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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#include <net/inet_dscp.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(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 unsigned int data_len = 0;
145 struct ip_tunnel *t;
146
147 if (tpi->proto == htons(ETH_P_TEB))
148 itn = net_generic(net, gre_tap_net_id);
149 else if (tpi->proto == htons(ETH_P_ERSPAN) ||
150 tpi->proto == htons(ETH_P_ERSPAN2))
151 itn = net_generic(net, erspan_net_id);
152 else
153 itn = net_generic(net, ipgre_net_id);
154
155 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
156 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
157 iph->daddr, iph->saddr, tpi->key);
158
159 if (!t)
160 return -ENOENT;
161
162 switch (type) {
163 default:
164 case ICMP_PARAMETERPROB:
165 return 0;
166
167 case ICMP_DEST_UNREACH:
168 switch (code) {
169 case ICMP_SR_FAILED:
170 case ICMP_PORT_UNREACH:
171 /* Impossible event. */
172 return 0;
173 default:
174 /* All others are translated to HOST_UNREACH.
175 rfc2003 contains "deep thoughts" about NET_UNREACH,
176 I believe they are just ether pollution. --ANK
177 */
178 break;
179 }
180 break;
181
182 case ICMP_TIME_EXCEEDED:
183 if (code != ICMP_EXC_TTL)
184 return 0;
185 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
186 break;
187
188 case ICMP_REDIRECT:
189 break;
190 }
191
192#if IS_ENABLED(CONFIG_IPV6)
193 if (tpi->proto == htons(ETH_P_IPV6) &&
194 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
195 type, data_len))
196 return 0;
197#endif
198
199 if (t->parms.iph.daddr == 0 ||
200 ipv4_is_multicast(t->parms.iph.daddr))
201 return 0;
202
203 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
204 return 0;
205
206 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
207 t->err_count++;
208 else
209 t->err_count = 1;
210 t->err_time = jiffies;
211
212 return 0;
213}
214
215static void gre_err(struct sk_buff *skb, u32 info)
216{
217 /* All the routers (except for Linux) return only
218 * 8 bytes of packet payload. It means, that precise relaying of
219 * ICMP in the real Internet is absolutely infeasible.
220 *
221 * Moreover, Cisco "wise men" put GRE key to the third word
222 * in GRE header. It makes impossible maintaining even soft
223 * state for keyed
224 * GRE tunnels with enabled checksum. Tell them "thank you".
225 *
226 * Well, I wonder, rfc1812 was written by Cisco employee,
227 * what the hell these idiots break standards established
228 * by themselves???
229 */
230
231 const struct iphdr *iph = (struct iphdr *)skb->data;
232 const int type = icmp_hdr(skb)->type;
233 const int code = icmp_hdr(skb)->code;
234 struct tnl_ptk_info tpi;
235
236 if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
237 iph->ihl * 4) < 0)
238 return;
239
240 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
241 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
242 skb->dev->ifindex, IPPROTO_GRE);
243 return;
244 }
245 if (type == ICMP_REDIRECT) {
246 ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
247 IPPROTO_GRE);
248 return;
249 }
250
251 ipgre_err(skb, info, &tpi);
252}
253
254static bool is_erspan_type1(int gre_hdr_len)
255{
256 /* Both ERSPAN type I (version 0) and type II (version 1) use
257 * protocol 0x88BE, but the type I has only 4-byte GRE header,
258 * while type II has 8-byte.
259 */
260 return gre_hdr_len == 4;
261}
262
263static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
264 int gre_hdr_len)
265{
266 struct net *net = dev_net(skb->dev);
267 struct metadata_dst *tun_dst = NULL;
268 struct erspan_base_hdr *ershdr;
269 IP_TUNNEL_DECLARE_FLAGS(flags);
270 struct ip_tunnel_net *itn;
271 struct ip_tunnel *tunnel;
272 const struct iphdr *iph;
273 struct erspan_md2 *md2;
274 int ver;
275 int len;
276
277 ip_tunnel_flags_copy(flags, tpi->flags);
278
279 itn = net_generic(net, erspan_net_id);
280 iph = ip_hdr(skb);
281 if (is_erspan_type1(gre_hdr_len)) {
282 ver = 0;
283 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
284 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
285 iph->saddr, iph->daddr, 0);
286 } else {
287 if (unlikely(!pskb_may_pull(skb,
288 gre_hdr_len + sizeof(*ershdr))))
289 return PACKET_REJECT;
290
291 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
292 ver = ershdr->ver;
293 iph = ip_hdr(skb);
294 __set_bit(IP_TUNNEL_KEY_BIT, flags);
295 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags,
296 iph->saddr, iph->daddr, tpi->key);
297 }
298
299 if (tunnel) {
300 if (is_erspan_type1(gre_hdr_len))
301 len = gre_hdr_len;
302 else
303 len = gre_hdr_len + erspan_hdr_len(ver);
304
305 if (unlikely(!pskb_may_pull(skb, len)))
306 return PACKET_REJECT;
307
308 if (__iptunnel_pull_header(skb,
309 len,
310 htons(ETH_P_TEB),
311 false, false) < 0)
312 goto drop;
313
314 if (tunnel->collect_md) {
315 struct erspan_metadata *pkt_md, *md;
316 struct ip_tunnel_info *info;
317 unsigned char *gh;
318 __be64 tun_id;
319
320 __set_bit(IP_TUNNEL_KEY_BIT, tpi->flags);
321 ip_tunnel_flags_copy(flags, tpi->flags);
322 tun_id = key32_to_tunnel_id(tpi->key);
323
324 tun_dst = ip_tun_rx_dst(skb, flags,
325 tun_id, sizeof(*md));
326 if (!tun_dst)
327 return PACKET_REJECT;
328
329 /* skb can be uncloned in __iptunnel_pull_header, so
330 * old pkt_md is no longer valid and we need to reset
331 * it
332 */
333 gh = skb_network_header(skb) +
334 skb_network_header_len(skb);
335 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
336 sizeof(*ershdr));
337 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
338 md->version = ver;
339 md2 = &md->u.md2;
340 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
341 ERSPAN_V2_MDSIZE);
342
343 info = &tun_dst->u.tun_info;
344 __set_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
345 info->key.tun_flags);
346 info->options_len = sizeof(*md);
347 }
348
349 skb_reset_mac_header(skb);
350 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
351 return PACKET_RCVD;
352 }
353 return PACKET_REJECT;
354
355drop:
356 kfree_skb(skb);
357 return PACKET_RCVD;
358}
359
360static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
361 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
362{
363 struct metadata_dst *tun_dst = NULL;
364 const struct iphdr *iph;
365 struct ip_tunnel *tunnel;
366
367 iph = ip_hdr(skb);
368 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
369 iph->saddr, iph->daddr, tpi->key);
370
371 if (tunnel) {
372 const struct iphdr *tnl_params;
373
374 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
375 raw_proto, false) < 0)
376 goto drop;
377
378 /* Special case for ipgre_header_parse(), which expects the
379 * mac_header to point to the outer IP header.
380 */
381 if (tunnel->dev->header_ops == &ipgre_header_ops)
382 skb_pop_mac_header(skb);
383 else
384 skb_reset_mac_header(skb);
385
386 tnl_params = &tunnel->parms.iph;
387 if (tunnel->collect_md || tnl_params->daddr == 0) {
388 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
389 __be64 tun_id;
390
391 __set_bit(IP_TUNNEL_CSUM_BIT, flags);
392 __set_bit(IP_TUNNEL_KEY_BIT, flags);
393 ip_tunnel_flags_and(flags, tpi->flags, flags);
394
395 tun_id = key32_to_tunnel_id(tpi->key);
396 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
397 if (!tun_dst)
398 return PACKET_REJECT;
399 }
400
401 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
402 return PACKET_RCVD;
403 }
404 return PACKET_NEXT;
405
406drop:
407 kfree_skb(skb);
408 return PACKET_RCVD;
409}
410
411static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
412 int hdr_len)
413{
414 struct net *net = dev_net(skb->dev);
415 struct ip_tunnel_net *itn;
416 int res;
417
418 if (tpi->proto == htons(ETH_P_TEB))
419 itn = net_generic(net, gre_tap_net_id);
420 else
421 itn = net_generic(net, ipgre_net_id);
422
423 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
424 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
425 /* ipgre tunnels in collect metadata mode should receive
426 * also ETH_P_TEB traffic.
427 */
428 itn = net_generic(net, ipgre_net_id);
429 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
430 }
431 return res;
432}
433
434static int gre_rcv(struct sk_buff *skb)
435{
436 struct tnl_ptk_info tpi;
437 bool csum_err = false;
438 int hdr_len;
439
440#ifdef CONFIG_NET_IPGRE_BROADCAST
441 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
442 /* Looped back packet, drop it! */
443 if (rt_is_output_route(skb_rtable(skb)))
444 goto drop;
445 }
446#endif
447
448 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
449 if (hdr_len < 0)
450 goto drop;
451
452 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
453 tpi.proto == htons(ETH_P_ERSPAN2))) {
454 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
455 return 0;
456 goto out;
457 }
458
459 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
460 return 0;
461
462out:
463 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
464drop:
465 kfree_skb(skb);
466 return 0;
467}
468
469static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
470 const struct iphdr *tnl_params,
471 __be16 proto)
472{
473 struct ip_tunnel *tunnel = netdev_priv(dev);
474 IP_TUNNEL_DECLARE_FLAGS(flags);
475
476 ip_tunnel_flags_copy(flags, tunnel->parms.o_flags);
477
478 /* Push GRE header. */
479 gre_build_header(skb, tunnel->tun_hlen,
480 flags, proto, tunnel->parms.o_key,
481 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
482 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
483
484 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
485}
486
487static int gre_handle_offloads(struct sk_buff *skb, bool csum)
488{
489 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
490}
491
492static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
493 __be16 proto)
494{
495 struct ip_tunnel *tunnel = netdev_priv(dev);
496 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
497 struct ip_tunnel_info *tun_info;
498 const struct ip_tunnel_key *key;
499 int tunnel_hlen;
500
501 tun_info = skb_tunnel_info(skb);
502 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
503 ip_tunnel_info_af(tun_info) != AF_INET))
504 goto err_free_skb;
505
506 key = &tun_info->key;
507 tunnel_hlen = gre_calc_hlen(key->tun_flags);
508
509 if (skb_cow_head(skb, dev->needed_headroom))
510 goto err_free_skb;
511
512 /* Push Tunnel header. */
513 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
514 tunnel->parms.o_flags)))
515 goto err_free_skb;
516
517 __set_bit(IP_TUNNEL_CSUM_BIT, flags);
518 __set_bit(IP_TUNNEL_KEY_BIT, flags);
519 __set_bit(IP_TUNNEL_SEQ_BIT, flags);
520 ip_tunnel_flags_and(flags, tun_info->key.tun_flags, flags);
521
522 gre_build_header(skb, tunnel_hlen, flags, proto,
523 tunnel_id_to_key32(tun_info->key.tun_id),
524 test_bit(IP_TUNNEL_SEQ_BIT, flags) ?
