- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r272889 and r287402:

- Virtualize if_epair(4). An if_xname check for both "a" and "b" interfaces
is added to return EEXIST when only "b" interface exists---this can happen
when epair<N>b is moved to a vnet jail and then "ifconfig epair<N> create"
is invoked there.

- Fix a panic which was reproducible by an infinite loop of
"ifconfig epair0 create && ifconfig epair0a destroy".
This was caused by an uninitialized function pointer in
softc->media.

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

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

Utilize new macro to initialize if_baudrate().

Make the "struct if_clone" opaque to users of the cloning API. Users
now use function calls:

if_clone_simple()
if_clone_advanced()

to initialize a cloner, instead of macros that initialize if_clone
structure.

Discussed with: brooks, bz, 1 year ago

Revert previous commit...

Pointyhat to: kevlo (myself)

Prefer NULL over 0 for pointers

In epair_clone_destroy(), when destroying the second half, we have to
switch to its vnet before calling ether_ifdetach(). Otherwise if the
second half resides in a different vnet, if_detach() silently fails
leaving a stale pointer in V_ifnet list, and the system crashes trying
to access this pointer later.

Another solution could be not to allow to destroy epair unless both
ends are in the home vnet.

Discussed with: bz
Tested by: delphij

Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.

The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.

Allow for vlan(4) interfaces with MTU of 1500 bytes to be configured
on top of epair(4) virtual interfaces, since there's no physical
hardware associated with epair interfaces which would imply any
constraints on MTU sizes.

MFC after: 3 days

Let epair(4) virtual interfaces report fake link / media status,
by borrowing the skeleton of if_media manipulation and reporting
code from if_lagg(4). The main motivation behind this change is
to allow for epair(4) interfaces to participate in STP if_bridge(4)
configurations.

Reviewed by: bz
MFC after: 3 days

Add a missing ';' and change the debugging sysctl from xint to int.

Submitted by: Mikolaj Golub (to.my.trociny gmail.com)
MFC after: 3 days

MFp4 CH=183259:

No reason to use if_free_type() as we don't change our type.
Just if_free() is fine.

MFC after: 3 days

MFp4 CH=182972:

Add explicit linkstate UP/DOWN for the epair. This is needed by carp(4)
and other things to work.

MFC after: 5 days

Update several places that iterate over CPUs to use CPU_FOREACH().

Rework reference counting in case we queue into the netisr,
or overflow the netisr queue and fall back to the interface
queue so that we can garuantee that the ifnet pointer stays
valid. Formerly we ended up with reference counts <= 0 in
case the netisr had returned ENOBUFS. The idea is to track
any packet in the netisr queue and only change the refount
on edge operations for the fallback interface queue. This
also avoids problems in case the if_snd.ifq_len lies to us.

Also rework refount assertions to make sure they trigger if
we go below 1. Formerly a negative refence count did not
trigger the assert as the refcount variable is u_int.

Sponsored by: ISPsystem
MFC after: 5 days

Correct a typo.

MFC after: 5 days

Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by: bz
Approved by: re (vimage blanket)

Update epair(4) to the new netisr implementation and polish
things a bit:
- use dpcpu data to track the ifps with packets queued up,
- per-cpu locking and driver flags
- along with .nh_drainedcpu and NETISR_POLICY_CPU.
- Put the mbufs in flight reference count, preventing interfaces
from going away, under INVARIANTS as this is a general problem
of the stack and should be solved in if.c/netisr but still good
to verify the internal queuing logic.
- Permit changing the MTU to virtually everythinkg like we do for loopback.

Hook epair(4) up to the build.

Approved by: re (kib)

Merge from p4: CH154790,154793,154874

Import if_epair(4), a virtual cross-over Ethernet-like interface pair.

Note these files are 1:1 from p4 and not yet connected to the build
not knowing about the new netisr interface.

Sponsored by: The FreeBSD Foundation