* carl9170: Unintentional transmission in monitor mode? @ 2012-08-09 16:54 Marco Fonseca 2012-08-09 19:43 ` Christian Lamparter 0 siblings, 1 reply; 9+ messages in thread From: Marco Fonseca @ 2012-08-09 16:54 UTC (permalink / raw) To: linux-wireless Hello All, I've noticed unexpected transmissions from the AR9170 while in monitor mode and using tcpdump (and sometimes without tcpdump running). These transmissions degrade (pretty significantly) performance of other STA/AP on the channel (as seen by iperf going from 60mbit/s to almost nill). As best I can tell these transmissions never coalesces into an actual frame in the air (at least not one I'm able to pick up with a second different adapter in monitor mode). Are there any known reasons/bugs on this? Is there anyway to completely silence the transmitter of the AR9170 while still allowing reception? Some additional information that may give some context: - This seems to happen over a wide range of releases of compat wireless I've tried, I've tested between compat wireless 2.6.39-rc6-1 and 2012-7-03, various drivers and firmware (the latest being driver 1.9.4 and firmware 1.9.5). I've also seen the problem across multiple AR9170 adapters, as well as different linux hosts. - I've put a few printk's in the carl driver & stubbed out (somewhat blindly) some of the tx functions in wlan.c in the firmware to see if I could silence or get a clue on whats going on, with not much success. The problem still occurred (No prink's told me the kernel wasn't actively generating any pkts). - Seems like the transmissions only occur when monitoring 802.11n speeds. (That is if I manual configure the AP to 54mbit/s, I don't see the issue). Happens in both 2.4 or 5ghz band. - I was able to also observe this behavior with a single ping. Only seemed to occur with larger ICMP pings (would occur with -s 2000 pings, but not a standard (56 byte) ping). - Along with iperf degradation, I've verified transmissions with a spectrum analyzer. Thank you, Marco Fonseca ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-09 16:54 carl9170: Unintentional transmission in monitor mode? Marco Fonseca @ 2012-08-09 19:43 ` Christian Lamparter 2012-08-10 18:49 ` Marco Fonseca 2012-08-16 19:20 ` Johannes Berg 0 siblings, 2 replies; 9+ messages in thread From: Christian Lamparter @ 2012-08-09 19:43 UTC (permalink / raw) To: Marco Fonseca; +Cc: linux-wireless On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > Hello All, > > I've noticed unexpected transmissions from the AR9170 while in monitor mode > and using tcpdump (and sometimes without tcpdump running). These > transmissions degrade (pretty significantly) performance of other STA/AP on > the channel (as seen by iperf going from 60mbit/s to almost nill). As best I > can tell these transmissions never coalesces into an actual frame in the air > (at least not one I'm able to pick up with a second different adapter in > monitor mode). > > Are there any known reasons/bugs on this? Is there anyway to completely > silence the transmitter of the AR9170 while still allowing reception? > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> a solution is described in: <http://www.spinics.net/lists/linux-wireless/msg89279.html> (iw dev wlanX set monitor none - if I'm not mistaken) Regards, Chr ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-09 19:43 ` Christian Lamparter @ 2012-08-10 18:49 ` Marco Fonseca 2012-08-16 19:20 ` Johannes Berg 1 sibling, 0 replies; 9+ messages in thread From: Marco Fonseca @ 2012-08-10 18:49 UTC (permalink / raw) To: Christian Lamparter; +Cc: linux-wireless On Thu, Aug 09, 2012 at 09:43:28PM +0200, Christian Lamparter wrote: > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > Hello