TIMOTHY POWELL wrote Thu, 11 Jul 2002 17:59:47 -0700 (PDT):

C++. Where can I find documentation on receiving the
ax25 packet frames from the kernel and some C or C++
coding examples?

Have you checked out the sources of listen, the ncurses based ax25 packet
monitor? It's distributed as a part of ax25-apps. I haven't checked out
other pieces of code as ax25 reference so I can't compare the quality of
coding, but it was enough for me (relatively inexperienced) to
make a simple dx cluster monitoring program in C.