### Home Classes Methods

### In Files

- lib/packetfu/protos/eth/header.rb

### Parent

Struct.new(:eth_dst, :eth_src, :eth_proto, :body)

### Methods

- ::mac2str
- ::new
- ::str2mac
- #eth_daddr
- #eth_daddr=
- #eth_dst
- #eth_dst=
- #eth_dst_readable
- #eth_proto
- #eth_proto=
- #eth_proto_readable
- #eth_saddr
- #eth_saddr=
- #eth_src
- #eth_src=
- #eth_src_readable
- #read
- #to_s

### Included Modules

- StructFu

### Files

- .document
- README.rdoc

### Class/Module Index

Quicksearch

- PacketFu
- PacketFu::ARPHeader
- PacketFu::ARPHeaderMixin
- PacketFu::ARPPacket
- PacketFu::AddrIpv6
- PacketFu::Capture
- PacketFu::Config
- PacketFu::EthHeader
- PacketFu::EthHeaderMixin
- PacketFu::EthMac
- PacketFu::EthNic
- PacketFu::EthOui
- PacketFu::EthPacket
- PacketFu::HSRPHeader
- PacketFu::HSRPHeaderMixin
- PacketFu::HSRPPacket
- PacketFu::ICMPHeader
- PacketFu::ICMPHeaderMixin
- PacketFu::ICMPPacket
- PacketFu::IPHeader
- PacketFu::IPHeaderMixin
- PacketFu::IPPacket
- PacketFu::IPv6Header
- PacketFu::IPv6HeaderMixin
- PacketFu::IPv6Packet
- PacketFu::Inject
- PacketFu::InvalidHeader
- PacketFu::InvalidPacket
- PacketFu::LLDPHeader
- PacketFu::LLDPHeaderMixin
- PacketFu::LLDPPacket
- PacketFu::Octets
- PacketFu::Packet
- PacketFu::PcapFile
- PacketFu::PcapHeader
- PacketFu::PcapPacket
- PacketFu::PcapPackets
- PacketFu::Read
- PacketFu::TCPHeader
- PacketFu::TCPHeaderMixin
- PacketFu::TCPPacket
- PacketFu::TcpEcn
- PacketFu::TcpFlags
- PacketFu::TcpHlen
- PacketFu::TcpOption
- PacketFu::TcpOption::ECHO
- PacketFu::TcpOption::ECHOREPLY
- PacketFu::TcpOption::EOL
- PacketFu::TcpOption::MSS
- PacketFu::TcpOption::NOP
- PacketFu::TcpOption::SACK
- PacketFu::TcpOption::SACKOK
- PacketFu::TcpOption::TS
- PacketFu::TcpOption::WS
- PacketFu::TcpOptions
- PacketFu::TcpReserved
- PacketFu::Timestamp
- PacketFu::UDPHeader
- PacketFu::UDPHeaderMixin
- PacketFu::UDPPacket
- PacketFu::Utils
- PacketFu::Write
- StructFu
- StructFu::Int
- StructFu::Int16
- StructFu::Int16be
- StructFu::Int16le
- StructFu::Int32
- StructFu::Int32be
- StructFu::Int32le
- StructFu::Int8
- StructFu::IntString
- StructFu::String
- Struct

No matching classes.

# PacketFu::EthHeader

EthHeader is a complete Ethernet struct, used in EthPacket. It's the base header for all other protocols, such as IPHeader, TCPHeader, etc.

For more on the construction on MAC addresses, see en.wikipedia.org/wiki/MAC_address

TODO: Need to come up with a good way of dealing with vlan tagging. Having a usually empty struct member seems weird, but there may not be another way to do it if I want to preserve the Eth-ness of vlan-tagged 802.1Q packets. Also, may as well deal with 0x88a8 as well (en.wikipedia.org/wiki/802.1ad)

#### Header Definition

    EthMac  :eth_dst                     # See EthMac
    EthMac  :eth_src                     # See EthMac
    Int16   :eth_proto, Default: 0x8000  # IP 0x0800, Arp 0x0806
    String  :body

### Public Class Methods

mac2str(mac) click to toggle source

Converts a readable MAC (11:22:33:44:55:66) to a binary string. Readable MAC's may be split on colons, dots, spaces, or underscores.

irb> PacketFu::EthHeader.mac2str("11:22:33:44:55:66")

#=> "021"3DUf"

    # File lib/packetfu/protos/eth/header.rb, line 193
    def self.mac2str(mac)
      if mac.split(/[:\x2d\x2e\x5f]+/).size == 6
        ret =   mac.split(/[:\x2d\x2e\x20\x5f]+/).collect {|x| x.to_i(16)}.pack("C6")
      else
        raise ArgumentError, "Unkown format for mac address."
      end
      return ret
    end

new(args={}) click to toggle source

    # File lib/packetfu/protos/eth/header.rb, line 149
    def initialize(args={})
      super(
        EthMac.new.read(args[:eth_dst]),
        EthMac.new.read(args[:eth_src]),
        Int16.new(args[:eth_proto] || 0x0800),
        StructFu::String.new.read(args[:body])
      )
    end

str2mac(mac='') click to toggle source

Converts a binary string to a readable MAC (11:22:33:44:55:66).

irb> PacketFu::EthHeader.str2mac("x11x22x33x44x55x66")

#=> "11:22:33:44:55:66"

    # File lib/packetfu/protos/eth/header.rb, line 207
    def self.str2mac(mac='')
      if mac.to_s.size == 6 && mac.kind_of?(::String)
        ret = mac.unpack("C6").map {|x| sprintf("%02x",x)}.join(":")
      end
    end

### Public Instance Methods

eth_daddr() click to toggle source

Gets the destination MAC address in a more readable way.

    # File lib/packetfu/protos/eth/header.rb, line 233
    def eth_daddr
      EthHeader.str2mac(self[:eth_dst].to_s)
    end

Also aliased as: eth_dst_readable
eth_daddr=(mac) click to toggle source

Set the destination MAC address in a more readable way.

    # File lib/packetfu/protos/eth/header.rb, line 226
    def eth_daddr=(mac)
      mac = EthHeader.mac2str(mac)
      self[:eth_dst].read mac
      self[:eth_dst]
    end

eth_dst() click to toggle source

Getter for the Ethernet destination address.

    # File lib/packetfu/protos/eth/header.rb, line 161
    def eth_dst; self[:eth_dst].to_s; end

eth_dst=(i) click to toggle source

Setter for the Ethernet destination address.

    # File lib/packetfu/protos/eth/header.rb, line 159
    def eth_dst=(i); typecast(i); end

eth_dst_readable() click to toggle source

Readability aliases

Alias for: eth_daddr
eth_proto() click to toggle source

Getter for the Ethernet protocol number.

    # File lib/packetfu/protos/eth/header.rb, line 169
    def eth_proto; self[:eth_proto].to_i; end

eth_proto=(i) click to toggle source

Setter for the Ethernet protocol number.

    # File lib/packetfu/protos/eth/header.rb, line 167
    def eth_proto=(i); typecast(i); end

eth_proto_readable() click to toggle source

    # File lib/packetfu/protos/eth/header.rb, line 242
    def eth_proto_readable
      "0x%04x" % eth_proto
    end

eth_saddr() click to toggle source

Gets the source MAC address in a more readable way.

    # File lib/packetfu/protos/eth/header.rb, line 221
    def eth_saddr
      EthHeader.str2mac(self[:eth_src].to_s)
    end

Also aliased as: eth_src_readable
eth_saddr=(mac) click to toggle source

Sets the source MAC address in a more readable way.

    # File lib/packetfu/protos/eth/header.rb, line 214
    def eth_saddr=(mac)
      mac = EthHeader.mac2str(mac)
      self[:eth_src].read mac
      self[:eth_src]
    end

eth_src() click to toggle source

Getter for the Ethernet source address.

    # File lib/packetfu/protos/eth/header.rb, line 165
    def eth_src; self[:eth_src].to_s; end

eth_src=(i) click to toggle source

Setter for the Ethernet source address.

    # File lib/packetfu/protos/eth/header.rb, line 163
    def eth_src=(i); typecast(i); end

eth_src_readable() click to toggle source
Alias for: eth_saddr
read(str) click to toggle source

Reads a string to populate the object.

    # File lib/packetfu/protos/eth/header.rb, line 177
    def read(str)
      force_binary(str)
      return self if str.nil?
      self[:eth_dst].read str[0,6]
      self[:eth_src].read str[6,6]
      self[:eth_proto].read str[12,2]
      self[:body].read str[14,str.size]
      self
    end

to_s() click to toggle source

Returns the object in string form.

    # File lib/packetfu/protos/eth/header.rb, line 172
    def to_s
      self.to_a.map {|x| x.to_s}.join
    end

[Validate]

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