525 htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
526
527 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
528
529 return;
530
531err_free_skb:
532 kfree_skb(skb);
533 DEV_STATS_INC(dev, tx_dropped);
534}
535
536static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
537{
538 struct ip_tunnel *tunnel = netdev_priv(dev);
539 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
540 struct ip_tunnel_info *tun_info;
541 const struct ip_tunnel_key *key;
542 struct erspan_metadata *md;
543 bool truncate = false;
544 __be16 proto;
545 int tunnel_hlen;
546 int version;
547 int nhoff;
548
549 tun_info = skb_tunnel_info(skb);
550 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
551 ip_tunnel_info_af(tun_info) != AF_INET))
552 goto err_free_skb;
553
554 key = &tun_info->key;
555 if (!test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags))
556 goto err_free_skb;
557 if (tun_info->options_len < sizeof(*md))
558 goto err_free_skb;
559 md = ip_tunnel_info_opts(tun_info);
560
561 /* ERSPAN has fixed 8 byte GRE header */
562 version = md->version;
563 tunnel_hlen = 8 + erspan_hdr_len(version);
564
565 if (skb_cow_head(skb, dev->needed_headroom))
566 goto err_free_skb;
567
568 if (gre_handle_offloads(skb, false))
569 goto err_free_skb;
570
571 if (skb->len > dev->mtu + dev->hard_header_len) {
572 if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
573 goto err_free_skb;
574 truncate = true;
575 }
576
577 nhoff = skb_network_offset(skb);
578 if (skb->protocol == htons(ETH_P_IP) &&
579 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
580 truncate = true;
581
582 if (skb->protocol == htons(ETH_P_IPV6)) {
583 int thoff;
584
585 if (skb_transport_header_was_set(skb))
586 thoff = skb_transport_offset(skb);
587 else
588 thoff = nhoff + sizeof(struct ipv6hdr);
589 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
590 truncate = true;
591 }
592
593 if (version == 1) {
594 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
595 ntohl(md->u.index), truncate, true);
596 proto = htons(ETH_P_ERSPAN);
597 } else if (version == 2) {
598 erspan_build_header_v2(skb,
599 ntohl(tunnel_id_to_key32(key->tun_id)),
600 md->u.md2.dir,
601 get_hwid(&md->u.md2),
602 truncate, true);
603 proto = htons(ETH_P_ERSPAN2);
604 } else {
605 goto err_free_skb;
606 }
607
608 __set_bit(IP_TUNNEL_SEQ_BIT, flags);
609 gre_build_header(skb, 8, flags, proto, 0,
610 htonl(atomic_fetch_inc(&tunnel->o_seqno)));
611
612 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
613
614 return;
615
616err_free_skb:
617 kfree_skb(skb);
618 DEV_STATS_INC(dev, tx_dropped);
619}
620
621static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
622{
623 struct ip_tunnel_info *info = skb_tunnel_info(skb);
624 const struct ip_tunnel_key *key;
625 struct rtable *rt;
626 struct flowi4 fl4;
627
628 if (ip_tunnel_info_af(info) != AF_INET)
629 return -EINVAL;
630
631 key = &info->key;
632 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
633 tunnel_id_to_key32(key->tun_id),
634 key->tos & ~INET_ECN_MASK, dev_net(dev), 0,
635 skb->mark, skb_get_hash(skb), key->flow_flags);
636 rt = ip_route_output_key(dev_net(dev), &fl4);
637 if (IS_ERR(rt))
638 return PTR_ERR(rt);
639
640 ip_rt_put(rt);
641 info->key.u.ipv4.src = fl4.saddr;
642 return 0;
643}
644
645static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
646 struct net_device *dev)
647{
648 struct ip_tunnel *tunnel = netdev_priv(dev);
649 const struct iphdr *tnl_params;
650
651 if (!pskb_inet_may_pull(skb))
652 goto free_skb;
653
654 if (tunnel->collect_md) {
655 gre_fb_xmit(skb, dev, skb->protocol);
656 return NETDEV_TX_OK;
657 }
658
659 if (dev->header_ops) {
660 int pull_len = tunnel->hlen + sizeof(struct iphdr);
661
662 if (skb_cow_head(skb, 0))
663 goto free_skb;
664
665 if (!pskb_may_pull(skb, pull_len))
666 goto free_skb;
667
668 tnl_params = (const struct iphdr *)skb->data;
669
670 /* ip_tunnel_xmit() needs skb->data pointing to gre header. */
671 skb_pull(skb, pull_len);
672 skb_reset_mac_header(skb);
673
674 if (skb->ip_summed == CHECKSUM_PARTIAL &&
675 skb_checksum_start(skb) < skb->data)
676 goto free_skb;
677 } else {
678 if (skb_cow_head(skb, dev->needed_headroom))
679 goto free_skb;
680
681 tnl_params = &tunnel->parms.iph;
682 }
683
684 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
685 tunnel->parms.o_flags)))
686 goto free_skb;
687
688 __gre_xmit(skb, dev, tnl_params, skb->protocol);
689 return NETDEV_TX_OK;
690
691free_skb:
692 kfree_skb(skb);
693 DEV_STATS_INC(dev, tx_dropped);
694 return NETDEV_TX_OK;
695}
696
697static netdev_tx_t erspan_xmit(struct sk_buff *skb,
698 struct net_device *dev)
699{
700 struct ip_tunnel *tunnel = netdev_priv(dev);
701 bool truncate = false;
702 __be16 proto;
703
704 if (!pskb_inet_may_pull(skb))
705 goto free_skb;
706
707 if (tunnel->collect_md) {
708 erspan_fb_xmit(skb, dev);
709 return NETDEV_TX_OK;
710 }
711
712 if (gre_handle_offloads(skb, false))
713 goto free_skb;
714
715 if (skb_cow_head(skb, dev->needed_headroom))
716 goto free_skb;
717
718 if (skb->len > dev->mtu + dev->hard_header_len) {
719 if (pskb_trim(skb, dev->mtu + dev->hard_header_len))
720 goto free_skb;
721 truncate = true;
722 }
723
724 /* Push ERSPAN header */
725 if (tunnel->erspan_ver == 0) {
726 proto = htons(ETH_P_ERSPAN);
727 __clear_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags);
728 } else if (tunnel->erspan_ver == 1) {
729 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
730 tunnel->index,
731 truncate, true);
732 proto = htons(ETH_P_ERSPAN);
733 } else if (tunnel->erspan_ver == 2) {
734 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
735 tunnel->dir, tunnel->hwid,
736 truncate, true);
737 proto = htons(ETH_P_ERSPAN2);
738 } else {
739 goto free_skb;
740 }
741
742 __clear_bit(IP_TUNNEL_KEY_BIT, tunnel->parms.o_flags);
743 __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
744 return NETDEV_TX_OK;
745
746free_skb:
747 kfree_skb(skb);
748 DEV_STATS_INC(dev, tx_dropped);
749 return NETDEV_TX_OK;
750}
751
752static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
753 struct net_device *dev)
754{
755 struct ip_tunnel *tunnel = netdev_priv(dev);
756
757 if (!pskb_inet_may_pull(skb))
758 goto free_skb;
759
760 if (tunnel->collect_md) {
761 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
762 return NETDEV_TX_OK;
763 }
764
765 if (gre_handle_offloads(skb, test_bit(IP_TUNNEL_CSUM_BIT,
766 tunnel->parms.o_flags)))
767 goto free_skb;
768
769 if (skb_cow_head(skb, dev->needed_headroom))
770 goto free_skb;
771
772 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
773 return NETDEV_TX_OK;
774
775free_skb:
776 kfree_skb(skb);
777 DEV_STATS_INC(dev, tx_dropped);
778 return NETDEV_TX_OK;
779}
780
781static void ipgre_link_update(struct net_device *dev, bool set_mtu)
782{
783 struct ip_tunnel *tunnel = netdev_priv(dev);
784 int len;
785
786 len = tunnel->tun_hlen;
787 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
788 len = tunnel->tun_hlen - len;
789 tunnel->hlen = tunnel->hlen + len;
790
791 if (dev->header_ops)
792 dev->hard_header_len += len;
793 else
794 dev->needed_headroom += len;
795
796 if (set_mtu)
797 WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68));
798
799 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) ||
800 (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
801 tunnel->encap.type != TUNNEL_ENCAP_NONE)) {
802 dev->features &= ~NETIF_F_GSO_SOFTWARE;
803 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
804 } else {
805 dev->features |= NETIF_F_GSO_SOFTWARE;
806 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
807 }
808}
809
810static int ipgre_tunnel_ctl(struct net_device *dev,
811 struct ip_tunnel_parm_kern *p,
812 int cmd)
813{
814 __be16 i_flags, o_flags;
815 int err;
816
817 if (!ip_tunnel_flags_is_be16_compat(p->i_flags) ||
818 !ip_tunnel_flags_is_be16_compat(p->o_flags))
819 return -EOVERFLOW;
820
821 i_flags = ip_tunnel_flags_to_be16(p->i_flags);
822 o_flags = ip_tunnel_flags_to_be16(p->o_flags);
823
824 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
825 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
826 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
827 ((i_flags | o_flags) & (GRE_VERSION | GRE_ROUTING)))
828 return -EINVAL;
829 }
830
831 gre_flags_to_tnl_flags(p->i_flags, i_flags);
832 gre_flags_to_tnl_flags(p->o_flags, o_flags);
833
834 err = ip_tunnel_ctl(dev, p, cmd);
835 if (err)
836 return err;
837
838 if (cmd == SIOCCHGTUNNEL) {
839 struct ip_tunnel *t = netdev_priv(dev);
840
841 ip_tunnel_flags_copy(t->parms.i_flags, p->i_flags);
842 ip_tunnel_flags_copy(t->parms.o_flags, p->o_flags);
843
844 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
845 ipgre_link_update(dev, true);
846 }
847
848 i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
849 ip_tunnel_flags_from_be16(p->i_flags, i_flags);
850 o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
851 ip_tunnel_flags_from_be16(p->o_flags, o_flags);
852
853 return 0;
854}
855
856/* Nice toy. Unfortunately, useless in real life :-)
857 It allows to construct virtual multiprotocol broadcast "LAN"
858 over the Internet, provided multicast routing is tuned.
859
860
861 I have no idea was this bicycle invented before me,
862 so that I had to set ARPHRD_IPGRE to a random value.
863 I have an impression, that Cisco could make something similar,
864 but this feature is apparently missing in IOS<=11.2(8).
865
866 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
867 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
868
869 ping -t 255 224.66.66.66
870
871 If nobody answers, mbone does not work.
872
873 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
874 ip addr add 10.66.66.<somewhat>/24 dev Universe
875 ifconfig Universe up
876 ifconfig Universe add fe80::<Your_real_addr>/10
877 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
878 ftp 10.66.66.66
879 ...
880 ftp fec0:6666:6666::193.233.7.65
881 ...
882 */
883static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
884 unsigned short type,
885 const void *daddr, const void *saddr, unsigned int len)
886{
887 struct ip_tunnel *t = netdev_priv(dev);
888 struct iphdr *iph;
889 struct gre_base_hdr *greh;
890
891 iph = skb_push(skb, t->hlen + sizeof(*iph));
892 greh = (struct gre_base_hdr *)(iph+1);
893 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
894 greh->protocol = htons(type);
895
896 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
897
898 /* Set the source hardware address. */
899 if (saddr)
900 memcpy(&iph->saddr, saddr, 4);
901 if (daddr)
902 memcpy(&iph->daddr, daddr, 4);
903 if (iph->daddr)
904 return t->hlen + sizeof(*iph);
905
906 return -(t->hlen + sizeof(*iph));
907}
908
909static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
910{
911 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
912 memcpy(haddr, &iph->saddr, 4);
913 return 4;
914}
915
916static const struct header_ops ipgre_header_ops = {
917 .create = ipgre_header,
918 .parse = ipgre_header_parse,
919};
920
921#ifdef CONFIG_NET_IPGRE_BROADCAST
922static int ipgre_open(struct net_device *dev)
923{
924 struct ip_tunnel *t = netdev_priv(dev);
925
926 if (ipv4_is_multicast(t->parms.iph.daddr)) {
927 struct flowi4 fl4;
928 struct rtable *rt;
929
930 rt = ip_route_output_gre(t->net, &fl4,
931 t->parms.iph.daddr,
932 t->parms.iph.saddr,
933 t->parms.o_key,
934 t->parms.iph.tos & INET_DSCP_MASK,
935 t->parms.link);
936 if (IS_ERR(rt))
937 return -EADDRNOTAVAIL;
938 dev = rt->dst.dev;
939 ip_rt_put(rt);
940 if (!__in_dev_get_rtnl(dev))
941 return -EADDRNOTAVAIL;
942 t->mlink = dev->ifindex;
943 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
944 }
945 return 0;
946}
947
948static int ipgre_close(struct net_device *dev)
949{
950 struct ip_tunnel *t = netdev_priv(dev);
951
952 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
953 struct in_device *in_dev;
954 in_dev = inetdev_by_index(t->net, t->mlink);
955 if (in_dev)
956 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
957 }
958 return 0;
959}
960#endif
961
962static const struct net_device_ops ipgre_netdev_ops = {
963 .ndo_init = ipgre_tunnel_init,
964 .ndo_uninit = ip_tunnel_uninit,
965#ifdef CONFIG_NET_IPGRE_BROADCAST
966 .ndo_open = ipgre_open,
967 .ndo_stop = ipgre_close,
968#endif
969 .ndo_start_xmit = ipgre_xmit,
970 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
971 .ndo_change_mtu = ip_tunnel_change_mtu,
972 .ndo_get_stats64 = dev_get_tstats64,
973 .ndo_get_iflink = ip_tunnel_get_iflink,
974 .ndo_tunnel_ctl = ipgre_tunnel_ctl,
975};
976
977#define GRE_FEATURES (NETIF_F_SG | \
978 NETIF_F_FRAGLIST | \
979 NETIF_F_HIGHDMA | \
980 NETIF_F_HW_CSUM)
981
982static void ipgre_tunnel_setup(struct net_device *dev)
983{
984 dev->netdev_ops = &ipgre_netdev_ops;
985 dev->type = ARPHRD_IPGRE;
986 ip_tunnel_setup(dev, ipgre_net_id);
987}
988
989static void __gre_tunnel_init(struct net_device *dev)
990{
991 struct ip_tunnel *tunnel;
992
993 tunnel = netdev_priv(dev);
994 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
995 tunnel->parms.iph.protocol = IPPROTO_GRE;
996
997 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
998 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
999
1000 dev->features |= GRE_FEATURES;
1001 dev->hw_features |= GRE_FEATURES;
1002
1003 /* TCP offload with GRE SEQ is not supported, nor can we support 2
1004 * levels of outer headers requiring an update.
