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Linux 2.6.33-rc8
[linux-2.6/lguest.git] / net / ipv4 / ip_gre.c
blobf36ce156cac6561da03d032e4f445f772d40b375
1 /*
2 * Linux NET3: GRE over IP protocol decoder.
3 *
4 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.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 #include <linux/capability.h>
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <asm/uaccess.h>
18 #include <linux/skbuff.h>
19 #include <linux/netdevice.h>
20 #include <linux/in.h>
21 #include <linux/tcp.h>
22 #include <linux/udp.h>
23 #include <linux/if_arp.h>
24 #include <linux/mroute.h>
25 #include <linux/init.h>
26 #include <linux/in6.h>
27 #include <linux/inetdevice.h>
28 #include <linux/igmp.h>
29 #include <linux/netfilter_ipv4.h>
30 #include <linux/etherdevice.h>
31 #include <linux/if_ether.h>
32
33 #include <net/sock.h>
34 #include <net/ip.h>
35 #include <net/icmp.h>
36 #include <net/protocol.h>
37 #include <net/ipip.h>
38 #include <net/arp.h>
39 #include <net/checksum.h>
40 #include <net/dsfield.h>
41 #include <net/inet_ecn.h>
42 #include <net/xfrm.h>
43 #include <net/net_namespace.h>
44 #include <net/netns/generic.h>
45 #include <net/rtnetlink.h>
46
47 #ifdef CONFIG_IPV6
48 #include <net/ipv6.h>
49 #include <net/ip6_fib.h>
50 #include <net/ip6_route.h>
51 #endif
52
53 /*
54 Problems & solutions
55 --------------------
56
57 1. The most important issue is detecting local dead loops.
58 They would cause complete host lockup in transmit, which
59 would be "resolved" by stack overflow or, if queueing is enabled,
60 with infinite looping in net_bh.
61
62 We cannot track such dead loops during route installation,
63 it is infeasible task. The most general solutions would be
64 to keep skb->encapsulation counter (sort of local ttl),
65 and silently drop packet when it expires. It is the best
66 solution, but it supposes maintaing new variable in ALL
67 skb, even if no tunneling is used.
68
69 Current solution: HARD_TX_LOCK lock breaks dead loops.
70
71
72
73 2. Networking dead loops would not kill routers, but would really
74 kill network. IP hop limit plays role of "t->recursion" in this case,
75 if we copy it from packet being encapsulated to upper header.
76 It is very good solution, but it introduces two problems:
77
78 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
79 do not work over tunnels.
80 - traceroute does not work. I planned to relay ICMP from tunnel,
81 so that this problem would be solved and traceroute output
82 would even more informative. This idea appeared to be wrong:
83 only Linux complies to rfc1812 now (yes, guys, Linux is the only
84 true router now :-)), all routers (at least, in neighbourhood of mine)
85 return only 8 bytes of payload. It is the end.
86
87 Hence, if we want that OSPF worked or traceroute said something reasonable,
88 we should search for another solution.
89
90 One of them is to parse packet trying to detect inner encapsulation
91 made by our node. It is difficult or even impossible, especially,
92 taking into account fragmentation. TO be short, tt is not solution at all.
93
94 Current solution: The solution was UNEXPECTEDLY SIMPLE.
95 We force DF flag on tunnels with preconfigured hop limit,
96 that is ALL. :-) Well, it does not remove the problem completely,
97 but exponential growth of network traffic is changed to linear
98 (branches, that exceed pmtu are pruned) and tunnel mtu
99 fastly degrades to value <68, where looping stops.
100 Yes, it is not good if there exists a router in the loop,
101 which does not force DF, even when encapsulating packets have DF set.
102 But it is not our problem! Nobody could accuse us, we made
103 all that we could make. Even if it is your gated who injected
104 fatal route to network, even if it were you who configured
105 fatal static route: you are innocent. :-)
106
107
108
109 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
110 practically identical code. It would be good to glue them
111 together, but it is not very evident, how to make them modular.
112 sit is integral part of IPv6, ipip and gre are naturally modular.
113 We could extract common parts (hash table, ioctl etc)
114 to a separate module (ip_tunnel.c).
115
116 Alexey Kuznetsov.
117 */
118
119 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
120 static int ipgre_tunnel_init(struct net_device *dev);
121 static void ipgre_tunnel_setup(struct net_device *dev);
122 static int ipgre_tunnel_bind_dev(struct net_device *dev);
123
124 /* Fallback tunnel: no source, no destination, no key, no options */
125
126 #define HASH_SIZE 16
127
128 static int ipgre_net_id __read_mostly;
129 struct ipgre_net {
130 struct ip_tunnel *tunnels[4][HASH_SIZE];
131
132 struct net_device *fb_tunnel_dev;
133 };
134
135 /* Tunnel hash table */
136
137 /*
138 4 hash tables:
139
140 3: (remote,local)
141 2: (remote,*)
142 1: (*,local)
143 0: (*,*)
144
145 We require exact key match i.e. if a key is present in packet
146 it will match only tunnel with the same key; if it is not present,
147 it will match only keyless tunnel.
148
149 All keysless packets, if not matched configured keyless tunnels
150 will match fallback tunnel.
