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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux NET3: IP/IP protocol decoder.
4 *
5 * Authors:
6 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
7 *
8 * Fixes:
9 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
10 * a module taking up 2 pages).
11 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
12 * to keep ip_forward happy.
13 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
14 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
15 * David Woodhouse : Perform some basic ICMP handling.
16 * IPIP Routing without decapsulation.
17 * Carlos Picoto : GRE over IP support
18 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
19 * I do not want to merge them together.
20 */
21
22/* tunnel.c: an IP tunnel driver
23
24 The purpose of this driver is to provide an IP tunnel through
25 which you can tunnel network traffic transparently across subnets.
26
27 This was written by looking at Nick Holloway's dummy driver
28 Thanks for the great code!
29
30 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
31
32 Minor tweaks:
33 Cleaned up the code a little and added some pre-1.3.0 tweaks.
34 dev->hard_header/hard_header_len changed to use no headers.
35 Comments/bracketing tweaked.
36 Made the tunnels use dev->name not tunnel: when error reporting.
37 Added tx_dropped stat
38
39 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
40
41 Reworked:
42 Changed to tunnel to destination gateway in addition to the
43 tunnel's pointopoint address
44 Almost completely rewritten
45 Note: There is currently no firewall or ICMP handling done.
46
47 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
48
49*/
50
51/* Things I wish I had known when writing the tunnel driver:
52
53 When the tunnel_xmit() function is called, the skb contains the
54 packet to be sent (plus a great deal of extra info), and dev
55 contains the tunnel device that _we_ are.
56
57 When we are passed a packet, we are expected to fill in the
58 source address with our source IP address.
59
60 What is the proper way to allocate, copy and free a buffer?
61 After you allocate it, it is a "0 length" chunk of memory
62 starting at zero. If you want to add headers to the buffer
63 later, you'll have to call "skb_reserve(skb, amount)" with
64 the amount of memory you want reserved. Then, you call
65 "skb_put(skb, amount)" with the amount of space you want in
66 the buffer. skb_put() returns a pointer to the top (#0) of
67 that buffer. skb->len is set to the amount of space you have
68 "allocated" with skb_put(). You can then write up to skb->len
69 bytes to that buffer. If you need more, you can call skb_put()
70 again with the additional amount of space you need. You can
71 find out how much more space you can allocate by calling
72 "skb_tailroom(skb)".
73 Now, to add header space, call "skb_push(skb, header_len)".
74 This creates space at the beginning of the buffer and returns
75 a pointer to this new space. If later you need to strip a
76 header from a buffer, call "skb_pull(skb, header_len)".
77 skb_headroom() will return how much space is left at the top
78 of the buffer (before the main data). Remember, this headroom
79 space must be reserved before the skb_put() function is called.
80 */
81
82/*
83 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
84
85 For comments look at net/ipv4/ip_gre.c --ANK
86 */
87
88
89#include <linux/capability.h>
90#include <linux/module.h>
91#include <linux/types.h>
92#include <linux/kernel.h>
93#include <linux/slab.h>
94#include <linux/uaccess.h>
95#include <linux/skbuff.h>
96#include <linux/netdevice.h>
97#include <linux/in.h>
98#include <linux/tcp.h>
99#include <linux/udp.h>
100#include <linux/if_arp.h>
101#include <linux/init.h>
102#include <linux/netfilter_ipv4.h>
103#include <linux/if_ether.h>
104
105#include <net/sock.h>
106#include <net/ip.h>
107#include <net/icmp.h>
108#include <net/ip_tunnels.h>
109#include <net/inet_ecn.h>
110#include <net/xfrm.h>
111#include <net/net_namespace.h>
112#include <net/netns/generic.h>
113#include <net/dst_metadata.h>
114
115static bool log_ecn_error = true;
116module_param(log_ecn_error, bool, 0644);
117MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
118
119static unsigned int ipip_net_id __read_mostly;
120
121static int ipip_tunnel_init(struct net_device *dev);
122static struct rtnl_link_ops ipip_link_ops __read_mostly;
123
124static int ipip_err(struct sk_buff *skb, u32 info)
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 struct net *net = dev_net(skb->dev);
131 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
132 const struct iphdr *iph = (const struct iphdr *)skb->data;
133 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
134 const int type = icmp_hdr(skb)->type;
135 const int code = icmp_hdr(skb)->code;
136 struct ip_tunnel *t;
137 int err = 0;
138
139 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
140
141 t = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->daddr,
142 iph->saddr, 0);
143 if (!t) {
144 err = -ENOENT;
145 goto out;
146 }
147
148 switch (type) {
149 case ICMP_DEST_UNREACH:
150 switch (code) {
151 case ICMP_SR_FAILED:
152 /* Impossible event. */
153 goto out;
154 default:
155 /* All others are translated to HOST_UNREACH.
