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Merge tag 'arm-soc/for-5.20/defconfig-arm64' of https://github.com/Broadcom/stblinux...
[people/ms/linux.git] / net / ipv4 / ip_gre.c
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
105 static bool log_ecn_error = true;
106 module_param(log_ecn_error, bool, 0644);
107 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
108
109 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
110 static const struct header_ops ipgre_header_ops;
111
112 static int ipgre_tunnel_init(struct net_device *dev);
113 static void erspan_build_header(struct sk_buff *skb,
114 u32 id, u32 index,
115 bool truncate, bool is_ipv4);
116
117 static unsigned int ipgre_net_id __read_mostly;
118 static unsigned int gre_tap_net_id __read_mostly;
119 static unsigned int erspan_net_id __read_mostly;
120
121 static 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
214 static 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
253 static 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
262 static 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
346 drop:
347 kfree_skb(skb);
348 return PACKET_RCVD;
349 }
350
351 static 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
394 drop:
395 kfree_skb(skb);
396 return PACKET_RCVD;
397 }
398
399 static 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
422 static int gre_rcv(struct sk_buff *skb)
423 {
424 struct tnl_ptk_info tpi;
425 bool csum_err = false;
426 int hdr_len;
427
428 #ifdef CONFIG_NET_IPGRE_BROADCAST
429 if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
430 /* Looped back packet, drop it! */
431 if (rt_is_output_route(skb_rtable(skb)))
432 goto drop;
433 }
434 #endif
435
436 hdr_len = 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
450 out:
451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
452 drop:
453 kfree_skb(skb);
454 return 0;
455 }
456
457 static 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
472 static 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
477 static 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
511 err_free_skb:
512 kfree_skb(skb);
513 dev->stats.tx_dropped++;
514 }
515
516 static 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
593 err_free_skb:
594 kfree_skb(skb);
595 dev->stats.tx_dropped++;
596 }
597
598 static 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));
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
622 static 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
664 free_skb:
665 kfree_skb(skb);
666 dev->stats.tx_dropped++;
667 return NETDEV_TX_OK;
668 }
669
670 static 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
718 free_skb:
719 kfree_skb(skb);
720 dev->stats.tx_dropped++;
721 return NETDEV_TX_OK;
722 }
723
724 static 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
746 free_skb:
747 kfree_skb(skb);
748 dev->stats.tx_dropped++;
749 return NETDEV_TX_OK;
750 }
751
752 static 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
783 static 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 */
844 static 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
870 static 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
877 static const struct header_ops ipgre_header_ops = {
878 .create = ipgre_header,
879 .parse = ipgre_header_parse,
880 };
881
882 #ifdef CONFIG_NET_IPGRE_BROADCAST
883 static 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
909 static 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
923 static 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
943 static 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
950 static 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
979 static 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
1013 static const struct gre_protocol ipgre_protocol = {
1014 .handler = gre_rcv,
1015 .err_handler = gre_err,
1016 };
1017
1018 static 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
1023 static 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
1028 static 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
1035 static 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
1059 static 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
1080 out:
1081 return ipgre_tunnel_validate(tb, data, extack);
1082 }
1083
1084 static 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
1124 static 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
1191 static 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 */
1236 static 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
1269 static 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
1278 static 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
1290 static 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
1311 static 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
1323 static 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
1333 static int
1334 ipgre_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
1349 static 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
1367 static 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
1385 static 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
1414 static 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
1441 static 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
1489 static 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 (t->erspan_ver <= 2) {
1496 if (t->erspan_ver != 0 && !t->collect_md)
1497 o_flags |= TUNNEL_KEY;
1498
1499 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
1500 goto nla_put_failure;
1501
1502 if (t->erspan_ver == 1) {
