diff options
Diffstat (limited to 'mx_recv.go')
| -rw-r--r-- | mx_recv.go | 231 |
1 files changed, 0 insertions, 231 deletions
diff --git a/mx_recv.go b/mx_recv.go deleted file mode 100644 index 33b4012..0000000 --- a/mx_recv.go +++ /dev/null @@ -1,231 +0,0 @@ -package main - -import ( - "bufio" - "bytes" - "context" - "crypto/tls" - "errors" - "io" - "net" - "slices" - "strings" - - "github.com/jackc/pgx/v5/pgxpool" - "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 -) - -type mx_recv_session struct { - buf_conn *bufio.ReadWriter - net_conn net.Conn - tls_conn *tls.Conn - my_server_name string - tls_config *tls.Config - db *pgxpool.Pool - remote_server_name string - current_mail_from string - current_rcpt_to []string - server_state server_state_t -} - -func (session *mx_recv_session) handle(ctx context.Context) error { - session.buf_conn = bufio.NewReadWriter(bufio.NewReader(session.net_conn), bufio.NewWriter(session.net_conn)) - config_consistent_run(func() { - session.my_server_name = config.Server_name - session.tls_config = config._tls_config - session.db = global_db - }) - _, _ = session.buf_conn.WriteString("220 " + session.my_server_name + " " + VERSION + "\r\n") - _ = session.buf_conn.Flush() - session.server_state = server_state_begin - for { - line, err := session.buf_conn.ReadString('\n') - if err != nil { - if err == io.EOF { - return err_connection_handler_eof - } - 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 != "" { - _, _ = session.buf_conn.WriteString("501 5.5.4 Syntax error (no parameters allowed)\r\n") - _ = session.buf_conn.Flush() - break - } - if session.tls_conn != nil { - _, _ = session.buf_conn.WriteString("554 5.5.1 Error: TLS already active\r\n") - _ = session.buf_conn.Flush() - break - } - _, _ = session.buf_conn.WriteString("220 2.0.0 Ready to start TLS\r\n") - _ = session.buf_conn.Flush() - session.tls_conn = tls.Server(session.net_conn, session.tls_config) - session.buf_conn = bufio.NewReadWriter(bufio.NewReader(session.tls_conn), bufio.NewWriter(session.tls_conn)) - session.server_state = server_state_begin - session.current_mail_from = "" - session.current_rcpt_to = []string{""} - case "HELO": - if param == "" { // TODO: actually validate the hostname - _, _ = session.buf_conn.WriteString("501 Syntax: HELO hostname\r\n") - _ = session.buf_conn.Flush() - break - } - session.remote_server_name = param - _ = session.remote_server_name // TODO - session.server_state = server_state_helo - _, _ = session.buf_conn.WriteString("250 " + session.my_server_name + "\r\n") - _ = session.buf_conn.Flush() - case "MAIL": - switch session.server_state { - case server_state_begin: - _, _ = session.buf_conn.WriteString("503 5.5.1 Error: send HELO/EHLO first\r\n") - _ = session.buf_conn.Flush() - break switch_cmd - case server_state_helo: - break - case server_state_mail: - _, _ = session.buf_conn.WriteString("503 5.5.1 Error: nested MAIL command\r\n") - _ = session.buf_conn.Flush() - break switch_cmd - } - if len(param) <= len("FROM:") || strings.ToUpper(param[:len("FROM:")]) != "FROM:" { - _, _ = session.buf_conn.WriteString("501 5.5.4 Syntax: MAIL FROM:<address>\r\n") - _ = session.buf_conn.Flush() - break - } - session.current_mail_from = param[len("FROM:"):] - session.current_rcpt_to = []string{} - session.server_state = server_state_mail - _, _ = session.buf_conn.WriteString("250 2.1.0 Ok\r\n") - _ = session.buf_conn.Flush() - // TODO: Address validation - case "RCPT": - if session.server_state != server_state_mail && session.server_state != server_state_rcpt { - _, _ = session.buf_conn.WriteString("503 5.5.1 Error: need MAIL command\r\n") - _ = session.buf_conn.Flush() - break - } - if len(param) <= len("TO:") || strings.ToUpper(param[:len("TO:")]) != "TO:" { - _, _ = session.buf_conn.WriteString("501 5.5.4 Syntax: RCPT TO:<address>\r\n") - _ = session.buf_conn.Flush() - break - } - recipient_address, _, _ := mailkit.Strip_angle_brackets(param[len("TO:"):]) - var count int - err := session.db.QueryRow(ctx, "SELECT COUNT (*) FROM addresses WHERE address = $1", recipient_address).Scan(&count) - if err != nil { - _, _ = session.buf_conn.WriteString("451 Internal error: " + err.Error() + "\r\n") - _ = session.buf_conn.Flush() - break - } - if count == 0 { - _, _ = session.buf_conn.WriteString("550 5.1.1 Recipient address rejected: Local recipients not found: " + recipient_address + "\r\n") - _ = session.buf_conn.Flush() - break - } - session.current_rcpt_to = append(session.current_rcpt_to, recipient_address) - session.server_state = server_state_rcpt - _, _ = session.buf_conn.WriteString("250 2.1.5 Ok\r\n") - _ = session.buf_conn.Flush() - case "DATA": - if session.server_state != server_state_rcpt { - _, _ = session.buf_conn.WriteString("503 5.5.1 Error: need RCPT command\r\n") - _ = session.buf_conn.Flush() - break - } - _, _ = session.buf_conn.WriteString("354 End data with <CR><LF>.<CR><LF>\r\n") - _ = session.buf_conn.Flush() - var current_data []byte - for { - tmp, err := session.buf_conn.ReadSlice('\r') - if err != nil { - return err - } - - // session.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 := session.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 := session.buf_conn.Discard(4) - if err != nil { - return err - } - err = deliver_local(ctx, session.db, session.current_mail_from, session.current_rcpt_to, current_data, session.current_rcpt_to) - var err_local_recipients_not_found *err_local_recipients_not_found_t - switch { - case errors.As(err, &err_local_recipients_not_found): - _, _ = session.buf_conn.WriteString("550 5.1.1 Recipient address rejected: " + err_local_recipients_not_found.Error() + "\r\n") - case err != nil: - _, _ = session.buf_conn.WriteString("500 2.0.0 Error: " + err.Error() + "\r\n") - default: - _, _ = session.buf_conn.WriteString("250 2.0.0 Ok: Accepted\r\n") - } - _ = session.buf_conn.Flush() - session.server_state = server_state_helo - case "QUIT": - _, _ = session.buf_conn.WriteString("221 2.0.0 Bye\r\n") - _ = session.buf_conn.Flush() - if session.tls_conn != nil { - session.tls_conn.Close() - } - session.net_conn.Close() - return nil - case "NOOP": - _, _ = session.buf_conn.WriteString("250 2.0.0 Ok\r\n") - _ = session.buf_conn.Flush() - case "RSET": - if session.server_state != server_state_begin { - session.server_state = server_state_helo - } - _, _ = session.buf_conn.WriteString("250 2.0.0 Ok\r\n") - _ = session.buf_conn.Flush() - default: - _, _ = session.buf_conn.WriteString("500 5.5.2 Error: command not recognized\r\n") - _ = session.buf_conn.Flush() - } - } -} - -func handle_mx_recv_conn(ctx context.Context, net_conn net.Conn) error { - session := mx_recv_session{ - net_conn: net_conn, - } - return session.handle(ctx) -} |