I'm writing a kind of wrapper over wlanapi. When receiving notifications via WlanRegisterNotification I'm getting unexpected media-specific module (MSM) notification with code 59 (which is 0x3B in hex). WLAN_NOTIFICATION_MSM MSDN page does not contain any helpful information. My wlanapi.h does not contain such value as well, in fact this enumeration is zero-based and contain only 18 values - from 0 to 17.
Does anybody knows the meaning of such notification, and why it is not documented at all?
Here is what I have so far.
Looks like this notification is a part of regular connection process. That is, I'm getting it when connecting to a wireless network - regardless of previous connection state. Here is the notification sequence which happens each time when I connect to a network:
wlan_notification_msm_associating
wlan_notification_msm_associated
wlan_notification_msm_authenticating
59 (0x3B)
wlan_notification_msm_signal_quality_change
wlan_notification_msm_associated and wlan_notification_msm_authenticating fires in the same moment of time, and then immediately (in 10-20 milliseconds) fires notification with code 59 (0x3F).
This notification has 16-bytes payload. Data structure does not look familiar to me, posting this in case if it looks familiar to someone (10 events):
80805E08 009B0000 F1F10800 C400D634 <-- Switching between two networks here and below in random order
D0D049FA 009B0000 A6A60800 01542A00
80805E08 009B0000 696902FF 00FF4C6F
80805E08 00C40000 04040E00 000093DF
80805E08 009B0000 04040900 6F009361 <-- Diconnect and connect to the same network
80805E08 009B0000 04000700 00009340 <-- Diconnect and connect to the same network
64640000 00450002 0400114D 00009363 <-- Disconnect and connect to another network
80805E08 009B0000 04040511 005B93E8 <-- Diconnect and connect to the same network
58580000 00450002 04000904 3D4293A1 <-- Connect to another network (i. e. switch)
80805E08 009B0000 04040100 10919316 <-- Connect to another network (i. e. switch)
Useful links
[Wlanapi] WLAN_NOTIFICATION_MSM NotificationCode 59 (Microsoft Q&A)
[Wlanapi] WLAN_NOTIFICATION_MSM NotificationCode 59 (c++ forums)
Will appreciate any help!
Update 1
Notifications sequence is the same when connecting via official sample:
HandleAcmNotification(type = ConnectionStart)
HandleMsmNotification(type = Associating)
HandleMsmNotification(type = Associated)
HandleMsmNotification(type = Authenticating)
HandleMsmNotification(type = Code59)
HandleMsmNotification(type = SignalQualityChange)
HandleMsmNotification(type = Connected)
HandleAcmNotification(type = ConnectionComplete)
Update 2
I've created a minimal test project on GitHub for this purpose - https://github.com/alexbereznikov/wlanapi-notification-code59-test.
Binary x64 release is located here - https://github.com/alexbereznikov/wlanapi-notification-code59-test/releases.
I'm getting the following output after successful connection to a wireless network:
This is by design.
The 0n59 notification code is a private notification code that is processed by the OS when the wireless network may be undergoing a network speed change.
For the end developer, this should be ignored by the end developer as it is not documented and subject to change in the future since it is a private notification handled by underlying OS.
Note:This will only be sent on newer OS now (Windows 10) when disabling and re-enabling the wireless network. This notification is not sent for older OS (example, Windows 7, Windows 8.1)
Related
I have an issue in being unable to recive the URC message from the modem whenever it receives an SMS.
I know that it receives them since i can find and read them if I use AT+CMGL but, i don't receive any notification when the modem gets them. I played around with the URC related commands but I've been unable to get it to work (other URCs work fine).
The modem is a BG600L M3 from Quectel and following is the sequence of commands i'm sending ("AT" is always omitted and the first command is literally "AT\r", basically an empty one).
//general config
AT\r
CFUN=1,0
E1
+QCFG=\"urc/ri/other\",\"pulse\",8,1
H0
&F
V1
+CMEE=1
&D0
E1
+CREG=2
+CGREG=2
+CEREG=2
//sms config
+CPMS=\"ME\",\"ME\",\"ME\"
+QINDCFG=\"smsincoming\",1
+CMGF=1
+CSDH=0
+CSCS=\"GSM\"
+CNMI=2,2,0,2,0
//doing some deleting and reading
+CMGD=1,3
+CPMS?
