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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/init.h>
 28 #include <linux/in6.h>
 29 #include <linux/inetdevice.h>
 30 #include <linux/igmp.h>
 31 #include <linux/netfilter_ipv4.h>
 32 #include <linux/etherdevice.h>
 33 #include <linux/if_ether.h>
 34 #include <linux/hash.h>
 35 #include <linux/if_tunnel.h>
 36 #include <linux/ip6_tunnel.h>
 37 
 38 #include <net/sock.h>
 39 #include <net/ip.h>
 40 #include <net/ip_tunnels.h>
 41 #include <net/icmp.h>
 42 #include <net/protocol.h>
 43 #include <net/addrconf.h>
 44 #include <net/arp.h>
 45 #include <net/checksum.h>
 46 #include <net/dsfield.h>
 47 #include <net/inet_ecn.h>
 48 #include <net/xfrm.h>
 49 #include <net/net_namespace.h>
 50 #include <net/netns/generic.h>
 51 #include <net/rtnetlink.h>
 52 
 53 #include <net/ipv6.h>
 54 #include <net/ip6_fib.h>
 55 #include <net/ip6_route.h>
 56 #include <net/ip6_tunnel.h>
 57 #include <net/gre.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 IP6_GRE_HASH_SIZE_SHIFT  5
 65 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
 66 
 67 static unsigned int ip6gre_net_id __read_mostly;
 68 struct ip6gre_net {
 69         struct ip6_tnl __rcu *tunnels[4][IP6_GRE_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))&(IP6_GRE_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, IP6_GRE_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 & TUNNEL_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         dst_cache_reset(&t->dst_cache);
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 gre_base_hdr *greh;
373         const struct ipv6hdr *ipv6h;
374         int grehlen = sizeof(*greh);
375         struct ip6_tnl *t;
376         int key_off = 0;
377         __be16 flags;
378         __be32 key;
379 
380         if (!pskb_may_pull(skb, offset + grehlen))
381                 return;
382         greh = (const struct gre_base_hdr *)(skb->data + offset);
383         flags = greh->flags;
384         if (flags & (GRE_VERSION | GRE_ROUTING))
385                 return;
386         if (flags & GRE_CSUM)
387                 grehlen += 4;
388         if (flags & GRE_KEY) {
389                 key_off = grehlen + offset;
390                 grehlen += 4;
391         }
392 
393         if (!pskb_may_pull(skb, offset + grehlen))
394                 return;
395         ipv6h = (const struct ipv6hdr *)skb->data;
396         greh = (const struct gre_base_hdr *)(skb->data + offset);
397         key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
398 
399         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
400                                  key, greh->protocol);
401         if (!t)
402                 return;
403 
404         switch (type) {
405                 __u32 teli;
406                 struct ipv6_tlv_tnl_enc_lim *tel;
407                 __u32 mtu;
408         case ICMPV6_DEST_UNREACH:
409                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
410                                     t->parms.name);
411                 if (code != ICMPV6_PORT_UNREACH)
412                         break;
413                 return;
414         case ICMPV6_TIME_EXCEED:
415                 if (code == ICMPV6_EXC_HOPLIMIT) {
416                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
417                                             t->parms.name);
418                         break;
419                 }
420                 return;
421         case ICMPV6_PARAMPROB:
422                 teli = 0;
423                 if (code == ICMPV6_HDR_FIELD)
424                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
425 
426                 if (teli && teli == be32_to_cpu(info) - 2) {
427                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
428                         if (tel->encap_limit == 0) {
429                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
430                                                     t->parms.name);
431                         }
432                 } else {
433                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
434                                             t->parms.name);
435                 }
436                 return;
437         case ICMPV6_PKT_TOOBIG:
438                 mtu = be32_to_cpu(info) - offset - t->tun_hlen;
439                 if (t->dev->type == ARPHRD_ETHER)
440                         mtu -= ETH_HLEN;
441                 if (mtu < IPV6_MIN_MTU)
442                         mtu = IPV6_MIN_MTU;
443                 t->dev->mtu = mtu;
444                 return;
445         }
446 
447         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
448                 t->err_count++;
449         else
450                 t->err_count = 1;
451         t->err_time = jiffies;
452 }
453 
454 static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
455 {
456         const struct ipv6hdr *ipv6h;
457         struct ip6_tnl *tunnel;
458 
459         ipv6h = ipv6_hdr(skb);
460         tunnel = ip6gre_tunnel_lookup(skb->dev,
461                                       &ipv6h->saddr, &ipv6h->daddr, tpi->key,
462                                       tpi->proto);
463         if (tunnel) {
464                 ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
465 
466                 return PACKET_RCVD;
467         }
468 
469         return PACKET_REJECT;
470 }
471 
472 static int gre_rcv(struct sk_buff *skb)
473 {
474         struct tnl_ptk_info tpi;
475         bool csum_err = false;
476         int hdr_len;
477 
478         hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
479         if (hdr_len < 0)
480                 goto drop;
481 
482         if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
483                 goto drop;
484 
485         if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
486                 return 0;
487 
488         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
