require("bit")
require("luci.util")
+--- Boolean; true if system is little endian
LITTLE_ENDIAN = not luci.util.bigendian()
+
+--- Boolean; true if system is big endian
BIG_ENDIAN = not LITTLE_ENDIAN
+--- Specifier for IPv4 address family
FAMILY_INET4 = 0x04
+
+--- Specifier for IPv6 address family
FAMILY_INET6 = 0x06
} )
end
+local function __array16( x, family )
+ local list
+
+ if type(x) == "number" then
+ list = { bit.rshift(x, 16), bit.band(x, 0xFFFF) }
+
+ elseif type(x) == "string" then
+ if x:find(":") then x = IPv6(x) else x = IPv4(x) end
+ if x then
+ assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" )
+ list = { unpack(x[2]) }
+ end
+
+ elseif type(x) == "table" and type(x[2]) == "table" then
+ assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" )
+ list = { unpack(x[2]) }
+
+ elseif type(x) == "table" then
+ list = x
+ end
+
+ assert( list, "Invalid operand" )
+
+ return list
+end
+
local function __mask16(bits)
- return bit.lshift(
- bit.rshift( 0xFFFF, 16 - bits % 16 ),
- 16 - bits % 16
- )
+ return bit.lshift( bit.rshift( 0xFFFF, 16 - bits % 16 ), 16 - bits % 16 )
end
-local function __length(family)
- if family == FAMILY_INET4 then
- return 32
- else
- return 128
- end
+local function __not16(bits)
+ return bit.band( bit.bnot( __mask16(bits) ), 0xFFFF )
end
+local function __maxlen(family)
+ return ( family == FAMILY_INET4 ) and 32 or 128
+end
+
+local function __sublen(family)
+ return ( family == FAMILY_INET4 ) and 30 or 127
+end
+
+
--- Convert given short value to network byte order on little endian hosts
-- @param x Unsigned integer value between 0x0000 and 0xFFFF
-- @return Byte-swapped value
function Hex( hex, prefix, family, swap )
family = ( family ~= nil ) and family or FAMILY_INET4
swap = ( swap == nil ) and true or swap
- prefix = prefix or __length(family)
+ prefix = prefix or __maxlen(family)
- local len = __length(family)
+ local len = __maxlen(family)
local tmp = ""
local data = { }
--- LuCI IP Library / CIDR instances
-- @class module
+-- @cstyle instance
-- @name luci.ip.cidr
cidr = luci.util.class()
--- Test whether the instance is a IPv4 address.
-- @return Boolean indicating a IPv4 address type
--- @see is6
+-- @see cidr.is6
function cidr.is4( self )
return self[1] == FAMILY_INET4
end
--- Test whether the instance is a IPv6 address.
-- @return Boolean indicating a IPv6 address type
--- @see is4
+-- @see cidr.is4
function cidr.is6( self )
return self[1] == FAMILY_INET6
end
-- family than this instance.
-- @param addr A luci.ip.cidr instance to compare against
-- @return Boolean indicating whether this instance is lower
--- @see higher
--- @see equal
+-- @see cidr.higher
+-- @see cidr.equal
function cidr.lower( self, addr )
assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
for i = 1, #self[2] do
-- family than this instance.
-- @param addr A luci.ip.cidr instance to compare against
-- @return Boolean indicating whether this instance is higher
--- @see lower
--- @see equal
+-- @see cidr.lower
+-- @see cidr.equal
function cidr.higher( self, addr )
assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
for i = 1, #self[2] do
return false
end
---- Test whether the value of the instance is uequal to the given address.
+--- Test whether the value of the instance is equal to the given address.
-- This function will throw an exception if the given address is a different
-- family than this instance.
-- @param addr A luci.ip.cidr instance to compare against
-- @return Boolean indicating whether this instance is equal
--- @see lower
--- @see higher
+-- @see cidr.lower
+-- @see cidr.higher
function cidr.equal( self, addr )
assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
for i = 1, #self[2] do
end
--- Return the prefix length of this CIDR instance.
--- @return Prefix length in bit
+-- @param mask Override instance prefix with given netmask (optional)
+-- @return Prefix length in bit
function cidr.prefix( self, mask )
local prefix = self[3]
-- instance.
-- @param bits Override prefix length of this instance (optional)
-- @return CIDR instance containing the network address
--- @see host
--- @see mask
+-- @see cidr.host
+-- @see cidr.broadcast
+-- @see cidr.mask
function cidr.network( self, bits )
local data = { }
bits = bits or self[3]
end
end
- return __bless({ self[1], data, __length(self[1]) })
+ return __bless({ self[1], data, __maxlen(self[1]) })
end
--- Return a corresponding CIDR representing the host address of this
-- instance. This is intended to extract the host address from larger subnet.
-- @return CIDR instance containing the network address
--- @see network
--- @see mask
+-- @see cidr.network
+-- @see cidr.broadcast
+-- @see cidr.mask
function cidr.host( self )
- return __bless({ self[1], data, __length(self[1]) })
+ return __bless({ self[1], data, __maxlen(self[1]) })
end
--- Return a corresponding CIDR representing the netmask of this instance.
-- @param bits Override prefix length of this instance (optional)
-- @return CIDR instance containing the netmask
--- @see network
--- @see host
+-- @see cidr.network
+-- @see cidr.host
+-- @see cidr.broadcast
function cidr.mask( self, bits )
local data = { }
bits = bits or self[3]
end
end
- return __bless({ self[1], data, __length(self[1]) })
+ return __bless({ self[1], data, __maxlen(self[1]) })
+end
+
+--- Return CIDR containing the broadcast address of this instance.
+-- @return CIDR instance containing the netmask, always nil for IPv6
+-- @see cidr.network
+-- @see cidr.host
+-- @see cidr.mask
+function cidr.broadcast( self )
+ -- IPv6 has no broadcast addresses (XXX: assert() instead?)
+ if self[1] == FAMILY_INET4 then
+ local data = { unpack(self[2]) }
+ local offset = math.floor( self[3] / 16 ) + 1
+
+ if offset <= #data then
+ data[offset] = bit.bor( data[offset], __not16(self[3]) )
+ for i = offset + 1, #data do data[i] = 0xFFFF end
+
+ return __bless({ self[1], data, __maxlen(self[1]) })
+ end
+ end
end
--- Test whether this instance fully contains the given CIDR instance.
--- Add specified amount of hosts to this instance.
-- @param amount Number of hosts to add to this instance
+-- @param inplace Boolen indicating whether to alter values inplace (optional)
-- @return CIDR representing the new address or nil on overflow error
--- @see sub
-function cidr.add( self, amount )
- local shorts = { bit.rshift(amount, 16), bit.band(amount, 0xFFFF) }
+-- @see cidr.sub
+function cidr.add( self, amount, inplace )
local data = { unpack(self[2]) }
-
- for pos = #data, 1, -1 do
- local add = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
- if ( data[pos] + add ) > 0xFFFF then
- data[pos] = ( data[pos] + add ) % 0xFFFF
- if pos > 1 then
- data[pos-1] = data[pos-1] + ( add - data[pos] )
+ local shorts = __array16( amount, self[1] )
+
+ if shorts then
+ for pos = #data, 1, -1 do
+ local add = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
+ if ( data[pos] + add ) > 0xFFFF then
+ data[pos] = ( data[pos] + add ) % 0xFFFF
+ if pos > 1 then
+ data[pos-1] = data[pos-1] + ( add - data[pos] )
+ else
+ return nil
+ end
else
- return nil
+ data[pos] = data[pos] + add
end
- else
- data[pos] = data[pos] + add
end
end
- return __bless({ self[1], data, self[3] })
+ if inplace then
+ self[2] = data
+ return self
+ else
+ return __bless({ self[1], data, self[3] })
+ end
end
--- Substract specified amount of hosts from this instance.
-- @param amount Number of hosts to substract from this instance
+-- @param inplace Boolen indicating whether to alter values inplace (optional)
-- @return CIDR representing the new address or nil on underflow error
--- @see add
-function cidr.sub( self, amount )
- local shorts = { bit.rshift(amount, 16), bit.band(amount, 0xFFFF) }
+-- @see cidr.add
+function cidr.sub( self, amount, inplace )
local data = { unpack(self[2]) }
-
- for pos = #data, 1, -1 do
- local sub = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
- if ( data[pos] - sub ) < 0 then
- data[pos] = ( sub - data[pos] ) % 0xFFFF
- if pos > 1 then
- data[pos-1] = data[pos-1] - ( sub + data[pos] )
+ local shorts = __array16( amount, self[1] )
+
+ if shorts then
+ for pos = #data, 1, -1 do
+ local sub = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
+ if ( data[pos] - sub ) < 0 then
+ data[pos] = ( sub - data[pos] ) % 0xFFFF
+ if pos > 1 then
+ data[pos-1] = data[pos-1] - ( sub + data[pos] )
+ else
+ return nil
+ end
else
- return nil
+ data[pos] = data[pos] - sub
end
- else
- data[pos] = data[pos] - sub
end
end
- return __bless({ self[1], data, self[3] })
+ if inplace then
+ self[2] = data
+ return self
+ else
+ return __bless({ self[1], data, self[3] })
+ end
+end
+
+--- Return CIDR containing the lowest available host address within this subnet.
+-- @return CIDR containing the host address, nil if subnet is too small
+-- @see cidr.maxhost
+function cidr.minhost( self )
+ if self[3] <= __sublen(self[1]) then
+ -- 1st is Network Address in IPv4 and Subnet-Router Anycast Adresse in IPv6
+ return self:network():add(1, true)
+ end
+end
+
+--- Return CIDR containing the highest available host address within the subnet.
+-- @return CIDR containing the host address, nil if subnet is too small
+-- @see cidr.minhost
+function cidr.maxhost( self )
+ if self[3] <= __sublen(self[1]) then
+ local data = { unpack(self[2]) }
+ local offset = math.floor( self[3] / 16 ) + 1
+
+ data[offset] = bit.bor( data[offset], __not16(self[3]) )
+ for i = offset + 1, #data do data[i] = 0xFFFF end
+ data = __bless({ self[1], data, __maxlen(self[1]) })
+
+ -- Last address in reserved for Broadcast Address in IPv4
+ if data[1] == FAMILY_INET4 then data:sub(1, true) end
+
+ return data
+ end
end
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