Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 1 | /* $NetBSD: ns_name.c,v 1.9 2012/03/13 21:13:39 christos Exp $ */ |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
| 5 | * Copyright (c) 1996,1999 by Internet Software Consortium. |
| 6 | * |
| 7 | * Permission to use, copy, modify, and distribute this software for any |
| 8 | * purpose with or without fee is hereby granted, provided that the above |
| 9 | * copyright notice and this permission notice appear in all copies. |
| 10 | * |
| 11 | * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES |
| 12 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 13 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR |
| 14 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 15 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 16 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| 17 | * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 18 | */ |
| 19 | |
| 20 | #include <sys/cdefs.h> |
| 21 | #ifndef lint |
| 22 | #ifdef notdef |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 23 | static const char rcsid[] = "Id: ns_name.c,v 1.11 2009/01/23 19:59:16 each Exp"; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 24 | #else |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 25 | __RCSID("$NetBSD: ns_name.c,v 1.9 2012/03/13 21:13:39 christos Exp $"); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 26 | #endif |
| 27 | #endif |
| 28 | |
| 29 | #include <sys/types.h> |
| 30 | |
| 31 | #include <netinet/in.h> |
Calin Juravle | 569fb98 | 2014-03-04 15:01:29 +0000 | [diff] [blame] | 32 | #include <arpa/nameser.h> |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 33 | |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 34 | #include <assert.h> |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 35 | #include <errno.h> |
| 36 | #ifdef ANDROID_CHANGES |
| 37 | #include "resolv_private.h" |
| 38 | #else |
| 39 | #include <resolv.h> |
| 40 | #endif |
| 41 | #include <string.h> |
| 42 | #include <ctype.h> |
| 43 | #include <stdlib.h> |
| 44 | #include <limits.h> |
| 45 | |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 46 | #define NS_TYPE_ELT 0x40 /* EDNS0 extended label type */ |
| 47 | #define DNS_LABELTYPE_BITSTRING 0x41 |
| 48 | |
| 49 | /* Data. */ |
| 50 | |
| 51 | static const char digits[] = "0123456789"; |
| 52 | |
| 53 | static const char digitvalue[256] = { |
| 54 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/ |
| 55 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/ |
| 56 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/ |
| 57 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/ |
| 58 | -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/ |
| 59 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/ |
| 60 | -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/ |
| 61 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/ |
| 62 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 63 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 64 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 65 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 66 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 67 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 68 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 69 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/ |
| 70 | }; |
| 71 | |
| 72 | /* Forward. */ |
| 73 | |
| 74 | static int special(int); |
| 75 | static int printable(int); |
| 76 | static int dn_find(const u_char *, const u_char *, |
| 77 | const u_char * const *, |
| 78 | const u_char * const *); |
| 79 | static int encode_bitsring(const char **, const char *, |
| 80 | unsigned char **, unsigned char **, |
| 81 | unsigned const char *); |
| 82 | static int labellen(const u_char *); |
| 83 | static int decode_bitstring(const unsigned char **, |
| 84 | char *, const char *); |
| 85 | |
| 86 | /* Public. */ |
| 87 | |
| 88 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 89 | * Convert an encoded domain name to printable ascii as per RFC1035. |
| 90 | * return: |
| 91 | * Number of bytes written to buffer, or -1 (with errno set) |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 92 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 93 | * notes: |
| 94 | * The root is returned as "." |
| 95 | * All other domains are returned in non absolute form |
| 96 | */ |
| 97 | int |
| 98 | ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) |
| 99 | { |
| 100 | const u_char *cp; |
| 101 | char *dn, *eom; |
| 102 | u_char c; |
| 103 | u_int n; |
| 104 | int l; |
| 105 | |
| 106 | cp = src; |
| 107 | dn = dst; |
| 108 | eom = dst + dstsiz; |
| 109 | |
| 110 | while ((n = *cp++) != 0) { |
| 111 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
| 112 | /* Some kind of compression pointer. */ |
| 113 | errno = EMSGSIZE; |
| 114 | return (-1); |
| 115 | } |
| 116 | if (dn != dst) { |
| 117 | if (dn >= eom) { |
| 118 | errno = EMSGSIZE; |
| 119 | return (-1); |
| 120 | } |
