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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 memcpy(dev->dev_addr, &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 strlcpy(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 ifreq *ifr)
303{
304 struct ip_tunnel_prl __user *a = ifr->ifr_ifru.ifru_data;
305 struct ip_tunnel *t = netdev_priv(dev);
306 struct ip_tunnel_prl kprl, *kp;
307 struct ip_tunnel_prl_entry *prl;
308 unsigned int cmax, c = 0, ca, len;
309 int ret = 0;
310
311 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
312 return -EINVAL;
313
314 if (copy_from_user(&kprl, a, sizeof(kprl)))
315 return -EFAULT;
316 cmax = kprl.datalen / sizeof(kprl);
317 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
318 cmax = 1;
319
320 /* For simple GET or for root users,
321 * we try harder to allocate.
322 */
323 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
324 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
325 NULL;
326
327 rcu_read_lock();
328
329 ca = min(t->prl_count, cmax);
330
331 if (!kp) {
332 /* We don't try hard to allocate much memory for
333 * non-root users.
334 * For root users, retry allocating enough memory for
335 * the answer.
336 */
337 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
338 if (!kp) {
339 ret = -ENOMEM;
340 goto out;
341 }
342 }
343
344 c = 0;
345 for_each_prl_rcu(t->prl) {
346 if (c >= cmax)
347 break;
348 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
349 continue;
350 kp[c].addr = prl->addr;
351 kp[c].flags = prl->flags;
352 c++;
353 if (kprl.addr != htonl(INADDR_ANY))
354 break;
355 }
356out:
357 rcu_read_unlock();
358
359 len = sizeof(*kp) * c;
360 ret = 0;
361 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
362 ret = -EFAULT;
363
364 kfree(kp);
365
366 return ret;
367}
368
369static int
370ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
371{
372 struct ip_tunnel_prl_entry *p;
373 int err = 0;
374
375 if (a->addr == htonl(INADDR_ANY))
376 return -EINVAL;
377
378 ASSERT_RTNL();
379
380 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
381 if (p->addr == a->addr) {
382 if (chg) {
383 p->flags = a->flags;
384 goto out;
385 }
386 err = -EEXIST;
387 goto out;
388 }
389 }
390
391 if (chg) {
392 err = -ENXIO;
393 goto out;
394 }
395
396 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
397 if (!p) {
398 err = -ENOBUFS;
399 goto out;
400 }
401
402 p->next = t->prl;
403 p->addr = a->addr;
404 p->flags = a->flags;
405 t->prl_count++;
406 rcu_assign_pointer(t->prl, p);
407out:
408 return err;
409}
410
411static void prl_list_destroy_rcu(struct rcu_head *head)
412{
413 struct ip_tunnel_prl_entry *p, *n;
414
415 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
416 do {
417 n = rcu_dereference_protected(p->next, 1);
418 kfree(p);
419 p = n;
420 } while (p);
421}
422
423static int
424ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
425{
426 struct ip_tunnel_prl_entry *x;
427 struct ip_tunnel_prl_entry __rcu **p;
428 int err = 0;
429
430 ASSERT_RTNL();
431
432 if (a && a->addr != htonl(INADDR_ANY)) {
433 for (p = &t->prl;
434 (x = rtnl_dereference(*p)) != NULL;
435 p = &x->next) {
436 if (x->addr == a->addr) {
437 *p = x->next;
438 kfree_rcu(x, rcu_head);
439 t->prl_count--;
440 goto out;
441 }
442 }
443 err = -ENXIO;
444 } else {
445 x = rtnl_dereference(t->prl);
446 if (x) {
447 t->prl_count = 0;
448 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
449 t->prl = NULL;
450 }
451 }
452out:
453 return err;
454}
455
456static int ipip6_tunnel_prl_ctl(struct net_device *dev, struct ifreq *ifr,
457 int cmd)
458{
459 struct ip_tunnel *t = netdev_priv(dev);
460 struct ip_tunnel_prl prl;
461 int err;
462
463 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
464 return -EPERM;
465 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
466 return -EINVAL;
467
468 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
469 return -EFAULT;
470
471 switch (cmd) {
472 case SIOCDELPRL:
473 err = ipip6_tunnel_del_prl(t, &prl);
474 break;
475 case SIOCADDPRL:
476 case SIOCCHGPRL:
477 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
478 break;
479 }
480 dst_cache_reset(&t->dst_cache);
481 netdev_state_change(dev);
482 return err;
483}
484
485static int
486isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
487{
488 struct ip_tunnel_prl_entry *p;
489 int ok = 1;
490
491 rcu_read_lock();
492 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
493 if (p) {
494 if (p->flags & PRL_DEFAULT)
495 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
496 else
497 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
498 } else {
499 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
500
501 if (ipv6_addr_is_isatap(addr6) &&
502 (addr6->s6_addr32[3] == iph->saddr) &&
503 ipv6_chk_prefix(addr6, t->dev))
504 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
505 else
506 ok = 0;
507 }
508 rcu_read_unlock();
509 return ok;
510}
511
512static void ipip6_tunnel_uninit(struct net_device *dev)
513{
514 struct ip_tunnel *tunnel = netdev_priv(dev);
515 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
516
517 if (dev == sitn->fb_tunnel_dev) {
518 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
519 } else {
520 ipip6_tunnel_unlink(sitn, tunnel);
521 ipip6_tunnel_del_prl(tunnel, NULL);
522 }
523 dst_cache_reset(&tunnel->dst_cache);
524 dev_put(dev);
525}
526
527static int ipip6_err(struct sk_buff *skb, u32 info)
528{
529 const struct iphdr *iph = (const struct iphdr *)skb->data;
530 const int type = icmp_hdr(skb)->type;
531 const int code = icmp_hdr(skb)->code;
532 unsigned int data_len = 0;
533 struct ip_tunnel *t;
534 int sifindex;
535 int err;
536
537 switch (type) {
538 default:
539 case ICMP_PARAMETERPROB:
540 return 0;
541
542 case ICMP_DEST_UNREACH:
543 switch (code) {
544 case ICMP_SR_FAILED:
545 /* Impossible event. */
546 return 0;
547 default:
548 /* All others are translated to HOST_UNREACH.
