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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 const int type = icmp_hdr(skb)->type;
134 const int code = icmp_hdr(skb)->code;
135 struct ip_tunnel *t;
136 int err = 0;
137
138 t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
139 iph->daddr, iph->saddr, 0);
140 if (!t) {
141 err = -ENOENT;
142 goto out;
143 }
144
145 switch (type) {
146 case ICMP_DEST_UNREACH:
147 switch (code) {
148 case ICMP_SR_FAILED:
149 /* Impossible event. */
150 goto out;
151 default:
152 /* All others are translated to HOST_UNREACH.
153 * rfc2003 contains "deep thoughts" about NET_UNREACH,
154 * I believe they are just ether pollution. --ANK
155 */
156 break;
157 }
158 break;
159
160 case ICMP_TIME_EXCEEDED:
161 if (code != ICMP_EXC_TTL)
162 goto out;
163 break;
164
165 case ICMP_REDIRECT:
166 break;
167
168 default:
169 goto out;
170 }
171
172 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
173 ipv4_update_pmtu(skb, net, info, t->parms.link, iph->protocol);
174 goto out;
175 }
176
177 if (type == ICMP_REDIRECT) {
178 ipv4_redirect(skb, net, t->parms.link, iph->protocol);
179 goto out;
180 }
181
182 if (t->parms.iph.daddr == 0) {
183 err = -ENOENT;
184 goto out;
185 }
186
187 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
188 goto out;
189
190 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
191 t->err_count++;
192 else
193 t->err_count = 1;
194 t->err_time = jiffies;
195
196out:
197 return err;
198}
199
200static const struct tnl_ptk_info ipip_tpi = {
201 /* no tunnel info required for ipip. */
202 .proto = htons(ETH_P_IP),
203};
204
205#if IS_ENABLED(CONFIG_MPLS)
206static const struct tnl_ptk_info mplsip_tpi = {
207 /* no tunnel info required for mplsip. */
208 .proto = htons(ETH_P_MPLS_UC),
209};
210#endif
211
212static int ipip_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
213{
214 struct net *net = dev_net(skb->dev);
215 struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
216 struct metadata_dst *tun_dst = NULL;
217 struct ip_tunnel *tunnel;
218 const struct iphdr *iph;
219
220 iph = ip_hdr(skb);
221 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
222 iph->saddr, iph->daddr, 0);
223 if (tunnel) {
224 const struct tnl_ptk_info *tpi;
225
226 if (tunnel->parms.iph.protocol != ipproto &&
227 tunnel->parms.iph.protocol != 0)
228 goto drop;
229
230 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
231 goto drop;
232#if IS_ENABLED(CONFIG_MPLS)
233 if (ipproto == IPPROTO_MPLS)
234 tpi = &mplsip_tpi;
235 else
236#endif
237 tpi = &ipip_tpi;
238 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
239 goto drop;
240 if (tunnel->collect_md) {
241 tun_dst = ip_tun_rx_dst(skb, 0, 0, 0);
242 if (!tun_dst)
243 return 0;
244 }
245 return ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
246 }
247
248 return -1;
249
250drop:
251 kfree_skb(skb);
252 return 0;
253}
254
255static int ipip_rcv(struct sk_buff *skb)
256{
257 return ipip_tunnel_rcv(skb, IPPROTO_IPIP);
258}
259
260#if IS_ENABLED(CONFIG_MPLS)
261static int mplsip_rcv(struct sk_buff *skb)
262{
263 return ipip_tunnel_rcv(skb, IPPROTO_MPLS);
264}
265#endif
266
267/*
268 * This function assumes it is being called from dev_queue_xmit()
269 * and that skb is filled properly by that function.
