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Merge branch 'x86/rdrand' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
[wandboard.git] / net / ipv4 / ip_gre.c
blob2b53a1f7abf6bf57509279cff831b7082040e558
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 IS_ENABLED(CONFIG_IPV6)
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 } __attribute__((aligned(4*sizeof(unsigned long))));
175
176 static struct net_device_stats *ipgre_get_stats(struct net_device *dev)
177 {
178 struct pcpu_tstats sum = { 0 };
179 int i;
180
181 for_each_possible_cpu(i) {
182 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
183
184 sum.rx_packets += tstats->rx_packets;
185 sum.rx_bytes += tstats->rx_bytes;
186 sum.tx_packets += tstats->tx_packets;
187 sum.tx_bytes += tstats->tx_bytes;
188 }
189 dev->stats.rx_packets = sum.rx_packets;
190 dev->stats.rx_bytes = sum.rx_bytes;
191 dev->stats.tx_packets = sum.tx_packets;
192 dev->stats.tx_bytes = sum.tx_bytes;
193 return &dev->stats;
194 }
195
196 /* Given src, dst and key, find appropriate for input tunnel. */
197
198 static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
199 __be32 remote, __be32 local,
200 __be32 key, __be16 gre_proto)
201 {
202 struct net *net = dev_net(dev);
203 int link = dev->ifindex;
204 unsigned int h0 = HASH(remote);
205 unsigned int h1 = HASH(key);
206 struct ip_tunnel *t, *cand = NULL;
207 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
208 int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
209 ARPHRD_ETHER : ARPHRD_IPGRE;
210 int score, cand_score = 4;
211
212 for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
213 if (local != t->parms.iph.saddr ||
214 remote != t->parms.iph.daddr ||
215 key != t->parms.i_key ||
216 !(t->dev->flags & IFF_UP))
217 continue;
218
219 if (t->dev->type != ARPHRD_IPGRE &&
220 t->dev->type != dev_type)
221 continue;
222
223 score = 0;
224 if (t->parms.link != link)
225 score |= 1;
226 if (t->dev->type != dev_type)
227 score |= 2;
228 if (score == 0)
229 return t;
230
231 if (score < cand_score) {
232 cand = t;
233 cand_score = score;
234 }
235 }
236
237 for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
238 if (remote != t->parms.iph.daddr ||
239 key != t->parms.i_key ||
240 !(t->dev->flags & IFF_UP))
241 continue;
242
243 if (t->dev->type != ARPHRD_IPGRE &&
244 t->dev->type != dev_type)
245 continue;
246
247 score = 0;
248 if (t->parms.link != link)
249 score |= 1;
250 if (t->dev->type != dev_type)
251 score |= 2;
252 if (score == 0)
253 return t;
254
255 if (score < cand_score) {
256 cand = t;
257 cand_score = score;
258 }
259 }
260
261 for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
262 if ((local != t->parms.iph.saddr &&
263 (local != t->parms.iph.daddr ||
264 !ipv4_is_multicast(local))) ||
265 key != t->parms.i_key ||
266 !(t->dev->flags & IFF_UP))
267 continue;
268
269 if (t->dev->type != ARPHRD_IPGRE &&
270 t->dev->type != dev_type)
271 continue;
272
273 score = 0;
274 if (t->parms.link != link)
275 score |= 1;
276 if (t->dev->type != dev_type)
277 score |= 2;
278 if (score == 0)
279 return t;
280
281 if (score < cand_score) {
282 cand = t;
283 cand_score = score;
284 }
285 }
286
287 for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
288 if (t->parms.i_key != key ||
289 !(t->dev->flags & IFF_UP))
290 continue;
291
292 if (t->dev->type != ARPHRD_IPGRE &&
293 t->dev->type != dev_type)
294 continue;
295
296 score = 0;
297 if (t->parms.link != link)
298 score |= 1;
299 if (t->dev->type != dev_type)
300 score |= 2;
301 if (score == 0)
302 return t;
303
304 if (score < cand_score) {
305 cand = t;
306 cand_score = score;
307 }
308 }
309
310 if (cand != NULL)
311 return cand;
312
313 dev = ign->fb_tunnel_dev;
314 if (dev->flags & IFF_UP)
315 return netdev_priv(dev);
316
317 return NULL;
318 }
319
320 static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
321 struct ip_tunnel_parm *parms)
322 {
323 __be32 remote = parms->iph.daddr;
324 __be32 local = parms->iph.saddr;
325 __be32 key = parms->i_key;
326 unsigned int h = HASH(key);
327 int prio = 0;
328
329 if (local)
330 prio |= 1;
331 if (remote && !ipv4_is_multicast(remote)) {
332 prio |= 2;
333 h ^= HASH(remote);
334 }
335
336 return &ign->tunnels[prio][h];
337 }
338
339 static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
340 struct ip_tunnel *t)
341 {
342 return __ipgre_bucket(ign, &t->parms);
343 }
344
345 static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
346 {
347 struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
348
349 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
350 rcu_assign_pointer(*tp, t);
351 }
352
353 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
354 {
355 struct ip_tunnel __rcu **tp;
356 struct ip_tunnel *iter;
357
358 for (tp = ipgre_bucket(ign, t);
359 (iter = rtnl_dereference(*tp)) != NULL;
360 tp = &iter->next) {
361 if (t == iter) {
362 rcu_assign_pointer(*tp, t->next);
363 break;
364 }
365 }
366 }
367
368 static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
369 struct ip_tunnel_parm *parms,
370 int type)
371 {
372 __be32 remote = parms->iph.daddr;
373 __be32 local = parms->iph.saddr;
374 __be32 key = parms->i_key;
375 int link = parms->link;
376 struct ip_tunnel *t;
377 struct ip_tunnel __rcu **tp;
378 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
379
380 for (tp = __ipgre_bucket(ign, parms);
381 (t = rtnl_dereference(*tp)) != NULL;
382 tp = &t->next)
383 if (local == t->parms.iph.saddr &&
384 remote == t->parms.iph.daddr &&
385 key == t->parms.i_key &&
386 link == t->parms.link &&
387 type == t->dev->type)
388 break;
389
390 return t;
391 }
392
393 static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
394 struct ip_tunnel_parm *parms, int create)
395 {
396 struct ip_tunnel *t, *nt;
397 struct net_device *dev;
398 char name[IFNAMSIZ];
399 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
400
401 t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
402 if (t || !create)
403 return t;
404
405 if (parms->name[0])
406 strlcpy(name, parms->name, IFNAMSIZ);
407 else
408 strcpy(name, "gre%d");
409
410 dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
411 if (!dev)
412 return NULL;
413
414 dev_net_set(dev, net);
415
416 nt = netdev_priv(dev);
417 nt->parms = *parms;
418 dev->rtnl_link_ops = &ipgre_link_ops;
419
420 dev->mtu = ipgre_tunnel_bind_dev(dev);
421
422 if (register_netdevice(dev) < 0)
423 goto failed_free;
424
425 dev_hold(dev);
426 ipgre_tunnel_link(ign, nt);
427 return nt;
428
429 failed_free:
430 free_netdev(dev);
431 return NULL;
432 }
433
434 static void ipgre_tunnel_uninit(struct net_device *dev)
435 {
436 struct net *net = dev_net(dev);
437 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
438
439 ipgre_tunnel_unlink(ign, netdev_priv(dev));
440 dev_put(dev);
441 }
442
443
444 static void ipgre_err(struct sk_buff *skb, u32 info)
