Files
bichon/crates/core/src/autoconfig/guess.rs
2026-05-26 15:19:39 +08:00

106 lines
3.5 KiB
Rust

//
// Copyright (c) 2025-2026 rustmailer.com (https://rustmailer.com)
//
// This file is part of the Bichon Email Archiving Project
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
use crate::account::entity::Encryption;
use crate::autoconfig::client::{IncomingServer, MailConfig};
use crate::imap::client::Client;
use tracing::{debug, info};
/// A single host:port:encryption combination to probe.
struct Guess {
hostname: String,
port: u16,
encryption: Encryption,
socket_type: &'static str,
}
/// Generate candidates in the same order Thunderbird uses:
/// 1. imap.{domain} — most common
/// 2. mail.{domain} — fallback
/// 3. {domain} — bare domain (rare)
fn make_guesses(domain: &str) -> Vec<Guess> {
let hosts = [
format!("imap.{domain}"),
format!("mail.{domain}"),
domain.to_string(),
];
let mut guesses = Vec::with_capacity(hosts.len() * 2);
for host in &hosts {
guesses.push(Guess {
hostname: host.clone(),
port: 993,
encryption: Encryption::Ssl,
socket_type: "SSL",
});
guesses.push(Guess {
hostname: host.clone(),
port: 143,
encryption: Encryption::StartTls,
socket_type: "STARTTLS",
});
}
guesses
}
/// Try to open a connection, read the IMAP banner, and close.
/// Returns `true` if the server responds with an IMAP greeting.
async fn probe(hostname: &str, port: u16, encryption: &Encryption) -> bool {
match Client::connection(hostname, encryption, port, None, true).await {
Ok(_) => {
debug!("GuessConfig probe succeeded: {hostname}:{port} ({encryption:?})");
true
}
Err(e) => {
debug!("GuessConfig probe failed for {hostname}:{port}: {e:?}");
false
}
}
}
/// Thunderbird-style guessing: try common hostnames and ports, probing
/// each with a real TCP connection.
///
/// Returns the first working `MailConfig`, or `None` if nothing works.
pub async fn guess_config(domain: &str) -> Option<MailConfig> {
let guesses = make_guesses(domain);
info!("GuessConfig: trying {} candidates for {domain}", guesses.len());
for g in &guesses {
if probe(&g.hostname, g.port, &g.encryption).await {
info!(
"GuessConfig: found working IMAP at {}:{} ({})",
g.hostname, g.port, g.socket_type
);
return Some(MailConfig {
incoming: vec![IncomingServer {
protocol: "imap".to_string(),
hostname: g.hostname.clone(),
port: g.port,
socket_type: g.socket_type.to_string(),
username: "%EMAILADDRESS%".to_string(),
authentication: String::new(),
}],
outgoing: vec![],
});
}
}
None
}