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
123 static int ipip_net_id __read_mostly;
124 struct 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
134 static int ipip_tunnel_init(struct net_device *dev);
135 static void ipip_tunnel_setup(struct net_device *dev);
136 static 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) */
146 struct pcpu_tstats {
147 unsigned long rx_packets;
148 unsigned long rx_bytes;
149 unsigned long tx_packets;
150 unsigned long tx_bytes;
151 };
152
ipip_get_stats(struct net_device * dev)153 static 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
ipip_tunnel_lookup(struct net * net,__be32 remote,__be32 local)173 static 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
__ipip_bucket(struct ipip_net * ipn,struct ip_tunnel_parm * parms)200 static 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
ipip_bucket(struct ipip_net * ipn,struct ip_tunnel * t)219 static 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
ipip_tunnel_unlink(struct ipip_net * ipn,struct ip_tunnel * t)225 static 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
ipip_tunnel_link(struct ipip_net * ipn,struct ip_tunnel * t)240 static 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
ipip_tunnel_locate(struct net * net,struct ip_tunnel_parm * parms,int create)248 static 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 if (strchr(name, '%')) {
280 if (dev_alloc_name(dev, name) < 0)
281 goto failed_free;
282 }
283
284 nt = netdev_priv(dev);
285 nt->parms = *parms;
286
287 if (ipip_tunnel_init(dev) < 0)
288 goto failed_free;
289
290 if (register_netdevice(dev) < 0)
291 goto failed_free;
292
293 dev_hold(dev);
294 ipip_tunnel_link(ipn, nt);
295 return nt;
296
297 failed_free:
298 ipip_dev_free(dev);
299 return NULL;
300 }
301
302 /* called with RTNL */
ipip_tunnel_uninit(struct net_device * dev)303 static void ipip_tunnel_uninit(struct net_device *dev)
304 {
305 struct net *net = dev_net(dev);
306 struct ipip_net *ipn = net_generic(net, ipip_net_id);
307
308 if (dev == ipn->fb_tunnel_dev)
309 rcu_assign_pointer(ipn->tunnels_wc[0], NULL);
310 else
311 ipip_tunnel_unlink(ipn, netdev_priv(dev));
312 dev_put(dev);
313 }
314
ipip_err(struct sk_buff * skb,u32 info)315 static int ipip_err(struct sk_buff *skb, u32 info)
316 {
317
318 /* All the routers (except for Linux) return only
319 8 bytes of packet payload. It means, that precise relaying of
320 ICMP in the real Internet is absolutely infeasible.
321 */
322 struct iphdr *iph = (struct iphdr *)skb->data;
323 const int type = icmp_hdr(skb)->type;
324 const int code = icmp_hdr(skb)->code;
325 struct ip_tunnel *t;
326 int err;
327
328 switch (type) {
329 default:
330 case ICMP_PARAMETERPROB:
331 return 0;
332
333 case ICMP_DEST_UNREACH:
334 switch (code) {
335 case ICMP_SR_FAILED:
336 case ICMP_PORT_UNREACH:
337 /* Impossible event. */
338 return 0;
339 case ICMP_FRAG_NEEDED:
340 /* Soft state for pmtu is maintained by IP core. */
341 return 0;
342 default:
343 /* All others are translated to HOST_UNREACH.
