MFC r287649:
Use a common subroutine to fetch and zero protocol stats instead of
duplicating roughly similar code for each protocol.

MFC r266418, r266448

Add the flowtype to the inpcb.
Add -R to netstat to dump RSS/flow information.

Reviewed by: delphij
Relnotes: yes (for r266448)
Sponsored by: Limelight Networks

Merge r262763, r262767, r262771, r262806 from head:
- Remove rt_metrics_lite and simply put its members into rtentry.
- Use counter(9) for rt_pksent (former rt_rmx.rmx_pksent). This
removes another cache trashing ++ from packet forwarding path.
- Create zini/fini methods for the rtentry UMA zone. Via initialize
mutex and counter in them.
- Fix reporting of rmx_pksent to routing socket.
- Fix netstat(1) to report "Use" both in kvm(3) and sysctl(3) mode.

Merge r259562,r259566,r259638,r259645,r260124 by melifaro:

Switch netstat -rn to use standard API for retrieving list
of routes instead of peeking inside in-kernel radix via kget.

Merge r261582, r261601, r261610, r261613, r261627, r261640, r261641, r261823,
r261825, r261859, r261875, r261883, r261911, r262027, r262028, r262029,
r262030, r262162 from head.

Large flowtable revamp. See commit messages for merged revisions for
details.

Sponsored by: Netflix

Merged /head:r256510,256512,257376,257469,260052:

Make 'netstat -i' use getifaddrs(3) instead of kvm(3).

MFC r266418, r266448

Add the flowtype to the inpcb.
Add -R to netstat to dump RSS/flow information.

Reviewed by: delphij
Relnotes: yes (for r266448)
Sponsored by: Limelight Networks

Merge r262763, r262767, r262771, r262806 from head:
- Remove rt_metrics_lite and simply put its members into rtentry.
- Use counter(9) for rt_pksent (former rt_rmx.rmx_pksent). This
removes another cache trashing ++ from packet forwarding path.
- Create zini/fini methods for the rtentry UMA zone. Via initialize
mutex and counter in them.
- Fix reporting of rmx_pksent to routing socket.
- Fix netstat(1) to report "Use" both in kvm(3) and sysctl(3) mode.

Merge r259562,r259566,r259638,r259645,r260124 by melifaro:

Switch netstat -rn to use standard API for retrieving list
of routes instead of peeking inside in-kernel radix via kget.

Merge r261582, r261601, r261610, r261613, r261627, r261640, r261641, r261823,
r261825, r261859, r261875, r261883, r261911, r262027, r262028, r262029,
r262030, r262162 from head.

Large flowtable revamp. See commit messages for merged revisions for
details.

Sponsored by: Netflix

Merged /head:r256510,256512,257376,257469,260052:

Make 'netstat -i' use getifaddrs(3) instead of kvm(3).