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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:59:48 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:59:48 +0000
commit3b9b6d0b8e7f798023c9d109c490449d528fde80 (patch)
tree2e1c188dd7b8d7475cd163de9ae02c428343669b /lib/isc/file.c
parentInitial commit. (diff)
downloadbind9-3b9b6d0b8e7f798023c9d109c490449d528fde80.tar.xz
bind9-3b9b6d0b8e7f798023c9d109c490449d528fde80.zip
Adding upstream version 1:9.18.19.upstream/1%9.18.19upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/isc/file.c')
-rw-r--r--lib/isc/file.c792
1 files changed, 792 insertions, 0 deletions
diff --git a/lib/isc/file.c b/lib/isc/file.c
new file mode 100644
index 0000000..e3a61de
--- /dev/null
+++ b/lib/isc/file.c
@@ -0,0 +1,792 @@
+/*
+ * 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.
+ */
+
+/*
+ * Portions Copyright (c) 1987, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*! \file */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <time.h> /* Required for utimes on some platforms. */
+#include <unistd.h> /* Required for mkstemp on NetBSD. */
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif /* ifdef HAVE_SYS_MMAN_H */
+
+#include <isc/dir.h>
+#include <isc/file.h>
+#include <isc/log.h>
+#include <isc/md.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/random.h>
+#include <isc/string.h>
+#include <isc/time.h>
+#include <isc/util.h>
+
+#include "errno2result.h"
+
+/*
+ * XXXDCL As the API for accessing file statistics undoubtedly gets expanded,
+ * it might be good to provide a mechanism that allows for the results
+ * of a previous stat() to be used again without having to do another stat,
+ * such as perl's mechanism of using "_" in place of a file name to indicate
+ * that the results of the last stat should be used. But then you get into
+ * annoying MP issues. BTW, Win32 has stat().
+ */
+static isc_result_t
+file_stats(const char *file, struct stat *stats) {
+ isc_result_t result = ISC_R_SUCCESS;
+
+ REQUIRE(file != NULL);
+ REQUIRE(stats != NULL);
+
+ if (stat(file, stats) != 0) {
+ result = isc__errno2result(errno);
+ }
+
+ return (result);
+}
+
+static isc_result_t
+fd_stats(int fd, struct stat *stats) {
+ isc_result_t result = ISC_R_SUCCESS;
+
+ REQUIRE(stats != NULL);
+
+ if (fstat(fd, stats) != 0) {
+ result = isc__errno2result(errno);
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_getsizefd(int fd, off_t *size) {
+ isc_result_t result;
+ struct stat stats;
+
+ REQUIRE(size != NULL);
+
+ result = fd_stats(fd, &stats);
+
+ if (result == ISC_R_SUCCESS) {
+ *size = stats.st_size;
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_mode(const char *file, mode_t *modep) {
+ isc_result_t result;
+ struct stat stats;
+
+ REQUIRE(modep != NULL);
+
+ result = file_stats(file, &stats);
+ if (result == ISC_R_SUCCESS) {
+ *modep = (stats.st_mode & 07777);
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_getmodtime(const char *file, isc_time_t *modtime) {
+ isc_result_t result;
+ struct stat stats;
+
+ REQUIRE(file != NULL);
+ REQUIRE(modtime != NULL);
+
+ result = file_stats(file, &stats);
+
+ if (result == ISC_R_SUCCESS) {
+#if defined(HAVE_STAT_NSEC)
+ isc_time_set(modtime, stats.st_mtime, stats.st_mtim.tv_nsec);
+#else /* if defined(HAVE_STAT_NSEC) */
+ isc_time_set(modtime, stats.st_mtime, 0);
+#endif /* if defined(HAVE_STAT_NSEC) */
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_getsize(const char *file, off_t *size) {
+ isc_result_t result;
+ struct stat stats;
+
+ REQUIRE(file != NULL);
+ REQUIRE(size != NULL);
+
+ result = file_stats(file, &stats);
+
+ if (result == ISC_R_SUCCESS) {
+ *size = stats.st_size;
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_settime(const char *file, isc_time_t *when) {
+ struct timeval times[2];
+
+ REQUIRE(file != NULL && when != NULL);
+
+ /*
+ * tv_sec is at least a 32 bit quantity on all platforms we're
+ * dealing with, but it is signed on most (all?) of them,
+ * so we need to make sure the high bit isn't set. This unfortunately
+ * loses when either:
+ * * tv_sec becomes a signed 64 bit integer but long is 32 bits
+ * and isc_time_seconds > LONG_MAX, or
+ * * isc_time_seconds is changed to be > 32 bits but long is 32 bits
+ * and isc_time_seconds has at least 33 significant bits.
