text: /*
   * Copyright 2017-2020 AVSystem <avsystem@avsystem.com>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /* This is from the BIND 4.9.4 release, modified to compile by itself */
  /* Modified with some AVSystem specific code */
  
  /* Copyright (c) 1996 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 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.
   */
  
  #include <avsystem/commons/avs_commons_config.h>
  
  #if defined(AVS_COMMONS_WITH_AVS_NET)                     \
          && defined(AVS_COMMONS_NET_WITH_POSIX_AVS_SOCKET) \
          && !defined(AVS_COMMONS_NET_POSIX_AVS_SOCKET_HAVE_INET_NTOP)
  
  #    include <avs_commons_posix_init.h>
  
  #    include <stdint.h>
  #    include <stdio.h>
  #    include <string.h>
  
  #    include <avsystem/commons/avs_errno.h>
  
  VISIBILITY_SOURCE_BEGIN
  
  #    if defined(LIBC_SCCS) && !defined(lint)
  static char rcsid[] = "$Id: inet_ntop.c,v 8.5 1996/05/22 04:56:30 vixie Exp $";
  #    endif /* LIBC_SCCS and not lint */
  
  #    ifndef __u_char_defined
  
  /* Type definitions for BSD code. */
  typedef unsigned long u_long;
  typedef unsigned int u_int;
  typedef unsigned short u_short;
  typedef unsigned char u_char;
  
  #    endif
  
  #    ifdef AVS_COMMONS_NET_WITH_IPV6
  #        define IN6ADDRSZ 16
  #        define INT16SZ 2
  
  #        ifndef AF_INET6
  #            define AF_INET6 (AF_MAX + 1) /* just to let this compile */
  #        endif
  #    endif /* AVS_COMMONS_NET_WITH_IPV6 */
  
  VISIBILITY_SOURCE_BEGIN
  
  /*
   * WARNING: Don't 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.
   */
  
  const char *_avs_inet_ntop(int af, const void *src, char *dst, size_t size);
  static const char *inet_ntop4(const u_char *src, char *dst, size_t size);
  #    ifdef AVS_COMMONS_NET_WITH_IPV6
  static const char *inet_ntop6(const u_char *src, char *dst, size_t size);
  #    endif /* AVS_COMMONS_NET_WITH_IPV6 */
  
  /* char *
   * inet_ntop(af, src, dst, size)
   *	convert a network format address to presentation format.
   * return:
   *	pointer to presentation format address (`dst'), or NULL (see errno).
   * author:
   *	Paul Vixie, 1996.
   */
  const char *_avs_inet_ntop(int af, const void *src, char *dst, size_t size) {
      switch (af) {
  #    ifdef AVS_COMMONS_NET_WITH_IPV4
      case AF_INET:
          return (inet_ntop4((const u_char *) src, dst, size));
  #    endif /* AVS_COMMONS_NET_WITH_IPV4 */
  #    ifdef AVS_COMMONS_NET_WITH_IPV6
      case AF_INET6:
          return (inet_ntop6((const u_char *) src, dst, size));
  #    endif /* AVS_COMMONS_NET_WITH_IPV6 */
      default:
          errno = EAFNOSUPPORT;
          return (NULL);
      }
      /* NOTREACHED */
  }
  
  /* const char *
   * inet_ntop4(src, dst, size)
   *	format an IPv4 address, more or less like inet_ntoa()
   * return:
   *	`dst' (as a const)
   * notes:
   *	(1) uses no statics
   *	(2) takes a u_char* not an in_addr as input
   * author:
   *	Paul Vixie, 1996.
   */
  static const char *inet_ntop4(const u_char *src, char *dst, size_t size) {
      static const char fmt[] = "%u.%u.%u.%u";
      char tmp[sizeof "255.255.255.255"];
  
      sprintf(tmp, fmt, src[0], src[1], src[2], src[3]);
      if (strlen(tmp) > size) {
          errno = ENOSPC;
          return (NULL);
      }
      strcpy(dst, tmp);
      return (dst);
  }
  
  #    ifdef AVS_COMMONS_NET_WITH_IPV6
  /* const char *
   * inet_ntop6(src, dst, size)
   *	convert IPv6 binary address into presentation (printable) format
   * author:
   *	Paul Vixie, 1996.
   */
  static const char *inet_ntop6(const u_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[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
      struct {
          int base, len;
      } best = { -1, -1 }, cur = { -1, -1 };
      u_int words[IN6ADDRSZ / INT16SZ];
      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 < IN6ADDRSZ; i++)
          words[i / 2] |= (u_int) (src[i] << ((1 - (i % 2)) << 3));
      for (i = 0; i < (IN6ADDRSZ / INT16SZ); 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 < (IN6ADDRSZ / INT16SZ); 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 == 5 && words[5] == 0xffff))) {
              if (!inet_ntop4(src + 12, tp, sizeof tmp - (size_t) (tp - tmp)))
                  return (NULL);
              tp += strlen(tp);
              break;
          }
          sprintf(tp, "%x", words[i]);
          tp += strlen(tp);
      }
      /* Was it a trailing run of 0x00's? */
      if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
          *tp++ = ':';
      *tp++ = '\0';
  
      /*
       * Check for overflow, copy, and we're done.
       */
      if ((size_t) (tp - tmp) > size) {
          errno = ENOSPC;
          return (NULL);
      }
      strcpy(dst, tmp);
      return (dst);
  }
  #    endif /* AVS_COMMONS_NET_WITH_IPV6 */
  
  #else
  
  typedef int translation_unit_not_empty;
  
  #endif // defined(AVS_COMMONS_WITH_AVS_NET) &&
         // defined(AVS_COMMONS_NET_WITH_POSIX_AVS_SOCKET) &&
         // !defined(AVS_COMMONS_NET_POSIX_AVS_SOCKET_HAVE_INET_NTOP)
  