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/flow.h>
32#include <net/sock.h>
33#include <net/ip.h>
34#include <net/icmp.h>
35#include <net/protocol.h>
36#include <net/ip_tunnels.h>
37#include <net/arp.h>
38#include <net/checksum.h>
39#include <net/dsfield.h>
40#include <net/inet_ecn.h>
41#include <net/xfrm.h>
42#include <net/net_namespace.h>
43#include <net/netns/generic.h>
44#include <net/rtnetlink.h>
45#include <net/gre.h>
46#include <net/dst_metadata.h>
47#include <net/erspan.h>
48
49/*
50 Problems & solutions
51 --------------------
52
53 1. The most important issue is detecting local dead loops.
54 They would cause complete host lockup in transmit, which
55 would be "resolved" by stack overflow or, if queueing is enabled,
56 with infinite looping in net_bh.
57
58 We cannot track such dead loops during route installation,
59 it is infeasible task. The most general solutions would be
60 to keep skb->encapsulation counter (sort of local ttl),
61 and silently drop packet when it expires. It is a good
62 solution, but it supposes maintaining new variable in ALL
63 skb, even if no tunneling is used.
64
65 Current solution: xmit_recursion breaks dead loops. This is a percpu
66 counter, since when we enter the first ndo_xmit(), cpu migration is
67 forbidden. We force an exit if this counter reaches RECURSION_LIMIT
68
69 2. Networking dead loops would not kill routers, but would really
70 kill network. IP hop limit plays role of "t->recursion" in this case,
71 if we copy it from packet being encapsulated to upper header.
72 It is very good solution, but it introduces two problems:
73
74 - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
75 do not work over tunnels.
76 - traceroute does not work. I planned to relay ICMP from tunnel,
77 so that this problem would be solved and traceroute output
78 would even more informative. This idea appeared to be wrong:
79 only Linux complies to rfc1812 now (yes, guys, Linux is the only
80 true router now :-)), all routers (at least, in neighbourhood of mine)
81 return only 8 bytes of payload. It is the end.
82
83 Hence, if we want that OSPF worked or traceroute said something reasonable,
84 we should search for another solution.
85
86 One of them is to parse packet trying to detect inner encapsulation
87 made by our node. It is difficult or even impossible, especially,
88 taking into account fragmentation. TO be short, ttl is not solution at all.
89
90 Current solution: The solution was UNEXPECTEDLY SIMPLE.
91 We force DF flag on tunnels with preconfigured hop limit,
92 that is ALL. :-) Well, it does not remove the problem completely,
93 but exponential growth of network traffic is changed to linear
94 (branches, that exceed pmtu are pruned) and tunnel mtu
95 rapidly degrades to value <68, where looping stops.
96 Yes, it is not good if there exists a router in the loop,
97 which does not force DF, even when encapsulating packets have DF set.
98 But it is not our problem! Nobody could accuse us, we made
99 all that we could make. Even if it is your gated who injected
100 fatal route to network, even if it were you who configured
101 fatal static route: you are innocent. :-)
102
103 Alexey Kuznetsov.
104 */
105
106static bool log_ecn_error = true;
107module_param(log_ecn_error, bool, 0644);
108MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
109
110static struct rtnl_link_ops ipgre_link_ops __read_mostly;
111static const struct header_ops ipgre_header_ops;
112
113static int ipgre_tunnel_init(struct net_device *dev);
114static void erspan_build_header(struct sk_buff *skb,
115 u32 id, u32 index,
116 bool truncate, bool is_ipv4);
117
118static unsigned int ipgre_net_id __read_mostly;
119static unsigned int gre_tap_net_id __read_mostly;
120static unsigned int erspan_net_id __read_mostly;
121
122static int ipgre_err(struct sk_buff *skb, u32 info,
123 const struct tnl_ptk_info *tpi)
124{
125
126 /* All the routers (except for Linux) return only
127 8 bytes of packet payload. It means, that precise relaying of
128 ICMP in the real Internet is absolutely infeasible.
129
130 Moreover, Cisco "wise men" put GRE key to the third word
131 in GRE header. It makes impossible maintaining even soft
132 state for keyed GRE tunnels with enabled checksum. Tell
133 them "thank you".
134
135 Well, I wonder, rfc1812 was written by Cisco employee,
136 what the hell these idiots break standards established
137 by themselves???
138 */
139 struct net *net = dev_net(dev: skb->dev);
140 struct ip_tunnel_net *itn;
141 const struct iphdr *iph;
142 const int type = icmp_hdr(skb)->type;
143 const int code = icmp_hdr(skb)->code;
144 struct ip_tunnel *t;
145
146 if (tpi->proto == htons(ETH_P_TEB))
147 itn = net_generic(net, id: 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, id: erspan_net_id);
151 else
152 itn = net_generic(net, id: ipgre_net_id);
153
154 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
155 t = ip_tunnel_lookup(itn, link: skb->dev->ifindex, flags: tpi->flags,
156 remote: iph->daddr, local: iph->saddr, key: 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 break;
185
186 case ICMP_REDIRECT:
187 break;
188 }
189
190#if IS_ENABLED(CONFIG_IPV6)
191 if (tpi->proto == htons(ETH_P_IPV6)) {
192 unsigned int data_len = 0;
193
194 if (type == ICMP_TIME_EXCEEDED)
195 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
196
197 if (!ip6_err_gen_icmpv6_unreach(skb, nhs: iph->ihl * 4 + tpi->hdr_len,
198 type, data_len))
199 return 0;
200 }
201#endif
202
203 if (t->parms.iph.daddr == 0 ||
204 ipv4_is_multicast(addr: t->parms.iph.daddr))
205 return 0;
206
207 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
208 return 0;
209
210 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
211 t->err_count++;
212 else
213 t->err_count = 1;
214 t->err_time = jiffies;
215
216 return 0;
217}
218
219static void gre_err(struct sk_buff *skb, u32 info)
220{
221 /* All the routers (except for Linux) return only
222 * 8 bytes of packet payload. It means, that precise relaying of
223 * ICMP in the real Internet is absolutely infeasible.
224 *
225 * Moreover, Cisco "wise men" put GRE key to the third word
226 * in GRE header. It makes impossible maintaining even soft
227 * state for keyed
228 * GRE tunnels with enabled checksum. Tell them "thank you".
229 *
230 * Well, I wonder, rfc1812 was written by Cisco employee,
231 * what the hell these idiots break standards established
232 * by themselves???
233 */
234
235 const struct iphdr *iph = (struct iphdr *)skb->data;
236 const int type = icmp_hdr(skb)->type;
237 const int code = icmp_hdr(skb)->code;
238 struct tnl_ptk_info tpi;
239
240 if (gre_parse_header(skb, tpi: &tpi, NULL, htons(ETH_P_IP),
241 nhs: iph->ihl * 4) < 0)
242 return;
243
244 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
245 ipv4_update_pmtu(skb, net: dev_net(dev: skb->dev), mtu: info,
246 oif: skb->dev->ifindex, IPPROTO_GRE);
247 return;
248 }
249 if (type == ICMP_REDIRECT) {
250 ipv4_redirect(skb, net: dev_net(dev: skb->dev), oif: skb->dev->ifindex,
251 IPPROTO_GRE);
252 return;
253 }
254
255 ipgre_err(skb, info, tpi: &tpi);
256}
257
258static bool is_erspan_type1(int gre_hdr_len)
259{
260 /* Both ERSPAN type I (version 0) and type II (version 1) use
261 * protocol 0x88BE, but the type I has only 4-byte GRE header,
262 * while type II has 8-byte.
