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per conn neighbor stall timeout removal
[cor_2_6_31.git] / net / ipv4 / ip_gre.c
blobcb4a0f4bd5e5654b465ddee4f32a42504711d5d3
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: t->recursion lock breaks dead loops. It looks
70 like dev->tbusy flag, but I preferred new variable, because
71 the semantics is different. One day, when hard_start_xmit
72 will be multithreaded we will have to use skb->encapsulation.
73
74
75
76 2. Networking dead loops would not kill routers, but would really
77 kill network. IP hop limit plays role of "t->recursion" in this case,
78 if we copy it from packet being encapsulated to upper header.
79 It is very good solution, but it introduces two problems:
80
81 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
82 do not work over tunnels.
83 - traceroute does not work. I planned to relay ICMP from tunnel,
84 so that this problem would be solved and traceroute output
85 would even more informative. This idea appeared to be wrong:
86 only Linux complies to rfc1812 now (yes, guys, Linux is the only
87 true router now :-)), all routers (at least, in neighbourhood of mine)
88 return only 8 bytes of payload. It is the end.
89
90 Hence, if we want that OSPF worked or traceroute said something reasonable,
91 we should search for another solution.
92
93 One of them is to parse packet trying to detect inner encapsulation
94 made by our node. It is difficult or even impossible, especially,
95 taking into account fragmentation. TO be short, tt is not solution at all.
96
97 Current solution: The solution was UNEXPECTEDLY SIMPLE.
98 We force DF flag on tunnels with preconfigured hop limit,
99 that is ALL. :-) Well, it does not remove the problem completely,
100 but exponential growth of network traffic is changed to linear
101 (branches, that exceed pmtu are pruned) and tunnel mtu
102 fastly degrades to value <68, where looping stops.
103 Yes, it is not good if there exists a router in the loop,
104 which does not force DF, even when encapsulating packets have DF set.
105 But it is not our problem! Nobody could accuse us, we made
106 all that we could make. Even if it is your gated who injected
107 fatal route to network, even if it were you who configured
108 fatal static route: you are innocent. :-)
109
110
111
112 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
113 practically identical code. It would be good to glue them
114 together, but it is not very evident, how to make them modular.
115 sit is integral part of IPv6, ipip and gre are naturally modular.
116 We could extract common parts (hash table, ioctl etc)
117 to a separate module (ip_tunnel.c).
118
119 Alexey Kuznetsov.
120 */
121
122 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
123 static int ipgre_tunnel_init(struct net_device *dev);
124 static void ipgre_tunnel_setup(struct net_device *dev);
125 static int ipgre_tunnel_bind_dev(struct net_device *dev);
126
127 /* Fallback tunnel: no source, no destination, no key, no options */
128
129 #define HASH_SIZE 16
130
131 static int ipgre_net_id;
132 struct ipgre_net {
133 struct ip_tunnel *tunnels[4][HASH_SIZE];
134
135 struct net_device *fb_tunnel_dev;
136 };
137
138 /* Tunnel hash table */
139
140 /*
141 4 hash tables:
142
143 3: (remote,local)
144 2: (remote,*)
145 1: (*,local)
146 0: (*,*)
147
148 We require exact key match i.e. if a key is present in packet
149 it will match only tunnel with the same key; if it is not present,
150 it will match only keyless tunnel.
151
152 All keysless packets, if not matched configured keyless tunnels
153 will match fallback tunnel.
154 */
155
156 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
157
158 #define tunnels_r_l tunnels[3]
159 #define tunnels_r tunnels[2]
160 #define tunnels_l tunnels[1]
161 #define tunnels_wc tunnels[0]
162
163 static DEFINE_RWLOCK(ipgre_lock);
164
165 /* Given src, dst and key, find appropriate for input tunnel. */
166
167 static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
168 __be32 remote, __be32 local,
169 __be32 key, __be16 gre_proto)
170 {
171 struct net *net = dev_net(dev);
172 int link = dev->ifindex;
173 unsigned h0 = HASH(remote);
174 unsigned h1 = HASH(key);
175 struct ip_tunnel *t, *cand = NULL;
176 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
177 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
178 ARPHRD_ETHER : ARPHRD_IPGRE;
179 int score, cand_score = 4;
180
181 for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
182 if (local != t->parms.iph.saddr ||
183 remote != t->parms.iph.daddr ||
184 key != t->parms.i_key ||
185 !(t->dev->flags & IFF_UP))
186 continue;
187
188 if (t->dev->type != ARPHRD_IPGRE &&
189 t->dev->type != dev_type)
190 continue;
191
192 score = 0;
193 if (t->parms.link != link)
194 score |= 1;
195 if (t->dev->type != dev_type)
196 score |= 2;
197 if (score == 0)
198 return t;
199
200 if (score < cand_score) {
201 cand = t;
202 cand_score = score;
203 }
204 }
205
206 for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
207 if (remote != t->parms.iph.daddr ||
208 key != t->parms.i_key ||
209 !(t->dev->flags & IFF_UP))
210 continue;
211
212 if (t->dev->type != ARPHRD_IPGRE &&
213 t->dev->type != dev_type)
214 continue;
215
216 score = 0;
217 if (t->parms.link != link)
218 score |= 1;
219 if (t->dev->type != dev_type)
220 score |= 2;
221 if (score == 0)
222 return t;
223
224 if (score < cand_score) {
225 cand = t;
226 cand_score = score;
227 }
228 }
229
230 for (t = ign->tunnels_l[h1]; t; t = t->next) {
231 if ((local != t->parms.iph.saddr &&
232 (local != t->parms.iph.daddr ||
233 !ipv4_is_multicast(local))) ||
