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ip_gre: comments change
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / ip_gre.c
blobfbe2c473a06a05ca82b0f0d2fff935924aa114e5
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 if (netif_rx(skb) == NET_RX_DROP)
683 tunnel->dev->stats.rx_dropped++;
684
685 rcu_read_unlock();
686 return 0;
687 }
688 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
689
690 drop:
691 rcu_read_unlock();
692 drop_nolock:
693 kfree_skb(skb);
694 return 0;
695 }
696
697 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
698 {
699 struct ip_tunnel *tunnel = netdev_priv(dev);
700 struct pcpu_tstats *tstats;
701 struct iphdr *old_iph = ip_hdr(skb);
702 struct iphdr *tiph;
703 u8 tos;
704 __be16 df;
705 struct rtable *rt; /* Route to the other host */
706 struct net_device *tdev; /* Device to other host */
707 struct iphdr *iph; /* Our new IP header */
708 unsigned int max_headroom; /* The extra header space needed */
709 int gre_hlen;
710 __be32 dst;
711 int mtu;
712
713 if (dev->type == ARPHRD_ETHER)
714 IPCB(skb)->flags = 0;
715
716 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
717 gre_hlen = 0;
718 tiph = (struct iphdr *)skb->data;
719 } else {
720 gre_hlen = tunnel->hlen;
721 tiph = &tunnel->parms.iph;
722 }
723
724 if ((dst = tiph->daddr) == 0) {
725 /* NBMA tunnel */
726
727 if (skb_dst(skb) == NULL) {
728 dev->stats.tx_fifo_errors++;
729 goto tx_error;
730 }
731
732 if (skb->protocol == htons(ETH_P_IP)) {
733 rt = skb_rtable(skb);
734 if ((dst = rt->rt_gateway) == 0)
735 goto tx_error_icmp;
736 }
737 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
738 else if (skb->protocol == htons(ETH_P_IPV6)) {
739 struct in6_addr *addr6;
740 int addr_type;
741 struct neighbour *neigh = skb_dst(skb)->neighbour;
742
743 if (neigh == NULL)
744 goto tx_error;
745
746 addr6 = (struct in6_addr *)&neigh->primary_key;
747 addr_type = ipv6_addr_type(addr6);
748
749 if (addr_type == IPV6_ADDR_ANY) {
750 addr6 = &ipv6_hdr(skb)->daddr;
751 addr_type = ipv6_addr_type(addr6);
752 }
753
754 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
755 goto tx_error_icmp;
756
757 dst = addr6->s6_addr32[3];
758 }
759 #endif
760 else
761 goto tx_error;
762 }
763
764 tos = tiph->tos;
765 if (tos == 1) {
766 tos = 0;
767 if (skb->protocol == htons(ETH_P_IP))
768 tos = old_iph->tos;
769 else if (skb->protocol == htons(ETH_P_IPV6))
770 tos = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
771 }
772
773 {
774 struct flowi fl = {
775 .oif = tunnel->parms.link,
776 .nl_u = {
777 .ip4_u = {
778 .daddr = dst,
779 .saddr = tiph->saddr,
780 .tos = RT_TOS(tos)
781 }
782 },
783 .proto = IPPROTO_GRE
784 }
785 ;
786 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
787 dev->stats.tx_carrier_errors++;
788 goto tx_error;
789 }
790 }
791 tdev = rt->dst.dev;
792
793 if (tdev == dev) {
794 ip_rt_put(rt);
795 dev->stats.collisions++;
796 goto tx_error;
797 }
798
799 df = tiph->frag_off;
800 if (df)
801 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
802 else
803 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
804
805 if (skb_dst(skb))
806 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
807
808 if (skb->protocol == htons(ETH_P_IP)) {
809 df |= (old_iph->frag_off&htons(IP_DF));
810
811 if ((old_iph->frag_off&htons(IP_DF)) &&
812 mtu < ntohs(old_iph->tot_len)) {
813 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
814 ip_rt_put(rt);
815 goto tx_error;
816 }
817 }
