Initial commit

src/blocking/mod.rs

@@ -0,0 +1,134 @@
+use std::io;
+use std::io::{BufRead, BufReader, Write};
+use std::net::{SocketAddr, TcpStream};
+
+use crate::cmd::{Command, Response};
+use crate::{ClientError, Config, Host, NutError};
+
+/// A blocking NUT client connection.
+pub enum Connection {
+    Tcp(TcpConnection),
+}
+
+impl Connection {
+    pub fn new(config: Config) -> crate::Result<Self> {
+        match &config.host {
+            Host::Tcp(socket_addr) => {
+                Ok(Self::Tcp(TcpConnection::new(config.clone(), socket_addr)?))
+            }
+        }
+    }
+
+    pub fn list_ups(&mut self) -> crate::Result<Vec<(String, String)>> {
+        match self {
+            Self::Tcp(conn) => conn.list_ups(),
+        }
+    }
+}
+
+/// A blocking TCP NUT client connection.
+#[derive(Debug)]
+pub struct TcpConnection {
+    config: Config,
+    tcp_stream: TcpStream,
+}
+
+impl TcpConnection {
+    fn new(config: Config, socket_addr: &SocketAddr) -> crate::Result<Self> {
+        // Create the TCP connection
+        let tcp_stream = TcpStream::connect_timeout(socket_addr, config.timeout)?;
+        let mut connection = Self { config, tcp_stream };
+
+        // Attempt login using `config.auth`
+        connection.login()?;
+
+        Ok(connection)
+    }
+
+    fn login(&mut self) -> crate::Result<()> {
+        if let Some(auth) = &self.config.auth {
+            // Pass username and check for 'OK'
+            Self::write_cmd(&mut self.tcp_stream, Command::SetUsername(&auth.username))?;
+            Self::read_response(&mut self.tcp_stream)?.expect_ok()?;
+
+            // Pass password and check for 'OK'
+            if let Some(password) = &auth.password {
+                Self::write_cmd(&mut self.tcp_stream, Command::SetPassword(&password))?;
+                Self::read_response(&mut self.tcp_stream)?.expect_ok()?;
+            }
+        }
+        Ok(())
+    }
+
+    fn list_ups(&mut self) -> crate::Result<Vec<(String, String)>> {
+        Self::write_cmd(&mut self.tcp_stream, Command::List(&["UPS"]))?;
+        let list = Self::read_list(&mut self.tcp_stream, &["UPS"])?;
+
+        Ok(list
+            .into_iter()
+            .map(|mut row| (row.remove(0), row.remove(0)))
+            .collect())
+    }
+
+    fn write_cmd(stream: &mut TcpStream, line: Command) -> crate::Result<()> {
+        let line = format!("{}\n", line);
+        stream.write_all(line.as_bytes())?;
+        stream.flush()?;
+        Ok(())
+    }
+
+    fn parse_line(reader: &mut BufReader<&mut TcpStream>) -> crate::Result<Vec<String>> {
+        let mut raw = String::new();
+        reader.read_line(&mut raw)?;
+        raw = raw[..raw.len() - 1].to_string(); // Strip off \n
+
+        // Parse args by splitting whitespace, minding quotes for args with multiple words
+        let args = shell_words::split(&raw)
+            .map_err(|e| NutError::Generic(format!("Parsing server response failed: {}", e)))?;
+
+        Ok(args)
+    }
+
+    fn read_response(stream: &mut TcpStream) -> crate::Result<Response> {
+        let mut reader = io::BufReader::new(stream);
+        let args = Self::parse_line(&mut reader)?;
+        Response::from_args(args)
+    }
+
+    fn read_list(stream: &mut TcpStream, query: &[&str]) -> crate::Result<Vec<Vec<String>>> {
+        let mut reader = io::BufReader::new(stream);
+        let args = Self::parse_line(&mut reader)?;
+
+        Response::from_args(args)?.expect_begin_list(query)?;
+        let mut lines: Vec<Vec<String>> = Vec::new();
+
+        loop {
+            let mut args = Self::parse_line(&mut reader)?;
+            let resp = Response::from_args(args.clone());
+
+            if let Ok(resp) = resp {
+                resp.expect_end_list(query)?;
+                break;
+            } else {
+                let err = resp.unwrap_err();
+                if let ClientError::Nut(err) = err {
+                    if let NutError::UnknownResponseType(_) = err {
+                        // Likely an item entry, let's check...
+                        if args.len() < query.len() || &args[0..query.len()] != query {
+                            return Err(ClientError::Nut(err));
+                        } else {
+                            let args = args.drain(query.len()..).collect();
+                            lines.push(args);
+                            continue;
+                        }
+                    } else {
+                        return Err(ClientError::Nut(err));
+                    }
+                } else {
+                    return Err(err);
+                }
+            }
+        }
+        Ok(lines)
+    }
+}