external/bsd/libbind/dist/inet/inet_cidr_pton.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (c) 1998,1999 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 #if defined(LIBC_SCCS) && !defined(lint)
  21 static const char rcsid[] = "Id: inet_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp";
  22 #endif
  23
  24 #include "port_before.h"
  25
  26 #include <sys/types.h>
  27 #include <sys/socket.h>
  28 #include <netinet/in.h>
  29 #include <arpa/nameser.h>
  30 #include <arpa/inet.h>
  31
  32 #include <isc/assertions.h>
  33 #include <ctype.h>
  34 #include <errno.h>
  35 #include <stdio.h>
  36 #include <string.h>
  37 #include <stdlib.h>
  38
  39 #include "port_after.h"
  40
  41 #ifdef SPRINTF_CHAR
  42 # define SPRINTF(x) strlen(sprintf/**/x)
  43 #else
  44 # define SPRINTF(x) ((size_t)sprintf x)
  45 #endif
  46
  47 static int      inet_cidr_pton_ipv4 __P((const char *src, u_char *dst,
  48                                          int *bits, int ipv6));
  49 static int      inet_cidr_pton_ipv6 __P((const char *src, u_char *dst,
  50                                          int *bits));
  51
  52 static int      getbits(const char *, int ipv6);
  53
  54 /*%
  55  * int
  56  * inet_cidr_pton(af, src, dst, *bits)
  57  *      convert network address from presentation to network format.
  58  *      accepts inet_pton()'s input for this "af" plus trailing "/CIDR".
  59  *      "dst" is assumed large enough for its "af".  "bits" is set to the
  60  *      /CIDR prefix length, which can have defaults (like /32 for IPv4).
  61  * return:
  62  *      -1 if an error occurred (inspect errno; ENOENT means bad format).
  63  *      0 if successful conversion occurred.
  64  * note:
  65  *      192.5.5.1/28 has a nonzero host part, which means it isn't a network
  66  *      as called for by inet_net_pton() but it can be a host address with
  67  *      an included netmask.
  68  * author:
  69  *      Paul Vixie (ISC), October 1998
  70  */
  71 int
  72 inet_cidr_pton(int af, const char *src, void *dst, int *bits) {
  73         switch (af) {
  74         case AF_INET:
  75                 return (inet_cidr_pton_ipv4(src, dst, bits, 0));
  76         case AF_INET6:
  77                 return (inet_cidr_pton_ipv6(src, dst, bits));
  78         default:
  79                 errno = EAFNOSUPPORT;
  80                 return (-1);
  81         }
  82 }
  83
  84 static const char digits[] = "0123456789";
  85
  86 static int
  87 inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) {
  88         const u_char *odst = dst;
  89         int n, ch, tmp, bits;
  90         size_t size = 4;
  91
  92         /* Get the mantissa. */
  93         while (ch = *src++, (isascii(ch) && isdigit(ch))) {
  94                 tmp = 0;
  95                 do {
  96                         n = strchr(digits, ch) - digits;
  97                         INSIST(n >= 0 && n <= 9);
  98                         tmp *= 10;
  99                         tmp += n;
 100                         if (tmp > 255)
 101                                 goto enoent;
 102                 } while ((ch = *src++) != '\0' && 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         }
 111
 112         /* Get the prefix length if any. */
 113         bits = -1;
 114         if (ch == '/' && dst > odst) {
 115                 bits = getbits(src, ipv6);
 116                 if (bits == -2)
 117                         goto enoent;
 118         } else if (ch != '\0')
 119                 goto enoent;
 120
 121         /* Prefix length can default to /32 only if all four octets spec'd. */
 122         if (bits == -1) {
 123                 if (dst - odst == 4)
 124                         bits = ipv6 ? 128 : 32;
 125                 else
 126                         goto enoent;
 127         }
 128
 129         /* If nothing was written to the destination, we found no address. */
 130         if (dst == odst)
 131                 goto enoent;
 132
 133         /* If prefix length overspecifies mantissa, life is bad. */
 134         if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst))
 135                 goto enoent;
 136
 137         /* Extend address to four octets. */
 138         while (size-- > 0U)
 139                 *dst++ = 0;
 140
 141         *pbits = bits;
 142         return (0);
 143
 144  enoent:
 145         errno = ENOENT;
 146         return (-1);
 147
 148  emsgsize:
 149         errno = EMSGSIZE;
 150         return (-1);
 151 }
 152
 153 static int
 154 inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) {
 155         static const char xdigits_l[] = "0123456789abcdef",
