pelf 0.1.5

A library for parsing/generating/analyzing ELF
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

use super::ElfParser;
use crate::header;

impl ElfParser {
    /// parses an 64-bit ELF header as the raw representation.
    pub(super) fn parse_raw_elf64_header<'a>(
        &'a self,
        b: &'a [u8],
    ) -> nom::IResult<&'a [u8], header::RawElf64Header> {
        let (b, e_ident) = self.parse_raw_elf_identification()(b)?;
        let (b, e_type) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_machine) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_version) = self.parse_elf64_word(e_ident.e_data, b)?;
        let (b, e_entry) = self.parse_elf64_address(e_ident.e_data, b)?;
        let (b, e_phoff) = self.parse_elf64_offset(e_ident.e_data, b)?;
        let (b, e_shoff) = self.parse_elf64_offset(e_ident.e_data, b)?;
        let (b, e_flags) = self.parse_elf64_word(e_ident.e_data, b)?;
        let (b, e_ehsize) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_phentsize) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_phnum) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_shentsize) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_shnum) = self.parse_elf64_half(e_ident.e_data, b)?;
        let (b, e_shstrndx) = self.parse_elf64_half(e_ident.e_data, b)?;

        let ehdr = header::RawElf64Header {
            e_ident,
            e_type,
            e_machine,
            e_version,
            e_entry,
            e_phoff,
            e_shoff,
            e_flags,
            e_ehsize,
            e_phentsize,
            e_phnum,
            e_shentsize,
            e_shnum,
            e_shstrndx,
        };

        Ok((b, ehdr))
    }

    /// tries to parse the e_ident field in ELF header as the raw representation.
    /// But the input bytes aren't consumed.
    pub(super) fn peek_raw_elf_identification<'a>(
        &'a self,
        b: &'a [u8],
    ) -> nom::IResult<&'a [u8], header::RawElfIdentification> {
        let mut p = nom::combinator::peek(self.parse_raw_elf_identification());
        let (b, e_ident) = p(b)?;

        Ok((b, e_ident))
    }

    /// parses the e_ident field in ELF header as the raw representation.
    fn parse_raw_elf_identification<'a>(
        &'a self,
    ) -> impl Fn(&'a [u8]) -> nom::IResult<&'a [u8], header::RawElfIdentification> {
        move |b: &[u8]| {
            let (b, e_magic) = nom::bytes::complete::tag(header::ELF_MAGICNUMBER_SIGNATURE)(b)?;

            let mut e_ident = header::RawElfIdentification::default();
            let magicnumber_indices = [
                header::ELF_IDENT_MAGICNUMBER0_INDEX,
                header::ELF_IDENT_MAGICNUMBER1_INDEX,
                header::ELF_IDENT_MAGICNUMBER2_INDEX,
                header::ELF_IDENT_MAGICNUMBER3_INDEX,
            ];

            for idx in magicnumber_indices.iter() {
                e_ident.e_magic[*idx] = e_magic[*idx];
            }

            let (b, e_class) = nom::number::complete::u8(b)?;
            e_ident.e_class = e_class;
            let (b, e_data) = nom::number::complete::u8(b)?;
            e_ident.e_data = e_data;
            let (b, e_version) = nom::number::complete::u8(b)?;
            e_ident.e_version = e_version;

            let (b, e_padding) = nom::multi::count(
                nom::number::complete::u8,
                header::ELF_IDENT_PADDING_FIELD_LENGTH,
            )(b)?;

            e_ident.e_padding[..header::ELF_IDENT_PADDING_FIELD_LENGTH]
                .copy_from_slice(&e_padding[..header::ELF_IDENT_PADDING_FIELD_LENGTH]);

            Ok((b, e_ident))
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::parser::ElfParserConfig;

    use super::*;

    #[test]
    fn test_parse_raw_elf64_header() {
        let p = ElfParserConfig::new().build();
        let input = vec![
            0x7f, 0x45, 0x4c, 0x46, // elf magic number
            0x02, // elf class
            0x01, // elf data
            0x01, // elf version
            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // padding
            0x03, 0x00, // elf type
            0x3e, 0x00, // machine
            0x01, 0x00, 0x00, 0x00, // object file version
            0xb0, 0x6a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // entry
            0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // phoff
            0x20, 0x14, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // shoff
            0x00, 0x00, 0x00, 0x00, // flags
            0x40, 0x00, // ehsize
            0x38, 0x00, // phentsize
            0x0d, 0x00, // phnum
            0x40, 0x00, // shentsize
            0x1f, 0x00, // shnum
            0x1e, 0x00, // shstrndx
        ];
        let result = p.parse_raw_elf64_header(&input);
        assert!(result.is_ok());

        let (b, ehdr) = result.unwrap();
        assert!(b.is_empty());

        assert_eq!(header::ELF_MAGICNUMBER_SIGNATURE, ehdr.e_ident.e_magic);
        assert_eq!(0x2, ehdr.e_ident.e_class);
        assert_eq!(0x1, ehdr.e_ident.e_data);
        assert_eq!(0x1, ehdr.e_ident.e_version);
        assert_eq!(
            [0x00; header::ELF_IDENT_PADDING_FIELD_LENGTH],
            ehdr.e_ident.e_padding
        );
        assert_eq!(0x3, ehdr.e_type);
        assert_eq!(0x3e, ehdr.e_machine);
        assert_eq!(0x1, ehdr.e_version);
        assert_eq!(0x6ab0, ehdr.e_entry);
        assert_eq!(0x40, ehdr.e_phoff);
        assert_eq!(0x21420, ehdr.e_shoff);
        assert_eq!(0, ehdr.e_flags);
        assert_eq!(0x40, ehdr.e_ehsize);
        assert_eq!(0x38, ehdr.e_phentsize);
        assert_eq!(0xd, ehdr.e_phnum);
        assert_eq!(0x40, ehdr.e_shentsize);
        assert_eq!(0x1f, ehdr.e_shnum);
        assert_eq!(0x1e, ehdr.e_shstrndx);
    }

    #[test]
    fn test_peek_raw_elf_identification() {
        let p = ElfParserConfig::new().build();
        let input = vec![
            0x7f, 0x45, 0x4c, 0x46, // elf magic number
            0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        ];
        let result = p.peek_raw_elf_identification(&input);
        assert!(result.is_ok());

        let (b, _e_ident) = result.unwrap();
        assert_eq!(&input, b);
    }

    #[test]
    fn test_parse_raw_elf_identification() {
        let p = ElfParserConfig::new().build();
        let input = vec![
            0x7f, 0x45, 0x4c, 0x46, // elf magic number
            0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        ];
        let result = p.parse_raw_elf_identification()(&input);
        assert!(result.is_ok());

        let (b, e_ident) = result.unwrap();
        assert_eq!(0, b.len());

        assert_eq!(header::ELF_MAGICNUMBER_SIGNATURE, e_ident.e_magic);
        assert_eq!(0x2, e_ident.e_class);
        assert_eq!(0x1, e_ident.e_data);
        assert_eq!(0x1, e_ident.e_version);
        assert_eq!(
            [0x00; header::ELF_IDENT_PADDING_FIELD_LENGTH],
            e_ident.e_padding
        );
    }
}