All, > > > > I've noticed unexpected transmissions from the AR9170 while in monitor mode > > and using tcpdump (and sometimes without tcpdump running). These > > transmissions degrade (pretty significantly) performance of other STA/AP on > > the channel (as seen by iperf going from 60mbit/s to almost nill). As best I > > can tell these transmissions never coalesces into an actual frame in the air > > (at least not one I'm able to pick up with a second different adapter in > > monitor mode). > > > > Are there any known reasons/bugs on this? Is there anyway to completely > > silence the transmitter of the AR9170 while still allowing reception? > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > a solution is described in: > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > (iw dev wlanX set monitor none - if I'm not mistaken) > > Regards, > Chr Excellent, this solved my problem. Thank you Christian. Marco ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-09 19:43 ` Christian Lamparter 2012-08-10 18:49 ` Marco Fonseca @ 2012-08-16 19:20 ` Johannes Berg 2012-08-16 19:34 ` Christian Lamparter 1 sibling, 1 reply; 9+ messages in thread From: Johannes Berg @ 2012-08-16 19:20 UTC (permalink / raw) To: Christian Lamparter; +Cc: Marco Fonseca, linux-wireless On Thu, 2012-08-09 at 21:43 +0200, Christian Lamparter wrote: > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > Hello All, > > > > I've noticed unexpected transmissions from the AR9170 while in monitor mode > > and using tcpdump (and sometimes without tcpdump running). These > > transmissions degrade (pretty significantly) performance of other STA/AP on > > the channel (as seen by iperf going from 60mbit/s to almost nill). As best I > > can tell these transmissions never coalesces into an actual frame in the air > > (at least not one I'm able to pick up with a second different adapter in > > monitor mode). > > > > Are there any known reasons/bugs on this? Is there anyway to completely > > silence the transmitter of the AR9170 while still allowing reception? > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > a solution is described in: > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > (iw dev wlanX set monitor none - if I'm not mistaken) I've seen this before too -- what flag causes the issue, and why? johannes ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-16 19:20 ` Johannes Berg @ 2012-08-16 19:34 ` Christian Lamparter 2012-08-17 2:03 ` Chen, Stephen 0 siblings, 1 reply; 9+ messages in thread From: Christian Lamparter @ 2012-08-16 19:34 UTC (permalink / raw) To: Johannes Berg; +Cc: Marco Fonseca, linux-wireless, Chen, Stephen On Thursday, August 16, 2012 09:20:55 PM Johannes Berg wrote: > On Thu, 2012-08-09 at 21:43 +0200, Christian Lamparter wrote: > > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > > Hello All, > > > > > > I've noticed unexpected transmissions from the AR9170 while in monitor mode > > > and using tcpdump (and sometimes without tcpdump running). These > > > transmissions degrade (pretty significantly) performance of other STA/AP on > > > the channel (as seen by iperf going from 60mbit/s to almost nill). As best I > > > can tell these transmissions never coalesces into an actual frame in the air > > > (at least not one I'm able to pick up with a second different adapter in > > > monitor mode). > > > > > > Are there any known reasons/bugs on this? Is there anyway to completely > > > silence the transmitter of the AR9170 while still allowing reception? > > > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > > > a solution is described in: > > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > > > (iw dev wlanX set monitor none - if I'm not mistaken) > > I've