summaryrefslogtreecommitdiff
path: root/net/packet.py
blob: 232cd521b4780d718e0d48c8d31c64d37a2d2b8b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
"""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