818 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
819 else if (skb->protocol == htons(ETH_P_IPV6)) {
820 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
821
822 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
823 if ((tunnel->parms.iph.daddr &&
824 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
825 rt6->rt6i_dst.plen == 128) {
826 rt6->rt6i_flags |= RTF_MODIFIED;
827 skb_dst(skb)->metrics[RTAX_MTU-1] = mtu;
828 }
829 }
830
831 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
832 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
833 ip_rt_put(rt);
834 goto tx_error;
835 }
836 }
837 #endif
838
839 if (tunnel->err_count > 0) {
840 if (time_before(jiffies,
841 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
842 tunnel->err_count--;
843
844 dst_link_failure(skb);
845 } else
846 tunnel->err_count = 0;
847 }
848
849 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
850
851 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
852 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
853 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
854 if (max_headroom > dev->needed_headroom)
855 dev->needed_headroom = max_headroom;
856 if (!new_skb) {
857 ip_rt_put(rt);
858 dev->stats.tx_dropped++;
859 dev_kfree_skb(skb);
860 return NETDEV_TX_OK;
861 }
862 if (skb->sk)
863 skb_set_owner_w(new_skb, skb->sk);
864 dev_kfree_skb(skb);
865 skb = new_skb;
866 old_iph = ip_hdr(skb);
867 }
868
869 skb_reset_transport_header(skb);
870 skb_push(skb, gre_hlen);
871 skb_reset_network_header(skb);
872 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
873 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
874 IPSKB_REROUTED);
875 skb_dst_drop(skb);
876 skb_dst_set(skb, &rt->dst);
877
878 /*
879 * Push down and install the IPIP header.
880 */
881
882 iph = ip_hdr(skb);
883 iph->version = 4;
884 iph->ihl = sizeof(struct iphdr) >> 2;
885 iph->frag_off = df;
886 iph->protocol = IPPROTO_GRE;
887 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
888 iph->daddr = rt->rt_dst;
889 iph->saddr = rt->rt_src;
890
891 if ((iph->ttl = tiph->ttl) == 0) {
892 if (skb->protocol == htons(ETH_P_IP))
893 iph->ttl = old_iph->ttl;
894 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
895 else if (skb->protocol == htons(ETH_P_IPV6))
896 iph->ttl = ((struct ipv6hdr *)old_iph)->hop_limit;
897 #endif
898 else
899 iph->ttl = dst_metric(&rt->dst, RTAX_HOPLIMIT);
900 }
901
902 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
903 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
904 htons(ETH_P_TEB) : skb->protocol;
905
906 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
907 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
908
909 if (tunnel->parms.o_flags&GRE_SEQ) {
910 ++tunnel->o_seqno;
911 *ptr = htonl(tunnel->o_seqno);
912 ptr--;
913 }
914 if (tunnel->parms.o_flags&GRE_KEY) {
915 *ptr = tunnel->parms.o_key;
916 ptr--;
917 }
918 if (tunnel->parms.o_flags&GRE_CSUM) {
919 *ptr = 0;
920 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
921 }
922 }
923
924 nf_reset(skb);
925 tstats = this_cpu_ptr(dev->tstats);
926 __IPTUNNEL_XMIT(tstats, &dev->stats);
927 return NETDEV_TX_OK;
928
929 tx_error_icmp:
930 dst_link_failure(skb);
931
932 tx_error:
933 dev->stats.tx_errors++;
934 dev_kfree_skb(skb);
935 return NETDEV_TX_OK;
936 }
937
938 static int ipgre_tunnel_bind_dev(struct net_device *dev)
939 {
940 struct net_device *tdev = NULL;
941 struct ip_tunnel *tunnel;
942 struct iphdr *iph;
943 int hlen = LL_MAX_HEADER;
944 int mtu = ETH_DATA_LEN;
