FM / rpc

/usr/lib64/python2.7/Demo/rpc

Name	Size	Mode	Actions
MANIFEST	361	0644	edit dl rm
mountclient.py	6632	0644	edit dl rm
mountclient.pyc	5712	0644	edit dl rm
mountclient.pyo	5712	0644	edit dl rm
nfsclient.py	5323	0644	edit dl rm
nfsclient.pyc	6903	0644	edit dl rm
nfsclient.pyo	6903	0644	edit dl rm
README	1261	0644	edit dl rm
rnusersclient.py	2629	0644	edit dl rm
rnusersclient.pyc	5131	0644	edit dl rm
rnusersclient.pyo	5131	0644	edit dl rm
rpc.py	27631	0644	edit dl rm
rpc.pyc	30438	0644	edit dl rm
rpc.pyo	30438	0644	edit dl rm
T.py	575	0644	edit dl rm
T.pyc	952	0644	edit dl rm
T.pyo	952	0644	edit dl rm
test	697	0644	edit dl rm
xdr.py	5047	0644	edit dl rm
xdr.pyc	7909	0644	edit dl rm
xdr.pyo	7909	0644	edit dl rm

Edit: /usr/lib64/python2.7/Demo/rpc/rpc.py (27631B)

# Sun RPC version 2 -- RFC1057.

# XXX There should be separate exceptions for the various reasons why
# XXX an RPC can fail, rather than using RuntimeError for everything

# XXX Need to use class based exceptions rather than string exceptions

# XXX The UDP version of the protocol resends requests when it does
# XXX not receive a timely reply -- use only for idempotent calls!

# XXX There is no provision for call timeout on TCP connections

import xdr
import socket
import os

RPCVERSION = 2

CALL = 0
REPLY = 1

AUTH_NULL = 0
AUTH_UNIX = 1
AUTH_SHORT = 2
AUTH_DES = 3

MSG_ACCEPTED = 0
MSG_DENIED = 1

SUCCESS = 0                             # RPC executed successfully
PROG_UNAVAIL  = 1                       # remote hasn't exported program
PROG_MISMATCH = 2                       # remote can't support version #
PROC_UNAVAIL  = 3                       # program can't support procedure
GARBAGE_ARGS  = 4                       # procedure can't decode params

RPC_MISMATCH = 0                        # RPC version number != 2
AUTH_ERROR = 1                          # remote can't authenticate caller

AUTH_BADCRED      = 1                   # bad credentials (seal broken)
AUTH_REJECTEDCRED = 2                   # client must begin new session
AUTH_BADVERF      = 3                   # bad verifier (seal broken)
AUTH_REJECTEDVERF = 4                   # verifier expired or replayed
AUTH_TOOWEAK      = 5                   # rejected for security reasons

class Packer(xdr.Packer):

def pack_auth(self, auth):
        flavor, stuff = auth
        self.pack_enum(flavor)
        self.pack_opaque(stuff)

def pack_auth_unix(self, stamp, machinename, uid, gid, gids):
        self.pack_uint(stamp)
        self.pack_string(machinename)
        self.pack_uint(uid)
        self.pack_uint(gid)
        self.pack_uint(len(gids))
        for i in gids:
            self.pack_uint(i)

def pack_callheader(self, xid, prog, vers, proc, cred, verf):
        self.pack_uint(xid)
        self.pack_enum(CALL)
        self.pack_uint(RPCVERSION)
        self.pack_uint(prog)
        self.pack_uint(vers)
        self.pack_uint(proc)
        self.pack_auth(cred)
        self.pack_auth(verf)
        # Caller must add procedure-specific part of call

def pack_replyheader(self, xid, verf):
        self.pack_uint(xid)
        self.pack_enum(REPLY)
        self.pack_uint(MSG_ACCEPTED)
        self.pack_auth(verf)
        self.pack_enum(SUCCESS)
        # Caller must add procedure-specific part of reply

