/* This is from the BIND 4.9.4 release, modified to compile by itself */

/* Copyright (c) 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS

 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE

 * CONSORTIUM 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.

 *

 * SPDX-License-Identifier: ISC

 */

#include "curl_setup.h"

#ifdef HAVE_SYS_PARAM_H

#include <sys/param.h>

#endif

#ifdef HAVE_NETINET_IN_H

#include <netinet/in.h>

#endif

#ifdef HAVE_ARPA_INET_H

#include <arpa/inet.h>

#endif

#include "curlx/inet_pton.h"

#include "curlx/strparse.h"

#define IN6ADDRSZ       16

#define INADDRSZ         4

#define INT16SZ          2

/*

 * If USE_IPV6 is disabled, we still want to parse IPv6 addresses, so make

 * sure we have _some_ value for AF_INET6 without polluting our fake value

 * everywhere.

 */

#if !defined(USE_IPV6) && !defined(AF_INET6)

#define AF_INET6 (AF_INET + 1)

#endif

/*

 * WARNING: Do not even consider trying to compile this on a system where

 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.

 */

/* int inet_pton4(src, dst)

 *      like inet_aton() but without all the hexadecimal and shorthand.

 * return:

 *      1 if `src' is a valid dotted quad, else 0.

 * notice:

 *      does not touch `dst' unless it is returning 1.

 * author:

 *      Paul Vixie, 1996.

 */

static int inet_pton4(const char *src, unsigned char *dst)

{

  int saw_digit, octets, ch;

  unsigned char tmp[INADDRSZ], *tp;

  saw_digit = 0;

  octets = 0;

  tp = tmp;

  *tp = 0;

  while((ch = (unsigned char)*src++) != '\0') {

    if(ISDIGIT(ch)) {

      unsigned int val = (*tp * 10) + (ch - '0');

      if(saw_digit && *tp == 0)

        return 0;

      if(val > 255)

        return 0;

      *tp = (unsigned char)val;

      if(!saw_digit) {

        if(++octets > 4)

          return 0;

        saw_digit = 1;

      }

    }

    else if(ch == '.' && saw_digit) {

      if(octets == 4)

        return 0;

      *++tp = 0;

      saw_digit = 0;

    }

    else

      return 0;

  }

  if(octets < 4)

    return 0;

  memcpy(dst, tmp, INADDRSZ);

  return 1;

}

/* int inet_pton6(src, dst)

 *      convert presentation level address to network order binary form.

 * return:

 *      1 if `src' is a valid [RFC1884 2.2] address, else 0.

 * notice:

 *      (1) does not touch `dst' unless it is returning 1.

 *      (2) :: in a full address is silently ignored.

 * credit:

 *      inspired by Mark Andrews.

 * author:

 *      Paul Vixie, 1996.

 */

static int inet_pton6(const char *src, unsigned char *dst)

{

  unsigned char tmp[IN6ADDRSZ], *tp, *endp, *colonp;

  const char *curtok;

  int ch, saw_xdigit;

  size_t val;

  memset((tp = tmp), 0, IN6ADDRSZ);

  endp = tp + IN6ADDRSZ;

  colonp = NULL;

  /* Leading :: requires some special handling. */

  if(*src == ':')

    if(*++src != ':')

      return 0;

  curtok = src;

  saw_xdigit = 0;

  val = 0;

  while((ch = (unsigned char)*src++) != '\0') {

    if(ISXDIGIT(ch)) {

      val <<= 4;

      val |= curlx_hexval(ch);

      if(++saw_xdigit > 4)

        return 0;

      continue;

    }

    if(ch == ':') {

      curtok = src;

      if(!saw_xdigit) {

        if(colonp)

          return 0;

        colonp = tp;

        continue;

      }

      if(tp + INT16SZ > endp)

        return 0;

      *tp++ = (unsigned char)((val >> 8) & 0xff);

      *tp++ = (unsigned char)(val & 0xff);

      saw_xdigit = 0;

      val = 0;

      continue;

    }

    if(ch == '.' && ((tp + INADDRSZ) <= endp) &&

       inet_pton4(curtok, tp) > 0) {

      tp += INADDRSZ;

      saw_xdigit = 0;

      break;    /* '\0' was seen by inet_pton4(). */

    }

    return 0;

  }

  if(saw_xdigit) {

    if(tp + INT16SZ > endp)

      return 0;

    *tp++ = (unsigned char)((val >> 8) & 0xff);

    *tp++ = (unsigned char)(val & 0xff);

  }

  if(colonp) {

    /*

     * Since some memmove()'s erroneously fail to handle

     * overlapping regions, we do the shift by hand.

     */

    const ssize_t n = tp - colonp;

    ssize_t i;

    if(tp == endp)

      return 0;

    for(i = 1; i <= n; i++) {

      *(endp - i) = *(colonp + n - i);

      *(colonp + n - i) = 0;

    }

    tp = endp;

  }

  if(tp != endp)

    return 0;

  memcpy(dst, tmp, IN6ADDRSZ);

  return 1;

}

/*

 * Convert from presentation format (which usually means ASCII printable)

 * to network format (which is usually some kind of binary format).

 *

 * Return:

 *   1 if the address was valid for the specified address family

 *   0 if the address was not valid (`dst' is untouched in this case)

 *  -1 if some other error occurred (`dst' is untouched in this case, too)

 *

 * On Windows we store the error in the thread errno, not in the Winsock error

 * code. This is to avoid losing the actual last Winsock error. When this

 * function returns NULL, check errno not SOCKERRNO.

 *

 * author:

 *      Paul Vixie, 1996.

 */

int curlx_inet_pton(int af, const char *src, void *dst)

{

  switch(af) {

  case AF_INET:

    return inet_pton4(src, (unsigned char *)dst);

  case AF_INET6:

    return inet_pton6(src, (unsigned char *)dst);

  default:

    errno = SOCKEAFNOSUPPORT;

    return -1;

  }

  /* NOTREACHED */

}