SNMP_Session.pm
上传用户:shbosideng
上传日期:2013-05-04
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文件大小:33k
- ### -*- mode: Perl -*-
- ######################################################################
- ### SNMP Request/Response Handling
- ######################################################################
- ### Copyright (c) 1995-2002, Simon Leinen.
- ###
- ### This program is free software; you can redistribute it under the
- ### "Artistic License" included in this distribution (file "Artistic").
- ######################################################################
- ### The abstract class SNMP_Session defines objects that can be used
- ### to communicate with SNMP entities. It has methods to send
- ### requests to and receive responses from an agent.
- ###
- ### Two instantiable subclasses are defined:
- ### SNMPv1_Session implements SNMPv1 (RFC 1157) functionality
- ### SNMPv2c_Session implements community-based SNMPv2.
- ######################################################################
- ### Created by: Simon Leinen <simon@switch.ch>
- ###
- ### Contributions and fixes by:
- ###
- ### Matthew Trunnell <matter@media.mit.edu>
- ### Tobias Oetiker <oetiker@ee.ethz.ch>
- ### Heine Peters <peters@dkrz.de>
- ### Daniel L. Needles <dan_needles@INS.COM>
- ### Mike Mitchell <mcm@unx.sas.com>
- ### Clinton Wong <clintdw@netcom.com>
- ### Alan Nichols <Alan.Nichols@Ebay.Sun.COM>
- ### Mike McCauley <mikem@open.com.au>
- ### Andrew W. Elble <elble@icculus.nsg.nwu.edu>
- ### Brett T Warden <wardenb@eluminant.com>: pretty UInteger32
- ### Michael Deegan <michael@cnspc18.murdoch.edu.au>
- ### Sergio Macedo <macedo@tmp.com.br>
- ### Jakob Ilves (/IlvJa) <jakob.ilves@oracle.com>: PDU capture
- ### Valerio Bontempi <v.bontempi@inwind.it>: IPv6 support
- ### Lorenzo Colitti <lorenzo@colitti.com>: IPv6 support
- ### Philippe Simonet <Philippe.Simonet@swisscom.com>: Export avoid...
- ### Luc Pauwels <Luc.Pauwels@xalasys.com>: use_16bit_request_ids
- ######################################################################
- package SNMP_Session;
- require 5.002;
- use strict;
- use Exporter;
- use vars qw(@ISA $VERSION @EXPORT $errmsg
- $suppress_warnings
- $default_avoid_negative_request_ids
- $default_use_16bit_request_ids);
- use Socket;
- use BER '1.05';
- use Carp;
- sub map_table ($$$ );
- sub map_table_4 ($$$$);
- sub map_table_start_end ($$$$$$);
- sub index_compare ($$);
- sub oid_diff ($$);
- $VERSION = '1.05';
- @ISA = qw(Exporter);
- @EXPORT = qw(errmsg suppress_warnings index_compare oid_diff recycle_socket ipv6available);
- my $default_debug = 0;
- ### Default initial timeout (in seconds) waiting for a response PDU
- ### after a request is sent. Note that when a request is retried, the
- ### timeout is increased by BACKOFF (see below).
- ###
- my $default_timeout = 2.0;
- ### Default number of attempts to get a reply for an SNMP request. If
- ### no response is received after TIMEOUT seconds, the request is
- ### resent and a new response awaited with a longer timeout (see the
- ### documentation on BACKOFF below). The "retries" value should be at
- ### least 1, because the first attempt counts, too (the name "retries"
- ### is confusing, sorry for that).
- ###
- my $default_retries = 5;
- ### Default backoff factor for SNMP_Session objects. This factor is
- ### used to increase the TIMEOUT every time an SNMP request is
- ### retried.
- ###
- my $default_backoff = 1.0;
- ### Default value for maxRepetitions. This specifies how many table
- ### rows are requested in getBulk requests. Used when walking tables
- ### using getBulk (only available in SNMPv2(c) and later). If this is
- ### too small, then a table walk will need unnecessarily many
- ### request/response exchanges. If it is too big, the agent may
- ### compute many variables after the end of the table. It is
- ### recommended to set this explicitly for each table walk by using
- ### map_table_4().
