/*

 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")

 * Copyright (c) 1996,1999 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 "ares_setup.h"

#ifdef HAVE_NETINET_IN_H

#  include <netinet/in.h>

#endif

#ifdef HAVE_ARPA_INET_H

#  include <arpa/inet.h>

#endif

#ifdef HAVE_ARPA_NAMESER_H

#  include <arpa/nameser.h>

#else

#  include "nameser.h"

#endif

#ifdef HAVE_ARPA_NAMESER_COMPAT_H

#  include <arpa/nameser_compat.h>

#endif

#include "ares.h"

#include "ares_ipv6.h"

#include "ares_nowarn.h"

#include "ares_inet_net_pton.h"

const struct ares_in6_addr ares_in6addr_any = { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };

#ifndef HAVE_INET_NET_PTON

/*

 * static int

 * inet_net_pton_ipv4(src, dst, size)

 *      convert IPv4 network number from presentation to network format.

 *      accepts hex octets, hex strings, decimal octets, and /CIDR.

 *      "size" is in bytes and describes "dst".

 * return:

 *      number of bits, either imputed classfully or specified with /CIDR,

 *      or -1 if some failure occurred (check errno).  ENOENT means it was

 *      not an IPv4 network specification.

 * note:

 *      network byte order assumed.  this means 192.5.5.240/28 has

 *      0b11110000 in its fourth octet.

 * note:

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

 *      in the winsock error code. This is to avoid loosing the

 *      actual last winsock error. So use macro ERRNO to fetch the

 *      errno this funtion sets when returning (-1), not SOCKERRNO.

 * author:

 *      Paul Vixie (ISC), June 1996

 */

static int

inet_net_pton_ipv4(const char *src, unsigned char *dst, size_t size)

{

  static const char xdigits[] = "0123456789abcdef";

  static const char digits[] = "0123456789";

  int n, ch, tmp = 0, dirty, bits;

  const unsigned char *odst = dst;

  ch = *src++;

  if (ch == '0' && (src[0] == 'x' || src[0] == 'X')

      && ISASCII(src[1])

      && ISXDIGIT(src[1])) {

    /* Hexadecimal: Eat nybble string. */

    if (!size)

      goto emsgsize;

    dirty = 0;

    src++;  /* skip x or X. */

    while ((ch = *src++) != '\0' && ISASCII(ch) && ISXDIGIT(ch)) {

      if (ISUPPER(ch))

        ch = tolower(ch);

      n = aresx_sztosi(strchr(xdigits, ch) - xdigits);

      if (dirty == 0)

        tmp = n;

      else

        tmp = (tmp << 4) | n;

      if (++dirty == 2) {

        if (!size--)

          goto emsgsize;

        *dst++ = (unsigned char) tmp;

        dirty = 0;

      }

    }

    if (dirty) {  /* Odd trailing nybble? */

      if (!size--)

        goto emsgsize;

      *dst++ = (unsigned char) (tmp << 4);

    }

  } else if (ISASCII(ch) && ISDIGIT(ch)) {

    /* Decimal: eat dotted digit string. */

    for (;;) {

      tmp = 0;

      do {

        n = aresx_sztosi(strchr(digits, ch) - digits);

        tmp *= 10;

        tmp += n;

        if (tmp > 255)

          goto enoent;

      } while ((ch = *src++) != '\0' &&

               ISASCII(ch) && ISDIGIT(ch));

      if (!size--)

        goto emsgsize;

      *dst++ = (unsigned char) tmp;

      if (ch == '\0' || ch == '/')

        break;

      if (ch != '.')

        goto enoent;

      ch = *src++;

      if (!ISASCII(ch) || !ISDIGIT(ch))

        goto enoent;