945 int addend = sizeof(struct iphdr) + 4;
946
947 tunnel = netdev_priv(dev);
948 iph = &tunnel->parms.iph;
949
950 /* Guess output device to choose reasonable mtu and needed_headroom */
951
952 if (iph->daddr) {
953 struct flowi fl = {
954 .oif = tunnel->parms.link,
955 .nl_u = {
956 .ip4_u = {
957 .daddr = iph->daddr,
958 .saddr = iph->saddr,
959 .tos = RT_TOS(iph->tos)
960 }
961 },
962 .proto = IPPROTO_GRE
963 };
964 struct rtable *rt;
965
966 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
967 tdev = rt->dst.dev;
968 ip_rt_put(rt);
969 }
970
971 if (dev->type != ARPHRD_ETHER)
972 dev->flags |= IFF_POINTOPOINT;
973 }
974
975 if (!tdev && tunnel->parms.link)
976 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
977
978 if (tdev) {
979 hlen = tdev->hard_header_len + tdev->needed_headroom;
980 mtu = tdev->mtu;
981 }
982 dev->iflink = tunnel->parms.link;
983
984 /* Precalculate GRE options length */
985 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
986 if (tunnel->parms.o_flags&GRE_CSUM)
987 addend += 4;
988 if (tunnel->parms.o_flags&GRE_KEY)
989 addend += 4;
990 if (tunnel->parms.o_flags&GRE_SEQ)
991 addend += 4;
992 }
993 dev->needed_headroom = addend + hlen;
994 mtu -= dev->hard_header_len + addend;
995
996 if (mtu < 68)
997 mtu = 68;
998
999 tunnel->hlen = addend;
1000
1001 return mtu;
1002 }
1003
1004 static int
1005 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1006 {
1007 int err = 0;
1008 struct ip_tunnel_parm p;
1009 struct ip_tunnel *t;
1010 struct net *net = dev_net(dev);
1011 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1012
1013 switch (cmd) {
1014 case SIOCGETTUNNEL:
1015 t = NULL;
1016 if (dev == ign->fb_tunnel_dev) {
1017 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1018 err = -EFAULT;
1019 break;
1020 }
1021 t = ipgre_tunnel_locate(net, &p, 0);
1022 }
1023 if (t == NULL)
1024 t = netdev_priv(dev);
1025 memcpy(&p, &t->parms, sizeof(p));
1026 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1027 err = -EFAULT;
1028 break;
1029
1030 case SIOCADDTUNNEL:
1031 case SIOCCHGTUNNEL:
1032 err = -EPERM;
1033 if (!capable(CAP_NET_ADMIN))
1034 goto done;
1035
1036 err = -EFAULT;
1037 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1038 goto done;
1039
1040 err = -EINVAL;
1041 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1042 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1043 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1044 goto done;
1045 if (p.iph.ttl)
1046 p.iph.frag_off |= htons(IP_DF);
1047
1048 if (!(p.i_flags&GRE_KEY))
1049 p.i_key = 0;
1050 if (!(p.o_flags&GRE_KEY))
1051 p.o_key = 0;
1052
1053 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1054
1055 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1056 if (t != NULL) {
1057 if (t->dev != dev) {
1058 err = -EEXIST;
1059 break;
1060 }
1061 } else {
1062 unsigned int nflags = 0;
1063
1064 t = netdev_priv(dev);
1065
1066 if (ipv4_is_multicast(p.iph.daddr))
1067 nflags = IFF_BROADCAST;
1068 else if (p.iph.daddr)
1069 nflags = IFF_POINTOPOINT;
1070
1071 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1072 err = -EINVAL;
1073 break;
1074 }
1075 ipgre_tunnel_unlink(ign, t);
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 in_dev_put(in_dev);
1252 }
1253 }
1254 return 0;
1255 }
1256
1257 #endif
1258
1259 static const struct net_device_ops ipgre_netdev_ops = {
1260 .ndo_init = ipgre_tunnel_init,
1261 .ndo_uninit = ipgre_tunnel_uninit,
1262 #ifdef CONFIG_NET_IPGRE_BROADCAST
