ia64/linux-2.6.18-xen.hg

view lib/parser.c @ 740:bf8b1ee634e2

balloon: Fix the build by including <linux/init.h>

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Nov 25 11:19:41 2008 +0000 (2008-11-25)
parents 831230e53067
children
line source
1 /*
2 * lib/parser.c - simple parser for mount, etc. options.
3 *
4 * This source code is licensed under the GNU General Public License,
5 * Version 2. See the file COPYING for more details.
6 */
8 #include <linux/ctype.h>
9 #include <linux/module.h>
10 #include <linux/parser.h>
11 #include <linux/slab.h>
12 #include <linux/string.h>
14 /**
15 * match_one: - Determines if a string matches a simple pattern
16 * @s: the string to examine for presense of the pattern
17 * @p: the string containing the pattern
18 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
19 * locations.
20 *
21 * Description: Determines if the pattern @p is present in string @s. Can only
22 * match extremely simple token=arg style patterns. If the pattern is found,
23 * the location(s) of the arguments will be returned in the @args array.
24 */
25 static int match_one(char *s, char *p, substring_t args[])
26 {
27 char *meta;
28 int argc = 0;
30 if (!p)
31 return 1;
33 while(1) {
34 int len = -1;
35 meta = strchr(p, '%');
36 if (!meta)
37 return strcmp(p, s) == 0;
39 if (strncmp(p, s, meta-p))
40 return 0;
42 s += meta - p;
43 p = meta + 1;
45 if (isdigit(*p))
46 len = simple_strtoul(p, &p, 10);
47 else if (*p == '%') {
48 if (*s++ != '%')
49 return 0;
50 p++;
51 continue;
52 }
54 if (argc >= MAX_OPT_ARGS)
55 return 0;
57 args[argc].from = s;
58 switch (*p++) {
59 case 's':
60 if (strlen(s) == 0)
61 return 0;
62 else if (len == -1 || len > strlen(s))
63 len = strlen(s);
64 args[argc].to = s + len;
65 break;
66 case 'd':
67 simple_strtol(s, &args[argc].to, 0);
68 goto num;
69 case 'u':
70 simple_strtoul(s, &args[argc].to, 0);
71 goto num;
72 case 'o':
73 simple_strtoul(s, &args[argc].to, 8);
74 goto num;
75 case 'x':
76 simple_strtoul(s, &args[argc].to, 16);
77 num:
78 if (args[argc].to == args[argc].from)
79 return 0;
80 break;
81 default:
82 return 0;
83 }
84 s = args[argc].to;
85 argc++;
86 }
87 }
89 /**
90 * match_token: - Find a token (and optional args) in a string
91 * @s: the string to examine for token/argument pairs
92 * @table: match_table_t describing the set of allowed option tokens and the
93 * arguments that may be associated with them. Must be terminated with a
94 * &struct match_token whose pattern is set to the NULL pointer.
95 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
96 * locations.
97 *
98 * Description: Detects which if any of a set of token strings has been passed
99 * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style
100 * format identifiers which will be taken into account when matching the
101 * tokens, and whose locations will be returned in the @args array.
102 */
103 int match_token(char *s, match_table_t table, substring_t args[])
104 {
105 struct match_token *p;
107 for (p = table; !match_one(s, p->pattern, args) ; p++)
108 ;
110 return p->token;
111 }
113 /**
114 * match_number: scan a number in the given base from a substring_t
115 * @s: substring to be scanned
116 * @result: resulting integer on success
117 * @base: base to use when converting string
118 *
119 * Description: Given a &substring_t and a base, attempts to parse the substring
120 * as a number in that base. On success, sets @result to the integer represented
121 * by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure.
122 */
123 static int match_number(substring_t *s, int *result, int base)
124 {
125 char *endp;
126 char *buf;
127 int ret;
129 buf = kmalloc(s->to - s->from + 1, GFP_KERNEL);
130 if (!buf)
131 return -ENOMEM;
132 memcpy(buf, s->from, s->to - s->from);
133 buf[s->to - s->from] = '\0';
134 *result = simple_strtol(buf, &endp, base);
135 ret = 0;
136 if (endp == buf)
137 ret = -EINVAL;
138 kfree(buf);
139 return ret;
140 }
142 /**
143 * match_int: - scan a decimal representation of an integer from a substring_t
144 * @s: substring_t to be scanned
145 * @result: resulting integer on success
146 *
147 * Description: Attempts to parse the &substring_t @s as a decimal integer. On
148 * success, sets @result to the integer represented by the string and returns 0.
149 * Returns either -ENOMEM or -EINVAL on failure.
150 */
151 int match_int(substring_t *s, int *result)
152 {
153 return match_number(s, result, 0);
154 }
156 /**
157 * match_octal: - scan an octal representation of an integer from a substring_t
158 * @s: substring_t to be scanned
159 * @result: resulting integer on success
160 *
161 * Description: Attempts to parse the &substring_t @s as an octal integer. On
162 * success, sets @result to the integer represented by the string and returns
163 * 0. Returns either -ENOMEM or -EINVAL on failure.
164 */
165 int match_octal(substring_t *s, int *result)
166 {
167 return match_number(s, result, 8);
168 }
170 /**
171 * match_hex: - scan a hex representation of an integer from a substring_t
172 * @s: substring_t to be scanned
173 * @result: resulting integer on success
174 *
175 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
176 * On success, sets @result to the integer represented by the string and
177 * returns 0. Returns either -ENOMEM or -EINVAL on failure.
178 */
179 int match_hex(substring_t *s, int *result)
180 {
181 return match_number(s, result, 16);
182 }
184 /**
185 * match_strcpy: - copies the characters from a substring_t to a string
186 * @to: string to copy characters to.
187 * @s: &substring_t to copy
188 *
189 * Description: Copies the set of characters represented by the given
190 * &substring_t @s to the c-style string @to. Caller guarantees that @to is
191 * large enough to hold the characters of @s.
192 */
193 void match_strcpy(char *to, substring_t *s)
194 {
195 memcpy(to, s->from, s->to - s->from);
196 to[s->to - s->from] = '\0';
197 }
199 /**
200 * match_strdup: - allocate a new string with the contents of a substring_t
201 * @s: &substring_t to copy
202 *
203 * Description: Allocates and returns a string filled with the contents of
204 * the &substring_t @s. The caller is responsible for freeing the returned
205 * string with kfree().
206 */
207 char *match_strdup(substring_t *s)
208 {
209 char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL);
210 if (p)
211 match_strcpy(p, s);
212 return p;
213 }
215 EXPORT_SYMBOL(match_token);
216 EXPORT_SYMBOL(match_int);
217 EXPORT_SYMBOL(match_octal);
218 EXPORT_SYMBOL(match_hex);
219 EXPORT_SYMBOL(match_strcpy);
220 EXPORT_SYMBOL(match_strdup);