/*      $NetBSD: inet_cidr_pton.c,v 1.10 2024/01/20 14:52:47 christos Exp $     */

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1998,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static const char rcsid[] = "Id: inet_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp";
#else
__RCSID("$NetBSD: inet_cidr_pton.c,v 1.10 2024/01/20 14:52:47 christos Exp $");
#endif
#endif

#include "port_before.h"

#include "namespace.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>

#include <isc/assertions.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>
#include <stdlib.h>

#include "port_after.h"

#ifdef __weak_alias
__weak_alias(inet_cidr_pton,_inet_cidr_pton)
#endif

static int      inet_cidr_pton_ipv4(const char *src, u_char *dst,
                                        int *bits, int ipv6);
static int      inet_cidr_pton_ipv6(const char *src, u_char *dst, int *bits);

static int      getbits(const char *, int ipv6);

/*%
* int
* inet_cidr_pton(af, src, dst, *bits)
*      convert network address from presentation to network format.
*      accepts inet_pton()'s input for this "af" plus trailing "/CIDR".
*      "dst" is assumed large enough for its "af".  "bits" is set to the
*      /CIDR prefix length, which can have defaults (like /32 for IPv4).
* return:
*      -1 if an error occurred (inspect errno; ENOENT means bad format).
*      0 if successful conversion occurred.
* note:
*      192.5.5.1/28 has a nonzero host part, which means it isn't a network
*      as called for by inet_net_pton() but it can be a host address with
*      an included netmask.
* author:
*      Paul Vixie (ISC), October 1998
*/
int
inet_cidr_pton(int af, const char *src, void *dst, int *bits) {
       switch (af) {
       case AF_INET:
               return inet_cidr_pton_ipv4(src, dst, bits, 0);
       case AF_INET6:
               return inet_cidr_pton_ipv6(src, dst, bits);
       default:
               errno = EAFNOSUPPORT;
               return -1;
       }
}

static const char digits[] = "0123456789";

static int
inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) {
       const u_char *odst = dst;
       int ch, bits;
       ptrdiff_t n, tmp;
       size_t size = 4;

       /* Get the mantissa. */
       while (ch = *src++, (isascii(ch) && isdigit(ch))) {
               tmp = 0;
               do {
                       n = strchr(digits, ch) - digits;
                       INSIST(n >= 0 && n <= 9);
                       tmp *= 10;
                       tmp += n;
                       if (tmp > 255)
                               goto enoent;
               } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
               if (size-- == 0U)
                       goto emsgsize;
               *dst++ = (u_char) tmp;
               if (ch == '\0' || ch == '/')
                       break;
               if (ch != '.')
                       goto enoent;
       }

       /* Get the prefix length if any. */
       bits = -1;
       if (ch == '/' && dst > odst) {
               bits = getbits(src, ipv6);
               if (bits == -2)
                       goto enoent;
       } else if (ch != '\0')
               goto enoent;

       /* Prefix length can default to /32 only if all four octets spec'd. */
       if (bits == -1) {
               if (dst - odst == 4)
                       bits = ipv6 ? 128 : 32;
               else
                       goto enoent;
       }

       /* If nothing was written to the destination, we found no address. */
       if (dst == odst)
               goto enoent;

       /* If prefix length overspecifies mantissa, life is bad. */
       if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst))
               goto enoent;

       /* Extend address to four octets. */
       while (size-- > 0U)
               *dst++ = 0;

       *pbits = bits;
       return 0;

enoent:
       errno = ENOENT;
       return -1;

emsgsize:
       errno = EMSGSIZE;
       return -1;
}

static int
inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) {
       static const char xdigits_l[] = "0123456789abcdef",
                         xdigits_u[] = "0123456789ABCDEF";
       u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
       const char *xdigits, *curtok;
       int ch, saw_xdigit;
       u_int val;
       int bits;

       memset((tp = tmp), '\0', NS_IN6ADDRSZ);
       endp = tp + NS_IN6ADDRSZ;
       colonp = NULL;
       /* Leading :: requires some special handling. */
       if (*src == ':')
               if (*++src != ':')
                       return 0;
       curtok = src;
       saw_xdigit = 0;
       val = 0;
       bits = -1;
       while ((ch = *src++) != '\0') {
               const char *pch;

               if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
                       pch = strchr((xdigits = xdigits_u), ch);
               if (pch != NULL) {
                       val <<= 4;
                       val |= (int)(pch - xdigits);
                       if (val > 0xffff)
                               return 0;
                       saw_xdigit = 1;
                       continue;
               }
               if (ch == ':') {
                       curtok = src;
                       if (!saw_xdigit) {
                               if (colonp)
                                       return 0;
                               colonp = tp;
                               continue;
                       } else if (*src == '\0') {
                               return 0;
                       }
                       if (tp + NS_INT16SZ > endp)
                               return 0;
                       *tp++ = (u_char) (val >> 8) & 0xff;
                       *tp++ = (u_char) val & 0xff;
                       saw_xdigit = 0;
                       val = 0;
                       continue;
               }
               if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
                   inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) {
                       tp += NS_INADDRSZ;
                       saw_xdigit = 0;
                       break;  /*%< '\\0' was seen by inet_pton4(). */
               }
               if (ch == '/') {
                       bits = getbits(src, 1);
                       if (bits == -2)
                               goto enoent;
                       break;
               }
               goto enoent;
       }
       if (saw_xdigit) {
               if (tp + NS_INT16SZ > endp)
                       goto emsgsize;
               *tp++ = (u_char) (val >> 8) & 0xff;
               *tp++ = (u_char) val & 0xff;
       }
       if (colonp != NULL) {
               /*
                * Since some memmove()'s erroneously fail to handle
                * overlapping regions, we'll do the shift by hand.
                */
               const ptrdiff_t n = tp - colonp;
               int i;

               if (tp == endp)
                       goto enoent;
               for (i = 1; i <= n; i++) {
                       endp[- i] = colonp[n - i];
                       colonp[n - i] = 0;
               }
               tp = endp;
       }

       memcpy(dst, tmp, NS_IN6ADDRSZ);

       *pbits = bits;
       return 0;

enoent:
       errno = ENOENT;
       return -1;

emsgsize:
       errno = EMSGSIZE;
       return -1;
}

static int
getbits(const char *src, int ipv6) {
       int bits = 0;

       if (*src == '\0')                       /*%< syntax */
               return -2;
       do {
               char ch = *src++;
               const char *cp = strchr(digits, ch);
               if (cp == NULL)                 /*%< syntax */
                       return -2;
               bits *= 10;
               bits += (int)(cp - digits);
               if (bits == 0 && *src != '\0')  /*%< no leading zeros */
                       return -2;
               if (bits > (ipv6 ? 128 : 32))   /*%< range error */
                       return -2;
       } while (*src != '\0');

       return bits;
}

/*! \file */

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.