seen this before too -- what flag causes the issue, and why? Well that would be: FIF_OTHER_BSS or FIF_PROMISC_IN_BSS either one of these will set following flags for the hardware: AR9170_MAC_RX_CTRL_ACK_IN_SNIFFER AR9170_MAC_SNIFFER_ENABLE_PROMISC About the issue, I'm really can't tell w/o schematics of the hardware. It could be that ACK_IN_SNIFFER is more of a debug/test flag than a real feature? (Anyway, I cc'd Stephen. Maybe he knows more) Regards, Chr ^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: carl9170: Unintentional transmission in monitor mode? 2012-08-16 19:34 ` Christian Lamparter @ 2012-08-17 2:03 ` Chen, Stephen 2012-08-17 2:30 ` Marco Fonseca 0 siblings, 1 reply; 9+ messages in thread From: Chen, Stephen @ 2012-08-17 2:03 UTC (permalink / raw) To: Christian Lamparter, Johannes Berg Cc: Marco Fonseca, linux-wireless@vger.kernel.org Q2FuIHdlIHRlbGwgd2hhdCBraW5kIG9mIHVuZXhwZWN0ZWQgZnJhbWUgYXJlIGJlZW4gdHJhbnNt aXR0ZWQ/IChEYXRhIGZyYW1lIG9yIHdoaWNoIGtpbmQgb2YgY29udHJvbCBmcmFtZT8pDQpUaGF0 IG1heSBnaXZlIHVzIGEgY2x1ZS4NCg0KDQpUaGFuayB5b3UuDQpTdGVwaGVuDQoNCi0tLS0tT3Jp Z2luYWwgTWVzc2FnZS0tLS0tDQpGcm9tOiBDaHJpc3RpYW4gTGFtcGFydGVyIFttYWlsdG86Y2h1 bmtlZXlAZ29vZ2xlbWFpbC5jb21dIA0KU2VudDogRnJpZGF5LCBBdWd1c3QgMTcsIDIwMTIgMzoz NSBBTQ0KVG86IEpvaGFubmVzIEJlcmcNCkNjOiBNYXJjbyBGb25zZWNhOyBsaW51eC13aXJlbGVz c0B2Z2VyLmtlcm5lbC5vcmc7IENoZW4sIFN0ZXBoZW4NClN1YmplY3Q6IFJlOiBjYXJsOTE3MDog VW5pbnRlbnRpb25hbCB0cmFuc21pc3Npb24gaW4gbW9uaXRvciBtb2RlPw0KDQpPbiBUaHVyc2Rh eSwgQXVndXN0IDE2LCAyMDEyIDA5OjIwOjU1IFBNIEpvaGFubmVzIEJlcmcgd3JvdGU6DQo+IE9u IFRodSwgMjAxMi0wOC0wOSBhdCAyMTo0MyArMDIwMCwgQ2hyaXN0aWFuIExhbXBhcnRlciB3cm90 ZToNCj4gPiBPbiBUaHVyc2RheSwgQXVndXN0IDA5LCAyMDEyIDA2OjU0OjM0IFBNIE1hcmNvIEZv bnNlY2Egd3JvdGU6DQo+ID4gPiBIZWxsbyBBbGwsDQo+ID4gPiANCj4gPiA+IEkndmUgbm90aWNl ZCB1bmV4cGVjdGVkIHRyYW5zbWlzc2lvbnMgZnJvbSB0aGUgQVI5MTcwIHdoaWxlIGluIA0KPiA+ ID4gbW9uaXRvciBtb2RlIGFuZCB1c2luZyB0Y3BkdW1wIChhbmQgc29tZXRpbWVzIHdpdGhvdXQg dGNwZHVtcCANCj4gPiA+IHJ1bm5pbmcpLiAgVGhlc2UgdHJhbnNtaXNzaW9ucyBkZWdyYWRlIChw cmV0dHkgc2lnbmlmaWNhbnRseSkgDQo+ID4gPiBwZXJmb3JtYW5jZSBvZiBvdGhlciBTVEEvQVAg b24gdGhlIGNoYW5uZWwgKGFzIHNlZW4gYnkgaXBlcmYgZ29pbmcgDQo+ID4gPiBmcm9tIDYwbWJp dC9zIHRvIGFsbW9zdCBuaWxsKS4gIEFzIGJlc3QgSSBjYW4gdGVsbCB0aGVzZSANCj4gPiA+IHRy YW5zbWlzc2lvbnMgbmV2ZXIgY29hbGVzY2VzIGludG8gYW4gYWN0dWFsIGZyYW1lIGluIHRoZSBh aXIgKGF0IA0KPiA+ID4gbGVhc3Qgbm90IG9uZSBJJ20gYWJsZSB0byBwaWNrIHVwIHdpdGggYSBz ZWNvbmQgZGlmZmVyZW50IGFkYXB0ZXIgaW4gbW9uaXRvciBtb2RlKS4NCj4gPiA+IA0KPiA+ID4g QXJlIHRoZXJlIGFueSBrbm93biByZWFzb25zL2J1Z3Mgb24gdGhpcz8gIElzIHRoZXJlIGFueXdh eSB0byANCj4gPiA+IGNvbXBsZXRlbHkgc2lsZW5jZSB0aGUgdHJhbnNtaXR0ZXIgb2YgdGhlIEFS OTE3MCB3aGlsZSBzdGlsbCBhbGxvd2luZyByZWNlcHRpb24/DQo+ID4gPiANCj4gPiB5ZXMuIDxo dHRwOi8vd3d3LnNwaW5pY3MubmV0L2xpc3RzL2xpbnV4LXdpcmVsZXNzL21zZzg4ODk2Lmh0bWw+ DQo+ID4gDQo+ID4gYSBzb2x1dGlvbiBpcyBkZXNjcmliZWQgaW46DQo+ID4gPGh0dHA6Ly93d3cu c3Bpbmljcy5uZXQvbGlzdHMvbGludXgtd2lyZWxlc3MvbXNnODkyNzkuaHRtbD4NCj4gPiANCj4g PiAoaXcgZGV2IHdsYW5YIHNldCBtb25pdG9yIG5vbmUgLSBpZiBJJ20gbm90IG1pc3Rha2VuKQ0K PiANCj4gSSd2ZSBzZWVuIHRoaXMgYmVmb3JlIHRvbyAtLSB3aGF0IGZsYWcgY2F1c2VzIHRoZSBp c3N1ZSwgYW5kIHdoeT8NCldlbGwgdGhhdCB3b3VsZCBiZToNCkZJRl9PVEhFUl9CU1Mgb3IgRklG X1BST01JU0NfSU5fQlNTDQoNCmVpdGhlciBvbmUgb2YgdGhlc2Ugd2lsbCBzZXQgZm9sbG93aW5n IGZsYWdzIGZvciB0aGUgaGFyZHdhcmU6DQoNCkFSOTE3MF9NQUNfUlhfQ1RSTF9BQ0tfSU5fU05J RkZFUg0KQVI5MTcwX01BQ19TTklGRkVSX0VOQUJMRV9QUk9NSVNDDQoNCkFib3V0IHRoZSBpc3N1 ZSwgSSdtIHJlYWxseSBjYW4ndCB0ZWxsIHcvbyBzY2hlbWF0aWNzIG9mIHRoZSBoYXJkd2FyZS4g SXQgY291bGQgYmUgdGhhdCBBQ0tfSU5fU05JRkZFUiBpcyBtb3JlIG9mIGEgZGVidWcvdGVzdCBm bGFnIHRoYW4gYSByZWFsIGZlYXR1cmU/DQoNCihBbnl3YXksIEkgY2MnZCBTdGVwaGVuLiBNYXli ZSBoZSBrbm93cyBtb3JlKQ0KDQpSZWdhcmRzLA0KCUNocg0K ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-17 