1503 if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
1504 goto nla_put_failure;
1505 } else if (t->erspan_ver == 2) {
1506 if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
1507 goto nla_put_failure;
1508 if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
1509 goto nla_put_failure;
1510 }
1511 }
1512
1513 if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
1514 nla_put_be16(skb, IFLA_GRE_IFLAGS,
1515 gre_tnl_flags_to_gre_flags(p->i_flags)) ||
1516 nla_put_be16(skb, IFLA_GRE_OFLAGS,
1517 gre_tnl_flags_to_gre_flags(o_flags)) ||
1518 nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
1519 nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
1520 nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
1521 nla_put_in_addr(skb, IFLA_GRE_REMOTE, p->iph.daddr) ||
1522 nla_put_u8(skb, IFLA_GRE_TTL, p->iph.ttl) ||
1523 nla_put_u8(skb, IFLA_GRE_TOS, p->iph.tos) ||
1524 nla_put_u8(skb, IFLA_GRE_PMTUDISC,
1525 !!(p->iph.frag_off & htons(IP_DF))) ||
1526 nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
1527 goto nla_put_failure;
1528
1529 if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
1530 t->encap.type) ||
1531 nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
1532 t->encap.sport) ||
1533 nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
1534 t->encap.dport) ||
1535 nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
1536 t->encap.flags))
1537 goto nla_put_failure;
1538
1539 if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
1540 goto nla_put_failure;
1541
1542 if (t->collect_md) {
1543 if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
1544 goto nla_put_failure;
1545 }
1546
1547 return 0;
1548
1549 nla_put_failure:
1550 return -EMSGSIZE;
1551 }
1552
1553 static void erspan_setup(struct net_device *dev)
1554 {
1555 struct ip_tunnel *t = netdev_priv(dev);
1556
1557 ether_setup(dev);
1558 dev->max_mtu = 0;
1559 dev->netdev_ops = &erspan_netdev_ops;
1560 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1561 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1562 ip_tunnel_setup(dev, erspan_net_id);
1563 t->erspan_ver = 1;
1564 }
1565
1566 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
1567 [IFLA_GRE_LINK] = { .type = NLA_U32 },
1568 [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
1569 [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
1570 [IFLA_GRE_IKEY] = { .type = NLA_U32 },
1571 [IFLA_GRE_OKEY] = { .type = NLA_U32 },
1572 [IFLA_GRE_LOCAL] = { .len = sizeof_field(struct iphdr, saddr) },
1573 [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
1574 [IFLA_GRE_TTL] = { .type = NLA_U8 },
1575 [IFLA_GRE_TOS] = { .type = NLA_U8 },
1576 [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
1577 [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
1578 [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
1579 [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
1580 [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
1581 [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
1582 [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
1583 [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
1584 [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
1585 [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
1586 [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
1587 [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
1588 };
1589
1590 static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
1591 .kind = "gre",
1592 .maxtype = IFLA_GRE_MAX,
1593 .policy = ipgre_policy,
1594 .priv_size = sizeof(struct ip_tunnel),
1595 .setup = ipgre_tunnel_setup,
1596 .validate = ipgre_tunnel_validate,
1597 .newlink = ipgre_newlink,
1598 .changelink = ipgre_changelink,
1599 .dellink = ip_tunnel_dellink,
1600 .get_size = ipgre_get_size,
1601 .fill_info = ipgre_fill_info,
1602 .get_link_net = ip_tunnel_get_link_net,
1603 };
1604
1605 static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
1606 .kind = "gretap",
1607 .maxtype = IFLA_GRE_MAX,
1608 .policy = ipgre_policy,
1609 .priv_size = sizeof(struct ip_tunnel),
1610 .setup = ipgre_tap_setup,
1611 .validate = ipgre_tap_validate,
1612 .newlink = ipgre_newlink,
1613 .changelink = ipgre_changelink,
1614 .dellink = ip_tunnel_dellink,
1615 .get_size = ipgre_get_size,
1616 .fill_info = ipgre_fill_info,
1617 .get_link_net = ip_tunnel_get_link_net,
1618 };
1619
1620 static struct rtnl_link_ops erspan_link_ops __read_mostly = {
1621 .kind = "erspan",
1622 .maxtype = IFLA_GRE_MAX,
1623 .policy = ipgre_policy,
1624 .priv_size = sizeof(struct ip_tunnel),
1625 .setup = erspan_setup,
1626 .validate = erspan_validate,
1627 .newlink = erspan_newlink,
1628 .changelink = erspan_changelink,
1629 .dellink = ip_tunnel_dellink,
1630 .get_size = ipgre_get_size,
1631 .fill_info = ipgre_fill_info,
1632 .get_link_net = ip_tunnel_get_link_net,
1633 };
1634
1635 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
1636 u8 name_assign_type)
1637 {
1638 struct nlattr *tb[IFLA_MAX + 1];
1639 struct net_device *dev;
1640 LIST_HEAD(list_kill);
1641 struct ip_tunnel *t;
1642 int err;
1643
1644 memset(&tb, 0, sizeof(tb));
1645
1646 dev = rtnl_create_link(net, name, name_assign_type,
1647 &ipgre_tap_ops, tb, NULL);
1648 if (IS_ERR(dev))
1649 return dev;
1650
1651 /* Configure flow based GRE device. */
1652 t = netdev_priv(dev);
1653 t->collect_md = true;
1654
1655 err = ipgre_newlink(net, dev, tb, NULL, NULL);
1656 if (err < 0) {
1657 free_netdev(dev);
1658 return ERR_PTR(err);
1659 }
1660
1661 /* openvswitch users expect packet sizes to be unrestricted,
1662 * so set the largest MTU we can.
