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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: GRE over IP protocol decoder.
4 *
5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/capability.h>
11#include <linux/module.h>
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <linux/uaccess.h>
16#include <linux/skbuff.h>
17#include <linux/netdevice.h>
18#include <linux/in.h>
19#include <linux/tcp.h>
20#include <linux/udp.h>
21#include <linux/if_arp.h>
22#include <linux/if_vlan.h>
23#include <linux/init.h>
24#include <linux/in6.h>
25#include <linux/inetdevice.h>
26#include <linux/igmp.h>
27#include <linux/netfilter_ipv4.h>
28#include <linux/etherdevice.h>
29#include <linux/if_ether.h>
30
31#include <net/sock.h>
32#include <net/ip.h>
33#include <net/icmp.h>
34#include <net/protocol.h>
35#include <net/ip_tunnels.h>
36#include <net/arp.h>
37#include <net/checksum.h>
38#include <net/dsfield.h>
39#include <net/inet_ecn.h>
40#include <net/xfrm.h>
41#include <net/net_namespace.h>
42#include <net/netns/generic.h>
43#include <net/rtnetlink.h>
44#include <net/gre.h>
45#include <net/dst_metadata.h>
46#include <net/erspan.h>
47
48/*
49 Problems & solutions
50 --------------------
51
52 1. The most important issue is detecting local dead loops.
53 They would cause complete host lockup in transmit, which
54 would be "resolved" by stack overflow or, if queueing is enabled,
55 with infinite looping in net_bh.
56
57 We cannot track such dead loops during route installation,
58 it is infeasible task. The most general solutions would be
59 to keep skb->encapsulation counter (sort of local ttl),
60 and silently drop packet when it expires. It is a good
61 solution, but it supposes maintaining new variable in ALL
62 skb, even if no tunneling is used.
63
64 Current solution: xmit_recursion breaks dead loops. This is a percpu
65 counter, since when we enter the first ndo_xmit(), cpu migration is
66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
67
68 2. Networking dead loops would not kill routers, but would really
69 kill network. IP hop limit plays role of "t->recursion" in this case,
70 if we copy it from packet being encapsulated to upper header.
71 It is very good solution, but it introduces two problems:
72
73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
74 do not work over tunnels.
75 - traceroute does not work. I planned to relay ICMP from tunnel,
76 so that this problem would be solved and traceroute output
77 would even more informative. This idea appeared to be wrong:
78 only Linux complies to rfc1812 now (yes, guys, Linux is the only
79 true router now :-)), all routers (at least, in neighbourhood of mine)
80 return only 8 bytes of payload. It is the end.
81
82 Hence, if we want that OSPF worked or traceroute said something reasonable,
83 we should search for another solution.
84
85 One of them is to parse packet trying to detect inner encapsulation
86 made by our node. It is difficult or even impossible, especially,
87 taking into account fragmentation. TO be short, ttl is not solution at all.
88
89 Current solution: The solution was UNEXPECTEDLY SIMPLE.
90 We force DF flag on tunnels with preconfigured hop limit,
91 that is ALL. :-) Well, it does not remove the problem completely,
92 but exponential growth of network traffic is changed to linear
93 (branches, that exceed pmtu are pruned) and tunnel mtu
94 rapidly degrades to value <68, where looping stops.
95 Yes, it is not good if there exists a router in the loop,
96 which does not force DF, even when encapsulating packets have DF set.
97 But it is not our problem! Nobody could accuse us, we made
98 all that we could make. Even if it is your gated who injected
99 fatal route to network, even if it were you who configured
100 fatal static route: you are innocent. :-)
101
102 Alexey Kuznetsov.
103 */
104
105static bool log_ecn_error = true;
106module_param(log_ecn_error, bool, 0644);
107MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
108
109static struct rtnl_link_ops ipgre_link_ops __read_mostly;
110static int ipgre_tunnel_init(struct net_device *dev);
111static void erspan_build_header(struct sk_buff *skb,
112 u32 id, u32 index,
113 bool truncate, bool is_ipv4);
114
115static unsigned int ipgre_net_id __read_mostly;
116static unsigned int gre_tap_net_id __read_mostly;
117static unsigned int erspan_net_id __read_mostly;
118
119static int ipgre_err(struct sk_buff *skb, u32 info,
120 const struct tnl_ptk_info *tpi)
121{
122
123 /* All the routers (except for Linux) return only
124 8 bytes of packet payload. It means, that precise relaying of
125 ICMP in the real Internet is absolutely infeasible.
126
127 Moreover, Cisco "wise men" put GRE key to the third word
128 in GRE header. It makes impossible maintaining even soft
129 state for keyed GRE tunnels with enabled checksum. Tell
130 them "thank you".
131
132 Well, I wonder, rfc1812 was written by Cisco employee,
133 what the hell these idiots break standards established
134 by themselves???
135 */
136 struct net *net = dev_net(skb->dev);
137 struct ip_tunnel_net *itn;
138 const struct iphdr *iph;
139 const int type = icmp_hdr(skb)->type;
140 const int code = icmp_hdr(skb)->code;
141 unsigned int data_len = 0;
142 struct ip_tunnel *t;
143
144 if (tpi->proto == htons(ETH_P_TEB))
145 itn = net_generic(net, gre_tap_net_id);
146 else if (tpi->proto == htons(ETH_P_ERSPAN) ||
147 tpi->proto == htons(ETH_P_ERSPAN2))
148 itn = net_generic(net, erspan_net_id);
149 else
150 itn = net_generic(net, ipgre_net_id);
151
152 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
153 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
154 iph->daddr, iph->saddr, tpi->key);
155
156 if (!t)
157 return -ENOENT;
158
159 switch (type) {
160 default:
161 case ICMP_PARAMETERPROB:
162 return 0;
163
164 case ICMP_DEST_UNREACH:
165 switch (code) {
166 case ICMP_SR_FAILED:
167 case ICMP_PORT_UNREACH:
168 /* Impossible event. */
169 return 0;
170 default:
171 /* All others are translated to HOST_UNREACH.
172 rfc2003 contains "deep thoughts" about NET_UNREACH,
173 I believe they are just ether pollution. --ANK
174 */
175 break;
176 }
177 break;
178
179 case ICMP_TIME_EXCEEDED:
180 if (code != ICMP_EXC_TTL)
181 return 0;
182 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
183 break;
184
185 case ICMP_REDIRECT:
186 break;
187 }
188
189#if IS_ENABLED(CONFIG_IPV6)
190 if (tpi->proto == htons(ETH_P_IPV6) &&
191 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
192 type, data_len))
193 return 0;
194#endif
195
196 if (t->parms.iph.daddr == 0 ||
197 ipv4_is_multicast(t->parms.iph.daddr))
198 return 0;
199
200 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
201 return 0;
202
203 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
204 t->err_count++;
205 else
206 t->err_count = 1;
207 t->err_time = jiffies;
208
209 return 0;
210}
211
212static void gre_err(struct sk_buff *skb, u32 info)
213{
214 /* All the routers (except for Linux) return only
215 * 8 bytes of packet payload. It means, that precise relaying of
216 * ICMP in the real Internet is absolutely infeasible.
217 *
218 * Moreover, Cisco "wise men" put GRE key to the third word
219 * in GRE header. It makes impossible maintaining even soft
220 * state for keyed
221 * GRE tunnels with enabled checksum. Tell them "thank you".
222 *
223 * Well, I wonder, rfc1812 was written by Cisco employee,
224 * what the hell these idiots break standards established
225 * by themselves???
226 */
227
228 const struct iphdr *iph = (struct iphdr *)skb->data;
229 const int type = icmp_hdr(skb)->type;
230 const int code = icmp_hdr(skb)->code;
231 struct tnl_ptk_info tpi;
232
233 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
234 iph->ihl * 4) < 0)
235 return;
236
237 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
238 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
239 skb->dev->ifindex, IPPROTO_GRE);
240 return;
241 }
242 if (type == ICMP_REDIRECT) {
243 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
244 IPPROTO_GRE);
245 return;
246 }
247
248 ipgre_err(skb, info, &tpi);
249}
250
251static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
252 int gre_hdr_len)
253{
254 struct net *net = dev_net(skb->dev);
255 struct metadata_dst *tun_dst = NULL;
256 struct erspan_base_hdr *ershdr;
257 struct ip_tunnel_net *itn;
258 struct ip_tunnel *tunnel;
259 const struct iphdr *iph;
260 struct erspan_md2 *md2;
261 int ver;
262 int len;
263
264 itn = net_generic(net, erspan_net_id);
265
266 iph = ip_hdr(skb);
267 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
268 ver = ershdr->ver;
269
270 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
271 tpi->flags | TUNNEL_KEY,
272 iph->saddr, iph->daddr, tpi->key);
273
274 if (tunnel) {
275 len = gre_hdr_len + erspan_hdr_len(ver);
276 if (unlikely(!pskb_may_pull(skb, len)))
277 return PACKET_REJECT;
278
279 if (__iptunnel_pull_header(skb,
280 len,
281 htons(ETH_P_TEB),
282 false, false) < 0)
283 goto drop;
284
285 if (tunnel->collect_md) {
286 struct erspan_metadata *pkt_md, *md;
287 struct ip_tunnel_info *info;
288 unsigned char *gh;
289 __be64 tun_id;
290 __be16 flags;
291
292 tpi->flags |= TUNNEL_KEY;
293 flags = tpi->flags;
294 tun_id = key32_to_tunnel_id(tpi->key);
295
296 tun_dst = ip_tun_rx_dst(skb, flags,
297 tun_id, sizeof(*md));
298 if (!tun_dst)
299 return PACKET_REJECT;
300
301 /* skb can be uncloned in __iptunnel_pull_header, so
302 * old pkt_md is no longer valid and we need to reset
303 * it
304 */
305 gh = skb_network_header(skb) +
306 skb_network_header_len(skb);
307 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
308 sizeof(*ershdr));
309 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
310 md->version = ver;
311 md2 = &md->u.md2;
312 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
313 ERSPAN_V2_MDSIZE);
314
315 info = &tun_dst->u.tun_info;
316 info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
317 info->options_len = sizeof(*md);
318 }
319
320 skb_reset_mac_header(skb);
321 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
322 return PACKET_RCVD;
323 }
324 return PACKET_REJECT;
325
326drop:
327 kfree_skb(skb);
328 return PACKET_RCVD;
329}
330
331static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
332 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
333{
334 struct metadata_dst *tun_dst = NULL;
335 const struct iphdr *iph;
336 struct ip_tunnel *tunnel;
337
338 iph = ip_hdr(skb);
339 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
340 iph->saddr, iph->daddr, tpi->key);
341
342 if (tunnel) {
343 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
344 raw_proto, false) < 0)
345 goto drop;
346
347 if (tunnel->dev->type != ARPHRD_NONE)
348 skb_pop_mac_header(skb);
349 else
350 skb_reset_mac_header(skb);
351 if (tunnel->collect_md) {
352 __be16 flags;
353 __be64 tun_id;
354
355 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
356 tun_id = key32_to_tunnel_id(tpi->key);
357 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
358 if (!tun_dst)
359 return PACKET_REJECT;
360 }
361
362 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
363 return PACKET_RCVD;
364 }
365 return PACKET_NEXT;
366
367drop:
368 kfree_skb(skb);
369 return PACKET_RCVD;
370}
371
372static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
373 int hdr_len)
374{
375 struct net *net = dev_net(skb->dev);
376 struct ip_tunnel_net *itn;
377 int res;
378
379 if (tpi->proto == htons(ETH_P_TEB))
380 itn = net_generic(net, gre_tap_net_id);
381 else
382 itn = net_generic(net, ipgre_net_id);
383
384 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
385 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
386 /* ipgre tunnels in collect metadata mode should receive
387 * also ETH_P_TEB traffic.
