1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * IPv6 tunneling device
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Ville Nuorvala <vnuorval@tcs.hut.fi>
8 * Yasuyuki Kozakai <kozakai@linux-ipv6.org>
9 *
10 * Based on:
11 * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
12 *
13 * RFC 2473
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/sockios.h>
23 #include <linux/icmp.h>
24 #include <linux/if.h>
25 #include <linux/in.h>
26 #include <linux/ip.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/icmpv6.h>
32 #include <linux/init.h>
33 #include <linux/route.h>
34 #include <linux/rtnetlink.h>
35 #include <linux/netfilter_ipv6.h>
36 #include <linux/slab.h>
37 #include <linux/hash.h>
38 #include <linux/etherdevice.h>
39
40 #include <linux/uaccess.h>
41 #include <linux/atomic.h>
42
43 #include <net/icmp.h>
44 #include <net/ip.h>
45 #include <net/ip_tunnels.h>
46 #include <net/ipv6.h>
47 #include <net/ip6_route.h>
48 #include <net/addrconf.h>
49 #include <net/ip6_tunnel.h>
50 #include <net/xfrm.h>
51 #include <net/dsfield.h>
52 #include <net/inet_ecn.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55 #include <net/dst_metadata.h>
56
57 MODULE_AUTHOR("Ville Nuorvala");
58 MODULE_DESCRIPTION("IPv6 tunneling device");
59 MODULE_LICENSE("GPL");
60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
61 MODULE_ALIAS_NETDEV("ip6tnl0");
62
63 #define IP6_TUNNEL_HASH_SIZE_SHIFT 5
64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
65
66 static bool log_ecn_error = true;
67 module_param(log_ecn_error, bool, 0644);
68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
69
HASH(const struct in6_addr * addr1,const struct in6_addr * addr2)70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
71 {
72 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
73
74 return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
75 }
76
77 static int ip6_tnl_dev_init(struct net_device *dev);
78 static void ip6_tnl_dev_setup(struct net_device *dev);
79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
80
81 static unsigned int ip6_tnl_net_id __read_mostly;
82 struct ip6_tnl_net {
83 /* the IPv6 tunnel fallback device */
84 struct net_device *fb_tnl_dev;
85 /* lists for storing tunnels in use */
86 struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
87 struct ip6_tnl __rcu *tnls_wc[1];
88 struct ip6_tnl __rcu **tnls[2];
89 struct ip6_tnl __rcu *collect_md_tun;
90 };
91
ip6_get_stats(struct net_device * dev)92 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
93 {
94 struct pcpu_sw_netstats tmp, sum = { 0 };
95 int i;
96
97 for_each_possible_cpu(i) {
98 unsigned int start;
99 const struct pcpu_sw_netstats *tstats =
100 per_cpu_ptr(dev->tstats, i);
101
102 do {
103 start = u64_stats_fetch_begin_irq(&tstats->syncp);
104 tmp.rx_packets = tstats->rx_packets;
105 tmp.rx_bytes = tstats->rx_bytes;
106 tmp.tx_packets = tstats->tx_packets;
107 tmp.tx_bytes = tstats->tx_bytes;
108 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
109
110 sum.rx_packets += tmp.rx_packets;
111 sum.rx_bytes += tmp.rx_bytes;
112 sum.tx_packets += tmp.tx_packets;
113 sum.tx_bytes += tmp.tx_bytes;
114 }
115 dev->stats.rx_packets = sum.rx_packets;
116 dev->stats.rx_bytes = sum.rx_bytes;
117 dev->stats.tx_packets = sum.tx_packets;
118 dev->stats.tx_bytes = sum.tx_bytes;
119 return &dev->stats;
120 }
121
122 /**
123 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
124 * @remote: the address of the tunnel exit-point
125 * @local: the address of the tunnel entry-point
126 *
127 * Return:
128 * tunnel matching given end-points if found,
129 * else fallback tunnel if its device is up,
130 * else %NULL
131 **/
132
133 #define for_each_ip6_tunnel_rcu(start) \
134 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
135
136 static struct ip6_tnl *
ip6_tnl_lookup(struct net * net,const struct in6_addr * remote,const struct in6_addr * local)137 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
138 {
139 unsigned int hash = HASH(remote, local);
140 struct ip6_tnl *t;
141 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
142 struct in6_addr any;
143
144 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
145 if (ipv6_addr_equal(local, &t->parms.laddr) &&
146 ipv6_addr_equal(remote, &t->parms.raddr) &&
147 (t->dev->flags & IFF_UP))
148 return t;
149 }
150
151 memset(&any, 0, sizeof(any));
152 hash = HASH(&any, local);
153 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
154 if (ipv6_addr_equal(local, &t->parms.laddr) &&
155 ipv6_addr_any(&t->parms.raddr) &&
156 (t->dev->flags & IFF_UP))
157 return t;
158 }
159
160 hash = HASH(remote, &any);
161 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
162 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
163 ipv6_addr_any(&t->parms.laddr) &&
164 (t->dev->flags & IFF_UP))
165 return t;
166 }
167
168 t = rcu_dereference(ip6n->collect_md_tun);
169 if (t && t->dev->flags & IFF_UP)
170 return t;
171
172 t = rcu_dereference(ip6n->tnls_wc[0]);
173 if (t && (t->dev->flags & IFF_UP))
174 return t;
175
176 return NULL;
177 }
178
179 /**
180 * ip6_tnl_bucket - get head of list matching given tunnel parameters
181 * @p: parameters containing tunnel end-points
182 *
183 * Description:
184 * ip6_tnl_bucket() returns the head of the list matching the
185 * &struct in6_addr entries laddr and raddr in @p.
186 *
187 * Return: head of IPv6 tunnel list
188 **/
189
190 static struct ip6_tnl __rcu **
ip6_tnl_bucket(struct ip6_tnl_net * ip6n,const struct __ip6_tnl_parm * p)191 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
192 {
193 const struct in6_addr *remote = &p->raddr;
194 const struct in6_addr *local = &p->laddr;
195 unsigned int h = 0;
196 int prio = 0;
197
198 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
199 prio = 1;
200 h = HASH(remote, local);
201 }
202 return &ip6n->tnls[prio][h];
203 }
204
205 /**
206 * ip6_tnl_link - add tunnel to hash table
207 * @t: tunnel to be added
208 **/
209
210 static void
ip6_tnl_link(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)211 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
212 {
213 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
214
215 if (t->parms.collect_md)
216 rcu_assign_pointer(ip6n->collect_md_tun, t);
217 rcu_assign_pointer(t->next , rtnl_dereference(*tp));
218 rcu_assign_pointer(*tp, t);
219 }
220
221 /**
222 * ip6_tnl_unlink - remove tunnel from hash table
223 * @t: tunnel to be removed
224 **/
225
226 static void
ip6_tnl_unlink(struct ip6_tnl_net * ip6n,struct ip6_tnl * t)227 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
228 {
229 struct ip6_tnl __rcu **tp;
230 struct ip6_tnl *iter;
231
232 if (t->parms.collect_md)
233 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
234
235 for (tp = ip6_tnl_bucket(ip6n, &t->parms);
236 (iter = rtnl_dereference(*tp)) != NULL;
237 tp = &iter->next) {
238 if (t == iter) {
239 rcu_assign_pointer(*tp, t->next);
240 break;
241 }
242 }
243 }
244
ip6_dev_free(struct net_device * dev)245 static void ip6_dev_free(struct net_device *dev)
246 {
247 struct ip6_tnl *t = netdev_priv(dev);
248
249 gro_cells_destroy(&t->gro_cells);
250 dst_cache_destroy(&t->dst_cache);
251 free_percpu(dev->tstats);
252 }
253
ip6_tnl_create2(struct net_device * dev)254 static int ip6_tnl_create2(struct net_device *dev)
255 {
256 struct ip6_tnl *t = netdev_priv(dev);
257 struct net *net = dev_net(dev);
258 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
259 int err;
260
261 t = netdev_priv(dev);
262
263 dev->rtnl_link_ops = &ip6_link_ops;
264 err = register_netdevice(dev);
265 if (err < 0)
266 goto out;
267
268 strcpy(t->parms.name, dev->name);
269
270 dev_hold(dev);
271 ip6_tnl_link(ip6n, t);
272 return 0;
273
274 out:
275 return err;
276 }
277
278 /**
279 * ip6_tnl_create - create a new tunnel
280 * @p: tunnel parameters
281 * @pt: pointer to new tunnel
282 *
283 * Description:
284 * Create tunnel matching given parameters.
