Relevant BUGIDs: 127625

Purpose of commit: documentation

Commit summary:
---------------
added a note to this man page explaining that we do support a
default directory for modules. Also added some text describing
the alternative control syntax for pam configuration files.

1 files changed, 106 insertions, 16 deletions

diff --git a/doc/man/pam.8 b/doc/man/pam.8
index 68280737..939a0fe9 100644
--- a/doc/man/pam.8
+++ b/doc/man/pam.8
@@ -1,7 +1,7 @@
 .\" Hey Emacs! This file is -*- nroff -*- source.
 .\" $Id$
-.\" Copyright (c) Andrew G. Morgan 1996-7 <morgan@linux.kernel.org>
-.TH PAM 8 "1997 Feb 9" "Linux-PAM 0.56" "Linux-PAM Manual"
+.\" Copyright (c) Andrew G. Morgan 1996-7,2001 <morgan@kernel.org>
+.TH PAM 8 "2001 Jan 20" "Linux-PAM 0.74" "Linux-PAM Manual"
 .SH NAME
 
 Linux-PAM \- Pluggable Authentication Modules for Linux
@@ -197,7 +197,14 @@ The meaning of each of these tokens was explained above.
 The third field,
 .BR control ", "
 indicates the behavior of the PAM-API should the module fail to
-succeed in its authentication task. Valid
+succeed in its authentication task. There are two types of syntax for
+this control field: the simple one has a single simple keyword; the
+more complicated one involves a square-bracketed selection of
+.B value=action
+pairs.
+
+.sp
+For the simple (historical) syntax valid
 .BR control
 values are:
 .BR requisite
@@ -224,8 +231,97 @@ only module in the stack associated with this
 .BR service "+" type "."
 
 .sp
+For the more complicated syntax valid
+.B control
+values have the following form:
+.sp
+.RB  [value1=action1 value2=action2 ...]
+.sp
+Where
+.B valueN
+corresponds to the return code from the function invoked in the module
+for which the line is defined. It is selected from one of these:
+.BR success ;
+.BR open_err ;
+.BR symbol_err ;
+.BR service_err ;
+.BR system_err ;
+.BR buf_err ;
+.BR perm_denied ;
+.BR auth_err ;
+.BR cred_insufficient ;
+.BR authinfo_unavail ;
+.BR user_unknown ;
+.BR maxtries ;
+.BR new_authtok_reqd ;
+.BR acct_expired ;
+.BR session_err ;
+.BR cred_unavail ;
+.BR cred_expired ;
+.BR cred_err ;
+.BR no_module_data ;
+.BR conv_err ;
+.BR authtok_err ;
+.BR authtok_recover_err ;
+.BR authtok_lock_busy ;
+.BR authtok_disable_aging ;
+.BR try_again ;
+.BR ignore ;
+.BR abort ;
+.BR authtok_expired ;
+.BR module_unknown ;
+.BR bad_item "; and"
+.BR default .
+The last of these,
+.BR default ,
+implies 'all
+.BR valueN 's
+not mentioned explicitly. Note, the full list of PAM errors is
+available in /usr/include/security/_pam_types.h . The
+.B actionN
+can be: an unsigned integer, 
+.BR J ,
+signifying an action of 'jump over the next J modules in the stack';
+or take one of the following forms:
+.br
+.B ignore
+- when used with a stack of modules, the module's return status will
+not contribute to the return code the application obtains;
+.br
+.B bad 
+- this action indicates that the return code should be thought of as
+indicative of the module failing. If this module is the first in the
+stack to fail, its status value will be used for that of the whole
+stack.
+.br
+.B die
+- equivalent to bad with the side effect of terminating the module
+stack and PAM immediately returning to the application.
+.br
+.B ok
+- this tells PAM that the administrator thinks this return code
+should contribute directly to the return code of the full stack of
+modules. In other words, if the former state of the stack would lead
+to a return of
+.BR PAM_SUCCESS ,
+the module's return code will override this value. Note, if the former
+state of the stack holds some value that is indicative of a modules
+failure, this 'ok' value will not be used to override that value.
+.br
+.B done
+- equivalent to ok with the side effect of terminating the module
+stack and PAM immediately returning to the application.
+.br
+.B reset
+- clear all memory of the state of the module stack and start again
+with the next stacked module.
+
+.sp
 .BR module-path
-- this is the full filename of the PAM to be used by the application
+- this is either the full filename of the PAM to be used by the
+application (it begins with a '/'), or a relative pathname from the
+default module location:
+.BR /lib/security/ .
 
 .sp
 .BR module-arguments
@@ -238,19 +334,13 @@ documented for each individual module.
 .br
 .BR /etc/pam.d/ " - the"
 .BR Linux-PAM
-configuration directory. If this directory is present, the
+configuration directory. Generally, if this directory is present, the
 .B /etc/pam.conf
 file is ignored.
 .br
-.BR /usr/lib/libpam.so.X " - the dynamic library"
+.BR /lib/libpam.so.X " - the dynamic library"
 .br
-.BR /usr/lib/security/*.so " - the PAMs
-
-.sp
-Note, to conform to the Linux File-system standard, the libraries and
-modules in your system may be located in
-.BR /lib " and " /lib/security 
-respectively.
+.BR /lib/security/*.so " - the PAMs
 
 .SH ERRORS
 Typically errors generated by the
@@ -261,8 +351,8 @@ system of libraries, will be written to
 .SH "CONFORMING TO"
 DCE-RFC 86.0, October 1995.
 .br
-Contains additional features, currently under consideration by the
-DCE-RFC committee.
+Contains additional features, but remains backwardly compatible with
+this RFC.
 
 .SH BUGS
 .sp 2
@@ -273,7 +363,7 @@ None known.
 The three
 .BR Linux-PAM
 Guides, for
-.BR "System administrators" ", "
+.BR "system administrators" ", "
 .BR "module developers" ", "
 and
 .BR "application developers" ". "