489 drop:
490         kfree_skb(skb);
491         return 0;
492 }
493 
494 static int gre_handle_offloads(struct sk_buff *skb, bool csum)
495 {
496         return iptunnel_handle_offloads(skb,
497                                         csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
498 }
499 
500 static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
501                                struct net_device *dev, __u8 dsfield,
502                                struct flowi6 *fl6, int encap_limit,
503                                __u32 *pmtu, __be16 proto)
504 {
505         struct ip6_tnl *tunnel = netdev_priv(dev);
506         struct dst_entry *dst = skb_dst(skb);
507         __be16 protocol;
508 
509         if (dev->type == ARPHRD_ETHER)
510                 IPCB(skb)->flags = 0;
511 
512         if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
513                 fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
514         else
515                 fl6->daddr = tunnel->parms.raddr;
516 
517         if (tunnel->parms.o_flags & TUNNEL_SEQ)
518                 tunnel->o_seqno++;
519 
520         /* Push GRE header. */
521         protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
522         gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
523                          protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
524 
525         /* TooBig packet may have updated dst->dev's mtu */
526         if (dst && dst_mtu(dst) > dst->dev->mtu)
527                 dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
528 
529         return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
530                             NEXTHDR_GRE);
531 }
532 
533 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
534 {
535         struct ip6_tnl *t = netdev_priv(dev);
536         const struct iphdr  *iph = ip_hdr(skb);
537         int encap_limit = -1;
538         struct flowi6 fl6;
539         __u8 dsfield;
540         __u32 mtu;
541         int err;
542 
543         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
544 
545         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
546                 encap_limit = t->parms.encap_limit;
547 
548         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
549 
550         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
551                 dsfield = ipv4_get_dsfield(iph);
552         else
553                 dsfield = ip6_tclass(t->parms.flowinfo);
554         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
555                 fl6.flowi6_mark = skb->mark;
556         else
557                 fl6.flowi6_mark = t->parms.fwmark;
558 
559         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
560 
561         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
562         if (err)
563                 return -1;
564 
565         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
566                           skb->protocol);
567         if (err != 0) {
568                 /* XXX: send ICMP error even if DF is not set. */
569                 if (err == -EMSGSIZE)
570                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
571                                   htonl(mtu));
572                 return -1;
573         }
574 
575         return 0;
576 }
577 
578 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
579 {
580         struct ip6_tnl *t = netdev_priv(dev);
581         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
582         int encap_limit = -1;
583         __u16 offset;
584         struct flowi6 fl6;
585         __u8 dsfield;
586         __u32 mtu;
587         int err;
588 
589         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
590                 return -1;
591 
592         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
593         /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
594         ipv6h = ipv6_hdr(skb);
595 
596         if (offset > 0) {
597                 struct ipv6_tlv_tnl_enc_lim *tel;
598                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
599                 if (tel->encap_limit == 0) {
600                         icmpv6_send(skb, ICMPV6_PARAMPROB,
601                                     ICMPV6_HDR_FIELD, offset + 2);
602                         return -1;
603                 }
604                 encap_limit = tel->encap_limit - 1;
605         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
606                 encap_limit = t->parms.encap_limit;
607 
608         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
609 
610         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
611                 dsfield = ipv6_get_dsfield(ipv6h);
612         else
613                 dsfield = ip6_tclass(t->parms.flowinfo);
614 
615         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
616                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
617         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
618                 fl6.flowi6_mark = skb->mark;
619         else
620                 fl6.flowi6_mark = t->parms.fwmark;
621 
622         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
623 
624         if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
625                 return -1;
626 
627         err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
628                           &mtu, skb->protocol);
629         if (err != 0) {
630                 if (err == -EMSGSIZE)
631                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
632                 return -1;
633         }
634 
635         return 0;
636 }
637 
638 /**
639  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
640  *   @t: the outgoing tunnel device
641  *   @hdr: IPv6 header from the incoming packet
642  *
643  * Description:
644  *   Avoid trivial tunneling loop by checking that tunnel exit-point
645  *   doesn't match source of incoming packet.
