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 #include <net/gre.h>
59
60
61 static bool log_ecn_error = true;
62 module_param(log_ecn_error, bool, 0644);
63 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
64
65 #define HASH_SIZE_SHIFT 5
66 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
67
68 static int ip6gre_net_id __read_mostly;
69 struct ip6gre_net {
70 struct ip6_tnl __rcu *tunnels[4][HASH_SIZE];
71
72 struct net_device *fb_tunnel_dev;
73 };
74
75 static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
76 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
77 static int ip6gre_tunnel_init(struct net_device *dev);
78 static void ip6gre_tunnel_setup(struct net_device *dev);
79 static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
80 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
81
82 /* Tunnel hash table */
83
84 /*
85 4 hash tables:
86
87 3: (remote,local)
88 2: (remote,*)
89 1: (*,local)
90 0: (*,*)
91
92 We require exact key match i.e. if a key is present in packet
93 it will match only tunnel with the same key; if it is not present,
94 it will match only keyless tunnel.
95
96 All keysless packets, if not matched configured keyless tunnels
97 will match fallback tunnel.
98 */
99
100 #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(HASH_SIZE - 1))
101 static u32 HASH_ADDR(const struct in6_addr *addr)
102 {
103 u32 hash = ipv6_addr_hash(addr);
104
105 return hash_32(hash, HASH_SIZE_SHIFT);
106 }
107
108 #define tunnels_r_l tunnels[3]
109 #define tunnels_r tunnels[2]
110 #define tunnels_l tunnels[1]
111 #define tunnels_wc tunnels[0]
112
113 /* Given src, dst and key, find appropriate for input tunnel. */
114
115 static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
116 const struct in6_addr *remote, const struct in6_addr *local,
117 __be32 key, __be16 gre_proto)
118 {
119 struct net *net = dev_net(dev);
120 int link = dev->ifindex;
121 unsigned int h0 = HASH_ADDR(remote);
122 unsigned int h1 = HASH_KEY(key);
123 struct ip6_tnl *t, *cand = NULL;
124 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
125 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
126 ARPHRD_ETHER : ARPHRD_IP6GRE;
127 int score, cand_score = 4;
128 struct net_device *ndev;
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)
229 return cand;
230
231 ndev = READ_ONCE(ign->fb_tunnel_dev);
232 if (ndev && ndev->flags & IFF_UP)
233 return netdev_priv(ndev);
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 NULL;
321 if (t || !create)
322 return t;
323
324 if (parms->name[0]) {
325 if (!dev_valid_name(parms->name))
326 return NULL;
327 strlcpy(name, parms->name, IFNAMSIZ);
328 } else {
329 strcpy(name, "ip6gre%d");
330 }
331 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
332 ip6gre_tunnel_setup);
333 if (!dev)
334 return NULL;
335
336 dev_net_set(dev, net);
337
338 nt = netdev_priv(dev);
339 nt->parms = *parms;
340 dev->rtnl_link_ops = &ip6gre_link_ops;
341
342 nt->dev = dev;
343 nt->net = dev_net(dev);
344 ip6gre_tnl_link_config(nt, 1);
345
346 if (register_netdevice(dev) < 0)
347 goto failed_free;
348
349 /* Can use a lockless transmit, unless we generate output sequences */
350 if (!(nt->parms.o_flags & GRE_SEQ))
351 dev->features |= NETIF_F_LLTX;
352
353 ip6gre_tunnel_link(ign, nt);
354 return nt;
355
356 failed_free:
357 free_netdev(dev);
358 return NULL;
359 }
360
361 static void ip6gre_tunnel_uninit(struct net_device *dev)
362 {
363 struct ip6_tnl *t = netdev_priv(dev);
364 struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
365
366 ip6gre_tunnel_unlink(ign, t);
367 if (ign->fb_tunnel_dev == dev)
368 WRITE_ONCE(ign->fb_tunnel_dev, NULL);
369 dst_cache_reset(&t->dst_cache);
370 dev_put(dev);
371 }
372
373
374 static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
375 u8 type, u8 code, int offset, __be32 info)
376 {
377 const struct gre_base_hdr *greh;
378 const struct ipv6hdr *ipv6h;
379 int grehlen = sizeof(*greh);
380 struct ip6_tnl *t;
381 int key_off = 0;
382 __be16 flags;
383 __be32 key;
384
385 if (!pskb_may_pull(skb, offset + grehlen))
386 return;
387 greh = (const struct gre_base_hdr *)(skb->data + offset);
388 flags = greh->flags;
389 if (flags & (GRE_VERSION | GRE_ROUTING))
390 return;
391 if (flags & GRE_CSUM)
392 grehlen += 4;
393 if (flags & GRE_KEY) {
394 key_off = grehlen + offset;
395 grehlen += 4;
396 }
397
398 if (!pskb_may_pull(skb, offset + grehlen))
399 return;
400 ipv6h = (const struct ipv6hdr *)skb->data;
401 greh = (const struct gre_base_hdr *)(skb->data + offset);
402 key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
403
404 t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
405 key, greh->protocol);
406 if (!t)
407 return;
408
409 switch (type) {
410 __u32 teli;
411 struct ipv6_tlv_tnl_enc_lim *tel;
412 __u32 mtu;
413 case ICMPV6_DEST_UNREACH:
414 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
415 t->parms.name);
416 if (code != ICMPV6_PORT_UNREACH)
417 break;
418 return;
419 case ICMPV6_TIME_EXCEED:
420 if (code == ICMPV6_EXC_HOPLIMIT) {
421 net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
422 t->parms.name);
423 break;
424 }
425 return;
426 case ICMPV6_PARAMPROB:
427 teli = 0;
428 if (code == ICMPV6_HDR_FIELD)
429 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
430
431 if (teli && teli == be32_to_cpu(info) - 2) {
432 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
433 if (tel->encap_limit == 0) {
434 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
435 t->parms.name);
436 }
437 } else {
438 net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
439 t->parms.name);
440 }
441 return;
442 case ICMPV6_PKT_TOOBIG:
443 mtu = be32_to_cpu(info) - offset;
444 if (mtu < IPV6_MIN_MTU)
445 mtu = IPV6_MIN_MTU;
446 t->dev->mtu = mtu;
447 return;
448 }
449
450 if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
451 t->err_count++;
452 else
453 t->err_count = 1;
454 t->err_time = jiffies;
455 }
456
457 static int ip6gre_rcv(struct sk_buff *skb)
458 {
459 const struct ipv6hdr *ipv6h;
460 u8 *h;
461 __be16 flags;
462 __sum16 csum = 0;
463 __be32 key = 0;
464 u32 seqno = 0;
465 struct ip6_tnl *tunnel;
466 int offset = 4;
467 __be16 gre_proto;
468 int err;
469
470 if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
471 goto drop;
472
473 ipv6h = ipv6_hdr(skb);
474 h = skb->data;
475 flags = *(__be16 *)h;
476
477 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
478 /* - Version must be 0.
