blob: 79069d7938ea60c2a0f2ca42a205a84070a60c62
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 | |
25 | static int get_range(char **str, int *pint, int n) |
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; n && x < upper_range; x++, n--) |
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 | |
52 | int 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 | } |
70 | EXPORT_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 | |
89 | char *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, nints - 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 | } |
116 | EXPORT_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 | |
127 | unsigned 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 | } |
162 | EXPORT_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 | */ |
174 | bool 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 |