151 */
152
153 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
154
155 #define tunnels_r_l tunnels[3]
156 #define tunnels_r tunnels[2]
157 #define tunnels_l tunnels[1]
158 #define tunnels_wc tunnels[0]
159 /*
160 * Locking : hash tables are protected by RCU and a spinlock
161 */
162 static DEFINE_SPINLOCK(ipgre_lock);
163
164 #define for_each_ip_tunnel_rcu(start) \
165 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
166
167 /* Given src, dst and key, find appropriate for input tunnel. */
168
169 static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
170 __be32 remote, __be32 local,
171 __be32 key, __be16 gre_proto)
172 {
173 struct net *net = dev_net(dev);
174 int link = dev->ifindex;
175 unsigned h0 = HASH(remote);
176 unsigned h1 = HASH(key);
177 struct ip_tunnel *t, *cand = NULL;
178 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
179 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
180 ARPHRD_ETHER : ARPHRD_IPGRE;
181 int score, cand_score = 4;
182
183 for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
184 if (local != t->parms.iph.saddr ||
185 remote != t->parms.iph.daddr ||
186 key != t->parms.i_key ||
187 !(t->dev->flags & IFF_UP))
188 continue;
189
190 if (t->dev->type != ARPHRD_IPGRE &&
191 t->dev->type != dev_type)
192 continue;
193
194 score = 0;
195 if (t->parms.link != link)
196 score |= 1;
197 if (t->dev->type != dev_type)
198 score |= 2;
199 if (score == 0)
200 return t;
201
202 if (score < cand_score) {
203 cand = t;
204 cand_score = score;
205 }
206 }
207
208 for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
209 if (remote != t->parms.iph.daddr ||
210 key != t->parms.i_key ||
211 !(t->dev->flags & IFF_UP))
212 continue;
213
214 if (t->dev->type != ARPHRD_IPGRE &&
215 t->dev->type != dev_type)
216 continue;
217
218 score = 0;
219 if (t->parms.link != link)
220 score |= 1;
221 if (t->dev->type != dev_type)
222 score |= 2;
223 if (score == 0)
224 return t;
225
226 if (score < cand_score) {
227 cand = t;
228 cand_score = score;
229 }
230 }
231
232 for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
233 if ((local != t->parms.iph.saddr &&
234 (local != t->parms.iph.daddr ||
235 !ipv4_is_multicast(local))) ||
236 key != t->parms.i_key ||
237 !(t->dev->flags & IFF_UP))
238 continue;
239
240 if (t->dev->type != ARPHRD_IPGRE &&
241 t->dev->type != dev_type)
242 continue;
243
244 score = 0;
245 if (t->parms.link != link)
246 score |= 1;
247 if (t->dev->type != dev_type)
248 score |= 2;
249 if (score == 0)
250 return t;
251
252 if (score < cand_score) {
253 cand = t;
254 cand_score = score;
255 }
256 }
257
258 for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
259 if (t->parms.i_key != key ||
260 !(t->dev->flags & IFF_UP))
261 continue;
262
263 if (t->dev->type != ARPHRD_IPGRE &&
264 t->dev->type != dev_type)
265 continue;
266
267 score = 0;
268 if (t->parms.link != link)
269 score |= 1;
270 if (t->dev->type != dev_type)
271 score |= 2;
272 if (score == 0)
273 return t;
274
275 if (score < cand_score) {
276 cand = t;
277 cand_score = score;
278 }
279 }
280
281 if (cand != NULL)
282 return cand;
283
284 dev = ign->fb_tunnel_dev;
285 if (dev->flags & IFF_UP)
286 return netdev_priv(dev);
287
288 return NULL;
289 }
290
291 static struct ip_tunnel **__ipgre_bucket(struct ipgre_net *ign,
292 struct ip_tunnel_parm *parms)
293 {
294 __be32 remote = parms->iph.daddr;
295 __be32 local = parms->iph.saddr;
296 __be32 key = parms->i_key;
297 unsigned h = HASH(key);
298 int prio = 0;
299
300 if (local)
301 prio |= 1;
302 if (remote && !ipv4_is_multicast(remote)) {
303 prio |= 2;
304 h ^= HASH(remote);
305 }
306
307 return &ign->tunnels[prio][h];
308 }
309
310 static inline struct ip_tunnel **ipgre_bucket(struct ipgre_net *ign,
311 struct ip_tunnel *t)
312 {
313 return __ipgre_bucket(ign, &t->parms);
314 }
315
316 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
317 {
318 struct ip_tunnel **tp = ipgre_bucket(ign, t);
319
320 spin_lock_bh(&ipgre_lock);
321 t->next = *tp;
322 rcu_assign_pointer(*tp, t);
323 spin_unlock_bh(&ipgre_lock);
324 }
325
326 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
327 {
328 struct ip_tunnel **tp;
329
330 for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
331 if (t == *tp) {
332 spin_lock_bh(&ipgre_lock);
333 *tp = t->next;
334 spin_unlock_bh(&ipgre_lock);
335 break;
336 }
337 }
338 }
339
340 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
341 struct ip_tunnel_parm *parms,
342 int type)
343 {
344 __be32 remote = parms->iph.daddr;
345 __be32 local = parms->iph.saddr;
346 __be32 key = parms->i_key;
347 int link = parms->link;
348 struct ip_tunnel *t, **tp;
349 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
350
351 for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next)
352 if (local == t->parms.iph.saddr &&
353 remote == t->parms.iph.daddr &&
354 key == t->parms.i_key &&
355 link == t->parms.link &&
356 type == t->dev->type)
357 break;
358
359 return t;
360 }
361
362 static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
363 struct ip_tunnel_parm *parms, int create)
364 {
365 struct ip_tunnel *t, *nt;
366 struct net_device *dev;
367 char name[IFNAMSIZ];
368 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
369
370 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
371 if (t || !create)
372 return t;
373
374 if (parms->name[0])
375 strlcpy(name, parms->name, IFNAMSIZ);
376 else
377 sprintf(name, "gre%%d");
378
379 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
380 if (!dev)
381 return NULL;
382
383 dev_net_set(dev, net);
384
385 if (strchr(name, '%')) {
386 if (dev_alloc_name(dev, name) < 0)
387 goto failed_free;
388 }
389
390 nt = netdev_priv(dev);
391 nt->parms = *parms;
392 dev->rtnl_link_ops = &ipgre_link_ops;
393
394 dev->mtu = ipgre_tunnel_bind_dev(dev);
395
396 if (register_netdevice(dev) < 0)
397 goto failed_free;
398
399 dev_hold(dev);
400 ipgre_tunnel_link(ign, nt);
401 return nt;
402
403 failed_free:
404 free_netdev(dev);
405 return NULL;
406 }
407
408 static void ipgre_tunnel_uninit(struct net_device *dev)
409 {
410 struct net *net = dev_net(dev);
411 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
412
413 ipgre_tunnel_unlink(ign, netdev_priv(dev));
414 dev_put(dev);
415 }
416
417
418 static void ipgre_err(struct sk_buff *skb, u32 info)
419 {
420
421 /* All the routers (except for Linux) return only
422 8 bytes of packet payload. It means, that precise relaying of
423 ICMP in the real Internet is absolutely infeasible.
424
425 Moreover, Cisco "wise men" put GRE key to the third word
426 in GRE header. It makes impossible maintaining even soft state for keyed
427 GRE tunnels with enabled checksum. Tell them "thank you".
428
429 Well, I wonder, rfc1812 was written by Cisco employee,
430 what the hell these idiots break standrads established
431 by themself???