285 *
286 * Return:
287 * created tunnel or error pointer
288 **/
289
ip6_tnl_create(struct net * net,struct __ip6_tnl_parm * p)290 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
291 {
292 struct net_device *dev;
293 struct ip6_tnl *t;
294 char name[IFNAMSIZ];
295 int err = -E2BIG;
296
297 if (p->name[0]) {
298 if (!dev_valid_name(p->name))
299 goto failed;
300 strlcpy(name, p->name, IFNAMSIZ);
301 } else {
302 sprintf(name, "ip6tnl%%d");
303 }
304 err = -ENOMEM;
305 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
306 ip6_tnl_dev_setup);
307 if (!dev)
308 goto failed;
309
310 dev_net_set(dev, net);
311
312 t = netdev_priv(dev);
313 t->parms = *p;
314 t->net = dev_net(dev);
315 err = ip6_tnl_create2(dev);
316 if (err < 0)
317 goto failed_free;
318
319 return t;
320
321 failed_free:
322 free_netdev(dev);
323 failed:
324 return ERR_PTR(err);
325 }
326
327 /**
328 * ip6_tnl_locate - find or create tunnel matching given parameters
329 * @p: tunnel parameters
330 * @create: != 0 if allowed to create new tunnel if no match found
331 *
332 * Description:
333 * ip6_tnl_locate() first tries to locate an existing tunnel
334 * based on @parms. If this is unsuccessful, but @create is set a new
335 * tunnel device is created and registered for use.
336 *
337 * Return:
338 * matching tunnel or error pointer
339 **/
340
ip6_tnl_locate(struct net * net,struct __ip6_tnl_parm * p,int create)341 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
342 struct __ip6_tnl_parm *p, int create)
343 {
344 const struct in6_addr *remote = &p->raddr;
345 const struct in6_addr *local = &p->laddr;
346 struct ip6_tnl __rcu **tp;
347 struct ip6_tnl *t;
348 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
349
350 for (tp = ip6_tnl_bucket(ip6n, p);
351 (t = rtnl_dereference(*tp)) != NULL;
352 tp = &t->next) {
353 if (ipv6_addr_equal(local, &t->parms.laddr) &&
354 ipv6_addr_equal(remote, &t->parms.raddr)) {
355 if (create)
356 return ERR_PTR(-EEXIST);
357
358 return t;
359 }
360 }
361 if (!create)
362 return ERR_PTR(-ENODEV);
363 return ip6_tnl_create(net, p);
364 }
365
366 /**
367 * ip6_tnl_dev_uninit - tunnel device uninitializer
368 * @dev: the device to be destroyed
369 *
370 * Description:
371 * ip6_tnl_dev_uninit() removes tunnel from its list
372 **/
373
374 static void
ip6_tnl_dev_uninit(struct net_device * dev)375 ip6_tnl_dev_uninit(struct net_device *dev)
376 {
377 struct ip6_tnl *t = netdev_priv(dev);
378 struct net *net = t->net;
379 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
380
381 if (dev == ip6n->fb_tnl_dev)
382 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
383 else
384 ip6_tnl_unlink(ip6n, t);
385 dst_cache_reset(&t->dst_cache);
386 dev_put(dev);
387 }
388
389 /**
390 * parse_tvl_tnl_enc_lim - handle encapsulation limit option
391 * @skb: received socket buffer
392 *
393 * Return:
394 * 0 if none was found,
395 * else index to encapsulation limit
396 **/
397
ip6_tnl_parse_tlv_enc_lim(struct sk_buff * skb,__u8 * raw)398 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
399 {
400 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
401 unsigned int nhoff = raw - skb->data;
402 unsigned int off = nhoff + sizeof(*ipv6h);
403 u8 next, nexthdr = ipv6h->nexthdr;
404
405 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
406 struct ipv6_opt_hdr *hdr;
407 u16 optlen;
408
409 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
410 break;
411
412 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
413 if (nexthdr == NEXTHDR_FRAGMENT) {
414 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
415 if (frag_hdr->frag_off)
416 break;
417 optlen = 8;
418 } else if (nexthdr == NEXTHDR_AUTH) {
419 optlen = ipv6_authlen(hdr);
420 } else {
421 optlen = ipv6_optlen(hdr);
422 }
423 /* cache hdr->nexthdr, since pskb_may_pull() might
424 * invalidate hdr
425 */
426 next = hdr->nexthdr;
427 if (nexthdr == NEXTHDR_DEST) {
428 u16 i = 2;
429
430 /* Remember : hdr is no longer valid at this point. */
431 if (!pskb_may_pull(skb, off + optlen))
432 break;
433
434 while (1) {
435 struct ipv6_tlv_tnl_enc_lim *tel;
436
437 /* No more room for encapsulation limit */
438 if (i + sizeof(*tel) > optlen)
439 break;
440
441 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
442 /* return index of option if found and valid */
443 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
444 tel->length == 1)
445 return i + off - nhoff;
446 /* else jump to next option */
447 if (tel->type)
448 i += tel->length + 2;
449 else
450 i++;
451 }
452 }
453 nexthdr = next;
454 off += optlen;
455 }
456 return 0;
457 }
458 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
459
460 /**
461 * ip6_tnl_err - tunnel error handler
462 *
463 * Description:
464 * ip6_tnl_err() should handle errors in the tunnel according
465 * to the specifications in RFC 2473.
466 **/
467
468 static int
ip6_tnl_err(struct sk_buff * skb,__u8 ipproto,struct inet6_skb_parm * opt,u8 * type,u8 * code,int * msg,__u32 * info,int offset)469 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
470 u8 *type, u8 *code, int *msg, __u32 *info, int offset)
471 {
472 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
473 struct net *net = dev_net(skb->dev);
474 u8 rel_type = ICMPV6_DEST_UNREACH;
475 u8 rel_code = ICMPV6_ADDR_UNREACH;
476 __u32 rel_info = 0;
477 struct ip6_tnl *t;
478 int err = -ENOENT;
479 int rel_msg = 0;
480 u8 tproto;
481 __u16 len;
482
483 /* If the packet doesn't contain the original IPv6 header we are
484 in trouble since we might need the source address for further
485 processing of the error. */
486
487 rcu_read_lock();
488 t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
489 if (!t)
490 goto out;
491
492 tproto = READ_ONCE(t->parms.proto);
493 if (tproto != ipproto && tproto != 0)
494 goto out;
495
496 err = 0;
497
498 switch (*type) {
499 struct ipv6_tlv_tnl_enc_lim *tel;
500 __u32 mtu, teli;
501 case ICMPV6_DEST_UNREACH:
502 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
503 t->parms.name);
504 rel_msg = 1;
505 break;
506 case ICMPV6_TIME_EXCEED:
507 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
508 net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
509 t->parms.name);
510 rel_msg = 1;
511 }
512 break;
513 case ICMPV6_PARAMPROB:
514 teli = 0;
515 if ((*code) == ICMPV6_HDR_FIELD)
516 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
517
518 if (teli && teli == *info - 2) {
519 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
520 if (tel->encap_limit == 0) {
521 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
522 t->parms.name);
523 rel_msg = 1;
524 }
525 } else {
526 net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
527 t->parms.name);
528 }
529 break;
530 case ICMPV6_PKT_TOOBIG:
531 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
532 sock_net_uid(net, NULL));
533 mtu = *info - offset;
534 if (mtu < IPV6_MIN_MTU)
535 mtu = IPV6_MIN_MTU;
536 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
537 if (len > mtu) {
538 rel_type = ICMPV6_PKT_TOOBIG;
539 rel_code = 0;
540 rel_info = mtu;
541 rel_msg = 1;
542 }
543 break;
544 case NDISC_REDIRECT:
545 ip6_redirect(skb, net, skb->dev->ifindex, 0,
546 sock_net_uid(net, NULL));
547 break;
548 }
549
550 *type = rel_type;
551 *code = rel_code;
552 *info = rel_info;
553 *msg = rel_msg;
554
555 out:
556 rcu_read_unlock();
557 return err;
558 }
559
560 static int
ip4ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)561 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
562 u8 type, u8 code, int offset, __be32 info)
563 {
564 __u32 rel_info = ntohl(info);
565 const struct iphdr *eiph;
566 struct sk_buff *skb2;
567 int err, rel_msg = 0;
568 u8 rel_type = type;
569 u8 rel_code = code;
570 struct rtable *rt;
571 struct flowi4 fl4;
572
573 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
574 &rel_msg, &rel_info, offset);
575 if (err < 0)
576 return err;
577
578 if (rel_msg == 0)
579 return 0;
580
581 switch (rel_type) {
582 case ICMPV6_DEST_UNREACH:
583 if (rel_code != ICMPV6_ADDR_UNREACH)
584 return 0;
585 rel_type = ICMP_DEST_UNREACH;
586 rel_code = ICMP_HOST_UNREACH;
587 break;
588 case ICMPV6_PKT_TOOBIG:
589 if (rel_code != 0)
590 return 0;
591 rel_type = ICMP_DEST_UNREACH;
592 rel_code = ICMP_FRAG_NEEDED;
593 break;
594 default:
595 return 0;
596 }
597
598 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
599 return 0;
600
601 skb2 = skb_clone(skb, GFP_ATOMIC);
602 if (!skb2)
603 return 0;
604
605 skb_dst_drop(skb2);
606
607 skb_pull(skb2, offset);
608 skb_reset_network_header(skb2);
609 eiph = ip_hdr(skb2);
610
611 /* Try to guess incoming interface */
612 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
613 0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
614 if (IS_ERR(rt))
615 goto out;
616
617 skb2->dev = rt->dst.dev;
618 ip_rt_put(rt);
619
620 /* route "incoming" packet */
621 if (rt->rt_flags & RTCF_LOCAL) {
622 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
623 eiph->daddr, eiph->saddr, 0, 0,
624 IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
625 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
626 if (!IS_ERR(rt))
627 ip_rt_put(rt);
628 goto out;
629 }
630 skb_dst_set(skb2, &rt->dst);
631 } else {
632 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
633 skb2->dev) ||
634 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
635 goto out;
636 }
637
638 /* change mtu on this route */
639 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
640 if (rel_info > dst_mtu(skb_dst(skb2)))
641 goto out;
642
643 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
644 }
645
646 icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
647
648 out:
649 kfree_skb(skb2);
650 return 0;
651 }
652
653 static int
ip6ip6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)654 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
655 u8 type, u8 code, int offset, __be32 info)
656 {
657 __u32 rel_info = ntohl(info);
658 int err, rel_msg = 0;
659 u8 rel_type = type;
660 u8 rel_code = code;
661
662 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
663 &rel_msg, &rel_info, offset);
664 if (err < 0)
665 return err;
666
667 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
668 struct rt6_info *rt;
669 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
670
671 if (!skb2)
672 return 0;
673
674 skb_dst_drop(skb2);
675 skb_pull(skb2, offset);
676 skb_reset_network_header(skb2);
677
678 /* Try to guess incoming interface */
679 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
680 NULL, 0, skb2, 0);
681
682 if (rt && rt->dst.dev)
683 skb2->dev = rt->dst.dev;
684
685 icmpv6_send(skb2, rel_type, rel_code, rel_info);
686
687 ip6_rt_put(rt);
688
689 kfree_skb(skb2);
690 }
691
692 return 0;
693 }
694
ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)695 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
696 const struct ipv6hdr *ipv6h,
697 struct sk_buff *skb)
698 {
699 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
700
701 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
702 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
703
704 return IP6_ECN_decapsulate(ipv6h, skb);
705 }
706
ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb)707 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
708 const struct ipv6hdr *ipv6h,
709 struct sk_buff *skb)
710 {
711 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
712 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
713
714 return IP6_ECN_decapsulate(ipv6h, skb);
715 }
716
ip6_tnl_get_cap(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)717 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
718 const struct in6_addr *laddr,
719 const struct in6_addr *raddr)
720 {
721 struct __ip6_tnl_parm *p = &t->parms;
722 int ltype = ipv6_addr_type(laddr);
723 int rtype = ipv6_addr_type(raddr);
724 __u32 flags = 0;
725
726 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
727 flags = IP6_TNL_F_CAP_PER_PACKET;
728 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
729 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
730 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
731 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
732 if (ltype&IPV6_ADDR_UNICAST)
733 flags |= IP6_TNL_F_CAP_XMIT;
734 if (rtype&IPV6_ADDR_UNICAST)
735 flags |= IP6_TNL_F_CAP_RCV;
736 }
737 return flags;
738 }
739 EXPORT_SYMBOL(ip6_tnl_get_cap);
740
741 /* called with rcu_read_lock() */
ip6_tnl_rcv_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)742 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
743 const struct in6_addr *laddr,
744 const struct in6_addr *raddr)
745 {
746 struct __ip6_tnl_parm *p = &t->parms;
747 int ret = 0;
748 struct net *net = t->net;
749
750 if ((p->flags & IP6_TNL_F_CAP_RCV) ||
751 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
752 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
753 struct net_device *ldev = NULL;
754
755 if (p->link)
756 ldev = dev_get_by_index_rcu(net, p->link);
757
758 if ((ipv6_addr_is_multicast(laddr) ||
759 likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
760 0, IFA_F_TENTATIVE))) &&
761 ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
762 likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
763 0, IFA_F_TENTATIVE))))
764 ret = 1;
765 }
766 return ret;
767 }
768 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
769
__ip6_tnl_rcv(struct ip6_tnl * tunnel,struct sk_buff * skb,const struct tnl_ptk_info * tpi,struct metadata_dst * tun_dst,int (* dscp_ecn_decapsulate)(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb),bool log_ecn_err)770 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
771 const struct tnl_ptk_info *tpi,
772 struct metadata_dst *tun_dst,
773 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
774 const struct ipv6hdr *ipv6h,
775 struct sk_buff *skb),
776 bool log_ecn_err)
777 {
778 struct pcpu_sw_netstats *tstats;
779 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
780 int err;
781
782 if ((!(tpi->flags & TUNNEL_CSUM) &&
783 (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
784 ((tpi->flags & TUNNEL_CSUM) &&
785 !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
786 tunnel->dev->stats.rx_crc_errors++;
787 tunnel->dev->stats.rx_errors++;
788 goto drop;
789 }
790
791 if (tunnel->parms.i_flags & TUNNEL_SEQ) {
792 if (!(tpi->flags & TUNNEL_SEQ) ||
793 (tunnel->i_seqno &&
794 (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
795 tunnel->dev->stats.rx_fifo_errors++;
796 tunnel->dev->stats.rx_errors++;
797 goto drop;
798 }
799 tunnel->i_seqno = ntohl(tpi->seq) + 1;
800 }
801
802 skb->protocol = tpi->proto;
803
804 /* Warning: All skb pointers will be invalidated! */
805 if (tunnel->dev->type == ARPHRD_ETHER) {
806 if (!pskb_may_pull(skb, ETH_HLEN)) {
807 tunnel->dev->stats.rx_length_errors++;
808 tunnel->dev->stats.rx_errors++;
809 goto drop;
810 }
811
812 ipv6h = ipv6_hdr(skb);
813 skb->protocol = eth_type_trans(skb, tunnel->dev);
814 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
815 } else {
816 skb->dev = tunnel->dev;
817 }
818
819 skb_reset_network_header(skb);
820 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
821
822 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
823
824 err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
825 if (unlikely(err)) {
826 if (log_ecn_err)
827 net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
828 &ipv6h->saddr,
829 ipv6_get_dsfield(ipv6h));
830 if (err > 1) {
831 ++tunnel->dev->stats.rx_frame_errors;
832 ++tunnel->dev->stats.rx_errors;
833 goto drop;
834 }
835 }
836
837 tstats = this_cpu_ptr(tunnel->dev->tstats);
838 u64_stats_update_begin(&tstats->syncp);
839 tstats->rx_packets++;
840 tstats->rx_bytes += skb->len;
841 u64_stats_update_end(&tstats->syncp);
842
843 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
844
845 if (tun_dst)
846 skb_dst_set(skb, (struct dst_entry *)tun_dst);
847
848 gro_cells_receive(&tunnel->gro_cells, skb);
849 return 0;
850
851 drop:
852 if (tun_dst)
853 dst_release((struct dst_entry *)tun_dst);
854 kfree_skb(skb);
855 return 0;
856 }
857
ip6_tnl_rcv(struct ip6_tnl * t,struct sk_buff * skb,const struct tnl_ptk_info * tpi,struct metadata_dst * tun_dst,bool log_ecn_err)858 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
859 const struct tnl_ptk_info *tpi,
860 struct metadata_dst *tun_dst,
861 bool log_ecn_err)
862 {
863 return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
864 log_ecn_err);
865 }
866 EXPORT_SYMBOL(ip6_tnl_rcv);
867
868 static const struct tnl_ptk_info tpi_v6 = {
869 /* no tunnel info required for ipxip6. */
870 .proto = htons(ETH_P_IPV6),
871 };
872
873 static const struct tnl_ptk_info tpi_v4 = {
874 /* no tunnel info required for ipxip6. */
875 .proto = htons(ETH_P_IP),
876 };
877
ipxip6_rcv(struct sk_buff * skb,u8 ipproto,const struct tnl_ptk_info * tpi,int (* dscp_ecn_decapsulate)(const struct ip6_tnl * t,const struct ipv6hdr * ipv6h,struct sk_buff * skb))878 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
879 const struct tnl_ptk_info *tpi,
880 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
881 const struct ipv6hdr *ipv6h,
882 struct sk_buff *skb))
883 {
884 struct ip6_tnl *t;
885 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
886 struct metadata_dst *tun_dst = NULL;
887 int ret = -1;
888
889 rcu_read_lock();
890 t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
891
892 if (t) {
893 u8 tproto = READ_ONCE(t->parms.proto);
894
895 if (tproto != ipproto && tproto != 0)
896 goto drop;
897 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
898 goto drop;
899 ipv6h = ipv6_hdr(skb);
900 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
901 goto drop;
902 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
903 goto drop;
904 if (t->parms.collect_md) {
905 tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
906 if (!tun_dst)
907 goto drop;
908 }
909 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
910 log_ecn_error);
911 }
912
913 rcu_read_unlock();
914
915 return ret;
916
917 drop:
918 rcu_read_unlock();
919 kfree_skb(skb);
920 return 0;
921 }
922
ip4ip6_rcv(struct sk_buff * skb)923 static int ip4ip6_rcv(struct sk_buff *skb)
924 {
925 return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
926 ip4ip6_dscp_ecn_decapsulate);
927 }
928
ip6ip6_rcv(struct sk_buff * skb)929 static int ip6ip6_rcv(struct sk_buff *skb)
930 {
931 return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
932 ip6ip6_dscp_ecn_decapsulate);
933 }
934
935 struct ipv6_tel_txoption {
936 struct ipv6_txoptions ops;
937 __u8 dst_opt[8];
938 };
939
init_tel_txopt(struct ipv6_tel_txoption * opt,__u8 encap_limit)940 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
941 {
942 memset(opt, 0, sizeof(struct ipv6_tel_txoption));
943
944 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
945 opt->dst_opt[3] = 1;
946 opt->dst_opt[4] = encap_limit;
947 opt->dst_opt[5] = IPV6_TLV_PADN;
948 opt->dst_opt[6] = 1;
949
950 opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
951 opt->ops.opt_nflen = 8;
952 }
953
954 /**
955 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
956 * @t: the outgoing tunnel device
957 * @hdr: IPv6 header from the incoming packet
958 *
959 * Description:
960 * Avoid trivial tunneling loop by checking that tunnel exit-point
961 * doesn't match source of incoming packet.
