Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/dns/ipv6.py

@@ -0,0 +1,217 @@
+# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
+
+# Copyright (C) 2003-2017 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation 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 NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM 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.
+
+"""IPv6 helper functions."""
+
+import binascii
+import re
+from typing import List, Union
+
+import dns.exception
+import dns.ipv4
+
+_leading_zero = re.compile(r"0+([0-9a-f]+)")
+
+
+def inet_ntoa(address: bytes) -> str:
+    """Convert an IPv6 address in binary form to text form.
+
+    *address*, a ``bytes``, the IPv6 address in binary form.
+
+    Raises ``ValueError`` if the address isn't 16 bytes long.
+    Returns a ``str``.
+    """
+
+    if len(address) != 16:
+        raise ValueError("IPv6 addresses are 16 bytes long")
+    hex = binascii.hexlify(address)
+    chunks = []
+    i = 0
+    l = len(hex)
+    while i < l:
+        chunk = hex[i : i + 4].decode()
+        # strip leading zeros.  we do this with an re instead of
+        # with lstrip() because lstrip() didn't support chars until
+        # python 2.2.2
+        m = _leading_zero.match(chunk)
+        if m is not None:
+            chunk = m.group(1)
+        chunks.append(chunk)
+        i += 4
+    #
+    # Compress the longest subsequence of 0-value chunks to ::
+    #
+    best_start = 0
+    best_len = 0
+    start = -1
+    last_was_zero = False
+    for i in range(8):
+        if chunks[i] != "0":
+            if last_was_zero:
+                end = i
+                current_len = end - start
+                if current_len > best_len:
+                    best_start = start
+                    best_len = current_len
+                last_was_zero = False
+        elif not last_was_zero:
+            start = i
+            last_was_zero = True
+    if last_was_zero:
+        end = 8
+        current_len = end - start
+        if current_len > best_len:
+            best_start = start
+            best_len = current_len
+    if best_len > 1:
+        if best_start == 0 and (best_len == 6 or best_len == 5 and chunks[5] == "ffff"):
+            # We have an embedded IPv4 address
+            if best_len == 6:
+                prefix = "::"
+            else:
+                prefix = "::ffff:"
+            thex = prefix + dns.ipv4.inet_ntoa(address[12:])
+        else:
+            thex = (
+                ":".join(chunks[:best_start])
+                + "::"
+                + ":".join(chunks[best_start + best_len :])
+            )
+    else:
+        thex = ":".join(chunks)
+    return thex
+
+
+_v4_ending = re.compile(rb"(.*):(\d+\.\d+\.\d+\.\d+)$")
+_colon_colon_start = re.compile(rb"::.*")
+_colon_colon_end = re.compile(rb".*::$")
+
+
+def inet_aton(text: Union[str, bytes], ignore_scope: bool = False) -> bytes:
+    """Convert an IPv6 address in text form to binary form.
+
+    *text*, a ``str`` or ``bytes``, the IPv6 address in textual form.
+
+    *ignore_scope*, a ``bool``.  If ``True``, a scope will be ignored.
+    If ``False``, the default, it is an error for a scope to be present.
+
+    Returns a ``bytes``.
+    """
+
+    #
+    # Our aim here is not something fast; we just want something that works.
+    #
+    if not isinstance(text, bytes):
+        btext = text.encode()
+    else:
+        btext = text
+
+    if ignore_scope:
+        parts = btext.split(b"%")
+        l = len(parts)
+        if l == 2:
+            btext = parts[0]
+        elif l > 2:
+            raise dns.exception.SyntaxError
+
+    if btext == b"":
+        raise dns.exception.SyntaxError
+    elif btext.endswith(b":") and not btext.endswith(b"::"):
+        raise dns.exception.SyntaxError
+    elif btext.startswith(b":") and not btext.startswith(b"::"):
+        raise dns.exception.SyntaxError
+    elif btext == b"::":
+        btext = b"0::"
+    #
+    # Get rid of the icky dot-quad syntax if we have it.
+    #
+    m = _v4_ending.match(btext)
+    if m is not None:
+        b = dns.ipv4.inet_aton(m.group(2))
+        btext = (
+            f"{m.group(1).decode()}:{b[0]:02x}{b[1]:02x}:{b[2]:02x}{b[3]:02x}"
+        ).encode()
+    #
+    # Try to turn '::<whatever>' into ':<whatever>'; if no match try to
+    # turn '<whatever>::' into '<whatever>:'
+    #
+    m = _colon_colon_start.match(btext)
+    if m is not None:
+        btext = btext[1:]
+    else:
+        m = _colon_colon_end.match(btext)
+        if m is not None:
+            btext = btext[:-1]
+    #
+    # Now canonicalize into 8 chunks of 4 hex digits each
+    #
+    chunks = btext.split(b":")
+    l = len(chunks)
+    if l > 8:
+        raise dns.exception.SyntaxError
+    seen_empty = False
+    canonical: List[bytes] = []
+    for c in chunks:
+        if c == b"":
+            if seen_empty:
+                raise dns.exception.SyntaxError
+            seen_empty = True
+            for _ in range(0, 8 - l + 1):
+                canonical.append(b"0000")
+        else:
+            lc = len(c)
+            if lc > 4:
+                raise dns.exception.SyntaxError
+            if lc != 4:
+                c = (b"0" * (4 - lc)) + c
+            canonical.append(c)
+    if l < 8 and not seen_empty:
+        raise dns.exception.SyntaxError
+    btext = b"".join(canonical)
+
+    #
+    # Finally we can go to binary.
+    #
+    try:
+        return binascii.unhexlify(btext)
+    except (binascii.Error, TypeError):
+        raise dns.exception.SyntaxError
+
+
+_mapped_prefix = b"\x00" * 10 + b"\xff\xff"
+
+
+def is_mapped(address: bytes) -> bool:
+    """Is the specified address a mapped IPv4 address?
+
+    *address*, a ``bytes`` is an IPv6 address in binary form.
+
+    Returns a ``bool``.
+    """
+
+    return address.startswith(_mapped_prefix)
+
+
+def canonicalize(text: Union[str, bytes]) -> str:
+    """Verify that *address* is a valid text form IPv6 address and return its
+    canonical text form.  Addresses with scopes are rejected.
+
+    *text*, a ``str`` or ``bytes``, the IPv6 address in textual form.
+
+    Raises ``dns.exception.SyntaxError`` if the text is not valid.
+    """
+    return dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(text))