| 121 | *dn++ = '.'; |
| 122 | } |
| 123 | if ((l = labellen(cp - 1)) < 0) { |
| 124 | errno = EMSGSIZE; /* XXX */ |
| 125 | return(-1); |
| 126 | } |
| 127 | if (dn + l >= eom) { |
| 128 | errno = EMSGSIZE; |
| 129 | return (-1); |
| 130 | } |
| 131 | if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) { |
| 132 | int m; |
| 133 | |
| 134 | if (n != DNS_LABELTYPE_BITSTRING) { |
| 135 | /* XXX: labellen should reject this case */ |
| 136 | errno = EINVAL; |
| 137 | return(-1); |
| 138 | } |
| 139 | if ((m = decode_bitstring(&cp, dn, eom)) < 0) |
| 140 | { |
| 141 | errno = EMSGSIZE; |
| 142 | return(-1); |
| 143 | } |
| 144 | dn += m; |
| 145 | continue; |
| 146 | } |
| 147 | for (; l > 0; l--) { |
| 148 | c = *cp++; |
| 149 | if (special(c)) { |
| 150 | if (dn + 1 >= eom) { |
| 151 | errno = EMSGSIZE; |
| 152 | return (-1); |
| 153 | } |
| 154 | *dn++ = '\\'; |
| 155 | *dn++ = (char)c; |
| 156 | } else if (!printable(c)) { |
| 157 | if (dn + 3 >= eom) { |
| 158 | errno = EMSGSIZE; |
| 159 | return (-1); |
| 160 | } |
| 161 | *dn++ = '\\'; |
| 162 | *dn++ = digits[c / 100]; |
| 163 | *dn++ = digits[(c % 100) / 10]; |
| 164 | *dn++ = digits[c % 10]; |
| 165 | } else { |
| 166 | if (dn >= eom) { |
| 167 | errno = EMSGSIZE; |
| 168 | return (-1); |
| 169 | } |
| 170 | *dn++ = (char)c; |
| 171 | } |
| 172 | } |
| 173 | } |
| 174 | if (dn == dst) { |
| 175 | if (dn >= eom) { |
| 176 | errno = EMSGSIZE; |
| 177 | return (-1); |
| 178 | } |
| 179 | *dn++ = '.'; |
| 180 | } |
| 181 | if (dn >= eom) { |
| 182 | errno = EMSGSIZE; |
| 183 | return (-1); |
| 184 | } |
| 185 | *dn++ = '\0'; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 186 | _DIAGASSERT(__type_fit(int, dn - dst)); |
| 187 | return (int)(dn - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 188 | } |
| 189 | |
| 190 | /* |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 191 | * Convert a ascii string into an encoded domain name as per RFC1035. |
| 192 | * |
| 193 | * return: |
| 194 | * |
| 195 | * -1 if it fails |
| 196 | * 1 if string was fully qualified |
| 197 | * 0 is string was not fully qualified |
| 198 | * |
| 199 | * notes: |
| 200 | * Enforces label and domain length limits. |
| 201 | */ |
| 202 | int |
| 203 | ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { |
| 204 | return (ns_name_pton2(src, dst, dstsiz, NULL)); |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * ns_name_pton2(src, dst, dstsiz, *dstlen) |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 209 | * Convert a ascii string into an encoded domain name as per RFC1035. |
| 210 | * return: |
| 211 | * -1 if it fails |
| 212 | * 1 if string was fully qualified |
| 213 | * 0 is string was not fully qualified |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 214 | * side effects: |
| 215 | * fills in *dstlen (if non-NULL) |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 216 | * notes: |
| 217 | * Enforces label and domain length limits. |
| 218 | */ |
| 219 | |
| 220 | int |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 221 | ns_name_pton2(const char *src, u_char *dst, size_t dstsiz, size_t *dstlen) { |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 222 | u_char *label, *bp, *eom; |
| 223 | int c, n, escaped, e = 0; |
| 224 | char *cp; |
| 225 | |
| 226 | escaped = 0; |
| 227 | bp = dst; |
| 228 | eom = dst + dstsiz; |
| 229 | label = bp++; |
| 230 | |
| 231 | while ((c = *src++) != 0) { |
| 232 | if (escaped) { |
| 233 | if (c == '[') { /* start a bit string label */ |
| 234 | if ((cp = strchr(src, ']')) == NULL) { |
| 235 | errno = EINVAL; /* ??? */ |
| 236 | return(-1); |
| 237 | } |
| 238 | if ((e = encode_bitsring(&src, cp + 2, |
| 239 | &label, &bp, eom)) |
| 240 | != 0) { |
| 241 | errno = e; |
| 242 | return(-1); |
| 243 | } |
| 244 | escaped = 0; |
| 245 | label = bp++; |
| 246 | if ((c = *src++) == 0) |
| 247 | goto done; |
| 248 | else if (c != '.') { |
| 249 | errno = EINVAL; |
| 250 | return(-1); |
| 251 | } |
| 252 | continue; |
| 253 | } |
| 254 | else if ((cp = strchr(digits, c)) != NULL) { |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 255 | n = (int)(cp - digits) * 100; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 256 | if ((c = *src++) == 0 || |
| 257 | (cp = strchr(digits, c)) == NULL) { |
| 258 | errno = EMSGSIZE; |
| 259 | return (-1); |
| 260 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 261 | n += (int)(cp - digits) * 10; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 262 | if ((c = *src++) == 0 || |
| 263 | (cp = strchr(digits, c)) == NULL) { |
| 264 | errno = EMSGSIZE; |
| 265 | return (-1); |
| 266 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 267 | n += (int)(cp - digits); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 268 | if (n > 255) { |
| 269 | errno = EMSGSIZE; |
| 270 | return (-1); |
| 271 | } |
| 272 | c = n; |
| 273 | } |
| 274 | escaped = 0; |
| 275 | } else if (c == '\\') { |
| 276 | escaped = 1; |
| 277 | continue; |
| 278 | } else if (c == '.') { |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 279 | c = (int)(bp - label - 1); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 280 | if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ |
| 281 | errno = EMSGSIZE; |
| 282 | return (-1); |
| 283 | } |
| 284 | if (label >= eom) { |
| 285 | errno = EMSGSIZE; |
| 286 | return (-1); |
| 287 | } |
| 288 | *label = c; |
| 289 | /* Fully qualified ? */ |
| 290 | if (*src == '\0') { |
| 291 | if (c != 0) { |
| 292 | if (bp >= eom) { |
| 293 | errno = EMSGSIZE; |
| 294 | return (-1); |
| 295 | } |
| 296 | *bp++ = '\0'; |
| 297 | } |
| 298 | if ((bp - dst) > MAXCDNAME) { |
| 299 | errno = EMSGSIZE; |
| 300 | return (-1); |
| 301 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 302 | if (dstlen != NULL) |
| 303 | *dstlen = (bp - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 304 | return (1); |
| 305 | } |
| 306 | if (c == 0 || *src == '.') { |
| 307 | errno = EMSGSIZE; |
| 308 | return (-1); |
| 309 | } |
| 310 | label = bp++; |
| 311 | continue; |
| 312 | } |
| 313 | if (bp >= eom) { |
| 314 | errno = EMSGSIZE; |
| 315 | return (-1); |
| 316 | } |
| 317 | *bp++ = (u_char)c; |
| 318 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 319 | c = (int)(bp - label - 1); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 320 | if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ |
| 321 | errno = EMSGSIZE; |
| 322 | return (-1); |
| 323 | } |
| 324 | done: |
| 325 | if (label >= eom) { |
| 326 | errno = EMSGSIZE; |
| 327 | return (-1); |
| 328 | } |
| 329 | *label = c; |
| 330 | if (c != 0) { |
| 331 | if (bp >= eom) { |
| 332 | errno = EMSGSIZE; |
| 333 | return (-1); |
| 334 | } |
| 335 | *bp++ = 0; |
| 336 | } |
| 337 | if ((bp - dst) > MAXCDNAME) { /* src too big */ |
| 338 | errno = EMSGSIZE; |
| 339 | return (-1); |
| 340 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 341 | if (dstlen != NULL) |
| 342 | *dstlen = (bp - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 343 | return (0); |
| 344 | } |
| 345 | |
| 346 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 347 | * Convert a network strings labels into all lowercase. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 348 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 349 | * return: |
| 350 | * Number of bytes written to buffer, or -1 (with errno set) |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 351 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 352 | * notes: |
| 353 | * Enforces label and domain length limits. |
| 354 | */ |
| 355 | |
| 356 | int |
| 357 | ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) |
| 358 | { |
| 359 | const u_char *cp; |
| 360 | u_char *dn, *eom; |
| 361 | u_char c; |
| 362 | u_int n; |
| 363 | int l; |
| 364 | |
| 365 | cp = src; |
| 366 | dn = dst; |
| 367 | eom = dst + dstsiz; |
| 368 | |
| 369 | if (dn >= eom) { |
| 370 | errno = EMSGSIZE; |
| 371 | return (-1); |
| 372 | } |
| 373 | while ((n = *cp++) != 0) { |
| 374 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
| 375 | /* Some kind of compression pointer. */ |
| 376 | errno = EMSGSIZE; |
| 377 | return (-1); |
| 378 | } |
| 379 | *dn++ = n; |
| 380 | if ((l = labellen(cp - 1)) < 0) { |
| 381 | errno = EMSGSIZE; |
| 382 | return (-1); |
| 383 | } |
| 384 | if (dn + l >= eom) { |
| 385 | errno = EMSGSIZE; |
| 386 | return (-1); |
| 387 | } |
| 388 | for (; l > 0; l--) { |
| 389 | c = *cp++; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 390 | if (isascii(c) && isupper(c)) |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 391 | *dn++ = tolower(c); |
| 392 | else |
| 393 | *dn++ = c; |
| 394 | } |
| 395 | } |
| 396 | *dn++ = '\0'; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 397 | _DIAGASSERT(__type_fit(int, dn - dst)); |
| 398 | return (int)(dn - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 399 | } |
| 400 | |
| 401 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 402 | * Unpack a domain name from a message, source may be compressed. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 403 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 404 | * return: |
| 405 | * -1 if it fails, or consumed octets if it succeeds. |
| 406 | */ |
| 407 | int |
| 408 | ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src, |
| 409 | u_char *dst, size_t dstsiz) |
| 410 | { |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 411 | return (ns_name_unpack2(msg, eom, src, dst, dstsiz, NULL)); |
| 412 | } |
| 413 | |
| 414 | /* |
| 415 | * ns_name_unpack2(msg, eom, src, dst, dstsiz, *dstlen) |
| 416 | * Unpack a domain name from a message, source may be compressed. |
| 417 | * return: |
| 418 | * -1 if it fails, or consumed octets if it succeeds. |
| 419 | * side effect: |
| 420 | * fills in *dstlen (if non-NULL). |
| 421 | */ |
| 422 | int |
| 423 | ns_name_unpack2(const u_char *msg, const u_char *eom, const u_char *src, |
| 424 | u_char *dst, size_t dstsiz, size_t *dstlen) |
| 425 | { |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 426 | const u_char *srcp, *dstlim; |
| 427 | u_char *dstp; |
| 428 | int n, len, checked, l; |
| 429 | |
| 430 | len = -1; |
| 431 | checked = 0; |
| 432 | dstp = dst; |
| 433 | srcp = src; |
| 434 | dstlim = dst + dstsiz; |
| 435 | if (srcp < msg || srcp >= eom) { |
| 436 | errno = EMSGSIZE; |
| 437 | return (-1); |
| 438 | } |
| 439 | /* Fetch next label in domain name. */ |
| 440 | while ((n = *srcp++) != 0) { |
| 441 | /* Check for indirection. */ |
| 442 | switch (n & NS_CMPRSFLGS) { |
| 443 | case 0: |
| 444 | case NS_TYPE_ELT: |
| 445 | /* Limit checks. */ |
| 446 | if ((l = labellen(srcp - 1)) < 0) { |
| 447 | errno = EMSGSIZE; |
| 448 | return(-1); |
| 449 | } |
| 450 | if (dstp + l + 1 >= dstlim || srcp + l >= eom) { |
| 451 | errno = EMSGSIZE; |
| 452 | return (-1); |
| 453 | } |
| 454 | checked += l + 1; |
| 455 | *dstp++ = n; |
| 456 | memcpy(dstp, srcp, (size_t)l); |
| 457 | dstp += l; |
| 458 | srcp += l; |
| 459 | break; |
| 460 | |
| 461 | case NS_CMPRSFLGS: |
| 462 | if (srcp >= eom) { |
| 463 | errno = EMSGSIZE; |
| 464 | return (-1); |
| 465 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 466 | if (len < 0) { |
| 467 | _DIAGASSERT(__type_fit(int, srcp - src + 1)); |
| 468 | len = (int)(srcp - src + 1); |
| 469 | } |
Calin Juravle | 85c5202 | 2014-03-06 17:05:49 +0000 | [diff] [blame] | 470 | // BEGIN android-changed: safer pointer overflow check |
| 471 | l = (((n & 0x3f) << 8) | (*srcp & 0xff)); |
| 472 | if (l >= eom - msg) { /* Out of range. */ |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 473 | errno = EMSGSIZE; |
| 474 | return (-1); |
| 475 | } |
Calin Juravle | 85c5202 | 2014-03-06 17:05:49 +0000 | [diff] [blame] | 476 | srcp = msg + l; |
| 477 | // END android-changed |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 478 | checked += 2; |
| 479 | /* |
| 480 | * Check for loops in the compressed name; |
| 481 | * if we've looked at the whole message, |
| 482 | * there must be a loop. |
| 483 | */ |
| 484 | if (checked >= eom - msg) { |
| 485 | errno = EMSGSIZE; |
| 486 | return (-1); |
| 487 | } |
| 488 | break; |
| 489 | |
| 490 | default: |
| 491 | errno = EMSGSIZE; |
| 492 | return (-1); /* flag error */ |
| 493 | } |
| 494 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 495 | *dstp++ = 0; |
| 496 | if (dstlen != NULL) |
| 497 | *dstlen = dstp - dst; |
| 498 | if (len < 0) { |
| 499 | _DIAGASSERT(__type_fit(int, srcp - src)); |
| 500 | len = (int)(srcp - src); |
| 501 | } |
| 502 | return len; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 503 | } |
| 504 | |
| 505 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 506 | * Pack domain name 'domain' into 'comp_dn'. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 507 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 508 | * return: |
| 509 | * Size of the compressed name, or -1. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 510 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 511 | * notes: |
| 512 | * 'dnptrs' is an array of pointers to previous compressed names. |
| 513 | * dnptrs[0] is a pointer to the beginning of the message. The array |
| 514 | * ends with NULL. |
| 515 | * 'lastdnptr' is a pointer to the end of the array pointed to |
| 516 | * by 'dnptrs'. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 517 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 518 | * Side effects: |
| 519 | * The list of pointers in dnptrs is updated for labels inserted into |
| 520 | * the message as we compress the name. If 'dnptr' is NULL, we don't |
| 521 | * try to compress names. If 'lastdnptr' is NULL, we don't update the |
| 522 | * list. |
| 523 | */ |
| 524 | int |
| 525 | ns_name_pack(const u_char *src, u_char *dst, int dstsiz, |
| 526 | const u_char **dnptrs, const u_char **lastdnptr) |
| 527 | { |
| 528 | u_char *dstp; |
| 529 | const u_char **cpp, **lpp, *eob, *msg; |
| 530 | const u_char *srcp; |
| 531 | int n, l, first = 1; |
| 532 | |
| 533 | srcp = src; |
| 534 | dstp = dst; |
| 535 | eob = dstp + dstsiz; |
| 536 | lpp = cpp = NULL; |
| 537 | if (dnptrs != NULL) { |
| 538 | if ((msg = *dnptrs++) != NULL) { |
| 539 | for (cpp = dnptrs; *cpp != NULL; cpp++) |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 540 | continue; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 541 | lpp = cpp; /* end of list to search */ |
| 542 | } |
| 543 | } else |
| 544 | msg = NULL; |
| 545 | |
| 546 | /* make sure the domain we are about to add is legal */ |
| 547 | l = 0; |
| 548 | do { |
| 549 | int l0; |
| 550 | |
| 551 | n = *srcp; |
| 552 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
| 553 | errno = EMSGSIZE; |
| 554 | return (-1); |
| 555 | } |
| 556 | if ((l0 = labellen(srcp)) < 0) { |
| 557 | errno = EINVAL; |
| 558 | return(-1); |
| 559 | } |
| 560 | l += l0 + 1; |
| 561 | if (l > MAXCDNAME) { |
| 562 | errno = EMSGSIZE; |
| 563 | return (-1); |
| 564 | } |
| 565 | srcp += l0 + 1; |
| 566 | } while (n != 0); |
| 567 | |
| 568 | /* from here on we need to reset compression pointer array on error */ |
| 569 | srcp = src; |
| 570 | do { |
| 571 | /* Look to see if we can use pointers. */ |
| 572 | n = *srcp; |
| 573 | if (n != 0 && msg != NULL) { |
| 574 | l = dn_find(srcp, msg, (const u_char * const *)dnptrs, |
| 575 | (const u_char * const *)lpp); |
| 576 | if (l >= 0) { |
| 577 | if (dstp + 1 >= eob) { |
| 578 | goto cleanup; |
| 579 | } |
| 580 | *dstp++ = ((u_int32_t)l >> 8) | NS_CMPRSFLGS; |
| 581 | *dstp++ = l % 256; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 582 | _DIAGASSERT(__type_fit(int, dstp - dst)); |
| 583 | return (int)(dstp - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 584 | } |
| 585 | /* Not found, save it. */ |
| 586 | if (lastdnptr != NULL && cpp < lastdnptr - 1 && |
| 587 | (dstp - msg) < 0x4000 && first) { |
| 588 | *cpp++ = dstp; |
| 589 | *cpp = NULL; |
| 590 | first = 0; |
| 591 | } |
| 592 | } |
| 593 | /* copy label to buffer */ |
| 594 | if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
| 595 | /* Should not happen. */ |
| 596 | goto cleanup; |
| 597 | } |
| 598 | n = labellen(srcp); |
| 599 | if (dstp + 1 + n >= eob) { |
| 600 | goto cleanup; |
| 601 | } |
| 602 | memcpy(dstp, srcp, (size_t)(n + 1)); |
| 603 | srcp += n + 1; |
| 604 | dstp += n + 1; |
| 605 | } while (n != 0); |
| 606 | |
| 607 | if (dstp > eob) { |
| 608 | cleanup: |
| 609 | if (msg != NULL) |
| 610 | *lpp = NULL; |
| 611 | errno = EMSGSIZE; |
| 612 | return (-1); |
| 613 | } |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 614 | _DIAGASSERT(__type_fit(int, dstp - dst)); |
| 615 | return (int)(dstp - dst); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 616 | } |
| 617 | |
| 618 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 619 | * Expand compressed domain name to presentation format. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 620 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 621 | * return: |
| 622 | * Number of bytes read out of `src', or -1 (with errno set). |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 623 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 624 | * note: |
| 625 | * Root domain returns as "." not "". |
| 626 | */ |
| 627 | int |
| 628 | ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src, |
| 629 | char *dst, size_t dstsiz) |
| 630 | { |
| 631 | u_char tmp[NS_MAXCDNAME]; |
| 632 | int n; |
| 633 | |
| 634 | if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1) |
| 635 | return (-1); |
| 636 | if (ns_name_ntop(tmp, dst, dstsiz) == -1) |
| 637 | return (-1); |
| 638 | return (n); |
| 639 | } |
| 640 | |
| 641 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 642 | * Compress a domain name into wire format, using compression pointers. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 643 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 644 | * return: |
| 645 | * Number of bytes consumed in `dst' or -1 (with errno set). |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 646 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 647 | * notes: |
| 648 | * 'dnptrs' is an array of pointers to previous compressed names. |
| 649 | * dnptrs[0] is a pointer to the beginning of the message. |
| 650 | * The list ends with NULL. 'lastdnptr' is a pointer to the end of the |
| 651 | * array pointed to by 'dnptrs'. Side effect is to update the list of |
| 652 | * pointers for labels inserted into the message as we compress the name. |
| 653 | * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr' |
| 654 | * is NULL, we don't update the list. |
| 655 | */ |
| 656 | int |
| 657 | ns_name_compress(const char *src, u_char *dst, size_t dstsiz, |
| 658 | const u_char **dnptrs, const u_char **lastdnptr) |
| 659 | { |
| 660 | u_char tmp[NS_MAXCDNAME]; |
| 661 | |
| 662 | if (ns_name_pton(src, tmp, sizeof tmp) == -1) |
| 663 | return (-1); |
| 664 | return (ns_name_pack(tmp, dst, (int)dstsiz, dnptrs, lastdnptr)); |
| 665 | } |
| 666 | |
| 667 | /* |
| 668 | * Reset dnptrs so that there are no active references to pointers at or |
| 669 | * after src. |
| 670 | */ |
| 671 | void |
| 672 | ns_name_rollback(const u_char *src, const u_char **dnptrs, |
| 673 | const u_char **lastdnptr) |
| 674 | { |
| 675 | while (dnptrs < lastdnptr && *dnptrs != NULL) { |
| 676 | if (*dnptrs >= src) { |
| 677 | *dnptrs = NULL; |
| 678 | break; |
| 679 | } |
| 680 | dnptrs++; |
| 681 | } |
| 682 | } |
| 683 | |
| 684 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 685 | * Advance *ptrptr to skip over the compressed name it points at. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 686 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 687 | * return: |
| 688 | * 0 on success, -1 (with errno set) on failure. |
| 689 | */ |
| 690 | int |
| 691 | ns_name_skip(const u_char **ptrptr, const u_char *eom) |
| 692 | { |
| 693 | const u_char *cp; |
| 694 | u_int n; |
| 695 | int l; |
| 696 | |
| 697 | cp = *ptrptr; |
| 698 | while (cp < eom && (n = *cp++) != 0) { |
| 699 | /* Check for indirection. */ |
| 700 | switch (n & NS_CMPRSFLGS) { |
| 701 | case 0: /* normal case, n == len */ |
| 702 | cp += n; |
| 703 | continue; |
| 704 | case NS_TYPE_ELT: /* EDNS0 extended label */ |
| 705 | if ((l = labellen(cp - 1)) < 0) { |
| 706 | errno = EMSGSIZE; /* XXX */ |
| 707 | return(-1); |
| 708 | } |
| 709 | cp += l; |
| 710 | continue; |
| 711 | case NS_CMPRSFLGS: /* indirection */ |
| 712 | cp++; |
| 713 | break; |
| 714 | default: /* illegal type */ |
| 715 | errno = EMSGSIZE; |
| 716 | return (-1); |
| 717 | } |
| 718 | break; |
| 719 | } |
| 720 | if (cp > eom) { |
| 721 | errno = EMSGSIZE; |
| 722 | return (-1); |
| 723 | } |
| 724 | *ptrptr = cp; |
| 725 | return (0); |
| 726 | } |
| 727 | |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 728 | /* Find the number of octets an nname takes up, including the root label. |
| 729 | * (This is basically ns_name_skip() without compression-pointer support.) |
| 730 | * ((NOTE: can only return zero if passed-in namesiz argument is zero.)) |
| 731 | */ |
| 732 | ssize_t |
| 733 | ns_name_length(ns_nname_ct nname, size_t namesiz) { |
| 734 | ns_nname_ct orig = nname; |
| 735 | u_int n; |
| 736 | |
| 737 | while (namesiz-- > 0 && (n = *nname++) != 0) { |
| 738 | if ((n & NS_CMPRSFLGS) != 0) { |
| 739 | errno = EISDIR; |
| 740 | return (-1); |
| 741 | } |
| 742 | if (n > namesiz) { |
| 743 | errno = EMSGSIZE; |
| 744 | return (-1); |
| 745 | } |
| 746 | nname += n; |
| 747 | namesiz -= n; |
| 748 | } |
| 749 | return (nname - orig); |
| 750 | } |
| 751 | |
| 752 | /* Compare two nname's for equality. Return -1 on error (setting errno). |
| 753 | */ |
| 754 | int |
| 755 | ns_name_eq(ns_nname_ct a, size_t as, ns_nname_ct b, size_t bs) { |
| 756 | ns_nname_ct ae = a + as, be = b + bs; |
| 757 | int ac, bc; |
| 758 | |
| 759 | while (ac = *a, bc = *b, ac != 0 && bc != 0) { |
| 760 | if ((ac & NS_CMPRSFLGS) != 0 || (bc & NS_CMPRSFLGS) != 0) { |
| 761 | errno = EISDIR; |
| 762 | return (-1); |
| 763 | } |
| 764 | if (a + ac >= ae || b + bc >= be) { |
| 765 | errno = EMSGSIZE; |
| 766 | return (-1); |
| 767 | } |
| 768 | if (ac != bc || strncasecmp((const char *) ++a, |
| 769 | (const char *) ++b, |
| 770 | (size_t)ac) != 0) |
| 771 | return (0); |
| 772 | a += ac, b += bc; |
| 773 | } |
| 774 | return (ac == 0 && bc == 0); |
| 775 | } |
| 776 | |
| 777 | /* Is domain "A" owned by (at or below) domain "B"? |
| 778 | */ |
| 779 | int |
| 780 | ns_name_owned(ns_namemap_ct a, int an, ns_namemap_ct b, int bn) { |
| 781 | /* If A is shorter, it cannot be owned by B. */ |
| 782 | if (an < bn) |
| 783 | return (0); |
| 784 | |
| 785 | /* If they are unequal before the length of the shorter, A cannot... */ |
| 786 | while (bn > 0) { |
| 787 | if (a->len != b->len || |
| 788 | strncasecmp((const char *) a->base, |
| 789 | (const char *) b->base, (size_t)a->len) != 0) |
| 790 | return (0); |
| 791 | a++, an--; |
| 792 | b++, bn--; |
| 793 | } |
| 794 | |
| 795 | /* A might be longer or not, but either way, B owns it. */ |
| 796 | return (1); |
| 797 | } |
| 798 | |
| 799 | /* Build an array of <base,len> tuples from an nname, top-down order. |
| 800 | * Return the number of tuples (labels) thus discovered. |
| 801 | */ |
| 802 | int |
| 803 | ns_name_map(ns_nname_ct nname, size_t namelen, ns_namemap_t map, int mapsize) { |
| 804 | u_int n; |
| 805 | int l; |
| 806 | |
| 807 | n = *nname++; |
| 808 | namelen--; |
| 809 | |
| 810 | /* Root zone? */ |
| 811 | if (n == 0) { |
| 812 | /* Extra data follows name? */ |
| 813 | if (namelen > 0) { |
| 814 | errno = EMSGSIZE; |
| 815 | return (-1); |
| 816 | } |
| 817 | return (0); |
| 818 | } |
| 819 | |
| 820 | /* Compression pointer? */ |
| 821 | if ((n & NS_CMPRSFLGS) != 0) { |
| 822 | errno = EISDIR; |
| 823 | return (-1); |
| 824 | } |
| 825 | |
| 826 | /* Label too long? */ |
| 827 | if (n > namelen) { |
| 828 | errno = EMSGSIZE; |
| 829 | return (-1); |
| 830 | } |
| 831 | |
| 832 | /* Recurse to get rest of name done first. */ |
| 833 | l = ns_name_map(nname + n, namelen - n, map, mapsize); |
| 834 | if (l < 0) |
| 835 | return (-1); |
| 836 | |
| 837 | /* Too many labels? */ |
| 838 | if (l >= mapsize) { |
| 839 | errno = ENAMETOOLONG; |
| 840 | return (-1); |
| 841 | } |
| 842 | |
| 843 | /* We're on our way back up-stack, store current map data. */ |
| 844 | map[l].base = nname; |
| 845 | map[l].len = n; |
| 846 | return (l + 1); |
| 847 | } |
| 848 | |
| 849 | /* Count the labels in a domain name. Root counts, so COM. has two. This |
| 850 | * is to make the result comparable to the result of ns_name_map(). |
| 851 | */ |
| 852 | int |
| 853 | ns_name_labels(ns_nname_ct nname, size_t namesiz) { |
| 854 | int ret = 0; |
| 855 | u_int n; |
| 856 | |
| 857 | while (namesiz-- > 0 && (n = *nname++) != 0) { |
| 858 | if ((n & NS_CMPRSFLGS) != 0) { |
| 859 | errno = EISDIR; |
| 860 | return (-1); |
| 861 | } |
| 862 | if (n > namesiz) { |
| 863 | errno = EMSGSIZE; |
| 864 | return (-1); |
| 865 | } |
| 866 | nname += n; |
| 867 | namesiz -= n; |
| 868 | ret++; |
| 869 | } |
| 870 | return (ret + 1); |
| 871 | } |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 872 | /* Private. */ |
| 873 | |
| 874 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 875 | * Thinking in noninternationalized USASCII (per the DNS spec), |
| 876 | * is this characted special ("in need of quoting") ? |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 877 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 878 | * return: |
| 879 | * boolean. |
| 880 | */ |
| 881 | static int |
| 882 | special(int ch) { |
| 883 | switch (ch) { |
| 884 | case 0x22: /* '"' */ |
| 885 | case 0x2E: /* '.' */ |
| 886 | case 0x3B: /* ';' */ |
| 887 | case 0x5C: /* '\\' */ |
| 888 | case 0x28: /* '(' */ |
| 889 | case 0x29: /* ')' */ |
| 890 | /* Special modifiers in zone files. */ |
| 891 | case 0x40: /* '@' */ |
| 892 | case 0x24: /* '$' */ |
| 893 | return (1); |
| 894 | default: |
| 895 | return (0); |
| 896 | } |
| 897 | } |
| 898 | |
| 899 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 900 | * Thinking in noninternationalized USASCII (per the DNS spec), |
| 901 | * is this character visible and not a space when printed ? |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 902 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 903 | * return: |
| 904 | * boolean. |
| 905 | */ |
| 906 | static int |
| 907 | printable(int ch) { |
| 908 | return (ch > 0x20 && ch < 0x7f); |
| 909 | } |
| 910 | |
| 911 | /* |
| 912 | * Thinking in noninternationalized USASCII (per the DNS spec), |
| 913 | * convert this character to lower case if it's upper case. |
| 914 | */ |
| 915 | static int |
| 916 | mklower(int ch) { |
| 917 | if (ch >= 0x41 && ch <= 0x5A) |
| 918 | return (ch + 0x20); |
| 919 | return (ch); |
| 920 | } |
| 921 | |
| 922 | /* |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 923 | * Search for the counted-label name in an array of compressed names. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 924 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 925 | * return: |
| 926 | * offset from msg if found, or -1. |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 927 | * |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 928 | * notes: |
| 929 | * dnptrs is the pointer to the first name on the list, |
| 930 | * not the pointer to the start of the message. |
| 931 | */ |
| 932 | static int |
| 933 | dn_find(const u_char *domain, const u_char *msg, |
| 934 | const u_char * const *dnptrs, |
| 935 | const u_char * const *lastdnptr) |
| 936 | { |
| 937 | const u_char *dn, *cp, *sp; |
| 938 | const u_char * const *cpp; |
| 939 | u_int n; |
| 940 | |
| 941 | for (cpp = dnptrs; cpp < lastdnptr; cpp++) { |
| 942 | sp = *cpp; |
| 943 | /* |
| 944 | * terminate search on: |
| 945 | * root label |
| 946 | * compression pointer |
| 947 | * unusable offset |
| 948 | */ |
| 949 | while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 && |
| 950 | (sp - msg) < 0x4000) { |
| 951 | dn = domain; |
| 952 | cp = sp; |
| 953 | while ((n = *cp++) != 0) { |
| 954 | /* |
| 955 | * check for indirection |
| 956 | */ |
| 957 | switch (n & NS_CMPRSFLGS) { |
| 958 | case 0: /* normal case, n == len */ |
| 959 | n = labellen(cp - 1); /* XXX */ |
| 960 | |
| 961 | if (n != *dn++) |
| 962 | goto next; |
| 963 | |
| 964 | for (; n > 0; n--) |
| 965 | if (mklower(*dn++) != |
| 966 | mklower(*cp++)) |
| 967 | goto next; |
| 968 | /* Is next root for both ? */ |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 969 | if (*dn == '\0' && *cp == '\0') { |
| 970 | _DIAGASSERT(__type_fit(int, |
| 971 | sp - msg)); |
| 972 | return (int)(sp - msg); |
| 973 | } |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 974 | if (*dn) |
| 975 | continue; |
| 976 | goto next; |
| 977 | case NS_CMPRSFLGS: /* indirection */ |
| 978 | cp = msg + (((n & 0x3f) << 8) | *cp); |
| 979 | break; |
| 980 | |
| 981 | default: /* illegal type */ |
| 982 | errno = EMSGSIZE; |
| 983 | return (-1); |
| 984 | } |
| 985 | } |
| 986 | next: ; |
| 987 | sp += *sp + 1; |
| 988 | } |
| 989 | } |
| 990 | errno = ENOENT; |
| 991 | return (-1); |
| 992 | } |
| 993 | |
| 994 | static int |
| 995 | decode_bitstring(const unsigned char **cpp, char *dn, const char *eom) |
| 996 | { |
| 997 | const unsigned char *cp = *cpp; |
| 998 | char *beg = dn, tc; |
| 999 | int b, blen, plen, i; |
| 1000 | |
| 1001 | if ((blen = (*cp & 0xff)) == 0) |
| 1002 | blen = 256; |
| 1003 | plen = (blen + 3) / 4; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 1004 | plen += (int)sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1005 | if (dn + plen >= eom) |
| 1006 | return(-1); |
| 1007 | |
| 1008 | cp++; |
Dan Albert | cfd8c45 | 2014-10-07 21:08:41 -0700 | [diff] [blame] | 1009 | i = snprintf(dn, eom - dn, "\\[x"); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1010 | if (i < 0) |
| 1011 | return (-1); |
| 1012 | dn += i; |
| 1013 | for (b = blen; b > 7; b -= 8, cp++) { |
Dan Albert | cfd8c45 | 2014-10-07 21:08:41 -0700 | [diff] [blame] | 1014 | i = snprintf(dn, eom - dn, "%02x", *cp & 0xff); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1015 | if (i < 0) |
| 1016 | return (-1); |
| 1017 | dn += i; |
| 1018 | } |
| 1019 | if (b > 4) { |
| 1020 | tc = *cp++; |
Dan Albert | cfd8c45 | 2014-10-07 21:08:41 -0700 | [diff] [blame] | 1021 | i = snprintf(dn, eom - dn, "%02x", tc & (0xff << (8 - b))); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1022 | if (i < 0) |
| 1023 | return (-1); |
| 1024 | dn += i; |
| 1025 | } else if (b > 0) { |
| 1026 | tc = *cp++; |
Dan Albert | cfd8c45 | 2014-10-07 21:08:41 -0700 | [diff] [blame] | 1027 | i = snprintf(dn, eom - dn, "%1x", |
| 1028 | (((u_int32_t)tc >> 4) & 0x0f) & (0x0f << (4 - b))); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1029 | if (i < 0) |
| 1030 | return (-1); |
| 1031 | dn += i; |
| 1032 | } |
Dan Albert | cfd8c45 | 2014-10-07 21:08:41 -0700 | [diff] [blame] | 1033 | i = snprintf(dn, eom - dn, "/%d]", blen); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1034 | if (i < 0) |
| 1035 | return (-1); |
| 1036 | dn += i; |
| 1037 | |
| 1038 | *cpp = cp; |
Calin Juravle | fcb502e | 2014-03-05 15:06:52 +0000 | [diff] [blame] | 1039 | _DIAGASSERT(__type_fit(int, dn - beg)); |
| 1040 | return (int)(dn - beg); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 1041 | } |
| 1042 | |
| 1043 | static int |
| 1044 | encode_bitsring(const char **bp, const char *end, unsigned char **labelp, |
| 1045 | unsigned char ** dst, unsigned const char *eom) |
| 1046 | { |
| 1047 | int afterslash = 0; |
| 1048 | const char *cp = *bp; |
| 1049 | unsigned char *tp; |
| 1050 | char c; |
| 1051 | const char *beg_blen; |
| 1052 | char *end_blen = NULL; |
| 1053 | int value = 0, count = 0, tbcount = 0, blen = 0; |
| 1054 | |
| 1055 | beg_blen = end_blen = NULL; |
| 1056 | |
| 1057 | /* a bitstring must contain at least 2 characters */ |
| 1058 | if (end - cp < 2) |
| 1059 | return(EINVAL); |
| 1060 | |
| 1061 | /* XXX: currently, only hex strings are supported */ |
| 1062 | if (*cp++ != 'x') |
| 1063 | return(EINVAL); |
| 1064 | if (!isxdigit((*cp) & 0xff)) /* reject '\[x/BLEN]' */ |
| 1065 | return(EINVAL); |
| 1066 | |
| 1067 | for (tp = *dst + 1; cp < end && tp < eom; cp++) { |
| 1068 | switch((c = *cp)) { |
| 1069 | case ']': /* end of the bitstring */ |
| 1070 | if (afterslash) { |
| 1071 | if (beg_blen == NULL) |
| 1072 | return(EINVAL); |
| 1073 | blen = (int)strtol(beg_blen, &end_blen, 10); |
| 1074 | if (*end_blen != ']') |
| 1075 | return(EINVAL); |
| 1076 | } |
| 1077 | if (count) |
| 1078 | *tp++ = ((value << 4) & 0xff); |
| 1079 | cp++; /* skip ']' */ |
| 1080 | goto done; |
| 1081 | case '/': |
| 1082 | afterslash = 1; |
| 1083 | break; |
| 1084 | default: |
| 1085 | if (afterslash) { |
| 1086 | if (!isdigit(c&0xff)) |
| 1087 | return(EINVAL); |
| 1088 | if (beg_blen == NULL) { |
| 1089 | |
| 1090 | if (c == '0') { |
| 1091 | /* blen never begings with 0 */ |
| 1092 | return(EINVAL); |
| 1093 | } |
| 1094 | beg_blen = cp; |
| 1095 | } |
| 1096 | } else { |
| 1097 | if (!isxdigit(c&0xff)) |
| 1098 | return(EINVAL); |
| 1099 | value <<= 4; |
| 1100 | value += digitvalue[(int)c]; |
| 1101 | count += 4; |
| 1102 | tbcount += 4; |
| 1103 | if (tbcount > 256) |
| 1104 | return(EINVAL); |
| 1105 | if (count == 8) { |
| 1106 | *tp++ = value; |
| 1107 | count = 0; |
| 1108 | } |
| 1109 | } |
| 1110 | break; |
| 1111 | } |
| 1112 | } |
| 1113 | done: |
| 1114 | if (cp >= end || tp >= eom) |
| 1115 | return(EMSGSIZE); |
| 1116 | |
| 1117 | /* |
| 1118 | * bit length validation: |
| 1119 | * If a <length> is present, the number of digits in the <bit-data> |
| 1120 | * MUST be just sufficient to contain the number of bits specified |
| 1121 | * by the <length>. If there are insignificant bits in a final |
| 1122 | * hexadecimal or octal digit, they MUST be zero. |
| 1123 | * RFC 2673, Section 3.2. |
| 1124 | */ |
| 1125 | if (blen > 0) { |
| 1126 | int traillen; |
| 1127 | |
| 1128 | if (((blen + 3) & ~3) != tbcount) |
| 1129 | return(EINVAL); |
| 1130 | traillen = tbcount - blen; /* between 0 and 3 */ |
| 1131 | if (((value << (8 - traillen)) & 0xff) != 0) |
| 1132 | return(EINVAL); |
| 1133 | } |
| 1134 | else |
| 1135 | blen = tbcount; |
| 1136 | if (blen == 256) |
| 1137 | blen = 0; |
| 1138 | |
| 1139 | /* encode the type and the significant bit fields */ |
| 1140 | **labelp = DNS_LABELTYPE_BITSTRING; |
| 1141 | **dst = blen; |
| 1142 | |
| 1143 | *bp = cp; |
| 1144 | *dst = tp; |
| 1145 | |
| 1146 | return(0); |
| 1147 | } |
| 1148 | |
| 1149 | static int |
| 1150 | labellen(const u_char *lp) |
| 1151 | { |
| 1152 | int bitlen; |
| 1153 | u_char l = *lp; |
| 1154 | |
| 1155 | if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) { |
| 1156 | /* should be avoided by the caller */ |
| 1157 | return(-1); |
| 1158 | } |
| 1159 | |
| 1160 | if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) { |
| 1161 | if (l == DNS_LABELTYPE_BITSTRING) { |
| 1162 | if ((bitlen = *(lp + 1)) == 0) |
| 1163 | bitlen = 256; |
| 1164 | return((bitlen + 7 ) / 8 + 1); |
| 1165 | } |
| 1166 | return(-1); /* unknwon ELT */ |
| 1167 | } |
| 1168 | return(l); |
| 1169 | } |