1
2
3
4
5
6
7
8
9
10
11
12
13
14#include <linux/capability.h>
15#include <linux/module.h>
16#include <linux/types.h>
17#include <asm/uaccess.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 opt->is_data = 0;
49
50 if (opt->srr)
51 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
52
53 if (!is_frag) {
54 if (opt->rr_needaddr)
55 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
56 if (opt->ts_needaddr)
57 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
58 if (opt->ts_needtime) {
59 struct timeval tv;
60 __be32 midtime;
61 do_gettimeofday(&tv);
62 midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
63 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
64 }
65 return;
66 }
67 if (opt->rr) {
68 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
69 opt->rr = 0;
70 opt->rr_needaddr = 0;
71 }
72 if (opt->ts) {
73 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
74 opt->ts = 0;
75 opt->ts_needaddr = opt->ts_needtime = 0;
76 }
77}
78
79
80
81
82
83
84
85
86
87
88int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
89{
90 struct ip_options *sopt;
91 unsigned char *sptr, *dptr;
92 int soffset, doffset;
93 int optlen;
94 __be32 daddr;
95
96 memset(dopt, 0, sizeof(struct ip_options));
97
98 dopt->is_data = 1;
99
100 sopt = &(IPCB(skb)->opt);
101
102 if (sopt->optlen == 0) {
103 dopt->optlen = 0;
104 return 0;
105 }
106
107 sptr = skb_network_header(skb);
108 dptr = dopt->__data;
109
110 if (skb->dst)
111 daddr = ((struct rtable*)skb->dst)->rt_spec_dst;
112 else
113 daddr = ip_hdr(skb)->daddr;
114
115 if (sopt->rr) {
116 optlen = sptr[sopt->rr+1];
117 soffset = sptr[sopt->rr+2];
118 dopt->rr = dopt->optlen + sizeof(struct iphdr);
119 memcpy(dptr, sptr+sopt->rr, optlen);
120 if (sopt->rr_needaddr && soffset <= optlen) {
121 if (soffset + 3 > optlen)
122 return -EINVAL;
123 dptr[2] = soffset + 4;
124 dopt->rr_needaddr = 1;
125 }
126 dptr += optlen;
127 dopt->optlen += optlen;
128 }
129 if (sopt->ts) {
130 optlen = sptr[sopt->ts+1];
131 soffset = sptr[sopt->ts+2];
132 dopt->ts = dopt->optlen + sizeof(struct iphdr);
133 memcpy(dptr, sptr+sopt->ts, optlen);
134 if (soffset <= optlen) {
135 if (sopt->ts_needaddr) {
136 if (soffset + 3 > optlen)
137 return -EINVAL;
138 dopt->ts_needaddr = 1;
139 soffset += 4;
140 }
141 if (sopt->ts_needtime) {
142 if (soffset + 3 > optlen)
143 return -EINVAL;
144 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
145 dopt->ts_needtime = 1;
146 soffset += 4;
147 } else {
148 dopt->ts_needtime = 0;
149
150 if (soffset + 8 <= optlen) {
151 __be32 addr;
152
153 memcpy(&addr, sptr+soffset-1, 4);
154 if (inet_addr_type(addr) != RTN_LOCAL) {
155 dopt->ts_needtime = 1;
156 soffset += 8;
157 }
158 }
159 }
160 }
161 dptr[2] = soffset;
162 }
163 dptr += optlen;
164 dopt->optlen += optlen;
165 }
166 if (sopt->srr) {
167 unsigned char * start = sptr+sopt->srr;
168 __be32 faddr;
169
170 optlen = start[1];
171 soffset = start[2];
172 doffset = 0;
173 if (soffset > optlen)
174 soffset = optlen + 1;
175 soffset -= 4;
176 if (soffset > 3) {
177 memcpy(&faddr, &start[soffset-1], 4);
178 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
179 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
180
181
182
183 if (memcmp(&ip_hdr(skb)->saddr,
184 &start[soffset + 3], 4) == 0)
185 doffset -= 4;
186 }
187 if (doffset > 3) {
188 memcpy(&start[doffset-1], &daddr, 4);
189 dopt->faddr = faddr;
190 dptr[0] = start[0];
191 dptr[1] = doffset+3;
192 dptr[2] = 4;
193 dptr += doffset+3;
194 dopt->srr = dopt->optlen + sizeof(struct iphdr);