234 key != t->parms.i_key ||
235 !(t->dev->flags & IFF_UP))
236 continue;
237
238 if (t->dev->type != ARPHRD_IPGRE &&
239 t->dev->type != dev_type)
240 continue;
241
242 score = 0;
243 if (t->parms.link != link)
244 score |= 1;
245 if (t->dev->type != dev_type)
246 score |= 2;
247 if (score == 0)
248 return t;
249
250 if (score < cand_score) {
251 cand = t;
252 cand_score = score;
253 }
254 }
255
256 for (t = ign->tunnels_wc[h1]; t; t = t->next) {
257 if (t->parms.i_key != key ||
258 !(t->dev->flags & IFF_UP))
259 continue;
260
261 if (t->dev->type != ARPHRD_IPGRE &&
262 t->dev->type != dev_type)
263 continue;
264
265 score = 0;
266 if (t->parms.link != link)
267 score |= 1;
268 if (t->dev->type != dev_type)
269 score |= 2;
270 if (score == 0)
271 return t;
272
273 if (score < cand_score) {
274 cand = t;
275 cand_score = score;
276 }
277 }
278
279 if (cand != NULL)
280 return cand;
281
282 if (ign->fb_tunnel_dev->flags & IFF_UP)
283 return netdev_priv(ign->fb_tunnel_dev);
284
285 return NULL;
286 }
287
288 static struct ip_tunnel **__ipgre_bucket(struct ipgre_net *ign,
289 struct ip_tunnel_parm *parms)
290 {
291 __be32 remote = parms->iph.daddr;
292 __be32 local = parms->iph.saddr;
293 __be32 key = parms->i_key;
294 unsigned h = HASH(key);
295 int prio = 0;
296
297 if (local)
298 prio |= 1;
299 if (remote && !ipv4_is_multicast(remote)) {
300 prio |= 2;
301 h ^= HASH(remote);
302 }
303
304 return &ign->tunnels[prio][h];
305 }
306
307 static inline struct ip_tunnel **ipgre_bucket(struct ipgre_net *ign,
308 struct ip_tunnel *t)
309 {
310 return __ipgre_bucket(ign, &t->parms);
311 }
312
313 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
314 {
315 struct ip_tunnel **tp = ipgre_bucket(ign, t);
316
317 t->next = *tp;
318 write_lock_bh(&ipgre_lock);
319 *tp = t;
320 write_unlock_bh(&ipgre_lock);
321 }
322
323 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
324 {
325 struct ip_tunnel **tp;
326
327 for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
328 if (t == *tp) {
329 write_lock_bh(&ipgre_lock);
330 *tp = t->next;
331 write_unlock_bh(&ipgre_lock);
332 break;
333 }
334 }
335 }
336
337 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
338 struct ip_tunnel_parm *parms,
339 int type)
340 {
341 __be32 remote = parms->iph.daddr;
342 __be32 local = parms->iph.saddr;
343 __be32 key = parms->i_key;
344 int link = parms->link;
345 struct ip_tunnel *t, **tp;
346 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
347
348 for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next)
349 if (local == t->parms.iph.saddr &&
350 remote == t->parms.iph.daddr &&
351 key == t->parms.i_key &&
352 link == t->parms.link &&
353 type == t->dev->type)
354 break;
355
356 return t;
357 }
358
359 static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
360 struct ip_tunnel_parm *parms, int create)
361 {
362 struct ip_tunnel *t, *nt;
363 struct net_device *dev;
364 char name[IFNAMSIZ];
365 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
366
367 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
368 if (t || !create)
369 return t;
370
371 if (parms->name[0])
372 strlcpy(name, parms->name, IFNAMSIZ);
373 else
374 sprintf(name, "gre%%d");
375
376 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
377 if (!dev)
378 return NULL;
379
380 dev_net_set(dev, net);
381
382 if (strchr(name, '%')) {
383 if (dev_alloc_name(dev, name) < 0)
384 goto failed_free;
385 }
386
387 nt = netdev_priv(dev);
388 nt->parms = *parms;
389 dev->rtnl_link_ops = &ipgre_link_ops;
390
391 dev->mtu = ipgre_tunnel_bind_dev(dev);
392
393 if (register_netdevice(dev) < 0)
394 goto failed_free;
395
396 dev_hold(dev);
397 ipgre_tunnel_link(ign, nt);
398 return nt;
399
400 failed_free:
401 free_netdev(dev);
402 return NULL;
403 }
404
405 static void ipgre_tunnel_uninit(struct net_device *dev)
406 {
407 struct net *net = dev_net(dev);
408 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
409
410 ipgre_tunnel_unlink(ign, netdev_priv(dev));
411 dev_put(dev);
412 }
413
414
415 static void ipgre_err(struct sk_buff *skb, u32 info)
416 {
417
418 /* All the routers (except for Linux) return only
419 8 bytes of packet payload. It means, that precise relaying of
420 ICMP in the real Internet is absolutely infeasible.
421
422 Moreover, Cisco "wise men" put GRE key to the third word
423 in GRE header. It makes impossible maintaining even soft state for keyed
424 GRE tunnels with enabled checksum. Tell them "thank you".
425
426 Well, I wonder, rfc1812 was written by Cisco employee,
427 what the hell these idiots break standrads established
428 by themself???
429 */
430
431 struct iphdr *iph = (struct iphdr *)skb->data;
432 __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
433 int grehlen = (iph->ihl<<2) + 4;
434 const int type = icmp_hdr(skb)->type;
435 const int code = icmp_hdr(skb)->code;
436 struct ip_tunnel *t;
437 __be16 flags;
438
439 flags = p[0];
440 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
441 if (flags&(GRE_VERSION|GRE_ROUTING))
442 return;
443 if (flags&GRE_KEY) {
444 grehlen += 4;
445 if (flags&GRE_CSUM)
446 grehlen += 4;
447 }
448 }
449
450 /* If only 8 bytes returned, keyed message will be dropped here */
451 if (skb_headlen(skb) < grehlen)
452 return;
453
454 switch (type) {
455 default:
456 case ICMP_PARAMETERPROB:
457 return;
458
459 case ICMP_DEST_UNREACH:
460 switch (code) {
461 case ICMP_SR_FAILED:
462 case ICMP_PORT_UNREACH:
463 /* Impossible event. */
464 return;
465 case ICMP_FRAG_NEEDED:
466 /* Soft state for pmtu is maintained by IP core. */
467 return;
468 default:
469 /* All others are translated to HOST_UNREACH.
