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
3service:lpr://bizserver/mainspool,en,65535
4scope=eng,corp
5make-model=Laserwriter II
6location-description=B16-2345
7color-supported=monochromatic
8fonts-supported=Courier,Times,Helvetica 9 10
9
10#Advertise FTP server
11
12ftp://archive/usr/src/public,en,65535,src-server
13content=Source code for projects
14
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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 21–1 SLP Proxy Registration File Description
Line Numbers
|
Description
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1 and 10
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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
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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.
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4
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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
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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.
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