mail_send/smtp/
ehlo.rs

1/*
2 * Copyright Stalwart Labs Ltd.
3 *
4 * Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
5 * https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 * <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
7 * option. This file may not be copied, modified, or distributed
8 * except according to those terms.
9 */
10
11use smtp_proto::{
12    response::parser::{ResponseReceiver, MAX_RESPONSE_LENGTH},
13    EhloResponse,
14};
15use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
16
17use crate::SmtpClient;
18
19impl<T: AsyncRead + AsyncWrite + Unpin> SmtpClient<T> {
20    /// Sends a EHLO command to the server.
21    pub async fn ehlo(&mut self, hostname: &str) -> crate::Result<EhloResponse<String>> {
22        tokio::time::timeout(self.timeout, async {
23            self.stream
24                .write_all(format!("EHLO {hostname}\r\n").as_bytes())
25                .await?;
26            self.stream.flush().await?;
27            self.read_ehlo().await
28        })
29        .await
30        .map_err(|_| crate::Error::Timeout)?
31    }
32
33    /// Sends a LHLO command to the server.
34    pub async fn lhlo(&mut self, hostname: &str) -> crate::Result<EhloResponse<String>> {
35        tokio::time::timeout(self.timeout, async {
36            self.stream
37                .write_all(format!("LHLO {hostname}\r\n").as_bytes())
38                .await?;
39            self.stream.flush().await?;
40            self.read_ehlo().await
41        })
42        .await
43        .map_err(|_| crate::Error::Timeout)?
44    }
45
46    pub async fn read_ehlo(&mut self) -> crate::Result<EhloResponse<String>> {
47        let mut buf = vec![0u8; 1024];
48        let mut buf_concat = Vec::with_capacity(0);
49
50        loop {
51            let br = self.stream.read(&mut buf).await?;
52
53            if br == 0 {
54                return Err(crate::Error::UnparseableReply);
55            }
56            let mut iter = if buf_concat.is_empty() {
57                buf[..br].iter()
58            } else if br + buf_concat.len() < MAX_RESPONSE_LENGTH {
59                buf_concat.extend_from_slice(&buf[..br]);
60                buf_concat.iter()
61            } else {
62                return Err(crate::Error::UnparseableReply);
63            };
64
65            match EhloResponse::parse(&mut iter) {
66                Ok(reply) => return Ok(reply),
67                Err(err) => match err {
68                    smtp_proto::Error::NeedsMoreData { .. } => {
69                        if buf_concat.is_empty() {
70                            buf_concat = buf[..br].to_vec();
71                        }
72                    }
73                    smtp_proto::Error::InvalidResponse { code } => {
74                        match ResponseReceiver::from_code(code).parse(&mut iter) {
75                            Ok(response) => {
76                                return Err(crate::Error::UnexpectedReply(response));
77                            }
78                            Err(smtp_proto::Error::NeedsMoreData { .. }) => {
79                                if buf_concat.is_empty() {
80                                    buf_concat = buf[..br].to_vec();
81                                }
82                            }
83                            Err(_) => return Err(crate::Error::UnparseableReply),
84                        }
85                    }
86                    _ => {
87                        return Err(crate::Error::UnparseableReply);
88                    }
89                },
90            }
91        }
92    }
93}
mail_send/smtp/ehlo.rs

mail_send/smtp/
ehlo.rs