479 - We do not support routing headers.
480 */
481 if (flags&(GRE_VERSION|GRE_ROUTING))
482 goto drop;
483
484 if (flags&GRE_CSUM) {
485 csum = skb_checksum_simple_validate(skb);
486 offset += 4;
487 }
488 if (flags&GRE_KEY) {
489 key = *(__be32 *)(h + offset);
490 offset += 4;
491 }
492 if (flags&GRE_SEQ) {
493 seqno = ntohl(*(__be32 *)(h + offset));
494 offset += 4;
495 }
496 }
497
498 gre_proto = *(__be16 *)(h + 2);
499
500 tunnel = ip6gre_tunnel_lookup(skb->dev,
501 &ipv6h->saddr, &ipv6h->daddr, key,
502 gre_proto);
503 if (tunnel) {
504 struct pcpu_sw_netstats *tstats;
505
506 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
507 goto drop;
508
509 if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
510 tunnel->dev->stats.rx_dropped++;
511 goto drop;
512 }
513
514 skb->protocol = gre_proto;
515 /* WCCP version 1 and 2 protocol decoding.
516 * - Change protocol to IPv6
517 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
518 */
519 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
520 skb->protocol = htons(ETH_P_IPV6);
521 if ((*(h + offset) & 0xF0) != 0x40)
522 offset += 4;
523 }
524
525 skb->mac_header = skb->network_header;
526 __pskb_pull(skb, offset);
527 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
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, tunnel->net);
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 ip6_tnl *tunnel = netdev_priv(dev);
620 struct net *net = tunnel->net;
621 struct net_device *tdev; /* Device to other host */
622 struct ipv6hdr *ipv6h; /* Our new IP header */
623 unsigned int max_headroom = 0; /* 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 __be16 protocol;
633
634 if (dev->type == ARPHRD_ETHER)
635 IPCB(skb)->flags = 0;
636
637 if (dev->header_ops && dev->type == ARPHRD_IP6GRE) {
638 gre_hlen = 0;
639 ipv6h = (struct ipv6hdr *)skb->data;
640 fl6->daddr = ipv6h->daddr;
641 } else {
642 gre_hlen = tunnel->hlen;
643 fl6->daddr = tunnel->parms.raddr;
644 }
645
646 if (!fl6->flowi6_mark)
647 dst = dst_cache_get(&tunnel->dst_cache);
648
649 if (!dst) {
650 dst = ip6_route_output(net, NULL, fl6);
651
652 if (dst->error)
653 goto tx_err_link_failure;
654 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
655 if (IS_ERR(dst)) {
656 err = PTR_ERR(dst);
657 dst = NULL;
658 goto tx_err_link_failure;
659 }
660 ndst = dst;
661 }
662
663 tdev = dst->dev;
664
665 if (tdev == dev) {
666 stats->collisions++;
667 net_warn_ratelimited("%s: Local routing loop detected!\n",
668 tunnel->parms.name);
669 goto tx_err_dst_release;
670 }
671
672 mtu = dst_mtu(dst) - sizeof(*ipv6h);
673 if (encap_limit >= 0) {
674 max_headroom += 8;
675 mtu -= 8;
676 }
677 if (mtu < IPV6_MIN_MTU)
678 mtu = IPV6_MIN_MTU;
679 if (skb_dst(skb))
680 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
681 if (skb->len > mtu) {
682 *pmtu = mtu;
683 err = -EMSGSIZE;
684 goto tx_err_dst_release;
685 }
686
687 if (tunnel->err_count > 0) {
688 if (time_before(jiffies,
689 tunnel->err_time + IP6TUNNEL_ERR_TIMEO)) {
690 tunnel->err_count--;
691
692 dst_link_failure(skb);
693 } else
694 tunnel->err_count = 0;
695 }
696
697 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
698
699 max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
700
701 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
702 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
703 new_skb = skb_realloc_headroom(skb, max_headroom);
704 if (max_headroom > dev->needed_headroom)
705 dev->needed_headroom = max_headroom;
706 if (!new_skb)
707 goto tx_err_dst_release;
708
709 if (skb->sk)
710 skb_set_owner_w(new_skb, skb->sk);
711 consume_skb(skb);
712 skb = new_skb;
713 }
714
715 if (!fl6->flowi6_mark && ndst)
716 dst_cache_set_ip6(&tunnel->dst_cache, ndst, &fl6->saddr);
717 skb_dst_set(skb, dst);
718
719 proto = NEXTHDR_GRE;
720 if (encap_limit >= 0) {
721 init_tel_txopt(&opt, encap_limit);
722 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
723 }
724
725 if (likely(!skb->encapsulation)) {
726 skb_reset_inner_headers(skb);
727 skb->encapsulation = 1;
728 }
729
730 skb_push(skb, gre_hlen);
731 skb_reset_network_header(skb);
732 skb_set_transport_header(skb, sizeof(*ipv6h));
733
734 /*
735 * Push down and install the IP header.
