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* lib/parser.c - simple parser for mount, etc. options.
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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#include <linux/config.h>
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#ifdef CONFIG_MODVERSIONS
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#include <linux/modversions.h>
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#include <linux/ctype.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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* match_one: - Determines if a string matches a simple pattern
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* @s: the string to examine for presense of the pattern
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* @p: the string containing the pattern
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* @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
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* Description: Determines if the pattern @p is present in string @s. Can only
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* match extremely simple token=arg style patterns. If the pattern is found,
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* the location(s) of the arguments will be returned in the @args array.
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static int match_one(char *s, char *p, substring_t args[])
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meta = strchr(p, '%');
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return strcmp(p, s) == 0;
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if (strncmp(p, s, meta-p))
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len = simple_strtoul(p, &p, 10);
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if (argc >= MAX_OPT_ARGS)
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else if (len == -1 || len > strlen(s))
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args[argc].to = s + len;
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simple_strtol(s, &args[argc].to, 0);
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simple_strtoul(s, &args[argc].to, 0);
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simple_strtoul(s, &args[argc].to, 8);
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simple_strtoul(s, &args[argc].to, 16);
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if (args[argc].to == args[argc].from)
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* match_token: - Find a token (and optional args) in a string
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* @s: the string to examine for token/argument pairs
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* @table: match_table_t describing the set of allowed option tokens and the
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* arguments that may be associated with them. Must be terminated with a
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* &struct match_token whose pattern is set to the NULL pointer.
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* @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
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* Description: Detects which if any of a set of token strings has been passed
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* to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style
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* format identifiers which will be taken into account when matching the
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* tokens, and whose locations will be returned in the @args array.
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int match_token(char *s, match_table_t table, substring_t args[])
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struct match_token *p;
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for (p = table; !match_one(s, p->pattern, args) ; p++)
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* match_number: scan a number in the given base from a substring_t
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* @s: substring to be scanned
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* @result: resulting integer on success
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* @base: base to use when converting string
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* Description: Given a &substring_t and a base, attempts to parse the substring
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* as a number in that base. On success, sets @result to the integer represented
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* by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure.
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static int match_number(substring_t *s, int *result, int base)
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buf = kmalloc(s->to - s->from + 1, GFP_KERNEL);
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memcpy(buf, s->from, s->to - s->from);
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buf[s->to - s->from] = '\0';
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*result = simple_strtol(buf, &endp, base);
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* match_int: - scan a decimal representation of an integer from a substring_t
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* @s: substring_t to be scanned
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* @result: resulting integer on success
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* Description: Attempts to parse the &substring_t @s as a decimal integer. On
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* success, sets @result to the integer represented by the string and returns 0.
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* Returns either -ENOMEM or -EINVAL on failure.
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int match_int(substring_t *s, int *result)
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return match_number(s, result, 0);
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* match_octal: - scan an octal representation of an integer from a substring_t
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* @s: substring_t to be scanned
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* @result: resulting integer on success
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* Description: Attempts to parse the &substring_t @s as an octal integer. On
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* success, sets @result to the integer represented by the string and returns
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* 0. Returns either -ENOMEM or -EINVAL on failure.
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int match_octal(substring_t *s, int *result)
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return match_number(s, result, 8);
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* match_hex: - scan a hex representation of an integer from a substring_t
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* @s: substring_t to be scanned
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* @result: resulting integer on success
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* Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
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* On success, sets @result to the integer represented by the string and
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* returns 0. Returns either -ENOMEM or -EINVAL on failure.
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int match_hex(substring_t *s, int *result)
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return match_number(s, result, 16);
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* match_strcpy: - copies the characters from a substring_t to a string
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* @to: string to copy characters to.
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* @s: &substring_t to copy
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* Description: Copies the set of characters represented by the given
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* &substring_t @s to the c-style string @to. Caller guarantees that @to is
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* large enough to hold the characters of @s.
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void match_strcpy(char *to, substring_t *s)
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memcpy(to, s->from, s->to - s->from);
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to[s->to - s->from] = '\0';
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* match_strdup: - allocate a new string with the contents of a substring_t
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* @s: &substring_t to copy
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* Description: Allocates and returns a string filled with the contents of
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* the &substring_t @s. The caller is responsible for freeing the returned
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* string with kfree().
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char *match_strdup(substring_t *s)
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char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL);
added
removed
kernel/compat/parser.c