470 rfc2003 contains "deep thoughts" about NET_UNREACH,
471 I believe they are just ether pollution. --ANK
472 */
473 break;
474 }
475 break;
476 case ICMP_TIME_EXCEEDED:
477 if (code != ICMP_EXC_TTL)
478 return;
479 break;
480 }
481
482 read_lock(&ipgre_lock);
483 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
484 flags & GRE_KEY ?
485 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
486 p[1]);
487 if (t == NULL || t->parms.iph.daddr == 0 ||
488 ipv4_is_multicast(t->parms.iph.daddr))
489 goto out;
490
491 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
492 goto out;
493
494 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
495 t->err_count++;
496 else
497 t->err_count = 1;
498 t->err_time = jiffies;
499 out:
500 read_unlock(&ipgre_lock);
501 return;
502 }
503
504 static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
505 {
506 if (INET_ECN_is_ce(iph->tos)) {
507 if (skb->protocol == htons(ETH_P_IP)) {
508 IP_ECN_set_ce(ip_hdr(skb));
509 } else if (skb->protocol == htons(ETH_P_IPV6)) {
510 IP6_ECN_set_ce(ipv6_hdr(skb));
511 }
512 }
513 }
514
515 static inline u8
516 ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
517 {
518 u8 inner = 0;
519 if (skb->protocol == htons(ETH_P_IP))
520 inner = old_iph->tos;
521 else if (skb->protocol == htons(ETH_P_IPV6))
522 inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
523 return INET_ECN_encapsulate(tos, inner);
524 }
525
526 static int ipgre_rcv(struct sk_buff *skb)
527 {
528 struct iphdr *iph;
529 u8 *h;
530 __be16 flags;
531 __sum16 csum = 0;
532 __be32 key = 0;
533 u32 seqno = 0;
534 struct ip_tunnel *tunnel;
535 int offset = 4;
536 __be16 gre_proto;
537 unsigned int len;
538
539 if (!pskb_may_pull(skb, 16))
540 goto drop_nolock;
541
542 iph = ip_hdr(skb);
543 h = skb->data;
544 flags = *(__be16*)h;
545
546 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
547 /* - Version must be 0.
548 - We do not support routing headers.
549 */
550 if (flags&(GRE_VERSION|GRE_ROUTING))
551 goto drop_nolock;
552
553 if (flags&GRE_CSUM) {
554 switch (skb->ip_summed) {
555 case CHECKSUM_COMPLETE:
556 csum = csum_fold(skb->csum);
557 if (!csum)
558 break;
559 /* fall through */
560 case CHECKSUM_NONE:
561 skb->csum = 0;
562 csum = __skb_checksum_complete(skb);
563 skb->ip_summed = CHECKSUM_COMPLETE;
564 }
565 offset += 4;
566 }
567 if (flags&GRE_KEY) {
568 key = *(__be32*)(h + offset);
569 offset += 4;
570 }
571 if (flags&GRE_SEQ) {
572 seqno = ntohl(*(__be32*)(h + offset));
573 offset += 4;
574 }
575 }
576
577 gre_proto = *(__be16 *)(h + 2);
578
579 read_lock(&ipgre_lock);
580 if ((tunnel = ipgre_tunnel_lookup(skb->dev,
581 iph->saddr, iph->daddr, key,
582 gre_proto))) {
583 struct net_device_stats *stats = &tunnel->dev->stats;
584
585 secpath_reset(skb);
586
587 skb->protocol = gre_proto;
588 /* WCCP version 1 and 2 protocol decoding.
589 * - Change protocol to IP
590 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
591 */
592 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
593 skb->protocol = htons(ETH_P_IP);
594 if ((*(h + offset) & 0xF0) != 0x40)
595 offset += 4;
596 }
597
598 skb->mac_header = skb->network_header;
599 __pskb_pull(skb, offset);
600 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
601 skb->pkt_type = PACKET_HOST;
602 #ifdef CONFIG_NET_IPGRE_BROADCAST
603 if (ipv4_is_multicast(iph->daddr)) {
604 /* Looped back packet, drop it! */
605 if (skb_rtable(skb)->fl.iif == 0)
606 goto drop;
607 stats->multicast++;
608 skb->pkt_type = PACKET_BROADCAST;
609 }
610 #endif
611
612 if (((flags&GRE_CSUM) && csum) ||
613 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
614 stats->rx_crc_errors++;
615 stats->rx_errors++;
616 goto drop;
617 }
618 if (tunnel->parms.i_flags&GRE_SEQ) {
619 if (!(flags&GRE_SEQ) ||
620 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
621 stats->rx_fifo_errors++;
622 stats->rx_errors++;
623 goto drop;
624 }
625 tunnel->i_seqno = seqno + 1;
626 }
627
628 len = skb->len;
629
630 /* Warning: All skb pointers will be invalidated! */
631 if (tunnel->dev->type == ARPHRD_ETHER) {
632 if (!pskb_may_pull(skb, ETH_HLEN)) {
633 stats->rx_length_errors++;
634 stats->rx_errors++;
635 goto drop;
636 }
637
638 iph = ip_hdr(skb);
639 skb->protocol = eth_type_trans(skb, tunnel->dev);
640 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
641 }
642
643 stats->rx_packets++;
644 stats->rx_bytes += len;
645 skb->dev = tunnel->dev;
646 skb_dst_drop(skb);
647 nf_reset(skb);
648
649 skb_reset_network_header(skb);
650 ipgre_ecn_decapsulate(iph, skb);
651
652 netif_rx(skb);
653 read_unlock(&ipgre_lock);
654 return(0);
655 }
656 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
657
