faillog(8) [linux man page]
FAILLOG(8) System Management Commands FAILLOG(8) NAME
faillog - display faillog records or set login failure limits SYNOPSIS
faillog [options] DESCRIPTION
faillog displays the contents of the failure log database (/var/log/faillog). It can also set the failure counters and limits. When faillog is run without arguments, it only displays the faillog records of the users who had a login failure. OPTIONS
The options which apply to the faillog command are: -a, --all Display (or act on) faillog records for all users having an entry in the faillog database. The range of users can be restricted with the -u option. In display mode, this is still restricted to existing users but forces the display of the faillog entries even if they are empty. With the -l, -m, -r, -t options, the users' records are changed, even if the user does not exist on the system. This is useful to reset records of users that have been deleted or to set a policy in advance for a range of users. -h, --help Display help message and exit. -l, --lock-secs SEC Lock account for SEC seconds after failed login. Write access to /var/log/faillog is required for this option. -m, --maximum MAX Set the maximum number of login failures after the account is disabled to MAX. Selecting a MAX value of 0 has the effect of not placing a limit on the number of failed logins. The maximum failure count should always be 0 for root to prevent a denial of services attack against the system. Write access to /var/log/faillog is required for this option. -r, --reset Reset the counters of login failures. Write access to /var/log/faillog is required for this option. -t, --time DAYS Display faillog records more recent than DAYS. -u, --user LOGIN|RANGE Display faillog record or maintains failure counters and limits (if used with -l, -m or -r options) only for the specified user(s). The users can be specified by a login name, a numerical user ID, or a RANGE of users. This RANGE of users can be specified with a min and max values (UID_MIN-UID_MAX), a max value (-UID_MAX), or a min value (UID_MIN-). When none of the -l, -m, or -r options are used, faillog displays the faillog record of the specified user(s). CAVEATS
faillog only prints out users with no successful login since the last failure. To print out a user who has had a successful login since their last failure, you must explicitly request the user with the -u flag, or print out all users with the -a flag. FILES
/var/log/faillog Failure logging file. SEE ALSO
login(1), faillog(5). System Management Commands 06/24/2011 FAILLOG(8)
Check Out this Related Man Page
PAM_TALLY(8) Linux-PAM Manual PAM_TALLY(8) NAME
pam_tally - The login counter (tallying) module SYNOPSIS
pam_tally.so [file=/path/to/counter] [onerr=[fail|succeed]] [magic_root] [even_deny_root_account] [deny=n] [lock_time=n] [unlock_time=n] [per_user] [no_lock_time] [no_reset] [audit] [silent] [no_log_info] pam_tally [--file /path/to/counter] [--user username] [--reset[=n]] [--quiet] DESCRIPTION
This module maintains a count of attempted accesses, can reset count on success, can deny access if too many attempts fail. pam_tally has several limitations, which are solved with pam_tally2. For this reason pam_tally is deprecated and will be removed in a future release. pam_tally comes in two parts: pam_tally.so and pam_tally. The former is the PAM module and the latter, a stand-alone program. pam_tally is an (optional) application which can be used to interrogate and manipulate the counter file. It can display users' counts, set individual counts, or clear all counts. Setting artificially high counts may be useful for blocking users without changing their passwords. For example, one might find it useful to clear all counts every midnight from a cron job. The faillog(8) command can be used instead of pam_tally to to maintain the counter file. Normally, failed attempts to access root will not cause the root account to become blocked, to prevent denial-of-service: if your users aren't given shell accounts and root may only login via su or at the machine console (not telnet/rsh, etc), this is safe. OPTIONS
GLOBAL OPTIONS This can be used for auth and account module types. onerr=[fail|succeed] If something weird happens (like unable to open the file), return with PAM_SUCCESS if onerr=succeed is given, else with the corresponding PAM error code. file=/path/to/counter File where to keep counts. Default is /var/log/faillog. audit Will log the user name into the system log if the user is not found. silent Don't print informative messages. no_log_info Don't log informative messages via syslog(3). AUTH OPTIONS Authentication phase first checks if user should be denied access and if not it increments attempted login counter. Then on call to pam_setcred(3) it resets the attempts counter. deny=n Deny access if tally for this user exceeds n. lock_time=n Always deny for n seconds after failed attempt. unlock_time=n Allow access after n seconds after failed attempt. If this option is used the user will be locked out for the specified amount of time after he exceeded his maximum allowed attempts. Otherwise the account is locked until the lock is removed by a manual intervention of the system administrator. magic_root If the module is invoked by a user with uid=0 the counter is not incremented. The sysadmin should use this for user launched services, like su, otherwise this argument should be omitted. no_lock_time Do not use the .fail_locktime field in /var/log/faillog for this user. no_reset Don't reset count on successful entry, only decrement. even_deny_root_account Root account can become unavailable. per_user If /var/log/faillog contains a non-zero .fail_max/.fail_locktime field for this user then use it instead of deny=n/ lock_time=n parameter. no_lock_time Don't use .fail_locktime filed in /var/log/faillog for this user. ACCOUNT OPTIONS Account phase resets attempts counter if the user is not magic root. This phase can be used optionally for services which don't call pam_setcred(3) correctly or if the reset should be done regardless of the failure of the account phase of other modules. magic_root If the module is invoked by a user with uid=0 the counter is not incremented. The sysadmin should use this for user launched services, like su, otherwise this argument should be omitted. no_reset Don't reset count on successful entry, only decrement. MODULE TYPES PROVIDED
The auth and account module types are provided. RETURN VALUES
PAM_AUTH_ERR A invalid option was given, the module was not able to retrieve the user name, no valid counter file was found, or too many failed logins. PAM_SUCCESS Everything was successful. PAM_USER_UNKNOWN User not known. EXAMPLES
Add the following line to /etc/pam.d/login to lock the account after too many failed logins. The number of allowed fails is specified by /var/log/faillog and needs to be set with pam_tally or faillog(8) before. auth required pam_securetty.so auth required pam_tally.so per_user auth required pam_env.so auth required pam_unix.so auth required pam_nologin.so account required pam_unix.so password required pam_unix.so session required pam_limits.so session required pam_unix.so session required pam_lastlog.so nowtmp session optional pam_mail.so standard FILES
/var/log/faillog failure logging file SEE ALSO
faillog(8), pam.conf(5), pam.d(5), pam(7) AUTHOR
pam_tally was written by Tim Baverstock and Tomas Mraz. Linux-PAM Manual 06/04/2011 PAM_TALLY(8)