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[mirror_ubuntu-jammy-kernel.git] / net / ipv6 / sit.c
1 /*
2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 *
14 * Changes:
15 * Roger Venning <r.venning@telstra.com>: 6to4 support
16 * Nate Thompson <nate@thebog.net>: 6to4 support
17 * Fred Templin <fred.l.templin@boeing.com>: isatap support
18 */
19
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22 #include <linux/module.h>
23 #include <linux/capability.h>
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/icmp.h>
33 #include <linux/slab.h>
34 #include <linux/uaccess.h>
35 #include <linux/init.h>
36 #include <linux/netfilter_ipv4.h>
37 #include <linux/if_ether.h>
38
39 #include <net/sock.h>
40 #include <net/snmp.h>
41
42 #include <net/ipv6.h>
43 #include <net/protocol.h>
44 #include <net/transp_v6.h>
45 #include <net/ip6_fib.h>
46 #include <net/ip6_route.h>
47 #include <net/ndisc.h>
48 #include <net/addrconf.h>
49 #include <net/ip.h>
50 #include <net/udp.h>
51 #include <net/icmp.h>
52 #include <net/ip_tunnels.h>
53 #include <net/inet_ecn.h>
54 #include <net/xfrm.h>
55 #include <net/dsfield.h>
56 #include <net/net_namespace.h>
57 #include <net/netns/generic.h>
58
59 /*
60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
61
62 For comments look at net/ipv4/ip_gre.c --ANK
63 */
64
65 #define IP6_SIT_HASH_SIZE 16
66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
67
68 static bool log_ecn_error = true;
69 module_param(log_ecn_error, bool, 0644);
70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
71
72 static int ipip6_tunnel_init(struct net_device *dev);
73 static void ipip6_tunnel_setup(struct net_device *dev);
74 static void ipip6_dev_free(struct net_device *dev);
75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
76 __be32 *v4dst);
77 static struct rtnl_link_ops sit_link_ops __read_mostly;
78
79 static unsigned int sit_net_id __read_mostly;
80 struct sit_net {
81 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
82 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
83 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
84 struct ip_tunnel __rcu *tunnels_wc[1];
85 struct ip_tunnel __rcu **tunnels[4];
86
87 struct net_device *fb_tunnel_dev;
88 };
89
90 /*
91 * Must be invoked with rcu_read_lock
92 */
93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
94 struct net_device *dev, __be32 remote, __be32 local)
95 {
96 unsigned int h0 = HASH(remote);
97 unsigned int h1 = HASH(local);
98 struct ip_tunnel *t;
99 struct sit_net *sitn = net_generic(net, sit_net_id);
100
101 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
102 if (local == t->parms.iph.saddr &&
103 remote == t->parms.iph.daddr &&
104 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
105 (t->dev->flags & IFF_UP))
106 return t;
107 }
108 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
109 if (remote == t->parms.iph.daddr &&
110 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
111 (t->dev->flags & IFF_UP))
112 return t;
113 }
114 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
115 if (local == t->parms.iph.saddr &&
116 (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
117 (t->dev->flags & IFF_UP))
118 return t;
119 }
120 t = rcu_dereference(sitn->tunnels_wc[0]);
121 if (t && (t->dev->flags & IFF_UP))
122 return t;
123 return NULL;
124 }
125
126 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
127 struct ip_tunnel_parm *parms)
128 {
129 __be32 remote = parms->iph.daddr;
130 __be32 local = parms->iph.saddr;
131 unsigned int h = 0;
132 int prio = 0;
133
134 if (remote) {
135 prio |= 2;
136 h ^= HASH(remote);
137 }
138 if (local) {
139 prio |= 1;
140 h ^= HASH(local);
141 }
142 return &sitn->tunnels[prio][h];
143 }
144
145 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
146 struct ip_tunnel *t)
147 {
148 return __ipip6_bucket(sitn, &t->parms);
149 }
150
151 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
152 {
153 struct ip_tunnel __rcu **tp;
154 struct ip_tunnel *iter;
155
156 for (tp = ipip6_bucket(sitn, t);
157 (iter = rtnl_dereference(*tp)) != NULL;
158 tp = &iter->next) {
159 if (t == iter) {
160 rcu_assign_pointer(*tp, t->next);
161 break;
162 }
163 }
164 }
165
166 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
167 {
168 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
169
170 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
171 rcu_assign_pointer(*tp, t);
172 }
173
174 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
175 {
176 #ifdef CONFIG_IPV6_SIT_6RD
177 struct ip_tunnel *t = netdev_priv(dev);
178
179 if (t->dev == sitn->fb_tunnel_dev) {
180 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
181 t->ip6rd.relay_prefix = 0;
182 t->ip6rd.prefixlen = 16;
183 t->ip6rd.relay_prefixlen = 0;
184 } else {
185 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
186 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
187 }
188 #endif
189 }
190
191 static int ipip6_tunnel_create(struct net_device *dev)
192 {
193 struct ip_tunnel *t = netdev_priv(dev);
194 struct net *net = dev_net(dev);
195 struct sit_net *sitn = net_generic(net, sit_net_id);
196 int err;
197
198 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
199 memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
200
201 if ((__force u16)t->parms.i_flags & SIT_ISATAP)
202 dev->priv_flags |= IFF_ISATAP;
203
204 dev->rtnl_link_ops = &sit_link_ops;
205
206 err = register_netdevice(dev);
207 if (err < 0)
208 goto out;
209
210 ipip6_tunnel_clone_6rd(dev, sitn);
211
212 dev_hold(dev);
213
214 ipip6_tunnel_link(sitn, t);
215 return 0;
216
217 out:
218 return err;
219 }
220
221 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
222 struct ip_tunnel_parm *parms, int create)
223 {
224 __be32 remote = parms->iph.daddr;
225 __be32 local = parms->iph.saddr;
226 struct ip_tunnel *t, *nt;
227 struct ip_tunnel __rcu **tp;
228 struct net_device *dev;
229 char name[IFNAMSIZ];
230 struct sit_net *sitn = net_generic(net, sit_net_id);
231
232 for (tp = __ipip6_bucket(sitn, parms);
233 (t = rtnl_dereference(*tp)) != NULL;
234 tp = &t->next) {
235 if (local == t->parms.iph.saddr &&
236 remote == t->parms.iph.daddr &&
237 parms->link == t->parms.link) {
238 if (create)
239 return NULL;
240 else
241 return t;
242 }
243 }
244 if (!create)
245 goto failed;
246
247 if (parms->name[0])
248 strlcpy(name, parms->name, IFNAMSIZ);
249 else
250 strcpy(name, "sit%d");
251
252 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
253 ipip6_tunnel_setup);
254 if (!dev)
255 return NULL;
256
257 dev_net_set(dev, net);
258
259 nt = netdev_priv(dev);
260
261 nt->parms = *parms;
262 if (ipip6_tunnel_create(dev) < 0)
263 goto failed_free;
264
265 return nt;
266
267 failed_free:
268 free_netdev(dev);
269 failed:
270 return NULL;
271 }
272
273 #define for_each_prl_rcu(start) \
274 for (prl = rcu_dereference(start); \
275 prl; \
276 prl = rcu_dereference(prl->next))
277
278 static struct ip_tunnel_prl_entry *
279 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
280 {
281 struct ip_tunnel_prl_entry *prl;
282
283 for_each_prl_rcu(t->prl)
284 if (prl->addr == addr)
285 break;
286 return prl;
287
288 }
289
290 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
291 struct ip_tunnel_prl __user *a)
292 {
293 struct ip_tunnel_prl kprl, *kp;
294 struct ip_tunnel_prl_entry *prl;
295 unsigned int cmax, c = 0, ca, len;
296 int ret = 0;
297
298 if (copy_from_user(&kprl, a, sizeof(kprl)))
299 return -EFAULT;
300 cmax = kprl.datalen / sizeof(kprl);
301 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
302 cmax = 1;
303
304 /* For simple GET or for root users,
305 * we try harder to allocate.