646  *
647  * Return:
648  *   1 if conflict,
649  *   0 else
650  **/
651 
652 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
653         const struct ipv6hdr *hdr)
654 {
655         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
656 }
657 
658 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
659 {
660         struct ip6_tnl *t = netdev_priv(dev);
661         int encap_limit = -1;
662         struct flowi6 fl6;
663         __u32 mtu;
664         int err;
665 
666         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
667                 encap_limit = t->parms.encap_limit;
668 
669         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
670 
671         err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
672         if (err)
673                 return err;
674 
675         err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
676 
677         return err;
678 }
679 
680 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
681         struct net_device *dev)
682 {
683         struct ip6_tnl *t = netdev_priv(dev);
684         struct net_device_stats *stats = &t->dev->stats;
685         int ret;
686 
687         if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
688                 goto tx_err;
689 
690         switch (skb->protocol) {
691         case htons(ETH_P_IP):
692                 ret = ip6gre_xmit_ipv4(skb, dev);
693                 break;
694         case htons(ETH_P_IPV6):
695                 ret = ip6gre_xmit_ipv6(skb, dev);
696                 break;
697         default:
698                 ret = ip6gre_xmit_other(skb, dev);
699                 break;
700         }
701 
702         if (ret < 0)
703                 goto tx_err;
704 
705         return NETDEV_TX_OK;
706 
707 tx_err:
708         stats->tx_errors++;
709         stats->tx_dropped++;
710         kfree_skb(skb);
711         return NETDEV_TX_OK;
712 }
713 
714 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
715 {
716         struct net_device *dev = t->dev;
717         struct __ip6_tnl_parm *p = &t->parms;
718         struct flowi6 *fl6 = &t->fl.u.ip6;
719         int t_hlen;
720 
721         if (dev->type != ARPHRD_ETHER) {
722                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
723                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
724         }
725 
726         /* Set up flowi template */
727         fl6->saddr = p->laddr;
728         fl6->daddr = p->raddr;
729         fl6->flowi6_oif = p->link;
730         fl6->flowlabel = 0;
731         fl6->flowi6_proto = IPPROTO_GRE;
732 
733         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
734                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
735         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
736                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
737 
738         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
739         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
740 
741         if (p->flags&IP6_TNL_F_CAP_XMIT &&
742                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
743                 dev->flags |= IFF_POINTOPOINT;
744         else
745                 dev->flags &= ~IFF_POINTOPOINT;
746 
747         t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
748 
749         t->hlen = t->encap_hlen + t->tun_hlen;
750 
751         t_hlen = t->hlen + sizeof(struct ipv6hdr);
752 
753         if (p->flags & IP6_TNL_F_CAP_XMIT) {
754                 int strict = (ipv6_addr_type(&p->raddr) &
755                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
756 
757                 struct rt6_info *rt = rt6_lookup(t->net,
758                                                  &p->raddr, &p->laddr,
759                                                  p->link, strict);
760 
761                 if (!rt)
762                         return;
763 
764                 if (rt->dst.dev) {
765                         dev->hard_header_len = rt->dst.dev->hard_header_len +
766                                                t_hlen;
767 
768                         if (set_mtu) {
769                                 dev->mtu = rt->dst.dev->mtu - t_hlen;
770                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
771                                         dev->mtu -= 8;
772                                 if (dev->type == ARPHRD_ETHER)
773                                         dev->mtu -= ETH_HLEN;
774 
775                                 if (dev->mtu < IPV6_MIN_MTU)
776                                         dev->mtu = IPV6_MIN_MTU;
777                         }
778                 }
779                 ip6_rt_put(rt);
780         }
781 }
782 
783 static int ip6gre_tnl_change(struct ip6_tnl *t,
784         const struct __ip6_tnl_parm *p, int set_mtu)
785 {
786         t->parms.laddr = p->laddr;
787         t->parms.raddr = p->raddr;
788         t->parms.flags = p->flags;
789         t->parms.hop_limit = p->hop_limit;
790         t->parms.encap_limit = p->encap_limit;
791         t->parms.flowinfo = p->flowinfo;
792         t->parms.link = p->link;
793         t->parms.proto = p->proto;
794         t->parms.i_key = p->i_key;
795         t->parms.o_key = p->o_key;
796         t->parms.i_flags = p->i_flags;
797         t->parms.o_flags = p->o_flags;
798         t->parms.fwmark = p->fwmark;
799         dst_cache_reset(&t->dst_cache);
800         ip6gre_tnl_link_config(t, set_mtu);
801         return 0;
802 }
803 
804 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
805         const struct ip6_tnl_parm2 *u)
806 {
807         p->laddr = u->laddr;
808         p->raddr = u->raddr;
809         p->flags = u->flags;
810         p->hop_limit = u->hop_limit;
811         p->encap_limit = u->encap_limit;
812         p->flowinfo = u->flowinfo;
813         p->link = u->link;
814         p->i_key = u->i_key;
815         p->o_key = u->o_key;
816         p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
817         p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
