Move process.rs module to own directory

1 files changed, 151 insertions, 0 deletions

diff --git a/src/process/mod.rs b/src/process/mod.rs
new file mode 100644
index 0000000000..2d06ab4ae0
--- /dev/null
+++ b/src/process/mod.rs
@@ -0,0 +1,151 @@
+use net::{RemoteAddr, ToRemoteAddrs};
+
+use std::ffi::{OsString, OsStr};
+use std::fmt;
+use std::io;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Child, Stdio};
+
+/// A module for monitoring child processes and get notified of events on them.
+pub mod monitor;
+
+/// An OpenVPN process builder, providing control over the different arguments that the OpenVPN
+/// binary accepts.
+pub struct OpenVpnBuilder {
+    openvpn_bin: OsString,
+    config: Option<PathBuf>,
+    remotes: Vec<RemoteAddr>,
+}
+
+impl OpenVpnBuilder {
+    /// Constructs a new `OpenVpnBuilder` for launching OpenVPN processes from the binary at
+    /// `openvpn_bin`.
+    pub fn new<P: AsRef<OsStr>>(openvpn_bin: P) -> Self {
+        OpenVpnBuilder {
+            openvpn_bin: OsString::from(openvpn_bin.as_ref()),
+            config: None,
+            remotes: vec![],
+        }
+    }
+
+    /// Sets what configuration file will be given to OpenVPN
+    pub fn config<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.config = Some(path.as_ref().to_path_buf());
+        self
+    }
+
+    /// Sets the addresses that OpenVPN will connect to. See OpenVPN documentation for how multiple
+    /// remotes are handled.
+    pub fn remotes<A: ToRemoteAddrs>(&mut self, remotes: A) -> io::Result<&mut Self> {
+        self.remotes = remotes.to_remote_addrs()?.collect();
+        Ok(self)
+    }
+
+    /// Executes the OpenVPN process as a child process, returning a handle to it.
+    pub fn spawn(&self) -> io::Result<Child> {
+        let mut command = self.create_command();
+        command.args(&self.get_arguments());
+        command.spawn()
+    }
+
+    fn create_command(&self) -> Command {
+        let mut command = Command::new(&self.openvpn_bin);
+        command.env_clear()
+            .stdin(Stdio::null())
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped());
+        command
+    }
+
+    /// Returns all arguments that the subprocess would be spawned with.
+    pub fn get_arguments(&self) -> Vec<OsString> {
+        let mut args = vec![];
+        if let Some(ref config) = self.config {
+            args.push(OsString::from("--config"));
+            args.push(OsString::from(config.as_os_str()));
+        }
+        for remote in &self.remotes {
+            args.push(OsString::from("--remote"));
+            args.push(OsString::from(remote.address()));
+            args.push(OsString::from(remote.port().to_string()));
+        }
+        args
+    }
+}
+
+impl fmt::Display for OpenVpnBuilder {
+    /// Format the program and arguments of an `OpenVpnBuilder` for display. Any non-utf8 data is
+    /// lossily converted using the utf8 replacement character.
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str(&self.openvpn_bin.to_string_lossy())?;
+        for arg in self.get_arguments().iter().map(|arg| arg.to_string_lossy()) {
+            write_argument(fmt, &arg)?;
+        }
+        Ok(())
+    }
+}
+
+fn write_argument(fmt: &mut fmt::Formatter, arg: &str) -> fmt::Result {
+    fmt.write_str(" ")?;
+    let quote = arg.contains(char::is_whitespace);
+    if quote {
+        fmt.write_str("\"")?;
+    }
+    fmt.write_str(arg)?;
+    if quote {
+        fmt.write_str("\"")?;
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use net::RemoteAddr;
+    use std::ffi::OsString;
+    use super::OpenVpnBuilder;
+
+    #[test]
+    fn no_arguments() {
+        let testee_args = OpenVpnBuilder::new("").get_arguments();
+        assert_eq!(0, testee_args.len());
+    }
+
+    #[test]
+    fn passes_one_remote() {
+        let remote = RemoteAddr::new("example.com", 3333);
+
+        let testee_args = OpenVpnBuilder::new("").remotes(remote).unwrap().get_arguments();
+
+        assert!(testee_args.contains(&OsString::from("example.com")));
+        assert!(testee_args.contains(&OsString::from("3333")));
+    }
+
+    #[test]
+    fn passes_two_remotes() {
+        let remotes = vec![RemoteAddr::new("127.0.0.1", 998), RemoteAddr::new("fe80::1", 1337)];
+
+        let testee_args = OpenVpnBuilder::new("").remotes(&remotes[..]).unwrap().get_arguments();
+
+        assert!(testee_args.contains(&OsString::from("127.0.0.1")));
+        assert!(testee_args.contains(&OsString::from("998")));
+        assert!(testee_args.contains(&OsString::from("fe80::1")));
+        assert!(testee_args.contains(&OsString::from("1337")));
+    }
+
+    #[test]
+    fn accepts_str() {
+        assert!(OpenVpnBuilder::new("").remotes("10.0.0.1:1377").is_ok());
+    }
+
+    #[test]
+    fn accepts_slice_of_str() {
+        let remotes = ["10.0.0.1:1337", "127.0.0.1:99"];
+
+        let testee_args = OpenVpnBuilder::new("").remotes(&remotes[..]).unwrap().get_arguments();
+
+        assert!(testee_args.contains(&OsString::from("10.0.0.1")));
+        assert!(testee_args.contains(&OsString::from("1337")));
+        assert!(testee_args.contains(&OsString::from("127.0.0.1")));
+        assert!(testee_args.contains(&OsString::from("99")));
+    }
+}