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 <asm/uaccess.h>
99 #include <linux/skbuff.h>
100 #include <linux/netdevice.h>
101 #include <linux/in.h>
102 #include <linux/tcp.h>
103 #include <linux/udp.h>
104 #include <linux/if_arp.h>
105 #include <linux/mroute.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/ipip.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
119 #define HASH_SIZE 16
120 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
121
122 static int ipip_net_id;
123 struct ipip_net {
124 struct ip_tunnel *tunnels_r_l[HASH_SIZE];
125 struct ip_tunnel *tunnels_r[HASH_SIZE];
126 struct ip_tunnel *tunnels_l[HASH_SIZE];
127 struct ip_tunnel *tunnels_wc[1];
128 struct ip_tunnel **tunnels[4];
129
130 struct net_device *fb_tunnel_dev;
131 };
132
133 static void ipip_fb_tunnel_init(struct net_device *dev);
134 static void ipip_tunnel_init(struct net_device *dev);
135 static void ipip_tunnel_setup(struct net_device *dev);
136
137 static DEFINE_RWLOCK(ipip_lock);
138
ipip_tunnel_lookup(struct net * net,__be32 remote,__be32 local)139 static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
140 __be32 remote, __be32 local)
141 {
142 unsigned h0 = HASH(remote);
143 unsigned h1 = HASH(local);
144 struct ip_tunnel *t;
145 struct ipip_net *ipn = net_generic(net, ipip_net_id);
146
147 for (t = ipn->tunnels_r_l[h0^h1]; t; t = t->next) {
148 if (local == t->parms.iph.saddr &&
149 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
150 return t;
151 }
152 for (t = ipn->tunnels_r[h0]; t; t = t->next) {
153 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
154 return t;
155 }
156 for (t = ipn->tunnels_l[h1]; t; t = t->next) {
157 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
158 return t;
159 }
160 if ((t = ipn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
161 return t;
162 return NULL;
163 }
164
__ipip_bucket(struct ipip_net * ipn,struct ip_tunnel_parm * parms)165 static struct ip_tunnel **__ipip_bucket(struct ipip_net *ipn,
166 struct ip_tunnel_parm *parms)
167 {
168 __be32 remote = parms->iph.daddr;
169 __be32 local = parms->iph.saddr;
170 unsigned h = 0;
171 int prio = 0;
172
173 if (remote) {
174 prio |= 2;
175 h ^= HASH(remote);
176 }
177 if (local) {
178 prio |= 1;
179 h ^= HASH(local);
180 }
181 return &ipn->tunnels[prio][h];
182 }
183
ipip_bucket(struct ipip_net * ipn,struct ip_tunnel * t)184 static inline struct ip_tunnel **ipip_bucket(struct ipip_net *ipn,
185 struct ip_tunnel *t)
186 {
187 return __ipip_bucket(ipn, &t->parms);
188 }
189
ipip_tunnel_unlink(struct ipip_net * ipn,struct ip_tunnel * t)190 static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
191 {
192 struct ip_tunnel **tp;
193
194 for (tp = ipip_bucket(ipn, t); *tp; tp = &(*tp)->next) {
195 if (t == *tp) {
196 write_lock_bh(&ipip_lock);
197 *tp = t->next;
198 write_unlock_bh(&ipip_lock);
199 break;
200 }
201 }
202 }
203
ipip_tunnel_link(struct ipip_net * ipn,struct ip_tunnel * t)204 static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
205 {
206 struct ip_tunnel **tp = ipip_bucket(ipn, t);
207
208 t->next = *tp;
209 write_lock_bh(&ipip_lock);
210 *tp = t;
211 write_unlock_bh(&ipip_lock);
212 }
213
ipip_tunnel_locate(struct net * net,struct ip_tunnel_parm * parms,int create)214 static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
215 struct ip_tunnel_parm *parms, int create)
216 {
217 __be32 remote = parms->iph.daddr;
218 __be32 local = parms->iph.saddr;
219 struct ip_tunnel *t, **tp, *nt;
220 struct net_device *dev;
221 char name[IFNAMSIZ];
222 struct ipip_net *ipn = net_generic(net, ipip_net_id);
223
224 for (tp = __ipip_bucket(ipn, parms); (t = *tp) != NULL; tp = &t->next) {
225 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
226 return t;
227 }
228 if (!create)
229 return NULL;
230
231 if (parms->name[0])
232 strlcpy(name, parms->name, IFNAMSIZ);
233 else