1263 .ndo_open = ipgre_open,
1264 .ndo_stop = ipgre_close,
1265 #endif
1266 .ndo_start_xmit = ipgre_tunnel_xmit,
1267 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1268 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1269 .ndo_get_stats = ipgre_get_stats,
1270 };
1271
1272 static void ipgre_dev_free(struct net_device *dev)
1273 {
1274 free_percpu(dev->tstats);
1275 free_netdev(dev);
1276 }
1277
1278 static void ipgre_tunnel_setup(struct net_device *dev)
1279 {
1280 dev->netdev_ops = &ipgre_netdev_ops;
1281 dev->destructor = ipgre_dev_free;
1282
1283 dev->type = ARPHRD_IPGRE;
1284 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1285 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1286 dev->flags = IFF_NOARP;
1287 dev->iflink = 0;
1288 dev->addr_len = 4;
1289 dev->features |= NETIF_F_NETNS_LOCAL;
1290 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1291 }
1292
1293 static int ipgre_tunnel_init(struct net_device *dev)
1294 {
1295 struct ip_tunnel *tunnel;
1296 struct iphdr *iph;
1297
1298 tunnel = netdev_priv(dev);
1299 iph = &tunnel->parms.iph;
1300
1301 tunnel->dev = dev;
1302 strcpy(tunnel->parms.name, dev->name);
1303
1304 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1305 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1306
1307 if (iph->daddr) {
1308 #ifdef CONFIG_NET_IPGRE_BROADCAST
1309 if (ipv4_is_multicast(iph->daddr)) {
1310 if (!iph->saddr)
1311 return -EINVAL;
1312 dev->flags = IFF_BROADCAST;
1313 dev->header_ops = &ipgre_header_ops;
1314 }
1315 #endif
1316 } else
1317 dev->header_ops = &ipgre_header_ops;
1318
1319 dev->tstats = alloc_percpu(struct pcpu_tstats);
1320 if (!dev->tstats)
1321 return -ENOMEM;
1322
1323 return 0;
1324 }
1325
1326 static void ipgre_fb_tunnel_init(struct net_device *dev)
1327 {
1328 struct ip_tunnel *tunnel = netdev_priv(dev);
1329 struct iphdr *iph = &tunnel->parms.iph;
1330 struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
1331
1332 tunnel->dev = dev;
1333 strcpy(tunnel->parms.name, dev->name);
1334
1335 iph->version = 4;
1336 iph->protocol = IPPROTO_GRE;
1337 iph->ihl = 5;
1338 tunnel->hlen = sizeof(struct iphdr) + 4;
1339
1340 dev_hold(dev);
1341 rcu_assign_pointer(ign->tunnels_wc[0], tunnel);
1342 }
1343
1344
1345 static const struct gre_protocol ipgre_protocol = {
1346 .handler = ipgre_rcv,
1347 .err_handler = ipgre_err,
1348 };
1349
1350 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1351 {
1352 int prio;
1353
1354 for (prio = 0; prio < 4; prio++) {
1355 int h;
1356 for (h = 0; h < HASH_SIZE; h++) {
1357 struct ip_tunnel *t;
1358
1359 t = rtnl_dereference(ign->tunnels[prio][h]);
1360
1361 while (t != NULL) {
1362 unregister_netdevice_queue(t->dev, head);
1363 t = rtnl_dereference(t->next);
1364 }
1365 }
1366 }
1367 }
1368
1369 static int __net_init ipgre_init_net(struct net *net)
1370 {
1371 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1372 int err;
1373
1374 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1375 ipgre_tunnel_setup);
1376 if (!ign->fb_tunnel_dev) {
1377 err = -ENOMEM;
1378 goto err_alloc_dev;
1379 }
1380 dev_net_set(ign->fb_tunnel_dev, net);
1381
1382 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1383 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1384
1385 if ((err = register_netdev(ign->fb_tunnel_dev)))
1386 goto err_reg_dev;
1387
1388 return 0;
1389
1390 err_reg_dev:
1391 free_netdev(ign->fb_tunnel_dev);
1392 err_alloc_dev:
1393 return err;
1394 }
1395
1396 static void __net_exit ipgre_exit_net(struct net *net)
