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Thomas Graf2de4ff72005-06-23 20:49:30 -07001#ifndef __LINUX_TEXTSEARCH_H
2#define __LINUX_TEXTSEARCH_H
3
Thomas Graf2de4ff72005-06-23 20:49:30 -07004#include <linux/types.h>
5#include <linux/list.h>
6#include <linux/kernel.h>
Thomas Graf2de4ff72005-06-23 20:49:30 -07007#include <linux/err.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -08008#include <linux/slab.h>
Thomas Graf2de4ff72005-06-23 20:49:30 -07009
Paul Gortmakerde477252011-05-26 13:46:22 -040010struct module;
11
Thomas Graf2de4ff72005-06-23 20:49:30 -070012struct ts_config;
13
Joonwoo Parkb9c79672008-07-08 02:37:31 -070014#define TS_AUTOLOAD 1 /* Automatically load textsearch modules when needed */
15#define TS_IGNORECASE 2 /* Searches string case insensitively */
Thomas Graf2de4ff72005-06-23 20:49:30 -070016
17/**
18 * struct ts_state - search state
19 * @offset: offset for next match
Jan Engelhardt03a67a42006-11-30 05:32:19 +010020 * @cb: control buffer, for persistent variables of get_next_block()
Thomas Graf2de4ff72005-06-23 20:49:30 -070021 */
22struct ts_state
23{
24 unsigned int offset;
25 char cb[40];
26};
27
28/**
29 * struct ts_ops - search module operations
30 * @name: name of search algorithm
31 * @init: initialization function to prepare a search
32 * @find: find the next occurrence of the pattern
33 * @destroy: destroy algorithm specific parts of a search configuration
34 * @get_pattern: return head of pattern
35 * @get_pattern_len: return length of pattern
36 * @owner: module reference to algorithm
37 */
38struct ts_ops
39{
40 const char *name;
Joonwoo Parkb9c79672008-07-08 02:37:31 -070041 struct ts_config * (*init)(const void *, unsigned int, gfp_t, int);
Thomas Graf2de4ff72005-06-23 20:49:30 -070042 unsigned int (*find)(struct ts_config *,
43 struct ts_state *);
44 void (*destroy)(struct ts_config *);
45 void * (*get_pattern)(struct ts_config *);
46 unsigned int (*get_pattern_len)(struct ts_config *);
47 struct module *owner;
48 struct list_head list;
49};
50
51/**
52 * struct ts_config - search configuration
53 * @ops: operations of chosen algorithm
Joonwoo Parkb9c79672008-07-08 02:37:31 -070054 * @flags: flags
Thomas Graf2de4ff72005-06-23 20:49:30 -070055 * @get_next_block: callback to fetch the next block to search in
56 * @finish: callback to finalize a search
57 */
58struct ts_config
59{
60 struct ts_ops *ops;
Joonwoo Parkb9c79672008-07-08 02:37:31 -070061 int flags;
Thomas Graf2de4ff72005-06-23 20:49:30 -070062
63 /**
64 * get_next_block - fetch next block of data
65 * @consumed: number of bytes consumed by the caller
66 * @dst: destination buffer
67 * @conf: search configuration
68 * @state: search state
69 *
70 * Called repeatedly until 0 is returned. Must assign the
71 * head of the next block of data to &*dst and return the length
72 * of the block or 0 if at the end. consumed == 0 indicates
Jan Engelhardt03a67a42006-11-30 05:32:19 +010073 * a new search. May store/read persistent values in state->cb.
Thomas Graf2de4ff72005-06-23 20:49:30 -070074 */
75 unsigned int (*get_next_block)(unsigned int consumed,
76 const u8 **dst,
77 struct ts_config *conf,
78 struct ts_state *state);
79
80 /**
81 * finish - finalize/clean a series of get_next_block() calls
82 * @conf: search configuration
83 * @state: search state
84 *
85 * Called after the last use of get_next_block(), may be used
86 * to cleanup any leftovers.
87 */
88 void (*finish)(struct ts_config *conf,
89 struct ts_state *state);
90};
91
92/**
93 * textsearch_next - continue searching for a pattern
94 * @conf: search configuration
95 * @state: search state
96 *
97 * Continues a search looking for more occurrences of the pattern.
98 * textsearch_find() must be called to find the first occurrence
99 * in order to reset the state.
100 *
101 * Returns the position of the next occurrence of the pattern or
102 * UINT_MAX if not match was found.
103 */
104static inline unsigned int textsearch_next(struct ts_config *conf,
105 struct ts_state *state)
106{
107 unsigned int ret = conf->ops->find(conf, state);
108
109 if (conf->finish)
110 conf->finish(conf, state);
111
112 return ret;
113}
114
115/**
116 * textsearch_find - start searching for a pattern
117 * @conf: search configuration
118 * @state: search state
119 *
120 * Returns the position of first occurrence of the pattern or
121 * UINT_MAX if no match was found.
122 */
123static inline unsigned int textsearch_find(struct ts_config *conf,
124 struct ts_state *state)
125{
126 state->offset = 0;
127 return textsearch_next(conf, state);
128}
129
130/**
131 * textsearch_get_pattern - return head of the pattern
132 * @conf: search configuration
133 */
134static inline void *textsearch_get_pattern(struct ts_config *conf)
135{
136 return conf->ops->get_pattern(conf);
137}
138
139/**
140 * textsearch_get_pattern_len - return length of the pattern
141 * @conf: search configuration
142 */
143static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf)
144{
145 return conf->ops->get_pattern_len(conf);
146}
147
148extern int textsearch_register(struct ts_ops *);
149extern int textsearch_unregister(struct ts_ops *);
150extern struct ts_config *textsearch_prepare(const char *, const void *,
Al Virofd4f2df2005-10-21 03:18:50 -0400151 unsigned int, gfp_t, int);
Thomas Graf2de4ff72005-06-23 20:49:30 -0700152extern void textsearch_destroy(struct ts_config *conf);
153extern unsigned int textsearch_find_continuous(struct ts_config *,
154 struct ts_state *,
155 const void *, unsigned int);
156
157
158#define TS_PRIV_ALIGNTO 8
159#define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1))
160
Randy Dunlap3d2aef62005-10-04 22:45:14 -0700161static inline struct ts_config *alloc_ts_config(size_t payload,
Al Virodd0fc662005-10-07 07:46:04 +0100162 gfp_t gfp_mask)
Thomas Graf2de4ff72005-06-23 20:49:30 -0700163{
164 struct ts_config *conf;
165
Joonwoo Parkdde77e602008-07-08 02:38:40 -0700166 conf = kzalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask);
Thomas Graf2de4ff72005-06-23 20:49:30 -0700167 if (conf == NULL)
168 return ERR_PTR(-ENOMEM);
169
Thomas Graf2de4ff72005-06-23 20:49:30 -0700170 return conf;
171}
172
173static inline void *ts_config_priv(struct ts_config *conf)
174{
175 return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config)));
176}
177
Thomas Graf2de4ff72005-06-23 20:49:30 -0700178#endif