FreeBSD Man Pages

login.conf(5)

NAME

     login.conf -- login class capability database

SYNOPSIS

     /etc/login.conf, ~/.login_conf

DESCRIPTION

     login.conf contains various attributes and capabilities of login classes.
     A login class (an optional annotation against each record in the user
     account database, /etc/master.passwd) determines session accounting,
     resource limits and user environment settings.  It is used by various
     programs in the system to set up a user's login environment and to
     enforce policy, accounting and administrative restrictions.  It also pro-
     vides the means by which users are able to be authenticated to the system
     and the types of authentication available.  Attributes in addition to the
     ones described here are available with third-party packages.

     A special record "default" in the system user class capability database
     /etc/login.conf is used automatically for any non-root user without a
     valid login class in /etc/master.passwd.  A user with a uid of 0 without
     a valid login class will use the record "root" if it exists, or "default"
     if not.

     In FreeBSD, users may individually create a file called .login_conf in
     their home directory using the same format, consisting of a single entry
     with a record id of "me".	If present, this file is used by login(1) to
     set user-defined environment settings which override those specified in
     the system login capabilities database.  Only a subset of login capabili-
     ties may be overridden, typically those which do not involve authentica-
     tion, resource limits and accounting.

     Records in a class capabilities database consist of a number of colon-
     separated fields.	The first entry for each record gives one or more
     names that a record is to be known by, each separated by a '|' character.
     The first name is the most common abbreviation.  The last name given
     should be a long name that is more descriptive of the capability entry,
     and all others are synonyms.  All names but the last should be in lower
     case and contain no blanks; the last name may contain upper case charac-
     ters and blanks for readability.

     See getcap(3) for a more in-depth description of the format of a capabil-
     ity database.

CAPABILITIES

     Fields within each record in the database follow the getcap(3) conven-
     tions for boolean, type string `=' and type numeric `#', although type
     numeric is deprecated in favour of the string format and either form is
     accepted for a numeric datum.  Values fall into the following categories:

     bool     If the name is present, then the boolean value is true; other-
	      wise, it is false

     file     Path name to a data file

     program  Path name to an executable file

     list     A list of values (or pairs of values) separated by commas or
	      only one numeric value is allowed.  Numeric types may also be
	      specified in string format (i.e., the capability tag being
	      delimited from the value by '=' instead of '#').	Whichever
	      method is used, then all records in the database must use the
	      same method to allow values to be correctly overridden in inter-
	      polated records.

     size     A number which expresses a size.	The default interpretation of
	      a value is the number of bytes, but a suffix may specify alter-
	      nate units:
		    b	  explicitly selects 512-byte blocks
		    k	  selects kilobytes (1024 bytes)
		    m	  specifies a multiplier of 1 megabyte (1048576
			  bytes),
		    g	  specifies units of gigabytes, and
		    t	  represents terabytes.
	      A size value is a numeric quantity and case of the suffix is not
	      significant.  Concatenated values are added together.

     time     A period of time, by default in seconds.	A prefix may specify a
	      different unit:
		    y	  indicates the number of 365 day years,
		    w	  indicates the number of weeks,
		    d	  the number of days,
		    h	  the number of hours,
		    m	  the number of minutes, and
		    s	  the number of seconds.
	      Concatenated values are added together.  For example, 2 hours
	      and 40 minutes may be written either as 9600s, 160m or 2h40m.

     The usual convention to interpolate capability entries using the special
     tc=value notation may be used.

RESOURCE LIMITS

     Name	     Type      Notes	 Description
     coredumpsize    size		 Maximum coredump size limit.
     cputime	     time		 CPU usage limit.
     datasize	     size		 Maximum data size limit.
     filesize	     size		 Maximum file size limit.
     maxproc	     number		 Maximum number of processes.
     memorylocked    size		 Maximum locked in core memory size
					 limit.
     memoryuse	     size		 Maximum of core memory use size
					 limit.
     openfiles	     number		 Maximum number of open files per
					 process.
     sbsize	     size		 Maximum permitted socketbuffer size.
     vmemoryuse      size		 Maximum permitted total VM usage per
					 process.
     stacksize	     size		 Maximum stack size limit.

     These resource limit entries actually specify both the maximum and cur-
     rent limits (see getrlimit(2)).  The current (soft) limit is the one nor-
     mally used, although the user is permitted to increase the current limit
     to the maximum (hard) limit.  The maximum and current limits may be spec-
     ified individually by appending a -max or -cur to the capability name.

ENVIRONMENT

     ftp-chroot       bool	false		 Limit FTP access with
						 chroot(2) to the HOME direc-
						 tory of the user.  See
						 ftpd(8) for details.
     label	      string			 Default MAC policy; see
						 maclabel(7).
     lang	      string			 Set $LANG environment
						 variable to the specified
						 value.
     manpath	      path			 Default search path for
						 manpages.
     nocheckmail      bool	false		 Display mail status at login.
     nologin	      file			 If the file exists it will be
						 displayed and the login ses-
						 sion will be terminated.
     path	      path	/bin /usr/bin	 Default search path.
     priority	      number			 Initial priority (nice)
						 level.
     requirehome      bool	false		 Require a valid home
						 directory to login.
     setenv	      list			 A comma-separated list of
						 environment variables and
						 values to which they are to
						 be set.
     shell	      prog			 Session shell to execute
						 rather than the shell speci-
						 fied in the passwd file.  The
						 SHELL environment variable
						 will contain the shell speci-
						 fied in the password file.
     term	      string			 Default terminal type if not
						 able to determine from other
						 means.
     timezone	      string			 Default value of $TZ
						 environment variable.
     umask	      number	022		 Initial umask. Should always
						 have a leading 0 to ensure
						 octal interpretation.
     welcome	      file	/etc/motd	 File containing welcome
						 message.

AUTHENTICATION

     Name	      Type	Notes	  Description
     copyright	      file		  File containing additional copyright
					  information
     host.allow       list		  List of remote host wildcards from
					  which users in the class may access.
     host.deny	      list		  List of remote host wildcards from
					  which users in the class may not
					  access.
     login_prompt     string		  The login prompt given by login(1)
     login-backoff    number	3	  The number of login attempts allowed
					  before the backoff delay is inserted
					  after each subsequent attempt.
     login-retries    number	10	  The number of login attempts allowed
					  before the login fails.
     passwd_format    string	md5	  The encryption format that new or
					  changed passwords will use.  Valid

     times.deny       list		  List of time periods during which
					  logins are disallowed.
     ttys.allow       list		  List of ttys and ttygroups which
					  users in the class may use for
					  access.
     ttys.deny	      list		  List of ttys and ttygroups which
					  users in the class may not use for
					  access.
     warnexpire       time		  Advance notice for pending account
					  expiry.
     warnpassword     time		  Advance notice for pending password
					  expiry.

     These fields are intended to be used by passwd(1) and other programs in
     the login authentication system.

     Capabilities that set environment variables are scanned for both `~' and
     `$' characters, which are substituted for a user's home directory and
     name respectively.  To pass these characters literally into the environ-
     ment variable, escape the character by preceding it with a backslash '\'.

     The host.allow and host.deny entries are comma separated lists used for
     checking remote access to the system, and consist of a list of hostnames
     and/or IP addresses against which remote network logins are checked.
     Items in these lists may contain wildcards in the form used by shell pro-
     grams for wildcard matching (See fnmatch(3) for details on the implemen-
     tation).  The check on hosts is made against both the remote system's
     Internet address and hostname (if available).  If both lists are empty or
     not specified, then logins from any remote host are allowed.  If
     host.allow contains one or more hosts, then only remote systems matching
     any of the items in that list are allowed to log in.  If host.deny con-
     tains one or more hosts, then a login from any matching hosts will be
     disallowed.

     The times.allow and times.deny entries consist of a comma-separated list
     of time periods during which the users in a class are allowed to be
     logged in.  These are expressed as one or more day codes followed by a
     start and end times expressed in 24 hour format, separated by a hyphen or
     dash.  For example, MoThSa0200-1300 translates to Monday, Thursday and
     Saturday between the hours of 2 am and 1 p.m..  If both of these time
     lists are empty, users in the class are allowed access at any time.  If
     times.allow is specified, then logins are only allowed during the periods
     given.  If times.deny is specified, then logins are denied during the
     periods given, regardless of whether one of the periods specified in
     times.allow applies.

     Note that login(1) enforces only that the actual login falls within peri-
     ods allowed by these entries.  Further enforcement over the life of a
     session requires a separate daemon to monitor transitions from an allowed
     period to a non-allowed one.

     The ttys.allow and ttys.deny entries contain a comma-separated list of
     tty devices (without the /dev/ prefix) that a user in a class may use to
     access the system, and/or a list of ttygroups (See getttyent(3) and
     ttys(5) for information on ttygroups).  If neither entry exists, then the
     choice of login device used by the user is unrestricted.  If only
     ttys.allow is specified, then the user is restricted only to ttys in the
     given group or device list.  If only ttys.deny is specified, then the

RESERVED CAPABILITIES

     The following capabilities are reserved for the purposes indicated and
     may be supported by third-party software.	They are not implemented in
     the base system.

     Name	       Type	 Notes	   Description
     accounted	       bool	 false	   Enable session time accounting for
					   all users in this class.
     autodelete        time		   Time after expiry when account is
					   auto-deleted.
     bootfull	       bool	 false	   Enable 'boot only if ttygroup is
					   full' strategy when terminating
					   sessions.
     daytime	       time		   Maximum login time per day.
     expireperiod      time		   Time for expiry allocation.
     graceexpire       time		   Grace days for expired account.
     gracetime	       time		   Additional grace login time
					   allowed.
     host.accounted    list		   List of remote host wildcards from
					   which login sessions will be
					   accounted.
     host.exempt       list		   List of remote host wildcards from
					   which login session accounting is
					   exempted.
     idletime	       time		   Maximum idle time before logout.
     minpasswordlen    number	 6	   The minimum length a local password
					   may be.
     mixpasswordcase   bool	 true	   Whether passwd(1) will warn the
					   user if an all lower case password
					   is entered.
     monthtime	       time		   Maximum login time per month.
     passwordtime      time		   Used by passwd(1) to set next pass-
					   word expiry date.
     refreshtime       time		   New time allowed on account
					   refresh.
     refreshperiod     str		   How often account time is
					   refreshed.
     sessiontime       time		   Maximum login time per session.
     sessionlimit      number		   Maximum number of concurrent login
					   sessions on ttys in any group.
     ttys.accounted    list		   List of ttys and ttygroups for
					   which login accounting is active.
     ttys.exempt       list		   List of ttys and ttygroups for
					   which login accounting is exempt.
     warntime	       time		   Advance notice for pending out-of-
					   time.
     weektime	       time		   Maximum login time per week.

     The ttys.accounted and ttys.exempt fields operate in a similar manner to
     ttys.allow and ttys.deny as explained above.  Similarly with the
     host.accounted and host.exempt lists.

SEE ALSO

     cap_mkdb(1), login(1), chroot(2), getcap(3), getttyent(3), login_cap(3),
     login_class(3), pam(3), passwd(5), ttys(5), ftpd(8), pam_passwdqc(8)

FreeBSD 5.4			August 6, 2004			   FreeBSD 5.4

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