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mirror of https://github.com/xcat2/confluent.git synced 2024-11-23 01:53:28 +00:00
confluent/confluent_client/confluent/tlvdata.py
Jarrod Johnson 83d92ecfcc Make file descriptor passing python2 friendly
python 2 did not have recvmsg/sendmsg,
so have to use ctypes to access
them through the c library.
2021-02-26 16:17:43 -05:00

258 lines
8.6 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2014 IBM Corporation
# Copyright 2015 Lenovo
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import array
import ctypes
import ctypes.util
import confluent.tlv as tlv
import eventlet.green.socket as socket
import eventlet.green.select as select
from datetime import datetime
import json
import os
import struct
try:
unicode
except NameError:
unicode = str
try:
range = xrange
except NameError:
pass
class iovec(ctypes.Structure): # from uio.h
_fields_ = [('iov_base', ctypes.c_void_p),
('iov_len', ctypes.c_size_t)]
iovec_ptr = ctypes.POINTER(iovec)
class cmsghdr(ctypes.Structure): # also from bits/socket.h
_fields_ = [('cmsg_len', ctypes.c_size_t),
('cmsg_level', ctypes.c_int),
('cmsg_type', ctypes.c_int)]
@classmethod
def init_data(cls, cmsg_len, cmsg_level, cmsg_type, cmsg_data):
Data = ctypes.c_ubyte * ctypes.sizeof(cmsg_data)
class _flexhdr(ctypes.Structure):
_fields_ = cls._fields_ + [('cmsg_data', Data)]
datab = Data(*bytearray(cmsg_data))
return _flexhdr(cmsg_len=cmsg_len, cmsg_level=cmsg_level,
cmsg_type=cmsg_type, cmsg_data=datab)
def CMSG_LEN(length):
sizeof_cmshdr = ctypes.sizeof(cmsghdr)
return ctypes.c_size_t(CMSG_ALIGN(sizeof_cmshdr).value + length)
SCM_RIGHTS = 1
class msghdr(ctypes.Structure): # from bits/socket.h
_fields_ = [('msg_name', ctypes.c_void_p),
('msg_namelen', ctypes.c_uint),
('msg_iov', ctypes.POINTER(iovec)),
('msg_iovlen', ctypes.c_size_t),
('msg_control', ctypes.c_void_p),
('msg_controllen', ctypes.c_size_t),
('msg_flags', ctypes.c_int)]
def CMSG_ALIGN(length): # bits/socket.h
ret = (length + ctypes.sizeof(ctypes.c_size_t) - 1
& ~(ctypes.sizeof(ctypes.c_size_t) - 1))
return ctypes.c_size_t(ret)
def CMSG_SPACE(length): # bits/socket.h
ret = CMSG_ALIGN(length).value + CMSG_ALIGN(ctypes.sizeof(cmsghdr)).value
return ctypes.c_size_t(ret)
class ClientFile(object):
def __init__(self, name, mode, fd):
self.fileobject = os.fdopen(fd, mode)
self.filename = name
libc = ctypes.CDLL(ctypes.util.find_library('c'))
recvmsg = libc.recvmsg
recvmsg.argtypes = [ctypes.c_int, ctypes.POINTER(msghdr), ctypes.c_int]
recvmsg.restype = ctypes.c_int
sendmsg = libc.sendmsg
sendmsg.argtypes = [ctypes.c_int, ctypes.POINTER(msghdr), ctypes.c_int]
sendmsg.restype = ctypes.c_size_t
def decodestr(value):
ret = None
try:
ret = value.decode('utf-8')
except UnicodeDecodeError:
try:
ret = value.decode('cp437')
except UnicodeDecodeError:
ret = value
except AttributeError:
return value
return ret
def unicode_dictvalues(dictdata):
for key in dictdata:
if isinstance(dictdata[key], bytes):
dictdata[key] = decodestr(dictdata[key])
elif isinstance(dictdata[key], datetime):
dictdata[key] = dictdata[key].strftime('%Y-%m-%dT%H:%M:%S')
elif isinstance(dictdata[key], list):
_unicode_list(dictdata[key])
elif isinstance(dictdata[key], dict):
unicode_dictvalues(dictdata[key])
def _unicode_list(currlist):
for i in range(len(currlist)):
if isinstance(currlist[i], str):
currlist[i] = decodestr(currlist[i])
elif isinstance(currlist[i], dict):
unicode_dictvalues(currlist[i])
elif isinstance(currlist[i], list):
_unicode_list(currlist[i])
def send(handle, data, filehandle=None):
