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|
use std::env;
use std::fs;
use std::io::{self, Write};
use std::path::{Component, Path, PathBuf};
use std::process::ExitCode;
use crate::render;
pub fn run() -> ExitCode {
let Ok(document_root) = env::var("DOCUMENT_ROOT") else {
return respond_error(500, "DOCUMENT_ROOT is not set");
};
let Some(raw_request) = request_path() else {
return respond_error(500, "no request path available");
};
let request = strip_query(&raw_request);
let Some(target) = safe_join(Path::new(&document_root), request) else {
return respond_error(404, "not found");
};
let Ok(metadata) = fs::metadata(&target) else {
return respond_error(404, "not found");
};
if !metadata.is_file() {
return respond_error(404, "not found");
}
let Ok(bytes) = fs::read(&target) else {
return respond_error(500, "read error");
};
let Ok(text) = String::from_utf8(bytes) else {
return respond_error(404, "not found");
};
let html = render::page(&target, &text);
let body = html.as_bytes();
let header = format!(
"Status: 200 OK\nContent-Type: text/html; charset=utf-8\nContent-Length: {}\n\n",
body.len()
);
let stdout = io::stdout();
let mut handle = stdout.lock();
if handle.write_all(header.as_bytes()).is_err() {
return ExitCode::from(1);
}
if handle.write_all(body).is_err() {
return ExitCode::from(1);
}
ExitCode::SUCCESS
}
fn request_path() -> Option<String> {
env::var("DOCUMENT_URI")
.or_else(|_| env::var("PATH_INFO"))
.ok()
}
fn strip_query(s: &str) -> &str {
let s = s.split('?').next().unwrap_or(s);
s.split('#').next().unwrap_or(s)
}
// Only top-level, non-dotfile names are servable: rejects paths with
// `..`, with subdirectories, and with names starting with `.`.
fn safe_join(root: &Path, request: &str) -> Option<PathBuf> {
let mut name = None;
for component in Path::new(request).components() {
match component {
Component::Normal(c) => {
if name.is_some() {
return None;
}
if c.as_encoded_bytes().first() == Some(&b'.') {
return None;
}
name = Some(c);
}
Component::RootDir | Component::CurDir => {}
Component::ParentDir | Component::Prefix(_) => return None,
}
}
name.map(|n| root.join(n))
}
fn respond_error(code: u16, message: &str) -> ExitCode {
let status = match code {
400 => "400 Bad Request",
403 => "403 Forbidden",
404 => "404 Not Found",
_ => "500 Internal Server Error",
};
println!("Status: {status}");
println!("Content-Type: text/plain; charset=utf-8");
println!();
println!("{message}");
ExitCode::SUCCESS
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn safe_join_normal() {
let r = safe_join(Path::new("/srv/p"), "/x.txt").unwrap();
assert_eq!(r, PathBuf::from("/srv/p/x.txt"));
}
#[test]
fn safe_join_rejects_subdirectories() {
assert!(safe_join(Path::new("/srv/p"), "/sub/x.txt").is_none());
assert!(safe_join(Path::new("/srv/p"), "/a/b/c").is_none());
}
#[test]
fn safe_join_rejects_dotfiles() {
assert!(safe_join(Path::new("/srv/p"), "/.ssh").is_none());
assert!(safe_join(Path::new("/srv/p"), "/.bashrc").is_none());
assert!(safe_join(Path::new("/srv/p"), ".env").is_none());
}
#[test]
fn safe_join_rejects_parent() {
assert!(safe_join(Path::new("/srv/p"), "/../etc/passwd").is_none());
assert!(safe_join(Path::new("/srv/p"), "../etc/passwd").is_none());
assert!(safe_join(Path::new("/srv/p"), "/sub/../../etc").is_none());
}
#[test]
fn safe_join_rejects_empty() {
assert!(safe_join(Path::new("/srv/p"), "").is_none());
assert!(safe_join(Path::new("/srv/p"), "/").is_none());
}
#[test]
fn strip_query_removes_query_and_fragment() {
assert_eq!(strip_query("/x.txt?foo=bar"), "/x.txt");
assert_eq!(strip_query("/x.txt#frag"), "/x.txt");
assert_eq!(strip_query("/x.txt?a=b#frag"), "/x.txt");
assert_eq!(strip_query("/x.txt"), "/x.txt");
}
}
|
