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1 | /* | |
2 | * Linux NET3: IP/IP protocol decoder. | |
3 | * | |
4 | * Authors: | |
5 | * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 | |
6 | * | |
7 | * Fixes: | |
8 | * Alan Cox : Merged and made usable non modular (its so tiny its silly as | |
9 | * a module taking up 2 pages). | |
10 | * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph) | |
11 | * to keep ip_forward happy. | |
12 | * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8). | |
13 | * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL | |
14 | * David Woodhouse : Perform some basic ICMP handling. | |
15 | * IPIP Routing without decapsulation. | |
16 | * Carlos Picoto : GRE over IP support | |
17 | * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c. | |
18 | * I do not want to merge them together. | |
19 | * | |
20 | * This program is free software; you can redistribute it and/or | |
21 | * modify it under the terms of the GNU General Public License | |
22 | * as published by the Free Software Foundation; either version | |
23 | * 2 of the License, or (at your option) any later version. | |
24 | * | |
25 | */ | |
26 | ||
27 | /* tunnel.c: an IP tunnel driver | |
28 | ||
29 | The purpose of this driver is to provide an IP tunnel through | |
30 | which you can tunnel network traffic transparently across subnets. | |
31 | ||
32 | This was written by looking at Nick Holloway's dummy driver | |
33 | Thanks for the great code! | |
34 | ||
35 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95 | |
36 | ||
37 | Minor tweaks: | |
38 | Cleaned up the code a little and added some pre-1.3.0 tweaks. | |
39 | dev->hard_header/hard_header_len changed to use no headers. | |
40 | Comments/bracketing tweaked. | |
41 | Made the tunnels use dev->name not tunnel: when error reporting. | |
42 | Added tx_dropped stat | |
43 | ||
44 | -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95 | |
45 | ||
46 | Reworked: | |
47 | Changed to tunnel to destination gateway in addition to the | |
48 | tunnel's pointopoint address | |
49 | Almost completely rewritten | |
50 | Note: There is currently no firewall or ICMP handling done. | |
51 | ||
52 | -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96 | |
53 | ||
54 | */ | |
55 | ||
56 | /* Things I wish I had known when writing the tunnel driver: | |
57 | ||
58 | When the tunnel_xmit() function is called, the skb contains the | |
59 | packet to be sent (plus a great deal of extra info), and dev | |
60 | contains the tunnel device that _we_ are. | |
61 | ||
62 | When we are passed a packet, we are expected to fill in the | |
63 | source address with our source IP address. | |
64 | ||
65 | What is the proper way to allocate, copy and free a buffer? | |
66 | After you allocate it, it is a "0 length" chunk of memory | |
67 | starting at zero. If you want to add headers to the buffer | |
68 | later, you'll have to call "skb_reserve(skb, amount)" with | |
69 | the amount of memory you want reserved. Then, you call | |
70 | "skb_put(skb, amount)" with the amount of space you want in | |
71 | the buffer. skb_put() returns a pointer to the top (#0) of | |
72 | that buffer. skb->len is set to the amount of space you have | |
73 | "allocated" with skb_put(). You can then write up to skb->len | |
74 | bytes to that buffer. If you need more, you can call skb_put() | |
75 | again with the additional amount of space you need. You can | |
76 | find out how much more space you can allocate by calling | |
77 | "skb_tailroom(skb)". | |
78 | Now, to add header space, call "skb_push(skb, header_len)". | |
79 | This creates space at the beginning of the buffer and returns | |
