Communications Access Methods for SAS/CONNECT and SAS/SHARE Software

SAS/SHARE

Client Tasks

User and Applications Programmer

To prepare for creating and accessing a SAS/SHARE server, make sure that you know how to:

Configure the server in the client SERVICES file.
Set security.
Specify the TCP/IP access method.
Specify a server name.

Configuring the Server in the SERVICES File

Each server must be defined as a service in the SERVICES file on each host node from which a client session will access the server. This file usually is located in the directory in which the TCP/IP software is installed. See Configuring the SERVICES File for information about editing the SERVICES file.

Setting Security for Connecting Clients

Requiring connecting clients to supply both a valid userid and password enforces server security. At the client, set the preferred security method for relaying a userid and password that are valid on the server host. For details, see Setting Security for SAS/CONNECT and SAS/SHARE.

Specifying the TCP/IP Access Method

You must specify the TCP/IP communications access method at the server before you can create a server.

Use the following syntax to specify the TCP/IP access method at each connecting client:

OPTIONS COMAMID=access-method-id;

where COMAMID is an acronym for Communications Access Method Identification. access-method-id identifies the method used by the client to communicate with the server. TCP (short for TCP/IP, which is an abbreviation for Transmission Control Protocol/Internet Protocol) is an example of an access-method-id.

Example:

options comamid=tcp;

The server is accessed using the TCP/IP access method.

You may specify the COMAMID option in an OPTIONS statement, at a SAS invocation, or in a SAS configuration file.

Additionally, you may use the COMAUX1 and COMAUX2 options to designate auxiliary communications access methods. See SAS/CONNECT and SAS/SHARE: Supported Access Methods According to Host Release for the supported access methods by host. If the first method fails to access a server, the second method is attempted, and so on. You can specify up to two auxiliary access methods, depending on the number of methods that are supported between client and server hosts.

COMAUX options can be specified only at a SAS invocation or in a SAS configuration file. The syntax for the COMAUX options follows:

COMAUX1=alternate-method
COMAUX2=alternate-method

An example of configuration file entries for an OS/390 client connecting to an OS/390 server follows:

comamid=tcp
comaux1=appc

If the server cannot be reached using the TCP/IP access method, a second attempt is made with the APPC access method.

Specifying a Server Name

If the client and server sessions are running on different network nodes, you must include the node in the server identifier in the LIBNAME and PROC OPERATE statements as follows:

SERVER=node.server

This representation is known as a two-level server name.

node must be a valid TCP/IP node name. If the server and the client sessions are running on the same node, you may omit the node name.

server can represent either a server-id or a port number.

server-id must be identical to the service name specified in the SERVICES file. See Configuring the Server in the SERVICES File for more information on specifying the server-id in the SERVICES file.
port is the location for passing data to and receiving data from the server. The port number is specified with two preceding underscore (_) characters. For example, you can specify the server port as 5000 using the SERVER= option in a LIBNAME statement:
```
libname mylib '.' server=srvnode._ _5000;
```

If the TCP/IP node name is not a valid SAS name, assign the name of the server's node to a SAS macro variable, then use the name of the macro variable for node in the two-level server name.

The access method evaluates the node name, in this order of precedence:

acceptable node name
SAS macro variable.

The following example shows the assignment of a SAS macro variable to a server's node name:

%let srvnode=mktserve.acme.com;
libname sales server=srvnode.server1;

Note: Do not use an ampersand (&) in a two-level server name. An ampersand would cause the macro variable to be resolved by the SAS parser prior to syntactic evaluation of the SERVER option. The access method evaluates the node name in a two-level server name. [cautionend]

See SAS Language Reference: Dictionary for details about SAS naming rules. See SAS/SHARE User's Guide for details about the LIBNAME and PROC OPERATE statements.

Client Example

The following example illustrates the statements that you specify in an OS/390 client SAS session to access a server with the TCP/IP access method:

options comamid=tcp;
libname sasdata 'edc.prog2.sasdata' user=_prompt_ server=rmtnode.share1;

The first line declares the TCP/IP access method. The LIBNAME statement specifies the data library that is accessed through the server, which is specified by the two-level server name RMTNODE.SHARE1, by means of a prompt for a username and a password that are valid on the server.

Server Tasks

Server Administrator

Your primary tasks are

Verify that the SAS SVC routine has been installed.
Configure SAS/SHARE servers in the SERVICES file.
Set server security through the TCPSEC option.
Set the AUTHENCR option to enforce userid and password encryption, as necessary.
Specify the TCP/IP access method.
Specify the server name.

Installing the SAS SVC Routine

The SAS SVC control program routine is an interface between the OS/390 operating system and a specific request, such as "third-party checking." This facility provides verification in the form of calls for authentication of userids and passwords and of library authority.

