// SPDX-License-Identifier: GPL-2.0-only/* * 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. * * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs */ #include <linux/export.h>#include <linux/kernel.h>#include <linux/string.h>#include <linux/ctype.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 n){	int x, inc_counter, upper_range; 	(*str)++;	upper_range = simple_strtol((*str), NULL, 0);	inc_counter = upper_range - *pint;	for (x = *pint; n && x < upper_range; x++, n--)		*pint++ = x;	return inc_counter;} /** *	get_option - Parse integer from an option string *	@str: option string *	@pint: (optional output) integer value parsed from @str * *	Read an int from an option string; if available accept a subsequent *	comma as well. * *	When @pint is NULL the function can be used as a validator of *	the current option in the string. * *	Return: *	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 * *	Leading hyphen without integer is no integer case, but we consume it *	for the sake of simplification. */ int get_option(char **str, int *pint){	char *cur = *str;	int value; 	if (!cur || !(*cur))		return 0;	if (*cur == '-')		value = -simple_strtoull(++cur, str, 0);	else		value = simple_strtoull(cur, str, 0);	if (pint)		*pint = value;	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 (must have room for at least one element) * *	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. * *	When @nints is 0, the function just validates the given @str and *	returns the amount of parseable integers as described below. * *	Returns: * *	The first element is filled by the number of collected integers *	in the range. The rest is what was parsed from the @str. * *	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){	bool validate = (nints == 0);	int res, i = 1; 	while (i < nints || validate) {		int *pint = validate ? ints : ints + i; 		res = get_option((char **)&str, pint);		if (res == 0)			break;		if (res == 3) {			int n = validate ? 0 : nints - i;			int range_nums; 			range_nums = get_range((char **)&str, pint, n);			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. * *	Return: The value as recognized by simple_strtoull() multiplied *	by the value as specified by suffix, if any. */ 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);	unsigned int shl = 0; 	/* Consume valid suffix even in case of overflow. */	switch (*endptr) {	case 'E':	case 'e':		shl += 10;		fallthrough;	case 'P':	case 'p':		shl += 10;		fallthrough;	case 'T':	case 't':		shl += 10;		fallthrough;	case 'G':	case 'g':		shl += 10;		fallthrough;	case 'M':	case 'm':		shl += 10;		fallthrough;	case 'K':	case 'k':		shl += 10;		fallthrough;	default:		break;	} 	if (shl && likely(ptr != endptr)) {		/* Have valid suffix with preceding number. */		if (unlikely(check_shl_overflow(ret, shl, &ret)))			ret = ULLONG_MAX;		endptr++;	} 	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 false otherwise. */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;} /* * Parse a string to get a param value pair. * You can use " around spaces, but can't escape ". * Hyphens and underscores equivalent in parameter names. */char *next_arg(char *args, char **param, char **val){	unsigned int i, equals = 0;	int in_quote = 0, quoted = 0; 	if (*args == '"') {		args++;		in_quote = 1;		quoted = 1;	} 	for (i = 0; args[i]; i++) {		if (isspace(args[i]) && !in_quote)			break;		if (equals == 0) {			if (args[i] == '=')				equals = i;		}		if (args[i] == '"')			in_quote = !in_quote;	} 	*param = args;	if (!equals)		*val = NULL;	else {		args[equals] = '\0';		*val = args + equals + 1; 		/* Don't include quotes in value. */		if (**val == '"') {			(*val)++;			if (args[i-1] == '"')				args[i-1] = '\0';		}	}	if (quoted && i > 0 && args[i-1] == '"')		args[i-1] = '\0'; 	if (args[i]) {		args[i] = '\0';		args += i + 1;	} else		args += i; 	/* Chew up trailing spaces. */	return skip_spaces(args);}EXPORT_SYMBOL(next_arg);