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[net-next-2.6.git] / net / ipv4 / ip_gre.c
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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/if_ether.h>
31
32#include <net/sock.h>
33#include <net/ip.h>
34#include <net/icmp.h>
35#include <net/protocol.h>
36#include <net/ipip.h>
37#include <net/arp.h>
38#include <net/checksum.h>
39#include <net/dsfield.h>
40#include <net/inet_ecn.h>
41#include <net/xfrm.h>
42#include <net/net_namespace.h>
43#include <net/netns/generic.h>
44
45#ifdef CONFIG_IPV6
46#include <net/ipv6.h>
47#include <net/ip6_fib.h>
48#include <net/ip6_route.h>
49#endif
50
51/*
52 Problems & solutions
53 --------------------
54
55 1. The most important issue is detecting local dead loops.
56 They would cause complete host lockup in transmit, which
57 would be "resolved" by stack overflow or, if queueing is enabled,
58 with infinite looping in net_bh.
59
60 We cannot track such dead loops during route installation,
61 it is infeasible task. The most general solutions would be
62 to keep skb->encapsulation counter (sort of local ttl),
63 and silently drop packet when it expires. It is the best
64 solution, but it supposes maintaing new variable in ALL
65 skb, even if no tunneling is used.
66
67 Current solution: t->recursion lock breaks dead loops. It looks
68 like dev->tbusy flag, but I preferred new variable, because
69 the semantics is different. One day, when hard_start_xmit
70 will be multithreaded we will have to use skb->encapsulation.
71
72
73
74 2. Networking dead loops would not kill routers, but would really
75 kill network. IP hop limit plays role of "t->recursion" in this case,
76 if we copy it from packet being encapsulated to upper header.
77 It is very good solution, but it introduces two problems:
78
79 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
80 do not work over tunnels.
81 - traceroute does not work. I planned to relay ICMP from tunnel,
82 so that this problem would be solved and traceroute output
83 would even more informative. This idea appeared to be wrong:
84 only Linux complies to rfc1812 now (yes, guys, Linux is the only
85 true router now :-)), all routers (at least, in neighbourhood of mine)
86 return only 8 bytes of payload. It is the end.
87
88 Hence, if we want that OSPF worked or traceroute said something reasonable,
89 we should search for another solution.
90
91 One of them is to parse packet trying to detect inner encapsulation
92 made by our node. It is difficult or even impossible, especially,
93 taking into account fragmentation. TO be short, tt is not solution at all.
94
95 Current solution: The solution was UNEXPECTEDLY SIMPLE.
96 We force DF flag on tunnels with preconfigured hop limit,
97 that is ALL. :-) Well, it does not remove the problem completely,
98 but exponential growth of network traffic is changed to linear
99 (branches, that exceed pmtu are pruned) and tunnel mtu
100 fastly degrades to value <68, where looping stops.
101 Yes, it is not good if there exists a router in the loop,
102 which does not force DF, even when encapsulating packets have DF set.
103 But it is not our problem! Nobody could accuse us, we made
104 all that we could make. Even if it is your gated who injected
105 fatal route to network, even if it were you who configured
106 fatal static route: you are innocent. :-)
107
108
109
110 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
111 practically identical code. It would be good to glue them
112 together, but it is not very evident, how to make them modular.
113 sit is integral part of IPv6, ipip and gre are naturally modular.
114 We could extract common parts (hash table, ioctl etc)
115 to a separate module (ip_tunnel.c).
116
117 Alexey Kuznetsov.
118 */
119
120static int ipgre_tunnel_init(struct net_device *dev);
121static void ipgre_tunnel_setup(struct net_device *dev);
122
123/* Fallback tunnel: no source, no destination, no key, no options */
124
125static int ipgre_fb_tunnel_init(struct net_device *dev);
126
127#define HASH_SIZE 16
128
129static int ipgre_net_id;
130struct ipgre_net {
131 struct ip_tunnel *tunnels[4][HASH_SIZE];
132
133 struct net_device *fb_tunnel_dev;
134};
135
136/* Tunnel hash table */
137
138/*
139 4 hash tables:
140
141 3: (remote,local)
142 2: (remote,*)
143 1: (*,local)
144 0: (*,*)
145
146 We require exact key match i.e. if a key is present in packet
147 it will match only tunnel with the same key; if it is not present,
148 it will match only keyless tunnel.
149
150 All keysless packets, if not matched configured keyless tunnels
151 will match fallback tunnel.