1397 {
1398 struct ipgre_net *ign;
1399 LIST_HEAD(list);
1400
1401 ign = net_generic(net, ipgre_net_id);
1402 rtnl_lock();
1403 ipgre_destroy_tunnels(ign, &list);
1404 unregister_netdevice_many(&list);
1405 rtnl_unlock();
1406 }
1407
1408 static struct pernet_operations ipgre_net_ops = {
1409 .init = ipgre_init_net,
1410 .exit = ipgre_exit_net,
1411 .id = &ipgre_net_id,
1412 .size = sizeof(struct ipgre_net),
1413 };
1414
1415 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1416 {
1417 __be16 flags;
1418
1419 if (!data)
1420 return 0;
1421
1422 flags = 0;
1423 if (data[IFLA_GRE_IFLAGS])
1424 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1425 if (data[IFLA_GRE_OFLAGS])
1426 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1427 if (flags & (GRE_VERSION|GRE_ROUTING))
1428 return -EINVAL;
1429
1430 return 0;
1431 }
1432
1433 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1434 {
1435 __be32 daddr;
1436
1437 if (tb[IFLA_ADDRESS]) {
1438 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1439 return -EINVAL;
1440 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1441 return -EADDRNOTAVAIL;
1442 }
1443
1444 if (!data)
1445 goto out;
1446
1447 if (data[IFLA_GRE_REMOTE]) {
1448 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1449 if (!daddr)
1450 return -EINVAL;
1451 }
1452
1453 out:
1454 return ipgre_tunnel_validate(tb, data);
1455 }
1456
1457 static void ipgre_netlink_parms(struct nlattr *data[],
1458 struct ip_tunnel_parm *parms)
1459 {
1460 memset(parms, 0, sizeof(*parms));
1461
1462 parms->iph.protocol = IPPROTO_GRE;
1463
1464 if (!data)
1465 return;
1466
1467 if (data[IFLA_GRE_LINK])
1468 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1469
1470 if (data[IFLA_GRE_IFLAGS])
1471 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1472
1473 if (data[IFLA_GRE_OFLAGS])
1474 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1475
1476 if (data[IFLA_GRE_IKEY])
1477 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1478
1479 if (data[IFLA_GRE_OKEY])
1480 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1481
1482 if (data[IFLA_GRE_LOCAL])
1483 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1484
1485 if (data[IFLA_GRE_REMOTE])
1486 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1487
1488 if (data[IFLA_GRE_TTL])
1489 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1490
1491 if (data[IFLA_GRE_TOS])
1492 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1493
1494 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1495 parms->iph.frag_off = htons(IP_DF);
1496 }
1497
1498 static int ipgre_tap_init(struct net_device *dev)
1499 {
1500 struct ip_tunnel *tunnel;
1501
1502 tunnel = netdev_priv(dev);
1503
1504 tunnel->dev = dev;
1505 strcpy(tunnel->parms.name, dev->name);
1506
1507 ipgre_tunnel_bind_dev(dev);
1508
1509 dev->tstats = alloc_percpu(struct pcpu_tstats);
1510 if (!dev->tstats)
1511 return -ENOMEM;
1512
1513 return 0;
1514 }
1515
1516 static const struct net_device_ops ipgre_tap_netdev_ops = {
1517 .ndo_init = ipgre_tap_init,
1518 .ndo_uninit = ipgre_tunnel_uninit,
1519 .ndo_start_xmit = ipgre_tunnel_xmit,
1520 .ndo_set_mac_address = eth_mac_addr,
1521 .ndo_validate_addr = eth_validate_addr,
1522 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1523 .ndo_get_stats = ipgre_get_stats,
1524 };
1525
1526 static void ipgre_tap_setup(struct net_device *dev)
1527 {
1528
1529 ether_setup(dev);
1530
1531 dev->netdev_ops = &ipgre_tap_netdev_ops;
