RAHHH

backend/lib/python3.12/site-packages/twisted/protocols/haproxy/_v1parser.py

@@ -0,0 +1,142 @@
+# -*- test-case-name: twisted.protocols.haproxy.test.test_v1parser -*-
+
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+IProxyParser implementation for version one of the PROXY protocol.
+"""
+from typing import Tuple, Union
+
+from zope.interface import implementer
+
+from twisted.internet import address
+from . import _info, _interfaces
+from ._exceptions import (
+    InvalidNetworkProtocol,
+    InvalidProxyHeader,
+    MissingAddressData,
+    convertError,
+)
+
+
+@implementer(_interfaces.IProxyParser)
+class V1Parser:
+    """
+    PROXY protocol version one header parser.
+
+    Version one of the PROXY protocol is a human readable format represented
+    by a single, newline delimited binary string that contains all of the
+    relevant source and destination data.
+    """
+
+    PROXYSTR = b"PROXY"
+    UNKNOWN_PROTO = b"UNKNOWN"
+    TCP4_PROTO = b"TCP4"
+    TCP6_PROTO = b"TCP6"
+    ALLOWED_NET_PROTOS = (
+        TCP4_PROTO,
+        TCP6_PROTO,
+        UNKNOWN_PROTO,
+    )
+    NEWLINE = b"\r\n"
+
+    def __init__(self) -> None:
+        self.buffer = b""
+
+    def feed(
+        self, data: bytes
+    ) -> Union[Tuple[_info.ProxyInfo, bytes], Tuple[None, None]]:
+        """
+        Consume a chunk of data and attempt to parse it.
+
+        @param data: A bytestring.
+        @type data: L{bytes}
+
+        @return: A two-tuple containing, in order, a
+            L{_interfaces.IProxyInfo} and any bytes fed to the
+            parser that followed the end of the header.  Both of these values
+            are None until a complete header is parsed.
+
+        @raises InvalidProxyHeader: If the bytes fed to the parser create an
+            invalid PROXY header.
+        """
+        self.buffer += data
+        if len(self.buffer) > 107 and self.NEWLINE not in self.buffer:
+            raise InvalidProxyHeader()
+        lines = (self.buffer).split(self.NEWLINE, 1)
+        if not len(lines) > 1:
+            return (None, None)
+        self.buffer = b""
+        remaining = lines.pop()
+        header = lines.pop()
+        info = self.parse(header)
+        return (info, remaining)
+
+    @classmethod
+    def parse(cls, line: bytes) -> _info.ProxyInfo:
+        """
+        Parse a bytestring as a full PROXY protocol header line.
+
+        @param line: A bytestring that represents a valid HAProxy PROXY
+            protocol header line.
+        @type line: bytes
+
+        @return: A L{_interfaces.IProxyInfo} containing the parsed data.
+
+        @raises InvalidProxyHeader: If the bytestring does not represent a
+            valid PROXY header.
+
+        @raises InvalidNetworkProtocol: When no protocol can be parsed or is
+            not one of the allowed values.
+
+        @raises MissingAddressData: When the protocol is TCP* but the header
+            does not contain a complete set of addresses and ports.
+        """
+        originalLine = line
+        proxyStr = None
+        networkProtocol = None
+        sourceAddr = None
+        sourcePort = None
+        destAddr = None
+        destPort = None
+
+        with convertError(ValueError, InvalidProxyHeader):
+            proxyStr, line = line.split(b" ", 1)
+
+        if proxyStr != cls.PROXYSTR:
+            raise InvalidProxyHeader()
+
+        with convertError(ValueError, InvalidNetworkProtocol):
+            networkProtocol, line = line.split(b" ", 1)
+
+        if networkProtocol not in cls.ALLOWED_NET_PROTOS:
+            raise InvalidNetworkProtocol()
+
+        if networkProtocol == cls.UNKNOWN_PROTO:
+            return _info.ProxyInfo(originalLine, None, None)
+
+        with convertError(ValueError, MissingAddressData):
+            sourceAddr, line = line.split(b" ", 1)
+
+        with convertError(ValueError, MissingAddressData):
+            destAddr, line = line.split(b" ", 1)
+
+        with convertError(ValueError, MissingAddressData):
+            sourcePort, line = line.split(b" ", 1)
+
+        with convertError(ValueError, MissingAddressData):
+            destPort = line.split(b" ")[0]
+
+        if networkProtocol == cls.TCP4_PROTO:
+            return _info.ProxyInfo(
+                originalLine,
+                address.IPv4Address("TCP", sourceAddr.decode(), int(sourcePort)),
+                address.IPv4Address("TCP", destAddr.decode(), int(destPort)),
+            )
+
+        return _info.ProxyInfo(
+            originalLine,
+            address.IPv6Address("TCP", sourceAddr.decode(), int(sourcePort)),
+            address.IPv6Address("TCP", destAddr.decode(), int(destPort)),
+        )