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.

confluent_client/confluent/tlvdata.py

@@ -20,6 +20,7 @@ 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
@@ -40,11 +41,32 @@ class iovec(ctypes.Structure):   # from uio.h
                 ('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),
@@ -75,7 +97,7 @@ class ClientFile(object):
 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_size_t
+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
@@ -150,7 +172,19 @@ def send(handle, data, filehandle=None):
         else:
             tl |= (2 << 24)
             handle.sendall(struct.pack("!I", tl))
-            handle.sendmsg([sdata], [(socket.SOL_SOCKET, socket.SCM_RIGHTS, array.array("i", [filehandle]))])
+            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):
@@ -183,13 +217,32 @@ def recv(handle):
         return None
     if datatype == tlv.Types.filehandle:
         filehandles = array.array('i')
-        data, adata, flags, addr = handle.recvmsg(
-            dlen, socket.CMSG_LEN(filehandles.itemsize))
-        for clev, ctype, cdata in adata:
-            if clev == socket.SOL_SOCKET and ctype == socket.SCM_RIGHTS:
-                filehandles.fromstring(
-                    cdata[:len(cdata) - len(cdata) % filehandles.itemsize])
-        data = json.loads(data)
+        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)

confluent_server/confluent/sockapi.py

@@ -21,8 +21,6 @@
 #
 
 import atexit
-import ctypes
-import ctypes.util
 import errno
 import os
 import pwd
@@ -77,24 +75,6 @@ except ImportError:
 
 plainsocket = None
 
-class iovec(ctypes.Structure):   # from uio.h
-    _fields_ = [('iov_base', ctypes.c_void_p),
-                ('iov_len', ctypes.c_size_t)]
-
-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)]
-
-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_size_t
-
 def _should_authlog(path, operation):
     if (operation == 'retrieve' and
             ('/sensors/' in path or '/health/' in path or