263 */
264 return gre_hdr_len == 4;
265}
266
267static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
268 int gre_hdr_len)
269{
270 struct net *net = dev_net(dev: skb->dev);
271 struct metadata_dst *tun_dst = NULL;
272 struct erspan_base_hdr *ershdr;
273 IP_TUNNEL_DECLARE_FLAGS(flags);
274 struct ip_tunnel_net *itn;
275 struct ip_tunnel *tunnel;
276 const struct iphdr *iph;
277 struct erspan_md2 *md2;
278 int ver;
279 int len;
280
281 ip_tunnel_flags_copy(flags, tpi->flags);
282
283 itn = net_generic(net, id: erspan_net_id);
284 iph = ip_hdr(skb);
285 if (is_erspan_type1(gre_hdr_len)) {
286 ver = 0;
287 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
288 tunnel = ip_tunnel_lookup(itn, link: skb->dev->ifindex, flags,
289 remote: iph->saddr, local: iph->daddr, key: 0);
290 } else {
291 if (unlikely(!pskb_may_pull(skb,
292 gre_hdr_len + sizeof(*ershdr))))
293 return PACKET_REJECT;
294
295 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
296 ver = ershdr->ver;
297 iph = ip_hdr(skb);
298 __set_bit(IP_TUNNEL_KEY_BIT, flags);
299 tunnel = ip_tunnel_lookup(itn, link: skb->dev->ifindex, flags,
300 remote: iph->saddr, local: iph->daddr, key: tpi->key);
301 }
302
303 if (tunnel) {
304 if (is_erspan_type1(gre_hdr_len))
305 len = gre_hdr_len;
306 else
307 len = gre_hdr_len + erspan_hdr_len(version: ver);
308
309 if (unlikely(!pskb_may_pull(skb, len)))
310 return PACKET_REJECT;
311
312 if (__iptunnel_pull_header(skb,
313 hdr_len: len,
314 htons(ETH_P_TEB),
315 raw_proto: false, xnet: false) < 0)
316 goto drop;
317
318 if (tunnel->collect_md) {
319 struct erspan_metadata *pkt_md, *md;
320 struct ip_tunnel_info *info;
321 unsigned char *gh;
322 __be64 tun_id;
323
324 __set_bit(IP_TUNNEL_KEY_BIT, tpi->flags);
325 ip_tunnel_flags_copy(flags, tpi->flags);
326 tun_id = key32_to_tunnel_id(key: tpi->key);
327
328 tun_dst = ip_tun_rx_dst(skb, flags,
329 tunnel_id: tun_id, md_size: sizeof(*md));
330 if (!tun_dst)
331 return PACKET_REJECT;
332
333 /* MUST set options_len before referencing options */
334 info = &tun_dst->u.tun_info;
335 info->options_len = sizeof(*md);
336
337 /* skb can be uncloned in __iptunnel_pull_header, so
338 * old pkt_md is no longer valid and we need to reset
339 * it
340 */
341 gh = skb_network_header(skb) +
342 skb_network_header_len(skb);
343 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
344 sizeof(*ershdr));
345 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
346 md->version = ver;
347 md2 = &md->u.md2;
348 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
349 ERSPAN_V2_MDSIZE);
350
351 __set_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
352 info->key.tun_flags);
353 }
354
355 skb_reset_mac_header(skb);
356 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
357 return PACKET_RCVD;
358 }
359 return PACKET_REJECT;
360
361drop:
362 kfree_skb(skb);
363 return PACKET_RCVD;
364}
365
366static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
367 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
368{
369 struct metadata_dst *tun_dst = NULL;
370 const struct iphdr *iph;
371 struct ip_tunnel *tunnel;
372
373 iph = ip_hdr(skb);
374 tunnel = ip_tunnel_lookup(itn, link: skb->dev->ifindex, flags: tpi->flags,
375 remote: iph->saddr, local: iph->daddr, key: tpi->key);
376
377 if (tunnel) {
378 const struct iphdr *tnl_params;
379
380 if (__iptunnel_pull_header(skb, hdr_len, inner_proto: tpi->proto,
381 raw_proto, xnet: false) < 0)
382 goto drop;
383
384 /* Special case for ipgre_header_parse(), which expects the
385 * mac_header to point to the outer IP header.
386 */
387 if (tunnel->dev->header_ops == &ipgre_header_ops)
388 skb_pop_mac_header(skb);
389 else
390 skb_reset_mac_header(skb);
391
392 tnl_params = &tunnel->parms.iph;
393 if (tunnel->collect_md || tnl_params->daddr == 0) {
394 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
395 __be64 tun_id;
396
397 __set_bit(IP_TUNNEL_CSUM_BIT, flags);
398 __set_bit(IP_TUNNEL_KEY_BIT, flags);
399 ip_tunnel_flags_and(flags, tpi->flags, flags);
400
401 tun_id = key32_to_tunnel_id(key: tpi->key);
402 tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id: tun_id, md_size: 0);
403 if (!tun_dst)
404 return PACKET_REJECT;
405 }
406
407 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
408 return PACKET_RCVD;
409 }
410 return PACKET_NEXT;
411
412drop:
413 kfree_skb(skb);
414 return PACKET_RCVD;
415}
416
417static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
418 int hdr_len)
419{
420 struct net *net = dev_net(dev: skb->dev);
421 struct ip_tunnel_net *itn;
422 int res;
423
424 if (tpi->proto == htons(ETH_P_TEB))
425 itn = net_generic(net, id: gre_tap_net_id);
426 else
427 itn = net_generic(net, id: ipgre_net_id);
428
429 res = __ipgre_rcv(skb, tpi, itn, hdr_len, raw_proto: false);
430 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
431 /* ipgre tunnels in collect metadata mode should receive
432 * also ETH_P_TEB traffic.
433 */
434 itn = net_generic(net, id: ipgre_net_id);
435 res = __ipgre_rcv(skb, tpi, itn, hdr_len, raw_proto: true);
436 }
437 return res;
438}
439
440static int gre_rcv(struct sk_buff *skb)
441{
442 struct tnl_ptk_info tpi;
443 bool csum_err = false;
444 int hdr_len;
445
446#ifdef CONFIG_NET_IPGRE_BROADCAST
447 if (ipv4_is_multicast(addr: ip_hdr(skb)->daddr)) {
448 /* Looped back packet, drop it! */
449 if (rt_is_output_route(rt: skb_rtable(skb)))
450 goto drop;
451 }
452#endif
453
454 hdr_len = gre_parse_header(skb, tpi: &tpi, csum_err: &csum_err, htons(ETH_P_IP), nhs: 0);
455 if (hdr_len < 0)
456 goto drop;
457
458 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
459 tpi.proto == htons(ETH_P_ERSPAN2))) {
460 if (erspan_rcv(skb, tpi: &tpi, gre_hdr_len: hdr_len) == PACKET_RCVD)
461 return 0;
462 goto out;
463 }
464
465 if (ipgre_rcv(skb, tpi: &tpi, hdr_len) == PACKET_RCVD)
466 return 0;
467
468out:
469 icmp_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, info: 0);
470drop:
471 kfree_skb(skb);
472 return 0;
473}
474
475static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
476 const struct iphdr *tnl_params,
477 __be16 proto)
478{
479 struct ip_tunnel *tunnel = netdev_priv(dev);
480 IP_TUNNEL_DECLARE_FLAGS(flags);
481
482 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags);
483
484 /* Push GRE header. */
485 gre_build_header(skb, hdr_len: tunnel->tun_hlen,
486 flags, proto, key: tunnel->parms.o_key,
487 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
488 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
489
490 ip_tunnel_xmit(skb, dev, tnl_params, protocol: tnl_params->protocol);
491}
492
493static int gre_handle_offloads(struct sk_buff *skb, bool csum)
494{
495 return iptunnel_handle_offloads(skb, gso_type_mask: csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
496}
497
498static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
499 __be16 proto)
500{
501 struct ip_tunnel *tunnel = netdev_priv(dev);
502 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
503 struct ip_tunnel_info *tun_info;
504 const struct ip_tunnel_key *key;
505 int tunnel_hlen;
506
507 tun_info = skb_tunnel_info(skb);
508 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
509 ip_tunnel_info_af(tun_info) != AF_INET))
510 goto err_free_skb;
511
512 key = &tun_info->key;
513 tunnel_hlen = gre_calc_hlen(o_flags: key->tun_flags);
514
515 if (skb_cow_head(skb, headroom: dev->needed_headroom))
516 goto err_free_skb;