1005 */
1006 if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags))
1007 return;
1008 if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&
1009 tunnel->encap.type != TUNNEL_ENCAP_NONE)
1010 return;
1011
1012 dev->features |= NETIF_F_GSO_SOFTWARE;
1013 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
1014
1015 dev->lltx = true;
1016}
1017
1018static int ipgre_tunnel_init(struct net_device *dev)
1019{
1020 struct ip_tunnel *tunnel = netdev_priv(dev);
1021 struct iphdr *iph = &tunnel->parms.iph;
1022
1023 __gre_tunnel_init(dev);
1024
1025 __dev_addr_set(dev, &iph->saddr, 4);
1026 memcpy(dev->broadcast, &iph->daddr, 4);
1027
1028 dev->flags = IFF_NOARP;
1029 netif_keep_dst(dev);
1030 dev->addr_len = 4;
1031
1032 if (iph->daddr && !tunnel->collect_md) {
1033#ifdef CONFIG_NET_IPGRE_BROADCAST
1034 if (ipv4_is_multicast(iph->daddr)) {
1035 if (!iph->saddr)
1036 return -EINVAL;
1037 dev->flags = IFF_BROADCAST;
1038 dev->header_ops = &ipgre_header_ops;
1039 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1040 dev->needed_headroom = 0;
1041 }
1042#endif
1043 } else if (!tunnel->collect_md) {
1044 dev->header_ops = &ipgre_header_ops;
1045 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1046 dev->needed_headroom = 0;
1047 }
1048
1049 return ip_tunnel_init(dev);
1050}
1051
1052static const struct gre_protocol ipgre_protocol = {
1053 .handler = gre_rcv,
1054 .err_handler = gre_err,
1055};
1056
1057static int __net_init ipgre_init_net(struct net *net)
1058{
1059 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
1060}
1061
1062static void __net_exit ipgre_exit_batch_rtnl(struct list_head *list_net,
1063 struct list_head *dev_to_kill)
1064{
1065 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops,
1066 dev_to_kill);
1067}
1068
1069static struct pernet_operations ipgre_net_ops = {
1070 .init = ipgre_init_net,
1071 .exit_batch_rtnl = ipgre_exit_batch_rtnl,
1072 .id = &ipgre_net_id,
1073 .size = sizeof(struct ip_tunnel_net),
1074};
1075
1076static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1077 struct netlink_ext_ack *extack)
1078{
1079 __be16 flags;
1080
1081 if (!data)
1082 return 0;
1083
1084 flags = 0;
1085 if (data[IFLA_GRE_IFLAGS])
1086 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1087 if (data[IFLA_GRE_OFLAGS])
1088 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1089 if (flags & (GRE_VERSION|GRE_ROUTING))
1090 return -EINVAL;
1091
1092 if (data[IFLA_GRE_COLLECT_METADATA] &&
1093 data[IFLA_GRE_ENCAP_TYPE] &&
1094 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1095 return -EINVAL;
1096
1097 return 0;
1098}
1099
1100static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1101 struct netlink_ext_ack *extack)
1102{
1103 __be32 daddr;
1104
1105 if (tb[IFLA_ADDRESS]) {
1106 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1107 return -EINVAL;
1108 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1109 return -EADDRNOTAVAIL;
1110 }
1111
1112 if (!data)
1113 goto out;
1114
1115 if (data[IFLA_GRE_REMOTE]) {
1116 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1117 if (!daddr)
1118 return -EINVAL;
1119 }
1120
1121out:
1122 return ipgre_tunnel_validate(tb, data, extack);
1123}
1124
1125static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1126 struct netlink_ext_ack *extack)
1127{
1128 __be16 flags = 0;
1129 int ret;
1130
1131 if (!data)
1132 return 0;
1133
1134 ret = ipgre_tap_validate(tb, data, extack);
1135 if (ret)
1136 return ret;
1137
1138 if (data[IFLA_GRE_ERSPAN_VER] &&
1139 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
1140 return 0;
1141
1142 /* ERSPAN type II/III should only have GRE sequence and key flag */
1143 if (data[IFLA_GRE_OFLAGS])
1144 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1145 if (data[IFLA_GRE_IFLAGS])
1146 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1147 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1148 flags != (GRE_SEQ | GRE_KEY))
1149 return -EINVAL;
1150
1151 /* ERSPAN Session ID only has 10-bit. Since we reuse
1152 * 32-bit key field as ID, check it's range.
1153 */
1154 if (data[IFLA_GRE_IKEY] &&
1155 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1156 return -EINVAL;
1157
1158 if (data[IFLA_GRE_OKEY] &&
1159 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1160 return -EINVAL;
1161
1162 return 0;
1163}
1164
1165static int ipgre_netlink_parms(struct net_device *dev,
1166 struct nlattr *data[],
1167 struct nlattr *tb[],
1168 struct ip_tunnel_parm_kern *parms,
1169 __u32 *fwmark)
1170{
1171 struct ip_tunnel *t = netdev_priv(dev);
1172
1173 memset(parms, 0, sizeof(*parms));
1174
1175 parms->iph.protocol = IPPROTO_GRE;
1176
1177 if (!data)
1178 return 0;
1179
1180 if (data[IFLA_GRE_LINK])
1181 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1182
1183 if (data[IFLA_GRE_IFLAGS])
1184 gre_flags_to_tnl_flags(parms->i_flags,
1185 nla_get_be16(data[IFLA_GRE_IFLAGS]));
1186
1187 if (data[IFLA_GRE_OFLAGS])
1188 gre_flags_to_tnl_flags(parms->o_flags,
1189 nla_get_be16(data[IFLA_GRE_OFLAGS]));
1190
1191 if (data[IFLA_GRE_IKEY])
1192 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1193
1194 if (data[IFLA_GRE_OKEY])
1195 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1196
1197 if (data[IFLA_GRE_LOCAL])
1198 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1199
1200 if (data[IFLA_GRE_REMOTE])
1201 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1202
1203 if (data[IFLA_GRE_TTL])
1204 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1205
1206 if (data[IFLA_GRE_TOS])
1207 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1208
1209 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1210 if (t->ignore_df)
1211 return -EINVAL;
1212 parms->iph.frag_off = htons(IP_DF);
1213 }
1214
1215 if (data[IFLA_GRE_COLLECT_METADATA]) {
1216 t->collect_md = true;
1217 if (dev->type == ARPHRD_IPGRE)
1218 dev->type = ARPHRD_NONE;
1219 }
1220
1221 if (data[IFLA_GRE_IGNORE_DF]) {
1222 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1223 && (parms->iph.frag_off & htons(IP_DF)))
1224 return -EINVAL;
1225 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1226 }
1227
1228 if (data[IFLA_GRE_FWMARK])
1229 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1230
1231 return 0;
1232}
1233
1234static int erspan_netlink_parms(struct net_device *dev,
1235 struct nlattr *data[],
1236 struct nlattr *tb[],
1237 struct ip_tunnel_parm_kern *parms,
1238 __u32 *fwmark)
1239{
1240 struct ip_tunnel *t = netdev_priv(dev);
1241 int err;
1242
1243 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1244 if (err)
1245 return err;
1246 if (!data)
1247 return 0;
1248
1249 if (data[IFLA_GRE_ERSPAN_VER]) {
1250 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1251
1252 if (t->erspan_ver > 2)
1253 return -EINVAL;
1254 }
1255
1256 if (t->erspan_ver == 1) {
1257 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1258 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1259 if (t->index & ~INDEX_MASK)
1260 return -EINVAL;
1261 }
1262 } else if (t->erspan_ver == 2) {
1263 if (data[IFLA_GRE_ERSPAN_DIR]) {
1264 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1265 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1266 return -EINVAL;
1267 }
1268 if (data[IFLA_GRE_ERSPAN_HWID]) {
1269 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1270 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1271 return -EINVAL;
1272 }
1273 }
1274
1275 return 0;
1276}
1277
1278/* This function returns true when ENCAP attributes are present in the nl msg */
1279static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1280 struct ip_tunnel_encap *ipencap)
1281{
1282 bool ret = false;
1283
1284 memset(ipencap, 0, sizeof(*ipencap));
1285
1286 if (!data)
1287 return ret;
1288
1289 if (data[IFLA_GRE_ENCAP_TYPE]) {
1290 ret = true;
1291 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1292 }
1293
1294 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1295 ret = true;
1296 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1297 }
1298
1299 if (data[IFLA_GRE_ENCAP_SPORT]) {
1300 ret = true;
1301 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1302 }
1303
1304 if (data[IFLA_GRE_ENCAP_DPORT]) {
1305 ret = true;
1306 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1307 }
1308
1309 return ret;
1310}
1311
1312static int gre_tap_init(struct net_device *dev)
1313{
1314 __gre_tunnel_init(dev);
1315 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1316 netif_keep_dst(dev);
1317
1318 return ip_tunnel_init(dev);
1319}
1320
1321static const struct net_device_ops gre_tap_netdev_ops = {
1322 .ndo_init = gre_tap_init,
1323 .ndo_uninit = ip_tunnel_uninit,
1324 .ndo_start_xmit = gre_tap_xmit,
1325 .ndo_set_mac_address = eth_mac_addr,
1326 .ndo_validate_addr = eth_validate_addr,
1327 .ndo_change_mtu = ip_tunnel_change_mtu,
1328 .ndo_get_stats64 = dev_get_tstats64,
1329 .ndo_get_iflink = ip_tunnel_get_iflink,
1330 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1331};
1332
1333static int erspan_tunnel_init(struct net_device *dev)
1334{
1335 struct ip_tunnel *tunnel = netdev_priv(dev);
1336
1337 if (tunnel->erspan_ver == 0)
1338 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1339 else
1340 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1341
1342 tunnel->parms.iph.protocol = IPPROTO_GRE;
1343 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1344 erspan_hdr_len(tunnel->erspan_ver);
1345
1346 dev->features |= GRE_FEATURES;
1347 dev->hw_features |= GRE_FEATURES;
1348 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1349 netif_keep_dst(dev);
1350
1351 return ip_tunnel_init(dev);
1352}
1353
1354static const struct net_device_ops erspan_netdev_ops = {
1355 .ndo_init = erspan_tunnel_init,
1356 .ndo_uninit = ip_tunnel_uninit,
1357 .ndo_start_xmit = erspan_xmit,
1358 .ndo_set_mac_address = eth_mac_addr,
1359 .ndo_validate_addr = eth_validate_addr,
1360 .ndo_change_mtu = ip_tunnel_change_mtu,
1361 .ndo_get_stats64 = dev_get_tstats64,
1362 .ndo_get_iflink = ip_tunnel_get_iflink,
1363 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1364};
1365
1366static void ipgre_tap_setup(struct net_device *dev)
1367{
1368 ether_setup(dev);
1369 dev->max_mtu = 0;
1370 dev->netdev_ops = &gre_tap_netdev_ops;
1371 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1372 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1373 ip_tunnel_setup(dev, gre_tap_net_id);
1374}
1375
