Class: Libnet::Header
- Inherits:
-
Object
show all
- Includes:
- Helpers
- Defined in:
- lib/libnet4r/header.rb
Overview
Constant Summary
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- HWADDR_RE =
/^[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}:[A-Fa-f0-9]{2}$/
- IPADDR_RE =
/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/
- DEFAULT_OPTS =
{
:units => :bytes,
:read_only => false,
:optional => false,
:aliases => []
}
- UNIT_MULTIPLIERS =
{
:bits => 1,
:bytes => 8,
:words => 16,
}
Instance Attribute Summary collapse
Class Method Summary
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Instance Method Summary
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Methods included from Helpers
#check_integer, #check_string
Constructor Details
#initialize(bytes = nil) ⇒ Header
Returns a new instance of Header.
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# File 'lib/libnet4r/header.rb', line 163
def initialize(bytes = nil)
self.class.decode(bytes) if bytes
@auto_checksum = true
self
end
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Instance Attribute Details
#ptag ⇒ Object
Returns the value of attribute ptag.
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# File 'lib/libnet4r/header.rb', line 161
def ptag
@ptag
end
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Class Method Details
.assignment_filter(*fields, &blk) ⇒ Object
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# File 'lib/libnet4r/header.rb', line 99
def assignment_filter(*fields, &blk)
fields.each do |f|
self.assignment_filters[f] = blk
end
end
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.decode(bytes) ⇒ Object
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# File 'lib/libnet4r/header.rb', line 105
def decode(bytes)
raise NotImplementedError, "class #{self} has not implemented a decode method"
end
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.fields ⇒ Object
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# File 'lib/libnet4r/header.rb', line 109
def fields
self.required_fields + self.optional_fields + self.read_only_fields
end
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.inherited(cl) ⇒ Object
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# File 'lib/libnet4r/header.rb', line 27
def inherited(cl)
cl.assignment_filters = {}
cl.required_fields = []
cl.optional_fields = []
cl.read_only_fields = []
end
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.octets_field(name, size = nil, opts = {}) ⇒ Object
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# File 'lib/libnet4r/header.rb', line 66
def octets_field(name, size = nil, opts = {})
opts = DEFAULT_OPTS.merge opts
ivar = "@#{name}".to_sym
unless opts[:read_only]
self.class_eval do
define_method("#{name}=") do |v|
if v
value = v.dup
if self.assignment_filters.has_key? name
value = self.assignment_filters[name].call(v)
end
check_string(value)
if size && value.length != size
raise ArgumentError, "value must be #{size} bytes long for field '#{name}'"
end
else
value = v
end
instance_variable_set(ivar, value)
end
end
end
add_field(name, opts)
nil
end
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.unsigned_field(name, size, opts = {}) ⇒ Object
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# File 'lib/libnet4r/header.rb', line 34
def unsigned_field(name, size, opts = {})
opts = DEFAULT_OPTS.merge opts
size = size * UNIT_MULTIPLIERS[opts[:units]]
ivar = "@#{name}".to_sym
range = 0..2**size-1
unless opts[:read_only]
self.class_eval do
define_method("#{name}=") do |v|
if v
if self.assignment_filters.has_key? name
v = self.assignment_filters[name].call(v)
end
check_integer(v)
unless range.include? v
raise ArgumentError, "value #{v} is out of range for field '#{name}'"
end
end
instance_variable_set(ivar, v)
end
end
end
add_field(name, opts)
nil
end
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