1 files changed, 260 insertions, 0 deletions
diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c
new file mode 100644
index 0000000..b380da4
--- /dev/null
+++ b/lib/inet_ntop.c
@@ -0,0 +1,260 @@
+/* inet_ntop.c -- convert IPv4 and IPv6 addresses from binary to text form
+
+   Copyright (C) 2005-2006, 2008-2020 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+/*
+ * 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 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 <config.h>
+
+/* Specification.  */
+#include <arpa/inet.h>
+
+/* Use this to suppress gcc's "...may be used before initialized" warnings.
+   Beware: The Code argument must not contain commas.  */
+#ifndef IF_LINT
+# if defined GCC_LINT || defined lint
+#  define IF_LINT(Code) Code
+# else
+#  define IF_LINT(Code) /* empty */
+# endif
+#endif
+
+#if HAVE_DECL_INET_NTOP
+
+# undef inet_ntop
+
+const char *
+rpl_inet_ntop (int af, const void *restrict src,
+               char *restrict dst, socklen_t cnt)
+{
+  return inet_ntop (af, src, dst, cnt);
+}
+
+#else
+
+# include <stdio.h>
+# include <string.h>
+# include <errno.h>
+
+# define NS_IN6ADDRSZ 16
+# define NS_INT16SZ 2
+
+/*
+ * 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.
+ */
+typedef int verify_int_size[4 <= sizeof (int) ? 1 : -1];
+
+static const char *inet_ntop4 (const unsigned char *src, char *dst, socklen_t size);
+# if HAVE_IPV6
+static const char *inet_ntop6 (const unsigned char *src, char *dst, socklen_t size);
+# endif
+
+
+/* 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 *
+inet_ntop (int af, const void *restrict src,
+           char *restrict dst, socklen_t cnt)
+{
+  switch (af)
+    {
+# if HAVE_IPV4
+    case AF_INET:
+      return (inet_ntop4 (src, dst, cnt));
+# endif
+
+# if HAVE_IPV6
+    case AF_INET6:
+      return (inet_ntop6 (src, dst, cnt));
+# endif
+
+    default:
+      errno = EAFNOSUPPORT;
+      return (NULL);
+    }
+  /* NOTREACHED */
+}
+
+/* const char *
+ * inet_ntop4(src, dst, size)
+ *      format an IPv4 address
+ * 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 unsigned char *src, char *dst, socklen_t size)
+{
+  char tmp[sizeof "255.255.255.255"];
+  int len;
+
+  len = sprintf (tmp, "%u.%u.%u.%u", src[0], src[1], src[2], src[3]);
+  if (len < 0)
+    return NULL;
+
+  if (len > size)
+    {
+      errno = ENOSPC;
+      return NULL;
+    }
+
+  return strcpy (dst, tmp);
+}
+
+# if HAVE_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 unsigned char *src, char *dst, socklen_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, cur;
+  unsigned int words[NS_IN6ADDRSZ / NS_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 < NS_IN6ADDRSZ; i += 2)
+    words[i / 2] = (src[i] << 8) | src[i + 1];
+  best.base = -1;
+  cur.base = -1;
+  IF_LINT(best.len = 0);
+  IF_LINT(cur.len = 0);
+  for (i = 0; i < (NS_IN6ADDRSZ / NS_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 < (NS_IN6ADDRSZ / NS_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 - (tp - tmp)))
+            return (NULL);
+          tp += strlen (tp);
+          break;
+        }
+      {
+        int len = sprintf (tp, "%x", words[i]);
+        if (len < 0)
+          return NULL;
+        tp += len;
+      }
+    }
+  /* Was it a trailing run of 0x00's? */
+  if (best.base != -1 && (best.base + best.len) ==
+      (NS_IN6ADDRSZ / NS_INT16SZ))
+    *tp++ = ':';
+  *tp++ = '\0';
+
+  /*
+   * Check for overflow, copy, and we're done.
+   */
+  if ((socklen_t) (tp - tmp) > size)
+    {
+      errno = ENOSPC;
+      return NULL;
+    }
+
+  return strcpy (dst, tmp);
+}
+
+# endif
+
+#endif