#include <stdio.h>
#include <string.h>
#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
#include <syslog.h>
#include <unistd.h>
/* argument parsing */
-#define LASTLOG_DATE 01 /* display the date of the last login */
-#define LASTLOG_HOST 02 /* display the last host used (if set) */
-#define LASTLOG_LINE 04 /* display the last terminal used */
-#define LASTLOG_NEVER 010 /* display a welcome message for first login */
-#define LASTLOG_DEBUG 020 /* send info to syslog(3) */
-#define LASTLOG_QUIET 040 /* keep quiet about things */
-#define LASTLOG_WTMP 0100 /* log to wtmp as well as lastlog */
-#define LASTLOG_BTMP 0200 /* display failed login info from btmp */
-#define LASTLOG_UPDATE 0400 /* update the lastlog and wtmp files (default) */
+#define LASTLOG_DATE 01 /* display the date of the last login */
+#define LASTLOG_HOST 02 /* display the last host used (if set) */
+#define LASTLOG_LINE 04 /* display the last terminal used */
+#define LASTLOG_NEVER 010 /* display a welcome message for first login */
+#define LASTLOG_DEBUG 020 /* send info to syslog(3) */
+#define LASTLOG_QUIET 040 /* keep quiet about things */
+#define LASTLOG_WTMP 0100 /* log to wtmp as well as lastlog */
+#define LASTLOG_BTMP 0200 /* display failed login info from btmp */
+#define LASTLOG_UPDATE 0400 /* update the lastlog and wtmp files (default) */
+#define LASTLOG_UNLIMITED 01000 /* unlimited file size (ignore 'fsize' limit) */
static int
_pam_auth_parse(pam_handle_t *pamh, int flags, int argc, const char **argv,
ctrl &= ~(LASTLOG_WTMP|LASTLOG_UPDATE);
} else if (!strcmp(*argv,"showfailed")) {
ctrl |= LASTLOG_BTMP;
+ } else if (!strcmp(*argv,"unlimited")) {
+ ctrl |= LASTLOG_UNLIMITED;
} else {
pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
}
last_login_write(pam_handle_t *pamh, int announce, int last_fd,
uid_t uid, const char *user)
{
+ static struct rlimit no_limit = {
+ RLIM_INFINITY,
+ RLIM_INFINITY
+ };
+ struct rlimit old_limit;
+ int setrlimit_res;
struct flock last_lock;
struct lastlog last_login;
time_t ll_time;
sleep(LASTLOG_IGNORE_LOCK_TIME);
}
+ /*
+ * Failing to set the 'fsize' limit is not a fatal error. We try to write
+ * lastlog anyway, under the risk of dying due to a SIGXFSZ.
+ */
+ D(("setting limit for 'fsize'"));
+
+ if ((announce & LASTLOG_UNLIMITED) == 0) { /* don't set to unlimted */
+ setrlimit_res = -1;
+ } else if (getrlimit(RLIMIT_FSIZE, &old_limit) == 0) {
+ if (old_limit.rlim_cur == RLIM_INFINITY) { /* already unlimited */
+ setrlimit_res = -1;
+ } else {
+ setrlimit_res = setrlimit(RLIMIT_FSIZE, &no_limit);
+ if (setrlimit_res != 0)
+ pam_syslog(pamh, LOG_WARNING, "Could not set limit for 'fsize': %m");
+ }
+ } else {
+ setrlimit_res = -1;
+ if (errno == EINVAL) {
+ pam_syslog(pamh, LOG_INFO, "Limit for 'fsize' not supported: %m");
+ } else {
+ pam_syslog(pamh, LOG_WARNING, "Could not get limit for 'fsize': %m");
+ }
+ }
+
D(("writing to the lastlog file"));
if (pam_modutil_write (last_fd, (char *) &last_login,
sizeof (last_login)) != sizeof(last_login)) {
retval = PAM_SERVICE_ERR;
}
+ /*
+ * Failing to restore the 'fsize' limit is a fatal error.
+ */
+ D(("restoring limit for 'fsize'"));
+ if (setrlimit_res == 0) {
+ setrlimit_res = setrlimit(RLIMIT_FSIZE, &old_limit);
+ if (setrlimit_res != 0) {
+ pam_syslog(pamh, LOG_ERR, "Could not restore limit for 'fsize': %m");
+ retval = PAM_SERVICE_ERR;
+ }
+ }
+
last_lock.l_type = F_UNLCK;
(void) fcntl(last_fd, F_SETLK, &last_lock); /* unlock */
D(("unlocked"));