netfilter: add nf_ipv6_ops hook to fix xt_addrtype with IPv6
[linux-3.10.git] / net / ipv6 / ip6_gre.c
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 IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
65 #define IPV6_TCLASS_SHIFT 20
66
67 #define HASH_SIZE_SHIFT  5
68 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
69
70 static int ip6gre_net_id __read_mostly;
71 struct ip6gre_net {
72         struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
73
74         struct net_device *fb_tunnel_dev;
75 };
76
77 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
78 static int ip6gre_tunnel_init(struct net_device *dev);
79 static void ip6gre_tunnel_setup(struct net_device *dev);
80 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
81 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
82
83 /* Tunnel hash table */
84
85 /*
86    4 hash tables:
87
88    3: (remote,local)
89    2: (remote,*)
90    1: (*,local)
91    0: (*,*)
92
93    We require exact key match i.e. if a key is present in packet
94    it will match only tunnel with the same key; if it is not present,
95    it will match only keyless tunnel.
96
97    All keysless packets, if not matched configured keyless tunnels
98    will match fallback tunnel.
99  */
100
101 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
102 static u32 HASH_ADDR(const struct in6_addr *addr)
103 {
104         u32 hash = ipv6_addr_hash(addr);
105
106         return hash_32(hash, HASH_SIZE_SHIFT);
107 }
108
109 #define tunnels_r_l     tunnels[3]
110 #define tunnels_r       tunnels[2]
111 #define tunnels_l       tunnels[1]
112 #define tunnels_wc      tunnels[0]
113
114 /* Given src, dst and key, find appropriate for input tunnel. */
115
116 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
117                 const struct in6_addr *remote, const struct in6_addr *local,
118                 __be32 key, __be16 gre_proto)
119 {
120         struct net *net = dev_net(dev);
121         int link = dev->ifindex;
122         unsigned int h0 = HASH_ADDR(remote);
123         unsigned int h1 = HASH_KEY(key);
124         struct ip6_tnl *t, *cand = NULL;
125         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
126         int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
127                        ARPHRD_ETHER : ARPHRD_IP6GRE;
128         int score, cand_score = 4;
129
130         for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
131                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
132                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
133                     key != t->parms.i_key ||
134                     !(t->dev->flags & IFF_UP))
135                         continue;
136
137                 if (t->dev->type != ARPHRD_IP6GRE &&
138                     t->dev->type != dev_type)
139                         continue;
140
141                 score = 0;
142                 if (t->parms.link != link)
143                         score |= 1;
144                 if (t->dev->type != dev_type)
145                         score |= 2;
146                 if (score == 0)
147                         return t;
148
149                 if (score < cand_score) {
150                         cand = t;
151                         cand_score = score;
152                 }
153         }
154
155         for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
156                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
157                     key != t->parms.i_key ||
158                     !(t->dev->flags & IFF_UP))
159                         continue;
160
161                 if (t->dev->type != ARPHRD_IP6GRE &&
162                     t->dev->type != dev_type)
163                         continue;
164
165                 score = 0;
166                 if (t->parms.link != link)
167                         score |= 1;
168                 if (t->dev->type != dev_type)
169                         score |= 2;
170                 if (score == 0)
171                         return t;
172
173                 if (score < cand_score) {
174                         cand = t;
175                         cand_score = score;
176                 }
177         }
178
179         for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
180                 if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
181                           (!ipv6_addr_equal(local, &t->parms.raddr) ||
182                                  !ipv6_addr_is_multicast(local))) ||
183                     key != t->parms.i_key ||
184                     !(t->dev->flags & IFF_UP))
185                         continue;
186
187                 if (t->dev->type != ARPHRD_IP6GRE &&
188                     t->dev->type != dev_type)
189                         continue;
190
191                 score = 0;
192                 if (t->parms.link != link)
193                         score |= 1;
194                 if (t->dev->type != dev_type)
195                         score |= 2;
196                 if (score == 0)
197                         return t;
198
199                 if (score < cand_score) {
200                         cand = t;
201                         cand_score = score;
202                 }
203         }
204
205         for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
206                 if (t->parms.i_key != key ||
207                     !(t->dev->flags & IFF_UP))
208                         continue;
209
210                 if (t->dev->type != ARPHRD_IP6GRE &&
211                     t->dev->type != dev_type)
212                         continue;
213
214                 score = 0;
215                 if (t->parms.link != link)
216                         score |= 1;
217                 if (t->dev->type != dev_type)
218                         score |= 2;
219                 if (score == 0)
220                         return t;
221
222                 if (score < cand_score) {
223                         cand = t;
224                         cand_score = score;
225                 }
226         }
227
228         if (cand != NULL)
229                 return cand;
230
231         dev = ign->fb_tunnel_dev;
232         if (dev->flags & IFF_UP)
233                 return netdev_priv(dev);
234
235         return NULL;
236 }
237
238 static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
239                 const struct __ip6_tnl_parm *p)
240 {
241         const struct in6_addr *remote = &p->raddr;
242         const struct in6_addr *local = &p->laddr;
243         unsigned int h = HASH_KEY(p->i_key);
244         int prio = 0;
245
246         if (!ipv6_addr_any(local))
247                 prio |= 1;
248         if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
249                 prio |= 2;
250                 h ^= HASH_ADDR(remote);
251         }
252
253         return &ign->tunnels[prio][h];
254 }
255
256 static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
257                 const struct ip6_tnl *t)
258 {
259         return __ip6gre_bucket(ign, &t->parms);
260 }
261
262 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
263 {
264         struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
265
266         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
267         rcu_assign_pointer(*tp, t);
268 }
269
270 static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
271 {
272         struct ip6_tnl __rcu **tp;
273         struct ip6_tnl *iter;
274
275         for (tp = ip6gre_bucket(ign, t);
276              (iter = rtnl_dereference(*tp)) != NULL;
277              tp = &iter->next) {
278                 if (t == iter) {
279                         rcu_assign_pointer(*tp, t->next);
280                         break;
281                 }
282         }
283 }
284
285 static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
286                                            const struct __ip6_tnl_parm *parms,
287                                            int type)
288 {
289         const struct in6_addr *remote = &parms->raddr;
