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 #include <linux/slab.h> 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 persistent 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; 44 struct ts_config * (*init)(const void *, unsigned int, gfp_t); 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 persistent 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 *, 152 unsigned int, gfp_t, int); 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)) 161 162 static inline struct ts_config *alloc_ts_config(size_t payload, 163 gfp_t gfp_mask) 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 183