549 rfc2003 contains "deep thoughts" about NET_UNREACH,
550 I believe they are just ether pollution. --ANK
551 */
552 break;
553 }
554 break;
555 case ICMP_TIME_EXCEEDED:
556 if (code != ICMP_EXC_TTL)
557 return 0;
558 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
559 break;
560 case ICMP_REDIRECT:
561 break;
562 }
563
564 err = -ENOENT;
565
566 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
567 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
568 iph->daddr, iph->saddr, sifindex);
569 if (!t)
570 goto out;
571
572 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
573 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
574 t->parms.link, iph->protocol);
575 err = 0;
576 goto out;
577 }
578 if (type == ICMP_REDIRECT) {
579 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
580 iph->protocol);
581 err = 0;
582 goto out;
583 }
584
585 err = 0;
586 if (__in6_dev_get(skb->dev) &&
587 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
588 goto out;
589
590 if (t->parms.iph.daddr == 0)
591 goto out;
592
593 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
594 goto out;
595
596 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
597 t->err_count++;
598 else
599 t->err_count = 1;
600 t->err_time = jiffies;
601out:
602 return err;
603}
604
605static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
606 const struct in6_addr *v6addr)
607{
608 __be32 v4embed = 0;
609 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
610 return true;
611 return false;
612}
613
614/* Checks if an address matches an address on the tunnel interface.
615 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
616 * Long story:
617 * This function is called after we considered the packet as spoofed
618 * in is_spoofed_6rd.
619 * We may have a router that is doing NAT for proto 41 packets
620 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
621 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
622 * function will return true, dropping the packet.
623 * But, we can still check if is spoofed against the IP
624 * addresses associated with the interface.
625 */
626static bool only_dnatted(const struct ip_tunnel *tunnel,
627 const struct in6_addr *v6dst)
628{
629 int prefix_len;
630
631#ifdef CONFIG_IPV6_SIT_6RD
632 prefix_len = tunnel->ip6rd.prefixlen + 32
633 - tunnel->ip6rd.relay_prefixlen;
634#else
635 prefix_len = 48;
636#endif
637 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
638}
639
640/* Returns true if a packet is spoofed */
641static bool packet_is_spoofed(struct sk_buff *skb,
642 const struct iphdr *iph,
643 struct ip_tunnel *tunnel)
644{
645 const struct ipv6hdr *ipv6h;
646
647 if (tunnel->dev->priv_flags & IFF_ISATAP) {
648 if (!isatap_chksrc(skb, iph, tunnel))
649 return true;
650
651 return false;
652 }
653
654 if (tunnel->dev->flags & IFF_POINTOPOINT)
655 return false;
656
657 ipv6h = ipv6_hdr(skb);
658
659 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
660 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
661 &iph->saddr, &ipv6h->saddr,
662 &iph->daddr, &ipv6h->daddr);
663 return true;
664 }
665
666 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
667 return false;
668
669 if (only_dnatted(tunnel, &ipv6h->daddr))
670 return false;
671
672 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
673 &iph->saddr, &ipv6h->saddr,
674 &iph->daddr, &ipv6h->daddr);
675 return true;
676}
677
678static int ipip6_rcv(struct sk_buff *skb)
679{
680 const struct iphdr *iph = ip_hdr(skb);
681 struct ip_tunnel *tunnel;
682 int sifindex;
683 int err;
684
685 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
686 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
687 iph->saddr, iph->daddr, sifindex);
688 if (tunnel) {
689 struct pcpu_sw_netstats *tstats;
690
691 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
692 tunnel->parms.iph.protocol != 0)
693 goto out;
694
695 skb->mac_header = skb->network_header;
696 skb_reset_network_header(skb);
697 IPCB(skb)->flags = 0;
698 skb->dev = tunnel->dev;
699
700 if (packet_is_spoofed(skb, iph, tunnel)) {
701 tunnel->dev->stats.rx_errors++;
702 goto out;
703 }
704
705 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
706 !net_eq(tunnel->net, dev_net(tunnel->dev))))
707 goto out;
708
709 /* skb can be uncloned in iptunnel_pull_header, so
710 * old iph is no longer valid
711 */
712 iph = (const struct iphdr *)skb_mac_header(skb);
713 skb_reset_mac_header(skb);
714
715 err = IP_ECN_decapsulate(iph, skb);
716 if (unlikely(err)) {
717 if (log_ecn_error)
718 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
719 &iph->saddr, iph->tos);
720 if (err > 1) {
721 ++tunnel->dev->stats.rx_frame_errors;
722 ++tunnel->dev->stats.rx_errors;
723 goto out;
724 }
725 }
726
727 tstats = this_cpu_ptr(tunnel->dev->tstats);
728 u64_stats_update_begin(&tstats->syncp);
729 tstats->rx_packets++;
730 tstats->rx_bytes += skb->len;
731 u64_stats_update_end(&tstats->syncp);
732
733 netif_rx(skb);
734
735 return 0;
736 }
737
738 /* no tunnel matched, let upstream know, ipsec may handle it */
739 return 1;
740out:
741 kfree_skb(skb);
742 return 0;
743}
744
745static const struct tnl_ptk_info ipip_tpi = {
746 /* no tunnel info required for ipip. */
747 .proto = htons(ETH_P_IP),
748};
749
750#if IS_ENABLED(CONFIG_MPLS)
751static const struct tnl_ptk_info mplsip_tpi = {
752 /* no tunnel info required for mplsip. */
753 .proto = htons(ETH_P_MPLS_UC),
754};
755#endif
756
757static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
758{
759 const struct iphdr *iph;
760 struct ip_tunnel *tunnel;
761 int sifindex;
762
763 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
764
765 iph = ip_hdr(skb);
766 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
767 iph->saddr, iph->daddr, sifindex);
768 if (tunnel) {
769 const struct tnl_ptk_info *tpi;
770
771 if (tunnel->parms.iph.protocol != ipproto &&
772 tunnel->parms.iph.protocol != 0)
773 goto drop;
774
775 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
776 goto drop;
777#if IS_ENABLED(CONFIG_MPLS)
778 if (ipproto == IPPROTO_MPLS)
779 tpi = &mplsip_tpi;
780 else
781#endif
782 tpi = &ipip_tpi;
783 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
784 goto drop;
785 skb_reset_mac_header(skb);
786
787 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
788 }
789
790 return 1;
791
792drop:
793 kfree_skb(skb);
794 return 0;
795}
796
797static int ipip_rcv(struct sk_buff *skb)
798{
799 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
800}
801
802#if IS_ENABLED(CONFIG_MPLS)
803static int mplsip_rcv(struct sk_buff *skb)
804{
805 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
806}
807#endif
808
809/*
810 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
811 * stores the embedded IPv4 address in v4dst and returns true.