152 */
153
154#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
155
156#define tunnels_r_l tunnels[3]
157#define tunnels_r tunnels[2]
158#define tunnels_l tunnels[1]
159#define tunnels_wc tunnels[0]
160
161static DEFINE_RWLOCK(ipgre_lock);
162
163/* Given src, dst and key, find appropriate for input tunnel. */
164
165static struct ip_tunnel * ipgre_tunnel_lookup(struct net *net,
166 __be32 remote, __be32 local, __be32 key)
167{
168 unsigned h0 = HASH(remote);
169 unsigned h1 = HASH(key);
170 struct ip_tunnel *t;
171 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
172
173 for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
174 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) {
175 if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
176 return t;
177 }
178 }
179 for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
180 if (remote == t->parms.iph.daddr) {
181 if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
182 return t;
183 }
184 }
185 for (t = ign->tunnels_l[h1]; t; t = t->next) {
186 if (local == t->parms.iph.saddr ||
187 (local == t->parms.iph.daddr &&
188 ipv4_is_multicast(local))) {
189 if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
190 return t;
191 }
192 }
193 for (t = ign->tunnels_wc[h1]; t; t = t->next) {
194 if (t->parms.i_key == key && (t->dev->flags&IFF_UP))
195 return t;
196 }
197
198 if (ign->fb_tunnel_dev->flags&IFF_UP)
199 return netdev_priv(ign->fb_tunnel_dev);
200 return NULL;
201}
202
203static struct ip_tunnel **__ipgre_bucket(struct ipgre_net *ign,
204 struct ip_tunnel_parm *parms)
205{
206 __be32 remote = parms->iph.daddr;
207 __be32 local = parms->iph.saddr;
208 __be32 key = parms->i_key;
209 unsigned h = HASH(key);
210 int prio = 0;
211
212 if (local)
213 prio |= 1;
214 if (remote && !ipv4_is_multicast(remote)) {
215 prio |= 2;
216 h ^= HASH(remote);
217 }
218
219 return &ign->tunnels[prio][h];
220}
221
222static inline struct ip_tunnel **ipgre_bucket(struct ipgre_net *ign,
223 struct ip_tunnel *t)
224{
225 return __ipgre_bucket(ign, &t->parms);
226}
227
228static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
229{
230 struct ip_tunnel **tp = ipgre_bucket(ign, t);
231
232 t->next = *tp;
233 write_lock_bh(&ipgre_lock);
234 *tp = t;
235 write_unlock_bh(&ipgre_lock);
236}
237
238static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
239{
240 struct ip_tunnel **tp;
241
242 for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
243 if (t == *tp) {
244 write_lock_bh(&ipgre_lock);
245 *tp = t->next;
246 write_unlock_bh(&ipgre_lock);
247 break;
248 }
249 }
250}
251
252static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
253 struct ip_tunnel_parm *parms, int create)
254{
255 __be32 remote = parms->iph.daddr;
256 __be32 local = parms->iph.saddr;
257 __be32 key = parms->i_key;
258 struct ip_tunnel *t, **tp, *nt;
259 struct net_device *dev;
260 char name[IFNAMSIZ];
261 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
262
263 for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next) {
264 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) {
265 if (key == t->parms.i_key)
266 return t;
267 }
268 }
269 if (!create)
270 return NULL;
271
272 if (parms->name[0])
273 strlcpy(name, parms->name, IFNAMSIZ);
274 else
275 sprintf(name, "gre%%d");
276
277 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
278 if (!dev)
279 return NULL;
280
281 dev_net_set(dev, net);
282
283 if (strchr(name, '%')) {
284 if (dev_alloc_name(dev, name) < 0)
285 goto failed_free;
286 }
287
288 dev->init = ipgre_tunnel_init;
289 nt = netdev_priv(dev);
290 nt->parms = *parms;
291
292 if (register_netdevice(dev) < 0)
293 goto failed_free;
294
295 dev_hold(dev);
296 ipgre_tunnel_link(ign, nt);
297 return nt;
298
299failed_free:
300 free_netdev(dev);
301 return NULL;
302}
303
304static void ipgre_tunnel_uninit(struct net_device *dev)
305{
306 struct net *net = dev_net(dev);
307 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
308
309 ipgre_tunnel_unlink(ign, netdev_priv(dev));
310 dev_put(dev);
311}
312
313
314static void ipgre_err(struct sk_buff *skb, u32 info)
315{
316#ifndef I_WISH_WORLD_WERE_PERFECT
317
318/* It is not :-( All the routers (except for Linux) return only
319 8 bytes of packet payload. It means, that precise relaying of
320 ICMP in the real Internet is absolutely infeasible.
321
322 Moreover, Cisco "wise men" put GRE key to the third word
323 in GRE header. It makes impossible maintaining even soft state for keyed
324 GRE tunnels with enabled checksum. Tell them "thank you".
325
326 Well, I wonder, rfc1812 was written by Cisco employee,
327 what the hell these idiots break standrads established
328 by themself???
329 */
330
331 struct iphdr *iph = (struct iphdr*)skb->data;
332 __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
333 int grehlen = (iph->ihl<<2) + 4;
334 const int type = icmp_hdr(skb)->type;
335 const int code = icmp_hdr(skb)->code;
336 struct ip_tunnel *t;
337 __be16 flags;
338
339 flags = p[0];
340 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
341 if (flags&(GRE_VERSION|GRE_ROUTING))
342 return;
343 if (flags&GRE_KEY) {
344 grehlen += 4;
345 if (flags&GRE_CSUM)
346 grehlen += 4;
347 }
348 }
349
350 /* If only 8 bytes returned, keyed message will be dropped here */
351 if (skb_headlen(skb) < grehlen)
352 return;
353
354 switch (type) {
355 default:
356 case ICMP_PARAMETERPROB:
357 return;
358
359 case ICMP_DEST_UNREACH:
360 switch (code) {
361 case ICMP_SR_FAILED:
362 case ICMP_PORT_UNREACH:
363 /* Impossible event. */
364 return;
365 case ICMP_FRAG_NEEDED:
366 /* Soft state for pmtu is maintained by IP core. */
367 return;
368 default:
369 /* All others are translated to HOST_UNREACH.
