bancho-packet 0.2.0

Library for handling osu!'s packets
Documentation 
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

use bytes::{BufMut, BytesMut, Buf, Bytes};

pub trait BytesMutExt {
    fn put_header(&mut self, id: i16);
    fn fix_header(&mut self, start: usize);
    fn len(&self) -> usize;
    
    fn put_bool(&mut self, val: bool);
    fn put_uleb(&mut self, len: usize);
    fn put_string(&mut self, string: &str);
    
    fn get_bool(&mut self) -> bool;
    fn get_uleb(&mut self) -> usize;
    fn get_string(&mut self) -> String;

    fn with_header(&mut self, id: i16, f: impl FnOnce(&mut Self) -> ()) {
        // record start and put header
        let start = self.len();
        self.put_header(id);
        
        // run caller provided code
        f(self);
        
        // cleanup
        self.fix_header(start);
    }
}

pub trait BytesExt {
    fn take_while(&mut self, f: impl FnMut(u8) -> bool) -> Bytes;
}

impl BytesMutExt for BytesMut {
    fn len(&self) -> usize {
        BytesMut::len(self) // call BytesMut.len() not BytesMutExt.len()
    }

    fn put_header(&mut self, id: i16) {
        self.put_i16_le(id);
        self.put_bool(false);
        self.put_u32_le(0);
    }

    fn fix_header(&mut self, start: usize) {
        let length = self.len() - start - 7;
        (self[start + 3]) = length as u8;
    }

    fn put_bool(&mut self, val: bool) {
        self.put_u8(val as u8);
    }

    fn put_uleb(&mut self, mut len: usize) {
        let mut uleb: Vec<u8> = vec![0; 32];

        let mut uleb_len: usize = 0;

        while len > 0 {
            uleb[uleb_len] = (len as u8) & 0x7f;

            len >>= 7;
            if len != 0 {
                uleb[uleb_len] |= 0x80;
            }

            uleb_len += 1;
        }

        uleb.retain(|&x| x != 0);

        self.put(uleb.as_slice());
    }
    fn put_string(&mut self, string: &str) {
        let length = string.len();
 
        self.put_u8(0xb);
        self.put_uleb(length);
        self.put(string.as_bytes());
    }

    fn get_bool(&mut self) -> bool {
        self.get_u8() != 0
    }

    fn get_uleb(&mut self) -> usize {
        let mut result = 0;
        let mut shift = 0;

        let mut byte = self.get_u8();

        if (byte & 0x80) == 0 {
            result |= (byte & 0x7f) << shift;
        } else {
            let mut end = false;

            while !end {
                if shift > 0 {
                    byte = self.get_u8();
                }

                result |= (byte & 0x7f) << shift;
                if (byte & 0x80) == 0 {
                    end = true;
                }
                shift += 7;
            }
        }

        result as usize
    }

    fn get_string(&mut self) -> String {
        let _ = self.get_u8();
        let length = self.get_uleb();
        let mut string = "".to_string();

        if length > 0 {
            let mut i = 0;

            while i < length + 1 {
                let current_char = self.get(i);
                let chr = match current_char {
                    Some(x) => *x as char,
                    None => '\0',
                };

                string = format!("{}{}", string, chr); //;
                i += 1;
            }

            self.advance(length);
        }
        string.retain(|x| x != '\0' && x != '\u{b}');
        string
    }

    
}

impl BytesExt for Bytes {
// TODO: This doesnt need to copy, could just slice into the buf
    fn take_while(&mut self, mut f: impl FnMut(u8) -> bool) -> Bytes {
        let mut len = 0;
        while let Some(b) = self.get(len) {
            if !f(*b) {
                break;
            }
            len += 1;
        }

        self.copy_to_bytes(len)
    }
}

pub type Buffer = BytesMut;