snmp.pm

开发snmp的开发包有两个开放的SNMP开发库

   %$this = @_;

   $this->{ErrorStr} = ''; # if methods return undef check for expln.
   $this->{ErrorNum} = 0;  # contains SNMP error return

   $this->{Version} ||= 
     NetSNMP::default_store::netsnmp_ds_get_int(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID, 
				      NetSNMP::default_store::NETSNMP_DS_LIB_SNMPVERSION) ||
					SNMP::SNMP_DEFAULT_VERSION();

   if ($this->{Version} eq 128) {
       # special handling of the bogus v1 definition.
       $this->{Version} = 1;
   }

   # allow override of local SNMP port
   $this->{LocalPort} ||= 0;

   # destination host defaults to localhost
   $this->{DestHost} ||= 'localhost';

   # community defaults to public
   $this->{Community} ||= NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
				        NetSNMP::default_store::NETSNMP_DS_LIB_COMMUNITY()) || 'public';

   # number of retries before giving up, defaults to SNMP_DEFAULT_RETRIES
   $this->{Retries} = SNMP::SNMP_DEFAULT_RETRIES() unless defined($this->{Retries});

   # timeout before retry, defaults to SNMP_DEFAULT_TIMEOUT
   $this->{Timeout} = SNMP::SNMP_DEFAULT_TIMEOUT() unless defined($this->{Timeout});
   # flag to enable fixing pdu and retrying with a NoSuch error
   $this->{RetryNoSuch} ||= 0;

   # backwards compatibility.  Make host = host:port
   if ($this->{RemotePort} && $this->{DestHost} !~ /:/) {
       $this->{DestHost} = $this->{DestHost} . ":" . $this->{RemotePort};
   }

   if ($this->{Version} eq '1' or $this->{Version} eq '2'
       or $this->{Version} eq '2c') {
       $this->{SessPtr} = SNMP::_new_session($this->{Version},
					     $this->{Community},
					     $this->{DestHost},
					     $this->{LocalPort},
					     $this->{Retries},
					     $this->{Timeout},
					     );
   } elsif ($this->{Version} eq '3' ) {
       $this->{SecName} ||= 
	   NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		         NetSNMP::default_store::NETSNMP_DS_LIB_SECNAME()) || 
			   'initial';
       if (!$this->{SecLevel}) {
	   $this->{SecLevel} = 
	       NetSNMP::default_store::netsnmp_ds_get_int(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
			  NetSNMP::default_store::NETSNMP_DS_LIB_SECLEVEL()) || 
			      $SNMP::V3_SEC_LEVEL_MAP{'noAuthNoPriv'};
       } elsif ($this->{SecLevel} !~ /^\d+$/) {
	   $this->{SecLevel} = $SNMP::V3_SEC_LEVEL_MAP{$this->{SecLevel}};
       }
       $this->{SecEngineId} ||= '';
       $this->{ContextEngineId} ||= $this->{SecEngineId};
       $this->{Context} ||= 
	   NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		         NetSNMP::default_store::NETSNMP_DS_LIB_CONTEXT()) || '';
       $this->{AuthProto} ||= 'DEFAULT'; # defaults to the library's default
       $this->{AuthPass} ||=
       NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		     NetSNMP::default_store::NETSNMP_DS_LIB_AUTHPASSPHRASE()) ||
       NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		     NetSNMP::default_store::NETSNMP_DS_LIB_PASSPHRASE()) || '';

       $this->{AuthMasterKey} ||= '';
       $this->{PrivMasterKey} ||= '';
       $this->{AuthLocalizedKey} ||= '';
       $this->{PrivLocalizedKey} ||= '';

       $this->{PrivProto} ||= 'DEFAULT';  # defaults to hte library's default
       $this->{PrivPass} ||=
       NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		     NetSNMP::default_store::NETSNMP_DS_LIB_PRIVPASSPHRASE()) ||
       NetSNMP::default_store::netsnmp_ds_get_string(NetSNMP::default_store::NETSNMP_DS_LIBRARY_ID(), 
		     NetSNMP::default_store::NETSNMP_DS_LIB_PASSPHRASE()) || '';
       $this->{EngineBoots} = 0 if not defined $this->{EngineBoots};
       $this->{EngineTime} = 0 if not defined $this->{EngineTime};

       $this->{SessPtr} = SNMP::_new_v3_session($this->{Version},
						$this->{DestHost},
						$this->{Retries},
						$this->{Timeout},
						$this->{SecName},
						$this->{SecLevel},
						$this->{SecEngineId},
						$this->{ContextEngineId},
						$this->{Context},
						$this->{AuthProto},
						$this->{AuthPass},
						$this->{PrivProto},
						$this->{PrivPass},
						$this->{EngineBoots},
						$this->{EngineTime},
						$this->{AuthMasterKey},
						length($this->{AuthMasterKey}),
						$this->{PrivMasterKey},
						length($this->{PrivMasterKey}),
						$this->{AuthLocalizedKey},
						length($this->{AuthLocalizedKey}),
						$this->{PrivLocalizedKey},
						length($this->{PrivLocalizedKey}),
					       );
   }
   unless ($this->{SessPtr}) {
       warn("unable to create session") if $SNMP::verbose;
       return undef;
   }

   SNMP::initMib($SNMP::auto_init_mib); # ensures that *some* mib is loaded

   $this->{UseLongNames} = $SNMP::use_long_names 
       unless exists $this->{UseLongNames};
   $this->{UseSprintValue} = $SNMP::use_sprint_value 
       unless exists $this->{UseSprintValue};
   $this->{BestGuess} = $SNMP::best_guess unless exists $this->{BestGuess};
   $this->{NonIncreasing} ||= $SNMP::non_increasing;
   $this->{UseEnums} = $SNMP::use_enums unless exists $this->{UseEnums};
   $this->{UseNumeric} = $SNMP::use_numeric unless exists $this->{UseNumeric};

   # Force UseLongNames if UseNumeric is in use.
   $this->{UseLongNames}++  if $this->{UseNumeric};

   bless $this, $type;
}

sub update {
# *Not Implemented*
# designed to update the fields of session to allow retargetting to different
# host, community name change, timeout, retry changes etc. Unfortunately not
# working yet because some updates (the address in particular) need to be
# done on the internal session pointer which cannot be fetched w/o touching
# globals at this point which breaks win32. A patch to the net-snmp toolkit
# is needed
   my $this = shift;
   my ($name, $aliases, $host_type, $len, $thisaddr);
   my %new_fields = @_;

   @$this{keys %new_fields} = values %new_fields;

   $this->{UseLongNames} = $SNMP::use_long_names 
       unless exists $this->{UseLongNames};
   $this->{UseSprintValue} = $SNMP::use_sprint_value 
       unless exists $this->{UseSprintValue};
   $this->{BestGuess} = $SNMP::best_guess unless exists $this->{BestGuess};
   $this->{NonIncreasing} ||= $SNMP::non_increasing;
   $this->{UseEnums} = $SNMP::use_enums unless exists $this->{UseEnums};
   $this->{UseNumeric} = $SNMP::use_numeric unless exists $this->{UseNumeric};

   # Force UseLongNames if UseNumeric is in use.
   $this->{UseLongNames}++  if $this->{UseNumeric};

   SNMP::_update_session($this->{Version},
		 $this->{Community},
		 $this->{DestHost},
		 $this->{RemotePort},
		 $this->{LocalPort},
		 $this->{Retries},
		 $this->{Timeout},
		);


}

sub set {
   my $this = shift;
   my $vars = shift;
   my $varbind_list_ref;
   my $res = 0;

   if (ref($vars) =~ /SNMP::VarList/) {
     $varbind_list_ref = $vars;
   } elsif (ref($vars) =~ /SNMP::Varbind/) {
     $varbind_list_ref = [$vars];
   } elsif (ref($vars) =~ /ARRAY/) {
     $varbind_list_ref = [$vars];
     $varbind_list_ref = $vars if ref($$vars[0]) =~ /ARRAY/;
   } else {
     #$varbind_list_ref = [[$tag, $iid, $val]];
     my $split_vars = SNMP::split_vars($vars);
     my $val = shift;
     push @$split_vars,$val;
     $varbind_list_ref = [$split_vars];
   }
   my $cb = shift;

