rupsc: parsing and basic usage (minus clients)

nut-client/src/blocking/mod.rs

@@ -38,6 +38,16 @@ impl Connection {
                 .collect()),
         }
     }
+
+    /// Queries one variable for a UPS device.
+    pub fn get_var(&mut self, ups_name: &str, variable: &str) -> crate::Result<Variable> {
+        match self {
+            Self::Tcp(conn) => {
+                let var = conn.get_var(ups_name, variable)?;
+                Ok(Variable::parse(var.0.as_str(), var.1))
+            }
+        }
+    }
 }
 
 /// A blocking TCP NUT client connection.
@@ -95,6 +105,15 @@ impl TcpConnection {
             .collect())
     }
 
+    fn get_var(&mut self, ups_name: &str, variable: &str) -> crate::Result<(String, String)> {
+        let query = &["VAR", ups_name, variable];
+        Self::write_cmd(&mut self.tcp_stream, Command::Get(query))?;
+
+        let resp = Self::read_response(&mut self.tcp_stream)?;
+        let (name, value) = resp.expect_var()?;
+        Ok((name.into(), value.into()))
+    }
+
     fn write_cmd(stream: &mut TcpStream, line: Command) -> crate::Result<()> {
         let line = format!("{}\n", line);
         stream.write_all(line.as_bytes())?;

nut-client/src/cmd.rs

@@ -1,9 +1,10 @@
 use core::fmt;
 
-use crate::NutError;
+use crate::{ClientError, NutError};
 
 #[derive(Debug, Clone)]
 pub enum Command<'a> {
+    Get(&'a [&'a str]),
     /// Passes the login username.
     SetUsername(&'a str),
     /// Passes the login password.
@@ -16,6 +17,7 @@ impl<'a> Command<'a> {
     /// The network identifier of the command.
     pub fn name(&self) -> &'static str {
         match self {
+            Self::Get(_) => "GET",
             Self::SetUsername(_) => "USERNAME",
             Self::SetPassword(_) => "PASSWORD",
             Self::List(_) => "LIST",
@@ -25,6 +27,7 @@ impl<'a> Command<'a> {
     /// The arguments of the command to serialize.
     pub fn args(&self) -> Vec<&str> {
         match self {
+            Self::Get(cmd) => cmd.to_vec(),
             Self::SetUsername(username) => vec![username],
             Self::SetPassword(password) => vec![password],
             Self::List(query) => query.to_vec(),
@@ -48,6 +51,8 @@ pub enum Response {
     BeginList(String),
     /// Marks the end of a list response.
     EndList(String),
+    /// A variable response.
+    Var(String, String),
 }
 
 impl Response {
@@ -109,6 +114,23 @@ impl Response {
                     }
                 }
             }
+            "VAR" => {
+                let var_name = if args.is_empty() {
+                    Err(ClientError::from(NutError::Generic(
+                        "Unspecified VAR name in response".into(),
+                    )))
+                } else {
+                    Ok(args.remove(0))
+                }?;
+                let var_value = if args.is_empty() {
+                    Err(ClientError::from(NutError::Generic(
+                        "Unspecified VAR value in response".into(),
+                    )))
+                } else {
+                    Ok(args.remove(0))
+                }?;
+                Ok(Response::Var(var_name, var_value))
+            }
             _ => Err(NutError::UnknownResponseType(cmd_name).into()),
         }
     }
@@ -145,4 +167,12 @@ impl Response {
             Err(NutError::UnexpectedResponse.into())
         }
     }
+
+    pub fn expect_var(&self) -> crate::Result<(&str, &str)> {
+        if let Self::Var(name, value) = &self {
+            Ok((name, value))
+        } else {
+            Err(NutError::UnexpectedResponse.into())
+        }
+    }
 }

nut-client/src/config.rs

@@ -21,6 +21,12 @@ impl Default for Host {
     }
 }
 
+impl From<SocketAddr> for Host {
+    fn from(addr: SocketAddr) -> Self {
+        Self::Tcp(addr)
+    }
+}
+
 /// An authentication mechanism.
 #[derive(Clone)]
 pub struct Auth {