80 | a pointer to this new space. If later you need to strip a | |
81 | header from a buffer, call "skb_pull(skb, header_len)". | |
82 | skb_headroom() will return how much space is left at the top | |
83 | of the buffer (before the main data). Remember, this headroom | |
84 | space must be reserved before the skb_put() function is called. | |
85 | */ | |
86 | ||
87 | /* | |
88 | This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c | |
89 | ||
90 | For comments look at net/ipv4/ip_gre.c --ANK | |
91 | */ | |
92 | ||
93 | ||
94 | #include <linux/capability.h> | |
95 | #include <linux/module.h> | |
96 | #include <linux/types.h> | |
97 | #include <linux/kernel.h> | |
98 | #include <linux/slab.h> | |
99 | #include <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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 */ | |
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 | ||
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 | ||
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 | ||
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 | ||
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 | { | |
464 | struct flowi fl = { | |
465 | .oif = tunnel->parms.link, | |
466 | .fl4_dst = dst, | |
467 | .fl4_src= tiph->saddr, | |
468 | .fl4_tos = RT_TOS(tos), | |
469 | .proto = IPPROTO_IPIP | |
470 | }; | |
471 | ||
472 | if (ip_route_output_key(dev_net(dev), &rt, &fl)) { | |
473 | dev->stats.tx_carrier_errors++; | |
474 | goto tx_error_icmp; | |
475 | } | |
476 | } | |
477 | tdev = rt->dst.dev; | |
478 | ||
479 | if (tdev == dev) { | |
480 | ip_rt_put(rt); | |
481 | dev->stats.collisions++; | |
482 | goto tx_error; | |
483 | } | |
484 | ||
485 | df |= old_iph->frag_off & htons(IP_DF); | |
486 | ||
487 | if (df) { | |
488 | mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); | |
489 | ||
490 | if (mtu < 68) { | |
491 | dev->stats.collisions++; | |
492 | ip_rt_put(rt); | |
493 | goto tx_error; | |
494 | } | |
495 | ||
496 | if (skb_dst(skb)) | |
497 | skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); | |
498 | ||
499 | if ((old_iph->frag_off & htons(IP_DF)) && | |
500 | mtu < ntohs(old_iph->tot_len)) { | |
501 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, | |
502 | htonl(mtu)); | |
503 | ip_rt_put(rt); | |
504 | goto tx_error; | |
505 | } | |
506 | } | |
507 | ||
508 | if (tunnel->err_count > 0) { | |
509 | if (time_before(jiffies, | |
510 | tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { | |
511 | tunnel->err_count--; | |
512 | dst_link_failure(skb); | |
513 | } else | |
514 | tunnel->err_count = 0; | |
515 | } | |
516 | ||
517 | /* | |
518 | * Okay, now see if we can stuff it in the buffer as-is. | |
519 | */ | |
520 | max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr)); | |
521 | ||
522 | if (skb_headroom(skb) < max_headroom || skb_shared(skb) || | |
523 | (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { | |
524 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
525 | if (!new_skb) { | |
526 | ip_rt_put(rt); | |
527 | dev->stats.tx_dropped++; | |
528 | dev_kfree_skb(skb); | |
529 | return NETDEV_TX_OK; | |
530 | } | |
531 | if (skb->sk) | |
532 | skb_set_owner_w(new_skb, skb->sk); | |
533 | dev_kfree_skb(skb); | |
534 | skb = new_skb; | |
535 | old_iph = ip_hdr(skb); | |
536 | } | |
537 | ||
538 | skb->transport_header = skb->network_header; | |
539 | skb_push(skb, sizeof(struct iphdr)); | |
540 | skb_reset_network_header(skb); | |
541 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
542 | IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | | |
543 | IPSKB_REROUTED); | |
544 | skb_dst_drop(skb); | |
545 | skb_dst_set(skb, &rt->dst); | |
546 | ||
547 | /* | |
548 | * Push down and install the IPIP header. | |
549 | */ | |
550 | ||
551 | iph = ip_hdr(skb); | |
552 | iph->version = 4; | |
553 | iph->ihl = sizeof(struct iphdr)>>2; | |
554 | iph->frag_off = df; | |
555 | iph->protocol = IPPROTO_IPIP; | |
556 | iph->tos = INET_ECN_encapsulate(tos, old_iph->tos); | |
557 | iph->daddr = rt->rt_dst; | |
558 | iph->saddr = rt->rt_src; | |
559 | ||
560 | if ((iph->ttl = tiph->ttl) == 0) | |
561 | iph->ttl = old_iph->ttl; | |
562 | ||
563 | nf_reset(skb); | |
564 | tstats = this_cpu_ptr(dev->tstats); | |
565 | __IPTUNNEL_XMIT(tstats, &dev->stats); | |
566 | return NETDEV_TX_OK; | |
567 | ||
568 | tx_error_icmp: | |
569 | dst_link_failure(skb); | |
570 | tx_error: | |
571 | dev->stats.tx_errors++; | |
572 | dev_kfree_skb(skb); | |
573 | return NETDEV_TX_OK; | |
574 | } | |
575 | ||
576 | static void ipip_tunnel_bind_dev(struct net_device *dev) | |
577 | { | |
578 | struct net_device *tdev = NULL; | |
579 | struct ip_tunnel *tunnel; | |
580 | struct iphdr *iph; | |
581 | ||
582 | tunnel = netdev_priv(dev); | |
583 | iph = &tunnel->parms.iph; | |
584 | ||
585 | if (iph->daddr) { | |
586 | struct flowi fl = { | |
587 | .oif = tunnel->parms.link, | |
588 | .fl4_dst = iph->daddr, | |
589 | .fl4_src = iph->saddr, | |
590 | .fl4_tos = RT_TOS(iph->tos), | |
591 | .proto = IPPROTO_IPIP | |
592 | }; | |
593 | struct rtable *rt; | |
594 | ||
595 | if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { | |
596 | tdev = rt->dst.dev; | |
597 | ip_rt_put(rt); | |
598 | } | |
599 | dev->flags |= IFF_POINTOPOINT; | |
600 | } | |
601 | ||
602 | if (!tdev && tunnel->parms.link) | |
603 | tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); | |
604 | ||
605 | if (tdev) { | |
606 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
607 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
608 | } | |
609 | dev->iflink = tunnel->parms.link; | |
610 | } | |
611 | ||
612 | static int | |
613 | ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
614 | { | |
615 | int err = 0; | |
616 | struct ip_tunnel_parm p; | |
617 | struct ip_tunnel *t; | |
618 | struct net *net = dev_net(dev); | |
619 | struct ipip_net *ipn = net_generic(net, ipip_net_id); | |
620 | ||
621 | switch (cmd) { | |
622 | case SIOCGETTUNNEL: | |
623 | t = NULL; | |
624 | if (dev == ipn->fb_tunnel_dev) { | |
625 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
626 | err = -EFAULT; | |
627 | break; | |
628 | } | |
629 | t = ipip_tunnel_locate(net, &p, 0); | |
630 | } | |
631 | if (t == NULL) | |
632 | t = netdev_priv(dev); | |
633 | memcpy(&p, &t->parms, sizeof(p)); | |
634 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
635 | err = -EFAULT; | |
636 | break; | |
637 | ||
638 | case SIOCADDTUNNEL: | |
639 | case SIOCCHGTUNNEL: | |
640 | err = -EPERM; | |
641 | if (!capable(CAP_NET_ADMIN)) | |
642 | goto done; | |
643 | ||
644 | err = -EFAULT; | |
645 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
646 | goto done; | |
647 | ||
648 | err = -EINVAL; | |
649 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || | |
650 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
651 | goto done; | |
652 | if (p.iph.ttl) | |
653 | p.iph.frag_off |= htons(IP_DF); | |
654 | ||
655 | t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); | |
656 | ||
657 | if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
658 | if (t != NULL) { | |
659 | if (t->dev != dev) { | |
660 | err = -EEXIST; | |
661 | break; | |
662 | } | |
663 | } else { | |
664 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
665 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
666 | err = -EINVAL; | |
667 | break; | |
668 | } | |
669 | t = netdev_priv(dev); | |
670 | ipip_tunnel_unlink(ipn, t); | |
671 | synchronize_net(); | |
672 | t->parms.iph.saddr = p.iph.saddr; | |
673 | t->parms.iph.daddr = p.iph.daddr; | |
674 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
675 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
676 | ipip_tunnel_link(ipn, t); | |
677 | netdev_state_change(dev); | |
678 | } | |
679 | } | |
680 | ||
681 | if (t) { | |
682 | err = 0; | |
683 | if (cmd == SIOCCHGTUNNEL) { | |
684 | t->parms.iph.ttl = p.iph.ttl; | |
685 | t->parms.iph.tos = p.iph.tos; | |
686 | t->parms.iph.frag_off = p.iph.frag_off; | |
687 | if (t->parms.link != p.link) { | |
688 | t->parms.link = p.link; | |
689 | ipip_tunnel_bind_dev(dev); | |
690 | netdev_state_change(dev); | |
691 | } | |
692 | } | |
693 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
694 | err = -EFAULT; | |
695 | } else | |
696 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
697 | break; | |
698 | ||
699 | case SIOCDELTUNNEL: | |
700 | err = -EPERM; | |
701 | if (!capable(CAP_NET_ADMIN)) | |
702 | goto done; | |
703 | ||
704 | if (dev == ipn->fb_tunnel_dev) { | |
705 | err = -EFAULT; | |
706 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
707 | goto done; | |
708 | err = -ENOENT; | |
709 | if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL) | |
710 | goto done; | |
711 | err = -EPERM; | |
712 | if (t->dev == ipn->fb_tunnel_dev) | |
713 | goto done; | |
714 | dev = t->dev; | |
715 | } | |
716 | unregister_netdevice(dev); | |
717 | err = 0; | |
718 | break; | |
719 | ||
720 | default: | |
721 | err = -EINVAL; | |
722 | } | |
723 | ||
724 | done: | |
725 | return err; | |
726 | } | |
727 | ||
728 | static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
729 | { | |
730 | if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
731 | return -EINVAL; | |
732 | dev->mtu = new_mtu; | |
733 | return 0; | |
734 | } | |
735 | ||
736 | static const struct net_device_ops ipip_netdev_ops = { | |
737 | .ndo_uninit = ipip_tunnel_uninit, | |
738 | .ndo_start_xmit = ipip_tunnel_xmit, | |
739 | .ndo_do_ioctl = ipip_tunnel_ioctl, | |
740 | .ndo_change_mtu = ipip_tunnel_change_mtu, | |
741 | .ndo_get_stats = ipip_get_stats, | |
742 | }; | |
743 | ||
744 | static void ipip_dev_free(struct net_device *dev) | |
745 | { | |
746 | free_percpu(dev->tstats); | |
747 | free_netdev(dev); | |
748 | } | |
749 | ||
750 | static void ipip_tunnel_setup(struct net_device *dev) | |
751 | { | |
752 | dev->netdev_ops = &ipip_netdev_ops; | |
753 | dev->destructor = ipip_dev_free; | |
754 | ||
755 | dev->type = ARPHRD_TUNNEL; | |
756 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
757 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); | |
758 | dev->flags = IFF_NOARP; | |
759 | dev->iflink = 0; | |
760 | dev->addr_len = 4; | |
761 | dev->features |= NETIF_F_NETNS_LOCAL; | |
762 | dev->features |= NETIF_F_LLTX; | |
763 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | |
764 | } | |
765 | ||
766 | static int ipip_tunnel_init(struct net_device *dev) | |
767 | { | |
768 | struct ip_tunnel *tunnel = netdev_priv(dev); | |
769 | ||
770 | tunnel->dev = dev; | |
771 | strcpy(tunnel->parms.name, dev->name); | |
772 | ||
773 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
774 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
775 | ||
776 | ipip_tunnel_bind_dev(dev); | |
777 | ||
778 | dev->tstats = alloc_percpu(struct pcpu_tstats); | |
779 | if (!dev->tstats) | |
780 | return -ENOMEM; | |
781 | ||
782 | return 0; | |
783 | } | |
784 | ||
785 | static int __net_init ipip_fb_tunnel_init(struct net_device *dev) | |
786 | { | |
787 | struct ip_tunnel *tunnel = netdev_priv(dev); | |
788 | struct iphdr *iph = &tunnel->parms.iph; | |
789 | struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id); | |
790 | ||
791 | tunnel->dev = dev; | |
792 | strcpy(tunnel->parms.name, dev->name); | |
793 | ||
794 | iph->version = 4; | |
795 | iph->protocol = IPPROTO_IPIP; | |
796 | iph->ihl = 5; | |
797 | ||
798 | dev->tstats = alloc_percpu(struct pcpu_tstats); | |
799 | if (!dev->tstats) | |
800 | return -ENOMEM; | |
801 | ||
802 | dev_hold(dev); | |
803 | rcu_assign_pointer(ipn->tunnels_wc[0], tunnel); | |
804 | return 0; | |
805 | } | |
806 | ||
807 | static struct xfrm_tunnel ipip_handler __read_mostly = { | |
808 | .handler = ipip_rcv, | |
809 | .err_handler = ipip_err, | |
810 | .priority = 1, | |
811 | }; | |
812 | ||
813 | static const char banner[] __initconst = | |
814 | KERN_INFO "IPv4 over IPv4 tunneling driver\n"; | |
815 | ||
816 | static void ipip_destroy_tunnels(struct ipip_net *ipn, struct list_head *head) | |
817 | { | |
818 | int prio; | |
819 | ||
820 | for (prio = 1; prio < 4; prio++) { | |
821 | int h; | |
822 | for (h = 0; h < HASH_SIZE; h++) { | |
823 | struct ip_tunnel *t; | |
824 | ||
825 | t = rtnl_dereference(ipn->tunnels[prio][h]); | |
826 | while (t != NULL) { | |
827 | unregister_netdevice_queue(t->dev, head); | |
828 | t = rtnl_dereference(t->next); | |
829 | } | |
830 | } | |
831 | } | |
832 | } | |
833 | ||
834 | static int __net_init ipip_init_net(struct net *net) | |
835 | { | |
836 | struct ipip_net *ipn = net_generic(net, ipip_net_id); | |
837 | int err; | |
838 | ||
839 | ipn->tunnels[0] = ipn->tunnels_wc; | |
840 | ipn->tunnels[1] = ipn->tunnels_l; | |
841 | ipn->tunnels[2] = ipn->tunnels_r; | |
842 | ipn->tunnels[3] = ipn->tunnels_r_l; | |
843 | ||
844 | ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), | |
845 | "tunl0", | |
846 | ipip_tunnel_setup); | |
847 | if (!ipn->fb_tunnel_dev) { | |
848 | err = -ENOMEM; | |
849 | goto err_alloc_dev; | |
850 | } | |
851 | dev_net_set(ipn->fb_tunnel_dev, net); | |
852 | ||
853 | err = ipip_fb_tunnel_init(ipn->fb_tunnel_dev); | |
854 | if (err) | |
855 | goto err_reg_dev; | |
856 | ||
857 | if ((err = register_netdev(ipn->fb_tunnel_dev))) | |
858 | goto err_reg_dev; | |
859 | ||
860 | return 0; | |
861 | ||
862 | err_reg_dev: | |
863 | ipip_dev_free(ipn->fb_tunnel_dev); | |
864 | err_alloc_dev: | |
865 | /* nothing */ | |
866 | return err; | |
867 | } | |
868 | ||
869 | static void __net_exit ipip_exit_net(struct net *net) | |
870 | { | |
871 | struct ipip_net *ipn = net_generic(net, ipip_net_id); | |
872 | LIST_HEAD(list); | |
873 | ||
874 | rtnl_lock(); | |
875 | ipip_destroy_tunnels(ipn, &list); | |
876 | unregister_netdevice_queue(ipn->fb_tunnel_dev, &list); | |
877 | unregister_netdevice_many(&list); | |
878 | rtnl_unlock(); | |
879 | } | |
880 | ||
881 | static struct pernet_operations ipip_net_ops = { | |
882 | .init = ipip_init_net, | |
883 | .exit = ipip_exit_net, | |
884 | .id = &ipip_net_id, | |
885 | .size = sizeof(struct ipip_net), | |
886 | }; | |
887 | ||
888 | static int __init ipip_init(void) | |
889 | { | |
890 | int err; | |
891 | ||
892 | printk(banner); | |
893 | ||
894 | err = register_pernet_device(&ipip_net_ops); | |
895 | if (err < 0) | |
896 | return err; | |
897 | err = xfrm4_tunnel_register(&ipip_handler, AF_INET); | |
898 | if (err < 0) { | |
899 | unregister_pernet_device(&ipip_net_ops); | |
900 | printk(KERN_INFO "ipip init: can't register tunnel\n"); | |
901 | } | |
902 | return err; | |
903 | } | |
904 | ||
905 | static void __exit ipip_fini(void) | |
906 | { | |
907 | if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET)) | |
908 | printk(KERN_INFO "ipip close: can't deregister tunnel\n"); | |
909 | ||
910 | unregister_pernet_device(&ipip_net_ops); | |
911 | } | |
912 | ||
913 | module_init(ipip_init); | |
914 | module_exit(ipip_fini); | |
915 | MODULE_LICENSE("GPL"); |