432 */
433
434 struct iphdr *iph = (struct iphdr *)skb->data;
435 __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
436 int grehlen = (iph->ihl<<2) + 4;
437 const int type = icmp_hdr(skb)->type;
438 const int code = icmp_hdr(skb)->code;
439 struct ip_tunnel *t;
440 __be16 flags;
441
442 flags = p[0];
443 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
444 if (flags&(GRE_VERSION|GRE_ROUTING))
445 return;
446 if (flags&GRE_KEY) {
447 grehlen += 4;
448 if (flags&GRE_CSUM)
449 grehlen += 4;
450 }
451 }
452
453 /* If only 8 bytes returned, keyed message will be dropped here */
454 if (skb_headlen(skb) < grehlen)
455 return;
456
457 switch (type) {
458 default:
459 case ICMP_PARAMETERPROB:
460 return;
461
462 case ICMP_DEST_UNREACH:
463 switch (code) {
464 case ICMP_SR_FAILED:
465 case ICMP_PORT_UNREACH:
466 /* Impossible event. */
467 return;
468 case ICMP_FRAG_NEEDED:
469 /* Soft state for pmtu is maintained by IP core. */
470 return;
471 default:
472 /* All others are translated to HOST_UNREACH.
473 rfc2003 contains "deep thoughts" about NET_UNREACH,
474 I believe they are just ether pollution. --ANK
475 */
476 break;
477 }
478 break;
479 case ICMP_TIME_EXCEEDED:
480 if (code != ICMP_EXC_TTL)
481 return;
482 break;
483 }
484
485 rcu_read_lock();
486 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
487 flags & GRE_KEY ?
488 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
489 p[1]);
490 if (t == NULL || t->parms.iph.daddr == 0 ||
491 ipv4_is_multicast(t->parms.iph.daddr))
492 goto out;
493
494 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
495 goto out;
496
497 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
498 t->err_count++;
499 else
500 t->err_count = 1;
501 t->err_time = jiffies;
502 out:
503 rcu_read_unlock();
504 return;
505 }
506
507 static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
508 {
509 if (INET_ECN_is_ce(iph->tos)) {
510 if (skb->protocol == htons(ETH_P_IP)) {
511 IP_ECN_set_ce(ip_hdr(skb));
512 } else if (skb->protocol == htons(ETH_P_IPV6)) {
513 IP6_ECN_set_ce(ipv6_hdr(skb));
514 }
515 }
516 }
517
518 static inline u8
519 ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
520 {
521 u8 inner = 0;
522 if (skb->protocol == htons(ETH_P_IP))
523 inner = old_iph->tos;
524 else if (skb->protocol == htons(ETH_P_IPV6))
525 inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
526 return INET_ECN_encapsulate(tos, inner);
527 }
528
529 static int ipgre_rcv(struct sk_buff *skb)
530 {
531 struct iphdr *iph;
532 u8 *h;
533 __be16 flags;
534 __sum16 csum = 0;
535 __be32 key = 0;
536 u32 seqno = 0;
537 struct ip_tunnel *tunnel;
538 int offset = 4;
539 __be16 gre_proto;
540 unsigned int len;
541
542 if (!pskb_may_pull(skb, 16))
543 goto drop_nolock;
544
545 iph = ip_hdr(skb);
546 h = skb->data;
547 flags = *(__be16*)h;
548
549 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
550 /* - Version must be 0.
551 - We do not support routing headers.
552 */
553 if (flags&(GRE_VERSION|GRE_ROUTING))
554 goto drop_nolock;
555
556 if (flags&GRE_CSUM) {
557 switch (skb->ip_summed) {
558 case CHECKSUM_COMPLETE:
559 csum = csum_fold(skb->csum);
560 if (!csum)
561 break;
562 /* fall through */
563 case CHECKSUM_NONE:
564 skb->csum = 0;
565 csum = __skb_checksum_complete(skb);
566 skb->ip_summed = CHECKSUM_COMPLETE;
567 }
568 offset += 4;
569 }
570 if (flags&GRE_KEY) {
571 key = *(__be32*)(h + offset);
572 offset += 4;
573 }
574 if (flags&GRE_SEQ) {
575 seqno = ntohl(*(__be32*)(h + offset));
576 offset += 4;
577 }
578 }
579
580 gre_proto = *(__be16 *)(h + 2);
581
582 rcu_read_lock();
583 if ((tunnel = ipgre_tunnel_lookup(skb->dev,
584 iph->saddr, iph->daddr, key,
585 gre_proto))) {
586 struct net_device_stats *stats = &tunnel->dev->stats;
587
588 secpath_reset(skb);
589
590 skb->protocol = gre_proto;
591 /* WCCP version 1 and 2 protocol decoding.
592 * - Change protocol to IP
593 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
594 */
595 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
596 skb->protocol = htons(ETH_P_IP);
597 if ((*(h + offset) & 0xF0) != 0x40)
598 offset += 4;
599 }
600
601 skb->mac_header = skb->network_header;
602 __pskb_pull(skb, offset);
603 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
604 skb->pkt_type = PACKET_HOST;
605 #ifdef CONFIG_NET_IPGRE_BROADCAST
606 if (ipv4_is_multicast(iph->daddr)) {
607 /* Looped back packet, drop it! */
608 if (skb_rtable(skb)->fl.iif == 0)
609 goto drop;
610 stats->multicast++;
611 skb->pkt_type = PACKET_BROADCAST;
612 }
613 #endif
614
615 if (((flags&GRE_CSUM) && csum) ||
616 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
617 stats->rx_crc_errors++;
618 stats->rx_errors++;
619 goto drop;
620 }
621 if (tunnel->parms.i_flags&GRE_SEQ) {
622 if (!(flags&GRE_SEQ) ||
623 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
624 stats->rx_fifo_errors++;
625 stats->rx_errors++;
626 goto drop;
627 }
628 tunnel->i_seqno = seqno + 1;
629 }
630
631 len = skb->len;
632
633 /* Warning: All skb pointers will be invalidated! */
634 if (tunnel->dev->type == ARPHRD_ETHER) {
635 if (!pskb_may_pull(skb, ETH_HLEN)) {
636 stats->rx_length_errors++;
637 stats->rx_errors++;
638 goto drop;
639 }
640
641 iph = ip_hdr(skb);
642 skb->protocol = eth_type_trans(skb, tunnel->dev);
643 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
644 }
645
646 stats->rx_packets++;
647 stats->rx_bytes += len;
648 skb->dev = tunnel->dev;
649 skb_dst_drop(skb);
650 nf_reset(skb);
651
652 skb_reset_network_header(skb);
653 ipgre_ecn_decapsulate(iph, skb);
654
655 netif_rx(skb);
656 rcu_read_unlock();
657 return(0);
658 }
659 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
660
661 drop:
662 rcu_read_unlock();
663 drop_nolock:
664 kfree_skb(skb);
665 return(0);
666 }
667
668 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
669 {
670 struct ip_tunnel *tunnel = netdev_priv(dev);
671 struct net_device_stats *stats = &dev->stats;
672 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
673 struct iphdr *old_iph = ip_hdr(skb);
674 struct iphdr *tiph;
675 u8 tos;
676 __be16 df;
677 struct rtable *rt; /* Route to the other host */
678 struct net_device *tdev; /* Device to other host */
679 struct iphdr *iph; /* Our new IP header */
680 unsigned int max_headroom; /* The extra header space needed */
681 int gre_hlen;
682 __be32 dst;
683 int mtu;
684
685 if (dev->type == ARPHRD_ETHER)
686 IPCB(skb)->flags = 0;
687
688 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
689 gre_hlen = 0;
690 tiph = (struct iphdr *)skb->data;
691 } else {
692 gre_hlen = tunnel->hlen;
693 tiph = &tunnel->parms.iph;
694 }
695
696 if ((dst = tiph->daddr) == 0) {
697 /* NBMA tunnel */
698
699 if (skb_dst(skb) == NULL) {
700 stats->tx_fifo_errors++;
701 goto tx_error;
702 }
703
704 if (skb->protocol == htons(ETH_P_IP)) {
705 rt = skb_rtable(skb);
706 if ((dst = rt->rt_gateway) == 0)
707 goto tx_error_icmp;
708 }
709 #ifdef CONFIG_IPV6
710 else if (skb->protocol == htons(ETH_P_IPV6)) {
711 struct in6_addr *addr6;
712 int addr_type;
713 struct neighbour *neigh = skb_dst(skb)->neighbour;
714
715 if (neigh == NULL)
716 goto tx_error;
717
718 addr6 = (struct in6_addr *)&neigh->primary_key;
719 addr_type = ipv6_addr_type(addr6);
720
721 if (addr_type == IPV6_ADDR_ANY) {
722 addr6 = &ipv6_hdr(skb)->daddr;
723 addr_type = ipv6_addr_type(addr6);
724 }
725
726 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
727 goto tx_error_icmp;
728
729 dst = addr6->s6_addr32[3];
730 }
731 #endif
732 else
733 goto tx_error;
734 }
735
736 tos = tiph->tos;
737 if (tos == 1) {
738 tos = 0;
739 if (skb->protocol == htons(ETH_P_IP))
740 tos = old_iph->tos;
741 }
742
743 {
744 struct flowi fl = { .oif = tunnel->parms.link,
745 .nl_u = { .ip4_u =
746 { .daddr = dst,
747 .saddr = tiph->saddr,
748 .tos = RT_TOS(tos) } },
749 .proto = IPPROTO_GRE };
750 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
751 stats->tx_carrier_errors++;
752 goto tx_error;
753 }
754 }
755 tdev = rt->u.dst.dev;
756
757 if (tdev == dev) {
758 ip_rt_put(rt);
759 stats->collisions++;
760 goto tx_error;
761 }
762
763 df = tiph->frag_off;
764 if (df)
765 mtu = dst_mtu(&rt->u.dst) - dev->hard_header_len - tunnel->hlen;
766 else
767 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
768
769 if (skb_dst(skb))
770 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
771
772 if (skb->protocol == htons(ETH_P_IP)) {
773 df |= (old_iph->frag_off&htons(IP_DF));
774
775 if ((old_iph->frag_off&htons(IP_DF)) &&
776 mtu < ntohs(old_iph->tot_len)) {
777 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
778 ip_rt_put(rt);
779 goto tx_error;
780 }
781 }
782 #ifdef CONFIG_IPV6
783 else if (skb->protocol == htons(ETH_P_IPV6)) {
784 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
785
786 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
787 if ((tunnel->parms.iph.daddr &&
788 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
789 rt6->rt6i_dst.plen == 128) {
790 rt6->rt6i_flags |= RTF_MODIFIED;
791 skb_dst(skb)->metrics[RTAX_MTU-1] = mtu;
792 }
793 }
794
795 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
796 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
797 ip_rt_put(rt);
798 goto tx_error;
799 }
800 }
801 #endif
802
803 if (tunnel->err_count > 0) {
804 if (time_before(jiffies,
805 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
806 tunnel->err_count--;
807
808 dst_link_failure(skb);
809 } else
810 tunnel->err_count = 0;
811 }
812
813 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
814
815 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
816 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
817 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
818 if (!new_skb) {
819 ip_rt_put(rt);
820 txq->tx_dropped++;
821 dev_kfree_skb(skb);
822 return NETDEV_TX_OK;
823 }
824 if (skb->sk)
825 skb_set_owner_w(new_skb, skb->sk);
826 dev_kfree_skb(skb);
827 skb = new_skb;
828 old_iph = ip_hdr(skb);
829 }
830
831 skb_reset_transport_header(skb);
832 skb_push(skb, gre_hlen);
833 skb_reset_network_header(skb);
834 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
835 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
836 IPSKB_REROUTED);
837 skb_dst_drop(skb);
838 skb_dst_set(skb, &rt->u.dst);
839
840 /*
841 * Push down and install the IPIP header.