156 * rfc2003 contains "deep thoughts" about NET_UNREACH,
157 * I believe they are just ether pollution. --ANK
158 */
159 break;
160 }
161 break;
162
163 case ICMP_TIME_EXCEEDED:
164 if (code != ICMP_EXC_TTL)
165 goto out;
166 break;
167
168 case ICMP_REDIRECT:
169 break;
170
171 default:
172 goto out;
173 }
174
175 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
176 ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
177 goto out;
178 }
179
180 if (type == ICMP_REDIRECT) {
181 ipv4_redirect(skb, net, t->parms.link, iph->protocol);
182 goto out;
183 }
184
185 if (t->parms.iph.daddr == 0) {
186 err = -ENOENT;
187 goto out;
188 }
189
190 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
191 goto out;
192
193 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
194 t->err_count++;
195 else
196 t->err_count = 1;
197 t->err_time = jiffies;
198
199out:
200 return err;
201}
202
203static const struct tnl_ptk_info ipip_tpi = {
204 /* no tunnel info required for ipip. */
205 .proto = htons(ETH_P_IP),
206};
207
208#if IS_ENABLED(CONFIG_MPLS)
209static const struct tnl_ptk_info mplsip_tpi = {
210 /* no tunnel info required for mplsip. */
211 .proto = htons(ETH_P_MPLS_UC),
212};
213#endif
214
215static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
216{
217 struct net *net = dev_net(skb->dev);
218 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
219 IP_TUNNEL_DECLARE_FLAGS(flags) = { };
220 struct metadata_dst *tun_dst = NULL;
221 struct ip_tunnel *tunnel;
222 const struct iphdr *iph;
223
224 __set_bit(IP_TUNNEL_NO_KEY_BIT, flags);
225
226 iph = ip_hdr(skb);
227 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, flags, iph->saddr,
228 iph->daddr, 0);
229 if (tunnel) {
230 const struct tnl_ptk_info *tpi;
231
232 if (tunnel->parms.iph.protocol != ipproto &&
233 tunnel->parms.iph.protocol != 0)
234 goto drop;
235
236 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
237 goto drop;
238#if IS_ENABLED(CONFIG_MPLS)
239 if (ipproto == IPPROTO_MPLS)
240 tpi = &mplsip_tpi;
241 else
242#endif
243 tpi = &ipip_tpi;
244 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
245 goto drop;
246 if (tunnel->collect_md) {
247 ip_tunnel_flags_zero(flags);
248
249 tun_dst = ip_tun_rx_dst(skb, flags, 0, 0);
250 if (!tun_dst)
251 return 0;
252 ip_tunnel_md_udp_encap(skb, &tun_dst->u.tun_info);
253 }
254 skb_reset_mac_header(skb);
255
256 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
257 }
258
259 return -1;
260
261drop:
262 kfree_skb(skb);
263 return 0;
264}
265
266static int ipip_rcv(struct sk_buff *skb)
267{
268 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
269}
270
271#if IS_ENABLED(CONFIG_MPLS)
272static int mplsip_rcv(struct sk_buff *skb)
273{
274 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
275}
276#endif
277
278/*
279 * This function assumes it is being called from dev_queue_xmit()
280 * and that skb is filled properly by that function.
281 */
282static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
283 struct net_device *dev)
284{
285 struct ip_tunnel *tunnel = netdev_priv(dev);
286 const struct iphdr *tiph = &tunnel->parms.iph;
287 u8 ipproto;
288
289 if (!pskb_inet_may_pull(skb))
290 goto tx_error;
291
292 switch (skb->protocol) {
293 case htons(ETH_P_IP):
294 ipproto = IPPROTO_IPIP;
295 break;
296#if IS_ENABLED(CONFIG_MPLS)
297 case htons(ETH_P_MPLS_UC):
298 ipproto = IPPROTO_MPLS;
299 break;
300#endif
301 default:
302 goto tx_error;
303 }
304
305 if (tiph->protocol != ipproto && tiph->protocol != 0)
306 goto tx_error;
307
308 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
309 goto tx_error;
310
311 skb_set_inner_ipproto(skb, ipproto);
312
313 if (tunnel->collect_md)
314 ip_md_tunnel_xmit(skb, dev, ipproto, 0);
315 else
316 ip_tunnel_xmit(skb, dev, tiph, ipproto);
317 return NETDEV_TX_OK;
318
319tx_error:
320 kfree_skb(skb);
321
322 DEV_STATS_INC(dev, tx_errors);
323 return NETDEV_TX_OK;
324}
325
326static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
327{
328 switch (ipproto) {
329 case 0:
330 case IPPROTO_IPIP:
331#if IS_ENABLED(CONFIG_MPLS)
332 case IPPROTO_MPLS:
333#endif
334 return true;
335 }
336
337 return false;
338}
339
340static int
341ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p, int cmd)
342{
343 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
344 if (p->iph.version != 4 ||
345 !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||
346 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
347 return -EINVAL;
348 }
349
350 p->i_key = p->o_key = 0;
351 ip_tunnel_flags_zero(p->i_flags);
352 ip_tunnel_flags_zero(p->o_flags);
353 return ip_tunnel_ctl(dev, p, cmd);
354}
355
356static const struct net_device_ops ipip_netdev_ops = {
357 .ndo_init = ipip_tunnel_init,
358 .ndo_uninit = ip_tunnel_uninit,
359 .ndo_start_xmit = ipip_tunnel_xmit,
360 .ndo_siocdevprivate = ip_tunnel_siocdevprivate,
361 .ndo_change_mtu = ip_tunnel_change_mtu,
362 .ndo_get_stats64 = dev_get_tstats64,
363 .ndo_get_iflink = ip_tunnel_get_iflink,
364 .ndo_tunnel_ctl = ipip_tunnel_ctl,
365};
366
367#define IPIP_FEATURES (NETIF_F_SG | \
368 NETIF_F_FRAGLIST | \
369 NETIF_F_HIGHDMA | \
370 NETIF_F_GSO_SOFTWARE | \
371 NETIF_F_HW_CSUM)
372
373static void ipip_tunnel_setup(struct net_device *dev)
374{
375 dev->netdev_ops = &ipip_netdev_ops;
376 dev->header_ops = &ip_tunnel_header_ops;
377
378 dev->type = ARPHRD_TUNNEL;
379 dev->flags = IFF_NOARP;
380 dev->addr_len = 4;
381 dev->lltx = true;
382 netif_keep_dst(dev);
383
384 dev->features |= IPIP_FEATURES;
385 dev->hw_features |= IPIP_FEATURES;
386 ip_tunnel_setup(dev, ipip_net_id);
387}
388
389static int ipip_tunnel_init(struct net_device *dev)
390{
391 struct ip_tunnel *tunnel = netdev_priv(dev);
392
393 __dev_addr_set(dev, &tunnel->parms.iph.saddr, 4);