658 drop:
659 read_unlock(&ipgre_lock);
660 drop_nolock:
661 kfree_skb(skb);
662 return(0);
663 }
664
665 static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
666 {
667 struct ip_tunnel *tunnel = netdev_priv(dev);
668 struct net_device_stats *stats = &tunnel->dev->stats;
669 struct iphdr *old_iph = ip_hdr(skb);
670 struct iphdr *tiph;
671 u8 tos;
672 __be16 df;
673 struct rtable *rt; /* Route to the other host */
674 struct net_device *tdev; /* Device to other host */
675 struct iphdr *iph; /* Our new IP header */
676 unsigned int max_headroom; /* The extra header space needed */
677 int gre_hlen;
678 __be32 dst;
679 int mtu;
680
681 if (tunnel->recursion++) {
682 stats->collisions++;
683 goto tx_error;
684 }
685
686 if (dev->type == ARPHRD_ETHER)
687 IPCB(skb)->flags = 0;
688
689 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
690 gre_hlen = 0;
691 tiph = (struct iphdr *)skb->data;
692 } else {
693 gre_hlen = tunnel->hlen;
694 tiph = &tunnel->parms.iph;
695 }
696
697 if ((dst = tiph->daddr) == 0) {
698 /* NBMA tunnel */
699
700 if (skb_dst(skb) == NULL) {
701 stats->tx_fifo_errors++;
702 goto tx_error;
703 }
704
705 if (skb->protocol == htons(ETH_P_IP)) {
706 rt = skb_rtable(skb);
707 if ((dst = rt->rt_gateway) == 0)
708 goto tx_error_icmp;
709 }
710 #ifdef CONFIG_IPV6
711 else if (skb->protocol == htons(ETH_P_IPV6)) {
712 struct in6_addr *addr6;
713 int addr_type;
714 struct neighbour *neigh = skb_dst(skb)->neighbour;
715
716 if (neigh == NULL)
717 goto tx_error;
718
719 addr6 = (struct in6_addr *)&neigh->primary_key;
720 addr_type = ipv6_addr_type(addr6);
721
722 if (addr_type == IPV6_ADDR_ANY) {
723 addr6 = &ipv6_hdr(skb)->daddr;
724 addr_type = ipv6_addr_type(addr6);
725 }
726
727 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
728 goto tx_error_icmp;
729
730 dst = addr6->s6_addr32[3];
731 }
732 #endif
733 else
734 goto tx_error;
735 }
736
737 tos = tiph->tos;
738 if (tos == 1) {
739 tos = 0;
740 if (skb->protocol == htons(ETH_P_IP))
741 tos = old_iph->tos;
742 }
743
744 {
745 struct flowi fl = { .oif = tunnel->parms.link,
746 .nl_u = { .ip4_u =
747 { .daddr = dst,
748 .saddr = tiph->saddr,
749 .tos = RT_TOS(tos) } },
750 .proto = IPPROTO_GRE };
751 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
752 stats->tx_carrier_errors++;
753 goto tx_error;
754 }
755 }
756 tdev = rt->u.dst.dev;
757
758 if (tdev == dev) {
759 ip_rt_put(rt);
760 stats->collisions++;
761 goto tx_error;
762 }
763
764 df = tiph->frag_off;
765 if (df)
766 mtu = dst_mtu(&rt->u.dst) - dev->hard_header_len - tunnel->hlen;
767 else
768 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
769
770 if (skb_dst(skb))
771 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
772
773 if (skb->protocol == htons(ETH_P_IP)) {
774 df |= (old_iph->frag_off&htons(IP_DF));
775
776 if ((old_iph->frag_off&htons(IP_DF)) &&
777 mtu < ntohs(old_iph->tot_len)) {
778 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
779 ip_rt_put(rt);
780 goto tx_error;
781 }
782 }
783 #ifdef CONFIG_IPV6
784 else if (skb->protocol == htons(ETH_P_IPV6)) {
785 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
786
787 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
788 if ((tunnel->parms.iph.daddr &&
789 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
790 rt6->rt6i_dst.plen == 128) {
791 rt6->rt6i_flags |= RTF_MODIFIED;
792 skb_dst(skb)->metrics[RTAX_MTU-1] = mtu;
793 }
794 }
795
796 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
797 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
798 ip_rt_put(rt);
799 goto tx_error;
800 }
801 }
802 #endif
803
804 if (tunnel->err_count > 0) {
805 if (time_before(jiffies,
806 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
807 tunnel->err_count--;
808
809 dst_link_failure(skb);
810 } else
811 tunnel->err_count = 0;
812 }
813
814 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
815
816 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
817 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
818 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
819 if (!new_skb) {
820 ip_rt_put(rt);
821 stats->tx_dropped++;
822 dev_kfree_skb(skb);
823 tunnel->recursion--;
824 return 0;
825 }
826 if (skb->sk)
827 skb_set_owner_w(new_skb, skb->sk);
828 dev_kfree_skb(skb);
829 skb = new_skb;
830 old_iph = ip_hdr(skb);
831 }
832
833 skb_reset_transport_header(skb);
834 skb_push(skb, gre_hlen);
835 skb_reset_network_header(skb);
836 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
837 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
838 IPSKB_REROUTED);
839 skb_dst_drop(skb);
840 skb_dst_set(skb, &rt->u.dst);
841
842 /*
843 * Push down and install the IPIP header.
