textsearch.h
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#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