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12#include <linux/capability.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/types.h>
16#include <asm/uaccess.h>
17#include <asm/unaligned.h>
18#include <linux/skbuff.h>
19#include <linux/ip.h>
20#include <linux/icmp.h>
21#include <linux/netdevice.h>
22#include <linux/rtnetlink.h>
23#include <net/sock.h>
24#include <net/ip.h>
25#include <net/icmp.h>
26#include <net/route.h>
27#include <net/cipso_ipv4.h>
28
29
30
31
32
33
34
35
36
37
38
39
40void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
41 __be32 daddr, struct rtable *rt, int is_frag)
42{
43 unsigned char *iph = skb_network_header(skb);
44
45 memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
46 memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
47 opt = &(IPCB(skb)->opt);
48
49 if (opt->srr)
50 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
51
52 if (!is_frag) {
53 if (opt->rr_needaddr)
54 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, skb, rt);
55 if (opt->ts_needaddr)
56 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, skb, rt);
57 if (opt->ts_needtime) {
58 struct timespec tv;
59 __be32 midtime;
60 getnstimeofday(&tv);
61 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
62 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
63 }
64 return;
65 }
66 if (opt->rr) {
67 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
68 opt->rr = 0;
69 opt->rr_needaddr = 0;
70 }
71 if (opt->ts) {
72 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
73 opt->ts = 0;
74 opt->ts_needaddr = opt->ts_needtime = 0;
75 }
76}
77
78
79
80
81
82
83
84
85
86
87int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
88{
89 const struct ip_options *sopt;
90 unsigned char *sptr, *dptr;
91 int soffset, doffset;
92 int optlen;
93 __be32 daddr;
94
95 memset(dopt, 0, sizeof(struct ip_options));
96
97 sopt = &(IPCB(skb)->opt);
98
99 if (sopt->optlen == 0)
100 return 0;
101
102 sptr = skb_network_header(skb);
103 dptr = dopt->__data;
104
105 daddr = skb_rtable(skb)->rt_spec_dst;
106
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;
117 }
118 dptr += optlen;
119 dopt->optlen += optlen;
120 }
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;
132 }
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;
141
142 if (soffset + 7 <= optlen) {
143 __be32 addr;
144
145 memcpy(&addr, dptr+soffset-1, 4);
146 if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_UNICAST) {
147 dopt->ts_needtime = 1;
148 soffset += 8;
149 }
150 }
151 }
152 }
153 dptr[2] = soffset;
154 }
155 dptr += optlen;
156 dopt->optlen += optlen;
157 }
158 if (sopt->srr) {
159 unsigned char *start = sptr+sopt->srr;
160 __be32 faddr;
161
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);
172
173
174
175 if (memcmp(&ip_hdr(skb)->saddr,
176 &start[soffset + 3], 4) == 0)
177 doffset -= 4;
178 }
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;
189 }
190 }
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;
197 }
198 while (dopt->optlen & 3) {
199 *dptr++ = IPOPT_END;
200 dopt->optlen++;
201 }
202 return 0;
203}
204
205
206
207
208
209
210
211void ip_options_fragment(struct sk_buff * skb)
212{
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;
217
218 while (l > 0) {
219 switch (*optptr) {
220 case IPOPT_END:
221 return;
222 case IPOPT_NOOP:
223 l--;
224 optptr++;
225 continue;
226 }
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;
234 }
235 opt->ts = 0;
236 opt->rr = 0;
237 opt->rr_needaddr = 0;
238 opt->ts_needaddr = 0;
239 opt->ts_needtime = 0;
240}
241
242
243
244
245
246
247
248int ip_options_compile(struct net *net,
249 struct ip_options * opt, struct sk_buff * skb)
250{
251 int l;
252 unsigned char * iph;
253 unsigned char * optptr;
254 int optlen;
255 unsigned char * pp_ptr = NULL;
256 struct rtable *rt = NULL;
257
258 if (skb != NULL) {
259 rt = skb_rtable(skb);
260 optptr = (unsigned char *)&(ip_hdr(skb)[1]);
261 } else
262 optptr = opt->__data;
263 iph = optptr - sizeof(struct iphdr);
264
265 for (l = opt->optlen; l > 0; ) {
266 switch (*optptr) {
267 case IPOPT_END:
268 for (optptr++, l--; l>0; optptr++, l--) {
269 if (*optptr != IPOPT_END) {
270 *optptr = IPOPT_END;
271 opt->is_changed = 1;
272 }
273 }
274 goto eol;
275 case IPOPT_NOOP:
276 l--;
277 optptr++;
278 continue;
279 }
280 optlen = optptr[1];
281 if (optlen<2 || optlen>l) {
282 pp_ptr = optptr;
283 goto error;
284 }
285 switch (*optptr) {
286 case IPOPT_SSRR:
287 case IPOPT_LSRR:
288 if (optlen < 3) {
289 pp_ptr = optptr + 1;
290 goto error;
291 }
292 if (optptr[2] < 4) {
293 pp_ptr = optptr + 2;
294 goto error;
295 }
296
297 if (opt->srr) {
298 pp_ptr = optptr;
299 goto error;
300 }
301 if (!skb) {
302 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
303 pp_ptr = optptr + 1;
304 goto error;
305 }
306 memcpy(&opt->faddr, &optptr[3], 4);
307 if (optlen > 7)
308 memmove(&optptr[3], &optptr[7], optlen-7);
309 }
310 opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
311 opt->srr = optptr - iph;
312 break;
313 case IPOPT_RR:
314 if (opt->rr) {
315 pp_ptr = optptr;
316 goto error;
317 }
318 if (optlen < 3) {
319 pp_ptr = optptr + 1;
320 goto error;
321 }
322 if (optptr[2] < 4) {
323 pp_ptr = optptr + 2;
324 goto error;
325 }
326 if (optptr[2] <= optlen) {
327 if (optptr[2]+3 > optlen) {
328 pp_ptr = optptr + 2;
329 goto error;
330 }
331 if (rt) {
332 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
333 opt->is_changed = 1;
334 }
335 optptr[2] += 4;
336 opt->rr_needaddr = 1;
337 }
338 opt->rr = optptr - iph;
339 break;
340 case IPOPT_TIMESTAMP:
341 if (opt->ts) {
342 pp_ptr = optptr;
343 goto error;
344 }
345 if (optlen < 4) {
346 pp_ptr = optptr + 1;
347 goto error;
348 }
349 if (optptr[2] < 5) {
350 pp_ptr = optptr + 2;
351 goto error;
352 }
353 if (optptr[2] <= optlen) {
354 unsigned char *timeptr = NULL;
355 if (optptr[2]+3 > optptr[1]) {
356 pp_ptr = optptr + 2;
357 goto error;
358 }
359 switch (optptr[3]&0xF) {
360 case IPOPT_TS_TSONLY:
361 opt->ts = optptr - iph;
362 if (skb)
363 timeptr = &optptr[optptr[2]-1];
364 opt->ts_needtime = 1;
365 optptr[2] += 4;
366 break;
367 case IPOPT_TS_TSANDADDR:
368 if (optptr[2]+7 > optptr[1]) {
369 pp_ptr = optptr + 2;
370 goto error;
371 }
372 opt->ts = optptr - iph;
373 if (rt) {
374 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
375 timeptr = &optptr[optptr[2]+3];
376 }
377 opt->ts_needaddr = 1;
378 opt->ts_needtime = 1;
379 optptr[2] += 8;
380 break;
381 case IPOPT_TS_PRESPEC:
382 if (optptr[2]+7 > optptr[1]) {
383 pp_ptr = optptr + 2;
384 goto error;
385 }
386 opt->ts = optptr - iph;
387 {
388 __be32 addr;
389 memcpy(&addr, &optptr[optptr[2]-1], 4);
390 if (inet_addr_type(net, addr) == RTN_UNICAST)
391 break;
392 if (skb)
393 timeptr = &optptr[optptr[2]+3];
394 }
395 opt->ts_needtime = 1;
396 optptr[2] += 8;
397 break;
398 default:
399 if (!skb && !capable(CAP_NET_RAW)) {
400 pp_ptr = optptr + 3;
401 goto error;
402 }
403 break;
404 }
405 if (timeptr) {
406 struct timespec tv;
407 u32 midtime;
408 getnstimeofday(&tv);
409 midtime = (tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC;
410 put_unaligned_be32(midtime, timeptr);
411 opt->is_changed = 1;
412 }
413 } else {
414 unsigned overflow = optptr[3]>>4;
415 if (overflow == 15) {
416 pp_ptr = optptr + 3;
417 goto error;
418 }
419 opt->ts = optptr - iph;
420 if (skb) {
421 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
422 opt->is_changed = 1;
423 }
424 }
425 break;
426 case IPOPT_RA:
427 if (optlen < 4) {
428 pp_ptr = optptr + 1;
429 goto error;
430 }
431 if (optptr[2] == 0 && optptr[3] == 0)
432 opt->router_alert = optptr - iph;
433 break;
434 case IPOPT_CIPSO:
435 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
436 pp_ptr = optptr;
437 goto error;
438 }
439 opt->cipso = optptr - iph;
440 if (cipso_v4_validate(skb, &optptr)) {
441 pp_ptr = optptr;
442 goto error;
443 }
444 break;
445 case IPOPT_SEC:
446 case IPOPT_SID:
447 default:
448 if (!skb && !capable(CAP_NET_RAW)) {
449 pp_ptr = optptr;
450 goto error;
451 }
452 break;
453 }
454 l -= optlen;
455 optptr += optlen;
456 }
457
458eol:
459 if (!pp_ptr)
460 return 0;
461
462error:
463 if (skb) {
464 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
465 }
466 return -EINVAL;
467}
468EXPORT_SYMBOL(ip_options_compile);
469
470
471
472
473
474void ip_options_undo(struct ip_options * opt)
475{
476 if (opt->srr) {
477 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
478 memmove(optptr+7, optptr+3, optptr[1]-7);
479 memcpy(optptr+3, &opt->faddr, 4);
480 }
481 if (opt->rr_needaddr) {
482 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
483 optptr[2] -= 4;
484 memset(&optptr[optptr[2]-1], 0, 4);
485 }
486 if (opt->ts) {
487 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
488 if (opt->ts_needtime) {
489 optptr[2] -= 4;
490 memset(&optptr[optptr[2]-1], 0, 4);
491 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
492 optptr[2] -= 4;
493 }
494 if (opt->ts_needaddr) {
495 optptr[2] -= 4;
496 memset(&optptr[optptr[2]-1], 0, 4);
497 }
498 }
499}
500
501static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
502{
503 return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
504 GFP_KERNEL);
505}
506
507static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
508 struct ip_options_rcu *opt, int optlen)
509{
510 while (optlen & 3)
511 opt->opt.__data[optlen++] = IPOPT_END;
512 opt->opt.optlen = optlen;
513 if (optlen && ip_options_compile(net, &opt->opt, NULL)) {
514 kfree(opt);
515 return -EINVAL;
516 }
517 kfree(*optp);
518 *optp = opt;
519 return 0;
520}
521
522int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
523 unsigned char __user *data, int optlen)
524{
525 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
526
527 if (!opt)
528 return -ENOMEM;
529 if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
530 kfree(opt);
531 return -EFAULT;
532 }
533 return ip_options_get_finish(net, optp, opt, optlen);
534}
535
536int ip_options_get(struct net *net, struct ip_options_rcu **optp,
537 unsigned char *data, int optlen)
538{
539 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
540
541 if (!opt)
542 return -ENOMEM;
543 if (optlen)
544 memcpy(opt->opt.__data, data, optlen);
545 return ip_options_get_finish(net, optp, opt, optlen);
546}
547
548void ip_forward_options(struct sk_buff *skb)
549{
550 struct ip_options * opt = &(IPCB(skb)->opt);
551 unsigned char * optptr;
552 struct rtable *rt = skb_rtable(skb);
553 unsigned char *raw = skb_network_header(skb);
554
555 if (opt->rr_needaddr) {
556 optptr = (unsigned char *)raw + opt->rr;
557 ip_rt_get_source(&optptr[optptr[2]-5], skb, rt);
558 opt->is_changed = 1;
559 }
560 if (opt->srr_is_hit) {
561 int srrptr, srrspace;
562
563 optptr = raw + opt->srr;
564
565 for ( srrptr=optptr[2], srrspace = optptr[1];
566 srrptr <= srrspace;
567 srrptr += 4
568 ) {
569 if (srrptr + 3 > srrspace)
570 break;
571 if (memcmp(&ip_hdr(skb)->daddr, &optptr[srrptr-1], 4) == 0)
572 break;
573 }
574 if (srrptr + 3 <= srrspace) {
575 opt->is_changed = 1;
576 ip_rt_get_source(&optptr[srrptr-1], skb, rt);
577 optptr[2] = srrptr+4;
578 } else if (net_ratelimit())
579 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
580 if (opt->ts_needaddr) {
581 optptr = raw + opt->ts;
582 ip_rt_get_source(&optptr[optptr[2]-9], skb, rt);
583 opt->is_changed = 1;
584 }
585 }
586 if (opt->is_changed) {
587 opt->is_changed = 0;
588 ip_send_check(ip_hdr(skb));
589 }
590}
591
592int ip_options_rcv_srr(struct sk_buff *skb)
593{
594 struct ip_options *opt = &(IPCB(skb)->opt);
595 int srrspace, srrptr;
596 __be32 nexthop;
597 struct iphdr *iph = ip_hdr(skb);
598 unsigned char *optptr = skb_network_header(skb) + opt->srr;
599 struct rtable *rt = skb_rtable(skb);
600 struct rtable *rt2;
601 unsigned long orefdst;
602 int err;
603
604 if (!rt)
605 return 0;
606
607 if (skb->pkt_type != PACKET_HOST)
608 return -EINVAL;
609 if (rt->rt_type == RTN_UNICAST) {
610 if (!opt->is_strictroute)
611 return 0;
612 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
613 return -EINVAL;
614 }
615 if (rt->rt_type != RTN_LOCAL)
616 return -EINVAL;
617
618 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
619 if (srrptr + 3 > srrspace) {
620 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
621 return -EINVAL;
622 }
623 memcpy(&nexthop, &optptr[srrptr-1], 4);
624
625 orefdst = skb->_skb_refdst;
626 skb_dst_set(skb, NULL);
627 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
628 rt2 = skb_rtable(skb);
629 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
630 skb_dst_drop(skb);
631 skb->_skb_refdst = orefdst;
632 return -EINVAL;
633 }
634 refdst_drop(orefdst);
635 if (rt2->rt_type != RTN_LOCAL)
636 break;
637
638 iph->daddr = nexthop;
639 opt->is_changed = 1;
640 }
641 if (srrptr <= srrspace) {
642 opt->srr_is_hit = 1;
643 opt->is_changed = 1;
644 }
645 return 0;
646}
647EXPORT_SYMBOL(ip_options_rcv_srr);
648