290         const struct in6_addr *local = &parms->laddr;
291         __be32 key = parms->i_key;
292         int link = parms->link;
293         struct ip6_tnl *t;
294         struct ip6_tnl __rcu **tp;
295         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
296
297         for (tp = __ip6gre_bucket(ign, parms);
298              (t = rtnl_dereference(*tp)) != NULL;
299              tp = &t->next)
300                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
301                     ipv6_addr_equal(remote, &t->parms.raddr) &&
302                     key == t->parms.i_key &&
303                     link == t->parms.link &&
304                     type == t->dev->type)
305                         break;
306
307         return t;
308 }
309
310 static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
311                 const struct __ip6_tnl_parm *parms, int create)
312 {
313         struct ip6_tnl *t, *nt;
314         struct net_device *dev;
315         char name[IFNAMSIZ];
316         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
317
318         t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
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, ip6gre_tunnel_setup);
328         if (!dev)
329                 return NULL;
330
331         dev_net_set(dev, net);
332
333         nt = netdev_priv(dev);
334         nt->parms = *parms;
335         dev->rtnl_link_ops = &ip6gre_link_ops;
336
337         nt->dev = dev;
338         ip6gre_tnl_link_config(nt, 1);
339
340         if (register_netdevice(dev) < 0)
341                 goto failed_free;
342
343         /* Can use a lockless transmit, unless we generate output sequences */
344         if (!(nt->parms.o_flags & GRE_SEQ))
345                 dev->features |= NETIF_F_LLTX;
346
347         dev_hold(dev);
348         ip6gre_tunnel_link(ign, nt);
349         return nt;
350
351 failed_free:
352         free_netdev(dev);
353         return NULL;
354 }
355
356 static void ip6gre_tunnel_uninit(struct net_device *dev)
357 {
358         struct net *net = dev_net(dev);
359         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
360
361         ip6gre_tunnel_unlink(ign, netdev_priv(dev));
362         dev_put(dev);
363 }
364
365
366 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
367                 u8 type, u8 code, int offset, __be32 info)
368 {
369         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
370         __be16 *p = (__be16 *)(skb->data + offset);
371         int grehlen = offset + 4;
372         struct ip6_tnl *t;
373         __be16 flags;
374
375         flags = p[0];
376         if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
377                 if (flags&(GRE_VERSION|GRE_ROUTING))
378                         return;
379                 if (flags&GRE_KEY) {
380                         grehlen += 4;
381                         if (flags&GRE_CSUM)
382                                 grehlen += 4;
383                 }
384         }
385
386         /* If only 8 bytes returned, keyed message will be dropped here */
387         if (!pskb_may_pull(skb, grehlen))
388                 return;
389         ipv6h = (const struct ipv6hdr *)skb->data;
390         p = (__be16 *)(skb->data + offset);
391
392         t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
393                                 flags & GRE_KEY ?
394                                 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
395                                 p[1]);
396         if (t == NULL)
397                 return;
398
399         switch (type) {
400                 __u32 teli;
401                 struct ipv6_tlv_tnl_enc_lim *tel;
402                 __u32 mtu;
403         case ICMPV6_DEST_UNREACH:
404                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
405                                      t->parms.name);
406                 break;
407         case ICMPV6_TIME_EXCEED:
408                 if (code == ICMPV6_EXC_HOPLIMIT) {
409                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
410                                              t->parms.name);
411                 }
412                 break;
413         case ICMPV6_PARAMPROB:
414                 teli = 0;
415                 if (code == ICMPV6_HDR_FIELD)
416                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
417
418                 if (teli && teli == info - 2) {
419                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
420                         if (tel->encap_limit == 0) {
421                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
422                                                      t->parms.name);
423                         }
424                 } else {
425                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
426                                              t->parms.name);
427                 }
428                 break;
429         case ICMPV6_PKT_TOOBIG:
430                 mtu = info - offset;
431                 if (mtu < IPV6_MIN_MTU)
432                         mtu = IPV6_MIN_MTU;
433                 t->dev->mtu = mtu;
434                 break;
435         }
436
437         if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
438                 t->err_count++;
439         else
440                 t->err_count = 1;
441         t->err_time = jiffies;
442 }
443
444 static int ip6gre_rcv(struct sk_buff *skb)
445 {
446         const struct ipv6hdr *ipv6h;
447         u8     *h;
448         __be16    flags;
449         __sum16   csum = 0;
450         __be32 key = 0;
451         u32    seqno = 0;
452         struct ip6_tnl *tunnel;
453         int    offset = 4;
454         __be16 gre_proto;
455         int err;
456
457         if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
458                 goto drop;
459
460         ipv6h = ipv6_hdr(skb);
461         h = skb->data;
462         flags = *(__be16 *)h;
463
464         if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
465                 /* - Version must be 0.
466                    - We do not support routing headers.
467                  */
468                 if (flags&(GRE_VERSION|GRE_ROUTING))
469                         goto drop;
470
471                 if (flags&GRE_CSUM) {
472                         switch (skb->ip_summed) {
473                         case CHECKSUM_COMPLETE:
474                                 csum = csum_fold(skb->csum);
475                                 if (!csum)
476                                         break;
477                                 /* fall through */
478                         case CHECKSUM_NONE:
479                                 skb->csum = 0;
480                                 csum = __skb_checksum_complete(skb);
481                                 skb->ip_summed = CHECKSUM_COMPLETE;
482                         }
483                         offset += 4;
484                 }
485                 if (flags&GRE_KEY) {
486                         key = *(__be32 *)(h + offset);
487                         offset += 4;
488                 }
489                 if (flags&GRE_SEQ) {
490                         seqno = ntohl(*(__be32 *)(h + offset));
491                         offset += 4;
492                 }
493         }
494
495         gre_proto = *(__be16 *)(h + 2);
496
497         tunnel = ip6gre_tunnel_lookup(skb->dev,
498                                           &ipv6h->saddr, &ipv6h->daddr, key,
499                                           gre_proto);
500         if (tunnel) {
501                 struct pcpu_tstats *tstats;
502
503                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
504                         goto drop;
505
506                 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
507                         tunnel->dev->stats.rx_dropped++;
508                         goto drop;
509                 }
510
511                 secpath_reset(skb);
512
513                 skb->protocol = gre_proto;
514                 /* WCCP version 1 and 2 protocol decoding.
