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[NET] IPV4: Fix whitespace errors.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / ip_options.c
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.
5 *
6 * The options processing module for ip.c
7 *
8 * Version: $Id: ip_options.c,v 1.21 2001/09/01 00:31:50 davem Exp $
9 *
10 * Authors: A.N.Kuznetsov
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 * Write options to IP header, record destination address to
31 * source route option, address of outgoing interface
32 * (we should already know it, so that this function is allowed be
33 * called only after routing decision) and timestamp,
34 * if we originate this datagram.
35 *
36 * daddr is real destination address, next hop is recorded in IP header.
37 * saddr is address of outgoing interface.
38 */
39
40 void 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->nh.raw;
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 * Provided (sopt, skb) points to received options,
81 * build in dopt compiled option set appropriate for answering.
82 * i.e. invert SRR option, copy anothers,
83 * and grab room in RR/TS options.
84 *
85 * NOTE: dopt cannot point to skb.
86 */
87
88 int 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->nh.raw;
108 dptr = dopt->__data;
109
110 if (skb->dst)
111 daddr = ((struct rtable*)skb->dst)->rt_spec_dst;
112 else
113 daddr = skb->nh.iph->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 * RFC1812 requires to fix illegal source routes.
182 */
183 if (memcmp(&skb->nh.iph->saddr, &start[soffset+3], 4) == 0)
184 doffset -= 4;
185 }
186 if (doffset > 3) {
187 memcpy(&start[doffset-1], &daddr, 4);
188 dopt->faddr = faddr;
189 dptr[0] = start[0];
190 dptr[1] = doffset+3;
191 dptr[2] = 4;
192 dptr += doffset+3;
193 dopt->srr = dopt->optlen + sizeof(struct iphdr);
194 dopt->optlen += doffset+3;
195 dopt->is_strictroute = sopt->is_strictroute;
196 }
197 }
198 if (sopt->cipso) {
199 optlen = sptr[sopt->cipso+1];
200 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
201 memcpy(dptr, sptr+sopt->cipso, optlen);
202 dptr += optlen;
203 dopt->optlen += optlen;
204 }
205 while (dopt->optlen & 3) {
206 *dptr++ = IPOPT_END;
207 dopt->optlen++;
208 }
209 return 0;
210 }
211
212 /*
213 * Options "fragmenting", just fill options not
214 * allowed in fragments with NOOPs.
215 * Simple and stupid 8), but the most efficient way.
216 */
217
218 void ip_options_fragment(struct sk_buff * skb)
219 {
220 unsigned char * optptr = skb->nh.raw + sizeof(struct iphdr);
221 struct ip_options * opt = &(IPCB(skb)->opt);
222 int l = opt->optlen;
223 int optlen;
224
225 while (l > 0) {
226 switch (*optptr) {
227 case IPOPT_END:
228 return;
229 case IPOPT_NOOP:
230 l--;
231 optptr++;
232 continue;
233 }
234 optlen = optptr[1];
235 if (optlen<2 || optlen>l)
236 return;
237 if (!IPOPT_COPIED(*optptr))
238 memset(optptr, IPOPT_NOOP, optlen);
239 l -= optlen;
240 optptr += optlen;
241 }
242 opt->ts = 0;
243 opt->rr = 0;
244 opt->rr_needaddr = 0;
245 opt->ts_needaddr = 0;
246 opt->ts_needtime = 0;
247 return;
248 }
249
250 /*
251 * Verify options and fill pointers in struct options.
252 * Caller should clear *opt, and set opt->data.
253 * If opt == NULL, then skb->data should point to IP header.
254 */
255
256 int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
257 {
258 int l;
259 unsigned char * iph;
260 unsigned char * optptr;
261 int optlen;
262 unsigned char * pp_ptr = NULL;
263 struct rtable *rt = skb ? (struct rtable*)skb->dst : NULL;
264
265 if (!opt) {
266 opt = &(IPCB(skb)->opt);
267 iph = skb->nh.raw;
268 opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
269 optptr = iph + sizeof(struct iphdr);
270 opt->is_data = 0;
271 } else {
272 optptr = opt->is_data ? opt->__data : (unsigned char*)&(skb->nh.iph[1]);
273 iph = optptr - sizeof(struct iphdr);
274 }
275
276 for (l = opt->optlen; l > 0; ) {
277 switch (*optptr) {
278 case IPOPT_END:
279 for (optptr++, l--; l>0; optptr++, l--) {
280 if (*optptr != IPOPT_END) {
281 *optptr = IPOPT_END;
282 opt->is_changed = 1;
283 }
284 }
285 goto eol;
286 case IPOPT_NOOP:
287 l--;
288 optptr++;
289 continue;
290 }
291 optlen = optptr[1];
292 if (optlen<2 || optlen>l) {
293 pp_ptr = optptr;
294 goto error;
295 }
296 switch (*optptr) {
297 case IPOPT_SSRR:
298 case IPOPT_LSRR:
299 if (optlen < 3) {
300 pp_ptr = optptr + 1;
301 goto error;
302 }
303 if (optptr[2] < 4) {
304 pp_ptr = optptr + 2;
305 goto error;
306 }
307 /* NB: cf RFC-1812 5.2.4.1 */
308 if (opt->srr) {
309 pp_ptr = optptr;
310 goto error;
311 }
312 if (!skb) {
313 if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
314 pp_ptr = optptr + 1;
315 goto error;
316 }
317 memcpy(&opt->faddr, &optptr[3], 4);
318 if (optlen > 7)
319 memmove(&optptr[3], &optptr[7], optlen-7);
320 }
321 opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
322 opt->srr = optptr - iph;
323 break;
324 case IPOPT_RR:
325 if (opt->rr) {
326 pp_ptr = optptr;
327 goto error;
328 }
329 if (optlen < 3) {
330 pp_ptr = optptr + 1;
331 goto error;
332 }
333 if (optptr[2] < 4) {
334 pp_ptr = optptr + 2;
335 goto error;
336 }
337 if (optptr[2] <= optlen) {
338 if (optptr[2]+3 > optlen) {
339 pp_ptr = optptr + 2;
340 goto error;
341 }
342 if (skb) {
343 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
344 opt->is_changed = 1;
345 }
346 optptr[2] += 4;
347 opt->rr_needaddr = 1;
348 }
349 opt->rr = optptr - iph;
350 break;
351 case IPOPT_TIMESTAMP:
352 if (opt->ts) {
353 pp_ptr = optptr;
354 goto error;
355 }
356 if (optlen < 4) {
357 pp_ptr = optptr + 1;
358 goto error;
359 }
360 if (optptr[2] < 5) {
361 pp_ptr = optptr + 2;
362 goto error;
363 }
364 if (optptr[2] <= optlen) {
365 __be32 *timeptr = NULL;
366 if (optptr[2]+3 > optptr[1]) {
367 pp_ptr = optptr + 2;
368 goto error;
369 }
370 switch (optptr[3]&0xF) {
371 case IPOPT_TS_TSONLY:
372 opt->ts = optptr - iph;
373 if (skb)
374 timeptr = (__be32*)&optptr[optptr[2]-1];
375 opt->ts_needtime = 1;
376 optptr[2] += 4;
377 break;
378 case IPOPT_TS_TSANDADDR:
379 if (optptr[2]+7 > optptr[1]) {
380 pp_ptr = optptr + 2;
381 goto error;
382 }
383 opt->ts = optptr - iph;
384 if (skb) {
385 memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
386 timeptr = (__be32*)&optptr[optptr[2]+3];
387 }
388 opt->ts_needaddr = 1;
389 opt->ts_needtime = 1;
390 optptr[2] += 8;
391 break;
392 case IPOPT_TS_PRESPEC:
393 if (optptr[2]+7 > optptr[1]) {
394 pp_ptr = optptr + 2;
395 goto error;
396 }
397 opt->ts = optptr - iph;
398 {
399 __be32 addr;
400 memcpy(&addr, &optptr[optptr[2]-1], 4);
401 if (inet_addr_type(addr) == RTN_UNICAST)
402 break;
403 if (skb)
404 timeptr = (__be32*)&optptr[optptr[2]+3];
405 }
406 opt->ts_needtime = 1;
407 optptr[2] += 8;
408 break;
409 default:
410 if (!skb && !capable(CAP_NET_RAW)) {
411 pp_ptr = optptr + 3;
412 goto error;
413 }
414 break;
415 }
416 if (timeptr) {
417 struct timeval tv;
418 __be32 midtime;
419 do_gettimeofday(&tv);
420 midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
421 memcpy(timeptr, &midtime, sizeof(__be32));
422 opt->is_changed = 1;
423 }
424 } else {
425 unsigned overflow = optptr[3]>>4;
426 if (overflow == 15) {
427 pp_ptr = optptr + 3;
428 goto error;
429 }
430 opt->ts = optptr - iph;
431 if (skb) {
432 optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
433 opt->is_changed = 1;
434 }
435 }
436 break;
437 case IPOPT_RA:
438 if (optlen < 4) {
439 pp_ptr = optptr + 1;
440 goto error;
441 }
442 if (optptr[2] == 0 && optptr[3] == 0)
443 opt->router_alert = optptr - iph;
444 break;
445 case IPOPT_CIPSO:
446 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
447 pp_ptr = optptr;
448 goto error;
449 }
450 opt->cipso = optptr - iph;
451 if (cipso_v4_validate(&optptr)) {
452 pp_ptr = optptr;
453 goto error;
454 }
455 break;
456 case IPOPT_SEC:
457 case IPOPT_SID:
458 default:
459 if (!skb && !capable(CAP_NET_RAW)) {
460 pp_ptr = optptr;
461 goto error;
462 }
463 break;
464 }
465 l -= optlen;
466 optptr += optlen;
467 }
468
469 eol:
470 if (!pp_ptr)
471 return 0;
472
473 error:
474 if (skb) {
475 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
476 }
477 return -EINVAL;
478 }
479
480
481 /*
482 * Undo all the changes done by ip_options_compile().
483 */
484
485 void ip_options_undo(struct ip_options * opt)
486 {
487 if (opt->srr) {
488 unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);
489 memmove(optptr+7, optptr+3, optptr[1]-7);
490 memcpy(optptr+3, &opt->faddr, 4);
491 }
492 if (opt->rr_needaddr) {
493 unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);
494 optptr[2] -= 4;
495 memset(&optptr[optptr[2]-1], 0, 4);
496 }
497 if (opt->ts) {
498 unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);
499 if (opt->ts_needtime) {
500 optptr[2] -= 4;
501 memset(&optptr[optptr[2]-1], 0, 4);
502 if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
503 optptr[2] -= 4;
504 }
505 if (opt->ts_needaddr) {
506 optptr[2] -= 4;
507 memset(&optptr[optptr[2]-1], 0, 4);
508 }
509 }
510 }
511
512 static struct ip_options *ip_options_get_alloc(const int optlen)
513 {
514 struct ip_options *opt = kmalloc(sizeof(*opt) + ((optlen + 3) & ~3),
515 GFP_KERNEL);
516 if (opt)
517 memset(opt, 0, sizeof(*opt));
518 return opt;
519 }
520
521 static int ip_options_get_finish(struct ip_options **optp,
522 struct ip_options *opt, int optlen)
523 {
524 while (optlen & 3)
525 opt->__data[optlen++] = IPOPT_END;
526 opt->optlen = optlen;
527 opt->is_data = 1;
528 if (optlen && ip_options_compile(opt, NULL)) {
529 kfree(opt);
530 return -EINVAL;
531 }
532 kfree(*optp);
533 *optp = opt;
534 return 0;
535 }
536
537 int ip_options_get_from_user(struct ip_options **optp, unsigned char __user *data, int optlen)
538 {
539 struct ip_options *opt = ip_options_get_alloc(optlen);
540
541 if (!opt)
542 return -ENOMEM;
543 if (optlen && copy_from_user(opt->__data, data, optlen)) {
544 kfree(opt);
545 return -EFAULT;
546 }
547 return ip_options_get_finish(optp, opt, optlen);
548 }
549
550 int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen)
551 {
552 struct ip_options *opt = ip_options_get_alloc(optlen);
553
554 if (!opt)
555 return -ENOMEM;
556 if (optlen)
557 memcpy(opt->__data, data, optlen);
558 return ip_options_get_finish(optp, opt, optlen);
559 }
560
561 void ip_forward_options(struct sk_buff *skb)
562 {
563 struct ip_options * opt = &(IPCB(skb)->opt);
564 unsigned char * optptr;
565 struct rtable *rt = (struct rtable*)skb->dst;
566 unsigned char *raw = skb->nh.raw;
567
568 if (opt->rr_needaddr) {
569 optptr = (unsigned char *)raw + opt->rr;
570 ip_rt_get_source(&optptr[optptr[2]-5], rt);
571 opt->is_changed = 1;
572 }
573 if (opt->srr_is_hit) {
574 int srrptr, srrspace;
575
576 optptr = raw + opt->srr;
577
578 for ( srrptr=optptr[2], srrspace = optptr[1];
579 srrptr <= srrspace;
580 srrptr += 4
581 ) {
582 if (srrptr + 3 > srrspace)
583 break;
584 if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
585 break;
586 }
587 if (srrptr + 3 <= srrspace) {
588 opt->is_changed = 1;
589 ip_rt_get_source(&optptr[srrptr-1], rt);
590 skb->nh.iph->daddr = rt->rt_dst;
591 optptr[2] = srrptr+4;
592 } else if (net_ratelimit())
593 printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
594 if (opt->ts_needaddr) {
595 optptr = raw + opt->ts;
596 ip_rt_get_source(&optptr[optptr[2]-9], rt);
597 opt->is_changed = 1;
598 }
599 }
600 if (opt->is_changed) {
601 opt->is_changed = 0;
602 ip_send_check(skb->nh.iph);
603 }
604 }
605
606 int ip_options_rcv_srr(struct sk_buff *skb)
607 {
608 struct ip_options *opt = &(IPCB(skb)->opt);
609 int srrspace, srrptr;
610 __be32 nexthop;
611 struct iphdr *iph = skb->nh.iph;
612 unsigned char * optptr = skb->nh.raw + opt->srr;
613 struct rtable *rt = (struct rtable*)skb->dst;
614 struct rtable *rt2;
615 int err;
616
617 if (!opt->srr)
618 return 0;
619
620 if (skb->pkt_type != PACKET_HOST)
621 return -EINVAL;
622 if (rt->rt_type == RTN_UNICAST) {
623 if (!opt->is_strictroute)
624 return 0;
625 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
626 return -EINVAL;
627 }
628 if (rt->rt_type != RTN_LOCAL)
629 return -EINVAL;
630
631 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
632 if (srrptr + 3 > srrspace) {
633 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
634 return -EINVAL;
635 }
636 memcpy(&nexthop, &optptr[srrptr-1], 4);
637
638 rt = (struct rtable*)skb->dst;
639 skb->dst = NULL;
640 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
641 rt2 = (struct rtable*)skb->dst;
642 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
643 ip_rt_put(rt2);
644 skb->dst = &rt->u.dst;
645 return -EINVAL;
646 }
647 ip_rt_put(rt);
648 if (rt2->rt_type != RTN_LOCAL)
649 break;
650 /* Superfast 8) loopback forward */
651 memcpy(&iph->daddr, &optptr[srrptr-1], 4);
652 opt->is_changed = 1;
653 }
654 if (srrptr <= srrspace) {
655 opt->srr_is_hit = 1;
656 opt->is_changed = 1;
657 }
658 return 0;
659 }
kernel source for telekom puls (alcatel/mediatek)