812 */
813static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
814 __be32 *v4dst)
815{
816#ifdef CONFIG_IPV6_SIT_6RD
817 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
818 tunnel->ip6rd.prefixlen)) {
819 unsigned int pbw0, pbi0;
820 int pbi1;
821 u32 d;
822
823 pbw0 = tunnel->ip6rd.prefixlen >> 5;
824 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
825
826 d = tunnel->ip6rd.relay_prefixlen < 32 ?
827 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
828 tunnel->ip6rd.relay_prefixlen : 0;
829
830 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
831 if (pbi1 > 0)
832 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
833 (32 - pbi1);
834
835 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
836 return true;
837 }
838#else
839 if (v6dst->s6_addr16[0] == htons(0x2002)) {
840 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
841 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
842 return true;
843 }
844#endif
845 return false;
846}
847
848static inline __be32 try_6rd(struct ip_tunnel *tunnel,
849 const struct in6_addr *v6dst)
850{
851 __be32 dst = 0;
852 check_6rd(tunnel, v6dst, &dst);
853 return dst;
854}
855
856/*
857 * This function assumes it is being called from dev_queue_xmit()
858 * and that skb is filled properly by that function.
859 */
860
861static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
862 struct net_device *dev)
863{
864 struct ip_tunnel *tunnel = netdev_priv(dev);
865 const struct iphdr *tiph = &tunnel->parms.iph;
866 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
867 u8 tos = tunnel->parms.iph.tos;
868 __be16 df = tiph->frag_off;
869 struct rtable *rt; /* Route to the other host */
870 struct net_device *tdev; /* Device to other host */
871 unsigned int max_headroom; /* The extra header space needed */
872 __be32 dst = tiph->daddr;
873 struct flowi4 fl4;
874 int mtu;
875 const struct in6_addr *addr6;
876 int addr_type;
877 u8 ttl;
878 u8 protocol = IPPROTO_IPV6;
879 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
880
881 if (tos == 1)
882 tos = ipv6_get_dsfield(iph6);
883
884 /* ISATAP (RFC4214) - must come before 6to4 */
885 if (dev->priv_flags & IFF_ISATAP) {
886 struct neighbour *neigh = NULL;
887 bool do_tx_error = false;
888
889 if (skb_dst(skb))
890 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
891
892 if (!neigh) {
893 net_dbg_ratelimited("nexthop == NULL\n");
894 goto tx_error;
895 }
896
897 addr6 = (const struct in6_addr *)&neigh->primary_key;
898 addr_type = ipv6_addr_type(addr6);
899
900 if ((addr_type & IPV6_ADDR_UNICAST) &&
901 ipv6_addr_is_isatap(addr6))
902 dst = addr6->s6_addr32[3];
903 else
904 do_tx_error = true;
905
906 neigh_release(neigh);
907 if (do_tx_error)
908 goto tx_error;
909 }
910
911 if (!dst)
912 dst = try_6rd(tunnel, &iph6->daddr);
913
914 if (!dst) {
915 struct neighbour *neigh = NULL;
916 bool do_tx_error = false;
917
918 if (skb_dst(skb))
919 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
920
921 if (!neigh) {
922 net_dbg_ratelimited("nexthop == NULL\n");
923 goto tx_error;
924 }
925
926 addr6 = (const struct in6_addr *)&neigh->primary_key;
927 addr_type = ipv6_addr_type(addr6);
928
929 if (addr_type == IPV6_ADDR_ANY) {
930 addr6 = &ipv6_hdr(skb)->daddr;
931 addr_type = ipv6_addr_type(addr6);
932 }
933
934 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
935 dst = addr6->s6_addr32[3];
936 else
937 do_tx_error = true;
938
939 neigh_release(neigh);
940 if (do_tx_error)
941 goto tx_error;
942 }
943
944 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
945 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
946 0, dst, tiph->saddr, 0, 0,
947 sock_net_uid(tunnel->net, NULL));
948
949 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
950 if (!rt) {
951 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
952 if (IS_ERR(rt)) {
953 dev->stats.tx_carrier_errors++;
954 goto tx_error_icmp;
955 }
956 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
957 }
958
959 if (rt->rt_type != RTN_UNICAST) {
960 ip_rt_put(rt);
961 dev->stats.tx_carrier_errors++;
962 goto tx_error_icmp;
963 }
964 tdev = rt->dst.dev;
965
966 if (tdev == dev) {
967 ip_rt_put(rt);
968 dev->stats.collisions++;
969 goto tx_error;
970 }
971
972 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
973 ip_rt_put(rt);
974 goto tx_error;
975 }
976
977 if (df) {
978 mtu = dst_mtu(&rt->dst) - t_hlen;
979
980 if (mtu < IPV4_MIN_MTU) {
981 dev->stats.collisions++;
982 ip_rt_put(rt);
983 goto tx_error;
984 }
985
986 if (mtu < IPV6_MIN_MTU) {
987 mtu = IPV6_MIN_MTU;
988 df = 0;
989 }
990
991 if (tunnel->parms.iph.daddr)
992 skb_dst_update_pmtu_no_confirm(skb, mtu);
993
994 if (skb->len > mtu && !skb_is_gso(skb)) {
995 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
996 ip_rt_put(rt);
997 goto tx_error;
998 }
999 }
1000
1001 if (tunnel->err_count > 0) {
1002 if (time_before(jiffies,
1003 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
1004 tunnel->err_count--;
1005 dst_link_failure(skb);
1006 } else
1007 tunnel->err_count = 0;
1008 }
1009
1010 /*
1011 * Okay, now see if we can stuff it in the buffer as-is.