# Exceptions
class BadRPCFormat(Exception): pass
class BadRPCVersion(Exception): pass
class GarbageArgs(Exception): pass

class Unpacker(xdr.Unpacker):

def unpack_auth(self):
        flavor = self.unpack_enum()
        stuff = self.unpack_opaque()
        return (flavor, stuff)

def unpack_callheader(self):
        xid = self.unpack_uint()
        temp = self.unpack_enum()
        if temp != CALL:
            raise BadRPCFormat, 'no CALL but %r' % (temp,)
        temp = self.unpack_uint()
        if temp != RPCVERSION:
            raise BadRPCVersion, 'bad RPC version %r' % (temp,)
        prog = self.unpack_uint()
        vers = self.unpack_uint()
        proc = self.unpack_uint()
        cred = self.unpack_auth()
        verf = self.unpack_auth()
        return xid, prog, vers, proc, cred, verf
        # Caller must add procedure-specific part of call

def unpack_replyheader(self):
        xid = self.unpack_uint()
        mtype = self.unpack_enum()
        if mtype != REPLY:
            raise RuntimeError, 'no REPLY but %r' % (mtype,)
        stat = self.unpack_enum()
        if stat == MSG_DENIED:
            stat = self.unpack_enum()
            if stat == RPC_MISMATCH:
                low = self.unpack_uint()
                high = self.unpack_uint()
                raise RuntimeError, \
                  'MSG_DENIED: RPC_MISMATCH: %r' % ((low, high),)
            if stat == AUTH_ERROR:
                stat = self.unpack_uint()
                raise RuntimeError, \
                        'MSG_DENIED: AUTH_ERROR: %r' % (stat,)
            raise RuntimeError, 'MSG_DENIED: %r' % (stat,)
        if stat != MSG_ACCEPTED:
            raise RuntimeError, \
              'Neither MSG_DENIED nor MSG_ACCEPTED: %r' % (stat,)
        verf = self.unpack_auth()
        stat = self.unpack_enum()
        if stat == PROG_UNAVAIL:
            raise RuntimeError, 'call failed: PROG_UNAVAIL'
        if stat == PROG_MISMATCH:
            low = self.unpack_uint()
            high = self.unpack_uint()
            raise RuntimeError, \
                    'call failed: PROG_MISMATCH: %r' % ((low, high),)
        if stat == PROC_UNAVAIL:
            raise RuntimeError, 'call failed: PROC_UNAVAIL'
        if stat == GARBAGE_ARGS:
            raise RuntimeError, 'call failed: GARBAGE_ARGS'
        if stat != SUCCESS:
            raise RuntimeError, 'call failed: %r' % (stat,)
        return xid, verf
        # Caller must get procedure-specific part of reply

# Subroutines to create opaque authentication objects

def make_auth_null():
    return ''

def make_auth_unix(seed, host, uid, gid, groups):
    p = Packer()
    p.pack_auth_unix(seed, host, uid, gid, groups)
    return p.get_buf()

def make_auth_unix_default():
    try:
        from os import getuid, getgid
        uid = getuid()
        gid = getgid()
    except ImportError:
        uid = gid = 0
    import time
    return make_auth_unix(int(time.time()-unix_epoch()), \
              socket.gethostname(), uid, gid, [])

_unix_epoch = -1
def unix_epoch():
    """Very painful calculation of when the Unix Epoch is.

This is defined as the return value of time.time() on Jan 1st,
    1970, 00:00:00 GMT.

On a Unix system, this should always return 0.0.  On a Mac, the
    calculations are needed -- and hard because of integer overflow
    and other limitations.

"""
    global _unix_epoch
    if _unix_epoch >= 0: return _unix_epoch
    import time
    now = time.time()
    localt = time.localtime(now)        # (y, m, d, hh, mm, ss, ..., ..., ...)
    gmt = time.gmtime(now)
    offset = time.mktime(localt) - time.mktime(gmt)
    y, m, d, hh, mm, ss = 1970, 1, 1, 0, 0, 0
    offset, ss = divmod(ss + offset, 60)
    offset, mm = divmod(mm + offset, 60)
    offset, hh = divmod(hh + offset, 24)
    d = d + offset
    _unix_epoch = time.mktime((y, m, d, hh, mm, ss, 0, 0, 0))
    print "Unix epoch:", time.ctime(_unix_epoch)
    return _unix_epoch