818         memcpy(p->name, u->name, sizeof(u->name));
819 }
820 
821 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
822         const struct __ip6_tnl_parm *p)
823 {
824         u->proto = IPPROTO_GRE;
825         u->laddr = p->laddr;
826         u->raddr = p->raddr;
827         u->flags = p->flags;
828         u->hop_limit = p->hop_limit;
829         u->encap_limit = p->encap_limit;
830         u->flowinfo = p->flowinfo;
831         u->link = p->link;
832         u->i_key = p->i_key;
833         u->o_key = p->o_key;
834         u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
835         u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
836         memcpy(u->name, p->name, sizeof(u->name));
837 }
838 
839 static int ip6gre_tunnel_ioctl(struct net_device *dev,
840         struct ifreq *ifr, int cmd)
841 {
842         int err = 0;
843         struct ip6_tnl_parm2 p;
844         struct __ip6_tnl_parm p1;
845         struct ip6_tnl *t = netdev_priv(dev);
846         struct net *net = t->net;
847         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
848 
849         memset(&p1, 0, sizeof(p1));
850 
851         switch (cmd) {
852         case SIOCGETTUNNEL:
853                 if (dev == ign->fb_tunnel_dev) {
854                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
855                                 err = -EFAULT;
856                                 break;
857                         }
858                         ip6gre_tnl_parm_from_user(&p1, &p);
859                         t = ip6gre_tunnel_locate(net, &p1, 0);
860                         if (!t)
861                                 t = netdev_priv(dev);
862                 }
863                 memset(&p, 0, sizeof(p));
864                 ip6gre_tnl_parm_to_user(&p, &t->parms);
865                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
866                         err = -EFAULT;
867                 break;
868 
869         case SIOCADDTUNNEL:
870         case SIOCCHGTUNNEL:
871                 err = -EPERM;
872                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
873                         goto done;
874 
875                 err = -EFAULT;
876                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
877                         goto done;
878 
879                 err = -EINVAL;
880                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
881                         goto done;
882 
883                 if (!(p.i_flags&GRE_KEY))
884                         p.i_key = 0;
885                 if (!(p.o_flags&GRE_KEY))
886                         p.o_key = 0;
887 
888                 ip6gre_tnl_parm_from_user(&p1, &p);
889                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
890 
891                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
892                         if (t) {
893                                 if (t->dev != dev) {
894                                         err = -EEXIST;
895                                         break;
896                                 }
897                         } else {
898                                 t = netdev_priv(dev);
899 
900                                 ip6gre_tunnel_unlink(ign, t);
901                                 synchronize_net();
902                                 ip6gre_tnl_change(t, &p1, 1);
903                                 ip6gre_tunnel_link(ign, t);
904                                 netdev_state_change(dev);
905                         }
906                 }
907 
908                 if (t) {
909                         err = 0;
910 
911                         memset(&p, 0, sizeof(p));
912                         ip6gre_tnl_parm_to_user(&p, &t->parms);
913                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
914                                 err = -EFAULT;
915                 } else
916                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
917                 break;
918 
919         case SIOCDELTUNNEL:
920                 err = -EPERM;
921                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
922                         goto done;
923 
924                 if (dev == ign->fb_tunnel_dev) {
925                         err = -EFAULT;
926                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
927                                 goto done;
928                         err = -ENOENT;
929                         ip6gre_tnl_parm_from_user(&p1, &p);
930                         t = ip6gre_tunnel_locate(net, &p1, 0);
931                         if (!t)
932                                 goto done;
933                         err = -EPERM;
934                         if (t == netdev_priv(ign->fb_tunnel_dev))
935                                 goto done;
936                         dev = t->dev;
937                 }
938                 unregister_netdevice(dev);
939                 err = 0;
940                 break;
941 
942         default:
943                 err = -EINVAL;
944         }
945 
946 done:
947         return err;
948 }
949 
950 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
951                          unsigned short type, const void *daddr,
952                          const void *saddr, unsigned int len)
953 {
954         struct ip6_tnl *t = netdev_priv(dev);
955         struct ipv6hdr *ipv6h;
956         __be16 *p;
957 
958         ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
959         ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
960                                                   t->fl.u.ip6.flowlabel,
961                                                   true, &t->fl.u.ip6));
962         ipv6h->hop_limit = t->parms.hop_limit;
963         ipv6h->nexthdr = NEXTHDR_GRE;
964         ipv6h->saddr = t->parms.laddr;
965         ipv6h->daddr = t->parms.raddr;
966 
967         p = (__be16 *)(ipv6h + 1);
968         p[0] = t->parms.o_flags;
969         p[1] = htons(type);
970 
971         /*
972          *      Set the source hardware address.