+ */
+ times[0].tv_sec = times[1].tv_sec = (long)isc_time_seconds(when);
+
+ /*
+ * Here is the real check for the high bit being set.
+ */
+ if ((times[0].tv_sec &
+ (1ULL << (sizeof(times[0].tv_sec) * CHAR_BIT - 1))) != 0)
+ {
+ return (ISC_R_RANGE);
+ }
+
+ /*
+ * isc_time_nanoseconds guarantees a value that divided by 1000 will
+ * fit into the minimum possible size tv_usec field.
+ */
+ times[0].tv_usec = times[1].tv_usec =
+ (int32_t)(isc_time_nanoseconds(when) / 1000);
+
+ if (utimes(file, times) < 0) {
+ return (isc__errno2result(errno));
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+#undef TEMPLATE
+#define TEMPLATE "tmp-XXXXXXXXXX" /*%< 14 characters. */
+
+isc_result_t
+isc_file_mktemplate(const char *path, char *buf, size_t buflen) {
+ return (isc_file_template(path, TEMPLATE, buf, buflen));
+}
+
+isc_result_t
+isc_file_template(const char *path, const char *templet, char *buf,
+ size_t buflen) {
+ const char *s;
+
+ REQUIRE(templet != NULL);
+ REQUIRE(buf != NULL);
+
+ if (path == NULL) {
+ path = "";
+ }
+
+ s = strrchr(templet, '/');
+ if (s != NULL) {
+ templet = s + 1;
+ }
+
+ s = strrchr(path, '/');
+
+ if (s != NULL) {
+ size_t prefixlen = s - path + 1;
+ if ((prefixlen + strlen(templet) + 1) > buflen) {
+ return (ISC_R_NOSPACE);
+ }
+
+ /* Copy 'prefixlen' bytes and NUL terminate. */
+ strlcpy(buf, path, ISC_MIN(prefixlen + 1, buflen));
+ strlcat(buf, templet, buflen);
+ } else {
+ if ((strlen(templet) + 1) > buflen) {
+ return (ISC_R_NOSPACE);
+ }
+
+ strlcpy(buf, templet, buflen);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+static const char alphnum[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuv"
+ "wxyz0123456789";
+
+isc_result_t
+isc_file_renameunique(const char *file, char *templet) {
+ char *x;
+ char *cp;
+
+ REQUIRE(file != NULL);
+ REQUIRE(templet != NULL);
+
+ cp = templet;
+ while (*cp != '\0') {
+ cp++;
+ }
+ if (cp == templet) {
+ return (ISC_R_FAILURE);
+ }
+
+ x = cp--;
+ while (cp >= templet && *cp == 'X') {
+ *cp = alphnum[isc_random_uniform(sizeof(alphnum) - 1)];
+ x = cp--;
+ }
+ while (link(file, templet) == -1) {
+ if (errno != EEXIST) {
+ return (isc__errno2result(errno));
+ }
+ for (cp = x;;) {
+ const char *t;
+ if (*cp == '\0') {
+ return (ISC_R_FAILURE);
+ }
+ t = strchr(alphnum, *cp);
+ if (t == NULL || *++t == '\0') {
+ *cp++ = alphnum[0];
+ } else {
+ *cp = *t;
+ break;
+ }
+ }
+ }
+ if (unlink(file) < 0) {
+ if (errno != ENOENT) {
+ return (isc__errno2result(errno));
+ }
+ }
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_openunique(char *templet, FILE **fp) {
+ int mode = S_IWUSR | S_IRUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+ return (isc_file_openuniquemode(templet, mode, fp));
+}
+
+isc_result_t
+isc_file_openuniqueprivate(char *templet, FILE **fp) {
+ int mode = S_IWUSR | S_IRUSR;
+ return (isc_file_openuniquemode(templet, mode, fp));
+}
+
+isc_result_t
+isc_file_openuniquemode(char *templet, int mode, FILE **fp) {
+ int fd;
+ FILE *f;
+ isc_result_t result = ISC_R_SUCCESS;
+ char *x;