# Common base class for clients

class Client:

def __init__(self, host, prog, vers, port):
        self.host = host
        self.prog = prog
        self.vers = vers
        self.port = port
        self.makesocket() # Assigns to self.sock
        self.bindsocket()
        self.connsocket()
        self.lastxid = 0 # XXX should be more random?
        self.addpackers()
        self.cred = None
        self.verf = None

def close(self):
        self.sock.close()

def makesocket(self):
        # This MUST be overridden
        raise RuntimeError, 'makesocket not defined'

def connsocket(self):
        # Override this if you don't want/need a connection
        self.sock.connect((self.host, self.port))

def bindsocket(self):
        # Override this to bind to a different port (e.g. reserved)
        self.sock.bind(('', 0))

def addpackers(self):
        # Override this to use derived classes from Packer/Unpacker
        self.packer = Packer()
        self.unpacker = Unpacker('')

def make_call(self, proc, args, pack_func, unpack_func):
        # Don't normally override this (but see Broadcast)
        if pack_func is None and args is not None:
            raise TypeError, 'non-null args with null pack_func'
        self.start_call(proc)
        if pack_func:
            pack_func(args)
        self.do_call()
        if unpack_func:
            result = unpack_func()
        else:
            result = None
        self.unpacker.done()
        return result

def start_call(self, proc):
        # Don't override this
        self.lastxid = xid = self.lastxid + 1
        cred = self.mkcred()
        verf = self.mkverf()
        p = self.packer
        p.reset()
        p.pack_callheader(xid, self.prog, self.vers, proc, cred, verf)

def do_call(self):
        # This MUST be overridden
        raise RuntimeError, 'do_call not defined'

def mkcred(self):
        # Override this to use more powerful credentials
        if self.cred is None:
            self.cred = (AUTH_NULL, make_auth_null())
        return self.cred

def mkverf(self):
        # Override this to use a more powerful verifier
        if self.verf is None:
            self.verf = (AUTH_NULL, make_auth_null())
        return self.verf

def call_0(self):               # Procedure 0 is always like this
        return self.make_call(0, None, None, None)

# Record-Marking standard support

def sendfrag(sock, last, frag):
    x = len(frag)
    if last: x = x | 0x80000000L
    header = (chr(int(x>>24 & 0xff)) + chr(int(x>>16 & 0xff)) + \
              chr(int(x>>8 & 0xff)) + chr(int(x & 0xff)))
    sock.send(header + frag)

def sendrecord(sock, record):
    sendfrag(sock, 1, record)

def recvfrag(sock):
    header = sock.recv(4)
    if len(header) < 4:
        raise EOFError
    x = long(ord(header[0]))<<24 | ord(header[1])<<16 | \
        ord(header[2])<<8 | ord(header[3])
    last = ((x & 0x80000000) != 0)
    n = int(x & 0x7fffffff)
    frag = ''
    while n > 0:
        buf = sock.recv(n)
        if not buf: raise EOFError
        n = n - len(buf)
        frag = frag + buf
    return last, frag

def recvrecord(sock):
    record = ''
    last = 0
    while not last:
        last, frag = recvfrag(sock)
        record = record + frag
    return record

# Try to bind to a reserved port (must be root)

last_resv_port_tried = None
def bindresvport(sock, host):
    global last_resv_port_tried
    FIRST, LAST = 600, 1024 # Range of ports to try
    if last_resv_port_tried is None:
        import os
        last_resv_port_tried = FIRST + os.getpid() % (LAST-FIRST)
    for i in range(last_resv_port_tried, LAST) + \
              range(FIRST, last_resv_port_tried):
        last_resv_port_tried = i
        try:
            sock.bind((host, i))
            return last_resv_port_tried
        except socket.error, (errno, msg):
            if errno != 114:
                raise socket.error, (errno, msg)
    raise RuntimeError, 'can\'t assign reserved port'