195 dopt->optlen += doffset+3;
196 dopt->is_strictroute = sopt->is_strictroute;
197 }
198 }
199 if (sopt->cipso) {
200 optlen = sptr[sopt->cipso+1];
201 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
202 memcpy(dptr, sptr+sopt->cipso, optlen);
203 dptr += optlen;
204 dopt->optlen += optlen;
205 }
206 while (dopt->optlen & 3) {
207 *dptr++ = IPOPT_END;
208 dopt->optlen++;
209 }
210 return 0;
211}
212
213
214
215
216
217
218
219void ip_options_fragment(struct sk_buff * skb)
220{
221 unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
222 struct ip_options * opt = &(IPCB(skb)->opt);
223 int l = opt->optlen;
224 int optlen;
225
226 while (l > 0) {
227 switch (*optptr) {
228 case IPOPT_END:
229 return;
230 case IPOPT_NOOP:
231 l--;
232 optptr++;
233 continue;
234 }
235 optlen = optptr[1];
236 if (optlen<2 || optlen>l)
237 return;
238 if (!IPOPT_COPIED(*optptr))
239 memset(optptr, IPOPT_NOOP, optlen);
240 l -= optlen;
241 optptr += optlen;
242 }
243 opt->ts = 0;
244 opt->rr = 0;
245 opt->rr_needaddr = 0;
246 opt->ts_needaddr = 0;
247 opt->ts_needtime = 0;
248 return;
249}
250
251
252
253
254
255
256
257int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
258{
259 int l;
260 unsigned char * iph;
261 unsigned char * optptr;
262 int optlen;
263 unsigned char * pp_ptr = NULL;
264 struct rtable *rt = skb ? (struct rtable*)skb->dst : NULL;
265
266 if (!opt) {
267 opt = &(IPCB(skb)->opt);
268 iph = skb_network_header(skb);
269 opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
270 optptr = iph + sizeof(struct iphdr);
271 opt->is_data = 0;
272 } else {
273 optptr = opt->is_data ? opt->__data :
274 (unsigned char *)&(ip_hdr(skb)[1]);
275 iph = optptr - sizeof(struct iphdr);
276 }
277
278 for (l = opt->optlen; l > 0; ) {
279 switch (*optptr) {
280 case IPOPT_END:
281 for (optptr++, l--; l>0; optptr++, l--) {
282 if (*optptr != IPOPT_END) {
283 *optptr = IPOPT_END;
284 opt->is_changed = 1;
285 }
286 }
287 goto eol;
288 case IPOPT_NOOP:
289 l--;
290 optptr++;
291 continue;
292 }
293 optlen = optptr[1];
294 if (optlen<2 || optlen>l) {
295 pp_ptr = optptr;
296 goto error;
297 }
298 switch (*optptr) {
299 case IPOPT_SSRR:
300 case IPOPT_LSRR:
301 if (optlen < 3) {
302 pp_ptr = optptr + 1;
303 goto error;
304 }
305 if (optptr[2] < 4) {
306 pp_ptr = optptr + 2;
307 goto error;
308 }
309
310 if (opt->srr) {
311 pp_ptr = optptr;
312 goto error;
313 }
314 if (!skb) {
315 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
316 pp_ptr = optptr + 1;
317 goto error;
318 }
319 memcpy(&opt->faddr, &optptr[3], 4);
320 if (optlen > 7)
321 memmove(&optptr[3], &optptr[7], optlen-7);
322 }
323 opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
324 opt->srr = optptr - iph;
325 break;
326 case IPOPT_RR:
327 if (opt->rr) {
328 pp_ptr = optptr;
329 goto error;
330 }
331 if (optlen < 3) {
332 pp_ptr = optptr + 1;
333 goto error;
334 }
335 if (optptr[2] < 4) {
336 pp_ptr = optptr + 2;
337 goto error;
338 }
339 if (optptr[2] <= optlen) {
340 if (optptr[2]+3 > optlen) {
341 pp_ptr = optptr + 2;
342 goto error;
343 }
344 if (skb) {
345 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
346 opt->is_changed = 1;
347 }
348 optptr[2] += 4;
349 opt->rr_needaddr = 1;
350 }
351 opt->rr = optptr - iph;
352 break;
353 case IPOPT_TIMESTAMP:
354 if (opt->ts) {
355 pp_ptr = optptr;
356 goto error;
357 }
358 if (optlen < 4) {
359 pp_ptr = optptr + 1;
360 goto error;
361 }
362 if (optptr[2] < 5) {
363 pp_ptr = optptr + 2;
364 goto error;
365 }
366 if (optptr[2] <= optlen) {
367 __be32 *timeptr = NULL;
368 if (optptr[2]+3 > optptr[1]) {
369 pp_ptr = optptr + 2;
370 goto error;
371 }
372 switch (optptr[3]&0xF) {
373 case IPOPT_TS_TSONLY:
374 opt->ts = optptr - iph;
375 if (skb)
376 timeptr = (__be32*)&optptr[optptr[2]-1];
377 opt->ts_needtime = 1;
378 optptr[2] += 4;
379 break;
380 case IPOPT_TS_TSANDADDR:
381 if (optptr[2]+7 > optptr[1]) {
382 pp_ptr = optptr + 2;
383 goto error;
384 }
385 opt->ts = optptr - iph;
386 if (skb) {
387 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
388 timeptr = (__be32*)&optptr[optptr[2]+3];
389 }
390 opt->ts_needaddr = 1;
391 opt->ts_needtime = 1;
392 optptr[2] += 8;
393 break;
394 case IPOPT_TS_PRESPEC:
395 if (optptr[2]+7 > optptr[1]) {
396 pp_ptr = optptr + 2;
397 goto error;
398 }
399 opt->ts = optptr - iph;
400 {
401 __be32 addr;
402 memcpy(&addr, &optptr[optptr[2]-1], 4);
403 if (inet_addr_type(addr) == RTN_UNICAST)
404 break;
405 if (skb)
406 timeptr = (__be32*)&optptr[optptr[2]+3];
407 }
408 opt->ts_needtime = 1;
409 optptr[2] += 8;
410 break;
411 default:
412 if (!skb && !capable(CAP_NET_RAW)) {
413 pp_ptr = optptr + 3;
414 goto error;
415 }
416 break;
417 }
418 if (timeptr) {
419 struct timeval tv;
420 __be32 midtime;
421 do_gettimeofday(&tv);
422 midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
423 memcpy(timeptr, &midtime, sizeof(__be32));
424 opt->is_changed = 1;
425 }
426 } else {
427 unsigned overflow = optptr[3]>>4;
428 if (overflow == 15) {
429 pp_ptr = optptr + 3;
430 goto error;
431 }
432 opt->ts = optptr - iph;
433 if (skb) {
434 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
435 opt->is_changed = 1;
436 }
437 }
438 break;
439 case IPOPT_RA:
440 if (optlen < 4) {
441 pp_ptr = optptr + 1;
442 goto error;
443 }
444 if (optptr[2] == 0 && optptr[3] == 0)
445 opt->router_alert = optptr - iph;
446 break;
447 case IPOPT_CIPSO:
448 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
449 pp_ptr = optptr;
450 goto error;
451 }
452 opt->cipso = optptr - iph;
453 if (cipso_v4_validate(&optptr)) {
454 pp_ptr = optptr;
455 goto error;
456 }
457 break;
458 case IPOPT_SEC:
459 case IPOPT_SID:
460 default:
461 if (!skb && !capable(CAP_NET_RAW)) {
462 pp_ptr = optptr;
463 goto error;
464 }
465 break;
466 }
467 l -= optlen;
468 optptr += optlen;
469 }
470
471eol:
472 if (!pp_ptr)
473 return 0;
474
475error:
476 if (skb) {
477 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
478 }
479 return -EINVAL;
480}
481
482
483
484
485
486
487void ip_options_undo(struct ip_options * opt)
488{
489 if (opt->srr) {
490 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
491 memmove(optptr+7, optptr+3, optptr[1]-7);
492 memcpy(optptr+3, &opt->faddr, 4);
493 }
494 if (opt->rr_needaddr) {
495 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
496 optptr[2] -= 4;
497 memset(&optptr[optptr[2]-1], 0, 4);
498 }
499 if (opt->ts) {
500 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
501 if (opt->ts_needtime) {
502 optptr[2] -= 4;
503 memset(&optptr[optptr[2]-1], 0, 4);
504 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
505 optptr[2] -= 4;
506 }
507 if (opt->ts_needaddr) {
508 optptr[2] -= 4;
509 memset(&optptr[optptr[2]-1], 0, 4);
510 }
511 }
512}
513
514static struct ip_options *ip_options_get_alloc(const int optlen)
515{
516 return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
517 GFP_KERNEL);
518}
519
520static int ip_options_get_finish(struct ip_options **optp,
521 struct ip_options *opt, int optlen)
522{
523 while (optlen & 3)
524 opt->__data[optlen++] = IPOPT_END;
525 opt->optlen = optlen;
526 opt->is_data = 1;
527 if (optlen && ip_options_compile(opt, NULL)) {
528 kfree(opt);
529 return -EINVAL;
530 }
531 kfree(*optp);
532 *optp = opt;
533 return 0;
534}
535
536int ip_options_get_from_user(struct ip_options **optp, unsigned char __user *data, int optlen)
537{
538 struct ip_options *opt = ip_options_get_alloc(optlen);
539
540 if (!opt)
541 return -ENOMEM;
542 if (optlen && copy_from_user(opt->__data, data, optlen)) {
543 kfree(opt);
544 return -EFAULT;
545 }
546 return ip_options_get_finish(optp, opt, optlen);
547}
548
549int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen)
550{
551 struct ip_options *opt = ip_options_get_alloc(optlen);
552
553 if (!opt)
554 return -ENOMEM;
555 if (optlen)
556 memcpy(opt->__data, data, optlen);
557 return ip_options_get_finish(optp, opt, optlen);
558}
559
560void ip_forward_options(struct sk_buff *skb)
561{
562 struct ip_options * opt = &(IPCB(skb)->opt);
563 unsigned char * optptr;
564 struct rtable *rt = (struct rtable*)skb->dst;
565 unsigned char *raw = skb_network_header(skb);
566
567 if (opt->rr_needaddr) {
568 optptr = (unsigned char *)raw + opt->rr;
569 ip_rt_get_source(&optptr[optptr[2]-5], rt);
570 opt->is_changed = 1;
571 }
572 if (opt->srr_is_hit) {
573 int srrptr, srrspace;
574
575 optptr = raw + opt->srr;
576
577 for ( srrptr=optptr[2], srrspace = optptr[1];
578 srrptr <= srrspace;
579 srrptr += 4
580 ) {
581 if (srrptr + 3 > srrspace)
582 break;
583 if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
584 break;
585 }
586 if (srrptr + 3 <= srrspace) {
587 opt->is_changed = 1;
588 ip_rt_get_source(&optptr[srrptr-1], rt);
589 ip_hdr(skb)->daddr = rt->rt_dst;
590 optptr[2] = srrptr+4;
591 } else if (net_ratelimit())
592 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
593 if (opt->ts_needaddr) {
594 optptr = raw + opt->ts;
595 ip_rt_get_source(&optptr[optptr[2]-9], rt);
596 opt->is_changed = 1;
597 }
598 }
599 if (opt->is_changed) {
600 opt->is_changed = 0;
601 ip_send_check(ip_hdr(skb));
602 }
603}
604
605int ip_options_rcv_srr(struct sk_buff *skb)
606{
607 struct ip_options *opt = &(IPCB(skb)->opt);
608 int srrspace, srrptr;
609 __be32 nexthop;
610 struct iphdr *iph = ip_hdr(skb);
611 unsigned char *optptr = skb_network_header(skb) + opt->srr;
612 struct rtable *rt = (struct rtable*)skb->dst;
613 struct rtable *rt2;
614 int err;
615
616 if (!opt->srr)
617 return 0;
618
619 if (skb->pkt_type != PACKET_HOST)
620 return -EINVAL;
621 if (rt->rt_type == RTN_UNICAST) {
622 if (!opt->is_strictroute)
623 return 0;
624 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
625 return -EINVAL;
626 }
627 if (rt->rt_type != RTN_LOCAL)
628 return -EINVAL;
629
630 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
631 if (srrptr + 3 > srrspace) {
632 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
633 return -EINVAL;
634 }
635 memcpy(&nexthop, &optptr[srrptr-1], 4);
636
637 rt = (struct rtable*)skb->dst;
638 skb->dst = NULL;
639 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
640 rt2 = (struct rtable*)skb->dst;
641 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
642 ip_rt_put(rt2);
643 skb->dst = &rt->u.dst;
644 return -EINVAL;
645 }
646 ip_rt_put(rt);
647 if (rt2->rt_type != RTN_LOCAL)
648 break;
649
650 memcpy(&iph->daddr, &optptr[srrptr-1], 4);
651 opt->is_changed = 1;
652 }
653 if (srrptr <= srrspace) {
654 opt->srr_is_hit = 1;
655 opt->is_changed = 1;
656 }
657 return 0;
658}
659