1376static int
1377ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1378{
1379 struct ip_tunnel_encap ipencap;
1380
1381 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1382 struct ip_tunnel *t = netdev_priv(dev);
1383 int err = ip_tunnel_encap_setup(t, &ipencap);
1384
1385 if (err < 0)
1386 return err;
1387 }
1388
1389 return 0;
1390}
1391
1392static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1393 struct nlattr *tb[], struct nlattr *data[],
1394 struct netlink_ext_ack *extack)
1395{
1396 struct ip_tunnel_parm_kern p;
1397 __u32 fwmark = 0;
1398 int err;
1399
1400 err = ipgre_newlink_encap_setup(dev, data);
1401 if (err)
1402 return err;
1403
1404 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1405 if (err < 0)
1406 return err;
1407 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1408}
1409
1410static int erspan_newlink(struct net *src_net, struct net_device *dev,
1411 struct nlattr *tb[], struct nlattr *data[],
1412 struct netlink_ext_ack *extack)
1413{
1414 struct ip_tunnel_parm_kern p;
1415 __u32 fwmark = 0;
1416 int err;
1417
1418 err = ipgre_newlink_encap_setup(dev, data);
1419 if (err)
1420 return err;
1421
1422 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1423 if (err)
1424 return err;
1425 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1426}
1427
1428static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1429 struct nlattr *data[],
1430 struct netlink_ext_ack *extack)
1431{
1432 struct ip_tunnel *t = netdev_priv(dev);
1433 struct ip_tunnel_parm_kern p;
1434 __u32 fwmark = t->fwmark;
1435 int err;
1436
1437 err = ipgre_newlink_encap_setup(dev, data);
1438 if (err)
1439 return err;
1440
1441 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1442 if (err < 0)
1443 return err;
1444
1445 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1446 if (err < 0)
1447 return err;
1448
1449 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
1450 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
1451
1452 ipgre_link_update(dev, !tb[IFLA_MTU]);
1453
1454 return 0;
1455}
1456
1457static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1458 struct nlattr *data[],
1459 struct netlink_ext_ack *extack)
1460{
1461 struct ip_tunnel *t = netdev_priv(dev);
1462 struct ip_tunnel_parm_kern p;
1463 __u32 fwmark = t->fwmark;
1464 int err;
1465
1466 err = ipgre_newlink_encap_setup(dev, data);
1467 if (err)
1468 return err;
1469
1470 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1471 if (err < 0)
1472 return err;
1473
1474 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1475 if (err < 0)
1476 return err;
1477
1478 ip_tunnel_flags_copy(t->parms.i_flags, p.i_flags);
1479 ip_tunnel_flags_copy(t->parms.o_flags, p.o_flags);
1480
1481 return 0;
1482}
1483
1484static size_t ipgre_get_size(const struct net_device *dev)
1485{
1486 return
1487 /* IFLA_GRE_LINK */
1488 nla_total_size(4) +
1489 /* IFLA_GRE_IFLAGS */
1490 nla_total_size(2) +
1491 /* IFLA_GRE_OFLAGS */
1492 nla_total_size(2) +
1493 /* IFLA_GRE_IKEY */
1494 nla_total_size(4) +
1495 /* IFLA_GRE_OKEY */
1496 nla_total_size(4) +
1497 /* IFLA_GRE_LOCAL */
1498 nla_total_size(4) +
1499 /* IFLA_GRE_REMOTE */
1500 nla_total_size(4) +
1501 /* IFLA_GRE_TTL */
1502 nla_total_size(1) +
1503 /* IFLA_GRE_TOS */
1504 nla_total_size(1) +
1505 /* IFLA_GRE_PMTUDISC */
1506 nla_total_size(1) +
1507 /* IFLA_GRE_ENCAP_TYPE */
1508 nla_total_size(2) +
1509 /* IFLA_GRE_ENCAP_FLAGS */
1510 nla_total_size(2) +
1511 /* IFLA_GRE_ENCAP_SPORT */
1512 nla_total_size(2) +
1513 /* IFLA_GRE_ENCAP_DPORT */
1514 nla_total_size(2) +
1515 /* IFLA_GRE_COLLECT_METADATA */
1516 nla_total_size(0) +
1517 /* IFLA_GRE_IGNORE_DF */
1518 nla_total_size(1) +
1519 /* IFLA_GRE_FWMARK */
1520 nla_total_size(4) +
1521 /* IFLA_GRE_ERSPAN_INDEX */
1522 nla_total_size(4) +
1523 /* IFLA_GRE_ERSPAN_VER */
1524 nla_total_size(1) +
1525 /* IFLA_GRE_ERSPAN_DIR */
1526 nla_total_size(1) +
1527 /* IFLA_GRE_ERSPAN_HWID */
1528 nla_total_size(2) +
1529 0;
1530}
1531
1532static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1533{
1534 struct ip_tunnel *t = netdev_priv(dev);
1535 struct ip_tunnel_parm_kern *p = &t->parms;
1536 IP_TUNNEL_DECLARE_FLAGS(o_flags);
1537
1538 ip_tunnel_flags_copy(o_flags, p->o_flags);
1539
1540 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1541 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1542 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1543 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1544 gre_tnl_flags_to_gre_flags(o_flags)) ||
1545 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1546 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1547 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1548 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1549 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1550 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1551 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1552 !!(p->iph.frag_off & htons(IP_DF))) ||
1553 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1554 goto nla_put_failure;
1555
1556 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1557 t->encap.type) ||
1558 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1559 t->encap.sport) ||
1560 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1561 t->encap.dport) ||
1562 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1563 t->encap.flags))
1564 goto nla_put_failure;
1565
1566 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1567 goto nla_put_failure;
1568
1569 if (t->collect_md) {
1570 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1571 goto nla_put_failure;
1572 }
1573
1574 return 0;
1575
1576nla_put_failure:
1577 return -EMSGSIZE;
1578}
1579
1580static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
1581{
1582 struct ip_tunnel *t = netdev_priv(dev);
1583
1584 if (t->erspan_ver <= 2) {
1585 if (t->erspan_ver != 0 && !t->collect_md)
1586 __set_bit(IP_TUNNEL_KEY_BIT, t->parms.o_flags);
1587
1588 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1589 goto nla_put_failure;
1590
1591 if (t->erspan_ver == 1) {
1592 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1593 goto nla_put_failure;
1594 } else if (t->erspan_ver == 2) {
1595 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1596 goto nla_put_failure;
1597 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1598 goto nla_put_failure;
1599 }
1600 }
1601
1602 return ipgre_fill_info(skb, dev);
1603
1604nla_put_failure:
1605 return -EMSGSIZE;
1606}
1607
1608static void erspan_setup(struct net_device *dev)
1609{
1610 struct ip_tunnel *t = netdev_priv(dev);
1611
1612 ether_setup(dev);
1613 dev->max_mtu = 0;
1614 dev->netdev_ops = &erspan_netdev_ops;
1615 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1616 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1617 ip_tunnel_setup(dev, erspan_net_id);
1618 t->erspan_ver = 1;
1619}
1620
1621static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1622 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1623 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1624 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1625 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1626 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1627 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1628 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1629 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1630 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1631 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1632 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1633 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1634 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1635 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1636 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1637 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1638 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1639 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1640 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1641 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1642 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1643};
1644
1645static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1646 .kind = "gre",
1647 .maxtype = IFLA_GRE_MAX,
1648 .policy = ipgre_policy,
1649 .priv_size = sizeof(struct ip_tunnel),
1650 .setup = ipgre_tunnel_setup,
1651 .validate = ipgre_tunnel_validate,
1652 .newlink = ipgre_newlink,
1653 .changelink = ipgre_changelink,
1654 .dellink = ip_tunnel_dellink,
1655 .get_size = ipgre_get_size,
1656 .fill_info = ipgre_fill_info,
1657 .get_link_net = ip_tunnel_get_link_net,
1658};
1659
1660static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1661 .kind = "gretap",
1662 .maxtype = IFLA_GRE_MAX,
1663 .policy = ipgre_policy,
1664 .priv_size = sizeof(struct ip_tunnel),
1665 .setup = ipgre_tap_setup,
1666 .validate = ipgre_tap_validate,
1667 .newlink = ipgre_newlink,
1668 .changelink = ipgre_changelink,
1669 .dellink = ip_tunnel_dellink,
1670 .get_size = ipgre_get_size,
1671 .fill_info = ipgre_fill_info,
1672 .get_link_net = ip_tunnel_get_link_net,
1673};
1674
1675static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1676 .kind = "erspan",
1677 .maxtype = IFLA_GRE_MAX,
1678 .policy = ipgre_policy,
1679 .priv_size = sizeof(struct ip_tunnel),
1680 .setup = erspan_setup,
1681 .validate = erspan_validate,
1682 .newlink = erspan_newlink,
1683 .changelink = erspan_changelink,
1684 .dellink = ip_tunnel_dellink,
1685 .get_size = ipgre_get_size,
1686 .fill_info = erspan_fill_info,
1687 .get_link_net = ip_tunnel_get_link_net,
1688};
1689
1690struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1691 u8 name_assign_type)
1692{
1693 struct nlattr *tb[IFLA_MAX + 1];
1694 struct net_device *dev;
1695 LIST_HEAD(list_kill);
1696 struct ip_tunnel *t;
1697 int err;
1698
1699 memset(&tb, 0, sizeof(tb));
1700
1701 dev = rtnl_create_link(net, name, name_assign_type,
1702 &ipgre_tap_ops, tb, NULL);
1703 if (IS_ERR(dev))
1704 return dev;
1705
1706 /* Configure flow based GRE device. */
1707 t = netdev_priv(dev);
1708 t->collect_md = true;
1709
1710 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1711 if (err < 0) {
1712 free_netdev(dev);
1713 return ERR_PTR(err);
1714 }
1715
1716 /* openvswitch users expect packet sizes to be unrestricted,
1717 * so set the largest MTU we can.
