summaryrefslogtreecommitdiffstats
path: root/lib/util/ttyname_dev.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--lib/util/ttyname_dev.c311
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..3236925
--- /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;
+ size_t 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 * restrict devname, char * restrict 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 15:37:14 +0000