shadow/libmisc/log.c

94 lines
2.3 KiB
C

/*
* SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2008 , Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <sys/types.h>
#include <pwd.h>
#include <fcntl.h>
#include <time.h>
#include "defines.h"
#include <lastlog.h>
#include "prototypes.h"
/*
* dolastlog - create lastlog entry
*
* A "last login" entry is created for the user being logged in. The
* UID is extracted from the global (struct passwd) entry and the
* TTY information is gotten from the (struct utmp).
*/
void dolastlog (
struct lastlog *ll,
const struct passwd *pw,
/*@unique@*/const char *line,
/*@unique@*/const char *host)
{
int fd;
off_t offset;
struct lastlog newlog;
time_t ll_time;
/*
* If the file does not exist, don't create it.
*/
fd = open (LASTLOG_FILE, O_RDWR);
if (-1 == fd) {
return;
}
/*
* The file is indexed by UID number. Seek to the record
* for this UID. Negative UID's will create problems, but ...
*/
offset = (off_t) pw->pw_uid * sizeof newlog;
if (lseek (fd, offset, SEEK_SET) != offset) {
SYSLOG ((LOG_WARN,
"Can't read last lastlog entry for UID %lu in %s. Entry not updated.",
(unsigned long) pw->pw_uid, LASTLOG_FILE));
(void) close (fd);
return;
}
/*
* Read the old entry so we can tell the user when they last
* logged in. Then construct the new entry and write it out
* the way we read the old one in.
*/
if (read (fd, (void *) &newlog, sizeof newlog) != (ssize_t) sizeof newlog) {
memzero (&newlog, sizeof newlog);
}
if (NULL != ll) {
*ll = newlog;
}
ll_time = newlog.ll_time;
(void) time (&ll_time);
newlog.ll_time = ll_time;
strncpy (newlog.ll_line, line, sizeof (newlog.ll_line) - 1);
#if HAVE_LL_HOST
strncpy (newlog.ll_host, host, sizeof (newlog.ll_host) - 1);
#endif
if ( (lseek (fd, offset, SEEK_SET) != offset)
|| (write (fd, (const void *) &newlog, sizeof newlog) != (ssize_t) sizeof newlog)
|| (close (fd) != 0)) {
SYSLOG ((LOG_WARN,
"Can't write lastlog entry for UID %lu in %s.",
(unsigned long) pw->pw_uid, LASTLOG_FILE));
(void) close (fd);
}
}