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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 dev_hold(dev);
222
223 ipip6_tunnel_link(sitn, t);
224 return 0;
225
226out:
227 return err;
228}
229
230static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
231 struct ip_tunnel_parm *parms, int create)
232{
233 __be32 remote = parms->iph.daddr;
234 __be32 local = parms->iph.saddr;
235 struct ip_tunnel *t, *nt;
236 struct ip_tunnel __rcu **tp;
237 struct net_device *dev;
238 char name[IFNAMSIZ];
239 struct sit_net *sitn = net_generic(net, sit_net_id);
240
241 for (tp = __ipip6_bucket(sitn, parms);
242 (t = rtnl_dereference(*tp)) != NULL;
243 tp = &t->next) {
244 if (local == t->parms.iph.saddr &&
245 remote == t->parms.iph.daddr &&
246 parms->link == t->parms.link) {
247 if (create)
248 return NULL;
249 else
250 return t;
251 }
252 }
253 if (!create)
254 goto failed;
255
256 if (parms->name[0]) {
257 if (!dev_valid_name(parms->name))
258 goto failed;
259 strlcpy(name, parms->name, IFNAMSIZ);
260 } else {
261 strcpy(name, "sit%d");
262 }
263 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
264 ipip6_tunnel_setup);
265 if (!dev)
266 return NULL;
267
268 dev_net_set(dev, net);
269
270 nt = netdev_priv(dev);
271
272 nt->parms = *parms;
273 if (ipip6_tunnel_create(dev) < 0)
274 goto failed_free;
275
276 return nt;
277
278failed_free:
279 free_netdev(dev);
280failed:
281 return NULL;
282}
283
284#define for_each_prl_rcu(start) \
285 for (prl = rcu_dereference(start); \
286 prl; \
287 prl = rcu_dereference(prl->next))
288
289static struct ip_tunnel_prl_entry *
290__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
291{
292 struct ip_tunnel_prl_entry *prl;
293
294 for_each_prl_rcu(t->prl)
295 if (prl->addr == addr)
296 break;
297 return prl;
298
299}
300
301static int ipip6_tunnel_get_prl(struct net_device *dev, struct ifreq *ifr)
302{
303 struct ip_tunnel_prl __user *a = ifr->ifr_ifru.ifru_data;
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 | __GFP_NOWARN) :
324 NULL;
325
326 rcu_read_lock();
327
328 ca = t->prl_count < cmax ? t->prl_count : cmax;
329
330 if (!kp) {
331 /* We don't try hard to allocate much memory for
332 * non-root users.
333 * For root users, retry allocating enough memory for
334 * the answer.
335 */
336 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
337 if (!kp) {
338 ret = -ENOMEM;
339 goto out;
340 }
341 }
342
343 c = 0;
344 for_each_prl_rcu(t->prl) {
345 if (c >= cmax)
346 break;
347 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
348 continue;
349 kp[c].addr = prl->addr;
350 kp[c].flags = prl->flags;
351 c++;
352 if (kprl.addr != htonl(INADDR_ANY))
353 break;
354 }
355out:
356 rcu_read_unlock();
357
358 len = sizeof(*kp) * c;
359 ret = 0;
360 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
361 ret = -EFAULT;
362
363 kfree(kp);
364
365 return ret;
366}
367
368static int
369ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
370{
371 struct ip_tunnel_prl_entry *p;
372 int err = 0;
373
374 if (a->addr == htonl(INADDR_ANY))
375 return -EINVAL;
376
377 ASSERT_RTNL();
378
379 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
380 if (p->addr == a->addr) {
381 if (chg) {
382 p->flags = a->flags;
383 goto out;
384 }
385 err = -EEXIST;
386 goto out;
387 }
388 }
389
390 if (chg) {
391 err = -ENXIO;
392 goto out;
393 }
394
395 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
396 if (!p) {
397 err = -ENOBUFS;
398 goto out;
399 }
400
401 p->next = t->prl;
402 p->addr = a->addr;
403 p->flags = a->flags;
404 t->prl_count++;
405 rcu_assign_pointer(t->prl, p);
406out:
407 return err;
408}
409
410static void prl_list_destroy_rcu(struct rcu_head *head)
411{
412 struct ip_tunnel_prl_entry *p, *n;
413
414 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
415 do {
416 n = rcu_dereference_protected(p->next, 1);
417 kfree(p);
418 p = n;
419 } while (p);
420}
421
422static int
423ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
424{
425 struct ip_tunnel_prl_entry *x;
426 struct ip_tunnel_prl_entry __rcu **p;
427 int err = 0;
428
429 ASSERT_RTNL();
430
431 if (a && a->addr != htonl(INADDR_ANY)) {
432 for (p = &t->prl;
433 (x = rtnl_dereference(*p)) != NULL;
434 p = &x->next) {
435 if (x->addr == a->addr) {
436 *p = x->next;
437 kfree_rcu(x, rcu_head);
438 t->prl_count--;
439 goto out;
440 }
441 }
442 err = -ENXIO;
443 } else {
444 x = rtnl_dereference(t->prl);
445 if (x) {
446 t->prl_count = 0;
447 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
448 t->prl = NULL;
449 }
450 }
451out:
452 return err;
453}
454
455static int ipip6_tunnel_prl_ctl(struct net_device *dev, struct ifreq *ifr,
456 int cmd)
457{
458 struct ip_tunnel *t = netdev_priv(dev);
459 struct ip_tunnel_prl prl;
460 int err;
461
462 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
463 return -EPERM;
464 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
465 return -EINVAL;
466
467 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
468 return -EFAULT;
469
470 switch (cmd) {
471 case SIOCDELPRL:
472 err = ipip6_tunnel_del_prl(t, &prl);
473 break;
474 case SIOCADDPRL:
475 case SIOCCHGPRL:
476 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
477 break;
478 }
479 dst_cache_reset(&t->dst_cache);
480 netdev_state_change(dev);
481 return err;
482}
483
484static int
485isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
486{
487 struct ip_tunnel_prl_entry *p;
488 int ok = 1;
489
490 rcu_read_lock();
491 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
492 if (p) {
493 if (p->flags & PRL_DEFAULT)
494 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
495 else
496 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
497 } else {
498 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
499
