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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 <linux/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/init.h>
107#include <linux/netfilter_ipv4.h>
108#include <linux/if_ether.h>
109
110#include <net/sock.h>
111#include <net/ip.h>
112#include <net/icmp.h>
113#include <net/ip_tunnels.h>
114#include <net/inet_ecn.h>
115#include <net/xfrm.h>
116#include <net/net_namespace.h>
117#include <net/netns/generic.h>
118#include <net/dst_metadata.h>
119
120static bool log_ecn_error = true;
121module_param(log_ecn_error, bool, 0644);
122MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
123
124static unsigned int ipip_net_id __read_mostly;
125
126static int ipip_tunnel_init(struct net_device *dev);
127static struct rtnl_link_ops ipip_link_ops __read_mostly;
128
129static int ipip_err(struct sk_buff *skb, u32 info)
130{
131 /* All the routers (except for Linux) return only
132 * 8 bytes of packet payload. It means, that precise relaying of
133 * ICMP in the real Internet is absolutely infeasible.
134 */
135 struct net *net = dev_net(skb->dev);
136 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
137 const struct iphdr *iph = (const struct iphdr *)skb->data;
138 const int type = icmp_hdr(skb)->type;
139 const int code = icmp_hdr(skb)->code;
140 struct ip_tunnel *t;
141 int err = 0;
142
143 switch (type) {
144 case ICMP_DEST_UNREACH:
145 switch (code) {
146 case ICMP_SR_FAILED:
147 /* Impossible event. */
148 goto out;
149 default:
150 /* All others are translated to HOST_UNREACH.
151 * rfc2003 contains "deep thoughts" about NET_UNREACH,
152 * I believe they are just ether pollution. --ANK
153 */
154 break;
155 }
156 break;
157
158 case ICMP_TIME_EXCEEDED:
159 if (code != ICMP_EXC_TTL)
160 goto out;
161 break;
162
163 case ICMP_REDIRECT:
164 break;
165
166 default:
167 goto out;
168 }
169
170 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
171 iph->daddr, iph->saddr, 0);
172 if (!t) {
173 err = -ENOENT;
174 goto out;
175 }
176
177 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
178 ipv4_update_pmtu(skb, net, info, t->parms.link, 0,
179 iph->protocol, 0);
180 goto out;
181 }
182
183 if (type == ICMP_REDIRECT) {
184 ipv4_redirect(skb, net, t->parms.link, 0, iph->protocol, 0);
185 goto out;
186 }
187
188 if (t->parms.iph.daddr == 0) {
189 err = -ENOENT;
190 goto out;
191 }
192
193 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
194 goto out;
195
196 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
197 t->err_count++;
198 else
199 t->err_count = 1;
200 t->err_time = jiffies;
201
202out:
203 return err;
204}
205
206static const struct tnl_ptk_info ipip_tpi = {
207 /* no tunnel info required for ipip. */
208 .proto = htons(ETH_P_IP),
209};
210
211#if IS_ENABLED(CONFIG_MPLS)
212static const struct tnl_ptk_info mplsip_tpi = {
213 /* no tunnel info required for mplsip. */
214 .proto = htons(ETH_P_MPLS_UC),
215};
216#endif
217
218static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
219{
220 struct net *net = dev_net(skb->dev);
221 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
222 struct metadata_dst *tun_dst = NULL;
223 struct ip_tunnel *tunnel;
224 const struct iphdr *iph;
225
226 iph = ip_hdr(skb);
227 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
228 iph->saddr, 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 tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
248 if (!tun_dst)
249 return 0;
250 }
251 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
252 }
253
254 return -1;
255
256drop:
257 kfree_skb(skb);
258 return 0;
259}
260
261static int ipip_rcv(struct sk_buff *skb)
262{
263 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
264}
265
266#if IS_ENABLED(CONFIG_MPLS)
267static int mplsip_rcv(struct sk_buff *skb)
268{
269 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
270}
271#endif
272
273/*
274 * This function assumes it is being called from dev_queue_xmit()
275 * and that skb is filled properly by that function.