- ###
- my $default_max_repetitions = 12;
- ### Default value for "avoid_negative_request_ids".
- ###
- ### Set this to non-zero if you have agents that have trouble with
- ### negative request IDs, and don't forget to complain to your agent
- ### vendor. According to the spec (RFC 1905), the request-id is an
- ### Integer32, i.e. its range is from -(2^31) to (2^31)-1. However,
- ### some agents erroneously encode the response ID as an unsigned,
- ### which prevents this code from matching such responses to requests.
- ###
- $SNMP_Session::default_avoid_negative_request_ids = 0;
- ### Default value for "use_16bit_request_ids".
- ###
- ### Set this to non-zero if you have agents that use 16bit request IDs,
- ### and don't forget to complain to your agent vendor.
- ###
- $SNMP_Session::default_use_16bit_request_ids = 0;
- ### Whether all SNMP_Session objects should share a single UDP socket.
- ###
- $SNMP_Session::recycle_socket = 0;
- ### IPv6 initialization code: check that IPv6 libraries are available,
- ### and if so load them.
- ### We store the length of an IPv6 socket address structure in the class
- ### so we can determine if a socket address is IPv4 or IPv6 just by checking
- ### its length. The proper way to do this would be to use sockaddr_family(),
- ### but this function is only available in recent versions of Socket.pm.
- my $ipv6_addr_len;
- BEGIN {
- $ipv6_addr_len = undef;
- $SNMP_Session::ipv6available = 0;
- if (eval {require Socket6;} &&
- eval {require IO::Socket::INET6; IO::Socket::INET6->VERSION("1.26");}) {
- import Socket6;
- $ipv6_addr_len = length(pack_sockaddr_in6(161, inet_pton(AF_INET6(), "::1")));
- $SNMP_Session::ipv6available = 1;
- }
- }
- my $the_socket;
- $SNMP_Session::errmsg = '';
- $SNMP_Session::suppress_warnings = 0;
- sub get_request { 0 | context_flag };
- sub getnext_request { 1 | context_flag };
- sub get_response { 2 | context_flag };
- sub set_request { 3 | context_flag };
- sub trap_request { 4 | context_flag };
- sub getbulk_request { 5 | context_flag };
- sub inform_request { 6 | context_flag };
- sub trap2_request { 7 | context_flag };
- sub standard_udp_port { 161 };
- sub open
- {
- return SNMPv1_Session::open (@_);
- }
- sub timeout { $_[0]->{timeout} }
- sub retries { $_[0]->{retries} }
- sub backoff { $_[0]->{backoff} }
- sub set_timeout {
- my ($session, $timeout) = @_;
- croak ("timeout ($timeout) must be a positive number") unless $timeout > 0.0;
- $session->{'timeout'} = $timeout;
- }
- sub set_retries {
- my ($session, $retries) = @_;
- croak ("retries ($retries) must be a non-negative integer")
- unless $retries == int ($retries) && $retries >= 0;
- $session->{'retries'} = $retries;
- }
- sub set_backoff {
- my ($session, $backoff) = @_;
- croak ("backoff ($backoff) must be a number >= 1.0")
- unless $backoff == int ($backoff) && $backoff >= 1.0;
- $session->{'backoff'} = $backoff;
- }
- sub encode_request_3 ($$$@) {
- my($this, $reqtype, $encoded_oids_or_pairs, $i1, $i2) = @_;
- my($request);
- local($_);
- $this->{request_id} = ($this->{request_id} == 0x7fffffff)
- ? -0x80000000 : $this->{request_id}+1;
- $this->{request_id} += 0x80000000
- if ($this->{avoid_negative_request_ids} && $this->{request_id} < 0);
- $this->{request_id} &= 0x0000ffff
- if ($this->{use_16bit_request_ids});
- foreach $_ (@{$encoded_oids_or_pairs}) {
- if (ref ($_) eq 'ARRAY') {
- $_ = &encode_sequence ($_->[0], $_->[1])
- || return $this->ber_error ("encoding pair");
- } else {
- $_ = &encode_sequence ($_, encode_null())
- || return $this->ber_error ("encoding value/null pair");
- }
- }
- $request = encode_tagged_sequence
- ($reqtype,
- encode_int ($this->{request_id}),
- defined $i1 ? encode_int ($i1) : encode_int_0 (),
