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xen mmu: fix a race window causing leave_mm BUG()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / ip_gre.c
blobd1d0e2c256fc4080033a01a621f73b1c3b080b7e
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 strcpy(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 (rt_is_output_route(skb_rtable(skb)))
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 .fl4_dst = dst,
776 .fl4_src = tiph->saddr,
777 .fl4_tos = RT_TOS(tos),
778 .proto = IPPROTO_GRE,
779 .fl_gre_key = tunnel->parms.o_key
780 };
781 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
782 dev->stats.tx_carrier_errors++;
783 goto tx_error;
784 }
785 }
786 tdev = rt->dst.dev;
787
788 if (tdev == dev) {
789 ip_rt_put(rt);
790 dev->stats.collisions++;
791 goto tx_error;
792 }
793
794 df = tiph->frag_off;
795 if (df)
796 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
797 else
798 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
799
800 if (skb_dst(skb))
801 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
802
803 if (skb->protocol == htons(ETH_P_IP)) {
804 df |= (old_iph->frag_off&htons(IP_DF));
805
806 if ((old_iph->frag_off&htons(IP_DF)) &&
807 mtu < ntohs(old_iph->tot_len)) {
808 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
809 ip_rt_put(rt);
810 goto tx_error;
811 }
812 }
813 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
814 else if (skb->protocol == htons(ETH_P_IPV6)) {
815 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
816
817 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
818 if ((tunnel->parms.iph.daddr &&
819 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
820 rt6->rt6i_dst.plen == 128) {
821 rt6->rt6i_flags |= RTF_MODIFIED;
822 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
823 }
824 }
825
826 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
827 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
828 ip_rt_put(rt);
829 goto tx_error;
830 }
831 }
832 #endif
833
834 if (tunnel->err_count > 0) {
835 if (time_before(jiffies,
836 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
837 tunnel->err_count--;
838
839 dst_link_failure(skb);
840 } else
841 tunnel->err_count = 0;
842 }
843
844 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
845
846 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
847 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
848 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
849 if (max_headroom > dev->needed_headroom)
850 dev->needed_headroom = max_headroom;
851 if (!new_skb) {
852 ip_rt_put(rt);
853 dev->stats.tx_dropped++;
854 dev_kfree_skb(skb);
855 return NETDEV_TX_OK;
856 }
857 if (skb->sk)
858 skb_set_owner_w(new_skb, skb->sk);
859 dev_kfree_skb(skb);
860 skb = new_skb;
861 old_iph = ip_hdr(skb);
862 }
863
864 skb_reset_transport_header(skb);
865 skb_push(skb, gre_hlen);
866 skb_reset_network_header(skb);
867 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
868 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
869 IPSKB_REROUTED);
870 skb_dst_drop(skb);
871 skb_dst_set(skb, &rt->dst);
872
873 /*
874 * Push down and install the IPIP header.
875 */
876
877 iph = ip_hdr(skb);
878 iph->version = 4;
879 iph->ihl = sizeof(struct iphdr) >> 2;
880 iph->frag_off = df;
881 iph->protocol = IPPROTO_GRE;
882 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
883 iph->daddr = rt->rt_dst;
884 iph->saddr = rt->rt_src;
885
886 if ((iph->ttl = tiph->ttl) == 0) {
887 if (skb->protocol == htons(ETH_P_IP))
888 iph->ttl = old_iph->ttl;
889 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
890 else if (skb->protocol == htons(ETH_P_IPV6))
891 iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
892 #endif
893 else
