sub index_compare ($$) {  my ($i1, $i2) = @_;  $i1 = '' unless defined $i1;  $i2 = '' unless defined $i2;  if ($i1 eq '') {      return $i2 eq '' ? 0 : 1;  } elsif ($i2 eq '') {      return 1;  } elsif (!$i1) {      return $i2 eq '' ? 1 : !$i2 ? 0 : 1;  } elsif (!$i2) {      return -1;  } else {    my ($f1,$r1) = split('\.',$i1,2);    my ($f2,$r2) = split('\.',$i2,2);    if ($f1 < $f2) {      return -1;    } elsif ($f1 > $f2) {      return 1;    } else {      return index_compare ($r1,$r2);    }  }}sub oid_diff ($$) {  my($base, $full) = @_;  my $base_dotnot = join ('.',@{$base});  my $full_dotnot = BER::pretty_oid ($full);  return undef unless substr ($full_dotnot, 0, length $base_dotnot)    eq $base_dotnot      && substr ($full_dotnot, length $base_dotnot, 1) eq '.';  substr ($full_dotnot, length ($base_dotnot)+1);}sub pretty_address{    my($addr) = shift;    my($port,$ipaddr) = unpack_sockaddr_in($addr);    return sprintf ("[%s].%d",inet_ntoa($ipaddr),$port);}sub version { $VERSION; }package SNMPv1_Session;use strict qw(vars subs);	# see aboveuse vars qw(@ISA);use SNMP_Session;use Socket;use BER;@ISA = qw(SNMP_Session);sub snmp_version { 0 }sub open{    my($this,$remote_hostname,$community,$port,       $max_pdu_len,$bind_to_port,$max_repetitions) = @_;    my($name,$aliases,$remote_addr,$socket);    my $udp_proto = 0;    $community = 'public' unless defined $community;    $port = SNMP_Session::standard_udp_port unless defined $port;    $max_pdu_len = 8000 unless defined $max_pdu_len;    $max_repetitions = $default_max_repetitions	unless defined $max_repetitions;    $remote_addr = inet_aton ($remote_hostname)	|| return $this->error_return ("can't resolve \"$remote_hostname\" to IP address");    $socket = 'SNMP'.sprintf ("%s:%d", inet_ntoa ($remote_addr), $port);    (($name,$aliases,$udp_proto) = getprotobyname('udp'))	unless $udp_proto;    $udp_proto=17 unless $udp_proto;    socket ($socket, PF_INET, SOCK_DGRAM, $udp_proto)	|| return $this->error_return ("creating socket: $!");    if (defined $bind_to_port) {	my $sockaddr = sockaddr_in ($bind_to_port, INADDR_ANY);	bind ($socket, $sockaddr)	    || return $this->error_return ("binding to port $bind_to_port: $!");    }    $remote_addr = pack_sockaddr_in ($port, $remote_addr);    bless {	   'sock' => $socket,	   'sockfileno' => fileno ($socket),	   'community' => $community,	   'remote_hostname' => $remote_hostname,	   'remote_addr' => $remote_addr,	   'max_pdu_len' => $max_pdu_len,	   'pdu_buffer' => '\0' x $max_pdu_len,	   'request_id' => int (rand 0x80000000 + rand 0xffff),	   'timeout' => $default_timeout,	   'retries' => $default_retries,	   'backoff' => $default_backoff,	   'debug' => $default_debug,	   'error_status' => 0,	   'error_index' => 0,	   'default_max_repetitions' => $max_repetitions,	  };}sub open_trap_session (@) {    my ($this, $port) = @_;    $port = 162 unless defined $port;    return $this->open ("0.0.0.0", "", 161, undef, $port);}sub sock { $_[0]->{sock} }sub sockfileno { $_[0]->{sockfileno} }sub remote_addr { $_[0]->{remote_addr} }sub pdu_buffer { $_[0]->{pdu_buffer} }sub max_pdu_len { $_[0]->{max_pdu_len} }sub default_max_repetitions { $_[0]->{default_max_repetitions} }sub close{    my($this) = shift;    close ($this->sock) || $this->error ("close: $!");}sub wrap_request{    my($this) = shift;    my($request) = shift;    encode_sequence (encode_int ($this->snmp_version),		     encode_string ($this->{community}),		     $request)      || return $this->ber_error ("wrapping up request PDU");}my @error_status_code = qw(noError tooBig noSuchName badValue readOnly			   genErr noAccess wrongType wrongLength			   wrongEncoding wrongValue noCreation			   inconsistentValue resourceUnavailable			   commitFailed undoFailed authorizationError			   notWritable inconsistentName);sub unwrap_response_5b{    my ($this,$response,$tag,$oids,$errorp) = @_;    my ($community,$request_id,@rest,$snmpver);    ($snmpver,$community,$request_id,     $this->{error_status},     $this->{error_index},     @rest)	= decode_by_template ($response, "%{%i%s%*{%i%i%i%{%@",			      $tag);    return $this->ber_error ("Error decoding response PDU")      unless defined $snmpver;    return $this->error ("Received SNMP response with unknown snmp-version field $snmpver")	unless $snmpver == $this->snmp_version;    if ($this->{error_status} != 0) {      if ($errorp) {	my ($oid, $errmsg);	$errmsg = $error_status_code[$this->{error_status}] || $this->{error_status};	$oid = $oids->[$this->{error_index}-1]	  if $this->{error_index} > 0 && $this->{error_index}-1 <= $#{$oids};	$oid = $oid->[0]	  if ref($oid) eq 'ARRAY';	return ($community, $request_id,		$this->error ("Received SNMP response with error code\n"			      ."  error status: $errmsg\n"			      ."  index ".$this->{error_index}			      .(defined $oid				? " (OID: ".&BER::pretty_oid($oid).")"				: "")));      } else {	if ($this->{error_index} == 1) {	  @rest[$this->{error_index}-1..$this->{error_index}] = ();	}      }    }    ($community, $request_id, @rest);}sub send_query ($$){    my ($this,$query) = @_;    send ($this->sock,$query,0,$this->remote_addr);}sub receive_response_3{    my ($this, $response_tag, $oids, $errorp) = @_;    my ($remote_addr);    $remote_addr = recv ($this->sock,$this->{'pdu_buffer'},$this->max_pdu_len,0);    return $this->error ("receiving response PDU: $!")	unless defined $remote_addr;    return $this->error ("short (".length $this->{'pdu_buffer'}			 ." bytes) response PDU")	unless length $this->{'pdu_buffer'} > 2;    my $response = $this->{'pdu_buffer'};    ##    ## Check whether the response came from the address we've sent the    ## request to.  If this is not the case, we should probably ignore    ## it, as it may relate to another request.    ##    if ($this->{'debug'} && $remote_addr ne $this->{'remote_addr'}) {	warn "Response came from ".&SNMP_Session::pretty_address($remote_addr)	    .", not ".&SNMP_Session::pretty_address($this->{'remote_addr'})		unless $SNMP_Session::suppress_warnings;    }    $this->{'last_sender_addr'} = $remote_addr;    my ($response_community, $response_id, @unwrapped)	= $this->unwrap_response_5b ($response, $response_tag,				     $oids, $errorp);    if ($response_community ne $this->{community}        || $response_id ne $this->{request_id}) {	if ($this->{'debug'}) {	    warn "$response_community != $this->{community}"		unless $SNMP_Session::suppress_warnings		    || $response_community eq $this->{community};	    warn "$response_id != $this->{request_id}"		unless $SNMP_Session::suppress_warnings		    || $response_id == $this->{request_id};	}	return 0;    }    if (!defined $unwrapped[0]) {	$this->{'unwrapped'} = undef;	return undef;    }    $this->{'unwrapped'} = \@unwrapped;    return length $this->pdu_buffer;}sub receive_trap{    my ($this) = @_;    my ($remote_addr, $iaddr, $port, $trap);    $remote_addr = recv ($this->sock,$this->{'pdu_buffer'},$this->max_pdu_len,0);    return undef unless $remote_addr;    ($port, $iaddr) = sockaddr_in($remote_addr);    $trap = $this->{'pdu_buffer'};    return ($trap, $iaddr, $port);}sub describe{    my($this) = shift;    print $this->to_string (),"\n";}sub to_string{    my($this) = shift;    my ($class,$prefix);    $class = ref($this);    $prefix = ' ' x (length ($class) + 2);    ($class." (remote host: \"".$this->{remote_hostname}     ."\" ".&SNMP_Session::pretty_address ($this->remote_addr)."\n"     .$prefix."  community: \"".$this->{'community'}."\"\n"     .$prefix." request ID: ".$this->{'request_id'}."\n"     .$prefix."PDU bufsize: ".$this->{'max_pdu_len'}." bytes\n"     .$prefix."    timeout: ".$this->{timeout}."s\n"     .$prefix."    retries: ".$this->{retries}."\n"     .$prefix."    backoff: ".$this->{backoff}.")");##    sprintf ("SNMP_Session: %s (size %d timeout %g)",##    &SNMP_Session::pretty_address ($this->remote_addr),$this->max_pdu_len,##	       $this->timeout);}### SNMP Agent support### contributed by Mike McCauley <mikem@open.com.au>###sub receive_request{    my ($this) = @_;    my ($remote_addr, $iaddr, $port, $request);    $remote_addr = recv($this->sock, $this->{'pdu_buffer'}, 			$this->{'max_pdu_len'}, 0);    return undef unless $remote_addr;    ($port, $iaddr) = sockaddr_in($remote_addr);    $request = $this->{'pdu_buffer'};    return ($request, $iaddr, $port);}sub decode_request{    my ($this, $request) = @_;    my ($snmp_version, $community, $requestid, $errorstatus, $errorindex, $bindings);    ($snmp_version, $community, $requestid, $errorstatus, $errorindex, $bindings)	= decode_by_template ($request, "%{%i%s%*{%i%i%i%@", SNMP_Session::get_request);    if (defined $snmp_version)    {	# Its a valid get_request	return(SNMP_Session::get_request, $requestid, $bindings, $community);    }    ($snmp_version, $community, $requestid, $errorstatus, $errorindex, $bindings)	= decode_by_template ($request, "%{%i%s%*{%i%i%i%@", SNMP_Session::getnext_request);    if (defined $snmp_version)    {	# Its a valid getnext_request	return(SNMP_Session::getnext_request, $requestid, $bindings, $community);    }    ($snmp_version, $community, $requestid, $errorstatus, $errorindex, $bindings)	= decode_by_template ($request, "%{%i%s%*{%i%i%i%@", SNMP_Session::set_request);    if (defined $snmp_version)    {	# Its a valid set_request	return(SNMP_Session::set_request, $requestid, $bindings, $community);    }    # Something wrong with this packet    # Decode failed    return undef;}package SNMPv2c_Session;use strict qw(vars subs);	# see aboveuse vars qw(@ISA);use SNMP_Session;use BER;@ISA = qw(SNMPv1_Session);sub snmp_version { 1 }sub open{    my $session = SNMPv1_Session::open (@_);    return bless $session;}sub map_table_start_end ($$$$$$) {    my ($session, $columns, $mapfn, $start, $end, $max_repetitions) = @_;    my @encoded_oids;    my $call_counter = 0;    my $base_index = $start;    $max_repetitions = $session->default_max_repetitions	unless defined $max_repetitions;    do {	foreach (@encoded_oids = @{$columns}) {	    $_=encode_oid (@{$_},split '\.',$base_index)		|| return $session->ber_error ("encoding OID $base_index");	}	if ($session->getbulk_request_response (0, $max_repetitions,						@encoded_oids)) {	    my $response = $session->pdu_buffer;	    my ($bindings) = $session->decode_get_response ($response);	    my $smallest_index = undef;	    my @collected_values = ();	    my @bases = @{$columns};	    my $n_bindings = 0;	    while ($bindings ne '') {		my ($binding, $oid, $value);		unless (defined $bases[0]) {		    @bases = @{$columns};		    (++$call_counter,		     &$mapfn ($smallest_index, @collected_values))			if defined $smallest_index;		    $base_index = $smallest_index;		    $smallest_index = undef;		    @collected_values = ();		}		my $base = shift @bases;		($binding, $bindings) = decode_sequence ($bindings);		($oid, $value) = decode_by_template ($binding, "%O%@");		my $out_index;		++$n_bindings;		$out_index = SNMP_Session::oid_diff ($base, $oid);		my $cmp;		if (!defined $smallest_index		    || ($cmp = SNMP_Session::index_compare			($out_index,$smallest_index)) == -1) {		    $smallest_index = $out_index;		    grep ($_=undef, @collected_values);		    push @collected_values, $value;		} elsif ($cmp == 1) {		    push @collected_values, undef;		} else {		    push @collected_values, $value;		}	    }	    @bases = @{$columns};	    (++$call_counter,	     &$mapfn ($smallest_index, @collected_values))		if defined $smallest_index;	    $base_index = $smallest_index;	    $smallest_index = undef;	    @collected_values = ();	} else {	    return undef;	}    }    while (defined $base_index	   && (!defined $end || index_compare ($base_index, $end) < 0));    $call_counter;}1;