diff --git a/app/smtpd/handler.go b/app/smtpd/handler.go index d8c3680..170e26e 100644 --- a/app/smtpd/handler.go +++ b/app/smtpd/handler.go @@ -1,75 +1,75 @@ package smtpd import ( - "bufio" - "container/list" - "fmt" - "net" - "strings" - "time" + "bufio" + "container/list" + "fmt" + "net" + "strings" + "time" ) type State int const ( - GREET State = iota // Waiting for HELO - READY // Got HELO, waiting for MAIL - MAIL // Got MAIL, accepting RCPTs - DATA // Got DATA, waiting for "." - QUIT // Close session + GREET State = iota // Waiting for HELO + READY // Got HELO, waiting for MAIL + MAIL // Got MAIL, accepting RCPTs + DATA // Got DATA, waiting for "." + QUIT // Close session ) func (s State) String() string { - switch s { - case GREET: - return "GREET" - case READY: - return "READY" - case MAIL: - return "MAIL" - case DATA: - return "DATA" - case QUIT: - return "QUIT" - } - return "Unknown" + switch s { + case GREET: + return "GREET" + case READY: + return "READY" + case MAIL: + return "MAIL" + case DATA: + return "DATA" + case QUIT: + return "QUIT" + } + return "Unknown" } - -var commands = map[string] bool { - "HELO": true, - "MAIL": true, - "RCPT": true, - "DATA": true, - "RSET": true, - "SEND": true, - "SOML": true, - "SAML": true, - "VRFY": true, - "EXPN": true, - "HELP": true, - "NOOP": true, - "QUIT": true, - "TURN": true, + +var commands = map[string]bool{ + "HELO": true, + "MAIL": true, + "RCPT": true, + "DATA": true, + "RSET": true, + "SEND": true, + "SOML": true, + "SAML": true, + "VRFY": true, + "EXPN": true, + "HELP": true, + "NOOP": true, + "QUIT": true, + "TURN": true, } type Session struct { - server *Server - id int - conn net.Conn - sendError error - state State - reader *bufio.Reader - from string - recipients *list.List + server *Server + id int + conn net.Conn + sendError error + state State + reader *bufio.Reader + from string + recipients *list.List } func NewSession(server *Server, id int, conn net.Conn) *Session { - reader := bufio.NewReader(conn) - return &Session{server: server, id: id, conn: conn, state: GREET, reader: reader} + reader := bufio.NewReader(conn) + return &Session{server: server, id: id, conn: conn, state: GREET, reader: reader} } func (ss *Session) String() string { - return fmt.Sprintf("Session{id: %v, state: %v}", ss.id, ss.state) + return fmt.Sprintf("Session{id: %v, state: %v}", ss.id, ss.state) } /* Session flow: @@ -80,282 +80,280 @@ func (ss *Session) String() string { * 5. Goto 2 */ func (s *Server) startSession(id int, conn net.Conn) { - s.trace("Starting session <%v>", id) - defer conn.Close() + s.trace("Starting session <%v>", id) + defer conn.Close() - ss := NewSession(s, id, conn) - ss.greet() + ss := NewSession(s, id, conn) + ss.greet() - // This is our command reading loop - for ss.state != QUIT && ss.sendError == nil { - if ss.state == DATA { - // Special case, does not use SMTP command format - ss.dataHandler() - continue - } - line, err := ss.readLine() - if err == nil { - if cmd, arg, ok := ss.parseCmd(line); ok { - // Check against valid SMTP commands - if cmd == "" { - ss.send("500 Speak up") - continue - } - if !commands[cmd] { - ss.send(fmt.Sprintf("500 Syntax error, %v command unrecognized", cmd)) - continue - } + // This is our command reading loop + for ss.state != QUIT && ss.sendError == nil { + if ss.state == DATA { + // Special case, does not use SMTP command format + ss.dataHandler() + continue + } + line, err := ss.readLine() + if err == nil { + if cmd, arg, ok := ss.parseCmd(line); ok { + // Check against valid SMTP commands + if cmd == "" { + ss.send("500 Speak up") + continue + } + if !commands[cmd] { + ss.send(fmt.Sprintf("500 Syntax error, %v command unrecognized", cmd)) + continue + } - // Commands we handle in any state - switch cmd { - case "SEND", "SOML", "SAML", "VRFY", "EXPN", "HELP", "TURN": - // These commands are not implemented in any state - ss.send(fmt.Sprintf("502 %v command not implemented", cmd)) - ss.warn("Command %v not implemented by Inbucket", cmd) - continue - case "NOOP": - ss.send("250 I have sucessfully done nothing") - continue - case "RSET": - // Reset session - ss.reset() - continue - case "QUIT": - ss.send("221 Goodnight and good luck") - ss.enterState(QUIT) - continue - } + // Commands we handle in any state + switch cmd { + case "SEND", "SOML", "SAML", "VRFY", "EXPN", "HELP", "TURN": + // These commands are not implemented in any state + ss.send(fmt.Sprintf("502 %v command not implemented", cmd)) + ss.warn("Command %v not implemented by Inbucket", cmd) + continue + case "NOOP": + ss.send("250 I have sucessfully done nothing") + continue + case "RSET": + // Reset session + ss.reset() + continue + case "QUIT": + ss.send("221 Goodnight and good luck") + ss.enterState(QUIT) + continue + } - // Send command to handler for current state - switch ss.state { - case GREET: - ss.greetHandler(cmd, arg) - continue - case READY: - ss.readyHandler(cmd, arg) - continue - case MAIL: - ss.mailHandler(cmd, arg) - continue + // Send command to handler for current state + switch ss.state { + case GREET: + ss.greetHandler(cmd, arg) + continue + case READY: + ss.readyHandler(cmd, arg) + continue + case MAIL: + ss.mailHandler(cmd, arg) + continue + } + ss.error("Session entered unexpected state %v", ss.state) + break + } else { + ss.send("500 Syntax error, command garbled") + } + } else { + // readLine() returned an error + ss.error("Connection error: %v", err) + if netErr, ok := err.