842 */
843
844 iph = ip_hdr(skb);
845 iph->version = 4;
846 iph->ihl = sizeof(struct iphdr) >> 2;
847 iph->frag_off = df;
848 iph->protocol = IPPROTO_GRE;
849 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
850 iph->daddr = rt->rt_dst;
851 iph->saddr = rt->rt_src;
852
853 if ((iph->ttl = tiph->ttl) == 0) {
854 if (skb->protocol == htons(ETH_P_IP))
855 iph->ttl = old_iph->ttl;
856 #ifdef CONFIG_IPV6
857 else if (skb->protocol == htons(ETH_P_IPV6))
858 iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
859 #endif
860 else
861 iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
862 }
863
864 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
865 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
866 htons(ETH_P_TEB) : skb->protocol;
867
868 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
869 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
870
871 if (tunnel->parms.o_flags&GRE_SEQ) {
872 ++tunnel->o_seqno;
873 *ptr = htonl(tunnel->o_seqno);
874 ptr--;
875 }
876 if (tunnel->parms.o_flags&GRE_KEY) {
877 *ptr = tunnel->parms.o_key;
878 ptr--;
879 }
880 if (tunnel->parms.o_flags&GRE_CSUM) {
881 *ptr = 0;
882 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
883 }
884 }
885
886 nf_reset(skb);
887
888 IPTUNNEL_XMIT();
889 return NETDEV_TX_OK;
890
891 tx_error_icmp:
892 dst_link_failure(skb);
893
894 tx_error:
895 stats->tx_errors++;
896 dev_kfree_skb(skb);
897 return NETDEV_TX_OK;
898 }
899
900 static int ipgre_tunnel_bind_dev(struct net_device *dev)
901 {
902 struct net_device *tdev = NULL;
903 struct ip_tunnel *tunnel;
904 struct iphdr *iph;
905 int hlen = LL_MAX_HEADER;
906 int mtu = ETH_DATA_LEN;
907 int addend = sizeof(struct iphdr) + 4;
908
909 tunnel = netdev_priv(dev);
910 iph = &tunnel->parms.iph;
911
912 /* Guess output device to choose reasonable mtu and needed_headroom */
913
914 if (iph->daddr) {
915 struct flowi fl = { .oif = tunnel->parms.link,
916 .nl_u = { .ip4_u =
917 { .daddr = iph->daddr,
918 .saddr = iph->saddr,
919 .tos = RT_TOS(iph->tos) } },
920 .proto = IPPROTO_GRE };
921 struct rtable *rt;
922 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
923 tdev = rt->u.dst.dev;
924 ip_rt_put(rt);
925 }
926
927 if (dev->type != ARPHRD_ETHER)
928 dev->flags |= IFF_POINTOPOINT;
929 }
930
931 if (!tdev && tunnel->parms.link)
932 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
933
934 if (tdev) {
935 hlen = tdev->hard_header_len + tdev->needed_headroom;
936 mtu = tdev->mtu;
937 }
938 dev->iflink = tunnel->parms.link;
939
940 /* Precalculate GRE options length */
941 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
942 if (tunnel->parms.o_flags&GRE_CSUM)
943 addend += 4;
944 if (tunnel->parms.o_flags&GRE_KEY)
945 addend += 4;
946 if (tunnel->parms.o_flags&GRE_SEQ)
947 addend += 4;
948 }
949 dev->needed_headroom = addend + hlen;
950 mtu -= dev->hard_header_len + addend;
951
952 if (mtu < 68)
953 mtu = 68;
954
955 tunnel->hlen = addend;
956
957 return mtu;
958 }
959
960 static int
961 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
962 {
963 int err = 0;
964 struct ip_tunnel_parm p;
965 struct ip_tunnel *t;
966 struct net *net = dev_net(dev);
967 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
968
969 switch (cmd) {
970 case SIOCGETTUNNEL:
971 t = NULL;
972 if (dev == ign->fb_tunnel_dev) {
973 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
974 err = -EFAULT;
975 break;
976 }
977 t = ipgre_tunnel_locate(net, &p, 0);
978 }
979 if (t == NULL)
980 t = netdev_priv(dev);
981 memcpy(&p, &t->parms, sizeof(p));
982 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
983 err = -EFAULT;
984 break;
985
986 case SIOCADDTUNNEL:
987 case SIOCCHGTUNNEL:
988 err = -EPERM;
989 if (!capable(CAP_NET_ADMIN))
990 goto done;
991
992 err = -EFAULT;
993 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
994 goto done;
995
996 err = -EINVAL;
997 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
998 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
999 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1000 goto done;
1001 if (p.iph.ttl)
1002 p.iph.frag_off |= htons(IP_DF);
1003
1004 if (!(p.i_flags&GRE_KEY))
1005 p.i_key = 0;
1006 if (!(p.o_flags&GRE_KEY))
1007 p.o_key = 0;
1008
1009 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1010
1011 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1012 if (t != NULL) {
1013 if (t->dev != dev) {
1014 err = -EEXIST;
1015 break;
1016 }
1017 } else {
1018 unsigned nflags = 0;
1019
1020 t = netdev_priv(dev);
1021
1022 if (ipv4_is_multicast(p.iph.daddr))
1023 nflags = IFF_BROADCAST;
1024 else if (p.iph.daddr)
1025 nflags = IFF_POINTOPOINT;
1026
1027 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1028 err = -EINVAL;
1029 break;
1030 }
1031 ipgre_tunnel_unlink(ign, t);
1032 t->parms.iph.saddr = p.iph.saddr;
1033 t->parms.iph.daddr = p.iph.daddr;
1034 t->parms.i_key = p.i_key;
1035 t->parms.o_key = p.o_key;
1036 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1037 memcpy(dev->broadcast, &p.iph.daddr, 4);
1038 ipgre_tunnel_link(ign, t);
1039 netdev_state_change(dev);
1040 }
1041 }
1042
1043 if (t) {
1044 err = 0;
1045 if (cmd == SIOCCHGTUNNEL) {
1046 t->parms.iph.ttl = p.iph.ttl;
1047 t->parms.iph.tos = p.iph.tos;
1048 t->parms.iph.frag_off = p.iph.frag_off;
1049 if (t->parms.link != p.link) {
1050 t->parms.link = p.link;
1051 dev->mtu = ipgre_tunnel_bind_dev(dev);
1052 netdev_state_change(dev);
1053 }
1054 }
1055 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1056 err = -EFAULT;
1057 } else
1058 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1059 break;
1060
1061 case SIOCDELTUNNEL:
1062 err = -EPERM;
1063 if (!capable(CAP_NET_ADMIN))
1064 goto done;
1065
1066 if (dev == ign->fb_tunnel_dev) {
1067 err = -EFAULT;
1068 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1069 goto done;
1070 err = -ENOENT;
1071 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1072 goto done;
1073 err = -EPERM;
1074 if (t == netdev_priv(ign->fb_tunnel_dev))
1075 goto done;
1076 dev = t->dev;
1077 }
1078 unregister_netdevice(dev);
1079 err = 0;
1080 break;
1081
1082 default:
1083 err = -EINVAL;
1084 }
1085
1086 done:
1087 return err;
1088 }
1089
1090 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1091 {
1092 struct ip_tunnel *tunnel = netdev_priv(dev);
1093 if (new_mtu < 68 ||
1094 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1095 return -EINVAL;
1096 dev->mtu = new_mtu;
1097 return 0;
1098 }
1099
1100 /* Nice toy. Unfortunately, useless in real life :-)
1101 It allows to construct virtual multiprotocol broadcast "LAN"
1102 over the Internet, provided multicast routing is tuned.