394 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
395
396 tunnel->tun_hlen = 0;
397 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
398 return ip_tunnel_init(dev);
399}
400
401static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
402 struct netlink_ext_ack *extack)
403{
404 u8 proto;
405
406 if (!data || !data[IFLA_IPTUN_PROTO])
407 return 0;
408
409 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
410 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
411 return -EINVAL;
412
413 return 0;
414}
415
416static void ipip_netlink_parms(struct nlattr *data[],
417 struct ip_tunnel_parm_kern *parms,
418 bool *collect_md, __u32 *fwmark)
419{
420 memset(parms, 0, sizeof(*parms));
421
422 parms->iph.version = 4;
423 parms->iph.protocol = IPPROTO_IPIP;
424 parms->iph.ihl = 5;
425 *collect_md = false;
426
427 if (!data)
428 return;
429
430 ip_tunnel_netlink_parms(data, parms);
431
432 if (data[IFLA_IPTUN_COLLECT_METADATA])
433 *collect_md = true;
434
435 if (data[IFLA_IPTUN_FWMARK])
436 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
437}
438
439static int ipip_newlink(struct net *src_net, struct net_device *dev,
440 struct nlattr *tb[], struct nlattr *data[],
441 struct netlink_ext_ack *extack)
442{
443 struct ip_tunnel *t = netdev_priv(dev);
444 struct ip_tunnel_encap ipencap;
445 struct ip_tunnel_parm_kern p;
446 __u32 fwmark = 0;
447
448 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
449 int err = ip_tunnel_encap_setup(t, &ipencap);
450
451 if (err < 0)
452 return err;
453 }
454
455 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
456 return ip_tunnel_newlink(dev, tb, &p, fwmark);
457}
458
459static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
460 struct nlattr *data[],
461 struct netlink_ext_ack *extack)
462{
463 struct ip_tunnel *t = netdev_priv(dev);
464 struct ip_tunnel_encap ipencap;
465 struct ip_tunnel_parm_kern p;
466 bool collect_md;
467 __u32 fwmark = t->fwmark;
468
469 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
470 int err = ip_tunnel_encap_setup(t, &ipencap);
471
472 if (err < 0)
473 return err;
474 }
475
476 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
477 if (collect_md)
478 return -EINVAL;
479
480 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
481 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
482 return -EINVAL;
483
484 return ip_tunnel_changelink(dev, tb, &p, fwmark);
485}
486
487static size_t ipip_get_size(const struct net_device *dev)
488{
489 return
490 /* IFLA_IPTUN_LINK */
491 nla_total_size(4) +
492 /* IFLA_IPTUN_LOCAL */
493 nla_total_size(4) +
494 /* IFLA_IPTUN_REMOTE */
495 nla_total_size(4) +
496 /* IFLA_IPTUN_TTL */
497 nla_total_size(1) +
498 /* IFLA_IPTUN_TOS */
499 nla_total_size(1) +
500 /* IFLA_IPTUN_PROTO */
501 nla_total_size(1) +
502 /* IFLA_IPTUN_PMTUDISC */
503 nla_total_size(1) +
504 /* IFLA_IPTUN_ENCAP_TYPE */
505 nla_total_size(2) +
506 /* IFLA_IPTUN_ENCAP_FLAGS */
507 nla_total_size(2) +
508 /* IFLA_IPTUN_ENCAP_SPORT */
509 nla_total_size(2) +
510 /* IFLA_IPTUN_ENCAP_DPORT */
511 nla_total_size(2) +
512 /* IFLA_IPTUN_COLLECT_METADATA */
513 nla_total_size(0) +
514 /* IFLA_IPTUN_FWMARK */
515 nla_total_size(4) +
516 0;
517}
518
519static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
520{
521 struct ip_tunnel *tunnel = netdev_priv(dev);
522 struct ip_tunnel_parm_kern *parm = &tunnel->parms;
523
524 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
525 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
526 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
527 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
528 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
529 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
530 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
531 !!(parm->iph.frag_off & htons(IP_DF))) ||
532 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
533 goto nla_put_failure;
534
535 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
536 tunnel->encap.type) ||
537 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
538 tunnel->encap.sport) ||
539 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
540 tunnel->encap.dport) ||
541 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
542 tunnel->encap.flags))
543 goto nla_put_failure;
544
545 if (tunnel->collect_md)
546 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
547 goto nla_put_failure;
548 return 0;
549
550nla_put_failure:
551 return -EMSGSIZE;
552}
553
554static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
555 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
556 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
557 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
558 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
559 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
560 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
561 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
562 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
563 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
564 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
565 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
566 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
567 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
568};
569
570static struct rtnl_link_ops ipip_link_ops __read_mostly = {
571 .kind = "ipip",
572 .maxtype = IFLA_IPTUN_MAX,
573 .policy = ipip_policy,
574 .priv_size = sizeof(struct ip_tunnel),
575 .setup = ipip_tunnel_setup,
576 .validate = ipip_tunnel_validate,
577 .newlink = ipip_newlink,
578 .changelink = ipip_changelink,
579 .dellink = ip_tunnel_dellink,
580 .get_size = ipip_get_size,
581 .fill_info = ipip_fill_info,
582 .get_link_net = ip_tunnel_get_link_net,
583};
584