1012 */
1013 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1014
1015 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1016 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1017 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1018 if (!new_skb) {
1019 ip_rt_put(rt);
1020 dev->stats.tx_dropped++;
1021 kfree_skb(skb);
1022 return NETDEV_TX_OK;
1023 }
1024 if (skb->sk)
1025 skb_set_owner_w(new_skb, skb->sk);
1026 dev_kfree_skb(skb);
1027 skb = new_skb;
1028 iph6 = ipv6_hdr(skb);
1029 }
1030 ttl = tiph->ttl;
1031 if (ttl == 0)
1032 ttl = iph6->hop_limit;
1033 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1034
1035 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
1036 ip_rt_put(rt);
1037 goto tx_error;
1038 }
1039
1040 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1041
1042 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1043 df, !net_eq(tunnel->net, dev_net(dev)));
1044 return NETDEV_TX_OK;
1045
1046tx_error_icmp:
1047 dst_link_failure(skb);
1048tx_error:
1049 kfree_skb(skb);
1050 dev->stats.tx_errors++;
1051 return NETDEV_TX_OK;
1052}
1053
1054static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1055 struct net_device *dev, u8 ipproto)
1056{
1057 struct ip_tunnel *tunnel = netdev_priv(dev);
1058 const struct iphdr *tiph = &tunnel->parms.iph;
1059
1060 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1061 goto tx_error;
1062
1063 skb_set_inner_ipproto(skb, ipproto);
1064
1065 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1066 return NETDEV_TX_OK;
1067tx_error:
1068 kfree_skb(skb);
1069 dev->stats.tx_errors++;
1070 return NETDEV_TX_OK;
1071}
1072
1073static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1074 struct net_device *dev)
1075{
1076 if (!pskb_inet_may_pull(skb))
1077 goto tx_err;
1078
1079 switch (skb->protocol) {
1080 case htons(ETH_P_IP):
1081 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1082 break;
1083 case htons(ETH_P_IPV6):
1084 ipip6_tunnel_xmit(skb, dev);
1085 break;
1086#if IS_ENABLED(CONFIG_MPLS)
1087 case htons(ETH_P_MPLS_UC):
1088 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1089 break;
1090#endif
1091 default:
1092 goto tx_err;
1093 }
1094
1095 return NETDEV_TX_OK;
1096
1097tx_err:
1098 dev->stats.tx_errors++;
1099 kfree_skb(skb);
1100 return NETDEV_TX_OK;
1101
1102}
1103
1104static void ipip6_tunnel_bind_dev(struct net_device *dev)
1105{
1106 struct net_device *tdev = NULL;
1107 struct ip_tunnel *tunnel;
1108 const struct iphdr *iph;
1109 struct flowi4 fl4;
1110
1111 tunnel = netdev_priv(dev);
1112 iph = &tunnel->parms.iph;
1113
1114 if (iph->daddr) {
1115 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1116 NULL,
1117 iph->daddr, iph->saddr,
1118 0, 0,
1119 IPPROTO_IPV6,
1120 RT_TOS(iph->tos),
1121 tunnel->parms.link);
1122
1123 if (!IS_ERR(rt)) {
1124 tdev = rt->dst.dev;
1125 ip_rt_put(rt);
1126 }
1127 dev->flags |= IFF_POINTOPOINT;
1128 }
1129
1130 if (!tdev && tunnel->parms.link)
1131 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1132
1133 if (tdev && !netif_is_l3_master(tdev)) {
1134 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1135
1136 dev->mtu = tdev->mtu - t_hlen;
1137 if (dev->mtu < IPV6_MIN_MTU)
1138 dev->mtu = IPV6_MIN_MTU;
1139 }
1140}
1141
1142static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1143 __u32 fwmark)
1144{
1145 struct net *net = t->net;
1146 struct sit_net *sitn = net_generic(net, sit_net_id);
1147
1148 ipip6_tunnel_unlink(sitn, t);
1149 synchronize_net();
1150 t->parms.iph.saddr = p->iph.saddr;
1151 t->parms.iph.daddr = p->iph.daddr;
1152 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1153 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1154 ipip6_tunnel_link(sitn, t);
1155 t->parms.iph.ttl = p->iph.ttl;
1156 t->parms.iph.tos = p->iph.tos;
1157 t->parms.iph.frag_off = p->iph.frag_off;
1158 if (t->parms.link != p->link || t->fwmark != fwmark) {
1159 t->parms.link = p->link;
1160 t->fwmark = fwmark;
1161 ipip6_tunnel_bind_dev(t->dev);
1162 }
1163 dst_cache_reset(&t->dst_cache);
1164 netdev_state_change(t->dev);
1165}
1166
1167#ifdef CONFIG_IPV6_SIT_6RD
1168static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1169 struct ip_tunnel_6rd *ip6rd)
1170{
1171 struct in6_addr prefix;
1172 __be32 relay_prefix;
1173
1174 if (ip6rd->relay_prefixlen > 32 ||
1175 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1176 return -EINVAL;
1177
1178 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1179 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1180 return -EINVAL;
1181 if (ip6rd->relay_prefixlen)
1182 relay_prefix = ip6rd->relay_prefix &
1183 htonl(0xffffffffUL <<
1184 (32 - ip6rd->relay_prefixlen));
1185 else
1186 relay_prefix = 0;
1187 if (relay_prefix != ip6rd->relay_prefix)
1188 return -EINVAL;
1189
1190 t->ip6rd.prefix = prefix;
1191 t->ip6rd.relay_prefix = relay_prefix;
1192 t->ip6rd.prefixlen = ip6rd->prefixlen;
1193 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1194 dst_cache_reset(&t->dst_cache);
1195 netdev_state_change(t->dev);
1196 return 0;
1197}
1198
1199static int
1200ipip6_tunnel_get6rd(struct net_device *dev, struct ifreq *ifr)
1201{
1202 struct ip_tunnel *t = netdev_priv(dev);
1203 struct ip_tunnel_6rd ip6rd;
1204 struct ip_tunnel_parm p;
1205
1206 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1207 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1208 return -EFAULT;
1209 t = ipip6_tunnel_locate(t->net, &p, 0);
1210 }
1211 if (!t)
1212 t = netdev_priv(dev);
1213
1214 ip6rd.prefix = t->ip6rd.prefix;
1215 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1216 ip6rd.prefixlen = t->ip6rd.prefixlen;
1217 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1218 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, sizeof(ip6rd)))
1219 return -EFAULT;
1220 return 0;
1221}
1222
1223static int
1224ipip6_tunnel_6rdctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1225{
1226 struct ip_tunnel *t = netdev_priv(dev);
1227 struct ip_tunnel_6rd ip6rd;
1228 int err;
1229
1230 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1231 return -EPERM;
1232 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, sizeof(ip6rd)))