- defined $i2 ? encode_int ($i2) : encode_int_0 (),
- encode_sequence (@{$encoded_oids_or_pairs}))
- || return $this->ber_error ("encoding request PDU");
- return $this->wrap_request ($request);
- }
- sub encode_get_request {
- my($this, @oids) = @_;
- return encode_request_3 ($this, get_request, @oids);
- }
- sub encode_getnext_request {
- my($this, @oids) = @_;
- return encode_request_3 ($this, getnext_request, @oids);
- }
- sub encode_getbulk_request {
- my($this, $non_repeaters, $max_repetitions, @oids) = @_;
- return encode_request_3 ($this, getbulk_request, @oids,
- $non_repeaters, $max_repetitions);
- }
- sub encode_set_request {
- my($this, @encoded_pairs) = @_;
- return encode_request_3 ($this, set_request, @encoded_pairs);
- }
- sub encode_trap_request ($$$$$$@) {
- my($this, $ent, $agent, $gen, $spec, $dt, @pairs) = @_;
- my($request);
- local($_);
- foreach $_ (@pairs) {
- if (ref ($_) eq 'ARRAY') {
- $_ = &encode_sequence ($_->[0], $_->[1])
- || return $this->ber_error ("encoding pair");
- } else {
- $_ = &encode_sequence ($_, encode_null())
- || return $this->ber_error ("encoding value/null pair");
- }
- }
- $request = encode_tagged_sequence
- (trap_request, $ent, $agent, $gen, $spec, $dt, encode_sequence (@pairs))
- || return $this->ber_error ("encoding trap PDU");
- return $this->wrap_request ($request);
- }
- sub encode_v2_trap_request ($@) {
- my($this, @pairs) = @_;
- return encode_request_3($this, trap2_request, @pairs);
- }
- sub decode_get_response {
- my($this, $response) = @_;
- my @rest;
- @{$this->{'unwrapped'}};
- }
- sub decode_trap_request ($$) {
- my ($this, $trap) = @_;
- my ($snmp_version, $community, $ent, $agent, $gen, $spec, $dt,
- $request_id, $error_status, $error_index,
- $bindings);
- ($snmp_version, $community,
- $ent, $agent,
- $gen, $spec, $dt,
- $bindings)
- = decode_by_template ($trap, "%{%i%s%*{%O%A%i%i%u%{%@",
- trap_request);
- if (! defined ($snmp_version)) {
- ($snmp_version, $community,
- $request_id, $error_status, $error_index,
- $bindings)
- = decode_by_template ($trap, "%{%i%s%*{%i%i%i%{%@",
- trap2_request);
- return $this->error_return ("v2 trap request contained errorStatus/errorIndex "
- .$error_status."/".$error_index)
- if defined $error_status && defined $error_index
- && ($error_status != 0 || $error_index != 0);
- }
- if (!defined $snmp_version) {
- return $this->error_return ("BER error decoding trap:n ".$BER::errmsg);
- }
- return ($community, $ent, $agent, $gen, $spec, $dt, $bindings);
- }
- sub wait_for_response {
- my($this) = shift;
- my($timeout) = shift || 10.0;
- my($rin,$win,$ein) = ('','','');
- my($rout,$wout,$eout);
- vec($rin,$this->sockfileno,1) = 1;
- select($rout=$rin,$wout=$win,$eout=$ein,$timeout);
- }
- sub get_request_response ($@) {
- my($this, @oids) = @_;
- return $this->request_response_5 ($this->encode_get_request (@oids),
- get_response, @oids, 1);
- }
- sub set_request_response ($@) {
- my($this, @pairs) = @_;
- return $this->request_response_5 ($this->encode_set_request (@pairs),
- get_response, @pairs, 1);
- }
- sub getnext_request_response ($@) {
- my($this,@oids) = @_;
- return $this->request_response_5 ($this->encode_getnext_request (@oids),
- get_response, @oids, 1);
- }
- sub getbulk_request_response ($$$@) {
- my($this,$non_repeaters,$max_repetitions,@oids) = @_;
- return $this->request_response_5
- ($this->encode_getbulk_request ($non_repeaters,$max_repetitions,@oids),
- get_response, @oids, 1);
- }
- sub trap_request_send ($$$$$$@) {
- my($this, $ent, $agent, $gen, $spec, $dt, @pairs) = @_;
- my($req);
- $req = $this->encode_trap_request ($ent, $agent, $gen, $spec, $dt, @pairs);
- ## Encoding may have returned an error.