   $res = SNMP::_set($this, $varbind_list_ref, $cb);
}

sub get {
   my $this = shift;
   my $vars = shift;
   my ($varbind_list_ref, @res);

   if (ref($vars) =~ /SNMP::VarList/) {
     $varbind_list_ref = $vars;
   } elsif (ref($vars) =~ /SNMP::Varbind/) {
     $varbind_list_ref = [$vars];
   } elsif (ref($vars) =~ /ARRAY/) {
     $varbind_list_ref = [$vars];
     $varbind_list_ref = $vars if ref($$vars[0]) =~ /ARRAY/;
   } else {
     $varbind_list_ref = [SNMP::split_vars($vars)];
   }

   my $cb = shift;

   @res = SNMP::_get($this, $this->{RetryNoSuch}, $varbind_list_ref, $cb);

   return(wantarray() ? @res : $res[0]);
}


use strict;

my $have_netsnmp_oid = eval { require NetSNMP::OID; };
sub gettable {

    #
    # getTable
    # --------
    #
    # Get OIDs starting at $table_oid, and continue down the tree
    # until we get to an OID which does not start with $table_oid,
    # i.e. we have reached the end of this table.
    #

    my $state;

    my ($this, $root_oid, @options) = @_;
    $state->{'options'} = {@options};
    my ($textnode, $varbinds, $vbl, $res, $repeat);

    # translate the OID into numeric form if its not
    if ($root_oid !~ /^[\.0-9]+$/) {
	$textnode = $root_oid;
	$root_oid = SNMP::translateObj($root_oid);
    } else {
	$textnode = SNMP::translateObj($root_oid);
    }

    # bail if we don't have a valid oid.
    return if (!$root_oid);

    # deficed if we're going to parse indexes
    my $parse_indexes = (defined($state->{'options'}{'noindexes'})) ? 
      0 : $have_netsnmp_oid;

    # get the list of columns we should look at.
    my @columns;
    if (!$state->{'options'}{'columns'}) {
	if ($textnode) {
	    my %indexes;

	    if ($parse_indexes) {
		# get indexes
		my @indexes =
		  @{$SNMP::MIB{$textnode}{'children'}[0]{'indexes'}};
		# quick translate into a hash
		map { $indexes{$_} = 1; } @indexes;
	    }

	    # calculate the list of accessible columns that aren't indexes
	    my $children = $SNMP::MIB{$textnode}{'children'}[0]{'children'};
	    foreach my $c (@$children) {
		push @{$state->{'columns'}},
		  $root_oid . ".1." . $c->{'subID'}
		    if (!$indexes{$c->{'label'}});
	    }
	    if ($#{$state->{'columns'}} == -1) {
		# some tables are only indexes, and we need to walk at
		# least one column.  We pick the last.
		push @{$state->{'columns'}}, $root_oid . ".1." .
		  $children->[$#$children]{'subID'};
	    }
	}
    } else {
	# XXX: requires specification in numeric OID...  ack.!
	@{$state->{'columns'}} = @{$state->{'options'}{'columns'}};

	# if the columns aren't numeric, we need to turn them into
	# numeric columns...
	map {
	    if ($_ !~ /\.1\.3/) {
		$_ = $SNMP::MIB{$_}{'objectID'};
	    }
	} @{$state->{'columns'}};
    }

    # create the initial walking info.
    foreach my $c (@{$state->{'columns'}}) {
	push @{$state->{'varbinds'}}, [$c];
	push @{$state->{'stopconds'}}, $c;
    }

    if ($#{$state->{'varbinds'}} == -1) {
	print STDERR "ack: gettable failed to find any columns to look for.\n";
	return;
    }

    $vbl = $state->{'varbinds'};
	
    my $repeatcount;
    if ($this->{Version} == 1 || $state->{'options'}{nogetbulk}) {
	$state->{'repeatcount'} = 1;
    } elsif ($state->{'options'}{'repeat'}) {
	$state->{'repeatcount'} = $state->{'options'}{'repeat'};
    } elsif ($#{$state->{'varbinds'}} == -1) {
	$state->{'repeatcount'} = 1;
    } else {
	# experimentally determined maybe guess at a best repeat value
	# 1000 bytes max (safe), 30 bytes average for encoding of the
	# varbind (experimentally determined to be closer to
	# 26.  Again, being safe.  Then devide by the number of
	# varbinds.
	$state->{'repeatcount'} = int(1000 / 36 / ($#{$state->{'varbinds'}} + 1));
    }

    #
    # if we've been configured with a callback, then call the
    # sub-functions with a callback to our own "next" processing
    # function (_gettable_do_it).  or else call the blocking method and
    # call the next processing function ourself.
    #
    if ($state->{'options'}{'callback'}) {
	if ($this->{Version} > 1 && !$state->{'options'}{'nogetbulk'}) {
	    $res = $this->getbulk(0, $state->{'repeatcount'}, $vbl,
				  [\&_gettable_do_it, $this, $vbl,
				   $parse_indexes, $textnode, $state]);
	} else {
	    $res = $this->getnext($vbl,
				  [\&_gettable_do_it, $this, $vbl,
				   $parse_indexes, $textnode, $state]);
	}
    } else {
	if ($this->{Version} > 1 && !$state->{'options'}{'nogetbulk'}) {
	    $res = $this->getbulk(0, $state->{'repeatcount'}, $vbl);
	} else {
	    $res = $this->getnext($vbl);
	}
	return $this->_gettable_do_it($vbl, $parse_indexes, $textnode, $state);
    }
    return 0;
}

sub _gettable_do_it() {
    my ($this, $vbl, $parse_indexes, $textnode, $state) = @_;

    my ($res);

    $vbl = $_[$#_] if ($state->{'options'}{'callback'});

    while ($#$vbl > -1 && !$this->{ErrorNum}) {
	if (($#$vbl + 1) % ($#{$state->{'stopconds'}} + 1) != 0) {
	    if ($vbl->[$#$vbl][2] ne 'ENDOFMIBVIEW') {
		# unless it's an end of mib view we didn't get the
		# proper number of results back.
		print STDERR "ack: gettable results not appropriate\n";
	    }
	    my @k = keys(%{$state->{'result_hash'}});
	    last if ($#k > -1);  # bail with what we have
	    return;
	}

	$state->{'varbinds'} = [];
	my $newstopconds;

	my $lastsetstart = ($state->{'repeatcount'}-1) * ($#{$state->{'stopconds'}}+1);

	for (my $i = 0; $i <= $#$vbl; $i++) {
	    my $row_oid = SNMP::translateObj($vbl->[$i][0]);
	    my $row_text = $vbl->[$i][0];
	    my $row_index = $vbl->[$i][1];
	    my $row_value = $vbl->[$i][2];
	    my $row_type = $vbl->[$i][3];

	    if ($row_oid =~ 
		/^$state->{'stopconds'}[$i % ($#{$state->{'stopconds'}}+1)]/ &&
		$row_value ne 'ENDOFMIBVIEW' ){

		if ($row_type eq "OBJECTID") {

		    # If the value returned is an OID, translate this
		    # back in to a textual OID

		    $row_value = SNMP::translateObj($row_value);

		}

		# Place the results in a hash

		$state->{'result_hash'}{$row_index}{$row_text} = $row_value;

		# continue past this next time
		if ($i >= $lastsetstart) {
		    push @$newstopconds,
		      $state->{'stopconds'}->[$i%($#{$state->{'stopconds'}}+1)];
		    push @{$state->{'varbinds'}},[$vbl->[$i][0],$vbl->[$i][1]];
		}
	    }
	}
	if ($#$newstopconds == -1) {
	    last;
	}
	if ($#{$state->{'varbinds'}} == -1) {
	    print "gettable ack.  shouldn't get here\n";
	}
	$vbl = $state->{'varbinds'};
	$state->{'stopconds'} = $newstopconds;

        #
        # if we've been configured with a callback, then call the
        # sub-functions with a callback to our own "next" processing
        # function (_gettable_do_it).  or else call the blocking method and
        # call the next processing function ourself.
        #