1103
1104
1105 I have no idea was this bicycle invented before me,
1106 so that I had to set ARPHRD_IPGRE to a random value.
1107 I have an impression, that Cisco could make something similar,
1108 but this feature is apparently missing in IOS<=11.2(8).
1109
1110 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1111 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1112
1113 ping -t 255 224.66.66.66
1114
1115 If nobody answers, mbone does not work.
1116
1117 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1118 ip addr add 10.66.66.<somewhat>/24 dev Universe
1119 ifconfig Universe up
1120 ifconfig Universe add fe80::<Your_real_addr>/10
1121 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1122 ftp 10.66.66.66
1123 ...
1124 ftp fec0:6666:6666::193.233.7.65
1125 ...
1126
1127 */
1128
1129 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1130 unsigned short type,
1131 const void *daddr, const void *saddr, unsigned len)
1132 {
1133 struct ip_tunnel *t = netdev_priv(dev);
1134 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1135 __be16 *p = (__be16*)(iph+1);
1136
1137 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1138 p[0] = t->parms.o_flags;
1139 p[1] = htons(type);
1140
1141 /*
1142 * Set the source hardware address.
1143 */
1144
1145 if (saddr)
1146 memcpy(&iph->saddr, saddr, 4);
1147
1148 if (daddr) {
1149 memcpy(&iph->daddr, daddr, 4);
1150 return t->hlen;
1151 }
1152 if (iph->daddr && !ipv4_is_multicast(iph->daddr))
1153 return t->hlen;
1154
1155 return -t->hlen;
1156 }
1157
1158 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1159 {
1160 struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
1161 memcpy(haddr, &iph->saddr, 4);
1162 return 4;
1163 }
1164
1165 static const struct header_ops ipgre_header_ops = {
1166 .create = ipgre_header,
1167 .parse = ipgre_header_parse,
1168 };
1169
1170 #ifdef CONFIG_NET_IPGRE_BROADCAST
1171 static int ipgre_open(struct net_device *dev)
1172 {
1173 struct ip_tunnel *t = netdev_priv(dev);
1174
1175 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1176 struct flowi fl = { .oif = t->parms.link,
1177 .nl_u = { .ip4_u =
1178 { .daddr = t->parms.iph.daddr,
1179 .saddr = t->parms.iph.saddr,
1180 .tos = RT_TOS(t->parms.iph.tos) } },
1181 .proto = IPPROTO_GRE };
1182 struct rtable *rt;
1183 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1184 return -EADDRNOTAVAIL;
1185 dev = rt->u.dst.dev;
1186 ip_rt_put(rt);
1187 if (__in_dev_get_rtnl(dev) == NULL)
1188 return -EADDRNOTAVAIL;
1189 t->mlink = dev->ifindex;
1190 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1191 }
1192 return 0;
1193 }
1194
1195 static int ipgre_close(struct net_device *dev)
1196 {
1197 struct ip_tunnel *t = netdev_priv(dev);
1198
1199 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1200 struct in_device *in_dev;
1201 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1202 if (in_dev) {
1203 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1204 in_dev_put(in_dev);
1205 }
1206 }
1207 return 0;
1208 }
1209
1210 #endif
1211
1212 static const struct net_device_ops ipgre_netdev_ops = {
1213 .ndo_init = ipgre_tunnel_init,
1214 .ndo_uninit = ipgre_tunnel_uninit,
1215 #ifdef CONFIG_NET_IPGRE_BROADCAST
1216 .ndo_open = ipgre_open,
1217 .ndo_stop = ipgre_close,
1218 #endif
1219 .ndo_start_xmit = ipgre_tunnel_xmit,
1220 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1221 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1222 };
1223
1224 static void ipgre_tunnel_setup(struct net_device *dev)
1225 {
1226 dev->netdev_ops = &ipgre_netdev_ops;
1227 dev->destructor = free_netdev;
1228
1229 dev->type = ARPHRD_IPGRE;
1230 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1231 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1232 dev->flags = IFF_NOARP;
1233 dev->iflink = 0;
1234 dev->addr_len = 4;
1235 dev->features |= NETIF_F_NETNS_LOCAL;
1236 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1237 }
1238
1239 static int ipgre_tunnel_init(struct net_device *dev)
1240 {
1241 struct ip_tunnel *tunnel;
1242 struct iphdr *iph;
1243
1244 tunnel = netdev_priv(dev);
1245 iph = &tunnel->parms.iph;
1246
1247 tunnel->dev = dev;
1248 strcpy(tunnel->parms.name, dev->name);
1249
1250 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1251 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1252
1253 if (iph->daddr) {
1254 #ifdef CONFIG_NET_IPGRE_BROADCAST
1255 if (ipv4_is_multicast(iph->daddr)) {
1256 if (!iph->saddr)
1257 return -EINVAL;
1258 dev->flags = IFF_BROADCAST;
1259 dev->header_ops = &ipgre_header_ops;
1260 }
1261 #endif
1262 } else
1263 dev->header_ops = &ipgre_header_ops;
1264
1265 return 0;
1266 }
1267
1268 static void ipgre_fb_tunnel_init(struct net_device *dev)
1269 {
1270 struct ip_tunnel *tunnel = netdev_priv(dev);
1271 struct iphdr *iph = &tunnel->parms.iph;
1272 struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
1273
1274 tunnel->dev = dev;
1275 strcpy(tunnel->parms.name, dev->name);
1276
1277 iph->version = 4;
1278 iph->protocol = IPPROTO_GRE;
1279 iph->ihl = 5;
1280 tunnel->hlen = sizeof(struct iphdr) + 4;
1281
1282 dev_hold(dev);
1283 ign->tunnels_wc[0] = tunnel;
1284 }
1285
1286
1287 static const struct net_protocol ipgre_protocol = {
1288 .handler = ipgre_rcv,
1289 .err_handler = ipgre_err,
1290 .netns_ok = 1,
1291 };
1292
1293 static void ipgre_destroy_tunnels(struct ipgre_net *ign, 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 ip_tunnel *t = ign->tunnels[prio][h];
1301
1302 while (t != NULL) {
