[svn-upgrade] Integrating new upstream version, shadow (19990709)

libmisc/console.c

@@ -0,0 +1,115 @@
+/*
+ * Copyright 1991, Julianne Frances Haugh and Chip Rosenthal
+ * 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 Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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 "rcsid.h"
+RCSID("$Id: console.c,v 1.5 1998/12/28 20:34:44 marekm Exp $")
+
+/*
+ * 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.
+ */
+int
+is_listed(const char *cfgin, const char *tty, int def)
+{
+	FILE *fp;
+	char buf[200], *cons, *s;
+
+	/*
+	 * If the CONSOLE configuration definition isn't given,
+	 * fallback to default.
+	 */
+
+	if ((cons = getdef_str(cfgin)) == NULL)
+		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 != '/') {
+		cons = strcpy(buf, cons);
+		while ((s = strtok(cons, ":")) != NULL) {
+			if (strcmp(s, tty) == 0)
+				return 1;
+
+			cons = NULL;
+		}
+		return 0;
+	}
+
+	/*
+	 * If we can't open the console list, then call everything a
+	 * console - otherwise root will never be allowed to login.
+	 */
+
+	if ((fp = fopen(cons, "r")) == NULL)
+		return def;
+
+	/*
+	 * See if this tty is listed in the console file.
+	 */
+
+	while (fgets(buf, sizeof(buf), fp) != NULL) {
+		buf[strlen(buf) - 1] = '\0';
+		if (strcmp(buf, tty) == 0) {
+			(void) fclose(fp);
+			return 1;
+		}
+	}
+
+	/*
+	 * This tty isn't a console.
+	 */
+
+	(void) fclose(fp);
+	return 0;
+}
+
+/*
+ * 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.
+ */
+
+int
+console(const char *tty)
+{
+	return is_listed("CONSOLE", tty, 1);
+}