Manual Pages  — PAM.CONF

facility control-flag module-path [arguments ...]
facility include other-service-name

In both cases, blank lines and comments introduced by a ‘#’ sign are ignored, and the normal shell quoting rules apply. The precise details of how the file is tokenized are described in openpam_readword(3).

The facility field specifies the facility the entry applies to, and is one of:

auth	Authentication functions ( pam_authenticate(3), pam_setcred(3) )
account
	Account management functions (pam_acct_mgmt(3))
session
	Session handling functions ( pam_open_session(3), pam_close_session(3) )
password
	Password management functions (pam_chauthtok(3))

The control-flag field determines how the result returned by the module affects the flow of control through (and the final result of) the rest of the chain, and is one of:

required
	If this module succeeds, the result of the chain will be success unless a later module fails. If it fails, the rest of the chain still runs, but the final result will be failure regardless of the success of later modules.
requisite
	If this module succeeds, the result of the chain will be success unless a later module fails. If the module fails, the chain is broken and the result is failure.
sufficient
	If this module succeeds, the chain is broken and the result is success. If it fails, the rest of the chain still runs, but the final result will be failure unless a later module succeeds.
binding
	If this module succeeds, the chain is broken and the result is success. If it fails, the rest of the chain still runs, but the final result will be failure regardless of the success of later modules.
optional
	If this module succeeds, the result of the chain will be success unless a later module fails. If this module fails, the result of the chain will be failure unless a later module succeeds.

There are two exceptions to the above: sufficient and binding modules are treated as optional by pam_setcred(3), and in the PAM_PRELIM_CHECK phase of pam_chauthtok(3).

The module-path field specifies the name or full path of the module to call. If only the name is specified, the PAM library will search for it in the following locations:

1. /usr/lib
2. /usr/local/lib

The remaining fields, if any, are passed unmodified to the module if and when it is invoked.

The include form of entry causes entries from a different chain (specified by other-system-name) to be included in the current one. This allows one to define system-wide policies which are then included into service-specific policies. The system-wide policy can then be modified without having to also modify each and every service-specific policy.

Take care not to introduce loops when using include rules, as there is currently no loop detection in place.