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TOMOYO Linux Cross Reference
Linux/net/ipv6/ip6_gre.c

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  1 /*
  2  *      GRE over IPv6 protocol decoder.
  3  *
  4  *      Authors: Dmitry Kozlov (xeb@mail.ru)
  5  *
  6  *      This program is free software; you can redistribute it and/or
  7  *      modify it under the terms of the GNU General Public License
  8  *      as published by the Free Software Foundation; either version
  9  *      2 of the License, or (at your option) any later version.
 10  *
 11  */
 12 
 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 14 
 15 #include <linux/capability.h>
 16 #include <linux/module.h>
 17 #include <linux/types.h>
 18 #include <linux/kernel.h>
 19 #include <linux/slab.h>
 20 #include <linux/uaccess.h>
 21 #include <linux/skbuff.h>
 22 #include <linux/netdevice.h>
 23 #include <linux/in.h>
 24 #include <linux/tcp.h>
 25 #include <linux/udp.h>
 26 #include <linux/if_arp.h>
 27 #include <linux/mroute.h>
 28 #include <linux/init.h>
 29 #include <linux/in6.h>
 30 #include <linux/inetdevice.h>
 31 #include <linux/igmp.h>
 32 #include <linux/netfilter_ipv4.h>
 33 #include <linux/etherdevice.h>
 34 #include <linux/if_ether.h>
 35 #include <linux/hash.h>
 36 #include <linux/if_tunnel.h>
 37 #include <linux/ip6_tunnel.h>
 38 
 39 #include <net/sock.h>
 40 #include <net/ip.h>
 41 #include <net/ip_tunnels.h>
 42 #include <net/icmp.h>
 43 #include <net/protocol.h>
 44 #include <net/addrconf.h>
 45 #include <net/arp.h>
 46 #include <net/checksum.h>
 47 #include <net/dsfield.h>
 48 #include <net/inet_ecn.h>
 49 #include <net/xfrm.h>
 50 #include <net/net_namespace.h>
 51 #include <net/netns/generic.h>
 52 #include <net/rtnetlink.h>
 53 
 54 #include <net/ipv6.h>
 55 #include <net/ip6_fib.h>
 56 #include <net/ip6_route.h>
 57 #include <net/ip6_tunnel.h>
 58 
 59 
 60 static bool log_ecn_error = true;
 61 module_param(log_ecn_error, bool, 0644);
 62 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 63 
 64 #define HASH_SIZE_SHIFT  5
 65 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
 66 
 67 static int ip6gre_net_id __read_mostly;
 68 struct ip6gre_net {
 69         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
 70 
 71         struct net_device *fb_tunnel_dev;
 72 };
 73 
 74 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
 75 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
 76 static int ip6gre_tunnel_init(struct net_device *dev);
 77 static void ip6gre_tunnel_setup(struct net_device *dev);
 78 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
 79 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
 80 
 81 /* Tunnel hash table */
 82 
 83 /*
 84    4 hash tables:
 85 
 86    3: (remote,local)
 87    2: (remote,*)
 88    1: (*,local)
 89    0: (*,*)
 90 
 91    We require exact key match i.e. if a key is present in packet
 92    it will match only tunnel with the same key; if it is not present,
 93    it will match only keyless tunnel.
 94 
 95    All keysless packets, if not matched configured keyless tunnels
 96    will match fallback tunnel.
 97  */
 98 
 99 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
100 static u32 HASH_ADDR(const struct in6_addr *addr)
101 {
102         u32 hash = ipv6_addr_hash(addr);
103 
104         return hash_32(hash, HASH_SIZE_SHIFT);
105 }
106 
107 #define tunnels_r_l     tunnels[3]
108 #define tunnels_r       tunnels[2]
109 #define tunnels_l       tunnels[1]
110 #define tunnels_wc      tunnels[0]
111 
112 /* Given src, dst and key, find appropriate for input tunnel. */
113 
114 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
115                 const struct in6_addr *remote, const struct in6_addr *local,
116                 __be32 key, __be16 gre_proto)
117 {
118         struct net *net = dev_net(dev);
119         int link = dev->ifindex;
120         unsigned int h0 = HASH_ADDR(remote);
121         unsigned int h1 = HASH_KEY(key);
122         struct ip6_tnl *t, *cand = NULL;
123         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
124         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
125                        ARPHRD_ETHER : ARPHRD_IP6GRE;
126         int score, cand_score = 4;
127 
128         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
129                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
130                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
131                     key != t->parms.i_key ||
132                     !(t->dev->flags & IFF_UP))
133                         continue;
134 
135                 if (t->dev->type != ARPHRD_IP6GRE &&
136                     t->dev->type != dev_type)
137                         continue;
138 
139                 score = 0;
140                 if (t->parms.link != link)
141                         score |= 1;
142                 if (t->dev->type != dev_type)
143                         score |= 2;
144                 if (score == 0)
145                         return t;
146 
147                 if (score < cand_score) {
148                         cand = t;
149                         cand_score = score;
150                 }
151         }
152 
153         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
154                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
155                     key != t->parms.i_key ||
156                     !(t->dev->flags & IFF_UP))
157                         continue;
158 
159                 if (t->dev->type != ARPHRD_IP6GRE &&
160                     t->dev->type != dev_type)
161                         continue;
162 
163                 score = 0;
164                 if (t->parms.link != link)
165                         score |= 1;
166                 if (t->dev->type != dev_type)
167                         score |= 2;
168                 if (score == 0)
169                         return t;
170 
171                 if (score < cand_score) {
172                         cand = t;
173                         cand_score = score;
174                 }
175         }
176 
177         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
178                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
179                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
180                                  !ipv6_addr_is_multicast(local))) ||
181                     key != t->parms.i_key ||
182                     !(t->dev->flags & IFF_UP))
183                         continue;
184 
185                 if (t->dev->type != ARPHRD_IP6GRE &&
186                     t->dev->type != dev_type)
187                         continue;
188 
189                 score = 0;
190                 if (t->parms.link != link)
191                         score |= 1;
192                 if (t->dev->type != dev_type)
193                         score |= 2;
194                 if (score == 0)
195                         return t;
196 
197                 if (score < cand_score) {
198                         cand = t;
199                         cand_score = score;
200                 }
201         }
202 
203         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
204                 if (t->parms.i_key != key ||
205                     !(t->dev->flags & IFF_UP))
206                         continue;
207 
208                 if (t->dev->type != ARPHRD_IP6GRE &&
209                     t->dev->type != dev_type)
210                         continue;
211 
212                 score = 0;
213                 if (t->parms.link != link)
214                         score |= 1;
215                 if (t->dev->type != dev_type)
216                         score |= 2;
217                 if (score == 0)
218                         return t;
219 
220                 if (score < cand_score) {
221                         cand = t;
222                         cand_score = score;
223                 }
224         }
225 
226         if (cand)
227                 return cand;
228 
229         dev = ign->fb_tunnel_dev;
230         if (dev->flags & IFF_UP)
231                 return netdev_priv(dev);
232 
233         return NULL;
234 }
235 