500 if (ipv6_addr_is_isatap(addr6) &&
501 (addr6->s6_addr32[3] == iph->saddr) &&
502 ipv6_chk_prefix(addr6, t->dev))
503 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
504 else
505 ok = 0;
506 }
507 rcu_read_unlock();
508 return ok;
509}
510
511static void ipip6_tunnel_uninit(struct net_device *dev)
512{
513 struct ip_tunnel *tunnel = netdev_priv(dev);
514 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
515
516 if (dev == sitn->fb_tunnel_dev) {
517 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
518 } else {
519 ipip6_tunnel_unlink(sitn, tunnel);
520 ipip6_tunnel_del_prl(tunnel, NULL);
521 }
522 dst_cache_reset(&tunnel->dst_cache);
523 dev_put(dev);
524}
525
526static int ipip6_err(struct sk_buff *skb, u32 info)
527{
528 const struct iphdr *iph = (const struct iphdr *)skb->data;
529 const int type = icmp_hdr(skb)->type;
530 const int code = icmp_hdr(skb)->code;
531 unsigned int data_len = 0;
532 struct ip_tunnel *t;
533 int sifindex;
534 int err;
535
536 switch (type) {
537 default:
538 case ICMP_PARAMETERPROB:
539 return 0;
540
541 case ICMP_DEST_UNREACH:
542 switch (code) {
543 case ICMP_SR_FAILED:
544 /* Impossible event. */
545 return 0;
546 default:
547 /* All others are translated to HOST_UNREACH.
548 rfc2003 contains "deep thoughts" about NET_UNREACH,
549 I believe they are just ether pollution. --ANK
550 */
551 break;
552 }
553 break;
554 case ICMP_TIME_EXCEEDED:
555 if (code != ICMP_EXC_TTL)
556 return 0;
557 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
558 break;
559 case ICMP_REDIRECT:
560 break;
561 }
562
563 err = -ENOENT;
564
565 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
566 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
567 iph->daddr, iph->saddr, sifindex);
568 if (!t)
569 goto out;
570
571 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
572 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
573 t->parms.link, iph->protocol);
574 err = 0;
575 goto out;
576 }
577 if (type == ICMP_REDIRECT) {
578 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
579 iph->protocol);
580 err = 0;
581 goto out;
582 }
583
584 err = 0;
585 if (__in6_dev_get(skb->dev) &&
586 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
587 goto out;
588
589 if (t->parms.iph.daddr == 0)
590 goto out;
591
592 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
593 goto out;
594
595 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
596 t->err_count++;
597 else
598 t->err_count = 1;
599 t->err_time = jiffies;
600out:
601 return err;
602}
603
604static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
605 const struct in6_addr *v6addr)
606{
607 __be32 v4embed = 0;
608 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
609 return true;
610 return false;
611}
612
613/* Checks if an address matches an address on the tunnel interface.
614 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
615 * Long story:
616 * This function is called after we considered the packet as spoofed
617 * in is_spoofed_6rd.
618 * We may have a router that is doing NAT for proto 41 packets
619 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
620 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
621 * function will return true, dropping the packet.
622 * But, we can still check if is spoofed against the IP
623 * addresses associated with the interface.
624 */
625static bool only_dnatted(const struct ip_tunnel *tunnel,
626 const struct in6_addr *v6dst)
627{
628 int prefix_len;
629
630#ifdef CONFIG_IPV6_SIT_6RD
631 prefix_len = tunnel->ip6rd.prefixlen + 32
632 - tunnel->ip6rd.relay_prefixlen;
633#else
634 prefix_len = 48;
635#endif
636 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
637}
638
639/* Returns true if a packet is spoofed */
640static bool packet_is_spoofed(struct sk_buff *skb,
641 const struct iphdr *iph,
642 struct ip_tunnel *tunnel)
643{
644 const struct ipv6hdr *ipv6h;
645
646 if (tunnel->dev->priv_flags & IFF_ISATAP) {
647 if (!isatap_chksrc(skb, iph, tunnel))
648 return true;
649
650 return false;
651 }
652
653 if (tunnel->dev->flags & IFF_POINTOPOINT)
654 return false;
655
656 ipv6h = ipv6_hdr(skb);
657
658 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
659 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
660 &iph->saddr, &ipv6h->saddr,
661 &iph->daddr, &ipv6h->daddr);
662 return true;
663 }
664
665 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
666 return false;
667
668 if (only_dnatted(tunnel, &ipv6h->daddr))
669 return false;
670
671 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
672 &iph->saddr, &ipv6h->saddr,
673 &iph->daddr, &ipv6h->daddr);
674 return true;
675}
676
677static int ipip6_rcv(struct sk_buff *skb)
678{
679 const struct iphdr *iph = ip_hdr(skb);
680 struct ip_tunnel *tunnel;
681 int sifindex;
682 int err;
683
684 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
685 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
686 iph->saddr, iph->daddr, sifindex);
687 if (tunnel) {
688 struct pcpu_sw_netstats *tstats;
689
690 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
691 tunnel->parms.iph.protocol != 0)
692 goto out;
693
694 skb->mac_header = skb->network_header;
695 skb_reset_network_header(skb);
696 IPCB(skb)->flags = 0;
697 skb->dev = tunnel->dev;
698
699 if (packet_is_spoofed(skb, iph, tunnel)) {
700 tunnel->dev->stats.rx_errors++;
701 goto out;
702 }
703
704 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
705 !net_eq(tunnel->net, dev_net(tunnel->dev))))
706 goto out;
707
708 /* skb can be uncloned in iptunnel_pull_header, so
709 * old iph is no longer valid
710 */
711 iph = (const struct iphdr *)skb_mac_header(skb);
712 err = IP_ECN_decapsulate(iph, skb);
713 if (unlikely(err)) {
714 if (log_ecn_error)
715 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
