This is something I promised to do before stable/11 branchpoint, but
failed. The goal is to stop userland applications using kernel
internal structures representing inet protocol control block and TCP
control block. And to stop appropriate sysctls from exporting them.
Basicly, back 25 years ago, when 'struct xsocket' was introduced,
the 'struct xinpcb' and 'struct xtcpcb' should had been designed
the same way - pasting all useful fields from corresponding kernel
Not done that time, so time to do it today, the hard way. This is
going to break a bunch of applications in ports, but I will fix them
as quickly as I can. I already went through such process when I've
hidden 'struct ifnet' and 'struct ifaddr' from userland. I already
started fixing applications...
What will we achieve with the change:
- There is no need for spares in 'struct inpcb', 'struct tcpcb'. We are free to move fields around the structure. And what is important Randall already has branch tossing around inpcb that has measurable performance gain.
- We will have binaries like netstat(1) working on next versions of FreeBSD. I have just checked, 10-th netstat won't work on 11, and 9-th won't work on 10, etc. But with this change 12-th is going to work on 13, 14, 15, etc...
- Hide struct inpcb, struct tcpcb under _KERNEL || _WANT_FOO.
- Make struct xinpcb, struct xtcpcb pure API structures, not including kernel structures inpcb and tcpcb inside.
- Provide some extra fields into struct xinpcb. Provide some spares. Convert inp_depend4 and inp_depend6 to anonymous structs to remove defines and make names of fields in inpcb and xinpcb same.
- Seems no good point to export ALL of struct tcpcb. Instead provide a ton of spare fields, to be used as we are in need to export smth.
- Make kernel and userland utilities compilable and working after these changes.
- Bump FreeBSD version.