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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
25
26
27
28
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30
31
32
33
34
35
36void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
37 u32 daddr, struct rtable *rt, int is_frag)
38{
39 unsigned char * iph = skb->nh.raw;
40
41 memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
42 memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
43 opt = &(IPCB(skb)->opt);
44 opt->is_data = 0;
45
46 if (opt->srr)
47 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
48
49 if (!is_frag) {
50 if (opt->rr_needaddr)
51 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
52 if (opt->ts_needaddr)
53 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
54 if (opt->ts_needtime) {
55 struct timeval tv;
56 __u32 midtime;
57 do_gettimeofday(&tv);
58 midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
59 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
60 }
61 return;
62 }
63 if (opt->rr) {
64 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
65 opt->rr = 0;
66 opt->rr_needaddr = 0;
67 }
68 if (opt->ts) {
69 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
70 opt->ts = 0;
71 opt->ts_needaddr = opt->ts_needtime = 0;
72 }
73}
74
75
76
77
78
79
80
81
82
83
84int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
85{
86 struct ip_options *sopt;
87 unsigned char *sptr, *dptr;
88 int soffset, doffset;
89 int optlen;
90 u32 daddr;
91
92 memset(dopt, 0, sizeof(struct ip_options));
93
94 dopt->is_data = 1;
95
96 sopt = &(IPCB(skb)->opt);
97
98 if (sopt->optlen == 0) {
99 dopt->optlen = 0;
100 return 0;
101 }
102
103 sptr = skb->nh.raw;
104 dptr = dopt->__data;
105
106 if (skb->dst)
107 daddr = ((struct rtable*)skb->dst)->rt_spec_dst;
108 else
109 daddr = skb->nh.iph->daddr;
110
111 if (sopt->rr) {
112 optlen = sptr[sopt->rr+1];
113 soffset = sptr[sopt->rr+2];
114 dopt->rr = dopt->optlen + sizeof(struct iphdr);
115 memcpy(dptr, sptr+sopt->rr, optlen);
116 if (sopt->rr_needaddr && soffset <= optlen) {
117 if (soffset + 3 > optlen)
118 return -EINVAL;
119 dptr[2] = soffset + 4;
120 dopt->rr_needaddr = 1;
121 }
122 dptr += optlen;
123 dopt->optlen += optlen;
124 }
125 if (sopt->ts) {
126 optlen = sptr[sopt->ts+1];
127 soffset = sptr[sopt->ts+2];
128 dopt->ts = dopt->optlen + sizeof(struct iphdr);
129 memcpy(dptr, sptr+sopt->ts, optlen);
130 if (soffset <= optlen) {
131 if (sopt->ts_needaddr) {
132 if (soffset + 3 > optlen)
133 return -EINVAL;
134 dopt->ts_needaddr = 1;
135 soffset += 4;
136 }
137 if (sopt->ts_needtime) {
138 if (soffset + 3 > optlen)
139 return -EINVAL;
140 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
141 dopt->ts_needtime = 1;
142 soffset += 4;
143 } else {
144 dopt->ts_needtime = 0;
145
146 if (soffset + 8 <= optlen) {
147 __u32 addr;
148
149 memcpy(&addr, sptr+soffset-1, 4);
150 if (inet_addr_type(addr) != RTN_LOCAL) {
151 dopt->ts_needtime = 1;
152 soffset += 8;
153 }
154 }
155 }
156 }
157 dptr[2] = soffset;
158 }
159 dptr += optlen;
160 dopt->optlen += optlen;
161 }
162 if (sopt->srr) {
163 unsigned char * start = sptr+sopt->srr;
164 u32 faddr;
165
166 optlen = start[1];
167 soffset = start[2];
168 doffset = 0;
169 if (soffset > optlen)
170 soffset = optlen + 1;
171 soffset -= 4;
172 if (soffset > 3) {
173 memcpy(&faddr, &start[soffset-1], 4);
174 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
175 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
176
177
178
179 if (memcmp(&skb->nh.iph->saddr, &start[soffset+3], 4) == 0)
180 doffset -= 4;
181 }
182 if (doffset > 3) {
183 memcpy(&start[doffset-1], &daddr, 4);
184 dopt->faddr = faddr;
185 dptr[0] = start[0];
186 dptr[1] = doffset+3;
187 dptr[2] = 4;
188 dptr += doffset+3;
189 dopt->srr = dopt->optlen + sizeof(struct iphdr);
190 dopt->optlen += doffset+3;
191 dopt->is_strictroute = sopt->is_strictroute;
192 }
193 }
194 while (dopt->optlen & 3) {
195 *dptr++ = IPOPT_END;
196 dopt->optlen++;
197 }
198 return 0;
199}
200
201
202
203
204
205
206
207void ip_options_fragment(struct sk_buff * skb)
208{
209 unsigned char * optptr = skb->nh.raw;
210 struct ip_options * opt = &(IPCB(skb)->opt);
211 int l = opt->optlen;
212 int optlen;
213
214 while (l > 0) {
215 switch (*optptr) {
216 case IPOPT_END:
217 return;
218 case IPOPT_NOOP:
219 l--;
220 optptr++;
221 continue;
222 }
223 optlen = optptr[1];
224 if (optlen<2 || optlen>l)
225 return;
226 if (!IPOPT_COPIED(*optptr))
227 memset(optptr, IPOPT_NOOP, optlen);
228 l -= optlen;
229 optptr += optlen;
230 }
231 opt->ts = 0;
232 opt->rr = 0;
233 opt->rr_needaddr = 0;
234 opt->ts_needaddr = 0;
235 opt->ts_needtime = 0;
236 return;
237}
238
239
240
241
242
243
244
245int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
246{
247 int l;
248 unsigned char * iph;
249 unsigned char * optptr;
250 int optlen;
251 unsigned char * pp_ptr = NULL;
252 struct rtable *rt = skb ? (struct rtable*)skb->dst : NULL;
253
254 if (!opt) {
255 opt = &(IPCB(skb)->opt);
256 memset(opt, 0, sizeof(struct ip_options));
257 iph = skb->nh.raw;
258 opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
259 optptr = iph + sizeof(struct iphdr);
260 opt->is_data = 0;
261 } else {
262 optptr = opt->is_data ? opt->__data : (unsigned char*)&(skb->nh.iph[1]);
263 iph = optptr - sizeof(struct iphdr);
264 }
265
266 for (l = opt->optlen; l > 0; ) {
267 switch (*optptr) {
268 case IPOPT_END:
269 for (optptr++, l--; l>0; l--) {
270 if (*optptr != IPOPT_END) {
271 *optptr = IPOPT_END;
272 opt->is_changed = 1;
273 }
274 }
275 goto eol;
276 case IPOPT_NOOP:
277 l--;
278 optptr++;
279 continue;
280 }
281 optlen = optptr[1];
282 if (optlen<2 || optlen>l) {
283 pp_ptr = optptr;
284 goto error;
285 }
286 switch (*optptr) {
287 case IPOPT_SSRR:
288 case IPOPT_LSRR:
289 if (optlen < 3) {
290 pp_ptr = optptr + 1;
291 goto error;
292 }
293 if (optptr[2] < 4) {
294 pp_ptr = optptr + 2;
295 goto error;
296 }
297
298 if (opt->srr) {
299 pp_ptr = optptr;
300 goto error;
301 }
302 if (!skb) {
303 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
304 pp_ptr = optptr + 1;
305 goto error;
306 }
307 memcpy(&opt->faddr, &optptr[3], 4);
308 if (optlen > 7)
309 memmove(&optptr[3], &optptr[7], optlen-7);
310 }
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;
318 }
319 if (optlen < 3) {
320 pp_ptr = optptr + 1;
321 goto error;
322 }
323 if (optptr[2] < 4) {
324 pp_ptr = optptr + 2;
325 goto error;
326 }
327 if (optptr[2] <= optlen) {
328 if (optptr[2]+3 > optlen) {
329 pp_ptr = optptr + 2;
330 goto error;
331 }
332 if (skb) {
333 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
334 opt->is_changed = 1;
335 }
336 optptr[2] += 4;
337 opt->rr_needaddr = 1;
338 }
339 opt->rr = optptr - iph;
340 break;
341 case IPOPT_TIMESTAMP:
342 if (opt->ts) {
343 pp_ptr = optptr;
344 goto error;
345 }
346 if (optlen < 4) {
347 pp_ptr = optptr + 1;
348 goto error;
349 }
350 if (optptr[2] < 5) {
351 pp_ptr = optptr + 2;
352 goto error;
353 }
354 if (optptr[2] <= optlen) {
355 __u32 * timeptr = NULL;
356 if (optptr[2]+3 > optptr[1]) {
357 pp_ptr = optptr + 2;
358 goto error;
359 }
360 switch (optptr[3]&0xF) {
361 case IPOPT_TS_TSONLY:
362 opt->ts = optptr - iph;
363 if (skb)
364 timeptr = (__u32*)&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;
372 }
373 opt->ts = optptr - iph;
374 if (skb) {
375 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
376 timeptr = (__u32*)&optptr[optptr[2]+3];
377 }
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;
386 }
387 opt->ts = optptr - iph;
388 {
389 u32 addr;
390 memcpy(&addr, &optptr[optptr[2]-1], 4);
391 if (inet_addr_type(addr) == RTN_UNICAST)
392 break;
393 if (skb)
394 timeptr = (__u32*)&optptr[optptr[2]+3];
395 }
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;
403 }
404 break;
405 }
406 if (timeptr) {
407 struct timeval tv;
408 __u32 midtime;
409 do_gettimeofday(&tv);
410 midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
411 memcpy(timeptr, &midtime, sizeof(__u32));
412 opt->is_changed = 1;
413 }
414 } else {
415 unsigned overflow = optptr[3]>>4;
416 if (overflow == 15) {
417 pp_ptr = optptr + 3;
418 goto error;
419 }
420 opt->ts = optptr - iph;
421 if (skb) {
422 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
423 opt->is_changed = 1;
424 }
425 }
426 break;
427 case IPOPT_RA:
428 if (optlen < 4) {
429 pp_ptr = optptr + 1;
430 goto error;
431 }
432 if (optptr[2] == 0 && optptr[3] == 0)
433 opt->router_alert = optptr - iph;
434 break;
435 case IPOPT_SEC:
436 case IPOPT_SID:
437 default:
438 if (!skb && !capable(CAP_NET_RAW)) {
439 pp_ptr = optptr;
440 goto error;
441 }
442 break;
443 }
444 l -= optlen;
445 optptr += optlen;
446 }
447
448eol:
449 if (!pp_ptr)
450 return 0;
451
452error:
453 if (skb) {
454 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
455 kfree_skb(skb);
456 }
457 return -EINVAL;
458}
459
460
461
462
463
464
465void ip_options_undo(struct ip_options * opt)
466{
467 if (opt->srr) {
468 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
469 memmove(optptr+7, optptr+3, optptr[1]-7);
470 memcpy(optptr+3, &opt->faddr, 4);
471 }
472 if (opt->rr_needaddr) {
473 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
474 optptr[2] -= 4;
475 memset(&optptr[optptr[2]-1], 0, 4);
476 }
477 if (opt->ts) {
478 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
479 if (opt->ts_needtime) {
480 optptr[2] -= 4;
481 memset(&optptr[optptr[2]-1], 0, 4);
482 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
483 optptr[2] -= 4;
484 }
485 if (opt->ts_needaddr) {
486 optptr[2] -= 4;
487 memset(&optptr[optptr[2]-1], 0, 4);
488 }
489 }
490}
491
492int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user)
493{
494 struct ip_options *opt;
495
496 opt = kmalloc(sizeof(struct ip_options)+((optlen+3)&~3), GFP_KERNEL);
497 if (!opt)
498 return -ENOMEM;
499 memset(opt, 0, sizeof(struct ip_options));
500 if (optlen) {
501 if (user) {
502 if (copy_from_user(opt->__data, data, optlen))
503 return -EFAULT;
504 } else
505 memcpy(opt->__data, data, optlen);
506 }
507 while (optlen & 3)
508 opt->__data[optlen++] = IPOPT_END;
509 opt->optlen = optlen;
510 opt->is_data = 1;
511 opt->is_setbyuser = 1;
512 if (optlen && ip_options_compile(opt, NULL)) {
513 kfree_s(opt, sizeof(struct ip_options) + optlen);
514 return -EINVAL;
515 }
516 *optp = opt;
517 return 0;
518}
519
520void ip_forward_options(struct sk_buff *skb)
521{
522 struct ip_options * opt = &(IPCB(skb)->opt);
523 unsigned char * optptr;
524 struct rtable *rt = (struct rtable*)skb->dst;
525 unsigned char *raw = skb->nh.raw;
526
527 if (opt->rr_needaddr) {
528 optptr = (unsigned char *)raw + opt->rr;
529 ip_rt_get_source(&optptr[optptr[2]-5], rt);
530 opt->is_changed = 1;
531 }
532 if (opt->srr_is_hit) {
533 int srrptr, srrspace;
534
535 optptr = raw + opt->srr;
536
537 for ( srrptr=optptr[2], srrspace = optptr[1];
538 srrptr <= srrspace;
539 srrptr += 4
540 ) {
541 if (srrptr + 3 > srrspace)
542 break;
543 if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
544 break;
545 }
546 if (srrptr + 3 <= srrspace) {
547 opt->is_changed = 1;
548 ip_rt_get_source(&optptr[srrptr-1], rt);
549 skb->nh.iph->daddr = rt->rt_dst;
550 optptr[2] = srrptr+4;
551 } else
552 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
553 if (opt->ts_needaddr) {
554 optptr = raw + opt->ts;
555 ip_rt_get_source(&optptr[optptr[2]-9], rt);
556 opt->is_changed = 1;
557 }
558 }
559 if (opt->is_changed) {
560 opt->is_changed = 0;
561 ip_send_check(skb->nh.iph);
562 }
563}
564
565int ip_options_rcv_srr(struct sk_buff *skb)
566{
567 struct ip_options *opt = &(IPCB(skb)->opt);
568 int srrspace, srrptr;
569 u32 nexthop;
570 struct iphdr *iph = skb->nh.iph;
571 unsigned char * optptr = skb->nh.raw + opt->srr;
572 struct rtable *rt = (struct rtable*)skb->dst;
573 struct rtable *rt2;
574 int err;
575
576 if (!opt->srr)
577 return 0;
578
579 if (skb->pkt_type != PACKET_HOST)
580 return -EINVAL;
581 if (rt->rt_type == RTN_UNICAST) {
582 if (!opt->is_strictroute)
583 return 0;
584 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
585 return -EINVAL;
586 }
587 if (rt->rt_type != RTN_LOCAL)
588 return -EINVAL;
589
590 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
591 if (srrptr + 3 > srrspace) {
592 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
593 return -EINVAL;
594 }
595 memcpy(&nexthop, &optptr[srrptr-1], 4);
596
597 rt = (struct rtable*)skb->dst;
598 skb->dst = NULL;
599 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
600 rt2 = (struct rtable*)skb->dst;
601 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
602 ip_rt_put(rt2);
603 skb->dst = &rt->u.dst;
604 return -EINVAL;
605 }
606 ip_rt_put(rt);
607 if (rt2->rt_type != RTN_LOCAL)
608 break;
609
610 memcpy(&iph->daddr, &optptr[srrptr-1], 4);
611 opt->is_changed = 1;
612 }
613 if (srrptr <= srrspace) {
614 opt->srr_is_hit = 1;
615 opt->is_changed = 1;
616 }
617 return 0;
618}
619
