Lines of
src/lib.rs
from check-in 512369f93e
that are changed by the sequence of edits moving toward
check-in 158c9cffc6:
1: //! SMTP-to-Telegram gateway main library.
2: //!
3: //! This module provides the core functionality for receiving emails via SMTP
4: //! and forwarding them to Telegram chats.
5: //!
6: //! As we are not actually exporting this lib there would be no local Error's
7: //! for now, everything will be just .stack()?'ed and propagated like in real
8: //! bin The lib here is just to separate all tests from main code into tests/
9:
10: pub mod mail;
11: mod telegram;
12: pub mod utils;
13:
14: use crate::mail::MailServer;
15:
16: use std::{
17: io::Cursor,
18: os::unix::fs::PermissionsExt,
19: path::Path,
20: };
21:
22: use clap::Parser;
23: use smol::{
24: fs::metadata,
25: };
26: use stacked_errors::{
27: Result,
28: StackableErr,
29: bail,
30: };
31:
32: /// SMTP-to-Telegram gateway
33: #[derive(Parser, Debug)]
34: #[command(name = "smtp2tg")]
35: #[command(about = format!("SMTP-to-Telegram gateway v{}, (C) 2024 - 2026", env!("CARGO_PKG_VERSION")), long_about = None)]
36: struct Args {
37: /// Set configuration file location
38: #[arg(short, long, default_value = "smtp2tg.toml")]
39: config: String,
40: }
41:
42: /// Main asynchronous entry point for the application.
43: ///
44: /// Parses command-line arguments, loads configuration, and starts the SMTP
45: /// server.
46: ///
47: /// # Errors
48: /// Returns an error if configuration is invalid, files are inaccessible, or
49: /// server fails to start.
50: pub async fn async_main () -> Result<()> {
51: let args = Args::parse();
52: let config_file = Path::new(&args.config);
53: if !config_file.exists() {
54: bail!("can't read configuration from {config_file:?}");
55: };
56: {
57: let meta = metadata(config_file).await.stack()?;
58: if (!0o100600 & meta.permissions().mode()) > 0 {
59: bail!("other users can read or write config file {config_file:?}\n\
60: File permissions: {:o}", meta.permissions().mode());
61: }
62: }
63: let settings: config::Config = config::Config::builder()
64: .set_default("api_gateway", "https://api.telegram.org").stack()?
65: .set_default("fields", vec!["date", "from", "subject"]).stack()?
66: .set_default("hostname", "smtp.2.tg").stack()?
67: .set_default("listen_on", "0.0.0.0:1025").stack()?
512369f93e 2026-08-01 68: .set_default("unknown", "relay").stack()?
69: .set_default("domains", vec!["localhost",
70: hostname::get().expect("Failed to get current hostname")
71: .to_str().expect("Can't convert hostname to string, bad UTF-8?")]).stack()?
72: .add_source(config::File::from(config_file))
73: .build()
74: .with_context(|| format!("[{config_file:?}] there was an error reading config\n\
75: \tplease consult \"smtp2tg.toml.example\" for details"))?;
76:
77: let listen_on = settings.get_string("listen_on").stack()?;
78: let server_name = settings.get_string("hostname").stack()?;
79: let core = MailServer::new(settings)?;
80: let mut server = mailin_embedded::Server::new(core);
81:
82: server.with_name(server_name)
83: .with_ssl(mailin_embedded::SslConfig::None).unwrap()
84: .with_addr(listen_on).unwrap();
85: server.serve().unwrap();
86:
87: Ok(())
88: }