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Linux/net/ipv6/ip6_tunnel.c

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  1 /*
  2  *      IPv6 tunneling device
  3  *      Linux INET6 implementation
  4  *
  5  *      Authors:
  6  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
  7  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
  8  *
  9  *      Based on:
 10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
 11  *
 12  *      RFC 2473
 13  *
 14  *      This program is free software; you can redistribute it and/or
 15  *      modify it under the terms of the GNU General Public License
 16  *      as published by the Free Software Foundation; either version
 17  *      2 of the License, or (at your option) any later version.
 18  *
 19  */
 20 
 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 22 
 23 #include <linux/module.h>
 24 #include <linux/capability.h>
 25 #include <linux/errno.h>
 26 #include <linux/types.h>
 27 #include <linux/sockios.h>
 28 #include <linux/icmp.h>
 29 #include <linux/if.h>
 30 #include <linux/in.h>
 31 #include <linux/ip.h>
 32 #include <linux/net.h>
 33 #include <linux/in6.h>
 34 #include <linux/netdevice.h>
 35 #include <linux/if_arp.h>
 36 #include <linux/icmpv6.h>
 37 #include <linux/init.h>
 38 #include <linux/route.h>
 39 #include <linux/rtnetlink.h>
 40 #include <linux/netfilter_ipv6.h>
 41 #include <linux/slab.h>
 42 #include <linux/hash.h>
 43 #include <linux/etherdevice.h>
 44 
 45 #include <linux/uaccess.h>
 46 #include <linux/atomic.h>
 47 
 48 #include <net/icmp.h>
 49 #include <net/ip.h>
 50 #include <net/ip_tunnels.h>
 51 #include <net/ipv6.h>
 52 #include <net/ip6_route.h>
 53 #include <net/addrconf.h>
 54 #include <net/ip6_tunnel.h>
 55 #include <net/xfrm.h>
 56 #include <net/dsfield.h>
 57 #include <net/inet_ecn.h>
 58 #include <net/net_namespace.h>
 59 #include <net/netns/generic.h>
 60 #include <net/dst_metadata.h>
 61 
 62 MODULE_AUTHOR("Ville Nuorvala");
 63 MODULE_DESCRIPTION("IPv6 tunneling device");
 64 MODULE_LICENSE("GPL");
 65 MODULE_ALIAS_RTNL_LINK("ip6tnl");
 66 MODULE_ALIAS_NETDEV("ip6tnl0");
 67 
 68 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
 69 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
 70 
 71 static bool log_ecn_error = true;
 72 module_param(log_ecn_error, bool, 0644);
 73 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 74 
 75 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
 76 {
 77         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
 78 
 79         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
 80 }
 81 
 82 static int ip6_tnl_dev_init(struct net_device *dev);
 83 static void ip6_tnl_dev_setup(struct net_device *dev);
 84 static struct rtnl_link_ops ip6_link_ops __read_mostly;
 85 
 86 static unsigned int ip6_tnl_net_id __read_mostly;
 87 struct ip6_tnl_net {
 88         /* the IPv6 tunnel fallback device */
 89         struct net_device *fb_tnl_dev;
 90         /* lists for storing tunnels in use */
 91         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
 92         struct ip6_tnl __rcu *tnls_wc[1];
 93         struct ip6_tnl __rcu **tnls[2];
 94         struct ip6_tnl __rcu *collect_md_tun;
 95 };
 96 
 97 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
 98 {
 99         struct pcpu_sw_netstats tmp, sum = { 0 };
100         int i;
101 
102         for_each_possible_cpu(i) {
103                 unsigned int start;
104                 const struct pcpu_sw_netstats *tstats =
105                                                    per_cpu_ptr(dev->tstats, i);
106 
107                 do {
108                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
109                         tmp.rx_packets = tstats->rx_packets;
110                         tmp.rx_bytes = tstats->rx_bytes;
111                         tmp.tx_packets = tstats->tx_packets;
112                         tmp.tx_bytes =  tstats->tx_bytes;
113                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
114 
115                 sum.rx_packets += tmp.rx_packets;
116                 sum.rx_bytes   += tmp.rx_bytes;
117                 sum.tx_packets += tmp.tx_packets;
118                 sum.tx_bytes   += tmp.tx_bytes;
119         }
120         dev->stats.rx_packets = sum.rx_packets;
121         dev->stats.rx_bytes   = sum.rx_bytes;
122         dev->stats.tx_packets = sum.tx_packets;
123         dev->stats.tx_bytes   = sum.tx_bytes;
124         return &dev->stats;
125 }
126 
127 /**
128  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
129  *   @remote: the address of the tunnel exit-point
130  *   @local: the address of the tunnel entry-point
131  *
132  * Return:
133  *   tunnel matching given end-points if found,
134  *   else fallback tunnel if its device is up,
135  *   else %NULL
136  **/
137 
138 #define for_each_ip6_tunnel_rcu(start) \
139         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
140 
141 static struct ip6_tnl *
142 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
143 {
144         unsigned int hash = HASH(remote, local);
145         struct ip6_tnl *t;
146         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
147         struct in6_addr any;
148 
149         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
150                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
151                     ipv6_addr_equal(remote, &t->parms.raddr) &&
152                     (t->dev->flags & IFF_UP))
153                         return t;
154         }
155 
156         memset(&any, 0, sizeof(any));
157         hash = HASH(&any, local);
158         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
159                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
160                     ipv6_addr_any(&t->parms.raddr) &&
161                     (t->dev->flags & IFF_UP))
162                         return t;
163         }
164 
165         hash = HASH(remote, &any);
166         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
167                 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
168                     ipv6_addr_any(&t->parms.laddr) &&
169                     (t->dev->flags & IFF_UP))
170                         return t;
171         }
172 
173         t = rcu_dereference(ip6n->collect_md_tun);
174         if (t)
175                 return t;
176 
177         t = rcu_dereference(ip6n->tnls_wc[0]);
178         if (t && (t->dev->flags & IFF_UP))
179                 return t;
180 
181         return NULL;
182 }
183 
184 /**
185  * ip6_tnl_bucket - get head of list matching given tunnel parameters
186  *   @p: parameters containing tunnel end-points
187  *
188  * Description:
189  *   ip6_tnl_bucket() returns the head of the list matching the
190  *   &struct in6_addr entries laddr and raddr in @p.
191  *
192  * Return: head of IPv6 tunnel list
193  **/
194 
195 static struct ip6_tnl __rcu **
196 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
197 {
198         const struct in6_addr *remote = &p->raddr;
199         const struct in6_addr *local = &p->laddr;
200         unsigned int h = 0;
201         int prio = 0;
202 
203         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
204                 prio = 1;
205                 h = HASH(remote, local);
206         }
207         return &ip6n->tnls[prio][h];
208 }
209 
210 /**
211  * ip6_tnl_link - add tunnel to hash table
212  *   @t: tunnel to be added
213  **/
214 
215 static void
216 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
217 {
218         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
219 
220         if (t->parms.collect_md)
221                 rcu_assign_pointer(ip6n->collect_md_tun, t);
222         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
223         rcu_assign_pointer(*tp, t);
224 }
225 
226 /**
227  * ip6_tnl_unlink - remove tunnel from hash table
228  *   @t: tunnel to be removed
229  **/
230 
231 static void
232 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
233 {
234         struct ip6_tnl __rcu **tp;
235         struct ip6_tnl *iter;
236 
237         if (t->parms.collect_md)
238                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
239 
240         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
241              (iter = rtnl_dereference(*tp)) != NULL;
242              tp = &iter->next) {
243                 if (t == iter) {
244                         rcu_assign_pointer(*tp, t->next);
245                         break;
246                 }
247         }
248 }
249 
250 static void ip6_dev_free(struct net_device *dev)
251 {
252         struct ip6_tnl *t = netdev_priv(dev);
253 
254         gro_cells_destroy(&t->gro_cells);
255         dst_cache_destroy(&t->dst_cache);
256         free_percpu(dev->tstats);
257 }
258 
259 static int ip6_tnl_create2(struct net_device *dev)
260 {
261         struct ip6_tnl *t = netdev_priv(dev);
262         struct net *net = dev_net(dev);
263         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
264         int err;
265 
266         t = netdev_priv(dev);
267 
268         dev->rtnl_link_ops = &ip6_link_ops;
269         err = register_netdevice(dev);
270         if (err < 0)
271                 goto out;
272 
273         strcpy(t->parms.name, dev->name);
274 
275         dev_hold(dev);
276         ip6_tnl_link(ip6n, t);
277         return 0;
278 
279 out:
280         return err;
281 }
282 
283 /**
284  * ip6_tnl_create - create a new tunnel
285  *   @p: tunnel parameters
286  *   @pt: pointer to new tunnel
287  *
288  * Description:
289  *   Create tunnel matching given parameters.
