[mpls-linux-general] packet journey in mpls linux (for experts)

[Francesco O. <f.o...@ti...>]

For my degree thesis i have to understand which is the real path a packet 
traverses in a linux mpls box.
Here is what a know:
when an (e.g.) ethernet frame arrives to the nic, it is stored in a skbuff 
structure; 
here a kernel function dermines the protocol field of the frame and calls the 
code of the corresponding layer; if this code is 0x0800 the frame is passed 
to the IP layer which in turn calls the first netfilter hook (prerouting)...
if the code is 0x8847 the frame is passed to the mpls layer; here are  my 
questions: 
this  means that no netfilter code is called because the frame is handled by 
mpls layer? 
So if i write a kernel module that hooks to the netfilter code, it will be 
bypassed in the mpls core nodes?  
Is there a documentation that explains step by step the funcions that are 
called by the mpls layer?

Thank you very much
Francesco Oppedisano