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1 | /* | |
2 | * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | * | |
14 | * Changes: | |
15 | * Roger Venning <r.venning@telstra.com>: 6to4 support | |
16 | * Nate Thompson <nate@thebog.net>: 6to4 support | |
17 | * Fred Templin <fred.l.templin@boeing.com>: isatap support | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/capability.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/socket.h> | |
25 | #include <linux/sockios.h> | |
26 | #include <linux/net.h> | |
27 | #include <linux/in6.h> | |
28 | #include <linux/netdevice.h> | |
29 | #include <linux/if_arp.h> | |
30 | #include <linux/icmp.h> | |
31 | #include <asm/uaccess.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/netfilter_ipv4.h> | |
34 | #include <linux/if_ether.h> | |
35 | ||
36 | #include <net/sock.h> | |
37 | #include <net/snmp.h> | |
38 | ||
39 | #include <net/ipv6.h> | |
40 | #include <net/protocol.h> | |
41 | #include <net/transp_v6.h> | |
42 | #include <net/ip6_fib.h> | |
43 | #include <net/ip6_route.h> | |
44 | #include <net/ndisc.h> | |
45 | #include <net/addrconf.h> | |
46 | #include <net/ip.h> | |
47 | #include <net/udp.h> | |
48 | #include <net/icmp.h> | |
49 | #include <net/ipip.h> | |
50 | #include <net/inet_ecn.h> | |
51 | #include <net/xfrm.h> | |
52 | #include <net/dsfield.h> | |
53 | #include <net/net_namespace.h> | |
54 | #include <net/netns/generic.h> | |
55 | ||
56 | /* | |
57 | This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c | |
58 | ||
59 | For comments look at net/ipv4/ip_gre.c --ANK | |
60 | */ | |
61 | ||
62 | #define HASH_SIZE 16 | |
63 | #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) | |
64 | ||
65 | static void ipip6_fb_tunnel_init(struct net_device *dev); | |
66 | static void ipip6_tunnel_init(struct net_device *dev); | |
67 | static void ipip6_tunnel_setup(struct net_device *dev); | |
68 | ||
69 | static int sit_net_id; | |
70 | struct sit_net { | |
71 | struct ip_tunnel *tunnels_r_l[HASH_SIZE]; | |
72 | struct ip_tunnel *tunnels_r[HASH_SIZE]; | |
73 | struct ip_tunnel *tunnels_l[HASH_SIZE]; | |
74 | struct ip_tunnel *tunnels_wc[1]; | |
75 | struct ip_tunnel **tunnels[4]; | |
76 | ||
77 | struct net_device *fb_tunnel_dev; | |
78 | }; | |
79 | ||
80 | static DEFINE_RWLOCK(ipip6_lock); | |
81 | ||
82 | static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, | |
83 | struct net_device *dev, __be32 remote, __be32 local) | |
84 | { | |
85 | unsigned h0 = HASH(remote); | |
86 | unsigned h1 = HASH(local); | |
87 | struct ip_tunnel *t; | |
88 | struct sit_net *sitn = net_generic(net, sit_net_id); | |
89 | ||
90 | for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) { | |
91 | if (local == t->parms.iph.saddr && | |
92 | remote == t->parms.iph.daddr && | |
93 | (!dev || !t->parms.link || dev->iflink == t->parms.link) && | |
94 | (t->dev->flags & IFF_UP)) | |
95 | return t; | |
96 | } | |
97 | for (t = sitn->tunnels_r[h0]; t; t = t->next) { | |
98 | if (remote == t->parms.iph.daddr && | |
99 | (!dev || !t->parms.link || dev->iflink == t->parms.link) && | |
100 | (t->dev->flags & IFF_UP)) | |
101 | return t; | |
102 | } | |
103 | for (t = sitn->tunnels_l[h1]; t; t = t->next) { | |
104 | if (local == t->parms.iph.saddr && | |
105 | (!dev || !t->parms.link || dev->iflink == t->parms.link) && | |
106 | (t->dev->flags & IFF_UP)) | |
107 | return t; | |
108 | } | |
109 | t = sitn->tunnels_wc[0]; | |
110 | if ((t != NULL) && (t->dev->flags & IFF_UP)) | |
111 | return t; | |
112 | return NULL; | |
113 | } | |
114 | ||
115 | static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, | |
116 | struct ip_tunnel_parm *parms) | |
117 | { | |
118 | __be32 remote = parms->iph.daddr; | |
119 | __be32 local = parms->iph.saddr; | |
120 | unsigned h = 0; | |
121 | int prio = 0; | |
122 | ||
123 | if (remote) { | |
124 | prio |= 2; | |
125 | h ^= HASH(remote); | |
126 | } | |
127 | if (local) { | |
128 | prio |= 1; | |
129 | h ^= HASH(local); | |
130 | } | |
131 | return &sitn->tunnels[prio][h]; | |
132 | } | |
133 | ||
134 | static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, | |
135 | struct ip_tunnel *t) | |
136 | { | |
137 | return __ipip6_bucket(sitn, &t->parms); | |
138 | } | |
139 | ||
140 | static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) | |
141 | { | |
142 | struct ip_tunnel **tp; | |
143 | ||
144 | for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { | |
145 | if (t == *tp) { | |
146 | write_lock_bh(&ipip6_lock); | |
147 | *tp = t->next; | |
148 | write_unlock_bh(&ipip6_lock); | |
149 | break; | |
150 | } | |
151 | } | |
152 | } | |
153 | ||
154 | static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) | |
155 | { | |
156 | struct ip_tunnel **tp = ipip6_bucket(sitn, t); | |
157 | ||
158 | t->next = *tp; | |
159 | write_lock_bh(&ipip6_lock); | |
160 | *tp = t; | |
161 | write_unlock_bh(&ipip6_lock); | |
162 | } | |
163 | ||
164 | static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, | |
165 | struct ip_tunnel_parm *parms, int create) | |
166 | { | |
167 | __be32 remote = parms->iph.daddr; | |
168 | __be32 local = parms->iph.saddr; | |
169 | struct ip_tunnel *t, **tp, *nt; | |
170 | struct net_device *dev; | |
171 | char name[IFNAMSIZ]; | |
172 | struct sit_net *sitn = net_generic(net, sit_net_id); | |
173 | ||
174 | for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { | |
175 | if (local == t->parms.iph.saddr && | |
176 | remote == t->parms.iph.daddr && | |
177 | parms->link == t->parms.link) { | |
178 | if (create) | |
179 | return NULL; | |
180 | else | |
181 | return t; | |
182 | } | |
183 | } | |
184 | if (!create) | |
185 | goto failed; | |
186 | ||
187 | if (parms->name[0]) | |
188 | strlcpy(name, parms->name, IFNAMSIZ); | |
189 | else | |
190 | sprintf(name, "sit%%d"); | |
191 | ||
192 | dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); | |
193 | if (dev == NULL) | |
194 | return NULL; | |
195 | ||
196 | dev_net_set(dev, net); | |
197 | ||
198 | if (strchr(name, '%')) { | |
199 | if (dev_alloc_name(dev, name) < 0) | |
200 | goto failed_free; | |
201 | } | |
202 | ||
203 | nt = netdev_priv(dev); | |
204 | ||
205 | nt->parms = *parms; | |
206 | ipip6_tunnel_init(dev); | |
207 | ||
208 | if (parms->i_flags & SIT_ISATAP) | |
209 | dev->priv_flags |= IFF_ISATAP; | |
210 | ||
211 | if (register_netdevice(dev) < 0) | |
212 | goto failed_free; | |
213 | ||
214 | dev_hold(dev); | |
215 | ||
216 | ipip6_tunnel_link(sitn, nt); | |
217 | return nt; | |
218 | ||
219 | failed_free: | |
220 | free_netdev(dev); | |
221 | failed: | |
222 | return NULL; | |
223 | } | |
224 | ||
225 | static struct ip_tunnel_prl_entry * | |
226 | __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) | |
227 | { | |
228 | struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL; | |
229 | ||
230 | for (p = t->prl; p; p = p->next) | |
231 | if (p->addr == addr) | |
232 | break; | |
233 | return p; | |
234 | ||
235 | } | |
236 | ||
237 | static int ipip6_tunnel_get_prl(struct ip_tunnel *t, | |
238 | struct ip_tunnel_prl __user *a) | |
239 | { | |
240 | struct ip_tunnel_prl kprl, *kp; | |
241 | struct ip_tunnel_prl_entry *prl; | |
242 | unsigned int cmax, c = 0, ca, len; | |
243 | int ret = 0; | |
244 | ||
245 | if (copy_from_user(&kprl, a, sizeof(kprl))) | |
246 | return -EFAULT; | |
247 | cmax = kprl.datalen / sizeof(kprl); | |
248 | if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) | |
249 | cmax = 1; | |
250 | ||
251 | /* For simple GET or for root users, | |
252 | * we try harder to allocate. | |
253 | */ | |
254 | kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? | |
255 | kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : | |
256 | NULL; | |
257 | ||
258 | read_lock(&ipip6_lock); | |
259 | ||
260 | ca = t->prl_count < cmax ? t->prl_count : cmax; | |
261 | ||
262 | if (!kp) { | |
263 | /* We don't try hard to allocate much memory for | |
264 | * non-root users. | |
265 | * For root users, retry allocating enough memory for | |
266 | * the answer. | |
267 | */ | |
268 | kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); | |
269 | if (!kp) { | |
270 | ret = -ENOMEM; | |
271 | goto out; | |
272 | } | |
273 | } | |
274 | ||
275 | c = 0; | |
276 | for (prl = t->prl; prl; prl = prl->next) { | |
277 | if (c > cmax) | |
278 | break; | |
279 | if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) | |
280 | continue; | |
281 | kp[c].addr = prl->addr; | |
282 | kp[c].flags = prl->flags; | |
283 | c++; | |
284 | if (kprl.addr != htonl(INADDR_ANY)) | |
285 | break; | |
286 | } | |
287 | out: | |
288 | read_unlock(&ipip6_lock); | |
289 | ||
290 | len = sizeof(*kp) * c; | |
291 | ret = 0; | |
292 | if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) | |
293 | ret = -EFAULT; | |
294 | ||
295 | kfree(kp); | |
296 | ||
297 | return ret; | |
298 | } | |
299 | ||
300 | static int | |
301 | ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) | |
302 | { | |
303 | struct ip_tunnel_prl_entry *p; | |
304 | int err = 0; | |
305 | ||
306 | if (a->addr == htonl(INADDR_ANY)) | |
307 | return -EINVAL; | |
308 | ||
309 | write_lock(&ipip6_lock); | |
310 | ||
311 | for (p = t->prl; p; p = p->next) { | |
312 | if (p->addr == a->addr) { | |
313 | if (chg) | |
314 | goto update; | |
315 | err = -EEXIST; | |
316 | goto out; | |
317 | } | |
318 | } | |
319 | ||
320 | if (chg) { | |
321 | err = -ENXIO; | |
322 | goto out; | |
323 | } | |
324 | ||
325 | p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); | |
326 | if (!p) { | |
327 | err = -ENOBUFS; | |
328 | goto out; | |
329 | } | |
330 | ||
331 | p->next = t->prl; | |
332 | t->prl = p; | |
333 | t->prl_count++; | |
334 | update: | |
335 | p->addr = a->addr; | |
336 | p->flags = a->flags; | |
337 | out: | |
338 | write_unlock(&ipip6_lock); | |
339 | return err; | |
340 | } | |
341 | ||
342 | static int | |
343 | ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) | |
344 | { | |
345 | struct ip_tunnel_prl_entry *x, **p; | |
346 | int err = 0; | |
347 | ||
348 | write_lock(&ipip6_lock); | |
349 | ||
350 | if (a && a->addr != htonl(INADDR_ANY)) { | |
351 | for (p = &t->prl; *p; p = &(*p)->next) { | |
352 | if ((*p)->addr == a->addr) { | |
353 | x = *p; | |
354 | *p = x->next; | |
355 | kfree(x); | |
356 | t->prl_count--; | |
357 | goto out; | |
358 | } | |
359 | } | |
360 | err = -ENXIO; | |
361 | } else { | |
362 | while (t->prl) { | |
363 | x = t->prl; | |
364 | t->prl = t->prl->next; | |
365 | kfree(x); | |
366 | t->prl_count--; | |
367 | } | |
368 | } | |
369 | out: | |
370 | write_unlock(&ipip6_lock); | |
371 | return err; | |
372 | } | |
373 | ||
374 | static int | |
375 | isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) | |
376 | { | |
377 | struct ip_tunnel_prl_entry *p; | |
378 | int ok = 1; | |
379 | ||
380 | read_lock(&ipip6_lock); | |
381 | p = __ipip6_tunnel_locate_prl(t, iph->saddr); | |
382 | if (p) { | |
383 | if (p->flags & PRL_DEFAULT) | |
384 | skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; | |
385 | else | |
386 | skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; | |
387 | } else { | |
388 | struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; | |
389 | if (ipv6_addr_is_isatap(addr6) && | |
390 | (addr6->s6_addr32[3] == iph->saddr) && | |
391 | ipv6_chk_prefix(addr6, t->dev)) | |
392 | skb->ndisc_nodetype = NDISC_NODETYPE_HOST; | |
393 | else | |
394 | ok = 0; | |
395 | } | |
396 | read_unlock(&ipip6_lock); | |
397 | return ok; | |
398 | } | |
399 | ||
400 | static void ipip6_tunnel_uninit(struct net_device *dev) | |
401 | { | |
402 | struct net *net = dev_net(dev); | |
403 | struct sit_net *sitn = net_generic(net, sit_net_id); | |
404 | ||
405 | if (dev == sitn->fb_tunnel_dev) { | |
406 | write_lock_bh(&ipip6_lock); | |
407 | sitn->tunnels_wc[0] = NULL; | |
408 | write_unlock_bh(&ipip6_lock); | |
409 | dev_put(dev); | |
410 | } else { | |
411 | ipip6_tunnel_unlink(sitn, netdev_priv(dev)); | |
412 | ipip6_tunnel_del_prl(netdev_priv(dev), NULL); | |
413 | dev_put(dev); | |
414 | } | |
415 | } | |
416 | ||
417 | ||
418 | static int ipip6_err(struct sk_buff *skb, u32 info) | |
419 | { | |
420 | ||
421 | /* All the routers (except for Linux) return only | |
422 | 8 bytes of packet payload. It means, that precise relaying of | |
423 | ICMP in the real Internet is absolutely infeasible. | |
424 | */ | |
425 | struct iphdr *iph = (struct iphdr*)skb->data; | |
426 | const int type = icmp_hdr(skb)->type; | |
427 | const int code = icmp_hdr(skb)->code; | |
428 | struct ip_tunnel *t; | |
429 | int err; | |
430 | ||
431 | switch (type) { | |
432 | default: | |
433 | case ICMP_PARAMETERPROB: | |
434 | return 0; | |
435 | ||
436 | case ICMP_DEST_UNREACH: | |
437 | switch (code) { | |
438 | case ICMP_SR_FAILED: | |
439 | case ICMP_PORT_UNREACH: | |
440 | /* Impossible event. */ | |
441 | return 0; | |
442 | case ICMP_FRAG_NEEDED: | |
443 | /* Soft state for pmtu is maintained by IP core. */ | |
444 | return 0; | |
445 | default: | |
446 | /* All others are translated to HOST_UNREACH. | |
447 | rfc2003 contains "deep thoughts" about NET_UNREACH, | |
448 | I believe they are just ether pollution. --ANK | |
449 | */ | |
450 | break; | |
451 | } | |
452 | break; | |
453 | case ICMP_TIME_EXCEEDED: | |
454 | if (code != ICMP_EXC_TTL) | |
455 | return 0; | |
456 | break; | |
457 | } | |
458 | ||
459 | err = -ENOENT; | |
460 | ||
461 | read_lock(&ipip6_lock); | |
462 | t = ipip6_tunnel_lookup(dev_net(skb->dev), | |
463 | skb->dev, | |
464 | iph->daddr, | |
465 | iph->saddr); | |
466 | if (t == NULL || t->parms.iph.daddr == 0) | |
467 | goto out; | |
468 | ||
469 | err = 0; | |
470 | if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) | |
471 | goto out; | |
472 | ||
473 | if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) | |
474 | t->err_count++; | |
475 | else | |
476 | t->err_count = 1; | |
477 | t->err_time = jiffies; | |
478 | out: | |
479 | read_unlock(&ipip6_lock); | |
480 | return err; | |
481 | } | |
482 | ||
483 | static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) | |
484 | { | |
485 | if (INET_ECN_is_ce(iph->tos)) | |
486 | IP6_ECN_set_ce(ipv6_hdr(skb)); | |
487 | } | |
488 | ||
489 | static int ipip6_rcv(struct sk_buff *skb) | |
490 | { | |
491 | struct iphdr *iph; | |
492 | struct ip_tunnel *tunnel; | |
493 | ||
494 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
495 | goto out; | |
496 | ||
497 | iph = ip_hdr(skb); | |
498 | ||
499 | read_lock(&ipip6_lock); | |
500 | tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, | |
501 | iph->saddr, iph->daddr); | |
502 | if (tunnel != NULL) { | |
503 | secpath_reset(skb); | |
504 | skb->mac_header = skb->network_header; | |
505 | skb_reset_network_header(skb); | |
506 | IPCB(skb)->flags = 0; | |
507 | skb->protocol = htons(ETH_P_IPV6); | |
508 | skb->pkt_type = PACKET_HOST; | |
509 | ||
510 | if ((tunnel->dev->priv_flags & IFF_ISATAP) && | |
511 | !isatap_chksrc(skb, iph, tunnel)) { | |
512 | tunnel->dev->stats.rx_errors++; | |
513 | read_unlock(&ipip6_lock); | |
514 | kfree_skb(skb); | |
515 | return 0; | |
516 | } | |
517 | tunnel->dev->stats.rx_packets++; | |
518 | tunnel->dev->stats.rx_bytes += skb->len; | |
519 | skb->dev = tunnel->dev; | |
520 | skb_dst_drop(skb); | |
521 | nf_reset(skb); | |
522 | ipip6_ecn_decapsulate(iph, skb); | |
523 | netif_rx(skb); | |
524 | read_unlock(&ipip6_lock); | |
525 | return 0; | |
526 | } | |
527 | ||
528 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); | |
529 | read_unlock(&ipip6_lock); | |
530 | out: | |
531 | kfree_skb(skb); | |
532 | return 0; | |
533 | } | |
534 | ||
535 | /* Returns the embedded IPv4 address if the IPv6 address | |
536 | comes from 6to4 (RFC 3056) addr space */ | |
537 | ||
538 | static inline __be32 try_6to4(struct in6_addr *v6dst) | |
539 | { | |
540 | __be32 dst = 0; | |
541 | ||
542 | if (v6dst->s6_addr16[0] == htons(0x2002)) { | |
543 | /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ | |
544 | memcpy(&dst, &v6dst->s6_addr16[1], 4); | |
545 | } | |
546 | return dst; | |
547 | } | |
548 | ||
549 | /* | |
550 | * This function assumes it is being called from dev_queue_xmit() | |
551 | * and that skb is filled properly by that function. | |
552 | */ | |
553 | ||
554 | static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, | |
555 | struct net_device *dev) | |
556 | { | |
557 | struct ip_tunnel *tunnel = netdev_priv(dev); | |
558 | struct net_device_stats *stats = &tunnel->dev->stats; | |
559 | struct iphdr *tiph = &tunnel->parms.iph; | |
560 | struct ipv6hdr *iph6 = ipv6_hdr(skb); | |
561 | u8 tos = tunnel->parms.iph.tos; | |
562 | struct rtable *rt; /* Route to the other host */ | |
563 | struct net_device *tdev; /* Device to other host */ | |
564 | struct iphdr *iph; /* Our new IP header */ | |
565 | unsigned int max_headroom; /* The extra header space needed */ | |
566 | __be32 dst = tiph->daddr; | |
567 | int mtu; | |
568 | struct in6_addr *addr6; | |
569 | int addr_type; | |
570 | ||
571 | if (skb->protocol != htons(ETH_P_IPV6)) | |
572 | goto tx_error; | |
573 | ||
574 | /* ISATAP (RFC4214) - must come before 6to4 */ | |
575 | if (dev->priv_flags & IFF_ISATAP) { | |
576 | struct neighbour *neigh = NULL; | |
577 | ||
578 | if (skb_dst(skb)) | |
579 | neigh = skb_dst(skb)->neighbour; | |
580 | ||
581 | if (neigh == NULL) { | |
582 | if (net_ratelimit()) | |
583 | printk(KERN_DEBUG "sit: nexthop == NULL\n"); | |
584 | goto tx_error; | |
585 | } | |
586 | ||
587 | addr6 = (struct in6_addr*)&neigh->primary_key; | |
588 | addr_type = ipv6_addr_type(addr6); | |
589 | ||
590 | if ((addr_type & IPV6_ADDR_UNICAST) && | |
591 | ipv6_addr_is_isatap(addr6)) | |
592 | dst = addr6->s6_addr32[3]; | |
593 | else | |
594 | goto tx_error; | |
595 | } | |
596 | ||
597 | if (!dst) | |
598 | dst = try_6to4(&iph6->daddr); | |
599 | ||
600 | if (!dst) { | |
601 | struct neighbour *neigh = NULL; | |
602 | ||
603 | if (skb_dst(skb)) | |
604 | neigh = skb_dst(skb)->neighbour; | |
605 | ||
606 | if (neigh == NULL) { | |
607 | if (net_ratelimit()) | |
608 | printk(KERN_DEBUG "sit: nexthop == NULL\n"); | |
609 | goto tx_error; | |
610 | } | |
611 | ||
612 | addr6 = (struct in6_addr*)&neigh->primary_key; | |
613 | addr_type = ipv6_addr_type(addr6); | |
614 | ||
615 | if (addr_type == IPV6_ADDR_ANY) { | |
616 | addr6 = &ipv6_hdr(skb)->daddr; | |
617 | addr_type = ipv6_addr_type(addr6); | |
618 | } | |
619 | ||
620 | if ((addr_type & IPV6_ADDR_COMPATv4) == 0) | |
621 | goto tx_error_icmp; | |
622 | ||
623 | dst = addr6->s6_addr32[3]; | |
624 | } | |
625 | ||
626 | { | |
627 | struct flowi fl = { .nl_u = { .ip4_u = | |
628 | { .daddr = dst, | |
629 | .saddr = tiph->saddr, | |
630 | .tos = RT_TOS(tos) } }, | |
631 | .oif = tunnel->parms.link, | |
632 | .proto = IPPROTO_IPV6 }; | |
633 | if (ip_route_output_key(dev_net(dev), &rt, &fl)) { | |
634 | stats->tx_carrier_errors++; | |
635 | goto tx_error_icmp; | |
636 | } | |
637 | } | |
638 | if (rt->rt_type != RTN_UNICAST) { | |
639 | ip_rt_put(rt); | |
640 | stats->tx_carrier_errors++; | |
641 | goto tx_error_icmp; | |
642 | } | |
643 | tdev = rt->u.dst.dev; | |
644 | ||
645 | if (tdev == dev) { | |
646 | ip_rt_put(rt); | |
647 | stats->collisions++; | |
648 | goto tx_error; | |
649 | } | |
650 | ||
651 | if (tiph->frag_off) | |
652 | mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); | |
653 | else | |
654 | mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; | |
655 | ||
656 | if (mtu < 68) { | |
657 | stats->collisions++; | |
658 | ip_rt_put(rt); | |
659 | goto tx_error; | |
660 | } | |
661 | if (mtu < IPV6_MIN_MTU) | |
662 | mtu = IPV6_MIN_MTU; | |
663 | if (tunnel->parms.iph.daddr && skb_dst(skb)) | |
664 | skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); | |
665 | ||
666 | if (skb->len > mtu) { | |
667 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); | |
668 | ip_rt_put(rt); | |
669 | goto tx_error; | |
670 | } | |
671 | ||
672 | if (tunnel->err_count > 0) { | |
673 | if (time_before(jiffies, | |
674 | tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { | |
675 | tunnel->err_count--; | |
676 | dst_link_failure(skb); | |
677 | } else | |
678 | tunnel->err_count = 0; | |
679 | } | |
680 | ||
681 | /* | |
682 | * Okay, now see if we can stuff it in the buffer as-is. | |
683 | */ | |
684 | max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); | |
685 | ||
686 | if (skb_headroom(skb) < max_headroom || skb_shared(skb) || | |
687 | (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { | |
688 | struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); | |
689 | if (!new_skb) { | |
690 | ip_rt_put(rt); | |
691 | stats->tx_dropped++; | |
692 | dev_kfree_skb(skb); | |
693 | return NETDEV_TX_OK; | |
694 | } | |
695 | if (skb->sk) | |
696 | skb_set_owner_w(new_skb, skb->sk); | |
697 | dev_kfree_skb(skb); | |
698 | skb = new_skb; | |
699 | iph6 = ipv6_hdr(skb); | |
700 | } | |
701 | ||
702 | skb->transport_header = skb->network_header; | |
703 | skb_push(skb, sizeof(struct iphdr)); | |
704 | skb_reset_network_header(skb); | |
705 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); | |
706 | IPCB(skb)->flags = 0; | |
707 | skb_dst_drop(skb); | |
708 | skb_dst_set(skb, &rt->u.dst); | |
709 | ||
710 | /* | |
711 | * Push down and install the IPIP header. | |
712 | */ | |
713 | ||
714 | iph = ip_hdr(skb); | |
715 | iph->version = 4; | |
716 | iph->ihl = sizeof(struct iphdr)>>2; | |
717 | if (mtu > IPV6_MIN_MTU) | |
718 | iph->frag_off = tiph->frag_off; | |
719 | else | |
720 | iph->frag_off = 0; | |
721 | ||
722 | iph->protocol = IPPROTO_IPV6; | |
723 | iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); | |
724 | iph->daddr = rt->rt_dst; | |
725 | iph->saddr = rt->rt_src; | |
726 | ||
727 | if ((iph->ttl = tiph->ttl) == 0) | |
728 | iph->ttl = iph6->hop_limit; | |
729 | ||
730 | nf_reset(skb); | |
731 | ||
732 | IPTUNNEL_XMIT(); | |
733 | return NETDEV_TX_OK; | |
734 | ||
735 | tx_error_icmp: | |
736 | dst_link_failure(skb); | |
737 | tx_error: | |
738 | stats->tx_errors++; | |
739 | dev_kfree_skb(skb); | |
740 | return NETDEV_TX_OK; | |
741 | } | |
742 | ||
743 | static void ipip6_tunnel_bind_dev(struct net_device *dev) | |
744 | { | |
745 | struct net_device *tdev = NULL; | |
746 | struct ip_tunnel *tunnel; | |
747 | struct iphdr *iph; | |
748 | ||
749 | tunnel = netdev_priv(dev); | |
750 | iph = &tunnel->parms.iph; | |
751 | ||
752 | if (iph->daddr) { | |
753 | struct flowi fl = { .nl_u = { .ip4_u = | |
754 | { .daddr = iph->daddr, | |
755 | .saddr = iph->saddr, | |
756 | .tos = RT_TOS(iph->tos) } }, | |
757 | .oif = tunnel->parms.link, | |
758 | .proto = IPPROTO_IPV6 }; | |
759 | struct rtable *rt; | |
760 | if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { | |
761 | tdev = rt->u.dst.dev; | |
762 | ip_rt_put(rt); | |
763 | } | |
764 | dev->flags |= IFF_POINTOPOINT; | |
765 | } | |
766 | ||
767 | if (!tdev && tunnel->parms.link) | |
768 | tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); | |
769 | ||
770 | if (tdev) { | |
771 | dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); | |
772 | dev->mtu = tdev->mtu - sizeof(struct iphdr); | |
773 | if (dev->mtu < IPV6_MIN_MTU) | |
774 | dev->mtu = IPV6_MIN_MTU; | |
775 | } | |
776 | dev->iflink = tunnel->parms.link; | |
777 | } | |
778 | ||
779 | static int | |
780 | ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) | |
781 | { | |
782 | int err = 0; | |
783 | struct ip_tunnel_parm p; | |
784 | struct ip_tunnel_prl prl; | |
785 | struct ip_tunnel *t; | |
786 | struct net *net = dev_net(dev); | |
787 | struct sit_net *sitn = net_generic(net, sit_net_id); | |
788 | ||
789 | switch (cmd) { | |
790 | case SIOCGETTUNNEL: | |
791 | t = NULL; | |
792 | if (dev == sitn->fb_tunnel_dev) { | |
793 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { | |
794 | err = -EFAULT; | |
795 | break; | |
796 | } | |
797 | t = ipip6_tunnel_locate(net, &p, 0); | |
798 | } | |
799 | if (t == NULL) | |
800 | t = netdev_priv(dev); | |
801 | memcpy(&p, &t->parms, sizeof(p)); | |
802 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) | |
803 | err = -EFAULT; | |
804 | break; | |
805 | ||
806 | case SIOCADDTUNNEL: | |
807 | case SIOCCHGTUNNEL: | |
808 | err = -EPERM; | |
809 | if (!capable(CAP_NET_ADMIN)) | |
810 | goto done; | |
811 | ||
812 | err = -EFAULT; | |
813 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
814 | goto done; | |
815 | ||
816 | err = -EINVAL; | |
817 | if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || | |
818 | p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) | |
819 | goto done; | |
820 | if (p.iph.ttl) | |
821 | p.iph.frag_off |= htons(IP_DF); | |
822 | ||
823 | t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); | |
824 | ||
825 | if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { | |
826 | if (t != NULL) { | |
827 | if (t->dev != dev) { | |
828 | err = -EEXIST; | |
829 | break; | |
830 | } | |
831 | } else { | |
832 | if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || | |
833 | (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { | |
834 | err = -EINVAL; | |
835 | break; | |
836 | } | |
837 | t = netdev_priv(dev); | |
838 | ipip6_tunnel_unlink(sitn, t); | |
839 | t->parms.iph.saddr = p.iph.saddr; | |
840 | t->parms.iph.daddr = p.iph.daddr; | |
841 | memcpy(dev->dev_addr, &p.iph.saddr, 4); | |
842 | memcpy(dev->broadcast, &p.iph.daddr, 4); | |
843 | ipip6_tunnel_link(sitn, t); | |
844 | netdev_state_change(dev); | |
845 | } | |
846 | } | |
847 | ||
848 | if (t) { | |
849 | err = 0; | |
850 | if (cmd == SIOCCHGTUNNEL) { | |
851 | t->parms.iph.ttl = p.iph.ttl; | |
852 | t->parms.iph.tos = p.iph.tos; | |
853 | if (t->parms.link != p.link) { | |
854 | t->parms.link = p.link; | |
855 | ipip6_tunnel_bind_dev(dev); | |
856 | netdev_state_change(dev); | |
857 | } | |
858 | } | |
859 | if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) | |
860 | err = -EFAULT; | |
861 | } else | |
862 | err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); | |
863 | break; | |
864 | ||
865 | case SIOCDELTUNNEL: | |
866 | err = -EPERM; | |
867 | if (!capable(CAP_NET_ADMIN)) | |
868 | goto done; | |
869 | ||
870 | if (dev == sitn->fb_tunnel_dev) { | |
871 | err = -EFAULT; | |
872 | if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) | |
873 | goto done; | |
874 | err = -ENOENT; | |
875 | if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) | |
876 | goto done; | |
877 | err = -EPERM; | |
878 | if (t == netdev_priv(sitn->fb_tunnel_dev)) | |
879 | goto done; | |
880 | dev = t->dev; | |
881 | } | |
882 | unregister_netdevice(dev); | |
883 | err = 0; | |
884 | break; | |
885 | ||
886 | case SIOCGETPRL: | |
887 | err = -EINVAL; | |
888 | if (dev == sitn->fb_tunnel_dev) | |
889 | goto done; | |
890 | err = -ENOENT; | |
891 | if (!(t = netdev_priv(dev))) | |
892 | goto done; | |
893 | err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); | |
894 | break; | |
895 | ||
896 | case SIOCADDPRL: | |
897 | case SIOCDELPRL: | |
898 | case SIOCCHGPRL: | |
899 | err = -EPERM; | |
900 | if (!capable(CAP_NET_ADMIN)) | |
901 | goto done; | |
902 | err = -EINVAL; | |
903 | if (dev == sitn->fb_tunnel_dev) | |
904 | goto done; | |
905 | err = -EFAULT; | |
906 | if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) | |
907 | goto done; | |
908 | err = -ENOENT; | |
909 | if (!(t = netdev_priv(dev))) | |
910 | goto done; | |
911 | ||
912 | switch (cmd) { | |
913 | case SIOCDELPRL: | |
914 | err = ipip6_tunnel_del_prl(t, &prl); | |
915 | break; | |
916 | case SIOCADDPRL: | |
917 | case SIOCCHGPRL: | |
918 | err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); | |
919 | break; | |
920 | } | |
921 | netdev_state_change(dev); | |
922 | break; | |
923 | ||
924 | default: | |
925 | err = -EINVAL; | |
926 | } | |
927 | ||
928 | done: | |
929 | return err; | |
930 | } | |
931 | ||
932 | static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) | |
933 | { | |
934 | if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) | |
935 | return -EINVAL; | |
936 | dev->mtu = new_mtu; | |
937 | return 0; | |
938 | } | |
939 | ||
940 | static const struct net_device_ops ipip6_netdev_ops = { | |
941 | .ndo_uninit = ipip6_tunnel_uninit, | |
942 | .ndo_start_xmit = ipip6_tunnel_xmit, | |
943 | .ndo_do_ioctl = ipip6_tunnel_ioctl, | |
944 | .ndo_change_mtu = ipip6_tunnel_change_mtu, | |
945 | }; | |
946 | ||
947 | static void ipip6_tunnel_setup(struct net_device *dev) | |
948 | { | |
949 | dev->netdev_ops = &ipip6_netdev_ops; | |
950 | dev->destructor = free_netdev; | |
951 | ||
952 | dev->type = ARPHRD_SIT; | |
953 | dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); | |
954 | dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); | |
955 | dev->flags = IFF_NOARP; | |
956 | dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; | |
957 | dev->iflink = 0; | |
958 | dev->addr_len = 4; | |
959 | dev->features |= NETIF_F_NETNS_LOCAL; | |
960 | } | |
961 | ||
962 | static void ipip6_tunnel_init(struct net_device *dev) | |
963 | { | |
964 | struct ip_tunnel *tunnel = netdev_priv(dev); | |
965 | ||
966 | tunnel->dev = dev; | |
967 | strcpy(tunnel->parms.name, dev->name); | |
968 | ||
969 | memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); | |
970 | memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); | |
971 | ||
972 | ipip6_tunnel_bind_dev(dev); | |
973 | } | |
974 | ||
975 | static void ipip6_fb_tunnel_init(struct net_device *dev) | |
976 | { | |
977 | struct ip_tunnel *tunnel = netdev_priv(dev); | |
978 | struct iphdr *iph = &tunnel->parms.iph; | |
979 | struct net *net = dev_net(dev); | |
980 | struct sit_net *sitn = net_generic(net, sit_net_id); | |
981 | ||
982 | tunnel->dev = dev; | |
983 | strcpy(tunnel->parms.name, dev->name); | |
984 | ||
985 | iph->version = 4; | |
986 | iph->protocol = IPPROTO_IPV6; | |
987 | iph->ihl = 5; | |
988 | iph->ttl = 64; | |
989 | ||
990 | dev_hold(dev); | |
991 | sitn->tunnels_wc[0] = tunnel; | |
992 | } | |
993 | ||
994 | static struct xfrm_tunnel sit_handler = { | |
995 | .handler = ipip6_rcv, | |
996 | .err_handler = ipip6_err, | |
997 | .priority = 1, | |
998 | }; | |
999 | ||
1000 | static void sit_destroy_tunnels(struct sit_net *sitn) | |
1001 | { | |
1002 | int prio; | |
1003 | ||
1004 | for (prio = 1; prio < 4; prio++) { | |
1005 | int h; | |
1006 | for (h = 0; h < HASH_SIZE; h++) { | |
1007 | struct ip_tunnel *t; | |
1008 | while ((t = sitn->tunnels[prio][h]) != NULL) | |
1009 | unregister_netdevice(t->dev); | |
1010 | } | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | static int sit_init_net(struct net *net) | |
1015 | { | |
1016 | int err; | |
1017 | struct sit_net *sitn; | |
1018 | ||
1019 | err = -ENOMEM; | |
1020 | sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL); | |
1021 | if (sitn == NULL) | |
1022 | goto err_alloc; | |
1023 | ||
1024 | err = net_assign_generic(net, sit_net_id, sitn); | |
1025 | if (err < 0) | |
1026 | goto err_assign; | |
1027 | ||
1028 | sitn->tunnels[0] = sitn->tunnels_wc; | |
1029 | sitn->tunnels[1] = sitn->tunnels_l; | |
1030 | sitn->tunnels[2] = sitn->tunnels_r; | |
1031 | sitn->tunnels[3] = sitn->tunnels_r_l; | |
1032 | ||
1033 | sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", | |
1034 | ipip6_tunnel_setup); | |
1035 | if (!sitn->fb_tunnel_dev) { | |
1036 | err = -ENOMEM; | |
1037 | goto err_alloc_dev; | |
1038 | } | |
1039 | dev_net_set(sitn->fb_tunnel_dev, net); | |
1040 | ||
1041 | ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); | |
1042 | ||
1043 | if ((err = register_netdev(sitn->fb_tunnel_dev))) | |
1044 | goto err_reg_dev; | |
1045 | ||
1046 | return 0; | |
1047 | ||
1048 | err_reg_dev: | |
1049 | dev_put(sitn->fb_tunnel_dev); | |
1050 | free_netdev(sitn->fb_tunnel_dev); | |
1051 | err_alloc_dev: | |
1052 | /* nothing */ | |
1053 | err_assign: | |
1054 | kfree(sitn); | |
1055 | err_alloc: | |
1056 | return err; | |
1057 | } | |
1058 | ||
1059 | static void sit_exit_net(struct net *net) | |
1060 | { | |
1061 | struct sit_net *sitn; | |
1062 | ||
1063 | sitn = net_generic(net, sit_net_id); | |
1064 | rtnl_lock(); | |
1065 | sit_destroy_tunnels(sitn); | |
1066 | unregister_netdevice(sitn->fb_tunnel_dev); | |
1067 | rtnl_unlock(); | |
1068 | kfree(sitn); | |
1069 | } | |
1070 | ||
1071 | static struct pernet_operations sit_net_ops = { | |
1072 | .init = sit_init_net, | |
1073 | .exit = sit_exit_net, | |
1074 | }; | |
1075 | ||
1076 | static void __exit sit_cleanup(void) | |
1077 | { | |
1078 | xfrm4_tunnel_deregister(&sit_handler, AF_INET6); | |
1079 | ||
1080 | unregister_pernet_gen_device(sit_net_id, &sit_net_ops); | |
1081 | } | |
1082 | ||
1083 | static int __init sit_init(void) | |
1084 | { | |
1085 | int err; | |
1086 | ||
1087 | printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); | |
1088 | ||
1089 | if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { | |
1090 | printk(KERN_INFO "sit init: Can't add protocol\n"); | |
1091 | return -EAGAIN; | |
1092 | } | |
1093 | ||
1094 | err = register_pernet_gen_device(&sit_net_id, &sit_net_ops); | |
1095 | if (err < 0) | |
1096 | xfrm4_tunnel_deregister(&sit_handler, AF_INET6); | |
1097 | ||
1098 | return err; | |
1099 | } | |
1100 | ||
1101 | module_init(sit_init); | |
1102 | module_exit(sit_cleanup); | |
1103 | MODULE_LICENSE("GPL"); | |
1104 | MODULE_ALIAS("sit0"); |