1233 return -EFAULT;
1234
1235 if (cmd != SIOCDEL6RD) {
1236 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1237 if (err < 0)
1238 return err;
1239 } else
1240 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1241 return 0;
1242}
1243
1244#endif /* CONFIG_IPV6_SIT_6RD */
1245
1246static bool ipip6_valid_ip_proto(u8 ipproto)
1247{
1248 return ipproto == IPPROTO_IPV6 ||
1249 ipproto == IPPROTO_IPIP ||
1250#if IS_ENABLED(CONFIG_MPLS)
1251 ipproto == IPPROTO_MPLS ||
1252#endif
1253 ipproto == 0;
1254}
1255
1256static int
1257__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1258{
1259 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1260 return -EPERM;
1261
1262 if (!ipip6_valid_ip_proto(p->iph.protocol))
1263 return -EINVAL;
1264 if (p->iph.version != 4 ||
1265 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1266 return -EINVAL;
1267
1268 if (p->iph.ttl)
1269 p->iph.frag_off |= htons(IP_DF);
1270 return 0;
1271}
1272
1273static int
1274ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1275{
1276 struct ip_tunnel *t = netdev_priv(dev);
1277
1278 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1279 t = ipip6_tunnel_locate(t->net, p, 0);
1280 if (!t)
1281 t = netdev_priv(dev);
1282 memcpy(p, &t->parms, sizeof(*p));
1283 return 0;
1284}
1285
1286static int
1287ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1288{
1289 struct ip_tunnel *t = netdev_priv(dev);
1290 int err;
1291
1292 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1293 if (err)
1294 return err;
1295
1296 t = ipip6_tunnel_locate(t->net, p, 1);
1297 if (!t)
1298 return -ENOBUFS;
1299 return 0;
1300}
1301
1302static int
1303ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1304{
1305 struct ip_tunnel *t = netdev_priv(dev);
1306 int err;
1307
1308 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1309 if (err)
1310 return err;
1311
1312 t = ipip6_tunnel_locate(t->net, p, 0);
1313 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1314 if (!t)
1315 return -ENOENT;
1316 } else {
1317 if (t) {
1318 if (t->dev != dev)
1319 return -EEXIST;
1320 } else {
1321 if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1322 (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1323 return -EINVAL;
1324 t = netdev_priv(dev);
1325 }
1326
1327 ipip6_tunnel_update(t, p, t->fwmark);
1328 }
1329
1330 return 0;
1331}
1332
1333static int
1334ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1335{
1336 struct ip_tunnel *t = netdev_priv(dev);
1337
1338 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1339 return -EPERM;
1340
1341 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1342 t = ipip6_tunnel_locate(t->net, p, 0);
1343 if (!t)
1344 return -ENOENT;
1345 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1346 return -EPERM;
1347 dev = t->dev;
1348 }
1349 unregister_netdevice(dev);
1350 return 0;
1351}
1352
1353static int
1354ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1355{
1356 switch (cmd) {
1357 case SIOCGETTUNNEL:
1358 return ipip6_tunnel_get(dev, p);
1359 case SIOCADDTUNNEL:
1360 return ipip6_tunnel_add(dev, p);
1361 case SIOCCHGTUNNEL:
1362 return ipip6_tunnel_change(dev, p);
1363 case SIOCDELTUNNEL:
1364 return ipip6_tunnel_del(dev, p);
1365 default:
1366 return -EINVAL;
1367 }
1368}
1369
1370static int
1371ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1372{
1373 switch (cmd) {
1374 case SIOCGETTUNNEL:
1375 case SIOCADDTUNNEL:
1376 case SIOCCHGTUNNEL:
1377 case SIOCDELTUNNEL:
1378 return ip_tunnel_ioctl(dev, ifr, cmd);
1379 case SIOCGETPRL:
1380 return ipip6_tunnel_get_prl(dev, ifr);
1381 case SIOCADDPRL:
1382 case SIOCDELPRL:
1383 case SIOCCHGPRL:
1384 return ipip6_tunnel_prl_ctl(dev, ifr, cmd);
1385#ifdef CONFIG_IPV6_SIT_6RD
1386 case SIOCGET6RD:
1387 return ipip6_tunnel_get6rd(dev, ifr);
1388 case SIOCADD6RD:
1389 case SIOCCHG6RD:
1390 case SIOCDEL6RD:
1391 return ipip6_tunnel_6rdctl(dev, ifr, cmd);
1392#endif
1393 default:
1394 return -EINVAL;
1395 }
1396}
1397
1398static const struct net_device_ops ipip6_netdev_ops = {
1399 .ndo_init = ipip6_tunnel_init,
1400 .ndo_uninit = ipip6_tunnel_uninit,
1401 .ndo_start_xmit = sit_tunnel_xmit,
1402 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1403 .ndo_get_stats64 = dev_get_tstats64,
1404 .ndo_get_iflink = ip_tunnel_get_iflink,
1405 .ndo_tunnel_ctl = ipip6_tunnel_ctl,
1406};
1407
1408static void ipip6_dev_free(struct net_device *dev)
1409{
1410 struct ip_tunnel *tunnel = netdev_priv(dev);
1411
1412 dst_cache_destroy(&tunnel->dst_cache);
1413 free_percpu(dev->tstats);
1414}
1415
1416#define SIT_FEATURES (NETIF_F_SG | \
1417 NETIF_F_FRAGLIST | \
1418 NETIF_F_HIGHDMA | \
1419 NETIF_F_GSO_SOFTWARE | \
1420 NETIF_F_HW_CSUM)
1421
1422static void ipip6_tunnel_setup(struct net_device *dev)
1423{
1424 struct ip_tunnel *tunnel = netdev_priv(dev);
1425 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1426
1427 dev->netdev_ops = &ipip6_netdev_ops;
1428 dev->header_ops = &ip_tunnel_header_ops;
1429 dev->needs_free_netdev = true;
1430 dev->priv_destructor = ipip6_dev_free;
1431
1432 dev->type = ARPHRD_SIT;
1433 dev->mtu = ETH_DATA_LEN - t_hlen;
1434 dev->min_mtu = IPV6_MIN_MTU;
1435 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1436 dev->flags = IFF_NOARP;
1437 netif_keep_dst(dev);
1438 dev->addr_len = 4;
1439 dev->features |= NETIF_F_LLTX;
1440 dev->features |= SIT_FEATURES;
1441 dev->hw_features |= SIT_FEATURES;
1442}
1443
1444static int ipip6_tunnel_init(struct net_device *dev)
1445{
1446 struct ip_tunnel *tunnel = netdev_priv(dev);
1447 int err;
1448
1449 tunnel->dev = dev;
1450 tunnel->net = dev_net(dev);
1451 strcpy(tunnel->parms.name, dev->name);
1452
1453 ipip6_tunnel_bind_dev(dev);
1454 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1455 if (!dev->tstats)
1456 return -ENOMEM;
1457
1458 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1459 if (err) {
1460 free_percpu(dev->tstats);
1461 dev->tstats = NULL;
1462 return err;
1463 }
1464 dev_hold(dev);
1465 return 0;
1466}
1467
1468static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1469{