517
518 /* Push Tunnel header. */
519 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
520 tunnel->parms.o_flags)))
521 goto err_free_skb;
522
523 __set_bit(IP_TUNNEL_CSUM_BIT, flags);
524 __set_bit(IP_TUNNEL_KEY_BIT, flags);
525 __set_bit(IP_TUNNEL_SEQ_BIT, flags);
526 ip_tunnel_flags_and(flags, tun_info->key.tun_flags, flags);
527
528 gre_build_header(skb, hdr_len: tunnel_hlen, flags, proto,
529 key: tunnel_id_to_key32(tun_id: tun_info->key.tun_id),
530 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
531 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
532
533 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
534
535 return;
536
537err_free_skb:
538 kfree_skb(skb);
539 DEV_STATS_INC(dev, tx_dropped);
540}
541
542static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
543{
544 struct ip_tunnel *tunnel = netdev_priv(dev);
545 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
546 struct ip_tunnel_info *tun_info;
547 const struct ip_tunnel_key *key;
548 struct erspan_metadata *md;
549 bool truncate = false;
550 __be16 proto;
551 int tunnel_hlen;
552 int version;
553 int nhoff;
554
555 tun_info = skb_tunnel_info(skb);
556 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
557 ip_tunnel_info_af(tun_info) != AF_INET))
558 goto err_free_skb;
559
560 key = &tun_info->key;
561 if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags))
562 goto err_free_skb;
563 if (tun_info->options_len < sizeof(*md))
564 goto err_free_skb;
565 md = ip_tunnel_info_opts(tun_info);
566
567 /* ERSPAN has fixed 8 byte GRE header */
568 version = md->version;
569 tunnel_hlen = 8 + erspan_hdr_len(version);
570
571 if (skb_cow_head(skb, headroom: dev->needed_headroom))
572 goto err_free_skb;
573
574 if (gre_handle_offloads(skb, csum: false))
575 goto err_free_skb;
576
577 if (skb->len > dev->mtu + dev->hard_header_len) {
578 if (pskb_trim(skb, len: dev->mtu + dev->hard_header_len))
579 goto err_free_skb;
580 truncate = true;
581 }
582
583 nhoff = skb_network_offset(skb);
584 if (skb->protocol == htons(ETH_P_IP) &&
585 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
586 truncate = true;
587
588 if (skb->protocol == htons(ETH_P_IPV6)) {
589 int thoff;
590
591 if (skb_transport_header_was_set(skb))
592 thoff = skb_transport_offset(skb);
593 else
594 thoff = nhoff + sizeof(struct ipv6hdr);
595 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
596 truncate = true;
597 }
598
599 if (version == 1) {
600 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
601 ntohl(md->u.index), truncate, is_ipv4: true);
602 proto = htons(ETH_P_ERSPAN);
603 } else if (version == 2) {
604 erspan_build_header_v2(skb,
605 ntohl(tunnel_id_to_key32(key->tun_id)),
606 direction: md->u.md2.dir,
607 hwid: get_hwid(md2: &md->u.md2),
608 truncate, is_ipv4: true);
609 proto = htons(ETH_P_ERSPAN2);
610 } else {
611 goto err_free_skb;
612 }
613
614 __set_bit(IP_TUNNEL_SEQ_BIT, flags);
615 gre_build_header(skb, hdr_len: 8, flags, proto, key: 0,
616 htonl(atomic_fetch_inc(&tunnel->o_seqno)));
617
618 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
619
620 return;
621
622err_free_skb:
623 kfree_skb(skb);
624 DEV_STATS_INC(dev, tx_dropped);
625}
626
627static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
628{
629 struct ip_tunnel_info *info = skb_tunnel_info(skb);
630 const struct ip_tunnel_key *key;
631 struct rtable *rt;
632 struct flowi4 fl4;
633
634 if (ip_tunnel_info_af(tun_info: info) != AF_INET)
635 return -EINVAL;
636
637 key = &info->key;
638 ip_tunnel_init_flow(fl4: &fl4, IPPROTO_GRE, daddr: key->u.ipv4.dst, saddr: key->u.ipv4.src,
639 key: tunnel_id_to_key32(tun_id: key->tun_id),
640 tos: key->tos & ~INET_ECN_MASK, net: dev_net(dev), oif: 0,
641 mark: skb->mark, tun_inner_hash: skb_get_hash(skb), flow_flags: key->flow_flags);
642 rt = ip_route_output_key(net: dev_net(dev), flp: &fl4);
643 if (IS_ERR(ptr: rt))
644 return PTR_ERR(ptr: rt);
645
646 ip_rt_put(rt);
647 info->key.u.ipv4.src = fl4.saddr;
648 return 0;
649}
650
651static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
652 struct net_device *dev)
653{
654 struct ip_tunnel *tunnel = netdev_priv(dev);
655 const struct iphdr *tnl_params;
656
657 if (!pskb_inet_may_pull(skb))
658 goto free_skb;
659
660 if (tunnel->collect_md) {
661 gre_fb_xmit(skb, dev, proto: skb->protocol);
662 return NETDEV_TX_OK;
663 }
664
665 if (dev->header_ops) {
666 int pull_len = tunnel->hlen + sizeof(struct iphdr);
667
668 if (skb_cow_head(skb, headroom: 0))
669 goto free_skb;
670
671 if (!pskb_may_pull(skb, len: pull_len))
672 goto free_skb;
673
674 tnl_params = (const struct iphdr *)skb->data;
675
676 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */
677 skb_pull(skb, len: pull_len);
678 skb_reset_mac_header(skb);
679
680 if (skb->ip_summed == CHECKSUM_PARTIAL &&
681 skb_checksum_start(skb) < skb->data)
682 goto free_skb;
683 } else {
684 if (skb_cow_head(skb, headroom: dev->needed_headroom))
685 goto free_skb;
686
687 tnl_params = &tunnel->parms.iph;
688 }
689
690 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
691 tunnel->parms.o_flags)))
692 goto free_skb;
693
694 __gre_xmit(skb, dev, tnl_params, proto: skb->protocol);
695 return NETDEV_TX_OK;
696
697free_skb:
698 kfree_skb(skb);
699 DEV_STATS_INC(dev, tx_dropped);
700 return NETDEV_TX_OK;
701}
702
703static netdev_tx_t erspan_xmit(struct sk_buff *skb,
704 struct net_device *dev)
705{
706 struct ip_tunnel *tunnel = netdev_priv(dev);
707 bool truncate = false;
708 __be16 proto;
709
710 if (!pskb_inet_may_pull(skb))
711 goto free_skb;
712
713 if (tunnel->collect_md) {
714 erspan_fb_xmit(skb, dev);
715 return NETDEV_TX_OK;
716 }
717
718 if (gre_handle_offloads(skb, csum: false))
719 goto free_skb;
720
721 if (skb_cow_head(skb, headroom: dev->needed_headroom))
722 goto free_skb;
723
724 if (skb->len > dev->mtu + dev->hard_header_len) {
725 if (pskb_trim(skb, len: dev->mtu + dev->hard_header_len))
726 goto free_skb;
727 truncate = true;
728 }
729
730 /* Push ERSPAN header */
731 if (tunnel->erspan_ver == 0) {
732 proto = htons(ETH_P_ERSPAN);
733 __clear_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags);
734 } else if (tunnel->erspan_ver == 1) {
735 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
736 index: tunnel->index,
737 truncate, is_ipv4: true);
738 proto = htons(ETH_P_ERSPAN);
739 } else if (tunnel->erspan_ver == 2) {
740 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
741 direction: tunnel->dir, hwid: tunnel->hwid,
742 truncate, is_ipv4: true);
743 proto = htons(ETH_P_ERSPAN2);
744 } else {
745 goto free_skb;
746 }
747
748 __clear_bit(IP_TUNNEL_KEY_BIT, tunnel->parms.o_flags);
749 __gre_xmit(skb, dev, tnl_params: &tunnel->parms.iph, proto);
750 return NETDEV_TX_OK;
751
752free_skb:
753 kfree_skb(skb);
754 DEV_STATS_INC(dev, tx_dropped);
755 return NETDEV_TX_OK;
756}
757
758static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
759 struct net_device *dev)
760{
761 struct ip_tunnel *tunnel = netdev_priv(dev);
762
763 if (!pskb_inet_may_pull(skb))
764 goto free_skb;
765
766 if (tunnel->collect_md) {
767 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
768 return NETDEV_TX_OK;
769 }
770
771 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
772 tunnel->parms.o_flags)))
773 goto free_skb;
774
775 if (skb_cow_head(skb, headroom: dev->needed_headroom))
776 goto free_skb;
777
778 __gre_xmit(skb, dev, tnl_params: &tunnel->parms.iph, htons(ETH_P_TEB));