515                  * - Change protocol to IP
516                  * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
517                  */
518                 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
519                         skb->protocol = htons(ETH_P_IP);
520                         if ((*(h + offset) & 0xF0) != 0x40)
521                                 offset += 4;
522                 }
523
524                 skb->mac_header = skb->network_header;
525                 __pskb_pull(skb, offset);
526                 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
527                 skb->pkt_type = PACKET_HOST;
528
529                 if (((flags&GRE_CSUM) && csum) ||
530                     (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
531                         tunnel->dev->stats.rx_crc_errors++;
532                         tunnel->dev->stats.rx_errors++;
533                         goto drop;
534                 }
535                 if (tunnel->parms.i_flags&GRE_SEQ) {
536                         if (!(flags&GRE_SEQ) ||
537                             (tunnel->i_seqno &&
538                                         (s32)(seqno - tunnel->i_seqno) < 0)) {
539                                 tunnel->dev->stats.rx_fifo_errors++;
540                                 tunnel->dev->stats.rx_errors++;
541                                 goto drop;
542                         }
543                         tunnel->i_seqno = seqno + 1;
544                 }
545
546                 /* Warning: All skb pointers will be invalidated! */
547                 if (tunnel->dev->type == ARPHRD_ETHER) {
548                         if (!pskb_may_pull(skb, ETH_HLEN)) {
549                                 tunnel->dev->stats.rx_length_errors++;
550                                 tunnel->dev->stats.rx_errors++;
551                                 goto drop;
552                         }
553
554                         ipv6h = ipv6_hdr(skb);
555                         skb->protocol = eth_type_trans(skb, tunnel->dev);
556                         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
557                 }
558
559                 __skb_tunnel_rx(skb, tunnel->dev);
560
561                 skb_reset_network_header(skb);
562
563                 err = IP6_ECN_decapsulate(ipv6h, skb);
564                 if (unlikely(err)) {
565                         if (log_ecn_error)
566                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
567                                                      &ipv6h->saddr,
568                                                      ipv6_get_dsfield(ipv6h));
569                         if (err > 1) {
570                                 ++tunnel->dev->stats.rx_frame_errors;
571                                 ++tunnel->dev->stats.rx_errors;
572                                 goto drop;
573                         }
574                 }
575
576                 tstats = this_cpu_ptr(tunnel->dev->tstats);
577                 u64_stats_update_begin(&tstats->syncp);
578                 tstats->rx_packets++;
579                 tstats->rx_bytes += skb->len;
580                 u64_stats_update_end(&tstats->syncp);
581
582                 netif_rx(skb);
583
584                 return 0;
585         }
586         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
587
588 drop:
589         kfree_skb(skb);
590         return 0;
591 }
592
593 struct ipv6_tel_txoption {
594         struct ipv6_txoptions ops;
595         __u8 dst_opt[8];
596 };
597
598 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
599 {
600         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
601
602         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
603         opt->dst_opt[3] = 1;
604         opt->dst_opt[4] = encap_limit;
605         opt->dst_opt[5] = IPV6_TLV_PADN;
606         opt->dst_opt[6] = 1;
607
608         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
609         opt->ops.opt_nflen = 8;
610 }
611
612 static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
613                          struct net_device *dev,
614                          __u8 dsfield,
615                          struct flowi6 *fl6,
616                          int encap_limit,
617                          __u32 *pmtu)
618 {
619         struct net *net = dev_net(dev);
620         struct ip6_tnl *tunnel = netdev_priv(dev);
621         struct net_device *tdev;    /* Device to other host */
622         struct ipv6hdr  *ipv6h;     /* Our new IP header */
623         unsigned int max_headroom;  /* The extra header space needed */
624         int    gre_hlen;
625         struct ipv6_tel_txoption opt;
626         int    mtu;
627         struct dst_entry *dst = NULL, *ndst = NULL;
628         struct net_device_stats *stats = &tunnel->dev->stats;
629         int err = -1;
630         u8 proto;
631         struct sk_buff *new_skb;
632
633         if (dev->type == ARPHRD_ETHER)
634                 IPCB(skb)->flags = 0;
635
636         if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
637                 gre_hlen = 0;
638                 ipv6h = (struct ipv6hdr *)skb->data;
639                 fl6->daddr = ipv6h->daddr;
640         } else {
641                 gre_hlen = tunnel->hlen;
642                 fl6->daddr = tunnel->parms.raddr;
643         }
644
645         if (!fl6->flowi6_mark)
646                 dst = ip6_tnl_dst_check(tunnel);
647
648         if (!dst) {
649                 ndst = ip6_route_output(net, NULL, fl6);
650
651                 if (ndst->error)
652                         goto tx_err_link_failure;
653                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
654                 if (IS_ERR(ndst)) {
655                         err = PTR_ERR(ndst);
656                         ndst = NULL;
657                         goto tx_err_link_failure;
658                 }
659                 dst = ndst;
660         }
661
662         tdev = dst->dev;
663
664         if (tdev == dev) {
665                 stats->collisions++;
666                 net_warn_ratelimited("%s: Local routing loop detected!\n",
667                                      tunnel->parms.name);
668                 goto tx_err_dst_release;
669         }
670
671         mtu = dst_mtu(dst) - sizeof(*ipv6h);
672         if (encap_limit >= 0) {
673                 max_headroom += 8;
674                 mtu -= 8;
675         }
676         if (mtu < IPV6_MIN_MTU)
677                 mtu = IPV6_MIN_MTU;
678         if (skb_dst(skb))
679                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
680         if (skb->len > mtu) {
681                 *pmtu = mtu;
682                 err = -EMSGSIZE;
683                 goto tx_err_dst_release;
684         }
685
686         if (tunnel->err_count > 0) {
687                 if (time_before(jiffies,
688                                 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
689                         tunnel->err_count--;
690
691                         dst_link_failure(skb);
692                 } else
693                         tunnel->err_count = 0;
694         }
695
696         max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
697
698         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
699             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
700                 new_skb = skb_realloc_headroom(skb, max_headroom);
701                 if (max_headroom > dev->needed_headroom)
702                         dev->needed_headroom = max_headroom;
703                 if (!new_skb)
704                         goto tx_err_dst_release;
705
706                 if (skb->sk)
707                         skb_set_owner_w(new_skb, skb->sk);
708                 consume_skb(skb);
709                 skb = new_skb;
710         }
711
712         skb_dst_drop(skb);
713
714         if (fl6->flowi6_mark) {
715                 skb_dst_set(skb, dst);
716                 ndst = NULL;
717         } else {
718                 skb_dst_set_noref(skb, dst);
719         }
720
721         proto = NEXTHDR_GRE;
722         if (encap_limit >= 0) {
723                 init_tel_txopt(&opt, encap_limit);
724                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
725         }
726
727         skb_push(skb, gre_hlen);
728         skb_reset_network_header(skb);
729         skb_set_transport_header(skb, sizeof(*ipv6h));
730
731         /*
732          *      Push down and install the IP header.