1303 unregister_netdevice_queue(t->dev, head);
1304 t = t->next;
1305 }
1306 }
1307 }
1308 }
1309
1310 static int ipgre_init_net(struct net *net)
1311 {
1312 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1313 int err;
1314
1315 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1316 ipgre_tunnel_setup);
1317 if (!ign->fb_tunnel_dev) {
1318 err = -ENOMEM;
1319 goto err_alloc_dev;
1320 }
1321 dev_net_set(ign->fb_tunnel_dev, net);
1322
1323 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1324 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1325
1326 if ((err = register_netdev(ign->fb_tunnel_dev)))
1327 goto err_reg_dev;
1328
1329 return 0;
1330
1331 err_reg_dev:
1332 free_netdev(ign->fb_tunnel_dev);
1333 err_alloc_dev:
1334 return err;
1335 }
1336
1337 static void ipgre_exit_net(struct net *net)
1338 {
1339 struct ipgre_net *ign;
1340 LIST_HEAD(list);
1341
1342 ign = net_generic(net, ipgre_net_id);
1343 rtnl_lock();
1344 ipgre_destroy_tunnels(ign, &list);
1345 unregister_netdevice_many(&list);
1346 rtnl_unlock();
1347 }
1348
1349 static struct pernet_operations ipgre_net_ops = {
1350 .init = ipgre_init_net,
1351 .exit = ipgre_exit_net,
1352 .id = &ipgre_net_id,
1353 .size = sizeof(struct ipgre_net),
1354 };
1355
1356 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1357 {
1358 __be16 flags;
1359
1360 if (!data)
1361 return 0;
1362
1363 flags = 0;
1364 if (data[IFLA_GRE_IFLAGS])
1365 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1366 if (data[IFLA_GRE_OFLAGS])
1367 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1368 if (flags & (GRE_VERSION|GRE_ROUTING))
1369 return -EINVAL;
1370
1371 return 0;
1372 }
1373
1374 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1375 {
1376 __be32 daddr;
1377
1378 if (tb[IFLA_ADDRESS]) {
1379 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1380 return -EINVAL;
1381 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1382 return -EADDRNOTAVAIL;
1383 }
1384
1385 if (!data)
1386 goto out;
1387
1388 if (data[IFLA_GRE_REMOTE]) {
1389 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1390 if (!daddr)
1391 return -EINVAL;
1392 }
1393
1394 out:
1395 return ipgre_tunnel_validate(tb, data);
1396 }
1397
1398 static void ipgre_netlink_parms(struct nlattr *data[],
1399 struct ip_tunnel_parm *parms)
1400 {
1401 memset(parms, 0, sizeof(*parms));
1402
1403 parms->iph.protocol = IPPROTO_GRE;
1404
1405 if (!data)
1406 return;
1407
1408 if (data[IFLA_GRE_LINK])
1409 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1410
1411 if (data[IFLA_GRE_IFLAGS])
1412 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1413
1414 if (data[IFLA_GRE_OFLAGS])
1415 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1416
1417 if (data[IFLA_GRE_IKEY])
1418 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1419
1420 if (data[IFLA_GRE_OKEY])
1421 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1422
1423 if (data[IFLA_GRE_LOCAL])
1424 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1425
1426 if (data[IFLA_GRE_REMOTE])
1427 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1428
1429 if (data[IFLA_GRE_TTL])
1430 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1431
1432 if (data[IFLA_GRE_TOS])
1433 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1434
1435 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1436 parms->iph.frag_off = htons(IP_DF);
1437 }
1438
1439 static int ipgre_tap_init(struct net_device *dev)
1440 {
1441 struct ip_tunnel *tunnel;
1442
1443 tunnel = netdev_priv(dev);
1444
1445 tunnel->dev = dev;
1446 strcpy(tunnel->parms.name, dev->name);
1447
1448 ipgre_tunnel_bind_dev(dev);
1449
1450 return 0;
1451 }
1452
1453 static const struct net_device_ops ipgre_tap_netdev_ops = {
1454 .ndo_init = ipgre_tap_init,
1455 .ndo_uninit = ipgre_tunnel_uninit,
1456 .ndo_start_xmit = ipgre_tunnel_xmit,
1457 .ndo_set_mac_address = eth_mac_addr,
1458 .ndo_validate_addr = eth_validate_addr,
1459 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1460 };
1461
1462 static void ipgre_tap_setup(struct net_device *dev)
1463 {
1464
1465 ether_setup(dev);
1466
1467 dev->netdev_ops = &ipgre_tap_netdev_ops;
1468 dev->destructor = free_netdev;
1469
1470 dev->iflink = 0;
1471 dev->features |= NETIF_F_NETNS_LOCAL;
1472 }
1473
1474 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1475 struct nlattr *data[])
1476 {
1477 struct ip_tunnel *nt;
1478 struct net *net = dev_net(dev);
1479 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1480 int mtu;
1481 int err;
1482
1483 nt = netdev_priv(dev);
1484 ipgre_netlink_parms(data, &nt->parms);
1485
1486 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1487 return -EEXIST;
1488
1489 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1490 random_ether_addr(dev->dev_addr);
1491
1492 mtu = ipgre_tunnel_bind_dev(dev);
1493 if (!tb[IFLA_MTU])
1494 dev->mtu = mtu;
1495
1496 err = register_netdevice(dev);
1497 if (err)
1498 goto out;
1499
1500 dev_hold(dev);
1501 ipgre_tunnel_link(ign, nt);
1502
1503 out:
1504 return err;
1505 }
1506
1507 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1508 struct nlattr *data[])
1509 {
1510 struct ip_tunnel *t, *nt;
1511 struct net *net = dev_net(dev);
1512 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1513 struct ip_tunnel_parm p;
1514 int mtu;
1515
1516 if (dev == ign->fb_tunnel_dev)
1517 return -EINVAL;
1518
1519 nt = netdev_priv(dev);
1520 ipgre_netlink_parms(data, &p);
1521
1522 t = ipgre_tunnel_locate(net, &p, 0);
1523
1524 if (t) {
1525 if (t->dev != dev)
1526 return -EEXIST;
1527 } else {
1528 t = nt;
1529
1530 if (dev->type != ARPHRD_ETHER) {
1531 unsigned nflags = 0;
1532
1533 if (ipv4_is_multicast(p.iph.daddr))
1534 nflags = IFF_BROADCAST;
1535 else if (p.iph.daddr)
1536 nflags = IFF_POINTOPOINT;
1537
1538 if ((dev->flags ^ nflags) &
1539 (IFF_POINTOPOINT | IFF_BROADCAST))
1540 return -EINVAL;
1541 }
1542
1543 ipgre_tunnel_unlink(ign, t);
1544 t->parms.iph.saddr = p.iph.saddr;
1545 t->parms.iph.daddr = p.iph.daddr;
1546 t->parms.i_key = p.i_key;
1547 if (dev->type != ARPHRD_ETHER) {
1548 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1549 memcpy(dev->broadcast, &p.iph.daddr, 4);
1550 }
1551 ipgre_tunnel_link(ign, t);
1552 netdev_state_change(dev);
1553 }
1554
1555 t->parms.o_key = p.o_key;
1556 t->parms.iph.ttl = p.iph.ttl;
1557 t->parms.iph.tos = p.iph.tos;
1558 t->parms.iph.frag_off = p.iph.frag_off;
1559
1560 if (t->parms.link != p.link) {
1561 t->parms.link = p.link;
1562 mtu = ipgre_tunnel_bind_dev(dev);
1563 if (!tb[IFLA_MTU])
1564 dev->mtu = mtu;
1565 netdev_state_change(dev);
1566 }
1567
1568 return 0;
1569 }
1570
1571 static size_t ipgre_get_size(const struct net_device *dev)
1572 {
1573 return
1574 /* IFLA_GRE_LINK */
1575 nla_total_size(4) +
1576 /* IFLA_GRE_IFLAGS */
1577 nla_total_size(2) +
1578 /* IFLA_GRE_OFLAGS */
1579 nla_total_size(2) +
1580 /* IFLA_GRE_IKEY */
1581 nla_total_size(4) +
1582 /* IFLA_GRE_OKEY */
1583 nla_total_size(4) +
1584 /* IFLA_GRE_LOCAL */
1585 nla_total_size(4) +
1586 /* IFLA_GRE_REMOTE */
1587 nla_total_size(4) +
1588 /* IFLA_GRE_TTL */
1589 nla_total_size(1) +
1590 /* IFLA_GRE_TOS */
1591 nla_total_size(1) +
1592 /* IFLA_GRE_PMTUDISC */
1593 nla_total_size(1) +
1594 0;
1595 }
1596
1597 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1598 {
1599 struct ip_tunnel *t = netdev_priv(dev);
1600 struct ip_tunnel_parm *p = &t->parms;
1601
1602 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1603 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1604 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1605 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1606 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1607 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1608 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1609 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1610 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1611 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1612
1613 return 0;
1614
1615 nla_put_failure:
1616 return -EMSGSIZE;
1617 }
1618
1619 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1620 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1621 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1622 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1623 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1624 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1625 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1626 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1627 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1628 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1629 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1630 };
1631
1632 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1633 .kind = "gre",
1634 .maxtype = IFLA_GRE_MAX,
1635 .policy = ipgre_policy,
1636 .priv_size = sizeof(struct ip_tunnel),
1637 .setup = ipgre_tunnel_setup,
1638 .validate = ipgre_tunnel_validate,
1639 .newlink = ipgre_newlink,
1640 .changelink = ipgre_changelink,
1641 .get_size = ipgre_get_size,
1642 .fill_info = ipgre_fill_info,
1643 };
1644
1645 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1646 .kind = "gretap",
1647 .maxtype = IFLA_GRE_MAX,
1648 .policy = ipgre_policy,
1649 .priv_size = sizeof(struct ip_tunnel),
1650 .setup = ipgre_tap_setup,
1651 .validate = ipgre_tap_validate,
1652 .newlink = ipgre_newlink,
1653 .changelink = ipgre_changelink,
1654 .get_size = ipgre_get_size,
1655 .fill_info = ipgre_fill_info,
1656 };
1657
1658 /*
1659 * And now the modules code and kernel interface.
1660 */
1661
1662 static int __init ipgre_init(void)
1663 {
1664 int err;
1665
1666 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1667
1668 if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
1669 printk(KERN_INFO "ipgre init: can't add protocol\n");
1670 return -EAGAIN;
1671 }
1672
1673 err = register_pernet_device(&ipgre_net_ops);
1674 if (err < 0)
1675 goto gen_device_failed;
1676
1677 err = rtnl_link_register(&ipgre_link_ops);
1678 if (err < 0)
1679 goto rtnl_link_failed;
1680
1681 err = rtnl_link_register(&ipgre_tap_ops);
1682 if (err < 0)
1683 goto tap_ops_failed;
1684
1685 out:
1686 return err;
1687
1688 tap_ops_failed:
1689 rtnl_link_unregister(&ipgre_link_ops);
1690 rtnl_link_failed:
1691 unregister_pernet_device(&ipgre_net_ops);
1692 gen_device_failed:
1693 inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
1694 goto out;
1695 }
1696
1697 static void __exit ipgre_fini(void)
1698 {
1699 rtnl_link_unregister(&ipgre_tap_ops);
1700 rtnl_link_unregister(&ipgre_link_ops);
1701 unregister_pernet_device(&ipgre_net_ops);
1702 if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
1703 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1704 }
1705
1706 module_init(ipgre_init);
1707 module_exit(ipgre_fini);
1708 MODULE_LICENSE("GPL");
1709 MODULE_ALIAS_RTNL_LINK("gre");
1710 MODULE_ALIAS_RTNL_LINK("gretap");
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