716 &iph->saddr, iph->tos);
717 if (err > 1) {
718 ++tunnel->dev->stats.rx_frame_errors;
719 ++tunnel->dev->stats.rx_errors;
720 goto out;
721 }
722 }
723
724 tstats = this_cpu_ptr(tunnel->dev->tstats);
725 u64_stats_update_begin(&tstats->syncp);
726 tstats->rx_packets++;
727 tstats->rx_bytes += skb->len;
728 u64_stats_update_end(&tstats->syncp);
729
730 netif_rx(skb);
731
732 return 0;
733 }
734
735 /* no tunnel matched, let upstream know, ipsec may handle it */
736 return 1;
737out:
738 kfree_skb(skb);
739 return 0;
740}
741
742static const struct tnl_ptk_info ipip_tpi = {
743 /* no tunnel info required for ipip. */
744 .proto = htons(ETH_P_IP),
745};
746
747#if IS_ENABLED(CONFIG_MPLS)
748static const struct tnl_ptk_info mplsip_tpi = {
749 /* no tunnel info required for mplsip. */
750 .proto = htons(ETH_P_MPLS_UC),
751};
752#endif
753
754static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
755{
756 const struct iphdr *iph;
757 struct ip_tunnel *tunnel;
758 int sifindex;
759
760 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
761
762 iph = ip_hdr(skb);
763 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
764 iph->saddr, iph->daddr, sifindex);
765 if (tunnel) {
766 const struct tnl_ptk_info *tpi;
767
768 if (tunnel->parms.iph.protocol != ipproto &&
769 tunnel->parms.iph.protocol != 0)
770 goto drop;
771
772 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
773 goto drop;
774#if IS_ENABLED(CONFIG_MPLS)
775 if (ipproto == IPPROTO_MPLS)
776 tpi = &mplsip_tpi;
777 else
778#endif
779 tpi = &ipip_tpi;
780 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
781 goto drop;
782 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
783 }
784
785 return 1;
786
787drop:
788 kfree_skb(skb);
789 return 0;
790}
791
792static int ipip_rcv(struct sk_buff *skb)
793{
794 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
795}
796
797#if IS_ENABLED(CONFIG_MPLS)
798static int mplsip_rcv(struct sk_buff *skb)
799{
800 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
801}
802#endif
803
804/*
805 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
806 * stores the embedded IPv4 address in v4dst and returns true.
807 */
808static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
809 __be32 *v4dst)
810{
811#ifdef CONFIG_IPV6_SIT_6RD
812 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
813 tunnel->ip6rd.prefixlen)) {
814 unsigned int pbw0, pbi0;
815 int pbi1;
816 u32 d;
817
818 pbw0 = tunnel->ip6rd.prefixlen >> 5;
819 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
820
821 d = tunnel->ip6rd.relay_prefixlen < 32 ?
822 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
823 tunnel->ip6rd.relay_prefixlen : 0;
824
825 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
826 if (pbi1 > 0)
827 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
828 (32 - pbi1);
829
830 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
831 return true;
832 }
833#else
834 if (v6dst->s6_addr16[0] == htons(0x2002)) {
835 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
836 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
837 return true;
838 }
839#endif
840 return false;
841}
842
843static inline __be32 try_6rd(struct ip_tunnel *tunnel,
844 const struct in6_addr *v6dst)
845{
846 __be32 dst = 0;
847 check_6rd(tunnel, v6dst, &dst);
848 return dst;
849}
850
851/*
852 * This function assumes it is being called from dev_queue_xmit()
853 * and that skb is filled properly by that function.
854 */
855
856static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
857 struct net_device *dev)
858{
859 struct ip_tunnel *tunnel = netdev_priv(dev);
860 const struct iphdr *tiph = &tunnel->parms.iph;
861 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
862 u8 tos = tunnel->parms.iph.tos;
863 __be16 df = tiph->frag_off;
864 struct rtable *rt; /* Route to the other host */
865 struct net_device *tdev; /* Device to other host */
866 unsigned int max_headroom; /* The extra header space needed */
867 __be32 dst = tiph->daddr;
868 struct flowi4 fl4;
869 int mtu;
870 const struct in6_addr *addr6;
871 int addr_type;
872 u8 ttl;
873 u8 protocol = IPPROTO_IPV6;
874 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
875
876 if (tos == 1)
877 tos = ipv6_get_dsfield(iph6);
878
879 /* ISATAP (RFC4214) - must come before 6to4 */
880 if (dev->priv_flags & IFF_ISATAP) {
881 struct neighbour *neigh = NULL;
882 bool do_tx_error = false;
883
884 if (skb_dst(skb))
885 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
886
887 if (!neigh) {
888 net_dbg_ratelimited("nexthop == NULL\n");
889 goto tx_error;
890 }
891
892 addr6 = (const struct in6_addr *)&neigh->primary_key;
893 addr_type = ipv6_addr_type(addr6);
894
895 if ((addr_type & IPV6_ADDR_UNICAST) &&
896 ipv6_addr_is_isatap(addr6))
897 dst = addr6->s6_addr32[3];
898 else
899 do_tx_error = true;
900
901 neigh_release(neigh);
902 if (do_tx_error)
903 goto tx_error;
904 }
905
906 if (!dst)
907 dst = try_6rd(tunnel, &iph6->daddr);
908
909 if (!dst) {
910 struct neighbour *neigh = NULL;
911 bool do_tx_error = false;
912
913 if (skb_dst(skb))
914 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
915
916 if (!neigh) {
917 net_dbg_ratelimited("nexthop == NULL\n");
918 goto tx_error;
919 }
920
921 addr6 = (const struct in6_addr *)&neigh->primary_key;
922 addr_type = ipv6_addr_type(addr6);
923
924 if (addr_type == IPV6_ADDR_ANY) {
925 addr6 = &ipv6_hdr(skb)->daddr;
926 addr_type = ipv6_addr_type(addr6);
927 }
928
929 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
930 dst = addr6->s6_addr32[3];
931 else
932 do_tx_error = true;
933
934 neigh_release(neigh);
935 if (do_tx_error)
936 goto tx_error;
937 }
938
939 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
940 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