2:03 ` Chen, Stephen @ 2012-08-17 2:30 ` Marco Fonseca 2012-08-17 2:59 ` Chen, Stephen 0 siblings, 1 reply; 9+ messages in thread From: Marco Fonseca @ 2012-08-17 2:30 UTC (permalink / raw) To: Chen, Stephen Cc: Christian Lamparter, Johannes Berg, linux-wireless@vger.kernel.org In my setup I had used a secondary sniffer in order to see what was going on. I was able to reproduce the problem with a single ping with a payload of 2000 (less to look at in wireshark), but I was never able to capture a valid frame from the AR9170. I do know it was transmitting though, as I could see it on the spectrum analyzer. I just assumed whatever was going out wasn't a valid frame...(?) Marco On Fri, Aug 17, 2012 at 02:03:00AM +0000, Chen, Stephen wrote: > Can we tell what kind of unexpected frame are been transmitted? (Data frame or which kind of control frame?) > That may give us a clue. > > > Thank you. > Stephen > > -----Original Message----- > From: Christian Lamparter [mailto:chunkeey@googlemail.com] > Sent: Friday, August 17, 2012 3:35 AM > To: Johannes Berg > Cc: Marco Fonseca; linux-wireless@vger.kernel.org; Chen, Stephen > Subject: Re: carl9170: Unintentional transmission in monitor mode? > > On Thursday, August 16, 2012 09:20:55 PM Johannes Berg wrote: > > On Thu, 2012-08-09 at 21:43 +0200, Christian Lamparter wrote: > > > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > > > Hello All, > > > > > > > > I've noticed unexpected transmissions from the AR9170 while in > > > > monitor mode and using tcpdump (and sometimes without tcpdump > > > > running). These transmissions degrade (pretty significantly) > > > > performance of other STA/AP on the channel (as seen by iperf going > > > > from 60mbit/s to almost nill). As best I can tell these > > > > transmissions never coalesces into an actual frame in the air (at > > > > least not one I'm able to pick up with a second different adapter in monitor mode). > > > > > > > > Are there any known reasons/bugs on this? Is there anyway to > > > > completely silence the transmitter of the AR9170 while still allowing reception? > > > > > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > > > > > a solution is described in: > > > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > > > > > (iw dev wlanX set monitor none - if I'm not mistaken) > > > > I've seen this before too -- what flag causes the issue, and why? > Well that would be: > FIF_OTHER_BSS or FIF_PROMISC_IN_BSS > > either one of these will set following flags for the hardware: > > AR9170_MAC_RX_CTRL_ACK_IN_SNIFFER > AR9170_MAC_SNIFFER_ENABLE_PROMISC > > About the issue, I'm really can't tell w/o schematics of the hardware. It could be that ACK_IN_SNIFFER is more of a debug/test flag than a real feature? > > (Anyway, I cc'd Stephen. Maybe he knows more) > > Regards, > Chr ^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: carl9170: Unintentional transmission in monitor mode? 2012-08-17 2:30 ` Marco Fonseca @ 2012-08-17 2:59 ` Chen, Stephen 2012-08-17 12:55 ` marco 0 siblings, 1 reply; 9+ messages in thread From: Chen, Stephen @ 2012-08-17 2:59 UTC (permalink / raw) To: Marco Fonseca Cc: Christian Lamparter, Johannes Berg, linux-wireless@vger.kernel.org To be honest, I have no idea why the device was transmitting invalid frame. If the device is not in monitor mode, will it still transmit invalid frame in your setup? Thank you. Stephen -----Original Message----- From: Marco Fonseca [mailto:marco@tampabay.rr.com] Sent: Friday, August 17, 2012 10:30 AM To: Chen, Stephen Cc: Christian Lamparter; Johannes Berg; linux-wireless@vger.kernel.org Subject: Re: carl9170: Unintentional transmission in monitor mode? In my setup I had used a secondary sniffer in order to see what was going on. I was able to reproduce the problem with a single ping with a payload of 2000 (less to look at in wireshark), but I was never able to capture a valid frame from the AR9170. I do know it was transmitting though, as I could see it on the spectrum analyzer. I just assumed whatever was going out wasn't a valid frame...