1 This README describes the ./local/mib2c script.
3 Author: Derek Simkowiak
6 (please mail questions to ucd-snmp-coders@ucd-snmp.ucdavis.edu,
7 not to the author directly. Thanks!)
9 Date: Wed Jan 20 02:51:06 PST 1999
10 -----------------------------------------------------------------------
15 mib2c is a Perl script that takes a MIB (such as those files found
16 in ./mibs/ ) and converts it into C code. That C code can then be used as a
17 "template" to implement your MIB. Then, when you are done editing the C
18 code and recompiling, the UCD-SNMP agent (snmpd) will support your MIB.
19 mib2c takes the place of "MIB Compilers" that come with commercial SNMP
23 REQUIREMENTS/INSTALLATION
25 mib2c requires the SNMP.pm Perl module. As of this writing the
26 latest version of the SNMP.pm module is 1.8.
28 The SNMP.pm module can be downloaded from CPAN at
30 http://www.cpan.org/modules/by-module/SNMP/
32 ...the file that you want is probably SNMP-1.8b5.tar.gz .
33 If you didn't know that already, most every Perl module can be downloaded
34 from CPAN (www.cpan.org). Follow the installation instructions for the
37 NOTE: If you are running Redhat Linux 5.2 (and perhaps other
38 versions), you might get the following errors during the "make test" phase
39 of the installation of the SNMP.pm module:
41 [root@olly SNMP-1.8b5]# make test # This is the command...
42 PERL_DL_NONLAZY=1 /usr/bin/perl -I./blib/arch -I./blib/lib
43 -I/usr/lib/perl5/i386-linux/5.00404 -I/usr/lib/perl5 -e 'use Test::Harness
44 qw(&runtests $verbose); $verbose=0; runtests @ARGV;' t/*.t
45 t/mib...............ok
46 t/session...........FAILED tests 7-8
47 Failed 2/14 tests, 85.71% okay
48 t/translate.........ok
49 Failed Test Status Wstat Total Fail Failed List of failed
50 -------------------------------------------------------------------------------
51 t/session.t 14 2 14.29% 7-8
52 Failed 1/3 test scripts, 66.67% okay. 2/24 subtests failed, 91.67% okay.
53 make: *** [test_dynamic] Error 9
56 If the "make" went okay, then you can ignore these test failures.
57 These indicate you don't have write access to the portions of the mib
58 tree that the test script is trying to use. Please don't email the
59 UCD-SNMP list with other errors regarding the SNMP.pm module.
60 comp.lang.perl.modules is probably the most appropriate spot to
61 discuss problems with the SNMP.pm perl module itself. Interelated
62 problems between ucd-snmp and SNMP could be discussed on the ucd-snmp
68 mib2c takes one argument: an OID. It then traces down that OID
69 and generates the template C code. Here is the documentation, from the
72 # This program, given an OID reference as an argument, creates some
73 # template mib module files to be used with the ucd-snmp agent. It is
74 # far from perfect and will not generate working modules, but it
75 # significantly shortens development time by outlining the basic
78 # Its up to you to verify what it does and change the default values
81 # You *must* correct the beginning of the var_XXX() function to
82 # correctly determine mib ownership of the incoming request.
87 Before you can specify the OID for your enterprise/MIB on the
88 command line, the script needs to be able to find your MIB so that it can
89 read it in and generate template code. Joe Marzot (gmarzot@nortelnetworks.com)
91 --------------------------------------
92 you should read (man mib_api). The defaultm behaviour for mib loading
93 from within the perl interface uses the environment variables described
94 there. You can also override these and explicitly define mibdirs and
95 load modules through the perl/SNMP api.
97 the easiest thing to do is toss the mibs in /usr/local/share/snmp/mibs
98 and set the env. var., MIBS, to 'ALL'.
99 --------------------------------------
101 I recommend following the last two lines of advice. I simply did
103 # cp /home/dereks/MY-MIB-FILE.txt /usr/local/share/snmp/mibs/
106 ...on my Redhat system (with a BASH shell) and it was able to find
112 Here are some examples from Wes Hardaker (wjhardaker@ucdavis.edu).
113 He's using a C shell. Wes writes:
114 --------------------------------------
115 Ok, in order to run the thing, you actually need to do something like
118 setenv MIBS MY-ITEM-MIB # assumes csh
121 Where, "itemNode" should be a node in the mib tree that you want to
122 generate C code for. Note, pick small pieces not large ones. Yes, it
123 will generate code for the entire mibII tree if you ask it to, in one
129 outputing to interfaces.c and interfaces.h ...
131 Number of Lines Created:
137 % mib2c mib-2 # Don't ever do this.
138 outputing to mib-2.c and mib-2.h ...
140 Number of Lines Created:
146 It may have some sorting problems with multiple level mib tree
147 branches being generated into one piece of code (reorder the .h file
148 structure to be in OID lexical order if needed).
149 --------------------------------------
151 WHAT TO DO WITH THE CODE THAT GETS GENERATED
153 You will need to edit your generated code to work with your
154 hardware. For instance, if your MIB is for a refridgerator, you will need
155 to write the code that talks to the refridgerator (through the serial
156 port, maybe?) in Fridge Protocol.
158 See the files in ./agent/mibgroup/examples/ and
159 ./agent/mibgroup/dummy/ for heavily-commented example code. Don't ask me
160 questions about this stuff--I'm just now figuring it out myself...
162 [NOTE: If anyone out there has tips about necessary options to
163 ./configure, or re-compiling snmpd with custom MIB support, please add
168 As of this writing, the mib2c compiler is a bit outdated and needs
169 some work. Wes writes:
170 --------------------------------------
171 It already needs changing, because the architecture has changed in the
172 3.6 line (though its backwards compatible, I'd prefer to generate
173 code from newer models than older ones).
174 --------------------------------------
175 When I asked him to elaborate on the new 3.6 archictecture, all I
177 --------------------------------------
178 It hopefully will be in the new documentation about mib module api
179 that Dave Shield is putting together (which is also currently wrong,
181 --------------------------------------
182 ...so I don't know what the hell he's talking about.
185 SOME ERRORS AND THEIR MEANING
187 If you get a large number of errors that look like:
190 unknown type: INTEGER for prIndex
191 unknown type: OCTETSTR for prNames
192 unknown type: INTEGER for prMin
195 ...then you are trying to use an old version of the mib2c script
196 that does not support the SNMP.pm module version 1.8. Get the latest
197 version of the script.
201 Couldn't find mib reference: myEnterpriseOID
203 ...when you know that it should be finding your MIB file(s), then
204 you forgot to put the word "END" at the very end of your MIB. (Uh...I'm
205 not speaking from experience here. Really.)
209 Many thanks to the people on the UCD-SNMP mailing list
210 (ucd-snmp@ucd-snmp.ucdavis.edu). In particular, many thanks to
212 Wes Hardaker <wjhardaker@ucdavis.edu>
213 Ken McNamara <conmara@tcon.net>
214 Joe Marzot <gmarzot@nortelnetworks.com>
216 ...since about half this document is just cut'n'pasted from emails
219 Good luck with your project.
223 http://www.kd-dev.com