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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
9 *
10 * Changes:
11 * Roger Venning <r.venning@telstra.com>: 6to4 support
12 * Nate Thompson <nate@thebog.net>: 6to4 support
13 * Fred Templin <fred.l.templin@boeing.com>: isatap support
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/capability.h>
20#include <linux/errno.h>
21#include <linux/types.h>
22#include <linux/socket.h>
23#include <linux/sockios.h>
24#include <linux/net.h>
25#include <linux/in6.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/icmp.h>
29#include <linux/slab.h>
30#include <linux/uaccess.h>
31#include <linux/init.h>
32#include <linux/netfilter_ipv4.h>
33#include <linux/if_ether.h>
34
35#include <net/sock.h>
36#include <net/snmp.h>
37
38#include <net/ipv6.h>
39#include <net/protocol.h>
40#include <net/transp_v6.h>
41#include <net/ip6_fib.h>
42#include <net/ip6_route.h>
43#include <net/ndisc.h>
44#include <net/addrconf.h>
45#include <net/ip.h>
46#include <net/udp.h>
47#include <net/icmp.h>
48#include <net/ip_tunnels.h>
49#include <net/inet_ecn.h>
50#include <net/xfrm.h>
51#include <net/dsfield.h>
52#include <net/net_namespace.h>
53#include <net/netns/generic.h>
54
55/*
56 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
57
58 For comments look at net/ipv4/ip_gre.c --ANK
59 */
60
61#define IP6_SIT_HASH_SIZE 16
62#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
63
64static bool log_ecn_error = true;
65module_param(log_ecn_error, bool, 0644);
66MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
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);
71static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
72 __be32 *v4dst);
73static struct rtnl_link_ops sit_link_ops __read_mostly;
74
75static unsigned int sit_net_id __read_mostly;
76struct sit_net {
77 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
78 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
79 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
80 struct ip_tunnel __rcu *tunnels_wc[1];
81 struct ip_tunnel __rcu **tunnels[4];
82
83 struct net_device *fb_tunnel_dev;
84};
85
86static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
87{
88 struct ip_tunnel *t = netdev_priv(dev);
89
90 return net_generic(t->net, sit_net_id);
91}
92
93/*
94 * Must be invoked with rcu_read_lock
95 */
96static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
97 struct net_device *dev,
98 __be32 remote, __be32 local,
99 int sifindex)
100{
101 unsigned int h0 = HASH(remote);
102 unsigned int h1 = HASH(local);
103 struct ip_tunnel *t;
104 struct sit_net *sitn = net_generic(net, sit_net_id);
105 int ifindex = dev ? dev->ifindex : 0;
106
107 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
108 if (local == t->parms.iph.saddr &&
109 remote == t->parms.iph.daddr &&
110 (!dev || !t->parms.link || ifindex == t->parms.link ||
111 sifindex == t->parms.link) &&
112 (t->dev->flags & IFF_UP))
113 return t;
114 }
115 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
116 if (remote == t->parms.iph.daddr &&
117 (!dev || !t->parms.link || ifindex == t->parms.link ||
118 sifindex == t->parms.link) &&
119 (t->dev->flags & IFF_UP))
120 return t;
121 }
122 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
123 if (local == t->parms.iph.saddr &&
124 (!dev || !t->parms.link || ifindex == t->parms.link ||
125 sifindex == t->parms.link) &&
126 (t->dev->flags & IFF_UP))
127 return t;
128 }
129 t = rcu_dereference(sitn->tunnels_wc[0]);
130 if (t && (t->dev->flags & IFF_UP))
131 return t;
132 return NULL;
133}
134
135static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
136 struct ip_tunnel_parm *parms)
137{
138 __be32 remote = parms->iph.daddr;
139 __be32 local = parms->iph.saddr;
140 unsigned int h = 0;
141 int prio = 0;
142
143 if (remote) {
144 prio |= 2;
145 h ^= HASH(remote);
146 }
147 if (local) {
148 prio |= 1;
149 h ^= HASH(local);
150 }
151 return &sitn->tunnels[prio][h];
152}
153
154static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
155 struct ip_tunnel *t)
156{
157 return __ipip6_bucket(sitn, &t->parms);
158}
159
160static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
161{
162 struct ip_tunnel __rcu **tp;
163 struct ip_tunnel *iter;
164
165 for (tp = ipip6_bucket(sitn, t);
166 (iter = rtnl_dereference(*tp)) != NULL;
167 tp = &iter->next) {
168 if (t == iter) {
169 rcu_assign_pointer(*tp, t->next);
170 break;
171 }
172 }
173}
174
175static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
176{
177 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
178
179 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
180 rcu_assign_pointer(*tp, t);
181}
182
183static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
184{
185#ifdef CONFIG_IPV6_SIT_6RD
186 struct ip_tunnel *t = netdev_priv(dev);
187
188 if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
189 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
190 t->ip6rd.relay_prefix = 0;
191 t->ip6rd.prefixlen = 16;
192 t->ip6rd.relay_prefixlen = 0;
193 } else {
194 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
195 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
196 }
197#endif
198}
199
200static int ipip6_tunnel_create(struct net_device *dev)
201{
202 struct ip_tunnel *t = netdev_priv(dev);
203 struct net *net = dev_net(dev);
204 struct sit_net *sitn = net_generic(net, sit_net_id);
205 int err;
206
207 __dev_addr_set(dev, &t->parms.iph.saddr, 4);
208 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
209
210 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
211 dev->priv_flags |= IFF_ISATAP;
212
213 dev->rtnl_link_ops = &sit_link_ops;
214
215 err = register_netdevice(dev);
216 if (err < 0)
217 goto out;
218
219 ipip6_tunnel_clone_6rd(dev, sitn);
220
221 ipip6_tunnel_link(sitn, t);
222 return 0;
223
224out:
225 return err;
226}
227
228static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
229 struct ip_tunnel_parm *parms, int create)
230{
231 __be32 remote = parms->iph.daddr;
232 __be32 local = parms->iph.saddr;
233 struct ip_tunnel *t, *nt;
234 struct ip_tunnel __rcu **tp;
235 struct net_device *dev;
236 char name[IFNAMSIZ];
237 struct sit_net *sitn = net_generic(net, sit_net_id);
238
239 for (tp = __ipip6_bucket(sitn, parms);
240 (t = rtnl_dereference(*tp)) != NULL;
241 tp = &t->next) {
242 if (local == t->parms.iph.saddr &&
243 remote == t->parms.iph.daddr &&
244 parms->link == t->parms.link) {
245 if (create)
246 return NULL;
247 else
248 return t;
249 }
250 }
251 if (!create)
252 goto failed;
253
254 if (parms->name[0]) {
255 if (!dev_valid_name(parms->name))
256 goto failed;
257 strscpy(name, parms->name, IFNAMSIZ);
258 } else {
259 strcpy(name, "sit%d");
260 }
261 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
262 ipip6_tunnel_setup);
263 if (!dev)
264 return NULL;
265
266 dev_net_set(dev, net);
267
268 nt = netdev_priv(dev);
269
270 nt->parms = *parms;
271 if (ipip6_tunnel_create(dev) < 0)
272 goto failed_free;
273
274 if (!parms->name[0])
275 strcpy(parms->name, dev->name);
276
277 return nt;
278
279failed_free:
280 free_netdev(dev);
281failed:
282 return NULL;
283}
284
285#define for_each_prl_rcu(start) \
286 for (prl = rcu_dereference(start); \
287 prl; \
288 prl = rcu_dereference(prl->next))
289
290static struct ip_tunnel_prl_entry *
291__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
292{
293 struct ip_tunnel_prl_entry *prl;
294
295 for_each_prl_rcu(t->prl)
296 if (prl->addr == addr)
297 break;
298 return prl;
299
300}
301
302static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a)
303{
304 struct ip_tunnel *t = netdev_priv(dev);
305 struct ip_tunnel_prl kprl, *kp;
306 struct ip_tunnel_prl_entry *prl;
307 unsigned int cmax, c = 0, ca, len;
308 int ret = 0;
309
310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
311 return -EINVAL;
312
313 if (copy_from_user(&kprl, a, sizeof(kprl)))
314 return -EFAULT;
315 cmax = kprl.datalen / sizeof(kprl);
316 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
317 cmax = 1;
318
319 /* For simple GET or for root users,
320 * we try harder to allocate.
