// 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 && 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);
