From 84cad4797dd15ba66763a32463c5580c0506a605 Mon Sep 17 00:00:00 2001
From: Robert Sesek <rsesek@bluestatic.org>
Date: Sun, 11 Dec 2016 23:35:56 -0500
Subject: [PATCH] Simple accept/listen loop for the SMTP server.

---
 mailpopbox.go  |  4 ++++
 smtp.go        | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 smtp/conn.go   | 11 +++++++++++
 smtp/server.go |  6 ++++++
 4 files changed, 69 insertions(+)
 create mode 100644 smtp.go
 create mode 100644 smtp/conn.go
 create mode 100644 smtp/server.go

diff --git a/mailpopbox.go b/mailpopbox.go
index 984acb3..2765ce9 100644
--- a/mailpopbox.go
+++ b/mailpopbox.go
@@ -24,4 +24,8 @@ func main() {
 		os.Exit(3)
 	}
 	configFile.Close()
+
+	smtp := runSMTPServer(config)
+	err = <-smtp
+	fmt.Println(err)
 }
diff --git a/smtp.go b/smtp.go
new file mode 100644
index 0000000..b7131d5
--- /dev/null
+++ b/smtp.go
@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"net"
+
+	"src.bluestatic.org/mailpopbox/smtp"
+)
+
+func runSMTPServer(config Config) <-chan error {
+	server := smtpServer{
+		config: config,
+		rc:     make(chan error),
+	}
+	go server.run()
+	return server.rc
+}
+
+type smtpServer struct {
+	config Config
+	rc     chan error
+}
+
+func (server *smtpServer) run() {
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", server.config.SMTPPort))
+	if err != nil {
+		server.rc <- err
+		return
+	}
+
+	for {
+		conn, err := l.Accept()
+		if err != nil {
+			server.rc <- err
+			return
+		}
+
+		go smtp.AcceptConnection(conn, server)
+	}
+}
+
+func (server *smtpServer) OnEHLO() error {
+	return nil
+}
+
+func (server *smtpServer) OnMessageDelivered() error {
+	return nil
+}
diff --git a/smtp/conn.go b/smtp/conn.go
new file mode 100644
index 0000000..e4734ae
--- /dev/null
+++ b/smtp/conn.go
@@ -0,0 +1,11 @@
+package smtp
+
+import (
+	"io"
+	"net"
+)
+
+func AcceptConnection(conn net.Conn, server Server) error {
+	conn.Close()
+	return nil
+}
diff --git a/smtp/server.go b/smtp/server.go
new file mode 100644
index 0000000..e9539e8
--- /dev/null
+++ b/smtp/server.go
@@ -0,0 +1,6 @@
+package smtp
+
+type Server interface {
+	OnEHLO() error
+	OnMessageDelivered() error
+}
-- 
2.22.5