?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
drivers/net/usb: Update WARN uses
[linux-2.6.git] / net / ipv4 / ip_gre.c
blob70ff77f02eee3b345fa94efd35563a95b2b582ef
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 synchronize_net();
1076 t->parms.iph.saddr = p.iph.saddr;
1077 t->parms.iph.daddr = p.iph.daddr;
1078 t->parms.i_key = p.i_key;
1079 t->parms.o_key = p.o_key;
1080 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1081 memcpy(dev->broadcast, &p.iph.daddr, 4);
1082 ipgre_tunnel_link(ign, t);
1083 netdev_state_change(dev);
1084 }
1085 }
1086
1087 if (t) {
1088 err = 0;
1089 if (cmd == SIOCCHGTUNNEL) {
1090 t->parms.iph.ttl = p.iph.ttl;
1091 t->parms.iph.tos = p.iph.tos;
1092 t->parms.iph.frag_off = p.iph.frag_off;
1093 if (t->parms.link != p.link) {
1094 t->parms.link = p.link;
1095 dev->mtu = ipgre_tunnel_bind_dev(dev);
1096 netdev_state_change(dev);
1097 }
1098 }
1099 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1100 err = -EFAULT;
1101 } else
1102 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1103 break;
1104
1105 case SIOCDELTUNNEL:
1106 err = -EPERM;
1107 if (!capable(CAP_NET_ADMIN))
1108 goto done;
1109
1110 if (dev == ign->fb_tunnel_dev) {
1111 err = -EFAULT;
1112 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1113 goto done;
1114 err = -ENOENT;
1115 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1116 goto done;
1117 err = -EPERM;
1118 if (t == netdev_priv(ign->fb_tunnel_dev))
1119 goto done;
1120 dev = t->dev;
1121 }
1122 unregister_netdevice(dev);
1123 err = 0;
1124 break;
1125
1126 default:
1127 err = -EINVAL;
1128 }
1129
1130 done:
1131 return err;
1132 }
1133
1134 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1135 {
1136 struct ip_tunnel *tunnel = netdev_priv(dev);
1137 if (new_mtu < 68 ||
1138 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1139 return -EINVAL;
1140 dev->mtu = new_mtu;
1141 return 0;
1142 }
1143
1144 /* Nice toy. Unfortunately, useless in real life :-)
1145 It allows to construct virtual multiprotocol broadcast "LAN"
1146 over the Internet, provided multicast routing is tuned.
1147
1148
1149 I have no idea was this bicycle invented before me,
1150 so that I had to set ARPHRD_IPGRE to a random value.
1151 I have an impression, that Cisco could make something similar,
1152 but this feature is apparently missing in IOS<=11.2(8).
1153
1154 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1155 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1156
1157 ping -t 255 224.66.66.66
1158
1159 If nobody answers, mbone does not work.
1160
1161 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1162 ip addr add 10.66.66.<somewhat>/24 dev Universe
1163 ifconfig Universe up
1164 ifconfig Universe add fe80::<Your_real_addr>/10
1165 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1166 ftp 10.66.66.66
1167 ...
1168 ftp fec0:6666:6666::193.233.7.65
1169 ...
1170
1171 */
1172
1173 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1174 unsigned short type,
1175 const void *daddr, const void *saddr, unsigned int len)
1176 {
1177 struct ip_tunnel *t = netdev_priv(dev);
1178 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1179 __be16 *p = (__be16*)(iph+1);
1180
1181 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1182 p[0] = t->parms.o_flags;
1183 p[1] = htons(type);
1184
1185 /*
1186 * Set the source hardware address.