585static struct xfrm_tunnel ipip_handler __read_mostly = {
586 .handler = ipip_rcv,
587 .err_handler = ipip_err,
588 .priority = 1,
589};
590
591#if IS_ENABLED(CONFIG_MPLS)
592static struct xfrm_tunnel mplsip_handler __read_mostly = {
593 .handler = mplsip_rcv,
594 .err_handler = ipip_err,
595 .priority = 1,
596};
597#endif
598
599static int __net_init ipip_init_net(struct net *net)
600{
601 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
602}
603
604static void __net_exit ipip_exit_batch_rtnl(struct list_head *list_net,
605 struct list_head *dev_to_kill)
606{
607 ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops,
608 dev_to_kill);
609}
610
611static struct pernet_operations ipip_net_ops = {
612 .init = ipip_init_net,
613 .exit_batch_rtnl = ipip_exit_batch_rtnl,
614 .id = &ipip_net_id,
615 .size = sizeof(struct ip_tunnel_net),
616};
617
618static int __init ipip_init(void)
619{
620 int err;
621
622 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
623
624 err = register_pernet_device(&ipip_net_ops);
625 if (err < 0)
626 return err;
627 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
628 if (err < 0) {
629 pr_info("%s: can't register tunnel\n", __func__);
630 goto xfrm_tunnel_ipip_failed;
631 }
632#if IS_ENABLED(CONFIG_MPLS)
633 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
634 if (err < 0) {
635 pr_info("%s: can't register tunnel\n", __func__);
636 goto xfrm_tunnel_mplsip_failed;
637 }
638#endif
639 err = rtnl_link_register(&ipip_link_ops);
640 if (err < 0)
641 goto rtnl_link_failed;
642
643out:
644 return err;
645
646rtnl_link_failed:
647#if IS_ENABLED(CONFIG_MPLS)
648 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
649xfrm_tunnel_mplsip_failed:
650
651#endif
652 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
653xfrm_tunnel_ipip_failed:
654 unregister_pernet_device(&ipip_net_ops);
655 goto out;
656}
657
658static void __exit ipip_fini(void)
659{
660 rtnl_link_unregister(&ipip_link_ops);
661 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
662 pr_info("%s: can't deregister tunnel\n", __func__);
663#if IS_ENABLED(CONFIG_MPLS)
664 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
665 pr_info("%s: can't deregister tunnel\n", __func__);
666#endif
667 unregister_pernet_device(&ipip_net_ops);
668}
669
670module_init(ipip_init);
671module_exit(ipip_fini);
672MODULE_DESCRIPTION("IP/IP protocol decoder library");
673MODULE_LICENSE("GPL");
674MODULE_ALIAS_RTNL_LINK("ipip");
675MODULE_ALIAS_NETDEV("tunl0");
1/*
2 * Linux NET3: IP/IP protocol decoder.
3 *
4 * Authors:
5 * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
6 *
7 * Fixes:
8 * Alan Cox : Merged and made usable non modular (its so tiny its silly as
9 * a module taking up 2 pages).
10 * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
11 * to keep ip_forward happy.
12 * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
13 * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
14 * David Woodhouse : Perform some basic ICMP handling.
15 * IPIP Routing without decapsulation.
16 * Carlos Picoto : GRE over IP support
17 * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
18 * I do not want to merge them together.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 *
25 */
26
27/* tunnel.c: an IP tunnel driver
28
29 The purpose of this driver is to provide an IP tunnel through
30 which you can tunnel network traffic transparently across subnets.
31
32 This was written by looking at Nick Holloway's dummy driver
33 Thanks for the great code!
34
35 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
36
37 Minor tweaks:
38 Cleaned up the code a little and added some pre-1.3.0 tweaks.
39 dev->hard_header/hard_header_len changed to use no headers.
40 Comments/bracketing tweaked.
41 Made the tunnels use dev->name not tunnel: when error reporting.
42 Added tx_dropped stat
43
44 -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
45
46 Reworked:
47 Changed to tunnel to destination gateway in addition to the
48 tunnel's pointopoint address
49 Almost completely rewritten
50 Note: There is currently no firewall or ICMP handling done.
51
52 -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
53
54*/
55
56/* Things I wish I had known when writing the tunnel driver:
57
58 When the tunnel_xmit() function is called, the skb contains the
59 packet to be sent (plus a great deal of extra info), and dev
60 contains the tunnel device that _we_ are.
61
62 When we are passed a packet, we are expected to fill in the
63 source address with our source IP address.
64
65 What is the proper way to allocate, copy and free a buffer?
66 After you allocate it, it is a "0 length" chunk of memory
67 starting at zero. If you want to add headers to the buffer
68 later, you'll have to call "skb_reserve(skb, amount)" with
69 the amount of memory you want reserved. Then, you call
70 "skb_put(skb, amount)" with the amount of space you want in
71 the buffer. skb_put() returns a pointer to the top (#0) of
72 that buffer. skb->len is set to the amount of space you have
73 "allocated" with skb_put(). You can then write up to skb->len
74 bytes to that buffer. If you need more, you can call skb_put()
75 again with the additional amount of space you need. You can
76 find out how much more space you can allocate by calling
77 "skb_tailroom(skb)".
78 Now, to add header space, call "skb_push(skb, header_len)".
79 This creates space at the beginning of the buffer and returns
80 a pointer to this new space. If later you need to strip a
81 header from a buffer, call "skb_pull(skb, header_len)".
82 skb_headroom() will return how much space is left at the top
83 of the buffer (before the main data). Remember, this headroom
84 space must be reserved before the skb_put() function is called.