894 iph->ttl = ip4_dst_hoplimit(&rt->dst);
895 }
896
897 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
898 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
899 htons(ETH_P_TEB) : skb->protocol;
900
901 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
902 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
903
904 if (tunnel->parms.o_flags&GRE_SEQ) {
905 ++tunnel->o_seqno;
906 *ptr = htonl(tunnel->o_seqno);
907 ptr--;
908 }
909 if (tunnel->parms.o_flags&GRE_KEY) {
910 *ptr = tunnel->parms.o_key;
911 ptr--;
912 }
913 if (tunnel->parms.o_flags&GRE_CSUM) {
914 *ptr = 0;
915 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
916 }
917 }
918
919 nf_reset(skb);
920 tstats = this_cpu_ptr(dev->tstats);
921 __IPTUNNEL_XMIT(tstats, &dev->stats);
922 return NETDEV_TX_OK;
923
924 tx_error_icmp:
925 dst_link_failure(skb);
926
927 tx_error:
928 dev->stats.tx_errors++;
929 dev_kfree_skb(skb);
930 return NETDEV_TX_OK;
931 }
932
933 static int ipgre_tunnel_bind_dev(struct net_device *dev)
934 {
935 struct net_device *tdev = NULL;
936 struct ip_tunnel *tunnel;
937 struct iphdr *iph;
938 int hlen = LL_MAX_HEADER;
939 int mtu = ETH_DATA_LEN;
940 int addend = sizeof(struct iphdr) + 4;
941
942 tunnel = netdev_priv(dev);
943 iph = &tunnel->parms.iph;
944
945 /* Guess output device to choose reasonable mtu and needed_headroom */
946
947 if (iph->daddr) {
948 struct flowi fl = {
949 .oif = tunnel->parms.link,
950 .fl4_dst = iph->daddr,
951 .fl4_src = iph->saddr,
952 .fl4_tos = RT_TOS(iph->tos),
953 .proto = IPPROTO_GRE,
954 .fl_gre_key = tunnel->parms.o_key
955 };
956 struct rtable *rt;
957
958 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
959 tdev = rt->dst.dev;
960 ip_rt_put(rt);
961 }
962
963 if (dev->type != ARPHRD_ETHER)
964 dev->flags |= IFF_POINTOPOINT;
965 }
966
967 if (!tdev && tunnel->parms.link)
968 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
969
970 if (tdev) {
971 hlen = tdev->hard_header_len + tdev->needed_headroom;
972 mtu = tdev->mtu;
973 }
974 dev->iflink = tunnel->parms.link;
975
976 /* Precalculate GRE options length */
977 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
978 if (tunnel->parms.o_flags&GRE_CSUM)
979 addend += 4;
980 if (tunnel->parms.o_flags&GRE_KEY)
981 addend += 4;
982 if (tunnel->parms.o_flags&GRE_SEQ)
983 addend += 4;
984 }
985 dev->needed_headroom = addend + hlen;
986 mtu -= dev->hard_header_len + addend;
987
988 if (mtu < 68)
989 mtu = 68;
990
991 tunnel->hlen = addend;
992
993 return mtu;
994 }
995
996 static int
997 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
998 {
999 int err = 0;
1000 struct ip_tunnel_parm p;
1001 struct ip_tunnel *t;
1002 struct net *net = dev_net(dev);
1003 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1004
1005 switch (cmd) {
1006 case SIOCGETTUNNEL:
1007 t = NULL;
1008 if (dev == ign->fb_tunnel_dev) {
1009 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1010 err = -EFAULT;
1011 break;
1012 }
1013 t = ipgre_tunnel_locate(net, &p, 0);
1014 }
1015 if (t == NULL)
1016 t = netdev_priv(dev);
1017 memcpy(&p, &t->parms, sizeof(p));
1018 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1019 err = -EFAULT;
1020 break;
1021
1022 case SIOCADDTUNNEL:
1023 case SIOCCHGTUNNEL:
1024 err = -EPERM;
1025 if (!capable(CAP_NET_ADMIN))
1026 goto done;
1027
1028 err = -EFAULT;
1029 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1030 goto done;
1031
1032 err = -EINVAL;
1033 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1034 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1035 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1036 goto done;
1037 if (p.iph.ttl)
1038 p.iph.frag_off |= htons(IP_DF);
1039
1040 if (!(p.i_flags&GRE_KEY))
1041 p.i_key = 0;
1042 if (!(p.o_flags&GRE_KEY))