236 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
237                 const struct __ip6_tnl_parm *p)
238 {
239         const struct in6_addr *remote = &p->raddr;
240         const struct in6_addr *local = &p->laddr;
241         unsigned int h = HASH_KEY(p->i_key);
242         int prio = 0;
243 
244         if (!ipv6_addr_any(local))
245                 prio |= 1;
246         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
247                 prio |= 2;
248                 h ^= HASH_ADDR(remote);
249         }
250 
251         return &ign->tunnels[prio][h];
252 }
253 
254 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
255                 const struct ip6_tnl *t)
256 {
257         return __ip6gre_bucket(ign, &t->parms);
258 }
259 
260 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
261 {
262         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
263 
264         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
265         rcu_assign_pointer(*tp, t);
266 }
267 
268 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
269 {
270         struct ip6_tnl __rcu **tp;
271         struct ip6_tnl *iter;
272 
273         for (tp = ip6gre_bucket(ign, t);
274              (iter = rtnl_dereference(*tp)) != NULL;
275              tp = &iter->next) {
276                 if (t == iter) {
277                         rcu_assign_pointer(*tp, t->next);
278                         break;
279                 }
280         }
281 }
282 
283 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
284                                            const struct __ip6_tnl_parm *parms,
285                                            int type)
286 {
287         const struct in6_addr *remote = &parms->raddr;
288         const struct in6_addr *local = &parms->laddr;
289         __be32 key = parms->i_key;
290         int link = parms->link;
291         struct ip6_tnl *t;
292         struct ip6_tnl __rcu **tp;
293         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
294 
295         for (tp = __ip6gre_bucket(ign, parms);
296              (t = rtnl_dereference(*tp)) != NULL;
297              tp = &t->next)
298                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
299                     ipv6_addr_equal(remote, &t->parms.raddr) &&
300                     key == t->parms.i_key &&
301                     link == t->parms.link &&
302                     type == t->dev->type)
303                         break;
304 
305         return t;
306 }
307 
308 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
309                 const struct __ip6_tnl_parm *parms, int create)
310 {
311         struct ip6_tnl *t, *nt;
312         struct net_device *dev;
313         char name[IFNAMSIZ];
314         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
315 
316         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
317         if (t && create)
318                 return NULL;
319         if (t || !create)
320                 return t;
321 
322         if (parms->name[0])
323                 strlcpy(name, parms->name, IFNAMSIZ);
324         else
325                 strcpy(name, "ip6gre%d");
326 
327         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
328                            ip6gre_tunnel_setup);
329         if (!dev)
330                 return NULL;
331 
332         dev_net_set(dev, net);
333 
334         nt = netdev_priv(dev);
335         nt->parms = *parms;
336         dev->rtnl_link_ops = &ip6gre_link_ops;
337 
338         nt->dev = dev;
339         nt->net = dev_net(dev);
340         ip6gre_tnl_link_config(nt, 1);
341 
342         if (register_netdevice(dev) < 0)
343                 goto failed_free;
344 
345         /* Can use a lockless transmit, unless we generate output sequences */
346         if (!(nt->parms.o_flags & GRE_SEQ))
347                 dev->features |= NETIF_F_LLTX;
348 
349         dev_hold(dev);
350         ip6gre_tunnel_link(ign, nt);
351         return nt;
352 
353 failed_free:
354         free_netdev(dev);
355         return NULL;
356 }
357 
358 static void ip6gre_tunnel_uninit(struct net_device *dev)
359 {
360         struct ip6_tnl *t = netdev_priv(dev);
361         struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
362 
363         ip6gre_tunnel_unlink(ign, t);
364         ip6_tnl_dst_reset(t);
365         dev_put(dev);
366 }
367 
368 
369 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
370                 u8 type, u8 code, int offset, __be32 info)
371 {
372         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
373         __be16 *p = (__be16 *)(skb->data + offset);
374         int grehlen = offset + 4;
375         struct ip6_tnl *t;
376         __be16 flags;
377 
378         flags = p[0];
379         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
380                 if (flags&(GRE_VERSION|GRE_ROUTING))
381                         return;
382                 if (flags&GRE_KEY) {
383                         grehlen += 4;
384                         if (flags&GRE_CSUM)
385                                 grehlen += 4;
386                 }
387         }
388 
389         /* If only 8 bytes returned, keyed message will be dropped here */
390         if (!pskb_may_pull(skb, grehlen))
391                 return;
392         ipv6h = (const struct ipv6hdr *)skb->data;
393         p = (__be16 *)(skb->data + offset);
394 
395         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
396                                 flags & GRE_KEY ?
397                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
398                                 p[1]);
399         if (!t)
400                 return;
401 
402         switch (type) {
403                 __u32 teli;
404                 struct ipv6_tlv_tnl_enc_lim *tel;
405                 __u32 mtu;
406         case ICMPV6_DEST_UNREACH:
407                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
408                                     t->parms.name);
409                 break;
410         case ICMPV6_TIME_EXCEED:
411                 if (code == ICMPV6_EXC_HOPLIMIT) {
412                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
413                                             t->parms.name);
414                 }
415                 break;
416         case ICMPV6_PARAMPROB:
417                 teli = 0;
418                 if (code == ICMPV6_HDR_FIELD)
419                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
420 
421                 if (teli && teli == be32_to_cpu(info) - 2) {
422                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
423                         if (tel->encap_limit == 0) {
424                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
425                                                     t->parms.name);
426                         }
427                 } else {
428                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
429                                             t->parms.name);
430                 }
431                 break;
432         case ICMPV6_PKT_TOOBIG:
433                 mtu = be32_to_cpu(info) - offset;
434                 if (mtu < IPV6_MIN_MTU)
435                         mtu = IPV6_MIN_MTU;
436                 t->dev->mtu = mtu;
437                 break;
438         }
439 
440         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
441                 t->err_count++;
442         else
443                 t->err_count = 1;
444         t->err_time = jiffies;
445 }
446 
447 static int ip6gre_rcv(struct sk_buff *skb)
448 {
449         const struct ipv6hdr *ipv6h;
450         u8     *h;
451         __be16    flags;
452         __sum16   csum = 0;
453         __be32 key = 0;
454         u32    seqno = 0;
455         struct ip6_tnl *tunnel;
456         int    offset = 4;
457         __be16 gre_proto;
458         int err;
459 
460         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
461                 goto drop;
462 
463         ipv6h = ipv6_hdr(skb);
464         h = skb->data;
465         flags = *(__be16 *)h;
466 
467         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
468                 /* - Version must be 0.