234 sprintf(name, "tunl%%d");
235
236 dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
237 if (dev == NULL)
238 return NULL;
239
240 dev_net_set(dev, net);
241
242 if (strchr(name, '%')) {
243 if (dev_alloc_name(dev, name) < 0)
244 goto failed_free;
245 }
246
247 nt = netdev_priv(dev);
248 nt->parms = *parms;
249
250 ipip_tunnel_init(dev);
251
252 if (register_netdevice(dev) < 0)
253 goto failed_free;
254
255 dev_hold(dev);
256 ipip_tunnel_link(ipn, nt);
257 return nt;
258
259 failed_free:
260 free_netdev(dev);
261 return NULL;
262 }
263
ipip_tunnel_uninit(struct net_device * dev)264 static void ipip_tunnel_uninit(struct net_device *dev)
265 {
266 struct net *net = dev_net(dev);
267 struct ipip_net *ipn = net_generic(net, ipip_net_id);
268
269 if (dev == ipn->fb_tunnel_dev) {
270 write_lock_bh(&ipip_lock);
271 ipn->tunnels_wc[0] = NULL;
272 write_unlock_bh(&ipip_lock);
273 } else
274 ipip_tunnel_unlink(ipn, netdev_priv(dev));
275 dev_put(dev);
276 }
277
ipip_err(struct sk_buff * skb,u32 info)278 static int ipip_err(struct sk_buff *skb, u32 info)
279 {
280
281 /* All the routers (except for Linux) return only
282 8 bytes of packet payload. It means, that precise relaying of
283 ICMP in the real Internet is absolutely infeasible.
284 */
285 struct iphdr *iph = (struct iphdr *)skb->data;
286 const int type = icmp_hdr(skb)->type;
287 const int code = icmp_hdr(skb)->code;
288 struct ip_tunnel *t;
289 int err;
290
291 switch (type) {
292 default:
293 case ICMP_PARAMETERPROB:
294 return 0;
295
296 case ICMP_DEST_UNREACH:
297 switch (code) {
298 case ICMP_SR_FAILED:
299 case ICMP_PORT_UNREACH:
300 /* Impossible event. */
301 return 0;
302 case ICMP_FRAG_NEEDED:
303 /* Soft state for pmtu is maintained by IP core. */
304 return 0;
305 default:
306 /* All others are translated to HOST_UNREACH.
307 rfc2003 contains "deep thoughts" about NET_UNREACH,
308 I believe they are just ether pollution. --ANK
309 */
310 break;
311 }
312 break;
313 case ICMP_TIME_EXCEEDED:
314 if (code != ICMP_EXC_TTL)
315 return 0;
316 break;
317 }
318
319 err = -ENOENT;
320
321 read_lock(&ipip_lock);
322 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
323 if (t == NULL || t->parms.iph.daddr == 0)
324 goto out;
325
326 err = 0;
327 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
328 goto out;
329
330 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
331 t->err_count++;
332 else
333 t->err_count = 1;
334 t->err_time = jiffies;
335 out:
336 read_unlock(&ipip_lock);
337 return err;
338 }
339
ipip_ecn_decapsulate(const struct iphdr * outer_iph,struct sk_buff * skb)340 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
341 struct sk_buff *skb)
342 {
343 struct iphdr *inner_iph = ip_hdr(skb);
344
345 if (INET_ECN_is_ce(outer_iph->tos))
346 IP_ECN_set_ce(inner_iph);
347 }
348
ipip_rcv(struct sk_buff * skb)349 static int ipip_rcv(struct sk_buff *skb)
350 {
351 struct ip_tunnel *tunnel;
352 const struct iphdr *iph = ip_hdr(skb);
353
354 read_lock(&ipip_lock);
355 if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev),
356 iph->saddr, iph->daddr)) != NULL) {
357 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
358 read_unlock(&ipip_lock);
359 kfree_skb(skb);
360 return 0;
361 }
362
363 secpath_reset(skb);
364
365 skb->mac_header = skb->network_header;
366 skb_reset_network_header(skb);
367 skb->protocol = htons(ETH_P_IP);
368 skb->pkt_type = PACKET_HOST;
369
370 tunnel->dev->stats.rx_packets++;
371 tunnel->dev->stats.rx_bytes += skb->len;
372 skb->dev = tunnel->dev;
373 dst_release(skb->dst);
374 skb->dst = NULL;
375 nf_reset(skb);
376 ipip_ecn_decapsulate(iph, skb);
377 netif_rx(skb);
378 read_unlock(&ipip_lock);
379 return 0;
380 }
381 read_unlock(&ipip_lock);
382
383 return -1;
384 }
385
386 /*
387 * This function assumes it is being called from dev_queue_xmit()
388 * and that skb is filled properly by that function.
