Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC/backport core kernel and userspace parts of r237263 (TCP_OFFLOAD
rework). MFC r237563, r239511, r243603, r245915, r245916, r245919,
r245921, r245922, r245924, r245925, r245932, r245934 too.

Build tested with make universe.

r237263:
- Updated TOE support in the kernel.
...

r237563:
Fix clang warning when compiling iw_cxgb.

r239511:
Correctly handle the case where an inp has already been dropped by the time
the TOE driver reports that an active open failed. toe_connect_failed is
supposed to handle this but it should be provided the inpcb instead of the
tcpcb which may no longer be around.

r243603:
Make sure that tcp_timer_activate() correctly sees TCP_OFFLOAD (or not).

r245915:
Heed SO_NO_OFFLOAD.

r245916:
Teach toe_4tuple_check() to deal with IPv6 4-tuples too.

r245919:
Add TCP_OFFLOAD hook in syncache_respond for IPv6 too, just like the one
that exists for IPv4.

r245921:
There is no need to call into the TOE driver twice in pru_rcvd (tod_rcvd
and then tod_output right after that).

r245922:
Avoid NULL dereference in nd6_storelladdr when no mbuf is provided. It
is called this way from a couple of places in the OFED code. (toecore
calls it too but that's going to change shortly).

r245924:
Move lle_event to if_llatbl.h

lle_event replaced arp_update_event after the ARP rewrite and ended up
in if_ether.h simply because arp_update_event used to be there too.
IPv6 neighbor discovery is going to grow lle_event support and this is a
good time to move it to if_llatbl.h.

The two in-tree consumers of this event - OFED and toecore - are not
affected.

r245925:
Generate lle_event in the IPv6 neighbor discovery code too.

r245932:
Teach toe_l2_resolve to resolve IPv6 destinations too.

r245934:
Add checks for SO_NO_OFFLOAD in a couple of places that I missed earlier
in r245915.

Merge r238990 (manually resolving absence of r237263):
Fix races between in_lltable_prefix_free(), lla_lookup(),
llentry_free() and arptimer():

o Use callout_init_rw() for lle timeout, this allows us safely
disestablish them.
- This allows us to simplify the arptimer() and make it
race safe.
o Consistently use ifp->if_afdata_lock to lock access to
linked lists in the lle hashes.
o Introduce new lle flag LLE_LINKED, which marks an entry that
is attached to the hash.
- Use LLE_LINKED to avoid double unlinking via consequent
calls to llentry_free().
- Mark lle with LLE_DELETED via |= operation istead of =,
so that other flags won't be lost.
o Make LLE_ADDREF(), LLE_REMREF() and LLE_FREE_LOCKED() more
consistent and provide more informative KASSERTs.

The patch is a collaborative work of all submitters and myself.

PR: kern/165863
Submitted by: zont, rstone
Submitted by: Eric van Gyzen <eric_van_gyzen dell.com>

Merge r238989:
The llentry_update() is used only by flowtable and the latter
always passes NULL pointer to it. Thus, code can be simplified
and function renamed to llentry_alloc() to match rtalloc().

Merge 238945,238967:
Some style(9) and whitespace changes.

Merge r232054 by kmacy:
When using flowtable llentrys can outlive the interface with
which they're associated at which the lle_tbl pointer points
to freed memory and the llt_free pointer is no longer valid.

Move the free pointer in to the llentry itself and update the
initalization sites.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Make KBI changes required for future MFCing of inpcb rtentry / llentry caching.

Reviewed by: rwatson, bz
Approved by: re (kib)

Permit ARP to proceed for IPv4 host routes for which the gateway is the
same as the host address. This already works fine for INET6 and ND6.

While here, remove two function pointers from struct lltable which are
only initialized but never used.

MFC after: 3 days

The statically configured (permanent) ARP entries are removed when an
interface is brought down, even though the interface address is still
valid. This patch maintains the permanent ARP entries as long as the
interface address (having the same prefix as that of the ARP entries)
is valid.

Reviewed by: delphij
MFC after: 5 days

- Merge changes to the base system to support OFED. These include
a wider arg2 for sysctl, updates to vlan code, IFT_INFINIBAND,
and other miscellaneous small features.

Use NULL rather than 0 to invalidate a pointer.

Rather than duplicating the LLE_FREE_LOCKED() macro code in LLE_FREE(),
call it directly (like we do for the RT_* macros).

Sponsored by: ISPsystem [1]
Reviewed by: julian [1]
MFC After: 1 week

[1] Early 2010.

Add a queue to hold packets while we await an ARP reply.

When a fast machine first brings up some non TCP networking program
it is quite possible that we will drop packets due to the fact that
only one packet can be held per ARP entry. This leads to packets
being missed when a program starts or restarts if the ARP data is
not currently in the ARP cache.

This code adds a new sysctl, net.link.ether.inet.maxhold, which defines
a system wide maximum number of packets to be held in each ARP entry.
Up to maxhold packets are queued until an ARP reply is received or
the ARP times out. The default setting is the old value of 1
which has been part of the BSD networking code since time
immemorial.

Expose the time we hold an incomplete ARP entry by adding
the sysctl net.link.ether.inet.wait, which defaults to 20
seconds, the value used when the new ARP code was added..

Reviewed by: bz, rpaulo
MFC after: 3 weeks

lltable_drain() has never been used so far, thus #if 0 it for now.
While touching it add the missing locking to the now disabled code
for the time when we'll resurrect it.

MFC after: 3 days

- restructure flowtable to support ipv6
- add a name argument to flowtable_alloc for printing with ddb commands
- extend ddb commands to print destination address or 4-tuples
- don't parse ports in ulp header if FL_HASH_ALL is not passed
- add kern_flowtable_insert to enable more generic use of flowtable
(e.g. system calls for adding entries)
- don't hash loopback addresses
- cleanup whitespace
- keep statistics per-cpu for per-cpu flowtables to avoid cache line contention
- add sysctls to accumulate stats and report aggregate

MFC after: 7 days

The proxy arp entries could not be added into the system over the
IFF_POINTOPOINT link types. The reason was due to the routing
entry returned from the kernel covering the remote end is of an
interface type that does not support ARP. This patch fixes this
problem by providing a hint to the kernel routing code, which
indicates the prefix route instead of the PPP host route should
be returned to the caller. Since a host route to the local end
point is also added into the routing table, and there could be
multiple such instantiations due to multiple PPP links can be
created with the same local end IP address, this patch also fixes
the loopback route installation failure problem observed prior to
this patch. The reference count of loopback route to local end would
be either incremented or decremented. The first instantiation would
create the entry and the last removal would delete the route entry.

MFC after: 5 days

Use locks specific to the lltable code, rather than borrow the ifnet
list/index locks, to protect link layer address tables. This avoids
lock order issues during interface teardown, but maintains the bug that
sysctl copy routines may be called while a non-sleepable lock is held.

Reviewed by: bz, kmacy
MFC after: 3 days

When an interface address is removed and the last prefix
route is also being deleted, the link-layer address table
(arp or nd6) will flush those L2 llinfo entries that match
the removed prefix.

Reviewed by: kmacy

add utility routine for updating an struct llentry *

add macro for destroying an llentry's rwlock

Add arpv2 management code