779 return NETDEV_TX_OK;
780
781free_skb:
782 kfree_skb(skb);
783 DEV_STATS_INC(dev, tx_dropped);
784 return NETDEV_TX_OK;
785}
786
787static void ipgre_link_update(struct net_device *dev, bool set_mtu)
788{
789 struct ip_tunnel *tunnel = netdev_priv(dev);
790 int len;
791
792 len = tunnel->tun_hlen;
793 tunnel->tun_hlen = gre_calc_hlen(o_flags: tunnel->parms.o_flags);
794 len = tunnel->tun_hlen - len;
795 tunnel->hlen = tunnel->hlen + len;
796
797 if (dev->header_ops)
798 dev->hard_header_len += len;
799 else
800 dev->needed_headroom += len;
801
802 if (set_mtu)
803 WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68));
804
805 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) ||
806 (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
807 tunnel->encap.type != TUNNEL_ENCAP_NONE)) {
808 dev->features &= ~NETIF_F_GSO_SOFTWARE;
809 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
810 } else {
811 dev->features |= NETIF_F_GSO_SOFTWARE;
812 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
813 }
814}
815
816static int ipgre_tunnel_ctl(struct net_device *dev,
817 struct ip_tunnel_parm_kern *p,
818 int cmd)
819{
820 __be16 i_flags, o_flags;
821 int err;
822
823 if (!ip_tunnel_flags_is_be16_compat(flags: p->i_flags) ||
824 !ip_tunnel_flags_is_be16_compat(flags: p->o_flags))
825 return -EOVERFLOW;
826
827 i_flags = ip_tunnel_flags_to_be16(flags: p->i_flags);
828 o_flags = ip_tunnel_flags_to_be16(flags: p->o_flags);
829
830 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
831 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
832 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
833 ((i_flags | o_flags) & (GRE_VERSION | GRE_ROUTING)))
834 return -EINVAL;
835 }
836
837 gre_flags_to_tnl_flags(dst: p->i_flags, flags: i_flags);
838 gre_flags_to_tnl_flags(dst: p->o_flags, flags: o_flags);
839
840 err = ip_tunnel_ctl(dev, p, cmd);
841 if (err)
842 return err;
843
844 if (cmd == SIOCCHGTUNNEL) {
845 struct ip_tunnel *t = netdev_priv(dev);
846
847 ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags);
848 ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags);
849
850 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
851 ipgre_link_update(dev, set_mtu: true);
852 }
853
854 i_flags = gre_tnl_flags_to_gre_flags(tflags: p->i_flags);
855 ip_tunnel_flags_from_be16(dst: p->i_flags, flags: i_flags);
856 o_flags = gre_tnl_flags_to_gre_flags(tflags: p->o_flags);
857 ip_tunnel_flags_from_be16(dst: p->o_flags, flags: o_flags);
858
859 return 0;
860}
861
862/* Nice toy. Unfortunately, useless in real life :-)
863 It allows to construct virtual multiprotocol broadcast "LAN"
864 over the Internet, provided multicast routing is tuned.
865
866
867 I have no idea was this bicycle invented before me,
868 so that I had to set ARPHRD_IPGRE to a random value.
869 I have an impression, that Cisco could make something similar,
870 but this feature is apparently missing in IOS<=11.2(8).
871
872 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
873 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
874
875 ping -t 255 224.66.66.66
876
877 If nobody answers, mbone does not work.
878
879 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
880 ip addr add 10.66.66.<somewhat>/24 dev Universe
881 ifconfig Universe up
882 ifconfig Universe add fe80::<Your_real_addr>/10
883 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
884 ftp 10.66.66.66
885 ...
886 ftp fec0:6666:6666::193.233.7.65
887 ...
888 */
889static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
890 unsigned short type,
891 const void *daddr, const void *saddr, unsigned int len)
892{
893 struct ip_tunnel *t = netdev_priv(dev);
894 struct gre_base_hdr *greh;
895 struct iphdr *iph;
896 int needed;
897
898 needed = t->hlen + sizeof(*iph);
899 if (skb_headroom(skb) < needed &&
900 pskb_expand_head(skb, HH_DATA_ALIGN(needed - skb_headroom(skb)),
901 ntail: 0, GFP_ATOMIC))
902 return -needed;
903
904 iph = skb_push(skb, len: needed);
905 greh = (struct gre_base_hdr *)(iph+1);
906 greh->flags = gre_tnl_flags_to_gre_flags(tflags: t->parms.o_flags);
907 greh->protocol = htons(type);
908
909 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
910
911 /* Set the source hardware address. */
912 if (saddr)
913 memcpy(&iph->saddr, saddr, 4);
914 if (daddr)
915 memcpy(&iph->daddr, daddr, 4);
916 if (iph->daddr)
917 return t->hlen + sizeof(*iph);
918
919 return -(t->hlen + sizeof(*iph));
920}
921
922static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
923{
924 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
925 memcpy(haddr, &iph->saddr, 4);
926 return 4;
927}
928
929static const struct header_ops ipgre_header_ops = {
930 .create = ipgre_header,
931 .parse = ipgre_header_parse,
932};
933
934#ifdef CONFIG_NET_IPGRE_BROADCAST
935static int ipgre_open(struct net_device *dev)
936{
937 struct ip_tunnel *t = netdev_priv(dev);
938
939 if (ipv4_is_multicast(addr: t->parms.iph.daddr)) {
940 struct flowi4 fl4 = {
941 .flowi4_oif = t->parms.link,
942 .flowi4_dscp = ip4h_dscp(ip4h: &t->parms.iph),
943 .flowi4_scope = RT_SCOPE_UNIVERSE,
944 .flowi4_proto = IPPROTO_GRE,
945 .saddr = t->parms.iph.saddr,
946 .daddr = t->parms.iph.daddr,
947 .fl4_gre_key = t->parms.o_key,
948 };
949 struct rtable *rt;
950
951 rt = ip_route_output_key(net: t->net, flp: &fl4);
952 if (IS_ERR(ptr: rt))
953 return -EADDRNOTAVAIL;
954 dev = rt->dst.dev;
955 ip_rt_put(rt);
956 if (!__in_dev_get_rtnl(dev))
957 return -EADDRNOTAVAIL;
958 t->mlink = dev->ifindex;
959 ip_mc_inc_group(in_dev: __in_dev_get_rtnl(dev), addr: t->parms.iph.daddr);
960 }
961 return 0;
962}
963
964static int ipgre_close(struct net_device *dev)
965{
966 struct ip_tunnel *t = netdev_priv(dev);
967
968 if (ipv4_is_multicast(addr: t->parms.iph.daddr) && t->mlink) {
969 struct in_device *in_dev;
970 in_dev = inetdev_by_index(t->net, t->mlink);
971 if (in_dev)
972 ip_mc_dec_group(in_dev, addr: t->parms.iph.daddr);
973 }
974 return 0;
975}
976#endif
977
978static const struct net_device_ops ipgre_netdev_ops = {
979 .ndo_init = ipgre_tunnel_init,
980 .ndo_uninit = ip_tunnel_uninit,
981#ifdef CONFIG_NET_IPGRE_BROADCAST
982 .ndo_open = ipgre_open,
983 .ndo_stop = ipgre_close,
984#endif
985 .ndo_start_xmit = ipgre_xmit,
986 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
987 .ndo_change_mtu = ip_tunnel_change_mtu,
988 .ndo_get_stats64 = dev_get_tstats64,
989 .ndo_get_iflink = ip_tunnel_get_iflink,
990 .ndo_tunnel_ctl = ipgre_tunnel_ctl,
991};
992
993#define GRE_FEATURES (NETIF_F_SG | \
994 NETIF_F_FRAGLIST | \
995 NETIF_F_HIGHDMA | \
996 NETIF_F_HW_CSUM)
997
998static void ipgre_tunnel_setup(struct net_device *dev)
999{
1000 dev->netdev_ops = &ipgre_netdev_ops;
1001 dev->type = ARPHRD_IPGRE;
1002 ip_tunnel_setup(dev, net_id: ipgre_net_id);
1003}
1004
1005static void __gre_tunnel_init(struct net_device *dev)
1006{
1007 struct ip_tunnel *tunnel;
1008
1009 tunnel = netdev_priv(dev);
1010 tunnel->tun_hlen = gre_calc_hlen(o_flags: tunnel->parms.o_flags);
1011 tunnel->parms.iph.protocol = IPPROTO_GRE;
1012
1013 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
1014 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
1015
1016 dev->features |= GRE_FEATURES;
1017 dev->hw_features |= GRE_FEATURES;
1018
1019 /* TCP offload with GRE SEQ is not supported, nor can we support 2
1020 * levels of outer headers requiring an update.