1532 dev->destructor = ipgre_dev_free;
1533
1534 dev->iflink = 0;
1535 dev->features |= NETIF_F_NETNS_LOCAL;
1536 }
1537
1538 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1539 struct nlattr *data[])
1540 {
1541 struct ip_tunnel *nt;
1542 struct net *net = dev_net(dev);
1543 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1544 int mtu;
1545 int err;
1546
1547 nt = netdev_priv(dev);
1548 ipgre_netlink_parms(data, &nt->parms);
1549
1550 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1551 return -EEXIST;
1552
1553 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1554 random_ether_addr(dev->dev_addr);
1555
1556 mtu = ipgre_tunnel_bind_dev(dev);
1557 if (!tb[IFLA_MTU])
1558 dev->mtu = mtu;
1559
1560 /* Can use a lockless transmit, unless we generate output sequences */
1561 if (!(nt->parms.o_flags & GRE_SEQ))
1562 dev->features |= NETIF_F_LLTX;
1563
1564 err = register_netdevice(dev);
1565 if (err)
1566 goto out;
1567
1568 dev_hold(dev);
1569 ipgre_tunnel_link(ign, nt);
1570
1571 out:
1572 return err;
1573 }
1574
1575 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1576 struct nlattr *data[])
1577 {
1578 struct ip_tunnel *t, *nt;
1579 struct net *net = dev_net(dev);
1580 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1581 struct ip_tunnel_parm p;
1582 int mtu;
1583
1584 if (dev == ign->fb_tunnel_dev)
1585 return -EINVAL;
1586
1587 nt = netdev_priv(dev);
1588 ipgre_netlink_parms(data, &p);
1589
1590 t = ipgre_tunnel_locate(net, &p, 0);
1591
1592 if (t) {
1593 if (t->dev != dev)
1594 return -EEXIST;
1595 } else {
1596 t = nt;
1597
1598 if (dev->type != ARPHRD_ETHER) {
1599 unsigned int nflags = 0;
1600
1601 if (ipv4_is_multicast(p.iph.daddr))
1602 nflags = IFF_BROADCAST;
1603 else if (p.iph.daddr)
1604 nflags = IFF_POINTOPOINT;
1605
1606 if ((dev->flags ^ nflags) &
1607 (IFF_POINTOPOINT | IFF_BROADCAST))
1608 return -EINVAL;
1609 }
1610
1611 ipgre_tunnel_unlink(ign, t);
1612 t->parms.iph.saddr = p.iph.saddr;
1613 t->parms.iph.daddr = p.iph.daddr;
1614 t->parms.i_key = p.i_key;
1615 if (dev->type != ARPHRD_ETHER) {
1616 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1617 memcpy(dev->broadcast, &p.iph.daddr, 4);
1618 }
1619 ipgre_tunnel_link(ign, t);
1620 netdev_state_change(dev);
1621 }
1622
1623 t->parms.o_key = p.o_key;
1624 t->parms.iph.ttl = p.iph.ttl;
1625 t->parms.iph.tos = p.iph.tos;
1626 t->parms.iph.frag_off = p.iph.frag_off;
1627
1628 if (t->parms.link != p.link) {
1629 t->parms.link = p.link;
1630 mtu = ipgre_tunnel_bind_dev(dev);
1631 if (!tb[IFLA_MTU])
1632 dev->mtu = mtu;
1633 netdev_state_change(dev);
1634 }
1635
1636 return 0;
1637 }
1638
1639 static size_t ipgre_get_size(const struct net_device *dev)
1640 {
1641 return
1642 /* IFLA_GRE_LINK */
1643 nla_total_size(4) +
1644 /* IFLA_GRE_IFLAGS */
1645 nla_total_size(2) +
1646 /* IFLA_GRE_OFLAGS */
1647 nla_total_size(2) +
1648 /* IFLA_GRE_IKEY */
1649 nla_total_size(4) +
1650 /* IFLA_GRE_OKEY */
1651 nla_total_size(4) +
1652 /* IFLA_GRE_LOCAL */
1653 nla_total_size(4) +
1654 /* IFLA_GRE_REMOTE */
1655 nla_total_size(4) +
1656 /* IFLA_GRE_TTL */
1657 nla_total_size(1) +
1658 /* IFLA_GRE_TOS */
1659 nla_total_size(1) +
1660 /* IFLA_GRE_PMTUDISC */
1661 nla_total_size(1) +
1662 0;
1663 }
1664
1665 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1666 {
1667 struct ip_tunnel *t = netdev_priv(dev);
1668 struct ip_tunnel_parm *p = &t->parms;
1669