Install the SAS SVC routine, if necessary.
If you have already installed the SAS SVC routine for Release 6.09 of SAS software, do not repeat the step here. If you need to perform the installation, see the Installation Instructions and System Manager's Guide, The SAS System under MVS for details.
Because SAS SVC in Release 6.09 is backward compatible, it replaces the SAS SVC routines from previous releases. You may continue using previous releases of base SAS and SAS/SHARE with the Release 6.09 SAS SVC that is installed on your system.
Verify the SVC routine SAS system options.
Verify that the SAS system options for the SVC routine accurately reflect the way that the SAS SVC is installed. The SAS system option SVC0SVC should be set to the number at which the SAS SVC is installed (for example, 251 or 109). If the SAS SVC is installed at 109 as an ESR SVC, the SAS system option SVC0R15 should be set to the ESR code (for example, 4).
Verify installation on all CPUs, as needed.
If you have more than one CPU, verify that the SAS SVC is installed on the systems that will be running SAS/SHARE at your site.

Configuring the Server in the SERVICES File

Each server must be defined as a service in the TCP/IP SERVICES file on each remote host node on which a server runs and on each node from which a client session will access the server. This file usually is located in the directory in which the TCP/IP software is installed. See Configuring the SERVICES File for more information.

Setting Server Security

You may use file permissions to restrict a user's access to libraries and files through a server. A secured server allows connections only from those clients that provide valid userids and passwords for the host on which the server is running. A secured server uses a validated userid and password to verify a user's authority to access a SAS library or a SAS file.

Requiring connecting clients to supply both a valid userid and a password enforces server security. From a server session, set the TCPSEC option to the value _SECURE_. For information about setting the TCPSEC option, see Providing Client Identification in a pre-Version 8 Session.

Enforcing Server Userid and Password Encryption

As a security measure, you may set the AUTHENCR option to enforce the encryption of userids and passwords when they are passed from the client to the server. For information about the AUTHENCR option, see SAS/SHARE Only Option.

Specifying the TCP/IP Access Method

You must specify the TCP/IP communications access method at the server before a client can access it.

Use the following syntax to specify the TCP/IP access method at the server:

OPTIONS COMAMID=access-method-id;

where COMAMID is an acronym for Communications Access Method Identification. access-method-id identifies the method used by the server to communicate with the client. TCP (short for TCP/IP, which is an abbreviation for Transmission Control Protocol/Internet Protocol) is an example of an access-method-id.

For a server that is running on a host on which only one communications access method is available, use only the COMAMID option.

Example:

options comamid=tcp;

The server will be available only to SAS/SHARE sessions that use the TCP/IP access method. You may specify the COMAMID option in an OPTIONS statement, at a SAS invocation, or in a SAS configuration file.

However, if the host on which a server is running supports multiple access methods, you may specify up to two auxiliary access methods by which clients may access the server. See SAS/CONNECT and SAS/SHARE: Supported Access Methods According to Host Release for the supported access methods by host.

All of the access methods initialize when the server initializes. The activation of multiple access methods makes a server available to several groups of clients, each using a different communications access method simultaneously.

COMAUX options can be specified only at a SAS invocation or in a SAS configuration file. The syntax for the COMAUX options follows:

COMAUX1=alternate-method
COMAUX2=alternate-method

An example of configuration file entries for a server that is running on an OS/390 host follows:

comamid=tcp
comaux1=appc
comaux2=xms

When the server starts, all of the communications access methods are initialized. The server is simultaneously available to client sessions that use the TCP/IP access method as well as to clients that use the APPC and XMS access methods.

Specifying a Server Name

You must specify the server name in the PROC SERVER statement. Use the following syntax:

SERVER=server

server can represent either a server-id or a port number.

server-id corresponds to the service that was configured in the SERVICES file. See Configuring the Server in the SERVICES File for more information.
port is the location for passing data to and receiving data from the server. The port number is specified with two preceding underscore (_) characters. For example, you can specify the server port as 5000 using the SERVER= option in a LIBNAME statement:
```
libname mylib '.' server=_ _5000;
```

See SAS Language Reference: Dictionary for details about SAS naming rules. See SAS/SHARE User's Guide for details about the PROC SERVER statement.

Server Example

The following example illustrates the statements that you specify in the server configuration file on the OS/390 host:

tcpsec=_secure_

The _SECURE_ value for TCPSEC requires clients to supply a userid and a password that are valid on the server.

The following example illustrates the statements that you specify in a SAS session on the OS/390 host at which you start a server:

options comamid=tcp;
proc server id=share1 authenticate=req;
run;

The TCP/IP access method is declared and the server SHARE1 is started on the OS/390 host.

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