962 *
963 * Return:
964 * 1 if conflict,
965 * 0 else
966 **/
967
968 static inline bool
ip6_tnl_addr_conflict(const struct ip6_tnl * t,const struct ipv6hdr * hdr)969 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
970 {
971 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
972 }
973
ip6_tnl_xmit_ctl(struct ip6_tnl * t,const struct in6_addr * laddr,const struct in6_addr * raddr)974 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
975 const struct in6_addr *laddr,
976 const struct in6_addr *raddr)
977 {
978 struct __ip6_tnl_parm *p = &t->parms;
979 int ret = 0;
980 struct net *net = t->net;
981
982 if (t->parms.collect_md)
983 return 1;
984
985 if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
986 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
987 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
988 struct net_device *ldev = NULL;
989
990 rcu_read_lock();
991 if (p->link)
992 ldev = dev_get_by_index_rcu(net, p->link);
993
994 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
995 0, IFA_F_TENTATIVE)))
996 pr_warn("%s xmit: Local address not yet configured!\n",
997 p->name);
998 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
999 !ipv6_addr_is_multicast(raddr) &&
1000 unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1001 true, 0, IFA_F_TENTATIVE)))
1002 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1003 p->name);
1004 else
1005 ret = 1;
1006 rcu_read_unlock();
1007 }
1008 return ret;
1009 }
1010 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1011
1012 /**
1013 * ip6_tnl_xmit - encapsulate packet and send
1014 * @skb: the outgoing socket buffer
1015 * @dev: the outgoing tunnel device
1016 * @dsfield: dscp code for outer header
1017 * @fl6: flow of tunneled packet
1018 * @encap_limit: encapsulation limit
1019 * @pmtu: Path MTU is stored if packet is too big
1020 * @proto: next header value
1021 *
1022 * Description:
1023 * Build new header and do some sanity checks on the packet before sending
1024 * it.
1025 *
1026 * Return:
1027 * 0 on success
1028 * -1 fail
1029 * %-EMSGSIZE message too big. return mtu in this case.
1030 **/
1031
ip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev,__u8 dsfield,struct flowi6 * fl6,int encap_limit,__u32 * pmtu,__u8 proto)1032 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1033 struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1034 __u8 proto)
1035 {
1036 struct ip6_tnl *t = netdev_priv(dev);
1037 struct net *net = t->net;
1038 struct net_device_stats *stats = &t->dev->stats;
1039 struct ipv6hdr *ipv6h;
1040 struct ipv6_tel_txoption opt;
1041 struct dst_entry *dst = NULL, *ndst = NULL;
1042 struct net_device *tdev;
1043 int mtu;
1044 unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1045 unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1046 unsigned int max_headroom = psh_hlen;
1047 bool use_cache = false;
1048 u8 hop_limit;
1049 int err = -1;
1050
1051 if (t->parms.collect_md) {
1052 hop_limit = skb_tunnel_info(skb)->key.ttl;
1053 goto route_lookup;
1054 } else {
1055 hop_limit = t->parms.hop_limit;
1056 }
1057
1058 /* NBMA tunnel */
1059 if (ipv6_addr_any(&t->parms.raddr)) {
1060 if (skb->protocol == htons(ETH_P_IPV6)) {
1061 struct in6_addr *addr6;
1062 struct neighbour *neigh;
1063 int addr_type;
1064
1065 if (!skb_dst(skb))
1066 goto tx_err_link_failure;
1067
1068 neigh = dst_neigh_lookup(skb_dst(skb),
1069 &ipv6_hdr(skb)->daddr);
1070 if (!neigh)
1071 goto tx_err_link_failure;
1072
1073 addr6 = (struct in6_addr *)&neigh->primary_key;
1074 addr_type = ipv6_addr_type(addr6);
1075
1076 if (addr_type == IPV6_ADDR_ANY)
1077 addr6 = &ipv6_hdr(skb)->daddr;
1078
1079 memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1080 neigh_release(neigh);
1081 }
1082 } else if (t->parms.proto != 0 && !(t->parms.flags &
1083 (IP6_TNL_F_USE_ORIG_TCLASS |
1084 IP6_TNL_F_USE_ORIG_FWMARK))) {
1085 /* enable the cache only if neither the outer protocol nor the
1086 * routing decision depends on the current inner header value
1087 */
1088 use_cache = true;
1089 }
1090
1091 if (use_cache)
1092 dst = dst_cache_get(&t->dst_cache);
1093
1094 if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1095 goto tx_err_link_failure;
1096
1097 if (!dst) {
1098 route_lookup:
1099 /* add dsfield to flowlabel for route lookup */
1100 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1101
1102 dst = ip6_route_output(net, NULL, fl6);
1103
1104 if (dst->error)
1105 goto tx_err_link_failure;
1106 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1107 if (IS_ERR(dst)) {
1108 err = PTR_ERR(dst);
1109 dst = NULL;
1110 goto tx_err_link_failure;
1111 }
1112 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1113 ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1114 &fl6->daddr, 0, &fl6->saddr))
1115 goto tx_err_link_failure;
1116 ndst = dst;
1117 }
1118
1119 tdev = dst->dev;
1120
1121 if (tdev == dev) {
1122 stats->collisions++;
1123 net_warn_ratelimited("%s: Local routing loop detected!\n",
1124 t->parms.name);
1125 goto tx_err_dst_release;
1126 }
1127 mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1128 if (encap_limit >= 0) {
1129 max_headroom += 8;
1130 mtu -= 8;
1131 }
1132 mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1133 IPV6_MIN_MTU : IPV4_MIN_MTU);
1134
1135 skb_dst_update_pmtu_no_confirm(skb, mtu);
1136 if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1137 *pmtu = mtu;
1138 err = -EMSGSIZE;
1139 goto tx_err_dst_release;
1140 }
1141
1142 if (t->err_count > 0) {
1143 if (time_before(jiffies,
1144 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1145 t->err_count--;
1146
1147 dst_link_failure(skb);
1148 } else {
1149 t->err_count = 0;
1150 }
1151 }
1152
1153 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1154
1155 /*
1156 * Okay, now see if we can stuff it in the buffer as-is.
1157 */
1158 max_headroom += LL_RESERVED_SPACE(tdev);
1159
1160 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1161 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1162 struct sk_buff *new_skb;
1163
1164 new_skb = skb_realloc_headroom(skb, max_headroom);
1165 if (!new_skb)
1166 goto tx_err_dst_release;
1167
1168 if (skb->sk)
1169 skb_set_owner_w(new_skb, skb->sk);
1170 consume_skb(skb);
1171 skb = new_skb;
1172 }
1173
1174 if (t->parms.collect_md) {
1175 if (t->encap.type != TUNNEL_ENCAP_NONE)
1176 goto tx_err_dst_release;
1177 } else {
1178 if (use_cache && ndst)
1179 dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1180 }
1181 skb_dst_set(skb, dst);
1182
1183 if (hop_limit == 0) {
1184 if (skb->protocol == htons(ETH_P_IP))
1185 hop_limit = ip_hdr(skb)->ttl;
1186 else if (skb->protocol == htons(ETH_P_IPV6))
1187 hop_limit = ipv6_hdr(skb)->hop_limit;
1188 else
1189 hop_limit = ip6_dst_hoplimit(dst);
1190 }
1191
1192 /* Calculate max headroom for all the headers and adjust
1193 * needed_headroom if necessary.