973          */
974 
975         if (saddr)
976                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
977         if (daddr)
978                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
979         if (!ipv6_addr_any(&ipv6h->daddr))
980                 return t->hlen;
981 
982         return -t->hlen;
983 }
984 
985 static const struct header_ops ip6gre_header_ops = {
986         .create = ip6gre_header,
987 };
988 
989 static const struct net_device_ops ip6gre_netdev_ops = {
990         .ndo_init               = ip6gre_tunnel_init,
991         .ndo_uninit             = ip6gre_tunnel_uninit,
992         .ndo_start_xmit         = ip6gre_tunnel_xmit,
993         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
994         .ndo_change_mtu         = ip6_tnl_change_mtu,
995         .ndo_get_stats64        = ip_tunnel_get_stats64,
996         .ndo_get_iflink         = ip6_tnl_get_iflink,
997 };
998 
999 static void ip6gre_dev_free(struct net_device *dev)
1000 {
1001         struct ip6_tnl *t = netdev_priv(dev);
1002 
1003         dst_cache_destroy(&t->dst_cache);
1004         free_percpu(dev->tstats);
1005 }
1006 
1007 static void ip6gre_tunnel_setup(struct net_device *dev)
1008 {
1009         dev->netdev_ops = &ip6gre_netdev_ops;
1010         dev->needs_free_netdev = true;
1011         dev->priv_destructor = ip6gre_dev_free;
1012 
1013         dev->type = ARPHRD_IP6GRE;
1014 
1015         dev->flags |= IFF_NOARP;
1016         dev->addr_len = sizeof(struct in6_addr);
1017         netif_keep_dst(dev);
1018         /* This perm addr will be used as interface identifier by IPv6 */
1019         dev->addr_assign_type = NET_ADDR_RANDOM;
1020         eth_random_addr(dev->perm_addr);
1021 }
1022 
1023 static int ip6gre_tunnel_init_common(struct net_device *dev)
1024 {
1025         struct ip6_tnl *tunnel;
1026         int ret;
1027         int t_hlen;
1028 
1029         tunnel = netdev_priv(dev);
1030 
1031         tunnel->dev = dev;
1032         tunnel->net = dev_net(dev);
1033         strcpy(tunnel->parms.name, dev->name);
1034 
1035         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1036         if (!dev->tstats)
1037                 return -ENOMEM;
1038 
1039         ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1040         if (ret) {
1041                 free_percpu(dev->tstats);
1042                 dev->tstats = NULL;
1043                 return ret;
1044         }
1045 
1046         tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
1047         tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1048         t_hlen = tunnel->hlen + sizeof(struct ipv6hdr);
1049 
1050         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1051         dev->mtu = ETH_DATA_LEN - t_hlen;
1052         if (dev->type == ARPHRD_ETHER)
1053                 dev->mtu -= ETH_HLEN;
1054         if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1055                 dev->mtu -= 8;
1056 
1057         return 0;
1058 }
1059 
1060 static int ip6gre_tunnel_init(struct net_device *dev)
1061 {
1062         struct ip6_tnl *tunnel;
1063         int ret;
1064 
1065         ret = ip6gre_tunnel_init_common(dev);
1066         if (ret)
1067                 return ret;
1068 
1069         tunnel = netdev_priv(dev);
1070 
1071         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1072         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1073 
1074         if (ipv6_addr_any(&tunnel->parms.raddr))
1075                 dev->header_ops = &ip6gre_header_ops;
1076 
1077         return 0;
1078 }
1079 
1080 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1081 {
1082         struct ip6_tnl *tunnel = netdev_priv(dev);
1083 
1084         tunnel->dev = dev;
1085         tunnel->net = dev_net(dev);
1086         strcpy(tunnel->parms.name, dev->name);
1087 
1088         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1089 
1090         dev_hold(dev);
1091 }
1092 
1093 
1094 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1095         .handler     = gre_rcv,
1096         .err_handler = ip6gre_err,
1097         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1098 };
1099 
1100 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1101 {
1102         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1103         struct net_device *dev, *aux;
1104         int prio;
1105 
1106         for_each_netdev_safe(net, dev, aux)
1107                 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1108                     dev->rtnl_link_ops == &ip6gre_tap_ops)
1109                         unregister_netdevice_queue(dev, head);
1110 
1111         for (prio = 0; prio < 4; prio++) {
1112                 int h;
1113                 for (h = 0; h < IP6_GRE_HASH_SIZE; h++) {
1114                         struct ip6_tnl *t;
1115 
1116                         t = rtnl_dereference(ign->tunnels[prio][h]);
1117 
1118                         while (t) {
1119                                 /* If dev is in the same netns, it has already
1120                                  * been added to the list by the previous loop.
1121                                  */
1122                                 if (!net_eq(dev_net(t->dev), net))
1123                                         unregister_netdevice_queue(t->dev,
1124                                                                    head);
1125                                 t = rtnl_dereference(t->next);
1126                         }
1127                 }
1128         }
1129 }
1130 
1131 static int __net_init ip6gre_init_net(struct net *net)
1132 {
1133         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1134         int err;
1135 
1136         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1137                                           NET_NAME_UNKNOWN,
1138                                           ip6gre_tunnel_setup);
1139         if (!ign->fb_tunnel_dev) {
1140                 err = -ENOMEM;
1141                 goto err_alloc_dev;
1142         }
1143         dev_net_set(ign->fb_tunnel_dev, net);
1144         /* FB netdevice is special: we have one, and only one per netns.
1145          * Allowing to move it to another netns is clearly unsafe.
