On Mon, Dec 18, 2023 at 1:00 PM Hiago De Franco <hiagofranco@xxxxxxxxx> wrote: > > Hi, > > On Fri, Dec 15, 2023 at 01:44:29PM -0800, Maciej Żenczykowski wrote: > > Here's my recommendation. > > On the gadget side. > > Print something when the timer is armed. > > Print something when the timer fires. > > Include the timestamp. > > > > Then try to send something (a single packet) that won't trigger a reply. > > > > For example run a script in a screen session that sends 1 unsolicited > > arp reply packet every 10 seconds. > > This is rare enough, it should obviously get the timer to fire. > > Again, wait 5 minutes, so you've had 30+ packets sent. > > See if it does even fire... > > You can run tcpdump on the receiver to see what you receive (and the > > timestamps on that) > > Thanks for the recommendation, I did what you suggested for 5 minutes > adding printk's for all 'hrtimer_*' function calls inside f_ncm.c. > Basically we only get 'hrtimer_start' and 'hrtimer_try_to_cancel' calls, > which makes sense. Here is the result, doing ARP pings from the device > to the host PC: > > [ 20.427879] hfranco: hrtimer_try_to_cancel > [ 21.270355] hfranco: hrtimer_start > [ 21.270732] hfranco: hrtimer_try_to_cancel > [ 31.695892] hfranco: hrtimer_start > [ 31.696215] hfranco: hrtimer_try_to_cancel > [ 36.324646] hfranco: hrtimer_start > [ 36.324989] hfranco: hrtimer_try_to_cancel > [ 37.168880] hfranco: hrtimer_start > [ 37.169216] hfranco: hrtimer_try_to_cancel > [ 60.359510] hfranco: hrtimer_start > [ 60.359836] hfranco: hrtimer_try_to_cancel > [ 68.188814] hfranco: hrtimer_start > [ 68.189141] hfranco: hrtimer_try_to_cancel > [ 69.035732] hfranco: hrtimer_start > [ 69.036062] hfranco: hrtimer_try_to_cancel > [ 90.413786] hfranco: hrtimer_start > [ 90.414116] hfranco: hrtimer_try_to_cancel > [ 100.380712] hfranco: hrtimer_start > [ 100.381048] hfranco: hrtimer_try_to_cancel > [ 110.349906] hfranco: hrtimer_start > [ 110.350247] hfranco: hrtimer_try_to_cancel > [ 120.321527] hfranco: hrtimer_start > [ 120.321872] hfranco: hrtimer_try_to_cancel > [ 120.325531] hfranco: hrtimer_start > [ 120.325869] hfranco: hrtimer_try_to_cancel > [ 130.295101] hfranco: hrtimer_start > [ 130.295428] hfranco: hrtimer_try_to_cancel > [ 131.992642] hfranco: hrtimer_start > [ 131.992984] hfranco: hrtimer_try_to_cancel > [ 132.839585] hfranco: hrtimer_start > [ 132.839927] hfranco: hrtimer_try_to_cancel > [ 140.270782] hfranco: hrtimer_start > [ 140.271112] hfranco: hrtimer_try_to_cancel > [ 150.248507] hfranco: hrtimer_start > [ 150.248848] hfranco: hrtimer_try_to_cancel > [ 160.228126] hfranco: hrtimer_start > [ 160.228453] hfranco: hrtimer_try_to_cancel > [ 170.209459] hfranco: hrtimer_start > [ 170.209822] hfranco: hrtimer_try_to_cancel > [ 180.192015] hfranco: hrtimer_start > [ 180.192351] hfranco: hrtimer_try_to_cancel > [ 190.176082] hfranco: hrtimer_start > [ 190.176423] hfranco: hrtimer_try_to_cancel > [ 200.161272] hfranco: hrtimer_start > [ 200.161600] hfranco: hrtimer_try_to_cancel > [ 210.147622] hfranco: hrtimer_start > [ 210.147949] hfranco: hrtimer_try_to_cancel > [ 220.135257] hfranco: hrtimer_start > [ 220.135582] hfranco: hrtimer_try_to_cancel > [ 230.123934] hfranco: hrtimer_start > [ 230.124274] hfranco: hrtimer_try_to_cancel > [ 237.879789] hfranco: hrtimer_start > [ 237.880133] hfranco: hrtimer_try_to_cancel > [ 240.113459] hfranco: hrtimer_start > [ 240.113794] hfranco: hrtimer_try_to_cancel > [ 250.103968] hfranco: hrtimer_start > [ 250.104309] hfranco: hrtimer_try_to_cancel > [ 259.800618] hfranco: hrtimer_start > [ 259.800946] hfranco: hrtimer_try_to_cancel > [ 260.095486] hfranco: hrtimer_start > [ 260.095828] hfranco: hrtimer_try_to_cancel > [ 260.646435] hfranco: hrtimer_start > [ 260.646776] hfranco: hrtimer_try_to_cancel > [ 270.087384] hfranco: hrtimer_start > [ 270.087711] hfranco: hrtimer_try_to_cancel > [ 280.080143] hfranco: hrtimer_start > [ 280.080468] hfranco: hrtimer_try_to_cancel > [ 290.073603] hfranco: hrtimer_start > [ 290.073945] hfranco: hrtimer_try_to_cancel > [ 300.067513] hfranco: hrtimer_start > [ 300.067852] hfranco: hrtimer_try_to_cancel > [ 310.061945] hfranco: hrtimer_start > [ 310.062297] hfranco: hrtimer_try_to_cancel > [ 320.056667] hfranco: hrtimer_start > [ 320.057008] hfranco: hrtimer_try_to_cancel > [ 330.051900] hfranco: hrtimer_start > [ 330.052255] hfranco: hrtimer_try_to_cancel > [ 340.047353] hfranco: hrtimer_start > [ 340.047678] hfranco: hrtimer_try_to_cancel > [ 350.044862] hfranco: hrtimer_start > [ 350.045221] hfranco: hrtimer_try_to_cancel > [ 360.043011] hfranco: hrtimer_start > [ 360.043352] hfranco: hrtimer_try_to_cancel > [ 370.041268] hfranco: hrtimer_start > [ 370.041611] hfranco: hrtimer_try_to_cancel > [ 380.039556] hfranco: hrtimer_start > [ 380.039891] hfranco: hrtimer_try_to_cancel > [ 390.037826] hfranco: hrtimer_start > [ 390.038150] hfranco: hrtimer_try_to_cancel > [ 400.036353] hfranco: hrtimer_start > > / # arping -U -I usb0 -i 10 -s 192.168.11.1 192.168.11.2 > ARPING 192.168.11.2 from 192.168.11.1 usb0 > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.504ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.459ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.612ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.676ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.509ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.696ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 3.008ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.446ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.776ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.529ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.669ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.523ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.574ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.872ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.654ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.639ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.576ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.584ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.560ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.393ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.627ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.799ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.980ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.661ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.707ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.523ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.711ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.704ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.566ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.678ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.592ms > Unicast reply from 192.168.11.2 [62:05:42:DF:6F:C2] 2.654ms > ^CSent 32 probes (1 broadcast(s)) > Received 32 response(s) > > $ sudo tcpdump -i enx620542df6fc2 > tcpdump: verbose output suppressed, use -v[v]... for full protocol decode > listening on enx620542df6fc2, link-type EN10MB (Ethernet), snapshot length 262144 bytes > 17:02:32.599638 IP6 hdebian > ip6-allrouters: ICMP6, router solicitation, length 8 > 17:02:35.425325 IP6 apalis-imx6-10692086.local > ip6-allrouters: ICMP6, router solicitation, length 16 > 17:02:42.810738 IP6 hdebian.mdns > ff02::fb.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:02:42.865794 IP6 hdebian.mdns > ff02::fb.mdns: 0 [b2&3=0x200] [2a] PTR (QM)? b.f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.f.f.ip6.arpa. (181) > 17:02:42.865832 IP6 hdebian.mdns > ff02::fb.mdns: 0 [0q] (12) > 17:02:43.253971 IP apalis-imx6-10692086.local.mdns > mdns.mcast.net.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:02:43.895157 IP6 hdebian.mdns > ff02::fb.mdns: 0 [b2&3=0x200] [2a] PTR (QM)? b.f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.f.f.ip6.arpa. (181) > 17:02:43.895196 IP6 hdebian.mdns > ff02::fb.mdns: 0 [0q] (12) > 17:02:44.100862 IP6 apalis-imx6-10692086.local.mdns > ff02::fb.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:02:44.961717 IP hdebian.mdns > mdns.mcast.net.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:02:46.145083 IP6 hdebian.mdns > ff02::fb.mdns: 0 [b2&3=0x200] [2a] PTR (QM)? b.f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.f.f.ip6.arpa. (181) > 17:02:46.145128 IP6 hdebian.mdns > ff02::fb.mdns: 0 [0q] (12) > 17:03:05.477178 ARP, Request who-has hdebian (Broadcast) tell apalis-imx6-10692086.local, length 28 > 17:03:05.477217 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:03:15.443291 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:03:15.443309 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:03:24.580306 IP6 hdebian > ip6-allrouters: ICMP6, router solicitation, length 8 > 17:03:25.411804 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:03:25.411821 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:03:35.382697 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:03:35.382717 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:03:35.386582 IP6 apalis-imx6-10692086.local > ip6-allrouters: ICMP6, router solicitation, length 16 > 17:03:45.355482 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:03:45.355504 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:03:46.811643 IP6 hdebian.mdns > ff02::fb.