resolv/inet_net_pton.c

   1 /*
   2  * Copyright (c) 1996 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 #if defined(LIBC_SCCS) && !defined(lint)
  19 static const char rcsid[] = "$Id$";
  20 #endif
  21
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <netinet/in.h>
  25 #include <arpa/inet.h>
  26
  27 #include <assert.h>
  28 #include <ctype.h>
  29 #include <errno.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <stdlib.h>
  33
  34 #ifdef SPRINTF_CHAR
  35 # define SPRINTF(x) strlen(sprintf/**/x)
  36 #else
  37 # define SPRINTF(x) ((size_t)sprintf x)
  38 #endif
  39
  40 static int      inet_net_pton_ipv4 __P((const char *src, u_char *dst,
  41                                         size_t size));
  42
  43 /*
  44  * static int
  45  * inet_net_pton(af, src, dst, size)
  46  *      convert network number from presentation to network format.
  47  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
  48  *      "size" is in bytes and describes "dst".
  49  * return:
  50  *      number of bits, either imputed classfully or specified with /CIDR,
  51  *      or -1 if some failure occurred (check errno).  ENOENT means it was
  52  *      not a valid network specification.
  53  * author:
  54  *      Paul Vixie (ISC), June 1996
  55  */
  56 int
  57 inet_net_pton(af, src, dst, size)
  58         int af;
  59         const char *src;
  60         void *dst;
  61         size_t size;
  62 {
  63         switch (af) {
  64         case AF_INET:
  65                 return (inet_net_pton_ipv4(src, dst, size));
  66         default:
  67                 __set_errno (EAFNOSUPPORT);
  68                 return (-1);
  69         }
  70 }
  71
  72 /*
  73  * static int
  74  * inet_net_pton_ipv4(src, dst, size)
  75  *      convert IPv4 network number from presentation to network format.
  76  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
  77  *      "size" is in bytes and describes "dst".
  78  * return:
  79  *      number of bits, either imputed classfully or specified with /CIDR,
  80  *      or -1 if some failure occurred (check errno).  ENOENT means it was
  81  *      not an IPv4 network specification.
  82  * note:
  83  *      network byte order assumed.  this means 192.5.5.240/28 has
  84  *      0x11110000 in its fourth octet.
  85  * author:
  86  *      Paul Vixie (ISC), June 1996
  87  */
  88 static int
  89 inet_net_pton_ipv4(src, dst, size)
  90         const char *src;
  91         u_char *dst;
  92         size_t size;
  93 {
  94         static const char
  95                 xdigits[] = "0123456789abcdef",
  96                 digits[] = "0123456789";
  97         int n, ch, tmp, dirty, bits;
  98         const u_char *odst = dst;
  99
 100         bits = -1;
 101         ch = *src++;
 102
 103         if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
 104             && isascii(src[1]) && isxdigit(src[1])) {
 105                 /* Hexadecimal: Eat nybble string. */
 106                 if (size <= 0)
 107                         goto emsgsize;
 108                 *dst = 0, dirty = 0;
 109                 src++;  /* skip x or X. */
 110                 while ((ch = *src++) != '\0' &&
 111                        isascii(ch) && isxdigit(ch)) {
 112                         if (isupper(ch))
 113                                 ch = tolower(ch);
 114                         n = strchr(xdigits, ch) - xdigits;
 115                         assert(n >= 0 && n <= 15);
 116                         *dst |= n;
 117                         if (!dirty++)
 118                                 *dst <<= 4;
 119                         else if (size-- > 0)
 120                                 *++dst = 0, dirty = 0;
 121                         else
 122                                 goto emsgsize;
 123                 }
 124                 if (dirty)
 125                         size--;
 126         } else if (isascii(ch) && isdigit(ch)) {
 127                 /* Decimal: eat dotted digit string. */
 128                 for (;;) {
 129                         tmp = 0;
 130                         do {
 131                                 n = strchr(digits, ch) - digits;
 132                                 assert(n >= 0 && n <= 9);
 133                                 tmp *= 10;
 134                                 tmp += n;
 135                                 if (tmp > 255)
 136                                         goto enoent;
 137                         } while ((ch = *src++) != '\0' &&
 138                                  isascii(ch) && isdigit(ch));
 139                         if (size-- <= 0)
 140                                 goto emsgsize;
 141                         *dst++ = (u_char) tmp;
 142                         if (ch == '\0' || ch == '/')
 143                                 break;
 144                         if (ch != '.')
 145                                 goto enoent;
 146                         ch = *src++;
 147                         if (!isascii(ch) || !isdigit(ch))
 148                                 goto enoent;
 149                 }
 150         } else
 151                 goto enoent;
 152
 153         if (ch == '/' && isascii(src[0]) && isdigit(src[0]) && dst > odst) {
 154                 /* CIDR width specifier.  Nothing can follow it. */
 155                 ch = *src++;    /* Skip over the /. */
 156                 bits = 0;
 157                 do {
 158                         n = strchr(digits, ch) - digits;
 159                         assert(n >= 0 && n <= 9);
 160                         bits *= 10;
 161                         bits += n;
 162                 } while ((ch = *src++) != '\0' &&
 163                          isascii(ch) && isdigit(ch));
 164                 if (ch != '\0')
 165                         goto enoent;
 166         }
 167
 168         /* Firey death and destruction unless we prefetched EOS. */
 169         if (ch != '\0')
 170                 goto enoent;
 171
 172         /* If nothing was written to the destination, we found no address. */
 173         if (dst == odst)
 174                 goto enoent;
 175         /* If no CIDR spec was given, infer width from net class. */
 176         if (bits == -1) {
 177                 if (*odst >= 224)
 178                         bits = 4;
 179                 else if (*odst >= 192)
 180                         bits = 24;
 181                 else if (*odst >= 128)
 182                         bits = 16;
 183                 else
 184                         bits = 8;
 185         }
 186         /* Extend network to cover the actual mask. */
 187         while (bits > ((dst - odst) * 8)) {
 188                 if (size-- <= 0)
 189                         goto emsgsize;
 190                 *dst++ = '\0';
 191         }
 192         return (bits);
 193
 194  enoent:
 195         __set_errno (ENOENT);
 196         return (-1);
 197
 198  emsgsize:
 199         __set_errno (EMSGSIZE);
 200         return (-1);
 201 }