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Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
[deliverable/linux.git] / net / ipv4 / ip_gre.c
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 <linux/slab.h>
18 #include <asm/uaccess.h>
19 #include <linux/skbuff.h>
20 #include <linux/netdevice.h>
21 #include <linux/in.h>
22 #include <linux/tcp.h>
23 #include <linux/udp.h>
24 #include <linux/if_arp.h>
25 #include <linux/mroute.h>
26 #include <linux/init.h>
27 #include <linux/in6.h>
28 #include <linux/inetdevice.h>
29 #include <linux/igmp.h>
30 #include <linux/netfilter_ipv4.h>
31 #include <linux/etherdevice.h>
32 #include <linux/if_ether.h>
33
34 #include <net/sock.h>
35 #include <net/ip.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <net/ipip.h>
39 #include <net/arp.h>
40 #include <net/checksum.h>
41 #include <net/dsfield.h>
42 #include <net/inet_ecn.h>
43 #include <net/xfrm.h>
44 #include <net/net_namespace.h>
45 #include <net/netns/generic.h>
46 #include <net/rtnetlink.h>
47 #include <net/gre.h>
48
49 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
50 #include <net/ipv6.h>
51 #include <net/ip6_fib.h>
52 #include <net/ip6_route.h>
53 #endif
54
55 /*
56 Problems & solutions
57 --------------------
58
59 1. The most important issue is detecting local dead loops.
60 They would cause complete host lockup in transmit, which
61 would be "resolved" by stack overflow or, if queueing is enabled,
62 with infinite looping in net_bh.
63
64 We cannot track such dead loops during route installation,
65 it is infeasible task. The most general solutions would be
66 to keep skb->encapsulation counter (sort of local ttl),
67 and silently drop packet when it expires. It is a good
68 solution, but it supposes maintaing new variable in ALL
69 skb, even if no tunneling is used.
70
71 Current solution: xmit_recursion breaks dead loops. This is a percpu
72 counter, since when we enter the first ndo_xmit(), cpu migration is
73 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
74
75 2. Networking dead loops would not kill routers, but would really
76 kill network. IP hop limit plays role of "t->recursion" in this case,
77 if we copy it from packet being encapsulated to upper header.
78 It is very good solution, but it introduces two problems:
79
80 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
81 do not work over tunnels.
82 - traceroute does not work. I planned to relay ICMP from tunnel,
83 so that this problem would be solved and traceroute output
84 would even more informative. This idea appeared to be wrong:
85 only Linux complies to rfc1812 now (yes, guys, Linux is the only
86 true router now :-)), all routers (at least, in neighbourhood of mine)
87 return only 8 bytes of payload. It is the end.
88
89 Hence, if we want that OSPF worked or traceroute said something reasonable,
90 we should search for another solution.
91
92 One of them is to parse packet trying to detect inner encapsulation
93 made by our node. It is difficult or even impossible, especially,
94 taking into account fragmentation. TO be short, tt is not solution at all.
95
96 Current solution: The solution was UNEXPECTEDLY SIMPLE.
97 We force DF flag on tunnels with preconfigured hop limit,
98 that is ALL. :-) Well, it does not remove the problem completely,
99 but exponential growth of network traffic is changed to linear
100 (branches, that exceed pmtu are pruned) and tunnel mtu
101 fastly degrades to value <68, where looping stops.
102 Yes, it is not good if there exists a router in the loop,
103 which does not force DF, even when encapsulating packets have DF set.
104 But it is not our problem! Nobody could accuse us, we made
105 all that we could make. Even if it is your gated who injected
106 fatal route to network, even if it were you who configured
107 fatal static route: you are innocent. :-)
108
109
110
111 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
112 practically identical code. It would be good to glue them
113 together, but it is not very evident, how to make them modular.
114 sit is integral part of IPv6, ipip and gre are naturally modular.
115 We could extract common parts (hash table, ioctl etc)
116 to a separate module (ip_tunnel.c).
117
118 Alexey Kuznetsov.
119 */
120
121 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
122 static int ipgre_tunnel_init(struct net_device *dev);
123 static void ipgre_tunnel_setup(struct net_device *dev);
124 static int ipgre_tunnel_bind_dev(struct net_device *dev);
125
126 /* Fallback tunnel: no source, no destination, no key, no options */
127
128 #define HASH_SIZE 16
129
130 static int ipgre_net_id __read_mostly;
131 struct ipgre_net {
132 struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
133
134 struct net_device *fb_tunnel_dev;
135 };
136
137 /* Tunnel hash table */
138
139 /*
140 4 hash tables:
141
142 3: (remote,local)
143 2: (remote,*)
144 1: (*,local)
145 0: (*,*)
146
147 We require exact key match i.e. if a key is present in packet
148 it will match only tunnel with the same key; if it is not present,
149 it will match only keyless tunnel.
150
151 All keysless packets, if not matched configured keyless tunnels
152 will match fallback tunnel.
153 */
154
155 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
156
157 #define tunnels_r_l tunnels[3]
158 #define tunnels_r tunnels[2]
159 #define tunnels_l tunnels[1]
160 #define tunnels_wc tunnels[0]
161 /*
162 * Locking : hash tables are protected by RCU and RTNL
163 */
164
165 #define for_each_ip_tunnel_rcu(start) \
166 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
167
168 /* often modified stats are per cpu, other are shared (netdev->stats) */
169 struct pcpu_tstats {
170 unsigned long rx_packets;
171 unsigned long rx_bytes;
172 unsigned long tx_packets;
173 unsigned long tx_bytes;
174 };
175
176 static struct net_device_stats *ipgre_get_stats(struct net_device *dev)
177 {
178 struct pcpu_tstats sum = { 0 };
179 int i;
180
181 for_each_possible_cpu(i) {
182 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
183
184 sum.rx_packets += tstats->rx_packets;
185 sum.rx_bytes += tstats->rx_bytes;
186 sum.tx_packets += tstats->tx_packets;
187 sum.tx_bytes += tstats->tx_bytes;
188 }
189 dev->stats.rx_packets = sum.rx_packets;
190 dev->stats.rx_bytes = sum.rx_bytes;
191 dev->stats.tx_packets = sum.tx_packets;
192 dev->stats.tx_bytes = sum.tx_bytes;
193 return &dev->stats;
194 }
195
196 /* Given src, dst and key, find appropriate for input tunnel. */
197
198 static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
199 __be32 remote, __be32 local,
200 __be32 key, __be16 gre_proto)
201 {
202 struct net *net = dev_net(dev);
203 int link = dev->ifindex;
204 unsigned int h0 = HASH(remote);
205 unsigned int h1 = HASH(key);
206 struct ip_tunnel *t, *cand = NULL;
207 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
208 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
209 ARPHRD_ETHER : ARPHRD_IPGRE;
210 int score, cand_score = 4;
211
212 for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
213 if (local != t->parms.iph.saddr ||
214 remote != t->parms.iph.daddr ||
215 key != t->parms.i_key ||
216 !(t->dev->flags & IFF_UP))
217 continue;
218
219 if (t->dev->type != ARPHRD_IPGRE &&
220 t->dev->type != dev_type)
221 continue;
222
223 score = 0;
224 if (t->parms.link != link)
225 score |= 1;
226 if (t->dev->type != dev_type)
227 score |= 2;
228 if (score == 0)
229 return t;
230
231 if (score < cand_score) {
232 cand = t;
233 cand_score = score;
234 }
235 }
236
237 for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
238 if (remote != t->parms.iph.daddr ||
239 key != t->parms.i_key ||
240 !(t->dev->flags & IFF_UP))
241 continue;
242
243 if (t->dev->type != ARPHRD_IPGRE &&
244 t->dev->type != dev_type)
245 continue;
246
247 score = 0;
248 if (t->parms.link != link)
249 score |= 1;
250 if (t->dev->type != dev_type)
251 score |= 2;
252 if (score == 0)
253 return t;
254
255 if (score < cand_score) {
256 cand = t;
257 cand_score = score;
258 }
259 }
260
261 for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
262 if ((local != t->parms.iph.saddr &&
263 (local != t->parms.iph.daddr ||
264 !ipv4_is_multicast(local))) ||
265 key != t->parms.i_key ||
266 !(t->dev->flags & IFF_UP))
267 continue;
268
269 if (t->dev->type != ARPHRD_IPGRE &&
270 t->dev->type != dev_type)
271 continue;
272
273 score = 0;
274 if (t->parms.link != link)
275 score |= 1;
276 if (t->dev->type != dev_type)
277 score |= 2;
278 if (score == 0)
279 return t;
280
281 if (score < cand_score) {
282 cand = t;
283 cand_score = score;
284 }
285 }
286
287 for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
288 if (t->parms.i_key != key ||
289 !(t->dev->flags & IFF_UP))
290 continue;
291
292 if (t->dev->type != ARPHRD_IPGRE &&
293 t->dev->type != dev_type)
294 continue;
295
296 score = 0;
297 if (t->parms.link != link)
298 score |= 1;
299 if (t->dev->type != dev_type)
300 score |= 2;
301 if (score == 0)
302 return t;
303
304 if (score < cand_score) {
305 cand = t;
306 cand_score = score;
307 }
308 }
309
310 if (cand != NULL)
311 return cand;
312
313 dev = ign->fb_tunnel_dev;
314 if (dev->flags & IFF_UP)
315 return netdev_priv(dev);
316
317 return NULL;
318 }
319
320 static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
321 struct ip_tunnel_parm *parms)
322 {
323 __be32 remote = parms->iph.daddr;
324 __be32 local = parms->iph.saddr;
325 __be32 key = parms->i_key;
326 unsigned int h = HASH(key);
327 int prio = 0;
328
329 if (local)
330 prio |= 1;
331 if (remote && !ipv4_is_multicast(remote)) {
332 prio |= 2;
333 h ^= HASH(remote);
334 }
335
336 return &ign->tunnels[prio][h];
337 }
338
339 static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
340 struct ip_tunnel *t)
341 {
342 return __ipgre_bucket(ign, &t->parms);
343 }
344
345 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
346 {
347 struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
348
349 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
350 rcu_assign_pointer(*tp, t);
351 }
352
353 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
354 {
355 struct ip_tunnel __rcu **tp;
356 struct ip_tunnel *iter;
357
358 for (tp = ipgre_bucket(ign, t);
359 (iter = rtnl_dereference(*tp)) != NULL;
360 tp = &iter->next) {
361 if (t == iter) {
362 rcu_assign_pointer(*tp, t->next);
363 break;
364 }
365 }
366 }
367
368 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
369 struct ip_tunnel_parm *parms,
370 int type)
371 {
372 __be32 remote = parms->iph.daddr;
373 __be32 local = parms->iph.saddr;
374 __be32 key = parms->i_key;
375 int link = parms->link;
376 struct ip_tunnel *t;
377 struct ip_tunnel __rcu **tp;
378 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
379
380 for (tp = __ipgre_bucket(ign, parms);
381 (t = rtnl_dereference(*tp)) != NULL;
382 tp = &t->next)
383 if (local == t->parms.iph.saddr &&
384 remote == t->parms.iph.daddr &&
385 key == t->parms.i_key &&
386 link == t->parms.link &&
387 type == t->dev->type)
388 break;
389
390 return t;
391 }
392
393 static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
394 struct ip_tunnel_parm *parms, int create)
395 {
396 struct ip_tunnel *t, *nt;
397 struct net_device *dev;
398 char name[IFNAMSIZ];
399 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
400
401 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
402 if (t || !create)
403 return t;
404
405 if (parms->name[0])
406 strlcpy(name, parms->name, IFNAMSIZ);
407 else
408 sprintf(name, "gre%%d");
409
410 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
411 if (!dev)
412 return NULL;
413
414 dev_net_set(dev, net);
415
416 if (strchr(name, '%')) {
417 if (dev_alloc_name(dev, name) < 0)
418 goto failed_free;
419 }
420
421 nt = netdev_priv(dev);
422 nt->parms = *parms;
423 dev->rtnl_link_ops = &ipgre_link_ops;
424
425 dev->mtu = ipgre_tunnel_bind_dev(dev);
426
427 if (register_netdevice(dev) < 0)
428 goto failed_free;
429
430 dev_hold(dev);
431 ipgre_tunnel_link(ign, nt);
432 return nt;
433
434 failed_free:
435 free_netdev(dev);
436 return NULL;
437 }
438
439 static void ipgre_tunnel_uninit(struct net_device *dev)
440 {
441 struct net *net = dev_net(dev);
442 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
443
444 ipgre_tunnel_unlink(ign, netdev_priv(dev));
445 dev_put(dev);
446 }
447
448
449 static void ipgre_err(struct sk_buff *skb, u32 info)
450 {
451
452 /* All the routers (except for Linux) return only
453 8 bytes of packet payload. It means, that precise relaying of
454 ICMP in the real Internet is absolutely infeasible.
455
456 Moreover, Cisco "wise men" put GRE key to the third word
457 in GRE header. It makes impossible maintaining even soft state for keyed
458 GRE tunnels with enabled checksum. Tell them "thank you".
459
460 Well, I wonder, rfc1812 was written by Cisco employee,
461 what the hell these idiots break standrads established
462 by themself???
463 */
464
465 struct iphdr *iph = (struct iphdr *)skb->data;
466 __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
467 int grehlen = (iph->ihl<<2) + 4;
468 const int type = icmp_hdr(skb)->type;
469 const int code = icmp_hdr(skb)->code;
470 struct ip_tunnel *t;
471 __be16 flags;
472
473 flags = p[0];
474 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
475 if (flags&(GRE_VERSION|GRE_ROUTING))
476 return;
477 if (flags&GRE_KEY) {
478 grehlen += 4;
479 if (flags&GRE_CSUM)
480 grehlen += 4;
481 }
482 }
483
484 /* If only 8 bytes returned, keyed message will be dropped here */
485 if (skb_headlen(skb) < grehlen)
486 return;
487
488 switch (type) {
489 default:
490 case ICMP_PARAMETERPROB:
491 return;
492
493 case ICMP_DEST_UNREACH:
494 switch (code) {
495 case ICMP_SR_FAILED:
496 case ICMP_PORT_UNREACH:
497 /* Impossible event. */
498 return;
499 case ICMP_FRAG_NEEDED:
500 /* Soft state for pmtu is maintained by IP core. */
501 return;
502 default:
503 /* All others are translated to HOST_UNREACH.
504 rfc2003 contains "deep thoughts" about NET_UNREACH,
505 I believe they are just ether pollution. --ANK
506 */
507 break;
508 }
509 break;
510 case ICMP_TIME_EXCEEDED:
511 if (code != ICMP_EXC_TTL)
512 return;
513 break;
514 }
515
516 rcu_read_lock();
517 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
518 flags & GRE_KEY ?
519 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
520 p[1]);
521 if (t == NULL || t->parms.iph.daddr == 0 ||
522 ipv4_is_multicast(t->parms.iph.daddr))
523 goto out;
524
525 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
526 goto out;
527
528 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
529 t->err_count++;
530 else
531 t->err_count = 1;
532 t->err_time = jiffies;
533 out:
534 rcu_read_unlock();
535 }
536
537 static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
538 {
539 if (INET_ECN_is_ce(iph->tos)) {
540 if (skb->protocol == htons(ETH_P_IP)) {
541 IP_ECN_set_ce(ip_hdr(skb));
542 } else if (skb->protocol == htons(ETH_P_IPV6)) {
543 IP6_ECN_set_ce(ipv6_hdr(skb));
544 }
545 }
546 }
547
548 static inline u8
549 ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
550 {
551 u8 inner = 0;
552 if (skb->protocol == htons(ETH_P_IP))
553 inner = old_iph->tos;
554 else if (skb->protocol == htons(ETH_P_IPV6))
555 inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
556 return INET_ECN_encapsulate(tos, inner);
557 }
558
559 static int ipgre_rcv(struct sk_buff *skb)
560 {
561 struct iphdr *iph;
562 u8 *h;
563 __be16 flags;
564 __sum16 csum = 0;
565 __be32 key = 0;
566 u32 seqno = 0;
567 struct ip_tunnel *tunnel;
568 int offset = 4;
569 __be16 gre_proto;
570
571 if (!pskb_may_pull(skb, 16))
572 goto drop_nolock;
573
574 iph = ip_hdr(skb);
575 h = skb->data;
576 flags = *(__be16*)h;
577
578 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
579 /* - Version must be 0.
580 - We do not support routing headers.
581 */
582 if (flags&(GRE_VERSION|GRE_ROUTING))
583 goto drop_nolock;
584
585 if (flags&GRE_CSUM) {
586 switch (skb->ip_summed) {
587 case CHECKSUM_COMPLETE:
588 csum = csum_fold(skb->csum);
589 if (!csum)
590 break;
591 /* fall through */
592 case CHECKSUM_NONE:
593 skb->csum = 0;
594 csum = __skb_checksum_complete(skb);
595 skb->ip_summed = CHECKSUM_COMPLETE;
596 }
597 offset += 4;
598 }
599 if (flags&GRE_KEY) {
600 key = *(__be32*)(h + offset);
601 offset += 4;
602 }
603 if (flags&GRE_SEQ) {
604 seqno = ntohl(*(__be32*)(h + offset));
605 offset += 4;
606 }
607 }
608
609 gre_proto = *(__be16 *)(h + 2);
610
611 rcu_read_lock();
612 if ((tunnel = ipgre_tunnel_lookup(skb->dev,
613 iph->saddr, iph->daddr, key,
614 gre_proto))) {
615 struct pcpu_tstats *tstats;
616
617 secpath_reset(skb);
618
619 skb->protocol = gre_proto;
620 /* WCCP version 1 and 2 protocol decoding.
621 * - Change protocol to IP
622 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
623 */
624 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
625 skb->protocol = htons(ETH_P_IP);
626 if ((*(h + offset) & 0xF0) != 0x40)
627 offset += 4;
628 }
629
630 skb->mac_header = skb->network_header;
631 __pskb_pull(skb, offset);
632 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
633 skb->pkt_type = PACKET_HOST;
634 #ifdef CONFIG_NET_IPGRE_BROADCAST
635 if (ipv4_is_multicast(iph->daddr)) {
636 /* Looped back packet, drop it! */
637 if (skb_rtable(skb)->fl.iif == 0)
638 goto drop;
639 tunnel->dev->stats.multicast++;
640 skb->pkt_type = PACKET_BROADCAST;
641 }
642 #endif
643
644 if (((flags&GRE_CSUM) && csum) ||
645 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
646 tunnel->dev->stats.rx_crc_errors++;
647 tunnel->dev->stats.rx_errors++;
648 goto drop;
649 }
650 if (tunnel->parms.i_flags&GRE_SEQ) {
651 if (!(flags&GRE_SEQ) ||
652 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
653 tunnel->dev->stats.rx_fifo_errors++;
654 tunnel->dev->stats.rx_errors++;
655 goto drop;
656 }
657 tunnel->i_seqno = seqno + 1;
658 }
659
660 /* Warning: All skb pointers will be invalidated! */
661 if (tunnel->dev->type == ARPHRD_ETHER) {
662 if (!pskb_may_pull(skb, ETH_HLEN)) {
663 tunnel->dev->stats.rx_length_errors++;
664 tunnel->dev->stats.rx_errors++;
665 goto drop;
666 }
667
668 iph = ip_hdr(skb);
669 skb->protocol = eth_type_trans(skb, tunnel->dev);
670 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
671 }
672
673 tstats = this_cpu_ptr(tunnel->dev->tstats);
674 tstats->rx_packets++;
675 tstats->rx_bytes += skb->len;
676
677 __skb_tunnel_rx(skb, tunnel->dev);
678
679 skb_reset_network_header(skb);
680 ipgre_ecn_decapsulate(iph, skb);
681
682 netif_rx(skb);
683
684 rcu_read_unlock();
685 return 0;
686 }
687 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
688
689 drop:
690 rcu_read_unlock();
691 drop_nolock:
692 kfree_skb(skb);
693 return 0;
694 }
695
696 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
697 {
698 struct ip_tunnel *tunnel = netdev_priv(dev);
699 struct pcpu_tstats *tstats;
700 struct iphdr *old_iph = ip_hdr(skb);
701 struct iphdr *tiph;
702 u8 tos;
703 __be16 df;
704 struct rtable *rt; /* Route to the other host */
705 struct net_device *tdev; /* Device to other host */
706 struct iphdr *iph; /* Our new IP header */
707 unsigned int max_headroom; /* The extra header space needed */
708 int gre_hlen;
709 __be32 dst;
710 int mtu;
711
712 if (dev->type == ARPHRD_ETHER)
713 IPCB(skb)->flags = 0;
714
715 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
716 gre_hlen = 0;
717 tiph = (struct iphdr *)skb->data;
718 } else {
719 gre_hlen = tunnel->hlen;
720 tiph = &tunnel->parms.iph;
721 }
722
723 if ((dst = tiph->daddr) == 0) {
724 /* NBMA tunnel */
725
726 if (skb_dst(skb) == NULL) {
727 dev->stats.tx_fifo_errors++;
728 goto tx_error;
729 }
730
731 if (skb->protocol == htons(ETH_P_IP)) {
732 rt = skb_rtable(skb);
733 if ((dst = rt->rt_gateway) == 0)
734 goto tx_error_icmp;
735 }
736 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
737 else if (skb->protocol == htons(ETH_P_IPV6)) {
738 struct in6_addr *addr6;
739 int addr_type;
740 struct neighbour *neigh = skb_dst(skb)->neighbour;
741
742 if (neigh == NULL)
743 goto tx_error;
744
745 addr6 = (struct in6_addr *)&neigh->primary_key;
746 addr_type = ipv6_addr_type(addr6);
747
748 if (addr_type == IPV6_ADDR_ANY) {
749 addr6 = &ipv6_hdr(skb)->daddr;
750 addr_type = ipv6_addr_type(addr6);
751 }
752
753 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
754 goto tx_error_icmp;
755
756 dst = addr6->s6_addr32[3];
757 }
758 #endif
759 else
760 goto tx_error;
761 }
762
763 tos = tiph->tos;
764 if (tos == 1) {
765 tos = 0;
766 if (skb->protocol == htons(ETH_P_IP))
767 tos = old_iph->tos;
768 else if (skb->protocol == htons(ETH_P_IPV6))
769 tos = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
770 }
771
772 {
773 struct flowi fl = {
774 .oif = tunnel->parms.link,
775 .nl_u = {
776 .ip4_u = {
777 .daddr = dst,
778 .saddr = tiph->saddr,
779 .tos = RT_TOS(tos)
780 }
781 },
782 .proto = IPPROTO_GRE
783 }
784 ;
785 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
786 dev->stats.tx_carrier_errors++;
787 goto tx_error;
788 }
789 }
790 tdev = rt->dst.dev;
791
792 if (tdev == dev) {
793 ip_rt_put(rt);
794 dev->stats.collisions++;
795 goto tx_error;
796 }
797
798 df = tiph->frag_off;
799 if (df)
800 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
801 else
802 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
803
804 if (skb_dst(skb))
805 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
806
807 if (skb->protocol == htons(ETH_P_IP)) {
808 df |= (old_iph->frag_off&htons(IP_DF));
809
810 if ((old_iph->frag_off&htons(IP_DF)) &&
811 mtu < ntohs(old_iph->tot_len)) {
812 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
813 ip_rt_put(rt);
814 goto tx_error;
815 }
816 }
817 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
818 else if (skb->protocol == htons(ETH_P_IPV6)) {
819 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
820
821 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
822 if ((tunnel->parms.iph.daddr &&
823 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
824 rt6->rt6i_dst.plen == 128) {
825 rt6->rt6i_flags |= RTF_MODIFIED;
826 skb_dst(skb)->metrics[RTAX_MTU-1] = mtu;
827 }
828 }
829
830 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
831 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
832 ip_rt_put(rt);
833 goto tx_error;
834 }
835 }
836 #endif
837
838 if (tunnel->err_count > 0) {
839 if (time_before(jiffies,
840 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
841 tunnel->err_count--;
842
843 dst_link_failure(skb);
844 } else
845 tunnel->err_count = 0;
846 }
847
848 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
849
850 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
851 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
852 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
853 if (max_headroom > dev->needed_headroom)
854 dev->needed_headroom = max_headroom;
855 if (!new_skb) {
856 ip_rt_put(rt);
857 dev->stats.tx_dropped++;
858 dev_kfree_skb(skb);
859 return NETDEV_TX_OK;
860 }
861 if (skb->sk)
862 skb_set_owner_w(new_skb, skb->sk);
863 dev_kfree_skb(skb);
864 skb = new_skb;
865 old_iph = ip_hdr(skb);
866 }
867
868 skb_reset_transport_header(skb);
869 skb_push(skb, gre_hlen);
870 skb_reset_network_header(skb);
871 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
872 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
873 IPSKB_REROUTED);
874 skb_dst_drop(skb);
875 skb_dst_set(skb, &rt->dst);
876
877 /*
878 * Push down and install the IPIP header.
879 */
880
881 iph = ip_hdr(skb);
882 iph->version = 4;
883 iph->ihl = sizeof(struct iphdr) >> 2;
884 iph->frag_off = df;
885 iph->protocol = IPPROTO_GRE;
886 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
887 iph->daddr = rt->rt_dst;
888 iph->saddr = rt->rt_src;
889
890 if ((iph->ttl = tiph->ttl) == 0) {
891 if (skb->protocol == htons(ETH_P_IP))
892 iph->ttl = old_iph->ttl;
893 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
894 else if (skb->protocol == htons(ETH_P_IPV6))
895 iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
896 #endif
897 else
898 iph->ttl = dst_metric(&rt->dst, RTAX_HOPLIMIT);
899 }
900
901 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
902 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
903 htons(ETH_P_TEB) : skb->protocol;
904
905 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
906 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
907
908 if (tunnel->parms.o_flags&GRE_SEQ) {
909 ++tunnel->o_seqno;
910 *ptr = htonl(tunnel->o_seqno);
911 ptr--;
912 }
913 if (tunnel->parms.o_flags&GRE_KEY) {
914 *ptr = tunnel->parms.o_key;
915 ptr--;
916 }
917 if (tunnel->parms.o_flags&GRE_CSUM) {
918 *ptr = 0;
919 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
920 }
921 }
922
923 nf_reset(skb);
924 tstats = this_cpu_ptr(dev->tstats);
925 __IPTUNNEL_XMIT(tstats, &dev->stats);
926 return NETDEV_TX_OK;
927
928 tx_error_icmp:
929 dst_link_failure(skb);
930
931 tx_error:
932 dev->stats.tx_errors++;
933 dev_kfree_skb(skb);
934 return NETDEV_TX_OK;
935 }
936
937 static int ipgre_tunnel_bind_dev(struct net_device *dev)
938 {
939 struct net_device *tdev = NULL;
940 struct ip_tunnel *tunnel;
941 struct iphdr *iph;
942 int hlen = LL_MAX_HEADER;
943 int mtu = ETH_DATA_LEN;
944 int addend = sizeof(struct iphdr) + 4;
945
946 tunnel = netdev_priv(dev);
947 iph = &tunnel->parms.iph;
948
949 /* Guess output device to choose reasonable mtu and needed_headroom */
950
951 if (iph->daddr) {
952 struct flowi fl = {
953 .oif = tunnel->parms.link,
954 .nl_u = {
955 .ip4_u = {
956 .daddr = iph->daddr,
957 .saddr = iph->saddr,
958 .tos = RT_TOS(iph->tos)
959 }
960 },
961 .proto = IPPROTO_GRE
962 };
963 struct rtable *rt;
964
965 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
966 tdev = rt->dst.dev;
967 ip_rt_put(rt);
968 }
969
970 if (dev->type != ARPHRD_ETHER)
971 dev->flags |= IFF_POINTOPOINT;
972 }
973
974 if (!tdev && tunnel->parms.link)
975 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
976
977 if (tdev) {
978 hlen = tdev->hard_header_len + tdev->needed_headroom;
979 mtu = tdev->mtu;
980 }
981 dev->iflink = tunnel->parms.link;
982
983 /* Precalculate GRE options length */
984 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
985 if (tunnel->parms.o_flags&GRE_CSUM)
986 addend += 4;
987 if (tunnel->parms.o_flags&GRE_KEY)
988 addend += 4;
989 if (tunnel->parms.o_flags&GRE_SEQ)
990 addend += 4;
991 }
992 dev->needed_headroom = addend + hlen;
993 mtu -= dev->hard_header_len + addend;
994
995 if (mtu < 68)
996 mtu = 68;
997
998 tunnel->hlen = addend;
999
1000 return mtu;
1001 }
1002
1003 static int
1004 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1005 {
1006 int err = 0;
1007 struct ip_tunnel_parm p;
1008 struct ip_tunnel *t;
1009 struct net *net = dev_net(dev);
1010 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1011
1012 switch (cmd) {
1013 case SIOCGETTUNNEL:
1014 t = NULL;
1015 if (dev == ign->fb_tunnel_dev) {
1016 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1017 err = -EFAULT;
1018 break;
1019 }
1020 t = ipgre_tunnel_locate(net, &p, 0);
1021 }
1022 if (t == NULL)
1023 t = netdev_priv(dev);
1024 memcpy(&p, &t->parms, sizeof(p));
1025 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1026 err = -EFAULT;
1027 break;
1028
1029 case SIOCADDTUNNEL:
1030 case SIOCCHGTUNNEL:
1031 err = -EPERM;
1032 if (!capable(CAP_NET_ADMIN))
1033 goto done;
1034
1035 err = -EFAULT;
1036 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1037 goto done;
1038
1039 err = -EINVAL;
1040 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1041 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1042 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1043 goto done;
1044 if (p.iph.ttl)
1045 p.iph.frag_off |= htons(IP_DF);
1046
1047 if (!(p.i_flags&GRE_KEY))
1048 p.i_key = 0;
1049 if (!(p.o_flags&GRE_KEY))
1050 p.o_key = 0;
1051
1052 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1053
1054 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1055 if (t != NULL) {
1056 if (t->dev != dev) {
1057 err = -EEXIST;
1058 break;
1059 }
1060 } else {
1061 unsigned int nflags = 0;
1062
1063 t = netdev_priv(dev);
1064
1065 if (ipv4_is_multicast(p.iph.daddr))
1066 nflags = IFF_BROADCAST;
1067 else if (p.iph.daddr)
1068 nflags = IFF_POINTOPOINT;
1069
1070 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1071 err = -EINVAL;
1072 break;
1073 }
1074 ipgre_tunnel_unlink(ign, t);
1075 t->parms.iph.saddr = p.iph.saddr;
1076 t->parms.iph.daddr = p.iph.daddr;
1077 t->parms.i_key = p.i_key;
1078 t->parms.o_key = p.o_key;
1079 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1080 memcpy(dev->broadcast, &p.iph.daddr, 4);
1081 ipgre_tunnel_link(ign, t);
1082 netdev_state_change(dev);
1083 }
1084 }
1085
1086 if (t) {
1087 err = 0;
1088 if (cmd == SIOCCHGTUNNEL) {
1089 t->parms.iph.ttl = p.iph.ttl;
1090 t->parms.iph.tos = p.iph.tos;
1091 t->parms.iph.frag_off = p.iph.frag_off;
1092 if (t->parms.link != p.link) {
1093 t->parms.link = p.link;
1094 dev->mtu = ipgre_tunnel_bind_dev(dev);
1095 netdev_state_change(dev);
1096 }
1097 }
1098 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1099 err = -EFAULT;
1100 } else
1101 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1102 break;
1103
1104 case SIOCDELTUNNEL:
1105 err = -EPERM;
1106 if (!capable(CAP_NET_ADMIN))
1107 goto done;
1108
1109 if (dev == ign->fb_tunnel_dev) {
1110 err = -EFAULT;
1111 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1112 goto done;
1113 err = -ENOENT;
1114 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1115 goto done;
1116 err = -EPERM;
1117 if (t == netdev_priv(ign->fb_tunnel_dev))
1118 goto done;
1119 dev = t->dev;
1120 }
1121 unregister_netdevice(dev);
1122 err = 0;
1123 break;
1124
1125 default:
1126 err = -EINVAL;
1127 }
1128
1129 done:
1130 return err;
1131 }
1132
1133 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1134 {
1135 struct ip_tunnel *tunnel = netdev_priv(dev);
1136 if (new_mtu < 68 ||
1137 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1138 return -EINVAL;
1139 dev->mtu = new_mtu;
1140 return 0;
1141 }
1142
1143 /* Nice toy. Unfortunately, useless in real life :-)
1144 It allows to construct virtual multiprotocol broadcast "LAN"
1145 over the Internet, provided multicast routing is tuned.
1146
1147
1148 I have no idea was this bicycle invented before me,
1149 so that I had to set ARPHRD_IPGRE to a random value.
1150 I have an impression, that Cisco could make something similar,
1151 but this feature is apparently missing in IOS<=11.2(8).
1152
1153 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1154 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1155
1156 ping -t 255 224.66.66.66
1157
1158 If nobody answers, mbone does not work.
1159
1160 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1161 ip addr add 10.66.66.<somewhat>/24 dev Universe
1162 ifconfig Universe up
1163 ifconfig Universe add fe80::<Your_real_addr>/10
1164 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1165 ftp 10.66.66.66
1166 ...
1167 ftp fec0:6666:6666::193.233.7.65
1168 ...
1169
1170 */
1171
1172 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1173 unsigned short type,
1174 const void *daddr, const void *saddr, unsigned int len)
1175 {
1176 struct ip_tunnel *t = netdev_priv(dev);
1177 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1178 __be16 *p = (__be16*)(iph+1);
1179
1180 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1181 p[0] = t->parms.o_flags;
1182 p[1] = htons(type);
1183
1184 /*
1185 * Set the source hardware address.
1186 */
1187
1188 if (saddr)
1189 memcpy(&iph->saddr, saddr, 4);
1190 if (daddr)
1191 memcpy(&iph->daddr, daddr, 4);
1192 if (iph->daddr)
1193 return t->hlen;
1194
1195 return -t->hlen;
1196 }
1197
1198 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1199 {
1200 struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
1201 memcpy(haddr, &iph->saddr, 4);
1202 return 4;
1203 }
1204
1205 static const struct header_ops ipgre_header_ops = {
1206 .create = ipgre_header,
1207 .parse = ipgre_header_parse,
1208 };
1209
1210 #ifdef CONFIG_NET_IPGRE_BROADCAST
1211 static int ipgre_open(struct net_device *dev)
1212 {
1213 struct ip_tunnel *t = netdev_priv(dev);
1214
1215 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1216 struct flowi fl = {
1217 .oif = t->parms.link,
1218 .nl_u = {
1219 .ip4_u = {
1220 .daddr = t->parms.iph.daddr,
1221 .saddr = t->parms.iph.saddr,
1222 .tos = RT_TOS(t->parms.iph.tos)
1223 }
1224 },
1225 .proto = IPPROTO_GRE
1226 };
1227 struct rtable *rt;
1228
1229 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1230 return -EADDRNOTAVAIL;
1231 dev = rt->dst.dev;
1232 ip_rt_put(rt);
1233 if (__in_dev_get_rtnl(dev) == NULL)
1234 return -EADDRNOTAVAIL;
1235 t->mlink = dev->ifindex;
1236 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1237 }
1238 return 0;
1239 }
1240
1241 static int ipgre_close(struct net_device *dev)
1242 {
1243 struct ip_tunnel *t = netdev_priv(dev);
1244
1245 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1246 struct in_device *in_dev;
1247 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1248 if (in_dev)
1249 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1250 }
1251 return 0;
1252 }
1253
1254 #endif
1255
1256 static const struct net_device_ops ipgre_netdev_ops = {
1257 .ndo_init = ipgre_tunnel_init,
1258 .ndo_uninit = ipgre_tunnel_uninit,
1259 #ifdef CONFIG_NET_IPGRE_BROADCAST
1260 .ndo_open = ipgre_open,
1261 .ndo_stop = ipgre_close,
1262 #endif
1263 .ndo_start_xmit = ipgre_tunnel_xmit,
1264 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1265 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1266 .ndo_get_stats = ipgre_get_stats,
1267 };
1268
1269 static void ipgre_dev_free(struct net_device *dev)
1270 {
1271 free_percpu(dev->tstats);
1272 free_netdev(dev);
1273 }
1274
1275 static void ipgre_tunnel_setup(struct net_device *dev)
1276 {
1277 dev->netdev_ops = &ipgre_netdev_ops;
1278 dev->destructor = ipgre_dev_free;
1279
1280 dev->type = ARPHRD_IPGRE;
1281 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1282 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1283 dev->flags = IFF_NOARP;
1284 dev->iflink = 0;
1285 dev->addr_len = 4;
1286 dev->features |= NETIF_F_NETNS_LOCAL;
1287 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1288 }
1289
1290 static int ipgre_tunnel_init(struct net_device *dev)
1291 {
1292 struct ip_tunnel *tunnel;
1293 struct iphdr *iph;
1294
1295 tunnel = netdev_priv(dev);
1296 iph = &tunnel->parms.iph;
1297
1298 tunnel->dev = dev;
1299 strcpy(tunnel->parms.name, dev->name);
1300
1301 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1302 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1303
1304 if (iph->daddr) {
1305 #ifdef CONFIG_NET_IPGRE_BROADCAST
1306 if (ipv4_is_multicast(iph->daddr)) {
1307 if (!iph->saddr)
1308 return -EINVAL;
1309 dev->flags = IFF_BROADCAST;
1310 dev->header_ops = &ipgre_header_ops;
1311 }
1312 #endif
1313 } else
1314 dev->header_ops = &ipgre_header_ops;
1315
1316 dev->tstats = alloc_percpu(struct pcpu_tstats);
1317 if (!dev->tstats)
1318 return -ENOMEM;
1319
1320 return 0;
1321 }
1322
1323 static void ipgre_fb_tunnel_init(struct net_device *dev)
1324 {
1325 struct ip_tunnel *tunnel = netdev_priv(dev);
1326 struct iphdr *iph = &tunnel->parms.iph;
1327 struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
1328
1329 tunnel->dev = dev;
1330 strcpy(tunnel->parms.name, dev->name);
1331
1332 iph->version = 4;
1333 iph->protocol = IPPROTO_GRE;
1334 iph->ihl = 5;
1335 tunnel->hlen = sizeof(struct iphdr) + 4;
1336
1337 dev_hold(dev);
1338 rcu_assign_pointer(ign->tunnels_wc[0], tunnel);
1339 }
1340
1341
1342 static const struct gre_protocol ipgre_protocol = {
1343 .handler = ipgre_rcv,
1344 .err_handler = ipgre_err,
1345 };
1346
1347 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1348 {
1349 int prio;
1350
1351 for (prio = 0; prio < 4; prio++) {
1352 int h;
1353 for (h = 0; h < HASH_SIZE; h++) {
1354 struct ip_tunnel *t;
1355
1356 t = rtnl_dereference(ign->tunnels[prio][h]);
1357
1358 while (t != NULL) {
1359 unregister_netdevice_queue(t->dev, head);
1360 t = rtnl_dereference(t->next);
1361 }
1362 }
1363 }
1364 }
1365
1366 static int __net_init ipgre_init_net(struct net *net)
1367 {
1368 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1369 int err;
1370
1371 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1372 ipgre_tunnel_setup);
1373 if (!ign->fb_tunnel_dev) {
1374 err = -ENOMEM;
1375 goto err_alloc_dev;
1376 }
1377 dev_net_set(ign->fb_tunnel_dev, net);
1378
1379 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1380 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1381
1382 if ((err = register_netdev(ign->fb_tunnel_dev)))
1383 goto err_reg_dev;
1384
1385 return 0;
1386
1387 err_reg_dev:
1388 free_netdev(ign->fb_tunnel_dev);
1389 err_alloc_dev:
1390 return err;
1391 }
1392
1393 static void __net_exit ipgre_exit_net(struct net *net)
1394 {
1395 struct ipgre_net *ign;
1396 LIST_HEAD(list);
1397
1398 ign = net_generic(net, ipgre_net_id);
1399 rtnl_lock();
1400 ipgre_destroy_tunnels(ign, &list);
1401 unregister_netdevice_many(&list);
1402 rtnl_unlock();
1403 }
1404
1405 static struct pernet_operations ipgre_net_ops = {
1406 .init = ipgre_init_net,
1407 .exit = ipgre_exit_net,
1408 .id = &ipgre_net_id,
1409 .size = sizeof(struct ipgre_net),
1410 };
1411
1412 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1413 {
1414 __be16 flags;
1415
1416 if (!data)
1417 return 0;
1418
1419 flags = 0;
1420 if (data[IFLA_GRE_IFLAGS])
1421 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1422 if (data[IFLA_GRE_OFLAGS])
1423 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1424 if (flags & (GRE_VERSION|GRE_ROUTING))
1425 return -EINVAL;
1426
1427 return 0;
1428 }
1429
1430 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1431 {
1432 __be32 daddr;
1433
1434 if (tb[IFLA_ADDRESS]) {
1435 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1436 return -EINVAL;
1437 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1438 return -EADDRNOTAVAIL;
1439 }
1440
1441 if (!data)
1442 goto out;
1443
1444 if (data[IFLA_GRE_REMOTE]) {
1445 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1446 if (!daddr)
1447 return -EINVAL;
1448 }
1449
1450 out:
1451 return ipgre_tunnel_validate(tb, data);
1452 }
1453
1454 static void ipgre_netlink_parms(struct nlattr *data[],
1455 struct ip_tunnel_parm *parms)
1456 {
1457 memset(parms, 0, sizeof(*parms));
1458
1459 parms->iph.protocol = IPPROTO_GRE;
1460
1461 if (!data)
1462 return;
1463
1464 if (data[IFLA_GRE_LINK])
1465 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1466
1467 if (data[IFLA_GRE_IFLAGS])
1468 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1469
1470 if (data[IFLA_GRE_OFLAGS])
1471 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1472
1473 if (data[IFLA_GRE_IKEY])
1474 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1475
1476 if (data[IFLA_GRE_OKEY])
1477 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1478
1479 if (data[IFLA_GRE_LOCAL])
1480 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1481
1482 if (data[IFLA_GRE_REMOTE])
1483 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1484
1485 if (data[IFLA_GRE_TTL])
1486 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1487
1488 if (data[IFLA_GRE_TOS])
1489 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1490
1491 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1492 parms->iph.frag_off = htons(IP_DF);
1493 }
1494
1495 static int ipgre_tap_init(struct net_device *dev)
1496 {
1497 struct ip_tunnel *tunnel;
1498
1499 tunnel = netdev_priv(dev);
1500
1501 tunnel->dev = dev;
1502 strcpy(tunnel->parms.name, dev->name);
1503
1504 ipgre_tunnel_bind_dev(dev);
1505
1506 dev->tstats = alloc_percpu(struct pcpu_tstats);
1507 if (!dev->tstats)
1508 return -ENOMEM;
1509
1510 return 0;
1511 }
1512
1513 static const struct net_device_ops ipgre_tap_netdev_ops = {
1514 .ndo_init = ipgre_tap_init,
1515 .ndo_uninit = ipgre_tunnel_uninit,
1516 .ndo_start_xmit = ipgre_tunnel_xmit,
1517 .ndo_set_mac_address = eth_mac_addr,
1518 .ndo_validate_addr = eth_validate_addr,
1519 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1520 .ndo_get_stats = ipgre_get_stats,
1521 };
1522
1523 static void ipgre_tap_setup(struct net_device *dev)
1524 {
1525
1526 ether_setup(dev);
1527
1528 dev->netdev_ops = &ipgre_tap_netdev_ops;
1529 dev->destructor = ipgre_dev_free;
1530
1531 dev->iflink = 0;
1532 dev->features |= NETIF_F_NETNS_LOCAL;
1533 }
1534
1535 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1536 struct nlattr *data[])
1537 {
1538 struct ip_tunnel *nt;
1539 struct net *net = dev_net(dev);
1540 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1541 int mtu;
1542 int err;
1543
1544 nt = netdev_priv(dev);
1545 ipgre_netlink_parms(data, &nt->parms);
1546
1547 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1548 return -EEXIST;
1549
1550 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1551 random_ether_addr(dev->dev_addr);
1552
1553 mtu = ipgre_tunnel_bind_dev(dev);
1554 if (!tb[IFLA_MTU])
1555 dev->mtu = mtu;
1556
1557 /* Can use a lockless transmit, unless we generate output sequences */
1558 if (!(nt->parms.o_flags & GRE_SEQ))
1559 dev->features |= NETIF_F_LLTX;
1560
1561 err = register_netdevice(dev);
1562 if (err)
1563 goto out;
1564
1565 dev_hold(dev);
1566 ipgre_tunnel_link(ign, nt);
1567
1568 out:
1569 return err;
1570 }
1571
1572 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1573 struct nlattr *data[])
1574 {
1575 struct ip_tunnel *t, *nt;
1576 struct net *net = dev_net(dev);
1577 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1578 struct ip_tunnel_parm p;
1579 int mtu;
1580
1581 if (dev == ign->fb_tunnel_dev)
1582 return -EINVAL;
1583
1584 nt = netdev_priv(dev);
1585 ipgre_netlink_parms(data, &p);
1586
1587 t = ipgre_tunnel_locate(net, &p, 0);
1588
1589 if (t) {
1590 if (t->dev != dev)
1591 return -EEXIST;
1592 } else {
1593 t = nt;
1594
1595 if (dev->type != ARPHRD_ETHER) {
1596 unsigned int nflags = 0;
1597
1598 if (ipv4_is_multicast(p.iph.daddr))
1599 nflags = IFF_BROADCAST;
1600 else if (p.iph.daddr)
1601 nflags = IFF_POINTOPOINT;
1602
1603 if ((dev->flags ^ nflags) &
1604 (IFF_POINTOPOINT | IFF_BROADCAST))
1605 return -EINVAL;
1606 }
1607
1608 ipgre_tunnel_unlink(ign, t);
1609 t->parms.iph.saddr = p.iph.saddr;
1610 t->parms.iph.daddr = p.iph.daddr;
1611 t->parms.i_key = p.i_key;
1612 if (dev->type != ARPHRD_ETHER) {
1613 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1614 memcpy(dev->broadcast, &p.iph.daddr, 4);
1615 }
1616 ipgre_tunnel_link(ign, t);
1617 netdev_state_change(dev);
1618 }
1619
1620 t->parms.o_key = p.o_key;
1621 t->parms.iph.ttl = p.iph.ttl;
1622 t->parms.iph.tos = p.iph.tos;
1623 t->parms.iph.frag_off = p.iph.frag_off;
1624
1625 if (t->parms.link != p.link) {
1626 t->parms.link = p.link;
1627 mtu = ipgre_tunnel_bind_dev(dev);
1628 if (!tb[IFLA_MTU])
1629 dev->mtu = mtu;
1630 netdev_state_change(dev);
1631 }
1632
1633 return 0;
1634 }
1635
1636 static size_t ipgre_get_size(const struct net_device *dev)
1637 {
1638 return
1639 /* IFLA_GRE_LINK */
1640 nla_total_size(4) +
1641 /* IFLA_GRE_IFLAGS */
1642 nla_total_size(2) +
1643 /* IFLA_GRE_OFLAGS */
1644 nla_total_size(2) +
1645 /* IFLA_GRE_IKEY */
1646 nla_total_size(4) +
1647 /* IFLA_GRE_OKEY */
1648 nla_total_size(4) +
1649 /* IFLA_GRE_LOCAL */
1650 nla_total_size(4) +
1651 /* IFLA_GRE_REMOTE */
1652 nla_total_size(4) +
1653 /* IFLA_GRE_TTL */
1654 nla_total_size(1) +
1655 /* IFLA_GRE_TOS */
1656 nla_total_size(1) +
1657 /* IFLA_GRE_PMTUDISC */
1658 nla_total_size(1) +
1659 0;
1660 }
1661
1662 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1663 {
1664 struct ip_tunnel *t = netdev_priv(dev);
1665 struct ip_tunnel_parm *p = &t->parms;
1666
1667 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1668 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1669 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1670 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1671 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1672 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1673 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1674 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1675 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1676 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1677
1678 return 0;
1679
1680 nla_put_failure:
1681 return -EMSGSIZE;
1682 }
1683
1684 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1685 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1686 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1687 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1688 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1689 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1690 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1691 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1692 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1693 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1694 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1695 };
1696
1697 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1698 .kind = "gre",
1699 .maxtype = IFLA_GRE_MAX,
1700 .policy = ipgre_policy,
1701 .priv_size = sizeof(struct ip_tunnel),
1702 .setup = ipgre_tunnel_setup,
1703 .validate = ipgre_tunnel_validate,
1704 .newlink = ipgre_newlink,
1705 .changelink = ipgre_changelink,
1706 .get_size = ipgre_get_size,
1707 .fill_info = ipgre_fill_info,
1708 };
1709
1710 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1711 .kind = "gretap",
1712 .maxtype = IFLA_GRE_MAX,
1713 .policy = ipgre_policy,
1714 .priv_size = sizeof(struct ip_tunnel),
1715 .setup = ipgre_tap_setup,
1716 .validate = ipgre_tap_validate,
1717 .newlink = ipgre_newlink,
1718 .changelink = ipgre_changelink,
1719 .get_size = ipgre_get_size,
1720 .fill_info = ipgre_fill_info,
1721 };
1722
1723 /*
1724 * And now the modules code and kernel interface.
1725 */
1726
1727 static int __init ipgre_init(void)
1728 {
1729 int err;
1730
1731 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1732
1733 err = register_pernet_device(&ipgre_net_ops);
1734 if (err < 0)
1735 return err;
1736
1737 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1738 if (err < 0) {
1739 printk(KERN_INFO "ipgre init: can't add protocol\n");
1740 goto add_proto_failed;
1741 }
1742
1743 err = rtnl_link_register(&ipgre_link_ops);
1744 if (err < 0)
1745 goto rtnl_link_failed;
1746
1747 err = rtnl_link_register(&ipgre_tap_ops);
1748 if (err < 0)
1749 goto tap_ops_failed;
1750
1751 out:
1752 return err;
1753
1754 tap_ops_failed:
1755 rtnl_link_unregister(&ipgre_link_ops);
1756 rtnl_link_failed:
1757 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1758 add_proto_failed:
1759 unregister_pernet_device(&ipgre_net_ops);
1760 goto out;
1761 }
1762
1763 static void __exit ipgre_fini(void)
1764 {
1765 rtnl_link_unregister(&ipgre_tap_ops);
1766 rtnl_link_unregister(&ipgre_link_ops);
1767 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1768 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1769 unregister_pernet_device(&ipgre_net_ops);
1770 }
1771
1772 module_init(ipgre_init);
1773 module_exit(ipgre_fini);
1774 MODULE_LICENSE("GPL");
1775 MODULE_ALIAS_RTNL_LINK("gre");
1776 MODULE_ALIAS_RTNL_LINK("gretap");
Linux kernel - Deliverables
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