# Client using TCP to a specific port

class RawTCPClient(Client):

def makesocket(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

def do_call(self):
        call = self.packer.get_buf()
        sendrecord(self.sock, call)
        reply = recvrecord(self.sock)
        u = self.unpacker
        u.reset(reply)
        xid, verf = u.unpack_replyheader()
        if xid != self.lastxid:
            # Can't really happen since this is TCP...
            raise RuntimeError, 'wrong xid in reply %r instead of %r' % (
                                 xid, self.lastxid)

# Client using UDP to a specific port

class RawUDPClient(Client):

def makesocket(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

def do_call(self):
        call = self.packer.get_buf()
        self.sock.send(call)
        try:
            from select import select
        except ImportError:
            print 'WARNING: select not found, RPC may hang'
            select = None
        BUFSIZE = 8192 # Max UDP buffer size
        timeout = 1
        count = 5
        while 1:
            r, w, x = [self.sock], [], []
            if select:
                r, w, x = select(r, w, x, timeout)
            if self.sock not in r:
                count = count - 1
                if count < 0: raise RuntimeError, 'timeout'
                if timeout < 25: timeout = timeout *2
##                              print 'RESEND', timeout, count
                self.sock.send(call)
                continue
            reply = self.sock.recv(BUFSIZE)
            u = self.unpacker
            u.reset(reply)
            xid, verf = u.unpack_replyheader()
            if xid != self.lastxid:
##                              print 'BAD xid'
                continue
            break

# Client using UDP broadcast to a specific port

class RawBroadcastUDPClient(RawUDPClient):

def __init__(self, bcastaddr, prog, vers, port):
        RawUDPClient.__init__(self, bcastaddr, prog, vers, port)
        self.reply_handler = None
        self.timeout = 30

def connsocket(self):
        # Don't connect -- use sendto
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

def set_reply_handler(self, reply_handler):
        self.reply_handler = reply_handler

def set_timeout(self, timeout):
        self.timeout = timeout # Use None for infinite timeout

def make_call(self, proc, args, pack_func, unpack_func):
        if pack_func is None and args is not None:
            raise TypeError, 'non-null args with null pack_func'
        self.start_call(proc)
        if pack_func:
            pack_func(args)
        call = self.packer.get_buf()
        self.sock.sendto(call, (self.host, self.port))
        try:
            from select import select
        except ImportError:
            print 'WARNING: select not found, broadcast will hang'
            select = None
        BUFSIZE = 8192 # Max UDP buffer size (for reply)
        replies = []
        if unpack_func is None:
            def dummy(): pass
            unpack_func = dummy
        while 1:
            r, w, x = [self.sock], [], []
            if select:
                if self.timeout is None:
                    r, w, x = select(r, w, x)
                else:
                    r, w, x = select(r, w, x, self.timeout)
            if self.sock not in r:
                break
            reply, fromaddr = self.sock.recvfrom(BUFSIZE)
            u = self.unpacker
            u.reset(reply)
            xid, verf = u.unpack_replyheader()
            if xid != self.lastxid:
##                              print 'BAD xid'
                continue
            reply = unpack_func()
            self.unpacker.done()
            replies.append((reply, fromaddr))
            if self.reply_handler:
                self.reply_handler(reply, fromaddr)
        return replies

# Port mapper interface

# Program number, version and (fixed!) port number
PMAP_PROG = 100000
PMAP_VERS = 2
PMAP_PORT = 111

# Procedure numbers
PMAPPROC_NULL = 0                       # (void) -> void
PMAPPROC_SET = 1                        # (mapping) -> bool
PMAPPROC_UNSET = 2                      # (mapping) -> bool
PMAPPROC_GETPORT = 3                    # (mapping) -> unsigned int
PMAPPROC_DUMP = 4                       # (void) -> pmaplist
PMAPPROC_CALLIT = 5                     # (call_args) -> call_result