469                    - We do not support routing headers.
470                  */
471                 if (flags&(GRE_VERSION|GRE_ROUTING))
472                         goto drop;
473 
474                 if (flags&GRE_CSUM) {
475                         csum = skb_checksum_simple_validate(skb);
476                         offset += 4;
477                 }
478                 if (flags&GRE_KEY) {
479                         key = *(__be32 *)(h + offset);
480                         offset += 4;
481                 }
482                 if (flags&GRE_SEQ) {
483                         seqno = ntohl(*(__be32 *)(h + offset));
484                         offset += 4;
485                 }
486         }
487 
488         gre_proto = *(__be16 *)(h + 2);
489 
490         tunnel = ip6gre_tunnel_lookup(skb->dev,
491                                           &ipv6h->saddr, &ipv6h->daddr, key,
492                                           gre_proto);
493         if (tunnel) {
494                 struct pcpu_sw_netstats *tstats;
495 
496                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
497                         goto drop;
498 
499                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
500                         tunnel->dev->stats.rx_dropped++;
501                         goto drop;
502                 }
503 
504                 skb->protocol = gre_proto;
505                 /* WCCP version 1 and 2 protocol decoding.
506                  * - Change protocol to IPv6
507                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
508                  */
509                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
510                         skb->protocol = htons(ETH_P_IPV6);
511                         if ((*(h + offset) & 0xF0) != 0x40)
512                                 offset += 4;
513                 }
514 
515                 skb->mac_header = skb->network_header;
516                 __pskb_pull(skb, offset);
517                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
518 
519                 if (((flags&GRE_CSUM) && csum) ||
520                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
521                         tunnel->dev->stats.rx_crc_errors++;
522                         tunnel->dev->stats.rx_errors++;
523                         goto drop;
524                 }
525                 if (tunnel->parms.i_flags&GRE_SEQ) {
526                         if (!(flags&GRE_SEQ) ||
527                             (tunnel->i_seqno &&
528                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
529                                 tunnel->dev->stats.rx_fifo_errors++;
530                                 tunnel->dev->stats.rx_errors++;
531                                 goto drop;
532                         }
533                         tunnel->i_seqno = seqno + 1;
534                 }
535 
536                 /* Warning: All skb pointers will be invalidated! */
537                 if (tunnel->dev->type == ARPHRD_ETHER) {
538                         if (!pskb_may_pull(skb, ETH_HLEN)) {
539                                 tunnel->dev->stats.rx_length_errors++;
540                                 tunnel->dev->stats.rx_errors++;
541                                 goto drop;
542                         }
543 
544                         ipv6h = ipv6_hdr(skb);
545                         skb->protocol = eth_type_trans(skb, tunnel->dev);
546                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
547                 }
548 
549                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
550 
551                 skb_reset_network_header(skb);
552 
553                 err = IP6_ECN_decapsulate(ipv6h, skb);
554                 if (unlikely(err)) {
555                         if (log_ecn_error)
556                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
557                                                      &ipv6h->saddr,
558                                                      ipv6_get_dsfield(ipv6h));
559                         if (err > 1) {
560                                 ++tunnel->dev->stats.rx_frame_errors;
561                                 ++tunnel->dev->stats.rx_errors;
562                                 goto drop;
563                         }
564                 }
565 
566                 tstats = this_cpu_ptr(tunnel->dev->tstats);
567                 u64_stats_update_begin(&tstats->syncp);
568                 tstats->rx_packets++;
569                 tstats->rx_bytes += skb->len;
570                 u64_stats_update_end(&tstats->syncp);
571 
572                 netif_rx(skb);
573 
574                 return 0;
575         }
576         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
577 
578 drop:
579         kfree_skb(skb);
580         return 0;
581 }
582 
583 struct ipv6_tel_txoption {
584         struct ipv6_txoptions ops;
585         __u8 dst_opt[8];
586 };
587 
588 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
589 {
590         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
591 
592         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
593         opt->dst_opt[3] = 1;
594         opt->dst_opt[4] = encap_limit;
595         opt->dst_opt[5] = IPV6_TLV_PADN;
596         opt->dst_opt[6] = 1;
597 
598         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
599         opt->ops.opt_nflen = 8;
600 }
601 
602 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
603                          struct net_device *dev,
604                          __u8 dsfield,
605                          struct flowi6 *fl6,
606                          int encap_limit,
607                          __u32 *pmtu)
608 {
609         struct ip6_tnl *tunnel = netdev_priv(dev);
610         struct net *net = tunnel->net;
611         struct net_device *tdev;    /* Device to other host */
612         struct ipv6hdr  *ipv6h;     /* Our new IP header */
613         unsigned int max_headroom = 0; /* The extra header space needed */
614         int    gre_hlen;
615         struct ipv6_tel_txoption opt;
616         int    mtu;
617         struct dst_entry *dst = NULL, *ndst = NULL;
618         struct net_device_stats *stats = &tunnel->dev->stats;
619         int err = -1;
620         u8 proto;
621         struct sk_buff *new_skb;
622         __be16 protocol;
623 
624         if (dev->type == ARPHRD_ETHER)
625                 IPCB(skb)->flags = 0;
626 
627         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
628                 gre_hlen = 0;
629                 ipv6h = (struct ipv6hdr *)skb->data;
630                 fl6->daddr = ipv6h->daddr;
631         } else {
632                 gre_hlen = tunnel->hlen;
633                 fl6->daddr = tunnel->parms.raddr;
634         }
635 
636         if (!fl6->flowi6_mark)
637                 dst = ip6_tnl_dst_get(tunnel);
638 
639         if (!dst) {
640                 dst = ip6_route_output(net, NULL, fl6);
641 
642                 if (dst->error)
643                         goto tx_err_link_failure;
644                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
645                 if (IS_ERR(dst)) {
646                         err = PTR_ERR(dst);
647                         dst = NULL;
648                         goto tx_err_link_failure;
649                 }
650                 ndst = dst;
651         }
652 
653         tdev = dst->dev;
654 
655         if (tdev == dev) {
656                 stats->collisions++;
657                 net_warn_ratelimited("%s: Local routing loop detected!\n",
658                                      tunnel->parms.name);
659                 goto tx_err_dst_release;
