271 lines
6.8 KiB
C
271 lines
6.8 KiB
C
/*
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* Copyright 1989 - 1994, Julianne Frances Haugh
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Julianne F. Haugh nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <config.h>
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#include "rcsid.h"
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RCSID ("$Id: failure.c,v 1.9 2003/04/25 21:11:08 kloczek Exp $")
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#include <fcntl.h>
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#include <stdio.h>
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#include "defines.h"
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#include "faillog.h"
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#include "getdef.h"
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#include "failure.h"
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#define YEAR (365L*DAY)
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/*
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* failure - make failure entry
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*
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* failure() creates a new (struct faillog) entry or updates an
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* existing one with the current failed login information.
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*/
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void failure (uid_t uid, const char *tty, struct faillog *fl)
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{
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int fd;
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/*
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* Don't do anything if failure logging isn't set up.
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*/
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if ((fd = open (FAILLOG_FILE, O_RDWR)) < 0)
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return;
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/*
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* The file is indexed by uid value meaning that shared UID's
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* share failure log records. That's OK since they really
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* share just about everything else ...
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*/
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lseek (fd, (off_t) (sizeof *fl) * uid, SEEK_SET);
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if (read (fd, (char *) fl, sizeof *fl) != sizeof *fl)
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memzero (fl, sizeof *fl);
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/*
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* Update the record. We increment the failure count to log the
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* latest failure. The only concern here is overflow, and we'll
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* check for that. The line name and time of day are both
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* updated as well.
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*/
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if (fl->fail_cnt + 1 > 0)
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fl->fail_cnt++;
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strncpy (fl->fail_line, tty, sizeof fl->fail_line);
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time (&fl->fail_time);
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/*
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* Seek back to the correct position in the file and write the
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* record out. Ideally we should lock the file in case the same
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* account is being logged simultaneously. But the risk doesn't
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* seem that great.
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*/
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lseek (fd, (off_t) (sizeof *fl) * uid, SEEK_SET);
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write (fd, (char *) fl, sizeof *fl);
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close (fd);
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}
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static int too_many_failures (const struct faillog *fl)
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{
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time_t now;
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if (fl->fail_max == 0 || fl->fail_cnt < fl->fail_max)
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return 0;
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if (fl->fail_locktime == 0)
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return 1; /* locked until reset manually */
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time (&now);
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if (fl->fail_time + fl->fail_locktime < now)
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return 0; /* enough time since last failure */
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return 1;
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}
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/*
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* failcheck - check for failures > allowable
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*
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* failcheck() is called AFTER the password has been validated. If the
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* account has been "attacked" with too many login failures, failcheck()
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* returns FALSE to indicate that the login should be denied even though
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* the password is valid.
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*/
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int failcheck (uid_t uid, struct faillog *fl, int failed)
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{
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int fd;
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struct faillog fail;
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/*
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* Suppress the check if the log file isn't there.
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*/
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if ((fd = open (FAILLOG_FILE, O_RDWR)) < 0)
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return 1;
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/*
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* Get the record from the file and determine if the user has
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* exceeded the failure limit. If "max" is zero, any number
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* of failures are permitted. Only when "max" is non-zero and
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* "cnt" is greater than or equal to "max" is the account
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* considered to be locked.
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*
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* If read fails, there is no record for this user yet (the
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* file is initially zero length and extended by writes), so
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* no need to reset the count.
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*/
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lseek (fd, (off_t) (sizeof *fl) * uid, SEEK_SET);
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if (read (fd, (char *) fl, sizeof *fl) != sizeof *fl) {
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close (fd);
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return 1;
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}
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if (too_many_failures (fl)) {
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close (fd);
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return 0;
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}
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/*
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* The record is updated if this is not a failure. The count will
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* be reset to zero, but the rest of the information will be left
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* in the record in case someone wants to see where the failed
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* login originated.
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*/
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if (!failed) {
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fail = *fl;
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fail.fail_cnt = 0;
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lseek (fd, (off_t) sizeof fail * uid, SEEK_SET);
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write (fd, (char *) &fail, sizeof fail);
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}
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close (fd);
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return 1;
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}
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/*
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* failprint - print line of failure information
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*
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* failprint takes a (struct faillog) entry and formats it into a
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* message which is displayed at login time.
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*/
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void failprint (const struct faillog *fail)
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{
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struct tm *tp;
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#if HAVE_STRFTIME
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char lasttimeb[256];
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char *lasttime = lasttimeb;
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const char *fmt;
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#else
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char *lasttime;
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#endif
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time_t NOW;
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if (fail->fail_cnt == 0)
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return;
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tp = localtime (&(fail->fail_time));
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time (&NOW);
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#if HAVE_STRFTIME
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/*
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* Only print as much date and time info as it needed to
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* know when the failure was.
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*/
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if (NOW - fail->fail_time >= YEAR)
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fmt = "%Y";
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else if (NOW - fail->fail_time >= DAY)
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fmt = "%A %T";
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else
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fmt = "%T";
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strftime (lasttimeb, sizeof lasttimeb, fmt, tp);
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#else
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/*
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* Do the same thing, but don't use strftime since it
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* probably doesn't exist on this system
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*/
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lasttime = asctime (tp);
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lasttime[24] = '\0';
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if (NOW - fail->fail_time < YEAR)
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lasttime[19] = '\0';
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if (NOW - fail->fail_time < DAY)
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lasttime = lasttime + 11;
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if (*lasttime == ' ')
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lasttime++;
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#endif
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printf (_("%d %s since last login. Last was %s on %s.\n"),
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fail->fail_cnt,
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fail->fail_cnt > 1 ? _("failures") : _("failure"),
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lasttime, fail->fail_line);
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}
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/*
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* failtmp - update the cummulative failure log
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*
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* failtmp updates the (struct utmp) formatted failure log which
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* maintains a record of all login failures.
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*/
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void failtmp (const struct utmp *failent)
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{
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char *ftmp;
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int fd;
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/*
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* Get the name of the failure file. If no file has been defined
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* in login.defs, don't do this.
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*/
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if (!(ftmp = getdef_str ("FTMP_FILE")))
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return;
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/*
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* Open the file for append. It must already exist for this
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* feature to be used.
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*/
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if ((fd = open (ftmp, O_WRONLY | O_APPEND)) == -1)
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return;
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/*
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* Output the new failure record and close the log file.
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*/
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write (fd, (const char *) failent, sizeof *failent);
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close (fd);
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}
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