"""The PacketBuffer class has been adapted from source originally released by gnufrk"""
import struct
packet_lengths = [
10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
#0x0040
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 50, 3, -1, 55, 17, 3, 37, 46, -1, 23, -1, 3,108, 3, 2,
3, 28, 19, 11, 3, -1, 9, 5, 54, 53, 58, 60, 41, 2, 6, 6,
#0x0080
7, 3, 2, 2, 2, 5, 16, 12, 10, 7, 29, 23, -1, -1, -1, 0,
7, 22, 28, 2, 6, 30, -1, -1, 3, -1, -1, 5, 9, 17, 17, 6,
23, 6, 6, -1, -1, -1, -1, 8, 7, 6, 7, 4, 7, 0, -1, 6,
8, 8, 3, 3, -1, 6, 6, -1, 7, 6, 2, 5, 6, 44, 5, 3,
#0x00C0
7, 2, 6, 8, 6, 7, -1, -1, -1, -1, 3, 3, 6, 6, 2, 27,
3, 4, 4, 2, -1, -1, 3, -1, 6, 14, 3, -1, 28, 29, -1, -1,
30, 30, 26, 2, 6, 26, 3, 3, 8, 19, 5, 2, 3, 2, 2, 2,
3, 2, 6, 8, 21, 8, 8, 2, 2, 26, 3, -1, 6, 27, 30, 10,
#0x0100
2, 6, 6, 30, 79, 31, 10, 10, -1, -1, 4, 6, 6, 2, 11, -1,
10, 39, 4, 10, 31, 35, 10, 18, 2, 13, 15, 20, 68, 2, 3, 16,
6, 14, -1, -1, 21, 8, 8, 8, 8, 8, 2, 2, 3, 4, 2, -1,
6, 86, 6, -1, -1, 7, -1, 6, 3, 16, 4, 4, 4, 6, 24, 26,
#0x0140
22, 14, 6, 10, 23, 19, 6, 39, 8, 9, 6, 27, -1, 2, 6, 6,
110, 6, -1, -1, -1, -1, -1, 6, -1, 54, 66, 54, 90, 42, 6, 42,
-1, -1, -1, -1, -1, 30, -1, 3, 14, 3, 30, 10, 43, 14,186,182,
14, 30, 10, 3, -1, 6,106, -1, 4, 5, 4, -1, 6, 7, -1, -1,
#0x0180
6, 3,106, 10, 10, 34, 0, 6, 8, 4, 4, 4, 29, -1, 10, 6,
90, 86, 24, 6, 30,102, 9, 4, 8, 4, 14, 10, 4, 6, 2, 6,
3, 3, 35, 5, 11, 26, -1, 4, 4, 6, 10, 12, 6, -1, 4, 4,
11, 7, -1, 67, 12, 18,114, 6, 3, 6, 26, 26, 26, 26, 2, 3,
#0x01C0
2, 14, 10, -1, 22, 22, 4, 2, 13, 97, 0, 9, 9, 29, 6, 28,
8, 14, 10, 35, 6, 8, 4, 11, 54, 53, 60, 2, -1, 47, 33, 6,
30, 8, 34, 14, 2, 6, 26, 2, 28, 81, 6, 10, 26, 2, -1, -1,
-1, -1, 20, 10, 32, 9, 34, 14, 2, 6, 48, 56, -1, 4, 5, 4,
#0x0200
26, 0, 0, 0, 18, 0, 0, 0, 0, 0, 0, 19, 10, 0, 0, 0,
0, 0, 16, 0, 8, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, -1, 10, -1, -1, -1, 0, 0, 0, 0, 0, 0,
-1, 34, 10, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
]
class PacketOut:
def __init__(self, out):
self.buff = ""
self.write_int16(out)
def __str__(self):
return self.buff
def write_string(self, string_val, length):
self.buff += string_val.ljust(length, '\0')
def write_int8(self, value):
self.buff += struct.pack("<B", value)
def write_int16(self, value):
self.buff += struct.pack("<H", value)
def write_int32(self, value):
self.buff += struct.pack("<L", value)
def write_coords(self, x, y, direction):
tmp = x
tmp <<= 6
d_0 = 0
d_1 = 1
d_2 = 2
d_0 = (tmp >> 8) % 256
d_1 = (tmp) % 256
tmp = y
tmp <<= 4
d_1 |= (tmp >> 8) % 256
d_2 = tmp % 256
d_2 |= direction
self.buff += chr(d_0) + chr(d_1) + chr(d_2)
class PacketIn:
def __init__(self, set_data, pkt_type):
self.data = set_data
self.pkttype = pkt_type
self.pos = 0
def is_type(self, pkt_type):
return self.pkttype == pkt_type
def get_type(self):
return self.pkttype
def read_string(self, length):
msg = self.data[self.pos:self.pos + length]
self.pos = self.pos + length
return msg[:msg.find('\0')]
def read_raw_string(self, length):
msg = self.data[self.pos:self.pos + length]
self.pos = self.pos + length
return msg
def read_int8(self):
int_value = struct.unpack("<B", self.data[self.pos:self.pos + 1])[0]
self.pos = self.pos + 1
return int_value
def make_word(self, low, high):
return (low | (high << 8))
def read_coord_pair(self):
cdata = self.data[self.pos:self.pos + 5]
dst_x = (self.make_word(struct.unpack("<B", cdata[3])[0], struct.unpack("<B", cdata[2])[0] & 0x000f) >> 2)
dst_y = self.make_word(struct.unpack("<B", cdata[4])[0], struct.unpack("<B", cdata[3])[0] & 0x0003)
src_x = (self.make_word(struct.unpack("<B", cdata[1])[0], struct.unpack("<B", cdata[0])[0]) >> 6)
src_y = (self.make_word(struct.unpack("<B", cdata[2])[0], struct.unpack("<B", cdata[1])[0] & 0x003f) >> 4)
self.pos = self.pos + 5
return src_x, src_y, dst_x, dst_y
def read_coord_dir(self):
cdata = self.data[self.pos:self.pos + 3]
x = (self.make_word(struct.unpack("<B", cdata[1])[0] & 0x00c0, struct.unpack("<B", cdata[0])[0] & 0x00ff) >> 6) % 255
y = (self.make_word(struct.unpack("<B", cdata[2])[0] & 0x00f0, struct.unpack("<B", cdata[1])[0] & 0x003f) >> 4) % 255
dir = struct.unpack("<B", cdata[2])[0] & 0x000f
self.pos = self.pos + 3
return x, y, dir
def read_int16(self):
int_value = struct.unpack("<H", self.data[self.pos:self.pos + 2])[0]
self.pos = self.pos + 2
return int_value
def read_int32(self):
int_value = struct.unpack("<L", self.data[self.pos:self.pos + 4])[0]
self.pos = self.pos + 4
return int_value
def skip(self, count):
self.pos = self.pos + count
class PacketBuffer:
def __init__(self):
self.buff = ""
def feed(self, data):
self.buff += data
def drop(self, count):
self.buff = self.buff[count:]
def __iter__(self):
return self
def next(self):
if len(self.buff) < 2:
raise StopIteration
pktlen = 0
pkttype = struct.unpack("<H", self.buff[:2])[0]
assert pkttype < len(packet_lengths)
assert packet_lengths[pkttype] != 0
if packet_lengths[pkttype] < 0:
if len(self.buff) < 4:
raise StopIteration
pktlen = struct.unpack("<H", self.buff[2:4])[0]
assert pktlen >= 4
else:
pktlen = packet_lengths[pkttype]
if len(self.buff) < pktlen:
raise StopIteration
packet = PacketIn(self.buff[2:pktlen], pkttype)
self.buff = self.buff[pktlen:]
return packet
