- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

General style cleanup, no functional change.

- Allocate scratch memory on stack instead of pre-allocating it with
the filter as we do from bpf_filter()[1].
- Revert experimental use of contigmalloc(9)/contigfree(9). It has no
performance benefit over malloc(9)/free(9)[2].

Requested by: rwatson[1]
Pointed out by: rwatson, jhb, alc[2]

- Change internal function bpf_jit_compile() to return allocated size of
the generated binary and remove page size limitation for userland.
- Use contigmalloc(9)/contigfree(9) instead of malloc(9)/free(9) to make
sure the generated binary aligns properly and make it physically contiguous.

- Make BPF JIT compiler working again in userland. We are limiting size of
generated native binary to page size for now.
- Update copyright date and fix some style nits.

Initialize scratch memory for JIT-compiled filter when it is allocated.
Previously it may have contained unnecessary (even sensitive) data from
the previous allocation.
As a (good) side effect, scratch memory may be used to store the previous
filter state(s) safely because it is allocated and freed with filter itself.
However, use it carefully because bpf_filter(9) does not have this behavior.

MFC after: 3 days

Move empty filter handling to MI source.

MFC after: 3 days

Fix a typo in copyrights.

Embed scratch memory in the filter structure.

MFC after: 3 days

- Make these files compilable on user land.
- Update copyrights and fix style(9).

Add BPF Just-In-Time compiler support for ng_bpf(4).

The sysctl is changed from net.bpf.jitter.enable to net.bpf_jitter.enable
and this controls both bpf(4) and ng_bpf(4) now.

s/M_WAITOK/M_NOWAIT/ while mutex is held.

Pointed out by: csjp

Add experimental BPF Just-In-Time compiler for amd64 and i386.

Use the following kernel configuration option to enable:

options BPF_JITTER

If you want to use bpf_filter() instead (e. g., debugging), do:

sysctl net.bpf.jitter.enable=0

to turn it off.

Currently BIOCSETWF and bpf_mtap2() are unsupported, and bpf_mtap() is
partially supported because 1) no need, 2) avoid expensive m_copydata(9).

Obtained from: WinPcap 3.1 (for i386)