- return undef unless defined $req;
- $this->send_query($req)
- || return $this->error ("send_trap: $!");
- return 1;
- }
- sub v2_trap_request_send ($$$@) {
- my($this, $trap_oid, $dt, @pairs) = @_;
- my @sysUptime_OID = ( 1,3,6,1,2,1,1,3 );
- my @snmpTrapOID_OID = ( 1,3,6,1,6,3,1,1,4,1 );
- my($req);
- unshift @pairs, [encode_oid (@snmpTrapOID_OID,0),
- encode_oid (@{$trap_oid})];
- unshift @pairs, [encode_oid (@sysUptime_OID,0),
- encode_timeticks ($dt)];
- $req = $this->encode_v2_trap_request (@pairs);
- ## Encoding may have returned an error.
- return undef unless defined $req;
- $this->send_query($req)
- || return $this->error ("send_trap: $!");
- return 1;
- }
- sub request_response_5 ($$$$$) {
- my ($this, $req, $response_tag, $oids, $errorp) = @_;
- my $retries = $this->retries;
- my $timeout = $this->timeout;
- my ($nfound, $timeleft);
- ## Encoding may have returned an error.
- return undef unless defined $req;
- $timeleft = $timeout;
- while ($retries > 0) {
- $this->send_query ($req)
- || return $this->error ("send_query: $!");
- # IlvJa
- # Add request pdu to capture_buffer
- push @{$this->{'capture_buffer'}}, $req
- if (defined $this->{'capture_buffer'}
- and ref $this->{'capture_buffer'} eq 'ARRAY');
- #
-
- wait_for_response:
- ($nfound, $timeleft) = $this->wait_for_response($timeleft);
- if ($nfound > 0) {
- my($response_length);
- $response_length
- = $this->receive_response_3 ($response_tag, $oids, $errorp);
- if ($response_length) {
- # IlvJa
- # Add response pdu to capture_buffer
- push (@{$this->{'capture_buffer'}},
- substr($this->{'pdu_buffer'}, 0, $response_length)
- )
- if (defined $this->{'capture_buffer'}
- and ref $this->{'capture_buffer'} eq 'ARRAY');
- #
-
- return $response_length;
- } elsif (defined ($response_length)) {
- goto wait_for_response;
- # A response has been received, but for a different
- # request ID or from a different IP address.
