![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to entities.tex CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [CSRG BSD Unix] / 43BSDReno / contrib / isode-beta / doc / manual|
Return to entities.tex CVS log | Up to [CSRG BSD Unix] / 43BSDReno / contrib / isode-beta / doc / manual |
1.1 root 1: % run this through LaTeX with the appropriate wrapper
2:
3: \chapter {The ISODE Entities Database}\label{isoentities}
4: The database \file{isoentities} in the ISODE \verb"ETCDIR" directory
5: (usually \file{/usr/etc/})
6: contains a simple mapping between
7: appli\-cat\-ion-entity information and presentation addresses.
8: This database is used by the stub-directory service.
9:
10: The database itself is an ordinary ASCII text file containing information
11: regarding the known ap\-pli\-ca\-tion-entities on the network.
12: Each entry contains:
13: \begin{itemize}
14: \item the object descriptor of the application-entity information,
15: realized as a designator-qualifier (host/service) pair
16: (the distinguished designator \verb"default" is used for a template
17: entry);
18:
19: \item the object identifier of the application-entity information
20: expressed in dot-notation
21: (if no application-entity information is desired,
22: the string ``NULL'' should be used instead);
23: and,
24:
25: \item the presentation address expressed in the string format described
26: in Section~\ref{addr:encodings} on page~\pageref{addr:encodings} in
27: \volone/.
28:
29: Note that since double-quotes are often used in the new string format,
30: it is {\bf very\/} important to quote them correctly in the
31: \man isoentities(5) file.
32: Usually preceeding the first character of the address with backslash
33: (``\verb"\"'') is adequate.
34: \end{itemize}
35: Blanks and/or tab characters are used to seperate items.
36: However, double-quotes may be used to prevent separation for items containing
37: embedded whitspace.
38: This is useful for defining the presetnation address.
39: The sharp character (`\verb"#"') at the beginning of a line indicates a
40: commentary line.
41:
42: It is suggested for readability purposes that a blank line should seperate
43: entries.
44:
45: \subsection* {RFC1085 Support}
46: Since applications using RFC1085 (the lightweight presentation protocol)
47: usually demultiplex on the basis of TCP or UDP port,
48: a further definition for the qualifier is placed in
49: \file{/etc/services},
50: one of:
51: \begin{quote}\small\begin{verbatim}
52: qualifier portno/lpp
53: qualifier portno/tcp
54: qualifier portno/udp
55: \end{verbatim}\end{quote}
56: The first alternative says that the service lives on both TCP and UDP;
57: the second alternative says that the service lives on TCP only;
58: and,
59: the third alternative says that the service lives on UDP only.
60:
61: \section {Accessing the Database}\label{isoentity}
62: The \man libacsap(3n) library contains the routines used to access the
63: database.
64: The high-level routines, \verb"_str2aei",
65: which returns application-entity information,
66: and \verb"aei2addr",
67: which maps the ap\-pli\-ca\-tion-entity information into a presentation
68: address have
69: already been discussed in Section~\ref{acs:aei}.
70: Similarly, the ``old-style'' routines,
71: \verb"is2paddr", \verb"is2saddr", \verb"is2taddr",
72: which maps a host and service directly into a prsentation, session,
73: or transport address (respectively) are discussed in
74: Sections~\ref{psap:addresses}, \ref{ssap:addresses}, and~\ref{tsap:addresses}
75: of \voltwo/ (respectively).
76: Hence, for the remainder of this chapter,
77: we need only consider the internal form used by the library in querying the
78: database.
79:
80: The \verb"isoentity" structure is the internal form.
81: \begin{quote}\index{isoentity}\small\begin{verbatim}
82: struct isoentity {
83: OIDentifier ie_identifier;
84: char *ie_descriptor;
85:
86: struct PSAPaddr ie_addr;
87: };
88: \end{verbatim}\end{quote}
89: The elements of this structure are:
90: \begin{describe}
91: \item[\verb"ie\_identifier":] an object identifier used to form
92: application-entity information;
93:
94: \item[\verb"ie\_identifier":] the corresponding object descriptor;
95: and,
96:
97: \item[\verb"ie\_addr":] the presentation address.
98: \end{describe}
99:
100: The routine \verb"getisoentity" reads the next entry in the database,
101: opening the database if necessary.
102: \begin{quote}\index{getisoentity}\small\begin{verbatim}
103: struct isoentity *getisoentity ()
104: \end{verbatim}\end{quote}
105: It returns the manifest constant \verb"NULL" on error or end-of-file.
106:
107: The routine \verb"setisoentity" opens and rewinds the database.
108: \begin{quote}\index{setisoentity}\small\begin{verbatim}
109: int setisoentity (f)
110: int f;
111: \end{verbatim}\end{quote}
112: The parameter to this procedure is:
113: \begin{describe}
114: \item[\verb"f":] the ``stayopen'' indicator,
115: if non-zero, then the database will remain open over subsequent calls to the
116: library.
117: \end{describe}
118: The routine \verb"endisoentity" closes the database.
119: \begin{quote}\index{endisoentity}\small\begin{verbatim}
120: int endisoentity ()
121: \end{verbatim}\end{quote}
122: Both of these routines return non-zero on success and zero otherwise.
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.