733          */
734         ipv6h = ipv6_hdr(skb);
735         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
736         ipv6h->hop_limit = tunnel->parms.hop_limit;
737         ipv6h->nexthdr = proto;
738         ipv6h->saddr = fl6->saddr;
739         ipv6h->daddr = fl6->daddr;
740
741         ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
742         ((__be16 *)(ipv6h + 1))[1] = (dev->type == ARPHRD_ETHER) ?
743                                    htons(ETH_P_TEB) : skb->protocol;
744
745         if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
746                 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
747
748                 if (tunnel->parms.o_flags&GRE_SEQ) {
749                         ++tunnel->o_seqno;
750                         *ptr = htonl(tunnel->o_seqno);
751                         ptr--;
752                 }
753                 if (tunnel->parms.o_flags&GRE_KEY) {
754                         *ptr = tunnel->parms.o_key;
755                         ptr--;
756                 }
757                 if (tunnel->parms.o_flags&GRE_CSUM) {
758                         *ptr = 0;
759                         *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
760                                 skb->len - sizeof(struct ipv6hdr));
761                 }
762         }
763
764         ip6tunnel_xmit(skb, dev);
765         if (ndst)
766                 ip6_tnl_dst_store(tunnel, ndst);
767         return 0;
768 tx_err_link_failure:
769         stats->tx_carrier_errors++;
770         dst_link_failure(skb);
771 tx_err_dst_release:
772         dst_release(ndst);
773         return err;
774 }
775
776 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
777 {
778         struct ip6_tnl *t = netdev_priv(dev);
779         const struct iphdr  *iph = ip_hdr(skb);
780         int encap_limit = -1;
781         struct flowi6 fl6;
782         __u8 dsfield;
783         __u32 mtu;
784         int err;
785
786         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
787                 encap_limit = t->parms.encap_limit;
788
789         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
790         fl6.flowi6_proto = IPPROTO_IPIP;
791
792         dsfield = ipv4_get_dsfield(iph);
793
794         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
795                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
796                                           & IPV6_TCLASS_MASK;
797         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
798                 fl6.flowi6_mark = skb->mark;
799
800         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
801         if (err != 0) {
802                 /* XXX: send ICMP error even if DF is not set. */
803                 if (err == -EMSGSIZE)
804                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
805                                   htonl(mtu));
806                 return -1;
807         }
808
809         return 0;
810 }
811
812 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
813 {
814         struct ip6_tnl *t = netdev_priv(dev);
815         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
816         int encap_limit = -1;
817         __u16 offset;
818         struct flowi6 fl6;
819         __u8 dsfield;
820         __u32 mtu;
821         int err;
822
823         if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
824                 return -1;
825
826         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
827         if (offset > 0) {
828                 struct ipv6_tlv_tnl_enc_lim *tel;
829                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
830                 if (tel->encap_limit == 0) {
831                         icmpv6_send(skb, ICMPV6_PARAMPROB,
832                                     ICMPV6_HDR_FIELD, offset + 2);
833                         return -1;
834                 }
835                 encap_limit = tel->encap_limit - 1;
836         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
837                 encap_limit = t->parms.encap_limit;
838
839         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
840         fl6.flowi6_proto = IPPROTO_IPV6;
841
842         dsfield = ipv6_get_dsfield(ipv6h);
843         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
844                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
845         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
846                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
847         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
848                 fl6.flowi6_mark = skb->mark;
849
850         err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
851         if (err != 0) {
852                 if (err == -EMSGSIZE)
853                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
854                 return -1;
855         }
856
857         return 0;
858 }
859
860 /**
861  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
862  *   @t: the outgoing tunnel device
863  *   @hdr: IPv6 header from the incoming packet
864  *
865  * Description:
866  *   Avoid trivial tunneling loop by checking that tunnel exit-point
867  *   doesn't match source of incoming packet.