736 */
737 ipv6h = ipv6_hdr(skb);
738 ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
739 ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
740 ipv6h->hop_limit = tunnel->parms.hop_limit;
741 ipv6h->nexthdr = proto;
742 ipv6h->saddr = fl6->saddr;
743 ipv6h->daddr = fl6->daddr;
744
745 ((__be16 *)(ipv6h + 1))[0] = tunnel->parms.o_flags;
746 protocol = (dev->type == ARPHRD_ETHER) ?
747 htons(ETH_P_TEB) : skb->protocol;
748 ((__be16 *)(ipv6h + 1))[1] = protocol;
749
750 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
751 __be32 *ptr = (__be32 *)(((u8 *)ipv6h) + tunnel->hlen - 4);
752
753 if (tunnel->parms.o_flags&GRE_SEQ) {
754 ++tunnel->o_seqno;
755 *ptr = htonl(tunnel->o_seqno);
756 ptr--;
757 }
758 if (tunnel->parms.o_flags&GRE_KEY) {
759 *ptr = tunnel->parms.o_key;
760 ptr--;
761 }
762 if (tunnel->parms.o_flags&GRE_CSUM) {
763 *ptr = 0;
764 *(__sum16 *)ptr = ip_compute_csum((void *)(ipv6h+1),
765 skb->len - sizeof(struct ipv6hdr));
766 }
767 }
768
769 skb_set_inner_protocol(skb, protocol);
770
771 ip6tunnel_xmit(NULL, skb, dev);
772 return 0;
773 tx_err_link_failure:
774 stats->tx_carrier_errors++;
775 dst_link_failure(skb);
776 tx_err_dst_release:
777 dst_release(dst);
778 return err;
779 }
780
781 static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev)
782 {
783 struct ip6_tnl *t = netdev_priv(dev);
784 const struct iphdr *iph = ip_hdr(skb);
785 int encap_limit = -1;
786 struct flowi6 fl6;
787 __u8 dsfield;
788 __u32 mtu;
789 int err;
790
791 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
792
793 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
794 encap_limit = t->parms.encap_limit;
795
796 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
797 fl6.flowi6_proto = IPPROTO_GRE;
798
799 dsfield = ipv4_get_dsfield(iph);
800
801 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
802 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
803 & IPV6_TCLASS_MASK;
804 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
805 fl6.flowi6_mark = skb->mark;
806
807 err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
808 if (err != 0) {
809 /* XXX: send ICMP error even if DF is not set. */
810 if (err == -EMSGSIZE)
811 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
812 htonl(mtu));
813 return -1;
814 }
815
816 return 0;
817 }
818
819 static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev)
820 {
821 struct ip6_tnl *t = netdev_priv(dev);
822 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
823 int encap_limit = -1;
824 __u16 offset;
825 struct flowi6 fl6;
826 __u8 dsfield;
827 __u32 mtu;
828 int err;
829
830 if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
831 return -1;
832
833 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
834 if (offset > 0) {
835 struct ipv6_tlv_tnl_enc_lim *tel;
836 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
837 if (tel->encap_limit == 0) {
838 icmpv6_send(skb, ICMPV6_PARAMPROB,
839 ICMPV6_HDR_FIELD, offset + 2);
840 return -1;
841 }
842 encap_limit = tel->encap_limit - 1;
843 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
844 encap_limit = t->parms.encap_limit;
845
846 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
847 fl6.flowi6_proto = IPPROTO_GRE;
848
849 dsfield = ipv6_get_dsfield(ipv6h);
850 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
851 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
852 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
853 fl6.flowlabel |= ip6_flowlabel(ipv6h);
854 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
855 fl6.flowi6_mark = skb->mark;
856
857 err = ip6gre_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
858 if (err != 0) {
859 if (err == -EMSGSIZE)
860 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
861 return -1;
862 }
863
864 return 0;
865 }
866
867 /**
868 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
869 * @t: the outgoing tunnel device
870 * @hdr: IPv6 header from the incoming packet
871 *
872 * Description:
873 * Avoid trivial tunneling loop by checking that tunnel exit-point
874 * doesn't match source of incoming packet.
