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

use libc;
use std;
use std::fs::File;
use std::io::Read;

pub type Pid = libc::pid_t;

/// A struct representing a single virtual memory region
/// While this structure only is for Linux, the OSX, Windows, and FreeBSD
/// variants have identical exposed methods
#[derive(Debug, Clone, PartialEq)]
pub struct MapRange {
    range_start: usize,
    range_end: usize,
    pub offset: usize,
    pub dev: String,
    pub flags: String,
    pub inode: usize,
    pathname: Option<String>,
}

impl MapRange {
    /// Returns the size of this MapRange in bytes
    pub fn size(&self) -> usize { self.range_end - self.range_start }
    /// Returns the address this MapRange starts at
    pub fn start(&self) -> usize { self.range_start }
    /// Returns the filename of the loaded module
    pub fn filename(&self) -> &Option<String> { &self.pathname }
    /// Returns whether this range contains executable code
    pub fn is_exec(&self) -> bool { &self.flags[2..3] == "x" }
    /// Returns whether this range contains writeable memory
    pub fn is_write(&self) -> bool { &self.flags[1..2] == "w" }
    /// Returns whether this range contains readable memory
    pub fn is_read(&self) -> bool { &self.flags[0..1] == "r" }
}

/// Gets a Vec of [`MapRange`](linux_maps/struct.MapRange.html) structs for
/// the passed in PID. (Note that while this function is for linux, the OSX,
/// Windows, and FreeBSD variants have the same interface)
pub fn get_process_maps(pid: Pid) -> std::io::Result<Vec<MapRange>> {
    // Parses /proc/PID/maps into a Vec<MapRange>
    let maps_file = format!("/proc/{}/maps", pid);
    let mut file = File::open(maps_file)?;
    let mut contents = String::new();
    file.read_to_string(&mut contents)?;
    Ok(parse_proc_maps(&contents))
}

fn parse_proc_maps(contents: &str) -> Vec<MapRange> {
    let mut vec: Vec<MapRange> = Vec::new();
    for line in contents.split("\n") {
        let mut split = line.split_whitespace();
        let range = split.next();
        if range == None {
            break;
        }
        let mut range_split = range.unwrap().split("-");
        let range_start = range_split.next().unwrap();
        let range_end = range_split.next().unwrap();
        let flags = split.next().unwrap();
        let offset = split.next().unwrap();
        let dev = split.next().unwrap();
        let inode = split.next().unwrap();

        vec.push(MapRange {
            range_start: usize::from_str_radix(range_start, 16).unwrap(),
            range_end: usize::from_str_radix(range_end, 16).unwrap(),
            offset: usize::from_str_radix(offset, 16).unwrap(),
            dev: dev.to_string(),
            flags: flags.to_string(),
            inode: usize::from_str_radix(inode, 10).unwrap(),
            pathname: Some(split.collect::<Vec<&str>>().join(" ")).filter(|x| !x.is_empty()),
        });
    }
    vec
}

#[test]
fn test_parse_maps() {
    let contents = include_str!("../ci/testdata/map.txt");
    let vec = parse_proc_maps(contents);
    let expected = vec![
        MapRange {
            range_start: 0x00400000,
            range_end: 0x00507000,
            offset: 0,
            dev: "00:14".to_string(),
            flags: "r-xp".to_string(),
            inode: 205736,
            pathname: Some("/usr/bin/fish".to_string()),
        },
        MapRange {
            range_start: 0x00708000,
            range_end: 0x0070a000,
            offset: 0,
            dev: "00:00".to_string(),
            flags: "rw-p".to_string(),
            inode: 0,
            pathname: None,
        },
        MapRange {
            range_start: 0x0178c000,
            range_end: 0x01849000,
            offset: 0,
            dev: "00:00".to_string(),
            flags: "rw-p".to_string(),
            inode: 0,
            pathname: Some("[heap]".to_string()),
        },
        MapRange {
            range_start: 0x7f438053b000,
            range_end: 0x7f438053f000,
            offset: 0,
            dev: "fd:01".to_string(),
            flags: "r--p".to_string(),
            inode: 59034409,
            pathname: Some("/usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0.4200.6 (deleted)".to_string()),
        }
    ];
    assert_eq!(vec, expected);

    // Also check that maps_contain_addr works as expected
    assert_eq!(super::maps_contain_addr(0x00400000, &vec), true);
    assert_eq!(super::maps_contain_addr(0x00300000, &vec), false);
}