blob: 766dfe56885a9a8a8a679447c02b13e7c0106dfb [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Authors: A.N.Kuznetsov
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09009 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11
Joe Perchesafd465032012-03-12 07:03:32 +000012#define pr_fmt(fmt) "IPv4: " fmt
13
Randy Dunlap4fc268d2006-01-11 12:17:47 -080014#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/types.h>
18#include <asm/uaccess.h>
Chris Metcalf48bdf072011-05-29 10:55:44 +000019#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/skbuff.h>
21#include <linux/ip.h>
22#include <linux/icmp.h>
23#include <linux/netdevice.h>
24#include <linux/rtnetlink.h>
25#include <net/sock.h>
26#include <net/ip.h>
27#include <net/icmp.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020028#include <net/route.h>
Paul Moore11a03f72006-08-03 16:46:20 -070029#include <net/cipso_ipv4.h>
David S. Miller35ebf652012-06-28 03:59:11 -070030#include <net/ip_fib.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090032/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 * Write options to IP header, record destination address to
34 * source route option, address of outgoing interface
35 * (we should already know it, so that this function is allowed be
36 * called only after routing decision) and timestamp,
37 * if we originate this datagram.
38 *
39 * daddr is real destination address, next hop is recorded in IP header.
40 * saddr is address of outgoing interface.
41 */
42
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000043void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
David S. Miller8e363602011-05-13 17:29:41 -040044 __be32 daddr, struct rtable *rt, int is_frag)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -070046 unsigned char *iph = skb_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48 memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
49 memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
50 opt = &(IPCB(skb)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52 if (opt->srr)
53 memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
54
55 if (!is_frag) {
56 if (opt->rr_needaddr)
David S. Miller8e363602011-05-13 17:29:41 -040057 ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 if (opt->ts_needaddr)
David S. Miller8e363602011-05-13 17:29:41 -040059 ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 if (opt->ts_needtime) {
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -070061 struct timespec tv;
Al Viroe25d2ca2006-09-27 18:28:47 -070062 __be32 midtime;
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -070063 getnstimeofday(&tv);
64 midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
66 }
67 return;
68 }
69 if (opt->rr) {
70 memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
71 opt->rr = 0;
72 opt->rr_needaddr = 0;
73 }
74 if (opt->ts) {
75 memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
76 opt->ts = 0;
77 opt->ts_needaddr = opt->ts_needtime = 0;
78 }
79}
80
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090081/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 * Provided (sopt, skb) points to received options,
83 * build in dopt compiled option set appropriate for answering.
84 * i.e. invert SRR option, copy anothers,
85 * and grab room in RR/TS options.
86 *
87 * NOTE: dopt cannot point to skb.
88 */
89
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000090int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000092 const struct ip_options *sopt;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 unsigned char *sptr, *dptr;
94 int soffset, doffset;
95 int optlen;
Al Viroe25d2ca2006-09-27 18:28:47 -070096 __be32 daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 memset(dopt, 0, sizeof(struct ip_options));
99
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 sopt = &(IPCB(skb)->opt);
101
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000102 if (sopt->optlen == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700105 sptr = skb_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 dptr = dopt->__data;
107
David S. Miller35ebf652012-06-28 03:59:11 -0700108 daddr = fib_compute_spec_dst(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
110 if (sopt->rr) {
111 optlen = sptr[sopt->rr+1];
112 soffset = sptr[sopt->rr+2];
113 dopt->rr = dopt->optlen + sizeof(struct iphdr);
114 memcpy(dptr, sptr+sopt->rr, optlen);
115 if (sopt->rr_needaddr && soffset <= optlen) {
116 if (soffset + 3 > optlen)
117 return -EINVAL;
118 dptr[2] = soffset + 4;
119 dopt->rr_needaddr = 1;
120 }
121 dptr += optlen;
122 dopt->optlen += optlen;
123 }
124 if (sopt->ts) {
125 optlen = sptr[sopt->ts+1];
126 soffset = sptr[sopt->ts+2];
127 dopt->ts = dopt->optlen + sizeof(struct iphdr);
128 memcpy(dptr, sptr+sopt->ts, optlen);
129 if (soffset <= optlen) {
130 if (sopt->ts_needaddr) {
131 if (soffset + 3 > optlen)
132 return -EINVAL;
133 dopt->ts_needaddr = 1;
134 soffset += 4;
135 }
136 if (sopt->ts_needtime) {
137 if (soffset + 3 > optlen)
138 return -EINVAL;
139 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
140 dopt->ts_needtime = 1;
141 soffset += 4;
142 } else {
143 dopt->ts_needtime = 0;
144
Jan Luebbe8628bd82011-03-24 07:44:22 +0000145 if (soffset + 7 <= optlen) {
Al Virofd683222006-09-26 22:17:51 -0700146 __be32 addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Jan Luebbe8628bd82011-03-24 07:44:22 +0000148 memcpy(&addr, dptr+soffset-1, 4);
149 if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_UNICAST) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 dopt->ts_needtime = 1;
151 soffset += 8;
152 }
153 }
154 }
155 }
156 dptr[2] = soffset;
157 }
158 dptr += optlen;
159 dopt->optlen += optlen;
160 }
161 if (sopt->srr) {
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000162 unsigned char *start = sptr+sopt->srr;
Al Viro3ca3c682006-09-27 18:28:07 -0700163 __be32 faddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 optlen = start[1];
166 soffset = start[2];
167 doffset = 0;
168 if (soffset > optlen)
169 soffset = optlen + 1;
170 soffset -= 4;
171 if (soffset > 3) {
172 memcpy(&faddr, &start[soffset-1], 4);
173 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
174 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
175 /*
176 * RFC1812 requires to fix illegal source routes.
177 */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700178 if (memcmp(&ip_hdr(skb)->saddr,
179 &start[soffset + 3], 4) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 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 }
Paul Moore11a03f72006-08-03 16:46:20 -0700194 if (sopt->cipso) {
195 optlen = sptr[sopt->cipso+1];
196 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
197 memcpy(dptr, sptr+sopt->cipso, optlen);
198 dptr += optlen;
199 dopt->optlen += optlen;
200 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 while (dopt->optlen & 3) {
202 *dptr++ = IPOPT_END;
203 dopt->optlen++;
204 }
205 return 0;
206}
207
208/*
209 * Options "fragmenting", just fill options not
210 * allowed in fragments with NOOPs.
211 * Simple and stupid 8), but the most efficient way.
212 */
213
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000214void ip_options_fragment(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700216 unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000217 struct ip_options *opt = &(IPCB(skb)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 int l = opt->optlen;
219 int optlen;
220
221 while (l > 0) {
222 switch (*optptr) {
223 case IPOPT_END:
224 return;
225 case IPOPT_NOOP:
226 l--;
227 optptr++;
228 continue;
229 }
230 optlen = optptr[1];
231 if (optlen<2 || optlen>l)
232 return;
233 if (!IPOPT_COPIED(*optptr))
234 memset(optptr, IPOPT_NOOP, optlen);
235 l -= optlen;
236 optptr += optlen;
237 }
238 opt->ts = 0;
239 opt->rr = 0;
240 opt->rr_needaddr = 0;
241 opt->ts_needaddr = 0;
242 opt->ts_needtime = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243}
244
245/*
246 * Verify options and fill pointers in struct options.
247 * Caller should clear *opt, and set opt->data.
248 * If opt == NULL, then skb->data should point to IP header.
249 */
250
Denis V. Lunev0e6bd4a2008-03-24 15:29:23 -0700251int ip_options_compile(struct net *net,
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000252 struct ip_options *opt, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
David S. Miller35ebf652012-06-28 03:59:11 -0700254 __be32 spec_dst = (__force __be32) 0;
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000255 unsigned char *pp_ptr = NULL;
David S. Miller35ebf652012-06-28 03:59:11 -0700256 unsigned char *optptr;
257 unsigned char *iph;
258 int optlen, l;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Denis V. Lunev22aba382008-03-22 16:36:20 -0700260 if (skb != NULL) {
David S. Miller35ebf652012-06-28 03:59:11 -0700261 spec_dst = fib_compute_spec_dst(skb);
Denis V. Lunev22aba382008-03-22 16:36:20 -0700262 optptr = (unsigned char *)&(ip_hdr(skb)[1]);
263 } else
Denis V. Lunev10fe7d82008-03-22 16:35:00 -0700264 optptr = opt->__data;
Denis V. Lunev22aba382008-03-22 16:36:20 -0700265 iph = optptr - sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
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 /* NB: cf RFC-1812 5.2.4.1 */
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 }
David S. Miller35ebf652012-06-28 03:59:11 -0700333 if (skb) {
334 memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 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) {
Chris Metcalf48bdf072011-05-29 10:55:44 +0000356 unsigned char *timeptr = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 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;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900364 if (skb)
Chris Metcalf48bdf072011-05-29 10:55:44 +0000365 timeptr = &optptr[optptr[2]-1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 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;
David S. Miller35ebf652012-06-28 03:59:11 -0700375 if (skb) {
376 memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
Chris Metcalf48bdf072011-05-29 10:55:44 +0000377 timeptr = &optptr[optptr[2]+3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 }
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 {
Al Virofd683222006-09-26 22:17:51 -0700390 __be32 addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 memcpy(&addr, &optptr[optptr[2]-1], 4);
Denis V. Lunev0e6bd4a2008-03-24 15:29:23 -0700392 if (inet_addr_type(net, addr) == RTN_UNICAST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 break;
394 if (skb)
Chris Metcalf48bdf072011-05-29 10:55:44 +0000395 timeptr = &optptr[optptr[2]+3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 }
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) {
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -0700408 struct timespec tv;
Chris Metcalf48bdf072011-05-29 10:55:44 +0000409 u32 midtime;
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -0700410 getnstimeofday(&tv);
Chris Metcalf48bdf072011-05-29 10:55:44 +0000411 midtime = (tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC;
412 put_unaligned_be32(midtime, timeptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 opt->is_changed = 1;
414 }
415 } else {
Eric Dumazet95c96172012-04-15 05:58:06 +0000416 unsigned int overflow = optptr[3]>>4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 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;
Paul Moore11a03f72006-08-03 16:46:20 -0700436 case IPOPT_CIPSO:
Paul Mooref8687af2006-10-30 15:22:15 -0800437 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
Paul Moore11a03f72006-08-03 16:46:20 -0700438 pp_ptr = optptr;
439 goto error;
440 }
441 opt->cipso = optptr - iph;
Paul Moore15c45f72008-10-10 10:16:34 -0400442 if (cipso_v4_validate(skb, &optptr)) {
Paul Moore11a03f72006-08-03 16:46:20 -0700443 pp_ptr = optptr;
444 goto error;
445 }
446 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 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}
Bandan Das462fb2a2010-09-19 09:34:33 +0000470EXPORT_SYMBOL(ip_options_compile);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472/*
473 * Undo all the changes done by ip_options_compile().
474 */
475
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000476void ip_options_undo(struct ip_options *opt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477{
478 if (opt->srr) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000479 unsigned char *optptr = opt->__data+opt->srr-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 memmove(optptr+7, optptr+3, optptr[1]-7);
481 memcpy(optptr+3, &opt->faddr, 4);
482 }
483 if (opt->rr_needaddr) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000484 unsigned char *optptr = opt->__data+opt->rr-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 optptr[2] -= 4;
486 memset(&optptr[optptr[2]-1], 0, 4);
487 }
488 if (opt->ts) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000489 unsigned char *optptr = opt->__data+opt->ts-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 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
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000503static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000505 return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
Mariusz Kozlowski37640702007-07-31 14:06:45 -0700506 GFP_KERNEL);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300507}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000509static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
510 struct ip_options_rcu *opt, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300511{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 while (optlen & 3)
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000513 opt->opt.__data[optlen++] = IPOPT_END;
514 opt->opt.optlen = optlen;
515 if (optlen && ip_options_compile(net, &opt->opt, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 kfree(opt);
517 return -EINVAL;
518 }
Jesper Juhla51482b2005-11-08 09:41:34 -0800519 kfree(*optp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 *optp = opt;
521 return 0;
522}
523
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000524int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700525 unsigned char __user *data, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300526{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000527 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300528
529 if (!opt)
530 return -ENOMEM;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000531 if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300532 kfree(opt);
533 return -EFAULT;
534 }
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700535 return ip_options_get_finish(net, optp, opt, optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300536}
537
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000538int ip_options_get(struct net *net, struct ip_options_rcu **optp,
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700539 unsigned char *data, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300540{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000541 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300542
543 if (!opt)
544 return -ENOMEM;
545 if (optlen)
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000546 memcpy(opt->opt.__data, data, optlen);
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700547 return ip_options_get_finish(net, optp, opt, optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300548}
549
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550void ip_forward_options(struct sk_buff *skb)
551{
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000552 struct ip_options *opt = &(IPCB(skb)->opt);
553 unsigned char *optptr;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000554 struct rtable *rt = skb_rtable(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700555 unsigned char *raw = skb_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 if (opt->rr_needaddr) {
558 optptr = (unsigned char *)raw + opt->rr;
David S. Miller8e363602011-05-13 17:29:41 -0400559 ip_rt_get_source(&optptr[optptr[2]-5], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 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;
Li Weiac8a4812011-11-22 23:33:10 +0000573 if (memcmp(&opt->nexthop, &optptr[srrptr-1], 4) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 break;
575 }
576 if (srrptr + 3 <= srrspace) {
577 opt->is_changed = 1;
Li Weiac8a4812011-11-22 23:33:10 +0000578 ip_hdr(skb)->daddr = opt->nexthop;
Li Wei5dc78832012-02-09 21:15:25 +0000579 ip_rt_get_source(&optptr[srrptr-1], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 optptr[2] = srrptr+4;
Joe Perchese87cc472012-05-13 21:56:26 +0000581 } else {
582 net_crit_ratelimited("%s(): Argh! Destination lost!\n",
583 __func__);
584 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 if (opt->ts_needaddr) {
586 optptr = raw + opt->ts;
David S. Miller8e363602011-05-13 17:29:41 -0400587 ip_rt_get_source(&optptr[optptr[2]-9], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 opt->is_changed = 1;
589 }
590 }
591 if (opt->is_changed) {
592 opt->is_changed = 0;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700593 ip_send_check(ip_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 }
595}
596
597int ip_options_rcv_srr(struct sk_buff *skb)
598{
599 struct ip_options *opt = &(IPCB(skb)->opt);
600 int srrspace, srrptr;
Al Viro9e12bb22006-09-26 21:25:20 -0700601 __be32 nexthop;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700602 struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700603 unsigned char *optptr = skb_network_header(skb) + opt->srr;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000604 struct rtable *rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 struct rtable *rt2;
Eric Dumazet7fee2262010-05-11 23:19:48 +0000606 unsigned long orefdst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 int err;
608
David S. Miller10949552011-05-12 19:26:57 -0400609 if (!rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 return 0;
611
612 if (skb->pkt_type != PACKET_HOST)
613 return -EINVAL;
614 if (rt->rt_type == RTN_UNICAST) {
615 if (!opt->is_strictroute)
616 return 0;
617 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
618 return -EINVAL;
619 }
620 if (rt->rt_type != RTN_LOCAL)
621 return -EINVAL;
622
623 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
624 if (srrptr + 3 > srrspace) {
625 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
626 return -EINVAL;
627 }
628 memcpy(&nexthop, &optptr[srrptr-1], 4);
629
Eric Dumazet7fee2262010-05-11 23:19:48 +0000630 orefdst = skb->_skb_refdst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000631 skb_dst_set(skb, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
Eric Dumazet511c3f92009-06-02 05:14:27 +0000633 rt2 = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
Eric Dumazet7fee2262010-05-11 23:19:48 +0000635 skb_dst_drop(skb);
636 skb->_skb_refdst = orefdst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 return -EINVAL;
638 }
Eric Dumazet7fee2262010-05-11 23:19:48 +0000639 refdst_drop(orefdst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 if (rt2->rt_type != RTN_LOCAL)
641 break;
642 /* Superfast 8) loopback forward */
David S. Millerc30883b2011-05-12 19:30:58 -0400643 iph->daddr = nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 opt->is_changed = 1;
645 }
646 if (srrptr <= srrspace) {
647 opt->srr_is_hit = 1;
Li Weiac8a4812011-11-22 23:33:10 +0000648 opt->nexthop = nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 opt->is_changed = 1;
650 }
651 return 0;
652}
Bandan Das462fb2a2010-09-19 09:34:33 +0000653EXPORT_SYMBOL(ip_options_rcv_srr);