1xpaacl(n)                     SAORD Documentation                    xpaacl(n)


6       XPAAcl: Access Control for XPA Messaging


9       XPA supports host-based access control for each XPA access point.  You
10       can enable/disable access control using the XPA_ACL environment
11       variable. You can specify access to specific XPA access points for
12       specific machines using the XPA_DEFACL and XPA_ACLFILE environment
13       variables. By default, an XPA access point is accessible only to
14       processes running on the same machine (same as X Windows).


17       When INET sockets are in use (the default, as specified by the
18       XPA_METHOD environment variable), XPA supports a host-based access
19       control mechanism for individual access points. This mean that access
20       can be specified for get, set, or info operations for each access point
21       on a machine by machine basis.  For LOCAL sockets, access is restricted
22       (by definition) to the host machine.
24       XPA access control is enabled by default, but can be turned off by
25       setting the XPA_ACL environment variable to false.  In this case, any
26       process can access any XPA server.
28       Assuming that access control is turned on, the ACL for an individual
29       XPA access point is set up when that access point is registered
30       (although it can be changed later on; see below). This can be done in
31       one of two ways:
33       Firstly, the XPA_ACLFILE environment variable can defined to point to a
34       file of access controls for individual access points. The format of
35       this file is:
37        class:name ip acl
39       The first argument is a template that specifies the class:name of the
40       access point covered by this ACL. See XPA Access Points and Templates
41       for more information about xpa templates.
43       The second argument is the IP address (in human-readable format) of the
44       machine which is being given access.  This argument can be * to match
45       all IP addresses.  It also can be $host to match the IP address of the
46       current host.
48       The third argument is a string combination of s, g, or i to allow
49       xpaset, xpaget, or xpainfo access respectively.  The ACL argument can
50       be + to give sgi access or it can be - to turn off all access.
52       For example,
54         *:xpa1  somehost sg
55         *:xpa1  myhost +
56         * * g
58       will allow processes on the machine somehost to make xpaget and xpaset
59       calls, allow processes on myhost to make any call, and allow all other
60       hosts to make xpaget (but not xpaset) calls.
62       Secondly, if the XPA_ACLFILE does not exist, then a single default
63       value for all access points can be specified using the XPA_DEFACL
64       environment variable.  The default value for this variable is:
66         #define XPA_DEFACL "*:* $host +"
68       meaning that all access points are fully accessible to all processes on
69       the current host. Thus, in the absence of any ACL environment
70       variables, processes on the current host have full access to all access
71       points created on that host. This parallels the X11 xhost mechanism.
73       Access to an individual XPA access point can be changed using the -acl
74       parameter for that access point.  For example:
76         xpaset -p xpa1 -acl "somehost -"
78       will turn off all access control for somehost to the xpa1 access point,
79       while:
81         xpaset -p XPA:xpa1 -acl "beberly gs"
83       will give beberly xpaget and xpaset access to the access point whose
84       class is XPA and whose name is xpa1.
86       Similarly, the current ACL for a given access point can be retrieved
87       using:
89         xpaget xpa1 -acl
91       Of course, you must have xpaget access to this XPA access point to
92       retrieve its ACL.
94       Note that the XPA access points registered in the xpans program also
95       behave according to the ACL rules.  That is, you cannot use xpaget to
96       view the access points registered with xpans unless you have the proper
97       ACL.
99       Note also when a client request is made to an XPA server, the access
100       control is checked when the initial connection is established.  This
101       access in effect at this time remains in effect so long as the client
102       connection is maintained, regardless of whether the access fro that XPA
103       is changed later on.
105       We recognize that host-based access control is only relatively secure
106       and will consider more stringent security (e.g., private key) in the
107       future if the community requires such support.


110       See xpa(n) for a list of XPA help pages
114version 2.1.15                   July 23, 2013                       xpaacl(n)