    }

  } else

    goto enoent;

  bits = -1;

  if (ch == '/' && ISASCII(src[0]) &&

      ISDIGIT(src[0]) && dst > odst) {

    /* CIDR width specifier.  Nothing can follow it. */

    ch = *src++;    /* Skip over the /. */

    bits = 0;

    do {

      n = aresx_sztosi(strchr(digits, ch) - digits);

      bits *= 10;

      bits += n;

      if (bits > 32)

        goto enoent;

    } while ((ch = *src++) != '\0' && ISASCII(ch) && ISDIGIT(ch));

    if (ch != '\0')

      goto enoent;

  }

  /* Firey death and destruction unless we prefetched EOS. */

  if (ch != '\0')

    goto enoent;

  /* If nothing was written to the destination, we found no address. */

  if (dst == odst)

    goto enoent;  /* LCOV_EXCL_LINE: all valid paths above increment dst */

  /* If no CIDR spec was given, infer width from net class. */

  if (bits == -1) {

    if (*odst >= 240)       /* Class E */

      bits = 32;

    else if (*odst >= 224)  /* Class D */

      bits = 8;

    else if (*odst >= 192)  /* Class C */

      bits = 24;

    else if (*odst >= 128)  /* Class B */

      bits = 16;

    else                    /* Class A */

      bits = 8;

    /* If imputed mask is narrower than specified octets, widen. */

    if (bits < ((dst - odst) * 8))

      bits = aresx_sztosi(dst - odst) * 8;

    /*

     * If there are no additional bits specified for a class D

     * address adjust bits to 4.

     */

    if (bits == 8 && *odst == 224)

      bits = 4;

  }

  /* Extend network to cover the actual mask. */

  while (bits > ((dst - odst) * 8)) {

    if (!size--)

      goto emsgsize;

    *dst++ = '\0';

  }

  return (bits);

  enoent:

  SET_ERRNO(ENOENT);

  return (-1);

  emsgsize:

  SET_ERRNO(EMSGSIZE);

  return (-1);

}

static int

getbits(const char *src, int *bitsp)

{

  static const char digits[] = "0123456789";

  int n;

  int val;

  char ch;

  val = 0;

  n = 0;

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

    const char *pch;

    pch = strchr(digits, ch);

    if (pch != NULL) {

      if (n++ != 0 && val == 0)       /* no leading zeros */

        return (0);

      val *= 10;

      val += aresx_sztosi(pch - digits);

      if (val > 128)                  /* range */

        return (0);

      continue;

    }

    return (0);

  }

  if (n == 0)

    return (0);

  *bitsp = val;

  return (1);

}

static int

getv4(const char *src, unsigned char *dst, int *bitsp)

{

  static const char digits[] = "0123456789";

  unsigned char *odst = dst;

  int n;

  unsigned int val;

  char ch;

  val = 0;

  n = 0;

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

    const char *pch;

    pch = strchr(digits, ch);

    if (pch != NULL) {

      if (n++ != 0 && val == 0)       /* no leading zeros */

        return (0);

      val *= 10;

      val += aresx_sztoui(pch - digits);

      if (val > 255)                  /* range */

        return (0);

      continue;

    }

    if (ch == '.' || ch == '/') {

      if (dst - odst > 3)             /* too many octets? */

        return (0);

      *dst++ = (unsigned char)val;

      if (ch == '/')

        return (getbits(src, bitsp));

      val = 0;

      n = 0;

      continue;

    }

    return (0);

  }

  if (n == 0)

    return (0);

  if (dst - odst > 3)             /* too many octets? */

    return (0);

  *dst = (unsigned char)val;

  return 1;

}

static int

inet_net_pton_ipv6(const char *src, unsigned char *dst, size_t size)

{

  static const char xdigits_l[] = "0123456789abcdef",

    xdigits_u[] = "0123456789ABCDEF";

  unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;

  const char *xdigits, *curtok;

  int ch, saw_xdigit;

  unsigned int val;

  int digits;

  int bits;

  size_t bytes;

  int words;

  int ipv4;

  memset((tp = tmp), '\0', NS_IN6ADDRSZ);

  endp = tp + NS_IN6ADDRSZ;

  colonp = NULL;

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

  if (*src == ':')

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

      goto enoent;

  curtok = src;

  saw_xdigit = 0;

  val = 0;

  digits = 0;

  bits = -1;

  ipv4 = 0;

  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 |= aresx_sztoui(pch - xdigits);

      if (++digits > 4)

        goto enoent;

      saw_xdigit = 1;

      continue;

    }

    if (ch == ':') {

      curtok = src;

      if (!saw_xdigit) {

        if (colonp)

          goto enoent;

        colonp = tp;

        continue;

      } else if (*src == '\0')

        goto enoent;

      if (tp + NS_INT16SZ > endp)

        return (0);

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

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

      saw_xdigit = 0;

      digits = 0;

      val = 0;

      continue;

    }

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

        getv4(curtok, tp, &bits) > 0) {

      tp += NS_INADDRSZ;

      saw_xdigit = 0;

      ipv4 = 1;

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

    }

    if (ch == '/' && getbits(src, &bits) > 0)

      break;

    goto enoent;

  }

  if (saw_xdigit) {

    if (tp + NS_INT16SZ > endp)

      goto enoent;

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

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

  }

  if (bits == -1)

    bits = 128;

  words = (bits + 15) / 16;

  if (words < 2)

    words = 2;

  if (ipv4)

    words = 8;

  endp =  tmp + 2 * words;

  if (colonp != NULL) {

    /*

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

     * overlapping regions, we'll do the shift by hand.

     */

    const ares_ssize_t n = tp - colonp;

    ares_ssize_t i;

    if (tp == endp)

      goto enoent;

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

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

      *(colonp + n - i) = 0;

    }

    tp = endp;

  }

  if (tp != endp)

    goto enoent;

  bytes = (bits + 7) / 8;

  if (bytes > size)

    goto emsgsize;

  memcpy(dst, tmp, bytes);

  return (bits);

  enoent:

  SET_ERRNO(ENOENT);

  return (-1);

  emsgsize:

  SET_ERRNO(EMSGSIZE);

  return (-1);

}

/*

 * int

 * inet_net_pton(af, src, dst, size)

 *      convert network number from presentation to network format.

 *      accepts hex octets, hex strings, decimal octets, and /CIDR.

 *      "size" is in bytes and describes "dst".

 * return:

 *      number of bits, either imputed classfully or specified with /CIDR,

 *      or -1 if some failure occurred (check errno).  ENOENT means it was

 *      not a valid network specification.

 * note:

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

 *      in the winsock error code. This is to avoid loosing the

 *      actual last winsock error. So use macro ERRNO to fetch the

 *      errno this funtion sets when returning (-1), not SOCKERRNO.

 * author:

 *      Paul Vixie (ISC), June 1996

 */

int

ares_inet_net_pton(int af, const char *src, void *dst, size_t size)

{

  switch (af) {

  case AF_INET:

    return (inet_net_pton_ipv4(src, dst, size));

  case AF_INET6:

    return (inet_net_pton_ipv6(src, dst, size));

  default:

    SET_ERRNO(EAFNOSUPPORT);

    return (-1);

  }

}

#endif /* HAVE_INET_NET_PTON */

#ifndef HAVE_INET_PTON

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

{

  int result;

  size_t size;

  if (af == AF_INET)

    size = sizeof(struct in_addr);

  else if (af == AF_INET6)

    size = sizeof(struct ares_in6_addr);

  else

  {

    SET_ERRNO(EAFNOSUPPORT);

    return -1;

  }

  result = ares_inet_net_pton(af, src, dst, size);

  if (result == -1 && ERRNO == ENOENT)

    return 0;

  return (result > -1 ? 1 : -1);

}

#else /* HAVE_INET_PTON */

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

{

  /* just relay this to the underlying function */

  return inet_pton(af, src, dst);

}

#endif