306 */
307 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
308 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
309 NULL;
310
311 rcu_read_lock();
312
313 ca = t->prl_count < cmax ? t->prl_count : cmax;
314
315 if (!kp) {
316 /* We don't try hard to allocate much memory for
317 * non-root users.
318 * For root users, retry allocating enough memory for
319 * the answer.
320 */
321 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
322 if (!kp) {
323 ret = -ENOMEM;
324 goto out;
325 }
326 }
327
328 c = 0;
329 for_each_prl_rcu(t->prl) {
330 if (c >= cmax)
331 break;
332 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
333 continue;
334 kp[c].addr = prl->addr;
335 kp[c].flags = prl->flags;
336 c++;
337 if (kprl.addr != htonl(INADDR_ANY))
338 break;
339 }
340 out:
341 rcu_read_unlock();
342
343 len = sizeof(*kp) * c;
344 ret = 0;
345 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
346 ret = -EFAULT;
347
348 kfree(kp);
349
350 return ret;
351 }
352
353 static int
354 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
355 {
356 struct ip_tunnel_prl_entry *p;
357 int err = 0;
358
359 if (a->addr == htonl(INADDR_ANY))
360 return -EINVAL;
361
362 ASSERT_RTNL();
363
364 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
365 if (p->addr == a->addr) {
366 if (chg) {
367 p->flags = a->flags;
368 goto out;
369 }
370 err = -EEXIST;
371 goto out;
372 }
373 }
374
375 if (chg) {
376 err = -ENXIO;
377 goto out;
378 }
379
380 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
381 if (!p) {
382 err = -ENOBUFS;
383 goto out;
384 }
385
386 p->next = t->prl;
387 p->addr = a->addr;
388 p->flags = a->flags;
389 t->prl_count++;
390 rcu_assign_pointer(t->prl, p);
391 out:
392 return err;
393 }
394
395 static void prl_list_destroy_rcu(struct rcu_head *head)
396 {
397 struct ip_tunnel_prl_entry *p, *n;
398
399 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
400 do {
401 n = rcu_dereference_protected(p->next, 1);
402 kfree(p);
403 p = n;
404 } while (p);
405 }
406
407 static int
408 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
409 {
410 struct ip_tunnel_prl_entry *x;
411 struct ip_tunnel_prl_entry __rcu **p;
412 int err = 0;
413
414 ASSERT_RTNL();
415
416 if (a && a->addr != htonl(INADDR_ANY)) {
417 for (p = &t->prl;
418 (x = rtnl_dereference(*p)) != NULL;
419 p = &x->next) {
420 if (x->addr == a->addr) {
421 *p = x->next;
422 kfree_rcu(x, rcu_head);
423 t->prl_count--;
424 goto out;
425 }
426 }
427 err = -ENXIO;
428 } else {
429 x = rtnl_dereference(t->prl);
430 if (x) {
431 t->prl_count = 0;
432 call_rcu(&x->rcu_head, prl_list_destroy_rcu);
433 t->prl = NULL;
434 }
435 }
436 out:
437 return err;
438 }
439
440 static int
441 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
442 {
443 struct ip_tunnel_prl_entry *p;
444 int ok = 1;
445
446 rcu_read_lock();
447 p = __ipip6_tunnel_locate_prl(t, iph->saddr);
448 if (p) {
449 if (p->flags & PRL_DEFAULT)
450 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
451 else
452 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
453 } else {
454 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
455
456 if (ipv6_addr_is_isatap(addr6) &&
457 (addr6->s6_addr32[3] == iph->saddr) &&
458 ipv6_chk_prefix(addr6, t->dev))
459 skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
460 else
461 ok = 0;
462 }
463 rcu_read_unlock();
464 return ok;
465 }
466
467 static void ipip6_tunnel_uninit(struct net_device *dev)
468 {
469 struct ip_tunnel *tunnel = netdev_priv(dev);
470 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
471
472 if (dev == sitn->fb_tunnel_dev) {
473 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
474 } else {
475 ipip6_tunnel_unlink(sitn, tunnel);
476 ipip6_tunnel_del_prl(tunnel, NULL);
477 }
478 dst_cache_reset(&tunnel->dst_cache);
479 dev_put(dev);
480 }
481
482 static int ipip6_err(struct sk_buff *skb, u32 info)
483 {
484 const struct iphdr *iph = (const struct iphdr *)skb->data;
485 const int type = icmp_hdr(skb)->type;
486 const int code = icmp_hdr(skb)->code;
487 unsigned int data_len = 0;
488 struct ip_tunnel *t;
489 int err;
490
491 switch (type) {
492 default:
493 case ICMP_PARAMETERPROB:
494 return 0;
495
496 case ICMP_DEST_UNREACH:
497 switch (code) {
498 case ICMP_SR_FAILED:
499 /* Impossible event. */
500 return 0;
501 default:
502 /* All others are translated to HOST_UNREACH.
503 rfc2003 contains "deep thoughts" about NET_UNREACH,
504 I believe they are just ether pollution. --ANK
505 */
506 break;
507 }
508 break;
509 case ICMP_TIME_EXCEEDED:
510 if (code != ICMP_EXC_TTL)
511 return 0;
512 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
513 break;
514 case ICMP_REDIRECT:
515 break;
516 }
517
518 err = -ENOENT;
519
520 t = ipip6_tunnel_lookup(dev_net(skb->dev),
521 skb->dev,
522 iph->daddr,
523 iph->saddr);
524 if (!t)
525 goto out;
526
527 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
528 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
529 t->parms.link, 0, iph->protocol, 0);
530 err = 0;
531 goto out;
532 }
533 if (type == ICMP_REDIRECT) {
534 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
535 iph->protocol, 0);
536 err = 0;
537 goto out;
538 }
539
540 err = 0;
541 if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
542 goto out;
543
544 if (t->parms.iph.daddr == 0)
545 goto out;
546
547 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
548 goto out;
549
550 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
551 t->err_count++;
552 else
553 t->err_count = 1;
554 t->err_time = jiffies;
555 out:
556 return err;
557 }
558
559 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
560 const struct in6_addr *v6addr)
561 {
562 __be32 v4embed = 0;
563 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
564 return true;
565 return false;
566 }
567
568 /* Checks if an address matches an address on the tunnel interface.
569 * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
570 * Long story:
571 * This function is called after we considered the packet as spoofed
572 * in is_spoofed_6rd.
573 * We may have a router that is doing NAT for proto 41 packets
574 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
575 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
576 * function will return true, dropping the packet.
577 * But, we can still check if is spoofed against the IP
578 * addresses associated with the interface.
579 */
580 static bool only_dnatted(const struct ip_tunnel *tunnel,
581 const struct in6_addr *v6dst)
582 {
583 int prefix_len;
584
585 #ifdef CONFIG_IPV6_SIT_6RD
586 prefix_len = tunnel->ip6rd.prefixlen + 32
587 - tunnel->ip6rd.relay_prefixlen;
588 #else
589 prefix_len = 48;
590 #endif
591 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
592 }
593
594 /* Returns true if a packet is spoofed */
595 static bool packet_is_spoofed(struct sk_buff *skb,
596 const struct iphdr *iph,
597 struct ip_tunnel *tunnel)
598 {
599 const struct ipv6hdr *ipv6h;
600
601 if (tunnel->dev->priv_flags & IFF_ISATAP) {
602 if (!isatap_chksrc(skb, iph, tunnel))
603 return true;
604
605 return false;
606 }
607
608 if (tunnel->dev->flags & IFF_POINTOPOINT)
609 return false;
610
611 ipv6h = ipv6_hdr(skb);
612
613 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
614 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
615 &iph->saddr, &ipv6h->saddr,
616 &iph->daddr, &ipv6h->daddr);
617 return true;
618 }
619
620 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
621 return false;
622
623 if (only_dnatted(tunnel, &ipv6h->daddr))
624 return false;
625
626 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
627 &iph->saddr, &ipv6h->saddr,
628 &iph->daddr, &ipv6h->daddr);
629 return true;
630 }
631
632 static int ipip6_rcv(struct sk_buff *skb)
633 {
634 const struct iphdr *iph = ip_hdr(skb);
635 struct ip_tunnel *tunnel;
636 int err;
637
638 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
639 iph->saddr, iph->daddr);
640 if (tunnel) {
641 struct pcpu_sw_netstats *tstats;
642
643 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
644 tunnel->parms.iph.protocol != 0)
645 goto out;
646
647 skb->mac_header = skb->network_header;
648 skb_reset_network_header(skb);
649 IPCB(skb)->flags = 0;
650 skb->dev = tunnel->dev;
651
652 if (packet_is_spoofed(skb, iph, tunnel)) {
653 tunnel->dev->stats.rx_errors++;
654 goto out;
655 }
656
657 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
658 !net_eq(tunnel->net, dev_net(tunnel->dev))))
659 goto out;
660
661 err = IP_ECN_decapsulate(iph, skb);
662 if (unlikely(err)) {
663 if (log_ecn_error)
664 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
665 &iph->saddr, iph->tos);
666 if (err > 1) {
667 ++tunnel->dev->stats.rx_frame_errors;
668 ++tunnel->dev->stats.rx_errors;
669 goto out;
670 }
671 }
672
673 tstats = this_cpu_ptr(tunnel->dev->tstats);
674 u64_stats_update_begin(&tstats->syncp);
675 tstats->rx_packets++;
676 tstats->rx_bytes += skb->len;
677 u64_stats_update_end(&tstats->syncp);
678
679 netif_rx(skb);
680
681 return 0;
682 }
683
684 /* no tunnel matched, let upstream know, ipsec may handle it */
685 return 1;
686 out:
687 kfree_skb(skb);
688 return 0;
689 }
690
691 static const struct tnl_ptk_info ipip_tpi = {
692 /* no tunnel info required for ipip. */
693 .proto = htons(ETH_P_IP),
694 };
695
696 #if IS_ENABLED(CONFIG_MPLS)
697 static const struct tnl_ptk_info mplsip_tpi = {
698 /* no tunnel info required for mplsip. */
699 .proto = htons(ETH_P_MPLS_UC),
700 };
701 #endif
702
703 static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
704 {
705 const struct iphdr *iph;
706 struct ip_tunnel *tunnel;
707
708 iph = ip_hdr(skb);
709 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
710 iph->saddr, iph->daddr);
711 if (tunnel) {
712 const struct tnl_ptk_info *tpi;
713
714 if (tunnel->parms.iph.protocol != ipproto &&
715 tunnel->parms.iph.protocol != 0)
716 goto drop;
717
718 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
719 goto drop;
720 #if IS_ENABLED(CONFIG_MPLS)
721 if (ipproto == IPPROTO_MPLS)
722 tpi = &mplsip_tpi;
723 else
724 #endif
725 tpi = &ipip_tpi;
726 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
727 goto drop;
728 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
729 }
730
731 return 1;
732
733 drop:
734 kfree_skb(skb);
735 return 0;
736 }
737
738 static int ipip_rcv(struct sk_buff *skb)
739 {
740 return sit_tunnel_rcv(skb, IPPROTO_IPIP);
741 }
742
743 #if IS_ENABLED(CONFIG_MPLS)
744 static int mplsip_rcv(struct sk_buff *skb)
745 {
746 return sit_tunnel_rcv(skb, IPPROTO_MPLS);
747 }
748 #endif
749
750 /*
751 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
752 * stores the embedded IPv4 address in v4dst and returns true.
753 */
754 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
755 __be32 *v4dst)
756 {
757 #ifdef CONFIG_IPV6_SIT_6RD
758 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
759 tunnel->ip6rd.prefixlen)) {
760 unsigned int pbw0, pbi0;
761 int pbi1;
762 u32 d;
763
764 pbw0 = tunnel->ip6rd.prefixlen >> 5;
765 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
766
767 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
768 tunnel->ip6rd.relay_prefixlen;
769
770 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
771 if (pbi1 > 0)
772 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
773 (32 - pbi1);
774
775 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
776 return true;
777 }
778 #else
779 if (v6dst->s6_addr16[0] == htons(0x2002)) {
780 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
781 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
782 return true;
783 }
784 #endif
785 return false;
786 }
787
788 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
789 const struct in6_addr *v6dst)
790 {
791 __be32 dst = 0;
792 check_6rd(tunnel, v6dst, &dst);
793 return dst;
794 }
795
796 /*
797 * This function assumes it is being called from dev_queue_xmit()
798 * and that skb is filled properly by that function.