1146          */
1147         ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1148 
1149 
1150         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1151         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1152 
1153         err = register_netdev(ign->fb_tunnel_dev);
1154         if (err)
1155                 goto err_reg_dev;
1156 
1157         rcu_assign_pointer(ign->tunnels_wc[0],
1158                            netdev_priv(ign->fb_tunnel_dev));
1159         return 0;
1160 
1161 err_reg_dev:
1162         free_netdev(ign->fb_tunnel_dev);
1163 err_alloc_dev:
1164         return err;
1165 }
1166 
1167 static void __net_exit ip6gre_exit_net(struct net *net)
1168 {
1169         LIST_HEAD(list);
1170 
1171         rtnl_lock();
1172         ip6gre_destroy_tunnels(net, &list);
1173         unregister_netdevice_many(&list);
1174         rtnl_unlock();
1175 }
1176 
1177 static struct pernet_operations ip6gre_net_ops = {
1178         .init = ip6gre_init_net,
1179         .exit = ip6gre_exit_net,
1180         .id   = &ip6gre_net_id,
1181         .size = sizeof(struct ip6gre_net),
1182 };
1183 
1184 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1185                                   struct netlink_ext_ack *extack)
1186 {
1187         __be16 flags;
1188 
1189         if (!data)
1190                 return 0;
1191 
1192         flags = 0;
1193         if (data[IFLA_GRE_IFLAGS])
1194                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1195         if (data[IFLA_GRE_OFLAGS])
1196                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1197         if (flags & (GRE_VERSION|GRE_ROUTING))
1198                 return -EINVAL;
1199 
1200         return 0;
1201 }
1202 
1203 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1204                                struct netlink_ext_ack *extack)
1205 {
1206         struct in6_addr daddr;
1207 
1208         if (tb[IFLA_ADDRESS]) {
1209                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1210                         return -EINVAL;
1211                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1212                         return -EADDRNOTAVAIL;
1213         }
1214 
1215         if (!data)
1216                 goto out;
1217 
1218         if (data[IFLA_GRE_REMOTE]) {
1219                 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1220                 if (ipv6_addr_any(&daddr))
1221                         return -EINVAL;
1222         }
1223 
1224 out:
1225         return ip6gre_tunnel_validate(tb, data, extack);
1226 }
1227 
1228 
1229 static void ip6gre_netlink_parms(struct nlattr *data[],
1230                                 struct __ip6_tnl_parm *parms)
1231 {
1232         memset(parms, 0, sizeof(*parms));
1233 
1234         if (!data)
1235                 return;
1236 
1237         if (data[IFLA_GRE_LINK])
1238                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1239 
1240         if (data[IFLA_GRE_IFLAGS])
1241                 parms->i_flags = gre_flags_to_tnl_flags(
1242                                 nla_get_be16(data[IFLA_GRE_IFLAGS]));
1243 
1244         if (data[IFLA_GRE_OFLAGS])
1245                 parms->o_flags = gre_flags_to_tnl_flags(
1246                                 nla_get_be16(data[IFLA_GRE_OFLAGS]));
1247 
1248         if (data[IFLA_GRE_IKEY])
1249                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1250 
1251         if (data[IFLA_GRE_OKEY])
1252                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1253 
1254         if (data[IFLA_GRE_LOCAL])
1255                 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1256 
1257         if (data[IFLA_GRE_REMOTE])
1258                 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1259 
1260         if (data[IFLA_GRE_TTL])
1261                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1262 
1263         if (data[IFLA_GRE_ENCAP_LIMIT])
1264                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1265 
1266         if (data[IFLA_GRE_FLOWINFO])
1267                 parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]);
1268 
1269         if (data[IFLA_GRE_FLAGS])
1270                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1271 
1272         if (data[IFLA_GRE_FWMARK])
1273                 parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1274 }
1275 
1276 static int ip6gre_tap_init(struct net_device *dev)
1277 {
1278         struct ip6_tnl *tunnel;
1279         int ret;
1280 
1281         ret = ip6gre_tunnel_init_common(dev);
1282         if (ret)
1283                 return ret;
1284 
1285         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1286 
1287         tunnel = netdev_priv(dev);
1288 
1289         ip6gre_tnl_link_config(tunnel, 1);
1290 
1291         return 0;
1292 }
1293 
1294 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1295         .ndo_init = ip6gre_tap_init,
1296         .ndo_uninit = ip6gre_tunnel_uninit,
1297         .ndo_start_xmit = ip6gre_tunnel_xmit,
1298         .ndo_set_mac_address = eth_mac_addr,
1299         .ndo_validate_addr = eth_validate_addr,
1300         .ndo_change_mtu = ip6_tnl_change_mtu,
1301         .ndo_get_stats64 = ip_tunnel_get_stats64,
1302         .ndo_get_iflink = ip6_tnl_get_iflink,
1303 };
1304 
1305 #define GRE6_FEATURES (NETIF_F_SG |             \
1306                        NETIF_F_FRAGLIST |       \
1307                        NETIF_F_HIGHDMA |                \
1308                        NETIF_F_HW_CSUM)
1309 
1310 static void ip6gre_tap_setup(struct net_device *dev)
1311 {
1312 
1313         ether_setup(dev);
1314 
1315         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1316         dev->needs_free_netdev = true;
1317         dev->priv_destructor = ip6gre_dev_free;
1318 
1319         dev->features |= NETIF_F_NETNS_LOCAL;
1320         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1321         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1322         netif_keep_dst(dev);
1323 }
1324 
1325 static bool ip6gre_netlink_encap_parms(struct nlattr *data[],
