aboutsummaryrefslogtreecommitdiff
path: root/lib/cmdline.c
blob: b390dd03363bd093a2a270881e1059cb79f96467 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
// 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
 *
 *	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.
 *
 *	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)
{
	int res, i = 1;

	while (i < nints) {
		res = get_option((char **)&str, ints + i);
		if (res == 0)
			break;
		if (res == 3) {
			int range_nums;
			range_nums = get_range((char **)&str, ints + i, nints - i);
			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;
	char *next;

	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';
		next = args + i + 1;
	} else
		next = args + i;

	/* Chew up trailing spaces. */
	return skip_spaces(next);
}