85 */
86
87/*
88 This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
89
90 For comments look at net/ipv4/ip_gre.c --ANK
91 */
92
93
94#include <linux/capability.h>
95#include <linux/module.h>
96#include <linux/types.h>
97#include <linux/kernel.h>
98#include <linux/slab.h>
99#include <asm/uaccess.h>
100#include <linux/skbuff.h>
101#include <linux/netdevice.h>
102#include <linux/in.h>
103#include <linux/tcp.h>
104#include <linux/udp.h>
105#include <linux/if_arp.h>
106#include <linux/mroute.h>
107#include <linux/init.h>
108#include <linux/netfilter_ipv4.h>
109#include <linux/if_ether.h>
110
111#include <net/sock.h>
112#include <net/ip.h>
113#include <net/icmp.h>
114#include <net/ipip.h>
115#include <net/inet_ecn.h>
116#include <net/xfrm.h>
117#include <net/net_namespace.h>
118#include <net/netns/generic.h>
119
120#define HASH_SIZE 16
121#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
122
123static int ipip_net_id __read_mostly;
124struct ipip_net {
125 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
126 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
127 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
128 struct ip_tunnel __rcu *tunnels_wc[1];
129 struct ip_tunnel __rcu **tunnels[4];
130
131 struct net_device *fb_tunnel_dev;
132};
133
134static int ipip_tunnel_init(struct net_device *dev);
135static void ipip_tunnel_setup(struct net_device *dev);
136static void ipip_dev_free(struct net_device *dev);
137
138/*
139 * Locking : hash tables are protected by RCU and RTNL
140 */
141
142#define for_each_ip_tunnel_rcu(start) \
143 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
144
145/* often modified stats are per cpu, other are shared (netdev->stats) */
146struct pcpu_tstats {
147 u64 rx_packets;
148 u64 rx_bytes;
149 u64 tx_packets;
150 u64 tx_bytes;
151 struct u64_stats_sync syncp;
152};
153
154static struct rtnl_link_stats64 *ipip_get_stats64(struct net_device *dev,
155 struct rtnl_link_stats64 *tot)
156{
157 int i;
158
159 for_each_possible_cpu(i) {
160 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
161 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
162 unsigned int start;
163
164 do {
165 start = u64_stats_fetch_begin_bh(&tstats->syncp);
166 rx_packets = tstats->rx_packets;
167 tx_packets = tstats->tx_packets;
168 rx_bytes = tstats->rx_bytes;
169 tx_bytes = tstats->tx_bytes;
170 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
171
172 tot->rx_packets += rx_packets;
173 tot->tx_packets += tx_packets;
174 tot->rx_bytes += rx_bytes;
175 tot->tx_bytes += tx_bytes;
176 }
177
178 tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
179 tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
180 tot->tx_dropped = dev->stats.tx_dropped;
181 tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
182 tot->tx_errors = dev->stats.tx_errors;
183 tot->collisions = dev->stats.collisions;
184
185 return tot;
186}
187
188static struct ip_tunnel *ipip_tunnel_lookup(struct net *net,
189 __be32 remote, __be32 local)
190{
191 unsigned int h0 = HASH(remote);
192 unsigned int h1 = HASH(local);
193 struct ip_tunnel *t;
194 struct ipip_net *ipn = net_generic(net, ipip_net_id);
195
196 for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1])
197 if (local == t->parms.iph.saddr &&
198 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
199 return t;
200
201 for_each_ip_tunnel_rcu(ipn->tunnels_r[h0])
202 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
203 return t;
204
205 for_each_ip_tunnel_rcu(ipn->tunnels_l[h1])
206 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
207 return t;
208
209 t = rcu_dereference(ipn->tunnels_wc[0]);
210 if (t && (t->dev->flags&IFF_UP))
211 return t;
212 return NULL;
213}
214
215static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn,
216 struct ip_tunnel_parm *parms)
217{
218 __be32 remote = parms->iph.daddr;
219 __be32 local = parms->iph.saddr;
220 unsigned int h = 0;
221 int prio = 0;
222
223 if (remote) {
224 prio |= 2;
225 h ^= HASH(remote);
226 }
227 if (local) {
228 prio |= 1;
229 h ^= HASH(local);
230 }
231 return &ipn->tunnels[prio][h];
232}
233
234static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn,
235 struct ip_tunnel *t)
236{
237 return __ipip_bucket(ipn, &t->parms);
238}
239
240static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
241{
242 struct ip_tunnel __rcu **tp;
243 struct ip_tunnel *iter;
244
245 for (tp = ipip_bucket(ipn, t);
246 (iter = rtnl_dereference(*tp)) != NULL;
247 tp = &iter->next) {
248 if (t == iter) {
249 rcu_assign_pointer(*tp, t->next);
250 break;
251 }
252 }
253}
254
255static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
256{
257 struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t);
258
259 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
260 rcu_assign_pointer(*tp, t);
261}
262
263static struct ip_tunnel *ipip_tunnel_locate(struct net *net,
264 struct ip_tunnel_parm *parms, int create)
265{
266 __be32 remote = parms->iph.daddr;
267 __be32 local = parms->iph.saddr;
268 struct ip_tunnel *t, *nt;
269 struct ip_tunnel __rcu **tp;
270 struct net_device *dev;
271 char name[IFNAMSIZ];
272 struct ipip_net *ipn = net_generic(net, ipip_net_id);
273
274 for (tp = __ipip_bucket(ipn, parms);
275 (t = rtnl_dereference(*tp)) != NULL;
276 tp = &t->next) {
277 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
278 return t;
279 }
280 if (!create)
281 return NULL;
282
283 if (parms->name[0])
284 strlcpy(name, parms->name, IFNAMSIZ);
285 else
286 strcpy(name, "tunl%d");
287
288 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
289 if (dev == NULL)
290 return NULL;
291
292 dev_net_set(dev, net);
293
294 nt = netdev_priv(dev);
295 nt->parms = *parms;
296
297 if (ipip_tunnel_init(dev) < 0)
298 goto failed_free;
299
300 if (register_netdevice(dev) < 0)
301 goto failed_free;
302
303 strcpy(nt->parms.name, dev->name);
304
305 dev_hold(dev);
306 ipip_tunnel_link(ipn, nt);
307 return nt;
308
309failed_free:
310 ipip_dev_free(dev);
311 return NULL;
312}
313
314/* called with RTNL */
315static void ipip_tunnel_uninit(struct net_device *dev)
316{
317 struct net *net = dev_net(dev);
318 struct ipip_net *ipn = net_generic(net, ipip_net_id);
319
320 if (dev == ipn->fb_tunnel_dev)
321 RCU_INIT_POINTER(ipn->tunnels_wc[0], NULL);
322 else
323 ipip_tunnel_unlink(ipn, netdev_priv(dev));
324 dev_put(dev);
325}
326
327static int ipip_err(struct sk_buff *skb, u32 info)
