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/if_vlan.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/ip_tunnels.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 #include <net/dst_metadata.h>
51
52 #if IS_ENABLED(CONFIG_IPV6)
53 #include <net/ipv6.h>
54 #include <net/ip6_fib.h>
55 #include <net/ip6_route.h>
56 #endif
57
58 /*
59 Problems & solutions
60 --------------------
61
62 1. The most important issue is detecting local dead loops.
63 They would cause complete host lockup in transmit, which
64 would be "resolved" by stack overflow or, if queueing is enabled,
65 with infinite looping in net_bh.
66
67 We cannot track such dead loops during route installation,
68 it is infeasible task. The most general solutions would be
69 to keep skb->encapsulation counter (sort of local ttl),
70 and silently drop packet when it expires. It is a good
71 solution, but it supposes maintaining new variable in ALL
72 skb, even if no tunneling is used.
73
74 Current solution: xmit_recursion breaks dead loops. This is a percpu
75 counter, since when we enter the first ndo_xmit(), cpu migration is
76 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
77
78 2. Networking dead loops would not kill routers, but would really
79 kill network. IP hop limit plays role of "t->recursion" in this case,
80 if we copy it from packet being encapsulated to upper header.
81 It is very good solution, but it introduces two problems:
82
83 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
84 do not work over tunnels.
85 - traceroute does not work. I planned to relay ICMP from tunnel,
86 so that this problem would be solved and traceroute output
87 would even more informative. This idea appeared to be wrong:
88 only Linux complies to rfc1812 now (yes, guys, Linux is the only
89 true router now :-)), all routers (at least, in neighbourhood of mine)
90 return only 8 bytes of payload. It is the end.
91
92 Hence, if we want that OSPF worked or traceroute said something reasonable,
93 we should search for another solution.
94
95 One of them is to parse packet trying to detect inner encapsulation
96 made by our node. It is difficult or even impossible, especially,
97 taking into account fragmentation. TO be short, ttl is not solution at all.
98
99 Current solution: The solution was UNEXPECTEDLY SIMPLE.
100 We force DF flag on tunnels with preconfigured hop limit,
101 that is ALL. :-) Well, it does not remove the problem completely,
102 but exponential growth of network traffic is changed to linear
103 (branches, that exceed pmtu are pruned) and tunnel mtu
104 rapidly degrades to value <68, where looping stops.
105 Yes, it is not good if there exists a router in the loop,
106 which does not force DF, even when encapsulating packets have DF set.
107 But it is not our problem! Nobody could accuse us, we made
108 all that we could make. Even if it is your gated who injected
109 fatal route to network, even if it were you who configured
110 fatal static route: you are innocent. :-)
111
112 Alexey Kuznetsov.
113 */
114
115 static bool log_ecn_error = true;
116 module_param(log_ecn_error, bool, 0644);
117 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118
119 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
120 static int ipgre_tunnel_init(struct net_device *dev);
121
122 static int ipgre_net_id __read_mostly;
123 static int gre_tap_net_id __read_mostly;
124
125 static int ip_gre_calc_hlen(__be16 o_flags)
126 {
127 int addend = 4;
128
129 if (o_flags & TUNNEL_CSUM)
130 addend += 4;
131 if (o_flags & TUNNEL_KEY)
132 addend += 4;
133 if (o_flags & TUNNEL_SEQ)
134 addend += 4;
135 return addend;
136 }
137
138 static __be16 gre_flags_to_tnl_flags(__be16 flags)
139 {
140 __be16 tflags = 0;
141
142 if (flags & GRE_CSUM)
143 tflags |= TUNNEL_CSUM;
144 if (flags & GRE_ROUTING)
145 tflags |= TUNNEL_ROUTING;
146 if (flags & GRE_KEY)
147 tflags |= TUNNEL_KEY;
148 if (flags & GRE_SEQ)
149 tflags |= TUNNEL_SEQ;
150 if (flags & GRE_STRICT)
151 tflags |= TUNNEL_STRICT;
152 if (flags & GRE_REC)
153 tflags |= TUNNEL_REC;
154 if (flags & GRE_VERSION)
155 tflags |= TUNNEL_VERSION;
156
157 return tflags;
158 }
159
160 static __be16 tnl_flags_to_gre_flags(__be16 tflags)
161 {
162 __be16 flags = 0;
163
164 if (tflags & TUNNEL_CSUM)
165 flags |= GRE_CSUM;
166 if (tflags & TUNNEL_ROUTING)
167 flags |= GRE_ROUTING;
168 if (tflags & TUNNEL_KEY)
169 flags |= GRE_KEY;
170 if (tflags & TUNNEL_SEQ)
171 flags |= GRE_SEQ;
172 if (tflags & TUNNEL_STRICT)
173 flags |= GRE_STRICT;
174 if (tflags & TUNNEL_REC)
175 flags |= GRE_REC;
176 if (tflags & TUNNEL_VERSION)
177 flags |= GRE_VERSION;
178
179 return flags;
180 }
181
182 /* Fills in tpi and returns header length to be pulled. */
183 static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
184 bool *csum_err)
185 {
186 const struct gre_base_hdr *greh;
187 __be32 *options;
188 int hdr_len;
189
190 if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
191 return -EINVAL;
192
193 greh = (struct gre_base_hdr *)skb_transport_header(skb);
194 if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
195 return -EINVAL;
196
197 tpi->flags = gre_flags_to_tnl_flags(greh->flags);
198 hdr_len = ip_gre_calc_hlen(tpi->flags);
199
200 if (!pskb_may_pull(skb, hdr_len))
201 return -EINVAL;
202
203 greh = (struct gre_base_hdr *)skb_transport_header(skb);
204 tpi->proto = greh->protocol;
205
206 options = (__be32 *)(greh + 1);
207 if (greh->flags & GRE_CSUM) {
208 if (skb_checksum_simple_validate(skb)) {
209 *csum_err = true;
210 return -EINVAL;
211 }
212
213 skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
214 null_compute_pseudo);
215 options++;
216 }
217
218 if (greh->flags & GRE_KEY) {
219 tpi->key = *options;
220 options++;
221 } else {
222 tpi->key = 0;
223 }
224 if (unlikely(greh->flags & GRE_SEQ)) {
225 tpi->seq = *options;
226 options++;
227 } else {
228 tpi->seq = 0;
229 }
230 /* WCCP version 1 and 2 protocol decoding.
