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tuntap: switch to use rtnl_dereference()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / ip_gre.c
blob303012adf9e6e0b442268b6f53b50ac8aea745fe
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/capability.h>
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <asm/uaccess.h>
21 #include <linux/skbuff.h>
22 #include <linux/netdevice.h>
23 #include <linux/in.h>
24 #include <linux/tcp.h>
25 #include <linux/udp.h>
26 #include <linux/if_arp.h>
27 #include <linux/mroute.h>
28 #include <linux/init.h>
29 #include <linux/in6.h>
30 #include <linux/inetdevice.h>
31 #include <linux/igmp.h>
32 #include <linux/netfilter_ipv4.h>
33 #include <linux/etherdevice.h>
34 #include <linux/if_ether.h>
35
36 #include <net/sock.h>
37 #include <net/ip.h>
38 #include <net/icmp.h>
39 #include <net/protocol.h>
40 #include <net/ipip.h>
41 #include <net/arp.h>
42 #include <net/checksum.h>
43 #include <net/dsfield.h>
44 #include <net/inet_ecn.h>
45 #include <net/xfrm.h>
46 #include <net/net_namespace.h>
47 #include <net/netns/generic.h>
48 #include <net/rtnetlink.h>
49 #include <net/gre.h>
50
51 #if IS_ENABLED(CONFIG_IPV6)
52 #include <net/ipv6.h>
53 #include <net/ip6_fib.h>
54 #include <net/ip6_route.h>
55 #endif
56
57 /*
58 Problems & solutions
59 --------------------
60
61 1. The most important issue is detecting local dead loops.
62 They would cause complete host lockup in transmit, which
63 would be "resolved" by stack overflow or, if queueing is enabled,
64 with infinite looping in net_bh.
65
66 We cannot track such dead loops during route installation,
67 it is infeasible task. The most general solutions would be
68 to keep skb->encapsulation counter (sort of local ttl),
69 and silently drop packet when it expires. It is a good
70 solution, but it supposes maintaining new variable in ALL
71 skb, even if no tunneling is used.
72
73 Current solution: xmit_recursion breaks dead loops. This is a percpu
74 counter, since when we enter the first ndo_xmit(), cpu migration is
75 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
76
77 2. Networking dead loops would not kill routers, but would really
78 kill network. IP hop limit plays role of "t->recursion" in this case,
79 if we copy it from packet being encapsulated to upper header.
80 It is very good solution, but it introduces two problems:
81
82 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
83 do not work over tunnels.
84 - traceroute does not work. I planned to relay ICMP from tunnel,
85 so that this problem would be solved and traceroute output
86 would even more informative. This idea appeared to be wrong:
87 only Linux complies to rfc1812 now (yes, guys, Linux is the only
88 true router now :-)), all routers (at least, in neighbourhood of mine)
89 return only 8 bytes of payload. It is the end.
90
91 Hence, if we want that OSPF worked or traceroute said something reasonable,
92 we should search for another solution.
93
94 One of them is to parse packet trying to detect inner encapsulation
95 made by our node. It is difficult or even impossible, especially,
96 taking into account fragmentation. TO be short, ttl is not solution at all.
97
98 Current solution: The solution was UNEXPECTEDLY SIMPLE.
99 We force DF flag on tunnels with preconfigured hop limit,
100 that is ALL. :-) Well, it does not remove the problem completely,
101 but exponential growth of network traffic is changed to linear
102 (branches, that exceed pmtu are pruned) and tunnel mtu
103 rapidly degrades to value <68, where looping stops.
104 Yes, it is not good if there exists a router in the loop,
105 which does not force DF, even when encapsulating packets have DF set.
106 But it is not our problem! Nobody could accuse us, we made
107 all that we could make. Even if it is your gated who injected
108 fatal route to network, even if it were you who configured
109 fatal static route: you are innocent. :-)
110
111
112
113 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
114 practically identical code. It would be good to glue them
115 together, but it is not very evident, how to make them modular.
116 sit is integral part of IPv6, ipip and gre are naturally modular.
117 We could extract common parts (hash table, ioctl etc)
118 to a separate module (ip_tunnel.c).
119
120 Alexey Kuznetsov.
121 */
122
123 static bool log_ecn_error = true;
124 module_param(log_ecn_error, bool, 0644);
125 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
126
127 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
128 static int ipgre_tunnel_init(struct net_device *dev);
129 static void ipgre_tunnel_setup(struct net_device *dev);
130 static int ipgre_tunnel_bind_dev(struct net_device *dev);
131
132 /* Fallback tunnel: no source, no destination, no key, no options */
133
134 #define HASH_SIZE 16
135
136 static int ipgre_net_id __read_mostly;
137 struct ipgre_net {
138 struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
139
140 struct net_device *fb_tunnel_dev;
141 };
142
143 /* Tunnel hash table */
144
145 /*
146 4 hash tables:
147
148 3: (remote,local)
149 2: (remote,*)
150 1: (*,local)
151 0: (*,*)
152
153 We require exact key match i.e. if a key is present in packet
154 it will match only tunnel with the same key; if it is not present,
155 it will match only keyless tunnel.
156
157 All keysless packets, if not matched configured keyless tunnels
158 will match fallback tunnel.