 156                           xdigits_u[] = "0123456789ABCDEF";
 157         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 158         const char *xdigits, *curtok;
 159         int ch, saw_xdigit;
 160         u_int val;
 161         int bits;
 162
 163         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 164         endp = tp + NS_IN6ADDRSZ;
 165         colonp = NULL;
 166         /* Leading :: requires some special handling. */
 167         if (*src == ':')
 168                 if (*++src != ':')
 169                         return (0);
 170         curtok = src;
 171         saw_xdigit = 0;
 172         val = 0;
 173         bits = -1;
 174         while ((ch = *src++) != '\0') {
 175                 const char *pch;
 176
 177                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 178                         pch = strchr((xdigits = xdigits_u), ch);
 179                 if (pch != NULL) {
 180                         val <<= 4;
 181                         val |= (pch - xdigits);
 182                         if (val > 0xffff)
 183                                 return (0);
 184                         saw_xdigit = 1;
 185                         continue;
 186                 }
 187                 if (ch == ':') {
 188                         curtok = src;
 189                         if (!saw_xdigit) {
 190                                 if (colonp)
 191                                         return (0);
 192                                 colonp = tp;
 193                                 continue;
 194                         } else if (*src == '\0') {
 195                                 return (0);
 196                         }
 197                         if (tp + NS_INT16SZ > endp)
 198                                 return (0);
 199                         *tp++ = (u_char) (val >> 8) & 0xff;
 200                         *tp++ = (u_char) val & 0xff;
 201                         saw_xdigit = 0;
 202                         val = 0;
 203                         continue;
 204                 }
 205                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 206                     inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) {
 207                         tp += NS_INADDRSZ;
 208                         saw_xdigit = 0;
 209                         break;  /*%< '\\0' was seen by inet_pton4(). */
 210                 }
 211                 if (ch == '/') {
 212                         bits = getbits(src, 1);
 213                         if (bits == -2)
 214                                 goto enoent;
 215                         break;
 216                 }
 217                 goto enoent;
 218         }
 219         if (saw_xdigit) {
 220                 if (tp + NS_INT16SZ > endp)
 221                         goto emsgsize;
 222                 *tp++ = (u_char) (val >> 8) & 0xff;
 223                 *tp++ = (u_char) val & 0xff;
 224         }
 225         if (colonp != NULL) {
 226                 /*
 227                  * Since some memmove()'s erroneously fail to handle
 228                  * overlapping regions, we'll do the shift by hand.
 229                  */
 230                 const int n = tp - colonp;
 231                 int i;
 232
 233                 if (tp == endp)
 234                         goto enoent;
 235                 for (i = 1; i <= n; i++) {
 236                         endp[- i] = colonp[n - i];
 237                         colonp[n - i] = 0;
 238                 }
 239                 tp = endp;
 240         }
 241
 242         memcpy(dst, tmp, NS_IN6ADDRSZ);
 243
 244         *pbits = bits;
 245         return (0);
 246
 247  enoent:
 248         errno = ENOENT;
 249         return (-1);
 250
 251  emsgsize:
 252         errno = EMSGSIZE;
 253         return (-1);
 254 }
 255
 256 static int
 257 getbits(const char *src, int ipv6) {
 258         int bits = 0;
 259         char *cp, ch;
 260
 261         if (*src == '\0')                       /*%< syntax */
 262                 return (-2);
 263         do {
 264                 ch = *src++;
 265                 cp = strchr(digits, ch);
 266                 if (cp == NULL)                 /*%< syntax */
 267                         return (-2);
 268                 bits *= 10;
 269                 bits += cp - digits;
 270                 if (bits == 0 && *src != '\0')  /*%< no leading zeros */
 271                         return (-2);
 272                 if (bits > (ipv6 ? 128 : 32))   /*%< range error */
 273                         return (-2);
 274         } while (*src != '\0');
 275
 276         return (bits);
 277 }
 278
 279 /*! \file */