1043 p.o_key = 0;
1044
1045 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1046
1047 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1048 if (t != NULL) {
1049 if (t->dev != dev) {
1050 err = -EEXIST;
1051 break;
1052 }
1053 } else {
1054 unsigned int nflags = 0;
1055
1056 t = netdev_priv(dev);
1057
1058 if (ipv4_is_multicast(p.iph.daddr))
1059 nflags = IFF_BROADCAST;
1060 else if (p.iph.daddr)
1061 nflags = IFF_POINTOPOINT;
1062
1063 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1064 err = -EINVAL;
1065 break;
1066 }
1067 ipgre_tunnel_unlink(ign, t);
1068 synchronize_net();
1069 t->parms.iph.saddr = p.iph.saddr;
1070 t->parms.iph.daddr = p.iph.daddr;
1071 t->parms.i_key = p.i_key;
1072 t->parms.o_key = p.o_key;
1073 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1074 memcpy(dev->broadcast, &p.iph.daddr, 4);
1075 ipgre_tunnel_link(ign, t);
1076 netdev_state_change(dev);
1077 }
1078 }
1079
1080 if (t) {
1081 err = 0;
1082 if (cmd == SIOCCHGTUNNEL) {
1083 t->parms.iph.ttl = p.iph.ttl;
1084 t->parms.iph.tos = p.iph.tos;
1085 t->parms.iph.frag_off = p.iph.frag_off;
1086 if (t->parms.link != p.link) {
1087 t->parms.link = p.link;
1088 dev->mtu = ipgre_tunnel_bind_dev(dev);
1089 netdev_state_change(dev);
1090 }
1091 }
1092 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1093 err = -EFAULT;
1094 } else
1095 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1096 break;
1097
1098 case SIOCDELTUNNEL:
1099 err = -EPERM;
1100 if (!capable(CAP_NET_ADMIN))
1101 goto done;
1102
1103 if (dev == ign->fb_tunnel_dev) {
1104 err = -EFAULT;
1105 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1106 goto done;
1107 err = -ENOENT;
1108 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1109 goto done;
1110 err = -EPERM;
1111 if (t == netdev_priv(ign->fb_tunnel_dev))
1112 goto done;
1113 dev = t->dev;
1114 }
1115 unregister_netdevice(dev);
1116 err = 0;
1117 break;
1118
1119 default:
1120 err = -EINVAL;
1121 }
1122
1123 done:
1124 return err;
1125 }
1126
1127 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1128 {
1129 struct ip_tunnel *tunnel = netdev_priv(dev);
1130 if (new_mtu < 68 ||
1131 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1132 return -EINVAL;
1133 dev->mtu = new_mtu;
1134 return 0;
1135 }
1136
1137 /* Nice toy. Unfortunately, useless in real life :-)
1138 It allows to construct virtual multiprotocol broadcast "LAN"
1139 over the Internet, provided multicast routing is tuned.
1140
1141
1142 I have no idea was this bicycle invented before me,
1143 so that I had to set ARPHRD_IPGRE to a random value.
1144 I have an impression, that Cisco could make something similar,
1145 but this feature is apparently missing in IOS<=11.2(8).
1146
1147 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1148 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1149
1150 ping -t 255 224.66.66.66
1151
1152 If nobody answers, mbone does not work.
1153
1154 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1155 ip addr add 10.66.66.<somewhat>/24 dev Universe
1156 ifconfig Universe up
1157 ifconfig Universe add fe80::<Your_real_addr>/10
1158 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1159 ftp 10.66.66.66
1160 ...
1161 ftp fec0:6666:6666::193.233.7.65
1162 ...
1163
1164 */
1165
1166 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1167 unsigned short type,
1168 const void *daddr, const void *saddr, unsigned int len)
1169 {
1170 struct ip_tunnel *t = netdev_priv(dev);
1171 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1172 __be16 *p = (__be16*)(iph+1);
1173
1174 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1175 p[0] = t->parms.o_flags;
1176 p[1] = htons(type);
1177
1178 /*
1179 * Set the source hardware address.
