[lwip-users] Patch implementing socket options

[Zschocke, Florian]

Hi All!

I have submitted a patch to Savannah for your perusal (#1399
https://savannah.nongnu.org/patch/index.php?func=detailpatch&patch_id=1399&g
roup_id=3159) which implements the following set of socket options:

SO_ACCEPTCONN
SO_BROADCAST
SO_KEEPALIVE
SO_TYPE

IP_TTL
IP_TOS

TCP_NODELAY
TCP_KEEPALIVE 

The set/getsocketopt() functions got almost completely rewritten. To
implement the functionality I had to change some core functions (e.g.
ip_output(_if)()) and also the PCBs. I have added a macro IP_PCB to ip.h
which defines the common subset of all PCB types. This is since we do not
have a seperate structure for this but instead need to have the same members
in the same order in all PCBs. This may look a bit awkward but has the
advantage that changes to the common subset of PCB members are done in one
place, only. 

See what you think and if you'd like to use it.

Work is underway to implement SO_REUSEADDR and SO_REUSEPORT.

Florian.