better error handling, intervals

Cargo.lock

@@ -19,12 +19,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "base64"
-version = "0.13.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
-
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -86,22 +80,6 @@ dependencies = [
  "os_str_bytes",
 ]
 
-[[package]]
-name = "core-foundation"
-version = "0.9.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "194a7a9e6de53fa55116934067c844d9d749312f75c6f6d0980e8c252f8c2146"
-dependencies = [
- "core-foundation-sys",
- "libc",
-]
-
-[[package]]
-name = "core-foundation-sys"
-version = "0.8.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5827cebf4670468b8772dd191856768aedcb1b0278a04f989f7766351917b9dc"
-
 [[package]]
 name = "heck"
 version = "0.4.0"
@@ -124,7 +102,6 @@ dependencies = [
  "anyhow",
  "clap",
  "rustls",
- "rustls-native-certs",
  "webpki-roots",
 ]
 
@@ -137,12 +114,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "lazy_static"
-version = "1.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
-
 [[package]]
 name = "libc"
 version = "0.2.137"
@@ -164,12 +135,6 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
 
-[[package]]
-name = "openssl-probe"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff011a302c396a5197692431fc1948019154afc178baf7d8e37367442a4601cf"
-
 [[package]]
 name = "os_str_bytes"
 version = "6.4.0"
@@ -245,37 +210,6 @@ dependencies = [
  "webpki",
 ]
 
-[[package]]
-name = "rustls-native-certs"
-version = "0.6.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0167bac7a9f490495f3c33013e7722b53cb087ecbe082fb0c6387c96f634ea50"
-dependencies = [
- "openssl-probe",
- "rustls-pemfile",
- "schannel",
- "security-framework",
-]
-
-[[package]]
-name = "rustls-pemfile"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0864aeff53f8c05aa08d86e5ef839d3dfcf07aeba2db32f12db0ef716e87bd55"
-dependencies = [
- "base64",
-]
-
-[[package]]
-name = "schannel"
-version = "0.1.20"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "88d6731146462ea25d9244b2ed5fd1d716d25c52e4d54aa4fb0f3c4e9854dbe2"
-dependencies = [
- "lazy_static",
- "windows-sys",
-]
-
 [[package]]
 name = "sct"
 version = "0.7.0"
@@ -286,29 +220,6 @@ dependencies = [
  "untrusted",
 ]
 
-[[package]]
-name = "security-framework"
-version = "2.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2bc1bb97804af6631813c55739f771071e0f2ed33ee20b68c86ec505d906356c"
-dependencies = [
- "bitflags",
- "core-foundation",
- "core-foundation-sys",
- "libc",
- "security-framework-sys",
-]
-
-[[package]]
-name = "security-framework-sys"
-version = "2.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0160a13a177a45bfb43ce71c01580998474f556ad854dcbca936dd2841a5c556"
-dependencies = [
- "core-foundation-sys",
- "libc",
-]
-
 [[package]]
 name = "spin"
 version = "0.5.2"
@@ -472,46 +383,3 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-
-[[package]]
-name = "windows-sys"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea04155a16a59f9eab786fe12a4a450e75cdb175f9e0d80da1e17db09f55b8d2"
-dependencies = [
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_msvc",
-]
-
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9bb8c3fd39ade2d67e9874ac4f3db21f0d710bee00fe7cab16949ec184eeaa47"
-
-[[package]]
-name = "windows_i686_gnu"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "180e6ccf01daf4c426b846dfc66db1fc518f074baa793aa7d9b9aaeffad6a3b6"
-
-[[package]]
-name = "windows_i686_msvc"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2e7917148b2812d1eeafaeb22a97e4813dfa60a3f8f78ebe204bcc88f12f024"
-
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4dcd171b8776c41b97521e5da127a2d86ad280114807d0b2ab1e462bc764d9e1"
-
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.36.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c811ca4a8c853ef420abd8592ba53ddbbac90410fab6903b3e79972a631f7680"

Cargo.toml

@@ -9,5 +9,4 @@ edition = "2021"
 anyhow = "1.0.66"
 clap = { version = "4.0.26", features = ["derive"] }
 rustls = "0.20.7"
-rustls-native-certs = "0.6.2"
 webpki-roots = "0.22.5"

src/lib.rs

@@ -1,11 +1,13 @@
 use rustls::{OwnedTrustAnchor, ClientConfig, RootCertStore, ClientConnection};
-use anyhow::{Result as AResult, anyhow};
+use anyhow::{Result as AResult, bail};
-use std::sync::Arc;
+use std::net::{TcpStream, ToSocketAddrs};
-use std::net::TcpStream;
+use std::io::{self, ErrorKind, Read, Write};
-use std::io::{Read, Write};
 use std::process::Command;
 use std::time::Duration;
 use std::path::PathBuf;
+use std::sync::{Arc, Mutex};
+use std::thread;
+use std::mem;
 use clap::Parser;
 
 #[derive(Parser)]
@@ -27,10 +29,15 @@ pub struct Cli {
 	#[arg(short, long)]
 	password: String,
 
+	/// interval (in seconds) at which to run even if no email arrives
+	#[arg(short, long)]
+	interval: Option<u64>,
+
 	/// command to run when new mail arrives
 	#[arg(short, long)]
 	command: PathBuf,
 
+	/// show all server responses
 	#[arg(short, long, action = clap::ArgAction::Count)]
 	verbose: u8,
 }
@@ -44,6 +51,26 @@ enum State {
 }
 
 pub fn run(cli: &Cli) -> AResult<()> {
+	// a mutex to avoid running the command concurrently
+	let mutex_mainthread = Arc::new(Mutex::new(()));
+	let mutex_subthread = Arc::clone(&mutex_mainthread);
+
+	if let Some(interval) = cli.interval {
+		let cmd = cli.command.clone();
+		thread::spawn(move || {
+			loop {
+				thread::sleep(Duration::from_secs(interval));
+				let lock = mutex_subthread.lock().unwrap();
+				println!("Interval timer expired, running command ...");
+				Command::new(cmd.as_os_str())
+					.output()
+					.expect("command execution failed");
+				println!("Command finished.");
+				mem::drop(lock);
+			}
+		});
+	}
+
 	let tls_config = ClientConfig::builder()
 		.with_safe_defaults()
 		.with_root_certificates(RootCertStore {
@@ -54,12 +81,16 @@ pub fn run(cli: &Cli) -> AResult<()> {
 		})
 		.with_no_client_auth();
 
-	let mut buffer = [0; 2048];
+	let mut buffer = [0u8; 2048];
 
 	let mut tls_client = ClientConnection::new(
 		Arc::new(tls_config),
 		cli.server.as_str().try_into().unwrap())?;
-	let mut socket = TcpStream::connect((cli.server.as_str(), cli.port))?;
+	let addrs = (cli.server.as_str(), cli.port)
+		.to_socket_addrs()
+		.map_err(|e|io::Error::new(ErrorKind::NotConnected, e.to_string()))?
+		.collect::<Vec<_>>();
+	let mut socket = TcpStream::connect(addrs.as_slice())?;
 	let mut state = State::Unauthenticated;
 
 	socket.set_read_timeout(Some(Duration::from_secs(10*60)))?;
@@ -94,6 +125,12 @@ pub fn run(cli: &Cli) -> AResult<()> {
 
 			for response in responses {
 				if cli.verbose > 0 {
+					if state == State::Unauthenticated {
+						if let Some(suite) = tls_client.negotiated_cipher_suite() {
+							println!("negotiated cipher suite: {:?}", suite);
+						}
+					}
+
 					println!("{}", String::from_utf8_lossy(response));
 				}
 
@@ -107,20 +144,24 @@ pub fn run(cli: &Cli) -> AResult<()> {
 						tls_client.writer().write(b"A002 select inbox\r\n")?;
 						state = State::Inbox;
 					} else if response.starts_with(b"A001") {
-						return Err(anyhow!("The server rejected authentication"));
+						bail!("The server rejected authentication");
 					},
 					State::Inbox => if response.starts_with(b"A002 OK") {
 						tls_client.writer().write(b"A003 idle\r\n")?;
 						state = State::Idling;
 					} else if response.starts_with(b"A002") {
-						return Err(anyhow!("Selecting inbox failed"));
+						bail!("Selecting inbox failed");
 					},
 					State::Idling => if response.starts_with(b"+ idling") {
 						println!("Connected and idling ...");
 					} else if response.starts_with(b"*") && response.ends_with(b"EXISTS") {
-						println!("NEW EMAIL!");
+						let lock = mutex_mainthread.lock().unwrap();
+						println!("New email, running command ...");
 						Command::new(cli.command.as_os_str())
-							.output()?;
+							.output()
+							.expect("command execution failed");
+						println!("Command finished.");
+						mem::drop(lock);
 					}
 				}
 			}
@@ -132,3 +173,13 @@ pub fn run(cli: &Cli) -> AResult<()> {
 
 	Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_dns_lookup() {
+
+	}
+}

src/main.rs

@@ -6,11 +6,17 @@ use std::thread;
 use std::time::Duration;
 use clap::Parser;
 
-const CONNECTION_ERRORS: &[ErrorKind] = &[
+const CONNECTION_LOST_ERRORS: &[ErrorKind] = &[
+	ErrorKind::Interrupted,
+	ErrorKind::WouldBlock,      // when a read times out
+];
+
+const CANT_CONNECT_ERRORS: &[ErrorKind] = &[
 	ErrorKind::ConnectionAborted,
 	ErrorKind::ConnectionReset,
+	ErrorKind::NotConnected,
 	ErrorKind::NetworkUnreachable,
-	ErrorKind::HostUnreachable
+	ErrorKind::HostUnreachable,
 ];
 
 fn main() -> AResult<()> {
@@ -20,13 +26,13 @@ fn main() -> AResult<()> {
 		return match imapidle::run(&cli) {
 			Ok(_) => Ok(()),
 			Err(err) => match err.downcast_ref::<IOError>() {
-				Some(io_err) if io_err.kind() == ErrorKind::WouldBlock => {
+				Some(io_err) if CONNECTION_LOST_ERRORS.contains(&io_err.kind()) => {
 					let secs_to_reconnect = 10;
-					println!("Timed out, reconnecting in {secs_to_reconnect} seconds");
+					println!("Connection lost, reconnecting in {secs_to_reconnect} seconds");
 					thread::sleep(Duration::from_secs(secs_to_reconnect));
 					continue;
 				},
-				Some(io_err) if CONNECTION_ERRORS.contains(&io_err.kind()) => {
+				Some(io_err) if CANT_CONNECT_ERRORS.contains(&io_err.kind()) => {
 					let secs_to_reconnect = 10*60;
 					println!("Cannot connect currently, retrying in {secs_to_reconnect} seconds");
 					thread::sleep(Duration::from_secs(secs_to_reconnect));