159 */
160
161 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
162
163 #define tunnels_r_l tunnels[3]
164 #define tunnels_r tunnels[2]
165 #define tunnels_l tunnels[1]
166 #define tunnels_wc tunnels[0]
167
168 static struct rtnl_link_stats64 *ipgre_get_stats64(struct net_device *dev,
169 struct rtnl_link_stats64 *tot)
170 {
171 int i;
172
173 for_each_possible_cpu(i) {
174 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
175 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
176 unsigned int start;
177
178 do {
179 start = u64_stats_fetch_begin_bh(&tstats->syncp);
180 rx_packets = tstats->rx_packets;
181 tx_packets = tstats->tx_packets;
182 rx_bytes = tstats->rx_bytes;
183 tx_bytes = tstats->tx_bytes;
184 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
185
186 tot->rx_packets += rx_packets;
187 tot->tx_packets += tx_packets;
188 tot->rx_bytes += rx_bytes;
189 tot->tx_bytes += tx_bytes;
190 }
191
192 tot->multicast = dev->stats.multicast;
193 tot->rx_crc_errors = dev->stats.rx_crc_errors;
194 tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
195 tot->rx_length_errors = dev->stats.rx_length_errors;
196 tot->rx_frame_errors = dev->stats.rx_frame_errors;
197 tot->rx_errors = dev->stats.rx_errors;
198
199 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
200 tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
201 tot->tx_dropped = dev->stats.tx_dropped;
202 tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
203 tot->tx_errors = dev->stats.tx_errors;
204
205 return tot;
206 }
207
208 /* Does key in tunnel parameters match packet */
209 static bool ipgre_key_match(const struct ip_tunnel_parm *p,
210 __be16 flags, __be32 key)
211 {
212 if (p->i_flags & GRE_KEY) {
213 if (flags & GRE_KEY)
214 return key == p->i_key;
215 else
216 return false; /* key expected, none present */
217 } else
218 return !(flags & GRE_KEY);
219 }
220
221 /* Given src, dst and key, find appropriate for input tunnel. */
222
223 static struct ip_tunnel *ipgre_tunnel_lookup(struct net_device *dev,
224 __be32 remote, __be32 local,
225 __be16 flags, __be32 key,
226 __be16 gre_proto)
227 {
228 struct net *net = dev_net(dev);
229 int link = dev->ifindex;
230 unsigned int h0 = HASH(remote);
231 unsigned int h1 = HASH(key);
232 struct ip_tunnel *t, *cand = NULL;
233 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
234 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
235 ARPHRD_ETHER : ARPHRD_IPGRE;
236 int score, cand_score = 4;
237
238 for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
239 if (local != t->parms.iph.saddr ||
240 remote != t->parms.iph.daddr ||
241 !(t->dev->flags & IFF_UP))
242 continue;
243
244 if (!ipgre_key_match(&t->parms, flags, key))
245 continue;
246
247 if (t->dev->type != ARPHRD_IPGRE &&
248 t->dev->type != dev_type)
249 continue;
250
251 score = 0;
252 if (t->parms.link != link)
253 score |= 1;
254 if (t->dev->type != dev_type)
255 score |= 2;
256 if (score == 0)
257 return t;
258
259 if (score < cand_score) {
260 cand = t;
261 cand_score = score;
262 }
263 }
264
265 for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
266 if (remote != t->parms.iph.daddr ||
267 !(t->dev->flags & IFF_UP))
268 continue;
269
270 if (!ipgre_key_match(&t->parms, flags, key))
271 continue;
272
273 if (t->dev->type != ARPHRD_IPGRE &&
274 t->dev->type != dev_type)
275 continue;
276
277 score = 0;
278 if (t->parms.link != link)
279 score |= 1;
280 if (t->dev->type != dev_type)
281 score |= 2;
282 if (score == 0)
283 return t;
284
285 if (score < cand_score) {
286 cand = t;
287 cand_score = score;
288 }
289 }
290
291 for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
292 if ((local != t->parms.iph.saddr &&
293 (local != t->parms.iph.daddr ||
294 !ipv4_is_multicast(local))) ||
295 !(t->dev->flags & IFF_UP))
296 continue;
297
298 if (!ipgre_key_match(&t->parms, flags, key))
299 continue;
300
301 if (t->dev->type != ARPHRD_IPGRE &&
302 t->dev->type != dev_type)
303 continue;
304
305 score = 0;
306 if (t->parms.link != link)
307 score |= 1;
308 if (t->dev->type != dev_type)
309 score |= 2;
310 if (score == 0)
311 return t;
312
313 if (score < cand_score) {
314 cand = t;
315 cand_score = score;
316 }
317 }
318
319 for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
320 if (t->parms.i_key != key ||
321 !(t->dev->flags & IFF_UP))
322 continue;
323
324 if (t->dev->type != ARPHRD_IPGRE &&
325 t->dev->type != dev_type)
326 continue;
327
328 score = 0;
329 if (t->parms.link != link)
330 score |= 1;
331 if (t->dev->type != dev_type)
332 score |= 2;
333 if (score == 0)
334 return t;
335
336 if (score < cand_score) {
337 cand = t;
338 cand_score = score;
339 }
340 }
341
342 if (cand != NULL)
343 return cand;
344
345 dev = ign->fb_tunnel_dev;
346 if (dev->flags & IFF_UP)
347 return netdev_priv(dev);
348
349 return NULL;
350 }
351
352 static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
353 struct ip_tunnel_parm *parms)
354 {
355 __be32 remote = parms->iph.daddr;
356 __be32 local = parms->iph.saddr;
357 __be32 key = parms->i_key;
358 unsigned int h = HASH(key);
359 int prio = 0;
360
361 if (local)
362 prio |= 1;
363 if (remote && !ipv4_is_multicast(remote)) {
364 prio |= 2;
365 h ^= HASH(remote);
366 }
367
368 return &ign->tunnels[prio][h];
369 }
370
371 static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
372 struct ip_tunnel *t)
373 {
374 return __ipgre_bucket(ign, &t->parms);
375 }
376
377 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
378 {
379 struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
380
381 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
382 rcu_assign_pointer(*tp, t);
383 }
384
385 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
386 {
387 struct ip_tunnel __rcu **tp;
388 struct ip_tunnel *iter;
389
390 for (tp = ipgre_bucket(ign, t);
391 (iter = rtnl_dereference(*tp)) != NULL;
392 tp = &iter->next) {
393 if (t == iter) {
394 rcu_assign_pointer(*tp, t->next);
395 break;
396 }
397 }
398 }
399
400 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
401 struct ip_tunnel_parm *parms,
402 int type)
403 {
404 __be32 remote = parms->iph.daddr;
405 __be32 local = parms->iph.saddr;
406 __be32 key = parms->i_key;
407 int link = parms->link;
408 struct ip_tunnel *t;
409 struct ip_tunnel __rcu **tp;
410 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
411
412 for (tp = __ipgre_bucket(ign, parms);
413 (t = rtnl_dereference(*tp)) != NULL;
414 tp = &t->next)
415 if (local == t->parms.iph.saddr &&
416 remote == t->parms.iph.daddr &&
417 key == t->parms.i_key &&
418 link == t->parms.link &&
419 type == t->dev->type)
420 break;
421
422 return t;
423 }
424
425 static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
426 struct ip_tunnel_parm *parms, int create)
427 {
428 struct ip_tunnel *t, *nt;
429 struct net_device *dev;
430 char name[IFNAMSIZ];
431 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
432
433 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
434 if (t || !create)
435 return t;
436
437 if (parms->name[0])
438 strlcpy(name, parms->name, IFNAMSIZ);
439 else
440 strcpy(name, "gre%d");
441
442 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
443 if (!dev)
444 return NULL;
445
446 dev_net_set(dev, net);
447
448 nt = netdev_priv(dev);
449 nt->parms = *parms;
450 dev->rtnl_link_ops = &ipgre_link_ops;
451
452 dev->mtu = ipgre_tunnel_bind_dev(dev);
453
454 if (register_netdevice(dev) < 0)
455 goto failed_free;
456
457 /* Can use a lockless transmit, unless we generate output sequences */
458 if (!(nt->parms.o_flags & GRE_SEQ))
459 dev->features |= NETIF_F_LLTX;
460
461 dev_hold(dev);
462 ipgre_tunnel_link(ign, nt);
463 return nt;
464
465 failed_free:
466 free_netdev(dev);
467 return NULL;
468 }
469
470 static void ipgre_tunnel_uninit(struct net_device *dev)
471 {
472 struct net *net = dev_net(dev);
473 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
474
475 ipgre_tunnel_unlink(ign, netdev_priv(dev));
476 dev_put(dev);
477 }
478
479
480 static void ipgre_err(struct sk_buff *skb, u32 info)
481 {
482
483 /* All the routers (except for Linux) return only
484 8 bytes of packet payload. It means, that precise relaying of
485 ICMP in the real Internet is absolutely infeasible.
486
487 Moreover, Cisco "wise men" put GRE key to the third word
488 in GRE header. It makes impossible maintaining even soft state for keyed
489 GRE tunnels with enabled checksum. Tell them "thank you".
490
491 Well, I wonder, rfc1812 was written by Cisco employee,
492 what the hell these idiots break standards established
493 by themselves???