660         }
661 
662         mtu = dst_mtu(dst) - sizeof(*ipv6h);
663         if (encap_limit >= 0) {
664                 max_headroom += 8;
665                 mtu -= 8;
666         }
667         if (mtu < IPV6_MIN_MTU)
668                 mtu = IPV6_MIN_MTU;
669         if (skb_dst(skb))
670                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
671         if (skb->len > mtu) {
672                 *pmtu = mtu;
673                 err = -EMSGSIZE;
674                 goto tx_err_dst_release;
675         }
676 
677         if (tunnel->err_count > 0) {
678                 if (time_before(jiffies,
679                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
680                         tunnel->err_count--;
681 
682                         dst_link_failure(skb);
683                 } else
684                         tunnel->err_count = 0;
685         }
686 
687         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
688 
689         max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
690 
691         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
692             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
693                 new_skb = skb_realloc_headroom(skb, max_headroom);
694                 if (max_headroom > dev->needed_headroom)
695                         dev->needed_headroom = max_headroom;
696                 if (!new_skb)
697                         goto tx_err_dst_release;
698 
699                 if (skb->sk)
700                         skb_set_owner_w(new_skb, skb->sk);
701                 consume_skb(skb);
702                 skb = new_skb;
703         }
704 
705         if (!fl6->flowi6_mark && ndst)
706                 ip6_tnl_dst_set(tunnel, ndst);
707         skb_dst_set(skb, dst);
708 
709         proto = NEXTHDR_GRE;
710         if (encap_limit >= 0) {
711                 init_tel_txopt(&opt, encap_limit);
712                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
713         }
714 
715         if (likely(!skb->encapsulation)) {
716                 skb_reset_inner_headers(skb);
717                 skb->encapsulation = 1;
718         }
719 
720         skb_push(skb, gre_hlen);
721         skb_reset_network_header(skb);
722         skb_set_transport_header(skb, sizeof(*ipv6h));
723 
724         /*
725          *      Push down and install the IP header.
726          */
727         ipv6h = ipv6_hdr(skb);
728         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
729                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
730         ipv6h->hop_limit = tunnel->parms.hop_limit;
731         ipv6h->nexthdr = proto;
732         ipv6h->saddr = fl6->saddr;
733         ipv6h->daddr = fl6->daddr;
734 
735         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
736         protocol = (dev->type == ARPHRD_ETHER) ?
737                     htons(ETH_P_TEB) : skb->protocol;
738         ((__be16 *)(ipv6h + 1))[1] = protocol;
739 
740         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
741                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
742 
743                 if (tunnel->parms.o_flags&GRE_SEQ) {
744                         ++tunnel->o_seqno;
745                         *ptr = htonl(tunnel->o_seqno);
746                         ptr--;
747                 }
748                 if (tunnel->parms.o_flags&GRE_KEY) {
749                         *ptr = tunnel->parms.o_key;
750                         ptr--;
751                 }
752                 if (tunnel->parms.o_flags&GRE_CSUM) {
753                         *ptr = 0;
754                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
755                                 skb->len - sizeof(struct ipv6hdr));
756                 }
757         }
758 
759         skb_set_inner_protocol(skb, protocol);
760 
761         ip6tunnel_xmit(NULL, skb, dev);
762         return 0;
763 tx_err_link_failure:
764         stats->tx_carrier_errors++;
765         dst_link_failure(skb);
766 tx_err_dst_release:
767         dst_release(dst);
768         return err;
769 }
770 
771 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
772 {
773         struct ip6_tnl *t = netdev_priv(dev);
774         const struct iphdr  *iph = ip_hdr(skb);
775         int encap_limit = -1;
776         struct flowi6 fl6;
777         __u8 dsfield;
778         __u32 mtu;
779         int err;
780 
781         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
782                 encap_limit = t->parms.encap_limit;
783 
784         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
785         fl6.flowi6_proto = IPPROTO_GRE;
786 
787         dsfield = ipv4_get_dsfield(iph);
788 
789         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
790                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
791                                           & IPV6_TCLASS_MASK;
792         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
793                 fl6.flowi6_mark = skb->mark;
794 
795         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
796         if (err != 0) {
797                 /* XXX: send ICMP error even if DF is not set. */
798                 if (err == -EMSGSIZE)
799                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
800                                   htonl(mtu));
801                 return -1;
802         }
803 
804         return 0;
805 }
806 
807 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
808 {
809         struct ip6_tnl *t = netdev_priv(dev);
810         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
811         int encap_limit = -1;
812         __u16 offset;
813         struct flowi6 fl6;
814         __u8 dsfield;
815         __u32 mtu;
816         int err;
817 
818         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
819                 return -1;
820 
821         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
822         if (offset > 0) {
823                 struct ipv6_tlv_tnl_enc_lim *tel;
824                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
825                 if (tel->encap_limit == 0) {
826                         icmpv6_send(skb, ICMPV6_PARAMPROB,
827                                     ICMPV6_HDR_FIELD, offset + 2);
828                         return -1;
829                 }
830                 encap_limit = tel->encap_limit - 1;
831         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
832                 encap_limit = t->parms.encap_limit;
833 
834         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
835         fl6.flowi6_proto = IPPROTO_GRE;
836 
837         dsfield = ipv6_get_dsfield(ipv6h);
838         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
839                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
840         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
841                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
842         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
843                 fl6.flowi6_mark = skb->mark;
844 
845         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
846         if (err != 0) {
847                 if (err == -EMSGSIZE)
848                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
849                 return -1;
850         }
851 
852         return 0;
853 }
854 
855 /**
856  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
857  *   @t: the outgoing tunnel device
858  *   @hdr: IPv6 header from the incoming packet
859  *
860  * Description:
861  *   Avoid trivial tunneling loop by checking that tunnel exit-point
862  *   doesn't match source of incoming packet.