328{
329
330/* All the routers (except for Linux) return only
331 8 bytes of packet payload. It means, that precise relaying of
332 ICMP in the real Internet is absolutely infeasible.
333 */
334 const struct iphdr *iph = (const struct iphdr *)skb->data;
335 const int type = icmp_hdr(skb)->type;
336 const int code = icmp_hdr(skb)->code;
337 struct ip_tunnel *t;
338 int err;
339
340 switch (type) {
341 default:
342 case ICMP_PARAMETERPROB:
343 return 0;
344
345 case ICMP_DEST_UNREACH:
346 switch (code) {
347 case ICMP_SR_FAILED:
348 case ICMP_PORT_UNREACH:
349 /* Impossible event. */
350 return 0;
351 case ICMP_FRAG_NEEDED:
352 /* Soft state for pmtu is maintained by IP core. */
353 return 0;
354 default:
355 /* All others are translated to HOST_UNREACH.
356 rfc2003 contains "deep thoughts" about NET_UNREACH,
357 I believe they are just ether pollution. --ANK
358 */
359 break;
360 }
361 break;
362 case ICMP_TIME_EXCEEDED:
363 if (code != ICMP_EXC_TTL)
364 return 0;
365 break;
366 }
367
368 err = -ENOENT;
369
370 rcu_read_lock();
371 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
372 if (t == NULL || t->parms.iph.daddr == 0)
373 goto out;
374
375 err = 0;
376 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
377 goto out;
378
379 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
380 t->err_count++;
381 else
382 t->err_count = 1;
383 t->err_time = jiffies;
384out:
385 rcu_read_unlock();
386 return err;
387}
388
389static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
390 struct sk_buff *skb)
391{
392 struct iphdr *inner_iph = ip_hdr(skb);
393
394 if (INET_ECN_is_ce(outer_iph->tos))
395 IP_ECN_set_ce(inner_iph);
396}
397
398static int ipip_rcv(struct sk_buff *skb)
399{
400 struct ip_tunnel *tunnel;
401 const struct iphdr *iph = ip_hdr(skb);
402
403 rcu_read_lock();
404 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
405 if (tunnel != NULL) {
406 struct pcpu_tstats *tstats;
407
408 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
409 rcu_read_unlock();
410 kfree_skb(skb);
411 return 0;
412 }
413
414 secpath_reset(skb);
415
416 skb->mac_header = skb->network_header;
417 skb_reset_network_header(skb);
418 skb->protocol = htons(ETH_P_IP);
419 skb->pkt_type = PACKET_HOST;
420
421 tstats = this_cpu_ptr(tunnel->dev->tstats);
422 u64_stats_update_begin(&tstats->syncp);
423 tstats->rx_packets++;
424 tstats->rx_bytes += skb->len;
425 u64_stats_update_end(&tstats->syncp);
426
427 __skb_tunnel_rx(skb, tunnel->dev);
428
429 ipip_ecn_decapsulate(iph, skb);
430
431 netif_rx(skb);
432
433 rcu_read_unlock();
434 return 0;
435 }
436 rcu_read_unlock();
437
438 return -1;
439}
440
441/*
442 * This function assumes it is being called from dev_queue_xmit()
443 * and that skb is filled properly by that function.
444 */
445
446static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
447{
448 struct ip_tunnel *tunnel = netdev_priv(dev);
449 struct pcpu_tstats *tstats;
450 const struct iphdr *tiph = &tunnel->parms.iph;
451 u8 tos = tunnel->parms.iph.tos;
452 __be16 df = tiph->frag_off;
453 struct rtable *rt; /* Route to the other host */
454 struct net_device *tdev; /* Device to other host */
455 const struct iphdr *old_iph = ip_hdr(skb);
456 struct iphdr *iph; /* Our new IP header */
457 unsigned int max_headroom; /* The extra header space needed */
458 __be32 dst = tiph->daddr;
459 struct flowi4 fl4;
460 int mtu;
461
462 if (skb->protocol != htons(ETH_P_IP))
463 goto tx_error;
464
465 if (tos & 1)
466 tos = old_iph->tos;
467
468 if (!dst) {
469 /* NBMA tunnel */
470 if ((rt = skb_rtable(skb)) == NULL) {
471 dev->stats.tx_fifo_errors++;
472 goto tx_error;
473 }
474 dst = rt->rt_gateway;
475 }
476
477 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
478 dst, tiph->saddr,
479 0, 0,
480 IPPROTO_IPIP, RT_TOS(tos),
481 tunnel->parms.link);
482 if (IS_ERR(rt)) {
483 dev->stats.tx_carrier_errors++;
484 goto tx_error_icmp;
485 }
486 tdev = rt->dst.dev;
487
488 if (tdev == dev) {
489 ip_rt_put(rt);
490 dev->stats.collisions++;
491 goto tx_error;
492 }
493
494 df |= old_iph->frag_off & htons(IP_DF);
495
496 if (df) {
497 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
498
499 if (mtu < 68) {
500 dev->stats.collisions++;
501 ip_rt_put(rt);
502 goto tx_error;
503 }
504
505 if (skb_dst(skb))
506 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
507
508 if ((old_iph->frag_off & htons(IP_DF)) &&
509 mtu < ntohs(old_iph->tot_len)) {
510 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
511 htonl(mtu));
512 ip_rt_put(rt);
513 goto tx_error;
514 }
515 }
516
517 if (tunnel->err_count > 0) {
518 if (time_before(jiffies,
519 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
520 tunnel->err_count--;
521 dst_link_failure(skb);
522 } else
523 tunnel->err_count = 0;
524 }
525
526 /*
527 * Okay, now see if we can stuff it in the buffer as-is.
