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Diffstat (limited to 'lib/isc/include/isc/file.h')
| -rw-r--r-- | lib/isc/include/isc/file.h | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/lib/isc/include/isc/file.h b/lib/isc/include/isc/file.h new file mode 100644 index 0000000..f78c5c5 --- /dev/null +++ b/lib/isc/include/isc/file.h @@ -0,0 +1,381 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +#pragma once + +/*! \file isc/file.h */ + +#include <stdbool.h> +#include <stdio.h> + +#include <isc/lang.h> +#include <isc/stat.h> +#include <isc/types.h> + +ISC_LANG_BEGINDECLS + +isc_result_t +isc_file_settime(const char *file, isc_time_t *time); + +isc_result_t +isc_file_mode(const char *file, mode_t *modep); + +isc_result_t +isc_file_getmodtime(const char *file, isc_time_t *time); +/*!< + * \brief Get the time of last modification of a file. + * + * Notes: + *\li The time that is set is relative to the (OS-specific) epoch, as are + * all isc_time_t structures. + * + * Requires: + *\li file != NULL. + *\li time != NULL. + * + * Ensures: + *\li If the file could not be accessed, 'time' is unchanged. + * + * Returns: + *\li #ISC_R_SUCCESS + * Success. + *\li #ISC_R_NOTFOUND + * No such file exists. + *\li #ISC_R_INVALIDFILE + * The path specified was not usable by the operating system. + *\li #ISC_R_NOPERM + * The file's metainformation could not be retrieved because + * permission was denied to some part of the file's path. + *\li #ISC_R_IOERROR + * Hardware error interacting with the filesystem. + *\li #ISC_R_UNEXPECTED + * Something totally unexpected happened. + * + */ + +isc_result_t +isc_file_mktemplate(const char *path, char *buf, size_t buflen); +/*!< + * \brief Generate a template string suitable for use with + * isc_file_openunique(). + * + * Notes: + *\li This function is intended to make creating temporary files + * portable between different operating systems. + * + *\li The path is prepended to an implementation-defined string and + * placed into buf. The string has no path characters in it, + * and its maximum length is 14 characters plus a NUL. Thus + * buflen should be at least strlen(path) + 15 characters or + * an error will be returned. + * + * Requires: + *\li buf != NULL. + * + * Ensures: + *\li If result == #ISC_R_SUCCESS: + * buf contains a string suitable for use as the template argument + * to isc_file_openunique(). + * + *\li If result != #ISC_R_SUCCESS: + * buf is unchanged. + * + * Returns: + *\li #ISC_R_SUCCESS Success. + *\li #ISC_R_NOSPACE buflen indicates buf is too small for the catenation + * of the path with the internal template string. + */ + +isc_result_t +isc_file_openunique(char *templet, FILE **fp); +isc_result_t +isc_file_openuniqueprivate(char *templet, FILE **fp); +isc_result_t +isc_file_openuniquemode(char *templet, int mode, FILE **fp); +isc_result_t +isc_file_bopenunique(char *templet, FILE **fp); +isc_result_t +isc_file_bopenuniqueprivate(char *templet, FILE **fp); +isc_result_t +isc_file_bopenuniquemode(char *templet, int mode, FILE **fp); +/*!< + * \brief Create and open a file with a unique name based on 'templet'. + * isc_file_bopen*() open the file in binary mode in Windows. + * isc_file_open*() open the file in text mode in Windows. + * + * Notes: + *\li 'template' is a reserved work in C++. If you want to complain + * about the spelling of 'templet', first look it up in the + * Merriam-Webster English dictionary. (http://www.m-w.com/) + * + *\li This function works by using the template to generate file names. + * The template must be a writable string, as it is modified in place. + * Trailing X characters in the file name (full file name on Unix, + * basename on Win32 -- eg, tmp-XXXXXX vs XXXXXX.tmp, respectively) + * are replaced with ASCII characters until a non-existent filename + * is found. If the template does not include pathname information, + * the files in the working directory of the program are searched. + * + *\li isc_file_mktemplate is a good, portable way to get a template. + * + * Requires: + *\li 'fp' is non-NULL and '*fp' is NULL. + * + *\li 'template' is non-NULL, and of a form suitable for use by + * the system as described above. + * + * Ensures: + *\li If result is #ISC_R_SUCCESS: + * *fp points to an stream opening in stdio's "w+" mode. + * + *\li If result is not #ISC_R_SUCCESS: + * *fp is NULL. + * + * No file is open. Even if one was created (but unable + * to be reopened as a stdio FILE pointer) then it has been + * removed. + * + *\li This function does *not* ensure that the template string has not been + * modified, even if the operation was unsuccessful. + * + * Returns: + *\li #ISC_R_SUCCESS + * Success. + *\li #ISC_R_EXISTS + * No file with a unique name could be created based on the + * template. + *\li #ISC_R_INVALIDFILE + * The path specified was not usable by the operating system. + *\li #ISC_R_NOPERM + * The file could not be created because permission was denied + * to some part of the file's path. + *\li #ISC_R_IOERROR + * Hardware error interacting with the filesystem. + *\li #ISC_R_UNEXPECTED + * Something totally unexpected happened. + */ + +isc_result_t +isc_file_remove(const char *filename); +/*!< + * \brief Remove the file named by 'filename'. + */ + +isc_result_t +isc_file_rename(const char *oldname, const char *newname); +/*!< + * \brief Rename the file 'oldname' to 'newname'. + */ + +bool +isc_file_exists(const char *pathname); +/*!< + * \brief Return #true if the calling process can tell that the given file + * exists. Will not return true if the calling process has insufficient + * privileges to search the entire path. + */ + +bool +isc_file_isabsolute(const char *filename); +/*!