868  *
869  * Return:
870  *   1 if conflict,
871  *   0 else
872  **/
873
874 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
875         const struct ipv6hdr *hdr)
876 {
877         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
878 }
879
880 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
881 {
882         struct ip6_tnl *t = netdev_priv(dev);
883         int encap_limit = -1;
884         struct flowi6 fl6;
885         __u32 mtu;
886         int err;
887
888         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
889                 encap_limit = t->parms.encap_limit;
890
891         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
892         fl6.flowi6_proto = skb->protocol;
893
894         err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
895
896         return err;
897 }
898
899 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
900         struct net_device *dev)
901 {
902         struct ip6_tnl *t = netdev_priv(dev);
903         struct net_device_stats *stats = &t->dev->stats;
904         int ret;
905
906         if (!ip6_tnl_xmit_ctl(t))
907                 goto tx_err;
908
909         switch (skb->protocol) {
910         case htons(ETH_P_IP):
911                 ret = ip6gre_xmit_ipv4(skb, dev);
912                 break;
913         case htons(ETH_P_IPV6):
914                 ret = ip6gre_xmit_ipv6(skb, dev);
915                 break;
916         default:
917                 ret = ip6gre_xmit_other(skb, dev);
918                 break;
919         }
920
921         if (ret < 0)
922                 goto tx_err;
923
924         return NETDEV_TX_OK;
925
926 tx_err:
927         stats->tx_errors++;
928         stats->tx_dropped++;
929         kfree_skb(skb);
930         return NETDEV_TX_OK;
931 }
932
933 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
934 {
935         struct net_device *dev = t->dev;
936         struct __ip6_tnl_parm *p = &t->parms;
937         struct flowi6 *fl6 = &t->fl.u.ip6;
938         int addend = sizeof(struct ipv6hdr) + 4;
939
940         if (dev->type != ARPHRD_ETHER) {
941                 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
942                 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
943         }
944
945         /* Set up flowi template */
946         fl6->saddr = p->laddr;
947         fl6->daddr = p->raddr;
948         fl6->flowi6_oif = p->link;
949         fl6->flowlabel = 0;
950
951         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
952                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
953         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
954                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
955
956         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
957         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
958
959         if (p->flags&IP6_TNL_F_CAP_XMIT &&
960                         p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
961                 dev->flags |= IFF_POINTOPOINT;
962         else
963                 dev->flags &= ~IFF_POINTOPOINT;
964
965         dev->iflink = p->link;
966
967         /* Precalculate GRE options length */
968         if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
969                 if (t->parms.o_flags&GRE_CSUM)
970                         addend += 4;
971                 if (t->parms.o_flags&GRE_KEY)
972                         addend += 4;
973                 if (t->parms.o_flags&GRE_SEQ)
974                         addend += 4;
975         }
976
977         if (p->flags & IP6_TNL_F_CAP_XMIT) {
978                 int strict = (ipv6_addr_type(&p->raddr) &
979                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
980
981                 struct rt6_info *rt = rt6_lookup(dev_net(dev),
982                                                  &p->raddr, &p->laddr,
983                                                  p->link, strict);
984
985                 if (rt == NULL)
986                         return;
987
988                 if (rt->dst.dev) {
989                         dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
990
991                         if (set_mtu) {
992                                 dev->mtu = rt->dst.dev->mtu - addend;
993                                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
994                                         dev->mtu -= 8;
995
996                                 if (dev->mtu < IPV6_MIN_MTU)
997                                         dev->mtu = IPV6_MIN_MTU;
998                         }
999                 }
1000                 ip6_rt_put(rt);
1001         }
1002
1003         t->hlen = addend;
1004 }
1005
1006 static int ip6gre_tnl_change(struct ip6_tnl *t,
1007         const struct __ip6_tnl_parm *p, int set_mtu)
1008 {
1009         t->parms.laddr = p->laddr;
1010         t->parms.raddr = p->raddr;
1011         t->parms.flags = p->flags;
1012         t->parms.hop_limit = p->hop_limit;
1013         t->parms.encap_limit = p->encap_limit;
1014         t->parms.flowinfo = p->flowinfo;
1015         t->parms.link = p->link;
1016         t->parms.proto = p->proto;
1017         t->parms.i_key = p->i_key;
1018         t->parms.o_key = p->o_key;
1019         t->parms.i_flags = p->i_flags;
1020         t->parms.o_flags = p->o_flags;
1021         ip6_tnl_dst_reset(t);
1022         ip6gre_tnl_link_config(t, set_mtu);
1023         return 0;
1024 }
1025
1026 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1027         const struct ip6_tnl_parm2 *u)
1028 {
1029         p->laddr = u->laddr;
1030         p->raddr = u->raddr;
1031         p->flags = u->flags;
1032         p->hop_limit = u->hop_limit;
1033         p->encap_limit = u->encap_limit;
1034         p->flowinfo = u->flowinfo;
1035         p->link = u->link;
1036         p->i_key = u->i_key;
1037         p->o_key = u->o_key;
1038         p->i_flags = u->i_flags;
1039         p->o_flags = u->o_flags;
1040         memcpy(p->name, u->name, sizeof(u->name));
1041 }
1042
1043 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1044         const struct __ip6_tnl_parm *p)
1045 {
1046         u->proto = IPPROTO_GRE;
1047         u->laddr = p->laddr;
1048         u->raddr = p->raddr;
1049         u->flags = p->flags;
1050         u->hop_limit = p->hop_limit;
1051         u->encap_limit = p->encap_limit;
1052         u->flowinfo = p->flowinfo;
1053         u->link = p->link;
1054         u->i_key = p->i_key;
1055         u->o_key = p->o_key;
1056         u->i_flags = p->i_flags;
1057         u->o_flags = p->o_flags;
1058         memcpy(u->name, p->name, sizeof(u->name));
1059 }
1060
1061 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1062         struct ifreq *ifr, int cmd)
1063 {
1064         int err = 0;
1065         struct ip6_tnl_parm2 p;
1066         struct __ip6_tnl_parm p1;
1067         struct ip6_tnl *t;
1068         struct net *net = dev_net(dev);
1069         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1070
1071         switch (cmd) {
1072         case SIOCGETTUNNEL:
1073                 t = NULL;
1074                 if (dev == ign->fb_tunnel_dev) {
1075                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1076                                 err = -EFAULT;
1077                                 break;
1078                         }
1079                         ip6gre_tnl_parm_from_user(&p1, &p);
