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When we try to switch wifi network through the sd_bus_call_method(...) interface the call fails with a dbus timeout message. First disconnecting from the current wifi and connecting does work however so it does not appear to be an issue with how we do the connection part. We are on a Warrior Yocto build with Connman 1.37, systemd 2.41. Here are some logs from the failing connection:

Jan  8 20:05:22 rc8000-5e2b avahi-daemon[195]: Withdrawing address record for 192.168.170.128 on wlan0.
Jan  8 20:05:22 rc8000-5e2b avahi-daemon[195]: Leaving mDNS multicast group on interface wlan0.IPv4 with address 192.168.170.128.
Jan  8 20:05:22 rc8000-5e2b wpa_supplicant[361]: wlan0: CTRL-EVENT-DISCONNECTED bssid=00:08:2f:ef:04:d3 reason=3 locally_generated=1
Jan  8 20:05:22 rc8000-5e2b systemd-networkd[217]: wlan0: Lost carrier
Jan  8 20:05:22 rc8000-5e2b avahi-daemon[195]: Interface wlan0.IPv4 no longer relevant for mDNS.
Jan  8 20:05:22 rc8000-5e2b avahi-daemon[195]: Withdrawing address record for fe80::76e1:82ff:fe08:5e2b on wlan0.
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {del} address 192.168.170.128/22 label wlan0
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {del} route 192.168.168.0 gw 0.0.0.0 scope 253 <LINK>
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {RX} 11740 packets 1072648 bytes
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {TX} 373 packets 56170 bytes
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {update} flags 36867 <UP>
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 address 74:E1:82:08:5E:2B mtu 1500
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 operstate 2 <DOWN>
Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {del} route fe80:: gw :: scope 0 <UNIVERSE>Jan  8 20:05:22 rc8000-5e2b connmand[5042]: wlan0 {del} route ff00:: gw :: scope 0 <UNIVERSE>
Jan  8 20:05:23 rc8000-5e2b connmand[5042]: Skipping disconnect of 5769736572_managed_psk, network is connecting.
Jan  8 20:05:28 rc8000-5e2b wpa_supplicant[361]: wlan0: SME: Trying to authenticate with 00:08:2f:ef:04:d0 (SSID='SBSR&D_2.4' freq=2437 MHz)
Jan  8 20:05:29 rc8000-5e2b wpa_supplicant[361]: wlan0: Trying to associate with 00:08:2f:ef:04:d0 (SSID='SBSR&D_2.4' freq=2437 MHz)
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {RX} 11741 packets 1072783 bytes
Jan  8 20:05:29 rc8000-5e2b wpa_supplicant[361]: wlan0: Associated with 00:08:2f:ef:04:d0
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {TX} 373 packets 56170 bytes
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {update} flags 102403 <UP,LOWER_UP>
Jan  8 20:05:29 rc8000-5e2b wpa_supplicant[361]: wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 address 74:E1:82:08:5E:2B mtu 1500
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 operstate 5 <DORMANT>
Jan  8 20:05:29 rc8000-5e2b wpa_supplicant[361]: wlan0: WPA: Key negotiation completed with 00:08:2f:ef:04:d0 [PTK=CCMP GTK=CCMP]
Jan  8 20:05:29 rc8000-5e2b wpa_supplicant[361]: wlan0: CTRL-EVENT-CONNECTED - Connection to 00:08:2f:ef:04:d0 completed [id=1 id_str=]
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {add} route ff00:: gw :: scope 0 <UNIVERSE>
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {add} route fe80:: gw :: scope 0 <UNIVERSE>
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {RX} 11742 packets 1072952 bytes
Jan  8 20:05:29 rc8000-5e2b systemd-networkd[217]: wlan0: Gained carrier
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {TX} 375 packets 56458 bytes
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {update} flags 102467 <UP,RUNNING,LOWER_UP>
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 address 74:E1:82:08:5E:2B mtu 1500
Jan  8 20:05:29 rc8000-5e2b connmand[5042]: wlan0 {newlink} index 3 operstate 6 <UP>
Jan  8 20:05:30 rc8000-5e2b wpa_supplicant[361]: wlan0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-48 noise=9999 txrate=58500
Jan  8 20:05:30 rc8000-5e2b avahi-daemon[195]: Joining mDNS multicast group on interface wlan0.IPv4 with address 10.175.79.251.
Jan  8 20:05:30 rc8000-5e2b avahi-daemon[195]: New relevant interface wlan0.IPv4 for mDNS.
Jan  8 20:05:30 rc8000-5e2b avahi-daemon[195]: Registering new address record for 10.175.79.251 on wlan0.IPv4.
Jan  8 20:05:30 rc8000-5e2b connmand[5042]: wlan0 {add} address 10.175.79.251/21 label wlan0 family 2Jan  8 20:05:30 rc8000-5e2b systemd-networkd[217]: wlan0: Gained IPv6LL
Jan  8 20:05:30 rc8000-5e2b avahi-daemon[195]: Registering new address record for fe80::76e1:82ff:fe08:5e2b on wlan0.*.
Jan  8 20:05:30 rc8000-5e2b connmand[5042]: wlan0 {add} route 10.175.72.0 gw 0.0.0.0 scope 253 <LINK>
Jan  8 20:05:30 rc8000-5e2b connmand[5042]: wlan0 {add} route 10.175.72.1 gw 0.0.0.0 scope 253 <LINK>
Jan  8 20:05:30 rc8000-5e2b connmand[5042]: wlan0 {add} route 0.0.0.0 gw 10.175.72.1 scope 0 <UNIVERSE>
Jan  8 20:05:47 rc8000-5e2b connman-client[5046]: Service Connect wifi_74e182085e2b_5342535226445f322e34_managed_psk: org.freedesktop.DBus.Error.Timeout