290  *
291  * Return:
292  *   created tunnel or error pointer
293  **/
294 
295 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
296 {
297         struct net_device *dev;
298         struct ip6_tnl *t;
299         char name[IFNAMSIZ];
300         int err = -ENOMEM;
301 
302         if (p->name[0])
303                 strlcpy(name, p->name, IFNAMSIZ);
304         else
305                 sprintf(name, "ip6tnl%%d");
306 
307         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
308                            ip6_tnl_dev_setup);
309         if (!dev)
310                 goto failed;
311 
312         dev_net_set(dev, net);
313 
314         t = netdev_priv(dev);
315         t->parms = *p;
316         t->net = dev_net(dev);
317         err = ip6_tnl_create2(dev);
318         if (err < 0)
319                 goto failed_free;
320 
321         return t;
322 
323 failed_free:
324         free_netdev(dev);
325 failed:
326         return ERR_PTR(err);
327 }
328 
329 /**
330  * ip6_tnl_locate - find or create tunnel matching given parameters
331  *   @p: tunnel parameters
332  *   @create: != 0 if allowed to create new tunnel if no match found
333  *
334  * Description:
335  *   ip6_tnl_locate() first tries to locate an existing tunnel
336  *   based on @parms. If this is unsuccessful, but @create is set a new
337  *   tunnel device is created and registered for use.
338  *
339  * Return:
340  *   matching tunnel or error pointer
341  **/
342 
343 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
344                 struct __ip6_tnl_parm *p, int create)
345 {
346         const struct in6_addr *remote = &p->raddr;
347         const struct in6_addr *local = &p->laddr;
348         struct ip6_tnl __rcu **tp;
349         struct ip6_tnl *t;
350         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
351 
352         for (tp = ip6_tnl_bucket(ip6n, p);
353              (t = rtnl_dereference(*tp)) != NULL;
354              tp = &t->next) {
355                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
356                     ipv6_addr_equal(remote, &t->parms.raddr)) {
357                         if (create)
358                                 return ERR_PTR(-EEXIST);
359 
360                         return t;
361                 }
362         }
363         if (!create)
364                 return ERR_PTR(-ENODEV);
365         return ip6_tnl_create(net, p);
366 }
367 
368 /**
369  * ip6_tnl_dev_uninit - tunnel device uninitializer
370  *   @dev: the device to be destroyed
371  *
372  * Description:
373  *   ip6_tnl_dev_uninit() removes tunnel from its list
374  **/
375 
376 static void
377 ip6_tnl_dev_uninit(struct net_device *dev)
378 {
379         struct ip6_tnl *t = netdev_priv(dev);
380         struct net *net = t->net;
381         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
382 
383         if (dev == ip6n->fb_tnl_dev)
384                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
385         else
386                 ip6_tnl_unlink(ip6n, t);
387         dst_cache_reset(&t->dst_cache);
388         dev_put(dev);
389 }
390 
391 /**
392  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
393  *   @skb: received socket buffer
394  *
395  * Return:
396  *   0 if none was found,
397  *   else index to encapsulation limit
398  **/
399 
400 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
401 {
402         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
403         unsigned int nhoff = raw - skb->data;
404         unsigned int off = nhoff + sizeof(*ipv6h);
405         u8 next, nexthdr = ipv6h->nexthdr;
406 
407         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
408                 struct ipv6_opt_hdr *hdr;
409                 u16 optlen;
410 
411                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
412                         break;
413 
414                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
415                 if (nexthdr == NEXTHDR_FRAGMENT) {
416                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
417                         if (frag_hdr->frag_off)
418                                 break;
419                         optlen = 8;
420                 } else if (nexthdr == NEXTHDR_AUTH) {
421                         optlen = (hdr->hdrlen + 2) << 2;
422                 } else {
423                         optlen = ipv6_optlen(hdr);
424                 }
425                 /* cache hdr->nexthdr, since pskb_may_pull() might
426                  * invalidate hdr
427                  */
428                 next = hdr->nexthdr;
429                 if (nexthdr == NEXTHDR_DEST) {
430                         u16 i = 2;
431 
432                         /* Remember : hdr is no longer valid at this point. */
433                         if (!pskb_may_pull(skb, off + optlen))
434                                 break;
435 
436                         while (1) {
437                                 struct ipv6_tlv_tnl_enc_lim *tel;
438 
439                                 /* No more room for encapsulation limit */
440                                 if (i + sizeof(*tel) > optlen)
441                                         break;
442 
443                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
444                                 /* return index of option if found and valid */
445                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
446                                     tel->length == 1)
447                                         return i + off - nhoff;
448                                 /* else jump to next option */
449                                 if (tel->type)
450                                         i += tel->length + 2;
451                                 else
452                                         i++;
453                         }
454                 }
455                 nexthdr = next;
456                 off += optlen;
457         }
458         return 0;
459 }
460 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
461 
462 /**
463  * ip6_tnl_err - tunnel error handler
464  *
465  * Description:
466  *   ip6_tnl_err() should handle errors in the tunnel according
467  *   to the specifications in RFC 2473.
468  **/
469 
470 static int
471 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
472             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
473 {
474         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
475         struct ip6_tnl *t;
476         int rel_msg = 0;
477         u8 rel_type = ICMPV6_DEST_UNREACH;
478         u8 rel_code = ICMPV6_ADDR_UNREACH;
479         u8 tproto;
480         __u32 rel_info = 0;
481         __u16 len;
482         int err = -ENOENT;
483 
484         /* If the packet doesn't contain the original IPv6 header we are
485            in trouble since we might need the source address for further
486            processing of the error. */
487 
488         rcu_read_lock();
489         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
490         if (!t)
491                 goto out;
492 
493         tproto = ACCESS_ONCE(t->parms.proto);
494         if (tproto != ipproto && tproto != 0)
495                 goto out;
496 
497         err = 0;
498 
499         switch (*type) {
500                 __u32 teli;
501                 struct ipv6_tlv_tnl_enc_lim *tel;
502                 __u32 mtu;
503         case ICMPV6_DEST_UNREACH:
504                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
505                                     t->parms.name);
506                 rel_msg = 1;
507                 break;
508         case ICMPV6_TIME_EXCEED:
509                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
510                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
511                                             t->parms.name);
512                         rel_msg = 1;
513                 }
514                 break;
515         case ICMPV6_PARAMPROB:
516                 teli = 0;
517                 if ((*code) == ICMPV6_HDR_FIELD)
518                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
519 
520                 if (teli && teli == *info - 2) {
521                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
522                         if (tel->encap_limit == 0) {
523                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
524                                                     t->parms.name);
525                                 rel_msg = 1;
526                         }
527                 } else {
528                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
529                                             t->parms.name);
530                 }
531                 break;
532         case ICMPV6_PKT_TOOBIG:
533                 mtu = *info - offset;
534                 if (mtu < IPV6_MIN_MTU)
535                         mtu = IPV6_MIN_MTU;
536                 t->dev->mtu = mtu;
537 
538                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
539                 if (len > mtu) {
540                         rel_type = ICMPV6_PKT_TOOBIG;
541                         rel_code = 0;
542                         rel_info = mtu;
543                         rel_msg = 1;
544                 }
545                 break;
546         }
547 
548         *type = rel_type;
549         *code = rel_code;
550         *info = rel_info;
551         *msg = rel_msg;
552 
553 out:
554         rcu_read_unlock();
555         return err;
556 }
557 
558 static int
559 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
560            u8 type, u8 code, int offset, __be32 info)
561 {
562         int rel_msg = 0;
563         u8 rel_type = type;
564         u8 rel_code = code;
565         __u32 rel_info = ntohl(info);
566         int err;
567         struct sk_buff *skb2;
568         const struct iphdr *eiph;
569         struct rtable *rt;
570         struct flowi4 fl4;
571 
572         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
573                           &rel_msg, &rel_info, offset);
574         if (err < 0)
575                 return err;
576 
577         if (rel_msg == 0)
578                 return 0;
579 
580         switch (rel_type) {
581         case ICMPV6_DEST_UNREACH:
582                 if (rel_code != ICMPV6_ADDR_UNREACH)
583                         return 0;
584                 rel_type = ICMP_DEST_UNREACH;
585                 rel_code = ICMP_HOST_UNREACH;
586                 break;
587         case ICMPV6_PKT_TOOBIG:
588                 if (rel_code != 0)
589                         return 0;
590                 rel_type = ICMP_DEST_UNREACH;
591                 rel_code = ICMP_FRAG_NEEDED;
592                 break;
593         case NDISC_REDIRECT:
594                 rel_type = ICMP_REDIRECT;
595                 rel_code = ICMP_REDIR_HOST;
596         default:
597                 return 0;
598         }
599 
600         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
601                 return 0;
602 
603         skb2 = skb_clone(skb, GFP_ATOMIC);
604         if (!skb2)
605                 return 0;
606 
607         skb_dst_drop(skb2);
608 
609         skb_pull(skb2, offset);
610         skb_reset_network_header(skb2);
611         eiph = ip_hdr(skb2);
612 
613         /* Try to guess incoming interface */
614         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
615                                    eiph->saddr, 0,
616                                    0, 0,
617                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
618         if (IS_ERR(rt))
619                 goto out;
620 
621         skb2->dev = rt->dst.dev;
622 
623         /* route "incoming" packet */
624         if (rt->rt_flags & RTCF_LOCAL) {
625                 ip_rt_put(rt);
626                 rt = NULL;
627                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
628                                            eiph->daddr, eiph->saddr,
629                                            0, 0,
630                                            IPPROTO_IPIP,
631                                            RT_TOS(eiph->tos), 0);
632                 if (IS_ERR(rt) ||
633                     rt->dst.dev->type != ARPHRD_TUNNEL) {
634                         if (!IS_ERR(rt))
635                                 ip_rt_put(rt);
636                         goto out;
637                 }
638                 skb_dst_set(skb2, &rt->dst);