494 */
495
496 const struct iphdr *iph = (const struct iphdr *)skb->data;
497 __be16 *p = (__be16 *)(skb->data+(iph->ihl<<2));
498 int grehlen = (iph->ihl<<2) + 4;
499 const int type = icmp_hdr(skb)->type;
500 const int code = icmp_hdr(skb)->code;
501 struct ip_tunnel *t;
502 __be16 flags;
503 __be32 key = 0;
504
505 flags = p[0];
506 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
507 if (flags&(GRE_VERSION|GRE_ROUTING))
508 return;
509 if (flags&GRE_KEY) {
510 grehlen += 4;
511 if (flags&GRE_CSUM)
512 grehlen += 4;
513 }
514 }
515
516 /* If only 8 bytes returned, keyed message will be dropped here */
517 if (skb_headlen(skb) < grehlen)
518 return;
519
520 if (flags & GRE_KEY)
521 key = *(((__be32 *)p) + (grehlen / 4) - 1);
522
523 switch (type) {
524 default:
525 case ICMP_PARAMETERPROB:
526 return;
527
528 case ICMP_DEST_UNREACH:
529 switch (code) {
530 case ICMP_SR_FAILED:
531 case ICMP_PORT_UNREACH:
532 /* Impossible event. */
533 return;
534 default:
535 /* All others are translated to HOST_UNREACH.
536 rfc2003 contains "deep thoughts" about NET_UNREACH,
537 I believe they are just ether pollution. --ANK
538 */
539 break;
540 }
541 break;
542 case ICMP_TIME_EXCEEDED:
543 if (code != ICMP_EXC_TTL)
544 return;
545 break;
546
547 case ICMP_REDIRECT:
548 break;
549 }
550
551 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
552 flags, key, p[1]);
553
554 if (t == NULL)
555 return;
556
557 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
558 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
559 t->parms.link, 0, IPPROTO_GRE, 0);
560 return;
561 }
562 if (type == ICMP_REDIRECT) {
563 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
564 IPPROTO_GRE, 0);
565 return;
566 }
567 if (t->parms.iph.daddr == 0 ||
568 ipv4_is_multicast(t->parms.iph.daddr))
569 return;
570
571 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
572 return;
573
574 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
575 t->err_count++;
576 else
577 t->err_count = 1;
578 t->err_time = jiffies;
579 }
580
581 static inline u8
582 ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
583 {
584 u8 inner = 0;
585 if (skb->protocol == htons(ETH_P_IP))
586 inner = old_iph->tos;
587 else if (skb->protocol == htons(ETH_P_IPV6))
588 inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
589 return INET_ECN_encapsulate(tos, inner);
590 }
591
592 static int ipgre_rcv(struct sk_buff *skb)
593 {
594 const struct iphdr *iph;
595 u8 *h;
596 __be16 flags;
597 __sum16 csum = 0;
598 __be32 key = 0;
599 u32 seqno = 0;
600 struct ip_tunnel *tunnel;
601 int offset = 4;
602 __be16 gre_proto;
603 int err;
604
605 if (!pskb_may_pull(skb, 16))
606 goto drop;
607
608 iph = ip_hdr(skb);
609 h = skb->data;
610 flags = *(__be16 *)h;
611
612 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
613 /* - Version must be 0.
614 - We do not support routing headers.
615 */
616 if (flags&(GRE_VERSION|GRE_ROUTING))
617 goto drop;
618
619 if (flags&GRE_CSUM) {
620 switch (skb->ip_summed) {
621 case CHECKSUM_COMPLETE:
622 csum = csum_fold(skb->csum);
623 if (!csum)
624 break;
625 /* fall through */
626 case CHECKSUM_NONE:
627 skb->csum = 0;
628 csum = __skb_checksum_complete(skb);
629 skb->ip_summed = CHECKSUM_COMPLETE;
630 }
631 offset += 4;
632 }
633 if (flags&GRE_KEY) {
634 key = *(__be32 *)(h + offset);
635 offset += 4;
636 }
637 if (flags&GRE_SEQ) {
638 seqno = ntohl(*(__be32 *)(h + offset));
639 offset += 4;
640 }
641 }
642
643 gre_proto = *(__be16 *)(h + 2);
644
645 tunnel = ipgre_tunnel_lookup(skb->dev,
646 iph->saddr, iph->daddr, flags, key,
647 gre_proto);
648 if (tunnel) {
649 struct pcpu_tstats *tstats;
650
651 secpath_reset(skb);
652
653 skb->protocol = gre_proto;
654 /* WCCP version 1 and 2 protocol decoding.
655 * - Change protocol to IP
656 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
657 */
658 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
659 skb->protocol = htons(ETH_P_IP);
660 if ((*(h + offset) & 0xF0) != 0x40)
661 offset += 4;
662 }
663
664 skb->mac_header = skb->network_header;
665 __pskb_pull(skb, offset);
666 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
667 skb->pkt_type = PACKET_HOST;
668 #ifdef CONFIG_NET_IPGRE_BROADCAST
669 if (ipv4_is_multicast(iph->daddr)) {
670 /* Looped back packet, drop it! */
671 if (rt_is_output_route(skb_rtable(skb)))
672 goto drop;
673 tunnel->dev->stats.multicast++;
674 skb->pkt_type = PACKET_BROADCAST;
675 }
676 #endif
677
678 if (((flags&GRE_CSUM) && csum) ||
679 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
680 tunnel->dev->stats.rx_crc_errors++;
681 tunnel->dev->stats.rx_errors++;
682 goto drop;
683 }
684 if (tunnel->parms.i_flags&GRE_SEQ) {
685 if (!(flags&GRE_SEQ) ||
686 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
687 tunnel->dev->stats.rx_fifo_errors++;
688 tunnel->dev->stats.rx_errors++;
689 goto drop;
690 }
691 tunnel->i_seqno = seqno + 1;
692 }
693
694 /* Warning: All skb pointers will be invalidated! */
695 if (tunnel->dev->type == ARPHRD_ETHER) {
696 if (!pskb_may_pull(skb, ETH_HLEN)) {
697 tunnel->dev->stats.rx_length_errors++;
698 tunnel->dev->stats.rx_errors++;
699 goto drop;
700 }
701
702 iph = ip_hdr(skb);
703 skb->protocol = eth_type_trans(skb, tunnel->dev);
704 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
705 }
706
707 __skb_tunnel_rx(skb, tunnel->dev);
708
709 skb_reset_network_header(skb);
710 err = IP_ECN_decapsulate(iph, skb);
711 if (unlikely(err)) {
712 if (log_ecn_error)
713 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
714 &iph->saddr, iph->tos);
715 if (err > 1) {
716 ++tunnel->dev->stats.rx_frame_errors;
717 ++tunnel->dev->stats.rx_errors;
718 goto drop;
719 }
720 }
721
722 tstats = this_cpu_ptr(tunnel->dev->tstats);
723 u64_stats_update_begin(&tstats->syncp);
724 tstats->rx_packets++;
725 tstats->rx_bytes += skb->len;
726 u64_stats_update_end(&tstats->syncp);
727
728 gro_cells_receive(&tunnel->gro_cells, skb);
729 return 0;
730 }
731 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
732
733 drop:
734 kfree_skb(skb);
735 return 0;
736 }
737
738 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
739 {
740 struct ip_tunnel *tunnel = netdev_priv(dev);
741 const struct iphdr *old_iph = ip_hdr(skb);
742 const struct iphdr *tiph;
743 struct flowi4 fl4;
744 u8 tos;
745 __be16 df;
746 struct rtable *rt; /* Route to the other host */
747 struct net_device *tdev; /* Device to other host */
748 struct iphdr *iph; /* Our new IP header */
749 unsigned int max_headroom; /* The extra header space needed */
750 int gre_hlen;
751 __be32 dst;
752 int mtu;
753 u8 ttl;
754
755 if (skb->ip_summed == CHECKSUM_PARTIAL &&
756 skb_checksum_help(skb))
757 goto tx_error;
758
759 if (dev->type == ARPHRD_ETHER)
760 IPCB(skb)->flags = 0;
761
762 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
763 gre_hlen = 0;
764 if (skb->protocol == htons(ETH_P_IP))
765 tiph = (const struct iphdr *)skb->data;
766 else
767 tiph = &tunnel->parms.iph;
768 } else {
769 gre_hlen = tunnel->hlen;
770 tiph = &tunnel->parms.iph;
771 }
772
773 if ((dst = tiph->daddr) == 0) {
774 /* NBMA tunnel */
775
776 if (skb_dst(skb) == NULL) {
777 dev->stats.tx_fifo_errors++;
778 goto tx_error;
779 }
780
781 if (skb->protocol == htons(ETH_P_IP)) {
782 rt = skb_rtable(skb);
783 dst = rt_nexthop(rt, old_iph->daddr);
784 }
785 #if IS_ENABLED(CONFIG_IPV6)
786 else if (skb->protocol == htons(ETH_P_IPV6)) {
787 const struct in6_addr *addr6;
788 struct neighbour *neigh;
789 bool do_tx_error_icmp;
790 int addr_type;
791
792 neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
793 if (neigh == NULL)
794 goto tx_error;
795
796 addr6 = (const struct in6_addr *)&neigh->primary_key;
797 addr_type = ipv6_addr_type(addr6);
798
799 if (addr_type == IPV6_ADDR_ANY) {
800 addr6 = &ipv6_hdr(skb)->daddr;
801 addr_type = ipv6_addr_type(addr6);
802 }
803
804 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
805 do_tx_error_icmp = true;
806 else {
807 do_tx_error_icmp = false;
808 dst = addr6->s6_addr32[3];
809 }
810 neigh_release(neigh);
811 if (do_tx_error_icmp)
812 goto tx_error_icmp;
813 }
814 #endif
815 else
816 goto tx_error;
817 }
818
819 ttl = tiph->ttl;
820 tos = tiph->tos;
821 if (tos == 1) {
822 tos = 0;
823 if (skb->protocol == htons(ETH_P_IP))
824 tos = old_iph->tos;
825 else if (skb->protocol == htons(ETH_P_IPV6))
826 tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
827 }
828
829 rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
830 tunnel->parms.o_key, RT_TOS(tos),
831 tunnel->parms.link);
832 if (IS_ERR(rt)) {
833 dev->stats.tx_carrier_errors++;
834 goto tx_error;
835 }
836 tdev = rt->dst.dev;
837
838 if (tdev == dev) {
839 ip_rt_put(rt);
840 dev->stats.collisions++;
841 goto tx_error;
842 }
843
844 df = tiph->frag_off;
845 if (df)
846 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
847 else
848 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
849
850 if (skb_dst(skb))
851 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
852
853 if (skb->protocol == htons(ETH_P_IP)) {
854 df |= (old_iph->frag_off&htons(IP_DF));
855
856 if ((old_iph->frag_off&htons(IP_DF)) &&
857 mtu < ntohs(old_iph->tot_len)) {
858 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
859 ip_rt_put(rt);
860 goto tx_error;
861 }
862 }
863 #if IS_ENABLED(CONFIG_IPV6)
864 else if (skb->protocol == htons(ETH_P_IPV6)) {
865 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
866
867 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
868 if ((tunnel->parms.iph.daddr &&
869 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
870 rt6->rt6i_dst.plen == 128) {
871 rt6->rt6i_flags |= RTF_MODIFIED;
872 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
873 }
874 }
875
876 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
877 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
878 ip_rt_put(rt);
879 goto tx_error;
880 }
881 }
882 #endif
883
884 if (tunnel->err_count > 0) {
885 if (time_before(jiffies,
886 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
887 tunnel->err_count--;
888
889 dst_link_failure(skb);
890 } else
891 tunnel->err_count = 0;
892 }
893
894 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
895
896 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
897 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
898 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
899 if (max_headroom > dev->needed_headroom)
900 dev->needed_headroom = max_headroom;
901 if (!new_skb) {
902 ip_rt_put(rt);
903 dev->stats.tx_dropped++;
904 dev_kfree_skb(skb);
905 return NETDEV_TX_OK;
906 }
907 if (skb->sk)
908 skb_set_owner_w(new_skb, skb->sk);
909 dev_kfree_skb(skb);
910 skb = new_skb;
911 old_iph = ip_hdr(skb);
912 /* Warning : tiph value might point to freed memory */
913 }
914
915 skb_push(skb, gre_hlen);
916 skb_reset_network_header(skb);
917 skb_set_transport_header(skb, sizeof(*iph));
918 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
919 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
920 IPSKB_REROUTED);
921 skb_dst_drop(skb);
922 skb_dst_set(skb, &rt->dst);
923
924 /*
925 * Push down and install the IPIP header.
926 */
927
928 iph = ip_hdr(skb);
929 iph->version = 4;
930 iph->ihl = sizeof(struct iphdr) >> 2;
931 iph->frag_off = df;
932 iph->protocol = IPPROTO_GRE;
933 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
934 iph->daddr = fl4.daddr;
935 iph->saddr = fl4.saddr;
936 iph->ttl = ttl;
937
938 if (ttl == 0) {
939 if (skb->protocol == htons(ETH_P_IP))
940 iph->ttl = old_iph->ttl;
941 #if IS_ENABLED(CONFIG_IPV6)
942 else if (skb->protocol == htons(ETH_P_IPV6))
943 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
944 #endif
945 else
946 iph->ttl = ip4_dst_hoplimit(&rt->dst);
947 }
948
949 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
950 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
951 htons(ETH_P_TEB) : skb->protocol;
952
953 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
954 __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
955
956 if (tunnel->parms.o_flags&GRE_SEQ) {
957 ++tunnel->o_seqno;
958 *ptr = htonl(tunnel->o_seqno);
959 ptr--;
960 }
961 if (tunnel->parms.o_flags&GRE_KEY) {
962 *ptr = tunnel->parms.o_key;
963 ptr--;
964 }
965 if (tunnel->parms.o_flags&GRE_CSUM) {
966 *ptr = 0;
967 *(__sum16 *)ptr = ip_compute_csum((void *)(iph+1), skb->len - sizeof(struct iphdr));
968 }
969 }
970
971 iptunnel_xmit(skb, dev);
972 return NETDEV_TX_OK;
973
974 #if IS_ENABLED(CONFIG_IPV6)
975 tx_error_icmp:
976 dst_link_failure(skb);
977 #endif
978 tx_error:
979 dev->stats.tx_errors++;
980 dev_kfree_skb(skb);
981 return NETDEV_TX_OK;
982 }
983
984 static int ipgre_tunnel_bind_dev(struct net_device *dev)
985 {
986 struct net_device *tdev = NULL;
987 struct ip_tunnel *tunnel;
988 const struct iphdr *iph;
989 int hlen = LL_MAX_HEADER;
990 int mtu = ETH_DATA_LEN;
991 int addend = sizeof(struct iphdr) + 4;
992
993 tunnel = netdev_priv(dev);
994 iph = &tunnel->parms.iph;
995
996 /* Guess output device to choose reasonable mtu and needed_headroom */
997
998 if (iph->daddr) {
999 struct flowi4 fl4;
1000 struct rtable *rt;
1001
1002 rt = ip_route_output_gre(dev_net(dev), &fl4,
1003 iph->daddr, iph->saddr,
1004 tunnel->parms.o_key,
1005 RT_TOS(iph->tos),
1006 tunnel->parms.link);
1007 if (!IS_ERR(rt)) {
1008 tdev = rt->dst.dev;
1009 ip_rt_put(rt);
1010 }
1011
1012 if (dev->type != ARPHRD_ETHER)
1013 dev->flags |= IFF_POINTOPOINT;
1014 }
1015
1016 if (!tdev && tunnel->parms.link)
1017 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
1018
1019 if (tdev) {
1020 hlen = tdev->hard_header_len + tdev->needed_headroom;
1021 mtu = tdev->mtu;
1022 }
1023 dev->iflink = tunnel->parms.link;
1024
1025 /* Precalculate GRE options length */
1026 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
1027 if (tunnel->parms.o_flags&GRE_CSUM)
1028 addend += 4;
1029 if (tunnel->parms.o_flags&GRE_KEY)
1030 addend += 4;
1031 if (tunnel->parms.o_flags&GRE_SEQ)
1032 addend += 4;
1033 }
1034 dev->needed_headroom = addend + hlen;
1035 mtu -= dev->hard_header_len + addend;
1036
1037 if (mtu < 68)
1038 mtu = 68;
1039
1040 tunnel->hlen = addend;
1041
1042 return mtu;
1043 }
1044
1045 static int
1046 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1047 {
1048 int err = 0;
1049 struct ip_tunnel_parm p;
1050 struct ip_tunnel *t;
1051 struct net *net = dev_net(dev);
1052 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1053
1054 switch (cmd) {
1055 case SIOCGETTUNNEL:
1056 t = NULL;
1057 if (dev == ign->fb_tunnel_dev) {
1058 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1059 err = -EFAULT;
1060 break;
1061 }
1062 t = ipgre_tunnel_locate(net, &p, 0);
1063 }
1064 if (t == NULL)
1065 t = netdev_priv(dev);
1066 memcpy(&p, &t->parms, sizeof(p));
1067 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1068 err = -EFAULT;
1069 break;
1070
1071 case SIOCADDTUNNEL:
1072 case SIOCCHGTUNNEL:
1073 err = -EPERM;
1074 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1075 goto done;
1076
1077 err = -EFAULT;
1078 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1079 goto done;
1080
1081 err = -EINVAL;
1082 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1083 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1084 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1085 goto done;
1086 if (p.iph.ttl)
1087 p.iph.frag_off |= htons(IP_DF);
1088
1089 if (!(p.i_flags&GRE_KEY))
1090 p.i_key = 0;
1091 if (!(p.o_flags&GRE_KEY))
1092 p.o_key = 0;
1093
1094 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1095
1096 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1097 if (t != NULL) {
1098 if (t->dev != dev) {
1099 err = -EEXIST;
1100 break;
1101 }
1102 } else {
1103 unsigned int nflags = 0;
1104
1105 t = netdev_priv(dev);
1106
1107 if (ipv4_is_multicast(p.iph.daddr))
1108 nflags = IFF_BROADCAST;
1109 else if (p.iph.daddr)
1110 nflags = IFF_POINTOPOINT;
1111
1112 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1113 err = -EINVAL;
1114 break;
1115 }
1116 ipgre_tunnel_unlink(ign, t);
1117 synchronize_net();
1118 t->parms.iph.saddr = p.iph.saddr;
1119 t->parms.iph.daddr = p.iph.daddr;
1120 t->parms.i_key = p.i_key;
1121 t->parms.o_key = p.o_key;
1122 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1123 memcpy(dev->broadcast, &p.iph.daddr, 4);
1124 ipgre_tunnel_link(ign, t);
1125 netdev_state_change(dev);
1126 }
1127 }
1128
1129 if (t) {
1130 err = 0;
1131 if (cmd == SIOCCHGTUNNEL) {
1132 t->parms.iph.ttl = p.iph.ttl;
1133 t->parms.iph.tos = p.iph.tos;
1134 t->parms.iph.frag_off = p.iph.frag_off;
1135 if (t->parms.link != p.link) {
1136 t->parms.link = p.link;
1137 dev->mtu = ipgre_tunnel_bind_dev(dev);
1138 netdev_state_change(dev);
1139 }
1140 }
1141 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1142 err = -EFAULT;
1143 } else
1144 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1145 break;
1146
1147 case SIOCDELTUNNEL:
1148 err = -EPERM;
1149 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1150 goto done;
1151
1152 if (dev == ign->fb_tunnel_dev) {
1153 err = -EFAULT;
1154 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1155 goto done;
1156 err = -ENOENT;
1157 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1158 goto done;
1159 err = -EPERM;
1160 if (t == netdev_priv(ign->fb_tunnel_dev))
1161 goto done;
1162 dev = t->dev;
1163 }
1164 unregister_netdevice(dev);
1165 err = 0;
1166 break;
1167
1168 default:
1169 err = -EINVAL;
1170 }
1171
1172 done:
1173 return err;
1174 }
1175
1176 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1177 {
1178 struct ip_tunnel *tunnel = netdev_priv(dev);
1179 if (new_mtu < 68 ||
1180 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1181 return -EINVAL;
1182 dev->mtu = new_mtu;
1183 return 0;
1184 }
1185
1186 /* Nice toy. Unfortunately, useless in real life :-)
1187 It allows to construct virtual multiprotocol broadcast "LAN"
1188 over the Internet, provided multicast routing is tuned.
1189
1190
1191 I have no idea was this bicycle invented before me,
1192 so that I had to set ARPHRD_IPGRE to a random value.
1193 I have an impression, that Cisco could make something similar,
1194 but this feature is apparently missing in IOS<=11.2(8).
1195
1196 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1197 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1198
1199 ping -t 255 224.66.66.66
1200
1201 If nobody answers, mbone does not work.
1202
1203 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1204 ip addr add 10.66.66.<somewhat>/24 dev Universe
1205 ifconfig Universe up
1206 ifconfig Universe add fe80::<Your_real_addr>/10
1207 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1208 ftp 10.66.66.66
1209 ...
1210 ftp fec0:6666:6666::193.233.7.65
1211 ...
1212
1213 */
1214
1215 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1216 unsigned short type,
1217 const void *daddr, const void *saddr, unsigned int len)
1218 {
1219 struct ip_tunnel *t = netdev_priv(dev);
1220 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1221 __be16 *p = (__be16 *)(iph+1);
1222
1223 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1224 p[0] = t->parms.o_flags;
1225 p[1] = htons(type);
1226
1227 /*
1228 * Set the source hardware address.
1229 */
1230
1231 if (saddr)
1232 memcpy(&iph->saddr, saddr, 4);
1233 if (daddr)
1234 memcpy(&iph->daddr, daddr, 4);
1235 if (iph->daddr)
1236 return t->hlen;
1237
1238 return -t->hlen;
1239 }
1240
1241 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1242 {
1243 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1244 memcpy(haddr, &iph->saddr, 4);
1245 return 4;
1246 }
1247
1248 static const struct header_ops ipgre_header_ops = {
1249 .create = ipgre_header,
1250 .parse = ipgre_header_parse,
1251 };
1252
1253 #ifdef CONFIG_NET_IPGRE_BROADCAST
1254 static int ipgre_open(struct net_device *dev)
1255 {
1256 struct ip_tunnel *t = netdev_priv(dev);
1257
1258 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1259 struct flowi4 fl4;
1260 struct rtable *rt;
1261
1262 rt = ip_route_output_gre(dev_net(dev), &fl4,
1263 t->parms.iph.daddr,
1264 t->parms.iph.saddr,
1265 t->parms.o_key,
1266 RT_TOS(t->parms.iph.tos),
1267 t->parms.link);
1268 if (IS_ERR(rt))
1269 return -EADDRNOTAVAIL;
1270 dev = rt->dst.dev;
1271 ip_rt_put(rt);
1272 if (__in_dev_get_rtnl(dev) == NULL)
1273 return -EADDRNOTAVAIL;
1274 t->mlink = dev->ifindex;
1275 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1276 }
1277 return 0;
1278 }
1279
1280 static int ipgre_close(struct net_device *dev)
1281 {
1282 struct ip_tunnel *t = netdev_priv(dev);
1283
1284 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1285 struct in_device *in_dev;
1286 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1287 if (in_dev)
1288 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1289 }
1290 return 0;
1291 }
1292
1293 #endif
1294
1295 static const struct net_device_ops ipgre_netdev_ops = {
1296 .ndo_init = ipgre_tunnel_init,
1297 .ndo_uninit = ipgre_tunnel_uninit,
1298 #ifdef CONFIG_NET_IPGRE_BROADCAST
1299 .ndo_open = ipgre_open,
1300 .ndo_stop = ipgre_close,
1301 #endif
1302 .ndo_start_xmit = ipgre_tunnel_xmit,
1303 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1304 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1305 .ndo_get_stats64 = ipgre_get_stats64,
1306 };
1307
1308 static void ipgre_dev_free(struct net_device *dev)
1309 {
1310 struct ip_tunnel *tunnel = netdev_priv(dev);
1311
1312 gro_cells_destroy(&tunnel->gro_cells);
1313 free_percpu(dev->tstats);
1314 free_netdev(dev);
1315 }
1316
1317 #define GRE_FEATURES (NETIF_F_SG | \
1318 NETIF_F_FRAGLIST | \
1319 NETIF_F_HIGHDMA | \
1320 NETIF_F_HW_CSUM)
1321
1322 static void ipgre_tunnel_setup(struct net_device *dev)
1323 {
1324 dev->netdev_ops = &ipgre_netdev_ops;
1325 dev->destructor = ipgre_dev_free;
1326
1327 dev->type = ARPHRD_IPGRE;
1328 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1329 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1330 dev->flags = IFF_NOARP;
1331 dev->iflink = 0;
1332 dev->addr_len = 4;
1333 dev->features |= NETIF_F_NETNS_LOCAL;
1334 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1335
1336 dev->features |= GRE_FEATURES;
1337 dev->hw_features |= GRE_FEATURES;
1338 }
1339
1340 static int ipgre_tunnel_init(struct net_device *dev)
1341 {
1342 struct ip_tunnel *tunnel;
1343 struct iphdr *iph;
1344 int err;
1345
1346 tunnel = netdev_priv(dev);
1347 iph = &tunnel->parms.iph;
1348
1349 tunnel->dev = dev;
1350 strcpy(tunnel->parms.name, dev->name);
1351
1352 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1353 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1354
1355 if (iph->daddr) {
1356 #ifdef CONFIG_NET_IPGRE_BROADCAST
1357 if (ipv4_is_multicast(iph->daddr)) {
1358 if (!iph->saddr)
1359 return -EINVAL;
1360 dev->flags = IFF_BROADCAST;
1361 dev->header_ops = &ipgre_header_ops;
1362 }
1363 #endif
1364 } else
1365 dev->header_ops = &ipgre_header_ops;
1366
1367 dev->tstats = alloc_percpu(struct pcpu_tstats);
1368 if (!dev->tstats)
1369 return -ENOMEM;
1370
1371 err = gro_cells_init(&tunnel->gro_cells, dev);
1372 if (err) {
1373 free_percpu(dev->tstats);
1374 return err;
1375 }
1376
1377 return 0;
1378 }
1379
1380 static void ipgre_fb_tunnel_init(struct net_device *dev)
1381 {
1382 struct ip_tunnel *tunnel = netdev_priv(dev);
1383 struct iphdr *iph = &tunnel->parms.iph;
1384
1385 tunnel->dev = dev;
1386 strcpy(tunnel->parms.name, dev->name);
1387
1388 iph->version = 4;
1389 iph->protocol = IPPROTO_GRE;
1390 iph->ihl = 5;
1391 tunnel->hlen = sizeof(struct iphdr) + 4;
1392
1393 dev_hold(dev);
1394 }
1395
1396
1397 static const struct gre_protocol ipgre_protocol = {
1398 .handler = ipgre_rcv,
1399 .err_handler = ipgre_err,
1400 };
1401
1402 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1403 {
1404 int prio;
1405
1406 for (prio = 0; prio < 4; prio++) {
1407 int h;
1408 for (h = 0; h < HASH_SIZE; h++) {
1409 struct ip_tunnel *t;
1410
1411 t = rtnl_dereference(ign->tunnels[prio][h]);
1412
1413 while (t != NULL) {
1414 unregister_netdevice_queue(t->dev, head);
1415 t = rtnl_dereference(t->next);
1416 }
1417 }
1418 }
1419 }
1420
1421 static int __net_init ipgre_init_net(struct net *net)
1422 {
1423 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1424 int err;
1425
1426 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1427 ipgre_tunnel_setup);
1428 if (!ign->fb_tunnel_dev) {
1429 err = -ENOMEM;
1430 goto err_alloc_dev;
1431 }
1432 dev_net_set(ign->fb_tunnel_dev, net);
1433
1434 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1435 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1436
1437 if ((err = register_netdev(ign->fb_tunnel_dev)))
1438 goto err_reg_dev;
1439
1440 rcu_assign_pointer(ign->tunnels_wc[0],
1441 netdev_priv(ign->fb_tunnel_dev));
1442 return 0;
1443
1444 err_reg_dev:
1445 ipgre_dev_free(ign->fb_tunnel_dev);
1446 err_alloc_dev:
1447 return err;
1448 }
1449
1450 static void __net_exit ipgre_exit_net(struct net *net)
1451 {
1452 struct ipgre_net *ign;
1453 LIST_HEAD(list);
1454
1455 ign = net_generic(net, ipgre_net_id);
1456 rtnl_lock();
1457 ipgre_destroy_tunnels(ign, &list);
1458 unregister_netdevice_many(&list);
1459 rtnl_unlock();
1460 }
1461
1462 static struct pernet_operations ipgre_net_ops = {
1463 .init = ipgre_init_net,
1464 .exit = ipgre_exit_net,
1465 .id = &ipgre_net_id,
1466 .size = sizeof(struct ipgre_net),
1467 };
1468
1469 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1470 {
1471 __be16 flags;
1472
1473 if (!data)
1474 return 0;
1475
1476 flags = 0;
1477 if (data[IFLA_GRE_IFLAGS])
1478 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1479 if (data[IFLA_GRE_OFLAGS])
1480 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1481 if (flags & (GRE_VERSION|GRE_ROUTING))
1482 return -EINVAL;
1483
1484 return 0;
1485 }
1486
1487 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1488 {
1489 __be32 daddr;
1490
1491 if (tb[IFLA_ADDRESS]) {
1492 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1493 return -EINVAL;
1494 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1495 return -EADDRNOTAVAIL;
1496 }
1497
1498 if (!data)
1499 goto out;
1500
1501 if (data[IFLA_GRE_REMOTE]) {
1502 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1503 if (!daddr)
1504 return -EINVAL;
1505 }
1506
1507 out:
1508 return ipgre_tunnel_validate(tb, data);
1509 }
1510
1511 static void ipgre_netlink_parms(struct nlattr *data[],
1512 struct ip_tunnel_parm *parms)
1513 {
1514 memset(parms, 0, sizeof(*parms));
1515
1516 parms->iph.protocol = IPPROTO_GRE;
1517
1518 if (!data)
1519 return;
1520
1521 if (data[IFLA_GRE_LINK])
1522 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1523
1524 if (data[IFLA_GRE_IFLAGS])
1525 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1526
1527 if (data[IFLA_GRE_OFLAGS])
1528 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1529
1530 if (data[IFLA_GRE_IKEY])
1531 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1532
1533 if (data[IFLA_GRE_OKEY])
1534 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1535
1536 if (data[IFLA_GRE_LOCAL])
1537 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1538
1539 if (data[IFLA_GRE_REMOTE])
1540 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1541
1542 if (data[IFLA_GRE_TTL])
1543 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1544
1545 if (data[IFLA_GRE_TOS])
1546 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1547
1548 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1549 parms->iph.frag_off = htons(IP_DF);
1550 }
1551
1552 static int ipgre_tap_init(struct net_device *dev)
1553 {
1554 struct ip_tunnel *tunnel;
1555
1556 tunnel = netdev_priv(dev);
1557
1558 tunnel->dev = dev;
1559 strcpy(tunnel->parms.name, dev->name);
1560
1561 ipgre_tunnel_bind_dev(dev);
1562
1563 dev->tstats = alloc_percpu(struct pcpu_tstats);
1564 if (!dev->tstats)
1565 return -ENOMEM;
1566
1567 return 0;
1568 }
1569
1570 static const struct net_device_ops ipgre_tap_netdev_ops = {
1571 .ndo_init = ipgre_tap_init,
1572 .ndo_uninit = ipgre_tunnel_uninit,
1573 .ndo_start_xmit = ipgre_tunnel_xmit,
1574 .ndo_set_mac_address = eth_mac_addr,
1575 .ndo_validate_addr = eth_validate_addr,
1576 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1577 .ndo_get_stats64 = ipgre_get_stats64,
1578 };
1579
1580 static void ipgre_tap_setup(struct net_device *dev)
1581 {
1582
1583 ether_setup(dev);
1584
1585 dev->netdev_ops = &ipgre_tap_netdev_ops;
1586 dev->destructor = ipgre_dev_free;
1587
1588 dev->iflink = 0;
1589 dev->features |= NETIF_F_NETNS_LOCAL;
1590 }
1591
1592 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1593 struct nlattr *data[])
1594 {
1595 struct ip_tunnel *nt;
1596 struct net *net = dev_net(dev);
1597 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1598 int mtu;
1599 int err;
1600
1601 nt = netdev_priv(dev);
1602 ipgre_netlink_parms(data, &nt->parms);
1603
1604 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1605 return -EEXIST;
1606
1607 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1608 eth_hw_addr_random(dev);
1609
1610 mtu = ipgre_tunnel_bind_dev(dev);
1611 if (!tb[IFLA_MTU])
1612 dev->mtu = mtu;
1613
1614 /* Can use a lockless transmit, unless we generate output sequences */
1615 if (!(nt->parms.o_flags & GRE_SEQ))
1616 dev->features |= NETIF_F_LLTX;
1617
1618 err = register_netdevice(dev);
1619 if (err)
1620 goto out;
1621
1622 dev_hold(dev);
1623 ipgre_tunnel_link(ign, nt);
1624
1625 out:
1626 return err;
1627 }
1628
1629 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1630 struct nlattr *data[])
1631 {
1632 struct ip_tunnel *t, *nt;
1633 struct net *net = dev_net(dev);
