[Click] IP Header Option field

[Eddie Kohler]

Hi,

In addition to Beyers's comments, you might check elements such as IPGWOptions 
  that already process options, to see how we do it.

Eddie


Beyers Cronje wrote:
> Hi Haris,
> 
> The options field follows the standard 20-byte IP header and has variable
> length containing 0, 1 or multiple options. Each of the options can be
> either a single byte long, or multiple bytes in length, depending on how
> much information the option needs to convey. To gain access to the Options
> fields you would first determine if any options are present, i.e. IP header
> length > 20-bytes and then access the data from bytes 21 until end of
> options. Since the IP header length needs to be in multiples of 32bits there
> is a Padding field at the end of the options if the total length of all
> options is not a multiple of 32 bits.
> 
> I recommend you read the IP rfc or search google on more information on how
> to parse the options field.
> 
> Beyers
> 
> On 4/18/07, Haris Volos <hvolos at cs.wisc.edu> wrote:
>> Hey -
>>
>> I am new to Click. I was looking at the <clicknet/ip.h> IP header
>> definition, but I couldn't find the Option field. Is that field not
>> supported by Click? If not, is there any workaround for this?
>>
>> -Haris
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