276 */
277static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
278 struct net_device *dev)
279{
280 struct ip_tunnel *tunnel = netdev_priv(dev);
281 const struct iphdr *tiph = &tunnel->parms.iph;
282 u8 ipproto;
283
284 switch (skb->protocol) {
285 case htons(ETH_P_IP):
286 ipproto = IPPROTO_IPIP;
287 break;
288#if IS_ENABLED(CONFIG_MPLS)
289 case htons(ETH_P_MPLS_UC):
290 ipproto = IPPROTO_MPLS;
291 break;
292#endif
293 default:
294 goto tx_error;
295 }
296
297 if (tiph->protocol != ipproto && tiph->protocol != 0)
298 goto tx_error;
299
300 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
301 goto tx_error;
302
303 skb_set_inner_ipproto(skb, ipproto);
304
305 if (tunnel->collect_md)
306 ip_md_tunnel_xmit(skb, dev, ipproto);
307 else
308 ip_tunnel_xmit(skb, dev, tiph, ipproto);
309 return NETDEV_TX_OK;
310
311tx_error:
312 kfree_skb(skb);
313
314 dev->stats.tx_errors++;
315 return NETDEV_TX_OK;
316}
317
318static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
319{
320 switch (ipproto) {
321 case 0:
322 case IPPROTO_IPIP:
323#if IS_ENABLED(CONFIG_MPLS)
324 case IPPROTO_MPLS:
325#endif
326 return true;
327 }
328
329 return false;
330}
331
332static int
333ipip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
334{
335 int err = 0;
336 struct ip_tunnel_parm p;
337
338 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
339 return -EFAULT;
340
341 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
342 if (p.iph.version != 4 ||
343 !ipip_tunnel_ioctl_verify_protocol(p.iph.protocol) ||
344 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
345 return -EINVAL;
346 }
347
348 p.i_key = p.o_key = 0;
349 p.i_flags = p.o_flags = 0;
350 err = ip_tunnel_ioctl(dev, &p, cmd);
351 if (err)
352 return err;
353
354 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
355 return -EFAULT;
356
357 return 0;
358}
359
360static const struct net_device_ops ipip_netdev_ops = {
361 .ndo_init = ipip_tunnel_init,
362 .ndo_uninit = ip_tunnel_uninit,
363 .ndo_start_xmit = ipip_tunnel_xmit,
364 .ndo_do_ioctl = ipip_tunnel_ioctl,
365 .ndo_change_mtu = ip_tunnel_change_mtu,
366 .ndo_get_stats64 = ip_tunnel_get_stats64,
367 .ndo_get_iflink = ip_tunnel_get_iflink,
368};
369
370#define IPIP_FEATURES (NETIF_F_SG | \
371 NETIF_F_FRAGLIST | \
372 NETIF_F_HIGHDMA | \
373 NETIF_F_GSO_SOFTWARE | \
374 NETIF_F_HW_CSUM)
375
376static void ipip_tunnel_setup(struct net_device *dev)
377{
378 dev->netdev_ops = &ipip_netdev_ops;
379
380 dev->type = ARPHRD_TUNNEL;
381 dev->flags = IFF_NOARP;
382 dev->addr_len = 4;
383 dev->features |= NETIF_F_LLTX;
384 netif_keep_dst(dev);
385
386 dev->features |= IPIP_FEATURES;
387 dev->hw_features |= IPIP_FEATURES;
388 ip_tunnel_setup(dev, ipip_net_id);
389}
390
391static int ipip_tunnel_init(struct net_device *dev)
392{
393 struct ip_tunnel *tunnel = netdev_priv(dev);
394
395 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
396 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
397
398 tunnel->tun_hlen = 0;
399 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
400 return ip_tunnel_init(dev);
401}
402
403static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
404 struct netlink_ext_ack *extack)
405{
406 u8 proto;
407
408 if (!data || !data[IFLA_IPTUN_PROTO])
409 return 0;
410
411 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
412 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
413 return -EINVAL;
414
415 return 0;
416}
417
418static void ipip_netlink_parms(struct nlattr *data[],
419 struct ip_tunnel_parm *parms, bool *collect_md,
420 __u32 *fwmark)
421{
422 memset(parms, 0, sizeof(*parms));
423
424 parms->iph.version = 4;
425 parms->iph.protocol = IPPROTO_IPIP;
426 parms->iph.ihl = 5;
427 *collect_md = false;
428
429 if (!data)
430 return;
431
432 if (data[IFLA_IPTUN_LINK])
433 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
434
435 if (data[IFLA_IPTUN_LOCAL])
436 parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
437
438 if (data[IFLA_IPTUN_REMOTE])
439 parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
440
441 if (data[IFLA_IPTUN_TTL]) {
442 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
443 if (parms->iph.ttl)
444 parms->iph.frag_off = htons(IP_DF);
445 }
446
447 if (data[IFLA_IPTUN_TOS])
448 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
449
450 if (data[IFLA_IPTUN_PROTO])
451 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
452
453 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
454 parms->iph.frag_off = htons(IP_DF);
455
456 if (data[IFLA_IPTUN_COLLECT_METADATA])
457 *collect_md = true;
458
459 if (data[IFLA_IPTUN_FWMARK])
460 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
461}
462
463/* This function returns true when ENCAP attributes are present in the nl msg */
464static bool ipip_netlink_encap_parms(struct nlattr *data[],
465 struct ip_tunnel_encap *ipencap)
466{
467 bool ret = false;
