man netdisco (1): Internal API

DESCRIPTION

This is the inside guts of the Netdisco executable. You should be looking in README for how to use Netdisco.

FUNCTIONS

Network Discovery

discover(host): Discovers one device, stores its info, interfaces, and neighbors, and returns.
refresh_all(): Calls discover() for each file already in device table.
run(): Event loop that calls discover() as long as the @Discover_Queue has something in it.
schlop(file,topo_only_flag): Used to start a discovery based on topography file. Will then proceed to do an initial mac_suck() and arp_nip() unless the topo_only_flag is set.
queue_process(device, action, [status]): Queue a request for this controller to perform an action.
topo_add_link([{},{}]): Pass reference to array of hash references holding link: lines from manual topology info. Adds information to device_port table.
topo_load_file(filename): Loads and parses manual topography file.

Utility Functions

add_user()

Takes 4 optional arguments from @ARGV = (user,pw,port,admin)

If all 4 are not there, then interactive mode is entered and prompts are given.

batch_mode(name,time_too?)

Redirects STDOUT to a log file with timestamp.

Can be called recursively. call batch_mode_end() to return to previous Output.

batch_mode_end(no_compress_flag)

Returns control of stdout to previous value, optionally compresses the finished output file.

Function returns file name of closed output file.

Pass something as first parameter to force no compression.

end_int_handler

end()

Cleanup routine that is called upon interrupt (ctrl-c) or end of routines.

Prints various statistics to stdout or batch_redirect() and calls Netdisco::log().

load_old_devices()

Populates %Old_Devices with which devices are in the database.

load_old_nodes(days)

Populates %Old_Nodes with which nodes are in the database.

Nodes will have to have been seen in the last DAYS days.

parse_oui()

Parses file oui.txt in current directory. Uses contents to stuff table ``oui''.

timeout()

Signal handler for SIGALARM

ok_to(dev,name,what)

Given a device or IP address, a display name (hostname or IP address), and an action (arpnip, macsuck, discover), check the configuration file for _no and _only configurations. Return 1 if it's OK, or 0 if it's not OK.

SNMP Functions

arpnip()

Connects to device and reads its ARP cache. Then adds entries to "node_ip" table.

Cheers to Jim Warner for the original arpnip.

arpwalk()

Visits every Layer 3 device and trys to get its ARP Cache.

Calls arpnip() for each device.

create_device(%args)

All %args are passed straight through to SNMP::Info except 'Class' which when set turns off "AutoSpecify".

 my $dev = create_device(
            'DestHost'     => host,
            'Community'    => public,
            'Version'      => 2,
            'Retries'      => 2,
            'Class'        => 'SNMP::Info::Layer2',
            'VersionForce' => 1,

Connect to a device via SNMP::Info with a given host and community string.

If optional "Version" and "Class" are given, no device type discovery is done.

If a more specific device type is not found "-1" is returned. The target device is probably not a network device.

If "VersionForce" is true, no fallback to snmpv1 will happen.

device_root()

Looks to see if the device has a master IP instead of the one given. Checks for root_ip() method, then tries to lookup the reverse entry for sysName.0

find_neighbors()

Finds all the CDP information on the device and stores the results in device_node.

Adds to the @Discover_Queue

get_device(host)

Calls create_device() with a community string

If cached values are stored in the database for the SNMP version and community strings, they are used.

If no cached values are available, or if they fail, then the values from the config file are tried.

check_snmp_version(device,[version])

Check for a forced SNMP version by the configuration file arguments snmpforce_v1, snmpforce_v2, snmpforce_v3

get_snmp_args(device,version,comm/user,rw)

Returns the args used to connect to device with version

get_device_rw(device[,version])

Returns a SNMP::Info object for a given device, using the Read-Write Community Strings in the config file.

Returns undef or -1 on error.

get_subnets(device)

Grab netmask and ip from device interfaces. Determine device subnets mathematically based upon the interface information.

store_modules()

Gets all the physical module information using Table Methods in SNMP::Info.

Deletes the old module entries in device_module and puts in new ones.

mac_getportmacs()

Fills the global %PortMAC with MAC addresses of ports already discovered. This is to make sure we don't mac-suck existing ports, such as VLANs.

macsuck()

Walks forwarding table for a specific device.

Gets mac addresses that are listed in physical ports that do not have a neighbor listed. If the device has VLANs, it will walk each VLAN and get the MAC addresses from there.

macsuck_vlans(...)

For certain Cisco switches you have to connect to each VLAN and get the forwarding table out of it. Notably the Catalyst 5k, 6k, and 3500 series

This sub checks to see if the device supports this and then interrogates each VLAN.

Returns number of nodes discovered in forwarding tables.

wireless_client_info

Walks Cisco dot11 client associations, if present, and stores per-client association information.

mac_savecache({},{})

Does two things :

1. Checks for detected uplinks, warns of such and removes nodes on these uplinks from additions list

2. Stores the found forwarding table entries to the database.

macwalk()

Grabs all the devices out of the database. Runs macsuck() on each device that has layer2 capabilites.

send_monitor_email()

If there is an email address configured in netdisco.conf under node_monitor_email, look for any rows in the node_monitor table that are being monitored and if the mac address has arrived or moved, send the appropriate email. This function only works immediately after macsuck; if another macsuck happens in between this will not detect the arrival. Therefore, this function is only ever called from the end of macwalk.

set_status()

Sets $0 to a status string. Use sprintf-style arguments.

parallel_init()

Initializes parallelization with the maximum number of simultaneously running processes set in configuration file. Creates a dummy SNMP::Info object to load MIBs only once for each child. Disconnects the database handle so that it's not held open across a fork.

dispatcher(action, subroutine)

Multi-process dispatcher that handles the ``standard'' case of multiple macsuck/arpnip/nbtstat. It uses Parallel::ForkManager in a slightly unusual way, in that it forks off long-lived worker children that service the queue themselves, similar to Apache.

port_control(switch,port,direction)

port_switch({})

Used to shut ports on and off and to change VLANs.

store_device()

Calls all the global methods and sends the results off to the database

store_interfaces()

Gets all the interface information using Table Methods in SNMP::Info.

Deletes the old interface entries in device_port and puts in new ones.

store_vlans()

Gets all the VLAN information using Table Methods in SNMP::Info.

Deletes the old VLAN entries in device_port_vlan and puts in new ones.

store_power()

Gets all the Power-over-Ethernet information using Table Methods in SNMP::Info.

Deletes the old PoE entries in device_power and device_port_power and puts in new ones.

walk_fwtable()

Walks the Forwarding table from the "BRIDGE-MIB" for the given device, and then adds MAC addresses to the "node" table. Returns the number of entries fetched.

NetBIOS Functions

nbtstat(host): Connects to node and gets NetBIOS information. Then adds entries to node_nbt table.
Returns whether a node is answering netbios calls or not.
nbtwalk(): Visits every node and trys to get its NetBIOS information.
Calls nbtstat() for each device.

Maintenance Functions

alias_clean()

Routine to clean out devices that are now listed as aliases of another device. This is usually necessary after a device has been merged into another one.

arp_dump(dir)

Dumps node_ip table to files arp_current and arp_archive.

change_device_ip(from_ip, to_ip)

Used to move move over all the information from one device to a new IP address. First tries to discover new device, then proceeds to move over old information.

db_clean()

Removes all the entries in "node" that are switch ports.

Checks for nodes on non existant ports and prints a warning

Removes nodes that are on uplink ports.

dev_dump()

Dumps out the device,device_ip, and topology info from device_port to file 'devices'.

expire_data(type,days,archive_only)

"type" can be : node,device,process

"days" is a positive integer number of days in which an entry has not been updated.

"archive_only" for node only.

Removes devices and nodes that haven't been updated in "days" days or processes created "days" days ago. Process table clean up is for crashed or improperly terminated jobs still in the table. Called from nightly() and controlled through the "expire_*" directives in the config file.

Cheers to Brian Wilson for his patch for the start of this feature.

expire_device(device,expire_nodes?)

Removes device from the database

Set second argument to true to remove all the connected nodes and their IP mappings as well.

expire_nodes(device,archive_only,port)

Removes entries from node and node_ip for a given device.

Set port to limit the expiration to a specific port.

Set archive_only to 1 to archive the nodes on the device.

expire_nodes_subnet(subnet)

Subnet is in CIDR format, or any other format that Postgres likes.

    192.168.0.0/24

Runs expire_ips afterwards to cleanup.

expire_ips()

Expires IPs not in use in node.

 delete from node_ip where 
    mac not in
        (select mac from node)

mac_dump()

Dumps the node table out to mac_current.txt and mac_archive.txt. Adds a day stamp, no time-stamp.

netbios_dump()

Dumps the node_nbt table out to netbios_current.txt and netbios_archive.txt. Adds a day stamp, no time-stamp.

nightly(no_batch)

Nightly maintance routine that creates backups of the device,node, and node_ip tables.

Calls expire_data(), nmis_dump(), mac_dump(), arp_dump(), dev_dump(), netbios_dump(), db_clean() and VACUUM ANALYZE

nmis_dump()

Dumps the device table out to NMIS (http://www.sins.com.au/nmis/) style config file.

Graphing Functions

graph(no_batch): Creates netmap of network. Calls Netdisco::make_graph() and graph_each()
graph_each(Graph_obj, name): Generates subgraph. Called from graph(). Calls graph_node().
Does actual GraphViz calls.
graph_addnode(graphviz_obj,node_ip): Checks for mapping settings in config file and adds node to the GraphViz object.

Admin Daemon

admin_daemon_ctl(cmd): start,stop,restart,status
admin_daemon_status(pid): Returns 0 if daemon is not running or returns pid number if running.
pid argument is optional, used in stop function
admin_daemon(): Resident copy of netdisco to handle requests from the admin panel.
admin_daemon_pid(pid_to_write): If not supplied arguments, Reads pid of daemon pid from netdisco_daemon.pid
If supplied arguments, writes the pid out to that file.
admin_daemon_job(job_obj): Runs each job. Redirects output to data/admin/job-num-date.log job_obj is the sql hash object for each job.

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