321 */
322 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
323 kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) :
324 NULL;
325
326 ca = min(t->prl_count, cmax);
327
328 if (!kp) {
329 /* We don't try hard to allocate much memory for
330 * non-root users.
331 * For root users, retry allocating enough memory for
332 * the answer.
333 */
334 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT |
335 __GFP_NOWARN);
336 if (!kp) {
337 ret = -ENOMEM;
338 goto out;
339 }
340 }
341
342 rcu_read_lock();
343 for_each_prl_rcu(t->prl) {
344 if (c >= cmax)
345 break;
346 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
347 continue;
348 kp[c].addr = prl->addr;
349 kp[c].flags = prl->flags;
350 c++;
351 if (kprl.addr != htonl(INADDR_ANY))
352 break;
353 }
354
355 rcu_read_unlock();
356
357 len = sizeof(*kp) * c;
358 ret = 0;
359 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
360 ret = -EFAULT;
361
362 kfree(kp);
363out:
364 return ret;
365}
366
367static int
368ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
369{
370 struct ip_tunnel_prl_entry *p;
371 int err = 0;
372
373 if (a->addr == htonl(INADDR_ANY))
374 return -EINVAL;
375
376 ASSERT_RTNL();
377
378 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
379 if (p->addr == a->addr) {
380 if (chg) {
381 p->flags = a->flags;
382 goto out;
383 }
384 err = -EEXIST;
385 goto out;
386 }
387 }
388
389 if (chg) {
390 err = -ENXIO;
391 goto out;
392 }
393
394 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
395 if (!p) {
396 err = -ENOBUFS;
397 goto out;
398 }
399
400 p->next = t->prl;
401 p->addr = a->addr;
402 p->flags = a->flags;
403 t->prl_count++;
404 rcu_assign_pointer(t->prl, p);
405out:
406 return err;
407}
408
409static void prl_list_destroy_rcu(struct rcu_head *head)
410{
411 struct ip_tunnel_prl_entry *p, *n;
412
413 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
414 do {
415 n = rcu_dereference_protected(p->next, 1);
416 kfree(p);
417 p = n;
418 } while (p);
419}
420
421static int
422ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
423{
424 struct ip_tunnel_prl_entry *x;
425 struct ip_tunnel_prl_entry __rcu **p;
426 int err = 0;
427
428 ASSERT_RTNL();
429
430 if (a && a->addr != htonl(INADDR_ANY)) {
431 for (p = &t->prl;
432 (x = rtnl_dereference(*p)) != NULL;
433 p = &x->next) {
434 if (x->addr == a->addr) {
435 *p = x->next;
436 kfree_rcu(x, rcu_head);
437 t->prl_count--;
438 goto out;
439 }
440 }
441 err = -ENXIO;
442 } else {
443 x = rtnl_dereference(t->prl);
444 if (x) {
445 t->prl_count = 0;
446 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
447 t->prl = NULL;
448 }
449 }
450out:
451 return err;
452}
453
454static int ipip6_tunnel_prl_ctl(struct net_device *dev,
455 struct ip_tunnel_prl __user *data, int cmd)
456{
457 struct ip_tunnel *t = netdev_priv(dev);
458 struct ip_tunnel_prl prl;
459 int err;
460
461 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
462 return -EPERM;
463 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
464 return -EINVAL;
465
466 if (copy_from_user(&prl, data, sizeof(prl)))
467 return -EFAULT;
468
469 switch (cmd) {
470 case SIOCDELPRL:
471 err = ipip6_tunnel_del_prl(t, &prl);
472 break;
473 case SIOCADDPRL:
474 case SIOCCHGPRL:
475 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
476 break;
477 }
478 dst_cache_reset(&t->dst_cache);
479 netdev_state_change(dev);
480 return err;
481}
482
483static int
484isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
485{
486 struct ip_tunnel_prl_entry *p;
487 int ok = 1;
488
489 rcu_read_lock();
490 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
491 if (p) {
492 if (p->flags & PRL_DEFAULT)
493 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
494 else
495 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
496 } else {
497 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
498
499 if (ipv6_addr_is_isatap(addr6) &&
500 (addr6->s6_addr32[3] == iph->saddr) &&
501 ipv6_chk_prefix(addr6, t->dev))
502 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
503 else
504 ok = 0;
505 }
506 rcu_read_unlock();
507 return ok;
508}
509
510static void ipip6_tunnel_uninit(struct net_device *dev)
511{
512 struct ip_tunnel *tunnel = netdev_priv(dev);
513 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
514
515 if (dev == sitn->fb_tunnel_dev) {
516 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
517 } else {
518 ipip6_tunnel_unlink(sitn, tunnel);
519 ipip6_tunnel_del_prl(tunnel, NULL);
520 }
521 dst_cache_reset(&tunnel->dst_cache);
522 netdev_put(dev, &tunnel->dev_tracker);
523}
524
525static int ipip6_err(struct sk_buff *skb, u32 info)
526{
527 const struct iphdr *iph = (const struct iphdr *)skb->data;
528 const int type = icmp_hdr(skb)->type;
529 const int code = icmp_hdr(skb)->code;
530 unsigned int data_len = 0;
531 struct ip_tunnel *t;
532 int sifindex;
533 int err;
534
535 switch (type) {
536 default:
537 case ICMP_PARAMETERPROB:
538 return 0;
539
540 case ICMP_DEST_UNREACH:
541 switch (code) {
542 case ICMP_SR_FAILED:
543 /* Impossible event. */
544 return 0;
545 default:
546 /* All others are translated to HOST_UNREACH.
