diff options
Diffstat (limited to 'lib/textsearch.c')
| -rw-r--r-- | lib/textsearch.c | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/lib/textsearch.c b/lib/textsearch.c index 6f3093efbd7..0c7e9ab2d88 100644 --- a/lib/textsearch.c +++ b/lib/textsearch.c @@ -7,13 +7,13 @@ * 2 of the License, or (at your option) any later version. * * Authors: Thomas Graf <tgraf@suug.ch> - * Pablo Neira Ayuso <pablo@eurodev.net> + * Pablo Neira Ayuso <pablo@netfilter.org> * * ========================================================================== * * INTRODUCTION * - * The textsearch infrastructure provides text searching facitilies for + * The textsearch infrastructure provides text searching facilities for * both linear and non-linear data. Individual search algorithms are * implemented in modules and chosen by the user. * @@ -40,10 +40,10 @@ * configuration according to the specified parameters. * (3) User starts the search(es) by calling _find() or _next() to * fetch subsequent occurrences. A state variable is provided - * to the algorihtm to store persistant variables. + * to the algorithm to store persistent variables. * (4) Core eventually resets the search offset and forwards the find() * request to the algorithm. - * (5) Algorithm calls get_next_block() provided by the user continously + * (5) Algorithm calls get_next_block() provided by the user continuously * to fetch the data to be searched in block by block. * (6) Algorithm invokes finish() after the last call to get_next_block * to clean up any leftovers from get_next_block. (Optional) @@ -54,16 +54,19 @@ * USAGE * * Before a search can be performed, a configuration must be created - * by calling textsearch_prepare() specyfing the searching algorithm and - * the pattern to look for. The returned configuration may then be used - * for an arbitary amount of times and even in parallel as long as a - * separate struct ts_state variable is provided to every instance. + * by calling textsearch_prepare() specifying the searching algorithm, + * the pattern to look for and flags. As a flag, you can set TS_IGNORECASE + * to perform case insensitive matching. But it might slow down + * performance of algorithm, so you should use it at own your risk. + * The returned configuration may then be used for an arbitrary + * amount of times and even in parallel as long as a separate struct + * ts_state variable is provided to every instance. * * The actual search is performed by either calling textsearch_find_- * continuous() for linear data or by providing an own get_next_block() * implementation and calling textsearch_find(). Both functions return - * the position of the first occurrence of the patern or UINT_MAX if - * no match was found. Subsequent occurences can be found by calling + * the position of the first occurrence of the pattern or UINT_MAX if + * no match was found. Subsequent occurrences can be found by calling * textsearch_next() regardless of the linearity of the data. * * Once you're done using a configuration it must be given back via @@ -89,18 +92,18 @@ * panic("Oh my god, dancing chickens at %d\n", pos); * * textsearch_destroy(conf); - * * ========================================================================== */ -#include <linux/config.h> #include <linux/module.h> #include <linux/types.h> #include <linux/string.h> #include <linux/init.h> +#include <linux/rculist.h> #include <linux/rcupdate.h> #include <linux/err.h> #include <linux/textsearch.h> +#include <linux/slab.h> static LIST_HEAD(ts_ops); static DEFINE_SPINLOCK(ts_mod_lock); @@ -156,6 +159,7 @@ errout: spin_unlock(&ts_mod_lock); return err; } +EXPORT_SYMBOL(textsearch_register); /** * textsearch_unregister - unregister a textsearch module @@ -187,6 +191,7 @@ out: spin_unlock(&ts_mod_lock); return err; } +EXPORT_SYMBOL(textsearch_unregister); struct ts_linear_state { @@ -219,7 +224,7 @@ static unsigned int get_linear_data(unsigned int consumed, const u8 **dst, * Call textsearch_next() to retrieve subsequent matches. * * Returns the position of first occurrence of the pattern or - * UINT_MAX if no occurrence was found. + * %UINT_MAX if no occurrence was found. */ unsigned int textsearch_find_continuous(struct ts_config *conf, struct ts_state *state, @@ -233,6 +238,7 @@ unsigned int textsearch_find_continuous(struct ts_config *conf, return textsearch_find(conf, state); } +EXPORT_SYMBOL(textsearch_find_continuous); /** * textsearch_prepare - Prepare a search @@ -251,7 +257,8 @@ unsigned int textsearch_find_continuous(struct ts_config *conf, * the various search algorithms. * * Returns a new textsearch configuration according to the specified - * parameters or a ERR_PTR(). + * parameters or a ERR_PTR(). If a zero length pattern is passed, this + * function returns EINVAL. */ struct ts_config *textsearch_prepare(const char *algo, const void *pattern, unsigned int len, gfp_t gfp_mask, int flags) @@ -260,8 +267,11 @@ struct ts_config *textsearch_prepare(const char *algo, const void *pattern, struct ts_config *conf; struct ts_ops *ops; + if (len == 0) + return ERR_PTR(-EINVAL); + ops = lookup_ts_algo(algo); -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* * Why not always autoload you may ask. Some users are * in a situation where requesting a module may deadlock, @@ -276,7 +286,7 @@ struct ts_config *textsearch_prepare(const char *algo, const void *pattern, if (ops == NULL) goto errout; - conf = ops->init(pattern, len, gfp_mask); + conf = ops->init(pattern, len, gfp_mask, flags); if (IS_ERR(conf)) { err = PTR_ERR(conf); goto errout; @@ -291,6 +301,7 @@ errout: return ERR_PTR(err); } +EXPORT_SYMBOL(textsearch_prepare); /** * textsearch_destroy - destroy a search configuration @@ -309,9 +320,4 @@ void textsearch_destroy(struct ts_config *conf) kfree(conf); } - -EXPORT_SYMBOL(textsearch_register); -EXPORT_SYMBOL(textsearch_unregister); -EXPORT_SYMBOL(textsearch_prepare); -EXPORT_SYMBOL(textsearch_find_continuous); EXPORT_SYMBOL(textsearch_destroy); |