445 {
446
447 /* All the routers (except for Linux) return only
448 8 bytes of packet payload. It means, that precise relaying of
449 ICMP in the real Internet is absolutely infeasible.
450
451 Moreover, Cisco "wise men" put GRE key to the third word
452 in GRE header. It makes impossible maintaining even soft state for keyed
453 GRE tunnels with enabled checksum. Tell them "thank you".
454
455 Well, I wonder, rfc1812 was written by Cisco employee,
456 what the hell these idiots break standrads established
457 by themself???
458 */
459
460 const struct iphdr *iph = (const struct iphdr *)skb->data;
461 __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
462 int grehlen = (iph->ihl<<2) + 4;
463 const int type = icmp_hdr(skb)->type;
464 const int code = icmp_hdr(skb)->code;
465 struct ip_tunnel *t;
466 __be16 flags;
467
468 flags = p[0];
469 if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
470 if (flags&(GRE_VERSION|GRE_ROUTING))
471 return;
472 if (flags&GRE_KEY) {
473 grehlen += 4;
474 if (flags&GRE_CSUM)
475 grehlen += 4;
476 }
477 }
478
479 /* If only 8 bytes returned, keyed message will be dropped here */
480 if (skb_headlen(skb) < grehlen)
481 return;
482
483 switch (type) {
484 default:
485 case ICMP_PARAMETERPROB:
486 return;
487
488 case ICMP_DEST_UNREACH:
489 switch (code) {
490 case ICMP_SR_FAILED:
491 case ICMP_PORT_UNREACH:
492 /* Impossible event. */
493 return;
494 case ICMP_FRAG_NEEDED:
495 /* Soft state for pmtu is maintained by IP core. */
496 return;
497 default:
498 /* All others are translated to HOST_UNREACH.
499 rfc2003 contains "deep thoughts" about NET_UNREACH,
500 I believe they are just ether pollution. --ANK
501 */
502 break;
503 }
504 break;
505 case ICMP_TIME_EXCEEDED:
506 if (code != ICMP_EXC_TTL)
507 return;
508 break;
509 }
510
511 rcu_read_lock();
512 t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
513 flags & GRE_KEY ?
514 *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
515 p[1]);
516 if (t == NULL || t->parms.iph.daddr == 0 ||
517 ipv4_is_multicast(t->parms.iph.daddr))
518 goto out;
519
520 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
521 goto out;
522
523 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
524 t->err_count++;
525 else
526 t->err_count = 1;
527 t->err_time = jiffies;
528 out:
529 rcu_read_unlock();
530 }
531
532 static inline void ipgre_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
533 {
534 if (INET_ECN_is_ce(iph->tos)) {
535 if (skb->protocol == htons(ETH_P_IP)) {
536 IP_ECN_set_ce(ip_hdr(skb));
537 } else if (skb->protocol == htons(ETH_P_IPV6)) {
538 IP6_ECN_set_ce(ipv6_hdr(skb));
539 }
540 }
541 }
542
543 static inline u8
544 ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
545 {
546 u8 inner = 0;
547 if (skb->protocol == htons(ETH_P_IP))
548 inner = old_iph->tos;
549 else if (skb->protocol == htons(ETH_P_IPV6))
550 inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
551 return INET_ECN_encapsulate(tos, inner);
552 }
553
554 static int ipgre_rcv(struct sk_buff *skb)
555 {
556 const struct iphdr *iph;
557 u8 *h;
558 __be16 flags;
559 __sum16 csum = 0;
560 __be32 key = 0;
561 u32 seqno = 0;
562 struct ip_tunnel *tunnel;
563 int offset = 4;
564 __be16 gre_proto;
565
566 if (!pskb_may_pull(skb, 16))
567 goto drop_nolock;
568
569 iph = ip_hdr(skb);
570 h = skb->data;
571 flags = *(__be16*)h;
572
573 if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
574 /* - Version must be 0.
575 - We do not support routing headers.
576 */
577 if (flags&(GRE_VERSION|GRE_ROUTING))
578 goto drop_nolock;
579
580 if (flags&GRE_CSUM) {
581 switch (skb->ip_summed) {
582 case CHECKSUM_COMPLETE:
583 csum = csum_fold(skb->csum);
584 if (!csum)
585 break;
586 /* fall through */
587 case CHECKSUM_NONE:
588 skb->csum = 0;
589 csum = __skb_checksum_complete(skb);
590 skb->ip_summed = CHECKSUM_COMPLETE;
591 }
592 offset += 4;
593 }
594 if (flags&GRE_KEY) {
595 key = *(__be32*)(h + offset);
596 offset += 4;
597 }
598 if (flags&GRE_SEQ) {
599 seqno = ntohl(*(__be32*)(h + offset));
600 offset += 4;
601 }
602 }
603
604 gre_proto = *(__be16 *)(h + 2);
605
606 rcu_read_lock();
607 if ((tunnel = ipgre_tunnel_lookup(skb->dev,
608 iph->saddr, iph->daddr, key,
609 gre_proto))) {
610 struct pcpu_tstats *tstats;
611
612 secpath_reset(skb);
613
614 skb->protocol = gre_proto;
615 /* WCCP version 1 and 2 protocol decoding.
616 * - Change protocol to IP
617 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
618 */
619 if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
620 skb->protocol = htons(ETH_P_IP);
621 if ((*(h + offset) & 0xF0) != 0x40)
622 offset += 4;
623 }
624
625 skb->mac_header = skb->network_header;
626 __pskb_pull(skb, offset);
627 skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
628 skb->pkt_type = PACKET_HOST;
629 #ifdef CONFIG_NET_IPGRE_BROADCAST
630 if (ipv4_is_multicast(iph->daddr)) {
631 /* Looped back packet, drop it! */
632 if (rt_is_output_route(skb_rtable(skb)))
633 goto drop;
634 tunnel->dev->stats.multicast++;
635 skb->pkt_type = PACKET_BROADCAST;
636 }
637 #endif
638
639 if (((flags&GRE_CSUM) && csum) ||
640 (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
641 tunnel->dev->stats.rx_crc_errors++;
642 tunnel->dev->stats.rx_errors++;
643 goto drop;
644 }
645 if (tunnel->parms.i_flags&GRE_SEQ) {
646 if (!(flags&GRE_SEQ) ||
647 (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
648 tunnel->dev->stats.rx_fifo_errors++;
649 tunnel->dev->stats.rx_errors++;
650 goto drop;
651 }
652 tunnel->i_seqno = seqno + 1;
653 }
654
655 /* Warning: All skb pointers will be invalidated! */
656 if (tunnel->dev->type == ARPHRD_ETHER) {
657 if (!pskb_may_pull(skb, ETH_HLEN)) {
658 tunnel->dev->stats.rx_length_errors++;
659 tunnel->dev->stats.rx_errors++;
660 goto drop;
661 }
662
663 iph = ip_hdr(skb);
664 skb->protocol = eth_type_trans(skb, tunnel->dev);
665 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
666 }
667
668 tstats = this_cpu_ptr(tunnel->dev->tstats);
669 tstats->rx_packets++;
670 tstats->rx_bytes += skb->len;
671
672 __skb_tunnel_rx(skb, tunnel->dev);
673
674 skb_reset_network_header(skb);
675 ipgre_ecn_decapsulate(iph, skb);
676
677 netif_rx(skb);
678
679 rcu_read_unlock();
680 return 0;
681 }
682 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
683
684 drop:
685 rcu_read_unlock();
686 drop_nolock:
687 kfree_skb(skb);
688 return 0;
689 }
690
691 static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
692 {
693 struct ip_tunnel *tunnel = netdev_priv(dev);
694 struct pcpu_tstats *tstats;
695 const struct iphdr *old_iph = ip_hdr(skb);
696 const struct iphdr *tiph;
697 struct flowi4 fl4;
698 u8 tos;
699 __be16 df;
700 struct rtable *rt; /* Route to the other host */
701 struct net_device *tdev; /* Device to other host */
702 struct iphdr *iph; /* Our new IP header */
703 unsigned int max_headroom; /* The extra header space needed */
704 int gre_hlen;
705 __be32 dst;
706 int mtu;
707
708 if (dev->type == ARPHRD_ETHER)
709 IPCB(skb)->flags = 0;
710
711 if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
712 gre_hlen = 0;
713 tiph = (const struct iphdr *)skb->data;
714 } else {
715 gre_hlen = tunnel->hlen;
716 tiph = &tunnel->parms.iph;
717 }
718
719 if ((dst = tiph->daddr) == 0) {
720 /* NBMA tunnel */
721
722 if (skb_dst(skb) == NULL) {
723 dev->stats.tx_fifo_errors++;
724 goto tx_error;
725 }
726
727 if (skb->protocol == htons(ETH_P_IP)) {
728 rt = skb_rtable(skb);
729 if ((dst = rt->rt_gateway) == 0)
730 goto tx_error_icmp;
731 }
732 #if IS_ENABLED(CONFIG_IPV6)
733 else if (skb->protocol == htons(ETH_P_IPV6)) {
734 struct neighbour *neigh = dst_get_neighbour_noref(skb_dst(skb));
735 const struct in6_addr *addr6;
736 int addr_type;
737
738 if (neigh == NULL)
739 goto tx_error;
740
741 addr6 = (const struct in6_addr *)&neigh->primary_key;
742 addr_type = ipv6_addr_type(addr6);
743
744 if (addr_type == IPV6_ADDR_ANY) {
745 addr6 = &ipv6_hdr(skb)->daddr;
746 addr_type = ipv6_addr_type(addr6);
747 }
748
749 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
750 goto tx_error_icmp;
751
752 dst = addr6->s6_addr32[3];
753 }
754 #endif
755 else
756 goto tx_error;
757 }
758
759 tos = tiph->tos;
760 if (tos == 1) {
761 tos = 0;
762 if (skb->protocol == htons(ETH_P_IP))
763 tos = old_iph->tos;
764 else if (skb->protocol == htons(ETH_P_IPV6))
765 tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
766 }
767
768 rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
769 tunnel->parms.o_key, RT_TOS(tos),
770 tunnel->parms.link);
771 if (IS_ERR(rt)) {
772 dev->stats.tx_carrier_errors++;
773 goto tx_error;
774 }
775 tdev = rt->dst.dev;
776
777 if (tdev == dev) {
778 ip_rt_put(rt);
779 dev->stats.collisions++;
780 goto tx_error;
781 }
782
783 df = tiph->frag_off;
784 if (df)
785 mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
786 else
787 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
788
789 if (skb_dst(skb))
790 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
791
792 if (skb->protocol == htons(ETH_P_IP)) {
793 df |= (old_iph->frag_off&htons(IP_DF));
794
795 if ((old_iph->frag_off&htons(IP_DF)) &&
796 mtu < ntohs(old_iph->tot_len)) {
797 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
798 ip_rt_put(rt);
799 goto tx_error;
800 }
801 }
802 #if IS_ENABLED(CONFIG_IPV6)
803 else if (skb->protocol == htons(ETH_P_IPV6)) {
804 struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
805
806 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
807 if ((tunnel->parms.iph.daddr &&
808 !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
809 rt6->rt6i_dst.plen == 128) {
810 rt6->rt6i_flags |= RTF_MODIFIED;
811 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
812 }
813 }
814
815 if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
816 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
817 ip_rt_put(rt);
818 goto tx_error;
819 }
820 }
821 #endif
822
823 if (tunnel->err_count > 0) {
824 if (time_before(jiffies,
825 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
826 tunnel->err_count--;
827
828 dst_link_failure(skb);
829 } else
830 tunnel->err_count = 0;
831 }
832
833 max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
834
835 if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
836 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
837 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
838 if (max_headroom > dev->needed_headroom)
839 dev->needed_headroom = max_headroom;
840 if (!new_skb) {
841 ip_rt_put(rt);
842 dev->stats.tx_dropped++;
843 dev_kfree_skb(skb);
844 return NETDEV_TX_OK;
845 }
846 if (skb->sk)
847 skb_set_owner_w(new_skb, skb->sk);
848 dev_kfree_skb(skb);
849 skb = new_skb;
850 old_iph = ip_hdr(skb);
851 }
852
853 skb_reset_transport_header(skb);
854 skb_push(skb, gre_hlen);
855 skb_reset_network_header(skb);
856 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
857 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
858 IPSKB_REROUTED);
859 skb_dst_drop(skb);
860 skb_dst_set(skb, &rt->dst);
861
862 /*
863 * Push down and install the IPIP header.
864 */
865
866 iph = ip_hdr(skb);
867 iph->version = 4;
868 iph->ihl = sizeof(struct iphdr) >> 2;
869 iph->frag_off = df;
870 iph->protocol = IPPROTO_GRE;
871 iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
872 iph->daddr = fl4.daddr;
873 iph->saddr = fl4.saddr;
874
875 if ((iph->ttl = tiph->ttl) == 0) {
876 if (skb->protocol == htons(ETH_P_IP))
877 iph->ttl = old_iph->ttl;
878 #if IS_ENABLED(CONFIG_IPV6)
879 else if (skb->protocol == htons(ETH_P_IPV6))
880 iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
881 #endif
882 else
883 iph->ttl = ip4_dst_hoplimit(&rt->dst);
884 }
885
886 ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
887 ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
888 htons(ETH_P_TEB) : skb->protocol;
889
890 if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
891 __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
892
893 if (tunnel->parms.o_flags&GRE_SEQ) {
894 ++tunnel->o_seqno;
895 *ptr = htonl(tunnel->o_seqno);
896 ptr--;
897 }
898 if (tunnel->parms.o_flags&GRE_KEY) {
899 *ptr = tunnel->parms.o_key;
900 ptr--;
901 }
902 if (tunnel->parms.o_flags&GRE_CSUM) {
903 *ptr = 0;
904 *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
905 }
906 }
907
908 nf_reset(skb);
909 tstats = this_cpu_ptr(dev->tstats);
910 __IPTUNNEL_XMIT(tstats, &dev->stats);
911 return NETDEV_TX_OK;
912
913 tx_error_icmp:
914 dst_link_failure(skb);
915
916 tx_error:
917 dev->stats.tx_errors++;
918 dev_kfree_skb(skb);
919 return NETDEV_TX_OK;
920 }
921
922 static int ipgre_tunnel_bind_dev(struct net_device *dev)
923 {
924 struct net_device *tdev = NULL;
925 struct ip_tunnel *tunnel;
926 const struct iphdr *iph;
927 int hlen = LL_MAX_HEADER;
928 int mtu = ETH_DATA_LEN;
929 int addend = sizeof(struct iphdr) + 4;
930
931 tunnel = netdev_priv(dev);
932 iph = &tunnel->parms.iph;
933
934 /* Guess output device to choose reasonable mtu and needed_headroom */
935
936 if (iph->daddr) {
937 struct flowi4 fl4;
938 struct rtable *rt;
939
940 rt = ip_route_output_gre(dev_net(dev), &fl4,
941 iph->daddr, iph->saddr,
942 tunnel->parms.o_key,
943 RT_TOS(iph->tos),
944 tunnel->parms.link);
945 if (!IS_ERR(rt)) {
946 tdev = rt->dst.dev;
947 ip_rt_put(rt);
948 }
949
950 if (dev->type != ARPHRD_ETHER)
951 dev->flags |= IFF_POINTOPOINT;
952 }
953
954 if (!tdev && tunnel->parms.link)
955 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
956
957 if (tdev) {
958 hlen = tdev->hard_header_len + tdev->needed_headroom;
959 mtu = tdev->mtu;
960 }
961 dev->iflink = tunnel->parms.link;
962
963 /* Precalculate GRE options length */
964 if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
965 if (tunnel->parms.o_flags&GRE_CSUM)
966 addend += 4;
967 if (tunnel->parms.o_flags&GRE_KEY)
968 addend += 4;
969 if (tunnel->parms.o_flags&GRE_SEQ)
970 addend += 4;
971 }
972 dev->needed_headroom = addend + hlen;
973 mtu -= dev->hard_header_len + addend;
974
975 if (mtu < 68)
976 mtu = 68;
977
978 tunnel->hlen = addend;
979
980 return mtu;
981 }
982
983 static int
984 ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
985 {
986 int err = 0;
987 struct ip_tunnel_parm p;
988 struct ip_tunnel *t;
989 struct net *net = dev_net(dev);
990 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
991
992 switch (cmd) {
993 case SIOCGETTUNNEL:
994 t = NULL;
995 if (dev == ign->fb_tunnel_dev) {
996 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
997 err = -EFAULT;
998 break;
999 }
1000 t = ipgre_tunnel_locate(net, &p, 0);
1001 }
1002 if (t == NULL)
1003 t = netdev_priv(dev);
1004 memcpy(&p, &t->parms, sizeof(p));
1005 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1006 err = -EFAULT;
1007 break;
1008
1009 case SIOCADDTUNNEL:
1010 case SIOCCHGTUNNEL:
1011 err = -EPERM;
1012 if (!capable(CAP_NET_ADMIN))
1013 goto done;
1014
1015 err = -EFAULT;
1016 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1017 goto done;
1018
1019 err = -EINVAL;
1020 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
1021 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
1022 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
1023 goto done;
1024 if (p.iph.ttl)
1025 p.iph.frag_off |= htons(IP_DF);
1026
1027 if (!(p.i_flags&GRE_KEY))
1028 p.i_key = 0;
1029 if (!(p.o_flags&GRE_KEY))
1030 p.o_key = 0;
1031
1032 t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1033
1034 if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1035 if (t != NULL) {
1036 if (t->dev != dev) {
1037 err = -EEXIST;
1038 break;
1039 }
1040 } else {
1041 unsigned int nflags = 0;
1042
1043 t = netdev_priv(dev);
1044
1045 if (ipv4_is_multicast(p.iph.daddr))
1046 nflags = IFF_BROADCAST;
1047 else if (p.iph.daddr)
1048 nflags = IFF_POINTOPOINT;
1049
1050 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
1051 err = -EINVAL;
1052 break;
1053 }
1054 ipgre_tunnel_unlink(ign, t);
1055 synchronize_net();
1056 t->parms.iph.saddr = p.iph.saddr;
1057 t->parms.iph.daddr = p.iph.daddr;
1058 t->parms.i_key = p.i_key;
1059 t->parms.o_key = p.o_key;
1060 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1061 memcpy(dev->broadcast, &p.iph.daddr, 4);
1062 ipgre_tunnel_link(ign, t);
1063 netdev_state_change(dev);
1064 }
1065 }
1066
1067 if (t) {
1068 err = 0;
1069 if (cmd == SIOCCHGTUNNEL) {
1070 t->parms.iph.ttl = p.iph.ttl;
1071 t->parms.iph.tos = p.iph.tos;
1072 t->parms.iph.frag_off = p.iph.frag_off;
1073 if (t->parms.link != p.link) {
1074 t->parms.link = p.link;
1075 dev->mtu = ipgre_tunnel_bind_dev(dev);
1076 netdev_state_change(dev);
1077 }
1078 }
1079 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1080 err = -EFAULT;
1081 } else
1082 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1083 break;
1084
1085 case SIOCDELTUNNEL:
1086 err = -EPERM;
1087 if (!capable(CAP_NET_ADMIN))
1088 goto done;
1089
1090 if (dev == ign->fb_tunnel_dev) {
1091 err = -EFAULT;
1092 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1093 goto done;
1094 err = -ENOENT;
1095 if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
1096 goto done;
1097 err = -EPERM;
1098 if (t == netdev_priv(ign->fb_tunnel_dev))
1099 goto done;
1100 dev = t->dev;
1101 }
1102 unregister_netdevice(dev);
1103 err = 0;
1104 break;
1105
1106 default:
1107 err = -EINVAL;
1108 }
1109
1110 done:
1111 return err;
1112 }
1113
1114 static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1115 {
1116 struct ip_tunnel *tunnel = netdev_priv(dev);
1117 if (new_mtu < 68 ||
1118 new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
1119 return -EINVAL;
1120 dev->mtu = new_mtu;
1121 return 0;
1122 }
1123
1124 /* Nice toy. Unfortunately, useless in real life :-)
1125 It allows to construct virtual multiprotocol broadcast "LAN"
1126 over the Internet, provided multicast routing is tuned.
1127
1128
1129 I have no idea was this bicycle invented before me,
1130 so that I had to set ARPHRD_IPGRE to a random value.
1131 I have an impression, that Cisco could make something similar,
1132 but this feature is apparently missing in IOS<=11.2(8).
1133
1134 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
1135 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
1136
1137 ping -t 255 224.66.66.66
1138
1139 If nobody answers, mbone does not work.
1140
1141 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
1142 ip addr add 10.66.66.<somewhat>/24 dev Universe
1143 ifconfig Universe up
1144 ifconfig Universe add fe80::<Your_real_addr>/10
1145 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
1146 ftp 10.66.66.66
1147 ...
1148 ftp fec0:6666:6666::193.233.7.65
1149 ...
1150
1151 */
1152
1153 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
1154 unsigned short type,
1155 const void *daddr, const void *saddr, unsigned int len)
1156 {
1157 struct ip_tunnel *t = netdev_priv(dev);
1158 struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
1159 __be16 *p = (__be16*)(iph+1);
1160
1161 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
1162 p[0] = t->parms.o_flags;
1163 p[1] = htons(type);
1164
1165 /*
1166 * Set the source hardware address.
1167 */
1168
1169 if (saddr)
1170 memcpy(&iph->saddr, saddr, 4);
1171 if (daddr)
1172 memcpy(&iph->daddr, daddr, 4);
1173 if (iph->daddr)
1174 return t->hlen;
1175
1176 return -t->hlen;
1177 }
1178
1179 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
1180 {
1181 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
1182 memcpy(haddr, &iph->saddr, 4);
1183 return 4;
1184 }
1185
1186 static const struct header_ops ipgre_header_ops = {
1187 .create = ipgre_header,
1188 .parse = ipgre_header_parse,
1189 };
1190
1191 #ifdef CONFIG_NET_IPGRE_BROADCAST
1192 static int ipgre_open(struct net_device *dev)
1193 {
1194 struct ip_tunnel *t = netdev_priv(dev);
1195
1196 if (ipv4_is_multicast(t->parms.iph.daddr)) {
1197 struct flowi4 fl4;
1198 struct rtable *rt;
1199
1200 rt = ip_route_output_gre(dev_net(dev), &fl4,
1201 t->parms.iph.daddr,
1202 t->parms.iph.saddr,
1203 t->parms.o_key,
1204 RT_TOS(t->parms.iph.tos),
1205 t->parms.link);
1206 if (IS_ERR(rt))
1207 return -EADDRNOTAVAIL;
1208 dev = rt->dst.dev;
1209 ip_rt_put(rt);
1210 if (__in_dev_get_rtnl(dev) == NULL)
1211 return -EADDRNOTAVAIL;
1212 t->mlink = dev->ifindex;
1213 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
1214 }
1215 return 0;
1216 }
1217
1218 static int ipgre_close(struct net_device *dev)
1219 {
1220 struct ip_tunnel *t = netdev_priv(dev);
1221
1222 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
1223 struct in_device *in_dev;
1224 in_dev = inetdev_by_index(dev_net(dev), t->mlink);
1225 if (in_dev)
1226 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
1227 }
1228 return 0;
1229 }
1230
1231 #endif
1232
1233 static const struct net_device_ops ipgre_netdev_ops = {
1234 .ndo_init = ipgre_tunnel_init,
1235 .ndo_uninit = ipgre_tunnel_uninit,
1236 #ifdef CONFIG_NET_IPGRE_BROADCAST
1237 .ndo_open = ipgre_open,
1238 .ndo_stop = ipgre_close,
1239 #endif
1240 .ndo_start_xmit = ipgre_tunnel_xmit,
1241 .ndo_do_ioctl = ipgre_tunnel_ioctl,
1242 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1243 .ndo_get_stats = ipgre_get_stats,
1244 };
1245
1246 static void ipgre_dev_free(struct net_device *dev)
1247 {
1248 free_percpu(dev->tstats);
1249 free_netdev(dev);
1250 }
1251
1252 static void ipgre_tunnel_setup(struct net_device *dev)
1253 {
1254 dev->netdev_ops = &ipgre_netdev_ops;
1255 dev->destructor = ipgre_dev_free;
1256
1257 dev->type = ARPHRD_IPGRE;
1258 dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
1259 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
1260 dev->flags = IFF_NOARP;
1261 dev->iflink = 0;
1262 dev->addr_len = 4;
1263 dev->features |= NETIF_F_NETNS_LOCAL;
1264 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1265 }
1266
1267 static int ipgre_tunnel_init(struct net_device *dev)
1268 {
1269 struct ip_tunnel *tunnel;
1270 struct iphdr *iph;
1271
1272 tunnel = netdev_priv(dev);
1273 iph = &tunnel->parms.iph;
1274
1275 tunnel->dev = dev;
1276 strcpy(tunnel->parms.name, dev->name);
1277
1278 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1279 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1280
1281 if (iph->daddr) {
1282 #ifdef CONFIG_NET_IPGRE_BROADCAST
1283 if (ipv4_is_multicast(iph->daddr)) {
1284 if (!iph->saddr)
1285 return -EINVAL;
1286 dev->flags = IFF_BROADCAST;
1287 dev->header_ops = &ipgre_header_ops;
1288 }
1289 #endif
1290 } else
1291 dev->header_ops = &ipgre_header_ops;
1292
1293 dev->tstats = alloc_percpu(struct pcpu_tstats);
1294 if (!dev->tstats)
1295 return -ENOMEM;
1296
1297 return 0;
1298 }
1299
1300 static void ipgre_fb_tunnel_init(struct net_device *dev)
1301 {
1302 struct ip_tunnel *tunnel = netdev_priv(dev);
1303 struct iphdr *iph = &tunnel->parms.iph;
1304
1305 tunnel->dev = dev;
1306 strcpy(tunnel->parms.name, dev->name);
1307
1308 iph->version = 4;
1309 iph->protocol = IPPROTO_GRE;
1310 iph->ihl = 5;
1311 tunnel->hlen = sizeof(struct iphdr) + 4;
1312
1313 dev_hold(dev);
1314 }
1315
1316
1317 static const struct gre_protocol ipgre_protocol = {
1318 .handler = ipgre_rcv,
1319 .err_handler = ipgre_err,
1320 };
1321
1322 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
1323 {
1324 int prio;
1325
1326 for (prio = 0; prio < 4; prio++) {
1327 int h;
1328 for (h = 0; h < HASH_SIZE; h++) {
1329 struct ip_tunnel *t;
1330
1331 t = rtnl_dereference(ign->tunnels[prio][h]);
1332
1333 while (t != NULL) {
1334 unregister_netdevice_queue(t->dev, head);
1335 t = rtnl_dereference(t->next);
1336 }
1337 }
1338 }
1339 }
1340
1341 static int __net_init ipgre_init_net(struct net *net)
1342 {
1343 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1344 int err;
1345
1346 ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
1347 ipgre_tunnel_setup);
1348 if (!ign->fb_tunnel_dev) {
1349 err = -ENOMEM;
1350 goto err_alloc_dev;
1351 }
1352 dev_net_set(ign->fb_tunnel_dev, net);
1353
1354 ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
1355 ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
1356
1357 if ((err = register_netdev(ign->fb_tunnel_dev)))
1358 goto err_reg_dev;
1359
1360 rcu_assign_pointer(ign->tunnels_wc[0],
1361 netdev_priv(ign->fb_tunnel_dev));
1362 return 0;
1363
1364 err_reg_dev:
1365 ipgre_dev_free(ign->fb_tunnel_dev);
1366 err_alloc_dev:
1367 return err;
1368 }
1369
1370 static void __net_exit ipgre_exit_net(struct net *net)
1371 {
1372 struct ipgre_net *ign;
1373 LIST_HEAD(list);
1374
1375 ign = net_generic(net, ipgre_net_id);
1376 rtnl_lock();
1377 ipgre_destroy_tunnels(ign, &list);
1378 unregister_netdevice_many(&list);
1379 rtnl_unlock();
1380 }
1381
1382 static struct pernet_operations ipgre_net_ops = {
1383 .init = ipgre_init_net,
1384 .exit = ipgre_exit_net,
1385 .id = &ipgre_net_id,
1386 .size = sizeof(struct ipgre_net),
1387 };
1388
1389 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
1390 {
1391 __be16 flags;
1392
1393 if (!data)
1394 return 0;
1395
1396 flags = 0;
1397 if (data[IFLA_GRE_IFLAGS])
1398 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1399 if (data[IFLA_GRE_OFLAGS])
1400 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1401 if (flags & (GRE_VERSION|GRE_ROUTING))
1402 return -EINVAL;
1403
1404 return 0;
1405 }
1406
1407 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
1408 {
1409 __be32 daddr;
1410
1411 if (tb[IFLA_ADDRESS]) {
1412 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1413 return -EINVAL;
1414 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1415 return -EADDRNOTAVAIL;
1416 }
1417
1418 if (!data)
1419 goto out;
1420
1421 if (data[IFLA_GRE_REMOTE]) {
1422 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1423 if (!daddr)
1424 return -EINVAL;
1425 }
1426
1427 out:
1428 return ipgre_tunnel_validate(tb, data);
1429 }
1430
1431 static void ipgre_netlink_parms(struct nlattr *data[],
1432 struct ip_tunnel_parm *parms)
1433 {
1434 memset(parms, 0, sizeof(*parms));
1435
1436 parms->iph.protocol = IPPROTO_GRE;
1437
1438 if (!data)
1439 return;
1440
1441 if (data[IFLA_GRE_LINK])
1442 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1443
1444 if (data[IFLA_GRE_IFLAGS])
1445 parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
1446
1447 if (data[IFLA_GRE_OFLAGS])
1448 parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
1449
1450 if (data[IFLA_GRE_IKEY])
1451 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1452
1453 if (data[IFLA_GRE_OKEY])
1454 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1455
1456 if (data[IFLA_GRE_LOCAL])
1457 parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
1458
1459 if (data[IFLA_GRE_REMOTE])
1460 parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
1461
1462 if (data[IFLA_GRE_TTL])
1463 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1464
1465 if (data[IFLA_GRE_TOS])
1466 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1467
1468 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1469 parms->iph.frag_off = htons(IP_DF);
1470 }
1471
1472 static int ipgre_tap_init(struct net_device *dev)
1473 {
1474 struct ip_tunnel *tunnel;
1475
1476 tunnel = netdev_priv(dev);
1477
1478 tunnel->dev = dev;
1479 strcpy(tunnel->parms.name, dev->name);
1480
1481 ipgre_tunnel_bind_dev(dev);
1482
1483 dev->tstats = alloc_percpu(struct pcpu_tstats);
1484 if (!dev->tstats)
1485 return -ENOMEM;
1486
1487 return 0;
1488 }
1489
1490 static const struct net_device_ops ipgre_tap_netdev_ops = {
1491 .ndo_init = ipgre_tap_init,
1492 .ndo_uninit = ipgre_tunnel_uninit,
1493 .ndo_start_xmit = ipgre_tunnel_xmit,
1494 .ndo_set_mac_address = eth_mac_addr,
1495 .ndo_validate_addr = eth_validate_addr,
1496 .ndo_change_mtu = ipgre_tunnel_change_mtu,
1497 .ndo_get_stats = ipgre_get_stats,
1498 };
1499
1500 static void ipgre_tap_setup(struct net_device *dev)
1501 {
1502
1503 ether_setup(dev);
1504
1505 dev->netdev_ops = &ipgre_tap_netdev_ops;
1506 dev->destructor = ipgre_dev_free;
1507
1508 dev->iflink = 0;
1509 dev->features |= NETIF_F_NETNS_LOCAL;
1510 }
1511
1512 static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
1513 struct nlattr *data[])
1514 {
1515 struct ip_tunnel *nt;
1516 struct net *net = dev_net(dev);
1517 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1518 int mtu;
1519 int err;
1520
1521 nt = netdev_priv(dev);
1522 ipgre_netlink_parms(data, &nt->parms);
1523
1524 if (ipgre_tunnel_find(net, &nt->parms, dev->type))
1525 return -EEXIST;
1526
1527 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
1528 random_ether_addr(dev->dev_addr);
1529
1530 mtu = ipgre_tunnel_bind_dev(dev);
1531 if (!tb[IFLA_MTU])
1532 dev->mtu = mtu;
1533
1534 /* Can use a lockless transmit, unless we generate output sequences */
1535 if (!(nt->parms.o_flags & GRE_SEQ))
1536 dev->features |= NETIF_F_LLTX;
1537
1538 err = register_netdevice(dev);
1539 if (err)
1540 goto out;
1541
1542 dev_hold(dev);
1543 ipgre_tunnel_link(ign, nt);
1544
1545 out:
1546 return err;
1547 }
1548
1549 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1550 struct nlattr *data[])
1551 {
1552 struct ip_tunnel *t, *nt;
1553 struct net *net = dev_net(dev);
1554 struct ipgre_net *ign = net_generic(net, ipgre_net_id);
1555 struct ip_tunnel_parm p;
1556 int mtu;
1557
1558 if (dev == ign->fb_tunnel_dev)
1559 return -EINVAL;
1560
1561 nt = netdev_priv(dev);
1562 ipgre_netlink_parms(data, &p);
1563
1564 t = ipgre_tunnel_locate(net, &p, 0);
1565
1566 if (t) {
1567 if (t->dev != dev)
1568 return -EEXIST;
1569 } else {
1570 t = nt;
1571
1572 if (dev->type != ARPHRD_ETHER) {
1573 unsigned int nflags = 0;
1574
1575 if (ipv4_is_multicast(p.iph.daddr))
1576 nflags = IFF_BROADCAST;
1577 else if (p.iph.daddr)