1180 */
1181
1182 if (saddr)
1183 memcpy(&iph->saddr, saddr, 4);
1184 if (daddr)
1185 memcpy(&iph->daddr, daddr, 4);
1186 if (iph->daddr)
1187 return t->hlen;
1188
1189 return -t->hlen;
1190 }
1191
1192 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1193 {
1194 struct iphdr *iph = (struct iphdr *) skb_mac_header(skb);
1195 memcpy(haddr, &iph->saddr, 4);
1196 return 4;
1197 }
1198
1199 static const struct header_ops ipgre_header_ops = {
1200 .create = ipgre_header,
1201 .parse = ipgre_header_parse,
1202 };
1203
1204 #ifdef CONFIG_NET_IPGRE_BROADCAST
1205 static int ipgre_open(struct net_device *dev)
1206 {
1207 struct ip_tunnel *t = netdev_priv(dev);
1208
1209 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1210 struct flowi fl = {
1211 .oif = t->parms.link,
1212 .fl4_dst = t->parms.iph.daddr,
1213 .fl4_src = t->parms.iph.saddr,
1214 .fl4_tos = RT_TOS(t->parms.iph.tos),
1215 .proto = IPPROTO_GRE,
1216 .fl_gre_key = t->parms.o_key
1217 };
1218 struct rtable *rt;
1219
1220 if (ip_route_output_key(dev_net(dev), &rt, &fl))
1221 return -EADDRNOTAVAIL;
1222 dev = rt->dst.dev;
1223 ip_rt_put(rt);
1224 if (__in_dev_get_rtnl(dev) == NULL)
1225 return -EADDRNOTAVAIL;
1226 t->mlink = dev->ifindex;
1227 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1228 }
1229 return 0;
1230 }
1231
1232 static int ipgre_close(struct net_device *dev)
1233 {
1234 struct ip_tunnel *t = netdev_priv(dev);
1235
1236 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1237 struct in_device *in_dev;
1238 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1239 if (in_dev)
1240 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1241 }
1242 return 0;
1243 }
1244
1245 #endif
1246
1247 static const struct net_device_ops ipgre_netdev_ops = {
1248 .ndo_init = ipgre_tunnel_init,
1249 .ndo_uninit = ipgre_tunnel_uninit,
1250 #ifdef CONFIG_NET_IPGRE_BROADCAST
1251 .ndo_open = ipgre_open,
1252 .ndo_stop = ipgre_close,
1253 #endif
1254 .ndo_start_xmit = ipgre_tunnel_xmit,
1255 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1256 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1257 .ndo_get_stats = ipgre_get_stats,
1258 };
1259
1260 static void ipgre_dev_free(struct net_device *dev)
1261 {
1262 free_percpu(dev->tstats);
1263 free_netdev(dev);
1264 }
1265
1266 static void ipgre_tunnel_setup(struct net_device *dev)
1267 {
1268 dev->netdev_ops = &ipgre_netdev_ops;
1269 dev->destructor = ipgre_dev_free;
1270
1271 dev->type = ARPHRD_IPGRE;
1272 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1273 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1274 dev->flags = IFF_NOARP;
1275 dev->iflink = 0;
1276 dev->addr_len = 4;
1277 dev->features |= NETIF_F_NETNS_LOCAL;
1278 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1279 }
1280
1281 static int ipgre_tunnel_init(struct net_device *dev)
1282 {
1283 struct ip_tunnel *tunnel;
1284 struct iphdr *iph;
1285
1286 tunnel = netdev_priv(dev);
1287 iph = &tunnel->parms.iph;
1288
1289 tunnel->dev = dev;
1290 strcpy(tunnel->parms.name, dev->name);
1291
1292 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1293 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1294
1295 if (iph->daddr) {
1296 #ifdef CONFIG_NET_IPGRE_BROADCAST
1297 if (ipv4_is_multicast(iph->daddr)) {
1298 if (!iph->saddr)
1299 return -EINVAL;
1300 dev->flags = IFF_BROADCAST;
1301 dev->header_ops = &ipgre_header_ops;
1302 }
1303 #endif
1304 } else
1305 dev->header_ops = &ipgre_header_ops;
1306
1307 dev->tstats = alloc_percpu(struct pcpu_tstats);
1308 if (!dev->tstats)
1309 return -ENOMEM;
1310
1311 return 0;
1312 }
1313
1314 static void ipgre_fb_tunnel_init(struct net_device *dev)
1315 {
1316 struct ip_tunnel *tunnel = netdev_priv(dev);
1317 struct iphdr *iph = &tunnel->parms.iph;
1318
1319 tunnel->dev = dev;
1320 strcpy(tunnel->parms.name, dev->name);
1321
1322 iph->version = 4;
1323 iph->protocol = IPPROTO_GRE;
1324 iph->ihl = 5;
1325 tunnel->hlen = sizeof(struct iphdr) + 4;
1326
1327 dev_hold(dev);
1328 }
1329
1330
1331 static const struct gre_protocol ipgre_protocol = {
1332 .handler = ipgre_rcv,
1333 .err_handler = ipgre_err,
1334 };
1335
1336 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1337 {
1338 int prio;
1339
1340 for (prio = 0; prio < 4; prio++) {
1341 int h;
1342 for (h = 0; h < HASH_SIZE; h++) {
1343 struct ip_tunnel *t;
1344
1345 t = rtnl_dereference(ign->tunnels[prio][h]);
1346
1347 while (t != NULL) {
1348 unregister_netdevice_queue(t->dev, head);
1349 t = rtnl_dereference(t->next);
1350 }
1351 }
1352 }
1353 }
1354
1355 static int __net_init ipgre_init_net(struct net *net)
1356 {
1357 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1358 int err;
1359
1360 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1361 ipgre_tunnel_setup);
1362 if (!ign->fb_tunnel_dev) {
1363 err = -ENOMEM;
1364 goto err_alloc_dev;
1365 }
1366 dev_net_set(ign->fb_tunnel_dev, net);
1367
1368 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1369 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1370
1371 if ((err = register_netdev(ign->fb_tunnel_dev)))
1372 goto err_reg_dev;
1373
1374 rcu_assign_pointer(ign->tunnels_wc[0],
1375 netdev_priv(ign->fb_tunnel_dev));
1376 return 0;
1377
1378 err_reg_dev:
1379 ipgre_dev_free(ign->fb_tunnel_dev);
1380 err_alloc_dev:
1381 return err;
1382 }
1383
1384 static void __net_exit ipgre_exit_net(struct net *net)
1385 {
1386 struct ipgre_net *ign;
1387 LIST_HEAD(list);
1388
1389 ign = net_generic(net, ipgre_net_id);
1390 rtnl_lock();
1391 ipgre_destroy_tunnels(ign, &list);
1392 unregister_netdevice_many(&list);
1393 rtnl_unlock();
1394 }
1395
1396 static struct pernet_operations ipgre_net_ops = {
1397 .init = ipgre_init_net,
1398 .exit = ipgre_exit_net,
1399 .id = &ipgre_net_id,
1400 .size = sizeof(struct ipgre_net),
1401 };
1402
1403 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1404 {
1405 __be16 flags;
1406
1407 if (!data)
1408 return 0;
1409
1410 flags = 0;
1411 if (data[IFLA_GRE_IFLAGS])
1412 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1413 if (data[IFLA_GRE_OFLAGS])
1414 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1415 if (flags & (GRE_VERSION|GRE_ROUTING))
1416 return -EINVAL;
1417
1418 return 0;
1419 }
1420
1421 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1422 {
1423 __be32 daddr;
1424
1425 if (tb[IFLA_ADDRESS]) {
1426 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1427 return -EINVAL;
1428 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1429 return -EADDRNOTAVAIL;
1430 }
1431
1432 if (!data)
1433 goto out;
1434
1435 if (data[IFLA_GRE_REMOTE]) {
1436 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1437 if (!daddr)
1438 return -EINVAL;
1439 }
1440
1441 out:
1442 return ipgre_tunnel_validate(tb, data);
1443 }
1444
1445 static void ipgre_netlink_parms(struct nlattr *data[],
1446 struct ip_tunnel_parm *parms)
1447 {
1448 memset(parms, 0, sizeof(*parms));
1449
1450 parms->iph.protocol = IPPROTO_GRE;
1451
1452 if (!data)
1453 return;
1454
1455 if (data[IFLA_GRE_LINK])
1456 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1457
1458 if (data[IFLA_GRE_IFLAGS])
1459 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1460
1461 if (data[IFLA_GRE_OFLAGS])
1462 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1463
1464 if (data[IFLA_GRE_IKEY])
1465 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1466
1467 if (data[IFLA_GRE_OKEY])
1468 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1469
1470 if (data[IFLA_GRE_LOCAL])
1471 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1472
1473 if (data[IFLA_GRE_REMOTE])
1474 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1475
1476 if (data[IFLA_GRE_TTL])
1477 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1478
1479 if (data[IFLA_GRE_TOS])
1480 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1481
1482 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1483 parms->iph.frag_off = htons(IP_DF);
1484 }
1485
1486 static int ipgre_tap_init(struct net_device *dev)
1487 {
1488 struct ip_tunnel *tunnel;
1489
1490 tunnel = netdev_priv(dev);
1491
1492 tunnel->dev = dev;
1493 strcpy(tunnel->parms.name, dev->name);
1494
1495 ipgre_tunnel_bind_dev(dev);
1496
1497 dev->tstats = alloc_percpu(struct pcpu_tstats);
1498 if (!dev->tstats)
1499 return -ENOMEM;
1500
1501 return 0;
1502 }
1503
1504 static const struct net_device_ops ipgre_tap_netdev_ops = {
1505 .ndo_init = ipgre_tap_init,
1506 .ndo_uninit = ipgre_tunnel_uninit,
1507 .ndo_start_xmit = ipgre_tunnel_xmit,
1508 .ndo_set_mac_address = eth_mac_addr,
1509 .ndo_validate_addr = eth_validate_addr,
1510 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1511 .ndo_get_stats = ipgre_get_stats,
1512 };
1513
1514 static void ipgre_tap_setup(struct net_device *dev)
1515 {
1516
1517 ether_setup(dev);
1518
1519 dev->netdev_ops = &ipgre_tap_netdev_ops;
1520 dev->destructor = ipgre_dev_free;
1521
1522 dev->iflink = 0;
1523 dev->features |= NETIF_F_NETNS_LOCAL;
1524 }
1525
1526 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1527 struct nlattr *data[])
1528 {
1529 struct ip_tunnel *nt;
1530 struct net *net = dev_net(dev);
1531 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1532 int mtu;
1533 int err;
1534
1535 nt = netdev_priv(dev);
1536 ipgre_netlink_parms(data, &nt->parms);
1537
1538 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1539 return -EEXIST;
1540
1541 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1542 random_ether_addr(dev->dev_addr);
1543
1544 mtu = ipgre_tunnel_bind_dev(dev);
1545 if (!tb[IFLA_MTU])
1546 dev->mtu = mtu;
1547
1548 /* Can use a lockless transmit, unless we generate output sequences */
1549 if (!(nt->parms.o_flags & GRE_SEQ))
1550 dev->features |= NETIF_F_LLTX;
1551
1552 err = register_netdevice(dev);
1553 if (err)
1554 goto out;
1555
1556 dev_hold(dev);
1557 ipgre_tunnel_link(ign, nt);
1558
1559 out:
1560 return err;
1561 }
1562
1563 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1564 struct nlattr *data[])
1565 {
1566 struct ip_tunnel *t, *nt;
1567 struct net *net = dev_net(dev);
1568 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1569 struct ip_tunnel_parm p;
1570 int mtu;
1571
1572 if (dev == ign->fb_tunnel_dev)
1573 return -EINVAL;
1574
1575 nt = netdev_priv(dev);
1576 ipgre_netlink_parms(data, &p);
1577
1578 t = ipgre_tunnel_locate(net, &p, 0);
1579
1580 if (t) {
1581 if (t->dev != dev)
1582 return -EEXIST;
1583 } else {
1584 t = nt;
1585
1586 if (dev->type != ARPHRD_ETHER) {
1587 unsigned int nflags = 0;
1588
1589 if (ipv4_is_multicast(p.iph.daddr))
1590 nflags = IFF_BROADCAST;
1591 else if (p.iph.daddr)
1592 nflags = IFF_POINTOPOINT;
1593
1594 if ((dev->flags ^ nflags) &
1595 (IFF_POINTOPOINT | IFF_BROADCAST))
1596 return -EINVAL;
1597 }
1598
1599 ipgre_tunnel_unlink(ign, t);
1600 t->parms.iph.saddr = p.iph.saddr;
1601 t->parms.iph.daddr = p.iph.daddr;
1602 t->parms.i_key = p.i_key;
1603 if (dev->type != ARPHRD_ETHER) {
1604 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1605 memcpy(dev->broadcast, &p.iph.daddr, 4);
1606 }
1607 ipgre_tunnel_link(ign, t);
1608 netdev_state_change(dev);
1609 }
1610
1611 t->parms.o_key = p.o_key;
1612 t->parms.iph.ttl = p.iph.ttl;
1613 t->parms.iph.tos = p.iph.tos;
1614 t->parms.iph.frag_off = p.iph.frag_off;
1615
1616 if (t->parms.link != p.link) {
1617 t->parms.link = p.link;
1618 mtu = ipgre_tunnel_bind_dev(dev);
1619 if (!tb[IFLA_MTU])
1620 dev->mtu = mtu;
1621 netdev_state_change(dev);
1622 }
1623
1624 return 0;
1625 }
1626
1627 static size_t ipgre_get_size(const struct net_device *dev)
1628 {
1629 return
1630 /* IFLA_GRE_LINK */
1631 nla_total_size(4) +
1632 /* IFLA_GRE_IFLAGS */
1633 nla_total_size(2) +
1634 /* IFLA_GRE_OFLAGS */
1635 nla_total_size(2) +
1636 /* IFLA_GRE_IKEY */
1637 nla_total_size(4) +
1638 /* IFLA_GRE_OKEY */
1639 nla_total_size(4) +
1640 /* IFLA_GRE_LOCAL */
1641 nla_total_size(4) +
1642 /* IFLA_GRE_REMOTE */
1643 nla_total_size(4) +
1644 /* IFLA_GRE_TTL */
1645 nla_total_size(1) +
1646 /* IFLA_GRE_TOS */
1647 nla_total_size(1) +
1648 /* IFLA_GRE_PMTUDISC */
1649 nla_total_size(1) +
1650 0;
1651 }
1652
1653 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1654 {
1655 struct ip_tunnel *t = netdev_priv(dev);
1656 struct ip_tunnel_parm *p = &t->parms;
1657
1658 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1659 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1660 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1661 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1662 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1663 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1664 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1665 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1666 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1667 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1668
1669 return 0;
1670
1671 nla_put_failure:
1672 return -EMSGSIZE;
1673 }
1674
1675 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1676 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1677 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1678 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1679 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1680 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1681 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1682 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1683 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1684 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1685 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1686 };
1687
1688 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1689 .kind = "gre",
1690 .maxtype = IFLA_GRE_MAX,
1691 .policy = ipgre_policy,
1692 .priv_size = sizeof(struct ip_tunnel),
1693 .setup = ipgre_tunnel_setup,
1694 .validate = ipgre_tunnel_validate,
1695 .newlink = ipgre_newlink,
1696 .changelink = ipgre_changelink,
1697 .get_size = ipgre_get_size,
1698 .fill_info = ipgre_fill_info,
1699 };
1700
1701 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1702 .kind = "gretap",
1703 .maxtype = IFLA_GRE_MAX,
1704 .policy = ipgre_policy,
1705 .priv_size = sizeof(struct ip_tunnel),
1706 .setup = ipgre_tap_setup,
1707 .validate = ipgre_tap_validate,
1708 .newlink = ipgre_newlink,
1709 .changelink = ipgre_changelink,
1710 .get_size = ipgre_get_size,
1711 .fill_info = ipgre_fill_info,
1712 };
1713
1714 /*
1715 * And now the modules code and kernel interface.
1716 */
1717
1718 static int __init ipgre_init(void)
1719 {
1720 int err;
1721
1722 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1723
1724 err = register_pernet_device(&ipgre_net_ops);
1725 if (err < 0)
1726 return err;
1727
1728 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1729 if (err < 0) {
1730 printk(KERN_INFO "ipgre init: can't add protocol\n");
1731 goto add_proto_failed;
1732 }
1733
1734 err = rtnl_link_register(&ipgre_link_ops);
1735 if (err < 0)
1736 goto rtnl_link_failed;
1737
1738 err = rtnl_link_register(&ipgre_tap_ops);
1739 if (err < 0)
1740 goto tap_ops_failed;
1741
1742 out:
1743 return err;
1744
1745 tap_ops_failed:
1746 rtnl_link_unregister(&ipgre_link_ops);
1747 rtnl_link_failed:
1748 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1749 add_proto_failed:
1750 unregister_pernet_device(&ipgre_net_ops);
1751 goto out;
1752 }
1753
1754 static void __exit ipgre_fini(void)
1755 {
1756 rtnl_link_unregister(&ipgre_tap_ops);
1757 rtnl_link_unregister(&ipgre_link_ops);
1758 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1759 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1760 unregister_pernet_device(&ipgre_net_ops);
1761 }
1762
1763 module_init(ipgre_init);
1764 module_exit(ipgre_fini);
1765 MODULE_LICENSE("GPL");
1766 MODULE_ALIAS_RTNL_LINK("gre");
1767 MODULE_ALIAS_RTNL_LINK("gretap");
1768 MODULE_ALIAS_NETDEV("gre0");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree