- 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

PR: 168520 170096
Submitted by: adrian, zec

Fix multiple kernel panics when VIMAGE is enabled in the kernel.
These fixes are based on patches submitted by Adrian Chadd and Marko Zec.

(1) Set curthread->td_vnet to vnet0 in device_probe_and_attach() just before calling
device_attach(). This fixes multiple VIMAGE related kernel panics
when trying to attach Bluetooth or USB Ethernet devices because
curthread->td_vnet is NULL.

(2) Set curthread->td_vnet in if_detach(). This fixes kernel panics when detaching networking
interfaces, especially USB Ethernet devices.

(3) Use VNET_DOMAIN_SET() in ng_btsocket.c

(4) In ng_unref_node() set curthread->td_vnet. This fixes kernel panics
when detaching Netgraph nodes.

- Correct mispellings of the word necessary

Submitted by: Christoph Mallon <christoph.mallon@gmx.de> (via private mail)

Ensure that all cases that enqueue a netgraph item for delivery by a
ngthread properly set the item's depth to 1. In particular, prior to this
change if ng_snd_item failed to acquire a lock on a node, the item's depth
would not be set at all. This fix ensures that the error code from rcvmsg/
rcvdata is properly passed back to the apply callback. For example, this
fixes a bug where an error from rcvmsg/rcvdata would not previously
propagate back to a libnetgraph consumer when the message was queued.

Reviewed by: mav
MFC after: 1 month
Sponsored by: Sandvine Incorporated

Revert r231829, that was my braino.

Refactor the name hash and the ID hash, that are used to address nodes:

- Make hash sizes growable, to satisfy users running large mpd
installations, having thousands of nodes.
- NG_NAMEHASH() proved to give a very bad distribution in real life
name sets, while generic hash32_str(name, HASHINIT) proved to give
an even one, so you the latter for name hash.
- Do not store unnamed nodes in slot 0 of name hash, no reason for that.
- Use the ID hash in cases when we need to run through all nodes: the
NGM_LISTNODES command and in the vnet_netgraph_uninit().
- Implement NGM_LISTNODES and NGM_LISTNAMES as separate code, the former
iterates through the ID hash, and the latter through the name hash.
- Keep count of all nodes and of named nodes, so that we don't need
to count nodes in NGM_LISTNODES and NGM_LISTNAMES. The counters are
also used to estimate whether we need to grow hashes.
- Close a race between two threads running ng_name_node() assigning same
name to different nodes.

Specify correct loading order for core of netgraph(4).

Supply correct "how" argument to the uma_zcreate().

Fix includes list.

Submitted by: bde

Trim double empty lines.

Remove testing stuff, reducing kernel memory footprint by 1 Kb.

Anyway, when we are building a LINT kernel, all these macros
are tested via nodes.

In ng_bypass() add more protection against potential race
with ng_rmnode() and its followers.

style(9): sort includes.

Convert locks that protect name hash, ID hash and typelist from
mutex(9) to rwlock(9) based locks.

While here remove dropping lock when processing NGM_LISTNODES,
and NGM_LISTTYPES generic commands. We don't need to drop it
since memory allocation is done with M_NOWAIT.

style(9), whitespace and spelling nits.

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

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

Constify "address" argument of ng_address_path().

- If KDB & NETGRAPH_DEBUG are on, print traces on discovered failed
invariants.
- Reduce tautology in NETGRAPH_DEBUG output.

- Use refcount(9) API to manage node and hook refcounting.
- Make ng_unref_node() void, since caller shouldn't be
interested in whether node is valid after call or not,
since it can't be guaranteed to be valid. [1]

Ok from: julian [1]

Fix error where error variable was assigned result of comparison,
instead of function return value.

Submitted by: Przemyslaw Frasunek <przemyslaw frasunek.com>
MFC after: 4 days

Improve locking of creating and dropping links in the graph, acquiring
the topology mutex in the following functions, that manipulate pointers
to peer nodes:

- ng_bypass()
- ng_path2noderef() when switching to the next node in sequence.
Rewrite the function a bit.
- ng_address_hook()
- ng_address_path()

This patch improves stability of large mpd5 installations.

After some off-list discussion, revert a number of changes to the
DPCPU_DEFINE and VNET_DEFINE macros, as these cause problems for various
people working on the affected files. A better long-term solution is
still being considered. This reversal may give some modules empty
set_pcpu or set_vnet sections, but these are harmless.

Changes reverted:

------------------------------------------------------------------------
r215318 | dim | 2010-11-14 21:40:55 +0100 (Sun, 14 Nov 2010) | 4 lines

Instead of unconditionally emitting .globl's for the __start_set_xxx and
__stop_set_xxx symbols, only emit them when the set_vnet or set_pcpu
sections are actually defined.

------------------------------------------------------------------------
r215317 | dim | 2010-11-14 21:38:11 +0100 (Sun, 14 Nov 2010) | 3 lines

Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.

------------------------------------------------------------------------
r215316 | dim | 2010-11-14 21:23:02 +0100 (Sun, 14 Nov 2010) | 2 lines

Add macros to define static instances of VNET_DEFINE and DPCPU_DEFINE.

Apply the STATIC_VNET_DEFINE and STATIC_DPCPU_DEFINE macros throughout
the tree.

Increase the target buffer for performing NGM_ASCII2BINARY conversion
from 2000 bytes to 20 Kbytes, which now matches the buffer size used for
NGM_BINARY2ASCII conversions.

The aim of this change is to allow for bigger binary structures to be
managed via netgraph ASCII messages, until we come up with an API
improvement which would get rid of such arbitrary hardcoded limits.

MFC after: 3 days

When destroying a vnet, shut down all netgraph nodes tied to that vnet
before proceeding with dismantling other protocol domains.

This change only affects options VIMAGE builds.

Reviewed by: julian, bz
MFC after: 3 days

(S)LIST_HEAD_INITIALIZER takes a (S)LIST_HEAD as an argument.
Fix some wrong usages.
Note: this does not affect generated binaries as this argument is not used.

PR: 137213
Submitted by: Eygene Ryabinkin (initial version)
MFC after: 1 month

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)

Introduce and use a sysinit-based initialization scheme for virtual
network stacks, VNET_SYSINIT:

- Add VNET_SYSINIT and VNET_SYSUNINIT macros to declare events that will
occur each time a network stack is instantiated and destroyed. In the
!VIMAGE case, these are simply mapped into regular SYSINIT/SYSUNINIT.
For the VIMAGE case, we instead use SYSINIT's to track their order and
properties on registration, using them for each vnet when created/
destroyed, or immediately on module load for already-started vnets.
- Remove vnet_modinfo mechanism that existed to serve this purpose
previously, as well as its dependency scheme: we now just use the
SYSINIT ordering scheme.
- Implement VNET_DOMAIN_SET() to allow protocol domains to declare that
they want init functions to be called for each virtual network stack
rather than just once at boot, compiling down to DOMAIN_SET() in the
non-VIMAGE case.
- Walk all virtualized kernel subsystems and make use of these instead
of modinfo or DOMAIN_SET() for init/uninit events. In some cases,
convert modular components from using modevent to using sysinit (where
appropriate). In some cases, do minor rejuggling of SYSINIT ordering
to make room for or better manage events.

Portions submitted by: jhb (VNET_SYSINIT), bz (cleanup)
Discussed with: jhb, bz, julian, zec
Reviewed by: bz
Approved by: re (VIMAGE blanket)

Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used. Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with: bz, julian
Reviewed by: bz
Approved by: re (kensmith, kib)

Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)

Introduce a mechanism for detecting calls from outbound path of the
network stack when reentering the inbound path from netgraph, and
force queueing of mbufs at the outbound netgraph node.

The mechanism relies on two components. First, in netgraph nodes
where outbound path of the network stack calls into netgraph, the
current thread has to be appropriately marked using the new
NG_OUTBOUND_THREAD_REF() macro before proceeding to call further
into the netgraph topology, and unmarked using the
NG_OUTBOUND_THREAD_UNREF() macro before returning to the caller.
Second, netgraph nodes which can potentially reenter the network
stack in the inbound path have to mark their inbound hooks using
NG_HOOK_SET_TO_INBOUND() macro. The netgraph framework will then
detect when there is a danger of a call graph looping back from
outbound to inbound path via netgraph, and defer handing off the
mbufs to the "inbound" node to a worker thread with a clean stack.

In this first pass only the most obvious netgraph nodes have been
updated to ensure no outbound to inbound calls can occur. Nodes
such as ng_ipfw, ng_gif etc. should be further examined whether a
potential for outbound to inbound call looping exists.

This commit changes the layout of struct thread, but due to
__FreeBSD_version number shortage a version bump has been omitted
at this time, nevertheless kernel and modules have to be rebuilt.

Reviewed by: julian, rwatson, bz
Approved by: julian (mentor)

Introduce an infrastructure for dismantling vnet instances.

Vnet modules and protocol domains may now register destructor
functions to clean up and release per-module state. The destructor
mechanisms can be triggered by invoking "vimage -d", or a future
equivalent command which will be provided via the new jail framework.

While this patch introduces numerous placeholder destructor functions,
many of those are currently incomplete, thus leaking memory or (even
worse) failing to stop all running timers. Many of such issues are
already known and will be incrementaly fixed over the next weeks in
smaller incremental commits.

Apart from introducing new fields in structs ifnet, domain, protosw
and vnet_net, which requires the kernel and modules to be rebuilt, this
change should have no impact on nooptions VIMAGE builds, since vnet
destructors can only be called in VIMAGE kernels. Moreover,
destructor functions should be in general compiled in only in
options VIMAGE builds, except for kernel modules which can be safely
kldunloaded at run time.

Bump __FreeBSD_version to 800097.
Reviewed by: bz, julian
Approved by: rwatson, kib (re), julian (mentor)

Unbreak LINT build, caused by a change in struct ng_node layout introduced
with r191816, which become uncovered only with NETGRAPH_DEBUG defined.

NOT approved by mentor (julian) due to emergency.

In preparation to make options VIMAGE operational, where needed,
initialize / release netgraph related state in iattach() / idetach()
functions called via the vnet module registration / initialization
framework, instead of initialization / cleanups being done in
mod_event handlers.

While here, introduce a crude hack aimed at preventing ng_ether to
autoattach to ng_eiface ifnets, which are also netgraph nodes already.

Reviewed by: bz
Approved by: julian (mentor)

To avoid one doubtless netgraph SMP scalability limitation point, switch
node queues processing from single swi:net thread to several specialized
threads.

Reviewed by: julian
Tested with: Netperf Cluster

Revert rev. 183277:

Remove ng_rmnode_flags() function.
ng_rmnode_self() was made to be called only while having node locked.
When node is properly locked, any function call sent to it will always be
queued. So turning ng_rmnode_self() into the ng_rmnode_flags() is not just
meaningless, but incorrent, as it violates node locking when called outside.

No objections: julian, thompsa

Conditionally compile out V_ globals while instantiating the appropriate
container structures, depending on VIMAGE_GLOBALS compile time option.

Make VIMAGE_GLOBALS a new compile-time option, which by default will not
be defined, resulting in instatiations of global variables selected for
V_irtualization (enclosed in #ifdef VIMAGE_GLOBALS blocks) to be
effectively compiled out. Instantiate new global container structures
to hold V_irtualized variables: vnet_net_0, vnet_inet_0, vnet_inet6_0,
vnet_ipsec_0, vnet_netgraph_0, and vnet_gif_0.

Update the VSYM() macro so that depending on VIMAGE_GLOBALS the V_
macros resolve either to the original globals, or to fields inside
container structures, i.e. effectively

#ifdef VIMAGE_GLOBALS
#define V_rt_tables rt_tables
#else
#define V_rt_tables vnet_net_0._rt_tables
#endif

Update SYSCTL_V_*() macros to operate either on globals or on fields
inside container structs.

Extend the internal kldsym() lookups with the ability to resolve
selected fields inside the virtualization container structs. This
applies only to the fields which are explicitly registered for kldsym()
visibility via VNET_MOD_DECLARE() and vnet_mod_register(), currently
this is done only in sys/net/if.c.

Fix a few broken instances of MODULE_GLOBAL() macro use in SCTP code,
and modify the MODULE_GLOBAL() macro to resolve to V_ macros, which in
turn result in proper code being generated depending on VIMAGE_GLOBALS.

De-virtualize local static variables in sys/contrib/pf/net/pf_subr.c
which were prematurely V_irtualized by automated V_ prepending scripts
during earlier merging steps. PF virtualization will be done
separately, most probably after next PF import.

Convert a few variable initializations at instantiation to
initialization in init functions, most notably in ipfw. Also convert
TUNABLE_INT() initializers for V_ variables to TUNABLE_FETCH_INT() in
initializer functions.

Discussed at: devsummit Strassburg
Reviewed by: bz, julian
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Unhide declarations of network stack virtualization structs from
underneath #ifdef VIMAGE blocks.

This change introduces some churn in #include ordering and nesting
throughout the network stack and drivers but is not expected to cause
any additional issues.

In the next step this will allow us to instantiate the virtualization
container structures and switch from using global variables to their
"containerized" counterparts.

Reviewed by: bz, julian
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Remove unneeded NULL check. At first msg can't be null here and and at second
NG_FREE_MSG() also checks it.

Found with: Coverity Prevent(tm)

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

MFC after: 3 months

Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by: julian, bz, brooks, zec
Reviewed by: julian, bz, brooks, kris, rwatson, ...
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Add ng_rmnode_flags() so the caller can pass NG_QUEUE and have the node
destroyed asynchronously due to locking or other constraints.

Reviewed by: julian

We can't implicitly trust the hook on NGQF_FN/NGQF_FN2 processing in
ng_apply_item(). There are possible (and I have got one) use-after-free
class panics because of it.

If hook is specified, require it to be valid at the apply time. The only
exceptions are the internal ng_con_part2(), ng_con_part3() and
ng_rmhook_part2() functions which are specially made to work with invalid
hooks.

A bunch of formatting fixes brough to light by, or created by the Vimage commit
a few days ago.

Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch

Remove NETISR_MPSAFE, which allows specific netisr handlers to be directly
dispatched without Giant, and add NETISR_FORCEQUEUE, which allows specific
netisr handlers to always be dispatched via a queue (deferred). Mark the
usb and if_ppp netisr handlers as NETISR_FORCEQUEUE, and explicitly
acquire Giant in those handlers.

Previously, any netisr handler not marked NETISR_MPSAFE would necessarily
run deferred and with Giant acquired. This change removes Giant
scaffolding from the netisr infrastructure, but NETISR_FORCEQUEUE allows
non-MPSAFE handlers to continue to force deferred dispatch so as to avoid
lock order reversals between their acqusition of Giant and any calling
context.

It is likely we will be able to remove NETISR_FORCEQUEUE once
IFF_NEEDSGIANT is removed, as non-MPSAFE usb and if_ppp drivers will no
longer be supported.

Reviewed by: bz
MFC after: 1 month
X-MFC note: We can't remove NETISR_MPSAFE from stable/7 for KPI reasons,
but the rest can go back.

ng_address_hook() microoptimization. Use local variables as they should be.
It helps compiller to avoid some extra memory accesses.

Use separate UMA zone for data items allocation. It is a partial
rev. 1.149 rework.
It allows to save several percents of CPU time on SMP by using UMA's
internal per-CPU allocation limits instead of own global variable
each time updated with atomics.

Tested with: Netperf cluster

Several changes breaking netgraph module ABI collected together:
- reorder structures fields (XX_refs) a bit to group fields modified
same time together. According to my tests it gives up to 10%
SMP performance benefit on real workload due to reduced inter-CPU
cache trashing.
- change q_flags from long to int as long is not really needed there and
it's usage with atomics is argued by some people.
- move NGF_WORKQ flag into the separate field q_flags2 as it protected by
queue mutex instead of node writer protection used by the rest of flags.
- move nd_work queue entry to ng_queue structure to which it is more
related and make it STAILQ instead of TAILQ as now it is a classic FIFO.
- remove q_node pointer from ng_queue structure as it is not really needed.
- reimplement item queue using STAILQ instead of own equal implementation.
As soon as BT subsystem has own item queues using ng_item.el_next update
it also.
- change depth field in ng_item from uintptr_t to u_int. It was made
uintptr_t to keep ABI compatibility.

Reviewed by: julian, emax
Tested with: Netperf cluster

Add memory barriers to the node locking operations.
Add some comments.

Rewrite node's r/w/q-lock semantics using only atomics instead of mutex
and atomics combination. Mutex is now used only for queue protection.
Also avoid unneded extra swi scheduling calls.

Use new atomic_fetchadd() primitive instead of looping atomic_cmpset().

There is no need to erase hook->hk_node before freing hook.

Remove ng_setisr() call from ng_dequeue(). It is useless as we any way
will never exit ngintr(), while there is some ready requests on the queue.
It was made years ago with hope of parallel queue processing by several
net threads. But even if we have several threads sometimes, we have no
rights to process queue in parallel as it will break original requests
serialization that is critically important for some setups.

Remove impossible (hk_peer == NULL) check from ng_address_hook().
Valid hook can't have NULL peer. Even invalid one can't, as it is resets to
deadhook, but not NULL.

Improve apply callback error reporting:
Before this patch callback returned result of the last finished call chain.
Now it returns last nonzero result from all call chain results in this request.

As soon as this improvement gives reliable error reporting, it is now possible
to remove dirty workaround in ng_socket, made to return ENOBUFS error statuses
of request-response operations. That workaround was responsible for returning
ENOBUFS errors to completely unrelated requests working at the same time
on socket.

Increase default queue items allocation limit from 512 to 4096 items
to avoid terrible unpredicted effects for netgraph operation of their
exhaustion while allocating control messages.
Add separate configurable 512 items limit for data items allocation
for DoS/overload protection.

Discussed with: julian

Implement 128 items node name hash for faster name search.
Increase node ID hash size from 32 to 128 items.

Fix incorrect constant used in rev. 1.146 that broke node writer locking.

Cleanup and tune ng_snd_item() function as it is one of the
most busy netgraph functions.
Tune stack protection constants to avoid division operation.

Fix one more grammo.

Noticed by: ru

Reword recent comment a bit.

Add comments about stack protection mechanism.

Some code reformat.

Implement stack protection based on GET_STACK_USAGE() macro.
This fixes system panics possible with complicated netgraph setups
and allows to avoid unneded extra queueing for stack unwrapping.

Add a new 'why' argument to kdb_enter(), and a set of constants to use
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.

Assign approximate why values to all current consumers of the
kdb_enter() interface.

- Merge all the ng_send_fn2* functions into one - ng_send_fn2(),
removing some copy&pasted code.
- Reduce copy and paste in ng_apply_item().
- Resurrect ng_send_fn() as a valid symbol, not a define.

Reviewed by: mav, julian

Minor debug message fix.

Fix build with NETGRAPH_DEBUG.

Implement new apply callback mechanism to handle item forwarding.
When item forwarded refence counter is incremented, when item
processed, counter decremented. When counter reaches zero,
apply handler is getting called.
Now it allows to report right connect() call status from user-level
at the right time.

Add ng_send_fn() error handeling inside ng_con_nodes().
Without it some errors may left unnoticed and unhandeled
that will lead to hooks left in half-connected state.

Reviewed by: julian@
Approved by: re (kensmith), glebius (mentor)

Despite several examples in the kernel, the third argument of
sysctl_handle_int is not sizeof the int type you want to export.
The type must always be an int or an unsigned int.

Remove the instances where a sizeof(variable) is passed to stop
people accidently cut and pasting these examples.

In a few places this was sysctl_handle_int was being used on 64 bit
types, which would truncate the value to be exported. In these
cases use sysctl_handle_quad to export them and change the format
to Q so that sysctl(1) can still print them.

Partially back out rev. 1.127, to restore broken functionality. This
should be redesigned, but better enter RELENG_7 with a working ngctl(8).

Agreed by: julian

Universally adopt most conventional spelling of acquire.

We don't need spinning locks here. Change them to the adaptive mutexes. This
change should bring no performance decrease, as it did not in my tests.

Reviewed by: julian, glebius
Approved by: cognet (mentor)

Instead of direct manipulation on queue and worklist mutexes, bring macros
for doing this job. This change will make it easy to migrate from using
spinning locks to adaptive ones.

Reviewed by: glebius, julian
Approved by: cognet (mentor)

Prefer more traditional spellings of some words in comments.

oops committed the wrong patch.
try this one..

ng_apply_item should be void. It is called from the interrupt source or
from whoever has dequeued the item from the queue. Generally they have
no interest in the result, and even if it is called by the queuer, it
should still pretend that it was queued. The queuer should be assuming
that the call was queued and giving them the false confidence that they
are getting status leads to hard to find bugs.

Make it a void and remove all the code that tried to return status through it.

Do not leak hooks in ng_bypass().

Submitted by: Alexander Motin <mav alkar.net>

When counting nodes second time, use the same criteria as for
the first time.

PR: kern/98529
Submitted by: Michael Heyman

Use NET_CALLOUT_MPSAFE for netgraph callout initializer.

Conditionally acquire Giant in netgraph callouts to honor mpsafenet=0.

Reported by: sekes <gexlie at gmail dot com>
MFC after: 1 week

- Print also node ID in ktr(9) messages. [1]
- Use fixed length for function name, making ktrdump(8) output
easier to read.

Suggested by: julian [1]

Remove old debugging leftover.

Reviewed by: julian

Fix wording in last commit.

Submitted by: julian

Add ktr(9) hooks to easier tracing of the netgraph item flow through
netgraph.

Some whitespace and style cleanup.

Fix two races which happen when netgraph is restructuring:
- Introduce ng_topo_mtx, a mutex to protect topology changes.
- In ng_destroy_node() protect with ng_topo_mtx the process
of checking and pointing at ng_deadnode. [1]
- In ng_con_part2() check that our peer is not a ng_deadnode,
and protect the check with ng_topo_mtx.
- Add KASSERTs to ng_acquire_read/write, to make more
understandible synopsis in case if called on ng_deadnode.

Reported by: Roselyn Lee [1]

Rework the ng_item queueing on nodes:
- Introduce a new flags NGQF_QREADER and NGQF_QWRITER,
which tell how the item should be actually applied,
overriding NGQF_READER/NGQF_WRITER flags.
- Do not differ between pending reader or writer. Use only
one flag that is raised, when there are pending items.
- Schedule netgraph ISR in ng_queue_rw(), so that callers
do not need to do this job.
- Fix several comments.

Submitted by: julian

- When flushing node input queue, check whether item has a callback. If
it does, then call it suppling ENOENT as error value.
- Add assert, that helped to catch the above error.

After rev. 1.103 the oitem and ierror are no longer needed, remove them.

Fix a regression introduced in rev. 1.107. If an item once had a writer
semantics, and then was reused for next node, it still would be applied
as writer again.
To fix the regression the decision is made never to alter item->el_flags
after the item has been allocated. This requires checking for overrides
both in ng_dequeue() and in ng_snd_item().

Details:
- Caller of the ng_apply_item() knows what is the current access to
node and specifies it to ng_apply_item(). The latter drops the
given access after item has beem applied.
- ng_dequeue() needs to be supplied with int pointer, where it stores
the obtained access on node.
- Check for node/hook access overrides in ng_dequeue().

Fix an item leak, that happens when some node calls ng_callout() two
times consequently, without checking whether callout has been serviced
or not. (ng_pptpgre and ng_ppp were catched in this behavior).

- In ng_callout() save old item before calling callout_reset(). If the
latter has returned 1, then free this item.
- In ng_uncallout() clear c->c_arg.

Problem reported by: Alexandre Kardanev

Fix build.

In INVARIANTS case also check that nodes do not pass queues of mbufs
each other.

Raise one more bit in READER_MASK. I believe that before this change
it was possible to have 1 reader and 1 writer thread working on
a node simultaneously.

Reviewed by: julian

Use non-debug macros inside debugging functions, to prevent
important information from being rewritten.

Cleanup the reader/writer policy in netgraph(4). Assign
either reader or writer flag on item in the function, that
allocates the item. Do not modify these flags when item is
applied or queued.
The only exceptions are node and hook overrides - they can
change item flags to writer.

In ng_callout() assert that supplied arguments are non-NULL.

Fix cut-n-paste error, introduced in rev. 1.103.

Catch up with netgraph.h rev. 1.57 and fix build.

Problem description:

At the end of ng_snd_item(), node queue is processed. In certain
netgraph setups deep recursive calls can occur.
For example this happens, when two nodes are connected and can send
items to each other in both directions. If, for some reason, both nodes
have a lot of items in their queues, then the processing thread will
recurse between these two nodes, delivering items left and right, going
deeper in the stack. Other setups can suffer from deep recursion, too.
The following factors can influence risk of deep netgraph call:
- periodical write-access events on node
- combination of slow link and fast one in one graph
- net.inet.ip.fastforwarding

Changes made:

- In ng_acquire_{read,write}() do not dequeue another item. Instead,
call ng_setisr() for this node.
- At the end of ng_snd_item(), do not process queue. Call ng_setisr(),
if there are any dequeueable items on node queue.
- In ng_setisr() narrow worklist mutex holding.
- In ng_setisr() assert queue mutex.

Theoretically, the first two changes should negatively affect performance.
To check this, some profiling was made:

1) In general real tasks, no noticable performance difference was found.

2) The following test was made: two multithreaded nodes and one
single-threaded were connected into a ring. A large queues of packets
were sent around this ring. Time to pass the ring N times was measured.
This is a very vacuous test: no items/mbufs are allocated, no upcalls or
downcalls outside of netgraph. It doesn't represent a real load, it is
a stress test for ng_acquire_{read,write}() and item queueing functions.
Surprisingly, the performance impact was positive! New code is 13% faster
on UP and 17% faster on SMP, in this particular test.

The problem was originally found, described, analyzed and original patch
was written by Roselyn Lee from Vernier Networks. Thanks!

Submitted by: Roselyn Lee <rosel verniernetworks com>

In the splnet times, netgraph was functional and synchronous. Nowadays,
an item may be queued and processed later. While this is OK for mbufs,
this is a problem for control messages.

In the framework:
- Add optional callback function pointer to an item. When item gets
applied the callback is executed from ng_apply_item().
- Add new flag NG_PROGRESS. If this flag is supplied, then return
EINPROGRESS instead of 0 in case if item failed to deliver
synchronously and was queued.
- Honor NG_PROGRESS in ng_snd_item().

In ng_socket:
- When userland sends control message add callback to the item.
- If ng_snd_item() returns EINPROGRESS, then sleep.

This change fixes possible races in ngctl(8) scripts.

Reviewed by: julian
Approved by: re (scottl)

- Extend interface of ng_getqblk(), so that malloc wait flags are
specified by caller.
- Change ng_send_item() interface - use 'flags' argument instead of
boolean 'queue'.
- Extend ng_send_fn(), ng_package_data() and ng_package_msg()
interface - add possibility to pass flags. Rename ng_send_fn() to
ng_send_fn1(). Create macro for ng_send_fn().
- Update all macros, that use ng_package_data() and ng_package_msg().

Reviewed by: julian

Move queue element routines upper, so that all related
declarations are in one place, to improve readability.
No functional changes.

Use uma(9) for allocating netgraph items:
- ng_getqblk() simply runs uma_zalloc().
- ng_free_item() simply frees.
- ngq_mtx is pushed down under NETGRAPH_DEBUG.
- NGQF_FREE is removed.

Increase default maxalloc to 512.

Reviewed by: julian

Since there is no way to queue a function call to node, create
ng_queue_fn() - a queue version of ng_send_fn().

Plug item leak in case when NGI_FN is applied to invalid node.

Submitted by: Roselyn Lee
MFC after: 3 days

Make netgraph ISR and callout MPSAFE.

Reviewed by: rwatson, ru

Rename ng_callout_trapoline to ng_callout_trampoline.

Requested by: ru

With recent changes to _callout_stop_safe() we can remove a hack
in ng_uncallout().

Fix an evil typo.

Submitted by: Roselyn Lee
MFC after: 3 days

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

Introduce new startup level SI_SUB_NETGRAPH that is after
SI_SUB_INIT_IF but before SI_SUB_DRIVERS. Make Netgraph(4)
framework initialize at SI_SUB_NETGRAPH level.

This does not address the bigger problem: MODULE_DEPEND
does not seem to work when modules are compiled in the
kernel, but it fixes the problem with Netgraph Bluetooth
device drivers reported by a few folks.

PR: i386/69876
Reviewed by: julian, rik, scottl
MFC after: 3 days

Move systm.h up, since it is required by mbuf.h.

Requested by: ru

- sort includes
- remove duplicate include sys/sysctl.h

Assert queue mutex in ng_dequeue() and ng_queue_rw().

Mechanically rename s/ng_timeout/ng_callout/g, s/ng_untimeout/ng_uncallout/g.
This is done to keep both versions in RELENG_5 and support both APIs.

Reviewed by: scottl
Approved by: julian (mentor), implicitly

Partically backout previous commit. Since _callout_stop_safe() clears
out c->c_func, we can't take it after callout_stop(). To take it before
we need to acquire callout_lock, to avoid race. This commit narrows
down area where lock is held, but hack is still present.

This should be redesigned.

Approved by: julian (mentor)

- Make ng_timeout() to use callout() interface instead of timeout().
- Remove callout-hacking from ng_untimeout().

Approved by: julian (mentor)
MFC after: 1 month

When making a peer of unknown type framework tries to load module
using linker_load_module(). This works OK if NGM_MKPEER message came
from userland and we have process associated with thread. But when
NGM_MKPEER was queued because target node was busy, linker_load_module()
is called from netisr thread leading to panic.
To workaround that we do not load modules by framework, instead ng_socket
loads module (if this is required) before sending NGM_MKPEER.
However, the race condition between return from NgSendMsg() and actual
creation of node still exist and needs to be solved.

PR: kern/62789
Approved by: julian

Slight cosmetic changes.
Also introduce a macro to be called by persistent nodes to signal their
persistence during shutdown to hide this mechanism from the node author.

Make node flags have a consistent style in naming.

Document the change.

Reverse a lock/unlock pair that were the wrong way around in some code that
is obviously not run a lot. (but is in some test cases).
This code is not usually run because it covers a case that doesn't
happen a lot (removing a node that has data traversing it).

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

Update for the KDB framework:
o Call kdb_enter() instead of Debugger().
o Change comments accordingly.

Remove the home-grown metadata facility in favour of the now generic
mbuf tags facility. Netgraph modules will all need a recompile.

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

Not quite sure how that one got past me..

Make the frameworkl responsible for not passing the nodes a NULL mbuf pointer.
this allows the nodes to not test for this..

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

Clean up use of ng_hdhasb_mtx a little:

- Assert the mutex in NG_IDHASH_FIND() since the mutex is required to
safely walk the node lists in the ng_ID_hash table.

- Acquire the ng_nodelist_mtx when walking ng_allnodes or ng_allhooks
to generate state dump output from the netgraph sysctls.

Add a new netgraph method to allow restoration of some
behaviour lost in the change from 4.x style netgraph tee nodes.
Alter the tee node to use the new method. Document the behaviour.

Step the ABI version number... old netgraph klds will refuse to load.
Better than just crashing.

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

Get rid of the deprecated *LEN constants in favour of the new
*SIZ constants that include the trailing \0 byte.

The last argument to mtx_init() should be MTX_DEF, not 0. This is not a
functional change since MTX_DEF happens to be defined as 0.

o add a flags parameter to netisr_register that is used to specify
whether or not the isr needs to hold Giant when running; Giant-less
operation is also controlled by the setting of debug_mpsafenet
o mark all netisr's except NETISR_IP as needing Giant
o add a GIANT_REQUIRED assertion to the top of netisr's that need Giant
o pickup Giant (when debug_mpsafenet is 1) inside ip_input before
calling up with a packet
o change netisr handling so swi_net runs w/o Giant; instead we grab
Giant before invoking handlers based on whether the handler needs Giant
o change netisr handling so that netisr's that are marked MPSAFE may
have multiple instances active at a time
o add netisr statistics for packets dropped because the isr is inactive

Supported by: FreeBSD Foundation

Replace the lock-less algorithm for the free item list with a more
conservative lock. The problem with the lock-less algorithm is that
it suffers from the ABA problem. Running an application with funnels
a couple of 100kpkts/s through the netgraph system on a dual CPU system
with MPSAFE drivers will panic almost immediatly with the old algorithm.

It may be possible to eliminate the contention between threads that insert
free items into the list and those that get free items by using the
Michael/Scott queue algorithm that has two locks.

Change all SYSCTLS which are readonly and have a related TUNABLE
from CTLFLAG_RD to CTLFLAG_RDTUN so that sysctl(8) can provide
more useful error messages.