1470 struct ip_tunnel *tunnel = netdev_priv(dev);
1471 struct iphdr *iph = &tunnel->parms.iph;
1472 struct net *net = dev_net(dev);
1473 struct sit_net *sitn = net_generic(net, sit_net_id);
1474
1475 iph->version = 4;
1476 iph->protocol = IPPROTO_IPV6;
1477 iph->ihl = 5;
1478 iph->ttl = 64;
1479
1480 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1481}
1482
1483static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1484 struct netlink_ext_ack *extack)
1485{
1486 u8 proto;
1487
1488 if (!data || !data[IFLA_IPTUN_PROTO])
1489 return 0;
1490
1491 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1492 if (!ipip6_valid_ip_proto(proto))
1493 return -EINVAL;
1494
1495 return 0;
1496}
1497
1498static void ipip6_netlink_parms(struct nlattr *data[],
1499 struct ip_tunnel_parm *parms,
1500 __u32 *fwmark)
1501{
1502 memset(parms, 0, sizeof(*parms));
1503
1504 parms->iph.version = 4;
1505 parms->iph.protocol = IPPROTO_IPV6;
1506 parms->iph.ihl = 5;
1507 parms->iph.ttl = 64;
1508
1509 if (!data)
1510 return;
1511
1512 if (data[IFLA_IPTUN_LINK])
1513 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1514
1515 if (data[IFLA_IPTUN_LOCAL])
1516 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1517
1518 if (data[IFLA_IPTUN_REMOTE])
1519 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1520
1521 if (data[IFLA_IPTUN_TTL]) {
1522 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1523 if (parms->iph.ttl)
1524 parms->iph.frag_off = htons(IP_DF);
1525 }
1526
1527 if (data[IFLA_IPTUN_TOS])
1528 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1529
1530 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1531 parms->iph.frag_off = htons(IP_DF);
1532
1533 if (data[IFLA_IPTUN_FLAGS])
1534 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1535
1536 if (data[IFLA_IPTUN_PROTO])
1537 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1538
1539 if (data[IFLA_IPTUN_FWMARK])
1540 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1541}
1542
1543/* This function returns true when ENCAP attributes are present in the nl msg */
1544static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1545 struct ip_tunnel_encap *ipencap)
1546{
1547 bool ret = false;
1548
1549 memset(ipencap, 0, sizeof(*ipencap));
1550
1551 if (!data)
1552 return ret;
1553
1554 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1555 ret = true;
1556 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1557 }
1558
1559 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1560 ret = true;
1561 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1562 }
1563
1564 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1565 ret = true;
1566 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1567 }
1568
1569 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1570 ret = true;
1571 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1572 }
1573
1574 return ret;
1575}
1576
1577#ifdef CONFIG_IPV6_SIT_6RD
1578/* This function returns true when 6RD attributes are present in the nl msg */
1579static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1580 struct ip_tunnel_6rd *ip6rd)
1581{
1582 bool ret = false;
1583 memset(ip6rd, 0, sizeof(*ip6rd));
1584
1585 if (!data)
1586 return ret;
1587
1588 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1589 ret = true;
1590 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1591 }
1592
1593 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1594 ret = true;
1595 ip6rd->relay_prefix =
1596 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1597 }
1598
1599 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1600 ret = true;
1601 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1602 }
1603
1604 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1605 ret = true;
1606 ip6rd->relay_prefixlen =
1607 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1608 }
1609
1610 return ret;
1611}
1612#endif
1613
1614static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1615 struct nlattr *tb[], struct nlattr *data[],
1616 struct netlink_ext_ack *extack)
1617{
1618 struct net *net = dev_net(dev);
1619 struct ip_tunnel *nt;
1620 struct ip_tunnel_encap ipencap;
1621#ifdef CONFIG_IPV6_SIT_6RD
1622 struct ip_tunnel_6rd ip6rd;
1623#endif
1624 int err;
1625
1626 nt = netdev_priv(dev);
1627
1628 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1629 err = ip_tunnel_encap_setup(nt, &ipencap);
1630 if (err < 0)
1631 return err;
1632 }
1633
1634 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1635
1636 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1637 return -EEXIST;
1638
1639 err = ipip6_tunnel_create(dev);
1640 if (err < 0)
1641 return err;
1642
1643 if (tb[IFLA_MTU]) {
1644 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1645
1646 if (mtu >= IPV6_MIN_MTU &&
1647 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1648 dev->mtu = mtu;
1649 }
1650
1651#ifdef CONFIG_IPV6_SIT_6RD
1652 if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
1653 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1654 if (err < 0)
1655 unregister_netdevice_queue(dev, NULL);
1656 }
1657#endif
1658
1659 return err;
1660}
1661
1662static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1663 struct nlattr *data[],
1664 struct netlink_ext_ack *extack)
1665{
1666 struct ip_tunnel *t = netdev_priv(dev);
1667 struct ip_tunnel_parm p;
1668 struct ip_tunnel_encap ipencap;
1669 struct net *net = t->net;
1670 struct sit_net *sitn = net_generic(net, sit_net_id);
1671#ifdef CONFIG_IPV6_SIT_6RD
1672 struct ip_tunnel_6rd ip6rd;
1673#endif
1674 __u32 fwmark = t->fwmark;
1675 int err;
1676
1677 if (dev == sitn->fb_tunnel_dev)
1678 return -EINVAL;
1679
1680 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1681 err = ip_tunnel_encap_setup(t, &ipencap);
1682 if (err < 0)
1683 return err;
1684 }
1685
1686 ipip6_netlink_parms(data, &p, &fwmark);
1687
1688 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1689 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1690 return -EINVAL;
1691
1692 t = ipip6_tunnel_locate(net, &p, 0);
1693
1694 if (t) {
1695 if (t->dev != dev)
1696 return -EEXIST;
1697 } else