//getting the gps fix
+QGPS=1
+QGPSCFG=\"gnssconfig\",3
+QGPSLOC=1
+QGPSEND
//resetting the gms connection
+CFUN=0
+CFUN=1,0
//setting up the gsm connection
+QICFG=\"dataformat\",0,0
+QICFG=\"viewmode\",0
+QICFG=\"recvind\",1
+QICFG=\"tcp/retranscfg\",3,600
+QISDE=0
+QCFG=\"band\",0xf,0x80085,0x80085,1
+QCFG=\"nwscanmode\",1,1
+QCFG=\"nwscanseq\",010101,1
+QCFG=\"iotopmode\",2,1
// checking if it's connected
+CREG?
+QNWINFO
+COPS?
//Getting the time
+CTZU=3
+CTZR=0
+QLTS
+CCLK?
You can set AT+CNMI=2,1,2,0,0 , that should do the trick.
According to specification ETSI TS 127 005 V11.0.0 (2012-10)
+CNMI: <mode>,<mt>,<bm>,<ds>,<bfr>
by keeping <mt> value to 1 we should get indication when message is stored in ME/TA
<mt>: integer type (the rules for storing received SMs depend on its
data coding scheme
0 No SMS-DELIVER indications are routed to the TE.
1 If SMS-DELIVER is stored into ME/TA, indication of the memory location is routed to the TE using unsolicited result code:
+CMTI: <mem>,<index>
Edit: I started asking this as a PowerShell / .Net question and couldn't find any reference to it on the internet. With feedback, it appears to be a WINAPI issue so this is an edit/rewrite/retag, but much of the tests and background reference .Net for that reason.
Summary
WINAPI ping function IcmpSendEcho2 appears to have a timing bug if the ping timeout parameter is set below 1000ms (1 second). This causes it to return intermittent false timeout errors. Rather than a proportional "lower timeout = more fails" behaviour, it appears to be a cutoff of >=1000ms+ is expected behaviour, <=999ms triggers false timeouts, often in an alternating success/fail/success/fail pattern.
I call them false timeouts because I have WireShark packet capture showing a reply packet coming back well within the timeout, and partly because the 1ms change shouldn't be a significant amount of time when the replies normally have 500-800ms of headroom, and partly because I can run two concurrent sets of pings with different timeouts and see different behavior between the two.
In the comments of my original .Net question, #wOxxOm has:
located the Open Source .Net code where System.Net.NetworkInformation.Ping() wraps the WinAPI and there appears to be no specific handling of timeouts there, it's passed down to the lower layer directly - possibly line 675 with a call to UnsafeNetInfoNativeMethods.IcmpSendEcho2()
and #Lieven Keersmaekers has investigated and found things beyond my skill level to interpret:
"I can second this being an underlying WINAPI problem. Following a success and timedout call into IPHLPAPI!IcmpSendEcho2Ex: the 000003e7 parameter is on the stack, both set up an event and both return into IPHLPAPI!IcmpEchoRequestComplete with the difference of the success call's eax register containing 00000000 and the timedout call's eax register containing 00000102 (WAIT_TIMEOUT)
"Compiling a 64bit C# version, there's no more calls into IPHLPAPI. A consistent thing that shows up is clr.dll GetLastError() returning WSA_QOS_ADMISSION_FAILURE for timeouts. Also consistent in my sample is the order of thread executions between a success and a timeout call being slightly different."
This StackOverflow question hints that the WSA_QOS_ADMISSION_FAILURE might be a misleading error, and is actually IP_REQ_TIMED_OUT.
Testing steps:
Pick a distant host and set some continuous pings running. (The IP in my examples belongs to Baidu.cn (China) and has ping replies around ~310ms to me). Expected behaviour for all of them: almost entirely ping replies, with occasional drops due to network conditions.
PowerShell / .Net, with 999ms timeout, actual result is bizarre reply/drop/reply/drop patterns, far more drops than expected:
$Pinger = New-Object -TypeName System.Net.NetworkInformation.Ping
while($true) {
$Pinger.Send('111.13.101.208', 999)
start-sleep -Seconds 1
}
command prompt ping.exe with 999ms timeout, actual result is more reliable (edit: but later findings call this into question as well):
ping 111.13.101.208 -t -w 999
PowerShell / .Net, with 1000ms timeout, actual result is as expected:
$Pinger = New-Object -TypeName System.Net.NetworkInformation.Ping
while($true) {
$Pinger.Send('111.13.101.208', 1000)
start-sleep -Seconds 1
}
It's repeatable with C# as well, but I've edited that code out now it seems to be a WinAPI problem.
Example screenshot of these running side by side
On the left, .Net with 999ms timeout and 50% failure.
Center, command prompt, almost all replies.
On the right, .Net with 1000ms timeout, almost all replies.
