proka_exec/
sections.rs

1//! The definitions of section entry.
2use crate::{HEADER_SIZE, SECTION_SIZE};
3
4/// A section entry.
5#[repr(C, packed)]
6#[derive(Debug, Clone, Copy)]
7pub struct Section {
8    /// The section name (16 bytes max).
9    pub name: [u8; 16],
10
11    /// Assign is this section loadable
12    pub is_loadable: bool,
13
14    /// Assign is this section executable
15    pub is_execable: bool,
16
17    /// The offset of the section start.
18    pub base: u32,
19
20    /// The length of the section.
21    pub length: u32,
22
23    /// Reserved bits
24    pub _reserved: [u8; 6],
25}
26
27impl Section {
28    /// Convert this object to array.
29    #[inline]
30    pub const fn to_array(&self) -> [u8; SECTION_SIZE] {
31        // SAFETY: used `#[repr(C)]`
32        unsafe { core::ptr::read(self as *const Self as *const [u8; SECTION_SIZE]) }
33    }
34
35    /// Validate is this section not corrupted.
36    #[inline]
37    pub fn validate(&self) -> bool {
38        // Cannot executable if unloadable
39        let bit_ok = !(self.is_execable && !self.is_loadable);
40
41        // Length cannot be 0
42        let length_ok = self.length != 0;
43
44        // First check: base must >= 128+32
45        let base_ok = self.base as usize >= (HEADER_SIZE + SECTION_SIZE);
46
47        bit_ok || length_ok || base_ok
48    }
49}
50
51/// The iterator of each sections
52#[derive(Debug, Clone, Copy)]
53pub struct SectionIter {
54    buf: &'static [u8],
55    total: u16,
56    current: u16,
57}
58impl SectionIter {
59    pub(crate) fn new(buf: &'static [u8], total: u16, current: u16) -> Self {
60        Self {
61            buf,
62            total,
63            current,
64        }
65    }
66}
67
68// Iterator implementations
69impl Iterator for SectionIter {
70    type Item = Section;
71
72    fn next(&mut self) -> Option<Self::Item> {
73        // Check: is current over than total
74        if self.current >= self.total {
75            return None;
76        }
77
78        let base = HEADER_SIZE + self.current as usize * SECTION_SIZE;
79        let buf = &self.buf[base..base + SECTION_SIZE];
80
81        // Now convert it
82        let section = unsafe { *(buf.as_ptr() as *const Section) };
83
84        // Plus current value and return
85        self.current += 1;
86        Some(section)
87    }
88}
proka_exec/sections.rs

proka_exec/
sections.rs