And the dbus trace for the same problem:

method call time=1578952131.483910 sender=:1.22 -> destination=net.connman serial=20 path=/net/connman/service/wifi_74e182085e2b_5342535226445f322e34_managed_psk; interface=net.connman.Service; member=Connect
method call time=1578952131.507736 sender=:1.21 -> destination=fi.w1.wpa_supplicant1 serial=3697 path=/fi/w1/wpa_supplicant1/Interfaces/5; interface=fi.w1.wpa_supplicant1.Interface; member=Disconnect
signal time=1578952131.512794 sender=:1.21 -> destination=(null destination) serial=3698 path=/net/connman/service/wifi_74e182085e2b_5769736572_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "Domains"
   variant       array [
      ]
signal time=1578952131.639802 sender=:1.21 -> destination=(null destination) serial=3699 path=/; interface=net.connman.Manager; member=PropertyChanged
   string "State"
   variant       string "ready"

... Trimmed because too long ...

signal time=1578952132.045699 sender=:1.21 -> destination=(null destination) serial=3713 path=/net/connman/service/wifi_74e182085e2b_5769736572_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "State"
   variant       string "association"
method call time=1578952132.054770 sender=:1.21 -> destination=fi.w1.wpa_supplicant1 serial=3714 path=/fi/w1/wpa_supplicant1/Interfaces/5; interface=fi.w1.wpa_supplicant1.Interface; member=RemoveNetwork
   object path "/fi/w1/wpa_supplicant1/Interfaces/5/Networks/0"signal time=1578952132.066571 sender=:1.21 -> destination=(null destination) serial=3715 path=/; interface=net.connman.Manager; 

... Trimmed because too long ...

signal time=1578952147.533836 sender=:1.21 -> destination=(null destination) serial=3750 path=/net/connman/technology/wifi; interface=net.connman.Technology; member=PropertyChanged
   string "Connected
   variant       boolean true
signal time=1578952147.536193 sender=:1.21 -> destination=(null destination) serial=3751 path=/; interface=net.connman.Manager; member=PropertyChanged
   string "State"
   variant       string "ready"
signal time=1578952147.536811 sender=:1.21 -> destination=(null destination) serial=3752 path=/net/connman/service/wifi_74e182085e2b_5342535226445f322e34_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "IPv4"
   variant       array [
      ]
signal time=1578952147.543999 sender=:1.21 -> destination=(null destination) serial=3753 path=/net/connman/service/wifi_74e182085e2b_5342535226445f322e34_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "IPv4"
   variant       array [
      ]

