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 */

#include <stdio.h>
#include <string.h>

#if defined(_MSC_VER) && _MSC_VER < 1600
# include "uv/stdint-msvc2008.h"
#else
# include <stdint.h>
#endif

#include "uv.h"
#include "uv-common.h"

#define UV__INET_ADDRSTRLEN         16
#define UV__INET6_ADDRSTRLEN        46


static int inet_ntop4(const unsigned char *src, char *dst, size_t size);
static int inet_ntop6(const unsigned char *src, char *dst, size_t size);
static int inet_pton4(const char *src, unsigned char *dst);
static int inet_pton6(const char *src, unsigned char *dst);


int uv_inet_ntop(int af, const void* src, char* dst, size_t size) {
  switch (af) {
  case AF_INET:
    return (inet_ntop4(src, dst, size));
  case AF_INET6:
    return (inet_ntop6(src, dst, size));
  default:
    return UV_EAFNOSUPPORT;
  }
  /* NOTREACHED */
}


static int inet_ntop4(const unsigned char *src, char *dst, size_t size) {
  static const char fmt[] = "%u.%u.%u.%u";
  char tmp[UV__INET_ADDRSTRLEN];
  int l;

  l = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]);
  if (l <= 0 || (size_t) l >= size) {
    return UV_ENOSPC;
  }
  uv__strscpy(dst, tmp, size);
  return 0;
}


static int inet_ntop6(const unsigned char *src, char *dst, size_t size) {
  /*
   * Note that int32_t and int16_t need only be "at least" large enough
   * to contain a value of the specified size.  On some systems, like
   * Crays, there is no such thing as an integer variable with 16 bits.
   * Keep this in mind if you think this function should have been coded
   * to use pointer overlays.  All the world's not a VAX.
   */
  char tmp[UV__INET6_ADDRSTRLEN], *tp;
  struct { int base, len; } best, cur;
  unsigned int words[sizeof(struct in6_addr) / sizeof(uint16_t)];
  int i;

  /*
   * Preprocess:
   *  Copy the input (bytewise) array into a wordwise array.
   *  Find the longest run of 0x00's in src[] for :: shorthanding.
   */
  memset(words, '\0', sizeof words);
  for (i = 0; i < (int) sizeof(struct in6_addr); i++)
    words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
  best.base = -1;
  best.len = 0;
  cur.base = -1;
  cur.len = 0;
  for (i = 0; i < (int) ARRAY_SIZE(words); i++) {
    if (words[i] == 0) {
      if (cur.base == -1)
        cur.base = i, cur.len = 1;
      else
        cur.len++;
    } else {
      if (cur.base != -1) {
        if (best.base == -1 || cur.len > best.len)
          best = cur;
        cur.base = -1;
      }
    }
  }
  if (cur.base != -1) {
    if (best.base == -1 || cur.len > best.len)
      best = cur;
  }
  if (best.base != -1 && best.len < 2)
    best.base = -1;

  /*
   * Format the result.
   */
  tp = tmp;
  for (i = 0; i < (int) ARRAY_SIZE(words); i++) {
    /* Are we inside the best run of 0x00's? */
    if (best.base != -1 && i >= best.base &&
        i < (best.base + best.len)) {
      if (i == best.base)
        *tp++ = ':';
      continue;
    }
    /* Are we following an initial run of 0x00s or any real hex? */
    if (i != 0)
      *tp++ = ':';
    /* Is this address an encapsulated IPv4? */
    if (i == 6 && best.base == 0 && (best.len == 6 ||
        (best.len == 7 && words[7] != 0x0001) ||
        (best.len == 5 && words[5] == 0xffff))) {
      int err = inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp));
      if (err)
        return err;
      tp += strlen(tp);
      break;
    }
    tp += sprintf(tp, "%x", words[i]);
  }
  /* Was it a trailing run of 0x00's? */
  if (best.base != -1 && (best.base + best.len) == ARRAY_SIZE(words))
    *tp++ = ':';
  *tp++ = '\0';
  if (UV_E2BIG == uv__strscpy(dst, tmp, size))
    return UV_ENOSPC;
  return 0;
}


int uv_inet_pton(int af, const char* src, void* dst) {
  if (src == NULL || dst == NULL)
    return UV_EINVAL;

  switch (af) {
  case AF_INET:
    return (inet_pton4(src, dst));
  case AF_INET6: {
    int len;
    char tmp[UV__INET6_ADDRSTRLEN], *s, *p;
    s = (char*) src;
    p = strchr(src, '%');
    if (p != NULL) {
      s = tmp;
      len = p - src;
      if (len > UV__INET6_ADDRSTRLEN-1)
        return UV_EINVAL;
      memcpy(s, src, len);
      s[len] = '\0';
    }
    return inet_pton6(s, dst);
  }
  default:
    return UV_EAFNOSUPPORT;
  }
  /* NOTREACHED */
}


static int inet_pton4(const char *src, unsigned char *dst) {
  static const char digits[] = "0123456789";
  int saw_digit, octets, ch;
  unsigned char tmp[sizeof(struct in_addr)], *tp;

  saw_digit = 0;
  octets = 0;
  *(tp = tmp) = 0;
  while ((ch = *src++) != '\0') {
    const char *pch;

    if ((pch = strchr(digits, ch)) != NULL) {
      unsigned int nw = *tp * 10 + (pch - digits);

      if (saw_digit && *tp == 0)
        return UV_EINVAL;
      if (nw > 255)
        return UV_EINVAL;
      *tp = nw;
      if (!saw_digit) {
        if (++octets > 4)
          return UV_EINVAL;
        saw_digit = 1;