Files
netdisco/lib/App/Netdisco/Util/SNMP.pm
Oliver Gorwits 884a75a866 #659 speed up Macsuck::Nodes while using $snmp->cisco_comm_indexing (#661)
* #659 speed up Macsuck::Nodes while using $snmp->cisco_comm_indexing

* Do not read qb_fw_vlan when using cisco_comm_indexing
2019-10-14 22:08:38 +02:00

134 lines
3.9 KiB
Perl

package App::Netdisco::Util::SNMP;
use Dancer qw/:syntax :script/;
use App::Netdisco::Util::DeviceAuth 'get_external_credentials';
use base 'Exporter';
our @EXPORT = ();
our @EXPORT_OK = qw/ get_communities snmp_comm_reindex /;
our %EXPORT_TAGS = (all => \@EXPORT_OK);
=head1 NAME
App::Netdisco::Util::SNMP
=head1 DESCRIPTION
Helper functions for L<SNMP::Info> instances.
There are no default exports, however the C<:all> tag will export all
subroutines.
=head1 EXPORT_OK
=head2 get_communities( $device, $mode )
Takes the current C<device_auth> setting and pushes onto the front of the list
the last known good SNMP settings used for this mode (C<read> or C<write>).
=cut
sub get_communities {
my ($device, $mode) = @_;
$mode ||= 'read';
my $seen_tags = {}; # for cleaning community table
my $config = (setting('device_auth') || []);
my @communities = ();
# first of all, use external command if configured
push @communities, get_external_credentials($device, $mode);
# last known-good by tag
my $tag_name = 'snmp_auth_tag_'. $mode;
my $stored_tag = eval { $device->community->$tag_name };
if ($device->in_storage and $stored_tag) {
foreach my $stanza (@$config) {
if ($stanza->{tag} and $stored_tag eq $stanza->{tag}) {
push @communities, {%$stanza, only => [$device->ip]};
last;
}
}
}
# try last-known-good v2 read
push @communities, {
read => 1, write => 0, driver => 'snmp',
only => [$device->ip],
community => $device->snmp_comm,
} if defined $device->snmp_comm and $mode eq 'read';
# try last-known-good v2 write
my $snmp_comm_rw = eval { $device->community->snmp_comm_rw };
push @communities, {
write => 1, read => 0, driver => 'snmp',
only => [$device->ip],
community => $snmp_comm_rw,
} if $snmp_comm_rw and $mode eq 'write';
# clean the community table of obsolete tags
eval { $device->community->update({$tag_name => undef}) }
if $device->in_storage
and (not $stored_tag or !exists $seen_tags->{ $stored_tag });
return ( @communities, @$config );
}
=head2 snmp_comm_reindex( $snmp, $device, $vlan )
Takes an established L<SNMP::Info> instance and makes a fresh connection using
community indexing, with the given C<$vlan> ID. Works for all SNMP versions.
Inherits the C<vtp_version> from the previous L<SNMP::Info> instance.
Passing VLAN "C<0>" (zero) will reset the indexing to the basic v2 community
or v3 empty context.
=cut
sub snmp_comm_reindex {
my ($snmp, $device, $vlan) = @_;
my $ver = $snmp->snmp_ver;
my $vtp = $snmp->vtp_version;
if ($ver == 3) {
my $prefix = '';
my @comms = get_communities($device, 'read');
# find a context prefix configured by the user
foreach my $c (@comms) {
next unless $c->{tag}
and $c->{tag} eq (eval { $device->community->snmp_auth_tag_read } || '');
$prefix = $c->{context_prefix} and last;
}
$prefix ||= 'vlan-';
if ($vlan =~ /^[0-9]+$/i && $vlan) {
debug sprintf '[%s] reindexing to "%s%s" (ver: %s, class: %s)',
$device->ip, $prefix, $vlan, $ver, $snmp->class;
$snmp->update(Context => ($prefix . $vlan));
} elsif ($vlan =~ /^[a-z0-9]+$/i && $vlan) {
debug sprintf '[%s] reindexing to "%s" (ver: %s, class: %s)',
$device->ip, $vlan, $ver, $snmp->class;
$snmp->update(Context => ($vlan));
} else {
debug sprintf '[%s] reindexing without context (ver: %s, class: %s)',
$device->ip, $ver, $snmp->class;
$snmp->update(Context => '');
}
}
else {
my $comm = $snmp->snmp_comm;
debug sprintf '[%s] reindexing to vlan %s (ver: %s, class: %s)',
$device->ip, $vlan, $ver, $snmp->class;
$vlan ? $snmp->update(Community => $comm . '@' . $vlan)
: $snmp->update(Community => $comm);
}
$snmp->cache({ _vtp_version => $vtp });
return $snmp;
}
true;