863  *
864  * Return:
865  *   1 if conflict,
866  *   0 else
867  **/
868 
869 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
870         const struct ipv6hdr *hdr)
871 {
872         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
873 }
874 
875 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
876 {
877         struct ip6_tnl *t = netdev_priv(dev);
878         int encap_limit = -1;
879         struct flowi6 fl6;
880         __u32 mtu;
881         int err;
882 
883         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
884                 encap_limit = t->parms.encap_limit;
885 
886         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
887         fl6.flowi6_proto = skb->protocol;
888 
889         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
890 
891         return err;
892 }
893 
894 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
895         struct net_device *dev)
896 {
897         struct ip6_tnl *t = netdev_priv(dev);
898         struct net_device_stats *stats = &t->dev->stats;
899         int ret;
900 
901         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
902                 goto tx_err;
903 
904         switch (skb->protocol) {
905         case htons(ETH_P_IP):
906                 ret = ip6gre_xmit_ipv4(skb, dev);
907                 break;
908         case htons(ETH_P_IPV6):
909                 ret = ip6gre_xmit_ipv6(skb, dev);
910                 break;
911         default:
912                 ret = ip6gre_xmit_other(skb, dev);
913                 break;
914         }
915 
916         if (ret < 0)
917                 goto tx_err;
918 
919         return NETDEV_TX_OK;
920 
921 tx_err:
922         stats->tx_errors++;
923         stats->tx_dropped++;
924         kfree_skb(skb);
925         return NETDEV_TX_OK;
926 }
927 
928 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
929 {
930         struct net_device *dev = t->dev;
931         struct __ip6_tnl_parm *p = &t->parms;
932         struct flowi6 *fl6 = &t->fl.u.ip6;
933         int addend = sizeof(struct ipv6hdr) + 4;
934 
935         if (dev->type != ARPHRD_ETHER) {
936                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
937                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
938         }
939 
940         /* Set up flowi template */
941         fl6->saddr = p->laddr;
942         fl6->daddr = p->raddr;
943         fl6->flowi6_oif = p->link;
944         fl6->flowlabel = 0;
945 
946         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
947                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
948         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
949                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
950 
951         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
952         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
953 
954         if (p->flags&IP6_TNL_F_CAP_XMIT &&
955                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
956                 dev->flags |= IFF_POINTOPOINT;
957         else
958                 dev->flags &= ~IFF_POINTOPOINT;
959 
960         /* Precalculate GRE options length */
961         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
962                 if (t->parms.o_flags&GRE_CSUM)
963                         addend += 4;
964                 if (t->parms.o_flags&GRE_KEY)
965                         addend += 4;
966                 if (t->parms.o_flags&GRE_SEQ)
967                         addend += 4;
968         }
969         t->hlen = addend;
970 
971         if (p->flags & IP6_TNL_F_CAP_XMIT) {
972                 int strict = (ipv6_addr_type(&p->raddr) &
973                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
974 
975                 struct rt6_info *rt = rt6_lookup(t->net,
976                                                  &p->raddr, &p->laddr,
977                                                  p->link, strict);
978 
979                 if (!rt)
980                         return;
981 
982                 if (rt->dst.dev) {
983                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
984 
985                         if (set_mtu) {
986                                 dev->mtu = rt->dst.dev->mtu - addend;
987                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
988                                         dev->mtu -= 8;
989 
990                                 if (dev->mtu < IPV6_MIN_MTU)
991                                         dev->mtu = IPV6_MIN_MTU;
992                         }
993                 }
994                 ip6_rt_put(rt);
995         }
996 }
997 
998 static int ip6gre_tnl_change(struct ip6_tnl *t,
999         const struct __ip6_tnl_parm *p, int set_mtu)
1000 {
1001         t->parms.laddr = p->laddr;
1002         t->parms.raddr = p->raddr;
1003         t->parms.flags = p->flags;
1004         t->parms.hop_limit = p->hop_limit;
1005         t->parms.encap_limit = p->encap_limit;
1006         t->parms.flowinfo = p->flowinfo;
1007         t->parms.link = p->link;
1008         t->parms.proto = p->proto;
1009         t->parms.i_key = p->i_key;
1010         t->parms.o_key = p->o_key;
1011         t->parms.i_flags = p->i_flags;
1012         t->parms.o_flags = p->o_flags;
1013         ip6_tnl_dst_reset(t);
1014         ip6gre_tnl_link_config(t, set_mtu);
1015         return 0;
1016 }
1017 
1018 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1019         const struct ip6_tnl_parm2 *u)
1020 {
1021         p->laddr = u->laddr;
1022         p->raddr = u->raddr;
1023         p->flags = u->flags;
1024         p->hop_limit = u->hop_limit;
1025         p->encap_limit = u->encap_limit;
1026         p->flowinfo = u->flowinfo;
1027         p->link = u->link;
1028         p->i_key = u->i_key;
1029         p->o_key = u->o_key;
1030         p->i_flags = u->i_flags;
1031         p->o_flags = u->o_flags;
1032         memcpy(p->name, u->name, sizeof(u->name));
1033 }
1034 
1035 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1036         const struct __ip6_tnl_parm *p)
1037 {
1038         u->proto = IPPROTO_GRE;
1039         u->laddr = p->laddr;
1040         u->raddr = p->raddr;
1041         u->flags = p->flags;
1042         u->hop_limit = p->hop_limit;
1043         u->encap_limit = p->encap_limit;
1044         u->flowinfo = p->flowinfo;
1045         u->link = p->link;
1046         u->i_key = p->i_key;
1047         u->o_key = p->o_key;
1048         u->i_flags = p->i_flags;
1049         u->o_flags = p->o_flags;
1050         memcpy(u->name, p->name, sizeof(u->name));
1051 }
1052 
1053 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1054         struct ifreq *ifr, int cmd)
1055 {
1056         int err = 0;
1057         struct ip6_tnl_parm2 p;
1058         struct __ip6_tnl_parm p1;
1059         struct ip6_tnl *t = netdev_priv(dev);
1060         struct net *net = t->net;
1061         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1062 
1063         switch (cmd) {
1064         case SIOCGETTUNNEL:
1065                 if (dev == ign->fb_tunnel_dev) {
1066                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1067                                 err = -EFAULT;
1068                                 break;
1069                         }
1070                         ip6gre_tnl_parm_from_user(&p1, &p);
1071                         t = ip6gre_tunnel_locate(net, &p1, 0);
1072                         if (!t)
1073                                 t = netdev_priv(dev);
1074                 }
1075                 memset(&p, 0, sizeof(p));
1076                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1077                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1078                         err = -EFAULT;
1079                 break;
1080 
1081         case SIOCADDTUNNEL:
1082         case SIOCCHGTUNNEL:
1083                 err = -EPERM;
1084                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1085                         goto done;
1086 
1087                 err = -EFAULT;
1088                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1089                         goto done;
1090 
1091                 err = -EINVAL;
1092                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1093                         goto done;
1094 
1095                 if (!(p.i_flags&GRE_KEY))
1096                         p.i_key = 0;
1097                 if (!(p.o_flags&GRE_KEY))