1194 */
1195 max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1196 + dst->header_len + t->hlen;
1197 if (max_headroom > dev->needed_headroom)
1198 dev->needed_headroom = max_headroom;
1199
1200 err = ip6_tnl_encap(skb, t, &proto, fl6);
1201 if (err)
1202 return err;
1203
1204 if (encap_limit >= 0) {
1205 init_tel_txopt(&opt, encap_limit);
1206 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1207 }
1208
1209 skb_push(skb, sizeof(struct ipv6hdr));
1210 skb_reset_network_header(skb);
1211 ipv6h = ipv6_hdr(skb);
1212 ip6_flow_hdr(ipv6h, dsfield,
1213 ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1214 ipv6h->hop_limit = hop_limit;
1215 ipv6h->nexthdr = proto;
1216 ipv6h->saddr = fl6->saddr;
1217 ipv6h->daddr = fl6->daddr;
1218 ip6tunnel_xmit(NULL, skb, dev);
1219 return 0;
1220 tx_err_link_failure:
1221 stats->tx_carrier_errors++;
1222 dst_link_failure(skb);
1223 tx_err_dst_release:
1224 dst_release(dst);
1225 return err;
1226 }
1227 EXPORT_SYMBOL(ip6_tnl_xmit);
1228
1229 static inline int
ip4ip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev)1230 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1231 {
1232 struct ip6_tnl *t = netdev_priv(dev);
1233 const struct iphdr *iph;
1234 int encap_limit = -1;
1235 struct flowi6 fl6;
1236 __u8 dsfield;
1237 __u32 mtu;
1238 u8 tproto;
1239 int err;
1240
1241 iph = ip_hdr(skb);
1242 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1243
1244 tproto = READ_ONCE(t->parms.proto);
1245 if (tproto != IPPROTO_IPIP && tproto != 0)
1246 return -1;
1247
1248 if (t->parms.collect_md) {
1249 struct ip_tunnel_info *tun_info;
1250 const struct ip_tunnel_key *key;
1251
1252 tun_info = skb_tunnel_info(skb);
1253 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1254 ip_tunnel_info_af(tun_info) != AF_INET6))
1255 return -1;
1256 key = &tun_info->key;
1257 memset(&fl6, 0, sizeof(fl6));
1258 fl6.flowi6_proto = IPPROTO_IPIP;
1259 fl6.saddr = key->u.ipv6.src;
1260 fl6.daddr = key->u.ipv6.dst;
1261 fl6.flowlabel = key->label;
1262 dsfield = key->tos;
1263 } else {
1264 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1265 encap_limit = t->parms.encap_limit;
1266
1267 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1268 fl6.flowi6_proto = IPPROTO_IPIP;
1269
1270 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1271 dsfield = ipv4_get_dsfield(iph);
1272 else
1273 dsfield = ip6_tclass(t->parms.flowinfo);
1274 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1275 fl6.flowi6_mark = skb->mark;
1276 else
1277 fl6.flowi6_mark = t->parms.fwmark;
1278 }
1279
1280 fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1281 dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1282
1283 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1284 return -1;
1285
1286 skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1287
1288 err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1289 IPPROTO_IPIP);
1290 if (err != 0) {
1291 /* XXX: send ICMP error even if DF is not set. */
1292 if (err == -EMSGSIZE)
1293 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1294 htonl(mtu));
1295 return -1;
1296 }
1297
1298 return 0;
1299 }
1300
1301 static inline int
ip6ip6_tnl_xmit(struct sk_buff * skb,struct net_device * dev)1302 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1303 {
1304 struct ip6_tnl *t = netdev_priv(dev);
1305 struct ipv6hdr *ipv6h;
1306 int encap_limit = -1;
1307 __u16 offset;
1308 struct flowi6 fl6;
1309 __u8 dsfield;
1310 __u32 mtu;
1311 u8 tproto;
1312 int err;
1313
1314 ipv6h = ipv6_hdr(skb);
1315 tproto = READ_ONCE(t->parms.proto);
1316 if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1317 ip6_tnl_addr_conflict(t, ipv6h))
1318 return -1;
1319
1320 if (t->parms.collect_md) {
1321 struct ip_tunnel_info *tun_info;
1322 const struct ip_tunnel_key *key;
1323
1324 tun_info = skb_tunnel_info(skb);
1325 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1326 ip_tunnel_info_af(tun_info) != AF_INET6))
1327 return -1;
1328 key = &tun_info->key;
1329 memset(&fl6, 0, sizeof(fl6));
1330 fl6.flowi6_proto = IPPROTO_IPV6;
1331 fl6.saddr = key->u.ipv6.src;
1332 fl6.daddr = key->u.ipv6.dst;
1333 fl6.flowlabel = key->label;
1334 dsfield = key->tos;
1335 } else {
1336 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1337 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1338 ipv6h = ipv6_hdr(skb);
1339 if (offset > 0) {
1340 struct ipv6_tlv_tnl_enc_lim *tel;
1341
1342 tel = (void *)&skb_network_header(skb)[offset];
1343 if (tel->encap_limit == 0) {
1344 icmpv6_send(skb, ICMPV6_PARAMPROB,
1345 ICMPV6_HDR_FIELD, offset + 2);
1346 return -1;
1347 }
1348 encap_limit = tel->encap_limit - 1;
1349 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1350 encap_limit = t->parms.encap_limit;
1351 }
1352
1353 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1354 fl6.flowi6_proto = IPPROTO_IPV6;
1355
1356 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1357 dsfield = ipv6_get_dsfield(ipv6h);
1358 else
1359 dsfield = ip6_tclass(t->parms.flowinfo);
1360 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1361 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1362 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1363 fl6.flowi6_mark = skb->mark;
1364 else
1365 fl6.flowi6_mark = t->parms.fwmark;
1366 }
1367
1368 fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1369 dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1370
1371 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1372 return -1;
1373
1374 skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1375
1376 err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1377 IPPROTO_IPV6);
1378 if (err != 0) {
1379 if (err == -EMSGSIZE)
1380 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1381 return -1;
1382 }
1383
1384 return 0;
1385 }
1386
1387 static netdev_tx_t
ip6_tnl_start_xmit(struct sk_buff * skb,struct net_device * dev)1388 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1389 {
1390 struct ip6_tnl *t = netdev_priv(dev);
1391 struct net_device_stats *stats = &t->dev->stats;
1392 int ret;
1393
1394 if (!pskb_inet_may_pull(skb))
1395 goto tx_err;
1396
1397 switch (skb->protocol) {
1398 case htons(ETH_P_IP):
1399 ret = ip4ip6_tnl_xmit(skb, dev);
1400 break;
1401 case htons(ETH_P_IPV6):
1402 ret = ip6ip6_tnl_xmit(skb, dev);
1403 break;
1404 default:
1405 goto tx_err;
1406 }
1407
1408 if (ret < 0)
1409 goto tx_err;
1410
1411 return NETDEV_TX_OK;
1412
1413 tx_err:
1414 stats->tx_errors++;
1415 stats->tx_dropped++;
1416 kfree_skb(skb);
1417 return NETDEV_TX_OK;
1418 }
1419
ip6_tnl_link_config(struct ip6_tnl * t)1420 static void ip6_tnl_link_config(struct ip6_tnl *t)
1421 {
1422 struct net_device *dev = t->dev;
1423 struct __ip6_tnl_parm *p = &t->parms;
1424 struct flowi6 *fl6 = &t->fl.u.ip6;
1425 int t_hlen;
1426
1427 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1428 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1429
1430 /* Set up flowi template */
1431 fl6->saddr = p->laddr;
1432 fl6->daddr = p->raddr;
1433 fl6->flowi6_oif = p->link;
1434 fl6->flowlabel = 0;
1435
1436 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1437 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1438 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1439 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1440
1441 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1442 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1443
1444 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1445 dev->flags |= IFF_POINTOPOINT;
1446 else
1447 dev->flags &= ~IFF_POINTOPOINT;
1448
1449 t->tun_hlen = 0;
1450 t->hlen = t->encap_hlen + t->tun_hlen;
1451 t_hlen = t->hlen + sizeof(struct ipv6hdr);
1452
1453 if (p->flags & IP6_TNL_F_CAP_XMIT) {
1454 int strict = (ipv6_addr_type(&p->raddr) &
1455 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1456
1457 struct rt6_info *rt = rt6_lookup(t->net,
1458 &p->raddr, &p->laddr,
1459 p->link, NULL, strict);
1460
1461 if (!rt)
1462 return;
1463
1464 if (rt->dst.dev) {
1465 dev->hard_header_len = rt->dst.dev->hard_header_len +
1466 t_hlen;
1467
1468 dev->mtu = rt->dst.dev->mtu - t_hlen;
1469 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1470 dev->mtu -= 8;
1471
1472 if (dev->mtu < IPV6_MIN_MTU)
1473 dev->mtu = IPV6_MIN_MTU;
1474 }
1475 ip6_rt_put(rt);
1476 }
1477 }
1478
1479 /**
1480 * ip6_tnl_change - update the tunnel parameters
1481 * @t: tunnel to be changed
1482 * @p: tunnel configuration parameters
1483 *
1484 * Description:
1485 * ip6_tnl_change() updates the tunnel parameters
1486 **/
1487
1488 static int
ip6_tnl_change(struct ip6_tnl * t,const struct __ip6_tnl_parm * p)1489 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1490 {
1491 t->parms.laddr = p->laddr;
1492 t->parms.raddr = p->raddr;
1493 t->parms.flags = p->flags;
1494 t->parms.hop_limit = p->hop_limit;
1495 t->parms.encap_limit = p->encap_limit;
1496 t->parms.flowinfo = p->flowinfo;
1497 t->parms.link = p->link;
1498 t->parms.proto = p->proto;
1499 t->parms.fwmark = p->fwmark;
1500 dst_cache_reset(&t->dst_cache);
1501 ip6_tnl_link_config(t);
1502 return 0;
1503 }
1504
ip6_tnl_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1505 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1506 {
1507 struct net *net = t->net;
1508 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1509 int err;
1510
1511 ip6_tnl_unlink(ip6n, t);
1512 synchronize_net();
1513 err = ip6_tnl_change(t, p);
1514 ip6_tnl_link(ip6n, t);
1515 netdev_state_change(t->dev);
1516 return err;
1517 }
1518
ip6_tnl0_update(struct ip6_tnl * t,struct __ip6_tnl_parm * p)1519 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1520 {
1521 /* for default tnl0 device allow to change only the proto */
1522 t->parms.proto = p->proto;
1523 netdev_state_change(t->dev);
1524 return 0;
1525 }
1526
1527 static void
ip6_tnl_parm_from_user(struct __ip6_tnl_parm * p,const struct ip6_tnl_parm * u)1528 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1529 {
1530 p->laddr = u->laddr;
1531 p->raddr = u->raddr;
1532 p->flags = u->flags;
1533 p->hop_limit = u->hop_limit;
1534 p->encap_limit = u->encap_limit;
1535 p->flowinfo = u->flowinfo;
1536 p->link = u->link;
1537 p->proto = u->proto;
1538 memcpy(p->name, u->name, sizeof(u->name));
1539 }
1540
1541 static void
ip6_tnl_parm_to_user(struct ip6_tnl_parm * u,const struct __ip6_tnl_parm * p)1542 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1543 {
1544 u->laddr = p->laddr;
1545 u->raddr = p->raddr;
1546 u->flags = p->flags;
1547 u->hop_limit = p->hop_limit;
1548 u->encap_limit = p->encap_limit;
1549 u->flowinfo = p->flowinfo;
1550 u->link = p->link;
1551 u->proto = p->proto;
1552 memcpy(u->name, p->name, sizeof(u->name));
1553 }
1554
1555 /**
1556 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1557 * @dev: virtual device associated with tunnel
1558 * @ifr: parameters passed from userspace
1559 * @cmd: command to be performed
1560 *
1561 * Description:
1562 * ip6_tnl_ioctl() is used for managing IPv6 tunnels
1563 * from userspace.
1564 *
1565 * The possible commands are the following:
1566 * %SIOCGETTUNNEL: get tunnel parameters for device
1567 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1568 * %SIOCCHGTUNNEL: change tunnel parameters to those given
1569 * %SIOCDELTUNNEL: delete tunnel
1570 *
1571 * The fallback device "ip6tnl0", created during module
1572 * initialization, can be used for creating other tunnel devices.
1573 *
1574 * Return:
1575 * 0 on success,
1576 * %-EFAULT if unable to copy data to or from userspace,
1577 * %-EPERM if current process hasn't %CAP_NET_ADMIN set
1578 * %-EINVAL if passed tunnel parameters are invalid,
1579 * %-EEXIST if changing a tunnel's parameters would cause a conflict
1580 * %-ENODEV if attempting to change or delete a nonexisting device
1581 **/
1582
1583 static int
ip6_tnl_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)1584 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1585 {
1586 int err = 0;
1587 struct ip6_tnl_parm p;
1588 struct __ip6_tnl_parm p1;
1589 struct ip6_tnl *t = netdev_priv(dev);
1590 struct net *net = t->net;
1591 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1592
1593 memset(&p1, 0, sizeof(p1));
1594
1595 switch (cmd) {
1596 case SIOCGETTUNNEL:
1597 if (dev == ip6n->fb_tnl_dev) {
1598 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1599 err = -EFAULT;
1600 break;
1601 }
1602 ip6_tnl_parm_from_user(&p1, &p);
1603 t = ip6_tnl_locate(net, &p1, 0);
1604 if (IS_ERR(t))
1605 t = netdev_priv(dev);
1606 } else {
1607 memset(&p, 0, sizeof(p));
1608 }
1609 ip6_tnl_parm_to_user(&p, &t->parms);
1610 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1611 err = -EFAULT;
1612 }
1613 break;
1614 case SIOCADDTUNNEL:
1615 case SIOCCHGTUNNEL:
1616 err = -EPERM;
1617 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1618 break;
1619 err = -EFAULT;
1620 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1621 break;
1622 err = -EINVAL;
1623 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1624 p.proto != 0)
1625 break;
1626 ip6_tnl_parm_from_user(&p1, &p);
1627 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1628 if (cmd == SIOCCHGTUNNEL) {
1629 if (!IS_ERR(t)) {
1630 if (t->dev != dev) {
1631 err = -EEXIST;
1632 break;
1633 }
1634 } else
1635 t = netdev_priv(dev);
1636 if (dev == ip6n->fb_tnl_dev)
1637 err = ip6_tnl0_update(t, &p1);
1638 else
1639 err = ip6_tnl_update(t, &p1);
1640 }
1641 if (!IS_ERR(t)) {
1642 err = 0;
1643 ip6_tnl_parm_to_user(&p, &t->parms);
1644 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1645 err = -EFAULT;
1646
1647 } else {
1648 err = PTR_ERR(t);
1649 }
1650 break;
1651 case SIOCDELTUNNEL:
1652 err = -EPERM;
1653 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1654 break;
1655
1656 if (dev == ip6n->fb_tnl_dev) {
1657 err = -EFAULT;
1658 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1659 break;
1660 err = -ENOENT;
1661 ip6_tnl_parm_from_user(&p1, &p);
1662 t = ip6_tnl_locate(net, &p1, 0);
1663 if (IS_ERR(t))
1664 break;
1665 err = -EPERM;
1666 if (t->dev == ip6n->fb_tnl_dev)
1667 break;
1668 dev = t->dev;
1669 }
1670 err = 0;
1671 unregister_netdevice(dev);
1672 break;
1673 default:
1674 err = -EINVAL;
1675 }
1676 return err;
1677 }
1678
1679 /**
1680 * ip6_tnl_change_mtu - change mtu manually for tunnel device
1681 * @dev: virtual device associated with tunnel
1682 * @new_mtu: the new mtu
1683 *
1684 * Return:
1685 * 0 on success,
1686 * %-EINVAL if mtu too small
1687 **/
1688
ip6_tnl_change_mtu(struct net_device * dev,int new_mtu)1689 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1690 {
1691 struct ip6_tnl *tnl = netdev_priv(dev);
1692
1693 if (tnl->parms.proto == IPPROTO_IPV6) {
1694 if (new_mtu < IPV6_MIN_MTU)
1695 return -EINVAL;
1696 } else {
1697 if (new_mtu < ETH_MIN_MTU)
1698 return -EINVAL;
1699 }
1700 if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1701 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1702 return -EINVAL;
1703 } else {
1704 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1705 return -EINVAL;
1706 }
1707 dev->mtu = new_mtu;
1708 return 0;
1709 }
1710 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1711
ip6_tnl_get_iflink(const struct net_device * dev)1712 int ip6_tnl_get_iflink(const struct net_device *dev)
1713 {
1714 struct ip6_tnl *t = netdev_priv(dev);
1715
1716 return t->parms.link;
1717 }
1718 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1719
ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1720 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1721 unsigned int num)
1722 {
1723 if (num >= MAX_IPTUN_ENCAP_OPS)
1724 return -ERANGE;
1725
1726 return !cmpxchg((const struct ip6_tnl_encap_ops **)
1727 &ip6tun_encaps[num],
1728 NULL, ops) ? 0 : -1;
1729 }
1730 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1731
ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops * ops,unsigned int num)1732 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1733 unsigned int num)
1734 {
1735 int ret;
1736
1737 if (num >= MAX_IPTUN_ENCAP_OPS)
1738 return -ERANGE;
1739
1740 ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1741 &ip6tun_encaps[num],
1742 ops, NULL) == ops) ? 0 : -1;
1743
1744 synchronize_net();
1745
1746 return ret;
1747 }
1748 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1749
ip6_tnl_encap_setup(struct ip6_tnl * t,struct ip_tunnel_encap * ipencap)1750 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1751 struct ip_tunnel_encap *ipencap)
1752 {
1753 int hlen;
1754
1755 memset(&t->encap, 0, sizeof(t->encap));
1756
1757 hlen = ip6_encap_hlen(ipencap);
1758 if (hlen < 0)
1759 return hlen;
1760
1761 t->encap.type = ipencap->type;
1762 t->encap.sport = ipencap->sport;
1763 t->encap.dport = ipencap->dport;
1764 t->encap.flags = ipencap->flags;
1765
1766 t->encap_hlen = hlen;
1767 t->hlen = t->encap_hlen + t->tun_hlen;
1768
1769 return 0;
1770 }
1771 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1772
