attempting to duplicate Windows spinlocks. Windows spinlocks differ
from FreeBSD spinlocks in the way they block preemption. FreeBSD
spinlocks use critical_enter(), which masks off _all_ interrupts.
This prevents any other threads from being scheduled, but it also
prevents ISRs from running. In Windows, preemption is achieved by
raising the processor IRQL to DISPATCH_LEVEL, which prevents other
threads from preempting you, but does _not_ prevent device ISRs
from running. (This is essentially what Solaris calls dispatcher
locks.) The Windows spinlock itself (kspin_lock) is just an integer
value which is atomically set when you acquire the lock and atomically
cleared when you release it.
FreeBSD doesn't have IRQ levels, so we have to cheat a little by
using thread priorities: normal thread priority is PASSIVE_LEVEL,
lowest interrupt thread priority is DISPATCH_LEVEL, highest thread
priority is DEVICE_LEVEL (PI_REALTIME) and critical_enter() is
HIGH_LEVEL. In practice, only PASSIVE_LEVEL and DISPATCH_LEVEL
matter to us. The immediate benefit of all this is that I no
longer have to rely on a mutex pool.
Now, I'm sure many people will be seized by the urge to criticize
me for doing an end run around our own spinlock implementation, but
it makes more sense to do it this way. Well, it does to me anyway.
Overview of the changes:
- Properly implement hal_lock(), hal_unlock(), hal_irql(),
hal_raise_irql() and hal_lower_irql() so that they more closely
resemble their Windows counterparts. The IRQL is determined by
thread priority.
- Make ntoskrnl_lock_dpc() and ntoskrnl_unlock_dpc() do what they do
in Windows, which is to atomically set/clear the lock value. These
routines are designed to be called from DISPATCH_LEVEL, and are
actually half of the work involved in acquiring/releasing spinlocks.
- Add FASTCALL1(), FASTCALL2() and FASTCALL3() macros/wrappers
that allow us to call a _fastcall function in spite of the fact
that our version of gcc doesn't support __attribute__((__fastcall__))
yet. The macros take 1, 2 or 3 arguments, respectively. We need
to call hal_lock(), hal_unlock() etc... ourselves, but can't really
invoke the function directly. I could have just made the underlying
functions native routines and put _fastcall wrappers around them for
the benefit of Windows binaries, but that would create needless bloat.
- Remove ndis_mtxpool and all references to it. We don't need it
anymore.
- Re-implement the NdisSpinLock routines so that they use hal_lock()
and friends like they do in Windows.
- Use the new spinlock methods for handling lookaside lists and
linked list updates in place of the mutex locks that were there
before.
- Remove mutex locking from ndis_isr() and ndis_intrhand() since they're
already called with ndis_intrmtx held in if_ndis.c.
- Put ndis_destroy_lock() code under explicit #ifdef notdef/#endif.
It turns out there are some drivers which stupidly free the memory
in which their spinlocks reside before calling ndis_destroy_lock()
on them (touch-after-free bug). The ADMtek wireless driver
is guilty of this faux pas. (Why this doesn't clobber Windows I
have no idea.)
- Make NdisDprAcquireSpinLock() and NdisDprReleaseSpinLock() into
real functions instead of aliasing them to NdisAcaquireSpinLock()
and NdisReleaseSpinLock(). The Dpr routines use
KeAcquireSpinLockAtDpcLevel() level and KeReleaseSpinLockFromDpcLevel(),
which acquires the lock without twiddling the IRQL.
- In ndis_linksts_done(), do _not_ call ndis_80211_getstate(). Some
drivers may call the status/status done callbacks as the result of
setting an OID: ndis_80211_getstate() gets OIDs, which means we
might cause the driver to recursively access some of its internal
structures unexpectedly. The ndis_ticktask() routine will call
ndis_80211_getstate() for us eventually anyway.
- Fix the channel setting code a little in ndis_80211_setstate(),
and initialize the channel to IEEE80211_CHAN_ANYC. (The Microsoft
spec says you're not supposed to twiddle the channel in BSS mode;
I may need to enforce this later.) This fixes the problems I was
having with the ADMtek adm8211 driver: we were setting the channel
to a non-standard default, which would cause it to fail to associate
in BSS mode.
- Use hal_raise_irql() to raise our IRQL to DISPATCH_LEVEL when
calling certain miniport routines, per the Microsoft documentation.
I think that's everything. Hopefully, other than fixing the ADMtek
driver, there should be no apparent change in behavior.
case we should wait for the resetdone handler to be called before
returning.
- When providing resources via ndis_query_resources(), uses the
computed rsclen when using bcopy() to copy out the resource data
rather than the caller-supplied buffer length.
- Avoid using ndis_reset_nic() in if_ndis.c unless we really need
to reset the NIC because of a problem.
- Allow interrupts to be fielded during ndis_attach(), at least
as far as allowing ndis_isr() and ndis_intrhand() to run.
- Use ndis_80211_rates_ex when probing for supported rates. Technically,
this isn't supposed to work since, although Microsoft added the extended
rate structure with the NDIS 5.1 update, the spec still says that
the OID_802_11_SUPPORTED_RATES OID uses ndis_80211_rates. In spite of
this, it appears some drivers use it anyway.
- When adding in our guessed rates, check to see if they already exist
so that we avoid any duplicates.
- Add a printf() to ndis_open_file() that alerts the user when a
driver attempts to open a file under /compat/ndis.
With these changes, I can get the driver for the SMC 2802W 54g PCI
card to load and run. This board uses a Prism54G chip. Note that in
order for this driver to work, you must place the supplied smc2802w.arm
firmware image under /compat/ndis. (The firmware is not resident on
the device.)
Note that this should also allow the 3Com 3CRWE154G72 card to work
as well; as far as I can tell, these cards also use a Prism54G chip.
resource_var.h.
In kern_ndis.c:ndis_convert_res(), fill in the cprd_flags and
cprd_sharedisp fields as best we can.
In if_ndis.c:ndis_setmulti(), don't bother updating the multicast
filter if our multicast address list is empty.
Add some missing updates to ndis_var.h and ntoskrnl_var.h that I
forgot to check in when I added the KeDpc stuff.
are actually layered on top of the KeTimer API in subr_ntoskrnl.c, just
as it is in Windows. This reduces code duplication and more closely
imitates the way things are done in Windows.
- Modify ndis_encode_parm() to deal with the case where we have
a registry key expressed as a hex value ("0x1") which is being
read via NdisReadConfiguration() as an int. Previously, we tried
to decode things like "0x1" with strtol() using a base of 10, which
would always yield 0. This is what was causing problems with the
Intel 2200BG Centrino 802.11g driver: the .inf file that comes
with it has a key called RadioEnable with a value of 0x1. We
incorrectly decoded this value to '0' when it was queried, hence
the driver thought we wanted the radio turned off.
- In if_ndis.c, most drivers don't accept NDIS_80211_AUTHMODE_AUTO,
but NDIS_80211_AUTHMODE_SHARED may not be right in some cases,
so for now always use NDIS_80211_AUTHMODE_OPEN.
NOTE: There is still one problem with the Intel 2200BG driver: it
happens that the kernel stack in Windows is larger than the kernel
stack in FreeBSD. The 2200BG driver sometimes eats up more than 2
pages of stack space, which can lead to a double fault panic.
For the moment, I got things to work by adding the following to
my kernel config file:
options KSTACK_PAGES=8
I'm pretty sure 8 is too big; I just picked this value out of a hat
as a test, and it happened to work, so I left it. 4 pages might be
enough. Unfortunately, I don't think you can dynamically give a
thread a larger stack, so I'm not sure how to handle this short of
putting a note in the man page about it and dealing with the flood
of mail from people who never read man pages.
The Am1771 driver will sometimes do the following:
- Some thread-> NdisScheduleWorkItem(some work)
- Worker thread -> do some work, KeWaitForSingleObject(some event)
- Some other thread -> NdisScheduleWorkItem(some other work)
When the second call to NdisScheduleWorkItem() occurs, the NDIS worker
thread (in our case ndis taskqueue) is suspended in KeWaitForSingleObject()
and waiting for an event to be signaled. This is different from when
the worker thread is idle and waiting on NdisScheduleWorkItem() to
send it more jobs. However, the ndis_sched() function in kern_ndis.c
always calls kthread_resume() when queueing a new job. Normally this
would be ok, but here this causes KeWaitForSingleObject() to return
prematurely, which is not what we want.
To fix this, the NDIS threads created by kern_ndis.c maintain a state
variable to indicate whether they are running (scanning the job list
and executing jobs) or sleeping (blocked on kthread_suspend() in
ndis_runq()), and ndis_sched() will only call kthread_resume() if
the thread is in the sleeping state.
Note that we can't just check to see if the thread is on the run queue:
in both cases, the thread is sleeping, but it's sleeping for different
reasons.
This stops the Am1771 driver from emitting various "NDIS ERROR" messages
and fixes some cases where it crashes.
802.11b chipset work. This chip is present on the SMC2602W version 3
NIC, which is what was used for testing. This driver creates kernel
threads (12 of them!) for various purposes, and required the following
routines:
PsCreateSystemThread()
PsTerminateSystemThread()
KeInitializeEvent()
KeSetEvent()
KeResetEvent()
KeInitializeMutex()
KeReleaseMutex()
KeWaitForSingleObject()
KeWaitForMultipleObjects()
IoGetDeviceProperty()
and several more. Also, this driver abuses the fact that NDIS events
and timers are actually Windows events and timers, and uses NDIS events
with KeWaitForSingleObject(). The NDIS event routines have been rewritten
to interface with the ntoskrnl module. Many routines with incorrect
prototypes have been cleaned up.
Also, this driver puts jobs on the NDIS taskqueue (via NdisScheduleWorkItem())
which block on events, and this interferes with the operation of
NdisMAllocateSharedMemoryAsync(), which was also being put on the
NDIS taskqueue. To avoid the deadlock, NdisMAllocateSharedMemoryAsync()
is now performed in the NDIS SWI thread instead.
There's still room for some cleanups here, and I really should implement
KeInitializeTimer() and friends.
and NdisCancelTimer(). NdisInitializeTimer() doesn't accept an NDIS
miniport context argument, so we have to derive it from the timer
function context (which is supposed to be the adapter private context).
NdisCancelTimer is now an alias for NdisMCancelTimer().
Also add stubs for NdisMRegisterDevice() and NdisMDeregisterDevice().
These are no-ops for now, but will likely get fleshed in once I start
working on the Am1771/Am1772 wireless driver.
problem with using taskqueue_swi is that some of the things we defer
into threads might block for up to several seconds. This is an unfriendly
thing to do to taskqueue_swi, since it is assumed the taskqueue threads
will execute fairly quickly once a task is submitted. Reorganized the
locking in if_ndis.c in the process.
Cleaned up ndis_write_cfg() and ndis_decode_parm() a little.
According to the Windows DDK header files, KSPIN_LOCK is defined like this:
typedef ULONG_PTR KSPIN_LOCK;
From basetsd.h (SDK, Feb. 2003):
typedef [public] unsigned __int3264 ULONG_PTR, *PULONG_PTR;
typedef unsigned __int64 ULONG_PTR, *PULONG_PTR;
typedef _W64 unsigned long ULONG_PTR, *PULONG_PTR;
The keyword __int3264 specifies an integral type that has the following
properties:
+ It is 32-bit on 32-bit platforms
+ It is 64-bit on 64-bit platforms
+ It is 32-bit on the wire for backward compatibility.
It gets truncated on the sending side and extended appropriately
(signed or unsigned) on the receiving side.
Thus register_t seems the proper mapping onto FreeBSD for spin locks.
these add support for listing BSSIDs via wicontrol -l. I added code
to call OID_802_11_BSSID_LIST_SCAN to allow scanning for any nearby
wirelsss nets.
Convert from using individual mutexes to a mutex pool, created in
subr_ndis.c. This deals with the problem of drivers creating locks
in their DriverEntry() routines which might get trashed later.
Put some messages under IFF_DEBUG.
which has two important flags in it: the 'allocated by NDIS' flag
and the 'media specific info present' flag. There are two Windows macros
for getting/setting media specific info fields within the ndis_packet
structure which can behave improperly if these flags are not initialized
correctly when a packet is allocated. It seems the correct thing
to do is always set the NDIS_PACKET_ALLOCATED_BY_NDIS flag on
all newly allocated packets.
