1 files changed, 30 insertions, 0 deletions
diff --git a/src/smtp.rs b/src/smtp.rs
index 2ab79f8..00e2ae8 100644
--- a/src/smtp.rs
+++ b/src/smtp.rs
@@ -31,6 +31,7 @@ impl SmtpServer {
                 state: SessionState::default(),
                 client_host: String::new(),
                 from: None,
+                to: Vec::new(),
             };
             spawn(session.run(stream));
         }
@@ -43,6 +44,7 @@ struct SessionHandler {
     state: SessionState,
     client_host: String,
     from: Option<String>,
+    to: Vec<String>,
 }
 
 impl SessionHandler {
@@ -84,6 +86,7 @@ impl SessionHandler {
         match &command {
             Command::HELO(hostname) => self.helo(hostname).await,
             Command::MAIL(from) => self.mail(from).await,
+            Command::RCPT(to) => self.rcpt(to).await,
         }
     }
 
@@ -92,6 +95,7 @@ impl SessionHandler {
         self.client_host = String::from(hostname);
         self.state = SessionState::Normal;
         self.from = None;
+        self.to.clear();
         Ok(Reply::Completed(String::from(SERVER_NAME)))
     }
 
@@ -103,12 +107,29 @@ impl SessionHandler {
         }
 
         self.from = Some(String::from(from));
+        self.to.clear();
         self.state = SessionState::MailTransaction;
 
         Ok(Reply::Completed(String::from("Ok")))
     }
+
+    /// TODO: Validate email addresses
+    /// Only after having started a mail transaction
+    async fn rcpt(&mut self, to: &str) -> Result<Reply> {
+        if self.state != SessionState::MailTransaction {
+            return Ok(Reply::BadSequence);
+        }
+
+        if to.is_empty() {
+            return Ok(Reply::InvalidParameter);
+        }
+
+        self.to.push(String::from(to));
+        Ok(Reply::Completed(String::from("Ok")))
+    }
 }
 
+#[derive(PartialEq)]
 enum SessionState {
     WaitingHelo,
     MailTransaction,
@@ -126,6 +147,7 @@ enum Reply {
     Completed(String),
     InvalidCommand,
     InvalidParameter,
+    BadSequence,
 }
 
 impl ToString for Reply {
@@ -135,6 +157,7 @@ impl ToString for Reply {
             Reply::Completed(hostname) => format!("250 {}", hostname),
             Reply::InvalidCommand => format!("500 Command not recognized"),
             Reply::InvalidParameter => format!("501 Parameter error"),
+            Reply::BadSequence => format!("503 Bad sequence of commands"),
         }
     }
 }
@@ -142,6 +165,7 @@ impl ToString for Reply {
 enum Command {
     HELO(String),
     MAIL(String),
+    RCPT(String),
 }
 
 impl TryFrom<&str> for Command {
@@ -160,6 +184,12 @@ impl TryFrom<&str> for Command {
             return Ok(Command::MAIL(String::from(from)));
         }
 
+        if value.len() >= 9 && value.to_lowercase().starts_with("rcpt to:<") && value.contains('>')
+        {
+            let to = &value[9..value.find('>').unwrap()];
+            return Ok(Command::RCPT(String::from(to)));
+        }
+
         Err(anyhow::format_err!("Invalid command"))
     }
 }