1698 t = netdev_priv(dev);
1699
1700 ipip6_tunnel_update(t, &p, fwmark);
1701
1702#ifdef CONFIG_IPV6_SIT_6RD
1703 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1704 return ipip6_tunnel_update_6rd(t, &ip6rd);
1705#endif
1706
1707 return 0;
1708}
1709
1710static size_t ipip6_get_size(const struct net_device *dev)
1711{
1712 return
1713 /* IFLA_IPTUN_LINK */
1714 nla_total_size(4) +
1715 /* IFLA_IPTUN_LOCAL */
1716 nla_total_size(4) +
1717 /* IFLA_IPTUN_REMOTE */
1718 nla_total_size(4) +
1719 /* IFLA_IPTUN_TTL */
1720 nla_total_size(1) +
1721 /* IFLA_IPTUN_TOS */
1722 nla_total_size(1) +
1723 /* IFLA_IPTUN_PMTUDISC */
1724 nla_total_size(1) +
1725 /* IFLA_IPTUN_FLAGS */
1726 nla_total_size(2) +
1727 /* IFLA_IPTUN_PROTO */
1728 nla_total_size(1) +
1729#ifdef CONFIG_IPV6_SIT_6RD
1730 /* IFLA_IPTUN_6RD_PREFIX */
1731 nla_total_size(sizeof(struct in6_addr)) +
1732 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1733 nla_total_size(4) +
1734 /* IFLA_IPTUN_6RD_PREFIXLEN */
1735 nla_total_size(2) +
1736 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1737 nla_total_size(2) +
1738#endif
1739 /* IFLA_IPTUN_ENCAP_TYPE */
1740 nla_total_size(2) +
1741 /* IFLA_IPTUN_ENCAP_FLAGS */
1742 nla_total_size(2) +
1743 /* IFLA_IPTUN_ENCAP_SPORT */
1744 nla_total_size(2) +
1745 /* IFLA_IPTUN_ENCAP_DPORT */
1746 nla_total_size(2) +
1747 /* IFLA_IPTUN_FWMARK */
1748 nla_total_size(4) +
1749 0;
1750}
1751
1752static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1753{
1754 struct ip_tunnel *tunnel = netdev_priv(dev);
1755 struct ip_tunnel_parm *parm = &tunnel->parms;
1756
1757 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1758 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1759 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1760 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1761 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1762 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1763 !!(parm->iph.frag_off & htons(IP_DF))) ||
1764 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1765 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1766 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1767 goto nla_put_failure;
1768
1769#ifdef CONFIG_IPV6_SIT_6RD
1770 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1771 &tunnel->ip6rd.prefix) ||
1772 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1773 tunnel->ip6rd.relay_prefix) ||
1774 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1775 tunnel->ip6rd.prefixlen) ||
1776 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1777 tunnel->ip6rd.relay_prefixlen))
1778 goto nla_put_failure;
1779#endif
1780
1781 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1782 tunnel->encap.type) ||
1783 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1784 tunnel->encap.sport) ||
1785 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1786 tunnel->encap.dport) ||
1787 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1788 tunnel->encap.flags))
1789 goto nla_put_failure;
1790
1791 return 0;
1792
1793nla_put_failure:
1794 return -EMSGSIZE;
1795}
1796
1797static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1798 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1799 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1800 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1801 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1802 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1803 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1804 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1805 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1806#ifdef CONFIG_IPV6_SIT_6RD
1807 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1808 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1809 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1810 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1811#endif
1812 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1813 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1814 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1815 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1816 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1817};
1818
1819static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1820{
1821 struct net *net = dev_net(dev);
1822 struct sit_net *sitn = net_generic(net, sit_net_id);
1823
1824 if (dev != sitn->fb_tunnel_dev)
1825 unregister_netdevice_queue(dev, head);
1826}
1827
1828static struct rtnl_link_ops sit_link_ops __read_mostly = {
1829 .kind = "sit",
1830 .maxtype = IFLA_IPTUN_MAX,
1831 .policy = ipip6_policy,
1832 .priv_size = sizeof(struct ip_tunnel),
1833 .setup = ipip6_tunnel_setup,
1834 .validate = ipip6_validate,
1835 .newlink = ipip6_newlink,
1836 .changelink = ipip6_changelink,
1837 .get_size = ipip6_get_size,
1838 .fill_info = ipip6_fill_info,
1839 .dellink = ipip6_dellink,
1840 .get_link_net = ip_tunnel_get_link_net,
1841};
1842
1843static struct xfrm_tunnel sit_handler __read_mostly = {
1844 .handler = ipip6_rcv,
1845 .err_handler = ipip6_err,
1846 .priority = 1,
1847};
1848
1849static struct xfrm_tunnel ipip_handler __read_mostly = {
1850 .handler = ipip_rcv,
1851 .err_handler = ipip6_err,
1852 .priority = 2,
1853};
1854
1855#if IS_ENABLED(CONFIG_MPLS)
1856static struct xfrm_tunnel mplsip_handler __read_mostly = {
1857 .handler = mplsip_rcv,
1858 .err_handler = ipip6_err,
1859 .priority = 2,
1860};
1861#endif
1862
1863static void __net_exit sit_destroy_tunnels(struct net *net,
1864 struct list_head *head)
1865{
1866 struct sit_net *sitn = net_generic(net, sit_net_id);
1867 struct net_device *dev, *aux;
1868 int prio;
1869
1870 for_each_netdev_safe(net, dev, aux)
1871 if (dev->rtnl_link_ops == &sit_link_ops)
1872 unregister_netdevice_queue(dev, head);
1873
1874 for (prio = 0; prio < 4; prio++) {
1875 int h;
1876 for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
1877 struct ip_tunnel *t;
1878
1879 t = rtnl_dereference(sitn->tunnels[prio][h]);
1880 while (t) {
1881 /* If dev is in the same netns, it has already
1882 * been added to the list by the previous loop.