344 rfc2003 contains "deep thoughts" about NET_UNREACH,
345 I believe they are just ether pollution. --ANK
346 */
347 break;
348 }
349 break;
350 case ICMP_TIME_EXCEEDED:
351 if (code != ICMP_EXC_TTL)
352 return 0;
353 break;
354 }
355
356 err = -ENOENT;
357
358 rcu_read_lock();
359 t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
360 if (t == NULL || t->parms.iph.daddr == 0)
361 goto out;
362
363 err = 0;
364 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
365 goto out;
366
367 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
368 t->err_count++;
369 else
370 t->err_count = 1;
371 t->err_time = jiffies;
372 out:
373 rcu_read_unlock();
374 return err;
375 }
376
ipip_ecn_decapsulate(const struct iphdr * outer_iph,struct sk_buff * skb)377 static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
378 struct sk_buff *skb)
379 {
380 struct iphdr *inner_iph = ip_hdr(skb);
381
382 if (INET_ECN_is_ce(outer_iph->tos))
383 IP_ECN_set_ce(inner_iph);
384 }
385
ipip_rcv(struct sk_buff * skb)386 static int ipip_rcv(struct sk_buff *skb)
387 {
388 struct ip_tunnel *tunnel;
389 const struct iphdr *iph = ip_hdr(skb);
390
391 rcu_read_lock();
392 tunnel = ipip_tunnel_lookup(dev_net(skb->dev), iph->saddr, iph->daddr);
393 if (tunnel != NULL) {
394 struct pcpu_tstats *tstats;
395
396 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
397 rcu_read_unlock();
398 kfree_skb(skb);
399 return 0;
400 }
401
402 secpath_reset(skb);
403
404 skb->mac_header = skb->network_header;
405 skb_reset_network_header(skb);
406 skb->protocol = htons(ETH_P_IP);
407 skb->pkt_type = PACKET_HOST;
408
409 tstats = this_cpu_ptr(tunnel->dev->tstats);
410 tstats->rx_packets++;
411 tstats->rx_bytes += skb->len;
412
413 __skb_tunnel_rx(skb, tunnel->dev);
414
415 ipip_ecn_decapsulate(iph, skb);
416
417 netif_rx(skb);
418
419 rcu_read_unlock();
420 return 0;
421 }
422 rcu_read_unlock();
423
424 return -1;
425 }
426
427 /*
428 * This function assumes it is being called from dev_queue_xmit()
429 * and that skb is filled properly by that function.
430 */
431
ipip_tunnel_xmit(struct sk_buff * skb,struct net_device * dev)432 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
433 {
434 struct ip_tunnel *tunnel = netdev_priv(dev);
435 struct pcpu_tstats *tstats;
436 struct iphdr *tiph = &tunnel->parms.iph;
437 u8 tos = tunnel->parms.iph.tos;
438 __be16 df = tiph->frag_off;
439 struct rtable *rt; /* Route to the other host */
440 struct net_device *tdev; /* Device to other host */
441 struct iphdr *old_iph = ip_hdr(skb);
442 struct iphdr *iph; /* Our new IP header */
443 unsigned int max_headroom; /* The extra header space needed */
444 __be32 dst = tiph->daddr;
445 int mtu;
446
447 if (skb->protocol != htons(ETH_P_IP))
448 goto tx_error;
449
450 if (tos & 1)
451 tos = old_iph->tos;
452
453 if (!dst) {
454 /* NBMA tunnel */
455 if ((rt = skb_rtable(skb)) == NULL) {
456 dev->stats.tx_fifo_errors++;
457 goto tx_error;
458 }
459 if ((dst = rt->rt_gateway) == 0)
460 goto tx_error_icmp;
461 }
462
463 rt = ip_route_output_ports(dev_net(dev), NULL,
464 dst, tiph->saddr,
465 0, 0,
466 IPPROTO_IPIP, RT_TOS(tos),
467 tunnel->parms.link);
468 if (IS_ERR(rt)) {
469 dev->stats.tx_carrier_errors++;
470 goto tx_error_icmp;
471 }
472 tdev = rt->dst.dev;
473
474 if (tdev == dev) {
475 ip_rt_put(rt);
476 dev->stats.collisions++;
477 goto tx_error;
478 }
479
480 df |= old_iph->frag_off & htons(IP_DF);
481
482 if (df) {
483 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
484
485 if (mtu < 68) {
486 dev->stats.collisions++;
487 ip_rt_put(rt);
488 goto tx_error;
489 }
490
491 if (skb_dst(skb))
492 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
493
494 if ((old_iph->frag_off & htons(IP_DF)) &&
495 mtu < ntohs(old_iph->tot_len)) {
496 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
497 htonl(mtu));
498 ip_rt_put(rt);
499 goto tx_error;
500 }
501 }
502
503 if (tunnel->err_count > 0) {
504 if (time_before(jiffies,
505 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
506 tunnel->err_count--;
507 dst_link_failure(skb);
508 } else
509 tunnel->err_count = 0;
510 }
511
512 /*
513 * Okay, now see if we can stuff it in the buffer as-is.
514 */
515 max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
516
517 if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
518 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
519 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
520 if (!new_skb) {
521 ip_rt_put(rt);
522 dev->stats.tx_dropped++;
523 dev_kfree_skb(skb);
524 return NETDEV_TX_OK;
525 }
526 if (skb->sk)
527 skb_set_owner_w(new_skb, skb->sk);
528 dev_kfree_skb(skb);
529 skb = new_skb;
530 old_iph = ip_hdr(skb);
531 }
532
533 skb->transport_header = skb->network_header;
534 skb_push(skb, sizeof(struct iphdr));
535 skb_reset_network_header(skb);
536 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
537 IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
538 IPSKB_REROUTED);
539 skb_dst_drop(skb);
540 skb_dst_set(skb, &rt->dst);
541
542 /*
543 * Push down and install the IPIP header.
544 */
545
546 iph = ip_hdr(skb);
547 iph->version = 4;
548 iph->ihl = sizeof(struct iphdr)>>2;
549 iph->frag_off = df;
550 iph->protocol = IPPROTO_IPIP;
551 iph->tos = INET_ECN_encapsulate(tos, old_iph->tos);
552 iph->daddr = rt->rt_dst;
553 iph->saddr = rt->rt_src;
554
555 if ((iph->ttl = tiph->ttl) == 0)
556 iph->ttl = old_iph->ttl;
557
558 nf_reset(skb);
559 tstats = this_cpu_ptr(dev->tstats);
560 __IPTUNNEL_XMIT(tstats, &dev->stats);
561 return NETDEV_TX_OK;
562
563 tx_error_icmp:
564 dst_link_failure(skb);
565 tx_error:
566 dev->stats.tx_errors++;
567 dev_kfree_skb(skb);
568 return NETDEV_TX_OK;
569 }
570
ipip_tunnel_bind_dev(struct net_device * dev)571 static void ipip_tunnel_bind_dev(struct net_device *dev)
572 {
573 struct net_device *tdev = NULL;
574 struct ip_tunnel *tunnel;
575 struct iphdr *iph;
576
577 tunnel = netdev_priv(dev);
578 iph = &tunnel->parms.iph;
579
580 if (iph->daddr) {
581 struct rtable *rt = ip_route_output_ports(dev_net(dev), NULL,
582 iph->daddr, iph->saddr,
583 0, 0,
584 IPPROTO_IPIP,
585 RT_TOS(iph->tos),
586 tunnel->parms.link);
587
588 if (!IS_ERR(rt)) {
589 tdev = rt->dst.dev;
590 ip_rt_put(rt);
591 }
592 dev->flags |= IFF_POINTOPOINT;
593 }
594
595 if (!tdev && tunnel->parms.link)
596 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
597
598 if (tdev) {
599 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
600 dev->mtu = tdev->mtu - sizeof(struct iphdr);
601 }
602 dev->iflink = tunnel->parms.link;
603 }
604
605 static int
ipip_tunnel_ioctl(struct net_device * dev,struct ifreq * ifr,int cmd)606 ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
607 {
608 int err = 0;
609 struct ip_tunnel_parm p;
610 struct ip_tunnel *t;
611 struct net *net = dev_net(dev);
612 struct ipip_net *ipn = net_generic(net, ipip_net_id);
613
614 switch (cmd) {
615 case SIOCGETTUNNEL:
616 t = NULL;
617 if (dev == ipn->fb_tunnel_dev) {
618 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
619 err = -EFAULT;
620 break;
621 }
622 t = ipip_tunnel_locate(net, &p, 0);
623 }
624 if (t == NULL)
625 t = netdev_priv(dev);
626 memcpy(&p, &t->parms, sizeof(p));
627 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
628 err = -EFAULT;
629 break;
630
631 case SIOCADDTUNNEL:
632 case SIOCCHGTUNNEL:
633 err = -EPERM;
634 if (!capable(CAP_NET_ADMIN))
635 goto done;
636
637 err = -EFAULT;
638 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
639 goto done;
640
641 err = -EINVAL;
642 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
643 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
644 goto done;
645 if (p.iph.ttl)
646 p.iph.frag_off |= htons(IP_DF);
647
648 t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
649
650 if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
651 if (t != NULL) {
652 if (t->dev != dev) {
653 err = -EEXIST;
654 break;
655 }
656 } else {
657 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
658 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
659 err = -EINVAL;
660 break;
661 }
662 t = netdev_priv(dev);
663 ipip_tunnel_unlink(ipn, t);
664 synchronize_net();
665 t->parms.iph.saddr = p.iph.saddr;
666 t->parms.iph.daddr = p.iph.daddr;
667 memcpy(dev->dev_addr, &p.iph.saddr, 4);
668 memcpy(dev->broadcast, &p.iph.daddr, 4);
669 ipip_tunnel_link(ipn, t);
670 netdev_state_change(dev);
671 }
672 }
673
674 if (t) {
675 err = 0;
676 if (cmd == SIOCCHGTUNNEL) {
677 t->parms.iph.ttl = p.iph.ttl;
678 t->parms.iph.tos = p.iph.tos;
679 t->parms.iph.frag_off = p.iph.frag_off;
680 if (t->parms.link != p.link) {
681 t->parms.link = p.link;
682 ipip_tunnel_bind_dev(dev);
683 netdev_state_change(dev);
684 }
685 }
686 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
687 err = -EFAULT;
688 } else
689 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
690 break;
691
692 case SIOCDELTUNNEL:
693 err = -EPERM;
694 if (!capable(CAP_NET_ADMIN))
695 goto done;
696
697 if (dev == ipn->fb_tunnel_dev) {
698 err = -EFAULT;
699 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
700 goto done;
701 err = -ENOENT;
702 if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
703 goto done;
704 err = -EPERM;
705 if (t->dev == ipn->fb_tunnel_dev)
706 goto done;
707 dev = t->dev;
708 }
709 unregister_netdevice(dev);
710 err = 0;
711 break;
712
713 default:
714 err = -EINVAL;
715 }
716
717 done:
718 return err;
719 }
720
ipip_tunnel_change_mtu(struct net_device * dev,int new_mtu)721 static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
722 {
723 if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
724 return -EINVAL;
725 dev->mtu = new_mtu;
726 return 0;
727 }
728
729 static const struct net_device_ops ipip_netdev_ops = {
730 .ndo_uninit = ipip_tunnel_uninit,
731 .ndo_start_xmit = ipip_tunnel_xmit,
732 .ndo_do_ioctl = ipip_tunnel_ioctl,
733 .ndo_change_mtu = ipip_tunnel_change_mtu,
734 .ndo_get_stats = ipip_get_stats,
735 };
736
ipip_dev_free(struct net_device * dev)737 static void ipip_dev_free(struct net_device *dev)
738 {
739 free_percpu(dev->tstats);
740 free_netdev(dev);
741 }
742
ipip_tunnel_setup(struct net_device * dev)743 static void ipip_tunnel_setup(struct net_device *dev)
744 {
745 dev->netdev_ops = &ipip_netdev_ops;
746 dev->destructor = ipip_dev_free;
747
748 dev->type = ARPHRD_TUNNEL;
749 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
750 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
751 dev->flags = IFF_NOARP;
752 dev->iflink = 0;
753 dev->addr_len = 4;
754 dev->features |= NETIF_F_NETNS_LOCAL;
755 dev->features |= NETIF_F_LLTX;
756 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
757 }
758
ipip_tunnel_init(struct net_device * dev)759 static int ipip_tunnel_init(struct net_device *dev)
760 {
761 struct ip_tunnel *tunnel = netdev_priv(dev);
762
763 tunnel->dev = dev;
764 strcpy(tunnel->parms.name, dev->name);
765
766 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
767 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
768
769 ipip_tunnel_bind_dev(dev);
770
771 dev->tstats = alloc_percpu(struct pcpu_tstats);
772 if (!dev->tstats)
773 return -ENOMEM;
774
775 return 0;
776 }
777
ipip_fb_tunnel_init(struct net_device * dev)778 static int __net_init ipip_fb_tunnel_init(struct net_device *dev)
779 {
780 struct ip_tunnel *tunnel = netdev_priv(dev);
781 struct iphdr *iph = &tunnel->parms.iph;
782 struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
783
784 tunnel->dev = dev;
785 strcpy(tunnel->parms.name, dev->name);
786
787 iph->version = 4;
788 iph->protocol = IPPROTO_IPIP;
789 iph->ihl = 5;
790
791 dev->tstats = alloc_percpu(struct pcpu_tstats);
792 if (!dev->tstats)
793 return -ENOMEM;
794
795 dev_hold(dev);
796 rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
797 return 0;
798 }
799
800 static struct xfrm_tunnel ipip_handler __read_mostly = {
801 .handler = ipip_rcv,
802 .err_handler = ipip_err,
803 .priority = 1,
804 };
805
806 static const char banner[] __initconst =
807 KERN_INFO "IPv4 over IPv4 tunneling driver\n";
808
ipip_destroy_tunnels(struct ipip_net * ipn,struct list_head * head)809 static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head)
810 {
811 int prio;
812
813 for (prio = 1; prio < 4; prio++) {
814 int h;
815 for (h = 0; h < HASH_SIZE; h++) {
816 struct ip_tunnel *t;
817
818 t = rtnl_dereference(ipn->tunnels[prio][h]);
819 while (t != NULL) {
820 unregister_netdevice_queue(t->dev, head);
821 t = rtnl_dereference(t->next);
822 }
823 }
824 }
825 }
826
ipip_init_net(struct net * net)827 static int __net_init ipip_init_net(struct net *net)
828 {
829 struct ipip_net *ipn = net_generic(net, ipip_net_id);
830 int err;
831
832 ipn->tunnels[0] = ipn->tunnels_wc;
833 ipn->tunnels[1] = ipn->tunnels_l;
834 ipn->tunnels[2] = ipn->tunnels_r;
835 ipn->tunnels[3] = ipn->tunnels_r_l;
836
837 ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
838 "tunl0",
839 ipip_tunnel_setup);
840 if (!ipn->fb_tunnel_dev) {
841 err = -ENOMEM;
842 goto err_alloc_dev;
843 }
844 dev_net_set(ipn->fb_tunnel_dev, net);
845
846 err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev);
847 if (err)
848 goto err_reg_dev;
849
850 if ((err = register_netdev(ipn->fb_tunnel_dev)))
851 goto err_reg_dev;
852
853 return 0;
854
855 err_reg_dev:
856 ipip_dev_free(ipn->fb_tunnel_dev);
857 err_alloc_dev:
858 /* nothing */
859 return err;
860 }
861
ipip_exit_net(struct net * net)862 static void __net_exit ipip_exit_net(struct net *net)
863 {
864 struct ipip_net *ipn = net_generic(net, ipip_net_id);
865 LIST_HEAD(list);
866
867 rtnl_lock();
868 ipip_destroy_tunnels(ipn, &list);
869 unregister_netdevice_queue(ipn->fb_tunnel_dev, &list);
870 unregister_netdevice_many(&list);
871 rtnl_unlock();
872 }
873
874 static struct pernet_operations ipip_net_ops = {
875 .init = ipip_init_net,
876 .exit = ipip_exit_net,
877 .id = &ipip_net_id,
878 .size = sizeof(struct ipip_net),
879 };
880
ipip_init(void)881 static int __init ipip_init(void)
882 {
883 int err;
884
885 printk(banner);
886
887 err = register_pernet_device(&ipip_net_ops);
888 if (err < 0)
889 return err;
890 err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
891 if (err < 0) {
892 unregister_pernet_device(&ipip_net_ops);
893 printk(KERN_INFO "ipip init: can't register tunnel\n");
894 }
895 return err;
896 }
897
ipip_fini(void)898 static void __exit ipip_fini(void)
899 {
900 if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
901 printk(KERN_INFO "ipip close: can't deregister tunnel\n");
902
903 unregister_pernet_device(&ipip_net_ops);
904 }
905
906 module_init(ipip_init);
907 module_exit(ipip_fini);
908 MODULE_LICENSE("GPL");
909 MODULE_ALIAS_NETDEV("tunl0");
910