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-rw-r--r--lib/cmdline.c275
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diff --git a/lib/cmdline.c b/lib/cmdline.c
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+// 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);