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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:50:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:50:00 +0000
commit333f7ecfa3e040191c66b2b92f6c117ca2cbac1d (patch)
tree178a8f140927896970f47930dae9213161268f10 /libmisc/console.c
parentInitial commit. (diff)
downloadshadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.tar.xz
shadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.zip
Adding upstream version 1:4.8.1.upstream/1%4.8.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libmisc/console.c')
-rw-r--r--libmisc/console.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/libmisc/console.c b/libmisc/console.c
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--- /dev/null
+++ b/libmisc/console.c
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+/*
+ * Copyright (c) 1991 , Julianne Frances Haugh
+ * Copyright (c) 1991 , Chip Rosenthal
+ * Copyright (c) 1996 - 1998, Marek Michałkiewicz
+ * Copyright (c) 2003 - 2005, Tomasz Kłoczko
+ * Copyright (c) 2007 - 2010, Nicolas François
+ * 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. The name of the copyright holders or contributors may not be used to
+ * endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * HOLDERS 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.
+ */
+
+#include <config.h>
+#include "defines.h"
+#include <stdio.h>
+#include "getdef.h"
+#include "prototypes.h"
+
+#ident "$Id$"
+
+/* local function prototypes */
+static bool is_listed (const char *cfgin, const char *tty, bool def);
+
+/*
+ * This is now rather generic function which decides if "tty" is listed
+ * under "cfgin" in config (directly or indirectly). Fallback to default if
+ * something is bad.
+ */
+static bool is_listed (const char *cfgin, const char *tty, bool def)
+{
+ FILE *fp;
+ char buf[1024], *s;
+ const char *cons;
+
+ /*
+ * If the CONSOLE configuration definition isn't given,
+ * fallback to default.
+ */
+
+ cons = getdef_str (cfgin);
+ if (NULL == cons) {
+ return def;
+ }
+
+ /*
+ * If this isn't a filename, then it is a ":" delimited list of
+ * console devices upon which root logins are allowed.
+ */
+
+ if (*cons != '/') {
+ char *pbuf;
+ strncpy (buf, cons, sizeof (buf));
+ buf[sizeof (buf) - 1] = '\0';
+ pbuf = &buf[0];
+ while ((s = strtok (pbuf, ":")) != NULL) {
+ if (strcmp (s, tty) == 0) {
+ return true;
+ }
+
+ pbuf = NULL;
+ }
+ return false;
+ }
+
+ /*
+ * If we can't open the console list, then call everything a
+ * console - otherwise root will never be allowed to login.
+ */
+
+ fp = fopen (cons, "r");
+ if (NULL == fp) {
+ return def;
+ }
+
+ /*
+ * See if this tty is listed in the console file.
+ */
+
+ while (fgets (buf, (int) sizeof (buf), fp) != NULL) {
+ buf[strlen (buf) - 1] = '\0';
+ if (strcmp (buf, tty) == 0) {
+ (void) fclose (fp);
+ return true;
+ }
+ }
+
+ /*
+ * This tty isn't a console.
+ */
+
+ (void) fclose (fp);
+ return false;
+}
+
+/*
+ * console - return 1 if the "tty" is a console device, else 0.
+ *
+ * Note - we need to take extreme care here to avoid locking out root logins
+ * if something goes awry. That's why we do things like call everything a
+ * console if the consoles file can't be opened. Because of this, we must
+ * warn the user to protect against the remove of the consoles file since
+ * that would allow an unauthorized root login.
+ */
+
+bool console (const char *tty)
+{
+ if (strncmp (tty, "/dev/", 5) == 0) {
+ tty += 5;
+ }
+
+ return is_listed ("CONSOLE", tty, true);
+}
+