RunningJail: Expose jail_attach

src/error.rs

@@ -18,6 +18,9 @@ pub enum JailError {
     #[fail(display = "jail_set syscall failed. The error message returned was: {}", _0)]
     JailSetError(String),
 
+    #[fail(display = "jail_attach syscall failed. The error message returned was: {}", _0)]
+    JailAttachError(#[cause] io::Error),
+
     #[fail(display = "invalid return code from jail_remove")]
     JailRemoveFailed,
 

src/process.rs

@@ -1,12 +1,10 @@
 //! Jail-Specific extensions to the `std::process` module
 
-use libc;
-
 use std::process;
 
-use std::io::{Error, ErrorKind};
 use std::os::unix::process::CommandExt;
 
+use JailError;
 use RunningJail;
 
 /// Extension to the `std::process::Command` builder to run the command in a
@@ -45,17 +43,12 @@ pub trait Jailed {
 #[cfg(target_os = "freebsd")]
 impl Jailed for process::Command {
     fn jail(&mut self, jail: &RunningJail) -> &mut process::Command {
-        let jid = jail.jid;
+        let jail = *jail;
         self.before_exec(move || {
-            let ret = unsafe { libc::jail_attach(jid) };
-            match ret {
-                0 => Ok(()),
-                -1 => Err(Error::last_os_error()),
-                _ => Err(Error::new(
-                    ErrorKind::Other,
-                    "invalid return value from jail_attach",
-                )),
-            }
+            jail.attach().map_err(|err| match err {
+                JailError::JailAttachError(e) => e,
+                _ => panic!("jail.attach() failed with unexpected error"),
+            })
         });
 
         self

src/running.rs

@@ -1,10 +1,12 @@
+use libc;
 use param;
 use rctl;
 use sys;
 use JailError;
 use StoppedJail;
 
 use std::collections::HashMap;
+use std::io::{Error, ErrorKind};
 use std::net;
 use std::path;
 
@@ -417,6 +419,19 @@ impl RunningJail {
             .usage()
             .map_err(JailError::RctlError)
     }
+
+    /// Jail the current process into the given jail.
+    pub fn attach(&self) -> Result<(), JailError> {
+        let ret = unsafe { libc::jail_attach(self.jid) };
+        match ret {
+            0 => Ok(()),
+            -1 => Err(Error::last_os_error()),
+            _ => Err(Error::new(
+                ErrorKind::Other,
+                "invalid return value from jail_attach",
+            )),
+        }.map_err(JailError::JailAttachError)
+    }
 }
 
 /// An Iterator over running Jails