1773 static const struct net_device_ops ip6_tnl_netdev_ops = {
1774 .ndo_init = ip6_tnl_dev_init,
1775 .ndo_uninit = ip6_tnl_dev_uninit,
1776 .ndo_start_xmit = ip6_tnl_start_xmit,
1777 .ndo_do_ioctl = ip6_tnl_ioctl,
1778 .ndo_change_mtu = ip6_tnl_change_mtu,
1779 .ndo_get_stats = ip6_get_stats,
1780 .ndo_get_iflink = ip6_tnl_get_iflink,
1781 };
1782
1783 #define IPXIPX_FEATURES (NETIF_F_SG | \
1784 NETIF_F_FRAGLIST | \
1785 NETIF_F_HIGHDMA | \
1786 NETIF_F_GSO_SOFTWARE | \
1787 NETIF_F_HW_CSUM)
1788
1789 /**
1790 * ip6_tnl_dev_setup - setup virtual tunnel device
1791 * @dev: virtual device associated with tunnel
1792 *
1793 * Description:
1794 * Initialize function pointers and device parameters
1795 **/
1796
ip6_tnl_dev_setup(struct net_device * dev)1797 static void ip6_tnl_dev_setup(struct net_device *dev)
1798 {
1799 dev->netdev_ops = &ip6_tnl_netdev_ops;
1800 dev->needs_free_netdev = true;
1801 dev->priv_destructor = ip6_dev_free;
1802
1803 dev->type = ARPHRD_TUNNEL6;
1804 dev->flags |= IFF_NOARP;
1805 dev->addr_len = sizeof(struct in6_addr);
1806 dev->features |= NETIF_F_LLTX;
1807 netif_keep_dst(dev);
1808
1809 dev->features |= IPXIPX_FEATURES;
1810 dev->hw_features |= IPXIPX_FEATURES;
1811
1812 /* This perm addr will be used as interface identifier by IPv6 */
1813 dev->addr_assign_type = NET_ADDR_RANDOM;
1814 eth_random_addr(dev->perm_addr);
1815 }
1816
1817
1818 /**
1819 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1820 * @dev: virtual device associated with tunnel
1821 **/
1822
1823 static inline int
ip6_tnl_dev_init_gen(struct net_device * dev)1824 ip6_tnl_dev_init_gen(struct net_device *dev)
1825 {
1826 struct ip6_tnl *t = netdev_priv(dev);
1827 int ret;
1828 int t_hlen;
1829
1830 t->dev = dev;
1831 t->net = dev_net(dev);
1832 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1833 if (!dev->tstats)
1834 return -ENOMEM;
1835
1836 ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1837 if (ret)
1838 goto free_stats;
1839
1840 ret = gro_cells_init(&t->gro_cells, dev);
1841 if (ret)
1842 goto destroy_dst;
1843
1844 t->tun_hlen = 0;
1845 t->hlen = t->encap_hlen + t->tun_hlen;
1846 t_hlen = t->hlen + sizeof(struct ipv6hdr);
1847
1848 dev->type = ARPHRD_TUNNEL6;
1849 dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1850 dev->mtu = ETH_DATA_LEN - t_hlen;
1851 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1852 dev->mtu -= 8;
1853 dev->min_mtu = ETH_MIN_MTU;
1854 dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1855
1856 return 0;
1857
1858 destroy_dst:
1859 dst_cache_destroy(&t->dst_cache);
1860 free_stats:
1861 free_percpu(dev->tstats);
1862 dev->tstats = NULL;
1863
1864 return ret;
1865 }
1866
1867 /**
1868 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1869 * @dev: virtual device associated with tunnel
1870 **/
1871
ip6_tnl_dev_init(struct net_device * dev)1872 static int ip6_tnl_dev_init(struct net_device *dev)
1873 {
1874 struct ip6_tnl *t = netdev_priv(dev);
1875 int err = ip6_tnl_dev_init_gen(dev);
1876
1877 if (err)
1878 return err;
1879 ip6_tnl_link_config(t);
1880 if (t->parms.collect_md)
1881 netif_keep_dst(dev);
1882 return 0;
1883 }
1884
1885 /**
1886 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1887 * @dev: fallback device
1888 *
1889 * Return: 0
1890 **/
1891
ip6_fb_tnl_dev_init(struct net_device * dev)1892 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1893 {
1894 struct ip6_tnl *t = netdev_priv(dev);
1895 struct net *net = dev_net(dev);
1896 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1897
1898 t->parms.proto = IPPROTO_IPV6;
1899 dev_hold(dev);
1900
1901 rcu_assign_pointer(ip6n->tnls_wc[0], t);
1902 return 0;
1903 }
1904
ip6_tnl_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1905 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1906 struct netlink_ext_ack *extack)
1907 {
1908 u8 proto;
1909
1910 if (!data || !data[IFLA_IPTUN_PROTO])
1911 return 0;
1912
1913 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1914 if (proto != IPPROTO_IPV6 &&
1915 proto != IPPROTO_IPIP &&
1916 proto != 0)
1917 return -EINVAL;
1918
1919 return 0;
1920 }
1921
ip6_tnl_netlink_parms(struct nlattr * data[],struct __ip6_tnl_parm * parms)1922 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1923 struct __ip6_tnl_parm *parms)
1924 {
1925 memset(parms, 0, sizeof(*parms));
1926
1927 if (!data)
1928 return;
1929
1930 if (data[IFLA_IPTUN_LINK])
1931 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1932
1933 if (data[IFLA_IPTUN_LOCAL])
1934 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1935
1936 if (data[IFLA_IPTUN_REMOTE])
1937 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1938
1939 if (data[IFLA_IPTUN_TTL])
1940 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1941
1942 if (data[IFLA_IPTUN_ENCAP_LIMIT])
1943 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1944
1945 if (data[IFLA_IPTUN_FLOWINFO])
1946 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1947
1948 if (data[IFLA_IPTUN_FLAGS])
1949 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1950
1951 if (data[IFLA_IPTUN_PROTO])
1952 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1953
1954 if (data[IFLA_IPTUN_COLLECT_METADATA])
1955 parms->collect_md = true;
1956
1957 if (data[IFLA_IPTUN_FWMARK])
1958 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1959 }
1960
ip6_tnl_netlink_encap_parms(struct nlattr * data[],struct ip_tunnel_encap * ipencap)1961 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1962 struct ip_tunnel_encap *ipencap)
1963 {
1964 bool ret = false;
1965
1966 memset(ipencap, 0, sizeof(*ipencap));
1967
1968 if (!data)
1969 return ret;
1970
1971 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1972 ret = true;
1973 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1974 }
1975
1976 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1977 ret = true;
1978 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1979 }
1980
1981 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1982 ret = true;
1983 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1984 }
1985
1986 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1987 ret = true;
1988 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1989 }
1990
1991 return ret;
1992 }
1993
ip6_tnl_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1994 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1995 struct nlattr *tb[], struct nlattr *data[],
1996 struct netlink_ext_ack *extack)
1997 {
1998 struct net *net = dev_net(dev);
1999 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2000 struct ip_tunnel_encap ipencap;
2001 struct ip6_tnl *nt, *t;
2002 int err;
2003
2004 nt = netdev_priv(dev);
2005
2006 if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2007 err = ip6_tnl_encap_setup(nt, &ipencap);
2008 if (err < 0)
2009 return err;
2010 }
2011
2012 ip6_tnl_netlink_parms(data, &nt->parms);
2013
2014 if (nt->parms.collect_md) {
2015 if (rtnl_dereference(ip6n->collect_md_tun))
2016 return -EEXIST;
2017 } else {
2018 t = ip6_tnl_locate(net, &nt->parms, 0);
2019 if (!IS_ERR(t))
2020 return -EEXIST;
2021 }
2022
2023 err = ip6_tnl_create2(dev);
2024 if (!err && tb[IFLA_MTU])
2025 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2026
2027 return err;
2028 }
2029
ip6_tnl_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)2030 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2031 struct nlattr *data[],
2032 struct netlink_ext_ack *extack)
2033 {
2034 struct ip6_tnl *t = netdev_priv(dev);
2035 struct __ip6_tnl_parm p;
2036 struct net *net = t->net;
2037 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2038 struct ip_tunnel_encap ipencap;
2039
2040 if (dev == ip6n->fb_tnl_dev)
2041 return -EINVAL;
2042
2043 if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2044 int err = ip6_tnl_encap_setup(t, &ipencap);
2045
2046 if (err < 0)
2047 return err;
2048 }
2049 ip6_tnl_netlink_parms(data, &p);
2050 if (p.collect_md)
2051 return -EINVAL;
2052
2053 t = ip6_tnl_locate(net, &p, 0);
2054 if (!IS_ERR(t)) {
2055 if (t->dev != dev)
2056 return -EEXIST;
2057 } else
2058 t = netdev_priv(dev);
2059
2060 return ip6_tnl_update(t, &p);
2061 }
2062
ip6_tnl_dellink(struct net_device * dev,struct list_head * head)2063 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2064 {
2065 struct net *net = dev_net(dev);
2066 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2067
2068 if (dev != ip6n->fb_tnl_dev)
2069 unregister_netdevice_queue(dev, head);
2070 }
2071
