
975 t->parms.iph.ttl = p.iph.ttl;
976 t->parms.iph.tos = p.iph.tos;
977 if (t->parms.link != p.link) {
978 t->parms.link = p.link;
979 ipip6_tunnel_bind_dev(dev);
980 netdev_state_change(dev);
981 }
982 }
983 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
984 err = -EFAULT;
985 } else
986 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
987 break;
988
989 case SIOCDELTUNNEL:
990 err = -EPERM;
991 if (!capable(CAP_NET_ADMIN))
992 goto done;
993
994 if (dev == sitn->fb_tunnel_dev) {
995 err = -EFAULT;
996 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
997 goto done;
998 err = -ENOENT;
999 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1000 goto done;
1001 err = -EPERM;
1002 if (t == netdev_priv(sitn->fb_tunnel_dev))
1003 goto done;
1004 dev = t->dev;
1005 }
1006 unregister_netdevice(dev);
1007 err = 0;
1008 break;
1009
1010 case SIOCGETPRL:
1011 err = -EINVAL;
1012 if (dev == sitn->fb_tunnel_dev)
1013 goto done;
1014 err = -ENOENT;
1015 if (!(t = netdev_priv(dev)))
1016 goto done;
1017 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1018 break;
1019
1020 case SIOCADDPRL:
1021 case SIOCDELPRL:
1022 case SIOCCHGPRL:
1023 err = -EPERM;
1024 if (!capable(CAP_NET_ADMIN))
1025 goto done;
1026 err = -EINVAL;
1027 if (dev == sitn->fb_tunnel_dev)
1028 goto done;
1029 err = -EFAULT;
1030 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1031 goto done;
1032 err = -ENOENT;
1033 if (!(t = netdev_priv(dev)))
1034 goto done;
1035
1036 switch (cmd) {
1037 case SIOCDELPRL:
1038 err = ipip6_tunnel_del_prl(t, &prl);
1039 break;
1040 case SIOCADDPRL:
1041 case SIOCCHGPRL:
1042 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1043 break;
1044 }
1045 netdev_state_change(dev);
1046 break;
1047
1048#ifdef CONFIG_IPV6_SIT_6RD
1049 case SIOCADD6RD:
1050 case SIOCCHG6RD:
1051 case SIOCDEL6RD:
1052 err = -EPERM;
1053 if (!capable(CAP_NET_ADMIN))
1054 goto done;
1055
1056 err = -EFAULT;
1057 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1058 sizeof(ip6rd)))
1059 goto done;
1060
1061 t = netdev_priv(dev);
1062
1063 if (cmd != SIOCDEL6RD) {
1064 struct in6_addr prefix;
1065 __be32 relay_prefix;
1066
1067 err = -EINVAL;
1068 if (ip6rd.relay_prefixlen > 32 ||
1069 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1070 goto done;
1071
1072 ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1073 ip6rd.prefixlen);
1074 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1075 goto done;
1076 if (ip6rd.relay_prefixlen)
1077 relay_prefix = ip6rd.relay_prefix &
1078 htonl(0xffffffffUL <<
1079 (32 - ip6rd.relay_prefixlen));
1080 else
1081 relay_prefix = 0;
1082 if (relay_prefix != ip6rd.relay_prefix)
1083 goto done;
1084
1085 ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1086 t->ip6rd.relay_prefix = relay_prefix;
1087 t->ip6rd.prefixlen = ip6rd.prefixlen;
1088 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1089 } else
1090 ipip6_tunnel_clone_6rd(dev, sitn);
1091
1092 err = 0;
1093 break;
1094#endif
1095
1096 default:
1097 err = -EINVAL;
1098 }
1099
1100done:
1101 return err;
1102}
1103
1104static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1105{
1106 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1107 return -EINVAL;
1108 dev->mtu = new_mtu;
1109 return 0;
1110}
1111
1112static const struct net_device_ops ipip6_netdev_ops = {
1113 .ndo_uninit = ipip6_tunnel_uninit,
1114 .ndo_start_xmit = ipip6_tunnel_xmit,
1115 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1116 .ndo_change_mtu = ipip6_tunnel_change_mtu,
1117 .ndo_get_stats = ipip6_get_stats,
1118};
1119
1120static void ipip6_dev_free(struct net_device *dev)
1121{
1122 free_percpu(dev->tstats);
1123 free_netdev(dev);
1124}
1125
1126static void ipip6_tunnel_setup(struct net_device *dev)
1127{
1128 dev->netdev_ops = &ipip6_netdev_ops;
1129 dev->destructor = ipip6_dev_free;
1130
1131 dev->type = ARPHRD_SIT;
1132 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
1133 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
1134 dev->flags = IFF_NOARP;
1135 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1136 dev->iflink = 0;
1137 dev->addr_len = 4;
1138 dev->features |= NETIF_F_NETNS_LOCAL;
1139 dev->features |= NETIF_F_LLTX;
1140}
1141
1142static int ipip6_tunnel_init(struct net_device *dev)
1143{
1144 struct ip_tunnel *tunnel = netdev_priv(dev);
1145
1146 tunnel->dev = dev;
1147 strcpy(tunnel->parms.name, dev->name);
1148
1149 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1150 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1151
1152 ipip6_tunnel_bind_dev(dev);
1153 dev->tstats = alloc_percpu(struct pcpu_tstats);
1154 if (!dev->tstats)
1155 return -ENOMEM;
1156
1157 return 0;
1158}
1159
1160static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1161{
1162 struct ip_tunnel *tunnel = netdev_priv(dev);
1163 struct iphdr *iph = &tunnel->parms.iph;
1164 struct net *net = dev_net(dev);
1165 struct sit_net *sitn = net_generic(net, sit_net_id);
1166
1167 tunnel->dev = dev;
1168 strcpy(tunnel->parms.name, dev->name);
1169
1170 iph->version = 4;
1171 iph->protocol = IPPROTO_IPV6;
1172 iph->ihl = 5;
1173 iph->ttl = 64;
1174
1175 dev->tstats = alloc_percpu(struct pcpu_tstats);
1176 if (!dev->tstats)
1177 return -ENOMEM;
1178 dev_hold(dev);
1179 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1180 return 0;
1181}
1182
1183static struct xfrm_tunnel sit_handler __read_mostly = {
1184 .handler = ipip6_rcv,
1185 .err_handler = ipip6_err,
1186 .priority = 1,
1187};
1188
1189static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1190{
1191 int prio;
1192
1193 for (prio = 1; prio < 4; prio++) {
1194 int h;
1195 for (h = 0; h < HASH_SIZE; h++) {
1196 struct ip_tunnel *t;
1197
1198 t = rtnl_dereference(sitn->tunnels[prio][h]);
1199 while (t != NULL) {
1200 unregister_netdevice_queue(t->dev, head);
1201 t = rtnl_dereference(t->next);
1202 }
1203 }
1204 }
1205}
1206
1207static int __net_init sit_init_net(struct net *net)
1208{
1209 struct sit_net *sitn = net_generic(net, sit_net_id);
1210 int err;
1211
1212 sitn->tunnels[0] = sitn->tunnels_wc;
1213 sitn->tunnels[1] = sitn->tunnels_l;
1214 sitn->tunnels[2] = sitn->tunnels_r;
1215 sitn->tunnels[3] = sitn->tunnels_r_l;
1216
1217 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1218 ipip6_tunnel_setup);
1219 if (!sitn->fb_tunnel_dev) {
1220 err = -ENOMEM;
1221 goto err_alloc_dev;
1222 }
1223 dev_net_set(sitn->fb_tunnel_dev, net);
1224
1225 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1226 if (err)
1227 goto err_dev_free;
1228
1229 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1230
1231 if ((err = register_netdev(sitn->fb_tunnel_dev)))
1232 goto err_reg_dev;
1233
1234 return 0;
1235
1236err_reg_dev:
1237 dev_put(sitn->fb_tunnel_dev);
1238err_dev_free:
1239 ipip6_dev_free(sitn->fb_tunnel_dev);
1240err_alloc_dev:
1241 return err;
1242}
1243
1244static void __net_exit sit_exit_net(struct net *net)
1245{
1246 struct sit_net *sitn = net_generic(net, sit_net_id);
1247 LIST_HEAD(list);
1248
1249 rtnl_lock();
1250 sit_destroy_tunnels(sitn, &list);
1251 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1252 unregister_netdevice_many(&list);
1253 rtnl_unlock();
1254}
1255
1256static struct pernet_operations sit_net_ops = {
1257 .init = sit_init_net,
1258 .exit = sit_exit_net,
1259 .id = &sit_net_id,