Earlier investigations / Background
I started with a 500ms timeout, and the quantity of fake replies seems to vary depending on the ping reply time of the remote host:
pinging something 30ms away reports TimedOut around 1 in 10 pings
pinging something 100ms away reports TimedOut around 1 in 4 pings
pinging something 300ms away reports TimedOut around 1 in 2 pings
From the same computer, on the same internet connection, sending the same amount of data (32 byte buffer) with the same 500ms timeout setting, with no other heavy bandwidth use. I run no antivirus networking filter outside Windows 10 defaults, two other people I know have confirmed this frequent TimedOut behaviour on their computers (now two more have in the comments), with more or fewer timeouts, so it ought not to be my network card or drivers or ISP.
WireShark packet capture of ping reply which is falsely reported as a timeout
I ran the ping by hand four times to a ~100ms away host, with a 500ms timeout, with WireShark capturing network traffic. PowerShell screenshot:
WireShark screenshot:
Note that the WireShark log records 4 requests leaving, 4 replies coming back, each with a time difference of around 0.11s (110 ms) - all well inside the timeout, but PowerShell wrongly reports the last one as a timeout.
Related questions
Googling shows me heaps of issues with System.Net.NetworkInformation.Ping but none which look the same, e.g.
System.Net.NetworkInformation.Ping crashing - it crashes if allocated/destroyed in a loop in .Net 3.5 because its internals get wrongly garbage collected. (.Net 4 here and not allocating in a loop)
Blue screen when using Ping - 6+ years of ping being able to BSOD Windows (not debugging an Async ping here)
https://github.com/dotnet/corefx/issues/15989 - it doesn't timeout if you set a timeout to 1ms and a reply comes back in 20ms, it still succeeds. False positive, but not false negative.
The documentation for Ping() warns about the low-timeout-might-still-say-success but I can't see it warns that timeout might falsely report failure if set below 1 second.
Edit: Now that I'm searching for ICMPSendEcho2, I have found exactly this problem documented before in a blog post in May 2015 here: https://www.frameflow.com/ping-utility-flaw-in-windows-api-creating-false-timeouts/ - finding the same behavior, but having no further explanation. They say that ping.exe is affected, when I originally thought it wasn't. They also say:
"In our tests we could not reproduce it on Windows Server 2003 R2 nor on Windows Server 2008 R2. However it was seen consistently in Windows Server 2012 R2 and in the latest builds of Windows 10."
Why? What's wrong with the timeout handling that makes it ignore ping repsonses coming into the network stack completely? Why is 1000ms a significant cutoff?
I have two redis instances both running on the same machine on win64. The version is the one from https://github.com/MSOpenTech/redis with no amendments and the binaries are running as per download from github (ie version 2.6.12).
I would like to create a slave and sync it to the master. I am doing this on the same machine to ensure it works before creating a slave on a WAN located machine which will take around an hour to transfer the data that exists in the primary.
However, I get the following error:
[4100] 15 May 18:54:04.620 * Connecting to MASTER...
[4100] 15 May 18:54:04.620 * MASTER <-> SLAVE sync started
[4100] 15 May 18:54:04.620 * Non blocking connect for SYNC fired the event.
[4100] 15 May 18:54:04.620 * Master replied to PING, replication can continue...
[4100] 15 May 18:54:28.364 * MASTER <-> SLAVE sync: receiving 2147483647 bytes from master
[4100] 15 May 18:55:05.772 * MASTER <-> SLAVE sync: Loading DB in memory
[4100] 15 May 18:55:14.508 # Short read or OOM loading DB. Unrecoverable error, aborting now.
The only way I can sync up is via a mini script something along the lines of :
import orm.model
if __name__ == "__main__":
src = orm.model.caching.Redis(**{"host":"source_host","port":6379})
dest = orm.model.caching.Redis(**{"host":"source_host","port":7777})
ks = src.handle.keys()
for i,k in enumerate(ks):
if i % 1000 == 0:
print i, "%2.1f %%" % ( (i * 100.0) / len(ks))
dest.handle.set(k,src.handle.get(k))
where orm.model.caching.* are my middleware cache implementation bits (which for redis is just creating a self.handle instance variable).
Firstly, I am very suspicious of the number in the receiving bytes as that is 2^32-1 .. a very strange coincidence. Secondly, OOM can mean out of memory, yet I can fire up a 2nd process and sync that via the script but doing this via redis --slaveof fails with what appears to be out of memory. Surely this can't be right?
redis-check-dump does not run as this is the windows implementation.
Unfortunately there is sensitive data in the keys I am syncing so I can't offer it to anybody to investigate. Sorry about that.
I am definitely running the 64 bit version as it states this upon startup in the header.
I don't mind syncing via my mini script and then just enabling slave mode, but I don't think that is possible as the moment slaveof is executed, it drops all known data and resyncs from scratch (and then fails).
Any ideas ??
I have also seen this error earlier, but the latest bits from 2.8.4 seem to have resolved it https://github.com/MSOpenTech/redis/tree/2.8.4_msopen
Using Andrew Rapp's XBee-API, how can I sample I/O data via a coordinator from more than two endpoints?
I have 17 Series 1 XBees. I have programmed one to be a coordinator (API mode = 2) and the rest to be endpoints. Using XBee-API I am sending a Force I/O Sample ("IS") remote AT command, unicast to each endpoint. This works perfectly well when there are up to two endpoints, but as soon as a third is added, one of the three always becomes non-responsive (times out with XBeeTimeoutException). It's not always the same physical unit that stops responding, but it is always the third one (for example, if I send Force I/O Sample to Device1, Device2, and Device3, Device3 will time out, and if I change the order to Device3, Device1, Device2, Device2 will time out.
If I set up more than three XBees, about 1 out of 3 will time out - but not every third one.
I've verified that the XBees themselves are fine. I've searched the Internet and Stack Overflow in particular to no avail. I've tried using a simple ZNetRemoteAtRequest. I've tried opening and closing the XBee coordinator serial connection once for all three devices, once per device, and once per program run. I've tried varying the distance between the coordinator and endpoints (never more than five feet apart). I've tried different coordinator configuration parameters (from the Digi documentation). I've tried changing out the XBee for the coordinator.
This is the code I'm using to send the Force I/O Sample request to each endpoint and read the response:
xbee = new XBee(); // Coordinator
xbee.open("/dev/ttyUSB0, 115200)); // Happens before any of the endpoints are contacted
... // Loop through known endpoint addresses
XBeeRequest request = new ZBForceSampleRequest(new XBeeAddress64(endpointAddress));
ZNetRemoteAtResponse response = null;
response = (ZNetRemoteAtResponse) xbee.sendSynchronous(request, remoteXBeeTimeout);
if (response.isOk()) {
// Process response payload
}
... // End loop and finally close coordinator connection
What might help polling I/O samples from more than two endpoints?
EDIT: I found that Andrew Rapp's XBee-API library fakes multithreaded behavior, which causes the synchronization issues described in this question. I wrote a replacement library that is actually multithreaded and correctly maps responses from multiple XBee endpoints: https://github.com/steveperkins/xbee-api-for-java-1-4. When I wrote it Java 1.4 was necessary for use on the BeagleBone, Plug, and Zotac single-board PCs but it's an easy conversion to 1.7+.
Are you using hardware flow control on your serial port? Is it possible that you're sending requests out when the local XBee has deasserted CTS (e.g., asking you to stop sending)? I assume you're running at 115200 bps, so the XBee serial port can keep up with the network data rate.
Can you turn on debugging information, or connect some port monitoring hardware/software to display the data going over the serial port to the local XBee?
My program puts a file into a remote host using HTTP. For some unavoidable
reasons, the remote hosts needs some time to acknowledge the final packet of
the data transmission. More time than the default timeout, which according
to my experience is around 30 seconds.
Therefore I wanted to increase the timeout to 5 minutes, using this code:
DWORD dwTimeout= 300000; // 5 minutes
pFtpConnection->SetOption( // KB176420: this has no effect on some
INTERNET_OPTION_SEND_TIMEOUT, dwTimeout); // old versions of IE.
pFtpConnection->SetOption(
INTERNET_OPTION_RECEIVE_TIMEOUT, dwTimeout);
pFtpConnection->SetOption( // NB: Docs say these 2 are not implemented.
INTERNET_OPTION_DATA_SEND_TIMEOUT, dwTimeout);
pFtpConnection->SetOption( // our own tests show that they are!
INTERNET_OPTION_DATA_RECEIVE_TIMEOUT, dwTimeout);
This is MFC code which boils down to calling
InternetOption(hConnection, INTERNET_XXX, &dwTimeout, sizeof(dwTimeout))
The problem is that this code apparently fails to modify the timeout on a
non negligeable proportion of computers where the program is used.
How can I reliably set the data connection timeout?
TIA,
Serge Wautier.
It looks like this WinInet isue can'tbe solved reliably.
I eventually switched from WinInet to Ultimate TCP/IP.