162 lines
3 KiB
Go
162 lines
3 KiB
Go
package smtpd
|
|
|
|
import (
|
|
"net"
|
|
"bufio"
|
|
"strings"
|
|
"fmt"
|
|
"time"
|
|
)
|
|
|
|
type session struct {
|
|
server *Server
|
|
|
|
peer Peer
|
|
envelope *Envelope
|
|
|
|
conn net.Conn
|
|
|
|
reader *bufio.Reader
|
|
writer *bufio.Writer
|
|
scanner *bufio.Scanner
|
|
|
|
tls bool
|
|
}
|
|
|
|
|
|
func (session *session) serve() {
|
|
|
|
defer session.close()
|
|
|
|
if !session.server.EnableProxyProtocol {
|
|
session.welcome()
|
|
}
|
|
|
|
for {
|
|
|
|
for session.scanner.Scan() {
|
|
line := session.scanner.Text()
|
|
session.logf("received: %s", strings.TrimSpace(line))
|
|
session.handle(line)
|
|
}
|
|
|
|
err := session.scanner.Err()
|
|
|
|
if err == bufio.ErrTooLong {
|
|
|
|
session.reply(500, "Line too long")
|
|
|
|
// Advance reader to the next newline
|
|
|
|
session.reader.ReadString('\n')
|
|
session.scanner = bufio.NewScanner(session.reader)
|
|
|
|
// Reset and have the client start over.
|
|
|
|
session.reset()
|
|
|
|
continue
|
|
}
|
|
|
|
break
|
|
}
|
|
|
|
}
|
|
|
|
func (session *session) reject() {
|
|
session.reply(421, "Too busy. Try again later.")
|
|
session.close()
|
|
}
|
|
|
|
func (session *session) reset() {
|
|
session.envelope = nil
|
|
}
|
|
|
|
func (session *session) welcome() {
|
|
|
|
if session.server.ConnectionChecker != nil {
|
|
err := session.server.ConnectionChecker(session.peer)
|
|
if err != nil {
|
|
session.error(err)
|
|
session.close()
|
|
return
|
|
}
|
|
}
|
|
|
|
session.reply(220, session.server.WelcomeMessage)
|
|
|
|
}
|
|
|
|
func (session *session) reply(code int, message string) {
|
|
session.logf("sending: %d %s", code, message)
|
|
fmt.Fprintf(session.writer, "%d %s\r\n", code, message)
|
|
session.flush()
|
|
}
|
|
|
|
func (session *session) flush() {
|
|
session.conn.SetWriteDeadline(time.Now().Add(session.server.WriteTimeout))
|
|
session.writer.Flush()
|
|
session.conn.SetReadDeadline(time.Now().Add(session.server.ReadTimeout))
|
|
}
|
|
|
|
func (session *session) error(err error) {
|
|
if smtpdError, ok := err.(Error); ok {
|
|
session.reply(smtpdError.Code, smtpdError.Message)
|
|
} else {
|
|
session.reply(502, fmt.Sprintf("%s", err))
|
|
}
|
|
}
|
|
|
|
func (session *session) logf(format string, v ...interface{}) {
|
|
if session.server.ProtocolLogger == nil {
|
|
return
|
|
}
|
|
session.server.ProtocolLogger.Info(fmt.Sprintf(
|
|
"%s [peer:%s]",
|
|
fmt.Sprintf(format, v...),
|
|
session.peer.Addr,
|
|
))
|
|
|
|
}
|
|
|
|
func (session *session) logError(err error, desc string) {
|
|
session.server.ProtocolLogger.Error(desc, "error", err)
|
|
}
|
|
|
|
func (session *session) extensions() []string {
|
|
|
|
extensions := []string{
|
|
fmt.Sprintf("SIZE %d", session.server.MaxMessageSize),
|
|
"8BITMIME",
|
|
"PIPELINING",
|
|
}
|
|
|
|
if session.server.EnableXCLIENT {
|
|
extensions = append(extensions, "XCLIENT")
|
|
}
|
|
|
|
if session.server.TLSConfig != nil && !session.tls {
|
|
extensions = append(extensions, "STARTTLS")
|
|
}
|
|
|
|
if session.server.Authenticator != nil && session.tls {
|
|
extensions = append(extensions, "AUTH PLAIN LOGIN")
|
|
}
|
|
|
|
return extensions
|
|
|
|
}
|
|
|
|
func (session *session) deliver() error {
|
|
if session.server.Handler != nil {
|
|
return session.server.Handler(session.peer, *session.envelope)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (session *session) close() {
|
|
session.writer.Flush()
|
|
time.Sleep(200 * time.Millisecond)
|
|
session.conn.Close()
|
|
}
|
|
|