diff options
Diffstat (limited to '')
| -rw-r--r-- | main.go | 157 |
1 files changed, 1 insertions, 156 deletions
@@ -2,11 +2,8 @@ package main import ( "bufio" - "bytes" "net" "os" - "slices" - "strings" "go.lindenii.runxiyu.org/lindenii-common/clog" "go.lindenii.runxiyu.org/lindenii-common/scfg" @@ -38,7 +35,7 @@ func main() { } go func() { - err := handle_connection(bufio.NewReader(conn), bufio.NewWriter(conn)) + err := handle_incoming_server_connection(bufio.NewReader(conn), bufio.NewWriter(conn)) if err != nil { clog.Error("connection handler returned error", "err", err) } @@ -46,155 +43,3 @@ func main() { } } - -type server_state_t uint - -const ( - server_state_begin server_state_t = iota - server_state_helo - server_state_mail - server_state_rcpt -) - -func handle_connection(reader *bufio.Reader, writer *bufio.Writer) error { - _, _ = writer.WriteString("220 " + config.Server_name + " " + VERSION + "\r\n") - _ = writer.Flush() - server_state := server_state_begin - var remote_server_name string - var current_mail_from string - var current_rcpt_to []string - for { - line, err := reader.ReadString('\n') - if err != nil { - return err - } - line = strings.TrimSuffix(line, "\n") - line = strings.TrimSuffix(line, "\r") - cmd_end := strings.IndexByte(line, ' ') - var param_start int - if cmd_end == -1 { - cmd_end = len(line) - param_start = len(line) - } else { - param_start = cmd_end + 1 - } - cmd := strings.ToUpper(line[:cmd_end]) - param := line[param_start:] - switch_cmd: - switch cmd { - case "HELO": - if param == "" { // TODO: actually validate the hostname - _, _ = writer.WriteString("501 Syntax: HELO hostname\r\n") - _ = writer.Flush() - break - } - remote_server_name = param - _ = remote_server_name // TODO - server_state = server_state_helo - _, _ = writer.WriteString("250 " + config.Server_name + "\r\n") - _ = writer.Flush() - case "MAIL": - switch server_state { - case server_state_begin: - _, _ = writer.WriteString("503 5.5.1 Error: send HELO/EHLO first\r\n") - _ = writer.Flush() - break switch_cmd - case server_state_helo: - break - case server_state_mail: - _, _ = writer.WriteString("503 5.5.1 Error: nested MAIL command\r\n") - _ = writer.Flush() - break switch_cmd - } - if len(param) <= len("FROM:") || strings.ToUpper(param[:len("FROM:")]) != "FROM:" { - _, _ = writer.WriteString("501 5.5.4 Syntax: MAIL FROM:<address>\r\n") - _ = writer.Flush() - break - } - current_mail_from = param[len("FROM:"):] - current_rcpt_to = []string{} - server_state = server_state_mail - _, _ = writer.WriteString("250 2.1.0 Ok\r\n") - _ = writer.Flush() - // TODO: Address validation - case "RCPT": - if server_state != server_state_mail && server_state != server_state_rcpt { - _, _ = writer.WriteString("503 5.5.1 Error: need MAIL command\r\n") - _ = writer.Flush() - break - } - if len(param) <= len("TO:") || strings.ToUpper(param[:len("TO:")]) != "TO:" { - _, _ = writer.WriteString("501 5.5.4 Syntax: RCPT TO:<address>\r\n") - _ = writer.Flush() - break - } - current_rcpt_to = append(current_rcpt_to, param[len("TO:"):]) - server_state = server_state_rcpt - _, _ = writer.WriteString("250 2.1.5 Ok\r\n") - _ = writer.Flush() - case "DATA": - if server_state != server_state_rcpt { - _, _ = writer.WriteString("503 5.5.1 Error: need RCPT command\r\n") - _ = writer.Flush() - break - } - _, _ = writer.WriteString("354 End data with <CR><LF>.<CR><LF>\r\n") - _ = writer.Flush() - var current_data []byte - for { - tmp, err := reader.ReadSlice('\r') - if err != nil { - return err - } - - // reader.ReadSlice returns an internal buffer that gets - // overwritten on the next reader operation. So we must - // make a copy; also we have to allocate data_part to - // the correct length because [[builtin.copy]] copies - // min(len(dst), len(src)) items. - data_part := make([]byte, len(tmp)) - copy(data_part, tmp) - - next_four, err := reader.Peek(4) - if err != nil { - return err - } - if bytes.Equal(next_four, []byte{'\n', '.', '\r', '\n'}) { - current_data = slices.Concat(current_data, data_part[:len(data_part)-1]) - break - } - current_data = slices.Concat(current_data, data_part) - } - _, err := reader.Discard(4) - if err != nil { - return err - } - deliver_incoming(current_mail_from, current_rcpt_to, current_data) - server_state = server_state_helo - _, _ = writer.WriteString("250 2.0.0 Ok: Accepted\r\n") - _ = writer.Flush() - case "QUIT": - _, _ = writer.WriteString("221 2.0.0 Bye\r\n") - _ = writer.Flush() - return nil - case "RSET": - if server_state != server_state_begin { - server_state = server_state_helo - } - _, _ = writer.WriteString("250 2.0.0 Ok\r\n") - _ = writer.Flush() - default: - _, _ = writer.WriteString("500 5.5.2 Error: command not recognized\r\n") - _ = writer.Flush() - } - } -} - -func deliver_incoming(envelope_from string, envelope_recipients []string, data []byte) { - clog.Debug( - "incoming_mail", - "envelope_from", envelope_from, - "envelope_recipients", envelope_recipients, - "data", string(data), - ) -} |