468
469 memset(ipencap, 0, sizeof(*ipencap));
470
471 if (!data)
472 return ret;
473
474 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
475 ret = true;
476 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
477 }
478
479 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
480 ret = true;
481 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
482 }
483
484 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
485 ret = true;
486 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
487 }
488
489 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
490 ret = true;
491 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
492 }
493
494 return ret;
495}
496
497static int ipip_newlink(struct net *src_net, struct net_device *dev,
498 struct nlattr *tb[], struct nlattr *data[],
499 struct netlink_ext_ack *extack)
500{
501 struct ip_tunnel *t = netdev_priv(dev);
502 struct ip_tunnel_parm p;
503 struct ip_tunnel_encap ipencap;
504 __u32 fwmark = 0;
505
506 if (ipip_netlink_encap_parms(data, &ipencap)) {
507 int err = ip_tunnel_encap_setup(t, &ipencap);
508
509 if (err < 0)
510 return err;
511 }
512
513 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
514 return ip_tunnel_newlink(dev, tb, &p, fwmark);
515}
516
517static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
518 struct nlattr *data[],
519 struct netlink_ext_ack *extack)
520{
521 struct ip_tunnel *t = netdev_priv(dev);
522 struct ip_tunnel_parm p;
523 struct ip_tunnel_encap ipencap;
524 bool collect_md;
525 __u32 fwmark = t->fwmark;
526
527 if (ipip_netlink_encap_parms(data, &ipencap)) {
528 int err = ip_tunnel_encap_setup(t, &ipencap);
529
530 if (err < 0)
531 return err;
532 }
533
534 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
535 if (collect_md)
536 return -EINVAL;
537
538 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
539 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
540 return -EINVAL;
541
542 return ip_tunnel_changelink(dev, tb, &p, fwmark);
543}
544
545static size_t ipip_get_size(const struct net_device *dev)
546{
547 return
548 /* IFLA_IPTUN_LINK */
549 nla_total_size(4) +
550 /* IFLA_IPTUN_LOCAL */
551 nla_total_size(4) +
552 /* IFLA_IPTUN_REMOTE */
553 nla_total_size(4) +
554 /* IFLA_IPTUN_TTL */
555 nla_total_size(1) +
556 /* IFLA_IPTUN_TOS */
557 nla_total_size(1) +
558 /* IFLA_IPTUN_PROTO */
559 nla_total_size(1) +
560 /* IFLA_IPTUN_PMTUDISC */
561 nla_total_size(1) +
562 /* IFLA_IPTUN_ENCAP_TYPE */
563 nla_total_size(2) +
564 /* IFLA_IPTUN_ENCAP_FLAGS */
565 nla_total_size(2) +
566 /* IFLA_IPTUN_ENCAP_SPORT */
567 nla_total_size(2) +
568 /* IFLA_IPTUN_ENCAP_DPORT */
569 nla_total_size(2) +
570 /* IFLA_IPTUN_COLLECT_METADATA */
571 nla_total_size(0) +
572 /* IFLA_IPTUN_FWMARK */
573 nla_total_size(4) +
574 0;
575}
576
577static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
578{
579 struct ip_tunnel *tunnel = netdev_priv(dev);
580 struct ip_tunnel_parm *parm = &tunnel->parms;
581
582 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
583 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
584 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
585 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
586 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
587 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
588 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
589 !!(parm->iph.frag_off & htons(IP_DF))) ||
590 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
591 goto nla_put_failure;
592
593 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
594 tunnel->encap.type) ||
595 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
596 tunnel->encap.sport) ||
597 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
598 tunnel->encap.dport) ||
599 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
600 tunnel->encap.flags))
601 goto nla_put_failure;
602
603 if (tunnel->collect_md)
604 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
605 goto nla_put_failure;
606 return 0;
607
608nla_put_failure:
609 return -EMSGSIZE;
610}
611
612static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
613 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
614 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
615 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
616 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
617 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
618 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
619 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
620 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
621 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
622 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
623 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
624 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
625 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