- } else {
- return undef;
- }
- } else {
- ## No response received - retry
- --$retries;
- $timeout *= $this->backoff;
- $timeleft = $timeout;
- }
- }
- # IlvJa
- # Add empty packet to capture_buffer
- push @{$this->{'capture_buffer'}}, ""
- if (defined $this->{'capture_buffer'}
- and ref $this->{'capture_buffer'} eq 'ARRAY');
- #
- $this->error ("no response received");
- }
- sub map_table ($$$) {
- my ($session, $columns, $mapfn) = @_;
- return $session->map_table_4 ($columns, $mapfn,
- $session->default_max_repetitions ());
- }
- sub map_table_4 ($$$$) {
- my ($session, $columns, $mapfn, $max_repetitions) = @_;
- return $session->map_table_start_end ($columns, $mapfn,
- "", undef,
- $max_repetitions);
- }
- sub map_table_start_end ($$$$$$) {
- my ($session, $columns, $mapfn, $start, $end, $max_repetitions) = @_;
- my @encoded_oids;
- my $call_counter = 0;
- my $base_index = $start;
- do {
- foreach (@encoded_oids = @{$columns}) {
- $_=encode_oid (@{$_},split '.',$base_index)
- || return $session->ber_error ("encoding OID $base_index");
- }
- if ($session->getnext_request_response (@encoded_oids)) {
- my $response = $session->pdu_buffer;
- my ($bindings) = $session->decode_get_response ($response);
- my $smallest_index = undef;
- my @collected_values = ();
- my @bases = @{$columns};
- while ($bindings ne '') {
- my ($binding, $oid, $value);
- my $base = shift @bases;
- ($binding, $bindings) = decode_sequence ($bindings);
- ($oid, $value) = decode_by_template ($binding, "%O%@");
- my $out_index;
- $out_index = &oid_diff ($base, $oid);
- my $cmp;
- if (!defined $smallest_index
- || ($cmp = index_compare ($out_index,$smallest_index)) == -1) {
- $smallest_index = $out_index;
- grep ($_=undef, @collected_values);
- push @collected_values, $value;
- } elsif ($cmp == 1) {
- push @collected_values, undef;
- } else {
- push @collected_values, $value;
- }
- }
- (++$call_counter,
- &$mapfn ($smallest_index, @collected_values))
- if defined $smallest_index;
- $base_index = $smallest_index;
- } else {
- return undef;
- }
- }
- while (defined $base_index
- && (!defined $end || index_compare ($base_index, $end) < 0));
- $call_counter;
- }
- sub index_compare ($$) {
- 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 ($$) {
- my($base, $full) = @_;
- my $base_dotnot = join ('.',@{$base});
- my $full_dotnot = BER::pretty_oid ($full);
- return undef unless substr ($full_dotnot, 0, length $base_dotnot)
- eq $base_dotnot
- && substr ($full_dotnot, length $base_dotnot, 1) eq '.';
- substr ($full_dotnot, length ($base_dotnot)+1);
- }
- # Pretty_address returns a human-readable representation of an IPv4 or IPv6 address.
- sub pretty_address {
- my($addr) = shift;
- my($port, $addrunpack, $addrstr);
- # Disable strict subs to stop old versions of perl from
- # complaining about AF_INET6 when Socket6 is not available
- if( (defined $ipv6_addr_len) && (length $addr == $ipv6_addr_len)) {
- ($port,$addrunpack) = unpack_sockaddr_in6 ($addr);
- $addrstr = inet_ntop (AF_INET6(), $addrunpack);
- } else {
- ($port,$addrunpack) = unpack_sockaddr_in ($addr);
- $addrstr = inet_ntoa ($addrunpack);
- }
- return sprintf ("[%s].%d", $addrstr, $port);
- }
- sub version { $VERSION; }
- sub error_return ($$) {
- my ($this,$message) = @_;
- $SNMP_Session::errmsg = $message;
- unless ($SNMP_Session::suppress_warnings) {
- $message =~ s/^/ /mg;
- carp ("Error:n".$message."n");
- }
- return undef;
- }
- sub error ($$) {
- my ($this,$message) = @_;
- my $session = $this->to_string;
- $SNMP_Session::errmsg = $message."n".$session;
- unless ($SNMP_Session::suppress_warnings) {
- $session =~ s/^/ /mg;
- $message =~ s/^/ /mg;
- carp ("SNMP Error:n".$SNMP_Session::errmsg."n");
- }
- return undef;
- }
- sub ber_error ($$) {
- my ($this,$type) = @_;
- my ($errmsg) = $BER::errmsg;
- $errmsg =~ s/^/ /mg;
- return $this->error ("$type:n$errmsg");
- }
- package SNMPv1_Session;
- use strict qw(vars subs); # see above
- use vars qw(@ISA);
- use SNMP_Session;
- use Socket;
- use BER;
- use IO::Socket;
- use Carp;
- BEGIN {
- if($SNMP_Session::ipv6available) {
- import IO::Socket::INET6;
- import Socket6;
- }
- }
- @ISA = qw(SNMP_Session);
- sub snmp_version { 0 }
- # Supports both IPv4 and IPv6.