nut-client/src/var.rs

@@ -79,28 +79,46 @@ impl Variable {
             _ => Self::Other((name.into(), value)),
         }
     }
+
+    /// Returns the NUT name of the variable.
+    pub fn name(&self) -> &str {
+        use self::key::*;
+        match self {
+            Self::DeviceModel(_) => DEVICE_MODEL,
+            Self::DeviceManufacturer(_) => DEVICE_MANUFACTURER,
+            Self::DeviceSerial(_) => DEVICE_SERIAL,
+            Self::DeviceType(_) => DEVICE_TYPE,
+            Self::DeviceDescription(_) => DEVICE_DESCRIPTION,
+            Self::DeviceContact(_) => DEVICE_CONTACT,
+            Self::DeviceLocation(_) => DEVICE_LOCATION,
+            Self::DevicePart(_) => DEVICE_PART,
+            Self::DeviceMacAddress(_) => DEVICE_MAC_ADDRESS,
+            Self::DeviceUptime(_) => DEVICE_UPTIME,
+            Self::Other((name, _)) => name.as_str(),
+        }
+    }
+
+    /// Returns the value of the NUT variable.
+    pub fn value(&self) -> String {
+        match self {
+            Self::DeviceModel(value) => value.clone(),
+            Self::DeviceManufacturer(value) => value.clone(),
+            Self::DeviceSerial(value) => value.clone(),
+            Self::DeviceType(value) => value.to_string(),
+            Self::DeviceDescription(value) => value.clone(),
+            Self::DeviceContact(value) => value.clone(),
+            Self::DeviceLocation(value) => value.clone(),
+            Self::DevicePart(value) => value.clone(),
+            Self::DeviceMacAddress(value) => value.clone(),
+            Self::DeviceUptime(value) => value.as_secs().to_string(),
+            Self::Other((_, value)) => value.clone(),
+        }
+    }
 }
 
 impl fmt::Display for Variable {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        use self::key::*;
-
-        match self {
-            Self::DeviceModel(value) => write!(f, "{} = {}", DEVICE_MODEL, value),
-            Self::DeviceManufacturer(value) => write!(f, "{} = {}", DEVICE_MANUFACTURER, value),
-            Self::DeviceSerial(value) => write!(f, "{} = {}", DEVICE_SERIAL, value),
-            Self::DeviceType(value) => write!(f, "{} = {}", DEVICE_TYPE, value),
-            Self::DeviceDescription(value) => write!(f, "{} = {}", DEVICE_DESCRIPTION, value),
-            Self::DeviceContact(value) => write!(f, "{} = {}", DEVICE_CONTACT, value),
-            Self::DeviceLocation(value) => write!(f, "{} = {}", DEVICE_LOCATION, value),
-            Self::DevicePart(value) => write!(f, "{} = {}", DEVICE_PART, value),
-            Self::DeviceMacAddress(value) => write!(f, "{} = {}", DEVICE_MAC_ADDRESS, value),
-            Self::DeviceUptime(value) => {
-                write!(f, "{} = {} seconds", DEVICE_UPTIME, value.as_secs())
-            }
-
-            Self::Other((key, value)) => write!(f, "other({}) = {}", key, value),
-        }
+        write!(f, "{}: {}", self.name(), self.value())
     }
 }
 

rupsc/Cargo.toml

@@ -1,8 +1,21 @@
 [package]
 name = "rupsc"
-version = "0.1.0"
+version = "0.0.4"
+authors = ["Aram Peres <aram.peres@wavy.fm>"]
 edition = "2018"
+description = "A demo program to display UPS variables"
+categories = ["network-programming"]
+keywords = ["ups", "nut"]
+repository = "https://github.com/aramperes/nut-client-rs"
+readme = "../README.md"
+license = "MIT"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+clap = "2.33.3"
+anyhow = "1"
+
+[dependencies.nut-client]
+version = "0.0.4"
+path = "../nut-client"

rupsc/src/cmd.rs

@@ -0,0 +1,50 @@
+use crate::parser::UpsdName;
+use anyhow::Context;
+use core::convert::TryInto;
+use nut_client::blocking::Connection;
+
+/// Lists each UPS on the upsd server, one per line.
+pub fn list_devices(server: UpsdName, verbose: bool) -> anyhow::Result<()> {
+    let mut conn = connect(server)?;
+
+    for (name, description) in conn.list_ups()? {
+        if verbose {
+            println!("{}: {}", name, description);
+        } else {
+            println!("{}", name);
+        }
+    }
+
+    Ok(())
+}
+
+pub fn print_variable(server: UpsdName, variable: &str) -> anyhow::Result<()> {
+    let ups_name = server
+        .upsname
+        .with_context(|| "ups name must be specified: <upsname>[@<hostname>[:<port>]]")?;
+    let mut conn = connect(server)?;
+
+    let variable = conn.get_var(ups_name, variable)?;
+    println!("{}", variable.value());
+
+    Ok(())
+}
+
+pub fn list_variables(server: UpsdName) -> anyhow::Result<()> {
+    let ups_name = server
+        .upsname
+        .with_context(|| "ups name must be specified: <upsname>[@<hostname>[:<port>]]")?;
+    let mut conn = connect(server)?;
+
+    for var in conn.list_vars(ups_name)? {
+        println!("{}", var);
+    }
+
+    Ok(())
+}
+
+fn connect(server: UpsdName) -> anyhow::Result<Connection> {
+    let host = server.try_into()?;
+    let config = nut_client::ConfigBuilder::new().with_host(host).build();
+    Connection::new(config).with_context(|| format!("Failed to connect to upsd: {}", server))
+}

rupsc/src/main.rs

@@ -1,3 +1,77 @@
-fn main() {
-    println!("Hello, world!");
+///! # rupsc
+///! A demo program to display UPS variables.
+///! This a Rust clone of [upsc](https://github.com/networkupstools/nut/blob/master/clients/upsc.c).
+///!
+///! P.S.: pronounced "r-oopsie".
+mod cmd;
+mod parser;
+
+use crate::parser::UpsdName;
+use anyhow::Context;
+use clap::{App, Arg};
+use core::convert::TryInto;
+
+fn main() -> anyhow::Result<()> {
+    let args = App::new(clap::crate_name!())
+        .version(clap::crate_version!())
+        .author(clap::crate_authors!())
+        .about(clap::crate_description!())
+        .arg(
+            Arg::with_name("list")
+                .short("l")
+                .conflicts_with_all(&["list-full", "clients"])
+                .takes_value(false)
+                .help("Lists each UPS on <hostname>, one per line."),
+        )
+        .arg(
+            Arg::with_name("list-full")
+                .short("L")
+                .conflicts_with_all(&["list", "clients"])
+                .takes_value(false)
+                .help("Lists each UPS followed by its description (from ups.conf)."),
+        )
+        .arg(
+            Arg::with_name("clients")
+                .short("c")
+                .conflicts_with_all(&["list", "list-full"])
+                .takes_value(false)
+                .help("Lists each client connected on <upsname>, one per line."),
+        )
+        .arg(
+            Arg::with_name("upsd-server")
+                .required(false)
+                .value_name("[upsname][@<hostname>[:<port>]]")
+                .help("upsd server (with optional upsname, if applicable)."),
+        )
+        .arg(
+            Arg::with_name("variable")
+                .required(false)
+                .value_name("variable")
+                .help("Optional, display this variable only."),
+        )
+        .get_matches();
+
+    let server: parser::UpsdName = args.value_of("upsd-server").map_or_else(
+        || Ok(UpsdName::default()),
+        |s| s.try_into().with_context(|| "Invalid upsd server name"),
+    )?;
+
+    if args.is_present("list") {
+        return cmd::list_devices(server, false);
+    }
+
+    if args.is_present("list-full") {
+        return cmd::list_devices(server, true);
+    }
+
+    if args.is_present("clients") {
+        todo!("listing clients")
+    }
+
+    // Fallback: prints one variable (or all of them)
+    if let Some(variable) = args.value_of("variable") {
+        cmd::print_variable(server, variable)
+    } else {
+        cmd::list_variables(server)
+    }
 }

rupsc/src/parser.rs

@@ -0,0 +1,152 @@
+use anyhow::Context;
+use std::convert::{TryFrom, TryInto};
+use std::fmt;
+use std::net::ToSocketAddrs;
+
+pub const DEFAULT_HOSTNAME: &str = "localhost";
+pub const DEFAULT_PORT: u16 = 3493;
+
+/// Connection information for a upsd server.
+///
+/// The upsname is optional depending on context.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub struct UpsdName<'a> {
+    pub upsname: Option<&'a str>,
+    pub hostname: &'a str,
+    pub port: u16,
+}
+
+impl<'a> Default for UpsdName<'a> {
+    fn default() -> Self {
+        UpsdName {
+            upsname: None,
+            hostname: DEFAULT_HOSTNAME,
+            port: DEFAULT_PORT,
+        }
+    }
+}
+
+impl<'a> TryFrom<&'a str> for UpsdName<'a> {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &'a str) -> anyhow::Result<UpsdName<'a>> {
+        let mut upsname: Option<&str> = None;
+        let mut hostname = DEFAULT_HOSTNAME;
+        let mut port = DEFAULT_PORT;
+
+        if value.contains(':') {
+            let mut split = value.splitn(2, ':');
+            let prefix = split.next().unwrap();
+            port = split
+                .next()
+                .unwrap()
+                .parse::<u16>()
+                .with_context(|| "invalid port number")?;
+            if prefix.contains('@') {
+                let mut split = prefix.splitn(2, '@');
+                upsname = Some(split.next().unwrap());
+                hostname = split.next().unwrap();
+            } else {
+                hostname = prefix;
+            }
+        } else {
+            if value.contains('@') {
+                let mut split = value.splitn(2, '@');
+                upsname = Some(split.next().unwrap());
+                hostname = split.next().unwrap();
+            } else {
+                upsname = Some(value);
+            }
+        }
+
+        Ok(UpsdName {
+            upsname,
+            hostname,
+            port,
+        })
+    }
+}
+
+impl<'a> TryInto<nut_client::Host> for UpsdName<'a> {
+    type Error = anyhow::Error;
+
+    fn try_into(self) -> anyhow::Result<nut_client::Host> {
+        Ok((String::from(self.hostname), self.port)
+            .to_socket_addrs()
+            .with_context(|| "Failed to convert to SocketAddr")?
+            .next()
+            .with_context(|| "Failed to convert to SocketAddr")?
+            .into())
+    }
+}
+
+impl<'a> fmt::Display for UpsdName<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if let Some(upsname) = self.upsname {
+            write!(f, "{}@", upsname)?;
+        }
+        write!(f, "{}:{}", self.hostname, self.port)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use core::convert::TryInto;
+
+    #[test]
+    fn test_upsdname_parser_full() {
+        let name: UpsdName = "ups@notlocal:1234".try_into().unwrap();
+        assert_eq!(
+            name,
+            UpsdName {
+                upsname: Some("ups"),
+                hostname: "notlocal",
+                port: 1234
+            }
+        );
+        assert_eq!(format!("{}", name), "ups@notlocal:1234");
+    }
+
+    #[test]
+    fn test_upsdname_parser_no_name() {
+        let name: UpsdName = "notlocal:5678".try_into().unwrap();
+        assert_eq!(
+            name,
+            UpsdName {
+                upsname: None,
+                hostname: "notlocal",
+                port: 5678
+            }
+        );
+        assert_eq!(format!("{}", name), "notlocal:5678");
+    }
+
+    #[test]
+    fn test_upsdname_parser_no_port_no_hostname() {
+        let name: UpsdName = "ups0".try_into().unwrap();
+        assert_eq!(
+            name,
+            UpsdName {
+                upsname: Some("ups0"),
+                hostname: DEFAULT_HOSTNAME,
+                port: DEFAULT_PORT
+            }
+        );
+        assert_eq!(format!("{}", name), "ups0@localhost:3493");
+    }
+
+    #[test]
+    fn test_upsdname_parser_no_port() {
+        let name: UpsdName = "ups@notlocal".try_into().unwrap();
+        assert_eq!(
+            name,
+            UpsdName {
+                upsname: Some("ups"),
+                hostname: "notlocal",
+                port: DEFAULT_PORT
+            }
+        );
+        assert_eq!(format!("{}", name), "ups@notlocal:3493");
+    }
+}