941 0, dst, tiph->saddr, 0, 0,
942 sock_net_uid(tunnel->net, NULL));
943
944 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
945 if (!rt) {
946 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
947 if (IS_ERR(rt)) {
948 dev->stats.tx_carrier_errors++;
949 goto tx_error_icmp;
950 }
951 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
952 }
953
954 if (rt->rt_type != RTN_UNICAST) {
955 ip_rt_put(rt);
956 dev->stats.tx_carrier_errors++;
957 goto tx_error_icmp;
958 }
959 tdev = rt->dst.dev;
960
961 if (tdev == dev) {
962 ip_rt_put(rt);
963 dev->stats.collisions++;
964 goto tx_error;
965 }
966
967 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
968 ip_rt_put(rt);
969 goto tx_error;
970 }
971
972 if (df) {
973 mtu = dst_mtu(&rt->dst) - t_hlen;
974
975 if (mtu < 68) {
976 dev->stats.collisions++;
977 ip_rt_put(rt);
978 goto tx_error;
979 }
980
981 if (mtu < IPV6_MIN_MTU) {
982 mtu = IPV6_MIN_MTU;
983 df = 0;
984 }
985
986 if (tunnel->parms.iph.daddr)
987 skb_dst_update_pmtu_no_confirm(skb, mtu);
988
989 if (skb->len > mtu && !skb_is_gso(skb)) {
990 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
991 ip_rt_put(rt);
992 goto tx_error;
993 }
994 }
995
996 if (tunnel->err_count > 0) {
997 if (time_before(jiffies,
998 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
999 tunnel->err_count--;
1000 dst_link_failure(skb);
1001 } else
1002 tunnel->err_count = 0;
1003 }
1004
1005 /*
1006 * Okay, now see if we can stuff it in the buffer as-is.
1007 */
1008 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1009
1010 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1011 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1012 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1013 if (!new_skb) {
1014 ip_rt_put(rt);
1015 dev->stats.tx_dropped++;
1016 kfree_skb(skb);
1017 return NETDEV_TX_OK;
1018 }
1019 if (skb->sk)
1020 skb_set_owner_w(new_skb, skb->sk);
1021 dev_kfree_skb(skb);
1022 skb = new_skb;
1023 iph6 = ipv6_hdr(skb);
1024 }
1025 ttl = tiph->ttl;
1026 if (ttl == 0)
1027 ttl = iph6->hop_limit;
1028 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1029
1030 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
1031 ip_rt_put(rt);
1032 goto tx_error;
1033 }
1034
1035 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1036
1037 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1038 df, !net_eq(tunnel->net, dev_net(dev)));
1039 return NETDEV_TX_OK;
1040
1041tx_error_icmp:
1042 dst_link_failure(skb);
1043tx_error:
1044 kfree_skb(skb);
1045 dev->stats.tx_errors++;
1046 return NETDEV_TX_OK;
1047}
1048
1049static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1050 struct net_device *dev, u8 ipproto)
1051{
1052 struct ip_tunnel *tunnel = netdev_priv(dev);
1053 const struct iphdr *tiph = &tunnel->parms.iph;
1054
1055 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1056 goto tx_error;
1057
1058 skb_set_inner_ipproto(skb, ipproto);
1059
1060 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1061 return NETDEV_TX_OK;
1062tx_error:
1063 kfree_skb(skb);
1064 dev->stats.tx_errors++;
1065 return NETDEV_TX_OK;
1066}
1067
1068static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1069 struct net_device *dev)
1070{
1071 if (!pskb_inet_may_pull(skb))
1072 goto tx_err;
1073
1074 switch (skb->protocol) {
1075 case htons(ETH_P_IP):
1076 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1077 break;
1078 case htons(ETH_P_IPV6):
1079 ipip6_tunnel_xmit(skb, dev);
1080 break;
1081#if IS_ENABLED(CONFIG_MPLS)
1082 case htons(ETH_P_MPLS_UC):
1083 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1084 break;
1085#endif
1086 default:
1087 goto tx_err;
1088 }
1089
1090 return NETDEV_TX_OK;
1091
1092tx_err:
1093 dev->stats.tx_errors++;
1094 kfree_skb(skb);
1095 return NETDEV_TX_OK;
1096
1097}
1098
1099static void ipip6_tunnel_bind_dev(struct net_device *dev)
1100{
1101 struct net_device *tdev = NULL;
1102 struct ip_tunnel *tunnel;
1103 const struct iphdr *iph;
1104 struct flowi4 fl4;
1105
1106 tunnel = netdev_priv(dev);
1107 iph = &tunnel->parms.iph;
1108
1109 if (iph->daddr) {
1110 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1111 NULL,
1112 iph->daddr, iph->saddr,
1113 0, 0,
1114 IPPROTO_IPV6,
1115 RT_TOS(iph->tos),
1116 tunnel->parms.link);
1117
1118 if (!IS_ERR(rt)) {
1119 tdev = rt->dst.dev;
1120 ip_rt_put(rt);
1121 }
1122 dev->flags |= IFF_POINTOPOINT;
1123 }
1124
1125 if (!tdev && tunnel->parms.link)
1126 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1127
1128 if (tdev && !netif_is_l3_master(tdev)) {
1129 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1130
1131 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1132 dev->mtu = tdev->mtu - t_hlen;
1133 if (dev->mtu < IPV6_MIN_MTU)
1134 dev->mtu = IPV6_MIN_MTU;
1135 }
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 memcpy(t->dev->dev_addr, &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 ifreq *ifr)
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, ifr->ifr_ifru.ifru_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(ifr->ifr_ifru.ifru_data, &ip6rd, sizeof(ip6rd)))
1215 return -EFAULT;
1216 return 0;
1217}
1218
1219static int
1220ipip6_tunnel_6rdctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1221{
1222 struct ip_tunnel *t = netdev_priv(dev);
1223 struct ip_tunnel_6rd ip6rd;
1224 int err;
1225
1226 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1227 return -EPERM;
1228 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, sizeof(ip6rd)))
1229 return -EFAULT;
1230
1231 if (cmd != SIOCDEL6RD) {
1232 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1233 if (err < 0)
1234 return err;
1235 } else
1236 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1237 return 0;
1238}
1239