270 */
271static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb,
272 struct net_device *dev)
273{
274 struct ip_tunnel *tunnel = netdev_priv(dev);
275 const struct iphdr *tiph = &tunnel->parms.iph;
276 u8 ipproto;
277
278 if (!pskb_inet_may_pull(skb))
279 goto tx_error;
280
281 switch (skb->protocol) {
282 case htons(ETH_P_IP):
283 ipproto = IPPROTO_IPIP;
284 break;
285#if IS_ENABLED(CONFIG_MPLS)
286 case htons(ETH_P_MPLS_UC):
287 ipproto = IPPROTO_MPLS;
288 break;
289#endif
290 default:
291 goto tx_error;
292 }
293
294 if (tiph->protocol != ipproto && tiph->protocol != 0)
295 goto tx_error;
296
297 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
298 goto tx_error;
299
300 skb_set_inner_ipproto(skb, ipproto);
301
302 if (tunnel->collect_md)
303 ip_md_tunnel_xmit(skb, dev, ipproto, 0);
304 else
305 ip_tunnel_xmit(skb, dev, tiph, ipproto);
306 return NETDEV_TX_OK;
307
308tx_error:
309 kfree_skb(skb);
310
311 dev->stats.tx_errors++;
312 return NETDEV_TX_OK;
313}
314
315static bool ipip_tunnel_ioctl_verify_protocol(u8 ipproto)
316{
317 switch (ipproto) {
318 case 0:
319 case IPPROTO_IPIP:
320#if IS_ENABLED(CONFIG_MPLS)
321 case IPPROTO_MPLS:
322#endif
323 return true;
324 }
325
326 return false;
327}
328
329static int
330ipip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
331{
332 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
333 if (p->iph.version != 4 ||
334 !ipip_tunnel_ioctl_verify_protocol(p->iph.protocol) ||
335 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
336 return -EINVAL;
337 }
338
339 p->i_key = p->o_key = 0;
340 p->i_flags = p->o_flags = 0;
341 return ip_tunnel_ctl(dev, p, cmd);
342}
343
344static const struct net_device_ops ipip_netdev_ops = {
345 .ndo_init = ipip_tunnel_init,
346 .ndo_uninit = ip_tunnel_uninit,
347 .ndo_start_xmit = ipip_tunnel_xmit,
348 .ndo_do_ioctl = ip_tunnel_ioctl,
349 .ndo_change_mtu = ip_tunnel_change_mtu,
350 .ndo_get_stats64 = ip_tunnel_get_stats64,
351 .ndo_get_iflink = ip_tunnel_get_iflink,
352 .ndo_tunnel_ctl = ipip_tunnel_ctl,
353};
354
355#define IPIP_FEATURES (NETIF_F_SG | \
356 NETIF_F_FRAGLIST | \
357 NETIF_F_HIGHDMA | \
358 NETIF_F_GSO_SOFTWARE | \
359 NETIF_F_HW_CSUM)
360
361static void ipip_tunnel_setup(struct net_device *dev)
362{
363 dev->netdev_ops = &ipip_netdev_ops;
364 dev->header_ops = &ip_tunnel_header_ops;
365
366 dev->type = ARPHRD_TUNNEL;
367 dev->flags = IFF_NOARP;
368 dev->addr_len = 4;
369 dev->features |= NETIF_F_LLTX;
370 netif_keep_dst(dev);
371
372 dev->features |= IPIP_FEATURES;
373 dev->hw_features |= IPIP_FEATURES;
374 ip_tunnel_setup(dev, ipip_net_id);
375}
376
377static int ipip_tunnel_init(struct net_device *dev)
378{
379 struct ip_tunnel *tunnel = netdev_priv(dev);
380
381 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
382 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
383
384 tunnel->tun_hlen = 0;
385 tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
386 return ip_tunnel_init(dev);
387}
388
389static int ipip_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
390 struct netlink_ext_ack *extack)
391{
392 u8 proto;
393
394 if (!data || !data[IFLA_IPTUN_PROTO])
395 return 0;
396
397 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
398 if (proto != IPPROTO_IPIP && proto != IPPROTO_MPLS && proto != 0)
399 return -EINVAL;
400
401 return 0;
402}
403
404static void ipip_netlink_parms(struct nlattr *data[],
405 struct ip_tunnel_parm *parms, bool *collect_md,
406 __u32 *fwmark)
407{
408 memset(parms, 0, sizeof(*parms));
409
410 parms->iph.version = 4;
411 parms->iph.protocol = IPPROTO_IPIP;
412 parms->iph.ihl = 5;
413 *collect_md = false;
414
415 if (!data)
416 return;
417
418 if (data[IFLA_IPTUN_LINK])
419 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
420
421 if (data[IFLA_IPTUN_LOCAL])
422 parms->iph.saddr = nla_get_in_addr(data[IFLA_IPTUN_LOCAL]);
423
424 if (data[IFLA_IPTUN_REMOTE])
425 parms->iph.daddr = nla_get_in_addr(data[IFLA_IPTUN_REMOTE]);
426
427 if (data[IFLA_IPTUN_TTL]) {
428 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
429 if (parms->iph.ttl)
430 parms->iph.frag_off = htons(IP_DF);
431 }
432
433 if (data[IFLA_IPTUN_TOS])