1718 */
1719 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1720 if (err)
1721 goto out;
1722
1723 err = rtnl_configure_link(dev, NULL, 0, NULL);
1724 if (err < 0)
1725 goto out;
1726
1727 return dev;
1728out:
1729 ip_tunnel_dellink(dev, &list_kill);
1730 unregister_netdevice_many(&list_kill);
1731 return ERR_PTR(err);
1732}
1733EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1734
1735static int __net_init ipgre_tap_init_net(struct net *net)
1736{
1737 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1738}
1739
1740static void __net_exit ipgre_tap_exit_batch_rtnl(struct list_head *list_net,
1741 struct list_head *dev_to_kill)
1742{
1743 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops,
1744 dev_to_kill);
1745}
1746
1747static struct pernet_operations ipgre_tap_net_ops = {
1748 .init = ipgre_tap_init_net,
1749 .exit_batch_rtnl = ipgre_tap_exit_batch_rtnl,
1750 .id = &gre_tap_net_id,
1751 .size = sizeof(struct ip_tunnel_net),
1752};
1753
1754static int __net_init erspan_init_net(struct net *net)
1755{
1756 return ip_tunnel_init_net(net, erspan_net_id,
1757 &erspan_link_ops, "erspan0");
1758}
1759
1760static void __net_exit erspan_exit_batch_rtnl(struct list_head *net_list,
1761 struct list_head *dev_to_kill)
1762{
1763 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops,
1764 dev_to_kill);
1765}
1766
1767static struct pernet_operations erspan_net_ops = {
1768 .init = erspan_init_net,
1769 .exit_batch_rtnl = erspan_exit_batch_rtnl,
1770 .id = &erspan_net_id,
1771 .size = sizeof(struct ip_tunnel_net),
1772};
1773
1774static int __init ipgre_init(void)
1775{
1776 int err;
1777
1778 pr_info("GRE over IPv4 tunneling driver\n");
1779
1780 err = register_pernet_device(&ipgre_net_ops);
1781 if (err < 0)
1782 return err;
1783
1784 err = register_pernet_device(&ipgre_tap_net_ops);
1785 if (err < 0)
1786 goto pnet_tap_failed;
1787
1788 err = register_pernet_device(&erspan_net_ops);
1789 if (err < 0)
1790 goto pnet_erspan_failed;
1791
1792 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1793 if (err < 0) {
1794 pr_info("%s: can't add protocol\n", __func__);
1795 goto add_proto_failed;
1796 }
1797
1798 err = rtnl_link_register(&ipgre_link_ops);
1799 if (err < 0)
1800 goto rtnl_link_failed;
1801
1802 err = rtnl_link_register(&ipgre_tap_ops);
1803 if (err < 0)
1804 goto tap_ops_failed;
1805
1806 err = rtnl_link_register(&erspan_link_ops);
1807 if (err < 0)
1808 goto erspan_link_failed;
1809
1810 return 0;
1811
1812erspan_link_failed:
1813 rtnl_link_unregister(&ipgre_tap_ops);
1814tap_ops_failed:
1815 rtnl_link_unregister(&ipgre_link_ops);
1816rtnl_link_failed:
1817 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1818add_proto_failed:
1819 unregister_pernet_device(&erspan_net_ops);
1820pnet_erspan_failed:
1821 unregister_pernet_device(&ipgre_tap_net_ops);
1822pnet_tap_failed:
1823 unregister_pernet_device(&ipgre_net_ops);
1824 return err;
1825}
1826
1827static void __exit ipgre_fini(void)
1828{
1829 rtnl_link_unregister(&ipgre_tap_ops);
1830 rtnl_link_unregister(&ipgre_link_ops);
1831 rtnl_link_unregister(&erspan_link_ops);
1832 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1833 unregister_pernet_device(&ipgre_tap_net_ops);
1834 unregister_pernet_device(&ipgre_net_ops);
1835 unregister_pernet_device(&erspan_net_ops);
1836}
1837
1838module_init(ipgre_init);
1839module_exit(ipgre_fini);
1840MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
1841MODULE_LICENSE("GPL");
1842MODULE_ALIAS_RTNL_LINK("gre");
1843MODULE_ALIAS_RTNL_LINK("gretap");
1844MODULE_ALIAS_RTNL_LINK("erspan");
1845MODULE_ALIAS_NETDEV("gre0");
1846MODULE_ALIAS_NETDEV("gretap0");
1847MODULE_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 ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
284 ver = ershdr->ver;
285 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
286 tpi->flags | TUNNEL_KEY,
287 iph->saddr, iph->daddr, tpi->key);
288 }
289
290 if (tunnel) {
291 if (is_erspan_type1(gre_hdr_len))
292 len = gre_hdr_len;
293 else
294 len = gre_hdr_len + erspan_hdr_len(ver);
295
296 if (unlikely(!pskb_may_pull(skb, len)))
297 return PACKET_REJECT;
298
299 if (__iptunnel_pull_header(skb,
300 len,
301 htons(ETH_P_TEB),
302 false, false) < 0)
303 goto drop;
304
305 if (tunnel->collect_md) {
306 struct erspan_metadata *pkt_md, *md;
307 struct ip_tunnel_info *info;
308 unsigned char *gh;
309 __be64 tun_id;
310 __be16 flags;
311
312 tpi->flags |= TUNNEL_KEY;
313 flags = tpi->flags;
314 tun_id = key32_to_tunnel_id(tpi->key);
315
316 tun_dst = ip_tun_rx_dst(skb, flags,
317 tun_id, sizeof(*md));
318 if (!tun_dst)
319 return PACKET_REJECT;
320
321 /* skb can be uncloned in __iptunnel_pull_header, so
322 * old pkt_md is no longer valid and we need to reset
323 * it
324 */
325 gh = skb_network_header(skb) +
326 skb_network_header_len(skb);
327 pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
328 sizeof(*ershdr));
329 md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
330 md->version = ver;
331 md2 = &md->u.md2;
332 memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
333 ERSPAN_V2_MDSIZE);
334
335 info = &tun_dst->u.tun_info;
336 info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
337 info->options_len = sizeof(*md);
338 }
339
340 skb_reset_mac_header(skb);
341 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
342 return PACKET_RCVD;
343 }
344 return PACKET_REJECT;
345
346drop:
347 kfree_skb(skb);
348 return PACKET_RCVD;
349}
350
351static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
352 struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
353{
354 struct metadata_dst *tun_dst = NULL;
355 const struct iphdr *iph;
356 struct ip_tunnel *tunnel;
357
358 iph = ip_hdr(skb);
359 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
360 iph->saddr, iph->daddr, tpi->key);
361
362 if (tunnel) {
363 const struct iphdr *tnl_params;
364
365 if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
366 raw_proto, false) < 0)
367 goto drop;
368
369 /* Special case for ipgre_header_parse(), which expects the
370 * mac_header to point to the outer IP header.
371 */
372 if (tunnel->dev->header_ops == &ipgre_header_ops)
373 skb_pop_mac_header(skb);
374 else
375 skb_reset_mac_header(skb);
376
377 tnl_params = &tunnel->parms.iph;
378 if (tunnel->collect_md || tnl_params->daddr == 0) {
379 __be16 flags;
380 __be64 tun_id;
381
382 flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
383 tun_id = key32_to_tunnel_id(tpi->key);
384 tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
385 if (!tun_dst)
386 return PACKET_REJECT;
387 }
388
389 ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
390 return PACKET_RCVD;
391 }
392 return PACKET_NEXT;
393
394drop:
395 kfree_skb(skb);
396 return PACKET_RCVD;
397}
398
399static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
400 int hdr_len)
401{
402 struct net *net = dev_net(skb->dev);
403 struct ip_tunnel_net *itn;
404 int res;
405
406 if (tpi->proto == htons(ETH_P_TEB))
407 itn = net_generic(net, gre_tap_net_id);
408 else
409 itn = net_generic(net, ipgre_net_id);
410
411 res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
412 if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
413 /* ipgre tunnels in collect metadata mode should receive
414 * also ETH_P_TEB traffic.
415 */
416 itn = net_generic(net, ipgre_net_id);
417 res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
418 }
419 return res;
420}
421
422static int gre_rcv(struct sk_buff *skb)
423{
424 struct tnl_ptk_info tpi;
425 bool csum_err = false;
426 int hdr_len;
427
428#ifdef CONFIG_NET_IPGRE_BROADCAST
429 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
430 /* Looped back packet, drop it! */
431 if (rt_is_output_route(skb_rtable(skb)))
432 goto drop;
433 }
434#endif
435
436 hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
437 if (hdr_len < 0)
438 goto drop;
439
440 if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
441 tpi.proto == htons(ETH_P_ERSPAN2))) {
442 if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
443 return 0;
444 goto out;
445 }
446
447 if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
448 return 0;
449
450out:
451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
452drop:
453 kfree_skb(skb);
454 return 0;
455}
456
457static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
458 const struct iphdr *tnl_params,
459 __be16 proto)
460{
461 struct ip_tunnel *tunnel = netdev_priv(dev);
462 __be16 flags = tunnel->parms.o_flags;
463
464 /* Push GRE header. */
465 gre_build_header(skb, tunnel->tun_hlen,
466 flags, proto, tunnel->parms.o_key,
467 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
468
469 ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
470}
471
472static int gre_handle_offloads(struct sk_buff *skb, bool csum)
473{
474 return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
475}
476
477static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
478 __be16 proto)
479{
480 struct ip_tunnel *tunnel = netdev_priv(dev);
481 struct ip_tunnel_info *tun_info;
482 const struct ip_tunnel_key *key;
483 int tunnel_hlen;
484 __be16 flags;
485
486 tun_info = skb_tunnel_info(skb);
487 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
488 ip_tunnel_info_af(tun_info) != AF_INET))
489 goto err_free_skb;
490
491 key = &tun_info->key;
492 tunnel_hlen = gre_calc_hlen(key->tun_flags);
493
494 if (skb_cow_head(skb, dev->needed_headroom))
495 goto err_free_skb;
496
497 /* Push Tunnel header. */
498 if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
499 goto err_free_skb;
500
501 flags = tun_info->key.tun_flags &
502 (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
503 gre_build_header(skb, tunnel_hlen, flags, proto,
504 tunnel_id_to_key32(tun_info->key.tun_id),
505 (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
506
507 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
508
509 return;
510
511err_free_skb:
512 kfree_skb(skb);
513 DEV_STATS_INC(dev, tx_dropped);
514}
515
516static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
517{
518 struct ip_tunnel *tunnel = netdev_priv(dev);
519 struct ip_tunnel_info *tun_info;
520 const struct ip_tunnel_key *key;
521 struct erspan_metadata *md;
522 bool truncate = false;
523 __be16 proto;
524 int tunnel_hlen;
525 int version;
526 int nhoff;
527
528 tun_info = skb_tunnel_info(skb);
529 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
530 ip_tunnel_info_af(tun_info) != AF_INET))
531 goto err_free_skb;
532
533 key = &tun_info->key;
534 if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
535 goto err_free_skb;
536 if (tun_info->options_len < sizeof(*md))
537 goto err_free_skb;
538 md = ip_tunnel_info_opts(tun_info);
539
540 /* ERSPAN has fixed 8 byte GRE header */
541 version = md->version;
542 tunnel_hlen = 8 + erspan_hdr_len(version);
543
544 if (skb_cow_head(skb, dev->needed_headroom))
545 goto err_free_skb;
546
547 if (gre_handle_offloads(skb, false))
548 goto err_free_skb;
549
550 if (skb->len > dev->mtu + dev->hard_header_len) {
551 pskb_trim(skb, dev->mtu + dev->hard_header_len);
552 truncate = true;
553 }
554
555 nhoff = skb_network_header(skb) - skb_mac_header(skb);
556 if (skb->protocol == htons(ETH_P_IP) &&
557 (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
558 truncate = true;
559
560 if (skb->protocol == htons(ETH_P_IPV6)) {
561 int thoff;
562
563 if (skb_transport_header_was_set(skb))
564 thoff = skb_transport_header(skb) - skb_mac_header(skb);
565 else
566 thoff = nhoff + sizeof(struct ipv6hdr);
567 if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
568 truncate = true;
569 }
570
571 if (version == 1) {
572 erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
573 ntohl(md->u.index), truncate, true);
574 proto = htons(ETH_P_ERSPAN);
575 } else if (version == 2) {
576 erspan_build_header_v2(skb,
577 ntohl(tunnel_id_to_key32(key->tun_id)),
578 md->u.md2.dir,
579 get_hwid(&md->u.md2),
580 truncate, true);
581 proto = htons(ETH_P_ERSPAN2);
582 } else {
583 goto err_free_skb;
584 }
585
586 gre_build_header(skb, 8, TUNNEL_SEQ,
587 proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno)));
588
589 ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
590
591 return;
592
593err_free_skb:
594 kfree_skb(skb);
595 DEV_STATS_INC(dev, tx_dropped);
596}
597
598static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
599{
600 struct ip_tunnel_info *info = skb_tunnel_info(skb);
601 const struct ip_tunnel_key *key;
602 struct rtable *rt;
603 struct flowi4 fl4;
604
605 if (ip_tunnel_info_af(info) != AF_INET)
606 return -EINVAL;
607
608 key = &info->key;
609 ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
610 tunnel_id_to_key32(key->tun_id),
611 key->tos & ~INET_ECN_MASK, dev_net(dev), 0,
612 skb->mark, skb_get_hash(skb), key->flow_flags);
613 rt = ip_route_output_key(dev_net(dev), &fl4);
614 if (IS_ERR(rt))
615 return PTR_ERR(rt);
616
617 ip_rt_put(rt);
618 info->key.u.ipv4.src = fl4.saddr;
619 return 0;
620}
621
622static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
623 struct net_device *dev)
624{
625 struct ip_tunnel *tunnel = netdev_priv(dev);
626 const struct iphdr *tnl_params;
627
628 if (!pskb_inet_may_pull(skb))
629 goto free_skb;
630
631 if (tunnel->collect_md) {
632 gre_fb_xmit(skb, dev, skb->protocol);
633 return NETDEV_TX_OK;
634 }
635
636 if (dev->header_ops) {
637 if (skb_cow_head(skb, 0))
638 goto free_skb;
639
640 tnl_params = (const struct iphdr *)skb->data;
641
642 /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
643 * to gre header.