1187 */
1188
1189 if (saddr)
1190 memcpy(&iph->saddr, saddr, 4);
1191 if (daddr)
1192 memcpy(&iph->daddr, daddr, 4);
1193 if (iph->daddr)
1194 return t->hlen;
1195
1196 return -t->hlen;
1197 }
1198
1199 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1200 {
1201 struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
1202 memcpy(haddr, &iph->saddr, 4);
1203 return 4;
1204 }
1205
1206 static const struct header_ops ipgre_header_ops = {
1207 .create = ipgre_header,
1208 .parse = ipgre_header_parse,
1209 };
1210
1211 #ifdef CONFIG_NET_IPGRE_BROADCAST
1212 static int ipgre_open(struct net_device *dev)
1213 {
1214 struct ip_tunnel *t = netdev_priv(dev);
1215
1216 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1217 struct flowi fl = {
1218 .oif = t->parms.link,
1219 .nl_u = {
1220 .ip4_u = {
1221 .daddr = t->parms.iph.daddr,
1222 .saddr = t->parms.iph.saddr,
1223 .tos = RT_TOS(t->parms.iph.tos)
1224 }
1225 },
1226 .proto = IPPROTO_GRE
1227 };
1228 struct rtable *rt;
1229
1230 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1231 return -EADDRNOTAVAIL;
1232 dev = rt->dst.dev;
1233 ip_rt_put(rt);
1234 if (__in_dev_get_rtnl(dev) == NULL)
1235 return -EADDRNOTAVAIL;
1236 t->mlink = dev->ifindex;
1237 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1238 }
1239 return 0;
1240 }
1241
1242 static int ipgre_close(struct net_device *dev)
1243 {
1244 struct ip_tunnel *t = netdev_priv(dev);
1245
1246 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1247 struct in_device *in_dev;
1248 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1249 if (in_dev)
1250 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1251 }
1252 return 0;
1253 }
1254
1255 #endif
1256
1257 static const struct net_device_ops ipgre_netdev_ops = {
1258 .ndo_init = ipgre_tunnel_init,
1259 .ndo_uninit = ipgre_tunnel_uninit,
1260 #ifdef CONFIG_NET_IPGRE_BROADCAST
1261 .ndo_open = ipgre_open,
1262 .ndo_stop = ipgre_close,
1263 #endif
1264 .ndo_start_xmit = ipgre_tunnel_xmit,
1265 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1266 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1267 .ndo_get_stats = ipgre_get_stats,
1268 };
1269
1270 static void ipgre_dev_free(struct net_device *dev)
1271 {
1272 free_percpu(dev->tstats);
1273 free_netdev(dev);
1274 }
1275
1276 static void ipgre_tunnel_setup(struct net_device *dev)
1277 {
1278 dev->netdev_ops = &ipgre_netdev_ops;
1279 dev->destructor = ipgre_dev_free;
1280
1281 dev->type = ARPHRD_IPGRE;
1282 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1283 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1284 dev->flags = IFF_NOARP;
1285 dev->iflink = 0;
1286 dev->addr_len = 4;
1287 dev->features |= NETIF_F_NETNS_LOCAL;
1288 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1289 }
1290
1291 static int ipgre_tunnel_init(struct net_device *dev)
1292 {
1293 struct ip_tunnel *tunnel;
1294 struct iphdr *iph;
1295
1296 tunnel = netdev_priv(dev);
1297 iph = &tunnel->parms.iph;
1298
1299 tunnel->dev = dev;
1300 strcpy(tunnel->parms.name, dev->name);
1301
1302 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1303 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1304
1305 if (iph->daddr) {
1306 #ifdef CONFIG_NET_IPGRE_BROADCAST
1307 if (ipv4_is_multicast(iph->daddr)) {
1308 if (!iph->saddr)
1309 return -EINVAL;
1310 dev->flags = IFF_BROADCAST;
1311 dev->header_ops = &ipgre_header_ops;
1312 }
1313 #endif
1314 } else
1315 dev->header_ops = &ipgre_header_ops;
1316
1317 dev->tstats = alloc_percpu(struct pcpu_tstats);
1318 if (!dev->tstats)
1319 return -ENOMEM;
1320
1321 return 0;
1322 }
1323
1324 static void ipgre_fb_tunnel_init(struct net_device *dev)
1325 {
1326 struct ip_tunnel *tunnel = netdev_priv(dev);
1327 struct iphdr *iph = &tunnel->parms.iph;
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 }
1339
1340
1341 static const struct gre_protocol ipgre_protocol = {
1342 .handler = ipgre_rcv,
1343 .err_handler = ipgre_err,
1344 };
1345
1346 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1347 {
1348 int prio;
1349
1350 for (prio = 0; prio < 4; prio++) {
1351 int h;
1352 for (h = 0; h < HASH_SIZE; h++) {
1353 struct ip_tunnel *t;
1354
1355 t = rtnl_dereference(ign->tunnels[prio][h]);
1356
1357 while (t != NULL) {
1358 unregister_netdevice_queue(t->dev, head);
1359 t = rtnl_dereference(t->next);
1360 }
1361 }
1362 }
1363 }
1364
1365 static int __net_init ipgre_init_net(struct net *net)
1366 {
1367 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1368 int err;
1369
1370 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1371 ipgre_tunnel_setup);
1372 if (!ign->fb_tunnel_dev) {
1373 err = -ENOMEM;
1374 goto err_alloc_dev;
1375 }
1376 dev_net_set(ign->fb_tunnel_dev, net);
1377
1378 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1379 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1380
1381 if ((err = register_netdev(ign->fb_tunnel_dev)))
1382 goto err_reg_dev;
1383
1384 rcu_assign_pointer(ign->tunnels_wc[0],
1385 netdev_priv(ign->fb_tunnel_dev));
1386 return 0;
1387
1388 err_reg_dev:
1389 ipgre_dev_free(ign->fb_tunnel_dev);
1390 err_alloc_dev:
1391 return err;
1392 }
1393
1394 static void __net_exit ipgre_exit_net(struct net *net)
1395 {
1396 struct ipgre_net *ign;
1397 LIST_HEAD(list);
1398
1399 ign = net_generic(net, ipgre_net_id);
1400 rtnl_lock();
1401 ipgre_destroy_tunnels(ign, &list);
1402 unregister_netdevice_many(&list);
1403 rtnl_unlock();
1404 }
1405
1406 static struct pernet_operations ipgre_net_ops = {
1407 .init = ipgre_init_net,
1408 .exit = ipgre_exit_net,
1409 .id = &ipgre_net_id,
1410 .size = sizeof(struct ipgre_net),
1411 };
1412
1413 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1414 {
1415 __be16 flags;
1416
1417 if (!data)
1418 return 0;
1419
1420 flags = 0;
1421 if (data[IFLA_GRE_IFLAGS])
1422 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1423 if (data[IFLA_GRE_OFLAGS])
1424 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1425 if (flags & (GRE_VERSION|GRE_ROUTING))
1426 return -EINVAL;
1427
1428 return 0;
1429 }
1430
1431 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1432 {
1433 __be32 daddr;
1434
1435 if (tb[IFLA_ADDRESS]) {
1436 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1437 return -EINVAL;
1438 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1439 return -EADDRNOTAVAIL;
1440 }
1441
1442 if (!data)
1443 goto out;
1444
1445 if (data[IFLA_GRE_REMOTE]) {
1446 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1447 if (!daddr)
1448 return -EINVAL;
1449 }
1450
1451 out:
1452 return ipgre_tunnel_validate(tb, data);
1453 }
1454
1455 static void ipgre_netlink_parms(struct nlattr *data[],
1456 struct ip_tunnel_parm *parms)
1457 {
1458 memset(parms, 0, sizeof(*parms));
1459
1460 parms->iph.protocol = IPPROTO_GRE;
1461
1462 if (!data)
1463 return;
1464
1465 if (data[IFLA_GRE_LINK])
1466 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1467
1468 if (data[IFLA_GRE_IFLAGS])
1469 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1470
1471 if (data[IFLA_GRE_OFLAGS])
1472 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1473
1474 if (data[IFLA_GRE_IKEY])
1475 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1476
1477 if (data[IFLA_GRE_OKEY])
1478 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1479
1480 if (data[IFLA_GRE_LOCAL])
1481 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1482
1483 if (data[IFLA_GRE_REMOTE])
1484 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1485
1486 if (data[IFLA_GRE_TTL])
1487 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1488
1489 if (data[IFLA_GRE_TOS])
1490 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1491
1492 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1493 parms->iph.frag_off = htons(IP_DF);
1494 }
1495
1496 static int ipgre_tap_init(struct net_device *dev)
