# GetIP.pl - Query DOCSIS modem for network side IP address

use Net::SNMP;

# Use the standard Cable Modem address of 192.168.100.1 with a community string of public.
# Unless it has been changed, this should work without any problems.

my $HOST = @ARGV[0];
my $HOST = "192.168.100.1" unless $HOST;

($session, $error) = Net::SNMP->session(
  -hostname => shift | $HOST,
  -community => shift | "public",
  -port => shift | 161,
  -timeout => 60
  );
if (!defined($session)) {
  printf("ERROR: %s.\n", $error);
  exit 1;
}

############################################################
my $OID_IpAdEntAddr         = '1.3.6.1.2.1.4.20.1';
my $OID_QosMaxUpstream      = '1.3.6.1.2.1.10.127.1.1.3.1.3.1';
############################################################

$k = SNMPGetNextRequest($session, $OID_IpAdEntAddr);
($IPMib) = keys(%$k);
printf("Network IP Address:  %s\n",
  SNMPGetRequest($session, $IPMib)
);

$QosMaxUpstream = SNMPGetRequest($session, $OID_QosMaxUpstream);
printf("Qos Max Upstream Bandwidth: %s bps\n",
  Commas($QosMaxUpstream)
);
print "\n** THE UPSTREAM BANDWIDTH HAS BEEN CAPPED **\n"
  if ($QosMaxUpstream < 1000000);

$session->close();
exit 0;

#
# Commas( <Number> )
#
# RETURN: Comma seperated number
#

sub Commas {
  local($_) = @_;
  1 while s/(.*\d)(\d\d\d)/$1,$2/;
  $_;
}

#
# SNMPGetRequest(<SNMP Session Object>, <OID String> )
#
# RETURN: SNMP value for specified OID string
#

sub SNMPGetRequest {
  local($session) = shift @_;
  local($OID) = shift @_;

  if (!defined($response = $session->get_request($OID))) {
    printf("ERROR: %s.\n", $session->error());
    $session->close();
    exit 1;
  }
  return $response->{$OID}
}

#
# SNMPGetNextRequest(<SNMP Session Object>, <OID String> )
#
# RETURN: Hash containing found OID.
#

sub SNMPGetNextRequest {
  local($session) = shift @_;
  local($OID) = shift @_;

  if (!defined($response = $session->get_next_request($OID))) {
    printf("ERROR: %s.\n", $session->error());
    $session->close();
    exit 1;
  }
  return $response;
}