644 */
645 skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
646 skb_reset_mac_header(skb);
647
648 if (skb->ip_summed == CHECKSUM_PARTIAL &&
649 skb_checksum_start(skb) < skb->data)
650 goto free_skb;
651 } else {
652 if (skb_cow_head(skb, dev->needed_headroom))
653 goto free_skb;
654
655 tnl_params = &tunnel->parms.iph;
656 }
657
658 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
659 goto free_skb;
660
661 __gre_xmit(skb, dev, tnl_params, skb->protocol);
662 return NETDEV_TX_OK;
663
664free_skb:
665 kfree_skb(skb);
666 DEV_STATS_INC(dev, tx_dropped);
667 return NETDEV_TX_OK;
668}
669
670static netdev_tx_t erspan_xmit(struct sk_buff *skb,
671 struct net_device *dev)
672{
673 struct ip_tunnel *tunnel = netdev_priv(dev);
674 bool truncate = false;
675 __be16 proto;
676
677 if (!pskb_inet_may_pull(skb))
678 goto free_skb;
679
680 if (tunnel->collect_md) {
681 erspan_fb_xmit(skb, dev);
682 return NETDEV_TX_OK;
683 }
684
685 if (gre_handle_offloads(skb, false))
686 goto free_skb;
687
688 if (skb_cow_head(skb, dev->needed_headroom))
689 goto free_skb;
690
691 if (skb->len > dev->mtu + dev->hard_header_len) {
692 pskb_trim(skb, dev->mtu + dev->hard_header_len);
693 truncate = true;
694 }
695
696 /* Push ERSPAN header */
697 if (tunnel->erspan_ver == 0) {
698 proto = htons(ETH_P_ERSPAN);
699 tunnel->parms.o_flags &= ~TUNNEL_SEQ;
700 } else if (tunnel->erspan_ver == 1) {
701 erspan_build_header(skb, ntohl(tunnel->parms.o_key),
702 tunnel->index,
703 truncate, true);
704 proto = htons(ETH_P_ERSPAN);
705 } else if (tunnel->erspan_ver == 2) {
706 erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
707 tunnel->dir, tunnel->hwid,
708 truncate, true);
709 proto = htons(ETH_P_ERSPAN2);
710 } else {
711 goto free_skb;
712 }
713
714 tunnel->parms.o_flags &= ~TUNNEL_KEY;
715 __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
716 return NETDEV_TX_OK;
717
718free_skb:
719 kfree_skb(skb);
720 DEV_STATS_INC(dev, tx_dropped);
721 return NETDEV_TX_OK;
722}
723
724static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
725 struct net_device *dev)
726{
727 struct ip_tunnel *tunnel = netdev_priv(dev);
728
729 if (!pskb_inet_may_pull(skb))
730 goto free_skb;
731
732 if (tunnel->collect_md) {
733 gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
734 return NETDEV_TX_OK;
735 }
736
737 if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
738 goto free_skb;
739
740 if (skb_cow_head(skb, dev->needed_headroom))
741 goto free_skb;
742
743 __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
744 return NETDEV_TX_OK;
745
746free_skb:
747 kfree_skb(skb);
748 DEV_STATS_INC(dev, tx_dropped);
749 return NETDEV_TX_OK;
750}
751
752static void ipgre_link_update(struct net_device *dev, bool set_mtu)
753{
754 struct ip_tunnel *tunnel = netdev_priv(dev);
755 __be16 flags;
756 int len;
757
758 len = tunnel->tun_hlen;
759 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
760 len = tunnel->tun_hlen - len;
761 tunnel->hlen = tunnel->hlen + len;
762
763 if (dev->header_ops)
764 dev->hard_header_len += len;
765 else
766 dev->needed_headroom += len;
767
768 if (set_mtu)
769 dev->mtu = max_t(int, dev->mtu - len, 68);
770
771 flags = tunnel->parms.o_flags;
772
773 if (flags & TUNNEL_SEQ ||
774 (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)) {
775 dev->features &= ~NETIF_F_GSO_SOFTWARE;
776 dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
777 } else {
778 dev->features |= NETIF_F_GSO_SOFTWARE;
779 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
780 }
781}
782
783static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,
784 int cmd)
785{
786 int err;
787
788 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
789 if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
790 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)) ||
791 ((p->i_flags | p->o_flags) & (GRE_VERSION | GRE_ROUTING)))
792 return -EINVAL;
793 }
794
795 p->i_flags = gre_flags_to_tnl_flags(p->i_flags);
796 p->o_flags = gre_flags_to_tnl_flags(p->o_flags);
797
798 err = ip_tunnel_ctl(dev, p, cmd);
799 if (err)
800 return err;
801
802 if (cmd == SIOCCHGTUNNEL) {
803 struct ip_tunnel *t = netdev_priv(dev);
804
805 t->parms.i_flags = p->i_flags;
806 t->parms.o_flags = p->o_flags;
807
808 if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
809 ipgre_link_update(dev, true);
810 }
811
812 p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
813 p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
814 return 0;
815}
816
817/* Nice toy. Unfortunately, useless in real life :-)
818 It allows to construct virtual multiprotocol broadcast "LAN"
819 over the Internet, provided multicast routing is tuned.
820
821
822 I have no idea was this bicycle invented before me,
823 so that I had to set ARPHRD_IPGRE to a random value.
824 I have an impression, that Cisco could make something similar,
825 but this feature is apparently missing in IOS<=11.2(8).
826
827 I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
828 with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
829
830 ping -t 255 224.66.66.66
831
832 If nobody answers, mbone does not work.
833
834 ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
835 ip addr add 10.66.66.<somewhat>/24 dev Universe
836 ifconfig Universe up
837 ifconfig Universe add fe80::<Your_real_addr>/10
838 ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
839 ftp 10.66.66.66
840 ...
841 ftp fec0:6666:6666::193.233.7.65
842 ...
843 */
844static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
845 unsigned short type,
846 const void *daddr, const void *saddr, unsigned int len)
847{
848 struct ip_tunnel *t = netdev_priv(dev);
849 struct iphdr *iph;
850 struct gre_base_hdr *greh;
851
852 iph = skb_push(skb, t->hlen + sizeof(*iph));
853 greh = (struct gre_base_hdr *)(iph+1);
854 greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
855 greh->protocol = htons(type);
856
857 memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
858
859 /* Set the source hardware address. */
860 if (saddr)
861 memcpy(&iph->saddr, saddr, 4);
862 if (daddr)
863 memcpy(&iph->daddr, daddr, 4);
864 if (iph->daddr)
865 return t->hlen + sizeof(*iph);
866
867 return -(t->hlen + sizeof(*iph));
868}
869
870static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
871{
872 const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
873 memcpy(haddr, &iph->saddr, 4);
874 return 4;
875}
876
877static const struct header_ops ipgre_header_ops = {
878 .create = ipgre_header,
879 .parse = ipgre_header_parse,
880};
881
882#ifdef CONFIG_NET_IPGRE_BROADCAST
883static int ipgre_open(struct net_device *dev)
884{
885 struct ip_tunnel *t = netdev_priv(dev);
886
887 if (ipv4_is_multicast(t->parms.iph.daddr)) {
888 struct flowi4 fl4;
889 struct rtable *rt;
890
891 rt = ip_route_output_gre(t->net, &fl4,
892 t->parms.iph.daddr,
893 t->parms.iph.saddr,
894 t->parms.o_key,
895 RT_TOS(t->parms.iph.tos),
896 t->parms.link);
897 if (IS_ERR(rt))
898 return -EADDRNOTAVAIL;
899 dev = rt->dst.dev;
900 ip_rt_put(rt);
901 if (!__in_dev_get_rtnl(dev))
902 return -EADDRNOTAVAIL;
903 t->mlink = dev->ifindex;
904 ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
905 }
906 return 0;
907}
908
909static int ipgre_close(struct net_device *dev)
910{
911 struct ip_tunnel *t = netdev_priv(dev);
912
913 if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
914 struct in_device *in_dev;
915 in_dev = inetdev_by_index(t->net, t->mlink);
916 if (in_dev)
917 ip_mc_dec_group(in_dev, t->parms.iph.daddr);
918 }
919 return 0;
920}
921#endif
922
923static const struct net_device_ops ipgre_netdev_ops = {
924 .ndo_init = ipgre_tunnel_init,
925 .ndo_uninit = ip_tunnel_uninit,
926#ifdef CONFIG_NET_IPGRE_BROADCAST
927 .ndo_open = ipgre_open,
928 .ndo_stop = ipgre_close,
929#endif
930 .ndo_start_xmit = ipgre_xmit,
931 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
932 .ndo_change_mtu = ip_tunnel_change_mtu,
933 .ndo_get_stats64 = dev_get_tstats64,
934 .ndo_get_iflink = ip_tunnel_get_iflink,
935 .ndo_tunnel_ctl = ipgre_tunnel_ctl,
936};
937
938#define GRE_FEATURES (NETIF_F_SG | \
939 NETIF_F_FRAGLIST | \
940 NETIF_F_HIGHDMA | \
941 NETIF_F_HW_CSUM)
942
943static void ipgre_tunnel_setup(struct net_device *dev)
944{
945 dev->netdev_ops = &ipgre_netdev_ops;
946 dev->type = ARPHRD_IPGRE;
947 ip_tunnel_setup(dev, ipgre_net_id);
948}
949
950static void __gre_tunnel_init(struct net_device *dev)
951{
952 struct ip_tunnel *tunnel;
953 __be16 flags;
954
955 tunnel = netdev_priv(dev);
956 tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
957 tunnel->parms.iph.protocol = IPPROTO_GRE;
958
959 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
960 dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
961
962 dev->features |= GRE_FEATURES | NETIF_F_LLTX;
963 dev->hw_features |= GRE_FEATURES;
964
965 flags = tunnel->parms.o_flags;
966
967 /* TCP offload with GRE SEQ is not supported, nor can we support 2
968 * levels of outer headers requiring an update.