875 *
876 * Return:
877 * 1 if conflict,
878 * 0 else
879 **/
880
881 static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
882 const struct ipv6hdr *hdr)
883 {
884 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
885 }
886
887 static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
888 {
889 struct ip6_tnl *t = netdev_priv(dev);
890 int encap_limit = -1;
891 struct flowi6 fl6;
892 __u32 mtu;
893 int err;
894
895 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
896 encap_limit = t->parms.encap_limit;
897
898 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
899
900 err = ip6gre_xmit2(skb, dev, 0, &fl6, encap_limit, &mtu);
901
902 return err;
903 }
904
905 static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb,
906 struct net_device *dev)
907 {
908 struct ip6_tnl *t = netdev_priv(dev);
909 struct net_device_stats *stats = &t->dev->stats;
910 int ret;
911
912 if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
913 goto tx_err;
914
915 switch (skb->protocol) {
916 case htons(ETH_P_IP):
917 ret = ip6gre_xmit_ipv4(skb, dev);
918 break;
919 case htons(ETH_P_IPV6):
920 ret = ip6gre_xmit_ipv6(skb, dev);
921 break;
922 default:
923 ret = ip6gre_xmit_other(skb, dev);
924 break;
925 }
926
927 if (ret < 0)
928 goto tx_err;
929
930 return NETDEV_TX_OK;
931
932 tx_err:
933 stats->tx_errors++;
934 stats->tx_dropped++;
935 kfree_skb(skb);
936 return NETDEV_TX_OK;
937 }
938
939 static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
940 {
941 struct net_device *dev = t->dev;
942 struct __ip6_tnl_parm *p = &t->parms;
943 struct flowi6 *fl6 = &t->fl.u.ip6;
944 int addend = sizeof(struct ipv6hdr) + 4;
945
946 if (dev->type != ARPHRD_ETHER) {
947 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
948 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
949 }
950
951 /* Set up flowi template */
952 fl6->saddr = p->laddr;
953 fl6->daddr = p->raddr;
954 fl6->flowi6_oif = p->link;
955 fl6->flowlabel = 0;
956
957 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
958 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
959 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
960 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
961
962 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
963 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
964
965 if (p->flags&IP6_TNL_F_CAP_XMIT &&
966 p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER)
967 dev->flags |= IFF_POINTOPOINT;
968 else
969 dev->flags &= ~IFF_POINTOPOINT;
970
971 /* Precalculate GRE options length */
972 if (t->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
973 if (t->parms.o_flags&GRE_CSUM)
974 addend += 4;
975 if (t->parms.o_flags&GRE_KEY)
976 addend += 4;
977 if (t->parms.o_flags&GRE_SEQ)
978 addend += 4;
979 }
980 t->hlen = addend;
981
982 if (p->flags & IP6_TNL_F_CAP_XMIT) {
983 int strict = (ipv6_addr_type(&p->raddr) &
984 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
985
986 struct rt6_info *rt = rt6_lookup(t->net,
987 &p->raddr, &p->laddr,
988 p->link, strict);
989
990 if (!rt)
991 return;
992
993 if (rt->dst.dev) {
994 dev->hard_header_len = rt->dst.dev->hard_header_len + addend;
995
996 if (set_mtu) {
997 dev->mtu = rt->dst.dev->mtu - addend;
998 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
999 dev->mtu -= 8;
1000
1001 if (dev->mtu < IPV6_MIN_MTU)
1002 dev->mtu = IPV6_MIN_MTU;
1003 }
1004 }
1005 ip6_rt_put(rt);
1006 }
1007 }
1008
1009 static int ip6gre_tnl_change(struct ip6_tnl *t,
1010 const struct __ip6_tnl_parm *p, int set_mtu)
1011 {
1012 t->parms.laddr = p->laddr;
1013 t->parms.raddr = p->raddr;
1014 t->parms.flags = p->flags;
1015 t->parms.hop_limit = p->hop_limit;
1016 t->parms.encap_limit = p->encap_limit;
1017 t->parms.flowinfo = p->flowinfo;
1018 t->parms.link = p->link;
1019 t->parms.proto = p->proto;
1020 t->parms.i_key = p->i_key;
1021 t->parms.o_key = p->o_key;
1022 t->parms.i_flags = p->i_flags;
1023 t->parms.o_flags = p->o_flags;
1024 dst_cache_reset(&t->dst_cache);
1025 ip6gre_tnl_link_config(t, set_mtu);
1026 return 0;
1027 }
1028
1029 static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
1030 const struct ip6_tnl_parm2 *u)
1031 {
1032 p->laddr = u->laddr;
1033 p->raddr = u->raddr;
1034 p->flags = u->flags;
1035 p->hop_limit = u->hop_limit;
1036 p->encap_limit = u->encap_limit;