1021 */
1022 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags))
1023 return;
1024 if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
1025 tunnel->encap.type != TUNNEL_ENCAP_NONE)
1026 return;
1027
1028 dev->features |= NETIF_F_GSO_SOFTWARE;
1029 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1030
1031 dev->lltx = true;
1032}
1033
1034static int ipgre_tunnel_init(struct net_device *dev)
1035{
1036 struct ip_tunnel *tunnel = netdev_priv(dev);
1037 struct iphdr *iph = &tunnel->parms.iph;
1038
1039 __gre_tunnel_init(dev);
1040
1041 __dev_addr_set(dev, addr: &iph->saddr, len: 4);
1042 memcpy(dev->broadcast, &iph->daddr, 4);
1043
1044 dev->flags = IFF_NOARP;
1045 netif_keep_dst(dev);
1046 dev->addr_len = 4;
1047
1048 if (iph->daddr && !tunnel->collect_md) {
1049#ifdef CONFIG_NET_IPGRE_BROADCAST
1050 if (ipv4_is_multicast(addr: iph->daddr)) {
1051 if (!iph->saddr)
1052 return -EINVAL;
1053 dev->flags = IFF_BROADCAST;
1054 dev->header_ops = &ipgre_header_ops;
1055 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1056 dev->needed_headroom = 0;
1057 }
1058#endif
1059 } else if (!tunnel->collect_md) {
1060 dev->header_ops = &ipgre_header_ops;
1061 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1062 dev->needed_headroom = 0;
1063 }
1064
1065 return ip_tunnel_init(dev);
1066}
1067
1068static const struct gre_protocol ipgre_protocol = {
1069 .handler = gre_rcv,
1070 .err_handler = gre_err,
1071};
1072
1073static int __net_init ipgre_init_net(struct net *net)
1074{
1075 return ip_tunnel_init_net(net, ip_tnl_net_id: ipgre_net_id, ops: &ipgre_link_ops, NULL);
1076}
1077
1078static void __net_exit ipgre_exit_rtnl(struct net *net,
1079 struct list_head *dev_to_kill)
1080{
1081 ip_tunnel_delete_net(net, id: ipgre_net_id, ops: &ipgre_link_ops, dev_to_kill);
1082}
1083
1084static struct pernet_operations ipgre_net_ops = {
1085 .init = ipgre_init_net,
1086 .exit_rtnl = ipgre_exit_rtnl,
1087 .id = &ipgre_net_id,
1088 .size = sizeof(struct ip_tunnel_net),
1089};
1090
1091static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1092 struct netlink_ext_ack *extack)
1093{
1094 __be16 flags;
1095
1096 if (!data)
1097 return 0;
1098
1099 flags = 0;
1100 if (data[IFLA_GRE_IFLAGS])
1101 flags |= nla_get_be16(nla: data[IFLA_GRE_IFLAGS]);
1102 if (data[IFLA_GRE_OFLAGS])
1103 flags |= nla_get_be16(nla: data[IFLA_GRE_OFLAGS]);
1104 if (flags & (GRE_VERSION|GRE_ROUTING))
1105 return -EINVAL;
1106
1107 if (data[IFLA_GRE_COLLECT_METADATA] &&
1108 data[IFLA_GRE_ENCAP_TYPE] &&
1109 nla_get_u16(nla: data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1110 return -EINVAL;
1111
1112 return 0;
1113}
1114
1115static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1116 struct netlink_ext_ack *extack)
1117{
1118 __be32 daddr;
1119
1120 if (tb[IFLA_ADDRESS]) {
1121 if (nla_len(nla: tb[IFLA_ADDRESS]) != ETH_ALEN)
1122 return -EINVAL;
1123 if (!is_valid_ether_addr(addr: nla_data(nla: tb[IFLA_ADDRESS])))
1124 return -EADDRNOTAVAIL;
1125 }
1126
1127 if (!data)
1128 goto out;
1129
1130 if (data[IFLA_GRE_REMOTE]) {
1131 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1132 if (!daddr)
1133 return -EINVAL;
1134 }
1135
1136out:
1137 return ipgre_tunnel_validate(tb, data, extack);
1138}
1139
1140static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1141 struct netlink_ext_ack *extack)
1142{
1143 __be16 flags = 0;
1144 int ret;
1145
1146 if (!data)
1147 return 0;
1148
1149 ret = ipgre_tap_validate(tb, data, extack);
1150 if (ret)
1151 return ret;
1152
1153 if (data[IFLA_GRE_ERSPAN_VER] &&
1154 nla_get_u8(nla: data[IFLA_GRE_ERSPAN_VER]) == 0)
1155 return 0;
1156
1157 /* ERSPAN type II/III should only have GRE sequence and key flag */
1158 if (data[IFLA_GRE_OFLAGS])
1159 flags |= nla_get_be16(nla: data[IFLA_GRE_OFLAGS]);
1160 if (data[IFLA_GRE_IFLAGS])
1161 flags |= nla_get_be16(nla: data[IFLA_GRE_IFLAGS]);
1162 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1163 flags != (GRE_SEQ | GRE_KEY))
1164 return -EINVAL;
1165
1166 /* ERSPAN Session ID only has 10-bit. Since we reuse
1167 * 32-bit key field as ID, check it's range.
