snmp.pm

ucd-snmp源代码

decimal unsigned integer

=item COUNTER64

decimal unsigned integer

=item GAUGE

decimal unsigned integer

=item UINTEGER

decimal unsigned integer

=item TICKS

decimal unsigned integer

=item OPAQUE

perl scalar containing octets

=item NULL

perl scalar containing nothing

=back

=item <type>

SNMP data type (see list above), this field is
populated by 'get' and 'getnext' operations. In
some cases the programmer needs to populate this
field when passing to a 'set' operation. this
field need not be supplied when the attribute
indicated by <tag> is already described by loaded
Mib modules. for 'set's, if a numeric OID is used
and the object is not currently in the loaded Mib,
the <type> field must be supplied

=back

=item simple string

light weight form of <var> used to 'set' or 'get' a
single attribute without constructing an SNMP::Varbind.
stored in a perl scalar, has the form '<tag>.<iid>',
(e.g., 'sysDescr.0'). for 'set' operations the value
is passed as a second arg. Note: This argument form is
not updated in get[next] operations as are the other forms.

=back

=head1 Acceptable callback formats

<callback> may be one of the following forms:

=over

=item without arguments

=over

=item \&subname

=item sub { ... }

=back

=item or with arguments

=over

=item [ \&subname, $arg1, ... ]

=item [ sub { ... }, $arg1, ... ]

=item [ "method", $obj, $arg1, ... ]

=back

=back

callback will be called when response is received or timeout
occurs. the last argument passed to callback will be a
SNMP::VarList reference. In case of timeout the last argument
will be undef.

=over

=item &SNMP::MainLoop([<timeout>, [<callback>]])

to be used with async SNMP::Session
calls. MainLoop must be called after initial async calls
so return packets from the agent will not be processed.
If no args suplied this function enters an infinite loop
so program must be exited in a callback or externally
interupted. If <timeout(sic)

=item &SNMP::finish()

This function, when called from an SNMP::MainLoop() callback
function, will cause the current SNMP::MainLoop() to return
after the callback is completed.  finish() can be used to
terminate an otherwise-infinite MainLoop.  A new MainLoop()
instance can then be started to handle further requests.

=back

=head1 SNMP package variables and functions

=over

=item $SNMP::VERSION

the current version specifier (e.g., 3.1.0)

=item $SNMP::auto_init_mib

default '1', set to 0 to disable automatic reading
of the MIB upon session creation. set to non-zero
to call initMib at session creation which will result
in MIB loading according to UCD env. variables (see
man mib_api)

=item $SNMP::verbose

default '0', controls warning/info output of
SNMP module, 0 => no output, 1 => enables warning/info
output from SNMP module itself (is also controlled
by SNMP::debugging - see below)

=item $SNMP::use_long_names

default '0', set to non-zero to enable the use of
longer Mib identifiers. see translateObj. will also
influence the formatting of <tag> in varbinds returned
from 'getnext' operations. Can be set on a per session
basis (UseLongNames)

=item $SNMP::use_sprint_value

default '0', set to non-zero to enable formatting of
response values using the snmp libraries sprint_value
function. can also be set on a per session basis (see
UseSprintValue) Note: returned values may not be
suitable for 'set' operations

=item $SNMP::use_enums

default '0',set non-zero to return values as enums and
allow sets using enums where appropriate. integer data
will still be accepted for set operations. can also be
set on a per session basis (see UseEnums)

=item $SNMP::use_numeric

default to '0',set to non-zero to have <tags> for 'get'
methods returned as numeric OID's rather than descriptions.
if UseLongNames is set, returns the entire OID as given,
otherwise just the last two octets. setting 'UseLongNames'
is highly recommended.  Set on a per-session basis (see
UseNumeric).

=item $SNMP::timestamp_vars

defaults to 0, set to non-zero to have an additional element
added to each Varbind containing the time(2) timestamp.
Reference the timestamps through the $varbind_ref->stamp()
object method.

=item $SNMP::save_descriptions

default '0',set non-zero to have mib parser save
attribute descriptions. must be set prior to mib
initialization

=item $SNMP::debugging

default '0', controlls debugging output level
within SNMP module and libsnmp

=over

=item 1

enables 'SNMP::verbose' (see above)

=item 2

level 1 plus snmp_set_do_debugging(1)

=item 3

level 2 plus snmp_set_dump_packet(1)

=back

=item $SNMP::dump_packet

default '0', set [non-]zero to independently set
snmp_set_dump_packet()

=back

=head1 %SNMP::MIB

a tied hash to access parsed MIB information. After
the MIB has been loaded this hash allows access to
to the parsed in MIB meta-data(the structure of the
MIB (i.e., schema)). The hash returns blessed
references to SNMP::MIB::NODE objects which represent
a single MIB attribute. The nodes can be fetched with
multiple 'key' formats - the leaf name (e.g.,sysDescr)
or fully/partially qualified name (e.g.,
system.sysDescr) or fully qualified numeric OID. The
returned node object supports the following fields:

=over

=item objectID

dotted decimal fully qualified OID

=item label

leaf textual identifier (e.g., 'sysDescr')

=item subID

leaf numeric OID component of objectID (e.g., '1')

=item moduleID

textual identifier for module (e.g., 'RFC1213-MIB')

=item parent

parent node

=item children

array reference of children nodes

=item nextNode

next lexico node B<(BUG!does not return in lexico order)>

=item type

returns application type (see getType for values)

=item access

returns ACCESS (ReadOnly, ReadWrite, WriteOnly,
NoAccess, Notify, Create)

=item status

returns STATUS (Mandatory, Optional, Obsolete,
Deprecated)

=item syntax

returns 'textualConvention' if defined else 'type'

=item textualConvention

returns TEXTUAL-CONVENTION

=item units

returns UNITS

=item hint

returns HINT

=item enums

returns hash ref {tag => num, ...}

=item ranges

returns array ref of hash ref [{low => num, high => num}, ...]

