1/*
2 * linux/lib/cmdline.c
3 * Helper functions generally used for parsing kernel command line
4 * and module options.
5 *
6 * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
7 *
8 * This source code is licensed under the GNU General Public License,
9 * Version 2.  See the file COPYING for more details.
10 *
11 * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
12 *
13 */
14
15#include <linux/export.h>
16#include <linux/kernel.h>
17#include <linux/string.h>
18
19/*
20 *	If a hyphen was found in get_option, this will handle the
21 *	range of numbers, M-N.  This will expand the range and insert
22 *	the values[M, M+1, ..., N] into the ints array in get_options.
23 */
24
25static int get_range(char **str, int *pint)
26{
27	int x, inc_counter, upper_range;
28
29	(*str)++;
30	upper_range = simple_strtol((*str), NULL, 0);
31	inc_counter = upper_range - *pint;
32	for (x = *pint; x < upper_range; x++)
33		*pint++ = x;
34	return inc_counter;
35}
36
37/**
38 *	get_option - Parse integer from an option string
39 *	@str: option string
40 *	@pint: (output) integer value parsed from @str
41 *
42 *	Read an int from an option string; if available accept a subsequent
43 *	comma as well.
44 *
45 *	Return values:
46 *	0 - no int in string
47 *	1 - int found, no subsequent comma
48 *	2 - int found including a subsequent comma
49 *	3 - hyphen found to denote a range
50 */
51
52int get_option(char **str, int *pint)
53{
54	char *cur = *str;
55
56	if (!cur || !(*cur))
57		return 0;
58	*pint = simple_strtol(cur, str, 0);
59	if (cur == *str)
60		return 0;
61	if (**str == ',') {
62		(*str)++;
63		return 2;
64	}
65	if (**str == '-')
66		return 3;
67
68	return 1;
69}
70EXPORT_SYMBOL(get_option);
71
72/**
73 *	get_options - Parse a string into a list of integers
74 *	@str: String to be parsed
75 *	@nints: size of integer array
76 *	@ints: integer array
77 *
78 *	This function parses a string containing a comma-separated
79 *	list of integers, a hyphen-separated range of _positive_ integers,
80 *	or a combination of both.  The parse halts when the array is
81 *	full, or when no more numbers can be retrieved from the
82 *	string.
83 *
84 *	Return value is the character in the string which caused
85 *	the parse to end (typically a null terminator, if @str is
86 *	completely parseable).
87 */
88
89char *get_options(const char *str, int nints, int *ints)
90{
91	int res, i = 1;
92
93	while (i < nints) {
94		res = get_option((char **)&str, ints + i);
95		if (res == 0)
96			break;
97		if (res == 3) {
98			int range_nums;
99			range_nums = get_range((char **)&str, ints + i);
100			if (range_nums < 0)
101				break;
102			/*
103			 * Decrement the result by one to leave out the
104			 * last number in the range.  The next iteration
105			 * will handle the upper number in the range
106			 */
107			i += (range_nums - 1);
108		}
109		i++;
110		if (res == 1)
111			break;
112	}
113	ints[0] = i - 1;
114	return (char *)str;
115}
116EXPORT_SYMBOL(get_options);
117
118/**
119 *	memparse - parse a string with mem suffixes into a number
120 *	@ptr: Where parse begins
121 *	@retptr: (output) Optional pointer to next char after parse completes
122 *
123 *	Parses a string into a number.  The number stored at @ptr is
124 *	potentially suffixed with K, M, G, T, P, E.
125 */
126
127unsigned long long memparse(const char *ptr, char **retptr)
128{
129	char *endptr;	/* local pointer to end of parsed string */
130
131	unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
132
133	switch (*endptr) {
134	case 'E':
135	case 'e':
136		ret <<= 10;
137	case 'P':
138	case 'p':
139		ret <<= 10;
140	case 'T':
141	case 't':
142		ret <<= 10;
143	case 'G':
144	case 'g':
145		ret <<= 10;
146	case 'M':
147	case 'm':
148		ret <<= 10;
149	case 'K':
150	case 'k':
151		ret <<= 10;
152		endptr++;
153	default:
154		break;
155	}
156
157	if (retptr)
158		*retptr = endptr;
159
160	return ret;
161}
162EXPORT_SYMBOL(memparse);
163
164/**
165 *	parse_option_str - Parse a string and check an option is set or not
166 *	@str: String to be parsed
167 *	@option: option name
168 *
169 *	This function parses a string containing a comma-separated list of
170 *	strings like a=b,c.
171 *
172 *	Return true if there's such option in the string, or return false.
173 */
174bool parse_option_str(const char *str, const char *option)
175{
176	while (*str) {
177		if (!strncmp(str, option, strlen(option))) {
178			str += strlen(option);
179			if (!*str || *str == ',')
180				return true;
181		}
182
183		while (*str && *str != ',')
184			str++;
185
186		if (*str == ',')
187			str++;
188	}
189
190	return false;
191}
192