| /* SPDX-License-Identifier: GPL-2.0 */ |
| #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[48]; |
| }; |
| |
| /** |
| * 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 |