1168 */
1169 if (data[IFLA_GRE_IKEY] &&
1170 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1171 return -EINVAL;
1172
1173 if (data[IFLA_GRE_OKEY] &&
1174 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1175 return -EINVAL;
1176
1177 return 0;
1178}
1179
1180static int ipgre_netlink_parms(struct net_device *dev,
1181 struct nlattr *data[],
1182 struct nlattr *tb[],
1183 struct ip_tunnel_parm_kern *parms,
1184 __u32 *fwmark)
1185{
1186 struct ip_tunnel *t = netdev_priv(dev);
1187
1188 memset(parms, 0, sizeof(*parms));
1189
1190 parms->iph.protocol = IPPROTO_GRE;
1191
1192 if (!data)
1193 return 0;
1194
1195 if (data[IFLA_GRE_LINK])
1196 parms->link = nla_get_u32(nla: data[IFLA_GRE_LINK]);
1197
1198 if (data[IFLA_GRE_IFLAGS])
1199 gre_flags_to_tnl_flags(dst: parms->i_flags,
1200 flags: nla_get_be16(nla: data[IFLA_GRE_IFLAGS]));
1201
1202 if (data[IFLA_GRE_OFLAGS])
1203 gre_flags_to_tnl_flags(dst: parms->o_flags,
1204 flags: nla_get_be16(nla: data[IFLA_GRE_OFLAGS]));
1205
1206 if (data[IFLA_GRE_IKEY])
1207 parms->i_key = nla_get_be32(nla: data[IFLA_GRE_IKEY]);
1208
1209 if (data[IFLA_GRE_OKEY])
1210 parms->o_key = nla_get_be32(nla: data[IFLA_GRE_OKEY]);
1211
1212 if (data[IFLA_GRE_LOCAL])
1213 parms->iph.saddr = nla_get_in_addr(nla: data[IFLA_GRE_LOCAL]);
1214
1215 if (data[IFLA_GRE_REMOTE])
1216 parms->iph.daddr = nla_get_in_addr(nla: data[IFLA_GRE_REMOTE]);
1217
1218 if (data[IFLA_GRE_TTL])
1219 parms->iph.ttl = nla_get_u8(nla: data[IFLA_GRE_TTL]);
1220
1221 if (data[IFLA_GRE_TOS])
1222 parms->iph.tos = nla_get_u8(nla: data[IFLA_GRE_TOS]);
1223
1224 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(nla: data[IFLA_GRE_PMTUDISC])) {
1225 if (t->ignore_df)
1226 return -EINVAL;
1227 parms->iph.frag_off = htons(IP_DF);
1228 }
1229
1230 if (data[IFLA_GRE_COLLECT_METADATA]) {
1231 t->collect_md = true;
1232 if (dev->type == ARPHRD_IPGRE)
1233 dev->type = ARPHRD_NONE;
1234 }
1235
1236 if (data[IFLA_GRE_IGNORE_DF]) {
1237 if (nla_get_u8(nla: data[IFLA_GRE_IGNORE_DF])
1238 && (parms->iph.frag_off & htons(IP_DF)))
1239 return -EINVAL;
1240 t->ignore_df = !!nla_get_u8(nla: data[IFLA_GRE_IGNORE_DF]);
1241 }
1242
1243 if (data[IFLA_GRE_FWMARK])
1244 *fwmark = nla_get_u32(nla: data[IFLA_GRE_FWMARK]);
1245
1246 return 0;
1247}
1248
1249static int erspan_netlink_parms(struct net_device *dev,
1250 struct nlattr *data[],
1251 struct nlattr *tb[],
1252 struct ip_tunnel_parm_kern *parms,
1253 __u32 *fwmark)
1254{
1255 struct ip_tunnel *t = netdev_priv(dev);
1256 int err;
1257
1258 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1259 if (err)
1260 return err;
1261 if (!data)
1262 return 0;
1263
1264 if (data[IFLA_GRE_ERSPAN_VER]) {
1265 t->erspan_ver = nla_get_u8(nla: data[IFLA_GRE_ERSPAN_VER]);
1266
1267 if (t->erspan_ver > 2)
1268 return -EINVAL;
1269 }
1270
1271 if (t->erspan_ver == 1) {
1272 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1273 t->index = nla_get_u32(nla: data[IFLA_GRE_ERSPAN_INDEX]);
1274 if (t->index & ~INDEX_MASK)
1275 return -EINVAL;
1276 }
1277 } else if (t->erspan_ver == 2) {
1278 if (data[IFLA_GRE_ERSPAN_DIR]) {
1279 t->dir = nla_get_u8(nla: data[IFLA_GRE_ERSPAN_DIR]);
1280 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1281 return -EINVAL;
1282 }
1283 if (data[IFLA_GRE_ERSPAN_HWID]) {
1284 t->hwid = nla_get_u16(nla: data[IFLA_GRE_ERSPAN_HWID]);
1285 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1286 return -EINVAL;
1287 }
1288 }
1289
1290 return 0;
1291}
1292
1293/* This function returns true when ENCAP attributes are present in the nl msg */
1294static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1295 struct ip_tunnel_encap *ipencap)
1296{
1297 bool ret = false;
1298
1299 memset(ipencap, 0, sizeof(*ipencap));
1300
1301 if (!data)
1302 return ret;
1303
1304 if (data[IFLA_GRE_ENCAP_TYPE]) {
1305 ret = true;
1306 ipencap->type = nla_get_u16(nla: data[IFLA_GRE_ENCAP_TYPE]);
1307 }
1308
1309 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1310 ret = true;
1311 ipencap->flags = nla_get_u16(nla: data[IFLA_GRE_ENCAP_FLAGS]);
1312 }
1313
1314 if (data[IFLA_GRE_ENCAP_SPORT]) {
1315 ret = true;
1316 ipencap->sport = nla_get_be16(nla: data[IFLA_GRE_ENCAP_SPORT]);
1317 }
1318
1319 if (data[IFLA_GRE_ENCAP_DPORT]) {
1320 ret = true;
1321 ipencap->dport = nla_get_be16(nla: data[IFLA_GRE_ENCAP_DPORT]);
1322 }
1323
1324 return ret;
1325}
1326
1327static int gre_tap_init(struct net_device *dev)
1328{
1329 __gre_tunnel_init(dev);
1330 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1331 netif_keep_dst(dev);
1332
1333 return ip_tunnel_init(dev);
1334}
1335
1336static const struct net_device_ops gre_tap_netdev_ops = {
1337 .ndo_init = gre_tap_init,
1338 .ndo_uninit = ip_tunnel_uninit,
1339 .ndo_start_xmit = gre_tap_xmit,
1340 .ndo_set_mac_address = eth_mac_addr,
1341 .ndo_validate_addr = eth_validate_addr,
1342 .ndo_change_mtu = ip_tunnel_change_mtu,
1343 .ndo_get_stats64 = dev_get_tstats64,
1344 .ndo_get_iflink = ip_tunnel_get_iflink,
1345 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1346};
1347
1348static int erspan_tunnel_init(struct net_device *dev)
1349{
1350 struct ip_tunnel *tunnel = netdev_priv(dev);
1351
1352 if (tunnel->erspan_ver == 0)
1353 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1354 else
1355 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1356
1357 tunnel->parms.iph.protocol = IPPROTO_GRE;
1358 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1359 erspan_hdr_len(version: tunnel->erspan_ver);
1360
1361 dev->features |= GRE_FEATURES;
1362 dev->hw_features |= GRE_FEATURES;
1363 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1364 netif_keep_dst(dev);
1365
1366 return ip_tunnel_init(dev);
1367}
1368
1369static const struct net_device_ops erspan_netdev_ops = {
1370 .ndo_init = erspan_tunnel_init,
1371 .ndo_uninit = ip_tunnel_uninit,
1372 .ndo_start_xmit = erspan_xmit,
1373 .ndo_set_mac_address = eth_mac_addr,
1374 .ndo_validate_addr = eth_validate_addr,
1375 .ndo_change_mtu = ip_tunnel_change_mtu,
1376 .ndo_get_stats64 = dev_get_tstats64,
1377 .ndo_get_iflink = ip_tunnel_get_iflink,
1378 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1379};
1380
1381static void ipgre_tap_setup(struct net_device *dev)
1382{
1383 ether_setup(dev);
1384 dev->max_mtu = 0;
1385 dev->netdev_ops = &gre_tap_netdev_ops;
1386 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1387 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1388 ip_tunnel_setup(dev, net_id: gre_tap_net_id);
1389}
1390
1391static int
1392ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1393{
1394 struct ip_tunnel_encap ipencap;
1395
1396 if (ipgre_netlink_encap_parms(data, ipencap: &ipencap)) {
1397 struct ip_tunnel *t = netdev_priv(dev);
1398 int err = ip_tunnel_encap_setup(t, ipencap: &ipencap);
1399
1400 if (err < 0)
1401 return err;
1402 }
1403
1404 return 0;
1405}
1406
1407static int ipgre_newlink(struct net_device *dev,
1408 struct rtnl_newlink_params *params,
1409 struct netlink_ext_ack *extack)
1410{
1411 struct nlattr **data = params->data;
1412 struct nlattr **tb = params->tb;
1413 struct ip_tunnel_parm_kern p;
1414 __u32 fwmark = 0;
1415 int err;
1416
1417 err = ipgre_newlink_encap_setup(dev, data);