1240#endif /* CONFIG_IPV6_SIT_6RD */
1241
1242static bool ipip6_valid_ip_proto(u8 ipproto)
1243{
1244 return ipproto == IPPROTO_IPV6 ||
1245 ipproto == IPPROTO_IPIP ||
1246#if IS_ENABLED(CONFIG_MPLS)
1247 ipproto == IPPROTO_MPLS ||
1248#endif
1249 ipproto == 0;
1250}
1251
1252static int
1253__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1254{
1255 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1256 return -EPERM;
1257
1258 if (!ipip6_valid_ip_proto(p->iph.protocol))
1259 return -EINVAL;
1260 if (p->iph.version != 4 ||
1261 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1262 return -EINVAL;
1263
1264 if (p->iph.ttl)
1265 p->iph.frag_off |= htons(IP_DF);
1266 return 0;
1267}
1268
1269static int
1270ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1271{
1272 struct ip_tunnel *t = netdev_priv(dev);
1273
1274 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1275 t = ipip6_tunnel_locate(t->net, p, 0);
1276 if (!t)
1277 t = netdev_priv(dev);
1278 memcpy(p, &t->parms, sizeof(*p));
1279 return 0;
1280}
1281
1282static int
1283ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1284{
1285 struct ip_tunnel *t = netdev_priv(dev);
1286 int err;
1287
1288 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1289 if (err)
1290 return err;
1291
1292 t = ipip6_tunnel_locate(t->net, p, 1);
1293 if (!t)
1294 return -ENOBUFS;
1295 return 0;
1296}
1297
1298static int
1299ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1300{
1301 struct ip_tunnel *t = netdev_priv(dev);
1302 int err;
1303
1304 err = __ipip6_tunnel_ioctl_validate(t->net, p);
1305 if (err)
1306 return err;
1307
1308 t = ipip6_tunnel_locate(t->net, p, 0);
1309 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1310 if (!t)
1311 return -ENOENT;
1312 } else {
1313 if (t) {
1314 if (t->dev != dev)
1315 return -EEXIST;
1316 } else {
1317 if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1318 (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1319 return -EINVAL;
1320 t = netdev_priv(dev);
1321 }
1322
1323 ipip6_tunnel_update(t, p, t->fwmark);
1324 }
1325
1326 return 0;
1327}
1328
1329static int
1330ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1331{
1332 struct ip_tunnel *t = netdev_priv(dev);
1333
1334 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1335 return -EPERM;
1336
1337 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1338 t = ipip6_tunnel_locate(t->net, p, 0);
1339 if (!t)
1340 return -ENOENT;
1341 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1342 return -EPERM;
1343 dev = t->dev;
1344 }
1345 unregister_netdevice(dev);
1346 return 0;
1347}
1348
1349static int
1350ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1351{
1352 switch (cmd) {
1353 case SIOCGETTUNNEL:
1354 return ipip6_tunnel_get(dev, p);
1355 case SIOCADDTUNNEL:
1356 return ipip6_tunnel_add(dev, p);
1357 case SIOCCHGTUNNEL:
1358 return ipip6_tunnel_change(dev, p);
1359 case SIOCDELTUNNEL:
1360 return ipip6_tunnel_del(dev, p);
1361 default:
1362 return -EINVAL;
1363 }
1364}
1365
1366static int
1367ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1368{
1369 switch (cmd) {
1370 case SIOCGETTUNNEL:
1371 case SIOCADDTUNNEL:
1372 case SIOCCHGTUNNEL:
1373 case SIOCDELTUNNEL:
1374 return ip_tunnel_ioctl(dev, ifr, cmd);
1375 case SIOCGETPRL:
1376 return ipip6_tunnel_get_prl(dev, ifr);
1377 case SIOCADDPRL:
1378 case SIOCDELPRL:
1379 case SIOCCHGPRL:
1380 return ipip6_tunnel_prl_ctl(dev, ifr, cmd);
1381#ifdef CONFIG_IPV6_SIT_6RD
1382 case SIOCGET6RD:
1383 return ipip6_tunnel_get6rd(dev, ifr);
1384 case SIOCADD6RD:
1385 case SIOCCHG6RD:
1386 case SIOCDEL6RD:
1387 return ipip6_tunnel_6rdctl(dev, ifr, cmd);
1388#endif
1389 default:
1390 return -EINVAL;
1391 }
1392}
1393
1394static const struct net_device_ops ipip6_netdev_ops = {
1395 .ndo_init = ipip6_tunnel_init,
1396 .ndo_uninit = ipip6_tunnel_uninit,
1397 .ndo_start_xmit = sit_tunnel_xmit,
1398 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1399 .ndo_get_stats64 = ip_tunnel_get_stats64,
1400 .ndo_get_iflink = ip_tunnel_get_iflink,
1401 .ndo_tunnel_ctl = ipip6_tunnel_ctl,
1402};
1403
1404static void ipip6_dev_free(struct net_device *dev)
1405{
1406 struct ip_tunnel *tunnel = netdev_priv(dev);
1407
1408 dst_cache_destroy(&tunnel->dst_cache);
1409 free_percpu(dev->tstats);
1410}
1411
1412#define SIT_FEATURES (NETIF_F_SG | \
1413 NETIF_F_FRAGLIST | \
1414 NETIF_F_HIGHDMA | \
1415 NETIF_F_GSO_SOFTWARE | \
1416 NETIF_F_HW_CSUM)
1417
1418static void ipip6_tunnel_setup(struct net_device *dev)
1419{
1420 struct ip_tunnel *tunnel = netdev_priv(dev);
1421 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1422
1423 dev->netdev_ops = &ipip6_netdev_ops;
1424 dev->header_ops = &ip_tunnel_header_ops;
1425 dev->needs_free_netdev = true;
1426 dev->priv_destructor = ipip6_dev_free;
1427
1428 dev->type = ARPHRD_SIT;
1429 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1430 dev->mtu = ETH_DATA_LEN - t_hlen;
1431 dev->min_mtu = IPV6_MIN_MTU;
1432 dev->max_mtu = IP6_MAX_MTU - t_hlen;
1433 dev->flags = IFF_NOARP;
1434 netif_keep_dst(dev);
1435 dev->addr_len = 4;
1436 dev->features |= NETIF_F_LLTX;
1437 dev->features |= SIT_FEATURES;
1438 dev->hw_features |= SIT_FEATURES;
1439}
1440
1441static int ipip6_tunnel_init(struct net_device *dev)
1442{
1443 struct ip_tunnel *tunnel = netdev_priv(dev);
1444 int err;
1445
1446 tunnel->dev = dev;
1447 tunnel->net = dev_net(dev);
1448 strcpy(tunnel->parms.name, dev->name);
1449
1450 ipip6_tunnel_bind_dev(dev);
1451 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1452 if (!dev->tstats)
1453 return -ENOMEM;
1454
1455 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1456 if (err) {
1457 free_percpu(dev->tstats);
1458 dev->tstats = NULL;
1459 return err;
1460 }
1461
1462 return 0;
1463}
1464
