Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Randy Dunlap | 4fc268d | 2006-01-11 12:17:47 -0800 | [diff] [blame^] | 14 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 26 | #include <net/route.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
| 28 | /* |
| 29 | * Write options to IP header, record destination address to |
| 30 | * source route option, address of outgoing interface |
| 31 | * (we should already know it, so that this function is allowed be |
| 32 | * called only after routing decision) and timestamp, |
| 33 | * if we originate this datagram. |
| 34 | * |
| 35 | * daddr is real destination address, next hop is recorded in IP header. |
| 36 | * saddr is address of outgoing interface. |
| 37 | */ |
| 38 | |
| 39 | void ip_options_build(struct sk_buff * skb, struct ip_options * opt, |
| 40 | u32 daddr, struct rtable *rt, int is_frag) |
| 41 | { |
| 42 | unsigned char * iph = skb->nh.raw; |
| 43 | |
| 44 | memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options)); |
| 45 | memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen); |
| 46 | opt = &(IPCB(skb)->opt); |
| 47 | opt->is_data = 0; |
| 48 | |
| 49 | if (opt->srr) |
| 50 | memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4); |
| 51 | |
| 52 | if (!is_frag) { |
| 53 | if (opt->rr_needaddr) |
| 54 | ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt); |
| 55 | if (opt->ts_needaddr) |
| 56 | ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt); |
| 57 | if (opt->ts_needtime) { |
| 58 | struct timeval tv; |
| 59 | __u32 midtime; |
| 60 | do_gettimeofday(&tv); |
| 61 | midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000); |
| 62 | memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4); |
| 63 | } |
| 64 | return; |
| 65 | } |
| 66 | if (opt->rr) { |
| 67 | memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]); |
| 68 | opt->rr = 0; |
| 69 | opt->rr_needaddr = 0; |
| 70 | } |
| 71 | if (opt->ts) { |
| 72 | memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]); |
| 73 | opt->ts = 0; |
| 74 | opt->ts_needaddr = opt->ts_needtime = 0; |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * Provided (sopt, skb) points to received options, |
| 80 | * build in dopt compiled option set appropriate for answering. |
| 81 | * i.e. invert SRR option, copy anothers, |
| 82 | * and grab room in RR/TS options. |
| 83 | * |
| 84 | * NOTE: dopt cannot point to skb. |
| 85 | */ |
| 86 | |
| 87 | int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb) |
| 88 | { |
| 89 | struct ip_options *sopt; |
| 90 | unsigned char *sptr, *dptr; |
| 91 | int soffset, doffset; |
| 92 | int optlen; |
| 93 | u32 daddr; |
| 94 | |
| 95 | memset(dopt, 0, sizeof(struct ip_options)); |
| 96 | |
| 97 | dopt->is_data = 1; |
| 98 | |
| 99 | sopt = &(IPCB(skb)->opt); |
| 100 | |
| 101 | if (sopt->optlen == 0) { |
| 102 | dopt->optlen = 0; |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | sptr = skb->nh.raw; |
| 107 | dptr = dopt->__data; |
| 108 | |
| 109 | if (skb->dst) |
| 110 | daddr = ((struct rtable*)skb->dst)->rt_spec_dst; |
| 111 | else |
| 112 | daddr = skb->nh.iph->daddr; |
| 113 | |
| 114 | if (sopt->rr) { |
| 115 | optlen = sptr[sopt->rr+1]; |
| 116 | soffset = sptr[sopt->rr+2]; |
| 117 | dopt->rr = dopt->optlen + sizeof(struct iphdr); |
| 118 | memcpy(dptr, sptr+sopt->rr, optlen); |
| 119 | if (sopt->rr_needaddr && soffset <= optlen) { |
| 120 | if (soffset + 3 > optlen) |
| 121 | return -EINVAL; |
| 122 | dptr[2] = soffset + 4; |
| 123 | dopt->rr_needaddr = 1; |
| 124 | } |
| 125 | dptr += optlen; |
| 126 | dopt->optlen += optlen; |
| 127 | } |
| 128 | if (sopt->ts) { |
| 129 | optlen = sptr[sopt->ts+1]; |
| 130 | soffset = sptr[sopt->ts+2]; |
| 131 | dopt->ts = dopt->optlen + sizeof(struct iphdr); |
| 132 | memcpy(dptr, sptr+sopt->ts, optlen); |
| 133 | if (soffset <= optlen) { |
| 134 | if (sopt->ts_needaddr) { |
| 135 | if (soffset + 3 > optlen) |
| 136 | return -EINVAL; |
| 137 | dopt->ts_needaddr = 1; |
| 138 | soffset += 4; |
| 139 | } |
| 140 | if (sopt->ts_needtime) { |
| 141 | if (soffset + 3 > optlen) |
| 142 | return -EINVAL; |
| 143 | if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) { |
| 144 | dopt->ts_needtime = 1; |
| 145 | soffset += 4; |
| 146 | } else { |
| 147 | dopt->ts_needtime = 0; |
| 148 | |
| 149 | if (soffset + 8 <= optlen) { |
| 150 | __u32 addr; |
| 151 | |
| 152 | memcpy(&addr, sptr+soffset-1, 4); |
| 153 | if (inet_addr_type(addr) != RTN_LOCAL) { |
| 154 | dopt->ts_needtime = 1; |
| 155 | soffset += 8; |
| 156 | } |
| 157 | } |
| 158 | } |
| 159 | } |
| 160 | dptr[2] = soffset; |
| 161 | } |
| 162 | dptr += optlen; |
| 163 | dopt->optlen += optlen; |
| 164 | } |
| 165 | if (sopt->srr) { |
| 166 | unsigned char * start = sptr+sopt->srr; |
| 167 | u32 faddr; |
| 168 | |
| 169 | optlen = start[1]; |
| 170 | soffset = start[2]; |
| 171 | doffset = 0; |
| 172 | if (soffset > optlen) |
| 173 | soffset = optlen + 1; |
| 174 | soffset -= 4; |
| 175 | if (soffset > 3) { |
| 176 | memcpy(&faddr, &start[soffset-1], 4); |
| 177 | for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4) |
| 178 | memcpy(&dptr[doffset-1], &start[soffset-1], 4); |
| 179 | /* |
| 180 | * RFC1812 requires to fix illegal source routes. |
| 181 | */ |
| 182 | if (memcmp(&skb->nh.iph->saddr, &start[soffset+3], 4) == 0) |
| 183 | doffset -= 4; |
| 184 | } |
| 185 | if (doffset > 3) { |
| 186 | memcpy(&start[doffset-1], &daddr, 4); |
| 187 | dopt->faddr = faddr; |
| 188 | dptr[0] = start[0]; |
| 189 | dptr[1] = doffset+3; |
| 190 | dptr[2] = 4; |
| 191 | dptr += doffset+3; |
| 192 | dopt->srr = dopt->optlen + sizeof(struct iphdr); |
| 193 | dopt->optlen += doffset+3; |
| 194 | dopt->is_strictroute = sopt->is_strictroute; |
| 195 | } |
| 196 | } |
| 197 | while (dopt->optlen & 3) { |
| 198 | *dptr++ = IPOPT_END; |
| 199 | dopt->optlen++; |
| 200 | } |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * Options "fragmenting", just fill options not |
| 206 | * allowed in fragments with NOOPs. |
| 207 | * Simple and stupid 8), but the most efficient way. |
| 208 | */ |
| 209 | |
| 210 | void ip_options_fragment(struct sk_buff * skb) |
| 211 | { |
| 212 | unsigned char * optptr = skb->nh.raw; |
| 213 | struct ip_options * opt = &(IPCB(skb)->opt); |
| 214 | int l = opt->optlen; |
| 215 | int optlen; |
| 216 | |
| 217 | while (l > 0) { |
| 218 | switch (*optptr) { |
| 219 | case IPOPT_END: |
| 220 | return; |
| 221 | case IPOPT_NOOP: |
| 222 | l--; |
| 223 | optptr++; |
| 224 | continue; |
| 225 | } |
| 226 | optlen = optptr[1]; |
| 227 | if (optlen<2 || optlen>l) |
| 228 | return; |
| 229 | if (!IPOPT_COPIED(*optptr)) |
| 230 | memset(optptr, IPOPT_NOOP, optlen); |
| 231 | l -= optlen; |
| 232 | optptr += optlen; |
| 233 | } |
| 234 | opt->ts = 0; |
| 235 | opt->rr = 0; |
| 236 | opt->rr_needaddr = 0; |
| 237 | opt->ts_needaddr = 0; |
| 238 | opt->ts_needtime = 0; |
| 239 | return; |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * Verify options and fill pointers in struct options. |
| 244 | * Caller should clear *opt, and set opt->data. |
| 245 | * If opt == NULL, then skb->data should point to IP header. |
| 246 | */ |
| 247 | |
| 248 | int ip_options_compile(struct ip_options * opt, struct sk_buff * skb) |
| 249 | { |
| 250 | int l; |
| 251 | unsigned char * iph; |
| 252 | unsigned char * optptr; |
| 253 | int optlen; |
| 254 | unsigned char * pp_ptr = NULL; |
| 255 | struct rtable *rt = skb ? (struct rtable*)skb->dst : NULL; |
| 256 | |
| 257 | if (!opt) { |
| 258 | opt = &(IPCB(skb)->opt); |
| 259 | memset(opt, 0, sizeof(struct ip_options)); |
| 260 | iph = skb->nh.raw; |
| 261 | opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr); |
| 262 | optptr = iph + sizeof(struct iphdr); |
| 263 | opt->is_data = 0; |
| 264 | } else { |
| 265 | optptr = opt->is_data ? opt->__data : (unsigned char*)&(skb->nh.iph[1]); |
| 266 | iph = optptr - sizeof(struct iphdr); |
| 267 | } |
| 268 | |
| 269 | for (l = opt->optlen; l > 0; ) { |
| 270 | switch (*optptr) { |
| 271 | case IPOPT_END: |
| 272 | for (optptr++, l--; l>0; optptr++, l--) { |
| 273 | if (*optptr != IPOPT_END) { |
| 274 | *optptr = IPOPT_END; |
| 275 | opt->is_changed = 1; |
| 276 | } |
| 277 | } |
| 278 | goto eol; |
| 279 | case IPOPT_NOOP: |
| 280 | l--; |
| 281 | optptr++; |
| 282 | continue; |
| 283 | } |
| 284 | optlen = optptr[1]; |
| 285 | if (optlen<2 || optlen>l) { |
| 286 | pp_ptr = optptr; |
| 287 | goto error; |
| 288 | } |
| 289 | switch (*optptr) { |
| 290 | case IPOPT_SSRR: |
| 291 | case IPOPT_LSRR: |
| 292 | if (optlen < 3) { |
| 293 | pp_ptr = optptr + 1; |
| 294 | goto error; |
| 295 | } |
| 296 | if (optptr[2] < 4) { |
| 297 | pp_ptr = optptr + 2; |
| 298 | goto error; |
| 299 | } |
| 300 | /* NB: cf RFC-1812 5.2.4.1 */ |
| 301 | if (opt->srr) { |
| 302 | pp_ptr = optptr; |
| 303 | goto error; |
| 304 | } |
| 305 | if (!skb) { |
| 306 | if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) { |
| 307 | pp_ptr = optptr + 1; |
| 308 | goto error; |
| 309 | } |
| 310 | memcpy(&opt->faddr, &optptr[3], 4); |
| 311 | if (optlen > 7) |
| 312 | memmove(&optptr[3], &optptr[7], optlen-7); |
| 313 | } |
| 314 | opt->is_strictroute = (optptr[0] == IPOPT_SSRR); |
| 315 | opt->srr = optptr - iph; |
| 316 | break; |
| 317 | case IPOPT_RR: |
| 318 | if (opt->rr) { |
| 319 | pp_ptr = optptr; |
| 320 | goto error; |
| 321 | } |
| 322 | if (optlen < 3) { |
| 323 | pp_ptr = optptr + 1; |
| 324 | goto error; |
| 325 | } |
| 326 | if (optptr[2] < 4) { |
| 327 | pp_ptr = optptr + 2; |
| 328 | goto error; |
| 329 | } |
| 330 | if (optptr[2] <= optlen) { |
| 331 | if (optptr[2]+3 > optlen) { |
| 332 | pp_ptr = optptr + 2; |
| 333 | goto error; |
| 334 | } |
| 335 | if (skb) { |
| 336 | memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); |
| 337 | opt->is_changed = 1; |
| 338 | } |
| 339 | optptr[2] += 4; |
| 340 | opt->rr_needaddr = 1; |
| 341 | } |
| 342 | opt->rr = optptr - iph; |
| 343 | break; |
| 344 | case IPOPT_TIMESTAMP: |
| 345 | if (opt->ts) { |
| 346 | pp_ptr = optptr; |
| 347 | goto error; |
| 348 | } |
| 349 | if (optlen < 4) { |
| 350 | pp_ptr = optptr + 1; |
| 351 | goto error; |
| 352 | } |
| 353 | if (optptr[2] < 5) { |
| 354 | pp_ptr = optptr + 2; |
| 355 | goto error; |
| 356 | } |
| 357 | if (optptr[2] <= optlen) { |
| 358 | __u32 * timeptr = NULL; |
| 359 | if (optptr[2]+3 > optptr[1]) { |
| 360 | pp_ptr = optptr + 2; |
| 361 | goto error; |
| 362 | } |
| 363 | switch (optptr[3]&0xF) { |
| 364 | case IPOPT_TS_TSONLY: |
| 365 | opt->ts = optptr - iph; |
| 366 | if (skb) |
| 367 | timeptr = (__u32*)&optptr[optptr[2]-1]; |
| 368 | opt->ts_needtime = 1; |
| 369 | optptr[2] += 4; |
| 370 | break; |
| 371 | case IPOPT_TS_TSANDADDR: |
| 372 | if (optptr[2]+7 > optptr[1]) { |
| 373 | pp_ptr = optptr + 2; |
| 374 | goto error; |
| 375 | } |
| 376 | opt->ts = optptr - iph; |
| 377 | if (skb) { |
| 378 | memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); |
| 379 | timeptr = (__u32*)&optptr[optptr[2]+3]; |
| 380 | } |
| 381 | opt->ts_needaddr = 1; |
| 382 | opt->ts_needtime = 1; |
| 383 | optptr[2] += 8; |
| 384 | break; |
| 385 | case IPOPT_TS_PRESPEC: |
| 386 | if (optptr[2]+7 > optptr[1]) { |
| 387 | pp_ptr = optptr + 2; |
| 388 | goto error; |
| 389 | } |
| 390 | opt->ts = optptr - iph; |
| 391 | { |
| 392 | u32 addr; |
| 393 | memcpy(&addr, &optptr[optptr[2]-1], 4); |
| 394 | if (inet_addr_type(addr) == RTN_UNICAST) |
| 395 | break; |
| 396 | if (skb) |
| 397 | timeptr = (__u32*)&optptr[optptr[2]+3]; |
| 398 | } |
| 399 | opt->ts_needtime = 1; |
| 400 | optptr[2] += 8; |
| 401 | break; |
| 402 | default: |
| 403 | if (!skb && !capable(CAP_NET_RAW)) { |
| 404 | pp_ptr = optptr + 3; |
| 405 | goto error; |
| 406 | } |
| 407 | break; |
| 408 | } |
| 409 | if (timeptr) { |
| 410 | struct timeval tv; |
| 411 | __u32 midtime; |
| 412 | do_gettimeofday(&tv); |
| 413 | midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000); |
| 414 | memcpy(timeptr, &midtime, sizeof(__u32)); |
| 415 | opt->is_changed = 1; |
| 416 | } |
| 417 | } else { |
| 418 | unsigned overflow = optptr[3]>>4; |
| 419 | if (overflow == 15) { |
| 420 | pp_ptr = optptr + 3; |
| 421 | goto error; |
| 422 | } |
| 423 | opt->ts = optptr - iph; |
| 424 | if (skb) { |
| 425 | optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4); |
| 426 | opt->is_changed = 1; |
| 427 | } |
| 428 | } |
| 429 | break; |
| 430 | case IPOPT_RA: |
| 431 | if (optlen < 4) { |
| 432 | pp_ptr = optptr + 1; |
| 433 | goto error; |
| 434 | } |
| 435 | if (optptr[2] == 0 && optptr[3] == 0) |
| 436 | opt->router_alert = optptr - iph; |
| 437 | break; |
| 438 | case IPOPT_SEC: |
| 439 | case IPOPT_SID: |
| 440 | default: |
| 441 | if (!skb && !capable(CAP_NET_RAW)) { |
| 442 | pp_ptr = optptr; |
| 443 | goto error; |
| 444 | } |
| 445 | break; |
| 446 | } |
| 447 | l -= optlen; |
| 448 | optptr += optlen; |
| 449 | } |
| 450 | |
| 451 | eol: |
| 452 | if (!pp_ptr) |
| 453 | return 0; |
| 454 | |
| 455 | error: |
| 456 | if (skb) { |
| 457 | icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24)); |
| 458 | } |
| 459 | return -EINVAL; |
| 460 | } |
| 461 | |
| 462 | |
| 463 | /* |
| 464 | * Undo all the changes done by ip_options_compile(). |
| 465 | */ |
| 466 | |
| 467 | void ip_options_undo(struct ip_options * opt) |
| 468 | { |
| 469 | if (opt->srr) { |
| 470 | unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr); |
| 471 | memmove(optptr+7, optptr+3, optptr[1]-7); |
| 472 | memcpy(optptr+3, &opt->faddr, 4); |
| 473 | } |
| 474 | if (opt->rr_needaddr) { |
| 475 | unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr); |
| 476 | optptr[2] -= 4; |
| 477 | memset(&optptr[optptr[2]-1], 0, 4); |
| 478 | } |
| 479 | if (opt->ts) { |
| 480 | unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr); |
| 481 | if (opt->ts_needtime) { |
| 482 | optptr[2] -= 4; |
| 483 | memset(&optptr[optptr[2]-1], 0, 4); |
| 484 | if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC) |
| 485 | optptr[2] -= 4; |
| 486 | } |
| 487 | if (opt->ts_needaddr) { |
| 488 | optptr[2] -= 4; |
| 489 | memset(&optptr[optptr[2]-1], 0, 4); |
| 490 | } |
| 491 | } |
| 492 | } |
| 493 | |
Arnaldo Carvalho de Melo | 4c6ea29 | 2005-08-16 19:46:48 -0300 | [diff] [blame] | 494 | static struct ip_options *ip_options_get_alloc(const int optlen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | { |
Arnaldo Carvalho de Melo | 4c6ea29 | 2005-08-16 19:46:48 -0300 | [diff] [blame] | 496 | struct ip_options *opt = kmalloc(sizeof(*opt) + ((optlen + 3) & ~3), |
| 497 | GFP_KERNEL); |
| 498 | if (opt) |
| 499 | memset(opt, 0, sizeof(*opt)); |
| 500 | return opt; |
| 501 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | |
Arnaldo Carvalho de Melo | 4c6ea29 | 2005-08-16 19:46:48 -0300 | [diff] [blame] | 503 | static int ip_options_get_finish(struct ip_options **optp, |
| 504 | struct ip_options *opt, int optlen) |
| 505 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | while (optlen & 3) |
| 507 | opt->__data[optlen++] = IPOPT_END; |
| 508 | opt->optlen = optlen; |
| 509 | opt->is_data = 1; |
| 510 | opt->is_setbyuser = 1; |
| 511 | if (optlen && ip_options_compile(opt, NULL)) { |
| 512 | kfree(opt); |
| 513 | return -EINVAL; |
| 514 | } |
Jesper Juhl | a51482b | 2005-11-08 09:41:34 -0800 | [diff] [blame] | 515 | kfree(*optp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | *optp = opt; |
| 517 | return 0; |
| 518 | } |
| 519 | |
Arnaldo Carvalho de Melo | 4c6ea29 | 2005-08-16 19:46:48 -0300 | [diff] [blame] | 520 | int ip_options_get_from_user(struct ip_options **optp, unsigned char __user *data, int optlen) |
| 521 | { |
| 522 | struct ip_options *opt = ip_options_get_alloc(optlen); |
| 523 | |
| 524 | if (!opt) |
| 525 | return -ENOMEM; |
| 526 | if (optlen && copy_from_user(opt->__data, data, optlen)) { |
| 527 | kfree(opt); |
| 528 | return -EFAULT; |
| 529 | } |
| 530 | return ip_options_get_finish(optp, opt, optlen); |
| 531 | } |
| 532 | |
| 533 | int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen) |
| 534 | { |
| 535 | struct ip_options *opt = ip_options_get_alloc(optlen); |
| 536 | |
| 537 | if (!opt) |
| 538 | return -ENOMEM; |
| 539 | if (optlen) |
| 540 | memcpy(opt->__data, data, optlen); |
| 541 | return ip_options_get_finish(optp, opt, optlen); |
| 542 | } |
| 543 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | void ip_forward_options(struct sk_buff *skb) |
| 545 | { |
| 546 | struct ip_options * opt = &(IPCB(skb)->opt); |
| 547 | unsigned char * optptr; |
| 548 | struct rtable *rt = (struct rtable*)skb->dst; |
| 549 | unsigned char *raw = skb->nh.raw; |
| 550 | |
| 551 | if (opt->rr_needaddr) { |
| 552 | optptr = (unsigned char *)raw + opt->rr; |
| 553 | ip_rt_get_source(&optptr[optptr[2]-5], rt); |
| 554 | opt->is_changed = 1; |
| 555 | } |
| 556 | if (opt->srr_is_hit) { |
| 557 | int srrptr, srrspace; |
| 558 | |
| 559 | optptr = raw + opt->srr; |
| 560 | |
| 561 | for ( srrptr=optptr[2], srrspace = optptr[1]; |
| 562 | srrptr <= srrspace; |
| 563 | srrptr += 4 |
| 564 | ) { |
| 565 | if (srrptr + 3 > srrspace) |
| 566 | break; |
| 567 | if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0) |
| 568 | break; |
| 569 | } |
| 570 | if (srrptr + 3 <= srrspace) { |
| 571 | opt->is_changed = 1; |
| 572 | ip_rt_get_source(&optptr[srrptr-1], rt); |
| 573 | skb->nh.iph->daddr = rt->rt_dst; |
| 574 | optptr[2] = srrptr+4; |
| 575 | } else if (net_ratelimit()) |
| 576 | printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n"); |
| 577 | if (opt->ts_needaddr) { |
| 578 | optptr = raw + opt->ts; |
| 579 | ip_rt_get_source(&optptr[optptr[2]-9], rt); |
| 580 | opt->is_changed = 1; |
| 581 | } |
| 582 | } |
| 583 | if (opt->is_changed) { |
| 584 | opt->is_changed = 0; |
| 585 | ip_send_check(skb->nh.iph); |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | int ip_options_rcv_srr(struct sk_buff *skb) |
| 590 | { |
| 591 | struct ip_options *opt = &(IPCB(skb)->opt); |
| 592 | int srrspace, srrptr; |
| 593 | u32 nexthop; |
| 594 | struct iphdr *iph = skb->nh.iph; |
| 595 | unsigned char * optptr = skb->nh.raw + opt->srr; |
| 596 | struct rtable *rt = (struct rtable*)skb->dst; |
| 597 | struct rtable *rt2; |
| 598 | int err; |
| 599 | |
| 600 | if (!opt->srr) |
| 601 | return 0; |
| 602 | |
| 603 | if (skb->pkt_type != PACKET_HOST) |
| 604 | return -EINVAL; |
| 605 | if (rt->rt_type == RTN_UNICAST) { |
| 606 | if (!opt->is_strictroute) |
| 607 | return 0; |
| 608 | icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24)); |
| 609 | return -EINVAL; |
| 610 | } |
| 611 | if (rt->rt_type != RTN_LOCAL) |
| 612 | return -EINVAL; |
| 613 | |
| 614 | for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) { |
| 615 | if (srrptr + 3 > srrspace) { |
| 616 | icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24)); |
| 617 | return -EINVAL; |
| 618 | } |
| 619 | memcpy(&nexthop, &optptr[srrptr-1], 4); |
| 620 | |
| 621 | rt = (struct rtable*)skb->dst; |
| 622 | skb->dst = NULL; |
| 623 | err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev); |
| 624 | rt2 = (struct rtable*)skb->dst; |
| 625 | if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) { |
| 626 | ip_rt_put(rt2); |
| 627 | skb->dst = &rt->u.dst; |
| 628 | return -EINVAL; |
| 629 | } |
| 630 | ip_rt_put(rt); |
| 631 | if (rt2->rt_type != RTN_LOCAL) |
| 632 | break; |
| 633 | /* Superfast 8) loopback forward */ |
| 634 | memcpy(&iph->daddr, &optptr[srrptr-1], 4); |
| 635 | opt->is_changed = 1; |
| 636 | } |
| 637 | if (srrptr <= srrspace) { |
| 638 | opt->srr_is_hit = 1; |
| 639 | opt->is_changed = 1; |
| 640 | } |
| 641 | return 0; |
| 642 | } |