1080                         t = ip6gre_tunnel_locate(net, &p1, 0);
1081                 }
1082                 if (t == NULL)
1083                         t = netdev_priv(dev);
1084                 memset(&p, 0, sizeof(p));
1085                 ip6gre_tnl_parm_to_user(&p, &t->parms);
1086                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1087                         err = -EFAULT;
1088                 break;
1089
1090         case SIOCADDTUNNEL:
1091         case SIOCCHGTUNNEL:
1092                 err = -EPERM;
1093                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1094                         goto done;
1095
1096                 err = -EFAULT;
1097                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1098                         goto done;
1099
1100                 err = -EINVAL;
1101                 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1102                         goto done;
1103
1104                 if (!(p.i_flags&GRE_KEY))
1105                         p.i_key = 0;
1106                 if (!(p.o_flags&GRE_KEY))
1107                         p.o_key = 0;
1108
1109                 ip6gre_tnl_parm_from_user(&p1, &p);
1110                 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1111
1112                 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1113                         if (t != NULL) {
1114                                 if (t->dev != dev) {
1115                                         err = -EEXIST;
1116                                         break;
1117                                 }
1118                         } else {
1119                                 t = netdev_priv(dev);
1120
1121                                 ip6gre_tunnel_unlink(ign, t);
1122                                 synchronize_net();
1123                                 ip6gre_tnl_change(t, &p1, 1);
1124                                 ip6gre_tunnel_link(ign, t);
1125                                 netdev_state_change(dev);
1126                         }
1127                 }
1128
1129                 if (t) {
1130                         err = 0;
1131
1132                         memset(&p, 0, sizeof(p));
1133                         ip6gre_tnl_parm_to_user(&p, &t->parms);
1134                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1135                                 err = -EFAULT;
1136                 } else
1137                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1138                 break;
1139
1140         case SIOCDELTUNNEL:
1141                 err = -EPERM;
1142                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1143                         goto done;
1144
1145                 if (dev == ign->fb_tunnel_dev) {
1146                         err = -EFAULT;
1147                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1148                                 goto done;
1149                         err = -ENOENT;
1150                         ip6gre_tnl_parm_from_user(&p1, &p);
1151                         t = ip6gre_tunnel_locate(net, &p1, 0);
1152                         if (t == NULL)
1153                                 goto done;
1154                         err = -EPERM;
1155                         if (t == netdev_priv(ign->fb_tunnel_dev))
1156                                 goto done;
1157                         dev = t->dev;
1158                 }
1159                 unregister_netdevice(dev);
1160                 err = 0;
1161                 break;
1162
1163         default:
1164                 err = -EINVAL;
1165         }
1166
1167 done:
1168         return err;
1169 }
1170
1171 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1172 {
1173         struct ip6_tnl *tunnel = netdev_priv(dev);
1174         if (new_mtu < 68 ||
1175             new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1176                 return -EINVAL;
1177         dev->mtu = new_mtu;
1178         return 0;
1179 }
1180
1181 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1182                         unsigned short type,
1183                         const void *daddr, const void *saddr, unsigned int len)
1184 {
1185         struct ip6_tnl *t = netdev_priv(dev);
1186         struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen);
1187         __be16 *p = (__be16 *)(ipv6h+1);
1188
1189         ip6_flow_hdr(ipv6h, 0, t->fl.u.ip6.flowlabel);
1190         ipv6h->hop_limit = t->parms.hop_limit;
1191         ipv6h->nexthdr = NEXTHDR_GRE;
1192         ipv6h->saddr = t->parms.laddr;
1193         ipv6h->daddr = t->parms.raddr;
1194
1195         p[0]            = t->parms.o_flags;
1196         p[1]            = htons(type);
1197
1198         /*
1199          *      Set the source hardware address.
1200          */
1201
1202         if (saddr)
1203                 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1204         if (daddr)
1205                 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1206         if (!ipv6_addr_any(&ipv6h->daddr))
1207                 return t->hlen;
1208
1209         return -t->hlen;
1210 }
1211
1212 static const struct header_ops ip6gre_header_ops = {
1213         .create = ip6gre_header,
1214 };
1215
1216 static const struct net_device_ops ip6gre_netdev_ops = {
1217         .ndo_init               = ip6gre_tunnel_init,
1218         .ndo_uninit             = ip6gre_tunnel_uninit,
1219         .ndo_start_xmit         = ip6gre_tunnel_xmit,
1220         .ndo_do_ioctl           = ip6gre_tunnel_ioctl,
1221         .ndo_change_mtu         = ip6gre_tunnel_change_mtu,
1222         .ndo_get_stats64        = ip_tunnel_get_stats64,
1223 };
1224
1225 static void ip6gre_dev_free(struct net_device *dev)
1226 {
1227         free_percpu(dev->tstats);
1228         free_netdev(dev);
1229 }
1230
1231 static void ip6gre_tunnel_setup(struct net_device *dev)
1232 {
1233         struct ip6_tnl *t;
1234
1235         dev->netdev_ops = &ip6gre_netdev_ops;
1236         dev->destructor = ip6gre_dev_free;
1237
1238         dev->type = ARPHRD_IP6GRE;
1239         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1240         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1241         t = netdev_priv(dev);
1242         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1243                 dev->mtu -= 8;
1244         dev->flags |= IFF_NOARP;
1245         dev->iflink = 0;
1246         dev->addr_len = sizeof(struct in6_addr);
1247         dev->features |= NETIF_F_NETNS_LOCAL;
1248         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1249 }
1250
1251 static int ip6gre_tunnel_init(struct net_device *dev)
1252 {
1253         struct ip6_tnl *tunnel;
1254
1255         tunnel = netdev_priv(dev);
1256
1257         tunnel->dev = dev;
1258         strcpy(tunnel->parms.name, dev->name);
1259
1260         memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1261         memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1262
1263         if (ipv6_addr_any(&tunnel->parms.raddr))
1264                 dev->header_ops = &ip6gre_header_ops;
1265
1266         dev->tstats = alloc_percpu(struct pcpu_tstats);
1267         if (!dev->tstats)
1268                 return -ENOMEM;
1269
1270         return 0;
1271 }
1272
1273 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1274 {
1275         struct ip6_tnl *tunnel = netdev_priv(dev);
1276
1277         tunnel->dev = dev;
