// 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 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

*

* 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.

*/

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;

fallthrough;

case 'P':

case 'p':

ret <<= 10;

fallthrough;

case 'T':

case 't':

ret <<= 10;

fallthrough;

case 'G':

case 'g':

ret <<= 10;

fallthrough;

case 'M':

case 'm':

ret <<= 10;

fallthrough;

case 'K':

case 'k':

ret <<= 10;

endptr++;

fallthrough;

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;

}

/*

* 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 && 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);