This turns ieee80211_node_pwrsave(), ieee80211_sta_pwrsave() and
ieee80211_recv_pspoll() into methods.
The intent is to let drivers override these and tie into the power save
management pathway.
For ath(4), this is the beginning of forcing a node software queue to
stop and start as needed, as well as supporting "leaking" single frames
from the software queue to the hardware.
Right now, ieee80211_recv_pspoll() will attempt to transmit a single frame
to the hardware (whether it be a data frame on the power-save queue or
a NULL data frame) but the driver may have hardware/software queued frames
queued up. This initial work is an attempt at providing the hooks required
to implement correct behaviour.
Allowing ieee80211_node_pwrsave() to be overridden allows the ath(4)
driver to pause and unpause the entire software queue for a given node.
It doesn't make sense to transmit anything whilst the node is asleep.
Please note that there are other corner cases to correctly handle -
specifically, setting the MORE data bit correctly on frames to a station,
as well as keeping the TIM updated. Those particular issues can be
addressed later.
to craft environment variables with similar names like that:
a=1
a=2
...
unsetenv("a") should remove them all to make later getenv("a") impossible.
Fix it to do so (this is GNU autoconf test #3 failure too).
PR: 172273
MFC after: 1 week
the CAM "enc" peripheral (part of ses(4)). Previously the two modules
used the same name, so only one was included in a linked kernel causing
enc0 to not be created if you added IPSEC to GENERIC. The new module
name follows the pattern of other network interfaces (e.g. "if_loop").
MFC after: 1 week
Both functions need to obtain lock on the found PCB, and they can't do
classic inter-lock with the PCB hash lock, due to lock order reversal.
To keep the PCB stable, these functions put a reference on it and after PCB
lock is acquired drop it. If the reference was the last one, this means
we've raced with in_pcbfree() and the PCB is no longer valid.
This approach works okay only if we are acquiring writer-lock on the PCB.
In case of reader-lock, the following scenario can happen:
- 2 threads locate pcb, and do in_pcbref() on it.
- These 2 threads drop the inp hash lock.
- Another thread comes to delete pcb via in_pcbfree(), it obtains hash lock,
does in_pcbremlists(), drops hash lock, and runs in_pcbrele_wlocked(), which
doesn't free the pcb due to two references on it. Then it unlocks the pcb.
- 2 aforementioned threads acquire reader lock on the pcb and run
in_pcbrele_rlocked(). One gets 1 from in_pcbrele_rlocked() and continues,
second gets 0 and considers pcb freed, returns.
- The thread that got 1 continutes working with detached pcb, which later
leads to panic in the underlying protocol level.
To plumb that problem an additional INPCB flag introduced - INP_FREED. We
check for that flag in the in_pcbrele_rlocked() and if it is set, we pretend
that that was the last reference.
Discussed with: rwatson, jhb
Reported by: Vladimir Medvedkin <medved rambler-co.ru>
w.r.t. a Linux NFS client doing a krb5 NFS mount against the
FreeBSD server. We determined this was a Linux bug:
http://www.spinics.net/lists/linux-nfs/msg32466.html, however
the mount failed to work, because the Destroy operation with a
bogus encrypted checksum destroyed the authenticator handle.
This patch changes the rpcsec_gss code so that it doesn't
Destroy the authenticator handle for this case and, as such,
the Linux mount will work.
Tested by: Attila Bogar and Herbert Poeckl
MFC after: 2 weeks
this some compilers will place a cmp instruction before the atomic operation
and expect to be able to use the result afterwards. By adding "cc" to the
list of used registers we tell the compiler to not do this.
- Evaluate the memory order argument in atomic_fetch_*_explicit macros.
- Implement atomic_store_explicit using atomic_exchange_explicit instead
of a plain assignment.
Reviewed by: theraven
MFC after: 2 weeks
- Write method of a queue now is void,length of item is taken
as queue property.
- Write methods don't need to know about mbud, supply just buf
to them.
- No need for safe queue iterator in pfsync_sendout().
Obtained from: OpenBSD