1497 {
1498 struct ip_tunnel *tunnel;
1499
1500 tunnel = netdev_priv(dev);
1501
1502 tunnel->dev = dev;
1503 strcpy(tunnel->parms.name, dev->name);
1504
1505 ipgre_tunnel_bind_dev(dev);
1506
1507 dev->tstats = alloc_percpu(struct pcpu_tstats);
1508 if (!dev->tstats)
1509 return -ENOMEM;
1510
1511 return 0;
1512 }
1513
1514 static const struct net_device_ops ipgre_tap_netdev_ops = {
1515 .ndo_init = ipgre_tap_init,
1516 .ndo_uninit = ipgre_tunnel_uninit,
1517 .ndo_start_xmit = ipgre_tunnel_xmit,
1518 .ndo_set_mac_address = eth_mac_addr,
1519 .ndo_validate_addr = eth_validate_addr,
1520 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1521 .ndo_get_stats = ipgre_get_stats,
1522 };
1523
1524 static void ipgre_tap_setup(struct net_device *dev)
1525 {
1526
1527 ether_setup(dev);
1528
1529 dev->netdev_ops = &ipgre_tap_netdev_ops;
1530 dev->destructor = ipgre_dev_free;
1531
1532 dev->iflink = 0;
1533 dev->features |= NETIF_F_NETNS_LOCAL;
1534 }
1535
1536 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1537 struct nlattr *data[])
1538 {
1539 struct ip_tunnel *nt;
1540 struct net *net = dev_net(dev);
1541 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1542 int mtu;
1543 int err;
1544
1545 nt = netdev_priv(dev);
1546 ipgre_netlink_parms(data, &nt->parms);
1547
1548 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1549 return -EEXIST;
1550
1551 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1552 random_ether_addr(dev->dev_addr);
1553
1554 mtu = ipgre_tunnel_bind_dev(dev);
1555 if (!tb[IFLA_MTU])
1556 dev->mtu = mtu;
1557
1558 /* Can use a lockless transmit, unless we generate output sequences */
1559 if (!(nt->parms.o_flags & GRE_SEQ))
1560 dev->features |= NETIF_F_LLTX;
1561
1562 err = register_netdevice(dev);
1563 if (err)
1564 goto out;
1565
1566 dev_hold(dev);
1567 ipgre_tunnel_link(ign, nt);
1568
1569 out:
1570 return err;
1571 }
1572
1573 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1574 struct nlattr *data[])
1575 {
1576 struct ip_tunnel *t, *nt;
1577 struct net *net = dev_net(dev);
1578 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1579 struct ip_tunnel_parm p;
1580 int mtu;
1581
1582 if (dev == ign->fb_tunnel_dev)
1583 return -EINVAL;
1584
1585 nt = netdev_priv(dev);
1586 ipgre_netlink_parms(data, &p);
1587
1588 t = ipgre_tunnel_locate(net, &p, 0);
1589
1590 if (t) {
1591 if (t->dev != dev)
1592 return -EEXIST;
1593 } else {
1594 t = nt;
1595
1596 if (dev->type != ARPHRD_ETHER) {
1597 unsigned int nflags = 0;
1598
1599 if (ipv4_is_multicast(p.iph.daddr))
1600 nflags = IFF_BROADCAST;
1601 else if (p.iph.daddr)
1602 nflags = IFF_POINTOPOINT;
1603
1604 if ((dev->flags ^ nflags) &
1605 (IFF_POINTOPOINT | IFF_BROADCAST))
1606 return -EINVAL;
1607 }
1608
1609 ipgre_tunnel_unlink(ign, t);
1610 t->parms.iph.saddr = p.iph.saddr;
1611 t->parms.iph.daddr = p.iph.daddr;
1612 t->parms.i_key = p.i_key;
1613 if (dev->type != ARPHRD_ETHER) {
1614 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1615 memcpy(dev->broadcast, &p.iph.daddr, 4);
1616 }
1617 ipgre_tunnel_link(ign, t);
1618 netdev_state_change(dev);
1619 }
1620
1621 t->parms.o_key = p.o_key;
1622 t->parms.iph.ttl = p.iph.ttl;
1623 t->parms.iph.tos = p.iph.tos;
1624 t->parms.iph.frag_off = p.iph.frag_off;
1625
1626 if (t->parms.link != p.link) {
1627 t->parms.link = p.link;
1628 mtu = ipgre_tunnel_bind_dev(dev);
1629 if (!tb[IFLA_MTU])
1630 dev->mtu = mtu;
1631 netdev_state_change(dev);
1632 }
1633
1634 return 0;
1635 }
1636
1637 static size_t ipgre_get_size(const struct net_device *dev)
1638 {
1639 return
1640 /* IFLA_GRE_LINK */
1641 nla_total_size(4) +
1642 /* IFLA_GRE_IFLAGS */
1643 nla_total_size(2) +
1644 /* IFLA_GRE_OFLAGS */
1645 nla_total_size(2) +
1646 /* IFLA_GRE_IKEY */
1647 nla_total_size(4) +
1648 /* IFLA_GRE_OKEY */
1649 nla_total_size(4) +
1650 /* IFLA_GRE_LOCAL */
1651 nla_total_size(4) +
1652 /* IFLA_GRE_REMOTE */