1883 */
1884 if (!net_eq(dev_net(t->dev), net))
1885 unregister_netdevice_queue(t->dev,
1886 head);
1887 t = rtnl_dereference(t->next);
1888 }
1889 }
1890 }
1891}
1892
1893static int __net_init sit_init_net(struct net *net)
1894{
1895 struct sit_net *sitn = net_generic(net, sit_net_id);
1896 struct ip_tunnel *t;
1897 int err;
1898
1899 sitn->tunnels[0] = sitn->tunnels_wc;
1900 sitn->tunnels[1] = sitn->tunnels_l;
1901 sitn->tunnels[2] = sitn->tunnels_r;
1902 sitn->tunnels[3] = sitn->tunnels_r_l;
1903
1904 if (!net_has_fallback_tunnels(net))
1905 return 0;
1906
1907 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1908 NET_NAME_UNKNOWN,
1909 ipip6_tunnel_setup);
1910 if (!sitn->fb_tunnel_dev) {
1911 err = -ENOMEM;
1912 goto err_alloc_dev;
1913 }
1914 dev_net_set(sitn->fb_tunnel_dev, net);
1915 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1916 /* FB netdevice is special: we have one, and only one per netns.
1917 * Allowing to move it to another netns is clearly unsafe.
1918 */
1919 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1920
1921 err = register_netdev(sitn->fb_tunnel_dev);
1922 if (err)
1923 goto err_reg_dev;
1924
1925 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1926 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1927
1928 t = netdev_priv(sitn->fb_tunnel_dev);
1929
1930 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1931 return 0;
1932
1933err_reg_dev:
1934 ipip6_dev_free(sitn->fb_tunnel_dev);
1935 free_netdev(sitn->fb_tunnel_dev);
1936err_alloc_dev:
1937 return err;
1938}
1939
1940static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1941{
1942 LIST_HEAD(list);
1943 struct net *net;
1944
1945 rtnl_lock();
1946 list_for_each_entry(net, net_list, exit_list)
1947 sit_destroy_tunnels(net, &list);
1948
1949 unregister_netdevice_many(&list);
1950 rtnl_unlock();
1951}
1952
1953static struct pernet_operations sit_net_ops = {
1954 .init = sit_init_net,
1955 .exit_batch = sit_exit_batch_net,
1956 .id = &sit_net_id,
1957 .size = sizeof(struct sit_net),
1958};
1959
1960static void __exit sit_cleanup(void)
1961{
1962 rtnl_link_unregister(&sit_link_ops);
1963 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1964 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1965#if IS_ENABLED(CONFIG_MPLS)
1966 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1967#endif
1968
1969 unregister_pernet_device(&sit_net_ops);
1970 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1971}
1972
1973static int __init sit_init(void)
1974{
1975 int err;
1976
1977 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1978
1979 err = register_pernet_device(&sit_net_ops);
1980 if (err < 0)
1981 return err;
1982 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1983 if (err < 0) {
1984 pr_info("%s: can't register ip6ip4\n", __func__);
1985 goto xfrm_tunnel_failed;
1986 }
1987 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1988 if (err < 0) {
1989 pr_info("%s: can't register ip4ip4\n", __func__);
1990 goto xfrm_tunnel4_failed;
1991 }
1992#if IS_ENABLED(CONFIG_MPLS)
1993 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1994 if (err < 0) {
1995 pr_info("%s: can't register mplsip\n", __func__);
1996 goto xfrm_tunnel_mpls_failed;
1997 }
1998#endif
1999 err = rtnl_link_register(&sit_link_ops);
2000 if (err < 0)
2001 goto rtnl_link_failed;
2002
2003out:
2004 return err;
2005
2006rtnl_link_failed:
2007#if IS_ENABLED(CONFIG_MPLS)
2008 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
2009xfrm_tunnel_mpls_failed:
2010#endif
2011 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
2012xfrm_tunnel4_failed:
2013 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
2014xfrm_tunnel_failed:
2015 unregister_pernet_device(&sit_net_ops);
2016 goto out;
2017}
2018
2019module_init(sit_init);
2020module_exit(sit_cleanup);
2021MODULE_LICENSE("GPL");
2022MODULE_ALIAS_RTNL_LINK("sit");
2023MODULE_ALIAS_NETDEV("sit0");