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#!/usr/bin/env python3
import json
import os
import socket
import struct
def string(value):
data = value.encode() if isinstance(value, str) else value
return struct.pack('<H', len(data)) + data
class Client:
def __init__(self, address, timeout=5, msize=8192):
tcp = isinstance(address, tuple)
family = (socket.AF_INET6 if ':' in address[0] else socket.AF_INET) if tcp else socket.AF_UNIX
self.socket = socket.socket(family)
self.socket.settimeout(timeout)
if tcp:
self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
self.tag = 0
self.fid = 1
self.msize = msize
try:
self.socket.connect(address if tcp else os.fspath(address))
reply = self.rpc(100, struct.pack('<I', self.msize) + string('9P2000'), tag=65535)
self.msize = min(self.msize, struct.unpack_from('<I', reply)[0])
if self.msize < 256 or reply[4:] != string('9P2000'):
raise OSError('unsupported 9P version or message size')
attached = self.rpc(104, struct.pack('<II', 1, 0xffffffff) + string('pardes') + string(''))
if len(attached) != 13:
raise OSError('invalid attach qid')
except BaseException:
self.socket.close()
raise
def __enter__(self):
return self
def __exit__(self, *args):
self.socket.close()
def receive(self, count):
data = bytearray()
while len(data) < count:
chunk = self.socket.recv(count - len(data))
if not chunk:
raise EOFError('9P peer closed the connection')
data.extend(chunk)
return bytes(data)
def rpc(self, kind, payload, tag=None):
if tag is None:
self.tag = (self.tag + 1) % 65535
tag = self.tag
packet = struct.pack('<IBH', 7 + len(payload), kind, tag) + payload
if len(packet) > self.msize:
raise ValueError('request exceeds negotiated message size')
self.socket.sendall(packet)
size, answer, received_tag = struct.unpack('<IBH', self.receive(7))
if not 7 <= size <= self.msize or received_tag != tag:
raise OSError('invalid 9P reply header')
reply = self.receive(size - 7)
if answer == 107:
length = struct.unpack_from('<H', reply)[0]
raise OSError(reply[2:2 + length].decode(errors='replace'))
if answer != kind + 1:
raise OSError(f'expected reply {kind + 1}, received {answer}')
return reply
def open(self, path, mode=0):
names = [part for part in os.fspath(path).split('/') if part]
self.fid += 1
fid = self.fid
oldfid = 1
try:
for start in range(0, max(1, len(names)), 16):
part = names[start:start + 16]
reply = self.rpc(110, struct.pack('<IIH', oldfid, fid, len(part)) +
b''.join(string(name) for name in part))
walked = struct.unpack_from('<H', reply)[0]
if len(reply) != 2 + 13 * walked:
raise OSError('invalid walk qids')
if walked != len(part):
raise FileNotFoundError(path)
oldfid = fid
if len(self.rpc(112, struct.pack('<IB', fid, mode))) != 17:
raise OSError('invalid open reply')
return fid
except BaseException:
try:
self.close(fid)
except OSError:
pass
raise
def close(self, fid):
self.rpc(120, struct.pack('<I', fid))
def read_fid(self, fid, offset=0, count=None):
count = min(count if count is not None else self.msize - 11, self.msize - 11)
reply = self.rpc(116, struct.pack('<IQI', fid, offset, count))
size = struct.unpack_from('<I', reply)[0]
if size != len(reply) - 4 or size > count:
raise OSError('invalid 9P read length')
return reply[4:]
def read(self, path):
fid = self.open(path)
try:
data = bytearray()
while chunk := self.read_fid(fid, len(data)):
data.extend(chunk)
return bytes(data)
finally:
self.close(fid)
def screen(self):
return json.loads(self.read('/self/screen'))
def write(self, path, data, truncate=False):
fid = self.open(path, 1 | (16 if truncate else 0))
try:
offset = 0
while offset < len(data):
chunk = data[offset:offset + self.msize - 23]
reply = self.rpc(118, struct.pack('<IQI', fid, offset, len(chunk)) + chunk)
count = struct.unpack('<I', reply)[0]
if not 0 < count <= len(chunk):
raise OSError('invalid 9P write length')
offset += count
finally:
self.close(fid)
def list(self, path='/'):
data = self.read(path)
names = []
offset = 0
while offset < len(data):
size = struct.unpack_from('<H', data, offset)[0]
if size < 47 or offset + size + 2 > len(data):
raise OSError('invalid 9P directory entry')
length = struct.unpack_from('<H', data, offset + 41)[0]
if 43 + length > size + 2:
raise OSError('invalid directory name length')
names.append(data[offset + 43:offset + 43 + length].decode())
offset += size + 2
return names
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