639         } else {
640                 ip_rt_put(rt);
641                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
642                                    skb2->dev) ||
643                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
644                         goto out;
645         }
646 
647         /* change mtu on this route */
648         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
649                 if (rel_info > dst_mtu(skb_dst(skb2)))
650                         goto out;
651 
652                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
653         }
654         if (rel_type == ICMP_REDIRECT)
655                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
656 
657         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
658 
659 out:
660         kfree_skb(skb2);
661         return 0;
662 }
663 
664 static int
665 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
666            u8 type, u8 code, int offset, __be32 info)
667 {
668         int rel_msg = 0;
669         u8 rel_type = type;
670         u8 rel_code = code;
671         __u32 rel_info = ntohl(info);
672         int err;
673 
674         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
675                           &rel_msg, &rel_info, offset);
676         if (err < 0)
677                 return err;
678 
679         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
680                 struct rt6_info *rt;
681                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
682 
683                 if (!skb2)
684                         return 0;
685 
686                 skb_dst_drop(skb2);
687                 skb_pull(skb2, offset);
688                 skb_reset_network_header(skb2);
689 
690                 /* Try to guess incoming interface */
691                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
692                                 NULL, 0, 0);
693 
694                 if (rt && rt->dst.dev)
695                         skb2->dev = rt->dst.dev;
696 
697                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
698 
699                 ip6_rt_put(rt);
700 
701                 kfree_skb(skb2);
702         }
703 
704         return 0;
705 }
706 
707 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
708                                        const struct ipv6hdr *ipv6h,
709                                        struct sk_buff *skb)
710 {
711         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
712 
713         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
714                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
715 
716         return IP6_ECN_decapsulate(ipv6h, skb);
717 }
718 
719 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
720                                        const struct ipv6hdr *ipv6h,
721                                        struct sk_buff *skb)
722 {
723         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
724                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
725 
726         return IP6_ECN_decapsulate(ipv6h, skb);
727 }
728 
729 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
730                              const struct in6_addr *laddr,
731                              const struct in6_addr *raddr)
732 {
733         struct __ip6_tnl_parm *p = &t->parms;
734         int ltype = ipv6_addr_type(laddr);
735         int rtype = ipv6_addr_type(raddr);
736         __u32 flags = 0;
737 
738         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
739                 flags = IP6_TNL_F_CAP_PER_PACKET;
740         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
741                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
742                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
743                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
744                 if (ltype&IPV6_ADDR_UNICAST)
745                         flags |= IP6_TNL_F_CAP_XMIT;
746                 if (rtype&IPV6_ADDR_UNICAST)
747                         flags |= IP6_TNL_F_CAP_RCV;
748         }
749         return flags;
750 }
751 EXPORT_SYMBOL(ip6_tnl_get_cap);
752 
753 /* called with rcu_read_lock() */
754 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
755                                   const struct in6_addr *laddr,
756                                   const struct in6_addr *raddr)
757 {
758         struct __ip6_tnl_parm *p = &t->parms;
759         int ret = 0;
760         struct net *net = t->net;
761 
762         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
763             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
764              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
765                 struct net_device *ldev = NULL;
766 
767                 if (p->link)
768                         ldev = dev_get_by_index_rcu(net, p->link);
769 
770                 if ((ipv6_addr_is_multicast(laddr) ||
771                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
772                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
773                         ret = 1;
774         }
775         return ret;
776 }
777 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
778 
779 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
780                          const struct tnl_ptk_info *tpi,
781                          struct metadata_dst *tun_dst,
782                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
783                                                 const struct ipv6hdr *ipv6h,
784                                                 struct sk_buff *skb),
785                          bool log_ecn_err)
786 {
787         struct pcpu_sw_netstats *tstats;
788         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
789         int err;
790 
791         if ((!(tpi->flags & TUNNEL_CSUM) &&
792              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
793             ((tpi->flags & TUNNEL_CSUM) &&
794              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
795                 tunnel->dev->stats.rx_crc_errors++;
796                 tunnel->dev->stats.rx_errors++;
797                 goto drop;
798         }
799 
800         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
801                 if (!(tpi->flags & TUNNEL_SEQ) ||
802                     (tunnel->i_seqno &&
803                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
804                         tunnel->dev->stats.rx_fifo_errors++;
805                         tunnel->dev->stats.rx_errors++;
806                         goto drop;
807                 }
808                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
809         }
810 
811         skb->protocol = tpi->proto;
812 
813         /* Warning: All skb pointers will be invalidated! */
814         if (tunnel->dev->type == ARPHRD_ETHER) {
815                 if (!pskb_may_pull(skb, ETH_HLEN)) {
816                         tunnel->dev->stats.rx_length_errors++;
817                         tunnel->dev->stats.rx_errors++;
818                         goto drop;
819                 }
820 
821                 ipv6h = ipv6_hdr(skb);
822                 skb->protocol = eth_type_trans(skb, tunnel->dev);
823                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
824         } else {
825                 skb->dev = tunnel->dev;
826         }
827 
828         skb_reset_network_header(skb);
829         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
830 
831         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
832 
833         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
834         if (unlikely(err)) {
835                 if (log_ecn_err)
836                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
837                                              &ipv6h->saddr,
838                                              ipv6_get_dsfield(ipv6h));
839                 if (err > 1) {
840                         ++tunnel->dev->stats.rx_frame_errors;
841                         ++tunnel->dev->stats.rx_errors;
842                         goto drop;
843                 }
844         }
845 
846         tstats = this_cpu_ptr(tunnel->dev->tstats);
847         u64_stats_update_begin(&tstats->syncp);
848         tstats->rx_packets++;
849         tstats->rx_bytes += skb->len;
850         u64_stats_update_end(&tstats->syncp);
851 
852         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
853 
854         if (tun_dst)
855                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
856 
857         gro_cells_receive(&tunnel->gro_cells, skb);
858         return 0;
859 
860 drop:
861         if (tun_dst)
862                 dst_release((struct dst_entry *)tun_dst);
863         kfree_skb(skb);
864         return 0;
865 }
866 
867 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
868                 const struct tnl_ptk_info *tpi,
869                 struct metadata_dst *tun_dst,
870                 bool log_ecn_err)
871 {
872         return __ip6_tnl_rcv(t, skb, tpi, NULL, ip6ip6_dscp_ecn_decapsulate,
873                              log_ecn_err);
874 }
875 EXPORT_SYMBOL(ip6_tnl_rcv);
876 
877 static const struct tnl_ptk_info tpi_v6 = {
878         /* no tunnel info required for ipxip6. */
879         .proto = htons(ETH_P_IPV6),
880 };
881 
882 static const struct tnl_ptk_info tpi_v4 = {
883         /* no tunnel info required for ipxip6. */
884         .proto = htons(ETH_P_IP),
885 };
886 
887 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
888                       const struct tnl_ptk_info *tpi,
889                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
890                                                   const struct ipv6hdr *ipv6h,
891                                                   struct sk_buff *skb))
892 {
893         struct ip6_tnl *t;
894         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
895         struct metadata_dst *tun_dst = NULL;
896         int ret = -1;
897 
898         rcu_read_lock();
899         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
900 
901         if (t) {
902                 u8 tproto = ACCESS_ONCE(t->parms.proto);
903 
904                 if (tproto != ipproto && tproto != 0)
905                         goto drop;
906                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
907                         goto drop;
908                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
909                         goto drop;
910                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
911                         goto drop;
912                 if (t->parms.collect_md) {
913                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
914                         if (!tun_dst)
915                                 return 0;
916                 }
917                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
918                                     log_ecn_error);
919         }
920 
921         rcu_read_unlock();
922 
923         return ret;
924 
925 drop:
926         rcu_read_unlock();
927         kfree_skb(skb);
928         return 0;
929 }
930 
931 static int ip4ip6_rcv(struct sk_buff *skb)
932 {
933         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
934                           ip4ip6_dscp_ecn_decapsulate);
935 }
936 
937 static int ip6ip6_rcv(struct sk_buff *skb)
938 {
939         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
940                           ip6ip6_dscp_ecn_decapsulate);
941 }
942 
943 struct ipv6_tel_txoption {
944         struct ipv6_txoptions ops;
945         __u8 dst_opt[8];
946 };
947 
948 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
949 {
950         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
951 
952         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
953         opt->dst_opt[3] = 1;
954         opt->dst_opt[4] = encap_limit;
955         opt->dst_opt[5] = IPV6_TLV_PADN;
956         opt->dst_opt[6] = 1;
957 
958         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
959         opt->ops.opt_nflen = 8;
960 }
961 
962 /**
963  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
964  *   @t: the outgoing tunnel device
965  *   @hdr: IPv6 header from the incoming packet
966  *
967  * Description:
968  *   Avoid trivial tunneling loop by checking that tunnel exit-point
969  *   doesn't match source of incoming packet.