1278         strcpy(tunnel->parms.name, dev->name);
1279
1280         tunnel->hlen            = sizeof(struct ipv6hdr) + 4;
1281
1282         dev_hold(dev);
1283 }
1284
1285
1286 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1287         .handler     = ip6gre_rcv,
1288         .err_handler = ip6gre_err,
1289         .flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1290 };
1291
1292 static void ip6gre_destroy_tunnels(struct ip6gre_net *ign,
1293         struct list_head *head)
1294 {
1295         int prio;
1296
1297         for (prio = 0; prio < 4; prio++) {
1298                 int h;
1299                 for (h = 0; h < HASH_SIZE; h++) {
1300                         struct ip6_tnl *t;
1301
1302                         t = rtnl_dereference(ign->tunnels[prio][h]);
1303
1304                         while (t != NULL) {
1305                                 unregister_netdevice_queue(t->dev, head);
1306                                 t = rtnl_dereference(t->next);
1307                         }
1308                 }
1309         }
1310 }
1311
1312 static int __net_init ip6gre_init_net(struct net *net)
1313 {
1314         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1315         int err;
1316
1317         ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1318                                            ip6gre_tunnel_setup);
1319         if (!ign->fb_tunnel_dev) {
1320                 err = -ENOMEM;
1321                 goto err_alloc_dev;
1322         }
1323         dev_net_set(ign->fb_tunnel_dev, net);
1324
1325         ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1326         ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1327
1328         err = register_netdev(ign->fb_tunnel_dev);
1329         if (err)
1330                 goto err_reg_dev;
1331
1332         rcu_assign_pointer(ign->tunnels_wc[0],
1333                            netdev_priv(ign->fb_tunnel_dev));
1334         return 0;
1335
1336 err_reg_dev:
1337         ip6gre_dev_free(ign->fb_tunnel_dev);
1338 err_alloc_dev:
1339         return err;
1340 }
1341
1342 static void __net_exit ip6gre_exit_net(struct net *net)
1343 {
1344         struct ip6gre_net *ign;
1345         LIST_HEAD(list);
1346
1347         ign = net_generic(net, ip6gre_net_id);
1348         rtnl_lock();
1349         ip6gre_destroy_tunnels(ign, &list);
1350         unregister_netdevice_many(&list);
1351         rtnl_unlock();
1352 }
1353
1354 static struct pernet_operations ip6gre_net_ops = {
1355         .init = ip6gre_init_net,
1356         .exit = ip6gre_exit_net,
1357         .id   = &ip6gre_net_id,
1358         .size = sizeof(struct ip6gre_net),
1359 };
1360
1361 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1362 {
1363         __be16 flags;
1364
1365         if (!data)
1366                 return 0;
1367
1368         flags = 0;
1369         if (data[IFLA_GRE_IFLAGS])
1370                 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1371         if (data[IFLA_GRE_OFLAGS])
1372                 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1373         if (flags & (GRE_VERSION|GRE_ROUTING))
1374                 return -EINVAL;
1375
1376         return 0;
1377 }
1378
1379 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1380 {
1381         struct in6_addr daddr;
1382
1383         if (tb[IFLA_ADDRESS]) {
1384                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1385                         return -EINVAL;
1386                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1387                         return -EADDRNOTAVAIL;
1388         }
1389
1390         if (!data)
1391                 goto out;
1392
1393         if (data[IFLA_GRE_REMOTE]) {
1394                 nla_memcpy(&daddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1395                 if (ipv6_addr_any(&daddr))
1396                         return -EINVAL;
1397         }
1398
1399 out:
1400         return ip6gre_tunnel_validate(tb, data);
1401 }
1402
1403
1404 static void ip6gre_netlink_parms(struct nlattr *data[],
1405                                 struct __ip6_tnl_parm *parms)
1406 {
1407         memset(parms, 0, sizeof(*parms));
1408
1409         if (!data)
1410                 return;
1411
1412         if (data[IFLA_GRE_LINK])
1413                 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1414
1415         if (data[IFLA_GRE_IFLAGS])
1416                 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1417
1418         if (data[IFLA_GRE_OFLAGS])
1419                 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1420
1421         if (data[IFLA_GRE_IKEY])
1422                 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1423
1424         if (data[IFLA_GRE_OKEY])
1425                 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1426
1427         if (data[IFLA_GRE_LOCAL])
1428                 nla_memcpy(&parms->laddr, data[IFLA_GRE_LOCAL], sizeof(struct in6_addr));
1429
1430         if (data[IFLA_GRE_REMOTE])
1431                 nla_memcpy(&parms->raddr, data[IFLA_GRE_REMOTE], sizeof(struct in6_addr));
1432
1433         if (data[IFLA_GRE_TTL])
1434                 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1435
1436         if (data[IFLA_GRE_ENCAP_LIMIT])
1437                 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1438
1439         if (data[IFLA_GRE_FLOWINFO])
1440                 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1441
1442         if (data[IFLA_GRE_FLAGS])
1443                 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1444 }
1445
1446 static int ip6gre_tap_init(struct net_device *dev)
1447 {
1448         struct ip6_tnl *tunnel;
1449
1450         tunnel = netdev_priv(dev);
1451
1452         tunnel->dev = dev;
1453         strcpy(tunnel->parms.name, dev->name);
1454
1455         ip6gre_tnl_link_config(tunnel, 1);
1456
1457         dev->tstats = alloc_percpu(struct pcpu_tstats);
1458         if (!dev->tstats)
1459                 return -ENOMEM;
1460
1461         return 0;
1462 }
1463
1464 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1465         .ndo_init = ip6gre_tap_init,
1466         .ndo_uninit = ip6gre_tunnel_uninit,
1467         .ndo_start_xmit = ip6gre_tunnel_xmit,
1468         .ndo_set_mac_address = eth_mac_addr,
1469         .ndo_validate_addr = eth_validate_addr,
1470         .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1471         .ndo_get_stats64 = ip_tunnel_get_stats64,
1472 };
1473
1474 static void ip6gre_tap_setup(struct net_device *dev)
1475 {
1476
1477         ether_setup(dev);
1478
1479         dev->netdev_ops = &ip6gre_tap_netdev_ops;
1480         dev->destructor = ip6gre_dev_free;
1481
1482         dev->iflink = 0;
1483         dev->features |= NETIF_F_NETNS_LOCAL;
1484 }
1485
1486 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1487         struct nlattr *tb[], struct nlattr *data[])
1488 {
1489         struct ip6_tnl *nt;
1490         struct net *net = dev_net(dev);
1491         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1492         int err;
1493
1494         nt = netdev_priv(dev);
1495         ip6gre_netlink_parms(data, &nt->parms);
1496
1497         if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1498                 return -EEXIST;
1499
1500         if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1501                 eth_hw_addr_random(dev);
1502
1503         nt->dev = dev;
