gen.subproj/rthdr.c

   1 /*
   2  * Copyright (c) 2018 Apple Inc. All rights reserved.
   3  */
   4 /*      $KAME: rthdr.c,v 1.19 2003/06/06 10:48:51 itojun Exp $  */
   5
   6 /*
   7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the project nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 /* __FBSDID("$FreeBSD: src/lib/libc/net/rthdr.c,v 1.9.10.1.4.1 2010/06/14 02:09:06 kensmith Exp $"); */
  36
  37 #include "libinfo_common.h"
  38
  39 /*
  40  * These routines support RFC 2292.
  41  * __APPLE_USE_RFC_2292 selects the appropriate API in <netinet6/in6.h>
  42  */
  43 #define __APPLE_USE_RFC_2292
  44
  45 #include <sys/cdefs.h>
  46
  47 #include <sys/param.h>
  48 #include <sys/types.h>
  49 #include <sys/socket.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/ip6.h>
  53
  54 #include <string.h>
  55 #include <stdio.h>
  56
  57 /*
  58  * RFC2292 API
  59  */
  60
  61 LIBINFO_EXPORT
  62 size_t
  63 inet6_rthdr_space(type, seg)
  64 int type, seg;
  65 {
  66         switch (type) {
  67                 case IPV6_RTHDR_TYPE_0:
  68                         if (seg < 1 || seg > 23)
  69                                 return (0);
  70 #ifdef COMPAT_RFC2292
  71                         return (CMSG_SPACE(sizeof(struct in6_addr) * (seg - 1) +
  72                                                            sizeof(struct ip6_rthdr0)));
  73 #else
  74                         return (CMSG_SPACE(sizeof(struct in6_addr) * seg +
  75                                                            sizeof(struct ip6_rthdr0)));
  76 #endif
  77                 default:
  78                         return (0);
  79         }
  80 }
  81
  82 LIBINFO_EXPORT
  83 struct cmsghdr *
  84 inet6_rthdr_init(bp, type)
  85 void *bp;
  86 int type;
  87 {
  88         struct cmsghdr *ch = (struct cmsghdr *)bp;
  89         struct ip6_rthdr *rthdr;
  90
  91         rthdr = (struct ip6_rthdr *)CMSG_DATA(ch);
  92
  93         ch->cmsg_level = IPPROTO_IPV6;
  94         ch->cmsg_type = IPV6_RTHDR;
  95
  96         switch (type) {
  97                 case IPV6_RTHDR_TYPE_0:
  98 #ifdef COMPAT_RFC2292
  99                         ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0) -
 100                                                                         sizeof(struct in6_addr));
 101 #else
 102                         ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0));
 103 #endif
 104
 105                         bzero(rthdr, sizeof(struct ip6_rthdr0));
 106                         rthdr->ip6r_type = IPV6_RTHDR_TYPE_0;
 107                         return (ch);
 108                 default:
 109                         return (NULL);
 110         }
 111 }
 112
 113 /* ARGSUSED */
 114 LIBINFO_EXPORT
 115 int
 116 inet6_rthdr_add(cmsg, addr, flags)
 117 struct cmsghdr *cmsg;
 118 const struct in6_addr *addr;
 119 u_int flags;
 120 {
 121         struct ip6_rthdr *rthdr;
 122
 123         rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
 124
 125         switch (rthdr->ip6r_type) {
 126                 case IPV6_RTHDR_TYPE_0:
 127                 {
 128                         struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
 129                         if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
 130                                 return (-1);
 131                         if (rt0->ip6r0_segleft == 23)
 132                                 return (-1);
 133
 134 #ifdef COMPAT_RFC1883           /* XXX */
 135                         if (flags == IPV6_RTHDR_STRICT) {
 136                                 int c, b;
 137                                 c = rt0->ip6r0_segleft / 8;
 138                                 b = rt0->ip6r0_segleft % 8;
 139                                 rt0->ip6r0_slmap[c] |= (1 << (7 - b));
 140                         }
 141 #else
 142                         if (flags != IPV6_RTHDR_LOOSE)
 143                                 return (-1);
 144 #endif
 145                         rt0->ip6r0_segleft++;
 146                         bcopy(addr, (caddr_t)rt0 + ((rt0->ip6r0_len + 1) << 3),
 147                                   sizeof(struct in6_addr));
 148                         rt0->ip6r0_len += sizeof(struct in6_addr) >> 3;
 149                         cmsg->cmsg_len = CMSG_LEN((rt0->ip6r0_len + 1) << 3);
 150                         break;
 151                 }
 152                 default:
 153                         return (-1);
 154         }
 155
 156         return (0);
 157 }
 158
 159 /* ARGSUSED */
 160 LIBINFO_EXPORT
 161 int
 162 inet6_rthdr_lasthop(cmsg, flags)
 163 struct cmsghdr *cmsg;
 164 unsigned int flags;
 165 {
 166         struct ip6_rthdr *rthdr;
 167
 168         rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
 169
 170         switch (rthdr->ip6r_type) {
 171                 case IPV6_RTHDR_TYPE_0:
 172                 {
 173                         struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
 174 #ifdef COMPAT_RFC1883           /* XXX */
 175                         if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
 176                                 return (-1);
 177 #endif /* COMPAT_RFC1883 */
 178                         if (rt0->ip6r0_segleft > 23)
 179                                 return (-1);
 180 #ifdef COMPAT_RFC1883           /* XXX */
 181                         if (flags == IPV6_RTHDR_STRICT) {
 182                                 int c, b;
 183                                 c = rt0->ip6r0_segleft / 8;
 184                                 b = rt0->ip6r0_segleft % 8;
 185                                 rt0->ip6r0_slmap[c] |= (1 << (7 - b));
 186                         }
 187 #else
 188                         if (flags != IPV6_RTHDR_LOOSE)
 189                                 return (-1);
 190 #endif /* COMPAT_RFC1883 */
 191                         break;
 192                 }
 193                 default:
 194                         return (-1);
 195         }
 196
 197         return (0);
 198 }
 199
 200 #if 0
 201 int
 202 inet6_rthdr_reverse(in, out)
 203 const struct cmsghdr *in;
 204 struct cmsghdr *out;
 205 {
 206
 207         return (-1);
 208 }
 209 #endif
 210
 211 LIBINFO_EXPORT
 212 int
 213 inet6_rthdr_segments(cmsg)
 214 const struct cmsghdr *cmsg;
 215 {
 216         struct ip6_rthdr *rthdr;
 217
 218         rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
 219
 220         switch (rthdr->ip6r_type) {
 221                 case IPV6_RTHDR_TYPE_0:
 222                 {
 223                         struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
 224
 225                         if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
 226                                 return (-1);
 227
 228                         return (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
 229                 }
 230
 231                 default:
 232                         return (-1);
 233         }
 234 }
 235
 236 LIBINFO_EXPORT
 237 struct in6_addr *
 238 inet6_rthdr_getaddr(cmsg, idx)
 239 struct cmsghdr *cmsg;
 240 int idx;
 241 {
 242         struct ip6_rthdr *rthdr;
 243
 244         rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
 245
 246         switch (rthdr->ip6r_type) {
 247                 case IPV6_RTHDR_TYPE_0:
 248                 {
 249                         struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
 250                         int naddr;
 251
 252                         if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
 253                                 return NULL;
 254                         naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
 255                         if (idx <= 0 || naddr < idx)
 256                                 return NULL;
 257 #ifdef COMPAT_RFC2292
 258                         return (((struct in6_addr *)(rt0 + 1)) + idx - 1);
 259 #else
 260                         return (((struct in6_addr *)(rt0 + 1)) + idx);
 261 #endif
 262                 }
 263
 264                 default:
 265                         return NULL;
 266         }
 267 }
 268
 269 LIBINFO_EXPORT
 270 int
 271 inet6_rthdr_getflags(cmsg, idx)
 272 const struct cmsghdr *cmsg;
 273 int idx;
 274 {
 275         struct ip6_rthdr *rthdr;
 276
 277         rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
 278
 279         switch (rthdr->ip6r_type) {
 280                 case IPV6_RTHDR_TYPE_0:
 281                 {
 282                         struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
 283                         int naddr;
 284
 285                         if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
 286                                 return (-1);
 287                         naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
 288                         if (idx < 0 || naddr < idx)
 289                                 return (-1);
 290 #ifdef COMPAT_RFC1883           /* XXX */
 291                         if (rt0->ip6r0_slmap[idx / 8] & (0x80 >> (idx % 8)))
 292                                 return IPV6_RTHDR_STRICT;
 293                         else
 294                                 return IPV6_RTHDR_LOOSE;
 295 #else
 296                         return IPV6_RTHDR_LOOSE;
 297 #endif /* COMPAT_RFC1883 */
 298                 }
 299
 300                 default:
 301                         return (-1);
 302         }
 303 }
 304
 305 /*
 306  * RFC3542 API
 307  */
 308
 309 LIBINFO_EXPORT
 310 socklen_t
 311 inet6_rth_space(int type, int segments)
 312 {
 313         switch (type) {
 314                 case IPV6_RTHDR_TYPE_0:
 315                         if ((segments >= 0) && (segments <= 127))
 316                                 return (((segments * 2) + 1) << 3);
 317                         /* FALLTHROUGH */
 318                 default:
 319                         return (0);     /* type not suppported */
 320         }
 321 }
 322
 323 LIBINFO_EXPORT
 324 void *
 325 inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
 326 {
 327         struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
 328         struct ip6_rthdr0 *rth0;
 329
 330         switch (type) {
 331                 case IPV6_RTHDR_TYPE_0:
 332                         /* length validation */
 333                         if (bp_len < inet6_rth_space(IPV6_RTHDR_TYPE_0, segments))
 334                                 return (NULL);
 335                         /* segment validation */
 336                         if ((segments < 0) || (segments > 127))
 337                                 return (NULL);
 338
 339                         memset(bp, 0, bp_len);
 340                         rth0 = (struct ip6_rthdr0 *)rth;
 341                         rth0->ip6r0_len = segments * 2;
 342                         rth0->ip6r0_type = IPV6_RTHDR_TYPE_0;
 343                         rth0->ip6r0_segleft = 0;
 344                         rth0->ip6r0_reserved = 0;
 345                         break;
 346                 default:
 347                         return (NULL);  /* type not supported */
 348         }
 349
 350         return (bp);
 351 }
 352
 353 LIBINFO_EXPORT
 354 int
 355 inet6_rth_add(void *bp, const struct in6_addr *addr)
 356 {
 357         struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
 358         struct ip6_rthdr0 *rth0;
 359         struct in6_addr *nextaddr;
 360
 361         switch (rth->ip6r_type) {
 362                 case IPV6_RTHDR_TYPE_0:
 363                         rth0 = (struct ip6_rthdr0 *)rth;
 364                         /* Don't exceed the number of stated segments */
 365                         if (rth0->ip6r0_segleft == (rth0->ip6r0_len / 2))
 366                                 return (-1);
 367                         nextaddr = (struct in6_addr *)(rth0 + 1) + rth0->ip6r0_segleft;
 368                         *nextaddr = *addr;
 369                         rth0->ip6r0_segleft++;
 370                         break;
 371                 default:
 372                         return (-1);    /* type not supported */
 373         }
 374
 375         return (0);
 376 }
 377
 378 LIBINFO_EXPORT
 379 int
 380 inet6_rth_reverse(const void *in, void *out)
 381 {
 382         struct ip6_rthdr *rth_in = (struct ip6_rthdr *)in;
 383         struct ip6_rthdr0 *rth0_in, *rth0_out;
 384         int i, segments;
 385
 386         switch (rth_in->ip6r_type) {
 387                 case IPV6_RTHDR_TYPE_0:
 388                         rth0_in = (struct ip6_rthdr0 *)in;
 389                         rth0_out = (struct ip6_rthdr0 *)out;
 390
 391                         /* parameter validation XXX too paranoid? */
 392                         if (rth0_in->ip6r0_len % 2)
 393                                 return (-1);
 394                         segments = rth0_in->ip6r0_len / 2;
 395
 396                         /* we can't use memcpy here, since in and out may overlap */
 397                         memmove((void *)rth0_out, (void *)rth0_in,
 398                                         ((rth0_in->ip6r0_len) + 1) << 3);
 399                         rth0_out->ip6r0_segleft = segments;
 400
 401                         /* reverse the addresses */
 402                         for (i = 0; i < segments / 2; i++) {
 403                                 struct in6_addr addr_tmp, *addr1, *addr2;
 404
 405                                 addr1 = (struct in6_addr *)(rth0_out + 1) + i;
 406                                 addr2 = (struct in6_addr *)(rth0_out + 1) +
 407                                 (segments - i - 1);
 408                                 addr_tmp = *addr1;
 409                                 *addr1 = *addr2;
 410                                 *addr2 = addr_tmp;
 411                         }
 412
 413                         break;
 414                 default:
 415                         return (-1);    /* type not supported */
 416         }
 417
 418         return (0);
 419 }
 420
 421 LIBINFO_EXPORT
 422 int
 423 inet6_rth_segments(const void *bp)
 424 {
 425         struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
 426         struct ip6_rthdr0 *rh0;
 427         int addrs;
 428
 429         switch (rh->ip6r_type) {
 430                 case IPV6_RTHDR_TYPE_0:
 431                         rh0 = (struct ip6_rthdr0 *)bp;
 432
 433                         /*
 434                          * Validation for a type-0 routing header.
 435                          * Is this too strict?
 436                          */
 437                         if ((rh0->ip6r0_len % 2) != 0 ||
 438                                 (addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
 439                                 return (-1);
 440
 441                         return (addrs);
 442                 default:
 443                         return (-1);    /* unknown type */
 444         }
 445 }
 446
 447 LIBINFO_EXPORT
 448 struct in6_addr *
 449 inet6_rth_getaddr(const void *bp, int idx)
 450 {
 451         struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
 452         struct ip6_rthdr0 *rh0;
 453         int addrs;
 454
 455         switch (rh->ip6r_type) {
 456                 case IPV6_RTHDR_TYPE_0:
 457                         rh0 = (struct ip6_rthdr0 *)bp;
 458
 459                         /*
 460                          * Validation for a type-0 routing header.
 461                          * Is this too strict?
 462                          */
 463                         if ((rh0->ip6r0_len % 2) != 0 ||
 464                                 (addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
 465                                 return (NULL);
 466
 467                         if (idx < 0 || addrs <= idx)
 468                                 return (NULL);
 469
 470                         return (((struct in6_addr *)(rh0 + 1)) + idx);
 471                 default:
 472                         return (NULL);  /* unknown type */
 473                         break;
 474         }
 475 }