+use std::ffi::OsString;
+use std::os::fd::RawFd;
+
+use anyhow::{bail, Result};
+
+const CMD_HELP: &str = "\
+Usage: proxmox-termproxy [OPTIONS] --path <path> <listen-port> -- <terminal-cmd>...
+
+Arguments:
+ <listen-port> Port or file descriptor to listen for TCP connections
+ <terminal-cmd>... The command to run connected via a proxied PTY
+
+Options:
+ --authport <authport> Port to relay auth-request, default 85
+ --port-as-fd Use <listen-port> as file descriptor.
+ --path <path> ACL object path to test <perm> on.
+ --perm <perm> Permission to test.
+ -h, --help Print help
+";
+
+#[derive(Debug)]
+pub enum PortOrFd {
+ Port(u16),
+ Fd(RawFd),
+}
+
+impl PortOrFd {
+ fn from_cli(value: u64, use_as_fd: bool) -> Result<PortOrFd> {
+ if use_as_fd {
+ if value > RawFd::MAX as u64 {
+ bail!("FD value too big");
+ }
+ Ok(Self::Fd(value as RawFd))
+ } else {
+ if value > u16::MAX as u64 {
+ bail!("invalid port number");
+ }
+ Ok(Self::Port(value as u16))
+ }
+ }
+}
+
+#[derive(Debug)]
+pub struct Options {
+ /// The actual command to run proxied in a pseudo terminal.
+ pub terminal_command: Vec<OsString>,
+ /// The port or FD that termproxy will listen on for an incoming conection
+ pub listen_port: PortOrFd,
+ /// The port of the local privileged daemon that authentication is relayed to. Defaults to `85`
+ pub api_daemon_port: u16,
+ /// The ACL object path the 'acl_permission' is checked on
+ pub acl_path: String,
+ /// The ACL permission that the ticket, read from the stream, is required to have on 'acl_path'
+ pub acl_permission: Option<String>,
+}
+
+impl Options {
+ pub fn from_env() -> Result<Self> {
+ let mut args: Vec<_> = std::env::args_os().collect();
+ args.remove(0); // remove the executable path.
+
+ // handle finding command after `--` first so that we only parse our options later
+ let terminal_command = if let Some(dash_dash) = args.iter().position(|arg| arg == "--") {
+ let later_args = args.drain(dash_dash + 1..).collect();
+ args.pop(); // .. then remove the `--`
+ Some(later_args)
+ } else {
+ None
+ };
+
+ // Now pass the remaining arguments through to `pico_args`.
+ let mut args = pico_args::Arguments::from_vec(args);
+
+ if args.contains(["-h", "--help"]) {
+ print!("{CMD_HELP}");
+ std::process::exit(0);
+ } else if terminal_command.is_none() {
+ bail!("missing terminal command or -- option-end marker, see '-h' for usage");
+ }
+
+ let options = Self {
+ terminal_command: terminal_command.unwrap(), // checked above
+ listen_port: PortOrFd::from_cli(args.free_from_str()?, args.contains("--port-as-fd"))?,
+ api_daemon_port: args.opt_value_from_str("--authport")?.unwrap_or(85),
+ acl_path: args.value_from_str("--path")?,
+ acl_permission: args.opt_value_from_str("--perm")?,
+ };
+
+ if !args.finish().is_empty() {
+ bail!("unexpected extra arguments, use '-h' for usage");
+ }
+
+ Ok(options)
+ }
+
+ pub fn use_listen_port_as_fd(&self) -> bool {
+ match self.listen_port {
+ PortOrFd::Fd(_) => true,
+ _ => false,
+ }
+ }
+}