1326                                        struct ip_tunnel_encap *ipencap)
1327 {
1328         bool ret = false;
1329 
1330         memset(ipencap, 0, sizeof(*ipencap));
1331 
1332         if (!data)
1333                 return ret;
1334 
1335         if (data[IFLA_GRE_ENCAP_TYPE]) {
1336                 ret = true;
1337                 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1338         }
1339 
1340         if (data[IFLA_GRE_ENCAP_FLAGS]) {
1341                 ret = true;
1342                 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1343         }
1344 
1345         if (data[IFLA_GRE_ENCAP_SPORT]) {
1346                 ret = true;
1347                 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1348         }
1349 
1350         if (data[IFLA_GRE_ENCAP_DPORT]) {
1351                 ret = true;
1352                 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1353         }
1354 
1355         return ret;
1356 }
1357 
1358 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1359                           struct nlattr *tb[], struct nlattr *data[],
1360                           struct netlink_ext_ack *extack)
1361 {
1362         struct ip6_tnl *nt;
1363         struct net *net = dev_net(dev);
1364         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1365         struct ip_tunnel_encap ipencap;
1366         int err;
1367 
1368         nt = netdev_priv(dev);
1369 
1370         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1371                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1372 
1373                 if (err < 0)
1374                         return err;
1375         }
1376 
1377         ip6gre_netlink_parms(data, &nt->parms);
1378 
1379         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1380                 return -EEXIST;
1381 
1382         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1383                 eth_hw_addr_random(dev);
1384 
1385         nt->dev = dev;
1386         nt->net = dev_net(dev);
1387         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1388 
1389         dev->features           |= GRE6_FEATURES;
1390         dev->hw_features        |= GRE6_FEATURES;
1391 
1392         if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
1393                 /* TCP offload with GRE SEQ is not supported, nor
1394                  * can we support 2 levels of outer headers requiring
1395                  * an update.
1396                  */
1397                 if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
1398                     (nt->encap.type == TUNNEL_ENCAP_NONE)) {
1399                         dev->features    |= NETIF_F_GSO_SOFTWARE;
1400                         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1401                 }
1402 
1403                 /* Can use a lockless transmit, unless we generate
1404                  * output sequences
1405                  */
1406                 dev->features |= NETIF_F_LLTX;
1407         }
1408 
1409         err = register_netdevice(dev);
1410         if (err)
1411                 goto out;
1412 
1413         dev_hold(dev);
1414         ip6gre_tunnel_link(ign, nt);
1415 
1416 out:
1417         return err;
1418 }
1419 
1420 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1421                              struct nlattr *data[],
1422                              struct netlink_ext_ack *extack)
1423 {
1424         struct ip6_tnl *t, *nt = netdev_priv(dev);
1425         struct net *net = nt->net;
1426         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1427         struct __ip6_tnl_parm p;
1428         struct ip_tunnel_encap ipencap;
1429 
1430         if (dev == ign->fb_tunnel_dev)
1431                 return -EINVAL;
1432 
1433         if (ip6gre_netlink_encap_parms(data, &ipencap)) {
1434                 int err = ip6_tnl_encap_setup(nt, &ipencap);
1435 
1436                 if (err < 0)
1437                         return err;
1438         }
1439 
1440         ip6gre_netlink_parms(data, &p);
1441 
1442         t = ip6gre_tunnel_locate(net, &p, 0);
1443 
1444         if (t) {
1445                 if (t->dev != dev)
1446                         return -EEXIST;
1447         } else {
1448                 t = nt;
1449         }
1450 
1451         ip6gre_tunnel_unlink(ign, t);
1452         ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1453         ip6gre_tunnel_link(ign, t);
1454         return 0;
1455 }
1456 
1457 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1458 {
1459         struct net *net = dev_net(dev);
1460         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1461 
1462         if (dev != ign->fb_tunnel_dev)
1463                 unregister_netdevice_queue(dev, head);
1464 }
1465 
1466 static size_t ip6gre_get_size(const struct net_device *dev)
1467 {
1468         return
1469                 /* IFLA_GRE_LINK */
1470                 nla_total_size(4) +
1471                 /* IFLA_GRE_IFLAGS */
1472                 nla_total_size(2) +
1473                 /* IFLA_GRE_OFLAGS */
1474                 nla_total_size(2) +
1475                 /* IFLA_GRE_IKEY */
1476                 nla_total_size(4) +
1477                 /* IFLA_GRE_OKEY */
1478                 nla_total_size(4) +
1479                 /* IFLA_GRE_LOCAL */
1480                 nla_total_size(sizeof(struct in6_addr)) +
1481                 /* IFLA_GRE_REMOTE */
1482                 nla_total_size(sizeof(struct in6_addr)) +
1483                 /* IFLA_GRE_TTL */
1484                 nla_total_size(1) +
1485                 /* IFLA_GRE_ENCAP_LIMIT */
1486                 nla_total_size(1) +
1487                 /* IFLA_GRE_FLOWINFO */
1488                 nla_total_size(4) +
1489                 /* IFLA_GRE_FLAGS */
1490                 nla_total_size(4) +
1491                 /* IFLA_GRE_ENCAP_TYPE */
1492                 nla_total_size(2) +
1493                 /* IFLA_GRE_ENCAP_FLAGS */
1494                 nla_total_size(2) +
1495                 /* IFLA_GRE_ENCAP_SPORT */
1496                 nla_total_size(2) +
1497                 /* IFLA_GRE_ENCAP_DPORT */
1498                 nla_total_size(2) +