844 */
845
846 iph = ip_hdr(skb);
847 iph->version = 4;
848 iph->ihl = sizeof(struct iphdr) >> 2;
849 iph->frag_off = df;
850 iph->protocol = IPPROTO_GRE;
851 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
852 iph->daddr = rt->rt_dst;
853 iph->saddr = rt->rt_src;
854
855 if ((iph->ttl = tiph->ttl) == 0) {
856 if (skb->protocol == htons(ETH_P_IP))
857 iph->ttl = old_iph->ttl;
858 #ifdef CONFIG_IPV6
859 else if (skb->protocol == htons(ETH_P_IPV6))
860 iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
861 #endif
862 else
863 iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
864 }
865
866 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
867 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
868 htons(ETH_P_TEB) : skb->protocol;
869
870 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
871 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
872
873 if (tunnel->parms.o_flags&GRE_SEQ) {
874 ++tunnel->o_seqno;
875 *ptr = htonl(tunnel->o_seqno);
876 ptr--;
877 }
878 if (tunnel->parms.o_flags&GRE_KEY) {
879 *ptr = tunnel->parms.o_key;
880 ptr--;
881 }
882 if (tunnel->parms.o_flags&GRE_CSUM) {
883 *ptr = 0;
884 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
885 }
886 }
887
888 nf_reset(skb);
889
890 IPTUNNEL_XMIT();
891 tunnel->recursion--;
892 return 0;
893
894 tx_error_icmp:
895 dst_link_failure(skb);
896
897 tx_error:
898 stats->tx_errors++;
899 dev_kfree_skb(skb);
900 tunnel->recursion--;
901 return 0;
902 }
903
904 static int ipgre_tunnel_bind_dev(struct net_device *dev)
905 {
906 struct net_device *tdev = NULL;
907 struct ip_tunnel *tunnel;
908 struct iphdr *iph;
909 int hlen = LL_MAX_HEADER;
910 int mtu = ETH_DATA_LEN;
911 int addend = sizeof(struct iphdr) + 4;
912
913 tunnel = netdev_priv(dev);
914 iph = &tunnel->parms.iph;
915
916 /* Guess output device to choose reasonable mtu and needed_headroom */
917
918 if (iph->daddr) {
919 struct flowi fl = { .oif = tunnel->parms.link,
920 .nl_u = { .ip4_u =
921 { .daddr = iph->daddr,
922 .saddr = iph->saddr,
923 .tos = RT_TOS(iph->tos) } },
924 .proto = IPPROTO_GRE };
925 struct rtable *rt;
926 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
927 tdev = rt->u.dst.dev;
928 ip_rt_put(rt);
929 }
930
931 if (dev->type != ARPHRD_ETHER)
932 dev->flags |= IFF_POINTOPOINT;
933 }
934
935 if (!tdev && tunnel->parms.link)
936 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
937
938 if (tdev) {
939 hlen = tdev->hard_header_len + tdev->needed_headroom;
940 mtu = tdev->mtu;
941 }
942 dev->iflink = tunnel->parms.link;
943
944 /* Precalculate GRE options length */
945 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
946 if (tunnel->parms.o_flags&GRE_CSUM)
947 addend += 4;
948 if (tunnel->parms.o_flags&GRE_KEY)
949 addend += 4;
950 if (tunnel->parms.o_flags&GRE_SEQ)
951 addend += 4;
952 }
953 dev->needed_headroom = addend + hlen;
954 mtu -= dev->hard_header_len - addend;
955
956 if (mtu < 68)
957 mtu = 68;
958
959 tunnel->hlen = addend;
960
961 return mtu;
962 }
963
964 static int
965 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
966 {
967 int err = 0;
968 struct ip_tunnel_parm p;
969 struct ip_tunnel *t;
970 struct net *net = dev_net(dev);
971 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
972
973 switch (cmd) {
974 case SIOCGETTUNNEL:
975 t = NULL;
976 if (dev == ign->fb_tunnel_dev) {
977 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
978 err = -EFAULT;
979 break;
980 }
981 t = ipgre_tunnel_locate(net, &p, 0);
982 }
983 if (t == NULL)
984 t = netdev_priv(dev);
985 memcpy(&p, &t->parms, sizeof(p));
986 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
987 err = -EFAULT;
988 break;
989
990 case SIOCADDTUNNEL:
991 case SIOCCHGTUNNEL:
992 err = -EPERM;
993 if (!capable(CAP_NET_ADMIN))
994 goto done;
995
996 err = -EFAULT;
997 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
998 goto done;
999
1000 err = -EINVAL;
1001 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1002 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1003 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1004 goto done;
1005 if (p.iph.ttl)
1006 p.iph.frag_off |= htons(IP_DF);
1007
1008 if (!(p.i_flags&GRE_KEY))
1009 p.i_key = 0;
1010 if (!(p.o_flags&GRE_KEY))
1011 p.o_key = 0;
1012
1013 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1014
1015 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1016 if (t != NULL) {
1017 if (t->dev != dev) {
1018 err = -EEXIST;
1019 break;
1020 }
1021 } else {
1022 unsigned nflags = 0;
1023
1024 t = netdev_priv(dev);
1025
1026 if (ipv4_is_multicast(p.iph.daddr))
1027 nflags = IFF_BROADCAST;
1028 else if (p.iph.daddr)
1029 nflags = IFF_POINTOPOINT;
1030
1031 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1032 err = -EINVAL;
1033 break;
1034 }
1035 ipgre_tunnel_unlink(ign, t);
1036 t->parms.iph.saddr = p.iph.saddr;
1037 t->parms.iph.daddr = p.iph.daddr;
1038 t->parms.i_key = p.i_key;
1039 t->parms.o_key = p.o_key;
1040 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1041 memcpy(dev->broadcast, &p.iph.daddr, 4);
1042 ipgre_tunnel_link(ign, t);
1043 netdev_state_change(dev);
1044 }
1045 }
1046
1047 if (t) {
1048 err = 0;
1049 if (cmd == SIOCCHGTUNNEL) {
1050 t->parms.iph.ttl = p.iph.ttl;
1051 t->parms.iph.tos = p.iph.tos;
1052 t->parms.iph.frag_off = p.iph.frag_off;
1053 if (t->parms.link != p.link) {
1054 t->parms.link = p.link;
1055 dev->mtu = ipgre_tunnel_bind_dev(dev);
1056 netdev_state_change(dev);
1057 }
1058 }
1059 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1060 err = -EFAULT;
1061 } else
1062 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1063 break;
1064
1065 case SIOCDELTUNNEL:
1066 err = -EPERM;
1067 if (!capable(CAP_NET_ADMIN))
1068 goto done;
1069
1070 if (dev == ign->fb_tunnel_dev) {
1071 err = -EFAULT;
1072 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1073 goto done;
1074 err = -ENOENT;
1075 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1076 goto done;
1077 err = -EPERM;
1078 if (t == netdev_priv(ign->fb_tunnel_dev))
1079 goto done;
1080 dev = t->dev;
1081 }
1082 unregister_netdevice(dev);
1083 err = 0;
1084 break;
1085
1086 default:
1087 err = -EINVAL;
1088 }
1089
1090 done:
1091 return err;
1092 }
1093
1094 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1095 {
1096 struct ip_tunnel *tunnel = netdev_priv(dev);
1097 if (new_mtu < 68 ||
1098 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1099 return -EINVAL;
1100 dev->mtu = new_mtu;
1101 return 0;
1102 }
1103
1104 /* Nice toy. Unfortunately, useless in real life :-)
1105 It allows to construct virtual multiprotocol broadcast "LAN"
1106 over the Internet, provided multicast routing is tuned.
