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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 <linux/skbuff.h>
18#include <linux/ip.h>
19#include <linux/icmp.h>
20#include <linux/netdevice.h>
21#include <linux/rtnetlink.h>
22#include <net/sock.h>
23#include <net/ip.h>
24#include <net/icmp.h>
25#include <net/route.h>
26#include <net/cipso_ipv4.h>
27
28
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30
31
32
33
34
35
36
37
38
39void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
40 __be32 daddr, struct rtable *rt, int is_frag)
41{
42 unsigned char *iph = skb_network_header(skb);
43
44 memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
45 memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
46 opt = &(IPCB(skb)->opt);
47
48 if (opt->srr)
49 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
50
51 if (!is_frag) {
52 if (opt->rr_needaddr)
53 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
54 if (opt->ts_needaddr)
55 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
56 if (opt->ts_needtime) {
57 struct timespec tv;
58 __be32 midtime;
59 getnstimeofday(&tv);
60 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
61 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
62 }
63 return;
64 }
65 if (opt->rr) {
66 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
67 opt->rr = 0;
68 opt->rr_needaddr = 0;
69 }
70 if (opt->ts) {
71 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
72 opt->ts = 0;
73 opt->ts_needaddr = opt->ts_needtime = 0;
74 }
75}
76
77
78
79
80
81
82
83
84
85
86int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
87{
88 struct ip_options *sopt;
89 unsigned char *sptr, *dptr;
90 int soffset, doffset;
91 int optlen;
92 __be32 daddr;
93
94 memset(dopt, 0, sizeof(struct ip_options));
95
96 sopt = &(IPCB(skb)->opt);
97
98 if (sopt->optlen == 0) {
99 dopt->optlen = 0;
100 return 0;
101 }
102
103 sptr = skb_network_header(skb);
104 dptr = dopt->__data;
105
106 daddr = skb_rtable(skb)->rt_spec_dst;
107
108 if (sopt->rr) {
109 optlen = sptr[sopt->rr+1];
110 soffset = sptr[sopt->rr+2];
111 dopt->rr = dopt->optlen + sizeof(struct iphdr);
112 memcpy(dptr, sptr+sopt->rr, optlen);
113 if (sopt->rr_needaddr && soffset <= optlen) {
114 if (soffset + 3 > optlen)
115 return -EINVAL;
116 dptr[2] = soffset + 4;
117 dopt->rr_needaddr = 1;
118 }
119 dptr += optlen;
120 dopt->optlen += optlen;
121 }
122 if (sopt->ts) {
123 optlen = sptr[sopt->ts+1];
124 soffset = sptr[sopt->ts+2];
125 dopt->ts = dopt->optlen + sizeof(struct iphdr);
126 memcpy(dptr, sptr+sopt->ts, optlen);
127 if (soffset <= optlen) {
128 if (sopt->ts_needaddr) {
129 if (soffset + 3 > optlen)
130 return -EINVAL;
131 dopt->ts_needaddr = 1;
132 soffset += 4;
133 }
134 if (sopt->ts_needtime) {
135 if (soffset + 3 > optlen)
136 return -EINVAL;
137 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
138 dopt->ts_needtime = 1;
139 soffset += 4;
140 } else {
141 dopt->ts_needtime = 0;
142
143 if (soffset + 8 <= optlen) {
144 __be32 addr;
145
146 memcpy(&addr, sptr+soffset-1, 4);
147 if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_LOCAL) {
148 dopt->ts_needtime = 1;
149 soffset += 8;
150 }
151 }
152 }
153 }
154 dptr[2] = soffset;
155 }
156 dptr += optlen;
157 dopt->optlen += optlen;
158 }
159 if (sopt->srr) {
160 unsigned char * start = sptr+sopt->srr;
161 __be32 faddr;
162
163 optlen = start[1];
164 soffset = start[2];
165 doffset = 0;
166 if (soffset > optlen)
167 soffset = optlen + 1;
168 soffset -= 4;
169 if (soffset > 3) {
170 memcpy(&faddr, &start[soffset-1], 4);
171 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
172 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
173
174
175
176 if (memcmp(&ip_hdr(skb)->saddr,
177 &start[soffset + 3], 4) == 0)
178 doffset -= 4;
179 }
180 if (doffset > 3) {
181 memcpy(&start[doffset-1], &daddr, 4);
182 dopt->faddr = faddr;
183 dptr[0] = start[0];
184 dptr[1] = doffset+3;
185 dptr[2] = 4;
186 dptr += doffset+3;
187 dopt->srr = dopt->optlen + sizeof(struct iphdr);
188 dopt->optlen += doffset+3;
189 dopt->is_strictroute = sopt->is_strictroute;
190 }
191 }
192 if (sopt->cipso) {
193 optlen = sptr[sopt->cipso+1];
194 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
195 memcpy(dptr, sptr+sopt->cipso, optlen);
196 dptr += optlen;
197 dopt->optlen += optlen;
198 }
199 while (dopt->optlen & 3) {
200 *dptr++ = IPOPT_END;
201 dopt->optlen++;
202 }
203 return 0;
204}
205
206
207
208
209
210
211
212void ip_options_fragment(struct sk_buff * skb)
213{
214 unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
215 struct ip_options * opt = &(IPCB(skb)->opt);
216 int l = opt->optlen;
217 int optlen;
218
219 while (l > 0) {
220 switch (*optptr) {
221 case IPOPT_END:
222 return;
223 case IPOPT_NOOP:
224 l--;
225 optptr++;
226 continue;
227 }
228 optlen = optptr[1];
229 if (optlen<2 || optlen>l)
230 return;
231 if (!IPOPT_COPIED(*optptr))
232 memset(optptr, IPOPT_NOOP, optlen);
233 l -= optlen;
234 optptr += optlen;
235 }
236 opt->ts = 0;
237 opt->rr = 0;
238 opt->rr_needaddr = 0;
239 opt->ts_needaddr = 0;
240 opt->ts_needtime = 0;
241 return;
242}
243
244
245
246
247
248
249
250int ip_options_compile(struct net *net,
251 struct ip_options * opt, struct sk_buff * skb)
252{
253 int l;
254 unsigned char * iph;
255 unsigned char * optptr;
256 int optlen;
257 unsigned char * pp_ptr = NULL;
258 struct rtable *rt = NULL;
259
260 if (skb != NULL) {
261 rt = skb_rtable(skb);
262 optptr = (unsigned char *)&(ip_hdr(skb)[1]);
263 } else
264 optptr = opt->__data;
265 iph = optptr - sizeof(struct iphdr);
266
267 for (l = opt->optlen; l > 0; ) {
268 switch (*optptr) {
269 case IPOPT_END:
270 for (optptr++, l--; l>0; optptr++, l--) {
271 if (*optptr != IPOPT_END) {
272 *optptr = IPOPT_END;
273 opt->is_changed = 1;
274 }
275 }
276 goto eol;
277 case IPOPT_NOOP:
278 l--;
279 optptr++;
280 continue;
281 }
282 optlen = optptr[1];
283 if (optlen<2 || optlen>l) {
284 pp_ptr = optptr;
285 goto error;
286 }
287 switch (*optptr) {
288 case IPOPT_SSRR:
289 case IPOPT_LSRR:
290 if (optlen < 3) {
291 pp_ptr = optptr + 1;
292 goto error;
293 }
294 if (optptr[2] < 4) {
295 pp_ptr = optptr + 2;
296 goto error;
297 }
298
299 if (opt->srr) {
300 pp_ptr = optptr;
301 goto error;
302 }
303 if (!skb) {
304 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
305 pp_ptr = optptr + 1;
306 goto error;
307 }
308 memcpy(&opt->faddr, &optptr[3], 4);
309 if (optlen > 7)
310 memmove(&optptr[3], &optptr[7], optlen-7);
311 }
312 opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
313 opt->srr = optptr - iph;
314 break;
315 case IPOPT_RR:
316 if (opt->rr) {
317 pp_ptr = optptr;
318 goto error;
319 }
320 if (optlen < 3) {
321 pp_ptr = optptr + 1;
322 goto error;
323 }
324 if (optptr[2] < 4) {
325 pp_ptr = optptr + 2;
326 goto error;
327 }
328 if (optptr[2] <= optlen) {
329 if (optptr[2]+3 > optlen) {
330 pp_ptr = optptr + 2;
331 goto error;
332 }
333 if (skb) {
334 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
335 opt->is_changed = 1;
336 }
337 optptr[2] += 4;
338 opt->rr_needaddr = 1;
339 }
340 opt->rr = optptr - iph;
341 break;
342 case IPOPT_TIMESTAMP:
343 if (opt->ts) {
344 pp_ptr = optptr;
345 goto error;
346 }
347 if (optlen < 4) {
348 pp_ptr = optptr + 1;
349 goto error;
350 }
351 if (optptr[2] < 5) {
352 pp_ptr = optptr + 2;
353 goto error;
354 }
355 if (optptr[2] <= optlen) {
356 __be32 *timeptr = NULL;
357 if (optptr[2]+3 > optptr[1]) {
358 pp_ptr = optptr + 2;
359 goto error;
360 }
361 switch (optptr[3]&0xF) {
362 case IPOPT_TS_TSONLY:
363 opt->ts = optptr - iph;
364 if (skb)
365 timeptr = (__be32*)&optptr[optptr[2]-1];
366 opt->ts_needtime = 1;
367 optptr[2] += 4;
368 break;
369 case IPOPT_TS_TSANDADDR:
370 if (optptr[2]+7 > optptr[1]) {
371 pp_ptr = optptr + 2;
372 goto error;
373 }
374 opt->ts = optptr - iph;
375 if (skb) {
376 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
377 timeptr = (__be32*)&optptr[optptr[2]+3];
378 }
379 opt->ts_needaddr = 1;
380 opt->ts_needtime = 1;
381 optptr[2] += 8;
382 break;
383 case IPOPT_TS_PRESPEC:
384 if (optptr[2]+7 > optptr[1]) {
385 pp_ptr = optptr + 2;
386 goto error;
387 }
388 opt->ts = optptr - iph;
389 {
390 __be32 addr;
391 memcpy(&addr, &optptr[optptr[2]-1], 4);
392 if (inet_addr_type(net, addr) == RTN_UNICAST)
393 break;
394 if (skb)
395 timeptr = (__be32*)&optptr[optptr[2]+3];
396 }
397 opt->ts_needtime = 1;
398 optptr[2] += 8;
399 break;
400 default:
401 if (!skb && !capable(CAP_NET_RAW)) {
402 pp_ptr = optptr + 3;
403 goto error;
404 }
405 break;
406 }
407 if (timeptr) {
408 struct timespec tv;
409 __be32 midtime;
410 getnstimeofday(&tv);
411 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
412 memcpy(timeptr, &midtime, sizeof(__be32));
413 opt->is_changed = 1;
414 }
415 } else {
416 unsigned overflow = optptr[3]>>4;
417 if (overflow == 15) {
418 pp_ptr = optptr + 3;
419 goto error;
420 }
421 opt->ts = optptr - iph;
422 if (skb) {
423 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
424 opt->is_changed = 1;
425 }
426 }
427 break;
428 case IPOPT_RA:
429 if (optlen < 4) {
430 pp_ptr = optptr + 1;
431 goto error;
432 }
433 if (optptr[2] == 0 && optptr[3] == 0)
434 opt->router_alert = optptr - iph;
435 break;
436 case IPOPT_CIPSO:
437 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
438 pp_ptr = optptr;
439 goto error;
440 }
441 opt->cipso = optptr - iph;
442 if (cipso_v4_validate(skb, &optptr)) {
443 pp_ptr = optptr;
444 goto error;
445 }
446 break;
447 case IPOPT_SEC:
448 case IPOPT_SID:
449 default:
450 if (!skb && !capable(CAP_NET_RAW)) {
451 pp_ptr = optptr;
452 goto error;
453 }
454 break;
455 }
456 l -= optlen;
457 optptr += optlen;
458 }
459
460eol:
461 if (!pp_ptr)
462 return 0;
463
464error:
465 if (skb) {
466 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
467 }
468 return -EINVAL;
469}
470
471
472
473
474
475
476void ip_options_undo(struct ip_options * opt)
477{
478 if (opt->srr) {
479 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
480 memmove(optptr+7, optptr+3, optptr[1]-7);
481 memcpy(optptr+3, &opt->faddr, 4);
482 }
483 if (opt->rr_needaddr) {
484 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
485 optptr[2] -= 4;
486 memset(&optptr[optptr[2]-1], 0, 4);
487 }
488 if (opt->ts) {
489 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
490 if (opt->ts_needtime) {
491 optptr[2] -= 4;
492 memset(&optptr[optptr[2]-1], 0, 4);
493 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
494 optptr[2] -= 4;
495 }
496 if (opt->ts_needaddr) {
497 optptr[2] -= 4;
498 memset(&optptr[optptr[2]-1], 0, 4);
499 }
500 }
501}
502
503static struct ip_options *ip_options_get_alloc(const int optlen)
504{
505 return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
506 GFP_KERNEL);
507}
508
509static int ip_options_get_finish(struct net *net, struct ip_options **optp,
510 struct ip_options *opt, int optlen)
511{
512 while (optlen & 3)
513 opt->__data[optlen++] = IPOPT_END;
514 opt->optlen = optlen;
515 if (optlen && ip_options_compile(net, opt, NULL)) {
516 kfree(opt);
517 return -EINVAL;
518 }
519 kfree(*optp);
520 *optp = opt;
521 return 0;
522}
523
524int ip_options_get_from_user(struct net *net, struct ip_options **optp,
525 unsigned char __user *data, int optlen)
526{
527 struct ip_options *opt = ip_options_get_alloc(optlen);
528
529 if (!opt)
530 return -ENOMEM;
531 if (optlen && copy_from_user(opt->__data, data, optlen)) {
532 kfree(opt);
533 return -EFAULT;
534 }
535 return ip_options_get_finish(net, optp, opt, optlen);
536}
537
538int ip_options_get(struct net *net, struct ip_options **optp,
539 unsigned char *data, int optlen)
540{
541 struct ip_options *opt = ip_options_get_alloc(optlen);
542
543 if (!opt)
544 return -ENOMEM;
545 if (optlen)
546 memcpy(opt->__data, data, optlen);
547 return ip_options_get_finish(net, optp, opt, optlen);
548}
549
550void ip_forward_options(struct sk_buff *skb)
551{
552 struct ip_options * opt = &(IPCB(skb)->opt);
553 unsigned char * optptr;
554 struct rtable *rt = skb_rtable(skb);
555 unsigned char *raw = skb_network_header(skb);
556
557 if (opt->rr_needaddr) {
558 optptr = (unsigned char *)raw + opt->rr;
559 ip_rt_get_source(&optptr[optptr[2]-5], rt);
560 opt->is_changed = 1;
561 }
562 if (opt->srr_is_hit) {
563 int srrptr, srrspace;
564
565 optptr = raw + opt->srr;
566
567 for ( srrptr=optptr[2], srrspace = optptr[1];
568 srrptr <= srrspace;
569 srrptr += 4
570 ) {
571 if (srrptr + 3 > srrspace)
572 break;
573 if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
574 break;
575 }
576 if (srrptr + 3 <= srrspace) {
577 opt->is_changed = 1;
578 ip_rt_get_source(&optptr[srrptr-1], rt);
579 ip_hdr(skb)->daddr = rt->rt_dst;
580 optptr[2] = srrptr+4;
581 } else if (net_ratelimit())
582 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
583 if (opt->ts_needaddr) {
584 optptr = raw + opt->ts;
585 ip_rt_get_source(&optptr[optptr[2]-9], rt);
586 opt->is_changed = 1;
587 }
588 }
589 if (opt->is_changed) {
590 opt->is_changed = 0;
591 ip_send_check(ip_hdr(skb));
592 }
593}
594
595int ip_options_rcv_srr(struct sk_buff *skb)
596{
597 struct ip_options *opt = &(IPCB(skb)->opt);
598 int srrspace, srrptr;
599 __be32 nexthop;
600 struct iphdr *iph = ip_hdr(skb);
601 unsigned char *optptr = skb_network_header(skb) + opt->srr;
602 struct rtable *rt = skb_rtable(skb);
603 struct rtable *rt2;
604 int err;
605
606 if (!opt->srr)
607 return 0;
608
609 if (skb->pkt_type != PACKET_HOST)
610 return -EINVAL;
611 if (rt->rt_type == RTN_UNICAST) {
612 if (!opt->is_strictroute)
613 return 0;
614 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
615 return -EINVAL;
616 }
617 if (rt->rt_type != RTN_LOCAL)
618 return -EINVAL;
619
620 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
621 if (srrptr + 3 > srrspace) {
622 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
623 return -EINVAL;
624 }
625 memcpy(&nexthop, &optptr[srrptr-1], 4);
626
627 rt = skb_rtable(skb);
628 skb_dst_set(skb, NULL);
629 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
630 rt2 = skb_rtable(skb);
631 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
632 ip_rt_put(rt2);
633 skb_dst_set(skb, &rt->u.dst);
634 return -EINVAL;
635 }
636 ip_rt_put(rt);
637 if (rt2->rt_type != RTN_LOCAL)
638 break;
639
640 memcpy(&iph->daddr, &optptr[srrptr-1], 4);
641 opt->is_changed = 1;
642 }
643 if (srrptr <= srrspace) {
644 opt->srr_is_hit = 1;
645 opt->is_changed = 1;
646 }
647 return 0;
648}
649
