Mercurial > hg
view rust/chg/src/locator.rs @ 40289:7d3285f799cc
rust-chg: add struct holding information needed to spawn server process
The Locator will handle the initialization of the connection. It will spawn
server processes as needed.
author | Yuya Nishihara <yuya@tcha.org> |
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date | Sat, 06 Oct 2018 21:13:59 +0900 |
parents | 44840bcc411a |
children | ce088b38f92b |
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// Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org> // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. //! Utility for locating command-server process. use std::env; use std::ffi::{OsStr, OsString}; use std::fs::{self, DirBuilder}; use std::io; use std::os::unix::ffi::{OsStrExt, OsStringExt}; use std::os::unix::fs::{DirBuilderExt, MetadataExt}; use std::path::{Path, PathBuf}; use std::process; use std::time::Duration; use super::procutil; /// Helper to connect to and spawn a server process. #[derive(Clone, Debug)] pub struct Locator { hg_command: OsString, current_dir: PathBuf, env_vars: Vec<(OsString, OsString)>, process_id: u32, base_sock_path: PathBuf, timeout: Duration, } impl Locator { /// Creates locator capturing the current process environment. /// /// If no `$CHGSOCKNAME` is specified, the socket directory will be /// created as necessary. pub fn prepare_from_env() -> io::Result<Locator> { Ok(Locator { hg_command: default_hg_command(), current_dir: env::current_dir()?, env_vars: env::vars_os().collect(), process_id: process::id(), base_sock_path: prepare_server_socket_path()?, timeout: default_timeout(), }) } /// Temporary socket path for this client process. fn temp_sock_path(&self) -> PathBuf { let src = self.base_sock_path.as_os_str().as_bytes(); let mut buf = Vec::with_capacity(src.len() + 6); buf.extend_from_slice(src); buf.extend_from_slice(format!(".{}", self.process_id).as_bytes()); OsString::from_vec(buf).into() } } /// Determines the server socket to connect to. /// /// If no `$CHGSOCKNAME` is specified, the socket directory will be created /// as necessary. pub fn prepare_server_socket_path() -> io::Result<PathBuf> { if let Some(s) = env::var_os("CHGSOCKNAME") { Ok(PathBuf::from(s)) } else { let mut path = default_server_socket_dir(); create_secure_dir(&path)?; path.push("server"); Ok(path) } } /// Determines the default server socket path as follows. /// /// 1. `$XDG_RUNTIME_DIR/chg` /// 2. `$TMPDIR/chg$UID` /// 3. `/tmp/chg$UID` pub fn default_server_socket_dir() -> PathBuf { // XDG_RUNTIME_DIR should be ignored if it has an insufficient permission. // https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html if let Some(Ok(s)) = env::var_os("XDG_RUNTIME_DIR").map(check_secure_dir) { let mut path = PathBuf::from(s); path.push("chg"); path } else { let mut path = env::temp_dir(); path.push(format!("chg{}", procutil::get_effective_uid())); path } } /// Determines the default hg command. pub fn default_hg_command() -> OsString { // TODO: maybe allow embedding the path at compile time (or load from hgrc) env::var_os("CHGHG").or(env::var_os("HG")).unwrap_or(OsStr::new("hg").to_owned()) } fn default_timeout() -> Duration { let secs = env::var("CHGTIMEOUT").ok().and_then(|s| s.parse().ok()).unwrap_or(60); Duration::from_secs(secs) } /// Creates a directory which the other users cannot access to. /// /// If the directory already exists, tests its permission. fn create_secure_dir<P>(path: P) -> io::Result<()> where P: AsRef<Path>, { DirBuilder::new().mode(0o700).create(path.as_ref()).or_else(|err| { if err.kind() == io::ErrorKind::AlreadyExists { check_secure_dir(path).map(|_| ()) } else { Err(err) } }) } fn check_secure_dir<P>(path: P) -> io::Result<P> where P: AsRef<Path>, { let a = fs::symlink_metadata(path.as_ref())?; if a.is_dir() && a.uid() == procutil::get_effective_uid() && (a.mode() & 0o777) == 0o700 { Ok(path) } else { Err(io::Error::new(io::ErrorKind::Other, "insecure directory")) } }