blob: 1dc01f9793d59120a713213e7e65cc855bfb37b9 [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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 memset(dopt, 0, sizeof(struct ip_options));
98
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 sopt = &(IPCB(skb)->opt);
100
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000101 if (sopt->optlen == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700104 sptr = skb_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 dptr = dopt->__data;
106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 if (sopt->rr) {
108 optlen = sptr[sopt->rr+1];
109 soffset = sptr[sopt->rr+2];
110 dopt->rr = dopt->optlen + sizeof(struct iphdr);
111 memcpy(dptr, sptr+sopt->rr, optlen);
112 if (sopt->rr_needaddr && soffset <= optlen) {
113 if (soffset + 3 > optlen)
114 return -EINVAL;
115 dptr[2] = soffset + 4;
116 dopt->rr_needaddr = 1;
117 }
118 dptr += optlen;
119 dopt->optlen += optlen;
120 }
121 if (sopt->ts) {
122 optlen = sptr[sopt->ts+1];
123 soffset = sptr[sopt->ts+2];
124 dopt->ts = dopt->optlen + sizeof(struct iphdr);
125 memcpy(dptr, sptr+sopt->ts, optlen);
126 if (soffset <= optlen) {
127 if (sopt->ts_needaddr) {
128 if (soffset + 3 > optlen)
129 return -EINVAL;
130 dopt->ts_needaddr = 1;
131 soffset += 4;
132 }
133 if (sopt->ts_needtime) {
134 if (soffset + 3 > optlen)
135 return -EINVAL;
136 if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
137 dopt->ts_needtime = 1;
138 soffset += 4;
139 } else {
140 dopt->ts_needtime = 0;
141
Jan Luebbe8628bd82011-03-24 07:44:22 +0000142 if (soffset + 7 <= optlen) {
Al Virofd683222006-09-26 22:17:51 -0700143 __be32 addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Jan Luebbe8628bd82011-03-24 07:44:22 +0000145 memcpy(&addr, dptr+soffset-1, 4);
146 if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_UNICAST) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 dopt->ts_needtime = 1;
148 soffset += 8;
149 }
150 }
151 }
152 }
153 dptr[2] = soffset;
154 }
155 dptr += optlen;
156 dopt->optlen += optlen;
157 }
158 if (sopt->srr) {
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000159 unsigned char *start = sptr+sopt->srr;
Al Viro3ca3c682006-09-27 18:28:07 -0700160 __be32 faddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162 optlen = start[1];
163 soffset = start[2];
164 doffset = 0;
165 if (soffset > optlen)
166 soffset = optlen + 1;
167 soffset -= 4;
168 if (soffset > 3) {
169 memcpy(&faddr, &start[soffset-1], 4);
170 for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
171 memcpy(&dptr[doffset-1], &start[soffset-1], 4);
172 /*
173 * RFC1812 requires to fix illegal source routes.
174 */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700175 if (memcmp(&ip_hdr(skb)->saddr,
176 &start[soffset + 3], 4) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 doffset -= 4;
178 }
179 if (doffset > 3) {
Julian Anastasov6255e5e2012-07-18 21:34:24 +0000180 __be32 daddr = fib_compute_spec_dst(skb);
181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 memcpy(&start[doffset-1], &daddr, 4);
183 dopt->faddr = faddr;
184 dptr[0] = start[0];
185 dptr[1] = doffset+3;
186 dptr[2] = 4;
187 dptr += doffset+3;
188 dopt->srr = dopt->optlen + sizeof(struct iphdr);
189 dopt->optlen += doffset+3;
190 dopt->is_strictroute = sopt->is_strictroute;
191 }
192 }
Paul Moore11a03f72006-08-03 16:46:20 -0700193 if (sopt->cipso) {
194 optlen = sptr[sopt->cipso+1];
195 dopt->cipso = dopt->optlen+sizeof(struct iphdr);
196 memcpy(dptr, sptr+sopt->cipso, optlen);
197 dptr += optlen;
198 dopt->optlen += optlen;
199 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 while (dopt->optlen & 3) {
201 *dptr++ = IPOPT_END;
202 dopt->optlen++;
203 }
204 return 0;
205}
206
207/*
208 * Options "fragmenting", just fill options not
209 * allowed in fragments with NOOPs.
210 * Simple and stupid 8), but the most efficient way.
211 */
212
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000213void ip_options_fragment(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700215 unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000216 struct ip_options *opt = &(IPCB(skb)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 int l = opt->optlen;
218 int optlen;
219
220 while (l > 0) {
221 switch (*optptr) {
222 case IPOPT_END:
223 return;
224 case IPOPT_NOOP:
225 l--;
226 optptr++;
227 continue;
228 }
229 optlen = optptr[1];
230 if (optlen<2 || optlen>l)
231 return;
232 if (!IPOPT_COPIED(*optptr))
233 memset(optptr, IPOPT_NOOP, optlen);
234 l -= optlen;
235 optptr += optlen;
236 }
237 opt->ts = 0;
238 opt->rr = 0;
239 opt->rr_needaddr = 0;
240 opt->ts_needaddr = 0;
241 opt->ts_needtime = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
Eric Dumazetbf5e53e2012-07-04 22:30:09 +0000244/* helper used by ip_options_compile() to call fib_compute_spec_dst()
245 * at most one time.
246 */
247static void spec_dst_fill(__be32 *spec_dst, struct sk_buff *skb)
248{
249 if (*spec_dst == htonl(INADDR_ANY))
250 *spec_dst = fib_compute_spec_dst(skb);
251}
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253/*
254 * Verify options and fill pointers in struct options.
255 * Caller should clear *opt, and set opt->data.
256 * If opt == NULL, then skb->data should point to IP header.
257 */
258
Denis V. Lunev0e6bd4a2008-03-24 15:29:23 -0700259int ip_options_compile(struct net *net,
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000260 struct ip_options *opt, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261{
Eric Dumazetbf5e53e2012-07-04 22:30:09 +0000262 __be32 spec_dst = htonl(INADDR_ANY);
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000263 unsigned char *pp_ptr = NULL;
David S. Miller11604722012-07-04 16:13:17 -0700264 struct rtable *rt = NULL;
David S. Miller35ebf652012-06-28 03:59:11 -0700265 unsigned char *optptr;
266 unsigned char *iph;
267 int optlen, l;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Denis V. Lunev22aba382008-03-22 16:36:20 -0700269 if (skb != NULL) {
David S. Miller11604722012-07-04 16:13:17 -0700270 rt = skb_rtable(skb);
Denis V. Lunev22aba382008-03-22 16:36:20 -0700271 optptr = (unsigned char *)&(ip_hdr(skb)[1]);
272 } else
Denis V. Lunev10fe7d82008-03-22 16:35:00 -0700273 optptr = opt->__data;
Denis V. Lunev22aba382008-03-22 16:36:20 -0700274 iph = optptr - sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
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 }
David S. Miller11604722012-07-04 16:13:17 -0700342 if (rt) {
Eric Dumazetbf5e53e2012-07-04 22:30:09 +0000343 spec_dst_fill(&spec_dst, skb);
David S. Miller35ebf652012-06-28 03:59:11 -0700344 memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 opt->is_changed = 1;
346 }
347 optptr[2] += 4;
348 opt->rr_needaddr = 1;
349 }
350 opt->rr = optptr - iph;
351 break;
352 case IPOPT_TIMESTAMP:
353 if (opt->ts) {
354 pp_ptr = optptr;
355 goto error;
356 }
357 if (optlen < 4) {
358 pp_ptr = optptr + 1;
359 goto error;
360 }
361 if (optptr[2] < 5) {
362 pp_ptr = optptr + 2;
363 goto error;
364 }
365 if (optptr[2] <= optlen) {
Chris Metcalf48bdf072011-05-29 10:55:44 +0000366 unsigned char *timeptr = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 if (optptr[2]+3 > optptr[1]) {
368 pp_ptr = optptr + 2;
369 goto error;
370 }
371 switch (optptr[3]&0xF) {
372 case IPOPT_TS_TSONLY:
373 opt->ts = optptr - iph;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900374 if (skb)
Chris Metcalf48bdf072011-05-29 10:55:44 +0000375 timeptr = &optptr[optptr[2]-1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 opt->ts_needtime = 1;
377 optptr[2] += 4;
378 break;
379 case IPOPT_TS_TSANDADDR:
380 if (optptr[2]+7 > optptr[1]) {
381 pp_ptr = optptr + 2;
382 goto error;
383 }
384 opt->ts = optptr - iph;
David S. Miller11604722012-07-04 16:13:17 -0700385 if (rt) {
Eric Dumazetbf5e53e2012-07-04 22:30:09 +0000386 spec_dst_fill(&spec_dst, skb);
David S. Miller35ebf652012-06-28 03:59:11 -0700387 memcpy(&optptr[optptr[2]-1], &spec_dst, 4);
Chris Metcalf48bdf072011-05-29 10:55:44 +0000388 timeptr = &optptr[optptr[2]+3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 }
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 {
Al Virofd683222006-09-26 22:17:51 -0700401 __be32 addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 memcpy(&addr, &optptr[optptr[2]-1], 4);
Denis V. Lunev0e6bd4a2008-03-24 15:29:23 -0700403 if (inet_addr_type(net, addr) == RTN_UNICAST)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 break;
405 if (skb)
Chris Metcalf48bdf072011-05-29 10:55:44 +0000406 timeptr = &optptr[optptr[2]+3];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 }
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) {
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -0700419 struct timespec tv;
Chris Metcalf48bdf072011-05-29 10:55:44 +0000420 u32 midtime;
YOSHIFUJI Hideakif25c3d62008-04-21 02:34:08 -0700421 getnstimeofday(&tv);
Chris Metcalf48bdf072011-05-29 10:55:44 +0000422 midtime = (tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC;
423 put_unaligned_be32(midtime, timeptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 opt->is_changed = 1;
425 }
426 } else {
Eric Dumazet95c96172012-04-15 05:58:06 +0000427 unsigned int overflow = optptr[3]>>4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 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;
Paul Moore11a03f72006-08-03 16:46:20 -0700447 case IPOPT_CIPSO:
Paul Mooref8687af2006-10-30 15:22:15 -0800448 if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
Paul Moore11a03f72006-08-03 16:46:20 -0700449 pp_ptr = optptr;
450 goto error;
451 }
452 opt->cipso = optptr - iph;
Paul Moore15c45f72008-10-10 10:16:34 -0400453 if (cipso_v4_validate(skb, &optptr)) {
Paul Moore11a03f72006-08-03 16:46:20 -0700454 pp_ptr = optptr;
455 goto error;
456 }
457 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 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}
Bandan Das462fb2a2010-09-19 09:34:33 +0000481EXPORT_SYMBOL(ip_options_compile);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483/*
484 * Undo all the changes done by ip_options_compile().
485 */
486
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000487void ip_options_undo(struct ip_options *opt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488{
489 if (opt->srr) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000490 unsigned char *optptr = opt->__data+opt->srr-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 memmove(optptr+7, optptr+3, optptr[1]-7);
492 memcpy(optptr+3, &opt->faddr, 4);
493 }
494 if (opt->rr_needaddr) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000495 unsigned char *optptr = opt->__data+opt->rr-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 optptr[2] -= 4;
497 memset(&optptr[optptr[2]-1], 0, 4);
498 }
499 if (opt->ts) {
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000500 unsigned char *optptr = opt->__data+opt->ts-sizeof(struct iphdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 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
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000514static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000516 return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
Mariusz Kozlowski37640702007-07-31 14:06:45 -0700517 GFP_KERNEL);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300518}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000520static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
521 struct ip_options_rcu *opt, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300522{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 while (optlen & 3)
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000524 opt->opt.__data[optlen++] = IPOPT_END;
525 opt->opt.optlen = optlen;
526 if (optlen && ip_options_compile(net, &opt->opt, NULL)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 kfree(opt);
528 return -EINVAL;
529 }
Jesper Juhla51482b2005-11-08 09:41:34 -0800530 kfree(*optp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 *optp = opt;
532 return 0;
533}
534
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000535int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700536 unsigned char __user *data, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300537{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000538 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300539
540 if (!opt)
541 return -ENOMEM;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000542 if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300543 kfree(opt);
544 return -EFAULT;
545 }
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700546 return ip_options_get_finish(net, optp, opt, optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300547}
548
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000549int ip_options_get(struct net *net, struct ip_options_rcu **optp,
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700550 unsigned char *data, int optlen)
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300551{
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000552 struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300553
554 if (!opt)
555 return -ENOMEM;
556 if (optlen)
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000557 memcpy(opt->opt.__data, data, optlen);
Denis V. Lunevf2c48022008-03-24 15:29:55 -0700558 return ip_options_get_finish(net, optp, opt, optlen);
Arnaldo Carvalho de Melo4c6ea292005-08-16 19:46:48 -0300559}
560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561void ip_forward_options(struct sk_buff *skb)
562{
Daniel Baluta5e73ea12012-04-15 01:34:41 +0000563 struct ip_options *opt = &(IPCB(skb)->opt);
564 unsigned char *optptr;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000565 struct rtable *rt = skb_rtable(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700566 unsigned char *raw = skb_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 if (opt->rr_needaddr) {
569 optptr = (unsigned char *)raw + opt->rr;
David S. Miller8e363602011-05-13 17:29:41 -0400570 ip_rt_get_source(&optptr[optptr[2]-5], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 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;
Li Weiac8a4812011-11-22 23:33:10 +0000584 if (memcmp(&opt->nexthop, &optptr[srrptr-1], 4) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 break;
586 }
587 if (srrptr + 3 <= srrspace) {
588 opt->is_changed = 1;
Li Weiac8a4812011-11-22 23:33:10 +0000589 ip_hdr(skb)->daddr = opt->nexthop;
Li Wei5dc78832012-02-09 21:15:25 +0000590 ip_rt_get_source(&optptr[srrptr-1], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 optptr[2] = srrptr+4;
Joe Perchese87cc472012-05-13 21:56:26 +0000592 } else {
593 net_crit_ratelimited("%s(): Argh! Destination lost!\n",
594 __func__);
595 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 if (opt->ts_needaddr) {
597 optptr = raw + opt->ts;
David S. Miller8e363602011-05-13 17:29:41 -0400598 ip_rt_get_source(&optptr[optptr[2]-9], skb, rt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 opt->is_changed = 1;
600 }
601 }
602 if (opt->is_changed) {
603 opt->is_changed = 0;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700604 ip_send_check(ip_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 }
606}
607
608int ip_options_rcv_srr(struct sk_buff *skb)
609{
610 struct ip_options *opt = &(IPCB(skb)->opt);
611 int srrspace, srrptr;
Al Viro9e12bb22006-09-26 21:25:20 -0700612 __be32 nexthop;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700613 struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700614 unsigned char *optptr = skb_network_header(skb) + opt->srr;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000615 struct rtable *rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 struct rtable *rt2;
Eric Dumazet7fee2262010-05-11 23:19:48 +0000617 unsigned long orefdst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 int err;
619
David S. Miller10949552011-05-12 19:26:57 -0400620 if (!rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 return 0;
622
623 if (skb->pkt_type != PACKET_HOST)
624 return -EINVAL;
625 if (rt->rt_type == RTN_UNICAST) {
626 if (!opt->is_strictroute)
627 return 0;
628 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
629 return -EINVAL;
630 }
631 if (rt->rt_type != RTN_LOCAL)
632 return -EINVAL;
633
634 for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
635 if (srrptr + 3 > srrspace) {
636 icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
637 return -EINVAL;
638 }
639 memcpy(&nexthop, &optptr[srrptr-1], 4);
640
Eric Dumazet7fee2262010-05-11 23:19:48 +0000641 orefdst = skb->_skb_refdst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000642 skb_dst_set(skb, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
Eric Dumazet511c3f92009-06-02 05:14:27 +0000644 rt2 = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
Eric Dumazet7fee2262010-05-11 23:19:48 +0000646 skb_dst_drop(skb);
647 skb->_skb_refdst = orefdst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 return -EINVAL;
649 }
Eric Dumazet7fee2262010-05-11 23:19:48 +0000650 refdst_drop(orefdst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 if (rt2->rt_type != RTN_LOCAL)
652 break;
653 /* Superfast 8) loopback forward */
David S. Millerc30883b2011-05-12 19:30:58 -0400654 iph->daddr = nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 opt->is_changed = 1;
656 }
657 if (srrptr <= srrspace) {
658 opt->srr_is_hit = 1;
Li Weiac8a4812011-11-22 23:33:10 +0000659 opt->nexthop = nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 opt->is_changed = 1;
661 }
662 return 0;
663}
Bandan Das462fb2a2010-09-19 09:34:33 +0000664EXPORT_SYMBOL(ip_options_rcv_srr);