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# $Id: rpc.py 23 2006-11-08 15:45:33Z dugsong $
"""Remote Procedure Call."""
import struct
import dpkt
# RPC.dir
CALL = 0
REPLY = 1
# RPC.Auth.flavor
AUTH_NONE = AUTH_NULL = 0
AUTH_UNIX = 1
AUTH_SHORT = 2
AUTH_DES = 3
# RPC.Reply.stat
MSG_ACCEPTED = 0
MSG_DENIED = 1
# RPC.Reply.Accept.stat
SUCCESS = 0
PROG_UNAVAIL = 1
PROG_MISMATCH = 2
PROC_UNAVAIL = 3
GARBAGE_ARGS = 4
SYSTEM_ERR = 5
# RPC.Reply.Reject.stat
RPC_MISMATCH = 0
AUTH_ERROR = 1
class RPC(dpkt.Packet):
__hdr__ = (
('xid', 'I', 0),
('dir', 'I', CALL)
)
class Auth(dpkt.Packet):
__hdr__ = (('flavor', 'I', AUTH_NONE), )
def unpack(self, buf):
dpkt.Packet.unpack(self, buf)
n = struct.unpack('>I', self.data[:4])[0]
self.data = self.data[4:4+n]
def __len__(self):
return 8 + len(self.data)
def __str__(self):
return self.pack_hdr() + struct.pack('>I', len(self.data)) + \
str(self.data)
class Call(dpkt.Packet):
__hdr__ = (
('rpcvers', 'I', 2),
('prog', 'I', 0),
('vers', 'I', 0),
('proc', 'I', 0)
)
def unpack(self, buf):
dpkt.Packet.unpack(self, buf)
self.cred = RPC.Auth(self.data)
self.verf = RPC.Auth(self.data[len(self.cred):])
self.data = self.data[len(self.cred) + len(self.verf):]
def __len__(self):
return len(str(self)) # XXX
def __str__(self):
return dpkt.Packet.__str__(self) + \
str(getattr(self, 'cred', RPC.Auth())) + \
str(getattr(self, 'verf', RPC.Auth())) + \
str(self.data)
class Reply(dpkt.Packet):
__hdr__ = (('stat', 'I', MSG_ACCEPTED), )
class Accept(dpkt.Packet):
__hdr__ = (('stat', 'I', SUCCESS), )
def unpack(self, buf):
self.verf = RPC.Auth(buf)
buf = buf[len(self.verf):]
self.stat = struct.unpack('>I', buf[:4])[0]
if self.stat == SUCCESS:
self.data = buf[4:]
elif self.stat == PROG_MISMATCH:
self.low, self.high = struct.unpack('>II', buf[4:12])
self.data = buf[12:]
def __len__(self):
if self.stat == PROG_MISMATCH: n = 8
else: n = 0
return len(self.verf) + 4 + n + len(self.data)
def __str__(self):
if self.stat == PROG_MISMATCH:
return str(self.verf) + struct.pack('>III', self.stat,
self.low, self.high) + self.data
return str(self.verf) + dpkt.Packet.__str__(self)
class Reject(dpkt.Packet):
__hdr__ = (('stat', 'I', AUTH_ERROR), )
def unpack(self, buf):
dpkt.Packet.unpack(self, buf)
if self.stat == RPC_MISMATCH:
self.low, self.high = struct.unpack('>II', self.data[:8])
self.data = self.data[8:]
elif self.stat == AUTH_ERROR:
self.why = struct.unpack('>I', self.data[:4])[0]
self.data = self.data[4:]
def __len__(self):
if self.stat == RPC_MISMATCH: n = 8
elif self.stat == AUTH_ERROR: n =4
else: n = 0
return 4 + n + len(self.data)
def __str__(self):
if self.stat == RPC_MISMATCH:
return struct.pack('>III', self.stat, self.low,
self.high) + self.data
elif self.stat == AUTH_ERROR:
return struct.pack('>II', self.stat, self.why) + self.data
return dpkt.Packet.__str__(self)
def unpack(self, buf):
dpkt.Packet.unpack(self, buf)
if self.stat == MSG_ACCEPTED:
self.data = self.accept = self.Accept(self.data)
elif self.status == MSG_DENIED:
self.data = self.reject = self.Reject(self.data)
def unpack(self, buf):
dpkt.Packet.unpack(self, buf)
if self.dir == CALL:
self.data = self.call = self.Call(self.data)
elif self.dir == REPLY:
self.data = self.reply = self.Reply(self.data)
def unpack_xdrlist(cls, buf):
l = []
while buf:
if buf.startswith('\x00\x00\x00\x01'):
p = cls(buf[4:])
l.append(p)
buf = p.data
elif buf.startswith('\x00\x00\x00\x00'):
break
else:
raise dpkt.UnpackError, 'invalid XDR list'
return l
def pack_xdrlist(*args):
return '\x00\x00\x00\x01'.join(map(str, args)) + '\x00\x00\x00\x00'
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