1 /* SPDX-License-Identifier: LGPL-2.1+ */ 2 /* 3 * Declarations for System V style searching functions. 4 * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc. 5 * This file is part of the GNU C Library. 6 */ 7 8 /* 9 * Based on code from uClibc-0.9.30.3 10 * Extensions for use within U-Boot 11 * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> 12 */ 13 14 #ifndef _SEARCH_H_ 15 #define _SEARCH_H_ 16 17 #include <env.h> 18 #include <stddef.h> 19 20 #define set_errno(val) do { errno = val; } while (0) 21 22 /* enum env_action: action which shall be performed in the call to hsearch */ 23 enum env_action { 24 ENV_FIND, 25 ENV_ENTER, 26 }; 27 28 /** struct env_entry - An entry in the environment hashtable */ 29 struct env_entry { 30 const char *key; 31 char *data; 32 #ifndef CONFIG_SPL_BUILD 33 int (*callback)(const char *name, const char *value, enum env_op op, 34 int flags); 35 #endif 36 int flags; 37 }; 38 39 /* 40 * Family of hash table handling functions. The functions also 41 * have reentrant counterparts ending with _r. The non-reentrant 42 * functions all work on a single internal hash table. 43 */ 44 45 /* Data type for reentrant functions. */ 46 struct hsearch_data { 47 struct env_entry_node *table; 48 unsigned int size; 49 unsigned int filled; 50 /* 51 * Callback function which will check whether the given change for variable 52 * "item" to "newval" may be applied or not, and possibly apply such change. 53 * When (flag & H_FORCE) is set, it shall not print out any error message and 54 * shall force overwriting of write-once variables. 55 * Must return 0 for approval, 1 for denial. 56 */ 57 int (*change_ok)(const struct env_entry *item, const char *newval, 58 enum env_op, int flag); 59 }; 60 61 /* Create a new hash table which will contain at most "nel" elements. */ 62 int hcreate_r(size_t nel, struct hsearch_data *htab); 63 64 /* Destroy current internal hash table. */ 65 void hdestroy_r(struct hsearch_data *htab); 66 67 /* 68 * Search for entry matching item.key in internal hash table. If 69 * action is `ENV_FIND' return found entry or signal error by returning 70 * NULL. If action is `ENV_ENTER' replace existing data (if any) with 71 * item.data. 72 * */ 73 int hsearch_r(struct env_entry item, enum env_action action, 74 struct env_entry **retval, struct hsearch_data *htab, int flag); 75 76 /* 77 * Search for an entry matching "match". Otherwise, Same semantics 78 * as hsearch_r(). 79 */ 80 int hmatch_r(const char *match, int last_idx, struct env_entry **retval, 81 struct hsearch_data *htab); 82 83 /** 84 * hdelete_r() - Search and delete entry in internal hash table 85 * 86 * @key: Name of entry to delete 87 * @htab: Hash table 88 * @flag: Flags to use (H_...) 89 * @return 0 on success, -ENOENT if not found, -EPERM if the hash table callback 90 * rejected changing the variable, -EINVAL if the hash table refused to 91 * delete the variable 92 */ 93 int hdelete_r(const char *key, struct hsearch_data *htab, int flag); 94 95 ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag, 96 char **resp, size_t size, int argc, char *const argv[]); 97 98 /* 99 * nvars: length of vars array 100 * vars: array of strings (variable names) to import (nvars == 0 means all) 101 */ 102 int himport_r(struct hsearch_data *htab, const char *env, size_t size, 103 const char sep, int flag, int crlf_is_lf, int nvars, 104 char * const vars[]); 105 106 /* Walk the whole table calling the callback on each element */ 107 int hwalk_r(struct hsearch_data *htab, 108 int (*callback)(struct env_entry *entry)); 109 110 /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ 111 #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ 112 #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ 113 #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ 114 #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ 115 #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */ 116 #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */ 117 #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */ 118 #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */ 119 #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */ 120 #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */ 121 #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX) 122 #define H_PROGRAMMATIC (1 << 9) /* indicate that an import is from env_set() */ 123 #define H_ORIGIN_FLAGS (H_INTERACTIVE | H_PROGRAMMATIC) 124 #define H_DEFAULT (1 << 10) /* indicate that an import is default env */ 125 #define H_EXTERNAL (1 << 11) /* indicate that an import is external env */ 126 127 #endif /* _SEARCH_H_ */ 128