Add a PAM module that records sessions in utmp/wtmp/lastlog.

Sponsored by:	DARPA, NAI Labs

1 files changed, 240 insertions, 0 deletions

diff --git a/lib/libpam/modules/pam_lastlog/pam_lastlog.c b/lib/libpam/modules/pam_lastlog/pam_lastlog.c
new file mode 100644
index 0000000..e6ca3ce
--- /dev/null
+++ b/lib/libpam/modules/pam_lastlog/pam_lastlog.c
@@ -0,0 +1,240 @@
+/*-
+ * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 2001 Mark R V Murray
+ * All rights reserved.
+ * Copyright (c) 2001 Networks Associates Technologies, Inc.
+ * All rights reserved.
+ *
+ * Portions of this software were developed for the FreeBSD Project by
+ * ThinkSec AS and NAI Labs, the Security Research Division of Network
+ * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
+ * ("CBOSS"), as part of the DARPA CHATS research program.
+ *
+ * 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 author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ * 4. Neither the name of the University 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 THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#define _BSD_SOURCE
+
+#include <sys/param.h>
+
+#include <fcntl.h>
+#include <libutil.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+#include <utmp.h>
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+#define PAM_SM_SESSION
+#define PAM_SM_PASSWORD
+
+#include <security/pam_modules.h>
+#include <pam_mod_misc.h>
+
+extern int login_access(const char *, const char *);
+
+PAM_EXTERN int
+pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc ,const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_open_session(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+	struct passwd *pwd;
+	struct utmp utmp;
+	struct lastlog ll;
+	const char *rhost, *user, *tty;
+	char *buf;
+	off_t llpos;
+	int fd, pam_err;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	pam_err = pam_get_item(pamh, PAM_USER, (const void **)&user);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+	if (user == NULL || (pwd = getpwnam(user)) == NULL)
+		PAM_RETURN(PAM_SERVICE_ERR);
+	PAM_LOG("Got user: %s", user);
+
+	pam_err = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+	
+	pam_err = pam_get_item(pamh, PAM_TTY, (const void **)&tty);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+	if (tty == NULL)
+		PAM_RETURN(PAM_SERVICE_ERR);
+	
+	fd = open(_PATH_LASTLOG, O_RDWR, 0);
+	if (fd == -1) {
+		syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG);
+		PAM_RETURN(PAM_SERVICE_ERR);
+	}
+
+	/*
+	 * Record session in utmp(5) and wtmp(5).
+	 */
+	bzero(&utmp, sizeof(utmp));
+	time(&utmp.ut_time);
+	/* note: does not need to be NUL-terminated */
+	strncpy(utmp.ut_name, user, sizeof(utmp.ut_name));
+	if (rhost)
+		strncpy(utmp.ut_host, rhost, sizeof(utmp.ut_host));
+	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
+	login(&utmp);
+	
+	/*
+	 * Record session in lastlog(5).
+	 */
+	llpos = (off_t)(pwd->pw_uid * sizeof(ll));
+	if (lseek(fd, llpos, L_SET) != llpos)
+		goto file_err;
+	if ((flags & PAM_SILENT) == 0) {
+		if (read(fd, &ll, sizeof(ll)) == sizeof(ll) &&
+		    ll.ll_time != 0) {
+			asprintf(&buf, "Last login: %.*s ", 24 - 5,
+			    ctime(&ll.ll_time));
+			if (buf != NULL) {
+				pam_prompt(pamh, PAM_TEXT_INFO, buf, NULL);
+				free(buf);
+			}
+			if (*ll.ll_host != '\0')
+				asprintf(&buf, "from %.*s\n",
+				    (int)sizeof(ll.ll_host), ll.ll_host);
+			else
+				asprintf(&buf, "on %.*s\n",
+				    (int)sizeof(ll.ll_line), ll.ll_line);
+			if (buf != NULL) {
+				pam_prompt(pamh, PAM_TEXT_INFO, buf, NULL);
+				free(buf);
+			}
+		}
+		if (lseek(fd, llpos, L_SET) != llpos)
+			goto file_err;
+	}
+	
+	bzero(&ll, sizeof(ll));
+	time(&ll.ll_time);
+	
+	/* note: does not need to be NUL-terminated */
+	strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
+	if (rhost)
+		/* note: does not need to be NUL-terminated */
+		strncpy(ll.ll_host, rhost, sizeof(ll.ll_host));
+	
+	if (write(fd, (char *)&ll, sizeof(ll)) != sizeof(ll) || close(fd) != 0)
+		goto file_err;
+
+	PAM_LOG("Login recorded in %s", _PATH_LASTLOG);
+	PAM_RETURN(PAM_IGNORE);
+	
+ file_err:
+	syslog(LOG_ERR, "%s: %m", _PATH_LASTLOG);
+	close(fd);
+	PAM_RETURN(PAM_SERVICE_ERR);
+}
+
+PAM_EXTERN int
+pam_sm_close_session(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+	const char *tty;
+	int pam_err;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	pam_err = pam_get_item(pamh, PAM_TTY, (const void **)&tty);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+	if (tty != NULL)
+		logout(tty);
+	
+	PAM_RETURN(PAM_SUCCESS);
+}
+
+PAM_MODULE_ENTRY("pam_lastlog");