btfparse 1.3.3

A BTF parser library capable of navigating types
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
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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264

/*
  Copyright (c) 2024-present, Alessandro Gario
  All rights reserved.

  This source code is licensed in accordance with the terms specified in
  the LICENSE file found in the root directory of this source tree.
*/

use crate::btf::{
    parse_string, Error as BTFError, ErrorKind as BTFErrorKind, FileHeader, Header, Kind,
    Result as BTFResult, Type,
};
use crate::define_type;
use crate::utils::Reader;

/// Int data
#[derive(Debug, Clone)]
struct Data {
    /// The integer name
    name: Option<String>,

    /// The int type size, in bytes
    size: usize,

    /// Whether the integer is signed
    signed: bool,

    /// Whether the integer is a char
    char: bool,

    /// Whether the integer is a boolean
    boolean: bool,

    /// The offset, in bits, of the integer. Used for bitfields
    offset: usize,

    /// The number of bits in the integer. Used for bitfields
    bits: usize,
}

impl Data {
    /// The size of the extra data
    pub fn size(_type_header: &Header) -> usize {
        4
    }

    /// Creates a new `Data` object
    pub fn new(
        reader: &mut Reader,
        file_header: &FileHeader,
        type_header: &Header,
    ) -> BTFResult<Self> {
        let extra_info = reader.u32()?;
        let encoding = (extra_info & 0x0F000000) >> 24;
        let offset = ((extra_info & 0x00FF0000) >> 16) as usize;
        let bits = (extra_info & 0x000000FF) as usize;

        let name = if type_header.name_offset() != 0 {
            Some(parse_string(
                reader,
                file_header,
                type_header.name_offset(),
            )?)
        } else {
            None
        };

        Ok(Self {
            name,
            size: type_header.size_or_type() as usize,
            signed: (encoding & 1) != 0,
            char: (encoding & 2) != 0,
            boolean: (encoding & 4) != 0,
            offset,
            bits,
        })
    }
}

define_type!(Int, Data,
    name: Option<String>,
    size: usize,
    signed: bool,
    char: bool,
    boolean: bool,
    offset: usize,
    bits: usize
);

#[cfg(test)]
mod tests {
    use super::Int;
    use crate::btf::{FileHeader, Header};
    use crate::utils::{ReadableBuffer, Reader};

    #[test]
    fn test_int_no_encoding_options() {
        let readable_buffer = ReadableBuffer::new(&[
            //
            // BTF header
            //
            0x9F, 0xEB, // magic
            0x01, // version
            0x00, // flags
            0x18, 0x00, 0x00, 0x00, // hdr_len
            0x00, 0x00, 0x00, 0x00, // type_off
            0x10, 0x00, 0x00, 0x00, // type_len
            0x10, 0x00, 0x00, 0x00, // str_off
            0x0E, 0x00, 0x00, 0x00, // str_len
            //
            // Type section
            //
            0x01, 0x00, 0x00, 0x00, // type header: name_offset
            0x00, 0x00, 0x00, 0x01, // type header: info_flags
            0x04, 0x00, 0x00, 0x00, // type header: size_or_type
            // Extra info
            0x10, 0x00, 0x08, 0x00,
            //
            // String section
            //
            0x00, // mandatory null string
            0x75, 0x6E, 0x73, 0x69, 0x67, 0x6E, 0x65, 0x64, 0x20, 0x69, 0x6E, 0x74,
            0x00, // "unsigned int"
        ]);

        let mut reader = Reader::new(&readable_buffer);
        let file_header = FileHeader::new(&mut reader).unwrap();
        let type_header = Header::new(&mut reader, &file_header).unwrap();
        let int_type = Int::new(&mut reader, &file_header, type_header).unwrap();
        assert_eq!(int_type.name().as_deref(), Some("unsigned int"));
        assert_eq!(*int_type.size(), 4);
        assert!(!int_type.signed());
        assert!(!int_type.boolean());
        assert!(!int_type.char());
        assert_eq!(*int_type.offset(), 8);
        assert_eq!(*int_type.bits(), 16);
    }

    #[test]
    fn test_int_with_char_encoding_option() {
        let readable_buffer = ReadableBuffer::new(&[
            //
            // BTF header
            //
            0x9F, 0xEB, // magic
            0x01, // version
            0x00, // flags
            0x18, 0x00, 0x00, 0x00, // hdr_len
            0x00, 0x00, 0x00, 0x00, // type_off
            0x10, 0x00, 0x00, 0x00, // type_len
            0x10, 0x00, 0x00, 0x00, // str_off
            0x06, 0x00, 0x00, 0x00, // str_len
            //
            // Type section
            //
            0x01, 0x00, 0x00, 0x00, // type header: name_offset
            0x00, 0x00, 0x00, 0x01, // type header: info_flags
            0x01, 0x00, 0x00, 0x00, // type header: size_or_type
            // Extra info
            0x08, 0x00, 0x00, 0x02,
            //
            // String section
            //
            0x00, // mandatory null string
            0x63, 0x68, 0x61, 0x72, 0x00, // char
        ]);

        let mut reader = Reader::new(&readable_buffer);
        let file_header = FileHeader::new(&mut reader).unwrap();
        let type_header = Header::new(&mut reader, &file_header).unwrap();
        let int_type = Int::new(&mut reader, &file_header, type_header).unwrap();
        assert_eq!(int_type.name().as_deref(), Some("char"));
        assert_eq!(*int_type.size(), 1);
        assert!(!int_type.signed());
        assert!(!int_type.boolean());
        assert!(*int_type.char());
        assert_eq!(*int_type.offset(), 0);
        assert_eq!(*int_type.bits(), 8);
    }

    #[test]
    fn test_int_with_signed_encoding_option() {
        let readable_buffer = ReadableBuffer::new(&[
            //
            // BTF header
            //
            0x9F, 0xEB, // magic
            0x01, // version
            0x00, // flags
            0x18, 0x00, 0x00, 0x00, // hdr_len
            0x00, 0x00, 0x00, 0x00, // type_off
            0x10, 0x00, 0x00, 0x00, // type_len
            0x10, 0x00, 0x00, 0x00, // str_off
            0x05, 0x00, 0x00, 0x00, // str_len
            //
            // Type section
            //
            0x01, 0x00, 0x00, 0x00, // type header: name_offset
            0x00, 0x00, 0x00, 0x01, // type header: info_flags
            0x01, 0x00, 0x00, 0x00, // type header: size_or_type
            // Extra info
            0x08, 0x00, 0x00, 0x01,
            //
            // String section
            //
            0x00, // mandatory null string
            0x69, 0x6E, 0x74, 0x00, // "int"
        ]);

        let mut reader = Reader::new(&readable_buffer);
        let file_header = FileHeader::new(&mut reader).unwrap();
        let type_header = Header::new(&mut reader, &file_header).unwrap();
        let int_type = Int::new(&mut reader, &file_header, type_header).unwrap();
        assert_eq!(int_type.name().as_deref(), Some("int"));
        assert_eq!(*int_type.size(), 1);
        assert!(int_type.signed());
        assert!(!int_type.boolean());
        assert!(!int_type.char());
        assert_eq!(*int_type.offset(), 0);
        assert_eq!(*int_type.bits(), 8);
    }

    #[test]
    fn test_int_with_bool_encoding_option() {
        let readable_buffer = ReadableBuffer::new(&[
            //
            // BTF header
            //
            0x9F, 0xEB, // magic
            0x01, // version
            0x00, // flags
            0x18, 0x00, 0x00, 0x00, // hdr_len
            0x00, 0x00, 0x00, 0x00, // type_off
            0x10, 0x00, 0x00, 0x00, // type_len
            0x10, 0x00, 0x00, 0x00, // str_off
            0x06, 0x00, 0x00, 0x00, // str_len
            //
            // Type section
            //
            0x01, 0x00, 0x00, 0x00, // type header: name_offset
            0x00, 0x00, 0x00, 0x01, // type header: info_flags
            0x01, 0x00, 0x00, 0x00, // type header: size_or_type
            // Extra info
            0x08, 0x00, 0x00, 0x04,
            //
            // String section
            //
            0x00, // mandatory null string
            0x62, 0x6F, 0x6F, 0x6C, 0x00, // "bool"
        ]);

        let mut reader = Reader::new(&readable_buffer);
        let file_header = FileHeader::new(&mut reader).unwrap();
        let type_header = Header::new(&mut reader, &file_header).unwrap();
        let int_type = Int::new(&mut reader, &file_header, type_header).unwrap();
        assert_eq!(int_type.name().as_deref(), Some("bool"));
        assert_eq!(*int_type.size(), 1);
        assert!(!int_type.signed());
        assert!(int_type.boolean());
        assert!(!int_type.char());
        assert_eq!(*int_type.offset(), 0);
        assert_eq!(*int_type.bits(), 8);
    }
}