389 */
390
ipip_tunnel_xmit(struct sk_buff * skb,struct net_device * dev)391 static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
392 {
393 struct ip_tunnel *tunnel = netdev_priv(dev);
394 struct net_device_stats *stats = &tunnel->dev->stats;
395 struct iphdr *tiph = &tunnel->parms.iph;
396 u8 tos = tunnel->parms.iph.tos;
397 __be16 df = tiph->frag_off;
398 struct rtable *rt; /* Route to the other host */
399 struct net_device *tdev; /* Device to other host */
400 struct iphdr *old_iph = ip_hdr(skb);
401 struct iphdr *iph; /* Our new IP header */
402 unsigned int max_headroom; /* The extra header space needed */
403 __be32 dst = tiph->daddr;
404 int mtu;
405
406 if (tunnel->recursion++) {
407 stats->collisions++;
408 goto tx_error;
409 }
410
411 if (skb->protocol != htons(ETH_P_IP))
412 goto tx_error;
413
414 if (tos&1)
415 tos = old_iph->tos;
416
417 if (!dst) {
418 /* NBMA tunnel */
419 if ((rt = skb->rtable) == NULL) {
420 stats->tx_fifo_errors++;
421 goto tx_error;
422 }
423 if ((dst = rt->rt_gateway) == 0)
424 goto tx_error_icmp;
425 }
426
427 {
428 struct flowi fl = { .oif = tunnel->parms.link,
429 .nl_u = { .ip4_u =
430 { .daddr = dst,
431 .saddr = tiph->saddr,
432 .tos = RT_TOS(tos) } },
433 .proto = IPPROTO_IPIP };
434 if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
435 stats->tx_carrier_errors++;
436 goto tx_error_icmp;
437 }
438 }
439 tdev = rt->u.dst.dev;
440
441 if (tdev == dev) {
442 ip_rt_put(rt);
443 stats->collisions++;
444 goto tx_error;
445 }
446
447 if (tiph->frag_off)
448 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
449 else
450 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
451
452 if (mtu < 68) {
453 stats->collisions++;
454 ip_rt_put(rt);
455 goto tx_error;
456 }
457 if (skb->dst)
458 skb->dst->ops->update_pmtu(skb->dst, mtu);
459
460 df |= (old_iph->frag_off&htons(IP_DF));
461
462 if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) {
463 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
464 ip_rt_put(rt);
465 goto tx_error;
466 }
467
468 if (tunnel->err_count > 0) {
469 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
470 tunnel->err_count--;
471 dst_link_failure(skb);
472 } else
473 tunnel->err_count = 0;
474 }
475
476 /*
477 * Okay, now see if we can stuff it in the buffer as-is.
478 */
479 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
480
481 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
482 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
483 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
484 if (!new_skb) {
485 ip_rt_put(rt);
486 stats->tx_dropped++;
487 dev_kfree_skb(skb);
488 tunnel->recursion--;
489 return 0;
490 }
491 if (skb->sk)
492 skb_set_owner_w(new_skb, skb->sk);
493 dev_kfree_skb(skb);
494 skb = new_skb;
495 old_iph = ip_hdr(skb);
496 }
497
498 skb->transport_header = skb->network_header;
499 skb_push(skb, sizeof(struct iphdr));
500 skb_reset_network_header(skb);
501 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
502 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
503 IPSKB_REROUTED);
504 dst_release(skb->dst);
505 skb->dst = &rt->u.dst;
506
507 /*
508 * Push down and install the IPIP header.
509 */
510
511 iph = ip_hdr(skb);
512 iph->version = 4;
513 iph->ihl = sizeof(struct iphdr)>>2;
514 iph->frag_off = df;
515 iph->protocol = IPPROTO_IPIP;
516 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos);
517 iph->daddr = rt->rt_dst;
518 iph->saddr = rt->rt_src;
519
520 if ((iph->ttl = tiph->ttl) == 0)
521 iph->ttl = old_iph->ttl;
522
523 nf_reset(skb);
524
525 IPTUNNEL_XMIT();
526 tunnel->recursion--;
527 return 0;
528
529 tx_error_icmp:
530 dst_link_failure(skb);
531 tx_error:
532 stats->tx_errors++;
533 dev_kfree_skb(skb);
534 tunnel->recursion--;
535 return 0;
536 }
537
ipip_tunnel_bind_dev(struct net_device * dev)538 static void ipip_tunnel_bind_dev(struct net_device *dev)
539 {
540 struct net_device *tdev = NULL;
541 struct ip_tunnel *tunnel;
542 struct iphdr *iph;
543
544 tunnel = netdev_priv(dev);
545 iph = &tunnel->parms.iph;
546
547 if (iph->daddr) {
548 struct flowi fl = { .oif = tunnel->parms.link,
549 .nl_u = { .ip4_u =
550 { .daddr = iph->daddr,
551 .saddr = iph->saddr,
552 .tos = RT_TOS(iph->tos) } },
553 .proto = IPPROTO_IPIP };
554 struct rtable *rt;
555 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
556 tdev = rt->u.dst.dev;
557 ip_rt_put(rt);
558 }
559 dev->flags |= IFF_POINTOPOINT;
560 }
561
562 if (!tdev && tunnel->parms.link)
563 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
564
565 if (tdev) {
566 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
567 dev->mtu = tdev->mtu - sizeof(struct iphdr);
568 }
569 dev->iflink = tunnel->parms.link;
570 }
571
572 static int
ipip_tunnel_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)573 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
574 {
575 int err = 0;
576 struct ip_tunnel_parm p;
577 struct ip_tunnel *t;
578 struct net *net = dev_net(dev);
579 struct ipip_net *ipn = net_generic(net, ipip_net_id);
580
581 switch (cmd) {
582 case SIOCGETTUNNEL:
583 t = NULL;
584 if (dev == ipn->fb_tunnel_dev) {
585 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
586 err = -EFAULT;
587 break;
588 }
589 t = ipip_tunnel_locate(net, &p, 0);
590 }
591 if (t == NULL)
592 t = netdev_priv(dev);
593 memcpy(&p, &t->parms, sizeof(p));
594 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
595 err = -EFAULT;
596 break;
597
598 case SIOCADDTUNNEL:
599 case SIOCCHGTUNNEL:
600 err = -EPERM;
601 if (!capable(CAP_NET_ADMIN))
602 goto done;
603
604 err = -EFAULT;
605 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
606 goto done;
607
608 err = -EINVAL;
609 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
610 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
611 goto done;
612 if (p.iph.ttl)
613 p.iph.frag_off |= htons(IP_DF);
614
615 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
616
617 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
618 if (t != NULL) {
619 if (t->dev != dev) {
620 err = -EEXIST;
621 break;
622 }
623 } else {
624 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
625 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
626 err = -EINVAL;
627 break;
628 }
629 t = netdev_priv(dev);
630 ipip_tunnel_unlink(ipn, t);
631 t->parms.iph.saddr = p.iph.saddr;
632 t->parms.iph.daddr = p.iph.daddr;
633 memcpy(dev->dev_addr, &p.iph.saddr, 4);
634 memcpy(dev->broadcast, &p.iph.daddr, 4);
635 ipip_tunnel_link(ipn, t);
636 netdev_state_change(dev);
637 }
638 }
639
640 if (t) {
641 err = 0;
642 if (cmd == SIOCCHGTUNNEL) {
643 t->parms.iph.ttl = p.iph.ttl;
644 t->parms.iph.tos = p.iph.tos;
645 t->parms.iph.frag_off = p.iph.frag_off;
646 if (t->parms.link != p.link) {
647 t->parms.link = p.link;
648 ipip_tunnel_bind_dev(dev);
649 netdev_state_change(dev);
650 }
651 }
652 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
653 err = -EFAULT;
654 } else
655 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
656 break;
657
658 case SIOCDELTUNNEL:
659 err = -EPERM;
660 if (!capable(CAP_NET_ADMIN))
661 goto done;
662
663 if (dev == ipn->fb_tunnel_dev) {
664 err = -EFAULT;
665 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
666 goto done;
667 err = -ENOENT;
668 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
669 goto done;
670 err = -EPERM;
671 if (t->dev == ipn->fb_tunnel_dev)
672 goto done;
673 dev = t->dev;
674 }
675 unregister_netdevice(dev);
676 err = 0;
677 break;
678
679 default:
680 err = -EINVAL;
681 }
682
683 done:
684 return err;
685 }
686
ipip_tunnel_change_mtu(struct net_device * dev,int new_mtu)687 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
688 {
689 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
690 return -EINVAL;
691 dev->mtu = new_mtu;
692 return 0;
693 }
694
695 static const struct net_device_ops ipip_netdev_ops = {
696 .ndo_uninit = ipip_tunnel_uninit,
697 .ndo_start_xmit = ipip_tunnel_xmit,
698 .ndo_do_ioctl = ipip_tunnel_ioctl,
699 .ndo_change_mtu = ipip_tunnel_change_mtu,
700
701 };
702
ipip_tunnel_setup(struct net_device * dev)703 static void ipip_tunnel_setup(struct net_device *dev)
704 {
705 dev->netdev_ops = &ipip_netdev_ops;
706 dev->destructor = free_netdev;
707
708 dev->type = ARPHRD_TUNNEL;
709 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
710 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
711 dev->flags = IFF_NOARP;
712 dev->iflink = 0;
713 dev->addr_len = 4;
714 dev->features |= NETIF_F_NETNS_LOCAL;
715 }
716
ipip_tunnel_init(struct net_device * dev)717 static void ipip_tunnel_init(struct net_device *dev)
718 {
719 struct ip_tunnel *tunnel = netdev_priv(dev);
720
721 tunnel->dev = dev;
722 strcpy(tunnel->parms.name, dev->name);
723
724 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
725 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
726
727 ipip_tunnel_bind_dev(dev);
728 }
729
ipip_fb_tunnel_init(struct net_device * dev)730 static void ipip_fb_tunnel_init(struct net_device *dev)
731 {
732 struct ip_tunnel *tunnel = netdev_priv(dev);
733 struct iphdr *iph = &tunnel->parms.iph;
734 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
735
736 tunnel->dev = dev;
737 strcpy(tunnel->parms.name, dev->name);
738
739 iph->version = 4;
740 iph->protocol = IPPROTO_IPIP;
741 iph->ihl = 5;
742
743 dev_hold(dev);
744 ipn->tunnels_wc[0] = tunnel;
745 }
746
747 static struct xfrm_tunnel ipip_handler = {
748 .handler = ipip_rcv,
749 .err_handler = ipip_err,
750 .priority = 1,
751 };
752
753 static char banner[] __initdata =
754 KERN_INFO "IPv4 over IPv4 tunneling driver\n";
755
ipip_destroy_tunnels(struct ipip_net * ipn)756 static void ipip_destroy_tunnels(struct ipip_net *ipn)
757 {
758 int prio;
759
760 for (prio = 1; prio < 4; prio++) {
761 int h;
762 for (h = 0; h < HASH_SIZE; h++) {
763 struct ip_tunnel *t;
764 while ((t = ipn->tunnels[prio][h]) != NULL)
765 unregister_netdevice(t->dev);
766 }
767 }
768 }
769
ipip_init_net(struct net * net)770 static int ipip_init_net(struct net *net)
771 {
772 int err;
773 struct ipip_net *ipn;
774
775 err = -ENOMEM;
776 ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL);
777 if (ipn == NULL)
778 goto err_alloc;
779
780 err = net_assign_generic(net, ipip_net_id, ipn);
781 if (err < 0)
782 goto err_assign;
783
784 ipn->tunnels[0] = ipn->tunnels_wc;
785 ipn->tunnels[1] = ipn->tunnels_l;
786 ipn->tunnels[2] = ipn->tunnels_r;
787 ipn->tunnels[3] = ipn->tunnels_r_l;
788
789 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
790 "tunl0",
791 ipip_tunnel_setup);
792 if (!ipn->fb_tunnel_dev) {
793 err = -ENOMEM;
794 goto err_alloc_dev;
795 }
796 dev_net_set(ipn->fb_tunnel_dev, net);
797
798 ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
799
800 if ((err = register_netdev(ipn->fb_tunnel_dev)))
801 goto err_reg_dev;
802
803 return 0;
804
805 err_reg_dev:
806 free_netdev(ipn->fb_tunnel_dev);
807 err_alloc_dev:
808 /* nothing */
809 err_assign:
810 kfree(ipn);
811 err_alloc:
812 return err;
813 }
814
ipip_exit_net(struct net * net)815 static void ipip_exit_net(struct net *net)
816 {
817 struct ipip_net *ipn;
818
819 ipn = net_generic(net, ipip_net_id);
820 rtnl_lock();
821 ipip_destroy_tunnels(ipn);
822 unregister_netdevice(ipn->fb_tunnel_dev);
823 rtnl_unlock();
824 kfree(ipn);
825 }
826
827 static struct pernet_operations ipip_net_ops = {
828 .init = ipip_init_net,
829 .exit = ipip_exit_net,
830 };
831
ipip_init(void)832 static int __init ipip_init(void)
833 {
834 int err;
835
836 printk(banner);
837
838 if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) {
839 printk(KERN_INFO "ipip init: can't register tunnel\n");
840 return -EAGAIN;
841 }
842
843 err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops);
844 if (err)
845 xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
846
847 return err;
848 }
849
ipip_fini(void)850 static void __exit ipip_fini(void)
851 {
852 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
853 printk(KERN_INFO "ipip close: can't deregister tunnel\n");
854
855 unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops);
856 }
857
858 module_init(ipip_init);
859 module_exit(ipip_fini);
860 MODULE_LICENSE("GPL");
861