- # Numeric IPv6 addresses must be passed between square brackets []
- sub open {
- my($this,
- $remote_hostname,$community,$port,
- $max_pdu_len,$local_port,$max_repetitions,
- $local_hostname,$ipv4only) = @_;
- my($remote_addr,$socket,$sockfamily);
- $ipv4only = 1 unless defined $ipv4only;
- $sockfamily = AF_INET;
- $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 $max_repetitions;
- if ($ipv4only || ! $SNMP_Session::ipv6available) {
- # IPv4-only code, uses only Socket and INET calls
- if (defined $remote_hostname) {
- $remote_addr = inet_aton ($remote_hostname)
- or return $this->error_return ("can't resolve "$remote_hostname" to IP address");
- }
- if ($SNMP_Session::recycle_socket && defined $the_socket) {
- $socket = $the_socket;
- } else {
- $socket = IO::Socket::INET->new(Proto => 17,
- Type => SOCK_DGRAM,
- LocalAddr => $local_hostname,
- LocalPort => $local_port)
- || return $this->error_return ("creating socket: $!");
- $the_socket = $socket
- if $SNMP_Session::recycle_socket;
- }
- $remote_addr = pack_sockaddr_in ($port, $remote_addr)
- if defined $remote_addr;
- } else {
- # IPv6-capable code. Will use IPv6 or IPv4 depending on the address.
- # Uses Socket6 and INET6 calls.
- # If it's a numeric IPv6 addresses, remove square brackets
- if ($remote_hostname =~ /^[(.*)]$/) {
- $remote_hostname = $1;
- }
- my (@res, $socktype_tmp, $proto_tmp, $canonname_tmp);
- @res = getaddrinfo($remote_hostname, $port, AF_UNSPEC, SOCK_DGRAM);
- ($sockfamily, $socktype_tmp, $proto_tmp, $remote_addr, $canonname_tmp) = @res;
- if (scalar(@res) < 5) {
- return $this->error_return ("can't resolve "$remote_hostname" to IPv6 address");
- }
- if ($SNMP_Session::recycle_socket && defined $the_socket) {
- $socket = $the_socket;
- } elsif ($sockfamily == AF_INET) {
- $socket = IO::Socket::INET->new(Proto => 17,
- Type => SOCK_DGRAM,
- LocalAddr => $local_hostname,
- LocalPort => $local_port)
- || return $this->error_return ("creating socket: $!");
- } else {
- $socket = IO::Socket::INET6->new(Proto => 17,
- Type => SOCK_DGRAM,
- LocalAddr => $local_hostname,
- LocalPort => $local_port)
- || return $this->error_return ("creating socket: $!");
- $the_socket = $socket
- if $SNMP_Session::recycle_socket;
- }
- }
- bless {
- 'sock' => $socket,
- 'sockfileno' => fileno ($socket),
- 'community' => $community,
- 'remote_hostname' => $remote_hostname,
- 'remote_addr' => $remote_addr,
- 'sockfamily' => $sockfamily,
- 'max_pdu_len' => $max_pdu_len,
- 'pdu_buffer' => ' ' x $max_pdu_len,
- 'request_id' => (int (rand 0x10000) << 16)
- + int (rand 0x10000) - 0x80000000,
- 'timeout' => $default_timeout,
- 'retries' => $default_retries,
- 'backoff' => $default_backoff,
- 'debug' => $default_debug,
- 'error_status' => 0,
- 'error_index' => 0,
- 'default_max_repetitions' => $max_repetitions,
- 'use_getbulk' => 1,
- 'lenient_source_address_matching' => 1,
- 'lenient_source_port_matching' => 1,
- 'avoid_negative_request_ids' => $SNMP_Session::default_avoid_negative_request_ids,
- 'use_16bit_request_ids' => $SNMP_Session::default_use_16bit_request_ids,
- 'capture_buffer' => undef,
- };
- }
- sub open_trap_session (@) {
- my ($this, $port) = @_;
- $port = 162 unless defined $port;
- return $this->open (undef, "", 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 {
- defined $_[1]
- ? $_[0]->{default_max_repetitions} = $_[1]
- : $_[0]->{default_max_repetitions} }
- sub debug { defined $_[1] ? $_[0]->{debug} = $_[1] : $_[0]->{debug} }
- sub close {
- my($this) = shift;
- ## Avoid closing the socket if it may be shared with other session
- ## objects.