231 * - Change protocol to IP
232 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
233 */
234 if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
235 tpi->proto = htons(ETH_P_IP);
236 if ((*(u8 *)options & 0xF0) != 0x40) {
237 hdr_len += 4;
238 if (!pskb_may_pull(skb, hdr_len))
239 return -EINVAL;
240 }
241 }
242 return hdr_len;
243 }
244
245 static void ipgre_err(struct sk_buff *skb, u32 info,
246 const struct tnl_ptk_info *tpi)
247 {
248
249 /* All the routers (except for Linux) return only
250 8 bytes of packet payload. It means, that precise relaying of
251 ICMP in the real Internet is absolutely infeasible.
252
253 Moreover, Cisco "wise men" put GRE key to the third word
254 in GRE header. It makes impossible maintaining even soft
255 state for keyed GRE tunnels with enabled checksum. Tell
256 them "thank you".
257
258 Well, I wonder, rfc1812 was written by Cisco employee,
259 what the hell these idiots break standards established
260 by themselves???
261 */
262 struct net *net = dev_net(skb->dev);
263 struct ip_tunnel_net *itn;
264 const struct iphdr *iph;
265 const int type = icmp_hdr(skb)->type;
266 const int code = icmp_hdr(skb)->code;
267 struct ip_tunnel *t;
268
269 switch (type) {
270 default:
271 case ICMP_PARAMETERPROB:
272 return;
273
274 case ICMP_DEST_UNREACH:
275 switch (code) {
276 case ICMP_SR_FAILED:
277 case ICMP_PORT_UNREACH:
278 /* Impossible event. */
279 return;
280 default:
281 /* All others are translated to HOST_UNREACH.
282 rfc2003 contains "deep thoughts" about NET_UNREACH,
283 I believe they are just ether pollution. --ANK
284 */
285 break;
286 }
287 break;
288
289 case ICMP_TIME_EXCEEDED:
290 if (code != ICMP_EXC_TTL)
291 return;
292 break;
293
294 case ICMP_REDIRECT:
295 break;
296 }
297
298 if (tpi->proto == htons(ETH_P_TEB))
299 itn = net_generic(net, gre_tap_net_id);
300 else
301 itn = net_generic(net, ipgre_net_id);
302
303 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
304 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
305 iph->daddr, iph->saddr, tpi->key);
306
307 if (!t)
308 return;
309
310 if (t->parms.iph.daddr == 0 ||
311 ipv4_is_multicast(t->parms.iph.daddr))
312 return;
313
314 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
315 return;
316
317 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
318 t->err_count++;
319 else
320 t->err_count = 1;
321 t->err_time = jiffies;
322 }
323
324 static void gre_err(struct sk_buff *skb, u32 info)
325 {
326 /* All the routers (except for Linux) return only
327 * 8 bytes of packet payload. It means, that precise relaying of
328 * ICMP in the real Internet is absolutely infeasible.
329 *
330 * Moreover, Cisco "wise men" put GRE key to the third word
331 * in GRE header. It makes impossible maintaining even soft
332 * state for keyed
333 * GRE tunnels with enabled checksum. Tell them "thank you".
334 *
335 * Well, I wonder, rfc1812 was written by Cisco employee,
336 * what the hell these idiots break standards established
337 * by themselves???
