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Define System::setpgid
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@magicant
magicant committed Jan 29, 2023
1 parent 2a1cf01 commit 8e8bc23
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Showing 3 changed files with 208 additions and 20 deletions.
8 changes: 8 additions & 0 deletions yash-env/src/system.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -289,6 +289,11 @@ pub trait System: Debug {
#[must_use]
fn getppid(&self) -> Pid;

/// Modifies the process group ID of a process.
///
/// This is a thin wrapper around the `setpgid` system call.
fn setpgid(&mut self, pid: Pid, pgid: Pid) -> nix::Result<()>;

/// Creates a new child process.
///
/// This is a thin wrapper around the `fork` system call. Users of `Env`
Expand Down Expand Up @@ -736,6 +741,9 @@ impl System for SharedSystem {
fn getppid(&self) -> Pid {
self.0.borrow().getppid()
}
fn setpgid(&mut self, pid: Pid, pgid: Pid) -> nix::Result<()> {
self.0.borrow_mut().setpgid(pid, pgid)
}
fn new_child_process(&mut self) -> nix::Result<Box<dyn ChildProcess>> {
self.0.borrow_mut().new_child_process()
}
Expand Down
4 changes: 4 additions & 0 deletions yash-env/src/system/real.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -321,6 +321,10 @@ impl System for RealSystem {
nix::unistd::getppid()
}

fn setpgid(&mut self, pid: Pid, pgid: Pid) -> nix::Result<()> {
nix::unistd::setpgid(pid, pgid)
}

/// Creates a new child process.
///
/// This implementation calls the `fork` system call and returns both in the
Expand Down
216 changes: 196 additions & 20 deletions yash-env/src/system/virtual.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -680,6 +680,34 @@ impl System for VirtualSystem {
self.current_process().ppid
}

fn setpgid(&mut self, mut pid: Pid, mut pgid: Pid) -> nix::Result<()> {
if pgid.as_raw() < 0 {
return Err(Errno::EINVAL);
}
if pid.as_raw() == 0 {
pid = self.process_id;
}
if pgid.as_raw() == 0 {
pgid = pid;
}

let mut state = self.state.borrow_mut();
if pgid != pid && !state.processes.values().any(|p| p.pgid == pgid) {
return Err(Errno::EPERM);
}
let process = state.processes.get_mut(&pid).ok_or(Errno::ESRCH)?;
if pid != self.process_id && process.ppid != self.process_id {
return Err(Errno::ESRCH);
}
if process.last_exec.is_some() {
return Err(Errno::EACCES);
}

process.pgid = pgid;
Ok(())
// TODO Support sessions
}

/// Creates a new child process.
///
/// This implementation does not create any real child process. Instead,
Expand Down Expand Up @@ -939,6 +967,7 @@ mod tests {
use futures_executor::LocalPool;
use std::ffi::CString;
use std::ffi::OsString;
use std::future::pending;

impl Executor for futures_executor::LocalSpawner {
fn spawn(
Expand Down Expand Up @@ -1663,6 +1692,169 @@ mod tests {
);
}

fn virtual_system_with_executor() -> (VirtualSystem, LocalPool) {
let system = VirtualSystem::new();
let executor = LocalPool::new();
system.state.borrow_mut().executor = Some(Rc::new(executor.spawner()));
(system, executor)
}

#[test]
fn setpgid_creating_new_group_from_parent() {
let (system, mut executor) = virtual_system_with_executor();
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child = env.system.new_child_process().unwrap();
let future = child.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid = executor.run_until(future);
executor.run_until_stalled();

let result = env.system.setpgid(pid, pid);
assert_eq!(result, Ok(()));

let pgid = state.borrow().processes[&pid].pgid();
assert_eq!(pgid, pid);
}

#[test]
fn setpgid_creating_new_group_from_child() {
let (system, mut executor) = virtual_system_with_executor();
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child = env.system.new_child_process().unwrap();
let future = child.run(
&mut env,
Box::new(|child_env| {
Box::pin(async move {
let result = child_env.system.setpgid(Pid::from_raw(0), Pid::from_raw(0));
assert_eq!(result, Ok(()));
})
}),
);
let pid = executor.run_until(future);
executor.run_until_stalled();

let pgid = state.borrow().processes[&pid].pgid();
assert_eq!(pgid, pid);
}

#[test]
fn setpgid_extending_existing_group_from_parent() {
let (system, mut executor) = virtual_system_with_executor();
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child_1 = env.system.new_child_process().unwrap();
let future = child_1.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid_1 = executor.run_until(future);
env.system.setpgid(pid_1, pid_1).unwrap();
let mut child_2 = env.system.new_child_process().unwrap();
let future = child_2.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid_2 = executor.run_until(future);
executor.run_until_stalled();

let result = env.system.setpgid(pid_2, pid_1);
assert_eq!(result, Ok(()));

let pgid = state.borrow().processes[&pid_2].pgid();
assert_eq!(pgid, pid_1);
}

#[test]
fn setpgid_with_nonexisting_pid() {
let (system, mut executor) = virtual_system_with_executor();
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child = env.system.new_child_process().unwrap();
let future = child.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid = executor.run_until(future);
executor.run_until_stalled();

let dummy_pid = Pid::from_raw(123);
let result = env.system.setpgid(dummy_pid, dummy_pid);
assert_eq!(result, Err(Errno::ESRCH));

let pgid = state.borrow().processes[&pid].pgid();
assert_eq!(pgid, Pid::from_raw(1));
}

#[test]
fn setpgid_with_unrelated_pid() {
let (system, mut executor) = virtual_system_with_executor();
let parent_pid = system.process_id;
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child = env.system.new_child_process().unwrap();
let future = child.run(
&mut env,
Box::new(move |child_env| {
Box::pin(async move {
let result = child_env.system.setpgid(parent_pid, Pid::from_raw(0));
assert_eq!(result, Err(Errno::ESRCH));
})
}),
);
let _pid = executor.run_until(future);
executor.run_until_stalled();

let pgid = state.borrow().processes[&parent_pid].pgid();
assert_eq!(pgid, Pid::from_raw(1));
}

#[test]
fn setpgid_with_execed_child() {
let (system, mut executor) = virtual_system_with_executor();
let path = "/some/file";
let mut content = INode::default();
content.body = FileBody::Regular {
content: vec![],
is_native_executable: true,
};
content.permissions.0 |= 0o100;
let content = Rc::new(RefCell::new(content));
let state = Rc::clone(&system.state);
state.borrow_mut().file_system.save(path, content).unwrap();
let mut env = Env::with_system(Box::new(system));
let mut child = env.system.new_child_process().unwrap();
let future = child.run(
&mut env,
Box::new(move |child_env| {
Box::pin(async move {
let path = CString::new(path).unwrap();
let _ = child_env.system.execve(&path, &[], &[]);
})
}),
);
let pid = executor.run_until(future);
executor.run_until_stalled();

let result = env.system.setpgid(pid, pid);
assert_eq!(result, Err(Errno::EACCES));

let pgid = state.borrow().processes[&pid].pgid();
assert_eq!(pgid, Pid::from_raw(1));
}

#[test]
fn setpgid_with_nonexisting_pgid() {
let (system, mut executor) = virtual_system_with_executor();
let state = Rc::clone(&system.state);
let mut env = Env::with_system(Box::new(system));
let mut child_1 = env.system.new_child_process().unwrap();
let future = child_1.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid_1 = executor.run_until(future);
// env.system.setpgid(pid_1, pid_1).unwrap();
let mut child_2 = env.system.new_child_process().unwrap();
let future = child_2.run(&mut env, Box::new(|_env| Box::pin(pending())));
let pid_2 = executor.run_until(future);
executor.run_until_stalled();

let result = env.system.setpgid(pid_2, pid_1);
assert_eq!(result, Err(Errno::EPERM));

let pgid = state.borrow().processes[&pid_2].pgid();
assert_eq!(pgid, Pid::from_raw(1));
}

#[test]
fn new_child_process_without_executor() {
let mut system = VirtualSystem::new();
Expand All @@ -1672,11 +1864,7 @@ mod tests {

#[test]
fn new_child_process_with_executor() {
let mut system = VirtualSystem::new();
let mut executor = LocalPool::new();
let mut state = system.state.borrow_mut();
state.executor = Some(Rc::new(executor.spawner()));
drop(state);
let (mut system, mut executor) = virtual_system_with_executor();

let result = system.new_child_process();

Expand All @@ -1693,11 +1881,7 @@ mod tests {

#[test]
fn wait_for_running_child() {
let mut system = VirtualSystem::new();
let mut executor = LocalPool::new();
let mut state = system.state.borrow_mut();
state.executor = Some(Rc::new(executor.spawner()));
drop(state);
let (mut system, mut executor) = virtual_system_with_executor();

let child_process = system.new_child_process();

Expand All @@ -1712,11 +1896,7 @@ mod tests {

#[test]
fn wait_for_exited_child() {
let mut system = VirtualSystem::new();
let mut executor = LocalPool::new();
let mut state = system.state.borrow_mut();
state.executor = Some(Rc::new(executor.spawner()));
drop(state);
let (mut system, mut executor) = virtual_system_with_executor();

let child_process = system.new_child_process();

Expand Down Expand Up @@ -1756,11 +1936,7 @@ mod tests {

#[test]
fn exiting_child_sends_sigchld_to_parent() {
let mut system = VirtualSystem::new();
let mut executor = LocalPool::new();
let mut state = system.state.borrow_mut();
state.executor = Some(Rc::new(executor.spawner()));
drop(state);
let (mut system, mut executor) = virtual_system_with_executor();
system
.sigaction(Signal::SIGCHLD, SignalHandling::Catch)
.unwrap();
Expand Down

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