1037 p->flowinfo = u->flowinfo;
1038 p->link = u->link;
1039 p->i_key = u->i_key;
1040 p->o_key = u->o_key;
1041 p->i_flags = u->i_flags;
1042 p->o_flags = u->o_flags;
1043 memcpy(p->name, u->name, sizeof(u->name));
1044 }
1045
1046 static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
1047 const struct __ip6_tnl_parm *p)
1048 {
1049 u->proto = IPPROTO_GRE;
1050 u->laddr = p->laddr;
1051 u->raddr = p->raddr;
1052 u->flags = p->flags;
1053 u->hop_limit = p->hop_limit;
1054 u->encap_limit = p->encap_limit;
1055 u->flowinfo = p->flowinfo;
1056 u->link = p->link;
1057 u->i_key = p->i_key;
1058 u->o_key = p->o_key;
1059 u->i_flags = p->i_flags;
1060 u->o_flags = p->o_flags;
1061 memcpy(u->name, p->name, sizeof(u->name));
1062 }
1063
1064 static int ip6gre_tunnel_ioctl(struct net_device *dev,
1065 struct ifreq *ifr, int cmd)
1066 {
1067 int err = 0;
1068 struct ip6_tnl_parm2 p;
1069 struct __ip6_tnl_parm p1;
1070 struct ip6_tnl *t = netdev_priv(dev);
1071 struct net *net = t->net;
1072 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1073
1074 switch (cmd) {
1075 case SIOCGETTUNNEL:
1076 if (dev == ign->fb_tunnel_dev) {
1077 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1078 err = -EFAULT;
1079 break;
1080 }
1081 ip6gre_tnl_parm_from_user(&p1, &p);
1082 t = ip6gre_tunnel_locate(net, &p1, 0);
1083 if (!t)
1084 t = netdev_priv(dev);
1085 }
1086 memset(&p, 0, sizeof(p));
1087 ip6gre_tnl_parm_to_user(&p, &t->parms);
1088 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1089 err = -EFAULT;
1090 break;
1091
1092 case SIOCADDTUNNEL:
1093 case SIOCCHGTUNNEL:
1094 err = -EPERM;
1095 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1096 goto done;
1097
1098 err = -EFAULT;
1099 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1100 goto done;
1101
1102 err = -EINVAL;
1103 if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
1104 goto done;
1105
1106 if (!(p.i_flags&GRE_KEY))
1107 p.i_key = 0;
1108 if (!(p.o_flags&GRE_KEY))
1109 p.o_key = 0;
1110
1111 ip6gre_tnl_parm_from_user(&p1, &p);
1112 t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
1113
1114 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1115 if (t) {
1116 if (t->dev != dev) {
1117 err = -EEXIST;
1118 break;
1119 }
1120 } else {
1121 t = netdev_priv(dev);
1122
1123 ip6gre_tunnel_unlink(ign, t);
1124 synchronize_net();
1125 ip6gre_tnl_change(t, &p1, 1);
1126 ip6gre_tunnel_link(ign, t);
1127 netdev_state_change(dev);
1128 }
1129 }
1130
1131 if (t) {
1132 err = 0;
1133
1134 memset(&p, 0, sizeof(p));
1135 ip6gre_tnl_parm_to_user(&p, &t->parms);
1136 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1137 err = -EFAULT;
1138 } else
1139 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1140 break;
1141
1142 case SIOCDELTUNNEL:
1143 err = -EPERM;
1144 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1145 goto done;
1146
1147 if (dev == ign->fb_tunnel_dev) {
1148 err = -EFAULT;
1149 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1150 goto done;
1151 err = -ENOENT;
1152 ip6gre_tnl_parm_from_user(&p1, &p);
1153 t = ip6gre_tunnel_locate(net, &p1, 0);
1154 if (!t)
1155 goto done;
1156 err = -EPERM;
1157 if (t == netdev_priv(ign->fb_tunnel_dev))
1158 goto done;
1159 dev = t->dev;
1160 }
1161 unregister_netdevice(dev);
1162 err = 0;
1163 break;
1164
1165 default:
1166 err = -EINVAL;
1167 }
1168
1169 done:
1170 return err;
1171 }
1172
1173 static int ip6gre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1174 {
1175 if (new_mtu < 68 ||
1176 new_mtu > 0xFFF8 - dev->hard_header_len)
1177 return -EINVAL;
1178 dev->mtu = new_mtu;
1179 return 0;
1180 }
1181
1182 static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
1183 unsigned short type, const void *daddr,
1184 const void *saddr, unsigned int len)
1185 {
1186 struct ip6_tnl *t = netdev_priv(dev);
1187 struct ipv6hdr *ipv6h;
1188 __be16 *p;
1189
1190 ipv6h = (struct ipv6hdr *)skb_push(skb, t->hlen + sizeof(*ipv6h));
1191 ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
1192 t->fl.u.ip6.flowlabel,
1193 true, &t->fl.u.ip6));
1194 ipv6h->hop_limit = t->parms.hop_limit;
1195 ipv6h->nexthdr = NEXTHDR_GRE;
1196 ipv6h->saddr = t->parms.laddr;
1197 ipv6h->daddr = t->parms.raddr;
1198
1199 p = (__be16 *)(ipv6h + 1);
1200 p[0] = t->parms.o_flags;
1201 p[1] = htons(type);
1202
1203 /*
1204 * Set the source hardware address.