# A mapping is (prog, vers, prot, port) and prot is one of:

IPPROTO_TCP = 6
IPPROTO_UDP = 17

# A pmaplist is a variable-length list of mappings, as follows:
# either (1, mapping, pmaplist) or (0).

# A call_args is (prog, vers, proc, args) where args is opaque;
# a call_result is (port, res) where res is opaque.

class PortMapperPacker(Packer):

def pack_mapping(self, mapping):
        prog, vers, prot, port = mapping
        self.pack_uint(prog)
        self.pack_uint(vers)
        self.pack_uint(prot)
        self.pack_uint(port)

def pack_pmaplist(self, list):
        self.pack_list(list, self.pack_mapping)

def pack_call_args(self, ca):
        prog, vers, proc, args = ca
        self.pack_uint(prog)
        self.pack_uint(vers)
        self.pack_uint(proc)
        self.pack_opaque(args)

class PortMapperUnpacker(Unpacker):

def unpack_mapping(self):
        prog = self.unpack_uint()
        vers = self.unpack_uint()
        prot = self.unpack_uint()
        port = self.unpack_uint()
        return prog, vers, prot, port

def unpack_pmaplist(self):
        return self.unpack_list(self.unpack_mapping)

def unpack_call_result(self):
        port = self.unpack_uint()
        res = self.unpack_opaque()
        return port, res

class PartialPortMapperClient:

def addpackers(self):
        self.packer = PortMapperPacker()
        self.unpacker = PortMapperUnpacker('')

def Set(self, mapping):
        return self.make_call(PMAPPROC_SET, mapping, \
                self.packer.pack_mapping, \
                self.unpacker.unpack_uint)

def Unset(self, mapping):
        return self.make_call(PMAPPROC_UNSET, mapping, \
                self.packer.pack_mapping, \
                self.unpacker.unpack_uint)

def Getport(self, mapping):
        return self.make_call(PMAPPROC_GETPORT, mapping, \
                self.packer.pack_mapping, \
                self.unpacker.unpack_uint)

def Dump(self):
        return self.make_call(PMAPPROC_DUMP, None, \
                None, \
                self.unpacker.unpack_pmaplist)

def Callit(self, ca):
        return self.make_call(PMAPPROC_CALLIT, ca, \
                self.packer.pack_call_args, \
                self.unpacker.unpack_call_result)

class TCPPortMapperClient(PartialPortMapperClient, RawTCPClient):

def __init__(self, host):
        RawTCPClient.__init__(self, \
                host, PMAP_PROG, PMAP_VERS, PMAP_PORT)

class UDPPortMapperClient(PartialPortMapperClient, RawUDPClient):

def __init__(self, host):
        RawUDPClient.__init__(self, \
                host, PMAP_PROG, PMAP_VERS, PMAP_PORT)

class BroadcastUDPPortMapperClient(PartialPortMapperClient, \
                                   RawBroadcastUDPClient):

def __init__(self, bcastaddr):
        RawBroadcastUDPClient.__init__(self, \
                bcastaddr, PMAP_PROG, PMAP_VERS, PMAP_PORT)

# Generic clients that find their server through the Port mapper

class TCPClient(RawTCPClient):

def __init__(self, host, prog, vers):
        pmap = TCPPortMapperClient(host)
        port = pmap.Getport((prog, vers, IPPROTO_TCP, 0))
        pmap.close()
        if port == 0:
            raise RuntimeError, 'program not registered'
        RawTCPClient.__init__(self, host, prog, vers, port)

class UDPClient(RawUDPClient):

def __init__(self, host, prog, vers):
        pmap = UDPPortMapperClient(host)
        port = pmap.Getport((prog, vers, IPPROTO_UDP, 0))
        pmap.close()
        if port == 0:
            raise RuntimeError, 'program not registered'
        RawUDPClient.__init__(self, host, prog, vers, port)

class BroadcastUDPClient(Client):

def __init__(self, bcastaddr, prog, vers):
        self.pmap = BroadcastUDPPortMapperClient(bcastaddr)
        self.pmap.set_reply_handler(self.my_reply_handler)
        self.prog = prog
        self.vers = vers
        self.user_reply_handler = None
        self.addpackers()

def close(self):
        self.pmap.close()