370 rfc2003 contains "deep thoughts" about NET_UNREACH,
371 I believe they are just ether pollution. --ANK
372 */
373 break;
374 }
375 break;
376 case ICMP_TIME_EXCEEDED:
377 if (code != ICMP_EXC_TTL)
378 return;
379 break;
380 }
381
382 read_lock(&ipgre_lock);
383 t = ipgre_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr,
384 (flags&GRE_KEY) ?
385 *(((__be32*)p) + (grehlen>>2) - 1) : 0);
386 if (t == NULL || t->parms.iph.daddr == 0 ||
387 ipv4_is_multicast(t->parms.iph.daddr))
388 goto out;
389
390 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
391 goto out;
392
393 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
394 t->err_count++;
395 else
396 t->err_count = 1;
397 t->err_time = jiffies;
398out:
399 read_unlock(&ipgre_lock);
400 return;
401#else
402 struct iphdr *iph = (struct iphdr*)dp;
403 struct iphdr *eiph;
404 __be16 *p = (__be16*)(dp+(iph->ihl<<2));
405 const int type = icmp_hdr(skb)->type;
406 const int code = icmp_hdr(skb)->code;
407 int rel_type = 0;
408 int rel_code = 0;
409 __be32 rel_info = 0;
410 __u32 n = 0;
411 __be16 flags;
412 int grehlen = (iph->ihl<<2) + 4;
413 struct sk_buff *skb2;
414 struct flowi fl;
415 struct rtable *rt;
416
417 if (p[1] != htons(ETH_P_IP))
418 return;
419
420 flags = p[0];
421 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
422 if (flags&(GRE_VERSION|GRE_ROUTING))
423 return;
424 if (flags&GRE_CSUM)
425 grehlen += 4;
426 if (flags&GRE_KEY)
427 grehlen += 4;
428 if (flags&GRE_SEQ)
429 grehlen += 4;
430 }
431 if (len < grehlen + sizeof(struct iphdr))
432 return;
433 eiph = (struct iphdr*)(dp + grehlen);
434
435 switch (type) {
436 default:
437 return;
438 case ICMP_PARAMETERPROB:
439 n = ntohl(icmp_hdr(skb)->un.gateway) >> 24;
440 if (n < (iph->ihl<<2))
441 return;
442
443 /* So... This guy found something strange INSIDE encapsulated
444 packet. Well, he is fool, but what can we do ?
445 */
446 rel_type = ICMP_PARAMETERPROB;
447 n -= grehlen;
448 rel_info = htonl(n << 24);
449 break;
450
451 case ICMP_DEST_UNREACH:
452 switch (code) {
453 case ICMP_SR_FAILED:
454 case ICMP_PORT_UNREACH:
455 /* Impossible event. */
456 return;
457 case ICMP_FRAG_NEEDED:
458 /* And it is the only really necessary thing :-) */
459 n = ntohs(icmp_hdr(skb)->un.frag.mtu);
460 if (n < grehlen+68)
461 return;
462 n -= grehlen;
463 /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */
464 if (n > ntohs(eiph->tot_len))
465 return;
466 rel_info = htonl(n);
467 break;
468 default:
469 /* All others are translated to HOST_UNREACH.
470 rfc2003 contains "deep thoughts" about NET_UNREACH,
471 I believe, it is just ether pollution. --ANK
472 */
473 rel_type = ICMP_DEST_UNREACH;
474 rel_code = ICMP_HOST_UNREACH;
475 break;
476 }
477 break;
478 case ICMP_TIME_EXCEEDED:
479 if (code != ICMP_EXC_TTL)
480 return;
481 break;
482 }
483
484 /* Prepare fake skb to feed it to icmp_send */
485 skb2 = skb_clone(skb, GFP_ATOMIC);
486 if (skb2 == NULL)
487 return;
488 dst_release(skb2->dst);
489 skb2->dst = NULL;
490 skb_pull(skb2, skb->data - (u8*)eiph);
491 skb_reset_network_header(skb2);
492
493 /* Try to guess incoming interface */
494 memset(&fl, 0, sizeof(fl));
495 fl.fl4_dst = eiph->saddr;
496 fl.fl4_tos = RT_TOS(eiph->tos);
497 fl.proto = IPPROTO_GRE;
498 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) {
499 kfree_skb(skb2);
500 return;
501 }
502 skb2->dev = rt->u.dst.dev;
503
504 /* route "incoming" packet */
505 if (rt->rt_flags&RTCF_LOCAL) {
506 ip_rt_put(rt);
507 rt = NULL;
508 fl.fl4_dst = eiph->daddr;
509 fl.fl4_src = eiph->saddr;
510 fl.fl4_tos = eiph->tos;
511 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) ||
512 rt->u.dst.dev->type != ARPHRD_IPGRE) {
513 ip_rt_put(rt);
514 kfree_skb(skb2);
515 return;
516 }
517 } else {
518 ip_rt_put(rt);
519 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) ||
520 skb2->dst->dev->type != ARPHRD_IPGRE) {
521 kfree_skb(skb2);
522 return;
523 }
524 }
525
526 /* change mtu on this route */
527 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
528 if (n > dst_mtu(skb2->dst)) {
529 kfree_skb(skb2);
530 return;
531 }
532 skb2->dst->ops->update_pmtu(skb2->dst, n);
533 } else if (type == ICMP_TIME_EXCEEDED) {
534 struct ip_tunnel *t = netdev_priv(skb2->dev);
535 if (t->parms.iph.ttl) {
536 rel_type = ICMP_DEST_UNREACH;
537 rel_code = ICMP_HOST_UNREACH;
538 }
539 }
540
541 icmp_send(skb2, rel_type, rel_code, rel_info);
542 kfree_skb(skb2);
543#endif
544}
545
546static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
547{
548 if (INET_ECN_is_ce(iph->tos)) {
549 if (skb->protocol == htons(ETH_P_IP)) {
550 IP_ECN_set_ce(ip_hdr(skb));
551 } else if (skb->protocol == htons(ETH_P_IPV6)) {
552 IP6_ECN_set_ce(ipv6_hdr(skb));
553 }
554 }
555}
556
557static inline u8
558ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
559{
560 u8 inner = 0;
561 if (skb->protocol == htons(ETH_P_IP))
562 inner = old_iph->tos;
563 else if (skb->protocol == htons(ETH_P_IPV6))
564 inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
565 return INET_ECN_encapsulate(tos, inner);
566}
567
568static int ipgre_rcv(struct sk_buff *skb)
569{
570 struct iphdr *iph;
571 u8 *h;
572 __be16 flags;
573 __sum16 csum = 0;
574 __be32 key = 0;
575 u32 seqno = 0;
576 struct ip_tunnel *tunnel;
577 int offset = 4;
578
579 if (!pskb_may_pull(skb, 16))
580 goto drop_nolock;
581
582 iph = ip_hdr(skb);
583 h = skb->data;
584 flags = *(__be16*)h;
585
586 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
587 /* - Version must be 0.
588 - We do not support routing headers.
589 */
590 if (flags&(GRE_VERSION|GRE_ROUTING))
591 goto drop_nolock;
592
593 if (flags&GRE_CSUM) {
594 switch (skb->ip_summed) {
595 case CHECKSUM_COMPLETE:
596 csum = csum_fold(skb->csum);
597 if (!csum)
598 break;
599 /* fall through */
600 case CHECKSUM_NONE:
601 skb->csum = 0;
602 csum = __skb_checksum_complete(skb);
603 skb->ip_summed = CHECKSUM_COMPLETE;
604 }
605 offset += 4;
606 }
607 if (flags&GRE_KEY) {
608 key = *(__be32*)(h + offset);
609 offset += 4;
610 }
611 if (flags&GRE_SEQ) {
612 seqno = ntohl(*(__be32*)(h + offset));
613 offset += 4;
614 }
615 }
616
617 read_lock(&ipgre_lock);
618 if ((tunnel = ipgre_tunnel_lookup(dev_net(skb->dev),
619 iph->saddr, iph->daddr, key)) != NULL) {
620 secpath_reset(skb);
621
622 skb->protocol = *(__be16*)(h + 2);
623 /* WCCP version 1 and 2 protocol decoding.
624 * - Change protocol to IP
625 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
626 */
627 if (flags == 0 &&
628 skb->protocol == htons(ETH_P_WCCP)) {
629 skb->protocol = htons(ETH_P_IP);
630 if ((*(h + offset) & 0xF0) != 0x40)
631 offset += 4;
632 }
633
634 skb->mac_header = skb->network_header;
635 __pskb_pull(skb, offset);
636 skb_reset_network_header(skb);
637 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
638 skb->pkt_type = PACKET_HOST;
639#ifdef CONFIG_NET_IPGRE_BROADCAST
640 if (ipv4_is_multicast(iph->daddr)) {
641 /* Looped back packet, drop it! */
642 if (skb->rtable->fl.iif == 0)
643 goto drop;
644 tunnel->stat.multicast++;
645 skb->pkt_type = PACKET_BROADCAST;
646 }
647#endif
648
649 if (((flags&GRE_CSUM) && csum) ||
650 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
651 tunnel->stat.rx_crc_errors++;
652 tunnel->stat.rx_errors++;
653 goto drop;
654 }
655 if (tunnel->parms.i_flags&GRE_SEQ) {
656 if (!(flags&GRE_SEQ) ||
657 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
658 tunnel->stat.rx_fifo_errors++;
659 tunnel->stat.rx_errors++;
660 goto drop;
661 }
662 tunnel->i_seqno = seqno + 1;
663 }
664 tunnel->stat.rx_packets++;
665 tunnel->stat.rx_bytes += skb->len;
666 skb->dev = tunnel->dev;
667 dst_release(skb->dst);
668 skb->dst = NULL;
669 nf_reset(skb);
670 ipgre_ecn_decapsulate(iph, skb);
671 netif_rx(skb);
672 read_unlock(&ipgre_lock);
673 return(0);
674 }
675 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
676
677drop:
678 read_unlock(&ipgre_lock);
679drop_nolock:
680 kfree_skb(skb);
681 return(0);
682}
683
684static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
685{
686 struct ip_tunnel *tunnel = netdev_priv(dev);
687 struct net_device_stats *stats = &tunnel->stat;
688 struct iphdr *old_iph = ip_hdr(skb);
689 struct iphdr *tiph;
690 u8 tos;
691 __be16 df;
692 struct rtable *rt; /* Route to the other host */
693 struct net_device *tdev; /* Device to other host */
694 struct iphdr *iph; /* Our new IP header */
695 unsigned int max_headroom; /* The extra header space needed */
696 int gre_hlen;
697 __be32 dst;
698 int mtu;
699
700 if (tunnel->recursion++) {
701 tunnel->stat.collisions++;
702 goto tx_error;
703 }
704
705 if (dev->header_ops) {
706 gre_hlen = 0;
707 tiph = (struct iphdr*)skb->data;
708 } else {
709 gre_hlen = tunnel->hlen;
710 tiph = &tunnel->parms.iph;
711 }
712
713 if ((dst = tiph->daddr) == 0) {
714 /* NBMA tunnel */
715
716 if (skb->dst == NULL) {
717 tunnel->stat.tx_fifo_errors++;
718 goto tx_error;
719 }
720
721 if (skb->protocol == htons(ETH_P_IP)) {
722 rt = skb->rtable;
723 if ((dst = rt->rt_gateway) == 0)
724 goto tx_error_icmp;
725 }
726#ifdef CONFIG_IPV6
727 else if (skb->protocol == htons(ETH_P_IPV6)) {
728 struct in6_addr *addr6;
729 int addr_type;
730 struct neighbour *neigh = skb->dst->neighbour;
731
732 if (neigh == NULL)
733 goto tx_error;
734
735 addr6 = (struct in6_addr*)&neigh->primary_key;
736 addr_type = ipv6_addr_type(addr6);
737
738 if (addr_type == IPV6_ADDR_ANY) {
739 addr6 = &ipv6_hdr(skb)->daddr;
740 addr_type = ipv6_addr_type(addr6);
741 }
742
743 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
744 goto tx_error_icmp;
745
746 dst = addr6->s6_addr32[3];
747 }
748#endif
749 else
750 goto tx_error;
751 }
752
753 tos = tiph->tos;
754 if (tos&1) {
755 if (skb->protocol == htons(ETH_P_IP))
756 tos = old_iph->tos;
757 tos &= ~1;
758 }
759
760 {
761 struct flowi fl = { .oif = tunnel->parms.link,
762 .nl_u = { .ip4_u =
763 { .daddr = dst,
764 .saddr = tiph->saddr,
765 .tos = RT_TOS(tos) } },
766 .proto = IPPROTO_GRE };
767 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
768 tunnel->stat.tx_carrier_errors++;
769 goto tx_error;
770 }
771 }
772 tdev = rt->u.dst.dev;
773
774 if (tdev == dev) {
775 ip_rt_put(rt);
776 tunnel->stat.collisions++;
777 goto tx_error;
778 }
779
780 df = tiph->frag_off;
781 if (df)
782 mtu = dst_mtu(&rt->u.dst) - tunnel->hlen;
783 else
784 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
785
786 if (skb->dst)
787 skb->dst->ops->update_pmtu(skb->dst, mtu);
788
789 if (skb->protocol == htons(ETH_P_IP)) {
790 df |= (old_iph->frag_off&htons(IP_DF));
791
792 if ((old_iph->frag_off&htons(IP_DF)) &&
793 mtu < ntohs(old_iph->tot_len)) {
794 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
795 ip_rt_put(rt);
796 goto tx_error;
797 }
798 }
799#ifdef CONFIG_IPV6
800 else if (skb->protocol == htons(ETH_P_IPV6)) {
801 struct rt6_info *rt6 = (struct rt6_info*)skb->dst;
802
803 if (rt6 && mtu < dst_mtu(skb->dst) && mtu >= IPV6_MIN_MTU) {
804 if ((tunnel->parms.iph.daddr &&
805 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
806 rt6->rt6i_dst.plen == 128) {
807 rt6->rt6i_flags |= RTF_MODIFIED;
808 skb->dst->metrics[RTAX_MTU-1] = mtu;
809 }
810 }
811
812 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
813 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
814 ip_rt_put(rt);
815 goto tx_error;
816 }
817 }
818#endif
819
820 if (tunnel->err_count > 0) {
821 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
822 tunnel->err_count--;
823
824 dst_link_failure(skb);
825 } else
826 tunnel->err_count = 0;
827 }
828
829 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
830
831 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
832 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
833 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
834 if (!new_skb) {
835 ip_rt_put(rt);
836 stats->tx_dropped++;
837 dev_kfree_skb(skb);
838 tunnel->recursion--;
839 return 0;
840 }
841 if (skb->sk)
842 skb_set_owner_w(new_skb, skb->sk);
843 dev_kfree_skb(skb);
844 skb = new_skb;
845 old_iph = ip_hdr(skb);
846 }
847
848 skb->transport_header = skb->network_header;
849 skb_push(skb, gre_hlen);
850 skb_reset_network_header(skb);
851 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
852 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
853 IPSKB_REROUTED);
854 dst_release(skb->dst);
855 skb->dst = &rt->u.dst;
856
857 /*
858 * Push down and install the IPIP header.
859 */
860
861 iph = ip_hdr(skb);
862 iph->version = 4;
863 iph->ihl = sizeof(struct iphdr) >> 2;
864 iph->frag_off = df;
865 iph->protocol = IPPROTO_GRE;
866 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
867 iph->daddr = rt->rt_dst;
868 iph->saddr = rt->rt_src;
869
870 if ((iph->ttl = tiph->ttl) == 0) {
871 if (skb->protocol == htons(ETH_P_IP))
872 iph->ttl = old_iph->ttl;
873#ifdef CONFIG_IPV6
874 else if (skb->protocol == htons(ETH_P_IPV6))
875 iph->ttl = ((struct ipv6hdr*)old_iph)->hop_limit;
876#endif
877 else
878 iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
879 }
880
881 ((__be16*)(iph+1))[0] = tunnel->parms.o_flags;
882 ((__be16*)(iph+1))[1] = skb->protocol;
883
884 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
885 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
886
887 if (tunnel->parms.o_flags&GRE_SEQ) {
888 ++tunnel->o_seqno;
889 *ptr = htonl(tunnel->o_seqno);
890 ptr--;
891 }
892 if (tunnel->parms.o_flags&GRE_KEY) {
893 *ptr = tunnel->parms.o_key;
894 ptr--;
895 }
896 if (tunnel->parms.o_flags&GRE_CSUM) {
897 *ptr = 0;
898 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
899 }
900 }
901
902 nf_reset(skb);
903
904 IPTUNNEL_XMIT();
905 tunnel->recursion--;
906 return 0;
907
908tx_error_icmp:
909 dst_link_failure(skb);
910
911tx_error:
912 stats->tx_errors++;
913 dev_kfree_skb(skb);
914 tunnel->recursion--;
915 return 0;
916}
917
918static void ipgre_tunnel_bind_dev(struct net_device *dev)
919{
920 struct net_device *tdev = NULL;
921 struct ip_tunnel *tunnel;
922 struct iphdr *iph;
923 int hlen = LL_MAX_HEADER;
924 int mtu = ETH_DATA_LEN;
925 int addend = sizeof(struct iphdr) + 4;
926
927 tunnel = netdev_priv(dev);
928 iph = &tunnel->parms.iph;
929
930 /* Guess output device to choose reasonable mtu and hard_header_len */
931
932 if (iph->daddr) {
933 struct flowi fl = { .oif = tunnel->parms.link,
934 .nl_u = { .ip4_u =
935 { .daddr = iph->daddr,
936 .saddr = iph->saddr,
937 .tos = RT_TOS(iph->tos) } },
938 .proto = IPPROTO_GRE };
939 struct rtable *rt;
940 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
941 tdev = rt->u.dst.dev;
942 ip_rt_put(rt);
943 }
944 dev->flags |= IFF_POINTOPOINT;
945 }
946
947 if (!tdev && tunnel->parms.link)
948 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
949
950 if (tdev) {
951 hlen = tdev->hard_header_len;
952 mtu = tdev->mtu;
953 }
954 dev->iflink = tunnel->parms.link;
955
956 /* Precalculate GRE options length */
957 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
958 if (tunnel->parms.o_flags&GRE_CSUM)
959 addend += 4;
960 if (tunnel->parms.o_flags&GRE_KEY)
961 addend += 4;
962 if (tunnel->parms.o_flags&GRE_SEQ)
963 addend += 4;
964 }
965 dev->hard_header_len = hlen + addend;
966 dev->mtu = mtu - addend;
967 tunnel->hlen = addend;
968
969}
970
971static int
972ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
973{
974 int err = 0;
975 struct ip_tunnel_parm p;
976 struct ip_tunnel *t;
977 struct net *net = dev_net(dev);
978 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
979
980 switch (cmd) {
981 case SIOCGETTUNNEL:
982 t = NULL;
983 if (dev == ign->fb_tunnel_dev) {
984 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
985 err = -EFAULT;
986 break;
987 }
988 t = ipgre_tunnel_locate(net, &p, 0);
989 }
990 if (t == NULL)
991 t = netdev_priv(dev);
992 memcpy(&p, &t->parms, sizeof(p));
993 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
994 err = -EFAULT;
995 break;
996
997 case SIOCADDTUNNEL:
998 case SIOCCHGTUNNEL:
999 err = -EPERM;
1000 if (!capable(CAP_NET_ADMIN))
1001 goto done;
1002
1003 err = -EFAULT;
1004 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1005 goto done;
1006
1007 err = -EINVAL;
1008 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1009 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1010 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1011 goto done;
1012 if (p.iph.ttl)
1013 p.iph.frag_off |= htons(IP_DF);
1014
1015 if (!(p.i_flags&GRE_KEY))
1016 p.i_key = 0;
1017 if (!(p.o_flags&GRE_KEY))
1018 p.o_key = 0;
1019
1020 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1021
1022 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1023 if (t != NULL) {
1024 if (t->dev != dev) {
1025 err = -EEXIST;
1026 break;
1027 }
1028 } else {
1029 unsigned nflags=0;
1030
1031 t = netdev_priv(dev);
1032
1033 if (ipv4_is_multicast(p.iph.daddr))
1034 nflags = IFF_BROADCAST;
1035 else if (p.iph.daddr)
1036 nflags = IFF_POINTOPOINT;
1037
1038 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1039 err = -EINVAL;
1040 break;
1041 }
1042 ipgre_tunnel_unlink(ign, t);
1043 t->parms.iph.saddr = p.iph.saddr;
1044 t->parms.iph.daddr = p.iph.daddr;
1045 t->parms.i_key = p.i_key;
1046 t->parms.o_key = p.o_key;
1047 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1048 memcpy(dev->broadcast, &p.iph.daddr, 4);
1049 ipgre_tunnel_link(ign, t);
1050 netdev_state_change(dev);
1051 }
1052 }
1053
1054 if (t) {
1055 err = 0;
1056 if (cmd == SIOCCHGTUNNEL) {
1057 t->parms.iph.ttl = p.iph.ttl;
1058 t->parms.iph.tos = p.iph.tos;
1059 t->parms.iph.frag_off = p.iph.frag_off;
1060 if (t->parms.link != p.link) {
1061 t->parms.link = p.link;
1062 ipgre_tunnel_bind_dev(dev);
1063 netdev_state_change(dev);
1064 }
1065 }
1066 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1067 err = -EFAULT;
1068 } else
1069 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1070 break;
1071
1072 case SIOCDELTUNNEL:
1073 err = -EPERM;
1074 if (!capable(CAP_NET_ADMIN))
1075 goto done;
1076
1077 if (dev == ign->fb_tunnel_dev) {
1078 err = -EFAULT;
1079 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1080 goto done;
1081 err = -ENOENT;
1082 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1083 goto done;
1084 err = -EPERM;
1085 if (t == netdev_priv(ign->fb_tunnel_dev))
1086 goto done;
1087 dev = t->dev;
1088 }
1089 unregister_netdevice(dev);
1090 err = 0;
1091 break;
1092
1093 default:
1094 err = -EINVAL;
1095 }
1096
1097done:
1098 return err;
1099}
1100
1101static struct net_device_stats *ipgre_tunnel_get_stats(struct net_device *dev)
1102{
1103 return &(((struct ip_tunnel*)netdev_priv(dev))->stat);
1104}
1105
1106static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1107{
1108 struct ip_tunnel *tunnel = netdev_priv(dev);
1109 if (new_mtu < 68 || new_mtu > 0xFFF8 - tunnel->hlen)
1110 return -EINVAL;
1111 dev->mtu = new_mtu;
1112 return 0;
1113}
1114
1115/* Nice toy. Unfortunately, useless in real life :-)
1116 It allows to construct virtual multiprotocol broadcast "LAN"
1117 over the Internet, provided multicast routing is tuned.
1118
1119
1120 I have no idea was this bicycle invented before me,
1121 so that I had to set ARPHRD_IPGRE to a random value.
1122 I have an impression, that Cisco could make something similar,
1123 but this feature is apparently missing in IOS<=11.2(8).
1124
1125 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1126 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1127
1128 ping -t 255 224.66.66.66
1129
1130 If nobody answers, mbone does not work.
1131
1132 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1133 ip addr add 10.66.66.<somewhat>/24 dev Universe
1134 ifconfig Universe up
1135 ifconfig Universe add fe80::<Your_real_addr>/10
1136 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1137 ftp 10.66.66.66
1138 ...
1139 ftp fec0:6666:6666::193.233.7.65
1140 ...
1141
1142 */
1143
1144static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1145 unsigned short type,
1146 const void *daddr, const void *saddr, unsigned len)
1147{
1148 struct ip_tunnel *t = netdev_priv(dev);
1149 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1150 __be16 *p = (__be16*)(iph+1);
1151
1152 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1153 p[0] = t->parms.o_flags;
1154 p[1] = htons(type);
1155
1156 /*
1157 * Set the source hardware address.
1158 */
1159
1160 if (saddr)
1161 memcpy(&iph->saddr, saddr, 4);
1162
1163 if (daddr) {
1164 memcpy(&iph->daddr, daddr, 4);
1165 return t->hlen;
1166 }
1167 if (iph->daddr && !ipv4_is_multicast(iph->daddr))
1168 return t->hlen;
1169
1170 return -t->hlen;
1171}
1172
1173static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1174{
1175 struct iphdr *iph = (struct iphdr*) skb_mac_header(skb);
1176 memcpy(haddr, &iph->saddr, 4);
1177 return 4;
1178}
1179
1180static const struct header_ops ipgre_header_ops = {
1181 .create = ipgre_header,
1182 .parse = ipgre_header_parse,
1183};
1184
1185#ifdef CONFIG_NET_IPGRE_BROADCAST
1186static int ipgre_open(struct net_device *dev)
1187{
1188 struct ip_tunnel *t = netdev_priv(dev);
1189
1190 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1191 struct flowi fl = { .oif = t->parms.link,
1192 .nl_u = { .ip4_u =
1193 { .daddr = t->parms.iph.daddr,
1194 .saddr = t->parms.iph.saddr,
1195 .tos = RT_TOS(t->parms.iph.tos) } },
1196 .proto = IPPROTO_GRE };
1197 struct rtable *rt;
1198 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1199 return -EADDRNOTAVAIL;
1200 dev = rt->u.dst.dev;
1201 ip_rt_put(rt);
1202 if (__in_dev_get_rtnl(dev) == NULL)
1203 return -EADDRNOTAVAIL;
1204 t->mlink = dev->ifindex;
1205 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1206 }
1207 return 0;
1208}
1209
1210static int ipgre_close(struct net_device *dev)
1211{
1212 struct ip_tunnel *t = netdev_priv(dev);
1213 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1214 struct in_device *in_dev;
1215 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1216 if (in_dev) {
1217 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1218 in_dev_put(in_dev);
1219 }
1220 }
1221 return 0;
1222}
1223
1224#endif
1225
1226static void ipgre_tunnel_setup(struct net_device *dev)
1227{
1228 dev->uninit = ipgre_tunnel_uninit;
1229 dev->destructor = free_netdev;
1230 dev->hard_start_xmit = ipgre_tunnel_xmit;
1231 dev->get_stats = ipgre_tunnel_get_stats;
1232 dev->do_ioctl = ipgre_tunnel_ioctl;
1233 dev->change_mtu = ipgre_tunnel_change_mtu;
1234
1235 dev->type = ARPHRD_IPGRE;
1236 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1237 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1238 dev->flags = IFF_NOARP;
1239 dev->iflink = 0;
1240 dev->addr_len = 4;
1241 dev->features |= NETIF_F_NETNS_LOCAL;
1242}
1243
1244static int ipgre_tunnel_init(struct net_device *dev)
1245{
1246 struct ip_tunnel *tunnel;
1247 struct iphdr *iph;
1248
1249 tunnel = netdev_priv(dev);
1250 iph = &tunnel->parms.iph;
1251
1252 tunnel->dev = dev;
1253 strcpy(tunnel->parms.name, dev->name);
1254
1255 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1256 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1257
1258 ipgre_tunnel_bind_dev(dev);
1259
1260 if (iph->daddr) {
1261#ifdef CONFIG_NET_IPGRE_BROADCAST
1262 if (ipv4_is_multicast(iph->daddr)) {
1263 if (!iph->saddr)
1264 return -EINVAL;
1265 dev->flags = IFF_BROADCAST;
1266 dev->header_ops = &ipgre_header_ops;
1267 dev->open = ipgre_open;
1268 dev->stop = ipgre_close;
1269 }
1270#endif
1271 } else
1272 dev->header_ops = &ipgre_header_ops;
1273
1274 return 0;
1275}
1276
1277static int ipgre_fb_tunnel_init(struct net_device *dev)
1278{
1279 struct ip_tunnel *tunnel = netdev_priv(dev);
1280 struct iphdr *iph = &tunnel->parms.iph;
1281 struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
1282
1283 tunnel->dev = dev;
1284 strcpy(tunnel->parms.name, dev->name);
1285
1286 iph->version = 4;
1287 iph->protocol = IPPROTO_GRE;
1288 iph->ihl = 5;
1289 tunnel->hlen = sizeof(struct iphdr) + 4;
1290
1291 dev_hold(dev);
1292 ign->tunnels_wc[0] = tunnel;
1293 return 0;
1294}
1295
1296
1297static struct net_protocol ipgre_protocol = {
1298 .handler = ipgre_rcv,
1299 .err_handler = ipgre_err,
1300 .netns_ok = 1,
1301};
1302
1303static void ipgre_destroy_tunnels(struct ipgre_net *ign)
1304{
1305 int prio;
1306
1307 for (prio = 0; prio < 4; prio++) {
1308 int h;
1309 for (h = 0; h < HASH_SIZE; h++) {
1310 struct ip_tunnel *t;
1311 while ((t = ign->tunnels[prio][h]) != NULL)
1312 unregister_netdevice(t->dev);
1313 }
1314 }
1315}
1316
1317static int ipgre_init_net(struct net *net)
1318{
1319 int err;
1320 struct ipgre_net *ign;
1321
1322 err = -ENOMEM;
1323 ign = kzalloc(sizeof(struct ipgre_net), GFP_KERNEL);
1324 if (ign == NULL)
1325 goto err_alloc;
1326
1327 err = net_assign_generic(net, ipgre_net_id, ign);
1328 if (err < 0)
1329 goto err_assign;
1330
1331 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1332 ipgre_tunnel_setup);
1333 if (!ign->fb_tunnel_dev) {
1334 err = -ENOMEM;
1335 goto err_alloc_dev;
1336 }
1337
1338 ign->fb_tunnel_dev->init = ipgre_fb_tunnel_init;
1339 dev_net_set(ign->fb_tunnel_dev, net);
1340
1341 if ((err = register_netdev(ign->fb_tunnel_dev)))
1342 goto err_reg_dev;
1343
1344 return 0;
1345
1346err_reg_dev:
1347 free_netdev(ign->fb_tunnel_dev);
1348err_alloc_dev:
1349 /* nothing */
1350err_assign:
1351 kfree(ign);
1352err_alloc:
1353 return err;
1354}
1355
1356static void ipgre_exit_net(struct net *net)
1357{
1358 struct ipgre_net *ign;
1359
1360 ign = net_generic(net, ipgre_net_id);
1361 rtnl_lock();
1362 ipgre_destroy_tunnels(ign);
1363 rtnl_unlock();
1364 kfree(ign);
1365}
1366
1367static struct pernet_operations ipgre_net_ops = {
1368 .init = ipgre_init_net,
1369 .exit = ipgre_exit_net,
1370};
1371
1372/*
1373 * And now the modules code and kernel interface.
1374 */
1375
1376static int __init ipgre_init(void)
1377{
1378 int err;
1379
1380 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1381
1382 if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
1383 printk(KERN_INFO "ipgre init: can't add protocol\n");
1384 return -EAGAIN;
1385 }
1386
1387 err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops);
1388 if (err < 0)
1389 inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
1390
1391 return err;
1392}
1393
1394static void __exit ipgre_fini(void)
1395{
1396 if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
1397 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1398
1399 unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
1400}
1401
1402module_init(ipgre_init);
1403module_exit(ipgre_fini);
1404MODULE_LICENSE("GPL");
Clone of davem's net-next-2.6 tree