... Trimmed because too long ...```

I noticed that the IP information in the dbus trace appears incomplete and the connman state never gets to online. I also noticed that in syslog for a successful connection additional routes are added:

Jan 12 20:33:54 rc8000-5e2b avahi-daemon[205]: Registering new address record for 192.168.171.81 on wlan0.IPv4.
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} address 192.168.171.81/22 label wlan0 family 2
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 192.168.168.0 gw 0.0.0.0 scope 253 <LINK>
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 192.168.171.254 gw 0.0.0.0 scope 253 <LINK>
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 8.8.8.8 gw 192.168.171.254 scope 0 <UNIVERSE>
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 8.8.4.4 gw 192.168.171.254 scope 0 <UNIVERSE>
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 0.0.0.0 gw 192.168.171.254 scope 0 <UNIVERSE>
Jan 12 20:33:54 rc8000-5e2b connmand[222]: wlan0 {add} route 212.227.81.55 gw 192.168.171.254 scope 0 <UNIVERSE>

The last one appears to be a "phone home" IP to establish that the device is online. It disappears sometime later and connman does get to the online state.

I am pretty much stumped as to why connman (or systemd ?) behaves that way when trying to switch between wifi networks without first disconnecting. Any help would be appreciated.

EDIT The following trace show 2 associations going on at the same time

signal time=1578952132.045699 sender=:1.21 -> destination=(null destination) serial=3713 path=/net/connman/service/wifi_74e182085e2b_5769736572_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "State"
   variant       string "association"
method call time=1578952132.054770 sender=:1.21 -> destination=fi.w1.wpa_supplicant1 serial=3714 path=/fi/w1/wpa_supplicant1/Interfaces/5; interface=fi.w1.wpa_supplicant1.Interface; member=RemoveNetwork
   object path "/fi/w1/wpa_supplicant1/Interfaces/5/Networks/0"
signal time=1578952132.066571 sender=:1.21 -> destination=(null destination) serial=3715 path=/; interface=net.connman.Manager; member=ServicesChanged
....

signal time=1578952132.471595 sender=:1.21 -> destination=(null destination) serial=3718 path=/net/connman/service/wifi_74e182085e2b_5342535226445f322e34_managed_psk; interface=net.connman.Service; member=PropertyChanged
   string "State"
   variant       string "association"
signal time=1578952132.577805 sender=:1.21 -> destination=(null destination) serial=3719 path=/; interface=net.connman.Manager; member=ServicesChanged
....
method return time=1578952133.177367 sender=:1.10 -> destination=:1.21 serial=84264 reply_serial=3716
   object path "/fi/w1/wpa_supplicant1/Interfaces/5/Networks/0"
method call time=1578952133.181592 sender=:1.21 -> destination=fi.w1.wpa_supplicant1 serial=3720 path=/fi/w1/wpa_supplicant1/Interfaces/5; interface=fi.w1.wpa_supplicant1.Interface; member=SelectNetwork
   object path "/fi/w1/wpa_supplicant1/Interfaces/5/Networks/0"
signal time=1578952133.199893 sender=:1.10 -> destination=(null destination) serial=84265 path=/fi/w1/wpa_supplicant1/Interfaces/5; interface=fi.w1.wpa_supplicant1.Interface; member=NetworkAdded
   object path "/fi/w1/wpa_supplicant1/Interfaces/5/Networks/1"
William Durocher
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  • My first suspicion (assuming your code logic is fine -- which we can't know since you didn't show any) would be wifi driver/wpa-supplicant quirks: Is the wifi hardware in any way exotic? If you can run the code on another device (with other wireless hardware) that might help narrow it down. The other thing I would do is try to reproduce this with connmanctl. – Jussi Kukkonen Jan 16 '20 at 16:47
  • This is running on a AM335x with a TI WL1831MOD wifi chip. Build is Yocto warrior with Kernel 4.19.87 The design is derived from a beaglebone black wireless. No other device for us to run the code on. What part of the code would be useful for you ? We have an application that takes inputs from a web page through redis and then turns around to send the dbus commands on net.connman.Service and waits for messages on. I also notice that 2 dbus messages reporn a state change to association with the SSID being the ones I am swapping from and to ! I am adding this part of the dbus trace. – William Durocher Jan 17 '20 at 14:51

0 Answers0