626};
627
628static struct rtnl_link_ops ipip_link_ops __read_mostly = {
629 .kind = "ipip",
630 .maxtype = IFLA_IPTUN_MAX,
631 .policy = ipip_policy,
632 .priv_size = sizeof(struct ip_tunnel),
633 .setup = ipip_tunnel_setup,
634 .validate = ipip_tunnel_validate,
635 .newlink = ipip_newlink,
636 .changelink = ipip_changelink,
637 .dellink = ip_tunnel_dellink,
638 .get_size = ipip_get_size,
639 .fill_info = ipip_fill_info,
640 .get_link_net = ip_tunnel_get_link_net,
641};
642
643static struct xfrm_tunnel ipip_handler __read_mostly = {
644 .handler = ipip_rcv,
645 .err_handler = ipip_err,
646 .priority = 1,
647};
648
649#if IS_ENABLED(CONFIG_MPLS)
650static struct xfrm_tunnel mplsip_handler __read_mostly = {
651 .handler = mplsip_rcv,
652 .err_handler = ipip_err,
653 .priority = 1,
654};
655#endif
656
657static int __net_init ipip_init_net(struct net *net)
658{
659 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
660}
661
662static void __net_exit ipip_exit_batch_net(struct list_head *list_net)
663{
664 ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops);
665}
666
667static struct pernet_operations ipip_net_ops = {
668 .init = ipip_init_net,
669 .exit_batch = ipip_exit_batch_net,
670 .id = &ipip_net_id,
671 .size = sizeof(struct ip_tunnel_net),
672};
673
674static int __init ipip_init(void)
675{
676 int err;
677
678 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
679
680 err = register_pernet_device(&ipip_net_ops);
681 if (err < 0)
682 return err;
683 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
684 if (err < 0) {
685 pr_info("%s: can't register tunnel\n", __func__);
686 goto xfrm_tunnel_ipip_failed;
687 }
688#if IS_ENABLED(CONFIG_MPLS)
689 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
690 if (err < 0) {
691 pr_info("%s: can't register tunnel\n", __func__);
692 goto xfrm_tunnel_mplsip_failed;
693 }
694#endif
695 err = rtnl_link_register(&ipip_link_ops);
696 if (err < 0)
697 goto rtnl_link_failed;
698
699out:
700 return err;
701
702rtnl_link_failed:
703#if IS_ENABLED(CONFIG_MPLS)
704 xfrm4_tunnel_deregister(&mplsip_handler, AF_INET);
705xfrm_tunnel_mplsip_failed:
706
707#endif
708 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
709xfrm_tunnel_ipip_failed:
710 unregister_pernet_device(&ipip_net_ops);
711 goto out;
712}
713
714static void __exit ipip_fini(void)
715{
716 rtnl_link_unregister(&ipip_link_ops);
717 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
718 pr_info("%s: can't deregister tunnel\n", __func__);
719#if IS_ENABLED(CONFIG_MPLS)
720 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
721 pr_info("%s: can't deregister tunnel\n", __func__);
722#endif
723 unregister_pernet_device(&ipip_net_ops);
724}
725
726module_init(ipip_init);
727module_exit(ipip_fini);
728MODULE_LICENSE("GPL");
729MODULE_ALIAS_RTNL_LINK("ipip");
730MODULE_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 unsigned long rx_packets;
148 unsigned long rx_bytes;
149 unsigned long tx_packets;
150 unsigned long tx_bytes;
151};
152
153static struct net_device_stats *ipip_get_stats(struct net_device *dev)
154{
155 struct pcpu_tstats sum = { 0 };
156 int i;
157
158 for_each_possible_cpu(i) {
159 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
160
161 sum.rx_packets += tstats->rx_packets;
162 sum.rx_bytes += tstats->rx_bytes;
163 sum.tx_packets += tstats->tx_packets;
164 sum.tx_bytes += tstats->tx_bytes;
165 }
166 dev->stats.rx_packets = sum.rx_packets;
167 dev->stats.rx_bytes = sum.rx_bytes;
168 dev->stats.tx_packets = sum.tx_packets;
169 dev->stats.tx_bytes = sum.tx_bytes;
170 return &dev->stats;
171}
172
173static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
174 __be32 remote, __be32 local)
175{
176 unsigned int h0 = HASH(remote);
177 unsigned int h1 = HASH(local);
178 struct ip_tunnel *t;
179 struct ipip_net *ipn = net_generic(net, ipip_net_id);
180
181 for_each_ip_tunnel_rcu(ipn->tunnels_r_l[h0 ^ h1])
182 if (local == t->parms.iph.saddr &&
183 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
184 return t;
185
186 for_each_ip_tunnel_rcu(ipn->tunnels_r[h0])
187 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
188 return t;
189
190 for_each_ip_tunnel_rcu(ipn->tunnels_l[h1])
191 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
192 return t;
193
194 t = rcu_dereference(ipn->tunnels_wc[0]);
195 if (t && (t->dev->flags&IFF_UP))
196 return t;
197 return NULL;
198}
199
200static struct ip_tunnel __rcu **__ipip_bucket(struct ipip_net *ipn,
201 struct ip_tunnel_parm *parms)
202{
203 __be32 remote = parms->iph.daddr;
204 __be32 local = parms->iph.saddr;
205 unsigned int h = 0;
206 int prio = 0;
207
208 if (remote) {
209 prio |= 2;
210 h ^= HASH(remote);
211 }
212 if (local) {
213 prio |= 1;
214 h ^= HASH(local);
215 }
216 return &ipn->tunnels[prio][h];
217}
218
219static inline struct ip_tunnel __rcu **ipip_bucket(struct ipip_net *ipn,
220 struct ip_tunnel *t)
221{
222 return __ipip_bucket(ipn, &t->parms);
223}
224
225static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
226{
227 struct ip_tunnel __rcu **tp;
228 struct ip_tunnel *iter;
229
230 for (tp = ipip_bucket(ipn, t);
231 (iter = rtnl_dereference(*tp)) != NULL;
232 tp = &iter->next) {
233 if (t == iter) {
234 rcu_assign_pointer(*tp, t->next);
235 break;
236 }
237 }
238}
239
240static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
241{
242 struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t);
243
244 rcu_assign_pointer(t->next, rtnl_dereference(*tp));
245 rcu_assign_pointer(*tp, t);
246}
247
248static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
249 struct ip_tunnel_parm *parms, int create)
250{
251 __be32 remote = parms->iph.daddr;
252 __be32 local = parms->iph.saddr;
253 struct ip_tunnel *t, *nt;
254 struct ip_tunnel __rcu **tp;
255 struct net_device *dev;
256 char name[IFNAMSIZ];
257 struct ipip_net *ipn = net_generic(net, ipip_net_id);
258
259 for (tp = __ipip_bucket(ipn, parms);
260 (t = rtnl_dereference(*tp)) != NULL;
261 tp = &t->next) {
262 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
263 return t;
264 }
265 if (!create)
266 return NULL;
267
268 if (parms->name[0])
269 strlcpy(name, parms->name, IFNAMSIZ);
270 else
271 strcpy(name, "tunl%d");
272
273 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
274 if (dev == NULL)
275 return NULL;
276
277 dev_net_set(dev, net);
278
279 nt = netdev_priv(dev);
280 nt->parms = *parms;
281
282 if (ipip_tunnel_init(dev) < 0)
283 goto failed_free;
284
285 if (register_netdevice(dev) < 0)
286 goto failed_free;
287
288 dev_hold(dev);
289 ipip_tunnel_link(ipn, nt);
290 return nt;
291
292failed_free:
293 ipip_dev_free(dev);
294 return NULL;
295}
296
297/* called with RTNL */
298static void ipip_tunnel_uninit(struct net_device *dev)
299{
300 struct net *net = dev_net(dev);
301 struct ipip_net *ipn = net_generic(net, ipip_net_id);
302
303 if (dev == ipn->fb_tunnel_dev)
304 rcu_assign_pointer(ipn->tunnels_wc[0], NULL);
305 else
306 ipip_tunnel_unlink(ipn, netdev_priv(dev));
307 dev_put(dev);
308}
309
310static int ipip_err(struct sk_buff *skb, u32 info)
311{
312
313/* All the routers (except for Linux) return only
314 8 bytes of packet payload. It means, that precise relaying of
315 ICMP in the real Internet is absolutely infeasible.
316 */
317 const struct iphdr *iph = (const struct iphdr *)skb->data;
318 const int type = icmp_hdr(skb)->type;
319 const int code = icmp_hdr(skb)->code;
320 struct ip_tunnel *t;
321 int err;
322
323 switch (type) {
324 default:
325 case ICMP_PARAMETERPROB:
326 return 0;
327
328 case ICMP_DEST_UNREACH:
329 switch (code) {
330 case ICMP_SR_FAILED:
331 case ICMP_PORT_UNREACH:
332 /* Impossible event. */
333 return 0;
334 case ICMP_FRAG_NEEDED:
335 /* Soft state for pmtu is maintained by IP core. */
336 return 0;
337 default:
338 /* All others are translated to HOST_UNREACH.
339 rfc2003 contains "deep thoughts" about NET_UNREACH,
340 I believe they are just ether pollution. --ANK
341 */
342 break;
343 }
344 break;
345 case ICMP_TIME_EXCEEDED:
346 if (code != ICMP_EXC_TTL)
347 return 0;
348 break;
349 }
350
351 err = -ENOENT;
352
353 rcu_read_lock();
354 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
355 if (t == NULL || t->parms.iph.daddr == 0)
356 goto out;
357
358 err = 0;
359 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
360 goto out;
361
362 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
363 t->err_count++;
364 else
365 t->err_count = 1;
366 t->err_time = jiffies;
367out:
368 rcu_read_unlock();
369 return err;
370}
371
372static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
373 struct sk_buff *skb)
374{
375 struct iphdr *inner_iph = ip_hdr(skb);
376
377 if (INET_ECN_is_ce(outer_iph->tos))
378 IP_ECN_set_ce(inner_iph);
379}
380
381static int ipip_rcv(struct sk_buff *skb)
382{
383 struct ip_tunnel *tunnel;
384 const struct iphdr *iph = ip_hdr(skb);
385
386 rcu_read_lock();
387 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
388 if (tunnel != NULL) {
389 struct pcpu_tstats *tstats;
390
391 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
392 rcu_read_unlock();
393 kfree_skb(skb);
394 return 0;
395 }
396
397 secpath_reset(skb);
398
399 skb->mac_header = skb->network_header;
400 skb_reset_network_header(skb);
401 skb->protocol = htons(ETH_P_IP);
402 skb->pkt_type = PACKET_HOST;
403
404 tstats = this_cpu_ptr(tunnel->dev->tstats);
405 tstats->rx_packets++;
406 tstats->rx_bytes += skb->len;
407
408 __skb_tunnel_rx(skb, tunnel->dev);
409
410 ipip_ecn_decapsulate(iph, skb);
411
412 netif_rx(skb);
413
414 rcu_read_unlock();
415 return 0;
416 }
417 rcu_read_unlock();
418
419 return -1;
420}
421
422/*
423 * This function assumes it is being called from dev_queue_xmit()
424 * and that skb is filled properly by that function.
425 */
426
427static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
428{
429 struct ip_tunnel *tunnel = netdev_priv(dev);
430 struct pcpu_tstats *tstats;
431 const struct iphdr *tiph = &tunnel->parms.iph;
432 u8 tos = tunnel->parms.iph.tos;
433 __be16 df = tiph->frag_off;
434 struct rtable *rt; /* Route to the other host */
435 struct net_device *tdev; /* Device to other host */
436 const struct iphdr *old_iph = ip_hdr(skb);
437 struct iphdr *iph; /* Our new IP header */
438 unsigned int max_headroom; /* The extra header space needed */
439 __be32 dst = tiph->daddr;
440 struct flowi4 fl4;
441 int mtu;
442
443 if (skb->protocol != htons(ETH_P_IP))
444 goto tx_error;
445
446 if (tos & 1)
447 tos = old_iph->tos;
448
449 if (!dst) {
450 /* NBMA tunnel */
451 if ((rt = skb_rtable(skb)) == NULL) {
452 dev->stats.tx_fifo_errors++;
453 goto tx_error;
454 }
455 if ((dst = rt->rt_gateway) == 0)
456 goto tx_error_icmp;
457 }
458
459 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
460 dst, tiph->saddr,
461 0, 0,
462 IPPROTO_IPIP, RT_TOS(tos),
463 tunnel->parms.link);
464 if (IS_ERR(rt)) {
465 dev->stats.tx_carrier_errors++;
466 goto tx_error_icmp;
467 }
468 tdev = rt->dst.dev;
469
470 if (tdev == dev) {
471 ip_rt_put(rt);
472 dev->stats.collisions++;
473 goto tx_error;
474 }
475
476 df |= old_iph->frag_off & htons(IP_DF);
477
478 if (df) {
479 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
480
481 if (mtu < 68) {
482 dev->stats.collisions++;
483 ip_rt_put(rt);
484 goto tx_error;
485 }
486
487 if (skb_dst(skb))
488 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
489
490 if ((old_iph->frag_off & htons(IP_DF)) &&
491 mtu < ntohs(old_iph->tot_len)) {
492 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
493 htonl(mtu));
494 ip_rt_put(rt);
495 goto tx_error;
496 }
497 }
498
499 if (tunnel->err_count > 0) {
500 if (time_before(jiffies,
501 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
502 tunnel->err_count--;
503 dst_link_failure(skb);
504 } else
505 tunnel->err_count = 0;
506 }
507
508 /*
509 * Okay, now see if we can stuff it in the buffer as-is.
510 */
511 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
512
513 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
514 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
515 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
516 if (!new_skb) {
517 ip_rt_put(rt);
518 dev->stats.tx_dropped++;
519 dev_kfree_skb(skb);
520 return NETDEV_TX_OK;
521 }
522 if (skb->sk)
523 skb_set_owner_w(new_skb, skb->sk);
524 dev_kfree_skb(skb);
525 skb = new_skb;
526 old_iph = ip_hdr(skb);
527 }
528
529 skb->transport_header = skb->network_header;
530 skb_push(skb, sizeof(struct iphdr));
531 skb_reset_network_header(skb);
532 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
533 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
534 IPSKB_REROUTED);
535 skb_dst_drop(skb);
536 skb_dst_set(skb, &rt->dst);
537
538 /*
539 * Push down and install the IPIP header.
540 */
541
542 iph = ip_hdr(skb);
543 iph->version = 4;
544 iph->ihl = sizeof(struct iphdr)>>2;
545 iph->frag_off = df;
546 iph->protocol = IPPROTO_IPIP;
547 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos);
548 iph->daddr = fl4.daddr;
549 iph->saddr = fl4.saddr;
550
551 if ((iph->ttl = tiph->ttl) == 0)
552 iph->ttl = old_iph->ttl;
553
554 nf_reset(skb);
555 tstats = this_cpu_ptr(dev->tstats);
556 __IPTUNNEL_XMIT(tstats, &dev->stats);
557 return NETDEV_TX_OK;
558
559tx_error_icmp:
560 dst_link_failure(skb);
561tx_error:
562 dev->stats.tx_errors++;
563 dev_kfree_skb(skb);
564 return NETDEV_TX_OK;
565}
566
567static void ipip_tunnel_bind_dev(struct net_device *dev)
568{
569 struct net_device *tdev = NULL;
570 struct ip_tunnel *tunnel;
571 const struct iphdr *iph;
572
573 tunnel = netdev_priv(dev);
574 iph = &tunnel->parms.iph;
575
576 if (iph->daddr) {
577 struct rtable *rt;
578 struct flowi4 fl4;
579
580 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
581 iph->daddr, iph->saddr,
582 0, 0,
583 IPPROTO_IPIP,
584 RT_TOS(iph->tos),
585 tunnel->parms.link);
586 if (!IS_ERR(rt)) {
587 tdev = rt->dst.dev;
588 ip_rt_put(rt);
589 }
590 dev->flags |= IFF_POINTOPOINT;
591 }
592
593 if (!tdev && tunnel->parms.link)
594 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
595
596 if (tdev) {
597 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
598 dev->mtu = tdev->mtu - sizeof(struct iphdr);
599 }
600 dev->iflink = tunnel->parms.link;
601}
602
603static int
604ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
605{
606 int err = 0;
607 struct ip_tunnel_parm p;
608 struct ip_tunnel *t;
609 struct net *net = dev_net(dev);
610 struct ipip_net *ipn = net_generic(net, ipip_net_id);
611
612 switch (cmd) {
613 case SIOCGETTUNNEL:
614 t = NULL;
615 if (dev == ipn->fb_tunnel_dev) {
616 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
617 err = -EFAULT;
618 break;
619 }
620 t = ipip_tunnel_locate(net, &p, 0);
621 }
622 if (t == NULL)
623 t = netdev_priv(dev);
624 memcpy(&p, &t->parms, sizeof(p));
625 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
626 err = -EFAULT;
627 break;
628
629 case SIOCADDTUNNEL:
630 case SIOCCHGTUNNEL:
631 err = -EPERM;
632 if (!capable(CAP_NET_ADMIN))
633 goto done;
634
635 err = -EFAULT;
636 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
637 goto done;
638
639 err = -EINVAL;
640 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
641 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
642 goto done;
643 if (p.iph.ttl)
644 p.iph.frag_off |= htons(IP_DF);
645
646 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
647
648 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
649 if (t != NULL) {
650 if (t->dev != dev) {
651 err = -EEXIST;
652 break;
653 }
654 } else {
655 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
656 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
657 err = -EINVAL;
658 break;
659 }
660 t = netdev_priv(dev);
661 ipip_tunnel_unlink(ipn, t);
662 synchronize_net();
663 t->parms.iph.saddr = p.iph.saddr;
664 t->parms.iph.daddr = p.iph.daddr;
665 memcpy(dev->dev_addr, &p.iph.saddr, 4);
666 memcpy(dev->broadcast, &p.iph.daddr, 4);
667 ipip_tunnel_link(ipn, t);
668 netdev_state_change(dev);
669 }
670 }
671
672 if (t) {
673 err = 0;
674 if (cmd == SIOCCHGTUNNEL) {
675 t->parms.iph.ttl = p.iph.ttl;
676 t->parms.iph.tos = p.iph.tos;
677 t->parms.iph.frag_off = p.iph.frag_off;
678 if (t->parms.link != p.link) {
679 t->parms.link = p.link;
680 ipip_tunnel_bind_dev(dev);
681 netdev_state_change(dev);
682 }
683 }
684 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
685 err = -EFAULT;
686 } else
687 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
688 break;
689
690 case SIOCDELTUNNEL:
691 err = -EPERM;
692 if (!capable(CAP_NET_ADMIN))
693 goto done;
694
695 if (dev == ipn->fb_tunnel_dev) {
696 err = -EFAULT;
697 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
698 goto done;
699 err = -ENOENT;
700 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
701 goto done;
702 err = -EPERM;
703 if (t->dev == ipn->fb_tunnel_dev)
704 goto done;
705 dev = t->dev;
706 }
707 unregister_netdevice(dev);
708 err = 0;
709 break;
710
711 default:
712 err = -EINVAL;
713 }
714
715done:
716 return err;
717}
718
719static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
720{
721 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
722 return -EINVAL;
723 dev->mtu = new_mtu;
724 return 0;
725}
726
727static const struct net_device_ops ipip_netdev_ops = {
728 .ndo_uninit = ipip_tunnel_uninit,
729 .ndo_start_xmit = ipip_tunnel_xmit,
730 .ndo_do_ioctl = ipip_tunnel_ioctl,
731 .ndo_change_mtu = ipip_tunnel_change_mtu,
732 .ndo_get_stats = ipip_get_stats,
733};
734
735static void ipip_dev_free(struct net_device *dev)
736{
737 free_percpu(dev->tstats);
738 free_netdev(dev);
739}
740
741static void ipip_tunnel_setup(struct net_device *dev)
742{
743 dev->netdev_ops = &ipip_netdev_ops;
744 dev->destructor = ipip_dev_free;
745
746 dev->type = ARPHRD_TUNNEL;
747 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
748 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
749 dev->flags = IFF_NOARP;
750 dev->iflink = 0;
751 dev->addr_len = 4;
752 dev->features |= NETIF_F_NETNS_LOCAL;
753 dev->features |= NETIF_F_LLTX;
754 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
755}
756
757static int ipip_tunnel_init(struct net_device *dev)
758{
759 struct ip_tunnel *tunnel = netdev_priv(dev);
760
761 tunnel->dev = dev;
762 strcpy(tunnel->parms.name, dev->name);
763
764 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
765 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
766
767 ipip_tunnel_bind_dev(dev);
768
769 dev->tstats = alloc_percpu(struct pcpu_tstats);
770 if (!dev->tstats)
771 return -ENOMEM;
772
773 return 0;
774}
775
776static int __net_init ipip_fb_tunnel_init(struct net_device *dev)
777{
778 struct ip_tunnel *tunnel = netdev_priv(dev);
779 struct iphdr *iph = &tunnel->parms.iph;
780 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
781
782 tunnel->dev = dev;
783 strcpy(tunnel->parms.name, dev->name);
784
785 iph->version = 4;
786 iph->protocol = IPPROTO_IPIP;
787 iph->ihl = 5;
788
789 dev->tstats = alloc_percpu(struct pcpu_tstats);
790 if (!dev->tstats)
791 return -ENOMEM;
792
793 dev_hold(dev);
794 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
795 return 0;
796}
797
798static struct xfrm_tunnel ipip_handler __read_mostly = {
799 .handler = ipip_rcv,
800 .err_handler = ipip_err,
801 .priority = 1,
802};
803
804static const char banner[] __initconst =
805 KERN_INFO "IPv4 over IPv4 tunneling driver\n";
806
807static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
808{
809 int prio;
810
811 for (prio = 1; prio < 4; prio++) {
812 int h;
813 for (h = 0; h < HASH_SIZE; h++) {
814 struct ip_tunnel *t;
815
816 t = rtnl_dereference(ipn->tunnels[prio][h]);
817 while (t != NULL) {
818 unregister_netdevice_queue(t->dev, head);
819 t = rtnl_dereference(t->next);
820 }
821 }
822 }
823}
824
825static int __net_init ipip_init_net(struct net *net)
826{
827 struct ipip_net *ipn = net_generic(net, ipip_net_id);
828 int err;
829
830 ipn->tunnels[0] = ipn->tunnels_wc;
831 ipn->tunnels[1] = ipn->tunnels_l;
832 ipn->tunnels[2] = ipn->tunnels_r;
833 ipn->tunnels[3] = ipn->tunnels_r_l;
834
835 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
836 "tunl0",
837 ipip_tunnel_setup);
838 if (!ipn->fb_tunnel_dev) {
839 err = -ENOMEM;
840 goto err_alloc_dev;
841 }
842 dev_net_set(ipn->fb_tunnel_dev, net);
843
844 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
845 if (err)
846 goto err_reg_dev;
847
848 if ((err = register_netdev(ipn->fb_tunnel_dev)))
849 goto err_reg_dev;
850
851 return 0;
852
853err_reg_dev:
854 ipip_dev_free(ipn->fb_tunnel_dev);
855err_alloc_dev:
856 /* nothing */
857 return err;
858}
859
860static void __net_exit ipip_exit_net(struct net *net)
861{
862 struct ipip_net *ipn = net_generic(net, ipip_net_id);
863 LIST_HEAD(list);
864
865 rtnl_lock();
866 ipip_destroy_tunnels(ipn, &list);
867 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
868 unregister_netdevice_many(&list);
869 rtnl_unlock();
870}
871
872static struct pernet_operations ipip_net_ops = {
873 .init = ipip_init_net,
874 .exit = ipip_exit_net,
875 .id = &ipip_net_id,
876 .size = sizeof(struct ipip_net),
877};
878
879static int __init ipip_init(void)
880{
881 int err;
882
883 printk(banner);
884
885 err = register_pernet_device(&ipip_net_ops);
886 if (err < 0)
887 return err;
888 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
889 if (err < 0) {
890 unregister_pernet_device(&ipip_net_ops);
891 printk(KERN_INFO "ipip init: can't register tunnel\n");
892 }
893 return err;
894}
895
896static void __exit ipip_fini(void)
897{
898 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
899 printk(KERN_INFO "ipip close: can't deregister tunnel\n");
900
901 unregister_pernet_device(&ipip_net_ops);
902}
903
904module_init(ipip_init);
905module_exit(ipip_fini);
906MODULE_LICENSE("GPL");
907MODULE_ALIAS_NETDEV("tunl0");