diff options
Diffstat (limited to 'mta_recv.go')
| -rw-r--r-- | mta_recv.go | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/mta_recv.go b/mta_recv.go deleted file mode 100644 index b67beb4..0000000 --- a/mta_recv.go +++ /dev/null @@ -1,209 +0,0 @@ -package main - -import ( - "bufio" - "bytes" - "crypto/tls" - "net" - "slices" - "strings" - - "go.lindenii.runxiyu.org/lindenii-common/mailkit" -) - -type server_state_t uint - -const ( - server_state_begin server_state_t = iota - server_state_helo - server_state_mail - server_state_rcpt -) - -func handle_incoming_server_connection(buf_conn *bufio.ReadWriter, net_conn *net.Conn) error { - var tls_conn *tls.Conn - var my_server_name string - var routes map[string]string - var tls_config *tls.Config - config_consistent_run(func() { - my_server_name = config.Server_name - routes = config.Routes - tls_config = config._tls_config - }) - _, _ = buf_conn.WriteString("220 " + my_server_name + " " + VERSION + "\r\n") - _ = buf_conn.Flush() - server_state := server_state_begin - var remote_server_name string - var current_mail_from string - var current_rcpt_to []string - for { - line, err := buf_conn.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 "STARTTLS": - if param != "" { - _, _ = buf_conn.WriteString("501 5.5.4 Syntax error (no parameters allowed)\r\n") - _ = buf_conn.Flush() - break - } - if tls_conn != nil { - _, _ = buf_conn.WriteString("554 5.5.1 Error: TLS already active\r\n") - _ = buf_conn.Flush() - break - } - _, _ = buf_conn.WriteString("220 2.0.0 Ready to start TLS\r\n") - _ = buf_conn.Flush() - tls_conn = tls.Server(*net_conn, tls_config) - buf_conn = bufio.NewReadWriter(bufio.NewReader(tls_conn), bufio.NewWriter(tls_conn)) - server_state = server_state_begin - current_mail_from = "" - current_rcpt_to = []string{""} - case "HELO": - if param == "" { // TODO: actually validate the hostname - _, _ = buf_conn.WriteString("501 Syntax: HELO hostname\r\n") - _ = buf_conn.Flush() - break - } - remote_server_name = param - _ = remote_server_name // TODO - server_state = server_state_helo - _, _ = buf_conn.WriteString("250 " + my_server_name + "\r\n") - _ = buf_conn.Flush() - case "MAIL": - switch server_state { - case server_state_begin: - _, _ = buf_conn.WriteString("503 5.5.1 Error: send HELO/EHLO first\r\n") - _ = buf_conn.Flush() - break switch_cmd - case server_state_helo: - break - case server_state_mail: - _, _ = buf_conn.WriteString("503 5.5.1 Error: nested MAIL command\r\n") - _ = buf_conn.Flush() - break switch_cmd - } - if len(param) <= len("FROM:") || strings.ToUpper(param[:len("FROM:")]) != "FROM:" { - _, _ = buf_conn.WriteString("501 5.5.4 Syntax: MAIL FROM:<address>\r\n") - _ = buf_conn.Flush() - break - } - current_mail_from = param[len("FROM:"):] - current_rcpt_to = []string{} - server_state = server_state_mail - _, _ = buf_conn.WriteString("250 2.1.0 Ok\r\n") - _ = buf_conn.Flush() - // TODO: Address validation - case "RCPT": - if server_state != server_state_mail && server_state != server_state_rcpt { - _, _ = buf_conn.WriteString("503 5.5.1 Error: need MAIL command\r\n") - _ = buf_conn.Flush() - break - } - if len(param) <= len("TO:") || strings.ToUpper(param[:len("TO:")]) != "TO:" { - _, _ = buf_conn.WriteString("501 5.5.4 Syntax: RCPT TO:<address>\r\n") - _ = buf_conn.Flush() - break - } - recipient, _, _ := mailkit.Strip_angle_brackets(param[len("TO:"):]) - _, ok := routes[recipient] - if !ok { - _, _ = buf_conn.WriteString("550 5.1.1 <" + recipient + ">: Recipient address rejected: User unknown in local recipient table\r\n") - _ = buf_conn.Flush() - break switch_cmd - } - current_rcpt_to = append(current_rcpt_to, recipient) - server_state = server_state_rcpt - _, _ = buf_conn.WriteString("250 2.1.5 Ok\r\n") - _ = buf_conn.Flush() - case "DATA": - if server_state != server_state_rcpt { - _, _ = buf_conn.WriteString("503 5.5.1 Error: need RCPT command\r\n") - _ = buf_conn.Flush() - break - } - _, _ = buf_conn.WriteString("354 End data with <CR><LF>.<CR><LF>\r\n") - _ = buf_conn.Flush() - var current_data []byte - for { - tmp, err := buf_conn.ReadSlice('\r') - if err != nil { - return err - } - - // buf_conn.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 := buf_conn.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 := buf_conn.Discard(4) - if err != nil { - return err - } - { - inboxes_to_deliver_to := make(map[string]struct{}) - for _, recipient := range current_rcpt_to { - inbox, ok := routes[recipient] - if !ok { - _, _ = buf_conn.WriteString("550 5.1.1 <" + recipient + ">: Recipient address rejected: User unknown in local recipient table\r\n") - break switch_cmd - } - inboxes_to_deliver_to[inbox] = struct{}{} - } - for inbox := range inboxes_to_deliver_to { - err = deliver_to_local_directory(current_mail_from, current_rcpt_to, current_data, inbox) - } - } - if err == nil { - _, _ = buf_conn.WriteString("250 2.0.0 Ok: Accepted\r\n") - } else { - _, _ = buf_conn.WriteString("500 2.0.0 Error: " + err.Error() + "\r\n") - } - _ = buf_conn.Flush() - server_state = server_state_helo - case "QUIT": - _, _ = buf_conn.WriteString("221 2.0.0 Bye\r\n") - _ = buf_conn.Flush() - return nil - case "NOOP": - _, _ = buf_conn.WriteString("250 2.0.0 Ok\r\n") - _ = buf_conn.Flush() - case "RSET": - if server_state != server_state_begin { - server_state = server_state_helo - } - _, _ = buf_conn.WriteString("250 2.0.0 Ok\r\n") - _ = buf_conn.Flush() - default: - _, _ = buf_conn.WriteString("500 5.5.2 Error: command not recognized\r\n") - _ = buf_conn.Flush() - } - } -} |