1465static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1466{
1467 struct ip_tunnel *tunnel = netdev_priv(dev);
1468 struct iphdr *iph = &tunnel->parms.iph;
1469 struct net *net = dev_net(dev);
1470 struct sit_net *sitn = net_generic(net, sit_net_id);
1471
1472 iph->version = 4;
1473 iph->protocol = IPPROTO_IPV6;
1474 iph->ihl = 5;
1475 iph->ttl = 64;
1476
1477 dev_hold(dev);
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 if (data[IFLA_IPTUN_LINK])
1511 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1512
1513 if (data[IFLA_IPTUN_LOCAL])
1514 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1515
1516 if (data[IFLA_IPTUN_REMOTE])
1517 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1518
1519 if (data[IFLA_IPTUN_TTL]) {
1520 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1521 if (parms->iph.ttl)
1522 parms->iph.frag_off = htons(IP_DF);
1523 }
1524
1525 if (data[IFLA_IPTUN_TOS])
1526 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1527
1528 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1529 parms->iph.frag_off = htons(IP_DF);
1530
1531 if (data[IFLA_IPTUN_FLAGS])
1532 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1533
1534 if (data[IFLA_IPTUN_PROTO])
1535 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1536
1537 if (data[IFLA_IPTUN_FWMARK])
1538 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1539}
1540
1541/* This function returns true when ENCAP attributes are present in the nl msg */
1542static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1543 struct ip_tunnel_encap *ipencap)
1544{
1545 bool ret = false;
1546
1547 memset(ipencap, 0, sizeof(*ipencap));
1548
1549 if (!data)
1550 return ret;
1551
1552 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1553 ret = true;
1554 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1555 }
1556
1557 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1558 ret = true;
1559 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1560 }
1561
1562 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1563 ret = true;
1564 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1565 }
1566
1567 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1568 ret = true;
1569 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1570 }
1571
1572 return ret;
1573}
1574
1575#ifdef CONFIG_IPV6_SIT_6RD
1576/* This function returns true when 6RD attributes are present in the nl msg */
1577static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1578 struct ip_tunnel_6rd *ip6rd)
1579{
1580 bool ret = false;
1581 memset(ip6rd, 0, sizeof(*ip6rd));
1582
1583 if (!data)
1584 return ret;
1585
1586 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1587 ret = true;
1588 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1589 }
1590
1591 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1592 ret = true;
1593 ip6rd->relay_prefix =
1594 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1595 }
1596
1597 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1598 ret = true;
1599 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1600 }
1601
1602 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1603 ret = true;
1604 ip6rd->relay_prefixlen =
1605 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1606 }
1607
1608 return ret;
1609}
1610#endif
1611
1612static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1613 struct nlattr *tb[], struct nlattr *data[],
1614 struct netlink_ext_ack *extack)
1615{
1616 struct net *net = dev_net(dev);
1617 struct ip_tunnel *nt;
1618 struct ip_tunnel_encap ipencap;
1619#ifdef CONFIG_IPV6_SIT_6RD
1620 struct ip_tunnel_6rd ip6rd;
1621#endif
1622 int err;
1623
1624 nt = netdev_priv(dev);
1625
1626 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1627 err = ip_tunnel_encap_setup(nt, &ipencap);
1628 if (err < 0)
1629 return err;
1630 }
1631
1632 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1633
1634 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1635 return -EEXIST;
1636
1637 err = ipip6_tunnel_create(dev);
1638 if (err < 0)
1639 return err;
1640
1641 if (tb[IFLA_MTU]) {
1642 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1643
1644 if (mtu >= IPV6_MIN_MTU &&
1645 mtu <= IP6_MAX_MTU - dev->hard_header_len)
1646 dev->mtu = mtu;
1647 }
1648
1649#ifdef CONFIG_IPV6_SIT_6RD
1650 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1651 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1652#endif
1653
1654 return err;
1655}
1656
1657static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1658 struct nlattr *data[],
1659 struct netlink_ext_ack *extack)
1660{
1661 struct ip_tunnel *t = netdev_priv(dev);
1662 struct ip_tunnel_parm p;
1663 struct ip_tunnel_encap ipencap;
1664 struct net *net = t->net;
1665 struct sit_net *sitn = net_generic(net, sit_net_id);
1666#ifdef CONFIG_IPV6_SIT_6RD
1667 struct ip_tunnel_6rd ip6rd;
1668#endif
1669 __u32 fwmark = t->fwmark;
1670 int err;
1671
1672 if (dev == sitn->fb_tunnel_dev)
1673 return -EINVAL;
1674
1675 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1676 err = ip_tunnel_encap_setup(t, &ipencap);
1677 if (err < 0)
1678 return err;
1679 }
1680
1681 ipip6_netlink_parms(data, &p, &fwmark);
1682
1683 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1684 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1685 return -EINVAL;
1686
1687 t = ipip6_tunnel_locate(net, &p, 0);
1688
1689 if (t) {
1690 if (t->dev != dev)
1691 return -EEXIST;
1692 } else
1693 t = netdev_priv(dev);
1694
1695 ipip6_tunnel_update(t, &p, fwmark);
1696
1697#ifdef CONFIG_IPV6_SIT_6RD
1698 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1699 return ipip6_tunnel_update_6rd(t, &ip6rd);
1700#endif
1701
1702 return 0;
1703}
1704
1705static size_t ipip6_get_size(const struct net_device *dev)
1706{
1707 return
