54 lines
2.3 KiB
HTML
54 lines
2.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
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<!--Converted with LaTeX2HTML 96.1-c (Feb 29, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds -->
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<HTML>
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<HEAD>
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<TITLE>The Client Side of NIS</TITLE>
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</HEAD>
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<BODY LANG="EN">
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<A HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="contents_motif.gif"></A> <BR>
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<B> Next:</B> <A HREF="node134.html">Running a NIS Server</A>
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<B>Up:</B> <A HREF="node130.html">The Network Information System</A>
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<B> Previous:</B> <A HREF="node132.html">NIS versus NIS+</A>
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<BR> <P>
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<H1><A NAME="SECTION0012300000">The Client Side of NIS</A></H1>
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<P>
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<A NAME="nisclients"></A>
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<A NAME="5052"></A>
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<A NAME="5053"></A>
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<P>
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If you are familiar with writing or porting network applications, you
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will notice that most NIS maps listed above correspond to library
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functions in the C-library. For instance, to obtain passwd
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information, you generally use the getpwnam(3) and
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getpwuid(3) functions which return the account information
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associated with the given user name or numerical user id, respectively.
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Under normal circumstances, these functions will perform the requested
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lookup on the standard file, such as /etc/passwd.
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<P>
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A NIS-aware implementation of these functions, however, will modify this
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behavior, and place an RPC call to have the NIS server look up the user
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name or id. This happens completely transparent to the application. The
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function may either ``append'' the NIS map to or ``replace'' the
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original file with it. Of course, this does not refer to a real
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modification of the file, it only means that it <em>appears</em> to the
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application as if the file had been replaced or appended to.
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<P>
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For traditional NIS implementations, there used to be certain
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conventions as to which maps replaced, and which were appended to the
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original information. Some, like the passwd maps, required kludgy
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modifications of the passwd file which, when done wrong, would
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open up security holes. To avoid these pitfalls, NYS uses a general
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configuration scheme that determines whether a particular set of client
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functions uses the original files, NIS, or NIS+, and in which
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order. It will be described in a later section of this chapter.
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<P>
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<A NAME="5062"></A>
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<P>
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<BR> <HR>
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<P><ADDRESS>
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<I>Andrew Anderson <BR>
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Thu Mar 7 23:22:06 EST 1996</I>
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</ADDRESS>
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</BODY>
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</HTML>
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