1670 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1671 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1672 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1673 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1674 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1675 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1676 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1677 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1678 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1679 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1680
1681 return 0;
1682
1683 nla_put_failure:
1684 return -EMSGSIZE;
1685 }
1686
1687 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1688 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1689 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1690 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1691 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1692 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1693 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1694 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1695 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1696 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1697 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1698 };
1699
1700 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1701 .kind = "gre",
1702 .maxtype = IFLA_GRE_MAX,
1703 .policy = ipgre_policy,
1704 .priv_size = sizeof(struct ip_tunnel),
1705 .setup = ipgre_tunnel_setup,
1706 .validate = ipgre_tunnel_validate,
1707 .newlink = ipgre_newlink,
1708 .changelink = ipgre_changelink,
1709 .get_size = ipgre_get_size,
1710 .fill_info = ipgre_fill_info,
1711 };
1712
1713 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1714 .kind = "gretap",
1715 .maxtype = IFLA_GRE_MAX,
1716 .policy = ipgre_policy,
1717 .priv_size = sizeof(struct ip_tunnel),
1718 .setup = ipgre_tap_setup,
1719 .validate = ipgre_tap_validate,
1720 .newlink = ipgre_newlink,
1721 .changelink = ipgre_changelink,
1722 .get_size = ipgre_get_size,
1723 .fill_info = ipgre_fill_info,
1724 };
1725
1726 /*
1727 * And now the modules code and kernel interface.
1728 */
1729
1730 static int __init ipgre_init(void)
1731 {
1732 int err;
1733
1734 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1735
1736 err = register_pernet_device(&ipgre_net_ops);
1737 if (err < 0)
1738 return err;
1739
1740 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1741 if (err < 0) {
1742 printk(KERN_INFO "ipgre init: can't add protocol\n");
1743 goto add_proto_failed;
1744 }
1745
1746 err = rtnl_link_register(&ipgre_link_ops);
1747 if (err < 0)
1748 goto rtnl_link_failed;
1749
1750 err = rtnl_link_register(&ipgre_tap_ops);
1751 if (err < 0)
1752 goto tap_ops_failed;
1753
1754 out:
1755 return err;
1756
1757 tap_ops_failed:
1758 rtnl_link_unregister(&ipgre_link_ops);
1759 rtnl_link_failed:
1760 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1761 add_proto_failed:
1762 unregister_pernet_device(&ipgre_net_ops);
1763 goto out;
1764 }
1765
1766 static void __exit ipgre_fini(void)
1767 {
1768 rtnl_link_unregister(&ipgre_tap_ops);
1769 rtnl_link_unregister(&ipgre_link_ops);
1770 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1771 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1772 unregister_pernet_device(&ipgre_net_ops);
1773 }
1774
1775 module_init(ipgre_init);
1776 module_exit(ipgre_fini);
1777 MODULE_LICENSE("GPL");
1778 MODULE_ALIAS_RTNL_LINK("gre");
1779 MODULE_ALIAS_RTNL_LINK("gretap");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree