Linux kernel mirror (for testing)
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1#ifndef __LINUX_TEXTSEARCH_H
2#define __LINUX_TEXTSEARCH_H
3
4#ifdef __KERNEL__
5
6#include <linux/types.h>
7#include <linux/list.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/err.h>
11
12struct ts_config;
13
14/**
15 * TS_AUTOLOAD - Automatically load textsearch modules when needed
16 */
17#define TS_AUTOLOAD 1
18
19/**
20 * struct ts_state - search state
21 * @offset: offset for next match
22 * @cb: control buffer, for persistant variables of get_next_block()
23 */
24struct ts_state
25{
26 unsigned int offset;
27 char cb[40];
28};
29
30/**
31 * struct ts_ops - search module operations
32 * @name: name of search algorithm
33 * @init: initialization function to prepare a search
34 * @find: find the next occurrence of the pattern
35 * @destroy: destroy algorithm specific parts of a search configuration
36 * @get_pattern: return head of pattern
37 * @get_pattern_len: return length of pattern
38 * @owner: module reference to algorithm
39 */
40struct ts_ops
41{
42 const char *name;
43 struct ts_config * (*init)(const void *, unsigned int, int);
44 unsigned int (*find)(struct ts_config *,
45 struct ts_state *);
46 void (*destroy)(struct ts_config *);
47 void * (*get_pattern)(struct ts_config *);
48 unsigned int (*get_pattern_len)(struct ts_config *);
49 struct module *owner;
50 struct list_head list;
51};
52
53/**
54 * struct ts_config - search configuration
55 * @ops: operations of chosen algorithm
56 * @get_next_block: callback to fetch the next block to search in
57 * @finish: callback to finalize a search
58 */
59struct ts_config
60{
61 struct ts_ops *ops;
62
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
73 * a new search. May store/read persistant values in state->cb.
74 */
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 *,
151 unsigned int, int, int);
152extern 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
161static inline struct ts_config *alloc_ts_config(size_t payload, int gfp_mask)
162{
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
178#endif /* __KERNEL__ */
179
180#endif