547 rfc2003 contains "deep thoughts" about NET_UNREACH,
548 I believe they are just ether pollution. --ANK
549 */
550 break;
551 }
552 break;
553 case ICMP_TIME_EXCEEDED:
554 if (code != ICMP_EXC_TTL)
555 return 0;
556 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
557 break;
558 case ICMP_REDIRECT:
559 break;
560 }
561
562 err = -ENOENT;
563
564 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
565 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
566 iph->daddr, iph->saddr, sifindex);
567 if (!t)
568 goto out;
569
570 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
571 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
572 t->parms.link, iph->protocol);
573 err = 0;
574 goto out;
575 }
576 if (type == ICMP_REDIRECT) {
577 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
578 iph->protocol);
579 err = 0;
580 goto out;
581 }
582
583 err = 0;
584 if (__in6_dev_get(skb->dev) &&
585 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
586 goto out;
587
588 if (t->parms.iph.daddr == 0)
589 goto out;
590
591 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
592 goto out;
593
594 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
595 t->err_count++;
596 else
597 t->err_count = 1;
598 t->err_time = jiffies;
599out:
600 return err;
601}
602
603static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
604 const struct in6_addr *v6addr)
605{
606 __be32 v4embed = 0;
607 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
608 return true;
609 return false;
610}
611
612/* Checks if an address matches an address on the tunnel interface.
613 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
614 * Long story:
615 * This function is called after we considered the packet as spoofed
616 * in is_spoofed_6rd.
617 * We may have a router that is doing NAT for proto 41 packets
618 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
619 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
620 * function will return true, dropping the packet.
621 * But, we can still check if is spoofed against the IP
622 * addresses associated with the interface.
623 */
624static bool only_dnatted(const struct ip_tunnel *tunnel,
625 const struct in6_addr *v6dst)
626{
627 int prefix_len;
628
629#ifdef CONFIG_IPV6_SIT_6RD
630 prefix_len = tunnel->ip6rd.prefixlen + 32
631 - tunnel->ip6rd.relay_prefixlen;
632#else
633 prefix_len = 48;
634#endif
635 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
636}
637
638/* Returns true if a packet is spoofed */
639static bool packet_is_spoofed(struct sk_buff *skb,
640 const struct iphdr *iph,
641 struct ip_tunnel *tunnel)
642{
643 const struct ipv6hdr *ipv6h;
644
645 if (tunnel->dev->priv_flags & IFF_ISATAP) {
646 if (!isatap_chksrc(skb, iph, tunnel))
647 return true;
648
649 return false;
650 }
651
652 if (tunnel->dev->flags & IFF_POINTOPOINT)
653 return false;
654
655 ipv6h = ipv6_hdr(skb);
656
657 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
658 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
659 &iph->saddr, &ipv6h->saddr,
660 &iph->daddr, &ipv6h->daddr);
661 return true;
662 }
663
664 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
665 return false;
666
667 if (only_dnatted(tunnel, &ipv6h->daddr))
668 return false;
669
670 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
671 &iph->saddr, &ipv6h->saddr,
672 &iph->daddr, &ipv6h->daddr);
673 return true;
674}
675
676static int ipip6_rcv(struct sk_buff *skb)
677{
678 const struct iphdr *iph = ip_hdr(skb);
679 struct ip_tunnel *tunnel;
680 int sifindex;
681 int err;
682
683 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
684 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
685 iph->saddr, iph->daddr, sifindex);
686 if (tunnel) {
687 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
688 tunnel->parms.iph.protocol != 0)
689 goto out;
690
691 skb->mac_header = skb->network_header;
692 skb_reset_network_header(skb);
693 IPCB(skb)->flags = 0;
694 skb->dev = tunnel->dev;
695
696 if (packet_is_spoofed(skb, iph, tunnel)) {
697 DEV_STATS_INC(tunnel->dev, rx_errors);
698 goto out;
699 }
700
701 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
702 !net_eq(tunnel->net, dev_net(tunnel->dev))))
703 goto out;
704
705 /* skb can be uncloned in iptunnel_pull_header, so
706 * old iph is no longer valid
707 */
708 iph = (const struct iphdr *)skb_mac_header(skb);
709 skb_reset_mac_header(skb);
710
711 err = IP_ECN_decapsulate(iph, skb);
712 if (unlikely(err)) {
713 if (log_ecn_error)
714 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
715 &iph->saddr, iph->tos);
716 if (err > 1) {
717 DEV_STATS_INC(tunnel->dev, rx_frame_errors);
718 DEV_STATS_INC(tunnel->dev, rx_errors);
719 goto out;
720 }
721 }
722
723 dev_sw_netstats_rx_add(tunnel->dev, skb->len);
724
725 netif_rx(skb);
726
727 return 0;
728 }
729
730 /* no tunnel matched, let upstream know, ipsec may handle it */
731 return 1;
732out:
733 kfree_skb(skb);
734 return 0;
735}
736
737static const struct tnl_ptk_info ipip_tpi = {
738 /* no tunnel info required for ipip. */
739 .proto = htons(ETH_P_IP),
740};
741
742#if IS_ENABLED(CONFIG_MPLS)
743static const struct tnl_ptk_info mplsip_tpi = {
744 /* no tunnel info required for mplsip. */
745 .proto = htons(ETH_P_MPLS_UC),
746};
747#endif
748
749static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
750{
751 const struct iphdr *iph;
752 struct ip_tunnel *tunnel;
753 int sifindex;
754
755 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
756
757 iph = ip_hdr(skb);
758 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
759 iph->saddr, iph->daddr, sifindex);
760 if (tunnel) {
761 const struct tnl_ptk_info *tpi;
762
763 if (tunnel->parms.iph.protocol != ipproto &&
764 tunnel->parms.iph.protocol != 0)
765 goto drop;
766
767 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
768 goto drop;
769#if IS_ENABLED(CONFIG_MPLS)
770 if (ipproto == IPPROTO_MPLS)
771 tpi = &mplsip_tpi;
772 else
773#endif
774 tpi = &ipip_tpi;
775 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
776 goto drop;
777 skb_reset_mac_header(skb);
778
779 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
780 }
781
782 return 1;
783
784drop:
785 kfree_skb(skb);
786 return 0;
787}
788
789static int ipip_rcv(struct sk_buff *skb)
790{
791 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
792}
793
794#if IS_ENABLED(CONFIG_MPLS)
795static int mplsip_rcv(struct sk_buff *skb)
796{
797 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
798}
799#endif
800
801/*
802 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
803 * stores the embedded IPv4 address in v4dst and returns true.
