diff options
Diffstat (limited to 'lib/util/mktemp.c')
| -rw-r--r-- | lib/util/mktemp.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/lib/util/mktemp.c b/lib/util/mktemp.c new file mode 100644 index 0000000..1540e51 --- /dev/null +++ b/lib/util/mktemp.c @@ -0,0 +1,172 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2001, 2003, 2004, 2008-2011, 2013, 2015, 2017, 2018, 2022 + * Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include <config.h> + +#if (!defined(HAVE_MKDTEMPAT) && !defined(HAVE_MKDTEMPAT_NP)) || \ + (!defined(HAVE_MKOSTEMPSAT) && !defined(HAVE_MKOSTEMPSAT_NP)) + +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#if defined(HAVE_STDINT_H) +# include <stdint.h> +#elif defined(HAVE_INTTYPES_H) +# include <inttypes.h> +#endif +#include <string.h> +#include <ctype.h> +#include <unistd.h> + +#include "sudo_compat.h" +#include "sudo_rand.h" +#include "pathnames.h" + +#define MKTEMP_FILE 1 +#define MKTEMP_DIR 2 + +#define TEMPCHARS "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" +#define NUM_CHARS (sizeof(TEMPCHARS) - 1) +#define MIN_X 6 + +#define MKOTEMP_FLAGS (O_APPEND | O_CLOEXEC | O_SYNC) + +static int +mktemp_internal(int dfd, char *path, int slen, int mode, int flags) +{ + char *start, *cp, *ep; + const char tempchars[] = TEMPCHARS; + unsigned int tries; + size_t len; + int fd; + + len = strlen(path); + if (len < MIN_X || slen < 0 || (size_t)slen > len - MIN_X) { + errno = EINVAL; + return -1; + } + ep = path + len - slen; + + for (start = ep; start > path && start[-1] == 'X'; start--) + ; + if (ep - start < MIN_X) { + errno = EINVAL; + return -1; + } + + if (flags & ~MKOTEMP_FLAGS) { + errno = EINVAL; + return -1; + } + flags |= O_CREAT | O_EXCL | O_RDWR; + + tries = INT_MAX; + do { + cp = start; + do { + unsigned short rbuf[16]; + unsigned int i; + + /* + * Avoid lots of arc4random() calls by using + * a buffer sized for up to 16 Xs at a time. + */ + arc4random_buf(rbuf, sizeof(rbuf)); + for (i = 0; i < nitems(rbuf) && cp != ep; i++) + *cp++ = tempchars[rbuf[i] % NUM_CHARS]; + } while (cp != ep); + + switch (mode) { + case MKTEMP_FILE: + fd = openat(dfd, path, flags, S_IRUSR|S_IWUSR); + if (fd != -1 || errno != EEXIST) + return fd; + break; + case MKTEMP_DIR: + if (mkdirat(dfd, path, S_IRWXU) == 0) + return 0; + if (errno != EEXIST) + return -1; + break; + } + } while (--tries); + + errno = EEXIST; + return -1; +} + +char * +sudo_mkdtemp(char *path) +{ + if (mktemp_internal(AT_FDCWD, path, 0, MKTEMP_DIR, 0) == -1) + return NULL; + return path; +} + +char * +sudo_mkdtempat(int dfd, char *path) +{ + if (mktemp_internal(dfd, path, 0, MKTEMP_DIR, 0) == -1) + return NULL; + return path; +} + +int +sudo_mkostempsat(int dfd, char *path, int slen, int flags) +{ + return mktemp_internal(dfd, path, slen, MKTEMP_FILE, flags); +} + +#ifdef notyet +int +sudo_mkostemps(char *path, int slen, int flags) +{ + return mktemp_internal(AT_FDCWD, path, slen, MKTEMP_FILE, flags); +} +#endif + +int +sudo_mkstemp(char *path) +{ + return mktemp_internal(AT_FDCWD, path, 0, MKTEMP_FILE, 0); +} + +#ifdef notyet +int +sudo_mkostemp(char *path, int flags) +{ + return mktemp_internal(AT_FDCWD, path, 0, MKTEMP_FILE, flags); +} +#endif + +int +sudo_mkstemps(char *path, int slen) +{ + return mktemp_internal(AT_FDCWD, path, slen, MKTEMP_FILE, 0); +} +#endif /* !HAVE_MKDTEMPAT || !HAVE_MKOSTEMPSAT */ |