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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 17:35:20 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 17:35:20 +0000 |
commit | e106bf94eff07d9a59771d9ccc4406421e18ab64 (patch) | |
tree | edb6545500e39df9c67aa918a6125bffc8ec1aee /src/prompt_toolkit/contrib/telnet/protocol.py | |
parent | Initial commit. (diff) | |
download | prompt-toolkit-e106bf94eff07d9a59771d9ccc4406421e18ab64.tar.xz prompt-toolkit-e106bf94eff07d9a59771d9ccc4406421e18ab64.zip |
Adding upstream version 3.0.36.upstream/3.0.36upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/prompt_toolkit/contrib/telnet/protocol.py')
-rw-r--r-- | src/prompt_toolkit/contrib/telnet/protocol.py | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/prompt_toolkit/contrib/telnet/protocol.py b/src/prompt_toolkit/contrib/telnet/protocol.py new file mode 100644 index 0000000..68f3639 --- /dev/null +++ b/src/prompt_toolkit/contrib/telnet/protocol.py @@ -0,0 +1,207 @@ +""" +Parser for the Telnet protocol. (Not a complete implementation of the telnet +specification, but sufficient for a command line interface.) + +Inspired by `Twisted.conch.telnet`. +""" +import struct +from typing import Callable, Generator + +from .log import logger + +__all__ = [ + "TelnetProtocolParser", +] + + +def int2byte(number: int) -> bytes: + return bytes((number,)) + + +# Telnet constants. +NOP = int2byte(0) +SGA = int2byte(3) + +IAC = int2byte(255) +DO = int2byte(253) +DONT = int2byte(254) +LINEMODE = int2byte(34) +SB = int2byte(250) +WILL = int2byte(251) +WONT = int2byte(252) +MODE = int2byte(1) +SE = int2byte(240) +ECHO = int2byte(1) +NAWS = int2byte(31) +LINEMODE = int2byte(34) +SUPPRESS_GO_AHEAD = int2byte(3) + +TTYPE = int2byte(24) +SEND = int2byte(1) +IS = int2byte(0) + +DM = int2byte(242) +BRK = int2byte(243) +IP = int2byte(244) +AO = int2byte(245) +AYT = int2byte(246) +EC = int2byte(247) +EL = int2byte(248) +GA = int2byte(249) + + +class TelnetProtocolParser: + """ + Parser for the Telnet protocol. + Usage:: + + def data_received(data): + print(data) + + def size_received(rows, columns): + print(rows, columns) + + p = TelnetProtocolParser(data_received, size_received) + p.feed(binary_data) + """ + + def __init__( + self, + data_received_callback: Callable[[bytes], None], + size_received_callback: Callable[[int, int], None], + ttype_received_callback: Callable[[str], None], + ) -> None: + + self.data_received_callback = data_received_callback + self.size_received_callback = size_received_callback + self.ttype_received_callback = ttype_received_callback + + self._parser = self._parse_coroutine() + self._parser.send(None) # type: ignore + + def received_data(self, data: bytes) -> None: + self.data_received_callback(data) + + def do_received(self, data: bytes) -> None: + """Received telnet DO command.""" + logger.info("DO %r", data) + + def dont_received(self, data: bytes) -> None: + """Received telnet DONT command.""" + logger.info("DONT %r", data) + + def will_received(self, data: bytes) -> None: + """Received telnet WILL command.""" + logger.info("WILL %r", data) + + def wont_received(self, data: bytes) -> None: + """Received telnet WONT command.""" + logger.info("WONT %r", data) + + def command_received(self, command: bytes, data: bytes) -> None: + if command == DO: + self.do_received(data) + + elif command == DONT: + self.dont_received(data) + + elif command == WILL: + self.will_received(data) + + elif command == WONT: + self.wont_received(data) + + else: + logger.info("command received %r %r", command, data) + + def naws(self, data: bytes) -> None: + """ + Received NAWS. (Window dimensions.) + """ + if len(data) == 4: + # NOTE: the first parameter of struct.unpack should be + # a 'str' object. Both on Py2/py3. This crashes on OSX + # otherwise. + columns, rows = struct.unpack("!HH", data) + self.size_received_callback(rows, columns) + else: + logger.warning("Wrong number of NAWS bytes") + + def ttype(self, data: bytes) -> None: + """ + Received terminal type. + """ + subcmd, data = data[0:1], data[1:] + if subcmd == IS: + ttype = data.decode("ascii") + self.ttype_received_callback(ttype) + else: + logger.warning("Received a non-IS terminal type Subnegotiation") + + def negotiate(self, data: bytes) -> None: + """ + Got negotiate data. + """ + command, payload = data[0:1], data[1:] + + if command == NAWS: + self.naws(payload) + elif command == TTYPE: + self.ttype(payload) + else: + logger.info("Negotiate (%r got bytes)", len(data)) + + def _parse_coroutine(self) -> Generator[None, bytes, None]: + """ + Parser state machine. + Every 'yield' expression returns the next byte. + """ + while True: + d = yield + + if d == int2byte(0): + pass # NOP + + # Go to state escaped. + elif d == IAC: + d2 = yield + + if d2 == IAC: + self.received_data(d2) + + # Handle simple commands. + elif d2 in (NOP, DM, BRK, IP, AO, AYT, EC, EL, GA): + self.command_received(d2, b"") + + # Handle IAC-[DO/DONT/WILL/WONT] commands. + elif d2 in (DO, DONT, WILL, WONT): + d3 = yield + self.command_received(d2, d3) + + # Subnegotiation + elif d2 == SB: + # Consume everything until next IAC-SE + data = [] + + while True: + d3 = yield + + if d3 == IAC: + d4 = yield + if d4 == SE: + break + else: + data.append(d4) + else: + data.append(d3) + + self.negotiate(b"".join(data)) + else: + self.received_data(d) + + def feed(self, data: bytes) -> None: + """ + Feed data to the parser. + """ + for b in data: + self._parser.send(int2byte(b)) |