1260 .size = sizeof(struct sit_net),
1261};
1262
1263static void __exit sit_cleanup(void)
1264{
1265 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1266
1267 unregister_pernet_device(&sit_net_ops);
1268 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1269}
1270
1271static int __init sit_init(void)
1272{
1273 int err;
1274
1275 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1276
1277 err = register_pernet_device(&sit_net_ops);
1278 if (err < 0)
1279 return err;
1280 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1281 if (err < 0) {
1282 unregister_pernet_device(&sit_net_ops);
1283 printk(KERN_INFO "sit init: Can't add protocol\n");
1284 }
1285 return err;
1286}
1287
1288module_init(sit_init);
1289module_exit(sit_cleanup);
1290MODULE_LICENSE("GPL");
1291MODULE_ALIAS_NETDEV("sit0");
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 <linux/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/ip_tunnels.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 IP6_SIT_HASH_SIZE 16
66#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
67
68static bool log_ecn_error = true;
69module_param(log_ecn_error, bool, 0644);
70MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
71
72static int ipip6_tunnel_init(struct net_device *dev);
73static void ipip6_tunnel_setup(struct net_device *dev);
74static void ipip6_dev_free(struct net_device *dev);
75static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
76 __be32 *v4dst);
77static struct rtnl_link_ops sit_link_ops __read_mostly;
78
79static unsigned int sit_net_id __read_mostly;
80struct sit_net {
81 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
82 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
83 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
84 struct ip_tunnel __rcu *tunnels_wc[1];
85 struct ip_tunnel __rcu **tunnels[4];
86
87 struct net_device *fb_tunnel_dev;
88};
89
90/*
91 * Must be invoked with rcu_read_lock
92 */
93static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
94 struct net_device *dev, __be32 remote, __be32 local)
95{
96 unsigned int h0 = HASH(remote);
97 unsigned int h1 = HASH(local);
98 struct ip_tunnel *t;
99 struct sit_net *sitn = net_generic(net, sit_net_id);
100
101 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
102 if (local == t->parms.iph.saddr &&
103 remote == t->parms.iph.daddr &&
104 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
105 (t->dev->flags & IFF_UP))
106 return t;
107 }
108 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
109 if (remote == t->parms.iph.daddr &&
110 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
111 (t->dev->flags & IFF_UP))
112 return t;
113 }
114 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
115 if (local == t->parms.iph.saddr &&
116 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
117 (t->dev->flags & IFF_UP))
118 return t;
119 }
120 t = rcu_dereference(sitn->tunnels_wc[0]);
121 if (t && (t->dev->flags & IFF_UP))
122 return t;
123 return NULL;
124}
125
126static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
127 struct ip_tunnel_parm *parms)
128{
129 __be32 remote = parms->iph.daddr;
130 __be32 local = parms->iph.saddr;
131 unsigned int h = 0;
132 int prio = 0;
133
134 if (remote) {
135 prio |= 2;
136 h ^= HASH(remote);
137 }
138 if (local) {
139 prio |= 1;
140 h ^= HASH(local);
141 }
142 return &sitn->tunnels[prio][h];
143}
144
145static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
146 struct ip_tunnel *t)
147{
148 return __ipip6_bucket(sitn, &t->parms);
149}
150
151static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
152{
153 struct ip_tunnel __rcu **tp;
154 struct ip_tunnel *iter;
155
156 for (tp = ipip6_bucket(sitn, t);
157 (iter = rtnl_dereference(*tp)) != NULL;
158 tp = &iter->next) {
159 if (t == iter) {
160 rcu_assign_pointer(*tp, t->next);
161 break;
162 }
163 }
164}
165
166static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
167{
168 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
169
170 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
171 rcu_assign_pointer(*tp, t);
172}
173
174static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
175{
176#ifdef CONFIG_IPV6_SIT_6RD
177 struct ip_tunnel *t = netdev_priv(dev);
178
179 if (t->dev == sitn->fb_tunnel_dev) {
180 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
181 t->ip6rd.relay_prefix = 0;
182 t->ip6rd.prefixlen = 16;
183 t->ip6rd.relay_prefixlen = 0;
184 } else {
185 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
186 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
187 }
188#endif
189}
190
191static int ipip6_tunnel_create(struct net_device *dev)
192{
193 struct ip_tunnel *t = netdev_priv(dev);
194 struct net *net = dev_net(dev);
195 struct sit_net *sitn = net_generic(net, sit_net_id);
196 int err;
197
198 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
199 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
200
201 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
202 dev->priv_flags |= IFF_ISATAP;
203
204 dev->rtnl_link_ops = &sit_link_ops;
205
206 err = register_netdevice(dev);
207 if (err < 0)
208 goto out;
209
210 ipip6_tunnel_clone_6rd(dev, sitn);
211
212 dev_hold(dev);
213
214 ipip6_tunnel_link(sitn, t);
215 return 0;
216
217out:
218 return err;
219}
220
221static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
222 struct ip_tunnel_parm *parms, int create)
223{
224 __be32 remote = parms->iph.daddr;
225 __be32 local = parms->iph.saddr;
226 struct ip_tunnel *t, *nt;
227 struct ip_tunnel __rcu **tp;
228 struct net_device *dev;
229 char name[IFNAMSIZ];
230 struct sit_net *sitn = net_generic(net, sit_net_id);
231
232 for (tp = __ipip6_bucket(sitn, parms);
233 (t = rtnl_dereference(*tp)) != NULL;
234 tp = &t->next) {
235 if (local == t->parms.iph.saddr &&
236 remote == t->parms.iph.daddr &&
237 parms->link == t->parms.link) {
238 if (create)
239 return NULL;
240 else
241 return t;
242 }
243 }
244 if (!create)
245 goto failed;
246
247 if (parms->name[0])
248 strlcpy(name, parms->name, IFNAMSIZ);
249 else
250 strcpy(name, "sit%d");
251
252 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
253 ipip6_tunnel_setup);
254 if (!dev)
255 return NULL;
256
257 dev_net_set(dev, net);
258
259 nt = netdev_priv(dev);
260
261 nt->parms = *parms;
262 if (ipip6_tunnel_create(dev) < 0)
263 goto failed_free;
264
265 return nt;
266
267failed_free:
268 ipip6_dev_free(dev);
269failed:
270 return NULL;
271}
272
273#define for_each_prl_rcu(start) \
274 for (prl = rcu_dereference(start); \
275 prl; \
276 prl = rcu_dereference(prl->next))
277
278static struct ip_tunnel_prl_entry *
279__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
280{
281 struct ip_tunnel_prl_entry *prl;
282
283 for_each_prl_rcu(t->prl)
284 if (prl->addr == addr)
285 break;
286 return prl;
287
288}
289
290static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
291 struct ip_tunnel_prl __user *a)
292{
293 struct ip_tunnel_prl kprl, *kp;
294 struct ip_tunnel_prl_entry *prl;
295 unsigned int cmax, c = 0, ca, len;
296 int ret = 0;
297
298 if (copy_from_user(&kprl, a, sizeof(kprl)))
299 return -EFAULT;
300 cmax = kprl.datalen / sizeof(kprl);
301 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
302 cmax = 1;
303
304 /* For simple GET or for root users,
305 * we try harder to allocate.
306 */
307 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
308 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
309 NULL;
310
311 rcu_read_lock();
312
313 ca = t->prl_count < cmax ? t->prl_count : cmax;
314
315 if (!kp) {
316 /* We don't try hard to allocate much memory for
317 * non-root users.
318 * For root users, retry allocating enough memory for
319 * the answer.
320 */
321 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
322 if (!kp) {
323 ret = -ENOMEM;
324 goto out;
325 }
326 }
327
328 c = 0;
329 for_each_prl_rcu(t->prl) {
330 if (c >= cmax)
331 break;
332 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
333 continue;
334 kp[c].addr = prl->addr;
335 kp[c].flags = prl->flags;
336 c++;
337 if (kprl.addr != htonl(INADDR_ANY))
338 break;
339 }
340out:
341 rcu_read_unlock();
342
343 len = sizeof(*kp) * c;
344 ret = 0;
345 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
346 ret = -EFAULT;
347
348 kfree(kp);
349
350 return ret;
351}
352
353static int
354ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
355{
356 struct ip_tunnel_prl_entry *p;
357 int err = 0;
358
359 if (a->addr == htonl(INADDR_ANY))
360 return -EINVAL;
361
362 ASSERT_RTNL();
363
364 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
365 if (p->addr == a->addr) {
366 if (chg) {
367 p->flags = a->flags;
368 goto out;
369 }
370 err = -EEXIST;
371 goto out;
372 }
373 }
374
375 if (chg) {
376 err = -ENXIO;
377 goto out;
378 }
379
380 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
381 if (!p) {
382 err = -ENOBUFS;
383 goto out;
384 }
385
386 p->next = t->prl;
387 p->addr = a->addr;
388 p->flags = a->flags;
389 t->prl_count++;
390 rcu_assign_pointer(t->prl, p);
391out:
392 return err;
393}
394
395static void prl_list_destroy_rcu(struct rcu_head *head)
396{
397 struct ip_tunnel_prl_entry *p, *n;
398
399 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
400 do {
401 n = rcu_dereference_protected(p->next, 1);
402 kfree(p);
403 p = n;
404 } while (p);
405}
406
407static int
408ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
409{
410 struct ip_tunnel_prl_entry *x;
411 struct ip_tunnel_prl_entry __rcu **p;
412 int err = 0;
413
414 ASSERT_RTNL();
415
416 if (a && a->addr != htonl(INADDR_ANY)) {
417 for (p = &t->prl;
418 (x = rtnl_dereference(*p)) != NULL;
419 p = &x->next) {
420 if (x->addr == a->addr) {
421 *p = x->next;
422 kfree_rcu(x, rcu_head);
423 t->prl_count--;
424 goto out;
425 }
426 }
427 err = -ENXIO;
428 } else {
429 x = rtnl_dereference(t->prl);
430 if (x) {
431 t->prl_count = 0;
432 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
433 t->prl = NULL;
434 }
435 }
436out:
437 return err;
438}
439
440static int
441isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
442{
443 struct ip_tunnel_prl_entry *p;
444 int ok = 1;
445
446 rcu_read_lock();
447 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
448 if (p) {
449 if (p->flags & PRL_DEFAULT)
450 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
451 else
452 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
453 } else {
454 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
455
456 if (ipv6_addr_is_isatap(addr6) &&
457 (addr6->s6_addr32[3] == iph->saddr) &&
458 ipv6_chk_prefix(addr6, t->dev))
459 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
460 else
461 ok = 0;
462 }
463 rcu_read_unlock();
464 return ok;
465}
466
467static void ipip6_tunnel_uninit(struct net_device *dev)
468{
469 struct ip_tunnel *tunnel = netdev_priv(dev);
470 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
471
472 if (dev == sitn->fb_tunnel_dev) {
473 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
474 } else {
475 ipip6_tunnel_unlink(sitn, tunnel);
476 ipip6_tunnel_del_prl(tunnel, NULL);
477 }
478 dst_cache_reset(&tunnel->dst_cache);
479 dev_put(dev);
480}
481
482static int ipip6_err(struct sk_buff *skb, u32 info)
483{
484 const struct iphdr *iph = (const struct iphdr *)skb->data;
485 const int type = icmp_hdr(skb)->type;
486 const int code = icmp_hdr(skb)->code;
487 unsigned int data_len = 0;
488 struct ip_tunnel *t;
489 int err;
490
491 switch (type) {
492 default:
493 case ICMP_PARAMETERPROB:
494 return 0;
495
496 case ICMP_DEST_UNREACH:
497 switch (code) {
498 case ICMP_SR_FAILED:
499 /* Impossible event. */
500 return 0;
501 default:
502 /* All others are translated to HOST_UNREACH.
503 rfc2003 contains "deep thoughts" about NET_UNREACH,
504 I believe they are just ether pollution. --ANK
505 */
506 break;
507 }
508 break;
509 case ICMP_TIME_EXCEEDED:
510 if (code != ICMP_EXC_TTL)
511 return 0;
512 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
513 break;
514 case ICMP_REDIRECT:
515 break;
516 }
517
518 err = -ENOENT;
519
520 t = ipip6_tunnel_lookup(dev_net(skb->dev),
521 skb->dev,
522 iph->daddr,
523 iph->saddr);
524 if (!t)
525 goto out;
526
527 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
528 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
529 t->parms.link, 0, iph->protocol, 0);
530 err = 0;
531 goto out;
532 }
533 if (type == ICMP_REDIRECT) {
534 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
535 iph->protocol, 0);
536 err = 0;
537 goto out;
538 }
539
540 err = 0;
541 if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
542 goto out;
543
544 if (t->parms.iph.daddr == 0)
545 goto out;
546
547 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
548 goto out;
549
550 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
551 t->err_count++;
552 else
553 t->err_count = 1;
554 t->err_time = jiffies;
555out:
556 return err;
557}
558
559static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
560 const struct in6_addr *v6addr)
561{
562 __be32 v4embed = 0;
563 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
564 return true;
565 return false;
566}
567
568/* Checks if an address matches an address on the tunnel interface.
569 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
570 * Long story:
571 * This function is called after we considered the packet as spoofed
572 * in is_spoofed_6rd.
573 * We may have a router that is doing NAT for proto 41 packets
574 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
575 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
576 * function will return true, dropping the packet.
577 * But, we can still check if is spoofed against the IP
578 * addresses associated with the interface.
579 */
580static bool only_dnatted(const struct ip_tunnel *tunnel,
581 const struct in6_addr *v6dst)
582{
583 int prefix_len;
584
585#ifdef CONFIG_IPV6_SIT_6RD
586 prefix_len = tunnel->ip6rd.prefixlen + 32
587 - tunnel->ip6rd.relay_prefixlen;
588#else
589 prefix_len = 48;
590#endif
591 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
592}
593
594/* Returns true if a packet is spoofed */
595static bool packet_is_spoofed(struct sk_buff *skb,
596 const struct iphdr *iph,
597 struct ip_tunnel *tunnel)
598{
599 const struct ipv6hdr *ipv6h;
600
601 if (tunnel->dev->priv_flags & IFF_ISATAP) {
602 if (!isatap_chksrc(skb, iph, tunnel))
603 return true;
604
605 return false;
606 }
607
608 if (tunnel->dev->flags & IFF_POINTOPOINT)
609 return false;
610
611 ipv6h = ipv6_hdr(skb);
612
613 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
614 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
615 &iph->saddr, &ipv6h->saddr,
616 &iph->daddr, &ipv6h->daddr);
617 return true;
618 }
619
620 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
621 return false;
622
623 if (only_dnatted(tunnel, &ipv6h->daddr))
624 return false;
625
626 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
627 &iph->saddr, &ipv6h->saddr,
628 &iph->daddr, &ipv6h->daddr);
629 return true;
630}
631
632static int ipip6_rcv(struct sk_buff *skb)
633{
634 const struct iphdr *iph = ip_hdr(skb);
635 struct ip_tunnel *tunnel;
636 int err;
637
638 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
639 iph->saddr, iph->daddr);
640 if (tunnel) {
641 struct pcpu_sw_netstats *tstats;
642
643 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
644 tunnel->parms.iph.protocol != 0)
645 goto out;
646
647 skb->mac_header = skb->network_header;
648 skb_reset_network_header(skb);
649 IPCB(skb)->flags = 0;
650 skb->dev = tunnel->dev;
651
652 if (packet_is_spoofed(skb, iph, tunnel)) {
653 tunnel->dev->stats.rx_errors++;
654 goto out;
655 }
656
657 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
658 !net_eq(tunnel->net, dev_net(tunnel->dev))))
659 goto out;
660
661 err = IP_ECN_decapsulate(iph, skb);
662 if (unlikely(err)) {
663 if (log_ecn_error)
664 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
665 &iph->saddr, iph->tos);
666 if (err > 1) {
667 ++tunnel->dev->stats.rx_frame_errors;
668 ++tunnel->dev->stats.rx_errors;
669 goto out;
670 }
671 }
672
673 tstats = this_cpu_ptr(tunnel->dev->tstats);
674 u64_stats_update_begin(&tstats->syncp);
675 tstats->rx_packets++;
676 tstats->rx_bytes += skb->len;
677 u64_stats_update_end(&tstats->syncp);
678
679 netif_rx(skb);
680
681 return 0;
682 }
683
684 /* no tunnel matched, let upstream know, ipsec may handle it */
685 return 1;
686out:
687 kfree_skb(skb);
688 return 0;
689}
690
691static const struct tnl_ptk_info ipip_tpi = {
692 /* no tunnel info required for ipip. */
693 .proto = htons(ETH_P_IP),
694};
695
696#if IS_ENABLED(CONFIG_MPLS)
697static const struct tnl_ptk_info mplsip_tpi = {
698 /* no tunnel info required for mplsip. */
699 .proto = htons(ETH_P_MPLS_UC),
700};
701#endif
702
703static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
704{
705 const struct iphdr *iph;
706 struct ip_tunnel *tunnel;
707
708 iph = ip_hdr(skb);
709 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
710 iph->saddr, iph->daddr);
711 if (tunnel) {
712 const struct tnl_ptk_info *tpi;
713
714 if (tunnel->parms.iph.protocol != ipproto &&
715 tunnel->parms.iph.protocol != 0)
716 goto drop;
717
718 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
719 goto drop;
720#if IS_ENABLED(CONFIG_MPLS)
721 if (ipproto == IPPROTO_MPLS)
722 tpi = &mplsip_tpi;
723 else
724#endif
725 tpi = &ipip_tpi;
726 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
727 goto drop;
728 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
729 }
730
731 return 1;
732
733drop:
734 kfree_skb(skb);
735 return 0;
736}
737
738static int ipip_rcv(struct sk_buff *skb)
739{
740 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
741}
742
743#if IS_ENABLED(CONFIG_MPLS)
744static int mplsip_rcv(struct sk_buff *skb)
745{
746 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
747}
748#endif
749
750/*
751 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
752 * stores the embedded IPv4 address in v4dst and returns true.
753 */
754static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
755 __be32 *v4dst)
756{
757#ifdef CONFIG_IPV6_SIT_6RD
758 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
759 tunnel->ip6rd.prefixlen)) {
760 unsigned int pbw0, pbi0;
761 int pbi1;
762 u32 d;
763
764 pbw0 = tunnel->ip6rd.prefixlen >> 5;
765 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
766
767 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
768 tunnel->ip6rd.relay_prefixlen;
769
770 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
771 if (pbi1 > 0)
772 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
773 (32 - pbi1);
774
775 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
776 return true;
777 }
778#else
779 if (v6dst->s6_addr16[0] == htons(0x2002)) {
780 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
781 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
782 return true;
783 }
784#endif
785 return false;
786}
787
788static inline __be32 try_6rd(struct ip_tunnel *tunnel,
789 const struct in6_addr *v6dst)
790{
791 __be32 dst = 0;
792 check_6rd(tunnel, v6dst, &dst);
793 return dst;
794}
795
796/*
797 * This function assumes it is being called from dev_queue_xmit()
798 * and that skb is filled properly by that function.
799 */
800
801static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
802 struct net_device *dev)
803{
804 struct ip_tunnel *tunnel = netdev_priv(dev);
805 const struct iphdr *tiph = &tunnel->parms.iph;
806 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
807 u8 tos = tunnel->parms.iph.tos;
808 __be16 df = tiph->frag_off;
809 struct rtable *rt; /* Route to the other host */
810 struct net_device *tdev; /* Device to other host */
811 unsigned int max_headroom; /* The extra header space needed */
812 __be32 dst = tiph->daddr;
813 struct flowi4 fl4;
814 int mtu;
815 const struct in6_addr *addr6;
816 int addr_type;
817 u8 ttl;
818 u8 protocol = IPPROTO_IPV6;
819 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
820
821 if (tos == 1)
822 tos = ipv6_get_dsfield(iph6);
823
824 /* ISATAP (RFC4214) - must come before 6to4 */
825 if (dev->priv_flags & IFF_ISATAP) {
826 struct neighbour *neigh = NULL;
827 bool do_tx_error = false;
828
829 if (skb_dst(skb))
830 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
831
832 if (!neigh) {
833 net_dbg_ratelimited("nexthop == NULL\n");
834 goto tx_error;
835 }
836
837 addr6 = (const struct in6_addr *)&neigh->primary_key;
838 addr_type = ipv6_addr_type(addr6);
839
840 if ((addr_type & IPV6_ADDR_UNICAST) &&
841 ipv6_addr_is_isatap(addr6))
842 dst = addr6->s6_addr32[3];
843 else
844 do_tx_error = true;
845
846 neigh_release(neigh);
847 if (do_tx_error)
848 goto tx_error;
849 }
850
851 if (!dst)
852 dst = try_6rd(tunnel, &iph6->daddr);
853
854 if (!dst) {
855 struct neighbour *neigh = NULL;
856 bool do_tx_error = false;
857
858 if (skb_dst(skb))
859 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
860
861 if (!neigh) {
862 net_dbg_ratelimited("nexthop == NULL\n");
863 goto tx_error;
864 }
865
866 addr6 = (const struct in6_addr *)&neigh->primary_key;
867 addr_type = ipv6_addr_type(addr6);
868
869 if (addr_type == IPV6_ADDR_ANY) {
870 addr6 = &ipv6_hdr(skb)->daddr;
871 addr_type = ipv6_addr_type(addr6);
872 }
873
874 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
875 dst = addr6->s6_addr32[3];
876 else
877 do_tx_error = true;
878
879 neigh_release(neigh);
880 if (do_tx_error)
881 goto tx_error;
882 }
883
884 rt = ip_route_output_ports(tunnel->net, &fl4, NULL,
885 dst, tiph->saddr,
886 0, 0,
887 IPPROTO_IPV6, RT_TOS(tos),
888 tunnel->parms.link);
889 if (IS_ERR(rt)) {
890 dev->stats.tx_carrier_errors++;
891 goto tx_error_icmp;
892 }
893 if (rt->rt_type != RTN_UNICAST) {
894 ip_rt_put(rt);
895 dev->stats.tx_carrier_errors++;
896 goto tx_error_icmp;
897 }
898 tdev = rt->dst.dev;
899
900 if (tdev == dev) {
901 ip_rt_put(rt);
902 dev->stats.collisions++;
903 goto tx_error;
904 }
905
906 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
907 ip_rt_put(rt);
908 goto tx_error;
909 }
910
911 if (df) {
912 mtu = dst_mtu(&rt->dst) - t_hlen;
913
914 if (mtu < 68) {
915 dev->stats.collisions++;
916 ip_rt_put(rt);
917 goto tx_error;
918 }
919
920 if (mtu < IPV6_MIN_MTU) {
921 mtu = IPV6_MIN_MTU;
922 df = 0;
923 }
924
925 if (tunnel->parms.iph.daddr && skb_dst(skb))
926 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
927
928 if (skb->len > mtu && !skb_is_gso(skb)) {
929 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
930 ip_rt_put(rt);
931 goto tx_error;
932 }
933 }
934
935 if (tunnel->err_count > 0) {
936 if (time_before(jiffies,
937 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
938 tunnel->err_count--;
939 dst_link_failure(skb);
940 } else
941 tunnel->err_count = 0;
942 }
943
944 /*
945 * Okay, now see if we can stuff it in the buffer as-is.
946 */
947 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
948
949 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
950 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
951 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
952 if (!new_skb) {
953 ip_rt_put(rt);
954 dev->stats.tx_dropped++;
955 kfree_skb(skb);
956 return NETDEV_TX_OK;
957 }
958 if (skb->sk)
959 skb_set_owner_w(new_skb, skb->sk);
960 dev_kfree_skb(skb);
961 skb = new_skb;
962 iph6 = ipv6_hdr(skb);
963 }
964 ttl = tiph->ttl;
965 if (ttl == 0)
966 ttl = iph6->hop_limit;
967 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
968
969 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
970 ip_rt_put(rt);
971 goto tx_error;
972 }
973
974 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
975
976 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
977 df, !net_eq(tunnel->net, dev_net(dev)));
978 return NETDEV_TX_OK;
979
980tx_error_icmp:
981 dst_link_failure(skb);
982tx_error:
983 kfree_skb(skb);
984 dev->stats.tx_errors++;
985 return NETDEV_TX_OK;
986}
987
988static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
989 struct net_device *dev, u8 ipproto)
990{
991 struct ip_tunnel *tunnel = netdev_priv(dev);
992 const struct iphdr *tiph = &tunnel->parms.iph;
993
994 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
995 goto tx_error;
996
997 skb_set_inner_ipproto(skb, ipproto);
998
999 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1000 return NETDEV_TX_OK;
1001tx_error:
1002 kfree_skb(skb);
1003 dev->stats.tx_errors++;
1004 return NETDEV_TX_OK;
1005}
1006
1007static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1008 struct net_device *dev)
1009{
1010 switch (skb->protocol) {
1011 case htons(ETH_P_IP):
1012 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1013 break;
1014 case htons(ETH_P_IPV6):
1015 ipip6_tunnel_xmit(skb, dev);
1016 break;
1017#if IS_ENABLED(CONFIG_MPLS)
1018 case htons(ETH_P_MPLS_UC):
1019 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1020 break;
1021#endif
1022 default:
1023 goto tx_err;
1024 }
1025
1026 return NETDEV_TX_OK;
1027
1028tx_err:
1029 dev->stats.tx_errors++;
1030 kfree_skb(skb);
1031 return NETDEV_TX_OK;
1032
1033}
1034
1035static void ipip6_tunnel_bind_dev(struct net_device *dev)
1036{
1037 struct net_device *tdev = NULL;
1038 struct ip_tunnel *tunnel;
1039 const struct iphdr *iph;
1040 struct flowi4 fl4;
1041
1042 tunnel = netdev_priv(dev);
1043 iph = &tunnel->parms.iph;
1044
1045 if (iph->daddr) {
1046 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1047 NULL,
1048 iph->daddr, iph->saddr,
1049 0, 0,
1050 IPPROTO_IPV6,
1051 RT_TOS(iph->tos),
1052 tunnel->parms.link);
1053
1054 if (!IS_ERR(rt)) {
1055 tdev = rt->dst.dev;
1056 ip_rt_put(rt);
1057 }
1058 dev->flags |= IFF_POINTOPOINT;
1059 }
1060
1061 if (!tdev && tunnel->parms.link)
1062 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1063
1064 if (tdev) {
1065 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1066
1067 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1068 dev->mtu = tdev->mtu - t_hlen;
1069 if (dev->mtu < IPV6_MIN_MTU)
1070 dev->mtu = IPV6_MIN_MTU;
1071 }
1072}
1073
1074static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
1075{
1076 struct net *net = t->net;
1077 struct sit_net *sitn = net_generic(net, sit_net_id);
1078
1079 ipip6_tunnel_unlink(sitn, t);
1080 synchronize_net();
1081 t->parms.iph.saddr = p->iph.saddr;
1082 t->parms.iph.daddr = p->iph.daddr;
1083 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1084 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1085 ipip6_tunnel_link(sitn, t);
1086 t->parms.iph.ttl = p->iph.ttl;
1087 t->parms.iph.tos = p->iph.tos;
1088 if (t->parms.link != p->link) {
1089 t->parms.link = p->link;
1090 ipip6_tunnel_bind_dev(t->dev);
1091 }
1092 dst_cache_reset(&t->dst_cache);
1093 netdev_state_change(t->dev);
1094}
1095
1096#ifdef CONFIG_IPV6_SIT_6RD
1097static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1098 struct ip_tunnel_6rd *ip6rd)
1099{
1100 struct in6_addr prefix;
1101 __be32 relay_prefix;
1102
1103 if (ip6rd->relay_prefixlen > 32 ||
1104 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1105 return -EINVAL;
1106
1107 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1108 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1109 return -EINVAL;
1110 if (ip6rd->relay_prefixlen)
1111 relay_prefix = ip6rd->relay_prefix &
1112 htonl(0xffffffffUL <<
1113 (32 - ip6rd->relay_prefixlen));
1114 else
1115 relay_prefix = 0;
1116 if (relay_prefix != ip6rd->relay_prefix)
1117 return -EINVAL;
1118
1119 t->ip6rd.prefix = prefix;
1120 t->ip6rd.relay_prefix = relay_prefix;
1121 t->ip6rd.prefixlen = ip6rd->prefixlen;
1122 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1123 dst_cache_reset(&t->dst_cache);
1124 netdev_state_change(t->dev);
1125 return 0;
1126}
1127#endif
1128
1129static bool ipip6_valid_ip_proto(u8 ipproto)
1130{
1131 return ipproto == IPPROTO_IPV6 ||
1132 ipproto == IPPROTO_IPIP ||
1133#if IS_ENABLED(CONFIG_MPLS)
1134 ipproto == IPPROTO_MPLS ||
1135#endif
1136 ipproto == 0;
1137}
1138
1139static int
1140ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1141{
1142 int err = 0;
1143 struct ip_tunnel_parm p;
1144 struct ip_tunnel_prl prl;
1145 struct ip_tunnel *t = netdev_priv(dev);
1146 struct net *net = t->net;
1147 struct sit_net *sitn = net_generic(net, sit_net_id);
1148#ifdef CONFIG_IPV6_SIT_6RD
1149 struct ip_tunnel_6rd ip6rd;
1150#endif
1151
1152 switch (cmd) {
1153 case SIOCGETTUNNEL:
1154#ifdef CONFIG_IPV6_SIT_6RD
1155 case SIOCGET6RD:
1156#endif
1157 if (dev == sitn->fb_tunnel_dev) {
1158 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1159 err = -EFAULT;
1160 break;
1161 }
1162 t = ipip6_tunnel_locate(net, &p, 0);
1163 if (!t)
1164 t = netdev_priv(dev);
1165 }
1166
1167 err = -EFAULT;
1168 if (cmd == SIOCGETTUNNEL) {
1169 memcpy(&p, &t->parms, sizeof(p));
1170 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1171 sizeof(p)))
1172 goto done;
1173#ifdef CONFIG_IPV6_SIT_6RD
1174 } else {
1175 ip6rd.prefix = t->ip6rd.prefix;
1176 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1177 ip6rd.prefixlen = t->ip6rd.prefixlen;
1178 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1179 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1180 sizeof(ip6rd)))
1181 goto done;
1182#endif
1183 }
1184 err = 0;
1185 break;
1186
1187 case SIOCADDTUNNEL:
1188 case SIOCCHGTUNNEL:
1189 err = -EPERM;
1190 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1191 goto done;
1192
1193 err = -EFAULT;
1194 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1195 goto done;
1196
1197 err = -EINVAL;
1198 if (!ipip6_valid_ip_proto(p.iph.protocol))
1199 goto done;
1200 if (p.iph.version != 4 ||
1201 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1202 goto done;
1203 if (p.iph.ttl)
1204 p.iph.frag_off |= htons(IP_DF);
1205
1206 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1207
1208 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1209 if (t) {
1210 if (t->dev != dev) {
1211 err = -EEXIST;
1212 break;
1213 }
1214 } else {
1215 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1216 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1217 err = -EINVAL;
1218 break;
1219 }
1220 t = netdev_priv(dev);
1221 }
1222
1223 ipip6_tunnel_update(t, &p);
1224 }
1225
1226 if (t) {
1227 err = 0;
1228 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1229 err = -EFAULT;
1230 } else
1231 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1232 break;
1233
1234 case SIOCDELTUNNEL:
1235 err = -EPERM;
1236 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1237 goto done;
1238
1239 if (dev == sitn->fb_tunnel_dev) {
1240 err = -EFAULT;
1241 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1242 goto done;
1243 err = -ENOENT;
1244 t = ipip6_tunnel_locate(net, &p, 0);
1245 if (!t)
1246 goto done;
1247 err = -EPERM;
1248 if (t == netdev_priv(sitn->fb_tunnel_dev))
1249 goto done;
1250 dev = t->dev;
1251 }
1252 unregister_netdevice(dev);
1253 err = 0;
1254 break;
1255
1256 case SIOCGETPRL:
1257 err = -EINVAL;
1258 if (dev == sitn->fb_tunnel_dev)
1259 goto done;
1260 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1261 break;
1262
1263 case SIOCADDPRL:
1264 case SIOCDELPRL:
1265 case SIOCCHGPRL:
1266 err = -EPERM;
1267 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1268 goto done;
1269 err = -EINVAL;
1270 if (dev == sitn->fb_tunnel_dev)
1271 goto done;
1272 err = -EFAULT;
1273 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1274 goto done;
1275
1276 switch (cmd) {
1277 case SIOCDELPRL:
1278 err = ipip6_tunnel_del_prl(t, &prl);
1279 break;
1280 case SIOCADDPRL:
1281 case SIOCCHGPRL:
1282 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1283 break;
1284 }
1285 dst_cache_reset(&t->dst_cache);
1286 netdev_state_change(dev);
1287 break;
1288
1289#ifdef CONFIG_IPV6_SIT_6RD
1290 case SIOCADD6RD:
1291 case SIOCCHG6RD:
1292 case SIOCDEL6RD:
1293 err = -EPERM;
1294 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295 goto done;
1296
1297 err = -EFAULT;
1298 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1299 sizeof(ip6rd)))
1300 goto done;
1301
1302 if (cmd != SIOCDEL6RD) {
1303 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1304 if (err < 0)
1305 goto done;
1306 } else
1307 ipip6_tunnel_clone_6rd(dev, sitn);
1308
1309 err = 0;
1310 break;
1311#endif
1312
1313 default:
1314 err = -EINVAL;
1315 }
1316
1317done:
1318 return err;
1319}
1320
1321static const struct net_device_ops ipip6_netdev_ops = {
1322 .ndo_init = ipip6_tunnel_init,
1323 .ndo_uninit = ipip6_tunnel_uninit,
1324 .ndo_start_xmit = sit_tunnel_xmit,
1325 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1326 .ndo_get_stats64 = ip_tunnel_get_stats64,
1327 .ndo_get_iflink = ip_tunnel_get_iflink,
1328};
1329
1330static void ipip6_dev_free(struct net_device *dev)
1331{
1332 struct ip_tunnel *tunnel = netdev_priv(dev);
1333
1334 dst_cache_destroy(&tunnel->dst_cache);
1335 free_percpu(dev->tstats);
1336 free_netdev(dev);
1337}
1338
1339#define SIT_FEATURES (NETIF_F_SG | \
1340 NETIF_F_FRAGLIST | \
1341 NETIF_F_HIGHDMA | \
1342 NETIF_F_GSO_SOFTWARE | \
1343 NETIF_F_HW_CSUM)
1344
1345static void ipip6_tunnel_setup(struct net_device *dev)
1346{
1347 struct ip_tunnel *tunnel = netdev_priv(dev);
1348 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1349
1350 dev->netdev_ops = &ipip6_netdev_ops;
1351 dev->destructor = ipip6_dev_free;
1352
1353 dev->type = ARPHRD_SIT;
1354 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1355 dev->mtu = ETH_DATA_LEN - t_hlen;
1356 dev->min_mtu = IPV6_MIN_MTU;
1357 dev->max_mtu = 0xFFF8 - t_hlen;
1358 dev->flags = IFF_NOARP;
1359 netif_keep_dst(dev);
1360 dev->addr_len = 4;
1361 dev->features |= NETIF_F_LLTX;
1362 dev->features |= SIT_FEATURES;
1363 dev->hw_features |= SIT_FEATURES;
1364}
1365
1366static int ipip6_tunnel_init(struct net_device *dev)
1367{
1368 struct ip_tunnel *tunnel = netdev_priv(dev);
1369 int err;
1370
1371 tunnel->dev = dev;
1372 tunnel->net = dev_net(dev);
1373 strcpy(tunnel->parms.name, dev->name);
1374
1375 ipip6_tunnel_bind_dev(dev);
1376 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1377 if (!dev->tstats)
1378 return -ENOMEM;
1379
1380 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1381 if (err) {
1382 free_percpu(dev->tstats);
1383 dev->tstats = NULL;
1384 return err;
1385 }
1386
1387 return 0;
1388}
1389
1390static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1391{
1392 struct ip_tunnel *tunnel = netdev_priv(dev);
1393 struct iphdr *iph = &tunnel->parms.iph;
1394 struct net *net = dev_net(dev);
1395 struct sit_net *sitn = net_generic(net, sit_net_id);
1396
1397 iph->version = 4;
1398 iph->protocol = IPPROTO_IPV6;
1399 iph->ihl = 5;
1400 iph->ttl = 64;
1401
1402 dev_hold(dev);
1403 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1404}
1405
1406static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1407{
1408 u8 proto;
1409
1410 if (!data || !data[IFLA_IPTUN_PROTO])
1411 return 0;
1412
1413 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1414 if (!ipip6_valid_ip_proto(proto))
1415 return -EINVAL;
1416
1417 return 0;
1418}
1419
1420static void ipip6_netlink_parms(struct nlattr *data[],
1421 struct ip_tunnel_parm *parms)
1422{
1423 memset(parms, 0, sizeof(*parms));
1424
1425 parms->iph.version = 4;
1426 parms->iph.protocol = IPPROTO_IPV6;
1427 parms->iph.ihl = 5;
1428 parms->iph.ttl = 64;
1429
1430 if (!data)
1431 return;
1432
1433 if (data[IFLA_IPTUN_LINK])
1434 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1435
1436 if (data[IFLA_IPTUN_LOCAL])
1437 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1438
1439 if (data[IFLA_IPTUN_REMOTE])
1440 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1441
1442 if (data[IFLA_IPTUN_TTL]) {
1443 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1444 if (parms->iph.ttl)
1445 parms->iph.frag_off = htons(IP_DF);
1446 }
1447
1448 if (data[IFLA_IPTUN_TOS])
1449 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1450
1451 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1452 parms->iph.frag_off = htons(IP_DF);
1453
1454 if (data[IFLA_IPTUN_FLAGS])
1455 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1456
1457 if (data[IFLA_IPTUN_PROTO])
1458 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1459
1460}
1461
1462/* This function returns true when ENCAP attributes are present in the nl msg */
1463static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1464 struct ip_tunnel_encap *ipencap)
1465{
1466 bool ret = false;
1467
1468 memset(ipencap, 0, sizeof(*ipencap));
1469
1470 if (!data)
1471 return ret;
1472
1473 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1474 ret = true;
1475 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1476 }
1477
1478 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1479 ret = true;
1480 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1481 }
1482
1483 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1484 ret = true;
1485 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1486 }
1487
1488 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1489 ret = true;
1490 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1491 }
1492
1493 return ret;
1494}
1495
1496#ifdef CONFIG_IPV6_SIT_6RD
1497/* This function returns true when 6RD attributes are present in the nl msg */
1498static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1499 struct ip_tunnel_6rd *ip6rd)
1500{
1501 bool ret = false;
1502 memset(ip6rd, 0, sizeof(*ip6rd));
1503
1504 if (!data)
1505 return ret;
1506
1507 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1508 ret = true;
1509 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1510 }
1511
1512 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1513 ret = true;
1514 ip6rd->relay_prefix =
1515 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1516 }
1517
1518 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1519 ret = true;
1520 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1521 }
1522
1523 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1524 ret = true;
1525 ip6rd->relay_prefixlen =
1526 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1527 }
1528
1529 return ret;
1530}
1531#endif
1532
1533static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1534 struct nlattr *tb[], struct nlattr *data[])
1535{
1536 struct net *net = dev_net(dev);
1537 struct ip_tunnel *nt;
1538 struct ip_tunnel_encap ipencap;
1539#ifdef CONFIG_IPV6_SIT_6RD
1540 struct ip_tunnel_6rd ip6rd;
1541#endif
1542 int err;
1543
1544 nt = netdev_priv(dev);
1545
1546 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1547 err = ip_tunnel_encap_setup(nt, &ipencap);
1548 if (err < 0)
1549 return err;
1550 }
1551
1552 ipip6_netlink_parms(data, &nt->parms);
1553
1554 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1555 return -EEXIST;
1556
1557 err = ipip6_tunnel_create(dev);
1558 if (err < 0)
1559 return err;
1560
1561#ifdef CONFIG_IPV6_SIT_6RD
1562 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1563 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1564#endif
1565
1566 return err;
1567}
1568
1569static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1570 struct nlattr *data[])
1571{
1572 struct ip_tunnel *t = netdev_priv(dev);
1573 struct ip_tunnel_parm p;
1574 struct ip_tunnel_encap ipencap;
1575 struct net *net = t->net;
1576 struct sit_net *sitn = net_generic(net, sit_net_id);
1577#ifdef CONFIG_IPV6_SIT_6RD
1578 struct ip_tunnel_6rd ip6rd;
1579#endif
1580 int err;
1581
1582 if (dev == sitn->fb_tunnel_dev)
1583 return -EINVAL;
1584
1585 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1586 err = ip_tunnel_encap_setup(t, &ipencap);
1587 if (err < 0)
1588 return err;
1589 }
1590
1591 ipip6_netlink_parms(data, &p);
1592
1593 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1594 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1595 return -EINVAL;
1596
1597 t = ipip6_tunnel_locate(net, &p, 0);
1598
1599 if (t) {
1600 if (t->dev != dev)
1601 return -EEXIST;
1602 } else
1603 t = netdev_priv(dev);
1604
1605 ipip6_tunnel_update(t, &p);
1606
1607#ifdef CONFIG_IPV6_SIT_6RD
1608 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1609 return ipip6_tunnel_update_6rd(t, &ip6rd);
1610#endif
1611
1612 return 0;
1613}
1614
1615static size_t ipip6_get_size(const struct net_device *dev)
1616{
1617 return
1618 /* IFLA_IPTUN_LINK */
1619 nla_total_size(4) +
1620 /* IFLA_IPTUN_LOCAL */
1621 nla_total_size(4) +
1622 /* IFLA_IPTUN_REMOTE */
1623 nla_total_size(4) +
1624 /* IFLA_IPTUN_TTL */
1625 nla_total_size(1) +
1626 /* IFLA_IPTUN_TOS */
1627 nla_total_size(1) +
1628 /* IFLA_IPTUN_PMTUDISC */
1629 nla_total_size(1) +
1630 /* IFLA_IPTUN_FLAGS */
1631 nla_total_size(2) +
1632 /* IFLA_IPTUN_PROTO */
1633 nla_total_size(1) +
1634#ifdef CONFIG_IPV6_SIT_6RD
1635 /* IFLA_IPTUN_6RD_PREFIX */
1636 nla_total_size(sizeof(struct in6_addr)) +
1637 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1638 nla_total_size(4) +
1639 /* IFLA_IPTUN_6RD_PREFIXLEN */
1640 nla_total_size(2) +
1641 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1642 nla_total_size(2) +
1643#endif
1644 /* IFLA_IPTUN_ENCAP_TYPE */
1645 nla_total_size(2) +
1646 /* IFLA_IPTUN_ENCAP_FLAGS */
1647 nla_total_size(2) +
1648 /* IFLA_IPTUN_ENCAP_SPORT */
1649 nla_total_size(2) +
1650 /* IFLA_IPTUN_ENCAP_DPORT */
1651 nla_total_size(2) +
1652 0;
1653}
1654
1655static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1656{
1657 struct ip_tunnel *tunnel = netdev_priv(dev);
1658 struct ip_tunnel_parm *parm = &tunnel->parms;
1659
1660 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1661 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1662 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1663 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1664 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1665 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1666 !!(parm->iph.frag_off & htons(IP_DF))) ||
1667 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1668 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1669 goto nla_put_failure;
1670
1671#ifdef CONFIG_IPV6_SIT_6RD
1672 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1673 &tunnel->ip6rd.prefix) ||
1674 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1675 tunnel->ip6rd.relay_prefix) ||
1676 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1677 tunnel->ip6rd.prefixlen) ||
1678 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1679 tunnel->ip6rd.relay_prefixlen))
1680 goto nla_put_failure;
1681#endif
1682
1683 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1684 tunnel->encap.type) ||
1685 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1686 tunnel->encap.sport) ||
1687 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1688 tunnel->encap.dport) ||
1689 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1690 tunnel->encap.flags))
1691 goto nla_put_failure;
1692
1693 return 0;
1694
1695nla_put_failure:
1696 return -EMSGSIZE;