1098                         p.o_key = 0;
1099 
1100                 ip6gre_tnl_parm_from_user(&p1, &p);
1101                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1102 
1103                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1104                         if (t) {
1105                                 if (t->dev != dev) {
1106                                         err = -EEXIST;
1107                                         break;
1108                                 }
1109                         } else {
1110                                 t = netdev_priv(dev);
1111 
1112                                 ip6gre_tunnel_unlink(ign, t);
1113                                 synchronize_net();
1114                                 ip6gre_tnl_change(t, &p1, 1);
1115                                 ip6gre_tunnel_link(ign, t);
1116                                 netdev_state_change(dev);
1117                         }
1118                 }
1119 
1120                 if (t) {
1121                         err = 0;
1122 
1123                         memset(&p, 0, sizeof(p));
1124                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1125                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1126                                 err = -EFAULT;
1127                 } else
1128                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1129                 break;
1130 
1131         case SIOCDELTUNNEL:
1132                 err = -EPERM;
1133                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1134                         goto done;
1135 
1136                 if (dev == ign->fb_tunnel_dev) {
1137                         err = -EFAULT;
1138                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1139                                 goto done;
1140                         err = -ENOENT;
1141                         ip6gre_tnl_parm_from_user(&p1, &p);
1142                         t = ip6gre_tunnel_locate(net, &p1, 0);
1143                         if (!t)
1144                                 goto done;
1145                         err = -EPERM;
1146                         if (t == netdev_priv(ign->fb_tunnel_dev))
1147                                 goto done;
1148                         dev = t->dev;
1149                 }
1150                 unregister_netdevice(dev);
1151                 err = 0;
1152                 break;
1153 
1154         default:
1155                 err = -EINVAL;
1156         }
1157 
1158 done:
1159         return err;
1160 }
1161 
1162 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1163 {
1164         if (new_mtu < 68 ||
1165             new_mtu > 0xFFF8 - dev->hard_header_len)
1166                 return -EINVAL;
1167         dev->mtu = new_mtu;
1168         return 0;
1169 }
1170 
1171 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1172                         unsigned short type,
1173                         const void *daddr, const void *saddr, unsigned int len)
1174 {
1175         struct ip6_tnl *t = netdev_priv(dev);
1176         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1177         __be16 *p = (__be16 *)(ipv6h+1);
1178 
1179         ip6_flow_hdr(ipv6h, 0,
1180                      ip6_make_flowlabel(dev_net(dev), skb,
1181                                         t->fl.u.ip6.flowlabel, true,
1182                                         &t->fl.u.ip6));
1183         ipv6h->hop_limit = t->parms.hop_limit;
1184         ipv6h->nexthdr = NEXTHDR_GRE;
1185         ipv6h->saddr = t->parms.laddr;
1186         ipv6h->daddr = t->parms.raddr;
1187 
1188         p[0]            = t->parms.o_flags;
1189         p[1]            = htons(type);
1190 
1191         /*
1192          *      Set the source hardware address.
1193          */
1194 
1195         if (saddr)
1196                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1197         if (daddr)
1198                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1199         if (!ipv6_addr_any(&ipv6h->daddr))
1200                 return t->hlen;
1201 
1202         return -t->hlen;
1203 }
1204 
1205 static const struct header_ops ip6gre_header_ops = {
1206         .create = ip6gre_header,
1207 };
1208 
1209 static const struct net_device_ops ip6gre_netdev_ops = {
1210         .ndo_init               = ip6gre_tunnel_init,
1211         .ndo_uninit             = ip6gre_tunnel_uninit,
1212         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1213         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1214         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1215         .ndo_get_stats64        = ip_tunnel_get_stats64,
1216         .ndo_get_iflink         = ip6_tnl_get_iflink,
1217 };
1218 
1219 static void ip6gre_dev_free(struct net_device *dev)
1220 {
1221         struct ip6_tnl *t = netdev_priv(dev);
1222 
1223         ip6_tnl_dst_destroy(t);
1224         free_percpu(dev->tstats);
1225         free_netdev(dev);
1226 }
1227 
1228 static void ip6gre_tunnel_setup(struct net_device *dev)
1229 {
1230         struct ip6_tnl *t;
1231 
1232         dev->netdev_ops = &ip6gre_netdev_ops;
1233         dev->destructor = ip6gre_dev_free;
1234 
1235         dev->type = ARPHRD_IP6GRE;
1236         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1237         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1238         t = netdev_priv(dev);
1239         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1240                 dev->mtu -= 8;
1241         dev->flags |= IFF_NOARP;
1242         dev->addr_len = sizeof(struct in6_addr);
1243         netif_keep_dst(dev);
1244 }
1245 
1246 static int ip6gre_tunnel_init_common(struct net_device *dev)
1247 {
1248         struct ip6_tnl *tunnel;
1249         int ret;
1250 
1251         tunnel = netdev_priv(dev);
1252 
1253         tunnel->dev = dev;
1254         tunnel->net = dev_net(dev);
1255         strcpy(tunnel->parms.name, dev->name);
1256 
1257         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1258         if (!dev->tstats)
1259                 return -ENOMEM;
1260 
1261         ret = ip6_tnl_dst_init(tunnel);
1262         if (ret) {
1263                 free_percpu(dev->tstats);
1264                 dev->tstats = NULL;
1265                 return ret;
1266         }
1267 
1268         return 0;
1269 }
1270 
1271 static int ip6gre_tunnel_init(struct net_device *dev)
1272 {
1273         struct ip6_tnl *tunnel;
1274         int ret;
1275 
1276         ret = ip6gre_tunnel_init_common(dev);
1277         if (ret)
1278                 return ret;
1279 
1280         tunnel = netdev_priv(dev);
1281 
1282         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1283         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1284 
1285         if (ipv6_addr_any(&tunnel->parms.raddr))
1286                 dev->header_ops = &ip6gre_header_ops;
1287 
1288         return 0;
1289 }
1290 
1291 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1292 {
1293         struct ip6_tnl *tunnel = netdev_priv(dev);
1294 
1295         tunnel->dev = dev;
1296         tunnel->net = dev_net(dev);
1297         strcpy(tunnel->parms.name, dev->name);
1298 
1299         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1300 
1301         dev_hold(dev);
1302 }
1303 
1304 
1305 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1306         .handler     = ip6gre_rcv,
1307         .err_handler = ip6gre_err,
1308         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1309 };
1310 
1311 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1312 {
1313         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1314         struct net_device *dev, *aux;
1315         int prio;
1316 
1317         for_each_netdev_safe(net, dev, aux)
1318                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1319                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1320                         unregister_netdevice_queue(dev, head);
1321 
1322         for (prio = 0; prio < 4; prio++) {
1323                 int h;
1324                 for (h = 0; h < HASH_SIZE; h++) {
1325                         struct ip6_tnl *t;
1326 
1327                         t = rtnl_dereference(ign->tunnels[prio][h]);
1328 
1329                         while (t) {
1330                                 /* If dev is in the same netns, it has already
1331                                  * been added to the list by the previous loop.
1332                                  */
1333                                 if (!net_eq(dev_net(t->dev), net))
1334                                         unregister_netdevice_queue(t->dev,
1335                                                                    head);
1336                                 t = rtnl_dereference(t->next);
1337                         }
1338                 }
1339         }
1340 }
1341 
1342 static int __net_init ip6gre_init_net(struct net *net)
1343 {
1344         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1345         int err;
1346 
1347         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1348                                           NET_NAME_UNKNOWN,
1349                                           ip6gre_tunnel_setup);
1350         if (!ign->fb_tunnel_dev) {
1351                 err = -ENOMEM;
1352                 goto err_alloc_dev;
1353         }
1354         dev_net_set(ign->fb_tunnel_dev, net);
1355         /* FB netdevice is special: we have one, and only one per netns.
1356          * Allowing to move it to another netns is clearly unsafe.
1357          */
1358         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1359 
1360 
1361         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1362         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1363 
1364         err = register_netdev(ign->fb_tunnel_dev);
1365         if (err)
1366                 goto err_reg_dev;
1367 
1368         rcu_assign_pointer(ign->tunnels_wc[0],
1369                            netdev_priv(ign->fb_tunnel_dev));
1370         return 0;
1371 
1372 err_reg_dev:
1373         ip6gre_dev_free(ign->fb_tunnel_dev);
1374 err_alloc_dev:
1375         return err;
1376 }
1377 
1378 static void __net_exit ip6gre_exit_net(struct net *net)
1379 {
1380         LIST_HEAD(list);
1381 
1382         rtnl_lock();
1383         ip6gre_destroy_tunnels(net, &list);
1384         unregister_netdevice_many(&list);
1385         rtnl_unlock();
1386 }
1387 
1388 static struct pernet_operations ip6gre_net_ops = {
1389         .init = ip6gre_init_net,
1390         .exit = ip6gre_exit_net,
1391         .id   = &ip6gre_net_id,
1392         .size = sizeof(struct ip6gre_net),
1393 };
1394 
1395 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1396 {
1397         __be16 flags;
1398 
1399         if (!data)
1400                 return 0;
1401 
1402         flags = 0;
1403         if (data[IFLA_GRE_IFLAGS])
1404                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1405         if (data[IFLA_GRE_OFLAGS])
1406                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1407         if (flags & (GRE_VERSION|GRE_ROUTING))
1408                 return -EINVAL;
1409 
1410         return 0;
1411 }
1412 
1413 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1414 {
1415         struct in6_addr daddr;
1416 
1417         if (tb[IFLA_ADDRESS]) {
1418                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1419                         return -EINVAL;
1420                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1421                         return -EADDRNOTAVAIL;
1422         }
1423 
1424         if (!data)
1425                 goto out;
1426 
1427         if (data[IFLA_GRE_REMOTE]) {
1428                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1429                 if (ipv6_addr_any(&daddr))
1430                         return -EINVAL;
1431         }
1432 
1433 out:
1434         return ip6gre_tunnel_validate(tb, data);
1435 }
1436 
1437 
1438 static void ip6gre_netlink_parms(struct nlattr *data[],
1439                                 struct __ip6_tnl_parm *parms)
1440 {
1441         memset(parms, 0, sizeof(*parms));
1442 
1443         if (!data)
1444                 return;
1445 
1446         if (data[IFLA_GRE_LINK])
1447                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1448 
1449         if (data[IFLA_GRE_IFLAGS])
1450                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1451 
1452         if (data[IFLA_GRE_OFLAGS])
1453                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1454 
1455         if (data[IFLA_GRE_IKEY])
1456                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1457 
1458         if (data[IFLA_GRE_OKEY])
1459                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1460 
1461         if (data[IFLA_GRE_LOCAL])
1462                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1463 
1464         if (data[IFLA_GRE_REMOTE])
1465                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1466 
1467         if (data[IFLA_GRE_TTL])
1468                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1469 
1470         if (data[IFLA_GRE_ENCAP_LIMIT])
1471                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1472 
1473         if (data[IFLA_GRE_FLOWINFO])
1474                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1475 
1476         if (data[IFLA_GRE_FLAGS])
1477                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1478 }
1479 
1480 static int ip6gre_tap_init(struct net_device *dev)
1481 {
1482         struct ip6_tnl *tunnel;
1483         int ret;
1484 
1485         ret = ip6gre_tunnel_init_common(dev);
1486         if (ret)
1487                 return ret;
1488 
1489         tunnel = netdev_priv(dev);
1490 
1491         ip6gre_tnl_link_config(tunnel, 1);
1492 
1493         return 0;
1494 }
1495 
1496 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1497         .ndo_init = ip6gre_tap_init,
1498         .ndo_uninit = ip6gre_tunnel_uninit,
1499         .ndo_start_xmit = ip6gre_tunnel_xmit,
1500         .ndo_set_mac_address = eth_mac_addr,
1501         .ndo_validate_addr = eth_validate_addr,
1502         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1503         .ndo_get_stats64 = ip_tunnel_get_stats64,
1504         .ndo_get_iflink = ip6_tnl_get_iflink,
1505 };
1506 
1507 static void ip6gre_tap_setup(struct net_device *dev)
1508 {
1509 
1510         ether_setup(dev);
1511 
1512         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1513         dev->destructor = ip6gre_dev_free;
1514 
1515         dev->features |= NETIF_F_NETNS_LOCAL;
1516 }
1517 
1518 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1519         struct nlattr *tb[], struct nlattr *data[])
1520 {
1521         struct ip6_tnl *nt;
1522         struct net *net = dev_net(dev);
1523         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1524         int err;
1525 
1526         nt = netdev_priv(dev);
1527         ip6gre_netlink_parms(data, &nt->parms);
1528 
1529         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1530                 return -EEXIST;
1531 
1532         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1533                 eth_hw_addr_random(dev);
1534 
1535         nt->dev = dev;
1536         nt->net = dev_net(dev);
1537         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1538 
1539         /* Can use a lockless transmit, unless we generate output sequences */
1540         if (!(nt->parms.o_flags & GRE_SEQ))
1541                 dev->features |= NETIF_F_LLTX;
1542 
1543         err = register_netdevice(dev);
1544         if (err)
1545                 goto out;
1546 
1547         dev_hold(dev);
1548         ip6gre_tunnel_link(ign, nt);
1549 
1550 out:
1551         return err;