Deprecate machine/limits.h in favor of new sys/limits.h.
Change all in-tree consumers to include <sys/limits.h>

Discussed on: standards@
Partially submitted by: Craig Rodrigues <rodrigc@attbi.com>

Introduce an M_ASSERTPKTHDR() macro which performs the very common task
of asserting that an mbuf has a packet header. Use it instead of hand-
rolled versions wherever applicable.

Submitted by: Hiten Pandya <hiten@unixdaemons.com>

Update netisr handling; Each SWI now registers its queue, and all queue
drain routines are done by swi_net, which allows for better queue control
at some future point. Packets may also be directly dispatched to a netisr
instead of queued, this may be of interest at some installations, but
currently defaults to off.

Reviewed by: hsu, silby, jayanth, sam
Sponsored by: DARPA, NAI Labs

Add two loader tuneables that allow one to change the maximum number of
queue items that can be allocated by netgraph and the number of free queue
items that are cached on a private list.

Netgraph places an upper limit on the number of queue items it may allocate.
When there is a large number of netgraph messages travelling through the
system (100k/sec and more) there is a high probability, that messages get
queued at the nodes and netgraph runs out of queue items. In this case the data
flow through netgraph gets blocked. The tuneable for the number of free
items lets one trade memory for performance.

The tunables are also available as read-only sysctls.

PR: kern/47393
Reviewed by: julian
Approved by: jake (mentor)

Correct typos, mostly s/ a / an / where appropriate. Some whitespace cleanup,
especially in troff files.

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

Make the consumers of the linker_load_file() function use
linker_load_module() instead.

This fixes a bug where the kernel was unable to properly locate and
load a kernel module in vfs_mount() (and probably in the netgraph
code as well since it was using the same function). This is because
the linker_load_file() does not properly search the module path.

Problem found by: peter
Reviewed by: peter
Thanks to: peter

Fix GCC warnings caused by initializing a zero length array. In the process,
simply things a bit by getting rid of 'struct ng_parse_struct_info' which
was useless because it only contained one field.

MFC after: 2 weeks

Fix warnings: deprecated use of label at end of compound statement

Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on: i386, alpha, sparc64

Official timeout routines for netgraph nodes that know how to
use (and abuse) the node locking system.

MFC after: 1 week

Update to C99, s/__FUNCTION__/__func__/,
also don't use ANSI string concatenation.

Fix two typos

Add an external function to unlink a netgraph type from the types list.

remember to set the return address in a message when
sending it along a hook.

PR: 27906
Submitted by: Harti Brandt <brandt@fokus.gmd.de>

no MFC as code is different in 4.x

netgraph.h:
Change a prototype.
Add a function version of ng_ref_node() when debugging so
a breakpoint can be set on it.
ng_base.c:
add 'node' as an argument to ng_apply_item so that it is up
to the caller to take over and release the item's reference on
the node. If the release reports back that the node went away
due to the reference going to 0, the caller should cease referencing
the now defunct node. (e.g. the item was a 'kill node' message).
Alter ng_unref_node to report back the residual references as a result.
ng_pptpgre.c:
Don't reference a node after we dropped a reference to it.
(What if it was the last?)
Fixes a node leak reported by Harti Brandt <brandt@fokus.gmd.de>
which was due to an incorrect earlier attempt to fix the
"accessing node after dropping the last reference" problem.

Cleanups to Macros for sending data between netgraph nodes.

Shuffle netgraph mutexes a bit and hold a reference on a node
from the function that is calling the destructor.

Allow a changed MAC address to show up in ifconfig by changing it
in the ifaddr list as well. Also change an error return in the base system.

Add knowledge of the netgraph spinlocks into the Witness code.
Well, at least I think that's how it's done.

Shuffle sysctls a bit (thankyou whoever made them dynamic for modules)
and add a sysctl to pppoe to activate non standard ethertypes
so that idiot ISPs (apparently in France) who use
equipment from idiot suppliers (rumour says 3com)
who use nonstandard ethertypes can still connect.

"yep, sure we do pppoe, we use a different identifier to that dictated in
the standard, but sure it's pppoe!"

sysctl -w net.graph.stupid_isp=1 enables the changeover.

Preceed/preceeding are not english words. Use precede and preceding.

Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

Make netgraph modules refuse to link with modules of a different ABI version.
also try implement teh documented behaviour in socket nodes
so that when there is only one hook, an unaddressed write/send
will DTRT and send the data to that hook.

Clean up reference counting with relation to queued packets and the worklist,
and while I'm there, clean up the worklist insertion and removal.

Inspired by: Harti Brandt <brandt@fokus.gmd.de>

Add the ability to declare ore-ride methods on a per-hook basis
for the rcvdata() and rcvmsg() methods.

Also bring the man page up to sync with my last commit. (and this one)

Implement direct support for semipersistant nodes.
(e.g. ethernet nodes are persistent until you rip out the hardware)
Use this support in the ethernet and sample nodes.
Add some more abstraction on the 'item's so that node and
hook reference counting can be checked easier.
Slight man page correction.
Make pppoe type dependent on ethernet type.
Clean up node shutdown a little.
Move a mutex from MTX_SPIN to MTX_DEF (oops)
Fix small ref-counting bug.
remove warning on one2many type.

Only clear the 'free' bit if we were successful in getting a queue item off the free list.

Found by: Harti Brandt (address unknown)

Don't crash the kernel if the user tries to load a netgraph
module with the wrong version number.

Add MTX_SPIN to an mtx_init(

remove stupid braino (recursive mutex)
tripped over by: PHK

Add a generic "queued function callin" mechanism
Use it to implement (hopefully) SMP safe node/hook addition
and removal.
Fix some debug stuff.

remove debug sysctl
slight tweek to hook removal. (or is that tweak?)

Make hook deletion SMP safe.

Add an exported function ng_rmhook_self() that removes a hook
from a node, but does it via the locking queue, thus ensuring that the
node is locked when it's hook is removed.

Add 'deadnode' and 'deadhook' structures for when a node or hook is
invalidated but not yet freed. (not yet freed)

Unbreak compilation.

Changes to stop zombie nodes showing up in active node lists.
Also some changes resulting from debug work done earlier.

Bad julian.. forgot to destroy mutex before freeing the
structure it was part of!

Part 2 of the netgraph rewrite.
This is mostly cosmetic changes, (though I caught a bug or two while
makeing them)
Reviewed by: archie@freebsd.org

Rewrite of netgraph to start getting ready for SMP.
This version is functional and is aproaching solid..
notice I said APROACHING. There are many node types I cannot test
I have tested: echo hole ppp socket vjc iface tee bpf async tty
The rest compile and "Look" right. More changes to follow.
DEBUGGING is enabled in this code to help if people have problems.

Divorce the kernel binary ABI version number from the message
format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.

Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)

oops that commit included a local hack... take it out..

Reviewed by: Archie@freebsd.org
This clears out my outstanding netgraph changes.
There is a netgraph change of design in the offing and this is to some
extent a superset of soem of the new functionality and some of the old
functionality that may be removed.

This code works as before, but allows some new features that I want to
work with and evaluate. It is the basis for a version of netgraph
with integral locking for SMP use.

This is running on my test machine with no new problems :-)

Add splhigh()s to protect against a race condition
that shows up when running with ethernet bridging
at high speed.

Submitted by: Chris Csanady <ccsanady@iastate.edu>
(and extended by me)

Add the use of M_ZERO to netgraph.

Submitted by: josh@zipperup.org
Submitted by: Robert Drehmel <robd@gmx.net>
Submitted by: archie
Approved by: archie

Since neither archie nor I work at Whistle any more, change our email
addresses to be the more usefu @freebsd.org ones
so we can keep getting bug-reports.
- man pages to follow..

Use a bigger buffer for NGM_BINARY2ASCII conversion, to handle really
long ASCII control messages.

Allocate memory with M_NOWAIT instead of M_WAITOK, because it's possible
for these routines to be called from an interrupt context.

PR: kern/20057

Experiemntal ascii based device configuration mechanism.

This may or may not survive, decision will be made well before 5.0-R

Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by: msmith and others

Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by: phk
Reviewed by: phk
Approved by: mdodd

Don't assume *lasthook is initialized in ng_path2node().

Use 'type_name' structure field instead of 'typename', which is
a C++ reserved work.

Add a ng_copy_meta() function.

A temporary band-aid for ng_base. It works for some people, a better
fix will follow.

Submitted by: Gary Jennejohn <garyj@muc.de>

Minimal tweak to make the ng_XXX modules depend on netgraph so that they
see its symbols and link ok.

Two simple changes to the kernel internal API for netgraph modules,
to support future work in flow-control and 'packet reject/replace'
processing modes.

reviewed by: phk, archie

Fix uninitialized variable.

PR: kern/17911
Submitted by: Tom Pavel <pavel@alum.mit.edu>

Some minor prototype tweaks.

Remove a bunch of un-needed includes.
Submitted by: phk@freebsd.org

Add a new function ng_findhook() for finding a node's hook;
if the node type provides a more efficient implementation than
the normal linear scan, use it.

Reviewed by: julian

Add two new generic control messages, NGM_ASCII2BINARY and
NGM_BINARY2ASCII, which convert control messages to ASCII and back.
This allows control messages to be sent and received in ASCII form
using ngctl(8), which makes ngctl a lot more useful.

This also allows all the type-specific debugging code in libnetgraph
to go away -- instead, we just ask the node itself to do the ASCII
translation for us.

Currently, all generic control messages are supported, as well as
messages associated with the following node types: async, cisco,
ksocket, and ppp.

See /usr/share/examples/netgraph/ngctl for an example of using this.

Also give ngctl(8) the ability to print out incoming data and
control messages at any time. Eventually nghook(8) may be subsumed.

Several other misc. bug fixes.

Reviewed by: julian

Change the prototype of the strto* routines to make the second
parameter a char ** instead of a const char **. This make these
kernel routines consistent with the corresponding libc userland
routines.

Which is actually 'correct' is debatable, but consistency and
following the spec was deemed more important in this case.

Reviewed by (in concept): phk, bde

Use KASSERT() instead of old #ifdef DIAGNOSTICS.
Add more INVARIANTS-enabled sanity checking.

Remove a null pointer reference

Submitted by: Brian Somers (brian@freebsd.org)

Be more accepting about the format of node IDs.
Submitted by: Brian Somers <brian@Awfulhak.org>

Move isfoo() and friends to the newly created sys/ctype.h.

Urged by: bde

Simplify checking/parsing of strings using strtoul(), isdigit(), etc.

Start making the contents of the generic framework opaque to the nodes.
This step: IDs are no-longer the address of the node.
Reviewd by: Archie@freebsd.org

Whistle's Netgraph link-layer (sometimes more) networking infrastructure.
Been in production for 3 years now. Gives Instant Frame relay to if_sr
and if_ar drivers, and PPPOE support soon. See:
ftp://ftp.whistle.com/pub/archie/netgraph/index.html
for on-line manual pages.

Reviewed by: Doug Rabson (dfr@freebsd.org)
Obtained from: Whistle CVS tree