434 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
435
436 if (data[IFLA_IPTUN_PROTO])
437 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
438
439 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
440 parms->iph.frag_off = htons(IP_DF);
441
442 if (data[IFLA_IPTUN_COLLECT_METADATA])
443 *collect_md = true;
444
445 if (data[IFLA_IPTUN_FWMARK])
446 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
447}
448
449/* This function returns true when ENCAP attributes are present in the nl msg */
450static bool ipip_netlink_encap_parms(struct nlattr *data[],
451 struct ip_tunnel_encap *ipencap)
452{
453 bool ret = false;
454
455 memset(ipencap, 0, sizeof(*ipencap));
456
457 if (!data)
458 return ret;
459
460 if (data[IFLA_IPTUN_ENCAP_TYPE]) {
461 ret = true;
462 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
463 }
464
465 if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
466 ret = true;
467 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
468 }
469
470 if (data[IFLA_IPTUN_ENCAP_SPORT]) {
471 ret = true;
472 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
473 }
474
475 if (data[IFLA_IPTUN_ENCAP_DPORT]) {
476 ret = true;
477 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
478 }
479
480 return ret;
481}
482
483static int ipip_newlink(struct net *src_net, struct net_device *dev,
484 struct nlattr *tb[], struct nlattr *data[],
485 struct netlink_ext_ack *extack)
486{
487 struct ip_tunnel *t = netdev_priv(dev);
488 struct ip_tunnel_parm p;
489 struct ip_tunnel_encap ipencap;
490 __u32 fwmark = 0;
491
492 if (ipip_netlink_encap_parms(data, &ipencap)) {
493 int err = ip_tunnel_encap_setup(t, &ipencap);
494
495 if (err < 0)
496 return err;
497 }
498
499 ipip_netlink_parms(data, &p, &t->collect_md, &fwmark);
500 return ip_tunnel_newlink(dev, tb, &p, fwmark);
501}
502
503static int ipip_changelink(struct net_device *dev, struct nlattr *tb[],
504 struct nlattr *data[],
505 struct netlink_ext_ack *extack)
506{
507 struct ip_tunnel *t = netdev_priv(dev);
508 struct ip_tunnel_parm p;
509 struct ip_tunnel_encap ipencap;
510 bool collect_md;
511 __u32 fwmark = t->fwmark;
512
513 if (ipip_netlink_encap_parms(data, &ipencap)) {
514 int err = ip_tunnel_encap_setup(t, &ipencap);
515
516 if (err < 0)
517 return err;
518 }
519
520 ipip_netlink_parms(data, &p, &collect_md, &fwmark);
521 if (collect_md)
522 return -EINVAL;
523
524 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
525 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
526 return -EINVAL;
527
528 return ip_tunnel_changelink(dev, tb, &p, fwmark);
529}
530
531static size_t ipip_get_size(const struct net_device *dev)
532{
533 return
534 /* IFLA_IPTUN_LINK */
535 nla_total_size(4) +
536 /* IFLA_IPTUN_LOCAL */
537 nla_total_size(4) +
538 /* IFLA_IPTUN_REMOTE */
539 nla_total_size(4) +
540 /* IFLA_IPTUN_TTL */
541 nla_total_size(1) +
542 /* IFLA_IPTUN_TOS */
543 nla_total_size(1) +
544 /* IFLA_IPTUN_PROTO */
545 nla_total_size(1) +
546 /* IFLA_IPTUN_PMTUDISC */
547 nla_total_size(1) +
548 /* IFLA_IPTUN_ENCAP_TYPE */
549 nla_total_size(2) +
550 /* IFLA_IPTUN_ENCAP_FLAGS */
551 nla_total_size(2) +
552 /* IFLA_IPTUN_ENCAP_SPORT */
553 nla_total_size(2) +
554 /* IFLA_IPTUN_ENCAP_DPORT */
555 nla_total_size(2) +
556 /* IFLA_IPTUN_COLLECT_METADATA */
557 nla_total_size(0) +
558 /* IFLA_IPTUN_FWMARK */
559 nla_total_size(4) +
560 0;
561}
562
563static int ipip_fill_info(struct sk_buff *skb, const struct net_device *dev)
564{
565 struct ip_tunnel *tunnel = netdev_priv(dev);
566 struct ip_tunnel_parm *parm = &tunnel->parms;
567
568 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
569 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
570 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
571 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
572 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
573 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
574 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
575 !!(parm->iph.frag_off & htons(IP_DF))) ||
576 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
577 goto nla_put_failure;
578
579 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
580 tunnel->encap.type) ||
