/*
   * linux/lib/cmdline.c
   * Helper functions generally used for parsing kernel command line
   * and module options.
   *
   * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
   *
   * This source code is licensed under the GNU General Public License,
   * Version 2.  See the file COPYING for more details.
   *
   * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
   *
   */

  #include <linux/export.h>

  #include <linux/kernel.h>
  #include <linux/string.h>

  /*
   *	If a hyphen was found in get_option, this will handle the
   *	range of numbers, M-N.  This will expand the range and insert
   *	the values[M, M+1, ..., N] into the ints array in get_options.
   */
  
  static int get_range(char **str, int *pint)
  {
  	int x, inc_counter, upper_range;
  
  	(*str)++;
  	upper_range = simple_strtol((*str), NULL, 0);
  	inc_counter = upper_range - *pint;
  	for (x = *pint; x < upper_range; x++)
  		*pint++ = x;
  	return inc_counter;
  }

  
  /**
   *	get_option - Parse integer from an option string
   *	@str: option string
   *	@pint: (output) integer value parsed from @str
   *
   *	Read an int from an option string; if available accept a subsequent
   *	comma as well.
   *
   *	Return values:

   *	0 - no int in string
   *	1 - int found, no subsequent comma
   *	2 - int found including a subsequent comma
   *	3 - hyphen found to denote a range

   */

  int get_option(char **str, int *pint)

  {
  	char *cur = *str;
  
  	if (!cur || !(*cur))
  		return 0;

  	*pint = simple_strtol(cur, str, 0);

  	if (cur == *str)
  		return 0;
  	if (**str == ',') {
  		(*str)++;
  		return 2;
  	}

  	if (**str == '-')
  		return 3;

  
  	return 1;
  }

  EXPORT_SYMBOL(get_option);

  
  /**
   *	get_options - Parse a string into a list of integers
   *	@str: String to be parsed
   *	@nints: size of integer array
   *	@ints: integer array
   *
   *	This function parses a string containing a comma-separated

   *	list of integers, a hyphen-separated range of _positive_ integers,
   *	or a combination of both.  The parse halts when the array is

   *	full, or when no more numbers can be retrieved from the
   *	string.
   *
   *	Return value is the character in the string which caused
   *	the parse to end (typically a null terminator, if @str is
   *	completely parseable).
   */

  char *get_options(const char *str, int nints, int *ints)
  {
  	int res, i = 1;
  
  	while (i < nints) {

  		res = get_option((char **)&str, ints + i);

  		if (res == 0)
  			break;

  		if (res == 3) {
  			int range_nums;
  			range_nums = get_range((char **)&str, ints + i);
  			if (range_nums < 0)
  				break;
  			/*
  			 * Decrement the result by one to leave out the
  			 * last number in the range.  The next iteration
  			 * will handle the upper number in the range
  			 */
  			i += (range_nums - 1);
  		}

  		i++;
  		if (res == 1)
  			break;
  	}
  	ints[0] = i - 1;
  	return (char *)str;
  }

  EXPORT_SYMBOL(get_options);

  
  /**
   *	memparse - parse a string with mem suffixes into a number
   *	@ptr: Where parse begins

   *	@retptr: (output) Optional pointer to next char after parse completes

   *
   *	Parses a string into a number.  The number stored at @ptr is

   *	potentially suffixed with K, M, G, T, P, E.

   */

  unsigned long long memparse(const char *ptr, char **retptr)

  {

  	char *endptr;	/* local pointer to end of parsed string */

  	unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
  
  	switch (*endptr) {

  	case 'E':
  	case 'e':
  		ret <<= 10;
  	case 'P':
  	case 'p':
  		ret <<= 10;
  	case 'T':
  	case 't':
  		ret <<= 10;

  	case 'G':
  	case 'g':
  		ret <<= 10;
  	case 'M':
  	case 'm':
  		ret <<= 10;
  	case 'K':
  	case 'k':
  		ret <<= 10;

  		endptr++;

  	default:
  		break;
  	}

  
  	if (retptr)
  		*retptr = endptr;

  	return ret;
  }

  EXPORT_SYMBOL(memparse);

  
  /**
   *	parse_option_str - Parse a string and check an option is set or not
   *	@str: String to be parsed
   *	@option: option name
   *
   *	This function parses a string containing a comma-separated list of
   *	strings like a=b,c.
   *
   *	Return true if there's such option in the string, or return false.
   */
  bool parse_option_str(const char *str, const char *option)
  {
  	while (*str) {
  		if (!strncmp(str, option, strlen(option))) {
  			str += strlen(option);
  			if (!*str || *str == ',')
  				return true;
  		}
  
  		while (*str && *str != ',')
  			str++;
  
  		if (*str == ',')
  			str++;
  	}
  
  	return false;
  }