[lwip-users] Missing SOL_TCP?

[Grant Edwards]

It appears that there is code in lwip_getsockopt_impl to handle
setting tcp keepalive values via the keys TCP_KEEPIDLE, TCP_KEEPINTVL,
and TCP_KEEPCNT.

Using the Berekely socket API, these are set via calls to setsocktopt():

    setsockopt(s, SOL_TCP, TCP_KEEPxxxx, &n, sizeof n);

However, the only SOL_xxx "level" constant I can find defined by LWIP
is SOL_SOCKET, and those keys are ignored for that level.

Where are the definitions for other SOL_xxxxx values (e.g. SOL_TCP)
supposed to come from?

--
Grant