sys adding subset of procctl support for FreeBSD.

changelog/2164.added.md

@@ -0,0 +1 @@
+Added the `procctl` process feature to `::nix::sys` for FreeBSD.

src/sys/mod.rs

@@ -73,6 +73,12 @@ feature! {
     pub mod prctl;
 }
 
+#[cfg(target_os = "freebsd")]
+feature! {
+    #![feature = "process"]
+    pub mod procctl;
+}
+
 feature! {
     #![feature = "pthread"]
     pub mod pthread;

src/sys/procctl.rs

@@ -0,0 +1,58 @@
+//! procctl provides programmatic control over processes.
+//!
+//! Here we act on the current process, so we save a getpid syscall here.
+//!
+//! For more documentation, please read [procctl(2)](https://man.freebsd.org/cgi/man.cgi?query=procctl&sektion=2)
+use crate::errno::Errno;
+use crate::sys::signal::Signal;
+use crate::Result;
+
+use libc::c_int;
+use std::convert::TryFrom;
+
+/// Enable/disable tracing on the current process, allowing debugging and core dump generation.
+pub fn set_dumpable(attribute: bool) -> Result<()> {
+    let mut dumpable = match attribute {
+        true => libc::PROC_TRACE_CTL_ENABLE,
+        false => libc::PROC_TRACE_CTL_DISABLE
+    };
+
+    let res = unsafe { libc::procctl(libc::P_PID, 0, libc::PROC_TRACE_CTL, &mut dumpable as *mut c_int as _) };
+    Errno::result(res).map(drop)
+}
+
+/// Get the tracing status of the current process.
+pub fn get_dumpable() -> Result<bool> {
+    let mut dumpable: c_int = 0;
+
+    let res = unsafe { libc::procctl(libc::P_PID, 0, libc::PROC_TRACE_STATUS, &mut dumpable as *mut c_int as _) };
+    match Errno::result(res) {
+        Ok(_) => Ok(matches!(dumpable, libc::PROC_TRACE_CTL_ENABLE)),
+        Err(e) => Err(e),
+    }
+}
+
+/// Set the delivery of the `signal` when the parent of the calling process exits.
+pub fn set_pdeathsig<T: Into<Option<Signal>>>(signal: T) -> Result<()> {
+    let mut sig = match signal.into() {
+        Some(s) => s as c_int,
+        None => 0,
+    };
+
+    let res = unsafe { libc::procctl(libc::P_PID, 0, libc::PROC_PDEATHSIG_CTL, &mut sig as *mut c_int as _) };
+    Errno::result(res).map(drop)
+}
+
+/// Get the current signal id that will be delivered to the parent process when it's exiting.
+pub fn get_pdeathsig() -> Result<Option<Signal>> {
+    let mut sig: c_int = 0;
+
+    let res = unsafe { libc::procctl(libc::P_PID, 0, libc::PROC_PDEATHSIG_STATUS, &mut sig as *mut c_int as _) };
+    match Errno::result(res) {
+        Ok(_) => Ok(match sig {
+            0 => None,
+            _ => Some(Signal::try_from(sig)?),
+        }),
+        Err(e) => Err(e),
+    }
+}

test/sys/test_procctl.rs

@@ -0,0 +1,29 @@
+#[cfg(target_os = "freebsd")]
+#[cfg(feature = "process")]
+mod test_prctl {
+    use nix::sys::proctl;
+
+    #[test]
+    fn test_get_set_dumpable() {
+        let original = procctl::get_dumpable().unwrap();
+
+        prctl::set_dumpable(false).unwrap();
+        let dumpable = procctl::get_dumpable().unwrap();
+        assert!(!dumpable);
+
+        prctl::set_dumpable(original).unwrap();
+    }
+
+    #[test]
+    fn test_get_set_pdeathsig() {
+        use nix::sys::signal::Signal;
+
+        let original = procctl::get_pdeathsig().unwrap();
+
+        procctl::set_pdeathsig(Signal::SIGUSR1).unwrap();
+        let sig = procctl::get_pdeathsig().unwrap();
+        assert_eq!(sig, Some(Signal::SIGUSR1));
+
+        procctl::set_pdeathsig(original).unwrap();
+    }
+}