969 */
970 if (flags & TUNNEL_SEQ)
971 return;
972 if (flags & TUNNEL_CSUM && tunnel->encap.type != TUNNEL_ENCAP_NONE)
973 return;
974
975 dev->features |= NETIF_F_GSO_SOFTWARE;
976 dev->hw_features |= NETIF_F_GSO_SOFTWARE;
977}
978
979static int ipgre_tunnel_init(struct net_device *dev)
980{
981 struct ip_tunnel *tunnel = netdev_priv(dev);
982 struct iphdr *iph = &tunnel->parms.iph;
983
984 __gre_tunnel_init(dev);
985
986 __dev_addr_set(dev, &iph->saddr, 4);
987 memcpy(dev->broadcast, &iph->daddr, 4);
988
989 dev->flags = IFF_NOARP;
990 netif_keep_dst(dev);
991 dev->addr_len = 4;
992
993 if (iph->daddr && !tunnel->collect_md) {
994#ifdef CONFIG_NET_IPGRE_BROADCAST
995 if (ipv4_is_multicast(iph->daddr)) {
996 if (!iph->saddr)
997 return -EINVAL;
998 dev->flags = IFF_BROADCAST;
999 dev->header_ops = &ipgre_header_ops;
1000 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1001 dev->needed_headroom = 0;
1002 }
1003#endif
1004 } else if (!tunnel->collect_md) {
1005 dev->header_ops = &ipgre_header_ops;
1006 dev->hard_header_len = tunnel->hlen + sizeof(*iph);
1007 dev->needed_headroom = 0;
1008 }
1009
1010 return ip_tunnel_init(dev);
1011}
1012
1013static const struct gre_protocol ipgre_protocol = {
1014 .handler = gre_rcv,
1015 .err_handler = gre_err,
1016};
1017
1018static int __net_init ipgre_init_net(struct net *net)
1019{
1020 return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
1021}
1022
1023static void __net_exit ipgre_exit_batch_net(struct list_head *list_net)
1024{
1025 ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops);
1026}
1027
1028static struct pernet_operations ipgre_net_ops = {
1029 .init = ipgre_init_net,
1030 .exit_batch = ipgre_exit_batch_net,
1031 .id = &ipgre_net_id,
1032 .size = sizeof(struct ip_tunnel_net),
1033};
1034
1035static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
1036 struct netlink_ext_ack *extack)
1037{
1038 __be16 flags;
1039
1040 if (!data)
1041 return 0;
1042
1043 flags = 0;
1044 if (data[IFLA_GRE_IFLAGS])
1045 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1046 if (data[IFLA_GRE_OFLAGS])
1047 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1048 if (flags & (GRE_VERSION|GRE_ROUTING))
1049 return -EINVAL;
1050
1051 if (data[IFLA_GRE_COLLECT_METADATA] &&
1052 data[IFLA_GRE_ENCAP_TYPE] &&
1053 nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
1054 return -EINVAL;
1055
1056 return 0;
1057}
1058
1059static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
1060 struct netlink_ext_ack *extack)
1061{
1062 __be32 daddr;
1063
1064 if (tb[IFLA_ADDRESS]) {
1065 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1066 return -EINVAL;
1067 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1068 return -EADDRNOTAVAIL;
1069 }
1070
1071 if (!data)
1072 goto out;
1073
1074 if (data[IFLA_GRE_REMOTE]) {
1075 memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
1076 if (!daddr)
1077 return -EINVAL;
1078 }
1079
1080out:
1081 return ipgre_tunnel_validate(tb, data, extack);
1082}
1083
1084static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
1085 struct netlink_ext_ack *extack)
1086{
1087 __be16 flags = 0;
1088 int ret;
1089
1090 if (!data)
1091 return 0;
1092
1093 ret = ipgre_tap_validate(tb, data, extack);
1094 if (ret)
1095 return ret;
1096
1097 if (data[IFLA_GRE_ERSPAN_VER] &&
1098 nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
1099 return 0;
1100
1101 /* ERSPAN type II/III should only have GRE sequence and key flag */
1102 if (data[IFLA_GRE_OFLAGS])
1103 flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
1104 if (data[IFLA_GRE_IFLAGS])
1105 flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
1106 if (!data[IFLA_GRE_COLLECT_METADATA] &&
1107 flags != (GRE_SEQ | GRE_KEY))
1108 return -EINVAL;
1109
1110 /* ERSPAN Session ID only has 10-bit. Since we reuse
1111 * 32-bit key field as ID, check it's range.
1112 */
1113 if (data[IFLA_GRE_IKEY] &&
1114 (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
1115 return -EINVAL;
1116
1117 if (data[IFLA_GRE_OKEY] &&
1118 (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
1119 return -EINVAL;
1120
1121 return 0;
1122}
1123
1124static int ipgre_netlink_parms(struct net_device *dev,
1125 struct nlattr *data[],
1126 struct nlattr *tb[],
1127 struct ip_tunnel_parm *parms,
1128 __u32 *fwmark)
1129{
1130 struct ip_tunnel *t = netdev_priv(dev);
1131
1132 memset(parms, 0, sizeof(*parms));
1133
1134 parms->iph.protocol = IPPROTO_GRE;
1135
1136 if (!data)
1137 return 0;
1138
1139 if (data[IFLA_GRE_LINK])
1140 parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
1141
1142 if (data[IFLA_GRE_IFLAGS])
1143 parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
1144
1145 if (data[IFLA_GRE_OFLAGS])
1146 parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
1147
1148 if (data[IFLA_GRE_IKEY])
1149 parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
1150
1151 if (data[IFLA_GRE_OKEY])
1152 parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
1153
1154 if (data[IFLA_GRE_LOCAL])
1155 parms->iph.saddr = nla_get_in_addr(data[IFLA_GRE_LOCAL]);
1156
1157 if (data[IFLA_GRE_REMOTE])
1158 parms->iph.daddr = nla_get_in_addr(data[IFLA_GRE_REMOTE]);
1159
1160 if (data[IFLA_GRE_TTL])
1161 parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
1162
1163 if (data[IFLA_GRE_TOS])
1164 parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
1165
1166 if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) {
1167 if (t->ignore_df)
1168 return -EINVAL;
1169 parms->iph.frag_off = htons(IP_DF);
1170 }
1171
1172 if (data[IFLA_GRE_COLLECT_METADATA]) {
1173 t->collect_md = true;
1174 if (dev->type == ARPHRD_IPGRE)
1175 dev->type = ARPHRD_NONE;
1176 }
1177
1178 if (data[IFLA_GRE_IGNORE_DF]) {
1179 if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
1180 && (parms->iph.frag_off & htons(IP_DF)))
1181 return -EINVAL;
1182 t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
1183 }
1184
1185 if (data[IFLA_GRE_FWMARK])
1186 *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
1187
1188 return 0;
1189}
1190
1191static int erspan_netlink_parms(struct net_device *dev,
1192 struct nlattr *data[],
1193 struct nlattr *tb[],
1194 struct ip_tunnel_parm *parms,
1195 __u32 *fwmark)
1196{
1197 struct ip_tunnel *t = netdev_priv(dev);
1198 int err;
1199
1200 err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
1201 if (err)
1202 return err;
1203 if (!data)
1204 return 0;
1205
1206 if (data[IFLA_GRE_ERSPAN_VER]) {
1207 t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
1208
1209 if (t->erspan_ver > 2)
1210 return -EINVAL;
1211 }
1212
1213 if (t->erspan_ver == 1) {
1214 if (data[IFLA_GRE_ERSPAN_INDEX]) {
1215 t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
1216 if (t->index & ~INDEX_MASK)
1217 return -EINVAL;
1218 }
1219 } else if (t->erspan_ver == 2) {
1220 if (data[IFLA_GRE_ERSPAN_DIR]) {
1221 t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
1222 if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
1223 return -EINVAL;
1224 }
1225 if (data[IFLA_GRE_ERSPAN_HWID]) {
1226 t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
1227 if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
1228 return -EINVAL;
1229 }
1230 }
1231
1232 return 0;
1233}
1234
1235/* This function returns true when ENCAP attributes are present in the nl msg */
1236static bool ipgre_netlink_encap_parms(struct nlattr *data[],
1237 struct ip_tunnel_encap *ipencap)
1238{
1239 bool ret = false;
1240
1241 memset(ipencap, 0, sizeof(*ipencap));
1242
1243 if (!data)
1244 return ret;
1245
1246 if (data[IFLA_GRE_ENCAP_TYPE]) {
1247 ret = true;
1248 ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
1249 }
1250
1251 if (data[IFLA_GRE_ENCAP_FLAGS]) {
1252 ret = true;
1253 ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
1254 }
1255
1256 if (data[IFLA_GRE_ENCAP_SPORT]) {
1257 ret = true;
1258 ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
1259 }
1260
1261 if (data[IFLA_GRE_ENCAP_DPORT]) {
1262 ret = true;
1263 ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
1264 }
1265
1266 return ret;
1267}
1268
1269static int gre_tap_init(struct net_device *dev)
1270{
1271 __gre_tunnel_init(dev);
1272 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1273 netif_keep_dst(dev);
1274
1275 return ip_tunnel_init(dev);
1276}
1277
1278static const struct net_device_ops gre_tap_netdev_ops = {
1279 .ndo_init = gre_tap_init,
1280 .ndo_uninit = ip_tunnel_uninit,
1281 .ndo_start_xmit = gre_tap_xmit,
1282 .ndo_set_mac_address = eth_mac_addr,
1283 .ndo_validate_addr = eth_validate_addr,
1284 .ndo_change_mtu = ip_tunnel_change_mtu,
1285 .ndo_get_stats64 = dev_get_tstats64,
1286 .ndo_get_iflink = ip_tunnel_get_iflink,
1287 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1288};
1289
1290static int erspan_tunnel_init(struct net_device *dev)
1291{
1292 struct ip_tunnel *tunnel = netdev_priv(dev);
1293
1294 if (tunnel->erspan_ver == 0)
1295 tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
1296 else
1297 tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
1298
1299 tunnel->parms.iph.protocol = IPPROTO_GRE;
1300 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
1301 erspan_hdr_len(tunnel->erspan_ver);
1302
1303 dev->features |= GRE_FEATURES;
1304 dev->hw_features |= GRE_FEATURES;
1305 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1306 netif_keep_dst(dev);
1307
1308 return ip_tunnel_init(dev);
1309}
1310
1311static const struct net_device_ops erspan_netdev_ops = {
1312 .ndo_init = erspan_tunnel_init,
1313 .ndo_uninit = ip_tunnel_uninit,
1314 .ndo_start_xmit = erspan_xmit,
1315 .ndo_set_mac_address = eth_mac_addr,
1316 .ndo_validate_addr = eth_validate_addr,
1317 .ndo_change_mtu = ip_tunnel_change_mtu,
1318 .ndo_get_stats64 = dev_get_tstats64,
1319 .ndo_get_iflink = ip_tunnel_get_iflink,
1320 .ndo_fill_metadata_dst = gre_fill_metadata_dst,
1321};
1322
1323static void ipgre_tap_setup(struct net_device *dev)
1324{
1325 ether_setup(dev);
1326 dev->max_mtu = 0;
1327 dev->netdev_ops = &gre_tap_netdev_ops;
1328 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1329 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1330 ip_tunnel_setup(dev, gre_tap_net_id);
1331}
1332
1333static int
1334ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
1335{
1336 struct ip_tunnel_encap ipencap;
1337
1338 if (ipgre_netlink_encap_parms(data, &ipencap)) {
1339 struct ip_tunnel *t = netdev_priv(dev);
1340 int err = ip_tunnel_encap_setup(t, &ipencap);
1341
1342 if (err < 0)
1343 return err;
1344 }
1345
1346 return 0;
1347}
1348
1349static int ipgre_newlink(struct net *src_net, struct net_device *dev,
1350 struct nlattr *tb[], struct nlattr *data[],
1351 struct netlink_ext_ack *extack)
1352{
1353 struct ip_tunnel_parm p;
1354 __u32 fwmark = 0;
1355 int err;
1356
1357 err = ipgre_newlink_encap_setup(dev, data);
1358 if (err)
1359 return err;
1360
1361 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1362 if (err < 0)
1363 return err;
1364 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1365}
1366
1367static int erspan_newlink(struct net *src_net, struct net_device *dev,
1368 struct nlattr *tb[], struct nlattr *data[],
1369 struct netlink_ext_ack *extack)
1370{
1371 struct ip_tunnel_parm p;
1372 __u32 fwmark = 0;
1373 int err;
1374
1375 err = ipgre_newlink_encap_setup(dev, data);
1376 if (err)
1377 return err;
1378
1379 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1380 if (err)
1381 return err;
1382 return ip_tunnel_newlink(dev, tb, &p, fwmark);
1383}
1384
1385static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
1386 struct nlattr *data[],
1387 struct netlink_ext_ack *extack)
1388{
1389 struct ip_tunnel *t = netdev_priv(dev);
1390 __u32 fwmark = t->fwmark;
1391 struct ip_tunnel_parm p;
1392 int err;
1393
1394 err = ipgre_newlink_encap_setup(dev, data);
1395 if (err)
1396 return err;
1397
1398 err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
1399 if (err < 0)
1400 return err;