970  *
971  * Return:
972  *   1 if conflict,
973  *   0 else
974  **/
975 
976 static inline bool
977 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
978 {
979         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
980 }
981 
982 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
983                      const struct in6_addr *laddr,
984                      const struct in6_addr *raddr)
985 {
986         struct __ip6_tnl_parm *p = &t->parms;
987         int ret = 0;
988         struct net *net = t->net;
989 
990         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
991             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
992              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
993                 struct net_device *ldev = NULL;
994 
995                 rcu_read_lock();
996                 if (p->link)
997                         ldev = dev_get_by_index_rcu(net, p->link);
998 
999                 if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
1000                         pr_warn("%s xmit: Local address not yet configured!\n",
1001                                 p->name);
1002                 else if (!ipv6_addr_is_multicast(raddr) &&
1003                          unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
1004                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1005                                 p->name);
1006                 else
1007                         ret = 1;
1008                 rcu_read_unlock();
1009         }
1010         return ret;
1011 }
1012 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1013 
1014 /**
1015  * ip6_tnl_xmit - encapsulate packet and send
1016  *   @skb: the outgoing socket buffer
1017  *   @dev: the outgoing tunnel device
1018  *   @dsfield: dscp code for outer header
1019  *   @fl6: flow of tunneled packet
1020  *   @encap_limit: encapsulation limit
1021  *   @pmtu: Path MTU is stored if packet is too big
1022  *   @proto: next header value
1023  *
1024  * Description:
1025  *   Build new header and do some sanity checks on the packet before sending
1026  *   it.
1027  *
1028  * Return:
1029  *   0 on success
1030  *   -1 fail
1031  *   %-EMSGSIZE message too big. return mtu in this case.
1032  **/
1033 
1034 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1035                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1036                  __u8 proto)
1037 {
1038         struct ip6_tnl *t = netdev_priv(dev);
1039         struct net *net = t->net;
1040         struct net_device_stats *stats = &t->dev->stats;
1041         struct ipv6hdr *ipv6h;
1042         struct ipv6_tel_txoption opt;
1043         struct dst_entry *dst = NULL, *ndst = NULL;
1044         struct net_device *tdev;
1045         int mtu;
1046         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1047         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1048         unsigned int max_headroom = psh_hlen;
1049         bool use_cache = false;
1050         u8 hop_limit;
1051         int err = -1;
1052 
1053         if (t->parms.collect_md) {
1054                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1055                 goto route_lookup;
1056         } else {
1057                 hop_limit = t->parms.hop_limit;
1058         }
1059 
1060         /* NBMA tunnel */
1061         if (ipv6_addr_any(&t->parms.raddr)) {
1062                 if (skb->protocol == htons(ETH_P_IPV6)) {
1063                         struct in6_addr *addr6;
1064                         struct neighbour *neigh;
1065                         int addr_type;
1066 
1067                         if (!skb_dst(skb))
1068                                 goto tx_err_link_failure;
1069 
1070                         neigh = dst_neigh_lookup(skb_dst(skb),
1071                                                  &ipv6_hdr(skb)->daddr);
1072                         if (!neigh)
1073                                 goto tx_err_link_failure;
1074 
1075                         addr6 = (struct in6_addr *)&neigh->primary_key;
1076                         addr_type = ipv6_addr_type(addr6);
1077 
1078                         if (addr_type == IPV6_ADDR_ANY)
1079                                 addr6 = &ipv6_hdr(skb)->daddr;
1080 
1081                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1082                         neigh_release(neigh);
1083                 }
1084         } else if (!(t->parms.flags &
1085                      (IP6_TNL_F_USE_ORIG_TCLASS | IP6_TNL_F_USE_ORIG_FWMARK))) {
1086                 /* enable the cache only only if the routing decision does
1087                  * not depend on the current inner header value
1088                  */
1089                 use_cache = true;
1090         }
1091 
1092         if (use_cache)
1093                 dst = dst_cache_get(&t->dst_cache);
1094 
1095         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1096                 goto tx_err_link_failure;
1097 
1098         if (!dst) {
1099 route_lookup:
1100                 /* add dsfield to flowlabel for route lookup */
1101                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1102 
1103                 dst = ip6_route_output(net, NULL, fl6);
1104 
1105                 if (dst->error)
1106                         goto tx_err_link_failure;
1107                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1108                 if (IS_ERR(dst)) {
1109                         err = PTR_ERR(dst);
1110                         dst = NULL;
1111                         goto tx_err_link_failure;
1112                 }
1113                 if (t->parms.collect_md &&
1114                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1115                                        &fl6->daddr, 0, &fl6->saddr))
1116                         goto tx_err_link_failure;
1117                 ndst = dst;
1118         }
1119 
1120         tdev = dst->dev;
1121 
1122         if (tdev == dev) {
1123                 stats->collisions++;
1124                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1125                                      t->parms.name);
1126                 goto tx_err_dst_release;
1127         }
1128         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1129         if (encap_limit >= 0) {
1130                 max_headroom += 8;
1131                 mtu -= 8;
1132         }
1133         if (mtu < IPV6_MIN_MTU)
1134                 mtu = IPV6_MIN_MTU;
1135         if (skb_dst(skb) && !t->parms.collect_md)
1136                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1137         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1138                 *pmtu = mtu;
1139                 err = -EMSGSIZE;
1140                 goto tx_err_dst_release;
1141         }
1142 
1143         if (t->err_count > 0) {
1144                 if (time_before(jiffies,
1145                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1146                         t->err_count--;
1147 
1148                         dst_link_failure(skb);
1149                 } else {
1150                         t->err_count = 0;
1151                 }
1152         }
1153 
1154         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1155 
1156         /*
1157          * Okay, now see if we can stuff it in the buffer as-is.
1158          */
1159         max_headroom += LL_RESERVED_SPACE(tdev);
1160 
1161         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1162             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1163                 struct sk_buff *new_skb;
1164 
1165                 new_skb = skb_realloc_headroom(skb, max_headroom);
1166                 if (!new_skb)
1167                         goto tx_err_dst_release;
1168 
1169                 if (skb->sk)
1170                         skb_set_owner_w(new_skb, skb->sk);
1171                 consume_skb(skb);
1172                 skb = new_skb;
1173         }
1174 
1175         if (t->parms.collect_md) {
1176                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1177                         goto tx_err_dst_release;
1178         } else {
1179                 if (use_cache && ndst)
1180                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1181         }
1182         skb_dst_set(skb, dst);
1183 
1184         if (encap_limit >= 0) {
1185                 init_tel_txopt(&opt, encap_limit);
1186                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1187         }
1188 
1189         /* Calculate max headroom for all the headers and adjust
1190          * needed_headroom if necessary.
1191          */
1192         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1193                         + dst->header_len + t->hlen;
1194         if (max_headroom > dev->needed_headroom)
1195                 dev->needed_headroom = max_headroom;
1196 
1197         err = ip6_tnl_encap(skb, t, &proto, fl6);
1198         if (err)
1199                 return err;
1200 
1201         skb_push(skb, sizeof(struct ipv6hdr));
1202         skb_reset_network_header(skb);
1203         ipv6h = ipv6_hdr(skb);
1204         ip6_flow_hdr(ipv6h, dsfield,
1205                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1206         ipv6h->hop_limit = hop_limit;
1207         ipv6h->nexthdr = proto;
1208         ipv6h->saddr = fl6->saddr;
1209         ipv6h->daddr = fl6->daddr;
1210         ip6tunnel_xmit(NULL, skb, dev);
1211         return 0;
1212 tx_err_link_failure:
1213         stats->tx_carrier_errors++;
1214         dst_link_failure(skb);
1215 tx_err_dst_release:
1216         dst_release(dst);
1217         return err;
1218 }
1219 EXPORT_SYMBOL(ip6_tnl_xmit);
1220 
1221 static inline int
1222 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1223 {
1224         struct ip6_tnl *t = netdev_priv(dev);
1225         const struct iphdr  *iph = ip_hdr(skb);
1226         int encap_limit = -1;
1227         struct flowi6 fl6;
1228         __u8 dsfield;
1229         __u32 mtu;
1230         u8 tproto;
1231         int err;
1232 
1233         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1234 
1235         tproto = ACCESS_ONCE(t->parms.proto);
1236         if (tproto != IPPROTO_IPIP && tproto != 0)
1237                 return -1;
1238 
1239         if (t->parms.collect_md) {
1240                 struct ip_tunnel_info *tun_info;
1241                 const struct ip_tunnel_key *key;
1242 
1243                 tun_info = skb_tunnel_info(skb);
1244                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1245                              ip_tunnel_info_af(tun_info) != AF_INET6))
1246                         return -1;
1247                 key = &tun_info->key;
1248                 memset(&fl6, 0, sizeof(fl6));
1249                 fl6.flowi6_proto = IPPROTO_IPIP;
1250                 fl6.daddr = key->u.ipv6.dst;
1251                 fl6.flowlabel = key->label;
1252                 dsfield =  key->tos;
1253         } else {
1254                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1255                         encap_limit = t->parms.encap_limit;
1256 
1257                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1258                 fl6.flowi6_proto = IPPROTO_IPIP;
1259 
1260                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1261                         dsfield = ipv4_get_dsfield(iph);
1262                 else
1263                         dsfield = ip6_tclass(t->parms.flowinfo);
1264                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1265                         fl6.flowi6_mark = skb->mark;
1266                 else
1267                         fl6.flowi6_mark = t->parms.fwmark;
1268         }
1269 
1270         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1271 
1272         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1273                 return -1;
1274 
1275         dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1276 
1277         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1278 
1279         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1280                            IPPROTO_IPIP);
1281         if (err != 0) {
1282                 /* XXX: send ICMP error even if DF is not set. */
1283                 if (err == -EMSGSIZE)
1284                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1285                                   htonl(mtu));
1286                 return -1;
1287         }
1288 
1289         return 0;
1290 }
1291 
1292 static inline int
1293 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1294 {
1295         struct ip6_tnl *t = netdev_priv(dev);
1296         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1297         int encap_limit = -1;
1298         __u16 offset;
1299         struct flowi6 fl6;
1300         __u8 dsfield;
1301         __u32 mtu;
1302         u8 tproto;
1303         int err;
1304 
1305         tproto = ACCESS_ONCE(t->parms.proto);
1306         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1307             ip6_tnl_addr_conflict(t, ipv6h))
1308                 return -1;
1309 
1310         if (t->parms.collect_md) {
1311                 struct ip_tunnel_info *tun_info;
1312                 const struct ip_tunnel_key *key;
1313 
1314                 tun_info = skb_tunnel_info(skb);
1315                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1316                              ip_tunnel_info_af(tun_info) != AF_INET6))
1317                         return -1;
1318                 key = &tun_info->key;
1319                 memset(&fl6, 0, sizeof(fl6));
1320                 fl6.flowi6_proto = IPPROTO_IPV6;
1321                 fl6.daddr = key->u.ipv6.dst;
1322                 fl6.flowlabel = key->label;
1323                 dsfield = key->tos;
1324         } else {
1325                 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1326                 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1327                 ipv6h = ipv6_hdr(skb);
1328                 if (offset > 0) {
1329                         struct ipv6_tlv_tnl_enc_lim *tel;
1330 
1331                         tel = (void *)&skb_network_header(skb)[offset];
1332                         if (tel->encap_limit == 0) {
1333                                 icmpv6_send(skb, ICMPV6_PARAMPROB,
1334                                             ICMPV6_HDR_FIELD, offset + 2);
1335                                 return -1;
1336                         }
1337                         encap_limit = tel->encap_limit - 1;
1338                 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1339                         encap_limit = t->parms.encap_limit;
1340                 }
1341 
1342                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1343                 fl6.flowi6_proto = IPPROTO_IPV6;
1344 
1345                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1346                         dsfield = ipv6_get_dsfield(ipv6h);
1347                 else
1348                         dsfield = ip6_tclass(t->parms.flowinfo);
1349                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1350                         fl6.flowlabel |= ip6_flowlabel(ipv6h);
1351                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1352                         fl6.flowi6_mark = skb->mark;
1353                 else
1354                         fl6.flowi6_mark = t->parms.fwmark;
1355         }
1356 
1357         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1358 
1359         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1360                 return -1;
1361 
1362         dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1363 
1364         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1365 
1366         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1367                            IPPROTO_IPV6);
1368         if (err != 0) {
1369                 if (err == -EMSGSIZE)
1370                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1371                 return -1;
1372         }
1373 
1374         return 0;
1375 }
1376 
1377 static netdev_tx_t
1378 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1379 {
1380         struct ip6_tnl *t = netdev_priv(dev);
1381         struct net_device_stats *stats = &t->dev->stats;
1382         int ret;
1383 
1384         switch (skb->protocol) {
1385         case htons(ETH_P_IP):
1386                 ret = ip4ip6_tnl_xmit(skb, dev);
1387                 break;
1388         case htons(ETH_P_IPV6):
1389                 ret = ip6ip6_tnl_xmit(skb, dev);
1390                 break;
1391         default:
1392                 goto tx_err;
1393         }
1394 
1395         if (ret < 0)
1396                 goto tx_err;
1397 
1398         return NETDEV_TX_OK;
1399 
1400 tx_err:
1401         stats->tx_errors++;
1402         stats->tx_dropped++;
1403         kfree_skb(skb);
1404         return NETDEV_TX_OK;
1405 }
1406 
1407 static void ip6_tnl_link_config(struct ip6_tnl *t)
1408 {
1409         struct net_device *dev = t->dev;
1410         struct __ip6_tnl_parm *p = &t->parms;
1411         struct flowi6 *fl6 = &t->fl.u.ip6;
1412         int t_hlen;
1413 
1414         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1415         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1416 
1417         /* Set up flowi template */
1418         fl6->saddr = p->laddr;
1419         fl6->daddr = p->raddr;
1420         fl6->flowi6_oif = p->link;
1421         fl6->flowlabel = 0;
1422 
1423         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1424                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1425         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1426                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1427 
1428         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1429         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1430 
1431         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1432                 dev->flags |= IFF_POINTOPOINT;
1433         else
1434                 dev->flags &= ~IFF_POINTOPOINT;
1435 
1436         t->tun_hlen = 0;
1437         t->hlen = t->encap_hlen + t->tun_hlen;
1438         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1439 
1440         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1441                 int strict = (ipv6_addr_type(&p->raddr) &
1442                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1443 
1444                 struct rt6_info *rt = rt6_lookup(t->net,
1445                                                  &p->raddr, &p->laddr,
1446                                                  p->link, strict);
1447 
1448                 if (!rt)
1449                         return;
1450 
1451                 if (rt->dst.dev) {
1452                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1453                                 t_hlen;
1454 
1455                         dev->mtu = rt->dst.dev->mtu - t_hlen;
1456                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1457                                 dev->mtu -= 8;
1458 
1459                         if (dev->mtu < IPV6_MIN_MTU)
1460                                 dev->mtu = IPV6_MIN_MTU;
1461                 }
1462                 ip6_rt_put(rt);
1463         }
1464 }
1465 
1466 /**
1467  * ip6_tnl_change - update the tunnel parameters
1468  *   @t: tunnel to be changed
1469  *   @p: tunnel configuration parameters
1470  *
1471  * Description:
1472  *   ip6_tnl_change() updates the tunnel parameters
1473  **/
1474 
1475 static int
1476 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1477 {
1478         t->parms.laddr = p->laddr;
1479         t->parms.raddr = p->raddr;
1480         t->parms.flags = p->flags;
1481         t->parms.hop_limit = p->hop_limit;
1482         t->parms.encap_limit = p->encap_limit;
1483         t->parms.flowinfo = p->flowinfo;
1484         t->parms.link = p->link;
1485         t->parms.proto = p->proto;
1486         t->parms.fwmark = p->fwmark;
1487         dst_cache_reset(&t->dst_cache);
1488         ip6_tnl_link_config(t);
1489         return 0;
1490 }
1491 
1492 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1493 {
1494         struct net *net = t->net;
1495         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1496         int err;
1497 
1498         ip6_tnl_unlink(ip6n, t);
1499         synchronize_net();
1500         err = ip6_tnl_change(t, p);
1501         ip6_tnl_link(ip6n, t);
1502         netdev_state_change(t->dev);
1503         return err;
1504 }
1505 
1506 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1507 {
1508         /* for default tnl0 device allow to change only the proto */
1509         t->parms.proto = p->proto;
1510         netdev_state_change(t->dev);
1511         return 0;
1512 }
1513 
1514 static void
1515 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1516 {
1517         p->laddr = u->laddr;
1518         p->raddr = u->raddr;
1519         p->flags = u->flags;
1520         p->hop_limit = u->hop_limit;
1521         p->encap_limit = u->encap_limit;
1522         p->flowinfo = u->flowinfo;
1523         p->link = u->link;
1524         p->proto = u->proto;
1525         memcpy(p->name, u->name, sizeof(u->name));
1526 }
1527 
1528 static void
1529 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1530 {
1531         u->laddr = p->laddr;
1532         u->raddr = p->raddr;
1533         u->flags = p->flags;
1534         u->hop_limit = p->hop_limit;
1535         u->encap_limit = p->encap_limit;
1536         u->flowinfo = p->flowinfo;
1537         u->link = p->link;
1538         u->proto = p->proto;
1539         memcpy(u->name, p->name, sizeof(u->name));
1540 }
1541 
1542 /**
1543  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1544  *   @dev: virtual device associated with tunnel
1545  *   @ifr: parameters passed from userspace
1546  *   @cmd: command to be performed
1547  *
1548  * Description:
1549  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1550  *   from userspace.
1551  *
1552  *   The possible commands are the following:
1553  *     %SIOCGETTUNNEL: get tunnel parameters for device
1554  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1555  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1556  *     %SIOCDELTUNNEL: delete tunnel
1557  *
1558  *   The fallback device "ip6tnl0", created during module
1559  *   initialization, can be used for creating other tunnel devices.
1560  *
1561  * Return:
1562  *   0 on success,
1563  *   %-EFAULT if unable to copy data to or from userspace,
1564  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1565  *   %-EINVAL if passed tunnel parameters are invalid,
1566  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1567  *   %-ENODEV if attempting to change or delete a nonexisting device
1568  **/
1569 
1570 static int
1571 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1572 {
1573         int err = 0;
1574         struct ip6_tnl_parm p;
1575         struct __ip6_tnl_parm p1;
1576         struct ip6_tnl *t = netdev_priv(dev);
1577         struct net *net = t->net;
1578         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1579 
1580         memset(&p1, 0, sizeof(p1));
1581 
1582         switch (cmd) {
1583         case SIOCGETTUNNEL:
1584                 if (dev == ip6n->fb_tnl_dev) {
1585                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1586                                 err = -EFAULT;
1587                                 break;
1588                         }
1589                         ip6_tnl_parm_from_user(&p1, &p);
1590                         t = ip6_tnl_locate(net, &p1, 0);
1591                         if (IS_ERR(t))
1592                                 t = netdev_priv(dev);
1593                 } else {
1594                         memset(&p, 0, sizeof(p));
1595                 }
1596                 ip6_tnl_parm_to_user(&p, &t->parms);
1597                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1598                         err = -EFAULT;
1599                 }
1600                 break;
1601         case SIOCADDTUNNEL:
1602         case SIOCCHGTUNNEL:
1603                 err = -EPERM;
1604                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1605                         break;
1606                 err = -EFAULT;
1607                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1608                         break;
1609                 err = -EINVAL;
1610                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1611                     p.proto != 0)
1612                         break;
1613                 ip6_tnl_parm_from_user(&p1, &p);
1614                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1615                 if (cmd == SIOCCHGTUNNEL) {
1616                         if (!IS_ERR(t)) {
1617                                 if (t->dev != dev) {
1618                                         err = -EEXIST;
1619                                         break;
1620                                 }
1621                         } else
1622                                 t = netdev_priv(dev);
1623                         if (dev == ip6n->fb_tnl_dev)
1624                                 err = ip6_tnl0_update(t, &p1);
1625                         else
1626                                 err = ip6_tnl_update(t, &p1);
1627                 }
1628                 if (!IS_ERR(t)) {
1629                         err = 0;
1630                         ip6_tnl_parm_to_user(&p, &t->parms);
1631                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1632                                 err = -EFAULT;
1633 
1634                 } else {
1635                         err = PTR_ERR(t);
1636                 }
1637                 break;
1638         case SIOCDELTUNNEL:
1639                 err = -EPERM;
1640                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1641                         break;
1642 
1643                 if (dev == ip6n->fb_tnl_dev) {
1644                         err = -EFAULT;
1645                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1646                                 break;
1647                         err = -ENOENT;
1648                         ip6_tnl_parm_from_user(&p1, &p);
1649                         t = ip6_tnl_locate(net, &p1, 0);
1650                         if (IS_ERR(t))
1651                                 break;
1652                         err = -EPERM;
1653                         if (t->dev == ip6n->fb_tnl_dev)
1654                                 break;
1655                         dev = t->dev;
1656                 }
1657                 err = 0;
1658                 unregister_netdevice(dev);
1659                 break;
1660         default:
1661                 err = -EINVAL;
1662         }
1663         return err;
1664 }
1665 
1666 /**
1667  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1668  *   @dev: virtual device associated with tunnel
1669  *   @new_mtu: the new mtu
1670  *
1671  * Return:
1672  *   0 on success,
1673  *   %-EINVAL if mtu too small
1674  **/
1675 
1676 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1677 {
1678         struct ip6_tnl *tnl = netdev_priv(dev);
1679 
1680         if (tnl->parms.proto == IPPROTO_IPIP) {
1681                 if (new_mtu < ETH_MIN_MTU)
1682                         return -EINVAL;
1683         } else {
1684                 if (new_mtu < IPV6_MIN_MTU)
1685                         return -EINVAL;
1686         }
1687         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1688                 return -EINVAL;
1689         dev->mtu = new_mtu;
1690         return 0;
1691 }
1692 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1693 
1694 int ip6_tnl_get_iflink(const struct net_device *dev)
1695 {
1696         struct ip6_tnl *t = netdev_priv(dev);
1697 
1698         return t->parms.link;
1699 }
1700 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1701 
1702 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1703                           unsigned int num)
1704 {
1705         if (num >= MAX_IPTUN_ENCAP_OPS)
1706                 return -ERANGE;
1707 
1708         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1709                         &ip6tun_encaps[num],
1710                         NULL, ops) ? 0 : -1;
1711 }
1712 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1713 
1714 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1715                           unsigned int num)
1716 {
1717         int ret;
1718 
1719         if (num >= MAX_IPTUN_ENCAP_OPS)
1720                 return -ERANGE;
1721 
1722         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1723                        &ip6tun_encaps[num],
1724                        ops, NULL) == ops) ? 0 : -1;
1725 
1726         synchronize_net();
1727 
1728         return ret;
1729 }
1730 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1731 
1732 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1733                         struct ip_tunnel_encap *ipencap)
1734 {
1735         int hlen;
1736 
1737         memset(&t->encap, 0, sizeof(t->encap));
1738 
1739         hlen = ip6_encap_hlen(ipencap);
1740         if (hlen < 0)
1741                 return hlen;
1742 
1743         t->encap.type = ipencap->type;
1744         t->encap.sport = ipencap->sport;
1745         t->encap.dport = ipencap->dport;
1746         t->encap.flags = ipencap->flags;
1747 
1748         t->encap_hlen = hlen;
1749         t->hlen = t->encap_hlen + t->tun_hlen;
1750 
1751         return 0;
1752 }
1753 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1754 
1755 static const struct net_device_ops ip6_tnl_netdev_ops = {
1756         .ndo_init       = ip6_tnl_dev_init,
1757         .ndo_uninit     = ip6_tnl_dev_uninit,
1758         .ndo_start_xmit = ip6_tnl_start_xmit,
1759         .ndo_do_ioctl   = ip6_tnl_ioctl,
1760         .ndo_change_mtu = ip6_tnl_change_mtu,
1761         .ndo_get_stats  = ip6_get_stats,
1762         .ndo_get_iflink = ip6_tnl_get_iflink,
1763 };
1764 
1765 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1766                          NETIF_F_FRAGLIST |     \
1767                          NETIF_F_HIGHDMA |      \
1768                          NETIF_F_GSO_SOFTWARE | \
1769                          NETIF_F_HW_CSUM)
1770 
1771 /**
1772  * ip6_tnl_dev_setup - setup virtual tunnel device
1773  *   @dev: virtual device associated with tunnel
1774  *
1775  * Description:
1776  *   Initialize function pointers and device parameters
1777  **/
1778 
1779 static void ip6_tnl_dev_setup(struct net_device *dev)
1780 {
1781         dev->netdev_ops = &ip6_tnl_netdev_ops;
1782         dev->needs_free_netdev = true;
1783         dev->priv_destructor = ip6_dev_free;
1784 
1785         dev->type = ARPHRD_TUNNEL6;
1786         dev->flags |= IFF_NOARP;
1787         dev->addr_len = sizeof(struct in6_addr);
1788         dev->features |= NETIF_F_LLTX;
1789         netif_keep_dst(dev);
1790 
1791         dev->features           |= IPXIPX_FEATURES;
1792         dev->hw_features        |= IPXIPX_FEATURES;
1793 
1794         /* This perm addr will be used as interface identifier by IPv6 */
1795         dev->addr_assign_type = NET_ADDR_RANDOM;
1796         eth_random_addr(dev->perm_addr);
1797 }
1798 
1799 
1800 /**
1801  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1802  *   @dev: virtual device associated with tunnel
1803  **/
1804 
1805 static inline int
1806 ip6_tnl_dev_init_gen(struct net_device *dev)
1807 {
1808         struct ip6_tnl *t = netdev_priv(dev);
1809         int ret;
1810         int t_hlen;
1811 
1812         t->dev = dev;
1813         t->net = dev_net(dev);
1814         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1815         if (!dev->tstats)
1816                 return -ENOMEM;
1817 
1818         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1819         if (ret)
1820                 goto free_stats;
1821 
1822         ret = gro_cells_init(&t->gro_cells, dev);
1823         if (ret)
1824                 goto destroy_dst;
1825 
1826         t->tun_hlen = 0;
1827         t->hlen = t->encap_hlen + t->tun_hlen;
1828         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1829 
1830         dev->type = ARPHRD_TUNNEL6;
1831         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1832         dev->mtu = ETH_DATA_LEN - t_hlen;
1833         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1834                 dev->mtu -= 8;
1835         dev->min_mtu = ETH_MIN_MTU;
1836         dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1837 
1838         return 0;
1839 
1840 destroy_dst:
1841         dst_cache_destroy(&t->dst_cache);
1842 free_stats:
1843         free_percpu(dev->tstats);
1844         dev->tstats = NULL;
1845 
1846         return ret;
1847 }
1848 
1849 /**
1850  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1851  *   @dev: virtual device associated with tunnel
1852  **/
1853 
1854 static int ip6_tnl_dev_init(struct net_device *dev)
1855 {
1856         struct ip6_tnl *t = netdev_priv(dev);
1857         int err = ip6_tnl_dev_init_gen(dev);
1858 
1859         if (err)
1860                 return err;
1861         ip6_tnl_link_config(t);
1862         if (t->parms.collect_md) {
1863                 dev->features |= NETIF_F_NETNS_LOCAL;
1864                 netif_keep_dst(dev);
1865         }
1866         return 0;
1867 }
1868 
1869 /**
1870  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1871  *   @dev: fallback device
1872  *
1873  * Return: 0
1874  **/
1875 
1876 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1877 {
1878         struct ip6_tnl *t = netdev_priv(dev);
1879         struct net *net = dev_net(dev);
1880         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1881 
1882         t->parms.proto = IPPROTO_IPV6;
1883         dev_hold(dev);
1884 
1885         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1886         return 0;
1887 }
1888 
1889 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1890                             struct netlink_ext_ack *extack)
1891 {
1892         u8 proto;
1893 
1894         if (!data || !data[IFLA_IPTUN_PROTO])
1895                 return 0;
1896 
1897         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1898         if (proto != IPPROTO_IPV6 &&
1899             proto != IPPROTO_IPIP &&
1900             proto != 0)
1901                 return -EINVAL;
1902 
1903         return 0;
1904 }
1905 
1906 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1907                                   struct __ip6_tnl_parm *parms)
1908 {
1909         memset(parms, 0, sizeof(*parms));
1910 
1911         if (!data)
1912                 return;
1913 
1914         if (data[IFLA_IPTUN_LINK])
1915                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1916 
1917         if (data[IFLA_IPTUN_LOCAL])
1918                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1919 
1920         if (data[IFLA_IPTUN_REMOTE])
1921                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1922 
1923         if (data[IFLA_IPTUN_TTL])
1924                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1925 
1926         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1927                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1928 
1929         if (data[IFLA_IPTUN_FLOWINFO])
1930                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1931 
1932         if (data[IFLA_IPTUN_FLAGS])
1933                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1934 
1935         if (data[IFLA_IPTUN_PROTO])
1936                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1937 
1938         if (data[IFLA_IPTUN_COLLECT_METADATA])
1939                 parms->collect_md = true;
1940 
1941         if (data[IFLA_IPTUN_FWMARK])
1942                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1943 }
1944 
1945 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1946                                         struct ip_tunnel_encap *ipencap)
1947 {
1948         bool ret = false;
1949 
1950         memset(ipencap, 0, sizeof(*ipencap));
1951 
1952         if (!data)
1953                 return ret;
1954 
1955         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1956                 ret = true;
1957                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1958         }
1959 
1960         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1961                 ret = true;
1962                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1963         }
1964 
1965         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1966                 ret = true;
1967                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1968         }
1969 
1970         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1971                 ret = true;
1972                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1973         }
1974 
1975         return ret;
1976 }
1977 
1978 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1979                            struct nlattr *tb[], struct nlattr *data[],
1980                            struct netlink_ext_ack *extack)
1981 {
1982         struct net *net = dev_net(dev);
1983         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1984         struct ip6_tnl *nt, *t;
1985         struct ip_tunnel_encap ipencap;
1986 
1987         nt = netdev_priv(dev);
1988 
1989         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1990                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1991 
1992                 if (err < 0)
1993                         return err;
1994         }
1995 
1996         ip6_tnl_netlink_parms(data, &nt->parms);
1997 
1998         if (nt->parms.collect_md) {
1999                 if (rtnl_dereference(ip6n->collect_md_tun))
2000                         return -EEXIST;
2001         } else {
2002                 t = ip6_tnl_locate(net, &nt->parms, 0);
2003                 if (!IS_ERR(t))
2004                         return -EEXIST;
2005         }
2006 
2007         return ip6_tnl_create2(dev);
2008 }
2009 
2010 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2011                               struct nlattr *data[],
2012                               struct netlink_ext_ack *extack)
2013 {
2014         struct ip6_tnl *t = netdev_priv(dev);
2015         struct __ip6_tnl_parm p;
2016         struct net *net = t->net;
2017         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2018         struct ip_tunnel_encap ipencap;
2019 
2020         if (dev == ip6n->fb_tnl_dev)
2021                 return -EINVAL;
2022 
2023         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2024                 int err = ip6_tnl_encap_setup(t, &ipencap);
2025 
2026                 if (err < 0)
2027                         return err;
2028         }
2029         ip6_tnl_netlink_parms(data, &p);
2030         if (p.collect_md)
2031                 return -EINVAL;
2032 
2033         t = ip6_tnl_locate(net, &p, 0);
2034         if (!IS_ERR(t)) {
2035                 if (t->dev != dev)
2036                         return -EEXIST;
2037         } else
2038                 t = netdev_priv(dev);
2039 
2040         return ip6_tnl_update(t, &p);
2041 }
2042 
2043 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2044 {
