mac80211: dont add BSS when creating IBSS
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / ip_options.c
blob2c88da6e7862f2b49d4d9ba17197eb9d10205fe8
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * The options processing module for ip.c
8 * Authors: A.N.Kuznetsov
12 #include <linux/capability.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <asm/uaccess.h>
16 #include <linux/skbuff.h>
17 #include <linux/ip.h>
18 #include <linux/icmp.h>
19 #include <linux/netdevice.h>
20 #include <linux/rtnetlink.h>
21 #include <net/sock.h>
22 #include <net/ip.h>
23 #include <net/icmp.h>
24 #include <net/route.h>
25 #include <net/cipso_ipv4.h>
28 * Write options to IP header, record destination address to
29 * source route option, address of outgoing interface
30 * (we should already know it, so that this function is allowed be
31 * called only after routing decision) and timestamp,
32 * if we originate this datagram.
34 * daddr is real destination address, next hop is recorded in IP header.
35 * saddr is address of outgoing interface.
38 void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
39 __be32 daddr, struct rtable *rt, int is_frag)
41 unsigned char *iph = skb_network_header(skb);
43 memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
44 memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
45 opt = &(IPCB(skb)->opt);
47 if (opt->srr)
48 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
50 if (!is_frag) {
51 if (opt->rr_needaddr)
52 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
53 if (opt->ts_needaddr)
54 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
55 if (opt->ts_needtime) {
56 struct timespec tv;
57 __be32 midtime;
58 getnstimeofday(&tv);
59 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
60 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
62 return;
64 if (opt->rr) {
65 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
66 opt->rr = 0;
67 opt->rr_needaddr = 0;
69 if (opt->ts) {
70 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
71 opt->ts = 0;
72 opt->ts_needaddr = opt->ts_needtime = 0;
77 * Provided (sopt, skb) points to received options,
78 * build in dopt compiled option set appropriate for answering.
79 * i.e. invert SRR option, copy anothers,
80 * and grab room in RR/TS options.
82 * NOTE: dopt cannot point to skb.
85 int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
87 struct ip_options *sopt;
88 unsigned char *sptr, *dptr;
89 int soffset, doffset;
90 int optlen;
91 __be32 daddr;
93 memset(dopt, 0, sizeof(struct ip_options));
95 sopt = &(IPCB(skb)->opt);
97 if (sopt->optlen == 0) {
98 dopt->optlen = 0;
99 return 0;
102 sptr = skb_network_header(skb);
103 dptr = dopt->__data;
105 daddr = skb->rtable->rt_spec_dst;
107 if (sopt->rr) {
108 optlen = sptr[sopt->rr+1];
109 soffset = sptr[sopt->rr+2];
110 dopt->rr = dopt->optlen + sizeof(struct iphdr);
111 memcpy(dptr, sptr+sopt->rr, optlen);
112 if (sopt->rr_needaddr && soffset <= optlen) {
113 if (soffset + 3 > optlen)
114 return -EINVAL;
115 dptr[2] = soffset + 4;
116 dopt->rr_needaddr = 1;
118 dptr += optlen;
119 dopt->optlen += optlen;
121 if (sopt->ts) {
122 optlen = sptr[sopt->ts+1];
123 soffset = sptr[sopt->ts+2];
124 dopt->ts = dopt->optlen + sizeof(struct iphdr);
125 memcpy(dptr, sptr+sopt->ts, optlen);
126 if (soffset <= optlen) {
127 if (sopt->ts_needaddr) {
128 if (soffset + 3 > optlen)
129 return -EINVAL;
130 dopt->ts_needaddr = 1;
131 soffset += 4;
133 if (sopt->ts_needtime) {
134 if (soffset + 3 > optlen)
135 return -EINVAL;
136 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
137 dopt->ts_needtime = 1;
138 soffset += 4;
139 } else {
140 dopt->ts_needtime = 0;
142 if (soffset + 8 <= optlen) {
143 __be32 addr;
145 memcpy(&addr, sptr+soffset-1, 4);
146 if (inet_addr_type(dev_net(skb->dst->dev), addr) != RTN_LOCAL) {
147 dopt->ts_needtime = 1;
148 soffset += 8;
153 dptr[2] = soffset;
155 dptr += optlen;
156 dopt->optlen += optlen;
158 if (sopt->srr) {
159 unsigned char * start = sptr+sopt->srr;
160 __be32 faddr;
162 optlen = start[1];
163 soffset = start[2];
164 doffset = 0;
165 if (soffset > optlen)
166 soffset = optlen + 1;
167 soffset -= 4;
168 if (soffset > 3) {
169 memcpy(&faddr, &start[soffset-1], 4);
170 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
171 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
173 * RFC1812 requires to fix illegal source routes.
