diff options
Diffstat (limited to 'include/linux/textsearch.h')
| -rw-r--r-- | include/linux/textsearch.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/include/linux/textsearch.h b/include/linux/textsearch.h new file mode 100644 index 00000000..cfaee869 --- /dev/null +++ b/include/linux/textsearch.h @@ -0,0 +1,178 @@ +#ifndef __LINUX_TEXTSEARCH_H +#define __LINUX_TEXTSEARCH_H + +#include <linux/types.h> +#include <linux/list.h> +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/slab.h> + +struct module; + +struct ts_config; + +#define TS_AUTOLOAD 1 /* Automatically load textsearch modules when needed */ +#define TS_IGNORECASE 2 /* Searches string case insensitively */ + +/** + * struct ts_state - search state + * @offset: offset for next match + * @cb: control buffer, for persistent variables of get_next_block() + */ +struct ts_state +{ + unsigned int offset; + char cb[40]; +}; + +/** + * struct ts_ops - search module operations + * @name: name of search algorithm + * @init: initialization function to prepare a search + * @find: find the next occurrence of the pattern + * @destroy: destroy algorithm specific parts of a search configuration + * @get_pattern: return head of pattern + * @get_pattern_len: return length of pattern + * @owner: module reference to algorithm + */ +struct ts_ops +{ + const char *name; + struct ts_config * (*init)(const void *, unsigned int, gfp_t, int); + unsigned int (*find)(struct ts_config *, + struct ts_state *); + void (*destroy)(struct ts_config *); + void * (*get_pattern)(struct ts_config *); + unsigned int (*get_pattern_len)(struct ts_config *); + struct module *owner; + struct list_head list; +}; + +/** + * struct ts_config - search configuration + * @ops: operations of chosen algorithm + * @flags: flags + * @get_next_block: callback to fetch the next block to search in + * @finish: callback to finalize a search + */ +struct ts_config +{ + struct ts_ops *ops; + int flags; + + /** + * get_next_block - fetch next block of data + * @consumed: number of bytes consumed by the caller + * @dst: destination buffer + * @conf: search configuration + * @state: search state + * + * Called repeatedly until 0 is returned. Must assign the + * head of the next block of data to &*dst and return the length + * of the block or 0 if at the end. consumed == 0 indicates + * a new search. May store/read persistent values in state->cb. + */ + unsigned int (*get_next_block)(unsigned int consumed, + const u8 **dst, + struct ts_config *conf, + struct ts_state *state); + + /** + * finish - finalize/clean a series of get_next_block() calls + * @conf: search configuration + * @state: search state + * + * Called after the last use of get_next_block(), may be used + * to cleanup any leftovers. + */ + void (*finish)(struct ts_config *conf, + struct ts_state *state); +}; + +/** + * textsearch_next - continue searching for a pattern + * @conf: search configuration + * @state: search state + * + * Continues a search looking for more occurrences of the pattern. + * textsearch_find() must be called to find the first occurrence + * in order to reset the state. + * + * Returns the position of the next occurrence of the pattern or + * UINT_MAX if not match was found. + */ +static inline unsigned int textsearch_next(struct ts_config *conf, + struct ts_state *state) +{ + unsigned int ret = conf->ops->find(conf, state); + + if (conf->finish) + conf->finish(conf, state); + + return ret; +} + +/** + * textsearch_find - start searching for a pattern + * @conf: search configuration + * @state: search state + * + * Returns the position of first occurrence of the pattern or + * UINT_MAX if no match was found. + */ +static inline unsigned int textsearch_find(struct ts_config *conf, + struct ts_state *state) +{ + state->offset = 0; + return textsearch_next(conf, state); +} + +/** + * textsearch_get_pattern - return head of the pattern + * @conf: search configuration + */ +static inline void *textsearch_get_pattern(struct ts_config *conf) +{ + return conf->ops->get_pattern(conf); +} + +/** + * textsearch_get_pattern_len - return length of the pattern + * @conf: search configuration + */ +static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf) +{ + return conf->ops->get_pattern_len(conf); +} + +extern int textsearch_register(struct ts_ops *); +extern int textsearch_unregister(struct ts_ops *); +extern struct ts_config *textsearch_prepare(const char *, const void *, + unsigned int, gfp_t, int); +extern void textsearch_destroy(struct ts_config *conf); +extern unsigned int textsearch_find_continuous(struct ts_config *, + struct ts_state *, + const void *, unsigned int); + + +#define TS_PRIV_ALIGNTO 8 +#define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1)) + +static inline struct ts_config *alloc_ts_config(size_t payload, + gfp_t gfp_mask) +{ + struct ts_config *conf; + + conf = kzalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); + if (conf == NULL) + return ERR_PTR(-ENOMEM); + + return conf; +} + +static inline void *ts_config_priv(struct ts_config *conf) +{ + return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config))); +} + +#endif |