338 */
339
340 const int type = icmp_hdr(skb)->type;
341 const int code = icmp_hdr(skb)->code;
342 struct tnl_ptk_info tpi;
343 bool csum_err = false;
344
345 if (parse_gre_header(skb, &tpi, &csum_err) < 0) {
346 if (!csum_err) /* ignore csum errors. */
347 return;
348 }
349
350 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
351 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
352 skb->dev->ifindex, 0, IPPROTO_GRE, 0);
353 return;
354 }
355 if (type == ICMP_REDIRECT) {
356 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0,
357 IPPROTO_GRE, 0);
358 return;
359 }
360
361 ipgre_err(skb, info, &tpi);
362 }
363
364 static __be64 key_to_tunnel_id(__be32 key)
365 {
366 #ifdef __BIG_ENDIAN
367 return (__force __be64)((__force u32)key);
368 #else
369 return (__force __be64)((__force u64)key << 32);
370 #endif
371 }
372
373 /* Returns the least-significant 32 bits of a __be64. */
374 static __be32 tunnel_id_to_key(__be64 x)
375 {
376 #ifdef __BIG_ENDIAN
377 return (__force __be32)x;
378 #else
379 return (__force __be32)((__force u64)x >> 32);
380 #endif
381 }
382
383 static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
384 {
385 struct net *net = dev_net(skb->dev);
386 struct metadata_dst *tun_dst = NULL;
387 struct ip_tunnel_net *itn;
388 const struct iphdr *iph;
389 struct ip_tunnel *tunnel;
390
391 if (tpi->proto == htons(ETH_P_TEB))
392 itn = net_generic(net, gre_tap_net_id);
393 else
394 itn = net_generic(net, ipgre_net_id);
395
396 iph = ip_hdr(skb);
397 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
398 iph->saddr, iph->daddr, tpi->key);
399
400 if (tunnel) {
401 if (tunnel->dev->type != ARPHRD_NONE)
402 skb_pop_mac_header(skb);
403 else
404 skb_reset_mac_header(skb);
405 if (tunnel->collect_md) {
406 __be16 flags;
407 __be64 tun_id;
408
409 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
410 tun_id = key_to_tunnel_id(tpi->key);
411 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
412 if (!tun_dst)
413 return PACKET_REJECT;
414 }
415
416 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
417 return PACKET_RCVD;
418 }
419 return PACKET_REJECT;
420 }
421
422 static int gre_rcv(struct sk_buff *skb)
423 {
424 struct tnl_ptk_info tpi;
425 bool csum_err = false;
426 int hdr_len;
427
428 #ifdef CONFIG_NET_IPGRE_BROADCAST
429 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
430 /* Looped back packet, drop it! */
431 if (rt_is_output_route(skb_rtable(skb)))
432 goto drop;
433 }
434 #endif
435
436 hdr_len = parse_gre_header(skb, &tpi, &csum_err);
437 if (hdr_len < 0)
438 goto drop;
439 if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false) < 0)
440 goto drop;
441
442 if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
443 return 0;
444
445 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
446 drop:
447 kfree_skb(skb);
448 return 0;
449 }
450
451 static __sum16 gre_checksum(struct sk_buff *skb)
452 {
453 __wsum csum;
454
455 if (skb->ip_summed == CHECKSUM_PARTIAL)
456 csum = lco_csum(skb);
457 else
458 csum = skb_checksum(skb, 0, skb->len, 0);
459 return csum_fold(csum);
460 }
461
462 static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
463 __be16 proto, __be32 key, __be32 seq)
464 {
465 struct gre_base_hdr *greh;
466
467 skb_push(skb, hdr_len);
468
469 skb_reset_transport_header(skb);
470 greh = (struct gre_base_hdr *)skb->data;
471 greh->flags = tnl_flags_to_gre_flags(flags);
472 greh->protocol = proto;
473
474 if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
475 __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
476
477 if (flags & TUNNEL_SEQ) {
478 *ptr = seq;
479 ptr--;
480 }
481 if (flags & TUNNEL_KEY) {
482 *ptr = key;
483 ptr--;
484 }
485 if (flags & TUNNEL_CSUM &&
486 !(skb_shinfo(skb)->gso_type &
487 (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
488 *ptr = 0;
489 *(__sum16 *)ptr = gre_checksum(skb);
490 }
491 }
492 }
493
494 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
495 const struct iphdr *tnl_params,
496 __be16 proto)
497 {
498 struct ip_tunnel *tunnel = netdev_priv(dev);
499
500 if (tunnel->parms.o_flags & TUNNEL_SEQ)
501 tunnel->o_seqno++;
502
503 /* Push GRE header. */
504 build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
505 proto, tunnel->parms.o_key, htonl(tunnel->o_seqno));
506
507 skb_set_inner_protocol(skb, proto);
508 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
509 }
510
511 static struct sk_buff *gre_handle_offloads(struct sk_buff *skb,
512 bool csum)
513 {
514 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
515 }
516
517 static struct rtable *gre_get_rt(struct sk_buff *skb,
518 struct net_device *dev,
519 struct flowi4 *fl,
520 const struct ip_tunnel_key *key)
521 {
522 struct net *net = dev_net(dev);
523
524 memset(fl, 0, sizeof(*fl));
525 fl->daddr = key->u.ipv4.dst;
526 fl->saddr = key->u.ipv4.src;
527 fl->flowi4_tos = RT_TOS(key->tos);
528 fl->flowi4_mark = skb->mark;
529 fl->flowi4_proto = IPPROTO_GRE;
530
531 return ip_route_output_key(net, fl);
532 }
533
534 static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
535 __be16 proto)
536 {
537 struct ip_tunnel_info *tun_info;
538 const struct ip_tunnel_key *key;
539 struct rtable *rt = NULL;
540 struct flowi4 fl;
541 int min_headroom;
542 int tunnel_hlen;
543 __be16 df, flags;
544 bool use_cache;
545 int err;
546
547 tun_info = skb_tunnel_info(skb);
548 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
549 ip_tunnel_info_af(tun_info) != AF_INET))
550 goto err_free_skb;
551
552 key = &tun_info->key;
553 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
554 if (use_cache)
555 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr);
556 if (!rt) {
557 rt = gre_get_rt(skb, dev, &fl, key);
558 if (IS_ERR(rt))
559 goto err_free_skb;
560 if (use_cache)
561 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
562 fl.saddr);
563 }
564
565 tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);
566
567 min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
568 + tunnel_hlen + sizeof(struct iphdr);
569 if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
570 int head_delta = SKB_DATA_ALIGN(min_headroom -
571 skb_headroom(skb) +
572 16);
573 err = pskb_expand_head(skb, max_t(int, head_delta, 0),
574 0, GFP_ATOMIC);
575 if (unlikely(err))
576 goto err_free_rt;
577 }
578
579 /* Push Tunnel header. */
580 skb = gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM));
581 if (IS_ERR(skb)) {
582 skb = NULL;
583 goto err_free_rt;
584 }
585
586 flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY);
587 build_header(skb, tunnel_hlen, flags, proto,
588 tunnel_id_to_key(tun_info->key.tun_id), 0);
589
590 df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
591
592 iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE,
593 key->tos, key->ttl, df, false);
594 return;
595
596 err_free_rt:
597 ip_rt_put(rt);
598 err_free_skb:
599 kfree_skb(skb);
600 dev->stats.tx_dropped++;
601 }
602
603 static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
604 {
605 struct ip_tunnel_info *info = skb_tunnel_info(skb);
606 struct rtable *rt;
607 struct flowi4 fl4;
608
609 if (ip_tunnel_info_af(info) != AF_INET)
610 return -EINVAL;
611
612 rt = gre_get_rt(skb, dev, &fl4, &info->key);
613 if (IS_ERR(rt))
614 return PTR_ERR(rt);
615
616 ip_rt_put(rt);
617 info->key.u.ipv4.src = fl4.saddr;
618 return 0;
619 }
620
621 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
622 struct net_device *dev)
623 {
624 struct ip_tunnel *tunnel = netdev_priv(dev);
625 const struct iphdr *tnl_params;
626
627 if (tunnel->collect_md) {
628 gre_fb_xmit(skb, dev, skb->protocol);
629 return NETDEV_TX_OK;
630 }
631
632 if (dev->header_ops) {
633 /* Need space for new headers */
634 if (skb_cow_head(skb, dev->needed_headroom -
635 (tunnel->hlen + sizeof(struct iphdr))))
636 goto free_skb;
637
638 tnl_params = (const struct iphdr *)skb->data;
639
640 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
641 * to gre header.
642 */
643 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
644 skb_reset_mac_header(skb);
645 } else {
646 if (skb_cow_head(skb, dev->needed_headroom))
647 goto free_skb;
648
649 tnl_params = &tunnel->parms.iph;
650 }
651
652 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
653 if (IS_ERR(skb))
654 goto out;
655
656 __gre_xmit(skb, dev, tnl_params, skb->protocol);
657 return NETDEV_TX_OK;
658
659 free_skb:
660 kfree_skb(skb);
661 out:
662 dev->stats.tx_dropped++;
663 return NETDEV_TX_OK;
664 }
665
666 static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
667 struct net_device *dev)
668 {
669 struct ip_tunnel *tunnel = netdev_priv(dev);
670
671 if (tunnel->collect_md) {
672 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
673 return NETDEV_TX_OK;
674 }
675
676 skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
677 if (IS_ERR(skb))
678 goto out;
679
680 if (skb_cow_head(skb, dev->needed_headroom))
681 goto free_skb;
682
683 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
684 return NETDEV_TX_OK;
685
686 free_skb:
687 kfree_skb(skb);
688 out:
689 dev->stats.tx_dropped++;
690 return NETDEV_TX_OK;
691 }
692
693 static int ipgre_tunnel_ioctl(struct net_device *dev,
694 struct ifreq *ifr, int cmd)
695 {
696 int err;
697 struct ip_tunnel_parm p;
698
699 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
700 return -EFAULT;
701 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
702 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
703 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
704 ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
705 return -EINVAL;
706 }
707 p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
708 p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
709
710 err = ip_tunnel_ioctl(dev, &p, cmd);
711 if (err)
712 return err;
713
714 p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
715 p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
716
717 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
718 return -EFAULT;
719 return 0;
720 }
721
722 /* Nice toy. Unfortunately, useless in real life :-)
723 It allows to construct virtual multiprotocol broadcast "LAN"
724 over the Internet, provided multicast routing is tuned.
725
726
727 I have no idea was this bicycle invented before me,
728 so that I had to set ARPHRD_IPGRE to a random value.
729 I have an impression, that Cisco could make something similar,
730 but this feature is apparently missing in IOS<=11.2(8).
731
732 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
733 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
734
735 ping -t 255 224.66.66.66
736
737 If nobody answers, mbone does not work.
738
739 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
740 ip addr add 10.66.66.<somewhat>/24 dev Universe
741 ifconfig Universe up
742 ifconfig Universe add fe80::<Your_real_addr>/10
743 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
744 ftp 10.66.66.66
745 ...
746 ftp fec0:6666:6666::193.233.7.65
747 ...
748 */
749 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
750 unsigned short type,
751 const void *daddr, const void *saddr, unsigned int len)
752 {
753 struct ip_tunnel *t = netdev_priv(dev);
754 struct iphdr *iph;
755 struct gre_base_hdr *greh;
756
757 iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
758 greh = (struct gre_base_hdr *)(iph+1);
759 greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
760 greh->protocol = htons(type);
761
762 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
763
764 /* Set the source hardware address. */
765 if (saddr)
766 memcpy(&iph->saddr, saddr, 4);
767 if (daddr)
768 memcpy(&iph->daddr, daddr, 4);
769 if (iph->daddr)
770 return t->hlen + sizeof(*iph);
771
772 return -(t->hlen + sizeof(*iph));
773 }
774
775 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
776 {
777 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
778 memcpy(haddr, &iph->saddr, 4);
779 return 4;
780 }
781
782 static const struct header_ops ipgre_header_ops = {
783 .create = ipgre_header,
784 .parse = ipgre_header_parse,
785 };
786
787 #ifdef CONFIG_NET_IPGRE_BROADCAST
788 static int ipgre_open(struct net_device *dev)
789 {
790 struct ip_tunnel *t = netdev_priv(dev);
791
792 if (ipv4_is_multicast(t->parms.iph.daddr)) {
793 struct flowi4 fl4;
794 struct rtable *rt;
795
796 rt = ip_route_output_gre(t->net, &fl4,
797 t->parms.iph.daddr,
798 t->parms.iph.saddr,
799 t->parms.o_key,
800 RT_TOS(t->parms.iph.tos),
801 t->parms.link);
802 if (IS_ERR(rt))
803 return -EADDRNOTAVAIL;
804 dev = rt->dst.dev;
805 ip_rt_put(rt);
806 if (!__in_dev_get_rtnl(dev))
807 return -EADDRNOTAVAIL;
808 t->mlink = dev->ifindex;
809 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
810 }
811 return 0;
812 }
813
814 static int ipgre_close(struct net_device *dev)
815 {
816 struct ip_tunnel *t = netdev_priv(dev);
817
818 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
819 struct in_device *in_dev;
820 in_dev = inetdev_by_index(t->net, t->mlink);
821 if (in_dev)
822 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
823 }
824 return 0;
825 }
826 #endif
827
828 static const struct net_device_ops ipgre_netdev_ops = {
829 .ndo_init = ipgre_tunnel_init,
830 .ndo_uninit = ip_tunnel_uninit,
831 #ifdef CONFIG_NET_IPGRE_BROADCAST
832 .ndo_open = ipgre_open,
833 .ndo_stop = ipgre_close,
834 #endif
835 .ndo_start_xmit = ipgre_xmit,
836 .ndo_do_ioctl = ipgre_tunnel_ioctl,
837 .ndo_change_mtu = ip_tunnel_change_mtu,
838 .ndo_get_stats64 = ip_tunnel_get_stats64,
839 .ndo_get_iflink = ip_tunnel_get_iflink,
840 };
841
842 #define GRE_FEATURES (NETIF_F_SG | \
843 NETIF_F_FRAGLIST | \
844 NETIF_F_HIGHDMA | \
845 NETIF_F_HW_CSUM)
846
847 static void ipgre_tunnel_setup(struct net_device *dev)
848 {
849 dev->netdev_ops = &ipgre_netdev_ops;
850 dev->type = ARPHRD_IPGRE;
851 ip_tunnel_setup(dev, ipgre_net_id);
852 }
853
854 static void __gre_tunnel_init(struct net_device *dev)
855 {
856 struct ip_tunnel *tunnel;
857 int t_hlen;
858
859 tunnel = netdev_priv(dev);
860 tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
861 tunnel->parms.iph.protocol = IPPROTO_GRE;
862
863 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
864
865 t_hlen = tunnel->hlen + sizeof(struct iphdr);
866
867 dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4;
868 dev->mtu = ETH_DATA_LEN - t_hlen - 4;
869
870 dev->features |= GRE_FEATURES;
871 dev->hw_features |= GRE_FEATURES;
872
873 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
874 /* TCP offload with GRE SEQ is not supported, nor
875 * can we support 2 levels of outer headers requiring
876 * an update.
877 */
878 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
879 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
880 dev->features |= NETIF_F_GSO_SOFTWARE;
881 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
882 }
883
884 /* Can use a lockless transmit, unless we generate
885 * output sequences
886 */
887 dev->features |= NETIF_F_LLTX;
888 }
889 }
890
891 static int ipgre_tunnel_init(struct net_device *dev)
892 {
893 struct ip_tunnel *tunnel = netdev_priv(dev);
894 struct iphdr *iph = &tunnel->parms.iph;
895
896 __gre_tunnel_init(dev);
897
898 memcpy(dev->dev_addr, &iph->saddr, 4);
899 memcpy(dev->broadcast, &iph->daddr, 4);
900
901 dev->flags = IFF_NOARP;
902 netif_keep_dst(dev);
903 dev->addr_len = 4;
904
905 if (iph->daddr && !tunnel->collect_md) {
906 #ifdef CONFIG_NET_IPGRE_BROADCAST
907 if (ipv4_is_multicast(iph->daddr)) {
908 if (!iph->saddr)
909 return -EINVAL;
910 dev->flags = IFF_BROADCAST;
911 dev->header_ops = &ipgre_header_ops;
912 }
913 #endif
914 } else if (!tunnel->collect_md) {
915 dev->header_ops = &ipgre_header_ops;
916 }
917
918 return ip_tunnel_init(dev);
919 }
920
921 static const struct gre_protocol ipgre_protocol = {
922 .handler = gre_rcv,
923 .err_handler = gre_err,
924 };
925
926 static int __net_init ipgre_init_net(struct net *net)
927 {
928 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
929 }
930
931 static void __net_exit ipgre_exit_net(struct net *net)
932 {
933 struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
934 ip_tunnel_delete_net(itn, &ipgre_link_ops);
935 }
936
937 static struct pernet_operations ipgre_net_ops = {
938 .init = ipgre_init_net,
939 .exit = ipgre_exit_net,
940 .id = &ipgre_net_id,
941 .size = sizeof(struct ip_tunnel_net),
942 };
943
944 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
945 {
946 __be16 flags;
947
948 if (!data)
949 return 0;
950
951 flags = 0;
952 if (data[IFLA_GRE_IFLAGS])
953 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
954 if (data[IFLA_GRE_OFLAGS])
955 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
956 if (flags & (GRE_VERSION|GRE_ROUTING))
957 return -EINVAL;
958
959 if (data[IFLA_GRE_COLLECT_METADATA] &&
960 data[IFLA_GRE_ENCAP_TYPE] &&
961 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
962 return -EINVAL;
963
964 return 0;
965 }
966
967 static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
968 {
969 __be32 daddr;
970
971 if (tb[IFLA_ADDRESS]) {
972 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
973 return -EINVAL;
974 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
975 return -EADDRNOTAVAIL;
976 }
977
978 if (!data)
979 goto out;
980
981 if (data[IFLA_GRE_REMOTE]) {
982 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
983 if (!daddr)
984 return -EINVAL;
985 }
986
987 out:
988 return ipgre_tunnel_validate(tb, data);
989 }
990
991 static void ipgre_netlink_parms(struct net_device *dev,
992 struct nlattr *data[],
993 struct nlattr *tb[],
994 struct ip_tunnel_parm *parms)
995 {
996 memset(parms, 0, sizeof(*parms));
997
998 parms->iph.protocol = IPPROTO_GRE;
999
1000 if (!data)
1001 return;
1002
1003 if (data[IFLA_GRE_LINK])
1004 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1005
1006 if (data[IFLA_GRE_IFLAGS])
1007 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1008
1009 if (data[IFLA_GRE_OFLAGS])
1010 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1011
1012 if (data[IFLA_GRE_IKEY])
1013 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1014
1015 if (data[IFLA_GRE_OKEY])
1016 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1017
1018 if (data[IFLA_GRE_LOCAL])
1019 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1020
1021 if (data[IFLA_GRE_REMOTE])
1022 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1023
1024 if (data[IFLA_GRE_TTL])
1025 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1026
1027 if (data[IFLA_GRE_TOS])
1028 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1029
1030 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
1031 parms->iph.frag_off = htons(IP_DF);
1032
1033 if (data[IFLA_GRE_COLLECT_METADATA]) {
1034 struct ip_tunnel *t = netdev_priv(dev);
1035
1036 t->collect_md = true;
1037 if (dev->type == ARPHRD_IPGRE)
1038 dev->type = ARPHRD_NONE;
1039 }
1040 }
1041
1042 /* This function returns true when ENCAP attributes are present in the nl msg */
1043 static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1044 struct ip_tunnel_encap *ipencap)
1045 {
1046 bool ret = false;
1047
1048 memset(ipencap, 0, sizeof(*ipencap));
1049
1050 if (!data)
1051 return ret;
1052
1053 if (data[IFLA_GRE_ENCAP_TYPE]) {
1054 ret = true;
1055 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1056 }
1057
1058 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1059 ret = true;
1060 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1061 }
1062
1063 if (data[IFLA_GRE_ENCAP_SPORT]) {
1064 ret = true;
1065 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1066 }
1067
1068 if (data[IFLA_GRE_ENCAP_DPORT]) {
1069 ret = true;
1070 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1071 }
1072
1073 return ret;
1074 }
1075
1076 static int gre_tap_init(struct net_device *dev)
1077 {
1078 __gre_tunnel_init(dev);
1079 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1080
1081 return ip_tunnel_init(dev);
1082 }
1083
1084 static const struct net_device_ops gre_tap_netdev_ops = {
1085 .ndo_init = gre_tap_init,
1086 .ndo_uninit = ip_tunnel_uninit,
1087 .ndo_start_xmit = gre_tap_xmit,
1088 .ndo_set_mac_address = eth_mac_addr,
1089 .ndo_validate_addr = eth_validate_addr,
1090 .ndo_change_mtu = ip_tunnel_change_mtu,
1091 .ndo_get_stats64 = ip_tunnel_get_stats64,
1092 .ndo_get_iflink = ip_tunnel_get_iflink,
1093 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1094 };
1095
1096 static void ipgre_tap_setup(struct net_device *dev)
1097 {
1098 ether_setup(dev);
1099 dev->netdev_ops = &gre_tap_netdev_ops;
1100 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1101 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1102 ip_tunnel_setup(dev, gre_tap_net_id);
1103 }
1104
1105 static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1106 struct nlattr *tb[], struct nlattr *data[])
1107 {
1108 struct ip_tunnel_parm p;
1109 struct ip_tunnel_encap ipencap;
1110
1111 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1112 struct ip_tunnel *t = netdev_priv(dev);
1113 int err = ip_tunnel_encap_setup(t, &ipencap);
1114
1115 if (err < 0)
1116 return err;
1117 }
1118
1119 ipgre_netlink_parms(dev, data, tb, &p);
1120 return ip_tunnel_newlink(dev, tb, &p);
1121 }
1122
1123 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1124 struct nlattr *data[])
1125 {
1126 struct ip_tunnel_parm p;
1127 struct ip_tunnel_encap ipencap;
1128
1129 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1130 struct ip_tunnel *t = netdev_priv(dev);
1131 int err = ip_tunnel_encap_setup(t, &ipencap);
1132
1133 if (err < 0)
1134 return err;
1135 }
1136
1137 ipgre_netlink_parms(dev, data, tb, &p);
1138 return ip_tunnel_changelink(dev, tb, &p);
1139 }
1140
1141 static size_t ipgre_get_size(const struct net_device *dev)
1142 {
1143 return
1144 /* IFLA_GRE_LINK */
1145 nla_total_size(4) +
1146 /* IFLA_GRE_IFLAGS */
1147 nla_total_size(2) +
1148 /* IFLA_GRE_OFLAGS */
1149 nla_total_size(2) +
1150 /* IFLA_GRE_IKEY */
1151 nla_total_size(4) +
1152 /* IFLA_GRE_OKEY */
1153 nla_total_size(4) +
1154 /* IFLA_GRE_LOCAL */
1155 nla_total_size(4) +
1156 /* IFLA_GRE_REMOTE */
1157 nla_total_size(4) +
1158 /* IFLA_GRE_TTL */
1159 nla_total_size(1) +
1160 /* IFLA_GRE_TOS */
1161 nla_total_size(1) +
1162 /* IFLA_GRE_PMTUDISC */
1163 nla_total_size(1) +
1164 /* IFLA_GRE_ENCAP_TYPE */
1165 nla_total_size(2) +
1166 /* IFLA_GRE_ENCAP_FLAGS */
1167 nla_total_size(2) +
1168 /* IFLA_GRE_ENCAP_SPORT */
1169 nla_total_size(2) +
1170 /* IFLA_GRE_ENCAP_DPORT */
1171 nla_total_size(2) +
1172 /* IFLA_GRE_COLLECT_METADATA */
1173 nla_total_size(0) +
1174 0;
1175 }
1176
1177 static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1178 {
1179 struct ip_tunnel *t = netdev_priv(dev);
1180 struct ip_tunnel_parm *p = &t->parms;
1181
1182 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1183 nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
1184 nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
1185 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1186 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1187 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1188 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1189 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1190 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1191 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1192 !!(p->iph.frag_off & htons(IP_DF))))
1193 goto nla_put_failure;
1194
1195 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1196 t->encap.type) ||
1197 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1198 t->encap.sport) ||
1199 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1200 t->encap.dport) ||
1201 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1202 t->encap.flags))
1203 goto nla_put_failure;
1204
1205 if (t->collect_md) {
1206 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1207 goto nla_put_failure;
1208 }
1209
1210 return 0;
1211
1212 nla_put_failure:
1213 return -EMSGSIZE;
1214 }
1215
