1 #ifndef __LINUX_TEXTSEARCH_H 2 #define __LINUX_TEXTSEARCH_H 3 4 #include <linux/types.h> 5 #include <linux/list.h> 6 #include <linux/kernel.h> 7 #include <linux/err.h> 8 #include <linux/slab.h> 9 10 struct module; 11 12 struct ts_config; 13 14 #define TS_AUTOLOAD 1 /* Automatically load textsearch modules when needed */ 15 #define TS_IGNORECASE 2 /* Searches string case insensitively */ 16 17 /** 18 * struct ts_state - search state 19 * @offset: offset for next match 20 * @cb: control buffer, for persistent variables of get_next_block() 21 */ 22 struct 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 */ 38 struct ts_ops 39 { 40 const char *name; 41 struct ts_config * (*init)(const void *, unsigned int, gfp_t, int); 42 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 54 * @flags: flags 55 * @get_next_block: callback to fetch the next block to search in 56 * @finish: callback to finalize a search 57 */ 58 struct ts_config 59 { 60 struct ts_ops *ops; 61 int flags; 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 persistent 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 */ 104 static 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 */ 123 static 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 */ 134 static 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 */ 143 static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf) 144 { 145 return conf->ops->get_pattern_len(conf); 146 } 147 148 extern int textsearch_register(struct ts_ops *); 149 extern int textsearch_unregister(struct ts_ops *); 150 extern struct ts_config *textsearch_prepare(const char *, const void *, 151 unsigned int, gfp_t, int); 152 extern void textsearch_destroy(struct ts_config *conf); 153 extern 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)) 160 161 static inline struct ts_config *alloc_ts_config(size_t payload, 162 gfp_t gfp_mask) 163 { 164 struct ts_config *conf; 165 166 conf = kzalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); 167 if (conf == NULL) 168 return ERR_PTR(-ENOMEM); 169 170 return conf; 171 } 172 173 static 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 179