=item description

returns DESCRIPTION ($SNMP::save_descriptions must
be set prior to MIB initialization/parsing)

=back

=head1 MIB Functions

=over

=item &SNMP::setMib(<file>)

allows dynamic parsing of the mib and explicit
specification of mib file independent of enviroment
variables. called with no args acts like initMib,
loading MIBs indicated by environment variables (see
ucd mib_api docs). passing non-zero second arg
forces previous mib to be freed and replaced
B<(Note: second arg not working since freeing previous
Mib is more involved than before)>.

=item &SNMP::initMib()

calls library init_mib function if Mib not already
loaded - does nothing if Mib already loaded. will
parse directories and load modules according to
environment variables described in UCD documentations.
(see man mib_api, MIBDIRS, MIBS, MIBFILE(S), etc.)

=item &SNMP::addMibDirs(<dir>,...)

calls library add_mibdir for each directory
supplied. will cause directory(s) to be added to
internal list and made available for searching in
subsequent loadModules calls

=item &SNMP::addMibFiles(<file>,...)

calls library read_mib function. The file(s)
supplied will be read and all Mib module definitions
contained therein will be added to internal mib tree
structure

=item &SNMP::loadModules(<mod>,...)

calls library read_module function. The
module(s) supplied will be searched for in the
current mibdirs and and added to internal mib tree
structure. Passing special <mod>, 'ALL', will cause
all known modules to be loaded.

=item &SNMP::unloadModules(<mod>,...)

B<*Not Implemented*>

=item &SNMP::translateObj(<var>[,arg])

will convert a text obj tag to an OID and
vice-versa. any iid suffix is retained numerically.
default behaviour when converting a numeric OID
to text form is to return leaf indentifier only
(e.g.,'sysDescr') but when $SNMP::use_long_names
is non-zero or a non-zero second arg is supplied
will return longer textual identifier. If no Mib
is loaded when called and $SNMP::auto_init_mib is
enabled then the Mib will be loaded. Will return
'undef' upon failure.

=item &SNMP::getType(<var>)

return SNMP data type for given textual identifier
OBJECTID, OCTETSTR, INTEGER, NETADDR, IPADDR, COUNTER
GAUGE, TIMETICKS, OPAQUE, or undef

=item &SNMP::mapEnum(<var>)

converts integer value to enumertion tag defined
in Mib or converts tag to integer depending on
input. the function will return the corresponding
integer value *or* tag for a given MIB attribute
and value. The function will sense which direction
to perform the conversion. Various arg formats are
supported

=over

=item $val = SNMP::mapEnum($varbind);

where $varbind is SNMP::Varbind or equiv.
note: $varbind will be updated

=item $val = SNMP::mapEnum('ipForwarding', 'forwarding');

=item $val = SNMP::mapEnum('ipForwarding', 1);

=back

=back

=head1 Exported SNMP utility functions

Note: utility functions do not support async operation yet.

=over

=item &snmp_get()

takes args of SNMP::Session::new followed by those of
SNMP::Session::get

=item &snmp_getnext()

takes args of SNMP::Session::new followed by those of
SNMP::Session::getnext

=item &snmp_set()

takes args of SNMP::Session::new followed by those of
SNMP::Session::set

=item &snmp_trap()

takes args of SNMP::TrapSession::new followed by those of
SNMP::TrapSession::trap

=back

=head1 Trouble Shooting

If problems occur there are number areas to look at to narrow down the
possibilities.

The first step should be to test the UCD SNMP installation
independently from the Perl5 SNMP interface.

Try running the apps from the UCD SNMP distribution.

Make sure your agent (snmpd) is running and properly configured with
read-write access for the community you are using.

Ensure that your MIBs are installed and enviroment variables are set
appropriately (see man mib_api)

Be sure to remove old ucd-snmp installations and ensure headers and
libraries from old CMU installations are not being used by mistake.

If the problem occurs during compilation/linking check that the snmp
library being linked is actually the UCD SNMP library (there have been
name conflicts with existing snmp libs).

Also check that the header files are correct and up to date.

Sometimes compiling the UCD SNMP library with
'position-independent-code' enabled is required (HPUX specifically).

If you cannot resolve the problem you can post to
comp.lang.perl.modules or email me at [e-mail]
and/or [e-mail].

please give sufficient information to analyze the problem (OS type,
versions for OS/Perl/UCD/compiler, complete error output, etc.)

=head1 Acknowledments

Many thanks to all those who supplied patches, suggestions and
feedback.

 Wes Hardaker and the ucd-coders
 Dave Perkins
 Marcel Wiget
 David Blackburn
 John Stofell
 Gary Hayward
 Claire Harrison
 Achim Bohnet
 Doug Kingston
 Jacques Vidrine
 Carl Jacobsen
 Wayne Marquette
 Scott Schumate
 Michael Slifcak
 Perl5 Porters

Apologies to any/all who's patch/feature/request was not mentioned or
included - most likely it was lost when paying work intruded on my
fun. Please try again if you do not see a desired feature. This may
actually turn out to be a decent package with such excellent help and
the fact that I have more time to work on it than in the past.

=head1 AUTHOR

bugs, comments, questions to [e-mail]

=head1 Copyright

     Copyright (c) 1995-2000 G. S. Marzot. All rights reserved.
     This program is free software; you can redistribute it and/or
     modify it under the same terms as Perl itself.

=cut