2045         struct net *net = dev_net(dev);
2046         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2047 
2048         if (dev != ip6n->fb_tnl_dev)
2049                 unregister_netdevice_queue(dev, head);
2050 }
2051 
2052 static size_t ip6_tnl_get_size(const struct net_device *dev)
2053 {
2054         return
2055                 /* IFLA_IPTUN_LINK */
2056                 nla_total_size(4) +
2057                 /* IFLA_IPTUN_LOCAL */
2058                 nla_total_size(sizeof(struct in6_addr)) +
2059                 /* IFLA_IPTUN_REMOTE */
2060                 nla_total_size(sizeof(struct in6_addr)) +
2061                 /* IFLA_IPTUN_TTL */
2062                 nla_total_size(1) +
2063                 /* IFLA_IPTUN_ENCAP_LIMIT */
2064                 nla_total_size(1) +
2065                 /* IFLA_IPTUN_FLOWINFO */
2066                 nla_total_size(4) +
2067                 /* IFLA_IPTUN_FLAGS */
2068                 nla_total_size(4) +
2069                 /* IFLA_IPTUN_PROTO */
2070                 nla_total_size(1) +
2071                 /* IFLA_IPTUN_ENCAP_TYPE */
2072                 nla_total_size(2) +
2073                 /* IFLA_IPTUN_ENCAP_FLAGS */
2074                 nla_total_size(2) +
2075                 /* IFLA_IPTUN_ENCAP_SPORT */
2076                 nla_total_size(2) +
2077                 /* IFLA_IPTUN_ENCAP_DPORT */
2078                 nla_total_size(2) +
2079                 /* IFLA_IPTUN_COLLECT_METADATA */
2080                 nla_total_size(0) +
2081                 /* IFLA_IPTUN_FWMARK */
2082                 nla_total_size(4) +
2083                 0;
2084 }
2085 
2086 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2087 {
2088         struct ip6_tnl *tunnel = netdev_priv(dev);
2089         struct __ip6_tnl_parm *parm = &tunnel->parms;
2090 
2091         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2092             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2093             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2094             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2095             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2096             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2097             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2098             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2099             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2100                 goto nla_put_failure;
2101 
2102         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2103             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2104             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2105             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2106                 goto nla_put_failure;
2107 
2108         if (parm->collect_md)
2109                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2110                         goto nla_put_failure;
2111 
2112         return 0;
2113 
2114 nla_put_failure:
2115         return -EMSGSIZE;
2116 }
2117 
2118 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2119 {
2120         struct ip6_tnl *tunnel = netdev_priv(dev);
2121 
2122         return tunnel->net;
2123 }
2124 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2125 
2126 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2127         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2128         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2129         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2130         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2131         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2132         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2133         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2134         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2135         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2136         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2137         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2138         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2139         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2140         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2141 };
2142 
2143 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2144         .kind           = "ip6tnl",
2145         .maxtype        = IFLA_IPTUN_MAX,
2146         .policy         = ip6_tnl_policy,
2147         .priv_size      = sizeof(struct ip6_tnl),
2148         .setup          = ip6_tnl_dev_setup,
2149         .validate       = ip6_tnl_validate,
2150         .newlink        = ip6_tnl_newlink,
2151         .changelink     = ip6_tnl_changelink,
2152         .dellink        = ip6_tnl_dellink,
2153         .get_size       = ip6_tnl_get_size,
2154         .fill_info      = ip6_tnl_fill_info,
2155         .get_link_net   = ip6_tnl_get_link_net,
2156 };
2157 
2158 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2159         .handler        = ip4ip6_rcv,
2160         .err_handler    = ip4ip6_err,
2161         .priority       =       1,
2162 };
2163 
2164 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2165         .handler        = ip6ip6_rcv,
2166         .err_handler    = ip6ip6_err,
2167         .priority       =       1,
2168 };
2169 
2170 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
2171 {
2172         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2173         struct net_device *dev, *aux;
2174         int h;
2175         struct ip6_tnl *t;
2176         LIST_HEAD(list);
2177 
2178         for_each_netdev_safe(net, dev, aux)
2179                 if (dev->rtnl_link_ops == &ip6_link_ops)
2180                         unregister_netdevice_queue(dev, &list);
2181 
2182         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2183                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2184                 while (t) {
2185                         /* If dev is in the same netns, it has already
2186                          * been added to the list by the previous loop.
2187                          */
2188                         if (!net_eq(dev_net(t->dev), net))
2189                                 unregister_netdevice_queue(t->dev, &list);
2190                         t = rtnl_dereference(t->next);
2191                 }
2192         }
2193 
2194         unregister_netdevice_many(&list);
2195 }
2196 
2197 static int __net_init ip6_tnl_init_net(struct net *net)
2198 {
2199         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2200         struct ip6_tnl *t = NULL;
2201         int err;
2202 
2203         ip6n->tnls[0] = ip6n->tnls_wc;
2204         ip6n->tnls[1] = ip6n->tnls_r_l;
2205 
2206         err = -ENOMEM;
2207         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2208                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2209 
2210         if (!ip6n->fb_tnl_dev)
2211                 goto err_alloc_dev;
2212         dev_net_set(ip6n->fb_tnl_dev, net);
2213         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2214         /* FB netdevice is special: we have one, and only one per netns.
2215          * Allowing to move it to another netns is clearly unsafe.
2216          */
2217         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2218 
2219         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2220         if (err < 0)
2221                 goto err_register;
2222 
2223         err = register_netdev(ip6n->fb_tnl_dev);
2224         if (err < 0)
2225                 goto err_register;
2226 
2227         t = netdev_priv(ip6n->fb_tnl_dev);
2228 
2229         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2230         return 0;
2231 
2232 err_register:
2233         free_netdev(ip6n->fb_tnl_dev);
2234 err_alloc_dev:
2235         return err;
2236 }
2237 
2238 static void __net_exit ip6_tnl_exit_net(struct net *net)
2239 {
2240         rtnl_lock();
2241         ip6_tnl_destroy_tunnels(net);
2242         rtnl_unlock();
2243 }
2244 
2245 static struct pernet_operations ip6_tnl_net_ops = {
2246         .init = ip6_tnl_init_net,
2247         .exit = ip6_tnl_exit_net,
2248         .id   = &ip6_tnl_net_id,
2249         .size = sizeof(struct ip6_tnl_net),
2250 };
2251 
2252 /**
2253  * ip6_tunnel_init - register protocol and reserve needed resources
2254  *
2255  * Return: 0 on success
2256  **/
2257 
2258 static int __init ip6_tunnel_init(void)
2259 {
2260         int  err;
2261 
2262         if (!ipv6_mod_enabled())
2263                 return -EOPNOTSUPP;
2264 
2265         err = register_pernet_device(&ip6_tnl_net_ops);
2266         if (err < 0)
2267                 goto out_pernet;
2268 
2269         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2270         if (err < 0) {
2271                 pr_err("%s: can't register ip4ip6\n", __func__);
2272                 goto out_ip4ip6;
2273         }
2274 
2275         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2276         if (err < 0) {
2277                 pr_err("%s: can't register ip6ip6\n", __func__);
2278                 goto out_ip6ip6;
2279         }
2280         err = rtnl_link_register(&ip6_link_ops);
2281         if (err < 0)
2282                 goto rtnl_link_failed;
2283 
2284         return 0;
2285 
2286 rtnl_link_failed:
2287         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2288 out_ip6ip6:
2289         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2290 out_ip4ip6:
2291         unregister_pernet_device(&ip6_tnl_net_ops);
2292 out_pernet:
2293         return err;
2294 }
2295 
2296 /**
2297  * ip6_tunnel_cleanup - free resources and unregister protocol
2298  **/
2299 
2300 static void __exit ip6_tunnel_cleanup(void)
2301 {
2302         rtnl_link_unregister(&ip6_link_ops);
2303         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2304                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2305 
2306         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2307                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2308 
2309         unregister_pernet_device(&ip6_tnl_net_ops);
2310 }
2311 
2312 module_init(ip6_tunnel_init);
2313 module_exit(ip6_tunnel_cleanup);
2314 

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