1107
1108
1109 I have no idea was this bicycle invented before me,
1110 so that I had to set ARPHRD_IPGRE to a random value.
1111 I have an impression, that Cisco could make something similar,
1112 but this feature is apparently missing in IOS<=11.2(8).
1113
1114 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1115 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1116
1117 ping -t 255 224.66.66.66
1118
1119 If nobody answers, mbone does not work.
1120
1121 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1122 ip addr add 10.66.66.<somewhat>/24 dev Universe
1123 ifconfig Universe up
1124 ifconfig Universe add fe80::<Your_real_addr>/10
1125 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1126 ftp 10.66.66.66
1127 ...
1128 ftp fec0:6666:6666::193.233.7.65
1129 ...
1130
1131 */
1132
1133 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1134 unsigned short type,
1135 const void *daddr, const void *saddr, unsigned len)
1136 {
1137 struct ip_tunnel *t = netdev_priv(dev);
1138 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1139 __be16 *p = (__be16*)(iph+1);
1140
1141 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1142 p[0] = t->parms.o_flags;
1143 p[1] = htons(type);
1144
1145 /*
1146 * Set the source hardware address.
1147 */
1148
1149 if (saddr)
1150 memcpy(&iph->saddr, saddr, 4);
1151
1152 if (daddr) {
1153 memcpy(&iph->daddr, daddr, 4);
1154 return t->hlen;
1155 }
1156 if (iph->daddr && !ipv4_is_multicast(iph->daddr))
1157 return t->hlen;
1158
1159 return -t->hlen;
1160 }
1161
1162 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1163 {
1164 struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
1165 memcpy(haddr, &iph->saddr, 4);
1166 return 4;
1167 }
1168
1169 static const struct header_ops ipgre_header_ops = {
1170 .create = ipgre_header,
1171 .parse = ipgre_header_parse,
1172 };
1173
1174 #ifdef CONFIG_NET_IPGRE_BROADCAST
1175 static int ipgre_open(struct net_device *dev)
1176 {
1177 struct ip_tunnel *t = netdev_priv(dev);
1178
1179 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1180 struct flowi fl = { .oif = t->parms.link,
1181 .nl_u = { .ip4_u =
1182 { .daddr = t->parms.iph.daddr,
1183 .saddr = t->parms.iph.saddr,
1184 .tos = RT_TOS(t->parms.iph.tos) } },
1185 .proto = IPPROTO_GRE };
1186 struct rtable *rt;
1187 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1188 return -EADDRNOTAVAIL;
1189 dev = rt->u.dst.dev;
1190 ip_rt_put(rt);
1191 if (__in_dev_get_rtnl(dev) == NULL)
1192 return -EADDRNOTAVAIL;
1193 t->mlink = dev->ifindex;
1194 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1195 }
1196 return 0;
1197 }
1198
1199 static int ipgre_close(struct net_device *dev)
1200 {
1201 struct ip_tunnel *t = netdev_priv(dev);
1202
1203 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1204 struct in_device *in_dev;
1205 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1206 if (in_dev) {
1207 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1208 in_dev_put(in_dev);
1209 }
1210 }
1211 return 0;
1212 }
1213
1214 #endif
1215
1216 static const struct net_device_ops ipgre_netdev_ops = {
1217 .ndo_init = ipgre_tunnel_init,
1218 .ndo_uninit = ipgre_tunnel_uninit,
1219 #ifdef CONFIG_NET_IPGRE_BROADCAST
1220 .ndo_open = ipgre_open,
1221 .ndo_stop = ipgre_close,
1222 #endif
1223 .ndo_start_xmit = ipgre_tunnel_xmit,
1224 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1225 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1226 };
1227
1228 static void ipgre_tunnel_setup(struct net_device *dev)
1229 {
1230 dev->netdev_ops = &ipgre_netdev_ops;
1231 dev->destructor = free_netdev;
1232
1233 dev->type = ARPHRD_IPGRE;
1234 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1235 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1236 dev->flags = IFF_NOARP;
1237 dev->iflink = 0;
1238 dev->addr_len = 4;
1239 dev->features |= NETIF_F_NETNS_LOCAL;
1240 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1241 }
1242
1243 static int ipgre_tunnel_init(struct net_device *dev)
1244 {
1245 struct ip_tunnel *tunnel;
1246 struct iphdr *iph;
1247
1248 tunnel = netdev_priv(dev);
1249 iph = &tunnel->parms.iph;
1250
1251 tunnel->dev = dev;
1252 strcpy(tunnel->parms.name, dev->name);
1253
1254 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1255 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1256
1257 if (iph->daddr) {
1258 #ifdef CONFIG_NET_IPGRE_BROADCAST
1259 if (ipv4_is_multicast(iph->daddr)) {
1260 if (!iph->saddr)
1261 return -EINVAL;
1262 dev->flags = IFF_BROADCAST;
1263 dev->header_ops = &ipgre_header_ops;
1264 }
1265 #endif
1266 } else
1267 dev->header_ops = &ipgre_header_ops;
1268
1269 return 0;
1270 }
1271
1272 static void ipgre_fb_tunnel_init(struct net_device *dev)
1273 {
1274 struct ip_tunnel *tunnel = netdev_priv(dev);
1275 struct iphdr *iph = &tunnel->parms.iph;
1276 struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
1277
1278 tunnel->dev = dev;
1279 strcpy(tunnel->parms.name, dev->name);
1280
1281 iph->version = 4;
1282 iph->protocol = IPPROTO_GRE;
1283 iph->ihl = 5;
1284 tunnel->hlen = sizeof(struct iphdr) + 4;
1285
1286 dev_hold(dev);
1287 ign->tunnels_wc[0] = tunnel;
1288 }
1289
1290
1291 static struct net_protocol ipgre_protocol = {
1292 .handler = ipgre_rcv,
1293 .err_handler = ipgre_err,
1294 .netns_ok = 1,
1295 };
1296
1297 static void ipgre_destroy_tunnels(struct ipgre_net *ign)
1298 {
1299 int prio;
1300
1301 for (prio = 0; prio < 4; prio++) {
1302 int h;
1303 for (h = 0; h < HASH_SIZE; h++) {
1304 struct ip_tunnel *t;
