openSolaris 2008 - Advertising Legacy Services - System Administration Guide: Network Services

Advertising Legacy Services

You use any of the following methods to advertise legacy services.

Modify the service to incorporate an SLP SA.
Write a small program that advertises on behalf of a service that is not SLP enabled.
Use proxy advertising to have slpd advertise the service.

Modifying the Service

If the source code for the software server is available, you can incorporate a SLP SA. The C and Java APIs for SLP are relatively straightforward to use. See the man pages for information on the C API and documentation on the Java API. If the service is a hardware device, the manufacturer might have an updated PROM that incorporates SLP. Contact the device manufacturer for more information.

Advertising a Service That Is Not SLP Enabled

If the source code or an updated PROM that contains SLP is not available, you can write a small application that uses the SLP client library to advertise the service. This application could function as a small daemon that you start or stop from the same shell script you use to start and stop the service.

SLP Proxy Registration

Solaris slpd supports legacy service advertising with a proxy registration file. The proxy registration file is a list of service advertisements in a portable format.

How to Enable SLP Proxy Registration

Create a proxy registration file on the host file system or in any network directory that is accessible by HTTP.
Determine if a service type template exists for the service.
The template is a description of the service URL and attributes of a service type. A template is used to define the components of an advertisement for a particular service type:
- If a service type template exists, use the template to construct the proxy registration. See RFC 2609 for more information on service-type templates.
- If a service type template is not available for the service, select a collection of attributes that precisely describe the service. Use a naming authority other than the default for the advertisement. The default naming authority is allowed only for service types that have been standardized. See RFC 2609 for more information on naming authorities.
  For example, suppose a company that is called BizApp has a local database that is used to track software defects. To advertise the database, the company might use a URL with the service type service:bugdb.bizapp. The naming authority would then be bizapp.
Follow the next steps to configure the net.slp.serializedRegURL property in the /etc/inet/slp.conf file with the location of the registration file that was created in the previous steps.
Become superuser or assume an equivalent role.
Roles contain authorizations and privileged commands. For more information about roles, see Configuring RBAC (Task Map) in System Administration Guide: Security Services. To configure a role with the Primary Administrator profile, see Chapter 2, Working With the Solaris Management Console (Tasks), in System Administration Guide: Basic Administration.
Stop slpd and all SLP activity on the host.
```
# svcadm disable network/slp
```
Back up the default /etc/inet/slp.conf file before you change the configuration settings.
Specify the location of the proxy registration file in the net.slp.serializedRegURL property of the /etc/inet/slp.conf file.
```
net.slp.net.slp.serializedRegURL=proxy registration file URL
```
For example, if the serialized registration file is /net/inet/slp.reg, you configure the property as shown in the following:
```
net.slp.serializedRegURL=file:/etc/inet/slp.reg
```
Save your changes and close the file.
Restart slpd to activate your changes.
```
# svcadm enable network/slp
```

Using SLP Proxy Registration to Advertise

A service advertisement consists of lines that identify the service URL, an optional scope, and a series of attribute definitions. The SLP daemon reads, registers, and maintains proxy advertisements exactly as an SA client would. The following is an example of an advertisement from a proxy registration file.

In the example, a legacy printer that supports LPR protocol and an FTP server are advertised. Line numbers have been added for description purposes and are not part of the file.

 (1) #Advertise legacy printer. 
 (2) 
 (3) service:lpr://bizserver/mainspool,en,65535
 (4) scope=eng,corp
 (5) make-model=Laserwriter II
 (6) location-description=B16-2345
 (7) color-supported=monochromatic
 (8) fonts-supported=Courier,Times,Helvetica 9 10
 (9) 
 (10) #Advertise FTP server
 (11) 
 (12) ftp://archive/usr/src/public,en,65535,src-server
 (13) content=Source code for projects
 (14)

Note - The proxy registration file supports the same convention for escaping non-ASCII characters as the configuration file does. For more information about the format of the proxy registration file, see RFC 2614.

Table 10-1 SLP Proxy Registration File Description

Line Numbers	Description
1 and 10	Comment lines begin with a cross-hatch symbol (#) and do not affect the file's operation. All characters through the end of a comment line are ignored.
2, 9, and 14	Blank lines that delimit the advertisements.
3, 12	Service URLs that each have three required fields and one optional field that are separated by commas: Generic or `service: URL` advertised. See RFC 2609 for the specification of how to form a service: URL. Language of the advertisement. In the previous example, the field is designated English, en. Language is an RFC 1766 language tag. Lifetime of the registration, measured in seconds. The lifetime is restricted to an unsigned 16 bit-integer. If the lifetime is less than the maximum, 65535, `slpd` times out the advertisement. If the lifetime is 65535, `slpd` refreshes the advertisement periodically, and the lifetime is considered permanent, until `slpd` exits. (Optional) Service type field – If used, this field defines the service type. If the service URL is defined, you can change the service type under which the URL is advertised. In the previous example of a proxy registration file, line 12 contains a generic FTP URL. The optional type field causes the URL to be advertised under the service type name src-server. The `service` prefix is not added by default to the type name.
4	Scope designation. Optional line consists of the token `scope`, followed by an equal sign and a comma-separated list of scope names. Scope names are defined by the `net.slp.useScopes` configuration property. Only scopes that are configured for the host should be included in the list. When a scope line is not added, the registration is made in all scopes with which `slpd` is configured. The scope line must appear immediately after the URL line. Otherwise, scope names are recognized as attributes.
5–8	Attribute definitions. After the optional scope line, the bulk of the service advertisement contains attribute/value list pair lines. Each pair consists of the attribute tag, followed by an equal sign, and an attribute value or a comma-separated list of values. In the previous example of a proxy registration file, line 8 illustrates an attribute list with multiple values. All other lists have single values. The format for the attribute names and values is the same as on-the-wire SLP messages.