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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:52:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:52:13 +0000 |
commit | f8e5c55a036f0e2e2a958e30456270f3f9eba933 (patch) | |
tree | 4a06ff510774a7a3373e492df4e2984d7b0664b1 /lib/util/ttyname_dev.c | |
parent | Initial commit. (diff) | |
download | sudo-upstream.tar.xz sudo-upstream.zip |
Adding upstream version 1.9.5p2.upstream/1.9.5p2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/util/ttyname_dev.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/lib/util/ttyname_dev.c b/lib/util/ttyname_dev.c new file mode 100644 index 0000000..08b9777 --- /dev/null +++ b/lib/util/ttyname_dev.c @@ -0,0 +1,311 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2012-2018 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> + +#include <sys/types.h> +#include <sys/stat.h> +#if defined(MAJOR_IN_MKDEV) +# include <sys/mkdev.h> +#elif defined(MAJOR_IN_SYSMACROS) +# include <sys/sysmacros.h> +#else +# include <sys/param.h> +#endif +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <dirent.h> + +#include "pathnames.h" +#include "sudo_compat.h" +#include "sudo_debug.h" +#include "sudo_conf.h" +#include "sudo_util.h" + +#if defined(HAVE_DEVNAME) +/* + * Like ttyname() but uses a dev_t instead of an open fd. + * Returns name on success and NULL on failure, setting errno. + * The BSD version uses devname(). + */ +char * +sudo_ttyname_dev_v1(dev_t tdev, char *name, size_t namelen) +{ + char *dev; + debug_decl(sudo_ttyname_dev, SUDO_DEBUG_UTIL); + + /* Some versions of devname() return NULL on failure, others do not. */ + dev = devname(tdev, S_IFCHR); + if (dev != NULL && *dev != '?' && *dev != '#') { + if (strlcpy(name, _PATH_DEV, namelen) < namelen && + strlcat(name, dev, namelen) < namelen) + debug_return_str(name); + errno = ERANGE; + } else { + /* Not all versions of devname() set errno. */ + errno = ENOENT; + } + debug_return_str(NULL); +} +#elif defined(HAVE__TTYNAME_DEV) +extern char *_ttyname_dev(dev_t rdev, char *buffer, size_t buflen); + +/* + * Like ttyname() but uses a dev_t instead of an open fd. + * Returns name on success and NULL on failure, setting errno. + * This version is just a wrapper around _ttyname_dev(). + */ +char * +sudo_ttyname_dev_v1(dev_t tdev, char *name, size_t namelen) +{ + int serrno = errno; + debug_decl(sudo_ttyname_dev, SUDO_DEBUG_UTIL); + + /* + * _ttyname_dev() sets errno to ERANGE if namelen is too small + * but does not modify it if tdev is not found. + */ + errno = ENOENT; + if (_ttyname_dev(tdev, name, namelen) == NULL) + debug_return_str(NULL); + errno = serrno; + + debug_return_str(name); +} +#else +/* + * Device nodes to ignore. + */ +static const char *ignore_devs[] = { + _PATH_DEV "stdin", + _PATH_DEV "stdout", + _PATH_DEV "stderr", + NULL +}; + +/* + * Do a scan of a directory looking for the specified device. + * Does not descend into subdirectories. + * Returns name on success and NULL on failure, setting errno. + */ +static char * +sudo_ttyname_scan(const char *dir, dev_t rdev, char *name, size_t namelen) +{ + size_t sdlen; + char pathbuf[PATH_MAX]; + char *ret = NULL; + struct dirent *dp; + struct stat sb; + unsigned int i; + DIR *d = NULL; + debug_decl(sudo_ttyname_scan, SUDO_DEBUG_UTIL); + + if (dir[0] == '\0') { + errno = ENOENT; + goto done; + } + if ((d = opendir(dir)) == NULL) + goto done; + + if (fstat(dirfd(d), &sb) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to fstat %s", dir); + goto done; + } + if ((sb.st_mode & S_IWOTH) != 0) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "ignoring world-writable directory %s", dir); + errno = ENOENT; + goto done; + } + + sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO, + "scanning for dev %u in %s", (unsigned int)rdev, dir); + + sdlen = strlen(dir); + while (sdlen > 0 && dir[sdlen - 1] == '/') + sdlen--; + if (sdlen + 1 >= sizeof(pathbuf)) { + errno = ERANGE; + goto done; + } + memcpy(pathbuf, dir, sdlen); + pathbuf[sdlen++] = '/'; + + while ((dp = readdir(d)) != NULL) { + /* Skip anything starting with "." */ + if (dp->d_name[0] == '.') + continue; + + pathbuf[sdlen] = '\0'; + if (strlcat(pathbuf, dp->d_name, sizeof(pathbuf)) >= sizeof(pathbuf)) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "%s%s is too big to fit in pathbuf", pathbuf, dp->d_name); + continue; + } + + /* Ignore device nodes listed in ignore_devs[]. */ + for (i = 0; ignore_devs[i] != NULL; i++) { + if (strcmp(pathbuf, ignore_devs[i]) == 0) + break; + } + if (ignore_devs[i] != NULL) { + sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO, + "ignoring %s", pathbuf); + continue; + } + +# if defined(HAVE_STRUCT_DIRENT_D_TYPE) + /* + * Avoid excessive stat() calls by checking dp->d_type. + */ + switch (dp->d_type) { + case DT_CHR: + case DT_LNK: + case DT_UNKNOWN: + break; + default: + /* Not a character device or link, skip it. */ + sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO, + "skipping non-device %s", pathbuf); + continue; + } +# endif + if (stat(pathbuf, &sb) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO, + "unable to stat %s", pathbuf); + continue; + } + if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) { + sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO, + "resolved dev %u as %s", (unsigned int)rdev, pathbuf); + if (strlcpy(name, pathbuf, namelen) < namelen) { + ret = name; + } else { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to store %s, have %zu, need %zu", + pathbuf, namelen, strlen(pathbuf) + 1); + errno = ERANGE; + } + goto done; + } + } + +done: + if (d != NULL) + closedir(d); + debug_return_str(ret); +} + +static char * +sudo_dev_check(dev_t rdev, const char *devname, char *buf, size_t buflen) +{ + struct stat sb; + debug_decl(sudo_dev_check, SUDO_DEBUG_UTIL); + + if (stat(devname, &sb) == 0) { + if (S_ISCHR(sb.st_mode) && sb.st_rdev == rdev) { + sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO, + "comparing dev %u to %s: match!", + (unsigned int)rdev, devname); + if (strlcpy(buf, devname, buflen) < buflen) + debug_return_str(buf); + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to store %s, have %zu, need %zu", + devname, buflen, strlen(devname) + 1); + errno = ERANGE; + } + } + sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO, + "comparing dev %u to %s: no", (unsigned int)rdev, devname); + debug_return_str(NULL); +} + +/* + * Like ttyname() but uses a dev_t instead of an open fd. + * Returns name on success and NULL on failure, setting errno. + * Generic version. + */ +char * +sudo_ttyname_dev_v1(dev_t rdev, char *buf, size_t buflen) +{ + const char *devsearch, *devsearch_end; + char path[PATH_MAX], *ret; + const char *cp, *ep; + size_t len; + debug_decl(sudo_ttyname_dev, SUDO_DEBUG_UTIL); + + /* + * First, check /dev/console. + */ + ret = sudo_dev_check(rdev, _PATH_DEV "console", buf, buflen); + if (ret != NULL) + goto done; + + /* + * Then check the device search path. + */ + devsearch = sudo_conf_devsearch_path(); + devsearch_end = devsearch + strlen(devsearch); + for (cp = sudo_strsplit(devsearch, devsearch_end, ":", &ep); + cp != NULL; cp = sudo_strsplit(NULL, devsearch_end, ":", &ep)) { + + len = (size_t)(ep - cp); + if (len >= sizeof(path)) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "devsearch entry %.*s too long", (int)len, cp); + continue; + } + memcpy(path, cp, len); + path[len] = '\0'; + + if (strcmp(path, _PATH_DEV "pts") == 0) { + /* Special case /dev/pts */ + len = (size_t)snprintf(path, sizeof(path), "%spts/%u", + _PATH_DEV, (unsigned int)minor(rdev)); + if (len >= sizeof(path)) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "devsearch entry %spts/%u too long", + _PATH_DEV, (unsigned int)minor(rdev)); + continue; + } + ret = sudo_dev_check(rdev, path, buf, buflen); + if (ret != NULL) + goto done; + } else { + /* Scan path, looking for rdev. */ + ret = sudo_ttyname_scan(path, rdev, buf, buflen); + if (ret != NULL || errno == ENOMEM) + goto done; + } + } + +done: + debug_return_str(ret); +} +#endif |