(net.Error); ok { + if netErr.Timeout() { + ss.send("221 Idle timeout, bye bye") + break + } + } + ss.send("221 Connection error, sorry") + break + } } - ss.error("Session entered unexpected state %v", ss.state) - break - } else { - ss.send("500 Syntax error, command garbled") - } - } else { - // readLine() returned an error - ss.error("Connection error: %v", err) - if netErr, ok := err.(net.Error); ok { - if netErr.Timeout() { - ss.send("221 Idle timeout, bye bye") - break + if ss.sendError != nil { + ss.error("Network send error: %v", ss.sendError) } - } - ss.send("221 Connection error, sorry") - break - } - } - if ss.sendError != nil { - ss.error("Network send error: %v", ss.sendError) - } - ss.info("Closing connection") + ss.info("Closing connection") } // GREET state -> waiting for HELO func (ss *Session) greetHandler(cmd string, arg string) { - if cmd == "HELO" { - ss.send("250 Great, let's get this show on the road") - ss.enterState(READY) - } else { - ss.ooSeq(cmd) - } + if cmd == "HELO" { + ss.send("250 Great, let's get this show on the road") + ss.enterState(READY) + } else { + ss.ooSeq(cmd) + } } // READY state -> waiting for MAIL func (ss *Session) readyHandler(cmd string, arg string) { - if cmd == "MAIL" { - if (len(arg) < 6) || (strings.ToUpper(arg[0:5]) != "FROM:") { - ss.send("501 Was expecting MAIL arg syntax of FROM:
") - ss.warn("Bad MAIL argument: \"%v\"", arg) - return - } - // This trim is probably too forgiving - from := strings.Trim(arg[5:], "<> ") - ss.from = from - ss.recipients = list.New() - ss.info("Mail from: %v", from) - ss.send(fmt.Sprintf("250 Roger, accepting mail from <%v>", from)) - ss.enterState(MAIL) - } else { - ss.ooSeq(cmd) - } + if cmd == "MAIL" { + if (len(arg) < 6) || (strings.ToUpper(arg[0:5]) != "FROM:") { + ss.send("501 Was expecting MAIL arg syntax of FROM:") + ss.warn("Bad MAIL argument: \"%v\"", arg) + return + } + // This trim is probably too forgiving + from := strings.Trim(arg[5:], "<> ") + ss.from = from + ss.recipients = list.New() + ss.info("Mail from: %v", from) + ss.send(fmt.Sprintf("250 Roger, accepting mail from <%v>", from)) + ss.enterState(MAIL) + } else { + ss.ooSeq(cmd) + } } // MAIL state -> waiting for RCPTs followed by DATA func (ss *Session) mailHandler(cmd string, arg string) { - switch cmd { - case "RCPT": - if (len(arg) < 4) || (strings.ToUpper(arg[0:3]) != "TO:") { - ss.send("501 Was expecting RCPT arg syntax of TO:") - ss.warn("Bad RCPT argument: \"%v\"", arg) - return - } - // This trim is probably too forgiving - recip := strings.Trim(arg[3:], "<> ") - if ss.recipients.Len() >= ss.server.maxRecips { - ss.warn("Maximum limit of %v recipients reached", ss.server.maxRecips) - ss.send(fmt.Sprintf("552 Maximum limit of %v recipients reached", ss.server.maxRecips)) - return - } - ss.recipients.PushBack(recip) - ss.info("Recipient: %v", recip) - ss.send(fmt.Sprintf("250 I'll make sure <%v> gets this", recip)) - return - case "DATA": - if arg != "" { - ss.send("501 DATA command should not have any arguments") - ss.warn("Got unexpected args on DATA: \"%v\"", arg) - return - } - if ss.recipients.Len() > 0 { - // We have recipients, go to accept data - ss.enterState(DATA) - return - } else { - // DATA out of sequence - ss.ooSeq(cmd) - return - } - } - ss.ooSeq(cmd) + switch cmd { + case "RCPT": + if (len(arg) < 4) || (strings.ToUpper(arg[0:3]) != "TO:") { + ss.send("501 Was expecting RCPT arg syntax of TO:") + ss.warn("Bad RCPT argument: \"%v\"", arg) + return + } + // This trim is probably too forgiving + recip := strings.Trim(arg[3:], "<> ") + if ss.recipients.Len() >= ss.server.maxRecips { + ss.warn("Maximum limit of %v recipients reached", ss.server.maxRecips) + ss.send(fmt.Sprintf("552 Maximum limit of %v recipients reached", ss.server.maxRecips)) + return + } + ss.recipients.PushBack(recip) + ss.info("Recipient: %v", recip) + ss.send(fmt.Sprintf("250 I'll make sure <%v> gets this", recip)) + return + case "DATA": + if arg != "" { + ss.send("501 DATA command should not have any arguments") + ss.warn("Got unexpected args on DATA: \"%v\"", arg) + return + } + if ss.recipients.Len() > 0 { + // We have recipients, go to accept data + ss.enterState(DATA) + return + } else { + // DATA out of sequence + ss.ooSeq(cmd) + return + } + } + ss.ooSeq(cmd) } // DATA func (ss *Session) dataHandler() { - var msgSize uint64 = 0 - ss.send("354 Start mail input; end with