Mini Shell
### -*- mode: Perl -*-
######################################################################
### SNMP Request/Response Handling
######################################################################
### Copyright (c) 1995-2008, Simon Leinen.
###
### This program is free software; you can redistribute it under the
### "Artistic License 2.0" 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 <tobi@oetiker.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
### Andrew Cornford-Matheson <andrew.matheson@corenetworks.com>: inform
### Gerry Dalton <gerry.dalton@consolidated.com>: strict subs bug
### Mike Fischer <mlf2@tampabay.rr.com>: pass MSG_DONTWAIT to recv()
######################################################################
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 = '1.12';
@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;
### Flags to be passed to recv() when non-blocking behavior is
### desired. On most POSIX-like systems this will be set to
### MSG_DONTWAIT, on other systems we leave it at zero.
###
my $dont_wait_flags;
BEGIN {
$ipv6_addr_len = undef;
$SNMP_Session::ipv6available = 0;
$dont_wait_flags = 0;
if (eval {local $SIG{__DIE__};require Socket6;} &&
eval {local $SIG{__DIE__};require IO::Socket::INET6; IO::Socket::INET6->VERSION("1.26");}) {
Socket6->import(qw(inet_pton getaddrinfo inet_ntop));
$ipv6_addr_len = length(pack_sockaddr_in6(161, inet_pton(AF_INET6(), "::1")));
$SNMP_Session::ipv6available = 1;
}
eval 'local $SIG{__DIE__};local $SIG{__WARN__};$dont_wait_flags = MSG_DONTWAIT();';
}
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);
if (!defined $snmp_version) {
($snmp_version, $community,$request_id, $error_status, $error_index, $bindings)
= decode_by_template ($trap, "%{%i%s%*{%i%i%i%{%@", inform_request);
}
return $this->error_return ("v2 trap/inform request contained errorStatus/errorIndex "
.$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 ($$$$$) {
my ($this, $req, $response_tag, $oids, $errorp) = @_;
my $retries = $this->retries;
my $timeout = $this->timeout;
my ($nfound, $timeleft);
## Encoding may have returned an error.
return undef unless defined $req;
$timeleft = $timeout;
while ($retries > 0) {
$this->send_query ($req)
|| return $this->error ("send_query: $!");
# IlvJa
# Add request pdu to capture_buffer
push @{$this->{'capture_buffer'}}, $req
if (defined $this->{'capture_buffer'}
and ref $this->{'capture_buffer'} eq 'ARRAY');
#
wait_for_response:
($nfound, $timeleft) = $this->wait_for_response($timeleft);
if ($nfound > 0) {
my($response_length);
$response_length
= $this->receive_response_3 ($response_tag, $oids, $errorp, 1);
if ($response_length) {
# IlvJa
# Add response pdu to capture_buffer
push (@{$this->{'capture_buffer'}},
substr($this->{'pdu_buffer'}, 0, $response_length)
)
if (defined $this->{'capture_buffer'}
and ref $this->{'capture_buffer'} eq 'ARRAY');
#
return $response_length;
} elsif (defined ($response_length)) {
goto wait_for_response;
# A response has been received, but for a different
# request ID or from a different IP address.
} else {
return undef;
}
} else {
## No response received - retry
--$retries;
$timeout *= $this->backoff;
$timeleft = $timeout;
}
}
# IlvJa
# Add empty packet to capture_buffer
push @{$this->{'capture_buffer'}}, ""
if (defined $this->{'capture_buffer'}
and ref $this->{'capture_buffer'} eq 'ARRAY');
#
$this->error ("no response received");
}
sub map_table ($$$) {
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 ($$) {
my($base, $full) = @_;
my $base_dotnot = join ('.',@{$base});
my $full_dotnot = BER::pretty_oid ($full);
return undef unless substr ($full_dotnot, 0, length $base_dotnot)
eq $base_dotnot
&& substr ($full_dotnot, length $base_dotnot, 1) eq '.';
substr ($full_dotnot, length ($base_dotnot)+1);
}
# Pretty_address returns a human-readable representation of an IPv4 or IPv6 address.
sub pretty_address {
my($addr) = shift;
my($port, $addrunpack, $addrstr);
# Disable strict subs to stop old versions of perl from
# complaining about AF_INET6 when Socket6 is not available
if( (defined $ipv6_addr_len) && (length $addr == $ipv6_addr_len)) {
($port,$addrunpack) = Socket6::unpack_sockaddr_in6 ($addr);
$addrstr = inet_ntop (AF_INET6(), $addrunpack);
} else {
($port,$addrunpack) = unpack_sockaddr_in ($addr);
$addrstr = inet_ntoa ($addrunpack);
}
return sprintf ("[%s].%d", $addrstr, $port);
}
sub version { $VERSION; }
sub error_return ($$) {
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;
Socket6->import(qw(inet_pton getaddrinfo inet_ntop));
}
}
@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' => '\0' 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 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 ($$) {
my ($this,$query) = @_;
send ($this->sock,$query,0,$this->remote_addr);
}
## Compare two sockaddr_in structures for equality. This is used when
## matching incoming responses with outstanding requests. Previous
## versions of the code simply did a bytewise comparison ("eq") of the
## two sockaddr_in structures, but this didn't work on some systems
## where sockaddr_in contains other elements than just the IP address
## and port number, notably FreeBSD.
##
## We allow for varying degrees of leniency when checking the source
## address. By default we now ignore it altogether, because there are
## agents that don't respond from UDP port 161, and there are agents
## that don't respond from the IP address the query had been sent to.
##
## The address family is stored in the session object. We could use
## sockaddr_family() to determine it from the sockaddr, but this function
## is only available in recent versions of Socket.pm.
sub sa_equal_p ($$$) {
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,$a1) = Socket6::unpack_sockaddr_in6 ($sa1);
($p2,$a2) = Socket6::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, $dont_block_p) = @_;
my ($remote_addr);
my $flags = 0;
$flags = $dont_wait_flags if defined $dont_block_p and $dont_block_p;
$remote_addr = recv ($this->sock,$this->{'pdu_buffer'},$this->max_pdu_len,$flags);
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,$iaddr) = Socket6::unpack_sockaddr_in6($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: ".$this->{'max_pdu_len'}." bytes\n"
.$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;
if( (defined $ipv6_addr_len) && (length $remote_addr == $ipv6_addr_len)) {
($port,$iaddr) = Socket6::unpack_sockaddr_in6($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 $end
and SNMP_Session::index_compare ($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 $end
and SNMP_Session::index_compare ($base_index, $end) >= 0;
}
$call_counter;
}
1;
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