Netmasks and NetMaskGroups

There are two classes in the PowerDNS Recursor that can be used to match IP addresses against.

Netmask class

The Netmask class represents an IP netmask.

mask = newNetmask("192.0.2.1/24")
mask:isIPv4() -- true
mask:match("192.0.2.8") -- true
newNetmask(mask) → Netmask

Creates a new Netmask.

Parameters:mask (str) – The mask to convert.
class Netmask

Represents a netmask.

:empty() → bool

True if the netmask doesn’t contain a valid address.

:getBits() → int

The number of bits in the address.

:getNetwork() → ComboAddress

Returns a ComboAddress representing the network (no mask applied).

:getMaskedNetwork() → ComboAddress

Returns a ComboAddress representing the network (truncating according to the mask).

:isIpv4() → bool

True if the netmask is an IPv4 netmask.

:isIpv6() → bool

True if the netmask is an IPv6 netmask.

:match(address) → bool

True if the address passed in address matches

Parameters:address (str) – IP Address to match against.
:toString() → str

Returns a human-friendly representation.

NetMaskGroup class

NetMaskGroups are more powerful than plain Netmasks. They can be matched against netmasks objects:

nmg = newNMG()
nmg:addMask("127.0.0.0/8")
nmg:addMasks({"213.244.168.0/24", "130.161.0.0/16"})
nmg:addMasks(dofile("bad.ips")) -- contains return {"ip1","ip2"..}

if nmg:match(dq.remoteaddr) then
  print("Intercepting query from ", dq.remoteaddr)
end

Prefixing a mask with ! excludes that mask from matching.

newNMG() → NetMaskGroup

Returns a new, empty NetMaskGroup.

class NetMaskGroup

IP addresses are passed to Lua in native format.

:addMask(mask)

Adds mask to the NetMaskGroup.

Parameters:mask (str) – The mask to add.
:addMasks(masks)

Adds masks to the NetMaskGroup.

Parameters:mask ({str}) – The masks to add.
:match(address) → bool

Returns true if address matches any of the masks in the group.

Parameters:address (ComboAddress) – The IP addres to match the netmasks against.