175 if (memcmp(&ip_hdr(skb)->saddr,
176 &start[soffset + 3], 4) == 0)
177 doffset -= 4;
179 if (doffset > 3) {
180 memcpy(&start[doffset-1], &daddr, 4);
181 dopt->faddr = faddr;
182 dptr[0] = start[0];
183 dptr[1] = doffset+3;
184 dptr[2] = 4;
185 dptr += doffset+3;
186 dopt->srr = dopt->optlen + sizeof(struct iphdr);
187 dopt->optlen += doffset+3;
188 dopt->is_strictroute = sopt->is_strictroute;
191 if (sopt->cipso) {
192 optlen = sptr[sopt->cipso+1];
193 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
194 memcpy(dptr, sptr+sopt->cipso, optlen);
195 dptr += optlen;
196 dopt->optlen += optlen;
198 while (dopt->optlen & 3) {
199 *dptr++ = IPOPT_END;
200 dopt->optlen++;
202 return 0;
206 * Options "fragmenting", just fill options not
207 * allowed in fragments with NOOPs.
208 * Simple and stupid 8), but the most efficient way.
211 void ip_options_fragment(struct sk_buff * skb)
213 unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
214 struct ip_options * opt = &(IPCB(skb)->opt);
215 int l = opt->optlen;
216 int optlen;
218 while (l > 0) {
219 switch (*optptr) {
220 case IPOPT_END:
221 return;
222 case IPOPT_NOOP:
223 l--;
224 optptr++;
225 continue;
227 optlen = optptr[1];
228 if (optlen<2 || optlen>l)
229 return;
230 if (!IPOPT_COPIED(*optptr))
231 memset(optptr, IPOPT_NOOP, optlen);
232 l -= optlen;
233 optptr += optlen;
235 opt->ts = 0;
236 opt->rr = 0;
237 opt->rr_needaddr = 0;
238 opt->ts_needaddr = 0;
239 opt->ts_needtime = 0;
240 return;
244 * Verify options and fill pointers in struct options.
245 * Caller should clear *opt, and set opt->data.
246 * If opt == NULL, then skb->data should point to IP header.
249 int ip_options_compile(struct net *net,
250 struct ip_options * opt, struct sk_buff * skb)
252 int l;
253 unsigned char * iph;
254 unsigned char * optptr;
255 int optlen;
256 unsigned char * pp_ptr = NULL;
257 struct rtable *rt = NULL;
259 if (skb != NULL) {
260 rt = skb->rtable;
261 optptr = (unsigned char *)&(ip_hdr(skb)[1]);
262 } else
263 optptr = opt->__data;
264 iph = optptr - sizeof(struct iphdr);
266 for (l = opt->optlen; l > 0; ) {
267 switch (*optptr) {
268 case IPOPT_END:
269 for (optptr++, l--; l>0; optptr++, l--) {
270 if (*optptr != IPOPT_END) {
271 *optptr = IPOPT_END;
272 opt->is_changed = 1;
275 goto eol;
276 case IPOPT_NOOP:
277 l--;
278 optptr++;
279 continue;
281 optlen = optptr[1];
282 if (optlen<2 || optlen>l) {
283 pp_ptr = optptr;
284 goto error;
286 switch (*optptr) {
287 case IPOPT_SSRR:
288 case IPOPT_LSRR:
289 if (optlen < 3) {
290 pp_ptr = optptr + 1;
291 goto error;
293 if (optptr[2] < 4) {
294 pp_ptr = optptr + 2;
295 goto error;
297 /* NB: cf RFC-1812 5.2.4.1 */
298 if (opt->srr) {
299 pp_ptr = optptr;
300 goto error;
302 if (!skb) {
303 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
304 pp_ptr = optptr + 1;
305 goto error;
307 memcpy(&opt->faddr, &optptr[3], 4);
308 if (optlen > 7)
309 memmove(&optptr[3], &optptr[7], optlen-7);
311 opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
312 opt->srr = optptr - iph;
313 break;
314 case IPOPT_RR:
315 if (opt->rr) {
316 pp_ptr = optptr;
317 goto error;
319 if (optlen < 3) {
320 pp_ptr = optptr + 1;
321 goto error;
323 if (optptr[2] < 4) {
324 pp_ptr = optptr + 2;
325 goto error;
327 if (optptr[2] <= optlen) {
328 if (optptr[2]+3 > optlen) {
329 pp_ptr = optptr + 2;
330 goto error;
332 if (skb) {
333 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
334 opt->is_changed = 1;
336 optptr[2] += 4;
337 opt->rr_needaddr = 1;
339 opt->rr = optptr - iph;
340 break;
341 case IPOPT_TIMESTAMP:
342 if (opt->ts) {
343 pp_ptr = optptr;
344 goto error;
346 if (optlen < 4) {
347 pp_ptr = optptr + 1;
348 goto error;
350 if (optptr[2] < 5) {
351 pp_ptr = optptr + 2;
352 goto error;
354 if (optptr[2] <= optlen) {
355 __be32 *timeptr = NULL;
356 if (optptr[2]+3 > optptr[1]) {
357 pp_ptr = optptr + 2;
358 goto error;
360 switch (optptr[3]&0xF) {
361 case IPOPT_TS_TSONLY:
362 opt->ts = optptr - iph;
363 if (skb)
364 timeptr = (__be32*)&optptr[optptr[2]-1];
365 opt->ts_needtime = 1;
366 optptr[2] += 4;
367 break;
368 case IPOPT_TS_TSANDADDR:
369 if (optptr[2]+7 > optptr[1]) {
370 pp_ptr = optptr + 2;
371 goto error;
373 opt->ts = optptr - iph;
374 if (skb) {
375 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
376 timeptr = (__be32*)&optptr[optptr[2]+3];
378 opt->ts_needaddr = 1;
379 opt->ts_needtime = 1;
380 optptr[2] += 8;
381 break;
382 case IPOPT_TS_PRESPEC:
383 if (optptr[2]+7 > optptr[1]) {
384 pp_ptr = optptr + 2;
385 goto error;
387 opt->ts = optptr - iph;
389 __be32 addr;
390 memcpy(&addr, &optptr[optptr[2]-1], 4);
391 if (inet_addr_type(net, addr) == RTN_UNICAST)
392 break;
393 if (skb)
394 timeptr = (__be32*)&optptr[optptr[2]+3];
396 opt->ts_needtime = 1;
397 optptr[2] += 8;
398 break;
399 default:
400 if (!skb && !capable(CAP_NET_RAW)) {
401 pp_ptr = optptr + 3;
402 goto error;
404 break;
406 if (timeptr) {
407 struct timespec tv;
408 __be32 midtime;
409 getnstimeofday(&tv);
410 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
411 memcpy(timeptr, &midtime, sizeof(__be32));
412 opt->is_changed = 1;
414 } else {
415 unsigned overflow = optptr[3]>>4;
416 if (overflow == 15) {
417 pp_ptr = optptr + 3;
418 goto error;
420 opt->ts = optptr - iph;
421 if (skb) {
422 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
423 opt->is_changed = 1;
426 break;
427 case IPOPT_RA:
428 if (optlen < 4) {
429 pp_ptr = optptr + 1;
430 goto error;
432 if (optptr[2] == 0 && optptr[3] == 0)
433 opt->router_alert = optptr - iph;
434 break;
435 case IPOPT_CIPSO:
436 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
437 pp_ptr = optptr;
438 goto error;
440 opt->cipso = optptr - iph;
441 if (cipso_v4_validate(skb, &optptr)) {
442 pp_ptr = optptr;
443 goto error;
445 break;
446 case IPOPT_SEC:
447 case IPOPT_SID:
448 default:
449 if (!skb && !capable(CAP_NET_RAW)) {
450 pp_ptr = optptr;
451 goto error;
453 break;
455 l -= optlen;
456 optptr += optlen;
459 eol:
460 if (!pp_ptr)
461 return 0;
463 error:
464 if (skb) {
465 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
467 return -EINVAL;
472 * Undo all the changes done by ip_options_compile().
475 void ip_options_undo(struct ip_options * opt)
477 if (opt->srr) {
478 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
479 memmove(optptr+7, optptr+3, optptr[1]-7);
480 memcpy(optptr+3, &opt->faddr, 4);
482 if (opt->rr_needaddr) {
483 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
484 optptr[2] -= 4;
485 memset(&optptr[optptr[2]-1], 0, 4);
487 if (opt->ts) {
488 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
489 if (opt->ts_needtime) {
490 optptr[2] -= 4;
491 memset(&optptr[optptr[2]-1], 0, 4);
492 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
493 optptr[2] -= 4;
495 if (opt->ts_needaddr) {
496 optptr[2] -= 4;
497 memset(&optptr[optptr[2]-1], 0, 4);
502 static struct ip_options *ip_options_get_alloc(const int optlen)
504 return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
505 GFP_KERNEL);
508 static int ip_options_get_finish(struct net *net, struct ip_options **optp,
509 struct ip_options *opt, int optlen)
511 while (optlen & 3)
512 opt->__data[optlen++] = IPOPT_END;
513 opt->optlen = optlen;
514 if (optlen && ip_options_compile(net, opt, NULL)) {
515 kfree(opt);
516 return -EINVAL;
518 kfree(*optp);
519 *optp = opt;
520 return 0;
523 int ip_options_get_from_user(struct net *net, struct ip_options **optp,
524 unsigned char __user *data, int optlen)
526 struct ip_options *opt = ip_options_get_alloc(optlen);
528 if (!opt)
529 return -ENOMEM;
530 if (optlen && copy_from_user(opt->__data, data, optlen)) {
531 kfree(opt);
532 return -EFAULT;
534 return ip_options_get_finish(net, optp, opt, optlen);
537 int ip_options_get(struct net *net, struct ip_options **optp,
538 unsigned char *data, int optlen)
540 struct ip_options *opt = ip_options_get_alloc(optlen);
542 if (!opt)
543 return -ENOMEM;
544 if (optlen)
545 memcpy(opt->__data, data, optlen);
546 return ip_options_get_finish(net, optp, opt, optlen);
549 void ip_forward_options(struct sk_buff *skb)
551 struct ip_options * opt = &(IPCB(skb)->opt);
552 unsigned char * optptr;
553 struct rtable *rt = skb->rtable;
554 unsigned char *raw = skb_network_header(skb);
556 if (opt->rr_needaddr) {
557 optptr = (unsigned char *)raw + opt->rr;
558 ip_rt_get_source(&optptr[optptr[2]-5], rt);
559 opt->is_changed = 1;
561 if (opt->srr_is_hit) {
562 int srrptr, srrspace;
564 optptr = raw + opt->srr;
566 for ( srrptr=optptr[2], srrspace = optptr[1];
567 srrptr <= srrspace;
568 srrptr += 4
570 if (srrptr + 3 > srrspace)
571 break;
572 if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
573 break;
575 if (srrptr + 3 <= srrspace) {
576 opt->is_changed = 1;
577 ip_rt_get_source(&optptr[srrptr-1], rt);
578 ip_hdr(skb)->daddr = rt->rt_dst;
579 optptr[2] = srrptr+4;
580 } else if (net_ratelimit())
581 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
582 if (opt->ts_needaddr) {
583 optptr = raw + opt->ts;
584 ip_rt_get_source(&optptr[optptr[2]-9], rt);
585 opt->is_changed = 1;
588 if (opt->is_changed) {
589 opt->is_changed = 0;
590 ip_send_check(ip_hdr(skb));
594 int ip_options_rcv_srr(struct sk_buff *skb)
596 struct ip_options *opt = &(IPCB(skb)->opt);
597 int srrspace, srrptr;
598 __be32 nexthop;
599 struct iphdr *iph = ip_hdr(skb);
600 unsigned char *optptr = skb_network_header(skb) + opt->srr;
601 struct rtable *rt = skb->rtable;
602 struct rtable *rt2;
603 int err;
605 if (!opt->srr)
606 return 0;
608 if (skb->pkt_type != PACKET_HOST)
609 return -EINVAL;
610 if (rt->rt_type == RTN_UNICAST) {
611 if (!opt->is_strictroute)
612 return 0;
613 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
614 return -EINVAL;
616 if (rt->rt_type != RTN_LOCAL)
617 return -EINVAL;
619 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
620 if (srrptr + 3 > srrspace) {
621 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
622 return -EINVAL;
624 memcpy(&nexthop, &optptr[srrptr-1], 4);
626 rt = skb->rtable;
627 skb->rtable = NULL;
628 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
629 rt2 = skb->rtable;
630 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
631 ip_rt_put(rt2);
632 skb->rtable = rt;
633 return -EINVAL;
635 ip_rt_put(rt);
636 if (rt2->rt_type != RTN_LOCAL)
637 break;
638 /* Superfast 8) loopback forward */
639 memcpy(&iph->daddr, &optptr[srrptr-1], 4);
640 opt->is_changed = 1;
642 if (srrptr <= srrspace) {
643 opt->srr_is_hit = 1;
644 opt->is_changed = 1;
646 return 0;