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2de4ff7b TG |
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> | |
4e57b681 | 11 | #include <linux/slab.h> |
2de4ff7b TG |
12 | |
13 | struct ts_config; | |
14 | ||
15 | /** | |
16 | * TS_AUTOLOAD - Automatically load textsearch modules when needed | |
17 | */ | |
18 | #define TS_AUTOLOAD 1 | |
19 | ||
20 | /** | |
21 | * struct ts_state - search state | |
22 | * @offset: offset for next match | |
23 | * @cb: control buffer, for persistant variables of get_next_block() | |
24 | */ | |
25 | struct ts_state | |
26 | { | |
27 | unsigned int offset; | |
28 | char cb[40]; | |
29 | }; | |
30 | ||
31 | /** | |
32 | * struct ts_ops - search module operations | |
33 | * @name: name of search algorithm | |
34 | * @init: initialization function to prepare a search | |
35 | * @find: find the next occurrence of the pattern | |
36 | * @destroy: destroy algorithm specific parts of a search configuration | |
37 | * @get_pattern: return head of pattern | |
38 | * @get_pattern_len: return length of pattern | |
39 | * @owner: module reference to algorithm | |
40 | */ | |
41 | struct ts_ops | |
42 | { | |
43 | const char *name; | |
fd4f2df2 | 44 | struct ts_config * (*init)(const void *, unsigned int, gfp_t); |
2de4ff7b TG |
45 | unsigned int (*find)(struct ts_config *, |
46 | struct ts_state *); | |
47 | void (*destroy)(struct ts_config *); | |
48 | void * (*get_pattern)(struct ts_config *); | |
49 | unsigned int (*get_pattern_len)(struct ts_config *); | |
50 | struct module *owner; | |
51 | struct list_head list; | |
52 | }; | |
53 | ||
54 | /** | |
55 | * struct ts_config - search configuration | |
56 | * @ops: operations of chosen algorithm | |
57 | * @get_next_block: callback to fetch the next block to search in | |
58 | * @finish: callback to finalize a search | |
59 | */ | |
60 | struct ts_config | |
61 | { | |
62 | struct ts_ops *ops; | |
63 | ||
64 | /** | |
65 | * get_next_block - fetch next block of data | |
66 | * @consumed: number of bytes consumed by the caller | |
67 | * @dst: destination buffer | |
68 | * @conf: search configuration | |
69 | * @state: search state | |
70 | * | |
71 | * Called repeatedly until 0 is returned. Must assign the | |
72 | * head of the next block of data to &*dst and return the length | |
73 | * of the block or 0 if at the end. consumed == 0 indicates | |
74 | * a new search. May store/read persistant values in state->cb. | |
75 | */ | |
76 | unsigned int (*get_next_block)(unsigned int consumed, | |
77 | const u8 **dst, | |
78 | struct ts_config *conf, | |
79 | struct ts_state *state); | |
80 | ||
81 | /** | |
82 | * finish - finalize/clean a series of get_next_block() calls | |
83 | * @conf: search configuration | |
84 | * @state: search state | |
85 | * | |
86 | * Called after the last use of get_next_block(), may be used | |
87 | * to cleanup any leftovers. | |
88 | */ | |
89 | void (*finish)(struct ts_config *conf, | |
90 | struct ts_state *state); | |
91 | }; | |
92 | ||
93 | /** | |
94 | * textsearch_next - continue searching for a pattern | |
95 | * @conf: search configuration | |
96 | * @state: search state | |
97 | * | |
98 | * Continues a search looking for more occurrences of the pattern. | |
99 | * textsearch_find() must be called to find the first occurrence | |
100 | * in order to reset the state. | |
101 | * | |
102 | * Returns the position of the next occurrence of the pattern or | |
103 | * UINT_MAX if not match was found. | |
104 | */ | |
105 | static inline unsigned int textsearch_next(struct ts_config *conf, | |
106 | struct ts_state *state) | |
107 | { | |
108 | unsigned int ret = conf->ops->find(conf, state); | |
109 | ||
110 | if (conf->finish) | |
111 | conf->finish(conf, state); | |
112 | ||
113 | return ret; | |
114 | } | |
115 | ||
116 | /** | |
117 | * textsearch_find - start searching for a pattern | |
118 | * @conf: search configuration | |
119 | * @state: search state | |
120 | * | |
121 | * Returns the position of first occurrence of the pattern or | |
122 | * UINT_MAX if no match was found. | |
123 | */ | |
124 | static inline unsigned int textsearch_find(struct ts_config *conf, | |
125 | struct ts_state *state) | |
126 | { | |
127 | state->offset = 0; | |
128 | return textsearch_next(conf, state); | |
129 | } | |
130 | ||
131 | /** | |
132 | * textsearch_get_pattern - return head of the pattern | |
133 | * @conf: search configuration | |
134 | */ | |
135 | static inline void *textsearch_get_pattern(struct ts_config *conf) | |
136 | { | |
137 | return conf->ops->get_pattern(conf); | |
138 | } | |
139 | ||
140 | /** | |
141 | * textsearch_get_pattern_len - return length of the pattern | |
142 | * @conf: search configuration | |
143 | */ | |
144 | static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf) | |
145 | { | |
146 | return conf->ops->get_pattern_len(conf); | |
147 | } | |
148 | ||
149 | extern int textsearch_register(struct ts_ops *); | |
150 | extern int textsearch_unregister(struct ts_ops *); | |
151 | extern struct ts_config *textsearch_prepare(const char *, const void *, | |
fd4f2df2 | 152 | unsigned int, gfp_t, int); |
2de4ff7b TG |
153 | extern void textsearch_destroy(struct ts_config *conf); |
154 | extern unsigned int textsearch_find_continuous(struct ts_config *, | |
155 | struct ts_state *, | |
156 | const void *, unsigned int); | |
157 | ||
158 | ||
159 | #define TS_PRIV_ALIGNTO 8 | |
160 | #define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1)) | |
161 | ||
3d2aef66 | 162 | static inline struct ts_config *alloc_ts_config(size_t payload, |
dd0fc66f | 163 | gfp_t gfp_mask) |
2de4ff7b TG |
164 | { |
165 | struct ts_config *conf; | |
166 | ||
167 | conf = kmalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); | |
168 | if (conf == NULL) | |
169 | return ERR_PTR(-ENOMEM); | |
170 | ||
171 | memset(conf, 0, TS_PRIV_ALIGN(sizeof(*conf)) + payload); | |
172 | return conf; | |
173 | } | |
174 | ||
175 | static inline void *ts_config_priv(struct ts_config *conf) | |
176 | { | |
177 | return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config))); | |
178 | } | |
179 | ||
180 | #endif /* __KERNEL__ */ | |
181 | ||
182 | #endif |