1504         ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1505
1506         /* Can use a lockless transmit, unless we generate output sequences */
1507         if (!(nt->parms.o_flags & GRE_SEQ))
1508                 dev->features |= NETIF_F_LLTX;
1509
1510         err = register_netdevice(dev);
1511         if (err)
1512                 goto out;
1513
1514         dev_hold(dev);
1515         ip6gre_tunnel_link(ign, nt);
1516
1517 out:
1518         return err;
1519 }
1520
1521 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1522                             struct nlattr *data[])
1523 {
1524         struct ip6_tnl *t, *nt;
1525         struct net *net = dev_net(dev);
1526         struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1527         struct __ip6_tnl_parm p;
1528
1529         if (dev == ign->fb_tunnel_dev)
1530                 return -EINVAL;
1531
1532         nt = netdev_priv(dev);
1533         ip6gre_netlink_parms(data, &p);
1534
1535         t = ip6gre_tunnel_locate(net, &p, 0);
1536
1537         if (t) {
1538                 if (t->dev != dev)
1539                         return -EEXIST;
1540         } else {
1541                 t = nt;
1542
1543                 ip6gre_tunnel_unlink(ign, t);
1544                 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1545                 ip6gre_tunnel_link(ign, t);
1546                 netdev_state_change(dev);
1547         }
1548
1549         return 0;
1550 }
1551
1552 static size_t ip6gre_get_size(const struct net_device *dev)
1553 {
1554         return
1555                 /* IFLA_GRE_LINK */
1556                 nla_total_size(4) +
1557                 /* IFLA_GRE_IFLAGS */
1558                 nla_total_size(2) +
1559                 /* IFLA_GRE_OFLAGS */
1560                 nla_total_size(2) +
1561                 /* IFLA_GRE_IKEY */
1562                 nla_total_size(4) +
1563                 /* IFLA_GRE_OKEY */
1564                 nla_total_size(4) +
1565                 /* IFLA_GRE_LOCAL */
1566                 nla_total_size(sizeof(struct in6_addr)) +
1567                 /* IFLA_GRE_REMOTE */
1568                 nla_total_size(sizeof(struct in6_addr)) +
1569                 /* IFLA_GRE_TTL */
1570                 nla_total_size(1) +
1571                 /* IFLA_GRE_TOS */
1572                 nla_total_size(1) +
1573                 /* IFLA_GRE_ENCAP_LIMIT */
1574                 nla_total_size(1) +
1575                 /* IFLA_GRE_FLOWINFO */
1576                 nla_total_size(4) +
1577                 /* IFLA_GRE_FLAGS */
1578                 nla_total_size(4) +
1579                 0;
1580 }
1581
1582 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1583 {
1584         struct ip6_tnl *t = netdev_priv(dev);
1585         struct __ip6_tnl_parm *p = &t->parms;
1586
1587         if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1588             nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1589             nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1590             nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1591             nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1592             nla_put(skb, IFLA_GRE_LOCAL, sizeof(struct in6_addr), &p->laddr) ||
1593             nla_put(skb, IFLA_GRE_REMOTE, sizeof(struct in6_addr), &p->raddr) ||
1594             nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1595             /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1596             nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1597             nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1598             nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1599                 goto nla_put_failure;
1600         return 0;
1601
1602 nla_put_failure:
1603         return -EMSGSIZE;
1604 }
1605
1606 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1607         [IFLA_GRE_LINK]        = { .type = NLA_U32 },
1608         [IFLA_GRE_IFLAGS]      = { .type = NLA_U16 },
1609         [IFLA_GRE_OFLAGS]      = { .type = NLA_U16 },
1610         [IFLA_GRE_IKEY]        = { .type = NLA_U32 },
1611         [IFLA_GRE_OKEY]        = { .type = NLA_U32 },
1612         [IFLA_GRE_LOCAL]       = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1613         [IFLA_GRE_REMOTE]      = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1614         [IFLA_GRE_TTL]         = { .type = NLA_U8 },
1615         [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1616         [IFLA_GRE_FLOWINFO]    = { .type = NLA_U32 },
1617         [IFLA_GRE_FLAGS]       = { .type = NLA_U32 },
1618 };
1619
1620 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1621         .kind           = "ip6gre",
1622         .maxtype        = IFLA_GRE_MAX,
1623         .policy         = ip6gre_policy,
1624         .priv_size      = sizeof(struct ip6_tnl),
1625         .setup          = ip6gre_tunnel_setup,
1626         .validate       = ip6gre_tunnel_validate,
1627         .newlink        = ip6gre_newlink,
1628         .changelink     = ip6gre_changelink,
1629         .get_size       = ip6gre_get_size,
1630         .fill_info      = ip6gre_fill_info,
1631 };
1632
1633 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1634         .kind           = "ip6gretap",
1635         .maxtype        = IFLA_GRE_MAX,
1636         .policy         = ip6gre_policy,
1637         .priv_size      = sizeof(struct ip6_tnl),
1638         .setup          = ip6gre_tap_setup,
1639         .validate       = ip6gre_tap_validate,
1640         .newlink        = ip6gre_newlink,
1641         .changelink     = ip6gre_changelink,
1642         .get_size       = ip6gre_get_size,
1643         .fill_info      = ip6gre_fill_info,
1644 };
1645
1646 /*
1647  *      And now the modules code and kernel interface.
1648  */
1649
1650 static int __init ip6gre_init(void)
1651 {
1652         int err;
1653
1654         pr_info("GRE over IPv6 tunneling driver\n");
1655
1656         err = register_pernet_device(&ip6gre_net_ops);
1657         if (err < 0)
1658                 return err;
1659
1660         err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1661         if (err < 0) {
1662                 pr_info("%s: can't add protocol\n", __func__);
1663                 goto add_proto_failed;
1664         }
1665
1666         err = rtnl_link_register(&ip6gre_link_ops);
1667         if (err < 0)
1668                 goto rtnl_link_failed;
1669
1670         err = rtnl_link_register(&ip6gre_tap_ops);
1671         if (err < 0)
1672                 goto tap_ops_failed;
1673
1674 out:
1675         return err;
1676
1677 tap_ops_failed:
1678         rtnl_link_unregister(&ip6gre_link_ops);
1679 rtnl_link_failed:
1680         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1681 add_proto_failed:
1682         unregister_pernet_device(&ip6gre_net_ops);
1683         goto out;
1684 }
1685
1686 static void __exit ip6gre_fini(void)
1687 {
1688         rtnl_link_unregister(&ip6gre_tap_ops);
1689         rtnl_link_unregister(&ip6gre_link_ops);
1690         inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1691         unregister_pernet_device(&ip6gre_net_ops);
1692 }
1693
1694 module_init(ip6gre_init);
1695 module_exit(ip6gre_fini);
1696 MODULE_LICENSE("GPL");
1697 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1698 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1699 MODULE_ALIAS_RTNL_LINK("ip6gre");
1700 MODULE_ALIAS_NETDEV("ip6gre0");