1634 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1635 struct ip_tunnel_parm p;
1636 int mtu;
1637
1638 if (dev == ign->fb_tunnel_dev)
1639 return -EINVAL;
1640
1641 nt = netdev_priv(dev);
1642 ipgre_netlink_parms(data, &p);
1643
1644 t = ipgre_tunnel_locate(net, &p, 0);
1645
1646 if (t) {
1647 if (t->dev != dev)
1648 return -EEXIST;
1649 } else {
1650 t = nt;
1651
1652 if (dev->type != ARPHRD_ETHER) {
1653 unsigned int nflags = 0;
1654
1655 if (ipv4_is_multicast(p.iph.daddr))
1656 nflags = IFF_BROADCAST;
1657 else if (p.iph.daddr)
1658 nflags = IFF_POINTOPOINT;
1659
1660 if ((dev->flags ^ nflags) &
1661 (IFF_POINTOPOINT | IFF_BROADCAST))
1662 return -EINVAL;
1663 }
1664
1665 ipgre_tunnel_unlink(ign, t);
1666 t->parms.iph.saddr = p.iph.saddr;
1667 t->parms.iph.daddr = p.iph.daddr;
1668 t->parms.i_key = p.i_key;
1669 if (dev->type != ARPHRD_ETHER) {
1670 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1671 memcpy(dev->broadcast, &p.iph.daddr, 4);
1672 }
1673 ipgre_tunnel_link(ign, t);
1674 netdev_state_change(dev);
1675 }
1676
1677 t->parms.o_key = p.o_key;
1678 t->parms.iph.ttl = p.iph.ttl;
1679 t->parms.iph.tos = p.iph.tos;
1680 t->parms.iph.frag_off = p.iph.frag_off;
1681
1682 if (t->parms.link != p.link) {
1683 t->parms.link = p.link;
1684 mtu = ipgre_tunnel_bind_dev(dev);
1685 if (!tb[IFLA_MTU])
1686 dev->mtu = mtu;
1687 netdev_state_change(dev);
1688 }
1689
1690 return 0;
1691 }
1692
1693 static size_t ipgre_get_size(const struct net_device *dev)
1694 {
1695 return
1696 /* IFLA_GRE_LINK */
1697 nla_total_size(4) +
1698 /* IFLA_GRE_IFLAGS */
1699 nla_total_size(2) +
1700 /* IFLA_GRE_OFLAGS */
1701 nla_total_size(2) +
1702 /* IFLA_GRE_IKEY */
1703 nla_total_size(4) +
1704 /* IFLA_GRE_OKEY */
1705 nla_total_size(4) +
1706 /* IFLA_GRE_LOCAL */
1707 nla_total_size(4) +
1708 /* IFLA_GRE_REMOTE */
1709 nla_total_size(4) +
1710 /* IFLA_GRE_TTL */
1711 nla_total_size(1) +
1712 /* IFLA_GRE_TOS */
1713 nla_total_size(1) +
1714 /* IFLA_GRE_PMTUDISC */
1715 nla_total_size(1) +
1716 0;
1717 }
1718
1719 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1720 {
1721 struct ip_tunnel *t = netdev_priv(dev);
1722 struct ip_tunnel_parm *p = &t->parms;
1723
1724 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1725 nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
1726 nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
1727 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1728 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1729 nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1730 nla_put_be32(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1731 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1732 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1733 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1734 !!(p->iph.frag_off & htons(IP_DF))))
1735 goto nla_put_failure;
1736 return 0;
1737
1738 nla_put_failure:
1739 return -EMSGSIZE;
1740 }
1741
1742 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1743 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1744 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1745 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1746 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1747 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1748 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1749 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1750 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1751 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1752 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1753 };
1754
1755 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1756 .kind = "gre",
1757 .maxtype = IFLA_GRE_MAX,
1758 .policy = ipgre_policy,
1759 .priv_size = sizeof(struct ip_tunnel),
1760 .setup = ipgre_tunnel_setup,
1761 .validate = ipgre_tunnel_validate,
1762 .newlink = ipgre_newlink,
1763 .changelink = ipgre_changelink,
1764 .get_size = ipgre_get_size,
1765 .fill_info = ipgre_fill_info,
1766 };
1767
1768 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1769 .kind = "gretap",
1770 .maxtype = IFLA_GRE_MAX,
1771 .policy = ipgre_policy,
1772 .priv_size = sizeof(struct ip_tunnel),
1773 .setup = ipgre_tap_setup,
1774 .validate = ipgre_tap_validate,
1775 .newlink = ipgre_newlink,
1776 .changelink = ipgre_changelink,
1777 .get_size = ipgre_get_size,
1778 .fill_info = ipgre_fill_info,
1779 };
1780
1781 /*
1782 * And now the modules code and kernel interface.
1783 */
1784
1785 static int __init ipgre_init(void)
1786 {
1787 int err;
1788
1789 pr_info("GRE over IPv4 tunneling driver\n");
1790
1791 err = register_pernet_device(&ipgre_net_ops);
1792 if (err < 0)
1793 return err;
1794
1795 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1796 if (err < 0) {
1797 pr_info("%s: can't add protocol\n", __func__);
1798 goto add_proto_failed;
1799 }
1800
1801 err = rtnl_link_register(&ipgre_link_ops);
1802 if (err < 0)
1803 goto rtnl_link_failed;
1804
1805 err = rtnl_link_register(&ipgre_tap_ops);
1806 if (err < 0)
1807 goto tap_ops_failed;
1808
1809 out:
1810 return err;
1811
1812 tap_ops_failed:
1813 rtnl_link_unregister(&ipgre_link_ops);
1814 rtnl_link_failed:
1815 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1816 add_proto_failed:
1817 unregister_pernet_device(&ipgre_net_ops);
1818 goto out;
1819 }
1820
1821 static void __exit ipgre_fini(void)
1822 {
1823 rtnl_link_unregister(&ipgre_tap_ops);
1824 rtnl_link_unregister(&ipgre_link_ops);
1825 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1826 pr_info("%s: can't remove protocol\n", __func__);
1827 unregister_pernet_device(&ipgre_net_ops);
1828 }
1829
1830 module_init(ipgre_init);
1831 module_exit(ipgre_fini);
1832 MODULE_LICENSE("GPL");
1833 MODULE_ALIAS_RTNL_LINK("gre");
1834 MODULE_ALIAS_RTNL_LINK("gretap");
1835 MODULE_ALIAS_NETDEV("gre0");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree