use crate::Message;
use anyhow::{anyhow, Context, Result};
use cached::{proc_macro::cached, Return, TimedCache};
use ssh2::{KeyboardInteractivePrompt, Prompt, Session, Stream};
use std::{
fmt::Debug,
io::{BufRead, BufReader, Read, Write},
net::{Ipv4Addr, TcpStream},
};
const DEFAULT_PORT: u16 = 5022;
const OSSI_LOGOFF: &[u8] = b"clogoff\nt\ny\n";
const OSSI_MAN_TERM: &[u8] = b"ossiem\n";
const OSSI_TERM: &[u8] = b"ossie\n";
const TERM: &str = "vt100";
const TERM_DIMS: (u32, u32, u32, u32) = (81, 25, 0, 0);
const TIMEOUT_MS: u32 = 30000; // Thirty second read/write timeout.
/// Represents a Communication Manager and its login information. Executes
/// collections of [Message]s on an ACM over SSH.
#[derive(Clone)]
pub struct Acm {
addr: Ipv4Addr,
port: Option<u16>,
user: String,
pass: String,
}
impl Debug for Acm {
/// Formats an ACM's configuration information for debugging. Masks passwords.
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Acm")
.field("addr", &self.addr)
.field("port", &self.port.unwrap_or(DEFAULT_PORT))
.field("user", &self.user)
.field("pass", &"********")
.finish()
}
}
impl Default for Acm {
fn default() -> Self {
Self {
addr: Ipv4Addr::new(127, 0, 0, 1),
port: Default::default(),
user: Default::default(),
pass: Default::default(),
}
}
}
impl Acm {
/// Adds an IPv4 address to ACM config.
pub fn with_addr(&mut self, addr: Ipv4Addr) -> &mut Self {
self.addr = addr;
self
}
/// Adds a port to ACM config.
pub fn with_port(&mut self, port: u16) -> &mut Self {
self.port = Some(port);
self
}
/// Adds a login usermame to ACM config.
pub fn with_user(&mut self, user: &str) -> &mut Self {
self.user = user.into();
self
}
/// Adds a login password to ACM config.
pub fn with_pass(&mut self, pass: &str) -> &mut Self {
self.pass = pass.into();
self
}
/// Opens a readable and writable SSH stream into an ACM's Site Administration Terminal.
fn open_stream(&self, term: &[u8]) -> Result<Stream> {
// Initialize SSH session.
let stream = TcpStream::connect((self.addr, self.port.unwrap_or(DEFAULT_PORT)))
.with_context(|| "Failed to open TCP stream to host. Make sure the config is correct and the host is otherwise reachable.")?;
let mut session = Session::new().with_context(|| "Failed to start SSH session.")?;
session.set_tcp_stream(stream);
session.set_timeout(TIMEOUT_MS);
session
.handshake()
.with_context(|| "SSH handshake failed.")?;
session
.userauth_keyboard_interactive(&self.user, &mut SshPrompter::new(&self.pass))
.with_context(|| "Interactive SSH keyboard authentication failed.")?;
// Open shell on SSH channel.
let mut channel = session
.channel_session()
.with_context(|| "Failed to open SSH channel on SSH session.")?;
channel
.request_pty(TERM, None, Some(TERM_DIMS))
.with_context(|| "Failed to open PTY on SSH channel.")?;
channel
.shell()
.with_context(|| "Failed to open shell on SSH channel.")?;
channel
.write_all(term)
.with_context(|| "Failed to send OSSI term.")?;
// Waits until OSSI terminator is read to return channel. If this times
// out, something went wrong with login or ACM is unreachable.
let mut lines = BufReader::new(channel.stream(0)).lines();
while let Some(Ok(line)) = lines.next() {
if line == "t" {
return Ok(channel.stream(0));
}
}
Err(anyhow!("Never reached OSSI term prompt."))
}
/// Runs a given collection of [Message]s (OSSI commands) on the ACM and returns their resulting output.
pub fn run(&self, inputs: &[Message]) -> Result<Vec<Message>> {
let inputs: String = inputs.iter().map(Message::to_string).collect();
let mut stream = self.open_stream(OSSI_TERM)?;
write!(stream, "{}", inputs).with_context(|| "Failed to write inputs to OSSI stream.")?;
stream
.write_all(OSSI_LOGOFF)
.with_context(|| "Failed to write LOGOFF to OSSI stream.")?;
Message::from_output(stream)
}
/// Like [Self::run], but caches results with a timed cache of thirty minutes.
pub fn run_cached(&self, inputs: &[Message]) -> Result<Vec<Message>> {
Ok(run_cached(self, inputs)?.value)
}
/// Like [Self::run], but instead of running [Message]s, it returns the manual pages for the provided OSSI commands.
pub fn manual(&self, inputs: &[Message]) -> Result<String> {
let inputs: String = inputs.iter().map(Message::to_string).collect();
let mut stream = self.open_stream(OSSI_MAN_TERM)?;
write!(stream, "{}", inputs).with_context(|| "Failed to write inputs to OSSI stream.")?;
stream
.write_all(OSSI_LOGOFF)
.with_context(|| "Failed to write LOGOFF to OSSI stream.")?;
let mut output = String::new();
stream
.read_to_string(&mut output)
.with_context(|| "Failed to read manual pages to string.")?;
Ok(output)
}
/// Reads from `readable`, parsing lines as `asa.cfg`-formatted ACM logins.
/// Returns a collection of the parsed logins and their associated
/// names/labels. The spec looks like this:
///
/// ```text
/// (name user:pass@addr:optional_port)
/// ACM01 admin:secret@192.168.1.1:5022
/// ACM02 acdmin:secret@192.168.1.2
/// ACM03 acdmin:secret@192.168.1.3:5023
/// ```
///
/// The port is optional. If it is not provided, the default SAT port of
/// 5022 will be used.
pub fn from_logins(readable: impl Read) -> Result<Vec<(String, Self)>> {
let mut acms = Vec::new();
for line in BufReader::new(readable).lines() {
let line = line.with_context(|| "Failed to read line of config.")?;
let mut acm = Self::default();
if let Some((name, config)) = line.split_once(' ') {
if let Some((creds, dest)) = config.split_once('@') {
if let Some((user, pass)) = creds.split_once(':') {
if let Some((addr, port)) = dest.split_once(':') {
acm.with_port(
port.parse()
.with_context(|| "Failed to parse ACM socket port.")?,
)
.with_addr(
addr.parse()
.with_context(|| "Failed to parse ACM IP address.")?,
);
} else {
acm.with_addr(
dest.parse()
.with_context(|| "Failed to parse ACM IP address.")?,
);
}
acm.with_user(user).with_pass(pass);
acms.push((name.into(), acm));
}
}
}
}
Ok(acms)
}
}
/// This memoized function is a timed cache where entries are evicted after
/// thirty minutes. Errors are not cached, only successes.
#[cached(
result = true,
type = "TimedCache<String, Return<Vec<Message>>>",
create = "{ TimedCache::with_lifespan(1800) }",
convert = r#"{ format!("{}{:?}{:?}", acm.addr, acm.port, inputs) }"#
)]
fn run_cached(acm: &Acm, inputs: &[Message]) -> Result<Return<Vec<Message>>> {
Ok(Return::new(acm.run(inputs)?))
}
/// Used internally for password-based SSH authentication.
struct SshPrompter<'a> {
pass: &'a str,
}
impl<'a> SshPrompter<'a> {
fn new(pass: &'a str) -> Self {
Self { pass }
}
}
impl<'a> KeyboardInteractivePrompt for SshPrompter<'a> {
fn prompt<'b>(
&mut self,
_username: &str,
_instructions: &str,
_prompts: &[Prompt<'b>],
) -> Vec<String> {
vec![self.pass.to_owned()]
}
}