1708 /* IFLA_IPTUN_LINK */
1709 nla_total_size(4) +
1710 /* IFLA_IPTUN_LOCAL */
1711 nla_total_size(4) +
1712 /* IFLA_IPTUN_REMOTE */
1713 nla_total_size(4) +
1714 /* IFLA_IPTUN_TTL */
1715 nla_total_size(1) +
1716 /* IFLA_IPTUN_TOS */
1717 nla_total_size(1) +
1718 /* IFLA_IPTUN_PMTUDISC */
1719 nla_total_size(1) +
1720 /* IFLA_IPTUN_FLAGS */
1721 nla_total_size(2) +
1722 /* IFLA_IPTUN_PROTO */
1723 nla_total_size(1) +
1724#ifdef CONFIG_IPV6_SIT_6RD
1725 /* IFLA_IPTUN_6RD_PREFIX */
1726 nla_total_size(sizeof(struct in6_addr)) +
1727 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1728 nla_total_size(4) +
1729 /* IFLA_IPTUN_6RD_PREFIXLEN */
1730 nla_total_size(2) +
1731 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1732 nla_total_size(2) +
1733#endif
1734 /* IFLA_IPTUN_ENCAP_TYPE */
1735 nla_total_size(2) +
1736 /* IFLA_IPTUN_ENCAP_FLAGS */
1737 nla_total_size(2) +
1738 /* IFLA_IPTUN_ENCAP_SPORT */
1739 nla_total_size(2) +
1740 /* IFLA_IPTUN_ENCAP_DPORT */
1741 nla_total_size(2) +
1742 /* IFLA_IPTUN_FWMARK */
1743 nla_total_size(4) +
1744 0;
1745}
1746
1747static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1748{
1749 struct ip_tunnel *tunnel = netdev_priv(dev);
1750 struct ip_tunnel_parm *parm = &tunnel->parms;
1751
1752 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1753 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1754 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1755 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1756 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1757 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1758 !!(parm->iph.frag_off & htons(IP_DF))) ||
1759 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1760 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1761 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1762 goto nla_put_failure;
1763
1764#ifdef CONFIG_IPV6_SIT_6RD
1765 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1766 &tunnel->ip6rd.prefix) ||
1767 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1768 tunnel->ip6rd.relay_prefix) ||
1769 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1770 tunnel->ip6rd.prefixlen) ||
1771 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1772 tunnel->ip6rd.relay_prefixlen))
1773 goto nla_put_failure;
1774#endif
1775
1776 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1777 tunnel->encap.type) ||
1778 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1779 tunnel->encap.sport) ||
1780 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1781 tunnel->encap.dport) ||
1782 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1783 tunnel->encap.flags))
1784 goto nla_put_failure;
1785
1786 return 0;
1787
1788nla_put_failure:
1789 return -EMSGSIZE;
1790}
1791
1792static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1793 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1794 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1795 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1796 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1797 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1798 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1799 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1800 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1801#ifdef CONFIG_IPV6_SIT_6RD
1802 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1803 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1804 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1805 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1806#endif
1807 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1808 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1809 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1810 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1811 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1812};
1813
1814static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1815{
1816 struct net *net = dev_net(dev);
1817 struct sit_net *sitn = net_generic(net, sit_net_id);
1818
1819 if (dev != sitn->fb_tunnel_dev)
1820 unregister_netdevice_queue(dev, head);
1821}
1822
1823static struct rtnl_link_ops sit_link_ops __read_mostly = {
1824 .kind = "sit",
1825 .maxtype = IFLA_IPTUN_MAX,
1826 .policy = ipip6_policy,
1827 .priv_size = sizeof(struct ip_tunnel),
1828 .setup = ipip6_tunnel_setup,
1829 .validate = ipip6_validate,
1830 .newlink = ipip6_newlink,
1831 .changelink = ipip6_changelink,
1832 .get_size = ipip6_get_size,
1833 .fill_info = ipip6_fill_info,
1834 .dellink = ipip6_dellink,
1835 .get_link_net = ip_tunnel_get_link_net,
1836};
1837
1838static struct xfrm_tunnel sit_handler __read_mostly = {
1839 .handler = ipip6_rcv,
1840 .err_handler = ipip6_err,
1841 .priority = 1,
1842};
1843
1844static struct xfrm_tunnel ipip_handler __read_mostly = {
1845 .handler = ipip_rcv,
1846 .err_handler = ipip6_err,
1847 .priority = 2,
1848};
1849
1850#if IS_ENABLED(CONFIG_MPLS)
1851static struct xfrm_tunnel mplsip_handler __read_mostly = {
1852 .handler = mplsip_rcv,
1853 .err_handler = ipip6_err,
1854 .priority = 2,
1855};
1856#endif
1857
1858static void __net_exit sit_destroy_tunnels(struct net *net,
1859 struct list_head *head)
1860{
1861 struct sit_net *sitn = net_generic(net, sit_net_id);
1862 struct net_device *dev, *aux;
1863 int prio;
1864
1865 for_each_netdev_safe(net, dev, aux)
1866 if (dev->rtnl_link_ops == &sit_link_ops)
1867 unregister_netdevice_queue(dev, head);
1868
1869 for (prio = 1; prio < 4; prio++) {
1870 int h;
1871 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1872 struct ip_tunnel *t;
1873
1874 t = rtnl_dereference(sitn->tunnels[prio][h]);
1875 while (t) {
1876 /* If dev is in the same netns, it has already
1877 * been added to the list by the previous loop.
1878 */
1879 if (!net_eq(dev_net(t->dev), net))
1880 unregister_netdevice_queue(t->dev,
1881 head);
1882 t = rtnl_dereference(t->next);
1883 }
1884 }
1885 }
1886}
1887
1888static int __net_init sit_init_net(struct net *net)
1889{
1890 struct sit_net *sitn = net_generic(net, sit_net_id);
1891 struct ip_tunnel *t;
1892 int err;
1893
1894 sitn->tunnels[0] = sitn->tunnels_wc;
1895 sitn->tunnels[1] = sitn->tunnels_l;
1896 sitn->tunnels[2] = sitn->tunnels_r;
1897 sitn->tunnels[3] = sitn->tunnels_r_l;
1898
1899 if (!net_has_fallback_tunnels(net))
1900 return 0;
1901
1902 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1903 NET_NAME_UNKNOWN,
1904 ipip6_tunnel_setup);
1905 if (!sitn->fb_tunnel_dev) {
1906 err = -ENOMEM;
1907 goto err_alloc_dev;
1908 }
1909 dev_net_set(sitn->fb_tunnel_dev, net);
1910 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1911 /* FB netdevice is special: we have one, and only one per netns.
1912 * Allowing to move it to another netns is clearly unsafe.
1913 */
1914 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1915
1916 err = register_netdev(sitn->fb_tunnel_dev);
1917 if (err)
1918 goto err_reg_dev;
1919
1920 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1921 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1922
1923 t = netdev_priv(sitn->fb_tunnel_dev);
1924
1925 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1926 return 0;
1927
1928err_reg_dev:
1929 ipip6_dev_free(sitn->fb_tunnel_dev);
1930 free_netdev(sitn->fb_tunnel_dev);
1931err_alloc_dev:
1932 return err;
1933}
1934
1935static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1936{
1937 LIST_HEAD(list);
1938 struct net *net;
1939
1940 rtnl_lock();
1941 list_for_each_entry(net, net_list, exit_list)
1942 sit_destroy_tunnels(net, &list);
1943
1944 unregister_netdevice_many(&list);
1945 rtnl_unlock();
1946}
1947
1948static struct pernet_operations sit_net_ops = {
1949 .init = sit_init_net,
1950 .exit_batch = sit_exit_batch_net,
1951 .id = &sit_net_id,
1952 .size = sizeof(struct sit_net),
1953};
1954
1955static void __exit sit_cleanup(void)
1956{
1957 rtnl_link_unregister(&sit_link_ops);
1958 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1959 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1960#if IS_ENABLED(CONFIG_MPLS)
1961 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1962#endif
1963
1964 unregister_pernet_device(&sit_net_ops);
1965 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1966}
1967
1968static int __init sit_init(void)
1969{
1970 int err;
1971
1972 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1973
1974 err = register_pernet_device(&sit_net_ops);
1975 if (err < 0)
1976 return err;
1977 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1978 if (err < 0) {
1979 pr_info("%s: can't register ip6ip4\n", __func__);
1980 goto xfrm_tunnel_failed;
1981 }
1982 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1983 if (err < 0) {
1984 pr_info("%s: can't register ip4ip4\n", __func__);
1985 goto xfrm_tunnel4_failed;
1986 }
1987#if IS_ENABLED(CONFIG_MPLS)
1988 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1989 if (err < 0) {
1990 pr_info("%s: can't register mplsip\n", __func__);
1991 goto xfrm_tunnel_mpls_failed;
1992 }
1993#endif
1994 err = rtnl_link_register(&sit_link_ops);
1995 if (err < 0)
1996 goto rtnl_link_failed;
1997
1998out:
1999 return err;
2000
2001rtnl_link_failed:
2002#if IS_ENABLED(CONFIG_MPLS)
2003 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
2004xfrm_tunnel_mpls_failed:
2005#endif
2006 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
2007xfrm_tunnel4_failed:
2008 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
2009xfrm_tunnel_failed:
2010 unregister_pernet_device(&sit_net_ops);
2011 goto out;
2012}
2013
2014module_init(sit_init);
2015module_exit(sit_cleanup);
2016MODULE_LICENSE("GPL");
2017MODULE_ALIAS_RTNL_LINK("sit");
2018MODULE_ALIAS_NETDEV("sit0");