804 */
805static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
806 __be32 *v4dst)
807{
808#ifdef CONFIG_IPV6_SIT_6RD
809 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
810 tunnel->ip6rd.prefixlen)) {
811 unsigned int pbw0, pbi0;
812 int pbi1;
813 u32 d;
814
815 pbw0 = tunnel->ip6rd.prefixlen >> 5;
816 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
817
818 d = tunnel->ip6rd.relay_prefixlen < 32 ?
819 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
820 tunnel->ip6rd.relay_prefixlen : 0;
821
822 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
823 if (pbi1 > 0)
824 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
825 (32 - pbi1);
826
827 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
828 return true;
829 }
830#else
831 if (v6dst->s6_addr16[0] == htons(0x2002)) {
832 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
833 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
834 return true;
835 }
836#endif
837 return false;
838}
839
840static inline __be32 try_6rd(struct ip_tunnel *tunnel,
841 const struct in6_addr *v6dst)
842{
843 __be32 dst = 0;
844 check_6rd(tunnel, v6dst, &dst);
845 return dst;
846}
847
848/*
849 * This function assumes it is being called from dev_queue_xmit()
850 * and that skb is filled properly by that function.
851 */
852
853static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
854 struct net_device *dev)
855{
856 struct ip_tunnel *tunnel = netdev_priv(dev);
857 const struct iphdr *tiph = &tunnel->parms.iph;
858 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
859 u8 tos = tunnel->parms.iph.tos;
860 __be16 df = tiph->frag_off;
861 struct rtable *rt; /* Route to the other host */
862 struct net_device *tdev; /* Device to other host */
863 unsigned int max_headroom; /* The extra header space needed */
864 __be32 dst = tiph->daddr;
865 struct flowi4 fl4;
866 int mtu;
867 const struct in6_addr *addr6;
868 int addr_type;
869 u8 ttl;
870 u8 protocol = IPPROTO_IPV6;
871 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
872
873 if (tos == 1)
874 tos = ipv6_get_dsfield(iph6);
875
876 /* ISATAP (RFC4214) - must come before 6to4 */
877 if (dev->priv_flags & IFF_ISATAP) {
878 struct neighbour *neigh = NULL;
879 bool do_tx_error = false;
880
881 if (skb_dst(skb))
882 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
883
884 if (!neigh) {
885 net_dbg_ratelimited("nexthop == NULL\n");
886 goto tx_error;
887 }
888
889 addr6 = (const struct in6_addr *)&neigh->primary_key;
890 addr_type = ipv6_addr_type(addr6);
891
892 if ((addr_type & IPV6_ADDR_UNICAST) &&
893 ipv6_addr_is_isatap(addr6))
894 dst = addr6->s6_addr32[3];
895 else
896 do_tx_error = true;
897
898 neigh_release(neigh);
899 if (do_tx_error)
900 goto tx_error;
901 }
902
903 if (!dst)
904 dst = try_6rd(tunnel, &iph6->daddr);
905
906 if (!dst) {
907 struct neighbour *neigh = NULL;
908 bool do_tx_error = false;
909
910 if (skb_dst(skb))
911 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
912
913 if (!neigh) {
914 net_dbg_ratelimited("nexthop == NULL\n");
915 goto tx_error;
916 }
917
918 addr6 = (const struct in6_addr *)&neigh->primary_key;
919 addr_type = ipv6_addr_type(addr6);
920
921 if (addr_type == IPV6_ADDR_ANY) {
922 addr6 = &ipv6_hdr(skb)->daddr;
923 addr_type = ipv6_addr_type(addr6);
924 }
925
926 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
927 dst = addr6->s6_addr32[3];
928 else
929 do_tx_error = true;
930
931 neigh_release(neigh);
932 if (do_tx_error)
933 goto tx_error;
934 }
935
936 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
937 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
938 0, dst, tiph->saddr, 0, 0,
939 sock_net_uid(tunnel->net, NULL));
940
941 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
942 if (!rt) {
943 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
944 if (IS_ERR(rt)) {
945 DEV_STATS_INC(dev, tx_carrier_errors);
946 goto tx_error_icmp;
947 }
948 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
949 }
950
951 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
952 ip_rt_put(rt);
953 DEV_STATS_INC(dev, tx_carrier_errors);
954 goto tx_error_icmp;
955 }
956 tdev = rt->dst.dev;
957
958 if (tdev == dev) {
959 ip_rt_put(rt);
960 DEV_STATS_INC(dev, collisions);
961 goto tx_error;
962 }
963
964 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
965 ip_rt_put(rt);
966 goto tx_error;
967 }
968
969 if (df) {
970 mtu = dst_mtu(&rt->dst) - t_hlen;
971
972 if (mtu < IPV4_MIN_MTU) {
973 DEV_STATS_INC(dev, collisions);
974 ip_rt_put(rt);
975 goto tx_error;
976 }
977
978 if (mtu < IPV6_MIN_MTU) {
979 mtu = IPV6_MIN_MTU;
980 df = 0;
981 }
982
983 if (tunnel->parms.iph.daddr)
984 skb_dst_update_pmtu_no_confirm(skb, mtu);
985
986 if (skb->len > mtu && !skb_is_gso(skb)) {
987 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
988 ip_rt_put(rt);
989 goto tx_error;
990 }
991 }
992
993 if (tunnel->err_count > 0) {
994 if (time_before(jiffies,
995 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
996 tunnel->err_count--;
997 dst_link_failure(skb);
998 } else
999 tunnel->err_count = 0;
1000 }
1001
1002 /*
1003 * Okay, now see if we can stuff it in the buffer as-is.