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:03:47.052930 IP apalis-imx6-10692086.local.mdns > mdns.mcast.net.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:03:47.899743 IP6 apalis-imx6-10692086.local.mdns > ff02::fb.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:03:48.962107 IP hdebian.mdns > mdns.mcast.net.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:03:55.330407 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:03:55.330423 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:05.307308 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:05.307324 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:15.286180 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:15.286209 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:25.266785 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:25.266816 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:35.248474 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:35.248489 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:45.231873 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:45.231902 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:04:55.216288 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:04:55.216315 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:05.201924 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:05.201951 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:09.438461 IP6 hdebian > ip6-allrouters: ICMP6, router solicitation, length 8 > 17:05:15.188755 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:15.188799 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:25.176620 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:25.176648 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:32.931912 IP6 apalis-imx6-10692086.local > ip6-allrouters: ICMP6, router solicitation, length 16 > 17:05:35.165375 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:35.165399 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:45.155068 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:45.155082 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:54.813550 IP6 hdebian.mdns > ff02::fb.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:05:54.851012 IP apalis-imx6-10692086.local.mdns > mdns.mcast.net.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:05:55.145920 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:05:55.145943 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:05:55.696822 IP6 apalis-imx6-10692086.local.mdns > ff02::fb.mdns: 0 [1a] PTR (QM)? _tezi._tcp.local. (71) > 17:05:56.963151 IP hdebian.mdns > mdns.mcast.net.mdns: 0 [2q] PTR (QM)? _ipps._tcp.local. PTR (QM)? _ipp._tcp.local. (45) > 17:06:05.136948 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:05.137104 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:06:15.128897 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:15.128918 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:06:25.121662 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:25.121682 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:06:35.114912 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:35.114943 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:06:45.108576 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:45.108599 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:06:55.102468 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:06:55.102501 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:05.096969 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:05.096994 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:15.091619 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:15.091647 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:25.088359 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:25.088385 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:35.085718 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:35.085753 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:45.083263 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:45.083291 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:07:55.080759 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:07:55.080782 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:08:05.078303 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:08:05.078344 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 17:08:15.075990 ARP, Request who-has hdebian (62:05:42:df:6f:c2 (oui Unknown)) tell apalis-imx6-10692086.local, length 28 > 17:08:15.076012 ARP, Reply hdebian