799 */
800
801 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
802 struct net_device *dev)
803 {
804 struct ip_tunnel *tunnel = netdev_priv(dev);
805 const struct iphdr *tiph = &tunnel->parms.iph;
806 const struct ipv6hdr *iph6 = ipv6_hdr(skb);
807 u8 tos = tunnel->parms.iph.tos;
808 __be16 df = tiph->frag_off;
809 struct rtable *rt; /* Route to the other host */
810 struct net_device *tdev; /* Device to other host */
811 unsigned int max_headroom; /* The extra header space needed */
812 __be32 dst = tiph->daddr;
813 struct flowi4 fl4;
814 int mtu;
815 const struct in6_addr *addr6;
816 int addr_type;
817 u8 ttl;
818 u8 protocol = IPPROTO_IPV6;
819 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
820
821 if (tos == 1)
822 tos = ipv6_get_dsfield(iph6);
823
824 /* ISATAP (RFC4214) - must come before 6to4 */
825 if (dev->priv_flags & IFF_ISATAP) {
826 struct neighbour *neigh = NULL;
827 bool do_tx_error = false;
828
829 if (skb_dst(skb))
830 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
831
832 if (!neigh) {
833 net_dbg_ratelimited("nexthop == NULL\n");
834 goto tx_error;
835 }
836
837 addr6 = (const struct in6_addr *)&neigh->primary_key;
838 addr_type = ipv6_addr_type(addr6);
839
840 if ((addr_type & IPV6_ADDR_UNICAST) &&
841 ipv6_addr_is_isatap(addr6))
842 dst = addr6->s6_addr32[3];
843 else
844 do_tx_error = true;
845
846 neigh_release(neigh);
847 if (do_tx_error)
848 goto tx_error;
849 }
850
851 if (!dst)
852 dst = try_6rd(tunnel, &iph6->daddr);
853
854 if (!dst) {
855 struct neighbour *neigh = NULL;
856 bool do_tx_error = false;
857
858 if (skb_dst(skb))
859 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
860
861 if (!neigh) {
862 net_dbg_ratelimited("nexthop == NULL\n");
863 goto tx_error;
864 }
865
866 addr6 = (const struct in6_addr *)&neigh->primary_key;
867 addr_type = ipv6_addr_type(addr6);
868
869 if (addr_type == IPV6_ADDR_ANY) {
870 addr6 = &ipv6_hdr(skb)->daddr;
871 addr_type = ipv6_addr_type(addr6);
872 }
873
874 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
875 dst = addr6->s6_addr32[3];
876 else
877 do_tx_error = true;
878
879 neigh_release(neigh);
880 if (do_tx_error)
881 goto tx_error;
882 }
883
884 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
885 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
886 0, dst, tiph->saddr, 0, 0,
887 sock_net_uid(tunnel->net, NULL));
888 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
889
890 if (IS_ERR(rt)) {
891 dev->stats.tx_carrier_errors++;
892 goto tx_error_icmp;
893 }
894 if (rt->rt_type != RTN_UNICAST) {
895 ip_rt_put(rt);
896 dev->stats.tx_carrier_errors++;
897 goto tx_error_icmp;
898 }
899 tdev = rt->dst.dev;
900
901 if (tdev == dev) {
902 ip_rt_put(rt);
903 dev->stats.collisions++;
904 goto tx_error;
905 }
906
907 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
908 ip_rt_put(rt);
909 goto tx_error;
910 }
911
912 if (df) {
913 mtu = dst_mtu(&rt->dst) - t_hlen;
914
915 if (mtu < 68) {
916 dev->stats.collisions++;
917 ip_rt_put(rt);
918 goto tx_error;
919 }
920
921 if (mtu < IPV6_MIN_MTU) {
922 mtu = IPV6_MIN_MTU;
923 df = 0;
924 }
925
926 if (tunnel->parms.iph.daddr && skb_dst(skb))
927 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
928
929 if (skb->len > mtu && !skb_is_gso(skb)) {
930 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
931 ip_rt_put(rt);
932 goto tx_error;
933 }
934 }
935
936 if (tunnel->err_count > 0) {
937 if (time_before(jiffies,
938 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
939 tunnel->err_count--;
940 dst_link_failure(skb);
941 } else
942 tunnel->err_count = 0;
943 }
944
945 /*
946 * Okay, now see if we can stuff it in the buffer as-is.
947 */
948 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
949
950 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
951 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
952 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
953 if (!new_skb) {
954 ip_rt_put(rt);
955 dev->stats.tx_dropped++;
956 kfree_skb(skb);
957 return NETDEV_TX_OK;
958 }
959 if (skb->sk)
960 skb_set_owner_w(new_skb, skb->sk);
961 dev_kfree_skb(skb);
962 skb = new_skb;
963 iph6 = ipv6_hdr(skb);
964 }
965 ttl = tiph->ttl;
966 if (ttl == 0)
967 ttl = iph6->hop_limit;
968 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
969
970 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
971 ip_rt_put(rt);
972 goto tx_error;
973 }
974
975 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
976
977 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
978 df, !net_eq(tunnel->net, dev_net(dev)));
979 return NETDEV_TX_OK;
980
981 tx_error_icmp:
982 dst_link_failure(skb);
983 tx_error:
984 kfree_skb(skb);
985 dev->stats.tx_errors++;
986 return NETDEV_TX_OK;
987 }
988
989 static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
990 struct net_device *dev, u8 ipproto)
991 {
992 struct ip_tunnel *tunnel = netdev_priv(dev);
993 const struct iphdr *tiph = &tunnel->parms.iph;
994
995 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
996 goto tx_error;
997
998 skb_set_inner_ipproto(skb, ipproto);
999
1000 ip_tunnel_xmit(skb, dev, tiph, ipproto);
1001 return NETDEV_TX_OK;
1002 tx_error:
1003 kfree_skb(skb);
1004 dev->stats.tx_errors++;
1005 return NETDEV_TX_OK;
1006 }
1007
1008 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1009 struct net_device *dev)
1010 {
1011 switch (skb->protocol) {
1012 case htons(ETH_P_IP):
1013 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1014 break;
1015 case htons(ETH_P_IPV6):
1016 ipip6_tunnel_xmit(skb, dev);
1017 break;
1018 #if IS_ENABLED(CONFIG_MPLS)
1019 case htons(ETH_P_MPLS_UC):
1020 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1021 break;
1022 #endif
1023 default:
1024 goto tx_err;
1025 }
1026
1027 return NETDEV_TX_OK;
1028
1029 tx_err:
1030 dev->stats.tx_errors++;
1031 kfree_skb(skb);
1032 return NETDEV_TX_OK;
1033
1034 }
1035
1036 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1037 {
1038 struct net_device *tdev = NULL;
1039 struct ip_tunnel *tunnel;
1040 const struct iphdr *iph;
1041 struct flowi4 fl4;
1042
1043 tunnel = netdev_priv(dev);
1044 iph = &tunnel->parms.iph;
1045
1046 if (iph->daddr) {
1047 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1048 NULL,
1049 iph->daddr, iph->saddr,
1050 0, 0,
1051 IPPROTO_IPV6,
1052 RT_TOS(iph->tos),
1053 tunnel->parms.link);
1054
1055 if (!IS_ERR(rt)) {
1056 tdev = rt->dst.dev;
1057 ip_rt_put(rt);
1058 }
1059 dev->flags |= IFF_POINTOPOINT;
1060 }
1061
1062 if (!tdev && tunnel->parms.link)
1063 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1064
1065 if (tdev) {
1066 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1067
1068 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1069 dev->mtu = tdev->mtu - t_hlen;
1070 if (dev->mtu < IPV6_MIN_MTU)
1071 dev->mtu = IPV6_MIN_MTU;
1072 }
1073 }
1074
1075 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1076 __u32 fwmark)
1077 {
1078 struct net *net = t->net;
1079 struct sit_net *sitn = net_generic(net, sit_net_id);
1080
1081 ipip6_tunnel_unlink(sitn, t);
1082 synchronize_net();
1083 t->parms.iph.saddr = p->iph.saddr;
1084 t->parms.iph.daddr = p->iph.daddr;
1085 memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1086 memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1087 ipip6_tunnel_link(sitn, t);
1088 t->parms.iph.ttl = p->iph.ttl;
1089 t->parms.iph.tos = p->iph.tos;
1090 if (t->parms.link != p->link || t->fwmark != fwmark) {
1091 t->parms.link = p->link;
1092 t->fwmark = fwmark;
1093 ipip6_tunnel_bind_dev(t->dev);
1094 }
1095 dst_cache_reset(&t->dst_cache);
1096 netdev_state_change(t->dev);
1097 }
1098
1099 #ifdef CONFIG_IPV6_SIT_6RD
1100 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1101 struct ip_tunnel_6rd *ip6rd)
1102 {
1103 struct in6_addr prefix;
1104 __be32 relay_prefix;
1105
1106 if (ip6rd->relay_prefixlen > 32 ||
1107 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1108 return -EINVAL;
1109
1110 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1111 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1112 return -EINVAL;
1113 if (ip6rd->relay_prefixlen)
1114 relay_prefix = ip6rd->relay_prefix &
1115 htonl(0xffffffffUL <<
1116 (32 - ip6rd->relay_prefixlen));
1117 else
1118 relay_prefix = 0;
1119 if (relay_prefix != ip6rd->relay_prefix)
1120 return -EINVAL;
1121
1122 t->ip6rd.prefix = prefix;
1123 t->ip6rd.relay_prefix = relay_prefix;
1124 t->ip6rd.prefixlen = ip6rd->prefixlen;
1125 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1126 dst_cache_reset(&t->dst_cache);
1127 netdev_state_change(t->dev);
1128 return 0;
1129 }
1130 #endif
1131
1132 static bool ipip6_valid_ip_proto(u8 ipproto)
1133 {
1134 return ipproto == IPPROTO_IPV6 ||
1135 ipproto == IPPROTO_IPIP ||
1136 #if IS_ENABLED(CONFIG_MPLS)
1137 ipproto == IPPROTO_MPLS ||
1138 #endif
1139 ipproto == 0;
1140 }
1141
1142 static int
1143 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1144 {
1145 int err = 0;
1146 struct ip_tunnel_parm p;
1147 struct ip_tunnel_prl prl;
1148 struct ip_tunnel *t = netdev_priv(dev);
1149 struct net *net = t->net;
1150 struct sit_net *sitn = net_generic(net, sit_net_id);
1151 #ifdef CONFIG_IPV6_SIT_6RD
1152 struct ip_tunnel_6rd ip6rd;
1153 #endif
1154
1155 switch (cmd) {
1156 case SIOCGETTUNNEL:
1157 #ifdef CONFIG_IPV6_SIT_6RD
1158 case SIOCGET6RD:
1159 #endif
1160 if (dev == sitn->fb_tunnel_dev) {
1161 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1162 err = -EFAULT;
1163 break;
1164 }
1165 t = ipip6_tunnel_locate(net, &p, 0);
1166 if (!t)
1167 t = netdev_priv(dev);
1168 }
1169
1170 err = -EFAULT;
1171 if (cmd == SIOCGETTUNNEL) {
1172 memcpy(&p, &t->parms, sizeof(p));
1173 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1174 sizeof(p)))
1175 goto done;
1176 #ifdef CONFIG_IPV6_SIT_6RD
1177 } else {
1178 ip6rd.prefix = t->ip6rd.prefix;
1179 ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1180 ip6rd.prefixlen = t->ip6rd.prefixlen;
1181 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1182 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1183 sizeof(ip6rd)))
1184 goto done;
1185 #endif
1186 }
1187 err = 0;
1188 break;
1189
1190 case SIOCADDTUNNEL:
1191 case SIOCCHGTUNNEL:
1192 err = -EPERM;
1193 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1194 goto done;
1195
1196 err = -EFAULT;
1197 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1198 goto done;
1199
1200 err = -EINVAL;
1201 if (!ipip6_valid_ip_proto(p.iph.protocol))
1202 goto done;
1203 if (p.iph.version != 4 ||
1204 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1205 goto done;
1206 if (p.iph.ttl)
1207 p.iph.frag_off |= htons(IP_DF);
1208
1209 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1210
1211 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1212 if (t) {
1213 if (t->dev != dev) {
1214 err = -EEXIST;
1215 break;
1216 }
1217 } else {
1218 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1219 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1220 err = -EINVAL;
1221 break;
1222 }
1223 t = netdev_priv(dev);
1224 }
1225
1226 ipip6_tunnel_update(t, &p, t->fwmark);
1227 }
1228
1229 if (t) {
1230 err = 0;
1231 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1232 err = -EFAULT;
1233 } else
1234 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1235 break;
1236
1237 case SIOCDELTUNNEL:
1238 err = -EPERM;
1239 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1240 goto done;
1241
1242 if (dev == sitn->fb_tunnel_dev) {
1243 err = -EFAULT;
1244 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1245 goto done;
1246 err = -ENOENT;
1247 t = ipip6_tunnel_locate(net, &p, 0);
1248 if (!t)
1249 goto done;
1250 err = -EPERM;
1251 if (t == netdev_priv(sitn->fb_tunnel_dev))
1252 goto done;
1253 dev = t->dev;
1254 }
1255 unregister_netdevice(dev);
1256 err = 0;
1257 break;
1258
1259 case SIOCGETPRL:
1260 err = -EINVAL;
1261 if (dev == sitn->fb_tunnel_dev)
1262 goto done;
1263 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1264 break;
1265
1266 case SIOCADDPRL:
1267 case SIOCDELPRL:
1268 case SIOCCHGPRL:
1269 err = -EPERM;
1270 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1271 goto done;
1272 err = -EINVAL;
1273 if (dev == sitn->fb_tunnel_dev)
1274 goto done;
1275 err = -EFAULT;
1276 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1277 goto done;
1278
1279 switch (cmd) {
1280 case SIOCDELPRL:
1281 err = ipip6_tunnel_del_prl(t, &prl);
1282 break;
1283 case SIOCADDPRL:
1284 case SIOCCHGPRL:
1285 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1286 break;
1287 }
1288 dst_cache_reset(&t->dst_cache);
1289 netdev_state_change(dev);
1290 break;
1291
1292 #ifdef CONFIG_IPV6_SIT_6RD
1293 case SIOCADD6RD:
1294 case SIOCCHG6RD:
1295 case SIOCDEL6RD:
1296 err = -EPERM;
1297 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1298 goto done;
1299
1300 err = -EFAULT;
1301 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1302 sizeof(ip6rd)))
1303 goto done;
1304
1305 if (cmd != SIOCDEL6RD) {
1306 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1307 if (err < 0)
1308 goto done;
1309 } else
1310 ipip6_tunnel_clone_6rd(dev, sitn);
1311
1312 err = 0;
1313 break;
1314 #endif
1315
1316 default:
1317 err = -EINVAL;
1318 }
1319
1320 done:
1321 return err;
1322 }
1323
1324 static const struct net_device_ops ipip6_netdev_ops = {
1325 .ndo_init = ipip6_tunnel_init,
1326 .ndo_uninit = ipip6_tunnel_uninit,
1327 .ndo_start_xmit = sit_tunnel_xmit,
1328 .ndo_do_ioctl = ipip6_tunnel_ioctl,
1329 .ndo_get_stats64 = ip_tunnel_get_stats64,
1330 .ndo_get_iflink = ip_tunnel_get_iflink,
1331 };
1332
1333 static void ipip6_dev_free(struct net_device *dev)
1334 {
1335 struct ip_tunnel *tunnel = netdev_priv(dev);
1336
1337 dst_cache_destroy(&tunnel->dst_cache);
1338 free_percpu(dev->tstats);
1339 }
1340
1341 #define SIT_FEATURES (NETIF_F_SG | \
1342 NETIF_F_FRAGLIST | \
1343 NETIF_F_HIGHDMA | \
1344 NETIF_F_GSO_SOFTWARE | \
1345 NETIF_F_HW_CSUM)
1346
1347 static void ipip6_tunnel_setup(struct net_device *dev)
1348 {
1349 struct ip_tunnel *tunnel = netdev_priv(dev);
1350 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1351
1352 dev->netdev_ops = &ipip6_netdev_ops;
1353 dev->needs_free_netdev = true;
1354 dev->priv_destructor = ipip6_dev_free;
1355
1356 dev->type = ARPHRD_SIT;
1357 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1358 dev->mtu = ETH_DATA_LEN - t_hlen;
1359 dev->min_mtu = IPV6_MIN_MTU;
1360 dev->max_mtu = 0xFFF8 - t_hlen;
1361 dev->flags = IFF_NOARP;
1362 netif_keep_dst(dev);
1363 dev->addr_len = 4;
1364 dev->features |= NETIF_F_LLTX;
1365 dev->features |= SIT_FEATURES;
1366 dev->hw_features |= SIT_FEATURES;
1367 }
1368
1369 static int ipip6_tunnel_init(struct net_device *dev)
1370 {
1371 struct ip_tunnel *tunnel = netdev_priv(dev);
1372 int err;
1373
1374 tunnel->dev = dev;
1375 tunnel->net = dev_net(dev);
1376 strcpy(tunnel->parms.name, dev->name);
1377
1378 ipip6_tunnel_bind_dev(dev);
1379 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1380 if (!dev->tstats)
1381 return -ENOMEM;
1382
1383 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1384 if (err) {
1385 free_percpu(dev->tstats);
1386 dev->tstats = NULL;
1387 return err;
1388 }
1389
1390 return 0;
1391 }
1392
1393 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1394 {
1395 struct ip_tunnel *tunnel = netdev_priv(dev);
1396 struct iphdr *iph = &tunnel->parms.iph;
1397 struct net *net = dev_net(dev);
1398 struct sit_net *sitn = net_generic(net, sit_net_id);
1399
1400 iph->version = 4;
1401 iph->protocol = IPPROTO_IPV6;
1402 iph->ihl = 5;
1403 iph->ttl = 64;
1404
1405 dev_hold(dev);
1406 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1407 }
1408
1409 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1410 {
1411 u8 proto;
1412
1413 if (!data || !data[IFLA_IPTUN_PROTO])
1414 return 0;
1415
1416 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1417 if (!ipip6_valid_ip_proto(proto))
1418 return -EINVAL;
1419
1420 return 0;
1421 }
1422
1423 static void ipip6_netlink_parms(struct nlattr *data[],
1424 struct ip_tunnel_parm *parms,
1425 __u32 *fwmark)
1426 {
1427 memset(parms, 0, sizeof(*parms));
1428
1429 parms->iph.version = 4;
1430 parms->iph.protocol = IPPROTO_IPV6;
1431 parms->iph.ihl = 5;
1432 parms->iph.ttl = 64;
1433
1434 if (!data)
1435 return;
1436
1437 if (data[IFLA_IPTUN_LINK])
1438 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1439
1440 if (data[IFLA_IPTUN_LOCAL])
1441 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1442
1443 if (data[IFLA_IPTUN_REMOTE])
1444 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1445
1446 if (data[IFLA_IPTUN_TTL]) {
1447 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1448 if (parms->iph.ttl)
1449 parms->iph.frag_off = htons(IP_DF);
1450 }
1451
1452 if (data[IFLA_IPTUN_TOS])
1453 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1454
1455 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1456 parms->iph.frag_off = htons(IP_DF);
1457
1458 if (data[IFLA_IPTUN_FLAGS])
1459 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1460
1461 if (data[IFLA_IPTUN_PROTO])
1462 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1463
1464 if (data[IFLA_IPTUN_FWMARK])
1465 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1466 }
1467
1468 /* This function returns true when ENCAP attributes are present in the nl msg */
1469 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1470 struct ip_tunnel_encap *ipencap)
1471 {
1472 bool ret = false;
1473
1474 memset(ipencap, 0, sizeof(*ipencap));
1475
1476 if (!data)
1477 return ret;
1478
1479 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1480 ret = true;
1481 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1482 }
1483
1484 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1485 ret = true;
1486 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1487 }
1488
1489 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1490 ret = true;
1491 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1492 }
1493
1494 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1495 ret = true;
1496 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1497 }
1498
1499 return ret;
1500 }
1501
1502 #ifdef CONFIG_IPV6_SIT_6RD
1503 /* This function returns true when 6RD attributes are present in the nl msg */
1504 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1505 struct ip_tunnel_6rd *ip6rd)
1506 {
1507 bool ret = false;
1508 memset(ip6rd, 0, sizeof(*ip6rd));
1509
1510 if (!data)
1511 return ret;
1512
1513 if (data[IFLA_IPTUN_6RD_PREFIX]) {
1514 ret = true;
1515 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1516 }
1517
1518 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1519 ret = true;
1520 ip6rd->relay_prefix =
1521 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1522 }
1523
1524 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1525 ret = true;
1526 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1527 }
1528
1529 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1530 ret = true;
1531 ip6rd->relay_prefixlen =
1532 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1533 }
1534
1535 return ret;
1536 }
1537 #endif
1538
1539 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1540 struct nlattr *tb[], struct nlattr *data[],
1541 struct netlink_ext_ack *extack)
1542 {
1543 struct net *net = dev_net(dev);
1544 struct ip_tunnel *nt;
1545 struct ip_tunnel_encap ipencap;
1546 #ifdef CONFIG_IPV6_SIT_6RD
1547 struct ip_tunnel_6rd ip6rd;
1548 #endif
1549 int err;
1550
1551 nt = netdev_priv(dev);
1552
1553 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1554 err = ip_tunnel_encap_setup(nt, &ipencap);
1555 if (err < 0)
1556 return err;
1557 }
1558
1559 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1560
1561 if (ipip6_tunnel_locate(net, &nt->parms, 0))
1562 return -EEXIST;
1563
1564 err = ipip6_tunnel_create(dev);
1565 if (err < 0)
1566 return err;
1567
1568 #ifdef CONFIG_IPV6_SIT_6RD
1569 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1570 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1571 #endif
1572
1573 return err;
1574 }
1575
1576 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1577 struct nlattr *data[],
1578 struct netlink_ext_ack *extack)
1579 {
1580 struct ip_tunnel *t = netdev_priv(dev);
1581 struct ip_tunnel_parm p;
1582 struct ip_tunnel_encap ipencap;
1583 struct net *net = t->net;
1584 struct sit_net *sitn = net_generic(net, sit_net_id);
1585 #ifdef CONFIG_IPV6_SIT_6RD
1586 struct ip_tunnel_6rd ip6rd;
1587 #endif
1588 __u32 fwmark = t->fwmark;
1589 int err;
1590
1591 if (dev == sitn->fb_tunnel_dev)
1592 return -EINVAL;
1593
1594 if (ipip6_netlink_encap_parms(data, &ipencap)) {
1595 err = ip_tunnel_encap_setup(t, &ipencap);
1596 if (err < 0)
1597 return err;
1598 }
1599
1600 ipip6_netlink_parms(data, &p, &fwmark);
1601
1602 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1603 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1604 return -EINVAL;
1605
1606 t = ipip6_tunnel_locate(net, &p, 0);
1607
1608 if (t) {
1609 if (t->dev != dev)
1610 return -EEXIST;
1611 } else
1612 t = netdev_priv(dev);
1613
1614 ipip6_tunnel_update(t, &p, fwmark);
1615
1616 #ifdef CONFIG_IPV6_SIT_6RD
1617 if (ipip6_netlink_6rd_parms(data, &ip6rd))
1618 return ipip6_tunnel_update_6rd(t, &ip6rd);
1619 #endif
1620
1621 return 0;
1622 }
1623
1624 static size_t ipip6_get_size(const struct net_device *dev)
1625 {
1626 return
1627 /* IFLA_IPTUN_LINK */
1628 nla_total_size(4) +
1629 /* IFLA_IPTUN_LOCAL */
1630 nla_total_size(4) +
1631 /* IFLA_IPTUN_REMOTE */
1632 nla_total_size(4) +
1633 /* IFLA_IPTUN_TTL */
1634 nla_total_size(1) +
1635 /* IFLA_IPTUN_TOS */
1636 nla_total_size(1) +
1637 /* IFLA_IPTUN_PMTUDISC */
1638 nla_total_size(1) +
1639 /* IFLA_IPTUN_FLAGS */
1640 nla_total_size(2) +
1641 /* IFLA_IPTUN_PROTO */
1642 nla_total_size(1) +
1643 #ifdef CONFIG_IPV6_SIT_6RD
1644 /* IFLA_IPTUN_6RD_PREFIX */
1645 nla_total_size(sizeof(struct in6_addr)) +
1646 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1647 nla_total_size(4) +
1648 /* IFLA_IPTUN_6RD_PREFIXLEN */
1649 nla_total_size(2) +
1650 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1651 nla_total_size(2) +
1652 #endif
1653 /* IFLA_IPTUN_ENCAP_TYPE */
1654 nla_total_size(2) +
1655 /* IFLA_IPTUN_ENCAP_FLAGS */
1656 nla_total_size(2) +
1657 /* IFLA_IPTUN_ENCAP_SPORT */
1658 nla_total_size(2) +
1659 /* IFLA_IPTUN_ENCAP_DPORT */
1660 nla_total_size(2) +
1661 /* IFLA_IPTUN_FWMARK */
1662 nla_total_size(4) +
1663 0;
1664 }
1665
1666 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1667 {
1668 struct ip_tunnel *tunnel = netdev_priv(dev);
1669 struct ip_tunnel_parm *parm = &tunnel->parms;
1670
1671 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1672 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1673 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1674 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1675 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1676 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1677 !!(parm->iph.frag_off & htons(IP_DF))) ||
1678 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1679 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1680 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1681 goto nla_put_failure;
1682
1683 #ifdef CONFIG_IPV6_SIT_6RD
1684 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1685 &tunnel->ip6rd.prefix) ||
1686 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1687 tunnel->ip6rd.relay_prefix) ||
1688 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1689 tunnel->ip6rd.prefixlen) ||
1690 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1691 tunnel->ip6rd.relay_prefixlen))
1692 goto nla_put_failure;
1693 #endif
1694
1695 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1696 tunnel->encap.type) ||
1697 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1698 tunnel->encap.sport) ||
1699 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1700 tunnel->encap.dport) ||
1701 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1702 tunnel->encap.flags))
1703 goto nla_put_failure;
1704
1705 return 0;
1706
1707 nla_put_failure:
1708 return -EMSGSIZE;
1709 }
1710
1711 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1712 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
1713 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
1714 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
1715 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
1716 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
1717 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
1718 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
1719 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
1720 #ifdef CONFIG_IPV6_SIT_6RD
1721 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
1722 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
1723 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
1724 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1725 #endif
1726 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
1727 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
1728 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
1729 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
1730 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
1731 };
1732
1733 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1734 {
1735 struct net *net = dev_net(dev);
1736 struct sit_net *sitn = net_generic(net, sit_net_id);
1737
1738 if (dev != sitn->fb_tunnel_dev)
1739 unregister_netdevice_queue(dev, head);
1740 }
1741
1742 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1743 .kind = "sit",
1744 .maxtype = IFLA_IPTUN_MAX,
1745 .policy = ipip6_policy,
1746 .priv_size = sizeof(struct ip_tunnel),
1747 .setup = ipip6_tunnel_setup,
1748 .validate = ipip6_validate,
1749 .newlink = ipip6_newlink,
1750 .changelink = ipip6_changelink,
1751 .get_size = ipip6_get_size,
1752 .fill_info = ipip6_fill_info,
1753 .dellink = ipip6_dellink,
1754 .get_link_net = ip_tunnel_get_link_net,
1755 };
1756
1757 static struct xfrm_tunnel sit_handler __read_mostly = {
1758 .handler = ipip6_rcv,
1759 .err_handler = ipip6_err,
1760 .priority = 1,
1761 };
1762
1763 static struct xfrm_tunnel ipip_handler __read_mostly = {
1764 .handler = ipip_rcv,
1765 .err_handler = ipip6_err,
1766 .priority = 2,
1767 };
1768
1769 #if IS_ENABLED(CONFIG_MPLS)
1770 static struct xfrm_tunnel mplsip_handler __read_mostly = {
1771 .handler = mplsip_rcv,
1772 .err_handler = ipip6_err,
1773 .priority = 2,
1774 };
1775 #endif
1776
1777 static void __net_exit sit_destroy_tunnels(struct net *net,
1778 struct list_head *head)
1779 {
1780 struct sit_net *sitn = net_generic(net, sit_net_id);
1781 struct net_device *dev, *aux;
1782 int prio;
1783
1784 for_each_netdev_safe(net, dev, aux)
1785 if (dev->rtnl_link_ops == &sit_link_ops)
1786 unregister_netdevice_queue(dev, head);
1787
1788 for (prio = 1; prio < 4; prio++) {
1789 int h;
1790 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1791 struct ip_tunnel *t;
1792
1793 t = rtnl_dereference(sitn->tunnels[prio][h]);
1794 while (t) {
1795 /* If dev is in the same netns, it has already
1796 * been added to the list by the previous loop.
1797 */
1798 if (!net_eq(dev_net(t->dev), net))
1799 unregister_netdevice_queue(t->dev,
1800 head);
1801 t = rtnl_dereference(t->next);
1802 }
1803 }
1804 }
1805 }
1806
1807 static int __net_init sit_init_net(struct net *net)
1808 {
1809 struct sit_net *sitn = net_generic(net, sit_net_id);
1810 struct ip_tunnel *t;
1811 int err;
1812
1813 sitn->tunnels[0] = sitn->tunnels_wc;
1814 sitn->tunnels[1] = sitn->tunnels_l;
1815 sitn->tunnels[2] = sitn->tunnels_r;
1816 sitn->tunnels[3] = sitn->tunnels_r_l;
1817
1818 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1819 NET_NAME_UNKNOWN,
1820 ipip6_tunnel_setup);
1821 if (!sitn->fb_tunnel_dev) {
1822 err = -ENOMEM;
1823 goto err_alloc_dev;
1824 }
1825 dev_net_set(sitn->fb_tunnel_dev, net);
1826 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1827 /* FB netdevice is special: we have one, and only one per netns.
1828 * Allowing to move it to another netns is clearly unsafe.
1829 */
1830 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1831
1832 err = register_netdev(sitn->fb_tunnel_dev);
1833 if (err)
1834 goto err_reg_dev;
1835
1836 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1837 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1838
1839 t = netdev_priv(sitn->fb_tunnel_dev);
1840
1841 strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1842 return 0;
1843
1844 err_reg_dev:
1845 ipip6_dev_free(sitn->fb_tunnel_dev);
1846 err_alloc_dev:
1847 return err;
1848 }
1849
1850 static void __net_exit sit_exit_net(struct net *net)
1851 {
1852 LIST_HEAD(list);
1853
1854 rtnl_lock();
1855 sit_destroy_tunnels(net, &list);
1856 unregister_netdevice_many(&list);
1857 rtnl_unlock();
1858 }
1859
1860 static struct pernet_operations sit_net_ops = {
1861 .init = sit_init_net,
1862 .exit = sit_exit_net,
1863 .id = &sit_net_id,
1864 .size = sizeof(struct sit_net),
1865 };
1866
1867 static void __exit sit_cleanup(void)
1868 {
1869 rtnl_link_unregister(&sit_link_ops);
1870 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1871 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1872 #if IS_ENABLED(CONFIG_MPLS)
1873 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1874 #endif
1875
1876 unregister_pernet_device(&sit_net_ops);
1877 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1878 }
1879
1880 static int __init sit_init(void)
1881 {
1882 int err;
1883
1884 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1885
1886 err = register_pernet_device(&sit_net_ops);
1887 if (err < 0)
1888 return err;
1889 err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1890 if (err < 0) {
1891 pr_info("%s: can't register ip6ip4\n", __func__);
1892 goto xfrm_tunnel_failed;
1893 }
1894 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1895 if (err < 0) {
1896 pr_info("%s: can't register ip4ip4\n", __func__);
1897 goto xfrm_tunnel4_failed;
1898 }
1899 #if IS_ENABLED(CONFIG_MPLS)
1900 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1901 if (err < 0) {
1902 pr_info("%s: can't register mplsip\n", __func__);
1903 goto xfrm_tunnel_mpls_failed;
1904 }
1905 #endif
1906 err = rtnl_link_register(&sit_link_ops);
1907 if (err < 0)
1908 goto rtnl_link_failed;
1909
1910 out:
1911 return err;
1912
1913 rtnl_link_failed:
1914 #if IS_ENABLED(CONFIG_MPLS)
1915 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1916 xfrm_tunnel_mpls_failed:
1917 #endif
1918 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1919 xfrm_tunnel4_failed:
1920 xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1921 xfrm_tunnel_failed:
1922 unregister_pernet_device(&sit_net_ops);
1923 goto out;
1924 }
1925
1926 module_init(sit_init);
1927 module_exit(sit_cleanup);
1928 MODULE_LICENSE("GPL");
1929 MODULE_ALIAS_RTNL_LINK("sit");
1930 MODULE_ALIAS_NETDEV("sit0");
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