1205 */
1206
1207 if (saddr)
1208 memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
1209 if (daddr)
1210 memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
1211 if (!ipv6_addr_any(&ipv6h->daddr))
1212 return t->hlen;
1213
1214 return -t->hlen;
1215 }
1216
1217 static const struct header_ops ip6gre_header_ops = {
1218 .create = ip6gre_header,
1219 };
1220
1221 static const struct net_device_ops ip6gre_netdev_ops = {
1222 .ndo_init = ip6gre_tunnel_init,
1223 .ndo_uninit = ip6gre_tunnel_uninit,
1224 .ndo_start_xmit = ip6gre_tunnel_xmit,
1225 .ndo_do_ioctl = ip6gre_tunnel_ioctl,
1226 .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1227 .ndo_get_stats64 = ip_tunnel_get_stats64,
1228 .ndo_get_iflink = ip6_tnl_get_iflink,
1229 };
1230
1231 static void ip6gre_dev_free(struct net_device *dev)
1232 {
1233 struct ip6_tnl *t = netdev_priv(dev);
1234
1235 dst_cache_destroy(&t->dst_cache);
1236 free_percpu(dev->tstats);
1237 free_netdev(dev);
1238 }
1239
1240 static void ip6gre_tunnel_setup(struct net_device *dev)
1241 {
1242 struct ip6_tnl *t;
1243
1244 dev->netdev_ops = &ip6gre_netdev_ops;
1245 dev->destructor = ip6gre_dev_free;
1246
1247 dev->type = ARPHRD_IP6GRE;
1248 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr) + 4;
1249 dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr) - 4;
1250 t = netdev_priv(dev);
1251 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1252 dev->mtu -= 8;
1253 dev->flags |= IFF_NOARP;
1254 dev->addr_len = sizeof(struct in6_addr);
1255 netif_keep_dst(dev);
1256 }
1257
1258 static int ip6gre_tunnel_init_common(struct net_device *dev)
1259 {
1260 struct ip6_tnl *tunnel;
1261 int ret;
1262
1263 tunnel = netdev_priv(dev);
1264
1265 tunnel->dev = dev;
1266 tunnel->net = dev_net(dev);
1267 strcpy(tunnel->parms.name, dev->name);
1268
1269 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1270 if (!dev->tstats)
1271 return -ENOMEM;
1272
1273 ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1274 if (ret) {
1275 free_percpu(dev->tstats);
1276 dev->tstats = NULL;
1277 return ret;
1278 }
1279
1280 return 0;
1281 }
1282
1283 static int ip6gre_tunnel_init(struct net_device *dev)
1284 {
1285 struct ip6_tnl *tunnel;
1286 int ret;
1287
1288 ret = ip6gre_tunnel_init_common(dev);
1289 if (ret)
1290 return ret;
1291
1292 tunnel = netdev_priv(dev);
1293
1294 memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr));
1295 memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr));
1296
1297 if (ipv6_addr_any(&tunnel->parms.raddr))
1298 dev->header_ops = &ip6gre_header_ops;
1299
1300 return 0;
1301 }
1302
1303 static void ip6gre_fb_tunnel_init(struct net_device *dev)
1304 {
1305 struct ip6_tnl *tunnel = netdev_priv(dev);
1306
1307 tunnel->dev = dev;
1308 tunnel->net = dev_net(dev);
1309 strcpy(tunnel->parms.name, dev->name);
1310
1311 tunnel->hlen = sizeof(struct ipv6hdr) + 4;
1312 }
1313
1314
1315 static struct inet6_protocol ip6gre_protocol __read_mostly = {
1316 .handler = ip6gre_rcv,
1317 .err_handler = ip6gre_err,
1318 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1319 };
1320
1321 static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)
1322 {
1323 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1324 struct net_device *dev, *aux;
1325 int prio;
1326
1327 for_each_netdev_safe(net, dev, aux)
1328 if (dev->rtnl_link_ops == &ip6gre_link_ops ||
1329 dev->rtnl_link_ops == &ip6gre_tap_ops)
1330 unregister_netdevice_queue(dev, head);
1331
1332 for (prio = 0; prio < 4; prio++) {
1333 int h;
1334 for (h = 0; h < HASH_SIZE; h++) {
1335 struct ip6_tnl *t;
1336
1337 t = rtnl_dereference(ign->tunnels[prio][h]);
1338
1339 while (t) {
1340 /* If dev is in the same netns, it has already
1341 * been added to the list by the previous loop.
1342 */
1343 if (!net_eq(dev_net(t->dev), net))
1344 unregister_netdevice_queue(t->dev,
1345 head);
1346 t = rtnl_dereference(t->next);
1347 }
1348 }
1349 }
1350 }
1351
1352 static int __net_init ip6gre_init_net(struct net *net)
1353 {
1354 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1355 struct net_device *ndev;
1356 int err;
1357
1358 ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
1359 NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
1360 if (!ndev) {
1361 err = -ENOMEM;
1362 goto err_alloc_dev;
1363 }
1364 ign->fb_tunnel_dev = ndev;
1365 dev_net_set(ign->fb_tunnel_dev, net);
1366 /* FB netdevice is special: we have one, and only one per netns.
1367 * Allowing to move it to another netns is clearly unsafe.
