snmpstats.pl

来自「监控软件rrdtools」· PL 代码 · 共 364 行 · 第 1/2 页

#!/usr/bin/perl -w

# Q: Who wrote this?
# Bill Nash - [e-mail] / [e-mail]
#
# Q: Why?
# SNMP retrieval and storage of interface utilization, ala MRTG.
#
# Q: Is this a supported utility?
# Barely. That means if there's a serious problem with it, you can email me. I'll take feature requests
# provided they're presented in an intelligent manner. I will NOT write scripts for you. There's a plethora
# of information available to you, stop being lazy and do it yourself. Mostly, I wrote this for myself. I
# released it to the community at large because it's useful. Your mileage may vary. This code carries no 
# warranty and I'm not responsible if you do something stupid with it.
#
# Q: Why does the author sound like a grumpy curmudgeon?
# Because I'm releasing a utility to the public, and I detest people. I read the MRTG lists. I know what you 
# people are and are not capable of. I could jump up on my soapbox and rant about the general laziness of people,
# but no one will care. The user base at large is full of lazy bastards who just want someone else to create something
# that does exactly what they want, with as little effort required on their part.
#
# Q: Is it safe to ask questions about this utility?
# I will be more than happy to entertain discussions about this utility, provided:
#	It's a discussion of perl mechanics, and the person asking the question knows something about Perl.
#	It's a discussion of SNMP mechanics, and the person asking the question isn't asking where to find Mibs/objects.
#	You're a Playboy Bunny and you'd like to meet me for dinner.
#
# Q: Your code sucks, billn, why does this do [such and such], and why didn't you do condense [this and this]?
# This is intended to be a simple utility. No fancy obsfucation, no serious attention to efficiency. The only real creative 
# parts are using ifDescr/ifName as an interface basis (which offsets the nasty ifIndex shift problem by using ifIndex has a 
# value of the key, ifDescr/ifName, instead of vice versa. The ifIndex can change all it wants. Don't go saying 'Well, what if 
# interface name changes?', because I'll just say "Then it's a new interface. Cope."
# Also, by NOT obfuscating functions and keeping things simple, I'd hope people looking at this script that aren't fully versed
# in the intricacies and foibles of SNMP, PERL and RRD will have an easier time grasping the concepts, and maybe learn a bit from 
# this. Much of the code contained in here is interchangable, data sources can be substituted left and right, and I fully expect
# someone to hack this into a shining pearl of relative usefulness on a regular basis. It's not the end all, be all of SNMP pollers,
# but I expect it'll find widespread use.

$local_dir = "/usr/local/rrdtool-1.0.28";	# Where this script lives
$rrd_store = "$local_dir/rrd";		# Where to keep our rrd datastores

$debug = 0;

# This is Net::SNMP-2.00. It's not included with this script. Try CPAN.
use Net::SNMP;

# RRD Perl module. If you don't have it, why are you here?
use RRDs;

# This piece can be ripped out and subbed for any number of data storage methods. This is a simple method
# that works for those handling only a few devices. IP addresses are important because I don't use hostname
# matches for the SNMP calls. This eliminates DNS dependancies, but does require you to maintain your code or
# host registries.

$devices{"Hades"}{'ip_address'} = "10.0.0.254"; # my switch
$devices{"Hades"}{'snmp_read'} = "public";
$devices{"Bifrost"}{'ip_address'} = "10.0.0.253"; # my router
$devices{"Bifrost"}{'snmp_read'} = "public";

# Standard SNMP mib2 jazz. Feel free to edit. YMMV.

# Variables from the %oids hash we'll be referencing later. It's easier to call them by a name.
# What, you think I'm gonna memorize SNMP oids? =P

@poll_int = (
		"ifDescr",
		"ifOperStatus",
		"ifAlias",
		"ifInErrors",
		"ifInOctets",
		"ifOutErrors",
		"ifOutOctets",
		"ifSpeed"
);

%oids = (
	sysDescr              => "1.3.6.1.2.1.1.1.0",
	sysName               => "1.3.6.1.2.1.1.5.0",
	sysUptime             => "1.3.6.1.2.1.1.3.0",
	ifNumber              => "1.3.6.1.2.1.2.1.0",
	#ifDescr               => "1.3.6.1.2.1.2.2.1.2",
	ifType                => "1.3.6.1.2.1.2.2.1.3",
	ifSpeed               => "1.3.6.1.2.1.2.2.1.5",
	ifPhysAddress         => "1.3.6.1.2.1.2.2.1.6",
	ifAdminStatus         => "1.3.6.1.2.1.2.2.1.7", 
	ifOperStatus          => "1.3.6.1.2.1.2.2.1.8",
	ifAlias               => "1.3.6.1.2.1.31.1.1.1.18",
	ifInErrors            => "1.3.6.1.2.1.2.2.1.14",
	ifInOctets            => "1.3.6.1.2.1.2.2.1.10",
	ifInUnkProtos         => "1.3.6.1.2.1.2.2.1.15",
	ifLastChange          => "1.3.6.1.2.1.2.2.1.19",
	ifDescr                => "1.3.6.1.2.1.31.1.1.1.1", # was ifXName, subbed for ifDescr
	ifOutDiscards         => "1.3.6.1.2.1.2.2.1.19",
	ifOutErrors           => "1.3.6.1.2.1.2.2.1.20",
	ifOutOctets           => "1.3.6.1.2.1.2.2.1.16"
);

while(1) {
	$start = time;

	foreach $device_name (keys %devices) {
		undef(%ifAdmin);
		# Establish an snmp session with the device
        	my($session, $error) = Net::SNMP->session(
                                            Hostname  => $devices{$device_name}{'ip_address'},
                                            Community => $devices{$device_name}{'snmp_read'},
                                            Translate => 1,
                                            VerifyIP  => 1
        	);

	# This example may seem a bit long and drawn out, but it's better for a clear view of how the procedure works
	# It's entirely possible (and more efficient) to restructure this into a tight bundle of reusable code.
        	if ($session) {
                	print "$device_name: SNMP Session established ($device_name, $devices{$device_name}{'ip_address'})\n" if ($debug);

		# First step, find all the administratively active interfaces. Typically, this should be the ONLY
		# table that takes a walk across all interfaces. If you're doing smart and clean device management,
		# all unused/undesignated interfaces should be admin'd down and scrubbed of configs. If you don't
		# maintain this kind of device policy, don't cry to me because things take longer than you expect.

		# For the sake of efficiency, I should note here that this set of data doesn't HAVE to be generated with an SNMP poll
		# You can have an entirely external management system here that dictates what interfaces are tracked. You can rip this
		# chunk out and replace it with something else entirely.

		#print "Retrieving ifAdminStatus table: $oids{'ifAdminStatus'}\n" if ($debug);
                	$response = $session->get_table($oids{'ifAdminStatus'});
                	if($error_message = $session->error) {
                        	if($error_message eq "Requested table is empty" ||
                           		$error_message eq "Recieved SNMP noSuchName(2) error-status at error-index 1") {}
                        	else {
                                	print STDERR "ifAdmin table get failed ($device_name: $oids{'ifAdminStatus'}): $error_message\n"
                        	}	# end if
				next; # Can't get an ifAdminStatus table? No active interfaces or a borked SNMP engine. Next!
                	} # end if

                	%array = %{$response};
                	foreach $key (keys %array) {

				$ifIndex = $key;
				$ifIndex =~ s/^$oids{'ifAdminStatus'}.//g;

			# Hash the ifAdminStatus data if the status is 1. We aren't going to bother with any 
			# interfaces that aren't set active.
			# For the curious, possible values here are:
			# @OperStatus=("null", "Up", "Down", "Looped", "null", "Dormant", "Missing");

                       		$ifAdmin{$ifIndex} = $array{$key};
				#print "$device_name: ifIndex $ifIndex, ifAdmin $array{$key} $ifAdmin{$ifIndex}\n" if ($debug);
                	} #end foreach

			# Cycle through all The admin'd active interfaces, by ifIndex
			foreach $ifIndex (keys %ifAdmin) {
				undef(@interface_rrd);
				next if ($ifAdmin{$ifIndex} != 1);
			# Cycle through all the objects we want to track for each interface. This 
			# is a highly reusable set of code, set up to perform the same task repeatedly for 
			# (potentially long) lists of variables.
				foreach $object (@poll_int) {
				# get the numeric oid values from the oids table
					$object_id = $oids{$object};

				# go get the object.
	                		$response = $session->get_request("$object_id.$ifIndex");
      	         			if($error_message = $session->error) {
						if($error_message eq "Recieved SNMP noSuchName(2) error-status at error-index 1") {
						# It's a common occurence to poll an interface for an object that it
						# doesn't support, so we'll just U the object.
							$data{$device_name}{$ifIndex}{$object} = "U";
						} #end if

					# Whatever the object was, it didn't want to be 'gotten', so screw it.
       	                			print STDERR "Object get failed ($device_name: $object_id.$ifIndex):$error_message\n" if ($debug);
						next;
                			} #end if

                			%array = %{$response};

				# Shucks, got data, get to work. This chunk of code is pretty generic, and you'll 
				# recognize it from up above. I *could* use a single iteration here, but better save
				# in case the snmp engine did something hokey, or we used a table base variable in the get.
				# The multilayer hash prolly makes some of you twitch to see, but hey, if you don't like it,
				# why are you reading my code to begin with? It works, take a hike.