1305 while ((t = ign->tunnels[prio][h]) != NULL)
1306 unregister_netdevice(t->dev);
1307 }
1308 }
1309 }
1310
1311 static int ipgre_init_net(struct net *net)
1312 {
1313 int err;
1314 struct ipgre_net *ign;
1315
1316 err = -ENOMEM;
1317 ign = kzalloc(sizeof(struct ipgre_net), GFP_KERNEL);
1318 if (ign == NULL)
1319 goto err_alloc;
1320
1321 err = net_assign_generic(net, ipgre_net_id, ign);
1322 if (err < 0)
1323 goto err_assign;
1324
1325 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1326 ipgre_tunnel_setup);
1327 if (!ign->fb_tunnel_dev) {
1328 err = -ENOMEM;
1329 goto err_alloc_dev;
1330 }
1331 dev_net_set(ign->fb_tunnel_dev, net);
1332
1333 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1334 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1335
1336 if ((err = register_netdev(ign->fb_tunnel_dev)))
1337 goto err_reg_dev;
1338
1339 return 0;
1340
1341 err_reg_dev:
1342 free_netdev(ign->fb_tunnel_dev);
1343 err_alloc_dev:
1344 /* nothing */
1345 err_assign:
1346 kfree(ign);
1347 err_alloc:
1348 return err;
1349 }
1350
1351 static void ipgre_exit_net(struct net *net)
1352 {
1353 struct ipgre_net *ign;
1354
1355 ign = net_generic(net, ipgre_net_id);
1356 rtnl_lock();
1357 ipgre_destroy_tunnels(ign);
1358 rtnl_unlock();
1359 kfree(ign);
1360 }
1361
1362 static struct pernet_operations ipgre_net_ops = {
1363 .init = ipgre_init_net,
1364 .exit = ipgre_exit_net,
1365 };
1366
1367 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1368 {
1369 __be16 flags;
1370
1371 if (!data)
1372 return 0;
1373
1374 flags = 0;
1375 if (data[IFLA_GRE_IFLAGS])
1376 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1377 if (data[IFLA_GRE_OFLAGS])
1378 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1379 if (flags & (GRE_VERSION|GRE_ROUTING))
1380 return -EINVAL;
1381
1382 return 0;
1383 }
1384
1385 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1386 {
1387 __be32 daddr;
1388
1389 if (tb[IFLA_ADDRESS]) {
1390 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1391 return -EINVAL;
1392 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1393 return -EADDRNOTAVAIL;
1394 }
1395
1396 if (!data)
1397 goto out;
1398
1399 if (data[IFLA_GRE_REMOTE]) {
1400 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1401 if (!daddr)
1402 return -EINVAL;
1403 }
1404
1405 out:
1406 return ipgre_tunnel_validate(tb, data);
1407 }
1408
1409 static void ipgre_netlink_parms(struct nlattr *data[],
1410 struct ip_tunnel_parm *parms)
1411 {
1412 memset(parms, 0, sizeof(*parms));
1413
1414 parms->iph.protocol = IPPROTO_GRE;
1415
1416 if (!data)
1417 return;
1418
1419 if (data[IFLA_GRE_LINK])
1420 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1421
1422 if (data[IFLA_GRE_IFLAGS])
1423 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1424
1425 if (data[IFLA_GRE_OFLAGS])
1426 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1427
1428 if (data[IFLA_GRE_IKEY])
1429 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1430
1431 if (data[IFLA_GRE_OKEY])
1432 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1433
1434 if (data[IFLA_GRE_LOCAL])
1435 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1436
1437 if (data[IFLA_GRE_REMOTE])
1438 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1439
1440 if (data[IFLA_GRE_TTL])
1441 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1442
1443 if (data[IFLA_GRE_TOS])
1444 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1445
1446 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1447 parms->iph.frag_off = htons(IP_DF);
1448 }
1449
1450 static int ipgre_tap_init(struct net_device *dev)
1451 {
1452 struct ip_tunnel *tunnel;
1453
1454 tunnel = netdev_priv(dev);
1455
1456 tunnel->dev = dev;
1457 strcpy(tunnel->parms.name, dev->name);
1458
1459 ipgre_tunnel_bind_dev(dev);
1460
1461 return 0;
1462 }
1463
1464 static const struct net_device_ops ipgre_tap_netdev_ops = {
1465 .ndo_init = ipgre_tap_init,
1466 .ndo_uninit = ipgre_tunnel_uninit,
1467 .ndo_start_xmit = ipgre_tunnel_xmit,
1468 .ndo_set_mac_address = eth_mac_addr,
1469 .ndo_validate_addr = eth_validate_addr,
1470 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1471 };
1472
1473 static void ipgre_tap_setup(struct net_device *dev)
1474 {
1475
1476 ether_setup(dev);
1477
1478 dev->netdev_ops = &ipgre_netdev_ops;
1479 dev->destructor = free_netdev;
1480
1481 dev->iflink = 0;
1482 dev->features |= NETIF_F_NETNS_LOCAL;
1483 }
1484
1485 static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[],
1486 struct nlattr *data[])
1487 {
1488 struct ip_tunnel *nt;
1489 struct net *net = dev_net(dev);
1490 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1491 int mtu;
1492 int err;
1493
1494 nt = netdev_priv(dev);
1495 ipgre_netlink_parms(data, &nt->parms);
1496
1497 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1498 return -EEXIST;
1499
1500 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1501 random_ether_addr(dev->dev_addr);
1502
1503 mtu = ipgre_tunnel_bind_dev(dev);
1504 if (!tb[IFLA_MTU])
1505 dev->mtu = mtu;
1506
1507 err = register_netdevice(dev);
1508 if (err)
1509 goto out;
1510
1511 dev_hold(dev);
1512 ipgre_tunnel_link(ign, nt);
1513
1514 out:
1515 return err;
1516 }
1517
1518 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1519 struct nlattr *data[])
1520 {
1521 struct ip_tunnel *t, *nt;
1522 struct net *net = dev_net(dev);
1523 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1524 struct ip_tunnel_parm p;
1525 int mtu;
1526
1527 if (dev == ign->fb_tunnel_dev)
1528 return -EINVAL;
1529
1530 nt = netdev_priv(dev);
