Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Merge 260225:

Fix circular math macro.

PR: 146082

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

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

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

Node constructor methods are supposed to be called in syscall
context always. Convert nodes to consistently use M_WAITOK flag
for memory allocation.

Reviewed by: julian

Make ng_l2tp irrelevant to data alignment.

Add memmove() to the kernel, making the kernel compile with Clang.

When copying big structures, LLVM generates calls to memmove(), because
it may not be able to figure out whether structures overlap. This caused
linker errors to occur. memmove() is now implemented using bcopy().
Ideally it would be the other way around, but that can be solved in the
future. On ARM we don't do add anything, because it already has
memmove().

Discussed on: arch@
Reviewed by: rdivacky

Fix typo. Clear session stats instead of config and part of stats.

Found with: Coverity Prevent(tm)
CID: 2472

Fix a number of style issues in the MALLOC / FREE commit. I've tried to
be careful not to fix anything that was already broken; the NFSv4 code is
particularly bad in this respect.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

Don't use memcpy() to copy several bytes.
Store IDs is host order. It is not so important to bloat code for it.
Combine m_adj() and M_PREPEND() into single M_PREPEND().

Add session ID hashing to speedup incoming packets dispatch in case
of many connections working via the same tunnel. For example, in case
of full "client <-> LAC <-> LNS" setup.

Addition to the previous commit. Release inproc in case of memory error.

To avoid control data losses do not acknowledge recieving of control packet
if netgraph reported error while delivering to destination.
Reset 'next send' counter to the last requested by peer on ack timeout
to resend all subsequest packets after lost one again without additional hints.

Increase control channel xmit queue to 128 packets.
Previous value 16 was too small for real LAC as temporal activity
spike cound easily overflow queue demanding tunnel disconnection due
to possible state inconsistency.

Protect struct seq with mutex.

Approved by: glebius (mentor)

Remove one unneded assertion. It is also checked in
ng_l2tp_seq_check().

Approved by: glebius (mentor)

Replace single rcvdata with 3 distinct to simplify code and
reduce stack usage.

Approved by: mentor (glebius)

Remove duplicate variables.

Avoid false assertion on transmit and delayed ack timeout with enabled invariants.
Replace callout_pending() by callout_active() to remove race window.

Reviewed by: archie
Approved by: glebius (mentor)

Global xmit stats calculation fix.

Approved by: glebius (mentor)

Use the ISO standard function variable vs. a GCC'ism.

- Use ng_callout() instead of callout_reset(9).
- Use callout_pending() instead of our own flags.
- Remove home-grown protection of node, which has a scheduled
callout().
- Remove spl(9) calls.

Tested by: bz

/* -> /*- for license, minor formatting changes

Implement minimalistic L2TP sessions statistics and correct man page
for L2TP tunnel statistics (which do not take an argument sessionID).

Reviewed by: archie
Approved by: pjd (mentor)

add a new control message to set sequence numbers on an uninitialized node.

Reviewed by: archie
Approved by: pjd (mentor)

Correct L2TP header offset handling:
- according to RFC2661 an offset size of 0 is allowed.
- when skipping offset padding do not forget to also skip
the 2 octets of the offset size field.

Reviewed by: archie
Approved by: pjd (mentor)

Having moved metadata usage to mbuf tags, remove code that supports
the old way of doing it.

Submitted by: Gleb Smirnoff <glebius@cell.sick.ru>

Switch to using C99 sparse initialisers for the type methods array.
Should make no binary difference.

Submitted by: Gleb Smirnoff <glebius@cell.sick.ru>
Reviewed by: Harti Brandt <harti@freebsd.org>
MFC after: 1 week

Rename internal structure to fix cut & paste error.

Submitted by: Bjoern A. Zeeb <bzeeb+freebsd@zabbadoz.net>
MFC After: 3 days

Don't use ovbcopy().

Back out M_* changes, per decision of the TRB.

Approved by: trb

Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.

o Untangle the confusion with the malloc flags {M_WAITOK, M_NOWAIT} and
the mbuf allocator flags {M_TRYWAIT, M_DONTWAIT}.
o Fix a bpf_compat issue where malloc() was defined to just call
bpf_alloc() and pass the 'canwait' flag(s) along. It's been changed
to call bpf_alloc() but pass the corresponding M_TRYWAIT or M_DONTWAIT
flag (and only one of those two).

Submitted by: Hiten Pandya <hiten@unixdaemons.com> (hiten->commit_count++)

Don't use "NULL" when "0" is really meant.

New L2TP netgraph node type.

Obtained from: Packet Design