1401
1402 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1403 if (err < 0)
1404 return err;
1405
1406 t->parms.i_flags = p.i_flags;
1407 t->parms.o_flags = p.o_flags;
1408
1409 ipgre_link_update(dev, !tb[IFLA_MTU]);
1410
1411 return 0;
1412}
1413
1414static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
1415 struct nlattr *data[],
1416 struct netlink_ext_ack *extack)
1417{
1418 struct ip_tunnel *t = netdev_priv(dev);
1419 __u32 fwmark = t->fwmark;
1420 struct ip_tunnel_parm p;
1421 int err;
1422
1423 err = ipgre_newlink_encap_setup(dev, data);
1424 if (err)
1425 return err;
1426
1427 err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
1428 if (err < 0)
1429 return err;
1430
1431 err = ip_tunnel_changelink(dev, tb, &p, fwmark);
1432 if (err < 0)
1433 return err;
1434
1435 t->parms.i_flags = p.i_flags;
1436 t->parms.o_flags = p.o_flags;
1437
1438 return 0;
1439}
1440
1441static size_t ipgre_get_size(const struct net_device *dev)
1442{
1443 return
1444 /* IFLA_GRE_LINK */
1445 nla_total_size(4) +
1446 /* IFLA_GRE_IFLAGS */
1447 nla_total_size(2) +
1448 /* IFLA_GRE_OFLAGS */
1449 nla_total_size(2) +
1450 /* IFLA_GRE_IKEY */
1451 nla_total_size(4) +
1452 /* IFLA_GRE_OKEY */
1453 nla_total_size(4) +
1454 /* IFLA_GRE_LOCAL */
1455 nla_total_size(4) +
1456 /* IFLA_GRE_REMOTE */
1457 nla_total_size(4) +
1458 /* IFLA_GRE_TTL */
1459 nla_total_size(1) +
1460 /* IFLA_GRE_TOS */
1461 nla_total_size(1) +
1462 /* IFLA_GRE_PMTUDISC */
1463 nla_total_size(1) +
1464 /* IFLA_GRE_ENCAP_TYPE */
1465 nla_total_size(2) +
1466 /* IFLA_GRE_ENCAP_FLAGS */
1467 nla_total_size(2) +
1468 /* IFLA_GRE_ENCAP_SPORT */
1469 nla_total_size(2) +
1470 /* IFLA_GRE_ENCAP_DPORT */
1471 nla_total_size(2) +
1472 /* IFLA_GRE_COLLECT_METADATA */
1473 nla_total_size(0) +
1474 /* IFLA_GRE_IGNORE_DF */
1475 nla_total_size(1) +
1476 /* IFLA_GRE_FWMARK */
1477 nla_total_size(4) +
1478 /* IFLA_GRE_ERSPAN_INDEX */
1479 nla_total_size(4) +
1480 /* IFLA_GRE_ERSPAN_VER */
1481 nla_total_size(1) +
1482 /* IFLA_GRE_ERSPAN_DIR */
1483 nla_total_size(1) +
1484 /* IFLA_GRE_ERSPAN_HWID */
1485 nla_total_size(2) +
1486 0;
1487}
1488
1489static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
1490{
1491 struct ip_tunnel *t = netdev_priv(dev);
1492 struct ip_tunnel_parm *p = &t->parms;
1493 __be16 o_flags = p->o_flags;
1494
1495 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1496 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1497 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1498 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1499 gre_tnl_flags_to_gre_flags(o_flags)) ||
1500 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1501 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1502 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1503 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1504 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1505 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1506 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1507 !!(p->iph.frag_off & htons(IP_DF))) ||
1508 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1509 goto nla_put_failure;
1510
1511 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1512 t->encap.type) ||
1513 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1514 t->encap.sport) ||
1515 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1516 t->encap.dport) ||
1517 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1518 t->encap.flags))
1519 goto nla_put_failure;
1520
1521 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1522 goto nla_put_failure;
1523
1524 if (t->collect_md) {
1525 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1526 goto nla_put_failure;
1527 }
1528
1529 return 0;
1530
1531nla_put_failure:
1532 return -EMSGSIZE;
1533}
1534
1535static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
1536{
1537 struct ip_tunnel *t = netdev_priv(dev);
1538
1539 if (t->erspan_ver <= 2) {
1540 if (t->erspan_ver != 0 && !t->collect_md)
1541 t->parms.o_flags |= TUNNEL_KEY;
1542
1543 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1544 goto nla_put_failure;
1545
1546 if (t->erspan_ver == 1) {
1547 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1548 goto nla_put_failure;
1549 } else if (t->erspan_ver == 2) {
1550 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1551 goto nla_put_failure;
1552 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1553 goto nla_put_failure;
1554 }
1555 }
1556
1557 return ipgre_fill_info(skb, dev);
1558
1559nla_put_failure:
1560 return -EMSGSIZE;
1561}
1562
1563static void erspan_setup(struct net_device *dev)
1564{
1565 struct ip_tunnel *t = netdev_priv(dev);
1566
1567 ether_setup(dev);
1568 dev->max_mtu = 0;
1569 dev->netdev_ops = &erspan_netdev_ops;
1570 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1571 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1572 ip_tunnel_setup(dev, erspan_net_id);
1573 t->erspan_ver = 1;
1574}
1575
1576static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1577 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1578 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1579 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1580 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1581 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1582 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1583 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1584 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1585 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1586 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1587 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1588 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1589 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1590 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1591 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1592 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1593 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1594 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1595 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1596 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1597 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1598};
1599
1600static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1601 .kind = "gre",
1602 .maxtype = IFLA_GRE_MAX,
1603 .policy = ipgre_policy,
1604 .priv_size = sizeof(struct ip_tunnel),
1605 .setup = ipgre_tunnel_setup,
1606 .validate = ipgre_tunnel_validate,
1607 .newlink = ipgre_newlink,
1608 .changelink = ipgre_changelink,
1609 .dellink = ip_tunnel_dellink,
1610 .get_size = ipgre_get_size,
1611 .fill_info = ipgre_fill_info,
1612 .get_link_net = ip_tunnel_get_link_net,
1613};
1614
1615static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1616 .kind = "gretap",
1617 .maxtype = IFLA_GRE_MAX,
1618 .policy = ipgre_policy,
1619 .priv_size = sizeof(struct ip_tunnel),
1620 .setup = ipgre_tap_setup,
1621 .validate = ipgre_tap_validate,
1622 .newlink = ipgre_newlink,
1623 .changelink = ipgre_changelink,
1624 .dellink = ip_tunnel_dellink,
1625 .get_size = ipgre_get_size,
1626 .fill_info = ipgre_fill_info,
1627 .get_link_net = ip_tunnel_get_link_net,
1628};
1629
1630static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1631 .kind = "erspan",
1632 .maxtype = IFLA_GRE_MAX,
1633 .policy = ipgre_policy,
1634 .priv_size = sizeof(struct ip_tunnel),
1635 .setup = erspan_setup,
1636 .validate = erspan_validate,
1637 .newlink = erspan_newlink,
1638 .changelink = erspan_changelink,
1639 .dellink = ip_tunnel_dellink,
1640 .get_size = ipgre_get_size,
1641 .fill_info = erspan_fill_info,
1642 .get_link_net = ip_tunnel_get_link_net,
1643};
1644
1645struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1646 u8 name_assign_type)
1647{
1648 struct nlattr *tb[IFLA_MAX + 1];
1649 struct net_device *dev;
1650 LIST_HEAD(list_kill);
1651 struct ip_tunnel *t;
1652 int err;
1653
1654 memset(&tb, 0, sizeof(tb));
1655
1656 dev = rtnl_create_link(net, name, name_assign_type,
1657 &ipgre_tap_ops, tb, NULL);
1658 if (IS_ERR(dev))
1659 return dev;
1660
1661 /* Configure flow based GRE device. */
1662 t = netdev_priv(dev);
1663 t->collect_md = true;
1664
1665 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1666 if (err < 0) {
1667 free_netdev(dev);
1668 return ERR_PTR(err);
1669 }
1670
1671 /* openvswitch users expect packet sizes to be unrestricted,
1672 * so set the largest MTU we can.
1673 */
1674 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1675 if (err)
1676 goto out;
1677
1678 err = rtnl_configure_link(dev, NULL, 0, NULL);
1679 if (err < 0)
1680 goto out;
1681
1682 return dev;
1683out:
1684 ip_tunnel_dellink(dev, &list_kill);
1685 unregister_netdevice_many(&list_kill);
1686 return ERR_PTR(err);
1687}
1688EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1689
1690static int __net_init ipgre_tap_init_net(struct net *net)
1691{
1692 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1693}
1694
1695static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
1696{
1697 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
1698}
1699
1700static struct pernet_operations ipgre_tap_net_ops = {
1701 .init = ipgre_tap_init_net,
1702 .exit_batch = ipgre_tap_exit_batch_net,
1703 .id = &gre_tap_net_id,
1704 .size = sizeof(struct ip_tunnel_net),
1705};
1706
1707static int __net_init erspan_init_net(struct net *net)
1708{
1709 return ip_tunnel_init_net(net, erspan_net_id,
1710 &erspan_link_ops, "erspan0");
1711}
1712
1713static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
1714{
1715 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
1716}
1717
1718static struct pernet_operations erspan_net_ops = {
1719 .init = erspan_init_net,
1720 .exit_batch = erspan_exit_batch_net,
1721 .id = &erspan_net_id,
1722 .size = sizeof(struct ip_tunnel_net),
1723};
1724
1725static int __init ipgre_init(void)
1726{
1727 int err;
1728
1729 pr_info("GRE over IPv4 tunneling driver\n");
1730
1731 err = register_pernet_device(&ipgre_net_ops);
1732 if (err < 0)
1733 return err;
1734
1735 err = register_pernet_device(&ipgre_tap_net_ops);
1736 if (err < 0)
1737 goto pnet_tap_failed;
1738
1739 err = register_pernet_device(&erspan_net_ops);
1740 if (err < 0)
1741 goto pnet_erspan_failed;
1742
1743 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1744 if (err < 0) {
1745 pr_info("%s: can't add protocol\n", __func__);
1746 goto add_proto_failed;
1747 }
1748
1749 err = rtnl_link_register(&ipgre_link_ops);
1750 if (err < 0)
1751 goto rtnl_link_failed;
1752
1753 err = rtnl_link_register(&ipgre_tap_ops);
1754 if (err < 0)
1755 goto tap_ops_failed;
1756
1757 err = rtnl_link_register(&erspan_link_ops);
1758 if (err < 0)
1759 goto erspan_link_failed;
1760
1761 return 0;
1762
1763erspan_link_failed:
1764 rtnl_link_unregister(&ipgre_tap_ops);
1765tap_ops_failed:
1766 rtnl_link_unregister(&ipgre_link_ops);
1767rtnl_link_failed:
1768 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1769add_proto_failed:
1770 unregister_pernet_device(&erspan_net_ops);
1771pnet_erspan_failed:
1772 unregister_pernet_device(&ipgre_tap_net_ops);
1773pnet_tap_failed:
1774 unregister_pernet_device(&ipgre_net_ops);
1775 return err;
1776}
1777
1778static void __exit ipgre_fini(void)
1779{
1780 rtnl_link_unregister(&ipgre_tap_ops);
1781 rtnl_link_unregister(&ipgre_link_ops);
1782 rtnl_link_unregister(&erspan_link_ops);
1783 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1784 unregister_pernet_device(&ipgre_tap_net_ops);
1785 unregister_pernet_device(&ipgre_net_ops);
1786 unregister_pernet_device(&erspan_net_ops);
1787}
1788
1789module_init(ipgre_init);
1790module_exit(ipgre_fini);
1791MODULE_LICENSE("GPL");
1792MODULE_ALIAS_RTNL_LINK("gre");
1793MODULE_ALIAS_RTNL_LINK("gretap");
1794MODULE_ALIAS_RTNL_LINK("erspan");
1795MODULE_ALIAS_NETDEV("gre0");
1796MODULE_ALIAS_NETDEV("gretap0");
1797MODULE_ALIAS_NETDEV("erspan0");