1531 ipgre_netlink_parms(data, &p);
1532
1533 t = ipgre_tunnel_locate(net, &p, 0);
1534
1535 if (t) {
1536 if (t->dev != dev)
1537 return -EEXIST;
1538 } else {
1539 unsigned nflags = 0;
1540
1541 t = nt;
1542
1543 if (ipv4_is_multicast(p.iph.daddr))
1544 nflags = IFF_BROADCAST;
1545 else if (p.iph.daddr)
1546 nflags = IFF_POINTOPOINT;
1547
1548 if ((dev->flags ^ nflags) &
1549 (IFF_POINTOPOINT | IFF_BROADCAST))
1550 return -EINVAL;
1551
1552 ipgre_tunnel_unlink(ign, t);
1553 t->parms.iph.saddr = p.iph.saddr;
1554 t->parms.iph.daddr = p.iph.daddr;
1555 t->parms.i_key = p.i_key;
1556 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1557 memcpy(dev->broadcast, &p.iph.daddr, 4);
1558 ipgre_tunnel_link(ign, t);
1559 netdev_state_change(dev);
1560 }
1561
1562 t->parms.o_key = p.o_key;
1563 t->parms.iph.ttl = p.iph.ttl;
1564 t->parms.iph.tos = p.iph.tos;
1565 t->parms.iph.frag_off = p.iph.frag_off;
1566
1567 if (t->parms.link != p.link) {
1568 t->parms.link = p.link;
1569 mtu = ipgre_tunnel_bind_dev(dev);
1570 if (!tb[IFLA_MTU])
1571 dev->mtu = mtu;
1572 netdev_state_change(dev);
1573 }
1574
1575 return 0;
1576 }
1577
1578 static size_t ipgre_get_size(const struct net_device *dev)
1579 {
1580 return
1581 /* IFLA_GRE_LINK */
1582 nla_total_size(4) +
1583 /* IFLA_GRE_IFLAGS */
1584 nla_total_size(2) +
1585 /* IFLA_GRE_OFLAGS */
1586 nla_total_size(2) +
1587 /* IFLA_GRE_IKEY */
1588 nla_total_size(4) +
1589 /* IFLA_GRE_OKEY */
1590 nla_total_size(4) +
1591 /* IFLA_GRE_LOCAL */
1592 nla_total_size(4) +
1593 /* IFLA_GRE_REMOTE */
1594 nla_total_size(4) +
1595 /* IFLA_GRE_TTL */
1596 nla_total_size(1) +
1597 /* IFLA_GRE_TOS */
1598 nla_total_size(1) +
1599 /* IFLA_GRE_PMTUDISC */
1600 nla_total_size(1) +
1601 0;
1602 }
1603
1604 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1605 {
1606 struct ip_tunnel *t = netdev_priv(dev);
1607 struct ip_tunnel_parm *p = &t->parms;
1608
1609 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1610 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1611 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1612 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1613 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1614 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1615 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1616 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1617 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1618 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1619
1620 return 0;
1621
1622 nla_put_failure:
1623 return -EMSGSIZE;
1624 }
1625
1626 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1627 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1628 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1629 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1630 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1631 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1632 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1633 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1634 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1635 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1636 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1637 };
1638
1639 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1640 .kind = "gre",
1641 .maxtype = IFLA_GRE_MAX,
1642 .policy = ipgre_policy,
1643 .priv_size = sizeof(struct ip_tunnel),
1644 .setup = ipgre_tunnel_setup,
1645 .validate = ipgre_tunnel_validate,
1646 .newlink = ipgre_newlink,
1647 .changelink = ipgre_changelink,
1648 .get_size = ipgre_get_size,
1649 .fill_info = ipgre_fill_info,
1650 };
1651
1652 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1653 .kind = "gretap",
1654 .maxtype = IFLA_GRE_MAX,
1655 .policy = ipgre_policy,
1656 .priv_size = sizeof(struct ip_tunnel),
1657 .setup = ipgre_tap_setup,
1658 .validate = ipgre_tap_validate,
1659 .newlink = ipgre_newlink,
1660 .changelink = ipgre_changelink,
1661 .get_size = ipgre_get_size,
1662 .fill_info = ipgre_fill_info,
1663 };
1664
1665 /*
1666 * And now the modules code and kernel interface.
1667 */
1668
1669 static int __init ipgre_init(void)
1670 {
1671 int err;
1672
1673 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1674
1675 if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
1676 printk(KERN_INFO "ipgre init: can't add protocol\n");
1677 return -EAGAIN;
1678 }
1679
1680 err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops);
1681 if (err < 0)
1682 goto gen_device_failed;
1683
1684 err = rtnl_link_register(&ipgre_link_ops);
1685 if (err < 0)
1686 goto rtnl_link_failed;
1687
1688 err = rtnl_link_register(&ipgre_tap_ops);
1689 if (err < 0)
1690 goto tap_ops_failed;
1691
1692 out:
1693 return err;
1694
1695 tap_ops_failed:
1696 rtnl_link_unregister(&ipgre_link_ops);
1697 rtnl_link_failed:
1698 unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
1699 gen_device_failed:
1700 inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
1701 goto out;
1702 }
1703
1704 static void __exit ipgre_fini(void)
1705 {
1706 rtnl_link_unregister(&ipgre_tap_ops);
1707 rtnl_link_unregister(&ipgre_link_ops);
1708 unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
1709 if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
1710 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1711 }
1712
1713 module_init(ipgre_init);
1714 module_exit(ipgre_fini);
1715 MODULE_LICENSE("GPL");
1716 MODULE_ALIAS_RTNL_LINK("gre");
1717 MODULE_ALIAS_RTNL_LINK("gretap");
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