Add server config

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "tftpd"
+version = "0.0.0"

Cargo.toml

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+[package]
+name = "tftpd"
+version = "0.0.0"
+authors = ["Altuğ Bakan <mail@alt.ug>"]
+edition = "2021"
+description = "TFTP Server Daemon implemented in Rust"
+repository = "https://github.com/altugbakan/rs-tftpd"
+license = "MIT"
+keywords = ["tftp", "server"]
+categories = ["command-line-utilities"]

src/config.rs

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+use std::error::Error;
+use std::net::{AddrParseError, Ipv4Addr};
+use std::num::ParseIntError;
+use std::path::{Path, PathBuf};
+use std::{env, fmt, process};
+
+pub struct Config {
+    pub ip_address: Ipv4Addr,
+    pub port: u16,
+    pub directory: PathBuf,
+}
+
+impl Config {
+    pub fn new<T>(mut args: T) -> Result<Config, ConfigError>
+    where
+        T: Iterator<Item = String>,
+    {
+        let mut config = Config {
+            ip_address: Ipv4Addr::new(127, 0, 0, 1),
+            port: 69,
+            directory: env::current_dir().unwrap_or(env::temp_dir()),
+        };
+
+        args.next();
+
+        while let Some(arg) = args.next() {
+            match arg.as_str() {
+                "-i" | "--ip-address" => {
+                    if let Some(ip_str) = args.next() {
+                        config.ip_address = ip_str.parse::<Ipv4Addr>()?;
+                    } else {
+                        return Err("missing ip address after flag".into());
+                    }
+                }
+                "-p" | "--port" => {
+                    if let Some(port_str) = args.next() {
+                        config.port = port_str.parse::<u16>()?;
+                    } else {
+                        return Err("missing port number after flag".into());
+                    }
+                }
+                "-d" | "--directory" => {
+                    if let Some(dir_str) = args.next() {
+                        if !Path::new(&dir_str).exists() {
+                            return Err(format!("{} does not exist", dir_str).into());
+                        }
+                        config.directory = PathBuf::from(dir_str);
+                    } else {
+                        return Err("missing directory after flag".into());
+                    }
+                }
+                "-h" | "--help" => {
+                    println!("TFTP Server Daemon\n");
+                    println!("Usage: tftpd [OPTIONS]\n");
+                    println!("Options:");
+                    println!("  -i, --ip-address <IP ADDRESS>\tSet the ip address of the server (Default: 127.0.0.1)");
+                    println!(
+                        "  -p, --port <PORT>\t\tSet the listening port of the server (Default: )"
+                    );
+                    println!("  -d, --directory <DIRECTORY>\tSet the listening port of the server (Default: )");
+                    println!("  -h, --help\t\t\tPrint help information");
+                    process::exit(0);
+                }
+                invalid => return Err(format!("invalid flag: {}", invalid).into()),
+            }
+        }
+
+        Ok(config)
+    }
+}
+
+#[derive(Debug)]
+pub struct ConfigError {
+    description: String,
+}
+
+impl Error for ConfigError {
+    fn description(&self) -> &str {
+        self.description.as_str()
+    }
+}
+
+impl fmt::Display for ConfigError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.description)
+    }
+}
+
+impl From<AddrParseError> for ConfigError {
+    fn from(value: AddrParseError) -> Self {
+        ConfigError {
+            description: value.to_string(),
+        }
+    }
+}
+
+impl From<ParseIntError> for ConfigError {
+    fn from(value: ParseIntError) -> Self {
+        ConfigError {
+            description: value.to_string(),
+        }
+    }
+}
+
+impl From<String> for ConfigError {
+    fn from(value: String) -> Self {
+        ConfigError { description: value }
+    }
+}
+
+impl From<&str> for ConfigError {
+    fn from(value: &str) -> Self {
+        ConfigError {
+            description: value.to_string(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::str::FromStr;
+
+    use super::*;
+
+    #[test]
+    fn parses_full_config() {
+        let config = Config::new(
+            vec!["/", "-i", "0.0.0.0", "-p", "1234", "-d", "/"]
+                .iter()
+                .map(|s| s.to_string()),
+        )
+        .unwrap();
+
+        assert_eq!(config.ip_address, Ipv4Addr::new(0, 0, 0, 0));
+        assert_eq!(config.port, 1234);
+        assert_eq!(config.directory, PathBuf::from_str("/").unwrap());
+    }
+
+    #[test]
+    fn parses_some_config() {
+        let config = Config::new(
+            vec!["/", "-i", "0.0.0.0", "-d", "/"]
+                .iter()
+                .map(|s| s.to_string()),
+        )
+        .unwrap();
+
+        assert_eq!(config.ip_address, Ipv4Addr::new(0, 0, 0, 0));
+        assert_eq!(config.port, 69);
+        assert_eq!(config.directory, PathBuf::from_str("/").unwrap());
+    }
+
+    #[test]
+    fn returns_error_on_invalid_ip() {
+        assert!(Config::new(
+            vec!["/", "-i", "1234.5678.9012.3456"]
+                .iter()
+                .map(|s| s.to_string()),
+        )
+        .is_err());
+    }
+
+    #[test]
+    fn returns_error_on_invalid_port() {
+        assert!(Config::new(vec!["/", "-p", "1234567"].iter().map(|s| s.to_string()),).is_err());
+    }
+
+    #[test]
+    fn returns_error_on_invalid_directory() {
+        assert!(Config::new(
+            vec!["/", "-d", "/this/does/not/exist"]
+                .iter()
+                .map(|s| s.to_string()),
+        )
+        .is_err());
+    }
+}

src/lib.rs

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+pub mod config;
+pub use config::Config;

src/main.rs

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+use std::{env, process};
+use tftpd::Config;
+
+fn main() {
+    let config = Config::new(env::args()).unwrap_or_else(|err| {
+        eprintln!("Problem parsing arguments: {}", err);
+        process::exit(1)
+    });
+
+    println!(
+        "Running TFTP Server on {}:{}",
+        config.ip_address, config.port
+    );
+}