388 */
389 itn = net_generic(net, ipgre_net_id);
390 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
391 }
392 return res;
393}
394
395static int gre_rcv(struct sk_buff *skb)
396{
397 struct tnl_ptk_info tpi;
398 bool csum_err = false;
399 int hdr_len;
400
401#ifdef CONFIG_NET_IPGRE_BROADCAST
402 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
403 /* Looped back packet, drop it! */
404 if (rt_is_output_route(skb_rtable(skb)))
405 goto drop;
406 }
407#endif
408
409 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
410 if (hdr_len < 0)
411 goto drop;
412
413 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
414 tpi.proto == htons(ETH_P_ERSPAN2))) {
415 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
416 return 0;
417 goto out;
418 }
419
420 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
421 return 0;
422
423out:
424 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
425drop:
426 kfree_skb(skb);
427 return 0;
428}
429
430static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
431 const struct iphdr *tnl_params,
432 __be16 proto)
433{
434 struct ip_tunnel *tunnel = netdev_priv(dev);
435
436 if (tunnel->parms.o_flags & TUNNEL_SEQ)
437 tunnel->o_seqno++;
438
439 /* Push GRE header. */
440 gre_build_header(skb, tunnel->tun_hlen,
441 tunnel->parms.o_flags, proto, tunnel->parms.o_key,
442 htonl(tunnel->o_seqno));
443
444 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
445}
446
447static int gre_handle_offloads(struct sk_buff *skb, bool csum)
448{
449 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
450}
451
452static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
453 __be16 proto)
454{
455 struct ip_tunnel *tunnel = netdev_priv(dev);
456 struct ip_tunnel_info *tun_info;
457 const struct ip_tunnel_key *key;
458 int tunnel_hlen;
459 __be16 flags;
460
461 tun_info = skb_tunnel_info(skb);
462 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
463 ip_tunnel_info_af(tun_info) != AF_INET))
464 goto err_free_skb;
465
466 key = &tun_info->key;
467 tunnel_hlen = gre_calc_hlen(key->tun_flags);
468
469 if (skb_cow_head(skb, dev->needed_headroom))
470 goto err_free_skb;
471
472 /* Push Tunnel header. */
473 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
474 goto err_free_skb;
475
476 flags = tun_info->key.tun_flags &
477 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
478 gre_build_header(skb, tunnel_hlen, flags, proto,
479 tunnel_id_to_key32(tun_info->key.tun_id),
480 (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0);
481
482 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
483
484 return;
485
486err_free_skb:
487 kfree_skb(skb);
488 dev->stats.tx_dropped++;
489}
490
491static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
492{
493 struct ip_tunnel *tunnel = netdev_priv(dev);
494 struct ip_tunnel_info *tun_info;
495 const struct ip_tunnel_key *key;
496 struct erspan_metadata *md;
497 bool truncate = false;
498 __be16 proto;
499 int tunnel_hlen;
500 int version;
501 int nhoff;
502 int thoff;
503
504 tun_info = skb_tunnel_info(skb);
505 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
506 ip_tunnel_info_af(tun_info) != AF_INET))
507 goto err_free_skb;
508
509 key = &tun_info->key;
510 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
511 goto err_free_skb;
512 if (tun_info->options_len < sizeof(*md))
513 goto err_free_skb;
514 md = ip_tunnel_info_opts(tun_info);
515
516 /* ERSPAN has fixed 8 byte GRE header */
517 version = md->version;
518 tunnel_hlen = 8 + erspan_hdr_len(version);
519
520 if (skb_cow_head(skb, dev->needed_headroom))
521 goto err_free_skb;
522
523 if (gre_handle_offloads(skb, false))
524 goto err_free_skb;
525
526 if (skb->len > dev->mtu + dev->hard_header_len) {
527 pskb_trim(skb, dev->mtu + dev->hard_header_len);
528 truncate = true;
529 }
530
531 nhoff = skb_network_header(skb) - skb_mac_header(skb);
532 if (skb->protocol == htons(ETH_P_IP) &&
533 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
534 truncate = true;
535
536 thoff = skb_transport_header(skb) - skb_mac_header(skb);
537 if (skb->protocol == htons(ETH_P_IPV6) &&
538 (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff))
539 truncate = true;
540
541 if (version == 1) {
542 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
543 ntohl(md->u.index), truncate, true);
544 proto = htons(ETH_P_ERSPAN);
545 } else if (version == 2) {
546 erspan_build_header_v2(skb,
547 ntohl(tunnel_id_to_key32(key->tun_id)),
548 md->u.md2.dir,
549 get_hwid(&md->u.md2),
550 truncate, true);
551 proto = htons(ETH_P_ERSPAN2);
552 } else {
553 goto err_free_skb;
554 }
555
556 gre_build_header(skb, 8, TUNNEL_SEQ,
557 proto, 0, htonl(tunnel->o_seqno++));
558
559 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
560
561 return;
562
563err_free_skb:
564 kfree_skb(skb);
565 dev->stats.tx_dropped++;
566}
567
568static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
569{
570 struct ip_tunnel_info *info = skb_tunnel_info(skb);
571 const struct ip_tunnel_key *key;
572 struct rtable *rt;
573 struct flowi4 fl4;
574
575 if (ip_tunnel_info_af(info) != AF_INET)
576 return -EINVAL;
577
578 key = &info->key;
579 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
580 tunnel_id_to_key32(key->tun_id), key->tos, 0,
581 skb->mark, skb_get_hash(skb));
582 rt = ip_route_output_key(dev_net(dev), &fl4);
583 if (IS_ERR(rt))
584 return PTR_ERR(rt);
585
586 ip_rt_put(rt);
587 info->key.u.ipv4.src = fl4.saddr;
588 return 0;
589}
590
591static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
592 struct net_device *dev)
593{
594 struct ip_tunnel *tunnel = netdev_priv(dev);
595 const struct iphdr *tnl_params;
596
597 if (!pskb_inet_may_pull(skb))
598 goto free_skb;
599
600 if (tunnel->collect_md) {
601 gre_fb_xmit(skb, dev, skb->protocol);
602 return NETDEV_TX_OK;
603 }
604
605 if (dev->header_ops) {
606 /* Need space for new headers */
607 if (skb_cow_head(skb, dev->needed_headroom -
608 (tunnel->hlen + sizeof(struct iphdr))))
609 goto free_skb;
610
611 tnl_params = (const struct iphdr *)skb->data;
612
613 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
614 * to gre header.
615 */
616 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
617 skb_reset_mac_header(skb);
618 } else {
619 if (skb_cow_head(skb, dev->needed_headroom))
620 goto free_skb;
621
622 tnl_params = &tunnel->parms.iph;
623 }
624
625 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
626 goto free_skb;
627
628 __gre_xmit(skb, dev, tnl_params, skb->protocol);
629 return NETDEV_TX_OK;
630
631free_skb:
632 kfree_skb(skb);
633 dev->stats.tx_dropped++;
634 return NETDEV_TX_OK;
635}
636
637static netdev_tx_t erspan_xmit(struct sk_buff *skb,
638 struct net_device *dev)
639{
640 struct ip_tunnel *tunnel = netdev_priv(dev);
641 bool truncate = false;
642 __be16 proto;
643
644 if (!pskb_inet_may_pull(skb))
645 goto free_skb;
646
647 if (tunnel->collect_md) {
648 erspan_fb_xmit(skb, dev);
649 return NETDEV_TX_OK;
650 }
651
652 if (gre_handle_offloads(skb, false))
653 goto free_skb;
654
655 if (skb_cow_head(skb, dev->needed_headroom))
656 goto free_skb;
657
658 if (skb->len > dev->mtu + dev->hard_header_len) {
659 pskb_trim(skb, dev->mtu + dev->hard_header_len);
660 truncate = true;
661 }
662
663 /* Push ERSPAN header */
664 if (tunnel->erspan_ver == 1) {
665 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
666 tunnel->index,
667 truncate, true);
668 proto = htons(ETH_P_ERSPAN);
669 } else if (tunnel->erspan_ver == 2) {
670 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
671 tunnel->dir, tunnel->hwid,
672 truncate, true);
673 proto = htons(ETH_P_ERSPAN2);
674 } else {
675 goto free_skb;
676 }
677
678 tunnel->parms.o_flags &= ~TUNNEL_KEY;
679 __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
680 return NETDEV_TX_OK;
681
682free_skb:
683 kfree_skb(skb);
684 dev->stats.tx_dropped++;
685 return NETDEV_TX_OK;
686}
687
688static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
689 struct net_device *dev)
690{
691 struct ip_tunnel *tunnel = netdev_priv(dev);
692
693 if (!pskb_inet_may_pull(skb))
694 goto free_skb;
695
696 if (tunnel->collect_md) {
697 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
698 return NETDEV_TX_OK;
699 }
700
701 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
702 goto free_skb;
703
704 if (skb_cow_head(skb, dev->needed_headroom))
705 goto free_skb;
706
707 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
708 return NETDEV_TX_OK;
709
710free_skb:
711 kfree_skb(skb);
712 dev->stats.tx_dropped++;
713 return NETDEV_TX_OK;
714}
715
716static void ipgre_link_update(struct net_device *dev, bool set_mtu)
717{
718 struct ip_tunnel *tunnel = netdev_priv(dev);
719 int len;
720
721 len = tunnel->tun_hlen;
722 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
723 len = tunnel->tun_hlen - len;
724 tunnel->hlen = tunnel->hlen + len;
725
726 dev->needed_headroom = dev->needed_headroom + len;
727 if (set_mtu)
728 dev->mtu = max_t(int, dev->mtu - len, 68);
729
730 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
731 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
732 tunnel->encap.type == TUNNEL_ENCAP_NONE) {
733 dev->features |= NETIF_F_GSO_SOFTWARE;
734 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
735 } else {
736 dev->features &= ~NETIF_F_GSO_SOFTWARE;
737 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
738 }
739 dev->features |= NETIF_F_LLTX;
740 } else {
741 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
742 dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE);
743 }
744}
745
746static int ipgre_tunnel_ioctl(struct net_device *dev,
747 struct ifreq *ifr, int cmd)
748{
749 struct ip_tunnel_parm p;
750 int err;
751
752 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
753 return -EFAULT;
754
755 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
756 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
757 p.iph.ihl != 5 || (p.iph.frag_off & htons(~IP_DF)) ||
758 ((p.i_flags | p.o_flags) & (GRE_VERSION | GRE_ROUTING)))
759 return -EINVAL;
760 }
761
762 p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
763 p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
764
765 err = ip_tunnel_ioctl(dev, &p, cmd);
766 if (err)
767 return err;
768
769 if (cmd == SIOCCHGTUNNEL) {
770 struct ip_tunnel *t = netdev_priv(dev);
771
772 t->parms.i_flags = p.i_flags;
773 t->parms.o_flags = p.o_flags;
774
775 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
776 ipgre_link_update(dev, true);
777 }
778
779 p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags);
780 p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags);
781
782 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
783 return -EFAULT;
784
785 return 0;
786}
787
788/* Nice toy. Unfortunately, useless in real life :-)
789 It allows to construct virtual multiprotocol broadcast "LAN"
790 over the Internet, provided multicast routing is tuned.
791
792
793 I have no idea was this bicycle invented before me,
794 so that I had to set ARPHRD_IPGRE to a random value.
795 I have an impression, that Cisco could make something similar,
796 but this feature is apparently missing in IOS<=11.2(8).
797
798 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
799 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
800
801 ping -t 255 224.66.66.66
802
803 If nobody answers, mbone does not work.
804
805 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
806 ip addr add 10.66.66.<somewhat>/24 dev Universe
807 ifconfig Universe up
808 ifconfig Universe add fe80::<Your_real_addr>/10
809 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
810 ftp 10.66.66.66
811 ...
812 ftp fec0:6666:6666::193.233.7.65
813 ...
814 */
815static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
816 unsigned short type,
817 const void *daddr, const void *saddr, unsigned int len)
818{
819 struct ip_tunnel *t = netdev_priv(dev);
820 struct iphdr *iph;
821 struct gre_base_hdr *greh;
822
823 iph = skb_push(skb, t->hlen + sizeof(*iph));
824 greh = (struct gre_base_hdr *)(iph+1);
825 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
826 greh->protocol = htons(type);
827
828 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
829
830 /* Set the source hardware address. */
831 if (saddr)
832 memcpy(&iph->saddr, saddr, 4);
833 if (daddr)
834 memcpy(&iph->daddr, daddr, 4);
835 if (iph->daddr)
836 return t->hlen + sizeof(*iph);
837
838 return -(t->hlen + sizeof(*iph));
839}
840
841static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
842{
843 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
844 memcpy(haddr, &iph->saddr, 4);
845 return 4;
846}
847
848static const struct header_ops ipgre_header_ops = {
849 .create = ipgre_header,
850 .parse = ipgre_header_parse,
851};
852
853#ifdef CONFIG_NET_IPGRE_BROADCAST
854static int ipgre_open(struct net_device *dev)
855{
856 struct ip_tunnel *t = netdev_priv(dev);
857
858 if (ipv4_is_multicast(t->parms.iph.daddr)) {
859 struct flowi4 fl4;
860 struct rtable *rt;
861
862 rt = ip_route_output_gre(t->net, &fl4,
863 t->parms.iph.daddr,
864 t->parms.iph.saddr,
865 t->parms.o_key,
866 RT_TOS(t->parms.iph.tos),
867 t->parms.link);
868 if (IS_ERR(rt))
869 return -EADDRNOTAVAIL;
870 dev = rt->dst.dev;
871 ip_rt_put(rt);
872 if (!__in_dev_get_rtnl(dev))
873 return -EADDRNOTAVAIL;
874 t->mlink = dev->ifindex;
875 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
876 }
877 return 0;
878}
879
880static int ipgre_close(struct net_device *dev)
881{
882 struct ip_tunnel *t = netdev_priv(dev);
883
884 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
885 struct in_device *in_dev;
886 in_dev = inetdev_by_index(t->net, t->mlink);
887 if (in_dev)
888 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
889 }
890 return 0;
891}
892#endif
893
894static const struct net_device_ops ipgre_netdev_ops = {
895 .ndo_init = ipgre_tunnel_init,
896 .ndo_uninit = ip_tunnel_uninit,
897#ifdef CONFIG_NET_IPGRE_BROADCAST
898 .ndo_open = ipgre_open,
899 .ndo_stop = ipgre_close,
900#endif
901 .ndo_start_xmit = ipgre_xmit,
902 .ndo_do_ioctl = ipgre_tunnel_ioctl,
903 .ndo_change_mtu = ip_tunnel_change_mtu,
904 .ndo_get_stats64 = ip_tunnel_get_stats64,
905 .ndo_get_iflink = ip_tunnel_get_iflink,
906};
907
908#define GRE_FEATURES (NETIF_F_SG | \
909 NETIF_F_FRAGLIST | \
910 NETIF_F_HIGHDMA | \
911 NETIF_F_HW_CSUM)
912
913static void ipgre_tunnel_setup(struct net_device *dev)
914{
915 dev->netdev_ops = &ipgre_netdev_ops;
916 dev->type = ARPHRD_IPGRE;
917 ip_tunnel_setup(dev, ipgre_net_id);
918}
919
920static void __gre_tunnel_init(struct net_device *dev)
921{
922 struct ip_tunnel *tunnel;
923
924 tunnel = netdev_priv(dev);
925 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
926 tunnel->parms.iph.protocol = IPPROTO_GRE;
927
928 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
929
930 dev->features |= GRE_FEATURES;
931 dev->hw_features |= GRE_FEATURES;
932
933 if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
934 /* TCP offload with GRE SEQ is not supported, nor
935 * can we support 2 levels of outer headers requiring
936 * an update.
937 */
938 if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
939 (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
940 dev->features |= NETIF_F_GSO_SOFTWARE;
941 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
942 }
943
944 /* Can use a lockless transmit, unless we generate
945 * output sequences
946 */
947 dev->features |= NETIF_F_LLTX;
948 }
949}
950
951static int ipgre_tunnel_init(struct net_device *dev)
952{
953 struct ip_tunnel *tunnel = netdev_priv(dev);
954 struct iphdr *iph = &tunnel->parms.iph;
955
956 __gre_tunnel_init(dev);
957
958 memcpy(dev->dev_addr, &iph->saddr, 4);
959 memcpy(dev->broadcast, &iph->daddr, 4);
960
961 dev->flags = IFF_NOARP;
962 netif_keep_dst(dev);
963 dev->addr_len = 4;
964
965 if (iph->daddr && !tunnel->collect_md) {
966#ifdef CONFIG_NET_IPGRE_BROADCAST
967 if (ipv4_is_multicast(iph->daddr)) {
968 if (!iph->saddr)
969 return -EINVAL;
970 dev->flags = IFF_BROADCAST;
971 dev->header_ops = &ipgre_header_ops;
972 }
973#endif
974 } else if (!tunnel->collect_md) {
975 dev->header_ops = &ipgre_header_ops;
976 }
977
978 return ip_tunnel_init(dev);
979}
980
981static const struct gre_protocol ipgre_protocol = {
982 .handler = gre_rcv,
983 .err_handler = gre_err,
984};
985
986static int __net_init ipgre_init_net(struct net *net)
987{
988 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
989}
990
991static void __net_exit ipgre_exit_batch_net(struct list_head *list_net)
992{
993 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops);
994}
995
996static struct pernet_operations ipgre_net_ops = {
997 .init = ipgre_init_net,
998 .exit_batch = ipgre_exit_batch_net,
999 .id = &ipgre_net_id,
1000 .size = sizeof(struct ip_tunnel_net),
1001};
1002
1003static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1004 struct netlink_ext_ack *extack)
1005{
1006 __be16 flags;
1007
1008 if (!data)
1009 return 0;
1010
1011 flags = 0;
1012 if (data[IFLA_GRE_IFLAGS])
1013 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1014 if (data[IFLA_GRE_OFLAGS])
1015 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1016 if (flags & (GRE_VERSION|GRE_ROUTING))
1017 return -EINVAL;
1018
1019 if (data[IFLA_GRE_COLLECT_METADATA] &&
1020 data[IFLA_GRE_ENCAP_TYPE] &&
1021 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1022 return -EINVAL;
1023
1024 return 0;
1025}
1026
1027static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1028 struct netlink_ext_ack *extack)
1029{
1030 __be32 daddr;
1031
1032 if (tb[IFLA_ADDRESS]) {
1033 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1034 return -EINVAL;
1035 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1036 return -EADDRNOTAVAIL;
1037 }
1038
1039 if (!data)
1040 goto out;
1041
1042 if (data[IFLA_GRE_REMOTE]) {
1043 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1044 if (!daddr)
1045 return -EINVAL;
1046 }
1047
1048out:
1049 return ipgre_tunnel_validate(tb, data, extack);
1050}
1051
1052static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1053 struct netlink_ext_ack *extack)
1054{
1055 __be16 flags = 0;
1056 int ret;
1057
1058 if (!data)
1059 return 0;
1060
1061 ret = ipgre_tap_validate(tb, data, extack);
1062 if (ret)
1063 return ret;
1064
1065 /* ERSPAN should only have GRE sequence and key flag */
1066 if (data[IFLA_GRE_OFLAGS])
1067 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1068 if (data[IFLA_GRE_IFLAGS])
1069 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1070 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1071 flags != (GRE_SEQ | GRE_KEY))
1072 return -EINVAL;
1073
1074 /* ERSPAN Session ID only has 10-bit. Since we reuse
1075 * 32-bit key field as ID, check it's range.
1076 */
1077 if (data[IFLA_GRE_IKEY] &&
1078 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1079 return -EINVAL;
1080
1081 if (data[IFLA_GRE_OKEY] &&
1082 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1083 return -EINVAL;
1084
1085 return 0;
1086}
1087
1088static int ipgre_netlink_parms(struct net_device *dev,
1089 struct nlattr *data[],
1090 struct nlattr *tb[],
1091 struct ip_tunnel_parm *parms,
1092 __u32 *fwmark)
1093{
1094 struct ip_tunnel *t = netdev_priv(dev);
1095
1096 memset(parms, 0, sizeof(*parms));
1097
1098 parms->iph.protocol = IPPROTO_GRE;
1099
1100 if (!data)
1101 return 0;
1102
1103 if (data[IFLA_GRE_LINK])
1104 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1105
1106 if (data[IFLA_GRE_IFLAGS])
1107 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1108
1109 if (data[IFLA_GRE_OFLAGS])
1110 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1111
1112 if (data[IFLA_GRE_IKEY])
1113 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1114
1115 if (data[IFLA_GRE_OKEY])
1116 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1117
1118 if (data[IFLA_GRE_LOCAL])
1119 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1120
1121 if (data[IFLA_GRE_REMOTE])
1122 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1123
1124 if (data[IFLA_GRE_TTL])
1125 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1126
1127 if (data[IFLA_GRE_TOS])
1128 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1129
1130 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1131 if (t->ignore_df)
1132 return -EINVAL;
1133 parms->iph.frag_off = htons(IP_DF);
1134 }
1135
1136 if (data[IFLA_GRE_COLLECT_METADATA]) {
1137 t->collect_md = true;
1138 if (dev->type == ARPHRD_IPGRE)
1139 dev->type = ARPHRD_NONE;
1140 }
1141
1142 if (data[IFLA_GRE_IGNORE_DF]) {
1143 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1144 && (parms->iph.frag_off & htons(IP_DF)))
1145 return -EINVAL;
1146 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1147 }
1148
1149 if (data[IFLA_GRE_FWMARK])
1150 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1151
1152 if (data[IFLA_GRE_ERSPAN_VER]) {
1153 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1154
1155 if (t->erspan_ver != 1 && t->erspan_ver != 2)
1156 return -EINVAL;
1157 }
1158
1159 if (t->erspan_ver == 1) {
1160 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1161 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1162 if (t->index & ~INDEX_MASK)
1163 return -EINVAL;
1164 }
1165 } else if (t->erspan_ver == 2) {
1166 if (data[IFLA_GRE_ERSPAN_DIR]) {
1167 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1168 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1169 return -EINVAL;
1170 }
1171 if (data[IFLA_GRE_ERSPAN_HWID]) {
1172 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1173 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1174 return -EINVAL;
1175 }
1176 }
1177
1178 return 0;
1179}
1180
1181/* This function returns true when ENCAP attributes are present in the nl msg */
1182static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1183 struct ip_tunnel_encap *ipencap)
1184{
1185 bool ret = false;
1186
1187 memset(ipencap, 0, sizeof(*ipencap));
1188
1189 if (!data)
1190 return ret;
1191
1192 if (data[IFLA_GRE_ENCAP_TYPE]) {
1193 ret = true;
1194 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1195 }
1196
1197 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1198 ret = true;
1199 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1200 }
1201
1202 if (data[IFLA_GRE_ENCAP_SPORT]) {
1203 ret = true;
1204 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1205 }
1206
1207 if (data[IFLA_GRE_ENCAP_DPORT]) {
1208 ret = true;
1209 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1210 }
1211
1212 return ret;
1213}
1214
1215static int gre_tap_init(struct net_device *dev)
1216{
1217 __gre_tunnel_init(dev);
1218 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1219 netif_keep_dst(dev);
1220
1221 return ip_tunnel_init(dev);
1222}
1223
1224static const struct net_device_ops gre_tap_netdev_ops = {
1225 .ndo_init = gre_tap_init,
1226 .ndo_uninit = ip_tunnel_uninit,
1227 .ndo_start_xmit = gre_tap_xmit,
1228 .ndo_set_mac_address = eth_mac_addr,
1229 .ndo_validate_addr = eth_validate_addr,
1230 .ndo_change_mtu = ip_tunnel_change_mtu,
1231 .ndo_get_stats64 = ip_tunnel_get_stats64,
1232 .ndo_get_iflink = ip_tunnel_get_iflink,
1233 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1234};
1235
1236static int erspan_tunnel_init(struct net_device *dev)
1237{
1238 struct ip_tunnel *tunnel = netdev_priv(dev);
1239
1240 tunnel->tun_hlen = 8;
1241 tunnel->parms.iph.protocol = IPPROTO_GRE;
1242 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1243 erspan_hdr_len(tunnel->erspan_ver);
1244
1245 dev->features |= GRE_FEATURES;
1246 dev->hw_features |= GRE_FEATURES;
1247 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1248 netif_keep_dst(dev);
1249
1250 return ip_tunnel_init(dev);
1251}
1252
1253static const struct net_device_ops erspan_netdev_ops = {
1254 .ndo_init = erspan_tunnel_init,
1255 .ndo_uninit = ip_tunnel_uninit,
1256 .ndo_start_xmit = erspan_xmit,
1257 .ndo_set_mac_address = eth_mac_addr,
1258 .ndo_validate_addr = eth_validate_addr,
1259 .ndo_change_mtu = ip_tunnel_change_mtu,
1260 .ndo_get_stats64 = ip_tunnel_get_stats64,
1261 .ndo_get_iflink = ip_tunnel_get_iflink,
1262 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1263};
1264
1265static void ipgre_tap_setup(struct net_device *dev)
1266{
1267 ether_setup(dev);
1268 dev->max_mtu = 0;
1269 dev->netdev_ops = &gre_tap_netdev_ops;
1270 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1271 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1272 ip_tunnel_setup(dev, gre_tap_net_id);
1273}
1274
1275static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1276 struct nlattr *tb[], struct nlattr *data[],
1277 struct netlink_ext_ack *extack)
1278{
1279 struct ip_tunnel_parm p;
1280 struct ip_tunnel_encap ipencap;
1281 __u32 fwmark = 0;
1282 int err;
1283
1284 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1285 struct ip_tunnel *t = netdev_priv(dev);
1286 err = ip_tunnel_encap_setup(t, &ipencap);
1287
1288 if (err < 0)
1289 return err;
1290 }
1291
1292 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1293 if (err < 0)
1294 return err;
1295 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1296}
1297
1298static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1299 struct nlattr *data[],
1300 struct netlink_ext_ack *extack)
1301{
1302 struct ip_tunnel *t = netdev_priv(dev);
1303 struct ip_tunnel_encap ipencap;
1304 __u32 fwmark = t->fwmark;
1305 struct ip_tunnel_parm p;
1306 int err;
1307
1308 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1309 err = ip_tunnel_encap_setup(t, &ipencap);
1310
1311 if (err < 0)
1312 return err;
1313 }
1314
1315 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1316 if (err < 0)
1317 return err;
1318
1319 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1320 if (err < 0)
1321 return err;
1322
1323 t->parms.i_flags = p.i_flags;
1324 t->parms.o_flags = p.o_flags;
1325
1326 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
1327 ipgre_link_update(dev, !tb[IFLA_MTU]);
1328
1329 return 0;
1330}
1331
1332static size_t ipgre_get_size(const struct net_device *dev)
1333{
1334 return
1335 /* IFLA_GRE_LINK */
1336 nla_total_size(4) +
1337 /* IFLA_GRE_IFLAGS */
1338 nla_total_size(2) +
1339 /* IFLA_GRE_OFLAGS */
1340 nla_total_size(2) +
1341 /* IFLA_GRE_IKEY */
1342 nla_total_size(4) +
1343 /* IFLA_GRE_OKEY */
1344 nla_total_size(4) +
1345 /* IFLA_GRE_LOCAL */
1346 nla_total_size(4) +
1347 /* IFLA_GRE_REMOTE */
1348 nla_total_size(4) +
1349 /* IFLA_GRE_TTL */
1350 nla_total_size(1) +
1351 /* IFLA_GRE_TOS */
1352 nla_total_size(1) +
1353 /* IFLA_GRE_PMTUDISC */
1354 nla_total_size(1) +
1355 /* IFLA_GRE_ENCAP_TYPE */
1356 nla_total_size(2) +
1357 /* IFLA_GRE_ENCAP_FLAGS */
1358 nla_total_size(2) +
1359 /* IFLA_GRE_ENCAP_SPORT */
1360 nla_total_size(2) +
1361 /* IFLA_GRE_ENCAP_DPORT */
1362 nla_total_size(2) +
1363 /* IFLA_GRE_COLLECT_METADATA */
1364 nla_total_size(0) +
1365 /* IFLA_GRE_IGNORE_DF */
1366 nla_total_size(1) +
1367 /* IFLA_GRE_FWMARK */
1368 nla_total_size(4) +
1369 /* IFLA_GRE_ERSPAN_INDEX */
1370 nla_total_size(4) +
1371 /* IFLA_GRE_ERSPAN_VER */
1372 nla_total_size(1) +
1373 /* IFLA_GRE_ERSPAN_DIR */
1374 nla_total_size(1) +
1375 /* IFLA_GRE_ERSPAN_HWID */
1376 nla_total_size(2) +
1377 0;
1378}
1379
1380static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1381{
1382 struct ip_tunnel *t = netdev_priv(dev);
1383 struct ip_tunnel_parm *p = &t->parms;
1384 __be16 o_flags = p->o_flags;
1385
1386 if (t->erspan_ver == 1 || t->erspan_ver == 2) {
1387 if (!t->collect_md)
1388 o_flags |= TUNNEL_KEY;
1389
1390 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1391 goto nla_put_failure;
1392
1393 if (t->erspan_ver == 1) {
1394 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1395 goto nla_put_failure;
1396 } else {
1397 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1398 goto nla_put_failure;
1399 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1400 goto nla_put_failure;
1401 }
1402 }
1403
1404 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1405 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1406 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1407 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1408 gre_tnl_flags_to_gre_flags(o_flags)) ||
1409 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1410 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1411 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1412 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1413 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1414 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1415 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1416 !!(p->iph.frag_off & htons(IP_DF))) ||
1417 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1418 goto nla_put_failure;
1419
1420 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1421 t->encap.type) ||
1422 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1423 t->encap.sport) ||
1424 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1425 t->encap.dport) ||
1426 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1427 t->encap.flags))
1428 goto nla_put_failure;
1429
1430 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1431 goto nla_put_failure;
1432
1433 if (t->collect_md) {
1434 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1435 goto nla_put_failure;
1436 }
1437
1438 return 0;
1439
1440nla_put_failure:
1441 return -EMSGSIZE;
1442}
1443
1444static void erspan_setup(struct net_device *dev)
1445{
1446 struct ip_tunnel *t = netdev_priv(dev);
1447
1448 ether_setup(dev);
1449 dev->max_mtu = 0;
1450 dev->netdev_ops = &erspan_netdev_ops;
1451 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1452 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1453 ip_tunnel_setup(dev, erspan_net_id);
1454 t->erspan_ver = 1;
1455}
1456
1457static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1458 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1459 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1460 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1461 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1462 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1463 [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
1464 [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
1465 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1466 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1467 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1468 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1469 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1470 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1471 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1472 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1473 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1474 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1475 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1476 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1477 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1478 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1479};
1480
1481static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1482 .kind = "gre",
1483 .maxtype = IFLA_GRE_MAX,
1484 .policy = ipgre_policy,
1485 .priv_size = sizeof(struct ip_tunnel),
1486 .setup = ipgre_tunnel_setup,
1487 .validate = ipgre_tunnel_validate,
1488 .newlink = ipgre_newlink,
1489 .changelink = ipgre_changelink,
1490 .dellink = ip_tunnel_dellink,
1491 .get_size = ipgre_get_size,
1492 .fill_info = ipgre_fill_info,
1493 .get_link_net = ip_tunnel_get_link_net,
1494};
1495
1496static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1497 .kind = "gretap",
1498 .maxtype = IFLA_GRE_MAX,
1499 .policy = ipgre_policy,
1500 .priv_size = sizeof(struct ip_tunnel),
1501 .setup = ipgre_tap_setup,
1502 .validate = ipgre_tap_validate,
1503 .newlink = ipgre_newlink,
1504 .changelink = ipgre_changelink,
1505 .dellink = ip_tunnel_dellink,
1506 .get_size = ipgre_get_size,
1507 .fill_info = ipgre_fill_info,
1508 .get_link_net = ip_tunnel_get_link_net,
1509};
1510
1511static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1512 .kind = "erspan",
1513 .maxtype = IFLA_GRE_MAX,
1514 .policy = ipgre_policy,
1515 .priv_size = sizeof(struct ip_tunnel),
1516 .setup = erspan_setup,
1517 .validate = erspan_validate,
1518 .newlink = ipgre_newlink,
1519 .changelink = ipgre_changelink,
1520 .dellink = ip_tunnel_dellink,
1521 .get_size = ipgre_get_size,
1522 .fill_info = ipgre_fill_info,
1523 .get_link_net = ip_tunnel_get_link_net,
1524};
1525
1526struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1527 u8 name_assign_type)
1528{
1529 struct nlattr *tb[IFLA_MAX + 1];
1530 struct net_device *dev;
1531 LIST_HEAD(list_kill);
1532 struct ip_tunnel *t;
1533 int err;
1534
1535 memset(&tb, 0, sizeof(tb));
1536
1537 dev = rtnl_create_link(net, name, name_assign_type,
1538 &ipgre_tap_ops, tb, NULL);
1539 if (IS_ERR(dev))
1540 return dev;
1541
1542 /* Configure flow based GRE device. */
1543 t = netdev_priv(dev);
1544 t->collect_md = true;
1545
1546 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1547 if (err < 0) {
1548 free_netdev(dev);
1549 return ERR_PTR(err);
1550 }
1551
1552 /* openvswitch users expect packet sizes to be unrestricted,
1553 * so set the largest MTU we can.
1554 */
1555 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1556 if (err)
1557 goto out;
1558
1559 err = rtnl_configure_link(dev, NULL);
1560 if (err < 0)
1561 goto out;
1562
1563 return dev;
1564out:
1565 ip_tunnel_dellink(dev, &list_kill);
1566 unregister_netdevice_many(&list_kill);
1567 return ERR_PTR(err);
1568}
1569EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1570
1571static int __net_init ipgre_tap_init_net(struct net *net)
1572{
1573 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1574}
1575
1576static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
1577{
1578 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
1579}
1580
1581static struct pernet_operations ipgre_tap_net_ops = {
1582 .init = ipgre_tap_init_net,
1583 .exit_batch = ipgre_tap_exit_batch_net,
1584 .id = &gre_tap_net_id,
1585 .size = sizeof(struct ip_tunnel_net),
1586};
1587
1588static int __net_init erspan_init_net(struct net *net)
1589{
1590 return ip_tunnel_init_net(net, erspan_net_id,
1591 &erspan_link_ops, "erspan0");
1592}
1593
1594static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
1595{
1596 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
1597}
1598
1599static struct pernet_operations erspan_net_ops = {
1600 .init = erspan_init_net,
1601 .exit_batch = erspan_exit_batch_net,
1602 .id = &erspan_net_id,
1603 .size = sizeof(struct ip_tunnel_net),
1604};
1605
1606static int __init ipgre_init(void)
1607{
1608 int err;
1609
1610 pr_info("GRE over IPv4 tunneling driver\n");
1611
1612 err = register_pernet_device(&ipgre_net_ops);
1613 if (err < 0)
1614 return err;
1615
1616 err = register_pernet_device(&ipgre_tap_net_ops);
1617 if (err < 0)
1618 goto pnet_tap_failed;
1619
1620 err = register_pernet_device(&erspan_net_ops);
1621 if (err < 0)
1622 goto pnet_erspan_failed;
1623
1624 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1625 if (err < 0) {
1626 pr_info("%s: can't add protocol\n", __func__);
1627 goto add_proto_failed;
1628 }
1629
1630 err = rtnl_link_register(&ipgre_link_ops);
1631 if (err < 0)
1632 goto rtnl_link_failed;
1633
1634 err = rtnl_link_register(&ipgre_tap_ops);
1635 if (err < 0)
1636 goto tap_ops_failed;
1637
1638 err = rtnl_link_register(&erspan_link_ops);
1639 if (err < 0)
1640 goto erspan_link_failed;
1641
1642 return 0;
1643
1644erspan_link_failed:
1645 rtnl_link_unregister(&ipgre_tap_ops);
1646tap_ops_failed:
1647 rtnl_link_unregister(&ipgre_link_ops);
1648rtnl_link_failed:
1649 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1650add_proto_failed:
1651 unregister_pernet_device(&erspan_net_ops);
1652pnet_erspan_failed:
1653 unregister_pernet_device(&ipgre_tap_net_ops);
1654pnet_tap_failed:
1655 unregister_pernet_device(&ipgre_net_ops);
1656 return err;
1657}
1658
1659static void __exit ipgre_fini(void)
1660{
1661 rtnl_link_unregister(&ipgre_tap_ops);
1662 rtnl_link_unregister(&ipgre_link_ops);
1663 rtnl_link_unregister(&erspan_link_ops);
1664 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1665 unregister_pernet_device(&ipgre_tap_net_ops);
1666 unregister_pernet_device(&ipgre_net_ops);
1667 unregister_pernet_device(&erspan_net_ops);
1668}
1669
1670module_init(ipgre_init);
1671module_exit(ipgre_fini);
1672MODULE_LICENSE("GPL");
1673MODULE_ALIAS_RTNL_LINK("gre");
1674MODULE_ALIAS_RTNL_LINK("gretap");
1675MODULE_ALIAS_RTNL_LINK("erspan");
1676MODULE_ALIAS_NETDEV("gre0");
1677MODULE_ALIAS_NETDEV("gretap0");
1678MODULE_ALIAS_NETDEV("erspan0");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: GRE over IP protocol decoder.
4 *
5 * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/capability.h>
11#include <linux/module.h>
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/slab.h>
15#include <linux/uaccess.h>
16#include <linux/skbuff.h>
17#include <linux/netdevice.h>
18#include <linux/in.h>
19#include <linux/tcp.h>
20#include <linux/udp.h>
21#include <linux/if_arp.h>
22#include <linux/if_vlan.h>
23#include <linux/init.h>
24#include <linux/in6.h>
25#include <linux/inetdevice.h>
26#include <linux/igmp.h>
27#include <linux/netfilter_ipv4.h>
28#include <linux/etherdevice.h>
29#include <linux/if_ether.h>
30
31#include <net/sock.h>
32#include <net/ip.h>
33#include <net/icmp.h>
34#include <net/protocol.h>
35#include <net/ip_tunnels.h>
36#include <net/arp.h>
37#include <net/checksum.h>
38#include <net/dsfield.h>
39#include <net/inet_ecn.h>
40#include <net/xfrm.h>
41#include <net/net_namespace.h>
42#include <net/netns/generic.h>
43#include <net/rtnetlink.h>
44#include <net/gre.h>
45#include <net/dst_metadata.h>
46#include <net/erspan.h>
47
48/*
49 Problems & solutions
50 --------------------
51
52 1. The most important issue is detecting local dead loops.
53 They would cause complete host lockup in transmit, which
54 would be "resolved" by stack overflow or, if queueing is enabled,
55 with infinite looping in net_bh.
56
57 We cannot track such dead loops during route installation,
58 it is infeasible task. The most general solutions would be
59 to keep skb->encapsulation counter (sort of local ttl),
60 and silently drop packet when it expires. It is a good
61 solution, but it supposes maintaining new variable in ALL
62 skb, even if no tunneling is used.
63
64 Current solution: xmit_recursion breaks dead loops. This is a percpu
65 counter, since when we enter the first ndo_xmit(), cpu migration is
66 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
67
68 2. Networking dead loops would not kill routers, but would really
69 kill network. IP hop limit plays role of "t->recursion" in this case,
70 if we copy it from packet being encapsulated to upper header.
71 It is very good solution, but it introduces two problems:
72
73 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
74 do not work over tunnels.
75 - traceroute does not work. I planned to relay ICMP from tunnel,
76 so that this problem would be solved and traceroute output
77 would even more informative. This idea appeared to be wrong:
78 only Linux complies to rfc1812 now (yes, guys, Linux is the only
79 true router now :-)), all routers (at least, in neighbourhood of mine)
80 return only 8 bytes of payload. It is the end.
81
82 Hence, if we want that OSPF worked or traceroute said something reasonable,
83 we should search for another solution.
84
85 One of them is to parse packet trying to detect inner encapsulation
86 made by our node. It is difficult or even impossible, especially,
87 taking into account fragmentation. TO be short, ttl is not solution at all.
88
89 Current solution: The solution was UNEXPECTEDLY SIMPLE.
90 We force DF flag on tunnels with preconfigured hop limit,
91 that is ALL. :-) Well, it does not remove the problem completely,
92 but exponential growth of network traffic is changed to linear
93 (branches, that exceed pmtu are pruned) and tunnel mtu
94 rapidly degrades to value <68, where looping stops.
95 Yes, it is not good if there exists a router in the loop,
96 which does not force DF, even when encapsulating packets have DF set.
97 But it is not our problem! Nobody could accuse us, we made
98 all that we could make. Even if it is your gated who injected
99 fatal route to network, even if it were you who configured
100 fatal static route: you are innocent. :-)
101
102 Alexey Kuznetsov.
103 */
104
105static bool log_ecn_error = true;
106module_param(log_ecn_error, bool, 0644);
107MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
108
109static struct rtnl_link_ops ipgre_link_ops __read_mostly;
110static const struct header_ops ipgre_header_ops;
111
112static int ipgre_tunnel_init(struct net_device *dev);
113static void erspan_build_header(struct sk_buff *skb,
114 u32 id, u32 index,
115 bool truncate, bool is_ipv4);
116
117static unsigned int ipgre_net_id __read_mostly;
118static unsigned int gre_tap_net_id __read_mostly;
119static unsigned int erspan_net_id __read_mostly;
120
121static int ipgre_err(struct sk_buff *skb, u32 info,
122 const struct tnl_ptk_info *tpi)
123{
124
125 /* All the routers (except for Linux) return only
126 8 bytes of packet payload. It means, that precise relaying of
127 ICMP in the real Internet is absolutely infeasible.
128
129 Moreover, Cisco "wise men" put GRE key to the third word
130 in GRE header. It makes impossible maintaining even soft
131 state for keyed GRE tunnels with enabled checksum. Tell
132 them "thank you".
133
134 Well, I wonder, rfc1812 was written by Cisco employee,
135 what the hell these idiots break standards established
136 by themselves???
137 */
138 struct net *net = dev_net(skb->dev);
139 struct ip_tunnel_net *itn;
140 const struct iphdr *iph;
141 const int type = icmp_hdr(skb)->type;
142 const int code = icmp_hdr(skb)->code;
143 unsigned int data_len = 0;
144 struct ip_tunnel *t;
145
146 if (tpi->proto == htons(ETH_P_TEB))
147 itn = net_generic(net, gre_tap_net_id);
148 else if (tpi->proto == htons(ETH_P_ERSPAN) ||
149 tpi->proto == htons(ETH_P_ERSPAN2))
150 itn = net_generic(net, erspan_net_id);
151 else
152 itn = net_generic(net, ipgre_net_id);
153
154 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
155 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
156 iph->daddr, iph->saddr, tpi->key);
157
158 if (!t)
159 return -ENOENT;
160
161 switch (type) {
162 default:
163 case ICMP_PARAMETERPROB:
164 return 0;
165
166 case ICMP_DEST_UNREACH:
167 switch (code) {
168 case ICMP_SR_FAILED:
169 case ICMP_PORT_UNREACH:
170 /* Impossible event. */
171 return 0;
172 default:
173 /* All others are translated to HOST_UNREACH.
174 rfc2003 contains "deep thoughts" about NET_UNREACH,
175 I believe they are just ether pollution. --ANK
176 */
177 break;
178 }
179 break;
180
181 case ICMP_TIME_EXCEEDED:
182 if (code != ICMP_EXC_TTL)
183 return 0;
184 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
185 break;
186
187 case ICMP_REDIRECT:
188 break;
189 }
190
191#if IS_ENABLED(CONFIG_IPV6)
192 if (tpi->proto == htons(ETH_P_IPV6) &&
193 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
194 type, data_len))
195 return 0;
196#endif
197
198 if (t->parms.iph.daddr == 0 ||
199 ipv4_is_multicast(t->parms.iph.daddr))
200 return 0;
201
202 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
203 return 0;
204
205 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
206 t->err_count++;
207 else
208 t->err_count = 1;
209 t->err_time = jiffies;
210
211 return 0;
212}
213
214static void gre_err(struct sk_buff *skb, u32 info)
215{
216 /* All the routers (except for Linux) return only
217 * 8 bytes of packet payload. It means, that precise relaying of
218 * ICMP in the real Internet is absolutely infeasible.
219 *
220 * Moreover, Cisco "wise men" put GRE key to the third word
221 * in GRE header. It makes impossible maintaining even soft
222 * state for keyed
223 * GRE tunnels with enabled checksum. Tell them "thank you".
224 *
225 * Well, I wonder, rfc1812 was written by Cisco employee,
226 * what the hell these idiots break standards established
227 * by themselves???
228 */
229
230 const struct iphdr *iph = (struct iphdr *)skb->data;
231 const int type = icmp_hdr(skb)->type;
232 const int code = icmp_hdr(skb)->code;
233 struct tnl_ptk_info tpi;
234
235 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
236 iph->ihl * 4) < 0)
237 return;
238
239 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
240 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
241 skb->dev->ifindex, IPPROTO_GRE);
242 return;
243 }
244 if (type == ICMP_REDIRECT) {
245 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
246 IPPROTO_GRE);
247 return;
248 }
249
250 ipgre_err(skb, info, &tpi);
251}
252
253static bool is_erspan_type1(int gre_hdr_len)
254{
255 /* Both ERSPAN type I (version 0) and type II (version 1) use
256 * protocol 0x88BE, but the type I has only 4-byte GRE header,
257 * while type II has 8-byte.
258 */
259 return gre_hdr_len == 4;
260}
261
262static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
263 int gre_hdr_len)
264{
265 struct net *net = dev_net(skb->dev);
266 struct metadata_dst *tun_dst = NULL;
267 struct erspan_base_hdr *ershdr;
268 struct ip_tunnel_net *itn;
269 struct ip_tunnel *tunnel;
270 const struct iphdr *iph;
271 struct erspan_md2 *md2;
272 int ver;
273 int len;
274
275 itn = net_generic(net, erspan_net_id);
276 iph = ip_hdr(skb);
277 if (is_erspan_type1(gre_hdr_len)) {
278 ver = 0;
279 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
280 tpi->flags | TUNNEL_NO_KEY,
281 iph->saddr, iph->daddr, 0);
282 } else {
283 if (unlikely(!pskb_may_pull(skb,
284 gre_hdr_len + sizeof(*ershdr))))
285 return PACKET_REJECT;
286
287 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
288 ver = ershdr->ver;
289 iph = ip_hdr(skb);
290 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
291 tpi->flags | TUNNEL_KEY,
292 iph->saddr, iph->daddr, tpi->key);
293 }
294
295 if (tunnel) {
296 if (is_erspan_type1(gre_hdr_len))
297 len = gre_hdr_len;
298 else
299 len = gre_hdr_len + erspan_hdr_len(ver);
300
301 if (unlikely(!pskb_may_pull(skb, len)))
302 return PACKET_REJECT;
303
304 if (__iptunnel_pull_header(skb,
305 len,
306 htons(ETH_P_TEB),
307 false, false) < 0)
308 goto drop;
309
310 if (tunnel->collect_md) {
311 struct erspan_metadata *pkt_md, *md;
312 struct ip_tunnel_info *info;
313 unsigned char *gh;
314 __be64 tun_id;
315 __be16 flags;
316
317 tpi->flags |= TUNNEL_KEY;
318 flags = tpi->flags;
319 tun_id = key32_to_tunnel_id(tpi->key);
320
321 tun_dst = ip_tun_rx_dst(skb, flags,
322 tun_id, sizeof(*md));
323 if (!tun_dst)
324 return PACKET_REJECT;
325
326 /* skb can be uncloned in __iptunnel_pull_header, so
327 * old pkt_md is no longer valid and we need to reset
328 * it
329 */
330 gh = skb_network_header(skb) +
331 skb_network_header_len(skb);
332 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
333 sizeof(*ershdr));
334 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
335 md->version = ver;
336 md2 = &md->u.md2;
337 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
338 ERSPAN_V2_MDSIZE);
339
340 info = &tun_dst->u.tun_info;
341 info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
342 info->options_len = sizeof(*md);
343 }
344
345 skb_reset_mac_header(skb);
346 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
347 return PACKET_RCVD;
348 }
349 return PACKET_REJECT;
350
351drop:
352 kfree_skb(skb);
353 return PACKET_RCVD;
354}
355
356static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
357 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
358{
359 struct metadata_dst *tun_dst = NULL;
360 const struct iphdr *iph;
361 struct ip_tunnel *tunnel;
362
363 iph = ip_hdr(skb);
364 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
365 iph->saddr, iph->daddr, tpi->key);
366
367 if (tunnel) {
368 const struct iphdr *tnl_params;
369
370 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
371 raw_proto, false) < 0)
372 goto drop;
373
374 /* Special case for ipgre_header_parse(), which expects the
375 * mac_header to point to the outer IP header.
376 */
377 if (tunnel->dev->header_ops == &ipgre_header_ops)
378 skb_pop_mac_header(skb);
379 else
380 skb_reset_mac_header(skb);
381
382 tnl_params = &tunnel->parms.iph;
383 if (tunnel->collect_md || tnl_params->daddr == 0) {
384 __be16 flags;
385 __be64 tun_id;
386
387 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
388 tun_id = key32_to_tunnel_id(tpi->key);
389 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
390 if (!tun_dst)
391 return PACKET_REJECT;
392 }
393
394 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
395 return PACKET_RCVD;
396 }
397 return PACKET_NEXT;
398
399drop:
400 kfree_skb(skb);
401 return PACKET_RCVD;
402}
403
404static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
405 int hdr_len)
406{
407 struct net *net = dev_net(skb->dev);
408 struct ip_tunnel_net *itn;
409 int res;
410
411 if (tpi->proto == htons(ETH_P_TEB))
412 itn = net_generic(net, gre_tap_net_id);
413 else
414 itn = net_generic(net, ipgre_net_id);
415
416 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
417 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
418 /* ipgre tunnels in collect metadata mode should receive
419 * also ETH_P_TEB traffic.
420 */
421 itn = net_generic(net, ipgre_net_id);
422 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
423 }
424 return res;
425}
426
427static int gre_rcv(struct sk_buff *skb)
428{
429 struct tnl_ptk_info tpi;
430 bool csum_err = false;
431 int hdr_len;
432
433#ifdef CONFIG_NET_IPGRE_BROADCAST
434 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
435 /* Looped back packet, drop it! */
436 if (rt_is_output_route(skb_rtable(skb)))
437 goto drop;
438 }
439#endif
440
441 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
442 if (hdr_len < 0)
443 goto drop;
444
445 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
446 tpi.proto == htons(ETH_P_ERSPAN2))) {
447 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
448 return 0;
449 goto out;
450 }
451
452 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
453 return 0;
454
455out:
456 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
457drop:
458 kfree_skb(skb);
459 return 0;
460}
461
462static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
463 const struct iphdr *tnl_params,
464 __be16 proto)
465{
466 struct ip_tunnel *tunnel = netdev_priv(dev);
467 __be16 flags = tunnel->parms.o_flags;
468
469 /* Push GRE header. */
470 gre_build_header(skb, tunnel->tun_hlen,
471 flags, proto, tunnel->parms.o_key,
472 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
473
474 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
475}
476
477static int gre_handle_offloads(struct sk_buff *skb, bool csum)
478{
479 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
480}
481
482static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
483 __be16 proto)
484{
485 struct ip_tunnel *tunnel = netdev_priv(dev);
486 struct ip_tunnel_info *tun_info;
487 const struct ip_tunnel_key *key;
488 int tunnel_hlen;
489 __be16 flags;
490
491 tun_info = skb_tunnel_info(skb);
492 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
493 ip_tunnel_info_af(tun_info) != AF_INET))
494 goto err_free_skb;
495
496 key = &tun_info->key;
497 tunnel_hlen = gre_calc_hlen(key->tun_flags);
498
499 if (skb_cow_head(skb, dev->needed_headroom))
500 goto err_free_skb;
501
502 /* Push Tunnel header. */
503 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
504 goto err_free_skb;
505
506 flags = tun_info->key.tun_flags &
507 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
508 gre_build_header(skb, tunnel_hlen, flags, proto,
509 tunnel_id_to_key32(tun_info->key.tun_id),
510 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
511
512 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
513
514 return;
515
516err_free_skb:
517 kfree_skb(skb);
518 DEV_STATS_INC(dev, tx_dropped);
519}
520
521static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
522{
523 struct ip_tunnel *tunnel = netdev_priv(dev);
524 struct ip_tunnel_info *tun_info;
525 const struct ip_tunnel_key *key;
526 struct erspan_metadata *md;
527 bool truncate = false;
528 __be16 proto;
529 int tunnel_hlen;
530 int version;
531 int nhoff;
532
533 tun_info = skb_tunnel_info(skb);
534 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
535 ip_tunnel_info_af(tun_info) != AF_INET))
536 goto err_free_skb;
537
538 key = &tun_info->key;
539 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
540 goto err_free_skb;
541 if (tun_info->options_len < sizeof(*md))
542 goto err_free_skb;
543 md = ip_tunnel_info_opts(tun_info);
544
545 /* ERSPAN has fixed 8 byte GRE header */
546 version = md->version;
547 tunnel_hlen = 8 + erspan_hdr_len(version);
548
549 if (skb_cow_head(skb, dev->needed_headroom))
550 goto err_free_skb;
551
552 if (gre_handle_offloads(skb, false))
553 goto err_free_skb;
554
555 if (skb->len > dev->mtu + dev->hard_header_len) {
556 if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
557 goto err_free_skb;
558 truncate = true;
559 }
560
561 nhoff = skb_network_offset(skb);
562 if (skb->protocol == htons(ETH_P_IP) &&
563 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
564 truncate = true;
565
566 if (skb->protocol == htons(ETH_P_IPV6)) {
567 int thoff;
568
569 if (skb_transport_header_was_set(skb))
570 thoff = skb_transport_offset(skb);
571 else
572 thoff = nhoff + sizeof(struct ipv6hdr);
573 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
574 truncate = true;
575 }
576
577 if (version == 1) {
578 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
579 ntohl(md->u.index), truncate, true);
580 proto = htons(ETH_P_ERSPAN);
581 } else if (version == 2) {
582 erspan_build_header_v2(skb,
583 ntohl(tunnel_id_to_key32(key->tun_id)),
584 md->u.md2.dir,
585 get_hwid(&md->u.md2),
586 truncate, true);
587 proto = htons(ETH_P_ERSPAN2);
588 } else {
589 goto err_free_skb;
590 }
591
592 gre_build_header(skb, 8, TUNNEL_SEQ,
593 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno)));
594
595 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
596
597 return;
598
599err_free_skb:
600 kfree_skb(skb);
601 DEV_STATS_INC(dev, tx_dropped);
602}
603
604static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
605{
606 struct ip_tunnel_info *info = skb_tunnel_info(skb);
607 const struct ip_tunnel_key *key;
608 struct rtable *rt;
609 struct flowi4 fl4;
610
611 if (ip_tunnel_info_af(info) != AF_INET)
612 return -EINVAL;
613
614 key = &info->key;
615 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
616 tunnel_id_to_key32(key->tun_id),
617 key->tos & ~INET_ECN_MASK, dev_net(dev), 0,
618 skb->mark, skb_get_hash(skb), key->flow_flags);
619 rt = ip_route_output_key(dev_net(dev), &fl4);
620 if (IS_ERR(rt))
621 return PTR_ERR(rt);
622
623 ip_rt_put(rt);
624 info->key.u.ipv4.src = fl4.saddr;
625 return 0;
626}
627
628static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
629 struct net_device *dev)
630{
631 struct ip_tunnel *tunnel = netdev_priv(dev);
632 const struct iphdr *tnl_params;
633
634 if (!pskb_inet_may_pull(skb))
635 goto free_skb;
636
637 if (tunnel->collect_md) {
638 gre_fb_xmit(skb, dev, skb->protocol);
639 return NETDEV_TX_OK;
640 }
641
642 if (dev->header_ops) {
643 int pull_len = tunnel->hlen + sizeof(struct iphdr);
644
645 if (skb_cow_head(skb, 0))
646 goto free_skb;
647
648 tnl_params = (const struct iphdr *)skb->data;
649
650 if (!pskb_network_may_pull(skb, pull_len))
651 goto free_skb;
652
653 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */
654 skb_pull(skb, pull_len);
655 skb_reset_mac_header(skb);
656
657 if (skb->ip_summed == CHECKSUM_PARTIAL &&
658 skb_checksum_start(skb) < skb->data)
659 goto free_skb;
660 } else {
661 if (skb_cow_head(skb, dev->needed_headroom))
662 goto free_skb;
663
664 tnl_params = &tunnel->parms.iph;
665 }
666
667 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
668 goto free_skb;
669
670 __gre_xmit(skb, dev, tnl_params, skb->protocol);
671 return NETDEV_TX_OK;
672
673free_skb:
674 kfree_skb(skb);
675 DEV_STATS_INC(dev, tx_dropped);
676 return NETDEV_TX_OK;
677}
678
679static netdev_tx_t erspan_xmit(struct sk_buff *skb,
680 struct net_device *dev)
681{
682 struct ip_tunnel *tunnel = netdev_priv(dev);
683 bool truncate = false;
684 __be16 proto;
685
686 if (!pskb_inet_may_pull(skb))
687 goto free_skb;
688
689 if (tunnel->collect_md) {
690 erspan_fb_xmit(skb, dev);
691 return NETDEV_TX_OK;
692 }
693
694 if (gre_handle_offloads(skb, false))
695 goto free_skb;
696
697 if (skb_cow_head(skb, dev->needed_headroom))
698 goto free_skb;
699
700 if (skb->len > dev->mtu + dev->hard_header_len) {
701 if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
702 goto free_skb;
703 truncate = true;
704 }
705
706 /* Push ERSPAN header */
707 if (tunnel->erspan_ver == 0) {
708 proto = htons(ETH_P_ERSPAN);
709 tunnel->parms.o_flags &= ~TUNNEL_SEQ;
710 } else if (tunnel->erspan_ver == 1) {
711 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
712 tunnel->index,
713 truncate, true);
714 proto = htons(ETH_P_ERSPAN);
715 } else if (tunnel->erspan_ver == 2) {
716 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
717 tunnel->dir, tunnel->hwid,
718 truncate, true);
719 proto = htons(ETH_P_ERSPAN2);
720 } else {
721 goto free_skb;
722 }
723
724 tunnel->parms.o_flags &= ~TUNNEL_KEY;
725 __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
726 return NETDEV_TX_OK;
727
728free_skb:
729 kfree_skb(skb);
730 DEV_STATS_INC(dev, tx_dropped);
731 return NETDEV_TX_OK;
732}
733
734static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
735 struct net_device *dev)
736{
737 struct ip_tunnel *tunnel = netdev_priv(dev);
738
739 if (!pskb_inet_may_pull(skb))
740 goto free_skb;
741
742 if (tunnel->collect_md) {
743 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
744 return NETDEV_TX_OK;
745 }
746
747 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
748 goto free_skb;
749
750 if (skb_cow_head(skb, dev->needed_headroom))
751 goto free_skb;
752
753 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
754 return NETDEV_TX_OK;
755
756free_skb:
757 kfree_skb(skb);
758 DEV_STATS_INC(dev, tx_dropped);
759 return NETDEV_TX_OK;
760}
761
762static void ipgre_link_update(struct net_device *dev, bool set_mtu)
763{
764 struct ip_tunnel *tunnel = netdev_priv(dev);
765 __be16 flags;
766 int len;
767
768 len = tunnel->tun_hlen;
769 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
770 len = tunnel->tun_hlen - len;
771 tunnel->hlen = tunnel->hlen + len;
772
773 if (dev->header_ops)
774 dev->hard_header_len += len;
775 else
776 dev->needed_headroom += len;
777
778 if (set_mtu)
779 dev->mtu = max_t(int, dev->mtu - len, 68);
780
781 flags = tunnel->parms.o_flags;
782
783 if (flags & TUNNEL_SEQ ||
784 (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)) {
785 dev->features &= ~NETIF_F_GSO_SOFTWARE;
786 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
787 } else {
788 dev->features |= NETIF_F_GSO_SOFTWARE;
789 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
790 }
791}
792
793static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,
794 int cmd)
795{
796 int err;
797
798 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
799 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
800 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
801 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING)))
802 return -EINVAL;
803 }
804
805 p->i_flags = gre_flags_to_tnl_flags(p->i_flags);
806 p->o_flags = gre_flags_to_tnl_flags(p->o_flags);
807
808 err = ip_tunnel_ctl(dev, p, cmd);
809 if (err)
810 return err;
811
812 if (cmd == SIOCCHGTUNNEL) {
813 struct ip_tunnel *t = netdev_priv(dev);
814
815 t->parms.i_flags = p->i_flags;
816 t->parms.o_flags = p->o_flags;
817
818 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
819 ipgre_link_update(dev, true);
820 }
821
822 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
823 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
824 return 0;
825}
826
827/* Nice toy. Unfortunately, useless in real life :-)
828 It allows to construct virtual multiprotocol broadcast "LAN"
829 over the Internet, provided multicast routing is tuned.
830
831
832 I have no idea was this bicycle invented before me,
833 so that I had to set ARPHRD_IPGRE to a random value.
834 I have an impression, that Cisco could make something similar,
835 but this feature is apparently missing in IOS<=11.2(8).
836
837 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
838 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
839
840 ping -t 255 224.66.66.66
841
842 If nobody answers, mbone does not work.
843
844 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
845 ip addr add 10.66.66.<somewhat>/24 dev Universe
846 ifconfig Universe up
847 ifconfig Universe add fe80::<Your_real_addr>/10
848 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
849 ftp 10.66.66.66
850 ...
851 ftp fec0:6666:6666::193.233.7.65
852 ...
853 */
854static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
855 unsigned short type,
856 const void *daddr, const void *saddr, unsigned int len)
857{
858 struct ip_tunnel *t = netdev_priv(dev);
859 struct iphdr *iph;
860 struct gre_base_hdr *greh;
861
862 iph = skb_push(skb, t->hlen + sizeof(*iph));
863 greh = (struct gre_base_hdr *)(iph+1);
864 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
865 greh->protocol = htons(type);
866
867 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
868
869 /* Set the source hardware address. */
870 if (saddr)
871 memcpy(&iph->saddr, saddr, 4);
872 if (daddr)
873 memcpy(&iph->daddr, daddr, 4);
874 if (iph->daddr)
875 return t->hlen + sizeof(*iph);
876
877 return -(t->hlen + sizeof(*iph));
878}
879
880static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
881{
882 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
883 memcpy(haddr, &iph->saddr, 4);
884 return 4;
885}
886
887static const struct header_ops ipgre_header_ops = {
888 .create = ipgre_header,
889 .parse = ipgre_header_parse,
890};
891
892#ifdef CONFIG_NET_IPGRE_BROADCAST
893static int ipgre_open(struct net_device *dev)
894{
895 struct ip_tunnel *t = netdev_priv(dev);
896
897 if (ipv4_is_multicast(t->parms.iph.daddr)) {
898 struct flowi4 fl4;
899 struct rtable *rt;
900
901 rt = ip_route_output_gre(t->net, &fl4,
902 t->parms.iph.daddr,
903 t->parms.iph.saddr,
904 t->parms.o_key,
905 RT_TOS(t->parms.iph.tos),
906 t->parms.link);
907 if (IS_ERR(rt))
908 return -EADDRNOTAVAIL;
909 dev = rt->dst.dev;
910 ip_rt_put(rt);
911 if (!__in_dev_get_rtnl(dev))
912 return -EADDRNOTAVAIL;
913 t->mlink = dev->ifindex;
914 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
915 }
916 return 0;
917}
918
919static int ipgre_close(struct net_device *dev)
920{
921 struct ip_tunnel *t = netdev_priv(dev);
922
923 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
924 struct in_device *in_dev;
925 in_dev = inetdev_by_index(t->net, t->mlink);
926 if (in_dev)
927 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
928 }
929 return 0;
930}
931#endif
932
933static const struct net_device_ops ipgre_netdev_ops = {
934 .ndo_init = ipgre_tunnel_init,
935 .ndo_uninit = ip_tunnel_uninit,
936#ifdef CONFIG_NET_IPGRE_BROADCAST
937 .ndo_open = ipgre_open,
938 .ndo_stop = ipgre_close,
939#endif
940 .ndo_start_xmit = ipgre_xmit,
941 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
942 .ndo_change_mtu = ip_tunnel_change_mtu,
943 .ndo_get_stats64 = dev_get_tstats64,
944 .ndo_get_iflink = ip_tunnel_get_iflink,
945 .ndo_tunnel_ctl = ipgre_tunnel_ctl,
946};
947
948#define GRE_FEATURES (NETIF_F_SG | \
949 NETIF_F_FRAGLIST | \
950 NETIF_F_HIGHDMA | \
951 NETIF_F_HW_CSUM)
952
953static void ipgre_tunnel_setup(struct net_device *dev)
954{
955 dev->netdev_ops = &ipgre_netdev_ops;
956 dev->type = ARPHRD_IPGRE;
957 ip_tunnel_setup(dev, ipgre_net_id);
958}
959
960static void __gre_tunnel_init(struct net_device *dev)
961{
962 struct ip_tunnel *tunnel;
963 __be16 flags;
964
965 tunnel = netdev_priv(dev);
966 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
967 tunnel->parms.iph.protocol = IPPROTO_GRE;
968
969 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
970 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
971
972 dev->features |= GRE_FEATURES | NETIF_F_LLTX;
973 dev->hw_features |= GRE_FEATURES;
974
975 flags = tunnel->parms.o_flags;
976
977 /* TCP offload with GRE SEQ is not supported, nor can we support 2
978 * levels of outer headers requiring an update.
979 */
980 if (flags & TUNNEL_SEQ)
981 return;
982 if (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)
983 return;
984
985 dev->features |= NETIF_F_GSO_SOFTWARE;
986 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
987}
988
989static int ipgre_tunnel_init(struct net_device *dev)
990{
991 struct ip_tunnel *tunnel = netdev_priv(dev);
992 struct iphdr *iph = &tunnel->parms.iph;
993
994 __gre_tunnel_init(dev);
995
996 __dev_addr_set(dev, &iph->saddr, 4);
997 memcpy(dev->broadcast, &iph->daddr, 4);
998
999 dev->flags = IFF_NOARP;
1000 netif_keep_dst(dev);
1001 dev->addr_len = 4;
1002
1003 if (iph->daddr && !tunnel->collect_md) {
1004#ifdef CONFIG_NET_IPGRE_BROADCAST
1005 if (ipv4_is_multicast(iph->daddr)) {
1006 if (!iph->saddr)
1007 return -EINVAL;
1008 dev->flags = IFF_BROADCAST;
1009 dev->header_ops = &ipgre_header_ops;
1010 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1011 dev->needed_headroom = 0;
1012 }
1013#endif
1014 } else if (!tunnel->collect_md) {
1015 dev->header_ops = &ipgre_header_ops;
1016 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1017 dev->needed_headroom = 0;
1018 }
1019
1020 return ip_tunnel_init(dev);
1021}
1022
1023static const struct gre_protocol ipgre_protocol = {
1024 .handler = gre_rcv,
1025 .err_handler = gre_err,
1026};
1027
1028static int __net_init ipgre_init_net(struct net *net)
1029{
1030 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
1031}
1032
1033static void __net_exit ipgre_exit_batch_rtnl(struct list_head *list_net,
1034 struct list_head *dev_to_kill)
1035{
1036 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops,
1037 dev_to_kill);
1038}
1039
1040static struct pernet_operations ipgre_net_ops = {
1041 .init = ipgre_init_net,
1042 .exit_batch_rtnl = ipgre_exit_batch_rtnl,
1043 .id = &ipgre_net_id,
1044 .size = sizeof(struct ip_tunnel_net),
1045};
1046
1047static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1048 struct netlink_ext_ack *extack)
1049{
1050 __be16 flags;
1051
1052 if (!data)
1053 return 0;
1054
1055 flags = 0;
1056 if (data[IFLA_GRE_IFLAGS])
1057 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1058 if (data[IFLA_GRE_OFLAGS])
1059 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1060 if (flags & (GRE_VERSION|GRE_ROUTING))
1061 return -EINVAL;
1062
1063 if (data[IFLA_GRE_COLLECT_METADATA] &&
1064 data[IFLA_GRE_ENCAP_TYPE] &&
1065 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1066 return -EINVAL;
1067
1068 return 0;
1069}
1070
1071static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1072 struct netlink_ext_ack *extack)
1073{
1074 __be32 daddr;
1075
1076 if (tb[IFLA_ADDRESS]) {
1077 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1078 return -EINVAL;
1079 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1080 return -EADDRNOTAVAIL;
1081 }
1082
1083 if (!data)
1084 goto out;
1085
1086 if (data[IFLA_GRE_REMOTE]) {
1087 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1088 if (!daddr)
1089 return -EINVAL;
1090 }
1091
1092out:
1093 return ipgre_tunnel_validate(tb, data, extack);
1094}
1095
1096static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1097 struct netlink_ext_ack *extack)
1098{
1099 __be16 flags = 0;
1100 int ret;
1101
1102 if (!data)
1103 return 0;
1104
1105 ret = ipgre_tap_validate(tb, data, extack);
1106 if (ret)
1107 return ret;
1108
1109 if (data[IFLA_GRE_ERSPAN_VER] &&
1110 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
1111 return 0;
1112
1113 /* ERSPAN type II/III should only have GRE sequence and key flag */
1114 if (data[IFLA_GRE_OFLAGS])
1115 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1116 if (data[IFLA_GRE_IFLAGS])
1117 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1118 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1119 flags != (GRE_SEQ | GRE_KEY))
1120 return -EINVAL;
1121
1122 /* ERSPAN Session ID only has 10-bit. Since we reuse
1123 * 32-bit key field as ID, check it's range.
1124 */
1125 if (data[IFLA_GRE_IKEY] &&
1126 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1127 return -EINVAL;
1128
1129 if (data[IFLA_GRE_OKEY] &&
1130 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1131 return -EINVAL;
1132
1133 return 0;
1134}
1135
1136static int ipgre_netlink_parms(struct net_device *dev,
1137 struct nlattr *data[],
1138 struct nlattr *tb[],
1139 struct ip_tunnel_parm *parms,
1140 __u32 *fwmark)
1141{
1142 struct ip_tunnel *t = netdev_priv(dev);
1143
1144 memset(parms, 0, sizeof(*parms));
1145
1146 parms->iph.protocol = IPPROTO_GRE;
1147
1148 if (!data)
1149 return 0;
1150
1151 if (data[IFLA_GRE_LINK])
1152 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1153
1154 if (data[IFLA_GRE_IFLAGS])
1155 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1156
1157 if (data[IFLA_GRE_OFLAGS])
1158 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1159
1160 if (data[IFLA_GRE_IKEY])
1161 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1162
1163 if (data[IFLA_GRE_OKEY])
1164 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1165
1166 if (data[IFLA_GRE_LOCAL])
1167 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1168
1169 if (data[IFLA_GRE_REMOTE])
1170 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1171
1172 if (data[IFLA_GRE_TTL])
1173 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1174
1175 if (data[IFLA_GRE_TOS])
1176 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1177
1178 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1179 if (t->ignore_df)
1180 return -EINVAL;
1181 parms->iph.frag_off = htons(IP_DF);
1182 }
1183
1184 if (data[IFLA_GRE_COLLECT_METADATA]) {
1185 t->collect_md = true;
1186 if (dev->type == ARPHRD_IPGRE)
1187 dev->type = ARPHRD_NONE;
1188 }
1189
1190 if (data[IFLA_GRE_IGNORE_DF]) {
1191 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1192 && (parms->iph.frag_off & htons(IP_DF)))
1193 return -EINVAL;
1194 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1195 }
1196
1197 if (data[IFLA_GRE_FWMARK])
1198 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1199
1200 return 0;
1201}
1202
1203static int erspan_netlink_parms(struct net_device *dev,
1204 struct nlattr *data[],
1205 struct nlattr *tb[],
1206 struct ip_tunnel_parm *parms,
1207 __u32 *fwmark)
1208{
1209 struct ip_tunnel *t = netdev_priv(dev);
1210 int err;
1211
1212 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1213 if (err)
1214 return err;
1215 if (!data)
1216 return 0;
1217
1218 if (data[IFLA_GRE_ERSPAN_VER]) {
1219 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1220
1221 if (t->erspan_ver > 2)
1222 return -EINVAL;
1223 }
1224
1225 if (t->erspan_ver == 1) {
1226 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1227 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1228 if (t->index & ~INDEX_MASK)
1229 return -EINVAL;
1230 }
1231 } else if (t->erspan_ver == 2) {
1232 if (data[IFLA_GRE_ERSPAN_DIR]) {
1233 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1234 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1235 return -EINVAL;
1236 }
1237 if (data[IFLA_GRE_ERSPAN_HWID]) {
1238 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1239 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1240 return -EINVAL;
1241 }
1242 }
1243
1244 return 0;
1245}
1246
1247/* This function returns true when ENCAP attributes are present in the nl msg */
1248static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1249 struct ip_tunnel_encap *ipencap)
1250{
1251 bool ret = false;
1252
1253 memset(ipencap, 0, sizeof(*ipencap));
1254
1255 if (!data)
1256 return ret;
1257
1258 if (data[IFLA_GRE_ENCAP_TYPE]) {
1259 ret = true;
1260 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1261 }
1262
1263 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1264 ret = true;
1265 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1266 }
1267
1268 if (data[IFLA_GRE_ENCAP_SPORT]) {
1269 ret = true;
1270 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1271 }
1272
1273 if (data[IFLA_GRE_ENCAP_DPORT]) {
1274 ret = true;
1275 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1276 }
1277
1278 return ret;
1279}
1280
1281static int gre_tap_init(struct net_device *dev)
1282{
1283 __gre_tunnel_init(dev);
1284 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1285 netif_keep_dst(dev);
1286
1287 return ip_tunnel_init(dev);
1288}
1289
1290static const struct net_device_ops gre_tap_netdev_ops = {
1291 .ndo_init = gre_tap_init,
1292 .ndo_uninit = ip_tunnel_uninit,
1293 .ndo_start_xmit = gre_tap_xmit,
1294 .ndo_set_mac_address = eth_mac_addr,
1295 .ndo_validate_addr = eth_validate_addr,
1296 .ndo_change_mtu = ip_tunnel_change_mtu,
1297 .ndo_get_stats64 = dev_get_tstats64,
1298 .ndo_get_iflink = ip_tunnel_get_iflink,
1299 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1300};
1301
1302static int erspan_tunnel_init(struct net_device *dev)
1303{
1304 struct ip_tunnel *tunnel = netdev_priv(dev);
1305
1306 if (tunnel->erspan_ver == 0)
1307 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1308 else
1309 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1310
1311 tunnel->parms.iph.protocol = IPPROTO_GRE;
1312 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1313 erspan_hdr_len(tunnel->erspan_ver);
1314
1315 dev->features |= GRE_FEATURES;
1316 dev->hw_features |= GRE_FEATURES;
1317 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1318 netif_keep_dst(dev);
1319
1320 return ip_tunnel_init(dev);
1321}
1322
1323static const struct net_device_ops erspan_netdev_ops = {
1324 .ndo_init = erspan_tunnel_init,
1325 .ndo_uninit = ip_tunnel_uninit,
1326 .ndo_start_xmit = erspan_xmit,
1327 .ndo_set_mac_address = eth_mac_addr,
1328 .ndo_validate_addr = eth_validate_addr,
1329 .ndo_change_mtu = ip_tunnel_change_mtu,
1330 .ndo_get_stats64 = dev_get_tstats64,
1331 .ndo_get_iflink = ip_tunnel_get_iflink,
1332 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1333};
1334
1335static void ipgre_tap_setup(struct net_device *dev)
1336{
1337 ether_setup(dev);
1338 dev->max_mtu = 0;
1339 dev->netdev_ops = &gre_tap_netdev_ops;
1340 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1341 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1342 ip_tunnel_setup(dev, gre_tap_net_id);
1343}
1344
1345static int
1346ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1347{
1348 struct ip_tunnel_encap ipencap;
1349
1350 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1351 struct ip_tunnel *t = netdev_priv(dev);
1352 int err = ip_tunnel_encap_setup(t, &ipencap);
1353
1354 if (err < 0)
1355 return err;
1356 }
1357
1358 return 0;
1359}
1360
1361static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1362 struct nlattr *tb[], struct nlattr *data[],
1363 struct netlink_ext_ack *extack)
1364{
1365 struct ip_tunnel_parm p;
1366 __u32 fwmark = 0;
1367 int err;
1368
1369 err = ipgre_newlink_encap_setup(dev, data);
1370 if (err)
1371 return err;
1372
1373 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1374 if (err < 0)
1375 return err;
1376 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1377}
1378
1379static int erspan_newlink(struct net *src_net, struct net_device *dev,
1380 struct nlattr *tb[], struct nlattr *data[],
1381 struct netlink_ext_ack *extack)
1382{
1383 struct ip_tunnel_parm p;
1384 __u32 fwmark = 0;
1385 int err;
1386
1387 err = ipgre_newlink_encap_setup(dev, data);
1388 if (err)
1389 return err;
1390
1391 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1392 if (err)
1393 return err;
1394 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1395}
1396
1397static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1398 struct nlattr *data[],
1399 struct netlink_ext_ack *extack)
1400{
1401 struct ip_tunnel *t = netdev_priv(dev);
1402 __u32 fwmark = t->fwmark;
1403 struct ip_tunnel_parm p;
1404 int err;
1405
1406 err = ipgre_newlink_encap_setup(dev, data);
1407 if (err)
1408 return err;
1409
1410 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1411 if (err < 0)
1412 return err;
1413
1414 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1415 if (err < 0)
1416 return err;
1417
