lib/libc/inet/inet_net_pton.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1996,1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  *
  17  * $Id: inet_net_pton.c,v 1.8.672.1 2008/08/26 04:42:38 marka Exp $
  18  */
  19
  20 #include "port_before.h"
  21
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <arpa/nameser.h>
  26 #include <arpa/inet.h>
  27
  28 #include <assert.h>
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <stdlib.h>
  34
  35 #include "port_after.h"
  36
  37 /*%
  38  * static int
  39  * inet_net_pton_ipv4(src, dst, size)
  40  *      convert IPv4 network number from presentation to network format.
  41  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
  42  *      "size" is in bytes and describes "dst".
  43  * return:
  44  *      number of bits, either imputed classfully or specified with /CIDR,
  45  *      or -1 if some failure occurred (check errno).  ENOENT means it was
  46  *      not an IPv4 network specification.
  47  * note:
  48  *      network byte order assumed.  this means 192.5.5.240/28 has
  49  *      0b11110000 in its fourth octet.
  50  * author:
  51  *      Paul Vixie (ISC), June 1996
  52  */
  53 static int
  54 inet_net_pton_ipv4(const char *src, u_char *dst, size_t size) {
  55         static const char xdigits[] = "0123456789abcdef";
  56         static const char digits[] = "0123456789";
  57         int n, ch, tmp = 0, dirty, bits;
  58         const u_char *odst = dst;
  59
  60         ch = *src++;
  61         if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
  62             && isascii((unsigned char)(src[1]))
  63             && isxdigit((unsigned char)(src[1]))) {
  64                 /* Hexadecimal: Eat nybble string. */
  65                 if (size <= 0U)
  66                         goto emsgsize;
  67                 dirty = 0;
  68                 src++;  /*%< skip x or X. */
  69                 while ((ch = *src++) != '\0' && isascii(ch) && isxdigit(ch)) {
  70                         if (isupper(ch))
  71                                 ch = tolower(ch);
  72                         n = strchr(xdigits, ch) - xdigits;
  73                         assert(n >= 0 && n <= 15);
  74                         if (dirty == 0)
  75                                 tmp = n;
  76                         else
  77                                 tmp = (tmp << 4) | n;
  78                         if (++dirty == 2) {
  79                                 if (size-- <= 0U)
  80                                         goto emsgsize;
  81                                 *dst++ = (u_char) tmp;
  82                                 dirty = 0;
  83                         }
  84                 }
  85                 if (dirty) {  /*%< Odd trailing nybble? */
  86                         if (size-- <= 0U)
  87                                 goto emsgsize;
  88                         *dst++ = (u_char) (tmp << 4);
  89                 }
  90         } else if (isascii(ch) && isdigit(ch)) {
  91                 /* Decimal: eat dotted digit string. */
  92                 for (;;) {
  93                         tmp = 0;
  94                         do {
  95                                 n = strchr(digits, ch) - digits;
  96                                 assert(n >= 0 && n <= 9);
  97                                 tmp *= 10;
  98                                 tmp += n;
  99                                 if (tmp > 255)
 100                                         goto enoent;
 101                         } while ((ch = *src++) != '\0' &&
 102                                  isascii(ch) && isdigit(ch));
 103                         if (size-- <= 0U)
 104                                 goto emsgsize;
 105                         *dst++ = (u_char) tmp;
 106                         if (ch == '\0' || ch == '/')
 107                                 break;
 108                         if (ch != '.')
 109                                 goto enoent;
 110                         ch = *src++;
 111                         if (!isascii(ch) || !isdigit(ch))
 112                                 goto enoent;
 113                 }
 114         } else
 115                 goto enoent;
 116
 117         bits = -1;
 118         if (ch == '/' && isascii((unsigned char)(src[0])) &&
 119             isdigit((unsigned char)(src[0])) && dst > odst) {
 120                 /* CIDR width specifier.  Nothing can follow it. */
 121                 ch = *src++;    /*%< Skip over the /. */
 122                 bits = 0;
 123                 do {
 124                         n = strchr(digits, ch) - digits;
 125                         assert(n >= 0 && n <= 9);
 126                         bits *= 10;
 127                         bits += n;
 128                         if (bits > 32)
 129                                 goto enoent;
 130                 } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
 131                 if (ch != '\0')
 132                         goto enoent;
 133         }
 134
 135         /* Firey death and destruction unless we prefetched EOS. */
 136         if (ch != '\0')
 137                 goto enoent;
 138
 139         /* If nothing was written to the destination, we found no address. */
 140         if (dst == odst)
 141                 goto enoent;
 142         /* If no CIDR spec was given, infer width from net class. */
 143         if (bits == -1) {
 144                 if (*odst >= 240)       /*%< Class E */
 145                         bits = 32;
 146                 else if (*odst >= 224)  /*%< Class D */
 147                         bits = 8;
 148                 else if (*odst >= 192)  /*%< Class C */
 149                         bits = 24;
 150                 else if (*odst >= 128)  /*%< Class B */
 151                         bits = 16;
 152                 else                    /*%< Class A */
 153                         bits = 8;
 154                 /* If imputed mask is narrower than specified octets, widen. */
 155                 if (bits < ((dst - odst) * 8))
 156                         bits = (dst - odst) * 8;
 157                 /*
 158                  * If there are no additional bits specified for a class D
 159                  * address adjust bits to 4.
 160                  */
 161                 if (bits == 8 && *odst == 224)
 162                         bits = 4;
 163         }
 164         /* Extend network to cover the actual mask. */
 165         while (bits > ((dst - odst) * 8)) {
 166                 if (size-- <= 0U)
 167                         goto emsgsize;
 168                 *dst++ = '\0';
 169         }
 170         return (bits);
 171
 172  enoent:
 173         errno = ENOENT;
 174         return (-1);
 175
 176  emsgsize:
 177         errno = EMSGSIZE;
 178         return (-1);
 179 }
 180
 181 static int
 182 getbits(const char *src, int *bitsp) {
 183         static const char digits[] = "0123456789";
 184         int n;
 185         int val;
 186         char ch;
 187
 188         val = 0;
 189         n = 0;
 190         while ((ch = *src++) != '\0') {
 191                 const char *pch;
 192
 193                 pch = strchr(digits, ch);
 194                 if (pch != NULL) {
 195                         if (n++ != 0 && val == 0)       /*%< no leading zeros */
 196                                 return (0);
 197                         val *= 10;
 198                         val += (pch - digits);
 199                         if (val > 128)                  /*%< range */
 200                                 return (0);
 201                         continue;
 202                 }
 203                 return (0);
 204         }
 205         if (n == 0)
 206                 return (0);
 207         *bitsp = val;
 208         return (1);
 209 }
 210
 211 static int
 212 getv4(const char *src, u_char *dst, int *bitsp) {
 213         static const char digits[] = "0123456789";
 214         u_char *odst = dst;
 215         int n;
 216         u_int val;
 217         char ch;
 218
 219         val = 0;
 220         n = 0;
 221         while ((ch = *src++) != '\0') {
 222                 const char *pch;
 223
 224                 pch = strchr(digits, ch);
 225                 if (pch != NULL) {
 226                         if (n++ != 0 && val == 0)       /*%< no leading zeros */
 227                                 return (0);
 228                         val *= 10;
 229                         val += (pch - digits);
 230                         if (val > 255)                  /*%< range */
 231                                 return (0);
 232                         continue;
 233                 }
 234                 if (ch == '.' || ch == '/') {
 235                         if (dst - odst > 3)             /*%< too many octets? */
 236                                 return (0);
 237                         *dst++ = val;
 238                         if (ch == '/')
 239                                 return (getbits(src, bitsp));
 240                         val = 0;
 241                         n = 0;
 242                         continue;
 243                 }
 244                 return (0);
 245         }
 246         if (n == 0)
 247                 return (0);
 248         if (dst - odst > 3)             /*%< too many octets? */
 249                 return (0);
 250         *dst++ = val;
 251         return (1);
 252 }
 253
 254 static int
 255 inet_net_pton_ipv6(const char *src, u_char *dst, size_t size) {
 256         static const char xdigits_l[] = "0123456789abcdef",
 257                           xdigits_u[] = "0123456789ABCDEF";
 258         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 259         const char *xdigits, *curtok;
 260         int ch, saw_xdigit;
 261         u_int val;
 262         int digits;
 263         int bits;
 264         size_t bytes;
 265         int words;
 266         int ipv4;
 267
 268         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 269         endp = tp + NS_IN6ADDRSZ;
 270         colonp = NULL;
 271         /* Leading :: requires some special handling. */
 272         if (*src == ':')
 273                 if (*++src != ':')
 274                         goto enoent;
 275         curtok = src;
 276         saw_xdigit = 0;
 277         val = 0;
 278         digits = 0;
 279         bits = -1;
 280         ipv4 = 0;
 281         while ((ch = *src++) != '\0') {
 282                 const char *pch;
 283
 284                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 285                         pch = strchr((xdigits = xdigits_u), ch);
 286                 if (pch != NULL) {
 287                         val <<= 4;
 288                         val |= (pch - xdigits);
 289                         if (++digits > 4)
 290                                 goto enoent;
 291                         saw_xdigit = 1;
 292                         continue;
 293                 }
 294                 if (ch == ':') {
 295                         curtok = src;
 296                         if (!saw_xdigit) {
 297                                 if (colonp)
 298                                         goto enoent;
 299                                 colonp = tp;
 300                                 continue;
 301                         } else if (*src == '\0')
 302                                 goto enoent;
 303                         if (tp + NS_INT16SZ > endp)
 304                                 return (0);
 305                         *tp++ = (u_char) (val >> 8) & 0xff;
 306                         *tp++ = (u_char) val & 0xff;
 307                         saw_xdigit = 0;
 308                         digits = 0;
 309                         val = 0;
 310                         continue;
 311                 }
 312                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 313                      getv4(curtok, tp, &bits) > 0) {
 314                         tp += NS_INADDRSZ;
 315                         saw_xdigit = 0;
 316                         ipv4 = 1;
 317                         break;  /*%< '\\0' was seen by inet_pton4(). */
 318                 }
 319                 if (ch == '/' && getbits(src, &bits) > 0)
 320                         break;
 321                 goto enoent;
 322         }
 323         if (saw_xdigit) {
 324                 if (tp + NS_INT16SZ > endp)
 325                         goto enoent;
 326                 *tp++ = (u_char) (val >> 8) & 0xff;
 327                 *tp++ = (u_char) val & 0xff;
 328         }
 329         if (bits == -1)
 330                 bits = 128;
 331
 332         words = (bits + 15) / 16;
 333         if (words < 2)
 334                 words = 2;
 335         if (ipv4)
 336                 words = 8;
 337         endp =  tmp + 2 * words;
 338
 339         if (colonp != NULL) {
 340                 /*
 341                  * Since some memmove()'s erroneously fail to handle
 342                  * overlapping regions, we'll do the shift by hand.
 343                  */
 344                 const int n = tp - colonp;
 345                 int i;
 346
 347                 if (tp == endp)
 348                         goto enoent;
 349                 for (i = 1; i <= n; i++) {
 350                         endp[- i] = colonp[n - i];
 351                         colonp[n - i] = 0;
 352                 }
 353                 tp = endp;
 354         }
 355         if (tp != endp)
 356                 goto enoent;
 357
 358         bytes = (bits + 7) / 8;
 359         if (bytes > size)
 360                 goto emsgsize;
 361         memcpy(dst, tmp, bytes);
 362         return (bits);
 363
 364  enoent:
 365         errno = ENOENT;
 366         return (-1);
 367
 368  emsgsize:
 369         errno = EMSGSIZE;
 370         return (-1);
 371 }
 372
 373 /*%
 374  * int
 375  * inet_net_pton(af, src, dst, size)
 376  *      convert network number from presentation to network format.
 377  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
 378  *      "size" is in bytes and describes "dst".
 379  * return:
 380  *      number of bits, either imputed classfully or specified with /CIDR,
 381  *      or -1 if some failure occurred (check errno).  ENOENT means it was
 382  *      not a valid network specification.
 383  * author:
 384  *      Paul Vixie (ISC), June 1996
 385  */
 386 int
 387 inet_net_pton(int af, const char *src, void *dst, size_t size) {
 388         switch (af) {
 389         case AF_INET:
 390                 return (inet_net_pton_ipv4(src, dst, size));
 391         case AF_INET6:
 392                 return (inet_net_pton_ipv6(src, dst, size));
 393         default:
 394                 errno = EAFNOSUPPORT;
 395                 return (-1);
 396         }
 397 }
 398
 399 /*
 400  * Weak aliases for applications that use certain private entry points,
 401  * and fail to include <arpa/inet.h>.
 402  */
 403 #undef inet_net_pton
 404 __weak_reference(__inet_net_pton, inet_net_pton);