bddcd9b095
- Every non-const pointer converts automatically to void *. - Every pointer converts automatically to void *. - void * converts to any other pointer. - const void * converts to any other const pointer. - Integer variables convert to each other. I changed the declaration of a few variables in order to allow removing a cast. However, I didn't attempt to edit casts inside comparisons, since they are very delicate. I also kept casts in variadic functions, since they are necessary, and in allocation functions, because I have other plans for them. I also changed a few casts to int that are better as ptrdiff_t. This change has triggered some warnings about const correctness issues, which have also been fixed in this patch (see for example src/login.c). Signed-off-by: Alejandro Colomar <alx@kernel.org>
290 lines
6.9 KiB
C
290 lines
6.9 KiB
C
/*
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* SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
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* SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
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* SPDX-FileCopyrightText: 2002 - 2005, Tomasz Kłoczko
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* SPDX-FileCopyrightText: 2008 - 2010, Nicolas François
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <config.h>
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#ident "$Id$"
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#include <fcntl.h>
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#include <stdio.h>
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#include <unistd.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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off_t offset_uid = (off_t) (sizeof *fl) * uid;
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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 (access (FAILLOG_FILE, F_OK) != 0) {
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return;
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}
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fd = open (FAILLOG_FILE, O_RDWR);
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if (fd < 0) {
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SYSLOG ((LOG_WARN,
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"Can't write faillog entry for UID %lu in %s.",
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(unsigned long) uid, FAILLOG_FILE));
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return;
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}
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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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if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
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|| (read (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
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/* This is not necessarily a failure. The file is
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* initially zero length.
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*
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* If lseek() or read() failed for any other reason, this
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* might reset the counter. But the new failure will be
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* logged.
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*/
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memzero (fl, sizeof *fl);
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}
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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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}
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strncpy (fl->fail_line, tty, sizeof (fl->fail_line) - 1);
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(void) 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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if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
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|| (write (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)
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|| (close (fd) != 0)) {
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SYSLOG ((LOG_WARN,
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"Can't write faillog entry for UID %lu in %s.",
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(unsigned long) uid, FAILLOG_FILE));
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(void) close (fd);
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}
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}
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static bool too_many_failures (const struct faillog *fl)
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{
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time_t now;
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if ((0 == fl->fail_max) || (fl->fail_cnt < fl->fail_max)) {
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return false;
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}
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if (0 == fl->fail_locktime) {
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return true; /* locked until reset manually */
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}
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(void) time (&now);
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if ((fl->fail_time + fl->fail_locktime) < now) {
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return false; /* enough time since last failure */
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}
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return true;
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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 0 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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* failed indicates if the login failed AFTER the password has been
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* validated.
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*/
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int failcheck (uid_t uid, struct faillog *fl, bool failed)
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{
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int fd;
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struct faillog fail;
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off_t offset_uid = (off_t) (sizeof *fl) * uid;
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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 (access (FAILLOG_FILE, F_OK) != 0) {
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return 1;
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}
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fd = open (FAILLOG_FILE, failed?O_RDONLY:O_RDWR);
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if (fd < 0) {
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SYSLOG ((LOG_WARN,
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"Can't open the faillog file (%s) to check UID %lu. "
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"User access authorized.",
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FAILLOG_FILE, (unsigned long) uid));
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return 1;
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}
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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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if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
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|| (read (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
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(void) 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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(void) 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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if ( (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
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|| (write (fd, &fail, sizeof fail) != (ssize_t) sizeof fail)
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|| (close (fd) != 0)) {
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SYSLOG ((LOG_WARN,
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"Can't reset faillog entry for UID %lu in %s.",
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(unsigned long) uid, FAILLOG_FILE));
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(void) close (fd);
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}
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} else {
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(void) close (fd);
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}
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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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char lasttimeb[256];
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char *lasttime = lasttimeb;
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time_t NOW;
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if (0 == fail->fail_cnt) {
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return;
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}
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tp = localtime (&(fail->fail_time));
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(void) time (&NOW);
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/*
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* Print all information we have.
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*/
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(void) strftime (lasttimeb, sizeof lasttimeb, "%c", tp);
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/*@-formatconst@*/
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(void) printf (ngettext ("%d failure since last login.\n"
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"Last was %s on %s.\n",
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"%d failures since last login.\n"
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"Last was %s on %s.\n",
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(unsigned long) fail->fail_cnt),
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fail->fail_cnt, lasttime, fail->fail_line);
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/*@=formatconst@*/
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}
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/*
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* failtmp - update the cumulative 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 char *username, const struct utmp *failent)
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{
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const 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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ftmp = getdef_str ("FTMP_FILE");
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if (NULL == ftmp) {
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return;
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}
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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 (access (ftmp, F_OK) != 0) {
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return;
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}
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fd = open (ftmp, O_WRONLY | O_APPEND);
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if (-1 == fd) {
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SYSLOG ((LOG_WARN,
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"Can't append failure of user %s to %s.",
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username, ftmp));
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return;
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}
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/*
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* Append the new failure record and close the log file.
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*/
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if ( (write (fd, failent, sizeof *failent) != (ssize_t) sizeof *failent)
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|| (close (fd) != 0)) {
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SYSLOG ((LOG_WARN,
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"Can't append failure of user %s to %s.",
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username, ftmp));
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(void) close (fd);
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}
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}
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