From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- lib/parser.c | 220 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 220 insertions(+) create mode 100644 lib/parser.c (limited to 'lib/parser.c') diff --git a/lib/parser.c b/lib/parser.c new file mode 100644 index 00000000000..7ad2a48abc5 --- /dev/null +++ b/lib/parser.c @@ -0,0 +1,220 @@ +/* + * lib/parser.c - simple parser for mount, etc. options. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include +#include +#include +#include +#include + +/** + * match_one: - Determines if a string matches a simple pattern + * @s: the string to examine for presense of the pattern + * @p: the string containing the pattern + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Determines if the pattern @p is present in string @s. Can only + * match extremely simple token=arg style patterns. If the pattern is found, + * the location(s) of the arguments will be returned in the @args array. + */ +static int match_one(char *s, char *p, substring_t args[]) +{ + char *meta; + int argc = 0; + + if (!p) + return 1; + + while(1) { + int len = -1; + meta = strchr(p, '%'); + if (!meta) + return strcmp(p, s) == 0; + + if (strncmp(p, s, meta-p)) + return 0; + + s += meta - p; + p = meta + 1; + + if (isdigit(*p)) + len = simple_strtoul(p, &p, 10); + else if (*p == '%') { + if (*s++ != '%') + return 0; + p++; + continue; + } + + if (argc >= MAX_OPT_ARGS) + return 0; + + args[argc].from = s; + switch (*p++) { + case 's': + if (strlen(s) == 0) + return 0; + else if (len == -1 || len > strlen(s)) + len = strlen(s); + args[argc].to = s + len; + break; + case 'd': + simple_strtol(s, &args[argc].to, 0); + goto num; + case 'u': + simple_strtoul(s, &args[argc].to, 0); + goto num; + case 'o': + simple_strtoul(s, &args[argc].to, 8); + goto num; + case 'x': + simple_strtoul(s, &args[argc].to, 16); + num: + if (args[argc].to == args[argc].from) + return 0; + break; + default: + return 0; + } + s = args[argc].to; + argc++; + } +} + +/** + * match_token: - Find a token (and optional args) in a string + * @s: the string to examine for token/argument pairs + * @table: match_table_t describing the set of allowed option tokens and the + * arguments that may be associated with them. Must be terminated with a + * &struct match_token whose pattern is set to the NULL pointer. + * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match + * locations. + * + * Description: Detects which if any of a set of token strings has been passed + * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style + * format identifiers which will be taken into account when matching the + * tokens, and whose locations will be returned in the @args array. + */ +int match_token(char *s, match_table_t table, substring_t args[]) +{ + struct match_token *p; + + for (p = table; !match_one(s, p->pattern, args) ; p++) + ; + + return p->token; +} + +/** + * match_number: scan a number in the given base from a substring_t + * @s: substring to be scanned + * @result: resulting integer on success + * @base: base to use when converting string + * + * Description: Given a &substring_t and a base, attempts to parse the substring + * as a number in that base. On success, sets @result to the integer represented + * by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ +static int match_number(substring_t *s, int *result, int base) +{ + char *endp; + char *buf; + int ret; + + buf = kmalloc(s->to - s->from + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + memcpy(buf, s->from, s->to - s->from); + buf[s->to - s->from] = '\0'; + *result = simple_strtol(buf, &endp, base); + ret = 0; + if (endp == buf) + ret = -EINVAL; + kfree(buf); + return ret; +} + +/** + * match_int: - scan a decimal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a decimal integer. On + * success, sets @result to the integer represented by the string and returns 0. + * Returns either -ENOMEM or -EINVAL on failure. + */ +int match_int(substring_t *s, int *result) +{ + return match_number(s, result, 0); +} + +/** + * match_octal: - scan an octal representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as an octal integer. On + * success, sets @result to the integer represented by the string and returns + * 0. Returns either -ENOMEM or -EINVAL on failure. + */ +int match_octal(substring_t *s, int *result) +{ + return match_number(s, result, 8); +} + +/** + * match_hex: - scan a hex representation of an integer from a substring_t + * @s: substring_t to be scanned + * @result: resulting integer on success + * + * Description: Attempts to parse the &substring_t @s as a hexadecimal integer. + * On success, sets @result to the integer represented by the string and + * returns 0. Returns either -ENOMEM or -EINVAL on failure. + */ +int match_hex(substring_t *s, int *result) +{ + return match_number(s, result, 16); +} + +/** + * match_strcpy: - copies the characters from a substring_t to a string + * @to: string to copy characters to. + * @s: &substring_t to copy + * + * Description: Copies the set of characters represented by the given + * &substring_t @s to the c-style string @to. Caller guarantees that @to is + * large enough to hold the characters of @s. + */ +void match_strcpy(char *to, substring_t *s) +{ + memcpy(to, s->from, s->to - s->from); + to[s->to - s->from] = '\0'; +} + +/** + * match_strdup: - allocate a new string with the contents of a substring_t + * @s: &substring_t to copy + * + * Description: Allocates and returns a string filled with the contents of + * the &substring_t @s. The caller is responsible for freeing the returned + * string with kfree(). + */ +char *match_strdup(substring_t *s) +{ + char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL); + if (p) + match_strcpy(p, s); + return p; +} + +EXPORT_SYMBOL(match_token); +EXPORT_SYMBOL(match_int); +EXPORT_SYMBOL(match_octal); +EXPORT_SYMBOL(match_hex); +EXPORT_SYMBOL(match_strcpy); +EXPORT_SYMBOL(match_strdup); -- cgit v1.2.3-70-g09d2