ip6_tnl_get_size(const struct net_device * dev)2072 static size_t ip6_tnl_get_size(const struct net_device *dev)
2073 {
2074 return
2075 /* IFLA_IPTUN_LINK */
2076 nla_total_size(4) +
2077 /* IFLA_IPTUN_LOCAL */
2078 nla_total_size(sizeof(struct in6_addr)) +
2079 /* IFLA_IPTUN_REMOTE */
2080 nla_total_size(sizeof(struct in6_addr)) +
2081 /* IFLA_IPTUN_TTL */
2082 nla_total_size(1) +
2083 /* IFLA_IPTUN_ENCAP_LIMIT */
2084 nla_total_size(1) +
2085 /* IFLA_IPTUN_FLOWINFO */
2086 nla_total_size(4) +
2087 /* IFLA_IPTUN_FLAGS */
2088 nla_total_size(4) +
2089 /* IFLA_IPTUN_PROTO */
2090 nla_total_size(1) +
2091 /* IFLA_IPTUN_ENCAP_TYPE */
2092 nla_total_size(2) +
2093 /* IFLA_IPTUN_ENCAP_FLAGS */
2094 nla_total_size(2) +
2095 /* IFLA_IPTUN_ENCAP_SPORT */
2096 nla_total_size(2) +
2097 /* IFLA_IPTUN_ENCAP_DPORT */
2098 nla_total_size(2) +
2099 /* IFLA_IPTUN_COLLECT_METADATA */
2100 nla_total_size(0) +
2101 /* IFLA_IPTUN_FWMARK */
2102 nla_total_size(4) +
2103 0;
2104 }
2105
ip6_tnl_fill_info(struct sk_buff * skb,const struct net_device * dev)2106 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2107 {
2108 struct ip6_tnl *tunnel = netdev_priv(dev);
2109 struct __ip6_tnl_parm *parm = &tunnel->parms;
2110
2111 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2112 nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2113 nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2114 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2115 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2116 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2117 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2118 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2119 nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2120 goto nla_put_failure;
2121
2122 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2123 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2124 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2125 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2126 goto nla_put_failure;
2127
2128 if (parm->collect_md)
2129 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2130 goto nla_put_failure;
2131
2132 return 0;
2133
2134 nla_put_failure:
2135 return -EMSGSIZE;
2136 }
2137
ip6_tnl_get_link_net(const struct net_device * dev)2138 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2139 {
2140 struct ip6_tnl *tunnel = netdev_priv(dev);
2141
2142 return tunnel->net;
2143 }
2144 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2145
2146 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2147 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
2148 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) },
2149 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) },
2150 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
2151 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 },
2152 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 },
2153 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 },
2154 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
2155 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
2156 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
2157 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
2158 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
2159 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
2160 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
2161 };
2162
2163 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2164 .kind = "ip6tnl",
2165 .maxtype = IFLA_IPTUN_MAX,
2166 .policy = ip6_tnl_policy,
2167 .priv_size = sizeof(struct ip6_tnl),
2168 .setup = ip6_tnl_dev_setup,
2169 .validate = ip6_tnl_validate,
2170 .newlink = ip6_tnl_newlink,
2171 .changelink = ip6_tnl_changelink,
2172 .dellink = ip6_tnl_dellink,
2173 .get_size = ip6_tnl_get_size,
2174 .fill_info = ip6_tnl_fill_info,
2175 .get_link_net = ip6_tnl_get_link_net,
2176 };
2177
2178 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2179 .handler = ip4ip6_rcv,
2180 .err_handler = ip4ip6_err,
2181 .priority = 1,
2182 };
2183
2184 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2185 .handler = ip6ip6_rcv,
2186 .err_handler = ip6ip6_err,
2187 .priority = 1,
2188 };
2189
ip6_tnl_destroy_tunnels(struct net * net,struct list_head * list)2190 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2191 {
2192 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2193 struct net_device *dev, *aux;
2194 int h;
2195 struct ip6_tnl *t;
2196
2197 for_each_netdev_safe(net, dev, aux)
2198 if (dev->rtnl_link_ops == &ip6_link_ops)
2199 unregister_netdevice_queue(dev, list);
2200
2201 for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2202 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2203 while (t) {
2204 /* If dev is in the same netns, it has already
2205 * been added to the list by the previous loop.
2206 */
2207 if (!net_eq(dev_net(t->dev), net))
2208 unregister_netdevice_queue(t->dev, list);
2209 t = rtnl_dereference(t->next);
2210 }
2211 }
2212 }
2213
ip6_tnl_init_net(struct net * net)2214 static int __net_init ip6_tnl_init_net(struct net *net)
2215 {
2216 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2217 struct ip6_tnl *t = NULL;
2218 int err;
2219
2220 ip6n->tnls[0] = ip6n->tnls_wc;
2221 ip6n->tnls[1] = ip6n->tnls_r_l;
2222
2223 if (!net_has_fallback_tunnels(net))
2224 return 0;
2225 err = -ENOMEM;
2226 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2227 NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2228
2229 if (!ip6n->fb_tnl_dev)
2230 goto err_alloc_dev;
2231 dev_net_set(ip6n->fb_tnl_dev, net);
2232 ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2233 /* FB netdevice is special: we have one, and only one per netns.
2234 * Allowing to move it to another netns is clearly unsafe.
2235 */
2236 ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2237
2238 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2239 if (err < 0)
2240 goto err_register;
2241
2242 err = register_netdev(ip6n->fb_tnl_dev);
2243 if (err < 0)
2244 goto err_register;
2245
2246 t = netdev_priv(ip6n->fb_tnl_dev);
2247
2248 strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2249 return 0;
2250
2251 err_register:
2252 free_netdev(ip6n->fb_tnl_dev);
2253 err_alloc_dev:
2254 return err;
2255 }
2256
ip6_tnl_exit_batch_net(struct list_head * net_list)2257 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2258 {
2259 struct net *net;
2260 LIST_HEAD(list);
2261
2262 rtnl_lock();
2263 list_for_each_entry(net, net_list, exit_list)
2264 ip6_tnl_destroy_tunnels(net, &list);
2265 unregister_netdevice_many(&list);
2266 rtnl_unlock();
2267 }
2268
2269 static struct pernet_operations ip6_tnl_net_ops = {
2270 .init = ip6_tnl_init_net,
2271 .exit_batch = ip6_tnl_exit_batch_net,
2272 .id = &ip6_tnl_net_id,
2273 .size = sizeof(struct ip6_tnl_net),
2274 };
2275
2276 /**
2277 * ip6_tunnel_init - register protocol and reserve needed resources
2278 *
2279 * Return: 0 on success
2280 **/
2281
ip6_tunnel_init(void)2282 static int __init ip6_tunnel_init(void)
2283 {
2284 int err;
2285
2286 if (!ipv6_mod_enabled())
2287 return -EOPNOTSUPP;
2288
2289 err = register_pernet_device(&ip6_tnl_net_ops);
2290 if (err < 0)
2291 goto out_pernet;
2292
2293 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2294 if (err < 0) {
2295 pr_err("%s: can't register ip4ip6\n", __func__);
2296 goto out_ip4ip6;
2297 }
2298
2299 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2300 if (err < 0) {
2301 pr_err("%s: can't register ip6ip6\n", __func__);
2302 goto out_ip6ip6;
2303 }
2304 err = rtnl_link_register(&ip6_link_ops);
2305 if (err < 0)
2306 goto rtnl_link_failed;
2307
2308 return 0;
2309
2310 rtnl_link_failed:
2311 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2312 out_ip6ip6:
2313 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2314 out_ip4ip6:
2315 unregister_pernet_device(&ip6_tnl_net_ops);
2316 out_pernet:
2317 return err;
2318 }
2319
2320 /**
2321 * ip6_tunnel_cleanup - free resources and unregister protocol
2322 **/
2323
ip6_tunnel_cleanup(void)2324 static void __exit ip6_tunnel_cleanup(void)
2325 {
2326 rtnl_link_unregister(&ip6_link_ops);
2327 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2328 pr_info("%s: can't deregister ip4ip6\n", __func__);
2329
2330 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2331 pr_info("%s: can't deregister ip6ip6\n", __func__);
2332
2333 unregister_pernet_device(&ip6_tnl_net_ops);
2334 }
2335
2336 module_init(ip6_tunnel_init);
2337 module_exit(ip6_tunnel_cleanup);
2338