This fixes the crashes with the Intel Centrino wireless driver.
My sample card now seems to work correctly.
Also, fix a potential LOR involving ndis_txeof() in if_ndis.c.
the ni_dpccountlock member is an ndis_kspin_lock, not an
ndis_spin_lock (the latter is too big).
Run if_ndis.c:ndis_tick() via taskqueue_schedule(). Also run
ndis_start() via taskqueue in certain circumstances.
Using these tweaks, I can now get the Broadcom BCM5701 NDIS
driver to load and run. Unfortunately, the version I have seems
to suffer from the same bug as the SMC 83820 driver, which is
that it creates a spinlock during its DriverEntry() routine.
I'm still debating the right way to deal with this.
the RT_MESSAGETABLE resources that some driver binaries have.
This allows us to print error messages in ndis_syslog().
- Correct the implementation of InterlockedIncrement() and
InterlockedDecrement() -- they return uint32_t, not void.
- Correct the declarations of the 64-bit arithmetic shift
routines in subr_ntoskrnl.c (_allshr, allshl, etc...). These
do not follow the _stdcall convention: instead, they appear
to be __attribute__((regparm(3)).
- Change the implementation of KeInitializeSpinLock(). There is
no complementary KeFreeSpinLock() function, so creating a new
mutex on each call to KeInitializeSpinLock() leaks resources
when a driver is unloaded. For now, KeInitializeSpinLock()
returns a handle to the ntoskrnl interlock mutex.
- Use a driver's MiniportDisableInterrupt() and MiniportEnableInterrupt()
routines if they exist. I'm not sure if I'm doing this right
yet, but at the very least this shouldn't break any currently
working drivers, and it makes the Intel PRO/1000 driver work.
- In ndis_register_intr(), save some state that might be needed
later, and save a pointer to the driver's interrupt structure
in the ndis_miniport_block.
- Save a pointer to the driver image for use by ndis_syslog()
when it calls pe_get_message().
ndis_var.h
- In kern_ndis.c:ndis_send_packets(), avoid dereferencing NULL pointers
created when the driver's send routine immediately calls the txeof
handler (which releases the packets for us anyway).
- In if_ndis.c:ndis_80211_setstate(), implement WEP support.
evaluate them. Whatever they're meant to do, they're doing it wrong.
Also:
- Clean up last bits of NULL fallout in subr_pe
- Don't let ndis_ifmedia_sts() do anything if the IFF_UP flag isn't set
- Implement NdisSystemProcessorCount() and NdisQueryMapRegisterCount().
packet being freed has NDIS_STATUS_PENDING in the status field of
the OOB data. Finish implementing the "alternative" packet-releasing
function so it doesn't crash.
For those that are curious about ndis0: <ORiNOCO 802.11abg ComboCard Gold>:
1123 packets transmitted, 1120 packets received, 0% packet loss
round-trip min/avg/max/stddev = 3.837/6.146/13.919/1.925 ms
Not bad!
mbuf<->packet housekeeping. Instead, add a couple of extra fields
to the end of ndis_packet. These should be invisible to the Windows
driver module.
This also lets me get rid of a little bit of evil from ndis_ptom()
(frobbing of the ext_buf field instead of relying on the MEXTADD()
macro).
- Add explicit cardbus attachment in if_ndis.c
- Clean up after moving bus_setup_intr() in ndis_attach().
- When setting an ssid, program an empty ssid as a 1-byte string
with a single 0 byte. The Microsoft documentation says this is
how you're supposed to tell the NIC to attach to 'any' ssid.
- Keep trace of callout handles for timers externally from the
ndis_miniport_timer structs, and run through and clobber them
all after invoking the haltfunc just in case the driver left one
running. (We need to make sure all timers are cancelled on driver
unload.)
- Handle the 'cancelled' argument in ndis_cancel_timer() correctly.
NDIS_80211_NET_INFRA_BSS: I accidentally reversed them during
transcription from the Microsoft headers. Note that the
driver will default to BSS mode, and you need to specify
'mediaopt adhoc' to get it into IBSS mode.
- Make ndis_get_info()/ndis_set_info() sleep on the setdone/getdone
routines if they get back NDIS_STATUS_PENDING.
- Add a bunch of net80211 support so that 802.11 cards can be twiddled
with ifconfig. This still needs more work and is not guaranteed to
work for everyone. It works on my 802.11b/g card anyway.
The problem here is Microsoft doesn't provide a good way to a) learn
all the rates that a card supports (if it has more than 8, you're
kinda hosed) and b) doesn't provide a good way to distinguish between
802.11b, 802.11b/g an 802.11a/b/g cards, so you sort of have to guess.
Setting the SSID and switching between infrastructure/adhoc modes
should work. WEP still needs to be implemented. I can't find any API
for getting/setting the channel other than the registry/sysctl keys.
make it more robust. This should fix problems with crashes under
heavy traffic loads that have been reported. Also add a 'query done'
callback handler to satisfy the e100bex.sys sample Intel driver.
Yes, it's what you think it is. Yes, you should run away now.
This is a special compatibility module for allowing Windows NDIS
miniport network drivers to be used with FreeBSD/x86. This provides
_binary_ NDIS compatibility (not source): you can run NDIS driver
code, but you can't build it. There are three main parts:
sys/compat/ndis: the NDIS compat API, which provides binary
compatibility functions for many routines in NDIS.SYS, HAL.dll
and ntoskrnl.exe in Windows (these are the three modules that
most NDIS miniport drivers use). The compat module also contains
a small PE relocator/dynalinker which relocates the Windows .SYS
image and then patches in our native routines.
sys/dev/if_ndis: the if_ndis driver wrapper. This module makes
use of the ndis compat API and can be compiled with a specially
prepared binary image file (ndis_driver_data.h) containing the
Windows .SYS image and registry key information parsed out of the
accompanying .INF file. Once if_ndis.ko is built, it can be loaded
and unloaded just like a native FreeBSD kenrel module.
usr.sbin/ndiscvt: a special utility that converts foo.sys and foo.inf
into an ndis_driver_data.h file that can be compiled into if_ndis.o.
Contains an .inf file parser graciously provided by Matt Dodd (and
mercilessly hacked upon by me) that strips out device ID info and
registry key info from a .INF file and packages it up with a binary
image array. The ndiscvt(8) utility also does some manipulation of
the segments within the .sys file to make life easier for the kernel
loader. (Doing the manipulation here saves the kernel code from having
to move things around later, which would waste memory.)
ndiscvt is only built for the i386 arch. Only files.i386 has been
updated, and none of this is turned on in GENERIC. It should probably
work on pc98. I have no idea about amd64 or ia64 at this point.
This is still a work in progress. I estimate it's about %85 done, but
I want it under CVS control so I can track subsequent changes. It has
been tested with exactly three drivers: the LinkSys LNE100TX v4 driver
(Lne100v4.sys), the sample Intel 82559 driver from the Windows DDK
(e100bex.sys) and the Broadcom BCM43xx wireless driver (bcmwl5.sys). It
still needs to have a net80211 stuff added to it. To use it, you would
do something like this:
# cd /sys/modules/ndis
# make; make load
# cd /sys/modules/if_ndis
# ndiscvt -i /path/to/foo.inf -s /path/to/foo.sys -o ndis_driver_data.h
# make; make load
# sysctl -a | grep ndis
All registry keys are mapped to sysctl nodes. Sometimes drivers refer
to registry keys that aren't mentioned in foo.inf. If this happens,
the NDIS API module creates sysctl nodes for these keys on the fly so
you can tweak them.
An example usage of the Broadcom wireless driver would be:
# sysctl hw.ndis0.EnableAutoConnect=1
# sysctl hw.ndis0.SSID="MY_SSID"
# sysctl hw.ndis0.NetworkType=0 (0 for bss, 1 for adhoc)
# ifconfig ndis0 <my ipaddr> netmask 0xffffff00 up
Things to be done:
- get rid of debug messages
- add in ndis80211 support
- defer transmissions until after a status update with
NDIS_STATUS_CONNECTED occurs
- Create smarter lookaside list support
- Split off if_ndis_pci.c and if_ndis_pccard.c attachments
- Make sure PCMCIA support works
- Fix ndiscvt to properly parse PCMCIA device IDs from INF files
- write ndisapi.9 man page