1368 */
1369 ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1370
1371
1372 ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
1373 ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;
1374
1375 err = register_netdev(ign->fb_tunnel_dev);
1376 if (err)
1377 goto err_reg_dev;
1378
1379 rcu_assign_pointer(ign->tunnels_wc[0],
1380 netdev_priv(ign->fb_tunnel_dev));
1381 return 0;
1382
1383 err_reg_dev:
1384 ip6gre_dev_free(ndev);
1385 err_alloc_dev:
1386 return err;
1387 }
1388
1389 static void __net_exit ip6gre_exit_net(struct net *net)
1390 {
1391 LIST_HEAD(list);
1392
1393 rtnl_lock();
1394 ip6gre_destroy_tunnels(net, &list);
1395 unregister_netdevice_many(&list);
1396 rtnl_unlock();
1397 }
1398
1399 static struct pernet_operations ip6gre_net_ops = {
1400 .init = ip6gre_init_net,
1401 .exit = ip6gre_exit_net,
1402 .id = &ip6gre_net_id,
1403 .size = sizeof(struct ip6gre_net),
1404 };
1405
1406 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1407 {
1408 __be16 flags;
1409
1410 if (!data)
1411 return 0;
1412
1413 flags = 0;
1414 if (data[IFLA_GRE_IFLAGS])
1415 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1416 if (data[IFLA_GRE_OFLAGS])
1417 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1418 if (flags & (GRE_VERSION|GRE_ROUTING))
1419 return -EINVAL;
1420
1421 return 0;
1422 }
1423
1424 static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1425 {
1426 struct in6_addr daddr;
1427
1428 if (tb[IFLA_ADDRESS]) {
1429 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1430 return -EINVAL;
1431 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1432 return -EADDRNOTAVAIL;
1433 }
1434
1435 if (!data)
1436 goto out;
1437
1438 if (data[IFLA_GRE_REMOTE]) {
1439 daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1440 if (ipv6_addr_any(&daddr))
1441 return -EINVAL;
1442 }
1443
1444 out:
1445 return ip6gre_tunnel_validate(tb, data);
1446 }
1447
1448
1449 static void ip6gre_netlink_parms(struct nlattr *data[],
1450 struct __ip6_tnl_parm *parms)
1451 {
1452 memset(parms, 0, sizeof(*parms));
1453
1454 if (!data)
1455 return;
1456
1457 if (data[IFLA_GRE_LINK])
1458 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1459
1460 if (data[IFLA_GRE_IFLAGS])
1461 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1462
1463 if (data[IFLA_GRE_OFLAGS])
1464 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1465
1466 if (data[IFLA_GRE_IKEY])
1467 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1468
1469 if (data[IFLA_GRE_OKEY])
1470 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1471
1472 if (data[IFLA_GRE_LOCAL])
1473 parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]);
1474
1475 if (data[IFLA_GRE_REMOTE])
1476 parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]);
1477
1478 if (data[IFLA_GRE_TTL])
1479 parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]);
1480
1481 if (data[IFLA_GRE_ENCAP_LIMIT])
1482 parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]);
1483
1484 if (data[IFLA_GRE_FLOWINFO])
1485 parms->flowinfo = nla_get_u32(data[IFLA_GRE_FLOWINFO]);
1486
1487 if (data[IFLA_GRE_FLAGS])
1488 parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]);
1489 }
1490
1491 static int ip6gre_tap_init(struct net_device *dev)
1492 {
1493 struct ip6_tnl *tunnel;
1494 int ret;
1495
1496 ret = ip6gre_tunnel_init_common(dev);
1497 if (ret)
1498 return ret;
1499
1500 tunnel = netdev_priv(dev);
1501
1502 ip6gre_tnl_link_config(tunnel, 1);
1503
1504 return 0;
1505 }
1506
1507 static const struct net_device_ops ip6gre_tap_netdev_ops = {
1508 .ndo_init = ip6gre_tap_init,
1509 .ndo_uninit = ip6gre_tunnel_uninit,
1510 .ndo_start_xmit = ip6gre_tunnel_xmit,
1511 .ndo_set_mac_address = eth_mac_addr,
1512 .ndo_validate_addr = eth_validate_addr,
1513 .ndo_change_mtu = ip6gre_tunnel_change_mtu,
1514 .ndo_get_stats64 = ip_tunnel_get_stats64,
1515 .ndo_get_iflink = ip6_tnl_get_iflink,
1516 };
1517
1518 static void ip6gre_tap_setup(struct net_device *dev)
1519 {
1520
1521 ether_setup(dev);
1522
1523 dev->netdev_ops = &ip6gre_tap_netdev_ops;
1524 dev->destructor = ip6gre_dev_free;
1525
1526 dev->features |= NETIF_F_NETNS_LOCAL;
1527 }
1528
1529 static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
1530 struct nlattr *tb[], struct nlattr *data[])
1531 {
1532 struct ip6_tnl *nt;
1533 struct net *net = dev_net(dev);
1534 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1535 int err;
1536
1537 nt = netdev_priv(dev);
1538 ip6gre_netlink_parms(data, &nt->parms);
1539
1540 if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
1541 return -EEXIST;
1542
1543 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1544 eth_hw_addr_random(dev);
1545
1546 nt->dev = dev;
1547 nt->net = dev_net(dev);
1548 ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
1549
1550 /* Can use a lockless transmit, unless we generate output sequences */
1551 if (!(nt->parms.o_flags & GRE_SEQ))
1552 dev->features |= NETIF_F_LLTX;
1553
1554 err = register_netdevice(dev);
1555 if (err)
1556 goto out;
1557
1558 dev_hold(dev);
1559 ip6gre_tunnel_link(ign, nt);
1560
1561 out:
1562 return err;
1563 }
1564
1565 static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
1566 struct nlattr *data[])
1567 {
1568 struct ip6_tnl *t, *nt = netdev_priv(dev);
1569 struct net *net = nt->net;
1570 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1571 struct __ip6_tnl_parm p;
1572
1573 if (dev == ign->fb_tunnel_dev)
1574 return -EINVAL;
1575
1576 ip6gre_netlink_parms(data, &p);
1577
1578 t = ip6gre_tunnel_locate(net, &p, 0);
1579
1580 if (t) {
1581 if (t->dev != dev)
1582 return -EEXIST;
1583 } else {
1584 t = nt;
1585 }
1586
1587 ip6gre_tunnel_unlink(ign, t);
1588 ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
1589 ip6gre_tunnel_link(ign, t);
1590 return 0;
1591 }
1592
1593 static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
1594 {
1595 struct net *net = dev_net(dev);
1596 struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
1597
1598 if (dev != ign->fb_tunnel_dev)
1599 unregister_netdevice_queue(dev, head);
1600 }
1601
1602 static size_t ip6gre_get_size(const struct net_device *dev)
1603 {
1604 return
1605 /* IFLA_GRE_LINK */
1606 nla_total_size(4) +
1607 /* IFLA_GRE_IFLAGS */
1608 nla_total_size(2) +
1609 /* IFLA_GRE_OFLAGS */
1610 nla_total_size(2) +
1611 /* IFLA_GRE_IKEY */
1612 nla_total_size(4) +
1613 /* IFLA_GRE_OKEY */
1614 nla_total_size(4) +
1615 /* IFLA_GRE_LOCAL */
1616 nla_total_size(sizeof(struct in6_addr)) +
1617 /* IFLA_GRE_REMOTE */
1618 nla_total_size(sizeof(struct in6_addr)) +
1619 /* IFLA_GRE_TTL */
1620 nla_total_size(1) +
1621 /* IFLA_GRE_TOS */
1622 nla_total_size(1) +
1623 /* IFLA_GRE_ENCAP_LIMIT */
1624 nla_total_size(1) +
1625 /* IFLA_GRE_FLOWINFO */
1626 nla_total_size(4) +
1627 /* IFLA_GRE_FLAGS */
1628 nla_total_size(4) +
1629 0;
1630 }
1631
1632 static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1633 {
1634 struct ip6_tnl *t = netdev_priv(dev);
1635 struct __ip6_tnl_parm *p = &t->parms;
1636
1637 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1638 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1639 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1640 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1641 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1642 nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||
1643 nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) ||
1644 nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) ||
1645 /*nla_put_u8(skb, IFLA_GRE_TOS, t->priority) ||*/
1646 nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
1647 nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
1648 nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags))
1649 goto nla_put_failure;
1650 return 0;
1651
1652 nla_put_failure:
1653 return -EMSGSIZE;
1654 }
1655
1656 static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = {
1657 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1658 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1659 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1660 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1661 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1662 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) },
1663 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) },
1664 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1665 [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 },
1666 [IFLA_GRE_FLOWINFO] = { .type = NLA_U32 },
1667 [IFLA_GRE_FLAGS] = { .type = NLA_U32 },
1668 };
1669
1670 static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
1671 .kind = "ip6gre",
1672 .maxtype = IFLA_GRE_MAX,
1673 .policy = ip6gre_policy,
1674 .priv_size = sizeof(struct ip6_tnl),
1675 .setup = ip6gre_tunnel_setup,
1676 .validate = ip6gre_tunnel_validate,
1677 .newlink = ip6gre_newlink,
1678 .changelink = ip6gre_changelink,
1679 .dellink = ip6gre_dellink,
1680 .get_size = ip6gre_get_size,
1681 .fill_info = ip6gre_fill_info,
1682 .get_link_net = ip6_tnl_get_link_net,
1683 };
1684
1685 static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = {
1686 .kind = "ip6gretap",
1687 .maxtype = IFLA_GRE_MAX,
1688 .policy = ip6gre_policy,
1689 .priv_size = sizeof(struct ip6_tnl),
1690 .setup = ip6gre_tap_setup,
1691 .validate = ip6gre_tap_validate,
1692 .newlink = ip6gre_newlink,
1693 .changelink = ip6gre_changelink,
1694 .get_size = ip6gre_get_size,
1695 .fill_info = ip6gre_fill_info,
1696 .get_link_net = ip6_tnl_get_link_net,
1697 };
1698
1699 /*
1700 * And now the modules code and kernel interface.
1701 */
1702
1703 static int __init ip6gre_init(void)
1704 {
1705 int err;
1706
1707 pr_info("GRE over IPv6 tunneling driver\n");
1708
1709 err = register_pernet_device(&ip6gre_net_ops);
1710 if (err < 0)
1711 return err;
1712
1713 err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
1714 if (err < 0) {
1715 pr_info("%s: can't add protocol\n", __func__);
1716 goto add_proto_failed;
1717 }
1718
1719 err = rtnl_link_register(&ip6gre_link_ops);
1720 if (err < 0)
1721 goto rtnl_link_failed;
1722
1723 err = rtnl_link_register(&ip6gre_tap_ops);
1724 if (err < 0)
1725 goto tap_ops_failed;
1726
1727 out:
1728 return err;
1729
1730 tap_ops_failed:
1731 rtnl_link_unregister(&ip6gre_link_ops);
1732 rtnl_link_failed:
1733 inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1734 add_proto_failed:
1735 unregister_pernet_device(&ip6gre_net_ops);
1736 goto out;
1737 }
1738
1739 static void __exit ip6gre_fini(void)
1740 {
1741 rtnl_link_unregister(&ip6gre_tap_ops);
1742 rtnl_link_unregister(&ip6gre_link_ops);
1743 inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE);
1744 unregister_pernet_device(&ip6gre_net_ops);
1745 }
1746
1747 module_init(ip6gre_init);
1748 module_exit(ip6gre_fini);
1749 MODULE_LICENSE("GPL");
1750 MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
1751 MODULE_DESCRIPTION("GRE over IPv6 tunneling device");
1752 MODULE_ALIAS_RTNL_LINK("ip6gre");
1753 MODULE_ALIAS_RTNL_LINK("ip6gretap");
1754 MODULE_ALIAS_NETDEV("ip6gre0");
1755
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