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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>
7#include <linux/module.h>
8#include <linux/err.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -08009#include <linux/slab.h>
Thomas Graf2de4ff72005-06-23 20:49:30 -070010
11struct ts_config;
12
13/**
14 * TS_AUTOLOAD - Automatically load textsearch modules when needed
15 */
16#define TS_AUTOLOAD 1
17
18/**
19 * struct ts_state - search state
20 * @offset: offset for next match
Jan Engelhardt03a67a42006-11-30 05:32:19 +010021 * @cb: control buffer, for persistent variables of get_next_block()
Thomas Graf2de4ff72005-06-23 20:49:30 -070022 */
23struct ts_state
24{
25 unsigned int offset;
26 char cb[40];
27};
28
29/**
30 * struct ts_ops - search module operations
31 * @name: name of search algorithm
32 * @init: initialization function to prepare a search
33 * @find: find the next occurrence of the pattern
34 * @destroy: destroy algorithm specific parts of a search configuration
35 * @get_pattern: return head of pattern
36 * @get_pattern_len: return length of pattern
37 * @owner: module reference to algorithm
38 */
39struct ts_ops
40{
41 const char *name;
Al Virofd4f2df2005-10-21 03:18:50 -040042 struct ts_config * (*init)(const void *, unsigned int, gfp_t);
Thomas Graf2de4ff72005-06-23 20:49:30 -070043 unsigned int (*find)(struct ts_config *,
44 struct ts_state *);
45 void (*destroy)(struct ts_config *);
46 void * (*get_pattern)(struct ts_config *);
47 unsigned int (*get_pattern_len)(struct ts_config *);
48 struct module *owner;
49 struct list_head list;
50};
51
52/**
53 * struct ts_config - search configuration
54 * @ops: operations of chosen algorithm
55 * @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;
61
62 /**
63 * get_next_block - fetch next block of data
64 * @consumed: number of bytes consumed by the caller
65 * @dst: destination buffer
66 * @conf: search configuration
67 * @state: search state
68 *
69 * Called repeatedly until 0 is returned. Must assign the
70 * head of the next block of data to &*dst and return the length
71 * of the block or 0 if at the end. consumed == 0 indicates
Jan Engelhardt03a67a42006-11-30 05:32:19 +010072 * a new search. May store/read persistent values in state->cb.
Thomas Graf2de4ff72005-06-23 20:49:30 -070073 */
74 unsigned int (*get_next_block)(unsigned int consumed,
75 const u8 **dst,
76 struct ts_config *conf,
77 struct ts_state *state);
78
79 /**
80 * finish - finalize/clean a series of get_next_block() calls
81 * @conf: search configuration
82 * @state: search state
83 *
84 * Called after the last use of get_next_block(), may be used
85 * to cleanup any leftovers.
86 */
87 void (*finish)(struct ts_config *conf,
88 struct ts_state *state);
89};
90
91/**
92 * textsearch_next - continue searching for a pattern
93 * @conf: search configuration
94 * @state: search state
95 *
96 * Continues a search looking for more occurrences of the pattern.
97 * textsearch_find() must be called to find the first occurrence
98 * in order to reset the state.
99 *
100 * Returns the position of the next occurrence of the pattern or
101 * UINT_MAX if not match was found.
102 */
103static inline unsigned int textsearch_next(struct ts_config *conf,
104 struct ts_state *state)
105{
106 unsigned int ret = conf->ops->find(conf, state);
107
108 if (conf->finish)
109 conf->finish(conf, state);
110
111 return ret;
112}
113
114/**
115 * textsearch_find - start searching for a pattern
116 * @conf: search configuration
117 * @state: search state
118 *
119 * Returns the position of first occurrence of the pattern or
120 * UINT_MAX if no match was found.
121 */
122static inline unsigned int textsearch_find(struct ts_config *conf,
123 struct ts_state *state)
124{
125 state->offset = 0;
126 return textsearch_next(conf, state);
127}
128
129/**
130 * textsearch_get_pattern - return head of the pattern
131 * @conf: search configuration
132 */
133static inline void *textsearch_get_pattern(struct ts_config *conf)
134{
135 return conf->ops->get_pattern(conf);
136}
137
138/**
139 * textsearch_get_pattern_len - return length of the pattern
140 * @conf: search configuration
141 */
142static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf)
143{
144 return conf->ops->get_pattern_len(conf);
145}
146
147extern int textsearch_register(struct ts_ops *);
148extern int textsearch_unregister(struct ts_ops *);
149extern struct ts_config *textsearch_prepare(const char *, const void *,
Al Virofd4f2df2005-10-21 03:18:50 -0400150 unsigned int, gfp_t, int);
Thomas Graf2de4ff72005-06-23 20:49:30 -0700151extern void textsearch_destroy(struct ts_config *conf);
152extern unsigned int textsearch_find_continuous(struct ts_config *,
153 struct ts_state *,
154 const void *, unsigned int);
155
156
157#define TS_PRIV_ALIGNTO 8
158#define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1))
159
Randy Dunlap3d2aef62005-10-04 22:45:14 -0700160static inline struct ts_config *alloc_ts_config(size_t payload,
Al Virodd0fc662005-10-07 07:46:04 +0100161 gfp_t gfp_mask)
Thomas Graf2de4ff72005-06-23 20:49:30 -0700162{
163 struct ts_config *conf;
164
165 conf = kmalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask);
166 if (conf == NULL)
167 return ERR_PTR(-ENOMEM);
168
169 memset(conf, 0, TS_PRIV_ALIGN(sizeof(*conf)) + payload);
170 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