1578 nflags = IFF_POINTOPOINT;
1579
1580 if ((dev->flags ^ nflags) &
1581 (IFF_POINTOPOINT | IFF_BROADCAST))
1582 return -EINVAL;
1583 }
1584
1585 ipgre_tunnel_unlink(ign, t);
1586 t->parms.iph.saddr = p.iph.saddr;
1587 t->parms.iph.daddr = p.iph.daddr;
1588 t->parms.i_key = p.i_key;
1589 if (dev->type != ARPHRD_ETHER) {
1590 memcpy(dev->dev_addr, &p.iph.saddr, 4);
1591 memcpy(dev->broadcast, &p.iph.daddr, 4);
1592 }
1593 ipgre_tunnel_link(ign, t);
1594 netdev_state_change(dev);
1595 }
1596
1597 t->parms.o_key = p.o_key;
1598 t->parms.iph.ttl = p.iph.ttl;
1599 t->parms.iph.tos = p.iph.tos;
1600 t->parms.iph.frag_off = p.iph.frag_off;
1601
1602 if (t->parms.link != p.link) {
1603 t->parms.link = p.link;
1604 mtu = ipgre_tunnel_bind_dev(dev);
1605 if (!tb[IFLA_MTU])
1606 dev->mtu = mtu;
1607 netdev_state_change(dev);
1608 }
1609
1610 return 0;
1611 }
1612
1613 static size_t ipgre_get_size(const struct net_device *dev)
1614 {
1615 return
1616 /* IFLA_GRE_LINK */
1617 nla_total_size(4) +
1618 /* IFLA_GRE_IFLAGS */
1619 nla_total_size(2) +
1620 /* IFLA_GRE_OFLAGS */
1621 nla_total_size(2) +
1622 /* IFLA_GRE_IKEY */
1623 nla_total_size(4) +
1624 /* IFLA_GRE_OKEY */
1625 nla_total_size(4) +
1626 /* IFLA_GRE_LOCAL */
1627 nla_total_size(4) +
1628 /* IFLA_GRE_REMOTE */
1629 nla_total_size(4) +
1630 /* IFLA_GRE_TTL */
1631 nla_total_size(1) +
1632 /* IFLA_GRE_TOS */
1633 nla_total_size(1) +
1634 /* IFLA_GRE_PMTUDISC */
1635 nla_total_size(1) +
1636 0;
1637 }
1638
1639 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1640 {
1641 struct ip_tunnel *t = netdev_priv(dev);
1642 struct ip_tunnel_parm *p = &t->parms;
1643
1644 NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
1645 NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
1646 NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
1647 NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
1648 NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
1649 NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
1650 NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
1651 NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
1652 NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
1653 NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
1654
1655 return 0;
1656
1657 nla_put_failure:
1658 return -EMSGSIZE;
1659 }
1660
1661 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1662 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1663 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1664 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1665 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1666 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1667 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1668 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1669 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1670 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1671 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1672 };
1673
1674 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1675 .kind = "gre",
1676 .maxtype = IFLA_GRE_MAX,
1677 .policy = ipgre_policy,
1678 .priv_size = sizeof(struct ip_tunnel),
1679 .setup = ipgre_tunnel_setup,
1680 .validate = ipgre_tunnel_validate,
1681 .newlink = ipgre_newlink,
1682 .changelink = ipgre_changelink,
1683 .get_size = ipgre_get_size,
1684 .fill_info = ipgre_fill_info,
1685 };
1686
1687 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1688 .kind = "gretap",
1689 .maxtype = IFLA_GRE_MAX,
1690 .policy = ipgre_policy,
1691 .priv_size = sizeof(struct ip_tunnel),
1692 .setup = ipgre_tap_setup,
1693 .validate = ipgre_tap_validate,
1694 .newlink = ipgre_newlink,
1695 .changelink = ipgre_changelink,
1696 .get_size = ipgre_get_size,
1697 .fill_info = ipgre_fill_info,
1698 };
1699
1700 /*
1701 * And now the modules code and kernel interface.
1702 */
1703
1704 static int __init ipgre_init(void)
1705 {
1706 int err;
1707
1708 printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
1709
1710 err = register_pernet_device(&ipgre_net_ops);
1711 if (err < 0)
1712 return err;
1713
1714 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1715 if (err < 0) {
1716 printk(KERN_INFO "ipgre init: can't add protocol\n");
1717 goto add_proto_failed;
1718 }
1719
1720 err = rtnl_link_register(&ipgre_link_ops);
1721 if (err < 0)
1722 goto rtnl_link_failed;
1723
1724 err = rtnl_link_register(&ipgre_tap_ops);
1725 if (err < 0)
1726 goto tap_ops_failed;
1727
1728 out:
1729 return err;
1730
1731 tap_ops_failed:
1732 rtnl_link_unregister(&ipgre_link_ops);
1733 rtnl_link_failed:
1734 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1735 add_proto_failed:
1736 unregister_pernet_device(&ipgre_net_ops);
1737 goto out;
1738 }
1739
1740 static void __exit ipgre_fini(void)
1741 {
1742 rtnl_link_unregister(&ipgre_tap_ops);
1743 rtnl_link_unregister(&ipgre_link_ops);
1744 if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
1745 printk(KERN_INFO "ipgre close: can't remove protocol\n");
1746 unregister_pernet_device(&ipgre_net_ops);
1747 }
1748
1749 module_init(ipgre_init);
1750 module_exit(ipgre_fini);
1751 MODULE_LICENSE("GPL");
1752 MODULE_ALIAS_RTNL_LINK("gre");
1753 MODULE_ALIAS_RTNL_LINK("gretap");
1754 MODULE_ALIAS_NETDEV("gre0");
WandBoard kernel