1418 if (err)
1419 return err;
1420
1421 err = ipgre_netlink_parms(dev, data, tb, parms: &p, fwmark: &fwmark);
1422 if (err < 0)
1423 return err;
1424 return ip_tunnel_newlink(net: params->link_net ? : dev_net(dev), dev, tb, p: &p,
1425 fwmark);
1426}
1427
1428static int erspan_newlink(struct net_device *dev,
1429 struct rtnl_newlink_params *params,
1430 struct netlink_ext_ack *extack)
1431{
1432 struct nlattr **data = params->data;
1433 struct nlattr **tb = params->tb;
1434 struct ip_tunnel_parm_kern p;
1435 __u32 fwmark = 0;
1436 int err;
1437
1438 err = ipgre_newlink_encap_setup(dev, data);
1439 if (err)
1440 return err;
1441
1442 err = erspan_netlink_parms(dev, data, tb, parms: &p, fwmark: &fwmark);
1443 if (err)
1444 return err;
1445 return ip_tunnel_newlink(net: params->link_net ? : dev_net(dev), dev, tb, p: &p,
1446 fwmark);
1447}
1448
1449static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1450 struct nlattr *data[],
1451 struct netlink_ext_ack *extack)
1452{
1453 struct ip_tunnel *t = netdev_priv(dev);
1454 struct ip_tunnel_parm_kern p;
1455 __u32 fwmark = t->fwmark;
1456 int err;
1457
1458 err = ipgre_newlink_encap_setup(dev, data);
1459 if (err)
1460 return err;
1461
1462 err = ipgre_netlink_parms(dev, data, tb, parms: &p, fwmark: &fwmark);
1463 if (err < 0)
1464 return err;
1465
1466 err = ip_tunnel_changelink(dev, tb, p: &p, fwmark);
1467 if (err < 0)
1468 return err;
1469
1470 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
1471 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
1472
1473 ipgre_link_update(dev, set_mtu: !tb[IFLA_MTU]);
1474
1475 return 0;
1476}
1477
1478static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1479 struct nlattr *data[],
1480 struct netlink_ext_ack *extack)
1481{
1482 struct ip_tunnel *t = netdev_priv(dev);
1483 struct ip_tunnel_parm_kern p;
1484 __u32 fwmark = t->fwmark;
1485 int err;
1486
1487 err = ipgre_newlink_encap_setup(dev, data);
1488 if (err)
1489 return err;
1490
1491 err = erspan_netlink_parms(dev, data, tb, parms: &p, fwmark: &fwmark);
1492 if (err < 0)
1493 return err;
1494
1495 err = ip_tunnel_changelink(dev, tb, p: &p, fwmark);
1496 if (err < 0)
1497 return err;
1498
1499 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
1500 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
1501
1502 return 0;
1503}
1504
1505static size_t ipgre_get_size(const struct net_device *dev)
1506{
1507 return
1508 /* IFLA_GRE_LINK */
1509 nla_total_size(payload: 4) +
1510 /* IFLA_GRE_IFLAGS */
1511 nla_total_size(payload: 2) +
1512 /* IFLA_GRE_OFLAGS */
1513 nla_total_size(payload: 2) +
1514 /* IFLA_GRE_IKEY */
1515 nla_total_size(payload: 4) +
1516 /* IFLA_GRE_OKEY */
1517 nla_total_size(payload: 4) +
1518 /* IFLA_GRE_LOCAL */
1519 nla_total_size(payload: 4) +
1520 /* IFLA_GRE_REMOTE */
1521 nla_total_size(payload: 4) +
1522 /* IFLA_GRE_TTL */
1523 nla_total_size(payload: 1) +
1524 /* IFLA_GRE_TOS */
1525 nla_total_size(payload: 1) +
1526 /* IFLA_GRE_PMTUDISC */
1527 nla_total_size(payload: 1) +
1528 /* IFLA_GRE_ENCAP_TYPE */
1529 nla_total_size(payload: 2) +
1530 /* IFLA_GRE_ENCAP_FLAGS */
1531 nla_total_size(payload: 2) +
1532 /* IFLA_GRE_ENCAP_SPORT */
1533 nla_total_size(payload: 2) +
1534 /* IFLA_GRE_ENCAP_DPORT */
1535 nla_total_size(payload: 2) +
1536 /* IFLA_GRE_COLLECT_METADATA */
1537 nla_total_size(payload: 0) +
1538 /* IFLA_GRE_IGNORE_DF */
1539 nla_total_size(payload: 1) +
1540 /* IFLA_GRE_FWMARK */
1541 nla_total_size(payload: 4) +
1542 /* IFLA_GRE_ERSPAN_INDEX */
1543 nla_total_size(payload: 4) +
1544 /* IFLA_GRE_ERSPAN_VER */
1545 nla_total_size(payload: 1) +
1546 /* IFLA_GRE_ERSPAN_DIR */
1547 nla_total_size(payload: 1) +
1548 /* IFLA_GRE_ERSPAN_HWID */
1549 nla_total_size(payload: 2) +
1550 0;
1551}
1552
1553static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1554{
1555 struct ip_tunnel *t = netdev_priv(dev);
1556 struct ip_tunnel_parm_kern *p = &t->parms;
1557 IP_TUNNEL_DECLARE_FLAGS(o_flags);
1558
1559 ip_tunnel_flags_copy(o_flags, p->o_flags);
1560
1561 if (nla_put_u32(skb, attrtype: IFLA_GRE_LINK, value: p->link) ||
1562 nla_put_be16(skb, attrtype: IFLA_GRE_IFLAGS,
1563 value: gre_tnl_flags_to_gre_flags(tflags: p->i_flags)) ||
1564 nla_put_be16(skb, attrtype: IFLA_GRE_OFLAGS,
1565 value: gre_tnl_flags_to_gre_flags(tflags: o_flags)) ||
1566 nla_put_be32(skb, attrtype: IFLA_GRE_IKEY, value: p->i_key) ||
1567 nla_put_be32(skb, attrtype: IFLA_GRE_OKEY, value: p->o_key) ||
1568 nla_put_in_addr(skb, attrtype: IFLA_GRE_LOCAL, addr: p->iph.saddr) ||
1569 nla_put_in_addr(skb, attrtype: IFLA_GRE_REMOTE, addr: p->iph.daddr) ||
1570 nla_put_u8(skb, attrtype: IFLA_GRE_TTL, value: p->iph.ttl) ||
1571 nla_put_u8(skb, attrtype: IFLA_GRE_TOS, value: p->iph.tos) ||
1572 nla_put_u8(skb, attrtype: IFLA_GRE_PMTUDISC,
1573 value: !!(p->iph.frag_off & htons(IP_DF))) ||
1574 nla_put_u32(skb, attrtype: IFLA_GRE_FWMARK, value: t->fwmark))
1575 goto nla_put_failure;
1576
1577 if (nla_put_u16(skb, attrtype: IFLA_GRE_ENCAP_TYPE,
1578 value: t->encap.type) ||
1579 nla_put_be16(skb, attrtype: IFLA_GRE_ENCAP_SPORT,
1580 value: t->encap.sport) ||
1581 nla_put_be16(skb, attrtype: IFLA_GRE_ENCAP_DPORT,
1582 value: t->encap.dport) ||
1583 nla_put_u16(skb, attrtype: IFLA_GRE_ENCAP_FLAGS,
1584 value: t->encap.flags))
1585 goto nla_put_failure;
1586
1587 if (nla_put_u8(skb, attrtype: IFLA_GRE_IGNORE_DF, value: t->ignore_df))
1588 goto nla_put_failure;
1589
1590 if (t->collect_md) {
1591 if (nla_put_flag(skb, attrtype: IFLA_GRE_COLLECT_METADATA))
1592 goto nla_put_failure;
1593 }
1594
1595 return 0;
1596
1597nla_put_failure:
1598 return -EMSGSIZE;
1599}
1600
1601static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
1602{
1603 struct ip_tunnel *t = netdev_priv(dev);
1604
1605 if (t->erspan_ver <= 2) {
1606 if (t->erspan_ver != 0 && !t->collect_md)
1607 __set_bit(IP_TUNNEL_KEY_BIT, t->parms.o_flags);
1608
1609 if (nla_put_u8(skb, attrtype: IFLA_GRE_ERSPAN_VER, value: t->erspan_ver))
1610 goto nla_put_failure;
1611
1612 if (t->erspan_ver == 1) {
1613 if (nla_put_u32(skb, attrtype: IFLA_GRE_ERSPAN_INDEX, value: t->index))
1614 goto nla_put_failure;
1615 } else if (t->erspan_ver == 2) {
1616 if (nla_put_u8(skb, attrtype: IFLA_GRE_ERSPAN_DIR, value: t->dir))
1617 goto nla_put_failure;
1618 if (nla_put_u16(skb, attrtype: IFLA_GRE_ERSPAN_HWID, value: t->hwid))
1619 goto nla_put_failure;
1620 }
1621 }
1622
1623 return ipgre_fill_info(skb, dev);
1624
1625nla_put_failure:
1626 return -EMSGSIZE;
1627}
1628
1629static void erspan_setup(struct net_device *dev)
1630{
1631 struct ip_tunnel *t = netdev_priv(dev);
1632
1633 ether_setup(dev);
1634 dev->max_mtu = 0;
1635 dev->netdev_ops = &erspan_netdev_ops;
1636 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1637 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1638 ip_tunnel_setup(dev, net_id: erspan_net_id);
1639 t->erspan_ver = 1;
1640}
1641