1216 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1217 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1218 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1219 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1220 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1221 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1222 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1223 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1224 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1225 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1226 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1227 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1228 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1229 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1230 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1231 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1232 };
1233
1234 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1235 .kind = "gre",
1236 .maxtype = IFLA_GRE_MAX,
1237 .policy = ipgre_policy,
1238 .priv_size = sizeof(struct ip_tunnel),
1239 .setup = ipgre_tunnel_setup,
1240 .validate = ipgre_tunnel_validate,
1241 .newlink = ipgre_newlink,
1242 .changelink = ipgre_changelink,
1243 .dellink = ip_tunnel_dellink,
1244 .get_size = ipgre_get_size,
1245 .fill_info = ipgre_fill_info,
1246 .get_link_net = ip_tunnel_get_link_net,
1247 };
1248
1249 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1250 .kind = "gretap",
1251 .maxtype = IFLA_GRE_MAX,
1252 .policy = ipgre_policy,
1253 .priv_size = sizeof(struct ip_tunnel),
1254 .setup = ipgre_tap_setup,
1255 .validate = ipgre_tap_validate,
1256 .newlink = ipgre_newlink,
1257 .changelink = ipgre_changelink,
1258 .dellink = ip_tunnel_dellink,
1259 .get_size = ipgre_get_size,
1260 .fill_info = ipgre_fill_info,
1261 .get_link_net = ip_tunnel_get_link_net,
1262 };
1263
1264 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1265 u8 name_assign_type)
1266 {
1267 struct nlattr *tb[IFLA_MAX + 1];
1268 struct net_device *dev;
1269 struct ip_tunnel *t;
1270 int err;
1271
1272 memset(&tb, 0, sizeof(tb));
1273
1274 dev = rtnl_create_link(net, name, name_assign_type,
1275 &ipgre_tap_ops, tb);
1276 if (IS_ERR(dev))
1277 return dev;
1278
1279 /* Configure flow based GRE device. */
1280 t = netdev_priv(dev);
1281 t->collect_md = true;
1282
1283 err = ipgre_newlink(net, dev, tb, NULL);
1284 if (err < 0)
1285 goto out;
1286
1287 /* openvswitch users expect packet sizes to be unrestricted,
1288 * so set the largest MTU we can.
1289 */
1290 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1291 if (err)
1292 goto out;
1293
1294 return dev;
1295 out:
1296 free_netdev(dev);
1297 return ERR_PTR(err);
1298 }
1299 EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1300
1301 static int __net_init ipgre_tap_init_net(struct net *net)
1302 {
1303 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1304 }
1305
1306 static void __net_exit ipgre_tap_exit_net(struct net *net)
1307 {
1308 struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
1309 ip_tunnel_delete_net(itn, &ipgre_tap_ops);
1310 }
1311
1312 static struct pernet_operations ipgre_tap_net_ops = {
1313 .init = ipgre_tap_init_net,
1314 .exit = ipgre_tap_exit_net,
1315 .id = &gre_tap_net_id,
1316 .size = sizeof(struct ip_tunnel_net),
1317 };
1318
1319 static int __init ipgre_init(void)
1320 {
1321 int err;
1322
1323 pr_info("GRE over IPv4 tunneling driver\n");
1324
1325 err = register_pernet_device(&ipgre_net_ops);
1326 if (err < 0)
1327 return err;
1328
1329 err = register_pernet_device(&ipgre_tap_net_ops);
1330 if (err < 0)
1331 goto pnet_tap_faied;
1332
1333 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1334 if (err < 0) {
1335 pr_info("%s: can't add protocol\n", __func__);
1336 goto add_proto_failed;
1337 }
1338
1339 err = rtnl_link_register(&ipgre_link_ops);
1340 if (err < 0)
1341 goto rtnl_link_failed;
1342
1343 err = rtnl_link_register(&ipgre_tap_ops);
1344 if (err < 0)
1345 goto tap_ops_failed;
1346
1347 return 0;
1348
1349 tap_ops_failed:
1350 rtnl_link_unregister(&ipgre_link_ops);
1351 rtnl_link_failed:
1352 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1353 add_proto_failed:
1354 unregister_pernet_device(&ipgre_tap_net_ops);
1355 pnet_tap_faied:
1356 unregister_pernet_device(&ipgre_net_ops);
1357 return err;
1358 }
1359
1360 static void __exit ipgre_fini(void)
1361 {
1362 rtnl_link_unregister(&ipgre_tap_ops);
1363 rtnl_link_unregister(&ipgre_link_ops);
1364 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1365 unregister_pernet_device(&ipgre_tap_net_ops);
1366 unregister_pernet_device(&ipgre_net_ops);
1367 }
1368
1369 module_init(ipgre_init);
1370 module_exit(ipgre_fini);
1371 MODULE_LICENSE("GPL");
1372 MODULE_ALIAS_RTNL_LINK("gre");
1373 MODULE_ALIAS_RTNL_LINK("gretap");
1374 MODULE_ALIAS_NETDEV("gre0");
1375 MODULE_ALIAS_NETDEV("gretap0");
1376
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.