if isinstance(data, unicode):
try:
data = data.encode('utf-8')
except AttributeError:
pass
if isinstance(data, bytes) or isinstance(data, unicode):
# plain text, e.g. console data
tl = len(data)
if tl == 0:
# if you don't have anything to say, don't say anything at all
return
if tl < 16777216:
# type for string is '0', so we don't need
# to xor anything in
handle.sendall(struct.pack("!I", tl))
else:
raise Exception("String data length exceeds protocol")
handle.sendall(data)
elif isinstance(data, dict): # JSON currently only goes to 4 bytes
# Some structured message, like what would be seen in http responses
unicode_dictvalues(data) # make everything unicode, assuming UTF-8
sdata = json.dumps(data, ensure_ascii=False, separators=(',', ':'))
sdata = sdata.encode('utf-8')
tl = len(sdata)
if tl > 16777215:
raise Exception("JSON data exceeds protocol limits")
# xor in the type (0b1 << 24)
if filehandle is None:
tl |= 16777216
handle.sendall(struct.pack("!I", tl))
handle.sendall(sdata)
else:
tl |= (2 << 24)
handle.sendall(struct.pack("!I", tl))
cdtype = ctypes.c_ubyte * len(sdata)
cdata = cdtype.from_buffer(bytearray(sdata))
ciov = iovec(iov_base=ctypes.addressof(cdata),
iov_len=ctypes.c_size_t(ctypes.sizeof(cdata)))
fd = ctypes.c_int(filehandle)
cmh = cmsghdr.init_data(
cmsg_len=CMSG_LEN(
ctypes.sizeof(fd)), cmsg_level=socket.SOL_SOCKET,
cmsg_type=SCM_RIGHTS, cmsg_data=fd)
mh = msghdr(msg_name=None, msg_len=0, msg_iov=iovec_ptr(ciov),
msg_iovlen=1, msg_control=ctypes.addressof(cmh),
msg_controllen=ctypes.c_size_t(ctypes.sizeof(cmh)))
sendmsg(handle.fileno(), mh, 0)
def recvall(handle, size):
rd = handle.recv(size)
while len(rd) < size:
nd = handle.recv(size - len(rd))
if not nd:
raise Exception("Error reading data")
rd += nd
return rd
def recv(handle):
tl = handle.recv(4)
if not tl:
return None
while len(tl) < 4:
ndata = handle.recv(4 - len(tl))
if not ndata:
raise Exception("Error reading data")
tl += ndata
if len(tl) == 0:
return None
tl = struct.unpack("!I", tl)[0]
if tl & 0b10000000000000000000000000000000:
raise Exception("Protocol Violation, reserved bit set")
# 4 byte tlv
dlen = tl & 16777215 # grab lower 24 bits
datatype = (tl & 2130706432) >> 24 # grab 7 bits from near beginning
if dlen == 0:
return None
if datatype == tlv.Types.filehandle:
filehandles = array.array('i')
rawbuffer = bytearray(2048)
pkttype = ctypes.c_ubyte * 2048
data = pkttype.from_buffer(rawbuffer)
cmsgsize = CMSG_SPACE(ctypes.sizeof(ctypes.c_int)).value
cmsgarr = bytearray(cmsgsize)
cmtype = ctypes.c_ubyte * cmsgsize
cmsg = cmtype.from_buffer(cmsgarr)
cmsg.cmsg_level = socket.SOL_SOCKET
cmsg.cmsg_type = SCM_RIGHTS
cmsg.cmsg_len = CMSG_LEN(ctypes.sizeof(ctypes.c_int))
iov = iovec()
iov.iov_base = ctypes.addressof(data)
iov.iov_len = 2048
msg = msghdr()
msg.msg_iov = ctypes.pointer(iov)
msg.msg_iovlen = 1
msg.msg_control = ctypes.addressof(cmsg)
msg.msg_controllen = ctypes.sizeof(cmsg)
select.select([handle], [], [])
i = recvmsg(handle.fileno(), ctypes.pointer(msg), 0)
cdata = cmsgarr[CMSG_LEN(0).value:]
data = rawbuffer[:i]
if cmsg.cmsg_level == socket.SOL_SOCKET and cmsg.cmsg_type == SCM_RIGHTS:
filehandles.fromstring(bytes(
cdata[:len(cdata) - len(cdata) % filehandles.itemsize]))
data = json.loads(bytes(data))
return ClientFile(data['filename'], data['mode'], filehandles[0])
else:
data = handle.recv(dlen)
while len(data) < dlen:
ndata = handle.recv(dlen - len(data))
if not ndata:
raise Exception("Error reading data")
data += ndata
if datatype == tlv.Types.text:
return data
elif datatype == tlv.Types.json:
return json.loads(data)