1653 nla_total_size(4) +
1654 /* IFLA_GRE_TTL */
1655 nla_total_size(1) +
1656 /* IFLA_GRE_TOS */
1657 nla_total_size(1) +
1658 /* IFLA_GRE_PMTUDISC */
1659 nla_total_size(1) +
1660 0;
1661 }
1662
1663 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1664 {
1665 struct ip_tunnel *t = netdev_priv(dev);
1666 struct ip_tunnel_parm *p = &t->parms;
1667
1668 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1669 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1670 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1671 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1672 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1673 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1674 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1675 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1676 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1677 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1678
1679 return 0;
1680
1681 nla_put_failure:
1682 return -EMSGSIZE;
1683 }
1684
1685 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1686 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1687 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1688 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1689 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1690 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1691 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1692 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1693 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1694 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1695 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1696 };
1697
1698 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1699 .kind = "gre",
1700 .maxtype = IFLA_GRE_MAX,
1701 .policy = ipgre_policy,
1702 .priv_size = sizeof(struct ip_tunnel),
1703 .setup = ipgre_tunnel_setup,
1704 .validate = ipgre_tunnel_validate,
1705 .newlink = ipgre_newlink,
1706 .changelink = ipgre_changelink,
1707 .get_size = ipgre_get_size,
1708 .fill_info = ipgre_fill_info,
1709 };
1710
1711 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1712 .kind = "gretap",
1713 .maxtype = IFLA_GRE_MAX,
1714 .policy = ipgre_policy,
1715 .priv_size = sizeof(struct ip_tunnel),
1716 .setup = ipgre_tap_setup,
1717 .validate = ipgre_tap_validate,
1718 .newlink = ipgre_newlink,
1719 .changelink = ipgre_changelink,
1720 .get_size = ipgre_get_size,
1721 .fill_info = ipgre_fill_info,
1722 };
1723
1724 /*
1725 * And now the modules code and kernel interface.
1726 */
1727
1728 static int __init ipgre_init(void)
1729 {
1730 int err;
1731
1732 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1733
1734 err = register_pernet_device(&ipgre_net_ops);
1735 if (err < 0)
1736 return err;
1737
1738 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1739 if (err < 0) {
1740 printk(KERN_INFO "ipgre init: can't add protocol\n");
1741 goto add_proto_failed;
1742 }
1743
1744 err = rtnl_link_register(&ipgre_link_ops);
1745 if (err < 0)
1746 goto rtnl_link_failed;
1747
1748 err = rtnl_link_register(&ipgre_tap_ops);
1749 if (err < 0)
1750 goto tap_ops_failed;
1751
1752 out:
1753 return err;
1754
1755 tap_ops_failed:
1756 rtnl_link_unregister(&ipgre_link_ops);
1757 rtnl_link_failed:
1758 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1759 add_proto_failed:
1760 unregister_pernet_device(&ipgre_net_ops);
1761 goto out;
1762 }
1763
1764 static void __exit ipgre_fini(void)
1765 {
1766 rtnl_link_unregister(&ipgre_tap_ops);
1767 rtnl_link_unregister(&ipgre_link_ops);
1768 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1769 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1770 unregister_pernet_device(&ipgre_net_ops);
1771 }
1772
1773 module_init(ipgre_init);
1774 module_exit(ipgre_fini);
1775 MODULE_LICENSE("GPL");
1776 MODULE_ALIAS_RTNL_LINK("gre");
1777 MODULE_ALIAS_RTNL_LINK("gretap");
Linus' kernel tree