is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > ^C > 88 packets captured > 88 packets received by filter > 0 packets dropped by kernel > > Everything basically worked, without any freezing/slowness (please note > that during the test I wasn't using the VNC client, only the arping). I > also did it using screen with ssh/serial console disconnected. > > Although I passed -U flag to arping, I still get replies. Is this > expected? No. this defeats the purpose of the (since it's not unidirectional). Perhaps -A would work better. You could also probably pick an ip as the destination that isn't the device on the other side of the cable, so that it *doesn't* respond. The following seems to work for me: while true; do sudo arping -c 1 -i $DEV -b 1.2.3.4; sleep 10; done since nothing responds to 1.2.3.4 on my lan. But Oliver's point about it possibly needing 10 or 11 queued packets is also interesting... though that would be very very weird... > > > note that you're getting bidirectional transfer due to the icmp errors. > > > > if you want to test unidirectionally, you need to send something that > > won't get a reply. > > for example an unsolicited arp reply (with arping)... or a udp packet > > to a port drop'ed by a firewall. > > > > and of course make sure you don't run it in such a way that you get > > ssh traffic causing bidirectional traffic. > > (ie. run it (and tcpdump) under screen) > > [this is assuming you can't run it directly on the device without > > getting in via ssh, > > maybe you can via serial port or whatever - though do note that serial > > wakeups could potentially also 'trigger' / 'fix' your hrtimer, > > so probably best to run things silently under screen with no direct > > output via ssh/serial/console. > > I also tested by sending UDP packets with netcat, every 1 second: > > ``` > while true > do > echo 'hi' | nc -u 192.168.11.2 5201 > sleep 1 > done > ``` > > I also manually added the ARP entry to the table using the 'arp' > command, expecting I would get rid off ARP calls/replies, but it didn't. > Even though the ARP table is correct, I still see ARP calls. Also, I > can't get rid of ICMP packets, so at the end I couldn't truly test the > one-way direction communication. For example, this is a snippet from > tcpdump: > > 20:22:00.559786 IP 192.168.11.2.50323 > 192.168.11.1.5201: UDP, length 3 > 20:22:00.559857 IP 192.168.11.1 > 192.168.11.2: ICMP 192.168.11.1 udp port 5201 unreachable, length 39 > 20:22:01.563804 IP 192.168.11.2.44521 > 192.168.11.1.5201: UDP, length 3 > 20:22:01.563903 IP 192.168.11.1 > 192.168.11.2: ICMP 192.168.11.1 udp port 5201 unreachable, length 39 > 20:22:02.554294 ARP, Request who-has 192.168.11.2 tell 192.168.11.1, length 28 > 20:22:02.556414 ARP, Reply 192.168.11.2 is-at 62:05:42:df:6f:c2 (oui Unknown), length 28 > 20:22:02.569192 IP 192.168.11.2.56428 > 192.168.11.1.5201: UDP, length 3 > 20:22:02.569281 IP 192.168.11.1 > 192.168.11.2: ICMP 192.168.11.1 udp port 5201 unreachable, length 39 > 20:22:03.575838 IP 192.168.11.2.50178 > 192.168.11.1.5201: UDP, length 3 > 20:22:03.575903 IP 192.168.11.1 > 192.168.11.2: ICMP 192.168.11.1 udp port 5201 unreachable, length 39 > 20:22:03.717633 ARP, Request who-has 192.168.11.1 tell 192.168.11.2, length 28 > 20:22:03.717680 ARP, Reply 192.168.11.1 is-at be:8e:0a:23:00:70 (oui Unknown), length 28 > 20:22:04.582394 IP 192.168.11.2.41700 > 192.168.11.1.5201: UDP, length 3 > 20:22:04.582473 IP 192.168.11.1 > 192.168.11.2: ICMP 192.168.11.1 udp port 5201 unreachable, length 39 > 20:22:05.587417 IP 192.168.11.2.57901 > 192.168.11.1.5201: UDP, length 3 > > The same happens on both directions, host -> device and device -> host. > I couldn't see any slowness or freezing. > > On Mon, Dec 18, 2023 at 03:34:36PM +0100, Oliver Neukum wrote: > > > > > > On 15.12.23 22:44, Maciej Żenczykowski wrote: > > > On Fri, Dec 15, 2023 at 1:20 PM Hiago De Franco <hiagofranco@xxxxxxxxx> wrote: > > > > Hi, > > > > > Here's my recommendation. > > > On the gadget side. > > > Print something when the timer is armed. > > > Print something when the timer fires. > > > Include the timestamp. > > > > > > Then try to send something (a single packet) that won't trigger a reply. > > > > You are implicitly raising a question. > > Does this bug strike if a single package is queued? The failure > > case seems to be 10 or 11 packages. > > I think I will keep the same test but try to increase the number of > packages per second I'm sending, maybe one packet / 100 ms or something > like that. > > > > > Regards > > Oliver > > > > Best Regards, > Hiago. -- Maciej Żenczykowski, Kernel Networking Developer @ Google
