#ifndef __LINUX_TEXTSEARCH_H #define __LINUX_TEXTSEARCH_H #ifdef __KERNEL__ #include <linux/types.h> #include <linux/list.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/err.h> #include <linux/slab.h> struct ts_config; /** * TS_AUTOLOAD - Automatically load textsearch modules when needed */ #define TS_AUTOLOAD 1 /** * struct ts_state - search state * @offset: offset for next match * @cb: control buffer, for persistant 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); 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 * @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; /** * 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 persistant 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 = kmalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); if (conf == NULL) return ERR_PTR(-ENOMEM); memset(conf, 0, TS_PRIV_ALIGN(sizeof(*conf)) + payload); return conf; } static inline void *ts_config_priv(struct ts_config *conf) { return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config))); } #endif /* __KERNEL__ */ #endif