omcmd(1) - Linux man page

Name

omcmd - Update ISC dhcpd dynamically with OMAPI

Synopsis

omcmd [-k <keyname> <secret> | -K <keyfile> ] [-s server] [-v] <command> <objtype> <args>

Description

omcmd is a scriptable CLI program for performing actions on a running ISC dhcp server using OMAPI. It can currently be used to create, remove, modify and look up hosts and leases. Note that host and lease objects have persistent storage in the leases file.

The keyname and secret are the same as the values in the dhcpd.conf file; the secret should be base64 encoded. If using a 'keyfile', line1=keyname, line2=secret.

The -v option affects the lookup|find command, see below.

Commands

In the command descriptions below, 'indexproperty' is used to indicate a property that specifies the object uniquely to the dhcp server. I.e., ip-address uniquely specifies a lease object.

lookup|find <objecttype> <indexproperty=value> [property ...]: Look up a lease or host. For leases, specify the ip-address or hardware-address. For hosts, specify the name or hardware-address. If property names are specified after the lookup property, only those property values will be returned, one per line. if -v is given, they will be returned in property=value format.
create|add|new <objecttype> <property=value> ...: Create a new object, usually a 'host'. For hosts, specify name, hardware-address, hardware-type (usually 1 for ethernet), and optionally ip-address.
remove|delete <objecttype> <indexproperty=value>: Delete an object, usually a host. For hosts, you must specify name or hardware-address. At the time this was written, you cannot delete a lease; you can, however, modify the lease and change it's 'state' to 'free', but this requires a patched version of dhcp (as of dhcp-3.0.1, see the README included with the source). See modify, below.
modify|change|update <objecttype> <indexproperty=value> <property=value> ...: Change an object. Mostly used to change the 'state' of a 'lease'.

Object Types

Currently omcmd only has support for host and lease object types.

Properties

The following properties are known to omcmd:
state - the lease state
ip-address
dhcp-client-identifier
client-hostname
hardware-address
hardware-type - normally 1 for ethernet
ends
tstp
tsfp
cltt
name - unique name for host object
statements

known

Note: check the dhcp man pages listed in SEE ALSO, below, for more information on the properties and object types.

Return Value

On success, omcmd returns 0. For an OMAPI error, it returns the isc_result_t value. (See include/isc-dhcp/result.h). Command syntax errors return -1.

Examples

Lookup a lease and print everything:

$ ./omcmd -K ~/keyfile -s myserver lookup lease ip-address=10.20.93.155
state=active
ip-address=10.20.93.155
dhcp-client-identifier=01:00:e0:b8:72:8f:90
client-hostname=AU1201
hardware-address=00:e0:b8:72:8f:90
hardware-type=1
ends=Sat Jul 31 15:54:28 2004
tstp=Wed Dec 31 19:00:00 1969
tsfp=Wed Dec 31 19:00:00 1969
cltt=Wed Dec 31 19:00:00 1969

Lookup a lease and just give the hardware-address:

$ ./omcmd -K ~/keyfile -s myserver lookup lease ip-address=10.20.93.155 hardware-address
00:e0:b8:72:8f:90

Change a lease state to free:

$ ./omcmd -K ~/keyfile -s myserver modify

lease ip-address=10.20.162.42 state=free

Create a new host:

$ ./omcmd -K ~/keyfile

s myserver create host ip-address=10.20.162.242 name=ioreth hardware-type=1

hardware-address=00:e0:b8:50:0f:ab

Note: ip-address is optional.

Delete that host:

$ ./omcmd -K ~/keyfile -s myserver remove host name=ioreth

Bugs

Report all bugs (and send all patches) to parsley@linuxjedi.org.

Author

omcmd was written by David L. Parsley (parsley@linuxjedi.org) for use with a custom 'netreg' system.