1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  2/******************************************************************************
  3 *
  4 * Module Name: utascii - Utility ascii functions
  5 *
  6 * Copyright (C) 2000 - 2023, Intel Corp.
  7 *
  8 *****************************************************************************/
  9
 10#include <acpi/acpi.h>
 11#include "accommon.h"
 12
 13/*******************************************************************************
 14 *
 15 * FUNCTION:    acpi_ut_valid_nameseg
 16 *
 17 * PARAMETERS:  name            - The name or table signature to be examined.
 18 *                                Four characters, does not have to be a
 19 *                                NULL terminated string.
 20 *
 21 * RETURN:      TRUE if signature is has 4 valid ACPI characters
 22 *
 23 * DESCRIPTION: Validate an ACPI table signature.
 24 *
 25 ******************************************************************************/
 26
 27u8 acpi_ut_valid_nameseg(char *name)
 28{
 29	u32 i;
 30
 31	/* Validate each character in the signature */
 32
 33	for (i = 0; i < ACPI_NAMESEG_SIZE; i++) {
 34		if (!acpi_ut_valid_name_char(name[i], i)) {
 35			return (FALSE);
 36		}
 37	}
 38
 39	return (TRUE);
 40}
 41
 42/*******************************************************************************
 43 *
 44 * FUNCTION:    acpi_ut_valid_name_char
 45 *
 46 * PARAMETERS:  char            - The character to be examined
 47 *              position        - Byte position (0-3)
 48 *
 49 * RETURN:      TRUE if the character is valid, FALSE otherwise
 50 *
 51 * DESCRIPTION: Check for a valid ACPI character. Must be one of:
 52 *              1) Upper case alpha
 53 *              2) numeric
 54 *              3) underscore
 55 *
 56 *              We allow a '!' as the last character because of the ASF! table
 57 *
 58 ******************************************************************************/
 59
 60u8 acpi_ut_valid_name_char(char character, u32 position)
 61{
 62
 63	if (!((character >= 'A' && character <= 'Z') ||
 64	      (character >= '0' && character <= '9') || (character == '_'))) {
 65
 66		/* Allow a '!' in the last position */
 67
 68		if (character == '!' && position == 3) {
 69			return (TRUE);
 70		}
 71
 72		return (FALSE);
 73	}
 74
 75	return (TRUE);
 76}
 77
 78/*******************************************************************************
 79 *
 80 * FUNCTION:    acpi_ut_check_and_repair_ascii
 81 *
 82 * PARAMETERS:  name                - Ascii string
 83 *              count               - Number of characters to check
 84 *
 85 * RETURN:      None
 86 *
 87 * DESCRIPTION: Ensure that the requested number of characters are printable
 88 *              Ascii characters. Sets non-printable and null chars to <space>.
 89 *
 90 ******************************************************************************/
 91
 92void acpi_ut_check_and_repair_ascii(u8 *name, char *repaired_name, u32 count)
 93{
 94	u32 i;
 95
 96	for (i = 0; i < count; i++) {
 97		repaired_name[i] = (char)name[i];
 98
 99		if (!name[i]) {
100			return;
101		}
102		if (!isprint(name[i])) {
103			repaired_name[i] = ' ';
104		}
105	}
106}