1697}
1698
1699static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1700 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1701 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1702 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1703 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1704 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1705 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1706 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1707 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1708#ifdef CONFIG_IPV6_SIT_6RD
1709 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1710 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1711 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1712 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1713#endif
1714 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1715 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1716 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1717 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1718};
1719
1720static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1721{
1722 struct net *net = dev_net(dev);
1723 struct sit_net *sitn = net_generic(net, sit_net_id);
1724
1725 if (dev != sitn->fb_tunnel_dev)
1726 unregister_netdevice_queue(dev, head);
1727}
1728
1729static struct rtnl_link_ops sit_link_ops __read_mostly = {
1730 .kind = "sit",
1731 .maxtype = IFLA_IPTUN_MAX,
1732 .policy = ipip6_policy,
1733 .priv_size = sizeof(struct ip_tunnel),
1734 .setup = ipip6_tunnel_setup,
1735 .validate = ipip6_validate,
1736 .newlink = ipip6_newlink,
1737 .changelink = ipip6_changelink,
1738 .get_size = ipip6_get_size,
1739 .fill_info = ipip6_fill_info,
1740 .dellink = ipip6_dellink,
1741 .get_link_net = ip_tunnel_get_link_net,
1742};
1743
1744static struct xfrm_tunnel sit_handler __read_mostly = {
1745 .handler = ipip6_rcv,
1746 .err_handler = ipip6_err,
1747 .priority = 1,
1748};
1749
1750static struct xfrm_tunnel ipip_handler __read_mostly = {
1751 .handler = ipip_rcv,
1752 .err_handler = ipip6_err,
1753 .priority = 2,
1754};
1755
1756#if IS_ENABLED(CONFIG_MPLS)
1757static struct xfrm_tunnel mplsip_handler __read_mostly = {
1758 .handler = mplsip_rcv,
1759 .err_handler = ipip6_err,
1760 .priority = 2,
1761};
1762#endif
1763
1764static void __net_exit sit_destroy_tunnels(struct net *net,
1765 struct list_head *head)
1766{
1767 struct sit_net *sitn = net_generic(net, sit_net_id);
1768 struct net_device *dev, *aux;
1769 int prio;
1770
1771 for_each_netdev_safe(net, dev, aux)
1772 if (dev->rtnl_link_ops == &sit_link_ops)
1773 unregister_netdevice_queue(dev, head);
1774
1775 for (prio = 1; prio < 4; prio++) {
1776 int h;
1777 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1778 struct ip_tunnel *t;
1779
1780 t = rtnl_dereference(sitn->tunnels[prio][h]);
1781 while (t) {
1782 /* If dev is in the same netns, it has already
1783 * been added to the list by the previous loop.
1784 */
1785 if (!net_eq(dev_net(t->dev), net))
1786 unregister_netdevice_queue(t->dev,
1787 head);
1788 t = rtnl_dereference(t->next);
1789 }
1790 }
1791 }
1792}
1793
1794static int __net_init sit_init_net(struct net *net)
1795{
1796 struct sit_net *sitn = net_generic(net, sit_net_id);
1797 struct ip_tunnel *t;
1798 int err;
1799
1800 sitn->tunnels[0] = sitn->tunnels_wc;
1801 sitn->tunnels[1] = sitn->tunnels_l;
1802 sitn->tunnels[2] = sitn->tunnels_r;
1803 sitn->tunnels[3] = sitn->tunnels_r_l;
1804
1805 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1806 NET_NAME_UNKNOWN,
1807 ipip6_tunnel_setup);
1808 if (!sitn->fb_tunnel_dev) {
1809 err = -ENOMEM;
1810 goto err_alloc_dev;
1811 }
1812 dev_net_set(sitn->fb_tunnel_dev, net);
1813 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1814 /* FB netdevice is special: we have one, and only one per netns.
1815 * Allowing to move it to another netns is clearly unsafe.
1816 */
1817 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1818
1819 err = register_netdev(sitn->fb_tunnel_dev);
1820 if (err)
1821 goto err_reg_dev;
1822
1823 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1824 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1825
1826 t = netdev_priv(sitn->fb_tunnel_dev);
1827
1828 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1829 return 0;
1830
1831err_reg_dev:
1832 ipip6_dev_free(sitn->fb_tunnel_dev);
1833err_alloc_dev:
1834 return err;
1835}
1836
1837static void __net_exit sit_exit_net(struct net *net)
1838{
1839 LIST_HEAD(list);
1840
1841 rtnl_lock();
1842 sit_destroy_tunnels(net, &list);
1843 unregister_netdevice_many(&list);
1844 rtnl_unlock();
1845}
1846
1847static struct pernet_operations sit_net_ops = {
1848 .init = sit_init_net,
1849 .exit = sit_exit_net,
1850 .id = &sit_net_id,
1851 .size = sizeof(struct sit_net),
1852};
1853
1854static void __exit sit_cleanup(void)
1855{
1856 rtnl_link_unregister(&sit_link_ops);
1857 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1858 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1859#if IS_ENABLED(CONFIG_MPLS)
1860 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1861#endif
1862
1863 unregister_pernet_device(&sit_net_ops);
1864 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1865}
1866
1867static int __init sit_init(void)
1868{
1869 int err;
1870
1871 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1872
1873 err = register_pernet_device(&sit_net_ops);
1874 if (err < 0)
1875 return err;
1876 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1877 if (err < 0) {
1878 pr_info("%s: can't register ip6ip4\n", __func__);
1879 goto xfrm_tunnel_failed;
1880 }
1881 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1882 if (err < 0) {
1883 pr_info("%s: can't register ip4ip4\n", __func__);
1884 goto xfrm_tunnel4_failed;
1885 }
1886#if IS_ENABLED(CONFIG_MPLS)
1887 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1888 if (err < 0) {
1889 pr_info("%s: can't register mplsip\n", __func__);
1890 goto xfrm_tunnel_mpls_failed;
1891 }
1892#endif
1893 err = rtnl_link_register(&sit_link_ops);
1894 if (err < 0)
1895 goto rtnl_link_failed;
1896
1897out:
1898 return err;
1899
1900rtnl_link_failed:
1901#if IS_ENABLED(CONFIG_MPLS)
1902 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1903xfrm_tunnel_mpls_failed:
1904#endif
1905 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1906xfrm_tunnel4_failed:
1907 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1908xfrm_tunnel_failed:
1909 unregister_pernet_device(&sit_net_ops);
1910 goto out;
1911}
1912
1913module_init(sit_init);
1914module_exit(sit_cleanup);
1915MODULE_LICENSE("GPL");
1916MODULE_ALIAS_RTNL_LINK("sit");
1917MODULE_ALIAS_NETDEV("sit0");