+ char *cp;
+
+ REQUIRE(templet != NULL);
+ REQUIRE(fp != NULL && *fp == NULL);
+
+ cp = templet;
+ while (*cp != '\0') {
+ cp++;
+ }
+ if (cp == templet) {
+ return (ISC_R_FAILURE);
+ }
+
+ x = cp--;
+ while (cp >= templet && *cp == 'X') {
+ *cp = alphnum[isc_random_uniform(sizeof(alphnum) - 1)];
+ x = cp--;
+ }
+
+ while ((fd = open(templet, O_RDWR | O_CREAT | O_EXCL, mode)) == -1) {
+ if (errno != EEXIST) {
+ return (isc__errno2result(errno));
+ }
+ for (cp = x;;) {
+ char *t;
+ if (*cp == '\0') {
+ return (ISC_R_FAILURE);
+ }
+ t = strchr(alphnum, *cp);
+ if (t == NULL || *++t == '\0') {
+ *cp++ = alphnum[0];
+ } else {
+ *cp = *t;
+ break;
+ }
+ }
+ }
+ f = fdopen(fd, "w+");
+ if (f == NULL) {
+ result = isc__errno2result(errno);
+ if (remove(templet) < 0) {
+ isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
+ ISC_LOGMODULE_FILE, ISC_LOG_ERROR,
+ "remove '%s': failed", templet);
+ }
+ (void)close(fd);
+ } else {
+ *fp = f;
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_bopenunique(char *templet, FILE **fp) {
+ int mode = S_IWUSR | S_IRUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+ return (isc_file_openuniquemode(templet, mode, fp));
+}
+
+isc_result_t
+isc_file_bopenuniqueprivate(char *templet, FILE **fp) {
+ int mode = S_IWUSR | S_IRUSR;
+ return (isc_file_openuniquemode(templet, mode, fp));
+}
+
+isc_result_t
+isc_file_bopenuniquemode(char *templet, int mode, FILE **fp) {
+ return (isc_file_openuniquemode(templet, mode, fp));
+}
+
+isc_result_t
+isc_file_remove(const char *filename) {
+ int r;
+
+ REQUIRE(filename != NULL);
+
+ r = unlink(filename);
+ if (r == 0) {
+ return (ISC_R_SUCCESS);
+ } else {
+ return (isc__errno2result(errno));
+ }
+}
+
+isc_result_t
+isc_file_rename(const char *oldname, const char *newname) {
+ int r;
+
+ REQUIRE(oldname != NULL);
+ REQUIRE(newname != NULL);
+
+ r = rename(oldname, newname);
+ if (r == 0) {
+ return (ISC_R_SUCCESS);
+ } else {
+ return (isc__errno2result(errno));
+ }
+}
+
+bool
+isc_file_exists(const char *pathname) {
+ struct stat stats;
+
+ REQUIRE(pathname != NULL);
+
+ return (file_stats(pathname, &stats) == ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_isplainfile(const char *filename) {
+ /*
+ * This function returns success if filename is a plain file.
+ */
+ struct stat filestat;
+ memset(&filestat, 0, sizeof(struct stat));
+
+ if ((stat(filename, &filestat)) == -1) {
+ return (isc__errno2result(errno));
+ }
+
+ if (!S_ISREG(filestat.st_mode)) {
+ return (ISC_R_INVALIDFILE);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_isplainfilefd(int fd) {
+ /*
+ * This function returns success if filename is a plain file.
+ */
+ struct stat filestat;
+ memset(&filestat, 0, sizeof(struct stat));
+
+ if ((fstat(fd, &filestat)) == -1) {
+ return (isc__errno2result(errno));
+ }
+
+ if (!S_ISREG(filestat.st_mode)) {
+ return (ISC_R_INVALIDFILE);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_isdirectory(const char *filename) {
+ /*
+ * This function returns success if filename exists and is a
+ * directory.