1552 }
1553 
1554 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1555                             struct nlattr *data[])
1556 {
1557         struct ip6_tnl *t, *nt = netdev_priv(dev);
1558         struct net *net = nt->net;
1559         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1560         struct __ip6_tnl_parm p;
1561 
1562         if (dev == ign->fb_tunnel_dev)
1563                 return -EINVAL;
1564 
1565         ip6gre_netlink_parms(data, &p);
1566 
1567         t = ip6gre_tunnel_locate(net, &p, 0);
1568 
1569         if (t) {
1570                 if (t->dev != dev)
1571                         return -EEXIST;
1572         } else {
1573                 t = nt;
1574         }
1575 
1576         ip6gre_tunnel_unlink(ign, t);
1577         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1578         ip6gre_tunnel_link(ign, t);
1579         return 0;
1580 }
1581 
1582 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1583 {
1584         struct net *net = dev_net(dev);
1585         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1586 
1587         if (dev != ign->fb_tunnel_dev)
1588                 unregister_netdevice_queue(dev, head);
1589 }
1590 
1591 static size_t ip6gre_get_size(const struct net_device *dev)
1592 {
1593         return
1594                 /* IFLA_GRE_LINK */
1595                 nla_total_size(4) +
1596                 /* IFLA_GRE_IFLAGS */
1597                 nla_total_size(2) +
1598                 /* IFLA_GRE_OFLAGS */
1599                 nla_total_size(2) +
1600                 /* IFLA_GRE_IKEY */
1601                 nla_total_size(4) +
1602                 /* IFLA_GRE_OKEY */
1603                 nla_total_size(4) +
1604                 /* IFLA_GRE_LOCAL */
1605                 nla_total_size(sizeof(struct in6_addr)) +
1606                 /* IFLA_GRE_REMOTE */
1607                 nla_total_size(sizeof(struct in6_addr)) +
1608                 /* IFLA_GRE_TTL */
1609                 nla_total_size(1) +
1610                 /* IFLA_GRE_TOS */
1611                 nla_total_size(1) +
1612                 /* IFLA_GRE_ENCAP_LIMIT */
1613                 nla_total_size(1) +
1614                 /* IFLA_GRE_FLOWINFO */
1615                 nla_total_size(4) +
1616                 /* IFLA_GRE_FLAGS */
1617                 nla_total_size(4) +
1618                 0;
1619 }
1620 
1621 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1622 {
1623         struct ip6_tnl *t = netdev_priv(dev);
1624         struct __ip6_tnl_parm *p = &t->parms;
1625 
1626         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1627             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1628             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1629             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1630             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1631             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1632             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1633             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1634             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1635             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1636             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1637             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1638                 goto nla_put_failure;
1639         return 0;
1640 
1641 nla_put_failure:
1642         return -EMSGSIZE;
1643 }
1644 
1645 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1646         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1647         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1648         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1649         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1650         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1651         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1652         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1653         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1654         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1655         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1656         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1657 };
1658 
1659 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1660         .kind           = "ip6gre",
1661         .maxtype        = IFLA_GRE_MAX,
1662         .policy         = ip6gre_policy,
1663         .priv_size      = sizeof(struct ip6_tnl),
1664         .setup          = ip6gre_tunnel_setup,
1665         .validate       = ip6gre_tunnel_validate,
1666         .newlink        = ip6gre_newlink,
1667         .changelink     = ip6gre_changelink,
1668         .dellink        = ip6gre_dellink,
1669         .get_size       = ip6gre_get_size,
1670         .fill_info      = ip6gre_fill_info,
1671         .get_link_net   = ip6_tnl_get_link_net,
1672 };
1673 
1674 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1675         .kind           = "ip6gretap",
1676         .maxtype        = IFLA_GRE_MAX,
1677         .policy         = ip6gre_policy,
1678         .priv_size      = sizeof(struct ip6_tnl),
1679         .setup          = ip6gre_tap_setup,
1680         .validate       = ip6gre_tap_validate,
1681         .newlink        = ip6gre_newlink,
1682         .changelink     = ip6gre_changelink,
1683         .get_size       = ip6gre_get_size,
1684         .fill_info      = ip6gre_fill_info,
1685         .get_link_net   = ip6_tnl_get_link_net,
1686 };
1687 
1688 /*
1689  *      And now the modules code and kernel interface.
1690  */
1691 
1692 static int __init ip6gre_init(void)
1693 {
1694         int err;
1695 
1696         pr_info("GRE over IPv6 tunneling driver\n");
1697 
1698         err = register_pernet_device(&ip6gre_net_ops);
1699         if (err < 0)
1700                 return err;
1701 
1702         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1703         if (err < 0) {
1704                 pr_info("%s: can't add protocol\n", __func__);
1705                 goto add_proto_failed;
1706         }
1707 
1708         err = rtnl_link_register(&ip6gre_link_ops);
1709         if (err < 0)
1710                 goto rtnl_link_failed;
1711 
1712         err = rtnl_link_register(&ip6gre_tap_ops);
1713         if (err < 0)
1714                 goto tap_ops_failed;
1715 
1716 out:
1717         return err;
1718 
1719 tap_ops_failed:
1720         rtnl_link_unregister(&ip6gre_link_ops);
1721 rtnl_link_failed:
1722         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1723 add_proto_failed:
1724         unregister_pernet_device(&ip6gre_net_ops);
1725         goto out;
1726 }
1727 
1728 static void __exit ip6gre_fini(void)
1729 {
1730         rtnl_link_unregister(&ip6gre_tap_ops);
1731         rtnl_link_unregister(&ip6gre_link_ops);
1732         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1733         unregister_pernet_device(&ip6gre_net_ops);
1734 }
1735 
1736 module_init(ip6gre_init);
1737 module_exit(ip6gre_fini);
1738 MODULE_LICENSE("GPL");
1739 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1740 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1741 MODULE_ALIAS_RTNL_LINK("ip6gre");
1742 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1743 MODULE_ALIAS_NETDEV("ip6gre0");
1744 

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