1 files changed, 83 insertions, 0 deletions
diff --git a/lib/sulog.c b/lib/sulog.c
new file mode 100644
index 0000000..2ef22b2
--- /dev/null
+++ b/lib/sulog.c
@@ -0,0 +1,83 @@
+/*
+ * SPDX-FileCopyrightText: 1989 - 1992, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2001 - 2005, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2008 - 2010, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <time.h>
+#include "prototypes.h"
+#include "defines.h"
+#include "getdef.h"
+
+/*
+ * sulog - log a SU command execution result
+ */
+void sulog (const char *tty, bool success, const char *oldname, const char *name)
+{
+	const char *sulog_file;
+	time_t now;
+	struct tm *tm;
+	FILE *fp;
+	mode_t oldmask;
+	gid_t oldgid = 0;
+
+	if (success) {
+		SYSLOG ((LOG_INFO,
+			"Successful su for %s by %s",name,oldname));
+	} else {
+		SYSLOG ((LOG_NOTICE,
+			"FAILED su for %s by %s",name,oldname));
+	}
+
+	sulog_file = getdef_str ("SULOG_FILE");
+	if (NULL == sulog_file) {
+		return;
+	}
+
+	oldgid = getgid ();
+	oldmask = umask (077);
+	/* Switch to group root to avoid creating the sulog file with
+	 * the wrong group ownership. */
+	if ((oldgid != 0) && (setgid (0) != 0)) {
+		SYSLOG ((LOG_INFO,
+		         "su session not logged to %s", sulog_file));
+		/* Continue, but do not switch back to oldgid later */
+		oldgid = 0;
+	}
+	fp = fopen (sulog_file, "a+");
+	(void) umask (oldmask);
+	if ((oldgid != 0) && (setgid (oldgid) != 0)) {
+		perror ("setgid");
+		SYSLOG ((LOG_ERR,
+		         "can't switch back to group `%d' in sulog",
+		         oldgid));
+		/* Do not return if the group permission were raised. */
+		exit (EXIT_FAILURE);
+	}
+	if (fp == NULL) {
+		return;		/* can't open or create logfile */
+	}
+
+	(void) time (&now);
+	tm = localtime (&now);
+
+	fprintf (fp, "SU %.02d/%.02d %.02d:%.02d %c %s %s-%s\n",
+		 tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min,
+		 success ? '+' : '-', tty, oldname, name);
+
+	(void) fflush (fp);
+	fsync (fileno (fp));
+	fclose (fp);
+	/* TODO: log if failure */
+}
+