- if (! defined $the_socket || $this->sock ne $the_socket) {
- close ($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 coden"
- ." error status: $errmsgn"
- ." index ".$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 ($$) {
- my ($this,$query) = @_;
- send ($this->sock,$query,0,$this->remote_addr);
- }
- ## Compare two sockaddr_in structures for equality. This is used when
- ## matching incoming responses with outstanding requests. Previous
- ## versions of the code simply did a bytewise comparison ("eq") of the
- ## two sockaddr_in structures, but this didn't work on some systems
- ## where sockaddr_in contains other elements than just the IP address
- ## and port number, notably FreeBSD.
- ##
- ## We allow for varying degrees of leniency when checking the source
- ## address. By default we now ignore it altogether, because there are
- ## agents that don't respond from UDP port 161, and there are agents
- ## that don't respond from the IP address the query had been sent to.
- ##
- ## The address family is stored in the session object. We could use
- ## sockaddr_family() to determine it from the sockaddr, but this function
- ## is only available in recent versions of Socket.pm.
- sub sa_equal_p ($$$) {
- my ($this, $sa1, $sa2) = @_;
- my ($p1,$a1,$p2,$a2);
- # Disable strict subs to stop old versions of perl from
- # complaining about AF_INET6 when Socket6 is not available
- if($this->{'sockfamily'} == AF_INET) {
- # IPv4 addresses
- ($p1,$a1) = unpack_sockaddr_in ($sa1);
- ($p2,$a2) = unpack_sockaddr_in ($sa2);
- } elsif($this->{'sockfamily'} == AF_INET6()) {
- # IPv6 addresses
- ($p1,$a1) = unpack_sockaddr_in6 ($sa1);
- ($p2,$a2) = unpack_sockaddr_in6 ($sa2);
- } else {
- return 0;
- }
- use strict "subs";
- if (! $this->{'lenient_source_address_matching'}) {
- return 0 if $a1 ne $a2;
- }
- if (! $this->{'lenient_source_port_matching'}) {
- return 0 if $p1 != $p2;
- }
- return 1;
- }
- sub receive_response_3 {
- my ($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 (defined $this->{'remote_addr'}) {
- if (! $this->sa_equal_p ($remote_addr, $this->{'remote_addr'})) {
- if ($this->{'debug'} && !$SNMP_Session::recycle_socket) {
- carp ("Response came from ".&SNMP_Session::pretty_address($remote_addr)
- .", not ".&SNMP_Session::pretty_address($this->{'remote_addr'}))
- unless $SNMP_Session::suppress_warnings;
- }
- return 0;
- }
- }
- $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'}) {
- carp ("$response_community != $this->{community}")
- unless $SNMP_Session::suppress_warnings
- || $response_community eq $this->{community};
- carp ("$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;
- if( (defined $ipv6_addr_len) && (length $remote_addr == $ipv6_addr_len)) {
- ($port,$iaddr) = unpack_sockaddr_in6($remote_addr);
- } else {
- ($port,$iaddr) = unpack_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
- .(defined $this->{remote_hostname}
- ? " (remote host: "".$this->{remote_hostname}."""
- ." ".&SNMP_Session::pretty_address ($this->remote_addr).")"
- : " (no remote host specified)")
- ."n"
- .$prefix." community: "".$this->{'community'}.""n"
- .$prefix." request ID: ".$this->{'request_id'}."n"
- .$prefix."PDU bufsize: ".$this->{'max_pdu_len'}." bytesn"
- .$prefix." timeout: ".$this->{timeout}."sn"
- .$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;
- if( (defined $ipv6_addr_len) && (length $remote_addr == $ipv6_addr_len)) {
- ($port,$iaddr) = unpack_sockaddr_in6($remote_addr);
- } else {
- ($port,$iaddr) = unpack_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 above
- use vars qw(@ISA);
- use SNMP_Session;
- use BER;
- use Carp;
- @ISA = qw(SNMPv1_Session);
- sub snmp_version { 1 }
- sub open {
- my $session = SNMPv1_Session::open (@_);
- return undef unless defined $session;
- return bless $session;
- }
- ## map_table_start_end using get-bulk
- ##
- sub map_table_start_end ($$$$$$) {
- my ($session, $columns, $mapfn, $start, $end, $max_repetitions) = @_;
- my @encoded_oids;
- my $call_counter = 0;
- my $base_index = $start;
- my $ncols = @{$columns};
- my @collected_values = ();
- if (! $session->{'use_getbulk'}) {
- return SNMP_Session::map_table_start_end
- ($session, $columns, $mapfn, $start, $end, $max_repetitions);
- }
- $max_repetitions = $session->default_max_repetitions
- unless defined $max_repetitions;
- for (;;) {
- foreach (@encoded_oids = @{$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 @colstack = ();
- my $k = 0;
- my $j;
- my $min_index = undef;
- my @bases = @{$columns};
- my $n_bindings = 0;
- my $binding;
- ## Copy all bindings into the colstack.
- ## The colstack is a vector of vectors.
- ## It contains one vector for each "repeater" variable.
- ##
- while ($bindings ne '') {
- ($binding, $bindings) = decode_sequence ($bindings);
- my ($oid, $value) = decode_by_template ($binding, "%O%@");
- push @{$colstack[$k]}, [$oid, $value];
- ++$k; $k = 0 if $k >= $ncols;
- }
- ## Now collect rows from the column stack:
- ##
- ## Iterate through the column stacks to find the smallest
- ## index, collecting the values for that index in
- ## @collected_values.
- ##
- ## As long as a row can be assembled, the map function is
- ## called on it and the iteration proceeds.
- ##
- $base_index = undef;
- walk_rows_from_pdu:
- for (;;) {
- my $min_index = undef;
- for ($k = 0; $k < $ncols; ++$k) {
- $collected_values[$k] = undef;
- my $pair = $colstack[$k]->[0];
- unless (defined $pair) {
- $min_index = undef;
- last walk_rows_from_pdu;
- }
- my $this_index
- = SNMP_Session::oid_diff ($columns->[$k], $pair->[0]);
- if (defined $this_index) {
- my $cmp
- = !defined $min_index
- ? -1
- : SNMP_Session::index_compare
- ($this_index, $min_index);
- if ($cmp == -1) {
- for ($j = 0; $j < $k; ++$j) {
- unshift (@{$colstack[$j]},
- [$min_index,
- $collected_values[$j]]);
- $collected_values[$j] = undef;
- }
- $min_index = $this_index;
- }
- if ($cmp <= 0) {
- $collected_values[$k] = $pair->[1];
- shift @{$colstack[$k]};
- }
- }
- }
- ($base_index = undef), last
- if !defined $min_index;
- last if defined $end && index_compare ($min_index, $end) >= 0;
- &$mapfn ($min_index, @collected_values);
- ++$call_counter;
- $base_index = $min_index;
- }
- } else {
- return undef;
- }
- last if !defined $base_index;
- last if defined $end and index_compare ($base_index, $end) >= 0;
- }
- $call_counter;
- }
- 1;