< + * \brief Return #true if the given file name is absolute. + */ + +isc_result_t +isc_file_isplainfile(const char *name); + +isc_result_t +isc_file_isplainfilefd(int fd); +/*!< + * \brief Check that the file is a plain file + * + * Returns: + *\li #ISC_R_SUCCESS + * Success. The file is a plain file. + *\li #ISC_R_INVALIDFILE + * The path specified was not usable by the operating system. + *\li #ISC_R_FILENOTFOUND + * The file does not exist. This return code comes from + * errno=ENOENT when stat returns -1. This code is mentioned + * here, because in logconf.c, it is the one rcode that is + * permitted in addition to ISC_R_SUCCESS. This is done since + * the next call in logconf.c is to isc_stdio_open(), which + * will create the file if it can. + *\li other ISC_R_* errors translated from errno + * These occur when stat returns -1 and an errno. + */ + +isc_result_t +isc_file_isdirectory(const char *name); +/*!< + * \brief Check that 'name' exists and is a directory. + * + * Returns: + *\li #ISC_R_SUCCESS + * Success, file is a directory. + *\li #ISC_R_INVALIDFILE + * File is not a directory. + *\li #ISC_R_FILENOTFOUND + * File does not exist. + *\li other ISC_R_* errors translated from errno + * These occur when stat returns -1 and an errno. + */ + +bool +isc_file_iscurrentdir(const char *filename); +/*!< + * \brief Return #true if the given file name is the current directory ("."). + */ + +bool +isc_file_ischdiridempotent(const char *filename); +/*%< + * Return #true if calling chdir(filename) multiple times will give + * the same result as calling it once. + */ + +const char * +isc_file_basename(const char *filename); +/*%< + * Return the final component of the path in the file name. + */ + +isc_result_t +isc_file_progname(const char *filename, char *buf, size_t buflen); +/*!< + * \brief Given an operating system specific file name "filename" + * referring to a program, return the canonical program name. + * + * Any directory prefix or executable file name extension (if + * used on the OS in case) is stripped. On systems where program + * names are case insensitive, the name is canonicalized to all + * lower case. The name is written to 'buf', an array of 'buflen' + * chars, and null terminated. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOSPACE The name did not fit in 'buf'. + */ + +isc_result_t +isc_file_template(const char *path, const char *templet, char *buf, + size_t buflen); +/*%< + * Create an OS specific template using 'path' to define the directory + * 'templet' to describe the filename and store the result in 'buf' + * such that path can be renamed to buf atomically. + */ + +isc_result_t +isc_file_renameunique(const char *file, char *templet); +/*%< + * Rename 'file' using 'templet' as a template for the new file name. + */ + +isc_result_t +isc_file_absolutepath(const char *filename, char *path, size_t pathlen); +/*%< + * Given a file name, return the fully qualified path to the file. + */ + +/* + * XXX We should also have a isc_file_writeeopen() function + * for safely open a file in a publicly writable directory + * (see write_open() in BIND 8's ns_config.c). + */ + +isc_result_t +isc_file_truncate(const char *filename, isc_offset_t size); +/*%< + * Truncate/extend the file specified to 'size' bytes. + */ + +isc_result_t +isc_file_safecreate(const char *filename, FILE **fp); +/*%< + * Open 'filename' for writing, truncating if necessary. Ensure that + * if it existed it was a normal file. If creating the file, ensure + * that only the owner can read/write it. + */ + +isc_result_t +isc_file_splitpath(isc_mem_t *mctx, const char *path, char **dirname, + char const **basename); +/*%< + * Split a path into dirname and basename. If 'path' contains no slash + * (or, on windows, backslash), then '*dirname' is set to ".". + * + * Allocates memory for '*dirname', which can be freed with isc_mem_free(). + * + * Returns: + * - ISC_R_SUCCESS on success + * - ISC_R_INVALIDFILE if 'path' is empty or ends with '/' + * - ISC_R_NOMEMORY if unable to allocate memory + */ + +isc_result_t +isc_file_getsize(const char *file, off_t *size); +/*%< + * Return the size of the file (stored in the parameter pointed + * to by 'size') in bytes. + * + * Returns: + * - ISC_R_SUCCESS on success + */ + +isc_result_t +isc_file_getsizefd(int fd, off_t *size); +/*%< + * Return the size of the file (stored in the parameter pointed + * to by 'size') in bytes. + * + * Returns: + * - ISC_R_SUCCESS on success + */ + +isc_result_t +isc_file_sanitize(const char *dir, const char *base, const char *ext, + char *path, size_t length); +/*%< + * Generate a sanitized filename, such as for MKEYS or NZF files. + * + * Historically, MKEYS and NZF files used SHA256 hashes of the view + * name for the filename; this was to deal with the possibility of + * forbidden characters such as "/" being in a view name, and to + * avoid problems with case-insensitive file systems. + * + * Given a basename 'base' and an extension 'ext', this function checks + * for the existence of file using the old-style name format in directory + * 'dir'. If found, it returns the path to that file. If there is no + * file already in place, a new pathname is generated; if the basename + * contains any excluded characters, then a truncated SHA256 hash is + * used, otherwise the basename is used. The path name is copied + * into 'path', which must point to a buffer of at least 'length' + * bytes. + * + * Requires: + * - base != NULL + * - path != NULL + * + * Returns: + * - ISC_R_SUCCESS on success + * - ISC_R_NOSPACE if the resulting path would be longer than 'length' + */ + +bool +isc_file_isdirwritable(const char *path); +/*%< + * Return true if the path is a directory and is writable + */ + +ISC_LANG_ENDDECLS |