(?) Marco On Fri, Aug 17, 2012 at 02:03:00AM +0000, Chen, Stephen wrote: > Can we tell what kind of unexpected frame are been transmitted? (Data > frame or which kind of control frame?) That may give us a clue. > > > Thank you. > Stephen > > -----Original Message----- > From: Christian Lamparter [mailto:chunkeey@googlemail.com] > Sent: Friday, August 17, 2012 3:35 AM > To: Johannes Berg > Cc: Marco Fonseca; linux-wireless@vger.kernel.org; Chen, Stephen > Subject: Re: carl9170: Unintentional transmission in monitor mode? > > On Thursday, August 16, 2012 09:20:55 PM Johannes Berg wrote: > > On Thu, 2012-08-09 at 21:43 +0200, Christian Lamparter wrote: > > > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > > > Hello All, > > > > > > > > I've noticed unexpected transmissions from the AR9170 while in > > > > monitor mode and using tcpdump (and sometimes without tcpdump > > > > running). These transmissions degrade (pretty significantly) > > > > performance of other STA/AP on the channel (as seen by iperf > > > > going from 60mbit/s to almost nill). As best I can tell these > > > > transmissions never coalesces into an actual frame in the air > > > > (at least not one I'm able to pick up with a second different adapter in monitor mode). > > > > > > > > Are there any known reasons/bugs on this? Is there anyway to > > > > completely silence the transmitter of the AR9170 while still allowing reception? > > > > > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > > > > > a solution is described in: > > > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > > > > > (iw dev wlanX set monitor none - if I'm not mistaken) > > > > I've seen this before too -- what flag causes the issue, and why? > Well that would be: > FIF_OTHER_BSS or FIF_PROMISC_IN_BSS > > either one of these will set following flags for the hardware: > > AR9170_MAC_RX_CTRL_ACK_IN_SNIFFER > AR9170_MAC_SNIFFER_ENABLE_PROMISC > > About the issue, I'm really can't tell w/o schematics of the hardware. It could be that ACK_IN_SNIFFER is more of a debug/test flag than a real feature? > > (Anyway, I cc'd Stephen. Maybe he knows more) > > Regards, > Chr ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: carl9170: Unintentional transmission in monitor mode? 2012-08-17 2:59 ` Chen, Stephen @ 2012-08-17 12:55 ` marco 0 siblings, 0 replies; 9+ messages in thread From: marco @ 2012-08-17 12:55 UTC (permalink / raw) To: Chen, Stephen Cc: Christian Lamparter, Johannes Berg, linux-wireless@vger.kernel.org No, I don't believe so. I didn't do much testing in managed mode but when I did try it, it didn't exhibit the issue. Marco On Fri, Aug 17, 2012 at 02:59:40AM +0000, Chen, Stephen wrote: > To be honest, I have no idea why the device was transmitting invalid frame. > If the device is not in monitor mode, will it still transmit invalid frame in your setup? > > > Thank you. > Stephen > > ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2012-08-17 12:55 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-08-09 16:54 carl9170: Unintentional transmission in monitor mode? Marco Fonseca 2012-08-09 19:43 ` Christian Lamparter 2012-08-10 18:49 ` Marco Fonseca 2012-08-16 19:20 ` Johannes Berg 2012-08-16 19:34 ` Christian Lamparter 2012-08-17 2:03 ` Chen, Stephen 2012-08-17 2:30 ` Marco Fonseca 2012-08-17 2:59 ` Chen, Stephen 2012-08-17 12:55 ` marco
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