1/* $NetBSD: file.h,v 1.7 2024/02/21 22:52:30 christos Exp $ */ 2 3/* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 7 * 8 * This Source Code Form is subject to the terms of the Mozilla Public 9 * License, v. 2.0. If a copy of the MPL was not distributed with this 10 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11 * 12 * See the COPYRIGHT file distributed with this work for additional 13 * information regarding copyright ownership. 14 */ 15 16#pragma once 17 18/*! \file isc/file.h */ 19 20#include <stdbool.h> 21#include <stdio.h> 22 23#include <isc/lang.h> 24#include <isc/stat.h> 25#include <isc/types.h> 26 27ISC_LANG_BEGINDECLS 28 29isc_result_t 30isc_file_settime(const char *file, isc_time_t *time); 31 32isc_result_t 33isc_file_mode(const char *file, mode_t *modep); 34 35isc_result_t 36isc_file_getmodtime(const char *file, isc_time_t *time); 37/*!< 38 * \brief Get the time of last modification of a file. 39 * 40 * Notes: 41 *\li The time that is set is relative to the (OS-specific) epoch, as are 42 * all isc_time_t structures. 43 * 44 * Requires: 45 *\li file != NULL. 46 *\li time != NULL. 47 * 48 * Ensures: 49 *\li If the file could not be accessed, 'time' is unchanged. 50 * 51 * Returns: 52 *\li #ISC_R_SUCCESS 53 * Success. 54 *\li #ISC_R_NOTFOUND 55 * No such file exists. 56 *\li #ISC_R_INVALIDFILE 57 * The path specified was not usable by the operating system. 58 *\li #ISC_R_NOPERM 59 * The file's metainformation could not be retrieved because 60 * permission was denied to some part of the file's path. 61 *\li #ISC_R_IOERROR 62 * Hardware error interacting with the filesystem. 63 *\li #ISC_R_UNEXPECTED 64 * Something totally unexpected happened. 65 * 66 */ 67 68isc_result_t 69isc_file_mktemplate(const char *path, char *buf, size_t buflen); 70/*!< 71 * \brief Generate a template string suitable for use with 72 * isc_file_openunique(). 73 * 74 * Notes: 75 *\li This function is intended to make creating temporary files 76 * portable between different operating systems. 77 * 78 *\li The path is prepended to an implementation-defined string and 79 * placed into buf. The string has no path characters in it, 80 * and its maximum length is 14 characters plus a NUL. Thus 81 * buflen should be at least strlen(path) + 15 characters or 82 * an error will be returned. 83 * 84 * Requires: 85 *\li buf != NULL. 86 * 87 * Ensures: 88 *\li If result == #ISC_R_SUCCESS: 89 * buf contains a string suitable for use as the template argument 90 * to isc_file_openunique(). 91 * 92 *\li If result != #ISC_R_SUCCESS: 93 * buf is unchanged. 94 * 95 * Returns: 96 *\li #ISC_R_SUCCESS Success. 97 *\li #ISC_R_NOSPACE buflen indicates buf is too small for the catenation 98 * of the path with the internal template string. 99 */ 100 101isc_result_t 102isc_file_openunique(char *templet, FILE **fp); 103isc_result_t 104isc_file_openuniqueprivate(char *templet, FILE **fp); 105isc_result_t 106isc_file_openuniquemode(char *templet, int mode, FILE **fp); 107isc_result_t 108isc_file_bopenunique(char *templet, FILE **fp); 109isc_result_t 110isc_file_bopenuniqueprivate(char *templet, FILE **fp); 111isc_result_t 112isc_file_bopenuniquemode(char *templet, int mode, FILE **fp); 113/*!< 114 * \brief Create and open a file with a unique name based on 'templet'. 115 * isc_file_bopen*() open the file in binary mode in Windows. 116 * isc_file_open*() open the file in text mode in Windows. 117 * 118 * Notes: 119 *\li 'template' is a reserved work in C++. If you want to complain 120 * about the spelling of 'templet', first look it up in the 121 * Merriam-Webster English dictionary. (http://www.m-w.com/) 122 * 123 *\li This function works by using the template to generate file names. 124 * The template must be a writable string, as it is modified in place. 125 * Trailing X characters in the file name (full file name on Unix, 126 * basename on Win32 -- eg, tmp-XXXXXX vs XXXXXX.tmp, respectively) 127 * are replaced with ASCII characters until a non-existent filename 128 * is found. If the template does not include pathname information, 129 * the files in the working directory of the program are searched. 130 * 131 *\li isc_file_mktemplate is a good, portable way to get a template. 132 * 133 * Requires: 134 *\li 'fp' is non-NULL and '*fp' is NULL. 135 * 136 *\li 'template' is non-NULL, and of a form suitable for use by 137 * the system as described above. 138 * 139 * Ensures: 140 *\li If result is #ISC_R_SUCCESS: 141 * *fp points to an stream opening in stdio's "w+" mode. 142 * 143 *\li If result is not #ISC_R_SUCCESS: 144 * *fp is NULL. 145 * 146 * No file is open. Even if one was created (but unable 147 * to be reopened as a stdio FILE pointer) then it has been 148 * removed. 149 * 150 *\li This function does *not* ensure that the template string has not been 151 * modified, even if the operation was unsuccessful. 152 * 153 * Returns: 154 *\li #ISC_R_SUCCESS 155 * Success. 156 *\li #ISC_R_EXISTS 157 * No file with a unique name could be created based on the 158 * template. 159 *\li #ISC_R_INVALIDFILE 160 * The path specified was not usable by the operating system. 161 *\li #ISC_R_NOPERM 162 * The file could not be created because permission was denied 163 * to some part of the file's path. 164 *\li #ISC_R_IOERROR 165 * Hardware error interacting with the filesystem. 166 *\li #ISC_R_UNEXPECTED 167 * Something totally unexpected happened. 168 */ 169 170isc_result_t 171isc_file_remove(const char *filename); 172/*!< 173 * \brief Remove the file named by 'filename'. 174 */ 175 176isc_result_t 177isc_file_rename(const char *oldname, const char *newname); 178/*!< 179 * \brief Rename the file 'oldname' to 'newname'. 180 */ 181 182bool 183isc_file_exists(const char *pathname); 184/*!< 185 * \brief Return #true if the calling process can tell that the given file 186 * exists. Will not return true if the calling process has insufficient 187 * privileges to search the entire path. 188 */ 189 190bool 191isc_file_isabsolute(const char *filename); 192/*!< 193 * \brief Return #true if the given file name is absolute. 194 */ 195 196isc_result_t 197isc_file_isplainfile(const char *name); 198 199isc_result_t 200isc_file_isplainfilefd(int fd); 201/*!< 202 * \brief Check that the file is a plain file 203 * 204 * Returns: 205 *\li #ISC_R_SUCCESS 206 * Success. The file is a plain file. 207 *\li #ISC_R_INVALIDFILE 208 * The path specified was not usable by the operating system. 209 *\li #ISC_R_FILENOTFOUND 210 * The file does not exist. This return code comes from 211 * errno=ENOENT when stat returns -1. This code is mentioned 212 * here, because in logconf.c, it is the one rcode that is 213 * permitted in addition to ISC_R_SUCCESS. This is done since 214 * the next call in logconf.c is to isc_stdio_open(), which 215 * will create the file if it can. 216 *\li other ISC_R_* errors translated from errno 217 * These occur when stat returns -1 and an errno. 218 */ 219 220isc_result_t 221isc_file_isdirectory(const char *name); 222/*!< 223 * \brief Check that 'name' exists and is a directory. 224 * 225 * Returns: 226 *\li #ISC_R_SUCCESS 227 * Success, file is a directory. 228 *\li #ISC_R_INVALIDFILE 229 * File is not a directory. 230 *\li #ISC_R_FILENOTFOUND 231 * File does not exist. 232 *\li other ISC_R_* errors translated from errno 233 * These occur when stat returns -1 and an errno. 234 */ 235 236bool 237isc_file_iscurrentdir(const char *filename); 238/*!< 239 * \brief Return #true if the given file name is the current directory ("."). 240 */ 241 242bool 243isc_file_ischdiridempotent(const char *filename); 244/*%< 245 * Return #true if calling chdir(filename) multiple times will give 246 * the same result as calling it once. 247 */ 248 249const char * 250isc_file_basename(const char *filename); 251/*%< 252 * Return the final component of the path in the file name. 253 */ 254 255isc_result_t 256isc_file_progname(const char *filename, char *buf, size_t buflen); 257/*!< 258 * \brief Given an operating system specific file name "filename" 259 * referring to a program, return the canonical program name. 260 * 261 * Any directory prefix or executable file name extension (if 262 * used on the OS in case) is stripped. On systems where program 263 * names are case insensitive, the name is canonicalized to all 264 * lower case. The name is written to 'buf', an array of 'buflen' 265 * chars, and null terminated. 266 * 267 * Returns: 268 *\li #ISC_R_SUCCESS 269 *\li #ISC_R_NOSPACE The name did not fit in 'buf'. 270 */ 271 272isc_result_t 273isc_file_template(const char *path, const char *templet, char *buf, 274 size_t buflen); 275/*%< 276 * Create an OS specific template using 'path' to define the directory 277 * 'templet' to describe the filename and store the result in 'buf' 278 * such that path can be renamed to buf atomically. 279 */ 280 281isc_result_t 282isc_file_renameunique(const char *file, char *templet); 283/*%< 284 * Rename 'file' using 'templet' as a template for the new file name. 285 */ 286 287isc_result_t 288isc_file_absolutepath(const char *filename, char *path, size_t pathlen); 289/*%< 290 * Given a file name, return the fully qualified path to the file. 291 */ 292 293/* 294 * XXX We should also have a isc_file_writeeopen() function 295 * for safely open a file in a publicly writable directory 296 * (see write_open() in BIND 8's ns_config.c). 297 */ 298 299isc_result_t 300isc_file_truncate(const char *filename, isc_offset_t size); 301/*%< 302 * Truncate/extend the file specified to 'size' bytes. 303 */ 304 305isc_result_t 306isc_file_safecreate(const char *filename, FILE **fp); 307/*%< 308 * Open 'filename' for writing, truncating if necessary. Ensure that 309 * if it existed it was a normal file. If creating the file, ensure 310 * that only the owner can read/write it. 311 */ 312 313isc_result_t 314isc_file_splitpath(isc_mem_t *mctx, const char *path, char **dirname, 315 char const **basename); 316/*%< 317 * Split a path into dirname and basename. If 'path' contains no slash 318 * (or, on windows, backslash), then '*dirname' is set to ".". 319 * 320 * Allocates memory for '*dirname', which can be freed with isc_mem_free(). 321 * 322 * Returns: 323 * - ISC_R_SUCCESS on success 324 * - ISC_R_INVALIDFILE if 'path' is empty or ends with '/' 325 * - ISC_R_NOMEMORY if unable to allocate memory 326 */ 327 328isc_result_t 329isc_file_getsize(const char *file, off_t *size); 330/*%< 331 * Return the size of the file (stored in the parameter pointed 332 * to by 'size') in bytes. 333 * 334 * Returns: 335 * - ISC_R_SUCCESS on success 336 */ 337 338isc_result_t 339isc_file_getsizefd(int fd, off_t *size); 340/*%< 341 * Return the size of the file (stored in the parameter pointed 342 * to by 'size') in bytes. 343 * 344 * Returns: 345 * - ISC_R_SUCCESS on success 346 */ 347 348isc_result_t 349isc_file_sanitize(const char *dir, const char *base, const char *ext, 350 char *path, size_t length); 351/*%< 352 * Generate a sanitized filename, such as for MKEYS or NZF files. 353 * 354 * Historically, MKEYS and NZF files used SHA256 hashes of the view 355 * name for the filename; this was to deal with the possibility of 356 * forbidden characters such as "/" being in a view name, and to 357 * avoid problems with case-insensitive file systems. 358 * 359 * Given a basename 'base' and an extension 'ext', this function checks 360 * for the existence of file using the old-style name format in directory 361 * 'dir'. If found, it returns the path to that file. If there is no 362 * file already in place, a new pathname is generated; if the basename 363 * contains any excluded characters, then a truncated SHA256 hash is 364 * used, otherwise the basename is used. The path name is copied 365 * into 'path', which must point to a buffer of at least 'length' 366 * bytes. 367 * 368 * Requires: 369 * - base != NULL 370 * - path != NULL 371 * 372 * Returns: 373 * - ISC_R_SUCCESS on success 374 * - ISC_R_NOSPACE if the resulting path would be longer than 'length' 375 */ 376 377bool 378isc_file_isdirwritable(const char *path); 379/*%< 380 * Return true if the path is a directory and is writable 381 */ 382 383ISC_LANG_ENDDECLS 384