def set_reply_handler(self, reply_handler):
        self.user_reply_handler = reply_handler

def set_timeout(self, timeout):
        self.pmap.set_timeout(timeout)

def my_reply_handler(self, reply, fromaddr):
        port, res = reply
        self.unpacker.reset(res)
        result = self.unpack_func()
        self.unpacker.done()
        self.replies.append((result, fromaddr))
        if self.user_reply_handler is not None:
            self.user_reply_handler(result, fromaddr)

def make_call(self, proc, args, pack_func, unpack_func):
        self.packer.reset()
        if pack_func:
            pack_func(args)
        if unpack_func is None:
            def dummy(): pass
            self.unpack_func = dummy
        else:
            self.unpack_func = unpack_func
        self.replies = []
        packed_args = self.packer.get_buf()
        dummy_replies = self.pmap.Callit( \
                (self.prog, self.vers, proc, packed_args))
        return self.replies

# Server classes

# These are not symmetric to the Client classes
# XXX No attempt is made to provide authorization hooks yet

class Server:

def __init__(self, host, prog, vers, port):
        self.host = host # Should normally be '' for default interface
        self.prog = prog
        self.vers = vers
        self.port = port # Should normally be 0 for random port
        self.makesocket() # Assigns to self.sock and self.prot
        self.bindsocket()
        self.host, self.port = self.sock.getsockname()
        self.addpackers()

def register(self):
        mapping = self.prog, self.vers, self.prot, self.port
        p = TCPPortMapperClient(self.host)
        if not p.Set(mapping):
            raise RuntimeError, 'register failed'

def unregister(self):
        mapping = self.prog, self.vers, self.prot, self.port
        p = TCPPortMapperClient(self.host)
        if not p.Unset(mapping):
            raise RuntimeError, 'unregister failed'

def handle(self, call):
        # Don't use unpack_header but parse the header piecewise
        # XXX I have no idea if I am using the right error responses!
        self.unpacker.reset(call)
        self.packer.reset()
        xid = self.unpacker.unpack_uint()
        self.packer.pack_uint(xid)
        temp = self.unpacker.unpack_enum()
        if temp != CALL:
            return None # Not worthy of a reply
        self.packer.pack_uint(REPLY)
        temp = self.unpacker.unpack_uint()
        if temp != RPCVERSION:
            self.packer.pack_uint(MSG_DENIED)
            self.packer.pack_uint(RPC_MISMATCH)
            self.packer.pack_uint(RPCVERSION)
            self.packer.pack_uint(RPCVERSION)
            return self.packer.get_buf()
        self.packer.pack_uint(MSG_ACCEPTED)
        self.packer.pack_auth((AUTH_NULL, make_auth_null()))
        prog = self.unpacker.unpack_uint()
        if prog != self.prog:
            self.packer.pack_uint(PROG_UNAVAIL)
            return self.packer.get_buf()
        vers = self.unpacker.unpack_uint()
        if vers != self.vers:
            self.packer.pack_uint(PROG_MISMATCH)
            self.packer.pack_uint(self.vers)
            self.packer.pack_uint(self.vers)
            return self.packer.get_buf()
        proc = self.unpacker.unpack_uint()
        methname = 'handle_' + repr(proc)
        try:
            meth = getattr(self, methname)
        except AttributeError:
            self.packer.pack_uint(PROC_UNAVAIL)
            return self.packer.get_buf()
        cred = self.unpacker.unpack_auth()
        verf = self.unpacker.unpack_auth()
        try:
            meth() # Unpack args, call turn_around(), pack reply
        except (EOFError, GarbageArgs):
            # Too few or too many arguments
            self.packer.reset()
            self.packer.pack_uint(xid)
            self.packer.pack_uint(REPLY)
            self.packer.pack_uint(MSG_ACCEPTED)
            self.packer.pack_auth((AUTH_NULL, make_auth_null()))
            self.packer.pack_uint(GARBAGE_ARGS)
        return self.packer.get_buf()

def turn_around(self):
        try:
            self.unpacker.done()
        except RuntimeError:
            raise GarbageArgs
        self.packer.pack_uint(SUCCESS)

def handle_0(self): # Handle NULL message
        self.turn_around()

def makesocket(self):
        # This MUST be overridden
        raise RuntimeError, 'makesocket not defined'

def bindsocket(self):
        # Override this to bind to a different port (e.g. reserved)
        self.sock.bind((self.host, self.port))

def addpackers(self):
        # Override this to use derived classes from Packer/Unpacker
        self.packer = Packer()
        self.unpacker = Unpacker('')

class TCPServer(Server):

def makesocket(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.prot = IPPROTO_TCP

def loop(self):
        self.sock.listen(0)
        while 1:
            self.session(self.sock.accept())

def session(self, connection):
        sock, (host, port) = connection
        while 1:
            try:
                call = recvrecord(sock)
            except EOFError:
                break
            except socket.error, msg:
                print 'socket error:', msg
                break
            reply = self.handle(call)
            if reply is not None:
                sendrecord(sock, reply)

def forkingloop(self):
        # Like loop but uses forksession()
        self.sock.listen(0)
        while 1:
            self.forksession(self.sock.accept())

def forksession(self, connection):
        # Like session but forks off a subprocess
        import os
        # Wait for deceased children
        try:
            while 1:
                pid, sts = os.waitpid(0, 1)
        except os.error:
            pass
        pid = None
        try:
            pid = os.fork()
            if pid: # Parent
                connection[0].close()
                return
            # Child
            self.session(connection)
        finally:
            # Make sure we don't fall through in the parent
            if pid == 0:
                os._exit(0)

class UDPServer(Server):

def makesocket(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.prot = IPPROTO_UDP

def loop(self):
        while 1:
            self.session()

def session(self):
        call, host_port = self.sock.recvfrom(8192)
        reply = self.handle(call)
        if reply is not None:
            self.sock.sendto(reply, host_port)

# Simple test program -- dump local portmapper status

def test():
    pmap = UDPPortMapperClient('')
    list = pmap.Dump()
    list.sort()
    for prog, vers, prot, port in list:
        print prog, vers,
        if prot == IPPROTO_TCP: print 'tcp',
        elif prot == IPPROTO_UDP: print 'udp',
        else: print prot,
        print port

# Test program for broadcast operation -- dump everybody's portmapper status

def testbcast():
    import sys
    if sys.argv[1:]:
        bcastaddr = sys.argv[1]
    else:
        bcastaddr = '<broadcast>'
    def rh(reply, fromaddr):
        host, port = fromaddr
        print host + '\t' + repr(reply)
    pmap = BroadcastUDPPortMapperClient(bcastaddr)
    pmap.set_reply_handler(rh)
    pmap.set_timeout(5)
    replies = pmap.Getport((100002, 1, IPPROTO_UDP, 0))

# Test program for server, with corresponding client
# On machine A: python -c 'import rpc; rpc.testsvr()'
# On machine B: python -c 'import rpc; rpc.testclt()' A
# (A may be == B)

def testsvr():
    # Simple test class -- proc 1 doubles its string argument as reply
    class S(UDPServer):
        def handle_1(self):
            arg = self.unpacker.unpack_string()
            self.turn_around()
            print 'RPC function 1 called, arg', repr(arg)
            self.packer.pack_string(arg + arg)
    #
    s = S('', 0x20000000, 1, 0)
    try:
        s.unregister()
    except RuntimeError, msg:
        print 'RuntimeError:', msg, '(ignored)'
    s.register()
    print 'Service started...'
    try:
        s.loop()
    finally:
        s.unregister()
        print 'Service interrupted.'

def testclt():
    import sys
    if sys.argv[1:]: host = sys.argv[1]
    else: host = ''
    # Client for above server
    class C(UDPClient):
        def call_1(self, arg):
            return self.make_call(1, arg, \
                    self.packer.pack_string, \
                    self.unpacker.unpack_string)
    c = C(host, 0x20000000, 1)
    print 'making call...'
    reply = c.call_1('hello, world, ')
    print 'call returned', repr(reply)

cmd: