~danyspin97/initrz

ref: bc9c9308a9781511f758bf8518cd5d04a0e7eb59 initrz/src/initrz/src/module_loader.rs -rw-r--r-- 7.3 KiB
bc9c9308Danilo Spinella Remove common library and move code to module_loader module 6 months ago
                                                                                
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
use anyhow::{bail, Context, Result};
use dowser::Dowser;
use glob::{glob, Pattern};
use log::{debug, warn};
use nix::kmod::{init_module, ModuleInitFlags};
use xz2::bufread::XzDecoder;

use std::collections::{HashMap, HashSet};
use std::convert::TryFrom;
use std::ffi::CString;
use std::fs::File;
use std::io::{BufRead, BufReader, Read};
use std::mem::drop;
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::RwLock;

pub struct ModAlias {
    pattern: Pattern,
    module: String,
}

pub struct Module {
    pub filename: String,
    pub deps: Vec<String>,
}

pub struct ModuleLoader {
    modules: HashMap<String, Module>,
    aliases: Vec<ModAlias>,
    modules_loaded: RwLock<HashSet<String>>,
    kernel_root: PathBuf,
}

pub fn parse_module_dep(filename: &Path) -> Result<HashMap<String, Module>> {
    let file =
        File::open(filename).with_context(|| format!("unable to open filename {:?}", filename))?;
    let lines = BufReader::new(file).lines();
    Ok(lines
        .filter_map(|line: Result<String, _>| line.ok())
        .map(|line| -> Result<(String, Module)> {
            let token_index = line
                .find(':')
                .with_context(|| format!("could not find ':' in line:\n{}", line))?;
            let module_filename = &line[0..token_index];
            let module = if let Ok(module) = get_module_name(module_filename) {
                module
            } else {
                bail!("{} is not a valid module name", module_filename);
            };
            let mut deps: Vec<String> = Vec::new();
            let rest_of_line = &line[token_index + 1..];
            if rest_of_line.len() != 0 {
                // iter.rest() returns " kernel/..." so skip the first space
                let split = rest_of_line[1..].split(' ');
                split
                    .filter_map(|dep| get_module_name(dep).ok())
                    .for_each(|dep| deps.push(dep));

                deps.reverse();
            }
            Ok((
                module,
                Module {
                    filename: module_filename.to_string(),
                    deps,
                },
            ))
        })
        .filter_map(|res| res.ok())
        .collect())
}

fn get_module_name(filename: &str) -> Result<String> {
    Ok(Path::new(filename)
        .file_stem()
        .and_then(|module| std::path::Path::new(module).file_stem())
        .with_context(|| format!("failed to get module name of file {}", filename))?
        .to_str()
        .with_context(|| {
            format!(
                "failed to convert the module name in file {} from OsStr to Str",
                filename
            )
        })?
        .to_string())
}

pub fn parse_module_alias(filename: &Path) -> Result<Vec<ModAlias>> {
    let file =
        File::open(filename).with_context(|| format!("unable to open file {:?}", filename))?;
    let lines = BufReader::new(file).lines();

    Ok(lines
        .filter_map(|line: Result<String, _>| line.ok())
        .map(|line| -> Result<ModAlias> {
            let mut split = line[6..].splitn(2, ' ');
            Ok(ModAlias {
                pattern: Pattern::new(split.next().with_context(|| "no pattern found")?)?,
                module: split
                    .next()
                    .with_context(|| "no modalias found")?
                    .to_string(),
            })
        })
        .filter_map(|res| {
            if res.is_err() {
                warn!("unable to parse modalias line");
            }
            res.ok()
        })
        .collect())
}

impl ModuleLoader {
    pub fn init(kernel_version: &str) -> Result<ModuleLoader> {
        let kernel_root = Path::new("/lib/modules").join(kernel_version);
        let mut modules = HashSet::new();

        modules.reserve(glob(&kernel_root.join("*.ko.xz").as_os_str().to_string_lossy())?.count());
        Ok(ModuleLoader {
            modules: parse_module_dep(&kernel_root.join("modules.dep"))?,
            aliases: parse_module_alias(&kernel_root.join("modules.alias"))?,
            modules_loaded: RwLock::new(modules),
            kernel_root,
        })
    }

    pub fn load_module(&self, module_name: &str) -> Result<bool> {
        let modules_loaded = self.modules_loaded.read().unwrap();
        if !modules_loaded.contains(module_name) {
            drop(modules_loaded);
            debug!("loading module {}", module_name);
            let module = self.modules.get(module_name);
            if module.is_none() {
                return Ok(false);
            }
            let module = module.unwrap();
            // Some modules could be builtin, do not block
            module.deps.iter().try_for_each(|dep| -> Result<()> {
                self.load_module(&dep)?;
                Ok(())
            })?;
            let mut modules_loaded = self.modules_loaded.write().unwrap();
            if !modules_loaded.contains(module_name) {
                modules_loaded.insert(String::from(module_name));
            }
            // unlock so that other modules can be loaded in parallel
            drop(modules_loaded);
            let filename = self.kernel_root.join(&module.filename);
            let module_file =
                File::open(&filename).with_context(|| format!("unable to find {:?}", filename))?;
            let mut buf = Vec::new();
            XzDecoder::new(BufReader::new(module_file)).read_to_end(&mut buf)?;

            init_module(&buf, &CString::new("")?).with_context(|| {
                format!("finit_module call failed when loading {}", module_name)
            })?;
        }

        Ok(true)
    }

    pub fn load_modalias(&self, modalias: &str) -> Result<()> {
        let modalias = &self.aliases.iter().find(|m| m.pattern.matches(modalias));
        if let Some(modalias) = modalias {
            self.load_module(&modalias.module)?;
        }

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parse_module_dep_test() {
        let filename = Path::new(concat!(env!("CARGO_MANIFEST_DIR"), "/test/module.dep"));
        let map = parse_module_dep(filename).unwrap();

        let mut expected_map = HashMap::new();

        let mut mhi_deps: Vec<String> = Vec::new();
        mhi_deps.push("mhi".to_string());
        mhi_deps.push("ns".to_string());
        mhi_deps.push("qrtr".to_string());
        expected_map.insert(
            "qrtr-mhi".to_string(),
            Module {
                filename: String::from("kernel/net/qrtr/qrtr-mhi.ko.xz"),
                deps: mhi_deps,
            },
        );

        let mut nvidia_uvm_deps: Vec<String> = Vec::new();
        nvidia_uvm_deps.push("nvidia".to_string());
        expected_map.insert(
            "nvidia-uvm".to_string(),
            Module {
                filename: String::from("kernel/drivers/video/nvidia-uvm.ko.xz"),
                deps: nvidia_uvm_deps,
            },
        );

        expected_map.insert(
            "nvidia".to_string(),
            Module {
                filename: String::from("kernel/drivers/video/nvidia.ko.xz"),
                deps: Vec::new(),
            },
        );

        assert_eq!(map.len(), 3);
        for (module_name, module) in map {
            let expected_module = expected_map.get(&module_name).expect("no module found");
            assert_eq!(module.filename, expected_module.filename);
            assert_eq!(module.deps, expected_module.deps);
        }
    }
}