581 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
582 tunnel->encap.sport) ||
583 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
584 tunnel->encap.dport) ||
585 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
586 tunnel->encap.flags))
587 goto nla_put_failure;
588
589 if (tunnel->collect_md)
590 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
591 goto nla_put_failure;
592 return 0;
593
594nla_put_failure:
595 return -EMSGSIZE;
596}
597
598static const struct nla_policy ipip_policy[IFLA_IPTUN_MAX + 1] = {
599 [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
600 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
601 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
602 [IFLA_IPTUN_TTL] = { .type = NLA_U8 },
603 [IFLA_IPTUN_TOS] = { .type = NLA_U8 },
604 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
605 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
606 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
607 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
608 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
609 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
610 [IFLA_IPTUN_COLLECT_METADATA] = { .type = NLA_FLAG },
611 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
612};
613
614static struct rtnl_link_ops ipip_link_ops __read_mostly = {
615 .kind = "ipip",
616 .maxtype = IFLA_IPTUN_MAX,
617 .policy = ipip_policy,
618 .priv_size = sizeof(struct ip_tunnel),
619 .setup = ipip_tunnel_setup,
620 .validate = ipip_tunnel_validate,
621 .newlink = ipip_newlink,
622 .changelink = ipip_changelink,
623 .dellink = ip_tunnel_dellink,
624 .get_size = ipip_get_size,
625 .fill_info = ipip_fill_info,
626 .get_link_net = ip_tunnel_get_link_net,
627};
628
629static struct xfrm_tunnel ipip_handler __read_mostly = {
630 .handler = ipip_rcv,
631 .err_handler = ipip_err,
632 .priority = 1,
633};
634
635#if IS_ENABLED(CONFIG_MPLS)
636static struct xfrm_tunnel mplsip_handler __read_mostly = {
637 .handler = mplsip_rcv,
638 .err_handler = ipip_err,
639 .priority = 1,
640};
641#endif
642
643static int __net_init ipip_init_net(struct net *net)
644{
645 return ip_tunnel_init_net(net, ipip_net_id, &ipip_link_ops, "tunl0");
646}
647
648static void __net_exit ipip_exit_batch_net(struct list_head *list_net)
649{
650 ip_tunnel_delete_nets(list_net, ipip_net_id, &ipip_link_ops);
651}
652
653static struct pernet_operations ipip_net_ops = {
654 .init = ipip_init_net,
655 .exit_batch = ipip_exit_batch_net,
656 .id = &ipip_net_id,
657 .size = sizeof(struct ip_tunnel_net),
658};
659
660static int __init ipip_init(void)
661{
662 int err;
663
664 pr_info("ipip: IPv4 and MPLS over IPv4 tunneling driver\n");
665
666 err = register_pernet_device(&ipip_net_ops);
667 if (err < 0)
668 return err;
669 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
670 if (err < 0) {
671 pr_info("%s: can't register tunnel\n", __func__);
672 goto xfrm_tunnel_ipip_failed;
673 }
674#if IS_ENABLED(CONFIG_MPLS)
675 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
676 if (err < 0) {
677 pr_info("%s: can't register tunnel\n", __func__);
678 goto xfrm_tunnel_mplsip_failed;
679 }
680#endif
681 err = rtnl_link_register(&ipip_link_ops);
682 if (err < 0)
683 goto rtnl_link_failed;
684
685out:
686 return err;
687
688rtnl_link_failed:
689#if IS_ENABLED(CONFIG_MPLS)
690 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
691xfrm_tunnel_mplsip_failed:
692
693#endif
694 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
695xfrm_tunnel_ipip_failed:
696 unregister_pernet_device(&ipip_net_ops);
697 goto out;
698}
699
700static void __exit ipip_fini(void)
701{
702 rtnl_link_unregister(&ipip_link_ops);
703 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
704 pr_info("%s: can't deregister tunnel\n", __func__);
705#if IS_ENABLED(CONFIG_MPLS)
706 if (xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS))
707 pr_info("%s: can't deregister tunnel\n", __func__);
708#endif
709 unregister_pernet_device(&ipip_net_ops);
710}
711
712module_init(ipip_init);
713module_exit(ipip_fini);
714MODULE_LICENSE("GPL");
715MODULE_ALIAS_RTNL_LINK("ipip");
716MODULE_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");