1642static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1643 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1644 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1645 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1646 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1647 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1648 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1649 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1650 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1651 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1652 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1653 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1654 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1655 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1656 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1657 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1658 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1659 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1660 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1661 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1662 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1663 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1664};
1665
1666static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1667 .kind = "gre",
1668 .maxtype = IFLA_GRE_MAX,
1669 .policy = ipgre_policy,
1670 .priv_size = sizeof(struct ip_tunnel),
1671 .setup = ipgre_tunnel_setup,
1672 .validate = ipgre_tunnel_validate,
1673 .newlink = ipgre_newlink,
1674 .changelink = ipgre_changelink,
1675 .dellink = ip_tunnel_dellink,
1676 .get_size = ipgre_get_size,
1677 .fill_info = ipgre_fill_info,
1678 .get_link_net = ip_tunnel_get_link_net,
1679};
1680
1681static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1682 .kind = "gretap",
1683 .maxtype = IFLA_GRE_MAX,
1684 .policy = ipgre_policy,
1685 .priv_size = sizeof(struct ip_tunnel),
1686 .setup = ipgre_tap_setup,
1687 .validate = ipgre_tap_validate,
1688 .newlink = ipgre_newlink,
1689 .changelink = ipgre_changelink,
1690 .dellink = ip_tunnel_dellink,
1691 .get_size = ipgre_get_size,
1692 .fill_info = ipgre_fill_info,
1693 .get_link_net = ip_tunnel_get_link_net,
1694};
1695
1696static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1697 .kind = "erspan",
1698 .maxtype = IFLA_GRE_MAX,
1699 .policy = ipgre_policy,
1700 .priv_size = sizeof(struct ip_tunnel),
1701 .setup = erspan_setup,
1702 .validate = erspan_validate,
1703 .newlink = erspan_newlink,
1704 .changelink = erspan_changelink,
1705 .dellink = ip_tunnel_dellink,
1706 .get_size = ipgre_get_size,
1707 .fill_info = erspan_fill_info,
1708 .get_link_net = ip_tunnel_get_link_net,
1709};
1710
1711struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1712 u8 name_assign_type)
1713{
1714 struct rtnl_newlink_params params = { .src_net = net };
1715 struct nlattr *tb[IFLA_MAX + 1];
1716 struct net_device *dev;
1717 LIST_HEAD(list_kill);
1718 struct ip_tunnel *t;
1719 int err;
1720
1721 memset(&tb, 0, sizeof(tb));
1722 params.tb = tb;
1723
1724 dev = rtnl_create_link(net, ifname: name, name_assign_type,
1725 ops: &ipgre_tap_ops, tb, NULL);
1726 if (IS_ERR(ptr: dev))
1727 return dev;
1728
1729 /* Configure flow based GRE device. */
1730 t = netdev_priv(dev);
1731 t->collect_md = true;
1732
1733 err = ipgre_newlink(dev, params: &params, NULL);
1734 if (err < 0) {
1735 free_netdev(dev);
1736 return ERR_PTR(error: err);
1737 }
1738
1739 /* openvswitch users expect packet sizes to be unrestricted,
1740 * so set the largest MTU we can.
1741 */
1742 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, strict: false);
1743 if (err)
1744 goto out;
1745
1746 err = rtnl_configure_link(dev, NULL, portid: 0, NULL);
1747 if (err < 0)
1748 goto out;
1749
1750 return dev;
1751out:
1752 ip_tunnel_dellink(dev, head: &list_kill);
1753 unregister_netdevice_many(head: &list_kill);
1754 return ERR_PTR(error: err);
1755}
1756EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1757
1758static int __net_init ipgre_tap_init_net(struct net *net)
1759{
1760 return ip_tunnel_init_net(net, ip_tnl_net_id: gre_tap_net_id, ops: &ipgre_tap_ops, devname: "gretap0");
1761}
1762
1763static void __net_exit ipgre_tap_exit_rtnl(struct net *net,
1764 struct list_head *dev_to_kill)
1765{
1766 ip_tunnel_delete_net(net, id: gre_tap_net_id, ops: &ipgre_tap_ops, dev_to_kill);
1767}
1768
1769static struct pernet_operations ipgre_tap_net_ops = {
1770 .init = ipgre_tap_init_net,
1771 .exit_rtnl = ipgre_tap_exit_rtnl,
1772 .id = &gre_tap_net_id,
1773 .size = sizeof(struct ip_tunnel_net),
1774};
1775
1776static int __net_init erspan_init_net(struct net *net)
1777{
1778 return ip_tunnel_init_net(net, ip_tnl_net_id: erspan_net_id,
1779 ops: &erspan_link_ops, devname: "erspan0");
1780}
1781
1782static void __net_exit erspan_exit_rtnl(struct net *net,
1783 struct list_head *dev_to_kill)
1784{
1785 ip_tunnel_delete_net(net, id: erspan_net_id, ops: &erspan_link_ops, dev_to_kill);
1786}
1787
1788static struct pernet_operations erspan_net_ops = {
1789 .init = erspan_init_net,
1790 .exit_rtnl = erspan_exit_rtnl,
1791 .id = &erspan_net_id,
1792 .size = sizeof(struct ip_tunnel_net),
1793};
1794
1795static int __init ipgre_init(void)
1796{
1797 int err;
1798
1799 pr_info("GRE over IPv4 tunneling driver\n");
1800
1801 err = register_pernet_device(&ipgre_net_ops);
1802 if (err < 0)
1803 return err;
1804
1805 err = register_pernet_device(&ipgre_tap_net_ops);
1806 if (err < 0)
1807 goto pnet_tap_failed;
1808
1809 err = register_pernet_device(&erspan_net_ops);
1810 if (err < 0)
1811 goto pnet_erspan_failed;
1812
1813 err = gre_add_protocol(proto: &ipgre_protocol, GREPROTO_CISCO);
1814 if (err < 0) {
1815 pr_info("%s: can't add protocol\n", __func__);
1816 goto add_proto_failed;
1817 }
1818
1819 err = rtnl_link_register(ops: &ipgre_link_ops);
1820 if (err < 0)
1821 goto rtnl_link_failed;
1822
1823 err = rtnl_link_register(ops: &ipgre_tap_ops);
1824 if (err < 0)
1825 goto tap_ops_failed;
1826
1827 err = rtnl_link_register(ops: &erspan_link_ops);
1828 if (err < 0)
1829 goto erspan_link_failed;
1830
1831 return 0;
1832
1833erspan_link_failed:
1834 rtnl_link_unregister(ops: &ipgre_tap_ops);
1835tap_ops_failed:
1836 rtnl_link_unregister(ops: &ipgre_link_ops);
1837rtnl_link_failed:
1838 gre_del_protocol(proto: &ipgre_protocol, GREPROTO_CISCO);
1839add_proto_failed:
1840 unregister_pernet_device(&erspan_net_ops);
1841pnet_erspan_failed:
1842 unregister_pernet_device(&ipgre_tap_net_ops);
1843pnet_tap_failed:
1844 unregister_pernet_device(&ipgre_net_ops);
1845 return err;
1846}
1847
1848static void __exit ipgre_fini(void)
1849{
1850 rtnl_link_unregister(ops: &ipgre_tap_ops);
1851 rtnl_link_unregister(ops: &ipgre_link_ops);
1852 rtnl_link_unregister(ops: &erspan_link_ops);
1853 gre_del_protocol(proto: &ipgre_protocol, GREPROTO_CISCO);
1854 unregister_pernet_device(&ipgre_tap_net_ops);
1855 unregister_pernet_device(&ipgre_net_ops);
1856 unregister_pernet_device(&erspan_net_ops);
1857}
1858
1859module_init(ipgre_init);
1860module_exit(ipgre_fini);
1861MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
1862MODULE_LICENSE("GPL");
1863MODULE_ALIAS_RTNL_LINK("gre");
1864MODULE_ALIAS_RTNL_LINK("gretap");
1865MODULE_ALIAS_RTNL_LINK("erspan");
1866MODULE_ALIAS_NETDEV("gre0");
1867MODULE_ALIAS_NETDEV("gretap0");
1868MODULE_ALIAS_NETDEV("erspan0");
1869

source code of linux/net/ipv4/ip_gre.c