mirror of https://git.zx2c4.com/wireguard-rs
Mathias Hall-Andersen
6 years ago
5 changed files with 117 additions and 37 deletions
@ -0,0 +1,86 @@
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use std::fmt; |
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use std::process::exit; |
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use libc::{c_char, chdir, chroot, fork, getpwnam, getuid, setgid, setsid, setuid, umask}; |
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#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)] |
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pub enum DaemonizeError { |
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Fork, |
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SetSession, |
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SetGroup, |
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SetUser, |
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Chroot, |
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Chdir, |
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} |
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impl fmt::Display for DaemonizeError { |
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
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match *self { |
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DaemonizeError::Fork => "unable to fork", |
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DaemonizeError::SetSession => "unable to create new process session", |
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DaemonizeError::SetGroup => "unable to set group (drop privileges)", |
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DaemonizeError::SetUser => "unable to set user (drop privileges)", |
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DaemonizeError::Chroot => "unable to enter chroot jail", |
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DaemonizeError::Chdir => "failed to change directory", |
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} |
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.fmt(f) |
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} |
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} |
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fn fork_and_exit() -> Result<(), DaemonizeError> { |
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let pid = unsafe { fork() }; |
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if pid < 0 { |
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Err(DaemonizeError::Fork) |
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} else if pid == 0 { |
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Ok(()) |
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} else { |
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exit(0); |
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} |
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} |
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pub fn daemonize() -> Result<(), DaemonizeError> { |
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// fork from the original parent
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fork_and_exit()?; |
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// avoid killing the child when this parent dies
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if unsafe { setsid() } < 0 { |
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return Err(DaemonizeError::SetSession); |
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} |
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// fork again to create orphan
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fork_and_exit() |
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} |
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pub fn drop_privileges() -> Result<(), DaemonizeError> { |
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// retrieve nobody's uid & gid
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let usr = unsafe { getpwnam("nobody\x00".as_ptr() as *const c_char) }; |
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if usr.is_null() { |
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return Err(DaemonizeError::SetGroup); |
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} |
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// change root directory
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let uid = unsafe { getuid() }; |
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if uid == 0 && unsafe { chroot("/tmp\x00".as_ptr() as *const c_char) } != 0 { |
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return Err(DaemonizeError::Chroot); |
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} |
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// set umask for files
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unsafe { umask(0) }; |
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// change directory
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if unsafe { chdir("/\x00".as_ptr() as *const c_char) } != 0 { |
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return Err(DaemonizeError::Chdir); |
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} |
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// set group id to nobody
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if unsafe { setgid((*usr).pw_gid) } != 0 { |
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return Err(DaemonizeError::SetGroup); |
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} |
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// set user id to nobody
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if unsafe { setuid((*usr).pw_uid) } != 0 { |
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Err(DaemonizeError::SetUser) |
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} else { |
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Ok(()) |
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} |
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} |
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