+ */
+ struct stat filestat;
+ memset(&filestat, 0, sizeof(struct stat));
+
+ if ((stat(filename, &filestat)) == -1) {
+ return (isc__errno2result(errno));
+ }
+
+ if (!S_ISDIR(filestat.st_mode)) {
+ return (ISC_R_INVALIDFILE);
+ }
+
+ return (ISC_R_SUCCESS);
+}
+
+bool
+isc_file_isabsolute(const char *filename) {
+ REQUIRE(filename != NULL);
+ return (filename[0] == '/');
+}
+
+bool
+isc_file_iscurrentdir(const char *filename) {
+ REQUIRE(filename != NULL);
+ return (filename[0] == '.' && filename[1] == '\0');
+}
+
+bool
+isc_file_ischdiridempotent(const char *filename) {
+ REQUIRE(filename != NULL);
+ if (isc_file_isabsolute(filename)) {
+ return (true);
+ }
+ if (isc_file_iscurrentdir(filename)) {
+ return (true);
+ }
+ return (false);
+}
+
+const char *
+isc_file_basename(const char *filename) {
+ const char *s;
+
+ REQUIRE(filename != NULL);
+
+ s = strrchr(filename, '/');
+ if (s == NULL) {
+ return (filename);
+ }
+
+ return (s + 1);
+}
+
+isc_result_t
+isc_file_progname(const char *filename, char *buf, size_t buflen) {
+ const char *base;
+ size_t len;
+
+ REQUIRE(filename != NULL);
+ REQUIRE(buf != NULL);
+
+ base = isc_file_basename(filename);
+ len = strlen(base) + 1;
+
+ if (len > buflen) {
+ return (ISC_R_NOSPACE);
+ }
+ memmove(buf, base, len);
+
+ return (ISC_R_SUCCESS);
+}
+
+/*
+ * Put the absolute name of the current directory into 'dirname', which is
+ * a buffer of at least 'length' characters. End the string with the
+ * appropriate path separator, such that the final product could be
+ * concatenated with a relative pathname to make a valid pathname string.
+ */
+static isc_result_t
+dir_current(char *dirname, size_t length) {
+ char *cwd;
+ isc_result_t result = ISC_R_SUCCESS;
+
+ REQUIRE(dirname != NULL);
+ REQUIRE(length > 0U);
+
+ cwd = getcwd(dirname, length);
+
+ if (cwd == NULL) {
+ if (errno == ERANGE) {
+ result = ISC_R_NOSPACE;
+ } else {
+ result = isc__errno2result(errno);
+ }
+ } else {
+ if (strlen(dirname) + 1 == length) {
+ result = ISC_R_NOSPACE;
+ } else if (dirname[1] != '\0') {
+ strlcat(dirname, "/", length);
+ }
+ }
+
+ return (result);
+}
+
+isc_result_t
+isc_file_absolutepath(const char *filename, char *path, size_t pathlen) {
+ isc_result_t result;
+ result = dir_current(path, pathlen);
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+ if (strlen(path) + strlen(filename) + 1 > pathlen) {
+ return (ISC_R_NOSPACE);
+ }
+ strlcat(path, filename, pathlen);
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_truncate(const char *filename, isc_offset_t size) {
+ isc_result_t result = ISC_R_SUCCESS;
+
+ if (truncate(filename, size) < 0) {
+ result = isc__errno2result(errno);
+ }
+ return (result);
+}
+
+isc_result_t
+isc_file_safecreate(const char *filename, FILE **fp) {
+ isc_result_t result;
+ int flags;
+ struct stat sb;
+ FILE *f;
+ int fd;
+
+ REQUIRE(filename != NULL);
+ REQUIRE(fp != NULL && *fp == NULL);
+
+ result = file_stats(filename, &sb);
+ if (result == ISC_R_SUCCESS) {
+ if ((sb.st_mode & S_IFREG) == 0) {
+ return (ISC_R_INVALIDFILE);
+ }
+ flags = O_WRONLY | O_TRUNC;
+ } else if (result == ISC_R_FILENOTFOUND) {
+ flags = O_WRONLY | O_CREAT | O_EXCL;
+ } else {
+ return (result);
+ }
+
+ fd = open(filename, flags, S_IRUSR | S_IWUSR);
+ if (fd == -1) {
+ return (isc__errno2result(errno));
+ }
+
+ f = fdopen(fd, "w");
+ if (f == NULL) {
+ result = isc__errno2result(errno);
+ close(fd);
+ return (result);
+ }
+
+ *fp = f;
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_splitpath(isc_mem_t *mctx, const char *path, char **dirname,
+ char const **bname) {
+ char *dir;
+ const char *file, *slash;
+
+ if (path == NULL) {
+ return (ISC_R_INVALIDFILE);
+ }
+
+ slash = strrchr(path, '/');
+
+ if (slash == path) {
+ file = ++slash;
+ dir = isc_mem_strdup(mctx, "/");
+ } else if (slash != NULL) {
+ file = ++slash;
+ dir = isc_mem_allocate(mctx, slash - path);
+ strlcpy(dir, path, slash - path);
+ } else {
+ file = path;
+ dir = isc_mem_strdup(mctx, ".");
+ }
+
+ if (dir == NULL) {
+ return (ISC_R_NOMEMORY);
+ }
+
+ if (*file == '\0') {
+ isc_mem_free(mctx, dir);
+ return (ISC_R_INVALIDFILE);
+ }
+
+ *dirname = dir;
+ *bname = file;
+
+ return (ISC_R_SUCCESS);
+}
+
+#define DISALLOW "\\/ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+static isc_result_t
+digest2hex(unsigned char *digest, unsigned int digestlen, char *hash,
+ size_t hashlen) {
+ unsigned int i;
+ int ret;
+ for (i = 0; i < digestlen; i++) {
+ size_t left = hashlen - i * 2;
+ ret = snprintf(hash + i * 2, left, "%02x", digest[i]);
+ if (ret < 0 || (size_t)ret >= left) {
+ return (ISC_R_NOSPACE);
+ }
+ }
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_file_sanitize(const char *dir, const char *base, const char *ext,
+ char *path, size_t length) {
+ char buf[PATH_MAX];
+ unsigned char digest[ISC_MAX_MD_SIZE];
+ unsigned int digestlen;
+ char hash[ISC_MAX_MD_SIZE * 2 + 1];
+ size_t l = 0;
+ isc_result_t err;
+
+ REQUIRE(base != NULL);
+ REQUIRE(path != NULL);
+
+ l = strlen(base) + 1;
+
+ /*
+ * allow room for a full sha256 hash (64 chars
+ * plus null terminator)
+ */
+ if (l < 65U) {
+ l = 65;
+ }
+
+ if (dir != NULL) {
+ l += strlen(dir) + 1;
+ }
+ if (ext != NULL) {
+ l += strlen(ext) + 1;
+ }
+
+ if (l > length || l > (unsigned)PATH_MAX) {
+ return (ISC_R_NOSPACE);
+ }
+
+ /* Check whether the full-length SHA256 hash filename exists */
+ err = isc_md(ISC_MD_SHA256, (const unsigned char *)base, strlen(base),
+ digest, &digestlen);
+ if (err != ISC_R_SUCCESS) {
+ return (err);
+ }
+
+ err = digest2hex(digest, digestlen, hash, sizeof(hash));
+ if (err != ISC_R_SUCCESS) {
+ return (err);
+ }
+
+ snprintf(buf, sizeof(buf), "%s%s%s%s%s", dir != NULL ? dir : "",
+ dir != NULL ? "/" : "", hash, ext != NULL ? "." : "",
+ ext != NULL ? ext : "");
+ if (isc_file_exists(buf)) {
+ strlcpy(path, buf, length);
+ return (ISC_R_SUCCESS);
+ }
+
+ /* Check for a truncated SHA256 hash filename */
+ hash[16] = '\0';
+ snprintf(buf, sizeof(buf), "%s%s%s%s%s", dir != NULL ? dir : "",
+ dir != NULL ? "/" : "", hash, ext != NULL ? "." : "",
+ ext != NULL ? ext : "");
+ if (isc_file_exists(buf)) {
+ strlcpy(path, buf, length);
+ return (ISC_R_SUCCESS);
+ }
+
+ /*
+ * If neither hash filename already exists, then we'll use
+ * the original base name if it has no disallowed characters,
+ * or the truncated hash name if it does.
+ */
+ if (strpbrk(base, DISALLOW) != NULL) {
+ strlcpy(path, buf, length);
+ return (ISC_R_SUCCESS);
+ }
+
+ snprintf(buf, sizeof(buf), "%s%s%s%s%s", dir != NULL ? dir : "",
+ dir != NULL ? "/" : "", base, ext != NULL ? "." : "",
+ ext != NULL ? ext : "");
+ strlcpy(path, buf, length);
+ return (ISC_R_SUCCESS);
+}
+
+bool
+isc_file_isdirwritable(const char *path) {
+ return (access(path, W_OK | X_OK) == 0);
+}