1663 */
1664 err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
1665 if (err)
1666 goto out;
1667
1668 err = rtnl_configure_link(dev, NULL);
1669 if (err < 0)
1670 goto out;
1671
1672 return dev;
1673 out:
1674 ip_tunnel_dellink(dev, &list_kill);
1675 unregister_netdevice_many(&list_kill);
1676 return ERR_PTR(err);
1677 }
1678 EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
1679
1680 static int __net_init ipgre_tap_init_net(struct net *net)
1681 {
1682 return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
1683 }
1684
1685 static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
1686 {
1687 ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
1688 }
1689
1690 static struct pernet_operations ipgre_tap_net_ops = {
1691 .init = ipgre_tap_init_net,
1692 .exit_batch = ipgre_tap_exit_batch_net,
1693 .id = &gre_tap_net_id,
1694 .size = sizeof(struct ip_tunnel_net),
1695 };
1696
1697 static int __net_init erspan_init_net(struct net *net)
1698 {
1699 return ip_tunnel_init_net(net, erspan_net_id,
1700 &erspan_link_ops, "erspan0");
1701 }
1702
1703 static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
1704 {
1705 ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
1706 }
1707
1708 static struct pernet_operations erspan_net_ops = {
1709 .init = erspan_init_net,
1710 .exit_batch = erspan_exit_batch_net,
1711 .id = &erspan_net_id,
1712 .size = sizeof(struct ip_tunnel_net),
1713 };
1714
1715 static int __init ipgre_init(void)
1716 {
1717 int err;
1718
1719 pr_info("GRE over IPv4 tunneling driver\n");
1720
1721 err = register_pernet_device(&ipgre_net_ops);
1722 if (err < 0)
1723 return err;
1724
1725 err = register_pernet_device(&ipgre_tap_net_ops);
1726 if (err < 0)
1727 goto pnet_tap_failed;
1728
1729 err = register_pernet_device(&erspan_net_ops);
1730 if (err < 0)
1731 goto pnet_erspan_failed;
1732
1733 err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
1734 if (err < 0) {
1735 pr_info("%s: can't add protocol\n", __func__);
1736 goto add_proto_failed;
1737 }
1738
1739 err = rtnl_link_register(&ipgre_link_ops);
1740 if (err < 0)
1741 goto rtnl_link_failed;
1742
1743 err = rtnl_link_register(&ipgre_tap_ops);
1744 if (err < 0)
1745 goto tap_ops_failed;
1746
1747 err = rtnl_link_register(&erspan_link_ops);
1748 if (err < 0)
1749 goto erspan_link_failed;
1750
1751 return 0;
1752
1753 erspan_link_failed:
1754 rtnl_link_unregister(&ipgre_tap_ops);
1755 tap_ops_failed:
1756 rtnl_link_unregister(&ipgre_link_ops);
1757 rtnl_link_failed:
1758 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1759 add_proto_failed:
1760 unregister_pernet_device(&erspan_net_ops);
1761 pnet_erspan_failed:
1762 unregister_pernet_device(&ipgre_tap_net_ops);
1763 pnet_tap_failed:
1764 unregister_pernet_device(&ipgre_net_ops);
1765 return err;
1766 }
1767
1768 static void __exit ipgre_fini(void)
1769 {
1770 rtnl_link_unregister(&ipgre_tap_ops);
1771 rtnl_link_unregister(&ipgre_link_ops);
1772 rtnl_link_unregister(&erspan_link_ops);
1773 gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
1774 unregister_pernet_device(&ipgre_tap_net_ops);
1775 unregister_pernet_device(&ipgre_net_ops);
1776 unregister_pernet_device(&erspan_net_ops);
1777 }
1778
1779 module_init(ipgre_init);
1780 module_exit(ipgre_fini);
1781 MODULE_LICENSE("GPL");
1782 MODULE_ALIAS_RTNL_LINK("gre");
1783 MODULE_ALIAS_RTNL_LINK("gretap");
1784 MODULE_ALIAS_RTNL_LINK("erspan");
1785 MODULE_ALIAS_NETDEV("gre0");
1786 MODULE_ALIAS_NETDEV("gretap0");
1787 MODULE_ALIAS_NETDEV("erspan0");
Michael's Linux tree.