1004 */
1005 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1006
1007 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1008 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1009 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1010 if (!new_skb) {
1011 ip_rt_put(rt);
1012 DEV_STATS_INC(dev, tx_dropped);
1013 kfree_skb(skb);
1014 return NETDEV_TX_OK;
1015 }
1016 if (skb->sk)
1017 skb_set_owner_w(new_skb, skb->sk);
1018 dev_kfree_skb(skb);
1019 skb = new_skb;
1020 iph6 = ipv6_hdr(skb);
1021 }
1022 ttl = tiph->ttl;
1023 if (ttl == 0)
1024 ttl = iph6->hop_limit;
1025 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1026
1027 if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0) {
1028 ip_rt_put(rt);
1029 goto tx_error;
1030 }
1031
1032 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1033
1034 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1035 df, !net_eq(tunnel->net, dev_net(dev)));
1036 return NETDEV_TX_OK;
1037
1038tx_error_icmp:
1039 dst_link_failure(skb);
1040tx_error:
1041 kfree_skb(skb);
1042 DEV_STATS_INC(dev, tx_errors);
1043 return NETDEV_TX_OK;
1044}
1045
1046static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1047 struct net_device *dev, u8 ipproto)
1048{
1049 struct ip_tunnel *tunnel = netdev_priv(dev);
1050 const struct iphdr *tiph = &tunnel->parms.iph;
1051
1052 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1053 goto tx_error;
1054
1055 skb_set_inner_ipproto(skb, ipproto);
1056
1057 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1058 return NETDEV_TX_OK;
1059tx_error:
1060 kfree_skb(skb);
1061 DEV_STATS_INC(dev, tx_errors);
1062 return NETDEV_TX_OK;
1063}
1064
1065static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1066 struct net_device *dev)
1067{
1068 if (!pskb_inet_may_pull(skb))
1069 goto tx_err;
1070
1071 switch (skb->protocol) {
1072 case htons(ETH_P_IP):
1073 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1074 break;
1075 case htons(ETH_P_IPV6):
1076 ipip6_tunnel_xmit(skb, dev);
1077 break;
1078#if IS_ENABLED(CONFIG_MPLS)
1079 case htons(ETH_P_MPLS_UC):
1080 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1081 break;
1082#endif
1083 default:
1084 goto tx_err;
1085 }
1086
1087 return NETDEV_TX_OK;
1088
1089tx_err:
1090 DEV_STATS_INC(dev, tx_errors);
1091 kfree_skb(skb);
1092 return NETDEV_TX_OK;
1093
1094}
1095
1096static void ipip6_tunnel_bind_dev(struct net_device *dev)
1097{
1098 struct ip_tunnel *tunnel = netdev_priv(dev);
1099 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1100 struct net_device *tdev = NULL;
1101 int hlen = LL_MAX_HEADER;
1102 const struct iphdr *iph;
1103 struct flowi4 fl4;
1104
1105 iph = &tunnel->parms.iph;
1106
1107 if (iph->daddr) {
1108 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1109 NULL,
1110 iph->daddr, iph->saddr,
1111 0, 0,
1112 IPPROTO_IPV6,
1113 RT_TOS(iph->tos),
1114 tunnel->parms.link);
1115
1116 if (!IS_ERR(rt)) {
1117 tdev = rt->dst.dev;
1118 ip_rt_put(rt);
1119 }
1120 dev->flags |= IFF_POINTOPOINT;
1121 }
1122
1123 if (!tdev && tunnel->parms.link)
1124 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1125
1126 if (tdev && !netif_is_l3_master(tdev)) {
1127 int mtu;
1128
1129 mtu = tdev->mtu - t_hlen;
1130 if (mtu < IPV6_MIN_MTU)
1131 mtu = IPV6_MIN_MTU;
1132 WRITE_ONCE(dev->mtu, mtu);
1133 hlen = tdev->hard_header_len + tdev->needed_headroom;
1134 }
1135 dev->needed_headroom = t_hlen + hlen;
1136}
1137
1138static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1139 __u32 fwmark)
1140{
1141 struct net *net = t->net;
1142 struct sit_net *sitn = net_generic(net, sit_net_id);
1143
1144 ipip6_tunnel_unlink(sitn, t);
1145 synchronize_net();
1146 t->parms.iph.saddr = p->iph.saddr;
1147 t->parms.iph.daddr = p->iph.daddr;
1148 __dev_addr_set(t->dev, &p->iph.saddr, 4);
1149 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1150 ipip6_tunnel_link(sitn, t);
1151 t->parms.iph.ttl = p->iph.ttl;
1152 t->parms.iph.tos = p->iph.tos;
1153 t->parms.iph.frag_off = p->iph.frag_off;
1154 if (t->parms.link != p->link || t->fwmark != fwmark) {
1155 t->parms.link = p->link;
1156 t->fwmark = fwmark;
1157 ipip6_tunnel_bind_dev(t->dev);
1158 }
1159 dst_cache_reset(&t->dst_cache);
1160 netdev_state_change(t->dev);
1161}
1162
1163#ifdef CONFIG_IPV6_SIT_6RD
1164static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1165 struct ip_tunnel_6rd *ip6rd)
1166{
1167 struct in6_addr prefix;
1168 __be32 relay_prefix;
1169
1170 if (ip6rd->relay_prefixlen > 32 ||
1171 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1172 return -EINVAL;
1173
1174 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1175 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1176 return -EINVAL;
1177 if (ip6rd->relay_prefixlen)
1178 relay_prefix = ip6rd->relay_prefix &
1179 htonl(0xffffffffUL <<
1180 (32 - ip6rd->relay_prefixlen));
1181 else
1182 relay_prefix = 0;
1183 if (relay_prefix != ip6rd->relay_prefix)
1184 return -EINVAL;
1185
1186 t->ip6rd.prefix = prefix;
1187 t->ip6rd.relay_prefix = relay_prefix;
1188 t->ip6rd.prefixlen = ip6rd->prefixlen;
1189 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1190 dst_cache_reset(&t->dst_cache);
1191 netdev_state_change(t->dev);
1192 return 0;
1193}
1194
1195static int
1196ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data)
1197{
1198 struct ip_tunnel *t = netdev_priv(dev);
1199 struct ip_tunnel_6rd ip6rd;
1200 struct ip_tunnel_parm p;
1201
1202 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1203 if (copy_from_user(&p, data, sizeof(p)))
1204 return -EFAULT;
1205 t = ipip6_tunnel_locate(t->net, &p, 0);
1206 }
1207 if (!t)
1208 t = netdev_priv(dev);
1209
1210 ip6rd.prefix = t->ip6rd.prefix;
1211 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1212 ip6rd.prefixlen = t->ip6rd.prefixlen;
1213 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1214 if (copy_to_user(data, &ip6rd, sizeof(ip6rd)))
1215 return -EFAULT;
1216 return 0;
1217}
1218
1219static int
1220ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data,
1221 int cmd)
1222{
1223 struct ip_tunnel *t = netdev_priv(dev);
1224 struct ip_tunnel_6rd ip6rd;
1225 int err;
1226
1227 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1228 return -EPERM;
1229 if (copy_from_user(&ip6rd, data, sizeof(ip6rd)))
1230 return -EFAULT;
1231
1232 if (cmd != SIOCDEL6RD) {
1233 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1234 if (err < 0)
1235 return err;
1236 } else
1237 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1238 return 0;
1239}
1240
1241#endif /* CONFIG_IPV6_SIT_6RD */
1242
1243static bool ipip6_valid_ip_proto(u8 ipproto)
1244{
1245 return ipproto == IPPROTO_IPV6 ||
1246 ipproto == IPPROTO_IPIP ||
1247#if IS_ENABLED(CONFIG_MPLS)