1499                 /* IFLA_GRE_FWMARK */
1500                 nla_total_size(4) +
1501                 0;
1502 }
1503 
1504 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1505 {
1506         struct ip6_tnl *t = netdev_priv(dev);
1507         struct __ip6_tnl_parm *p = &t->parms;
1508 
1509         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1510             nla_put_be16(skb, IFLA_GRE_IFLAGS,
1511                          gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1512             nla_put_be16(skb, IFLA_GRE_OFLAGS,
1513                          gre_tnl_flags_to_gre_flags(p->o_flags)) ||
1514             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1515             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1516             nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1517             nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1518             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1519             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1520             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1521             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
1522             nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
1523                 goto nla_put_failure;
1524 
1525         if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1526                         t->encap.type) ||
1527             nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1528                          t->encap.sport) ||
1529             nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1530                          t->encap.dport) ||
1531             nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1532                         t->encap.flags))
1533                 goto nla_put_failure;
1534 
1535         return 0;
1536 
1537 nla_put_failure:
1538         return -EMSGSIZE;
1539 }
1540 
1541 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1542         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1543         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1544         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1545         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1546         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1547         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1548         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1549         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1550         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1551         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1552         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1553         [IFLA_GRE_ENCAP_TYPE]   = { .type = NLA_U16 },
1554         [IFLA_GRE_ENCAP_FLAGS]  = { .type = NLA_U16 },
1555         [IFLA_GRE_ENCAP_SPORT]  = { .type = NLA_U16 },
1556         [IFLA_GRE_ENCAP_DPORT]  = { .type = NLA_U16 },
1557         [IFLA_GRE_FWMARK]       = { .type = NLA_U32 },
1558 };
1559 
1560 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1561         .kind           = "ip6gre",
1562         .maxtype        = IFLA_GRE_MAX,
1563         .policy         = ip6gre_policy,
1564         .priv_size      = sizeof(struct ip6_tnl),
1565         .setup          = ip6gre_tunnel_setup,
1566         .validate       = ip6gre_tunnel_validate,
1567         .newlink        = ip6gre_newlink,
1568         .changelink     = ip6gre_changelink,
1569         .dellink        = ip6gre_dellink,
1570         .get_size       = ip6gre_get_size,
1571         .fill_info      = ip6gre_fill_info,
1572         .get_link_net   = ip6_tnl_get_link_net,
1573 };
1574 
1575 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1576         .kind           = "ip6gretap",
1577         .maxtype        = IFLA_GRE_MAX,
1578         .policy         = ip6gre_policy,
1579         .priv_size      = sizeof(struct ip6_tnl),
1580         .setup          = ip6gre_tap_setup,
1581         .validate       = ip6gre_tap_validate,
1582         .newlink        = ip6gre_newlink,
1583         .changelink     = ip6gre_changelink,
1584         .get_size       = ip6gre_get_size,
1585         .fill_info      = ip6gre_fill_info,
1586         .get_link_net   = ip6_tnl_get_link_net,
1587 };
1588 
1589 /*
1590  *      And now the modules code and kernel interface.
1591  */
1592 
1593 static int __init ip6gre_init(void)
1594 {
1595         int err;
1596 
1597         pr_info("GRE over IPv6 tunneling driver\n");
1598 
1599         err = register_pernet_device(&ip6gre_net_ops);
1600         if (err < 0)
1601                 return err;
1602 
1603         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1604         if (err < 0) {
1605                 pr_info("%s: can't add protocol\n", __func__);
1606                 goto add_proto_failed;
1607         }
1608 
1609         err = rtnl_link_register(&ip6gre_link_ops);
1610         if (err < 0)
1611                 goto rtnl_link_failed;
1612 
1613         err = rtnl_link_register(&ip6gre_tap_ops);
1614         if (err < 0)
1615                 goto tap_ops_failed;
1616 
1617 out:
1618         return err;
1619 
1620 tap_ops_failed:
1621         rtnl_link_unregister(&ip6gre_link_ops);
1622 rtnl_link_failed:
1623         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1624 add_proto_failed:
1625         unregister_pernet_device(&ip6gre_net_ops);
1626         goto out;
1627 }
1628 
1629 static void __exit ip6gre_fini(void)
1630 {
1631         rtnl_link_unregister(&ip6gre_tap_ops);
1632         rtnl_link_unregister(&ip6gre_link_ops);
1633         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1634         unregister_pernet_device(&ip6gre_net_ops);
1635 }
1636 
1637 module_init(ip6gre_init);
1638 module_exit(ip6gre_fini);
1639 MODULE_LICENSE("GPL");
1640 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1641 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1642 MODULE_ALIAS_RTNL_LINK("ip6gre");
1643 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1644 MODULE_ALIAS_NETDEV("ip6gre0");
1645 

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