528 */
529 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
530
531 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
532 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
533 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
534 if (!new_skb) {
535 ip_rt_put(rt);
536 dev->stats.tx_dropped++;
537 dev_kfree_skb(skb);
538 return NETDEV_TX_OK;
539 }
540 if (skb->sk)
541 skb_set_owner_w(new_skb, skb->sk);
542 dev_kfree_skb(skb);
543 skb = new_skb;
544 old_iph = ip_hdr(skb);
545 }
546
547 skb->transport_header = skb->network_header;
548 skb_push(skb, sizeof(struct iphdr));
549 skb_reset_network_header(skb);
550 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
551 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
552 IPSKB_REROUTED);
553 skb_dst_drop(skb);
554 skb_dst_set(skb, &rt->dst);
555
556 /*
557 * Push down and install the IPIP header.
558 */
559
560 iph = ip_hdr(skb);
561 iph->version = 4;
562 iph->ihl = sizeof(struct iphdr)>>2;
563 iph->frag_off = df;
564 iph->protocol = IPPROTO_IPIP;
565 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos);
566 iph->daddr = fl4.daddr;
567 iph->saddr = fl4.saddr;
568
569 if ((iph->ttl = tiph->ttl) == 0)
570 iph->ttl = old_iph->ttl;
571
572 nf_reset(skb);
573 tstats = this_cpu_ptr(dev->tstats);
574 __IPTUNNEL_XMIT(tstats, &dev->stats);
575 return NETDEV_TX_OK;
576
577tx_error_icmp:
578 dst_link_failure(skb);
579tx_error:
580 dev->stats.tx_errors++;
581 dev_kfree_skb(skb);
582 return NETDEV_TX_OK;
583}
584
585static void ipip_tunnel_bind_dev(struct net_device *dev)
586{
587 struct net_device *tdev = NULL;
588 struct ip_tunnel *tunnel;
589 const struct iphdr *iph;
590
591 tunnel = netdev_priv(dev);
592 iph = &tunnel->parms.iph;
593
594 if (iph->daddr) {
595 struct rtable *rt;
596 struct flowi4 fl4;
597
598 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
599 iph->daddr, iph->saddr,
600 0, 0,
601 IPPROTO_IPIP,
602 RT_TOS(iph->tos),
603 tunnel->parms.link);
604 if (!IS_ERR(rt)) {
605 tdev = rt->dst.dev;
606 ip_rt_put(rt);
607 }
608 dev->flags |= IFF_POINTOPOINT;
609 }
610
611 if (!tdev && tunnel->parms.link)
612 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
613
614 if (tdev) {
615 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
616 dev->mtu = tdev->mtu - sizeof(struct iphdr);
617 }
618 dev->iflink = tunnel->parms.link;
619}
620
621static int
622ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
623{
624 int err = 0;
625 struct ip_tunnel_parm p;
626 struct ip_tunnel *t;
627 struct net *net = dev_net(dev);
628 struct ipip_net *ipn = net_generic(net, ipip_net_id);
629
630 switch (cmd) {
631 case SIOCGETTUNNEL:
632 t = NULL;
633 if (dev == ipn->fb_tunnel_dev) {
634 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
635 err = -EFAULT;
636 break;
637 }
638 t = ipip_tunnel_locate(net, &p, 0);
639 }
640 if (t == NULL)
641 t = netdev_priv(dev);
642 memcpy(&p, &t->parms, sizeof(p));
643 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
644 err = -EFAULT;
645 break;
646
647 case SIOCADDTUNNEL:
648 case SIOCCHGTUNNEL:
649 err = -EPERM;
650 if (!capable(CAP_NET_ADMIN))
651 goto done;
652
653 err = -EFAULT;
654 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
655 goto done;
656
657 err = -EINVAL;
658 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
659 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
660 goto done;
661 if (p.iph.ttl)
662 p.iph.frag_off |= htons(IP_DF);
663
664 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
665
666 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
667 if (t != NULL) {
668 if (t->dev != dev) {
669 err = -EEXIST;
670 break;
671 }
672 } else {
673 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
674 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
675 err = -EINVAL;
676 break;
677 }
678 t = netdev_priv(dev);
679 ipip_tunnel_unlink(ipn, t);
680 synchronize_net();
681 t->parms.iph.saddr = p.iph.saddr;
682 t->parms.iph.daddr = p.iph.daddr;
683 memcpy(dev->dev_addr, &p.iph.saddr, 4);
684 memcpy(dev->broadcast, &p.iph.daddr, 4);
685 ipip_tunnel_link(ipn, t);
686 netdev_state_change(dev);
687 }
688 }
689
690 if (t) {
691 err = 0;
692 if (cmd == SIOCCHGTUNNEL) {
693 t->parms.iph.ttl = p.iph.ttl;
694 t->parms.iph.tos = p.iph.tos;
695 t->parms.iph.frag_off = p.iph.frag_off;
696 if (t->parms.link != p.link) {
697 t->parms.link = p.link;
698 ipip_tunnel_bind_dev(dev);
699 netdev_state_change(dev);
700 }
701 }
702 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
703 err = -EFAULT;
704 } else
705 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
706 break;
707
708 case SIOCDELTUNNEL:
709 err = -EPERM;
710 if (!capable(CAP_NET_ADMIN))
711 goto done;
712
713 if (dev == ipn->fb_tunnel_dev) {
714 err = -EFAULT;
715 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
716 goto done;
717 err = -ENOENT;
718 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
719 goto done;
720 err = -EPERM;
721 if (t->dev == ipn->fb_tunnel_dev)
722 goto done;
723 dev = t->dev;
724 }
725 unregister_netdevice(dev);
726 err = 0;
727 break;
728
729 default:
730 err = -EINVAL;
731 }
732
733done:
734 return err;
735}
736
737static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
738{
739 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
740 return -EINVAL;
741 dev->mtu = new_mtu;
742 return 0;
743}
744
745static const struct net_device_ops ipip_netdev_ops = {
746 .ndo_uninit = ipip_tunnel_uninit,
747 .ndo_start_xmit = ipip_tunnel_xmit,
748 .ndo_do_ioctl = ipip_tunnel_ioctl,
749 .ndo_change_mtu = ipip_tunnel_change_mtu,
750 .ndo_get_stats64 = ipip_get_stats64,
751};
752
753static void ipip_dev_free(struct net_device *dev)
754{
755 free_percpu(dev->tstats);
756 free_netdev(dev);
757}
758
759static void ipip_tunnel_setup(struct net_device *dev)
760{
761 dev->netdev_ops = &ipip_netdev_ops;
762 dev->destructor = ipip_dev_free;
763
764 dev->type = ARPHRD_TUNNEL;
765 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
766 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
767 dev->flags = IFF_NOARP;
768 dev->iflink = 0;
769 dev->addr_len = 4;
770 dev->features |= NETIF_F_NETNS_LOCAL;
771 dev->features |= NETIF_F_LLTX;
772 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
773}
774
775static int ipip_tunnel_init(struct net_device *dev)
776{
777 struct ip_tunnel *tunnel = netdev_priv(dev);
778
779 tunnel->dev = dev;
780
781 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
782 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
783
784 ipip_tunnel_bind_dev(dev);
785
786 dev->tstats = alloc_percpu(struct pcpu_tstats);
787 if (!dev->tstats)
788 return -ENOMEM;
789
790 return 0;
791}
792
793static int __net_init ipip_fb_tunnel_init(struct net_device *dev)
794{
795 struct ip_tunnel *tunnel = netdev_priv(dev);
796 struct iphdr *iph = &tunnel->parms.iph;
797 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
798
799 tunnel->dev = dev;
800 strcpy(tunnel->parms.name, dev->name);
801
802 iph->version = 4;
803 iph->protocol = IPPROTO_IPIP;
804 iph->ihl = 5;
805
806 dev->tstats = alloc_percpu(struct pcpu_tstats);
807 if (!dev->tstats)
808 return -ENOMEM;
809
810 dev_hold(dev);
811 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
812 return 0;
813}
814
815static struct xfrm_tunnel ipip_handler __read_mostly = {
816 .handler = ipip_rcv,
817 .err_handler = ipip_err,
818 .priority = 1,
819};
820
821static const char banner[] __initconst =
822 KERN_INFO "IPv4 over IPv4 tunneling driver\n";
823
824static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
825{
826 int prio;
827
828 for (prio = 1; prio < 4; prio++) {
829 int h;
830 for (h = 0; h < HASH_SIZE; h++) {
831 struct ip_tunnel *t;
832
833 t = rtnl_dereference(ipn->tunnels[prio][h]);
834 while (t != NULL) {
835 unregister_netdevice_queue(t->dev, head);
836 t = rtnl_dereference(t->next);
837 }
838 }
839 }
840}
841
842static int __net_init ipip_init_net(struct net *net)
843{
844 struct ipip_net *ipn = net_generic(net, ipip_net_id);
845 struct ip_tunnel *t;
846 int err;
847
848 ipn->tunnels[0] = ipn->tunnels_wc;
849 ipn->tunnels[1] = ipn->tunnels_l;
850 ipn->tunnels[2] = ipn->tunnels_r;
851 ipn->tunnels[3] = ipn->tunnels_r_l;
852
853 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
854 "tunl0",
855 ipip_tunnel_setup);
856 if (!ipn->fb_tunnel_dev) {
857 err = -ENOMEM;
858 goto err_alloc_dev;
859 }
860 dev_net_set(ipn->fb_tunnel_dev, net);
861
862 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
863 if (err)
864 goto err_reg_dev;
865
866 if ((err = register_netdev(ipn->fb_tunnel_dev)))
867 goto err_reg_dev;
868
869 t = netdev_priv(ipn->fb_tunnel_dev);
870
871 strcpy(t->parms.name, ipn->fb_tunnel_dev->name);
872 return 0;
873
874err_reg_dev:
875 ipip_dev_free(ipn->fb_tunnel_dev);
876err_alloc_dev:
877 /* nothing */
878 return err;
879}
880
881static void __net_exit ipip_exit_net(struct net *net)
882{
883 struct ipip_net *ipn = net_generic(net, ipip_net_id);
884 LIST_HEAD(list);
885
886 rtnl_lock();
887 ipip_destroy_tunnels(ipn, &list);
888 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
889 unregister_netdevice_many(&list);
890 rtnl_unlock();
891}
892
893static struct pernet_operations ipip_net_ops = {
894 .init = ipip_init_net,
895 .exit = ipip_exit_net,
896 .id = &ipip_net_id,
897 .size = sizeof(struct ipip_net),
898};
899
900static int __init ipip_init(void)
901{
902 int err;
903
904 printk(banner);
905
906 err = register_pernet_device(&ipip_net_ops);
907 if (err < 0)
908 return err;
909 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
910 if (err < 0) {
911 unregister_pernet_device(&ipip_net_ops);
912 pr_info("%s: can't register tunnel\n", __func__);
913 }
914 return err;
915}
916
917static void __exit ipip_fini(void)
918{
919 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
920 pr_info("%s: can't deregister tunnel\n", __func__);
921
922 unregister_pernet_device(&ipip_net_ops);
923}
924
925module_init(ipip_init);
926module_exit(ipip_fini);
927MODULE_LICENSE("GPL");
928MODULE_ALIAS_NETDEV("tunl0");