1248 ipproto == IPPROTO_MPLS ||
1249#endif
1250 ipproto == 0;
1251}
1252
1253static int
1254__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1255{
1256 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1257 return -EPERM;
1258
1259 if (!ipip6_valid_ip_proto(p->iph.protocol))
1260 return -EINVAL;
1261 if (p->iph.version != 4 ||
1262 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1263 return -EINVAL;
1264
1265 if (p->iph.ttl)
1266 p->iph.frag_off |= htons(IP_DF);
1267 return 0;
1268}
1269
1270static int
1271ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1272{
1273 struct ip_tunnel *t = netdev_priv(dev);
1274
1275 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1276 t = ipip6_tunnel_locate(t->net, p, 0);
1277 if (!t)
1278 t = netdev_priv(dev);
1279 memcpy(p, &t->parms, sizeof(*p));
1280 return 0;
1281}
1282
1283static int
1284ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1285{
1286 struct ip_tunnel *t = netdev_priv(dev);
1287 int err;
1288
1289 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1290 if (err)
1291 return err;
1292
1293 t = ipip6_tunnel_locate(t->net, p, 1);
1294 if (!t)
1295 return -ENOBUFS;
1296 return 0;
1297}
1298
1299static int
1300ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1301{
1302 struct ip_tunnel *t = netdev_priv(dev);
1303 int err;
1304
1305 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1306 if (err)
1307 return err;
1308
1309 t = ipip6_tunnel_locate(t->net, p, 0);
1310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1311 if (!t)
1312 return -ENOENT;
1313 } else {
1314 if (t) {
1315 if (t->dev != dev)
1316 return -EEXIST;
1317 } else {
1318 if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1319 (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1320 return -EINVAL;
1321 t = netdev_priv(dev);
1322 }
1323
1324 ipip6_tunnel_update(t, p, t->fwmark);
1325 }
1326
1327 return 0;
1328}
1329
1330static int
1331ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1332{
1333 struct ip_tunnel *t = netdev_priv(dev);
1334
1335 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1336 return -EPERM;
1337
1338 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1339 t = ipip6_tunnel_locate(t->net, p, 0);
1340 if (!t)
1341 return -ENOENT;
1342 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1343 return -EPERM;
1344 dev = t->dev;
1345 }
1346 unregister_netdevice(dev);
1347 return 0;
1348}
1349
1350static int
1351ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1352{
1353 switch (cmd) {
1354 case SIOCGETTUNNEL:
1355 return ipip6_tunnel_get(dev, p);
1356 case SIOCADDTUNNEL:
1357 return ipip6_tunnel_add(dev, p);
1358 case SIOCCHGTUNNEL:
1359 return ipip6_tunnel_change(dev, p);
1360 case SIOCDELTUNNEL:
1361 return ipip6_tunnel_del(dev, p);
1362 default:
1363 return -EINVAL;
1364 }
1365}
1366
1367static int
1368ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1369 void __user *data, int cmd)
1370{
1371 switch (cmd) {
1372 case SIOCGETTUNNEL:
1373 case SIOCADDTUNNEL:
1374 case SIOCCHGTUNNEL:
1375 case SIOCDELTUNNEL:
1376 return ip_tunnel_siocdevprivate(dev, ifr, data, cmd);
1377 case SIOCGETPRL:
1378 return ipip6_tunnel_get_prl(dev, data);
1379 case SIOCADDPRL:
1380 case SIOCDELPRL:
1381 case SIOCCHGPRL:
1382 return ipip6_tunnel_prl_ctl(dev, data, cmd);
1383#ifdef CONFIG_IPV6_SIT_6RD
1384 case SIOCGET6RD:
1385 return ipip6_tunnel_get6rd(dev, data);
1386 case SIOCADD6RD:
1387 case SIOCCHG6RD:
1388 case SIOCDEL6RD:
1389 return ipip6_tunnel_6rdctl(dev, data, cmd);
1390#endif
1391 default:
1392 return -EINVAL;
1393 }
1394}
1395
1396static const struct net_device_ops ipip6_netdev_ops = {
1397 .ndo_init = ipip6_tunnel_init,
1398 .ndo_uninit = ipip6_tunnel_uninit,
1399 .ndo_start_xmit = sit_tunnel_xmit,
1400 .ndo_siocdevprivate = ipip6_tunnel_siocdevprivate,
1401 .ndo_get_stats64 = dev_get_tstats64,
1402 .ndo_get_iflink = ip_tunnel_get_iflink,
1403 .ndo_tunnel_ctl = ipip6_tunnel_ctl,
1404};
1405
1406static void ipip6_dev_free(struct net_device *dev)
1407{
1408 struct ip_tunnel *tunnel = netdev_priv(dev);
1409
1410 dst_cache_destroy(&tunnel->dst_cache);
1411 free_percpu(dev->tstats);
1412}
1413
1414#define SIT_FEATURES (NETIF_F_SG | \
1415 NETIF_F_FRAGLIST | \
1416 NETIF_F_HIGHDMA | \
1417 NETIF_F_GSO_SOFTWARE | \
1418 NETIF_F_HW_CSUM)
1419
1420static void ipip6_tunnel_setup(struct net_device *dev)
1421{
1422 struct ip_tunnel *tunnel = netdev_priv(dev);
1423 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1424
1425 dev->netdev_ops = &ipip6_netdev_ops;
1426 dev->header_ops = &ip_tunnel_header_ops;
1427 dev->needs_free_netdev = true;
1428 dev->priv_destructor = ipip6_dev_free;
1429
1430 dev->type = ARPHRD_SIT;
1431 dev->mtu = ETH_DATA_LEN - t_hlen;
1432 dev->min_mtu = IPV6_MIN_MTU;
1433 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1434 dev->flags = IFF_NOARP;
1435 netif_keep_dst(dev);
1436 dev->addr_len = 4;
1437 dev->features |= NETIF_F_LLTX;
1438 dev->features |= SIT_FEATURES;
1439 dev->hw_features |= SIT_FEATURES;
1440}
1441
1442static int ipip6_tunnel_init(struct net_device *dev)
1443{
1444 struct ip_tunnel *tunnel = netdev_priv(dev);
1445 int err;
1446
1447 tunnel->dev = dev;
1448 tunnel->net = dev_net(dev);
1449 strcpy(tunnel->parms.name, dev->name);
1450
1451 ipip6_tunnel_bind_dev(dev);
1452 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1453 if (!dev->tstats)
1454 return -ENOMEM;
1455
1456 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1457 if (err) {
1458 free_percpu(dev->tstats);
1459 dev->tstats = NULL;
1460 return err;
1461 }
1462 netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
1463 return 0;
1464}
1465
1466static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1467{
1468 struct ip_tunnel *tunnel = netdev_priv(dev);
1469 struct iphdr *iph = &tunnel->parms.iph;
1470 struct net *net = dev_net(dev);
1471 struct sit_net *sitn = net_generic(net, sit_net_id);
1472
1473 iph->version = 4;
1474 iph->protocol = IPPROTO_IPV6;
1475 iph->ihl = 5;
1476 iph->ttl = 64;
1477
1478 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1479}
1480
1481static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1482 struct netlink_ext_ack *extack)
1483{
1484 u8 proto;
1485
1486 if (!data || !data[IFLA_IPTUN_PROTO])
1487 return 0;
1488
1489 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1490 if (!ipip6_valid_ip_proto(proto))
1491 return -EINVAL;
1492
1493 return 0;
1494}
1495
1496static void ipip6_netlink_parms(struct nlattr *data[],
1497 struct ip_tunnel_parm *parms,
1498 __u32 *fwmark)
1499{
1500 memset(parms, 0, sizeof(*parms));
1501
1502 parms->iph.version = 4;
1503 parms->iph.protocol = IPPROTO_IPV6;
1504 parms->iph.ihl = 5;
1505 parms->iph.ttl = 64;
1506
1507 if (!data)
1508 return;
1509
1510 ip_tunnel_netlink_parms(data, parms);
1511
1512 if (data[IFLA_IPTUN_FWMARK])
1513 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1514}
1515
1516#ifdef CONFIG_IPV6_SIT_6RD
1517/* This function returns true when 6RD attributes are present in the nl msg */
1518static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1519 struct ip_tunnel_6rd *ip6rd)
1520{
1521 bool ret = false;
1522 memset(ip6rd, 0, sizeof(*ip6rd));
1523
1524 if (!data)
1525 return ret;
1526
1527 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1528 ret = true;
1529 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1530 }
1531
1532 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1533 ret = true;
1534 ip6rd->relay_prefix =
1535 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1536 }
1537
1538 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1539 ret = true;
1540 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1541 }
1542
1543 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1544 ret = true;
1545 ip6rd->relay_prefixlen =
1546 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1547 }
1548
1549 return ret;
1550}
1551#endif
1552
1553static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1554 struct nlattr *tb[], struct nlattr *data[],
1555 struct netlink_ext_ack *extack)
1556{
1557 struct net *net = dev_net(dev);
1558 struct ip_tunnel *nt;
1559 struct ip_tunnel_encap ipencap;
1560#ifdef CONFIG_IPV6_SIT_6RD
1561 struct ip_tunnel_6rd ip6rd;
1562#endif
1563 int err;
1564
1565 nt = netdev_priv(dev);
1566
1567 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1568 err = ip_tunnel_encap_setup(nt, &ipencap);
1569 if (err < 0)
1570 return err;
1571 }
1572
1573 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1574
1575 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1576 return -EEXIST;
1577
1578 err = ipip6_tunnel_create(dev);
1579 if (err < 0)
1580 return err;
1581
1582 if (tb[IFLA_MTU]) {
1583 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1584
1585 if (mtu >= IPV6_MIN_MTU &&
1586 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1587 dev->mtu = mtu;
1588 }
1589
1590#ifdef CONFIG_IPV6_SIT_6RD
1591 if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
1592 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1593 if (err < 0)
1594 unregister_netdevice_queue(dev, NULL);
1595 }
1596#endif
1597
1598 return err;
1599}
1600
1601static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1602 struct nlattr *data[],
1603 struct netlink_ext_ack *extack)
1604{
1605 struct ip_tunnel *t = netdev_priv(dev);
1606 struct ip_tunnel_parm p;
1607 struct ip_tunnel_encap ipencap;
1608 struct net *net = t->net;
1609 struct sit_net *sitn = net_generic(net, sit_net_id);
1610#ifdef CONFIG_IPV6_SIT_6RD
1611 struct ip_tunnel_6rd ip6rd;
1612#endif
1613 __u32 fwmark = t->fwmark;
1614 int err;
1615
1616 if (dev == sitn->fb_tunnel_dev)
1617 return -EINVAL;
1618
1619 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
1620 err = ip_tunnel_encap_setup(t, &ipencap);
1621 if (err < 0)
1622 return err;
1623 }
1624
1625 ipip6_netlink_parms(data, &p, &fwmark);
1626
1627 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1628 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1629 return -EINVAL;
1630
1631 t = ipip6_tunnel_locate(net, &p, 0);
1632
1633 if (t) {
1634 if (t->dev != dev)
1635 return -EEXIST;
1636 } else
1637 t = netdev_priv(dev);
1638
1639 ipip6_tunnel_update(t, &p, fwmark);
1640
1641#ifdef CONFIG_IPV6_SIT_6RD
1642 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1643 return ipip6_tunnel_update_6rd(t, &ip6rd);
1644#endif
1645
1646 return 0;
1647}
1648
1649static size_t ipip6_get_size(const struct net_device *dev)
1650{
1651 return
1652 /* IFLA_IPTUN_LINK */
1653 nla_total_size(4) +
1654 /* IFLA_IPTUN_LOCAL */
1655 nla_total_size(4) +
1656 /* IFLA_IPTUN_REMOTE */
1657 nla_total_size(4) +
1658 /* IFLA_IPTUN_TTL */
1659 nla_total_size(1) +
1660 /* IFLA_IPTUN_TOS */
1661 nla_total_size(1) +
1662 /* IFLA_IPTUN_PMTUDISC */
1663 nla_total_size(1) +
1664 /* IFLA_IPTUN_FLAGS */
1665 nla_total_size(2) +
1666 /* IFLA_IPTUN_PROTO */
1667 nla_total_size(1) +
1668#ifdef CONFIG_IPV6_SIT_6RD
1669 /* IFLA_IPTUN_6RD_PREFIX */
1670 nla_total_size(sizeof(struct in6_addr)) +
1671 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1672 nla_total_size(4) +
1673 /* IFLA_IPTUN_6RD_PREFIXLEN */
1674 nla_total_size(2) +
1675 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1676 nla_total_size(2) +
1677#endif
1678 /* IFLA_IPTUN_ENCAP_TYPE */
1679 nla_total_size(2) +
1680 /* IFLA_IPTUN_ENCAP_FLAGS */
1681 nla_total_size(2) +
1682 /* IFLA_IPTUN_ENCAP_SPORT */
1683 nla_total_size(2) +
1684 /* IFLA_IPTUN_ENCAP_DPORT */
1685 nla_total_size(2) +
1686 /* IFLA_IPTUN_FWMARK */
1687 nla_total_size(4) +
1688 0;
1689}
1690
1691static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1692{
1693 struct ip_tunnel *tunnel = netdev_priv(dev);
1694 struct ip_tunnel_parm *parm = &tunnel->parms;
1695
1696 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1697 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1698 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1699 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1700 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1701 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1702 !!(parm->iph.frag_off & htons(IP_DF))) ||
1703 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1704 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1705 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1706 goto nla_put_failure;
1707
1708#ifdef CONFIG_IPV6_SIT_6RD
1709 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1710 &tunnel->ip6rd.prefix) ||
1711 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1712 tunnel->ip6rd.relay_prefix) ||
1713 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1714 tunnel->ip6rd.prefixlen) ||
1715 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1716 tunnel->ip6rd.relay_prefixlen))
1717 goto nla_put_failure;
1718#endif
1719
1720 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1721 tunnel->encap.type) ||
1722 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1723 tunnel->encap.sport) ||
1724 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1725 tunnel->encap.dport) ||
1726 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1727 tunnel->encap.flags))
1728 goto nla_put_failure;
1729
1730 return 0;
1731
1732nla_put_failure:
1733 return -EMSGSIZE;
1734}
1735
1736static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1737 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1738 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1739 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1740 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1741 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1742 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1743 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1744 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1745#ifdef CONFIG_IPV6_SIT_6RD
1746 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1747 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1748 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1749 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1750#endif
1751 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1752 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1753 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1754 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1755 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1756};
1757
1758static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1759{
1760 struct net *net = dev_net(dev);
1761 struct sit_net *sitn = net_generic(net, sit_net_id);
1762
1763 if (dev != sitn->fb_tunnel_dev)
1764 unregister_netdevice_queue(dev, head);
1765}
1766
1767static struct rtnl_link_ops sit_link_ops __read_mostly = {
1768 .kind = "sit",
1769 .maxtype = IFLA_IPTUN_MAX,
1770 .policy = ipip6_policy,
1771 .priv_size = sizeof(struct ip_tunnel),
1772 .setup = ipip6_tunnel_setup,
1773 .validate = ipip6_validate,
1774 .newlink = ipip6_newlink,
1775 .changelink = ipip6_changelink,
1776 .get_size = ipip6_get_size,
1777 .fill_info = ipip6_fill_info,
1778 .dellink = ipip6_dellink,
1779 .get_link_net = ip_tunnel_get_link_net,
1780};
1781
1782static struct xfrm_tunnel sit_handler __read_mostly = {
1783 .handler = ipip6_rcv,
1784 .err_handler = ipip6_err,
1785 .priority = 1,
1786};
1787
1788static struct xfrm_tunnel ipip_handler __read_mostly = {
1789 .handler = ipip_rcv,
1790 .err_handler = ipip6_err,
1791 .priority = 2,
1792};
1793
1794#if IS_ENABLED(CONFIG_MPLS)
1795static struct xfrm_tunnel mplsip_handler __read_mostly = {
1796 .handler = mplsip_rcv,
1797 .err_handler = ipip6_err,
1798 .priority = 2,
1799};
1800#endif
1801
1802static void __net_exit sit_destroy_tunnels(struct net *net,
1803 struct list_head *head)
1804{
1805 struct sit_net *sitn = net_generic(net, sit_net_id);
1806 struct net_device *dev, *aux;
1807 int prio;
1808
1809 for_each_netdev_safe(net, dev, aux)
1810 if (dev->rtnl_link_ops == &sit_link_ops)
1811 unregister_netdevice_queue(dev, head);
1812
1813 for (prio = 0; prio < 4; prio++) {
1814 int h;
1815 for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
1816 struct ip_tunnel *t;
1817
1818 t = rtnl_dereference(sitn->tunnels[prio][h]);
1819 while (t) {
1820 /* If dev is in the same netns, it has already
1821 * been added to the list by the previous loop.
1822 */
1823 if (!net_eq(dev_net(t->dev), net))
1824 unregister_netdevice_queue(t->dev,
1825 head);
1826 t = rtnl_dereference(t->next);
1827 }
1828 }
1829 }
1830}
1831
1832static int __net_init sit_init_net(struct net *net)
1833{
1834 struct sit_net *sitn = net_generic(net, sit_net_id);
1835 struct ip_tunnel *t;
1836 int err;
1837
1838 sitn->tunnels[0] = sitn->tunnels_wc;
1839 sitn->tunnels[1] = sitn->tunnels_l;
1840 sitn->tunnels[2] = sitn->tunnels_r;
1841 sitn->tunnels[3] = sitn->tunnels_r_l;
1842
1843 if (!net_has_fallback_tunnels(net))
1844 return 0;
1845
1846 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1847 NET_NAME_UNKNOWN,
1848 ipip6_tunnel_setup);
1849 if (!sitn->fb_tunnel_dev) {
1850 err = -ENOMEM;
1851 goto err_alloc_dev;
1852 }
1853 dev_net_set(sitn->fb_tunnel_dev, net);
1854 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1855 /* FB netdevice is special: we have one, and only one per netns.
1856 * Allowing to move it to another netns is clearly unsafe.
1857 */
1858 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1859
1860 err = register_netdev(sitn->fb_tunnel_dev);
1861 if (err)
1862 goto err_reg_dev;
1863
1864 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1865 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1866
1867 t = netdev_priv(sitn->fb_tunnel_dev);
1868
1869 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1870 return 0;
1871
1872err_reg_dev:
1873 free_netdev(sitn->fb_tunnel_dev);
1874err_alloc_dev:
1875 return err;
1876}
1877
1878static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1879{
1880 LIST_HEAD(list);
1881 struct net *net;
1882
1883 rtnl_lock();
1884 list_for_each_entry(net, net_list, exit_list)
1885 sit_destroy_tunnels(net, &list);
1886
1887 unregister_netdevice_many(&list);
1888 rtnl_unlock();
1889}
1890
1891static struct pernet_operations sit_net_ops = {
1892 .init = sit_init_net,
1893 .exit_batch = sit_exit_batch_net,
1894 .id = &sit_net_id,
1895 .size = sizeof(struct sit_net),
1896};
1897
1898static void __exit sit_cleanup(void)
1899{
1900 rtnl_link_unregister(&sit_link_ops);
1901 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1902 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1903#if IS_ENABLED(CONFIG_MPLS)
1904 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1905#endif
1906
1907 unregister_pernet_device(&sit_net_ops);
1908 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1909}
1910
1911static int __init sit_init(void)
1912{
1913 int err;
1914
1915 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1916
1917 err = register_pernet_device(&sit_net_ops);
1918 if (err < 0)
1919 return err;
1920 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1921 if (err < 0) {
1922 pr_info("%s: can't register ip6ip4\n", __func__);
1923 goto xfrm_tunnel_failed;
1924 }
1925 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1926 if (err < 0) {
1927 pr_info("%s: can't register ip4ip4\n", __func__);
1928 goto xfrm_tunnel4_failed;
1929 }
1930#if IS_ENABLED(CONFIG_MPLS)
1931 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1932 if (err < 0) {
1933 pr_info("%s: can't register mplsip\n", __func__);
1934 goto xfrm_tunnel_mpls_failed;
1935 }
1936#endif
1937 err = rtnl_link_register(&sit_link_ops);
1938 if (err < 0)
1939 goto rtnl_link_failed;
1940
1941out:
1942 return err;
1943
1944rtnl_link_failed:
1945#if IS_ENABLED(CONFIG_MPLS)
1946 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1947xfrm_tunnel_mpls_failed:
1948#endif
1949 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1950xfrm_tunnel4_failed:
1951 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1952xfrm_tunnel_failed:
1953 unregister_pernet_device(&sit_net_ops);
1954 goto out;
1955}
1956
1957module_init(sit_init);
1958module_exit(sit_cleanup);
1959MODULE_DESCRIPTION("IPv6-in-IPv4 tunnel SIT driver");
1960MODULE_LICENSE("GPL");
1961MODULE_ALIAS_RTNL_LINK("sit");
1962MODULE_ALIAS_NETDEV("sit0");