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1 | #ifndef __LINUX_TEXTSEARCH_H |
2 | #define __LINUX_TEXTSEARCH_H | |
3 | ||
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4 | #include <linux/types.h> |
5 | #include <linux/list.h> | |
6 | #include <linux/kernel.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/err.h> | |
4e57b681 | 9 | #include <linux/slab.h> |
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10 | |
11 | struct ts_config; | |
12 | ||
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13 | #define TS_AUTOLOAD 1 /* Automatically load textsearch modules when needed */ |
14 | #define TS_IGNORECASE 2 /* Searches string case insensitively */ | |
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15 | |
16 | /** | |
17 | * struct ts_state - search state | |
18 | * @offset: offset for next match | |
03a67a46 | 19 | * @cb: control buffer, for persistent variables of get_next_block() |
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20 | */ |
21 | struct ts_state | |
22 | { | |
23 | unsigned int offset; | |
24 | char cb[40]; | |
25 | }; | |
26 | ||
27 | /** | |
28 | * struct ts_ops - search module operations | |
29 | * @name: name of search algorithm | |
30 | * @init: initialization function to prepare a search | |
31 | * @find: find the next occurrence of the pattern | |
32 | * @destroy: destroy algorithm specific parts of a search configuration | |
33 | * @get_pattern: return head of pattern | |
34 | * @get_pattern_len: return length of pattern | |
35 | * @owner: module reference to algorithm | |
36 | */ | |
37 | struct ts_ops | |
38 | { | |
39 | const char *name; | |
b9c79678 | 40 | struct ts_config * (*init)(const void *, unsigned int, gfp_t, int); |
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41 | unsigned int (*find)(struct ts_config *, |
42 | struct ts_state *); | |
43 | void (*destroy)(struct ts_config *); | |
44 | void * (*get_pattern)(struct ts_config *); | |
45 | unsigned int (*get_pattern_len)(struct ts_config *); | |
46 | struct module *owner; | |
47 | struct list_head list; | |
48 | }; | |
49 | ||
50 | /** | |
51 | * struct ts_config - search configuration | |
52 | * @ops: operations of chosen algorithm | |
b9c79678 | 53 | * @flags: flags |
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54 | * @get_next_block: callback to fetch the next block to search in |
55 | * @finish: callback to finalize a search | |
56 | */ | |
57 | struct ts_config | |
58 | { | |
59 | struct ts_ops *ops; | |
b9c79678 | 60 | int flags; |
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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 | |
03a67a46 | 72 | * a new search. May store/read persistent values in state->cb. |
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73 | */ |
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 | */ | |
103 | static 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 | */ | |
122 | static 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 | */ | |
133 | static 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 | */ | |
142 | static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf) | |
143 | { | |
144 | return conf->ops->get_pattern_len(conf); | |
145 | } | |
146 | ||
147 | extern int textsearch_register(struct ts_ops *); | |
148 | extern int textsearch_unregister(struct ts_ops *); | |
149 | extern struct ts_config *textsearch_prepare(const char *, const void *, | |
fd4f2df2 | 150 | unsigned int, gfp_t, int); |
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151 | extern void textsearch_destroy(struct ts_config *conf); |
152 | extern 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 | ||
3d2aef66 | 160 | static inline struct ts_config *alloc_ts_config(size_t payload, |
dd0fc66f | 161 | gfp_t gfp_mask) |
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162 | { |
163 | struct ts_config *conf; | |
164 | ||
dde77e60 | 165 | conf = kzalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); |
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166 | if (conf == NULL) |
167 | return ERR_PTR(-ENOMEM); | |
168 | ||
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169 | return conf; |
170 | } | |
171 | ||
172 | static inline void *ts_config_priv(struct ts_config *conf) | |
173 | { | |
174 | return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config))); | |
175 | } | |
176 | ||
2de4ff7b | 177 | #endif |