1418 t->parms.i_flags = p.i_flags;
1419 t->parms.o_flags = p.o_flags;
1420
1421 ipgre_link_update(dev, !tb[IFLA_MTU]);
1422
1423 return 0;
1424}
1425
1426static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1427 struct nlattr *data[],
1428 struct netlink_ext_ack *extack)
1429{
1430 struct ip_tunnel *t = netdev_priv(dev);
1431 __u32 fwmark = t->fwmark;
1432 struct ip_tunnel_parm p;
1433 int err;
1434
1435 err = ipgre_newlink_encap_setup(dev, data);
1436 if (err)
1437 return err;
1438
1439 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1440 if (err < 0)
1441 return err;
1442
1443 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1444 if (err < 0)
1445 return err;
1446
1447 t->parms.i_flags = p.i_flags;
1448 t->parms.o_flags = p.o_flags;
1449
1450 return 0;
1451}
1452
1453static size_t ipgre_get_size(const struct net_device *dev)
1454{
1455 return
1456 /* IFLA_GRE_LINK */
1457 nla_total_size(4) +
1458 /* IFLA_GRE_IFLAGS */
1459 nla_total_size(2) +
1460 /* IFLA_GRE_OFLAGS */
1461 nla_total_size(2) +
1462 /* IFLA_GRE_IKEY */
1463 nla_total_size(4) +
1464 /* IFLA_GRE_OKEY */
1465 nla_total_size(4) +
1466 /* IFLA_GRE_LOCAL */
1467 nla_total_size(4) +
1468 /* IFLA_GRE_REMOTE */
1469 nla_total_size(4) +
1470 /* IFLA_GRE_TTL */
1471 nla_total_size(1) +
1472 /* IFLA_GRE_TOS */
1473 nla_total_size(1) +
1474 /* IFLA_GRE_PMTUDISC */
1475 nla_total_size(1) +
1476 /* IFLA_GRE_ENCAP_TYPE */
1477 nla_total_size(2) +
1478 /* IFLA_GRE_ENCAP_FLAGS */
1479 nla_total_size(2) +
1480 /* IFLA_GRE_ENCAP_SPORT */
1481 nla_total_size(2) +
1482 /* IFLA_GRE_ENCAP_DPORT */
1483 nla_total_size(2) +
1484 /* IFLA_GRE_COLLECT_METADATA */
1485 nla_total_size(0) +
1486 /* IFLA_GRE_IGNORE_DF */
1487 nla_total_size(1) +
1488 /* IFLA_GRE_FWMARK */
1489 nla_total_size(4) +
1490 /* IFLA_GRE_ERSPAN_INDEX */
1491 nla_total_size(4) +
1492 /* IFLA_GRE_ERSPAN_VER */
1493 nla_total_size(1) +
1494 /* IFLA_GRE_ERSPAN_DIR */
1495 nla_total_size(1) +
1496 /* IFLA_GRE_ERSPAN_HWID */
1497 nla_total_size(2) +
1498 0;
1499}
1500
1501static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1502{
1503 struct ip_tunnel *t = netdev_priv(dev);
1504 struct ip_tunnel_parm *p = &t->parms;
1505 __be16 o_flags = p->o_flags;
1506
1507 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1508 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1509 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1510 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1511 gre_tnl_flags_to_gre_flags(o_flags)) ||
1512 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1513 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1514 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1515 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1516 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1517 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1518 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1519 !!(p->iph.frag_off & htons(IP_DF))) ||
1520 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1521 goto nla_put_failure;
1522
1523 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1524 t->encap.type) ||
1525 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1526 t->encap.sport) ||
1527 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1528 t->encap.dport) ||
1529 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1530 t->encap.flags))
1531 goto nla_put_failure;
1532
1533 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1534 goto nla_put_failure;
1535
1536 if (t->collect_md) {
1537 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1538 goto nla_put_failure;
1539 }
1540
1541 return 0;
1542
1543nla_put_failure:
1544 return -EMSGSIZE;
1545}
1546
1547static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
1548{
1549 struct ip_tunnel *t = netdev_priv(dev);
1550
1551 if (t->erspan_ver <= 2) {
1552 if (t->erspan_ver != 0 && !t->collect_md)
1553 t->parms.o_flags |= TUNNEL_KEY;
1554
1555 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1556 goto nla_put_failure;
1557
1558 if (t->erspan_ver == 1) {
1559 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1560 goto nla_put_failure;
1561 } else if (t->erspan_ver == 2) {
1562 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1563 goto nla_put_failure;
1564 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1565 goto nla_put_failure;
1566 }
1567 }
1568
1569 return ipgre_fill_info(skb, dev);
1570
1571nla_put_failure:
1572 return -EMSGSIZE;
1573}
1574
1575static void erspan_setup(struct net_device *dev)
1576{
1577 struct ip_tunnel *t = netdev_priv(dev);
1578
1579 ether_setup(dev);
1580 dev->max_mtu = 0;
1581 dev->netdev_ops = &erspan_netdev_ops;
1582 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1583 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1584 ip_tunnel_setup(dev, erspan_net_id);
1585 t->erspan_ver = 1;
1586}
1587
1588static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1589 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1590 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1591 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1592 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1593 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1594 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1595 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1596 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1597 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1598 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1599 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1600 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1601 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1602 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1603 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1604 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1605 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1606 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1607 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1608 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1609 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1610};
1611
1612static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1613 .kind = "gre",
1614 .maxtype = IFLA_GRE_MAX,
1615 .policy = ipgre_policy,
1616 .priv_size = sizeof(struct ip_tunnel),
1617 .setup = ipgre_tunnel_setup,
1618 .validate = ipgre_tunnel_validate,
1619 .newlink = ipgre_newlink,
1620 .changelink = ipgre_changelink,
1621 .dellink = ip_tunnel_dellink,
1622 .get_size = ipgre_get_size,
1623 .fill_info = ipgre_fill_info,
1624 .get_link_net = ip_tunnel_get_link_net,
1625};
1626
1627static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1628 .kind = "gretap",
1629 .maxtype = IFLA_GRE_MAX,
1630 .policy = ipgre_policy,
1631 .priv_size = sizeof(struct ip_tunnel),
1632 .setup = ipgre_tap_setup,
1633 .validate = ipgre_tap_validate,
1634 .newlink = ipgre_newlink,
1635 .changelink = ipgre_changelink,
1636 .dellink = ip_tunnel_dellink,
1637 .get_size = ipgre_get_size,
1638 .fill_info = ipgre_fill_info,
1639 .get_link_net = ip_tunnel_get_link_net,
1640};
1641
1642static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1643 .kind = "erspan",
1644 .maxtype = IFLA_GRE_MAX,
1645 .policy = ipgre_policy,
1646 .priv_size = sizeof(struct ip_tunnel),
1647 .setup = erspan_setup,
1648 .validate = erspan_validate,
1649 .newlink = erspan_newlink,
1650 .changelink = erspan_changelink,
1651 .dellink = ip_tunnel_dellink,
1652 .get_size = ipgre_get_size,
1653 .fill_info = erspan_fill_info,
1654 .get_link_net = ip_tunnel_get_link_net,
1655};
1656
1657struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1658 u8 name_assign_type)
1659{
1660 struct nlattr *tb[IFLA_MAX + 1];
1661 struct net_device *dev;
1662 LIST_HEAD(list_kill);
1663 struct ip_tunnel *t;
1664 int err;
1665
1666 memset(&tb, 0, sizeof(tb));
1667
1668 dev = rtnl_create_link(net, name, name_assign_type,
1669 &ipgre_tap_ops, tb, NULL);
1670 if (IS_ERR(dev))
1671 return dev;
1672
1673 /* Configure flow based GRE device. */
1674 t = netdev_priv(dev);
1675 t->collect_md = true;
1676
1677 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1678 if (err < 0) {
1679 free_netdev(dev);
1680 return ERR_PTR(err);
1681 }
1682
1683 /* openvswitch users expect packet sizes to be unrestricted,
1684 * so set the largest MTU we can.
1685 */
1686 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1687 if (err)
1688 goto out;
1689
1690 err = rtnl_configure_link(dev, NULL, 0, NULL);
1691 if (err < 0)
1692 goto out;
1693
1694 return dev;
1695out:
1696 ip_tunnel_dellink(dev, &list_kill);
1697 unregister_netdevice_many(&list_kill);
1698 return ERR_PTR(err);
1699}
1700EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1701
1702static int __net_init ipgre_tap_init_net(struct net *net)
1703{
1704 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1705}
1706
1707static void __net_exit ipgre_tap_exit_batch_rtnl(struct list_head *list_net,
1708 struct list_head *dev_to_kill)
1709{
1710 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops,
1711 dev_to_kill);
1712}
1713
1714static struct pernet_operations ipgre_tap_net_ops = {
1715 .init = ipgre_tap_init_net,
1716 .exit_batch_rtnl = ipgre_tap_exit_batch_rtnl,
1717 .id = &gre_tap_net_id,
1718 .size = sizeof(struct ip_tunnel_net),
1719};
1720
1721static int __net_init erspan_init_net(struct net *net)
1722{
1723 return ip_tunnel_init_net(net, erspan_net_id,
1724 &erspan_link_ops, "erspan0");
1725}
1726
1727static void __net_exit erspan_exit_batch_rtnl(struct list_head *net_list,
1728 struct list_head *dev_to_kill)
1729{
1730 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops,
1731 dev_to_kill);
1732}
1733
1734static struct pernet_operations erspan_net_ops = {
1735 .init = erspan_init_net,
1736 .exit_batch_rtnl = erspan_exit_batch_rtnl,
1737 .id = &erspan_net_id,
1738 .size = sizeof(struct ip_tunnel_net),
1739};
1740
1741static int __init ipgre_init(void)
1742{
1743 int err;
1744
1745 pr_info("GRE over IPv4 tunneling driver\n");
1746
1747 err = register_pernet_device(&ipgre_net_ops);
1748 if (err < 0)
1749 return err;
1750
1751 err = register_pernet_device(&ipgre_tap_net_ops);
1752 if (err < 0)
1753 goto pnet_tap_failed;
1754
1755 err = register_pernet_device(&erspan_net_ops);
1756 if (err < 0)
1757 goto pnet_erspan_failed;
1758
1759 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1760 if (err < 0) {
1761 pr_info("%s: can't add protocol\n", __func__);
1762 goto add_proto_failed;
1763 }
1764
1765 err = rtnl_link_register(&ipgre_link_ops);
1766 if (err < 0)
1767 goto rtnl_link_failed;
1768
1769 err = rtnl_link_register(&ipgre_tap_ops);
1770 if (err < 0)
1771 goto tap_ops_failed;
1772
1773 err = rtnl_link_register(&erspan_link_ops);
1774 if (err < 0)
1775 goto erspan_link_failed;
1776
1777 return 0;
1778
1779erspan_link_failed:
1780 rtnl_link_unregister(&ipgre_tap_ops);
1781tap_ops_failed:
1782 rtnl_link_unregister(&ipgre_link_ops);
1783rtnl_link_failed:
1784 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1785add_proto_failed:
1786 unregister_pernet_device(&erspan_net_ops);
1787pnet_erspan_failed:
1788 unregister_pernet_device(&ipgre_tap_net_ops);
1789pnet_tap_failed:
1790 unregister_pernet_device(&ipgre_net_ops);
1791 return err;
1792}
1793
1794static void __exit ipgre_fini(void)
1795{
1796 rtnl_link_unregister(&ipgre_tap_ops);
1797 rtnl_link_unregister(&ipgre_link_ops);
1798 rtnl_link_unregister(&erspan_link_ops);
1799 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1800 unregister_pernet_device(&ipgre_tap_net_ops);
1801 unregister_pernet_device(&ipgre_net_ops);
1802 unregister_pernet_device(&erspan_net_ops);
1803}
1804
1805module_init(ipgre_init);
1806module_exit(ipgre_fini);
1807MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
1808MODULE_LICENSE("GPL");
1809MODULE_ALIAS_RTNL_LINK("gre");
1810MODULE_ALIAS_RTNL_LINK("gretap");
1811MODULE_ALIAS_RTNL_LINK("erspan");
1812MODULE_ALIAS_NETDEV("gre0");
1813MODULE_ALIAS_NETDEV("gretap0");
1814MODULE_ALIAS_NETDEV("erspan0");