"no wireless networks found" if >64 networks

Bug #1801751 reported by Anne Bennett
This bug affects 2 people
Affects Status Importance Assigned to Milestone
Guido Maria Serra

Bug Description

This is on a laptop running Slackware, with:


Quite often when I am attending a computer-related conference,
where there are many wireless networks available, in the "Wicd
Network Manager" window, "Refresh" returns "no wireless networks
found" as long as the count of available networks is over 64,
as reported by:

  iw wlan0 scan | grep -wc SSID

When that count is below 64, a list of networks is displayed
in the window, and I can select one and connect.

I tested this by running:

  while true ; do
      iw wlan0 scan | grep -wc SSID
      sleep 15

in a terminal window, while repeatedly trying to "Refresh"
in the Wicd Network Manager" window.


Revision history for this message
Guido Maria Serra (zeph1ro) wrote :

hi, the bug relies in the wireless-tools package, wicd & python-wicd are just wrappers around them

I came up with a patch... basically asking all ESSIDs via (a different tool != iwlist) 'iw <if> scan' and then ask for each the data using the 'iwlist <if> scan'essid <essid>' to reduce the amount of entries returned per each call

I know, we could do better, but hey... it is a start... also, I need to find the ticket, but you'll find issues also with non-ascii characters in the ESSID... but that's another topic (might have something in my patch for it though)

happy to work more on it, but i'm not yet that comfortable
with the packaging/patching procedures (i need menthorship*)

*even RTFM of "not a long unreadable bible" is welcome

Revision history for this message
Guido Maria Serra (zeph1ro) wrote :

p.s. le sigh! :/


...I'm digging into Wireless Extensions kernel API

Changed in wicd:
importance: Undecided → Medium
assignee: nobody → Guido Maria Serra (zeph1ro)
Revision history for this message
Karl Grimm (kjgrimm) wrote :

Dear Guido,

Thanks very much for the patch and your useful comments. I am wondering if you have succeeded in getting this working, or found another solution? I am using Ubuntu 16.04LTS with WICD, but I cannot get the patch to work.

This problem is of course getting worse and worse as the number of WiFi networks in the world keeps increasing. In most city areas, I simply cannot connect. And I assist many others to get connected over the phone, and they are having the same problem - no list of networks. They have to use WICD, as they are not capable of running commands in a Terminal (it's a long story). So I am keen to get WICD working.

I had a go at using your patch. I've never used the patch command before, but I figured out how to apply the patch, and it seems to have worked - the resultant file looks suitably different to the original. After I change wnettools.py, I restart WICD each time. After applying tha patch, WICD shows "scanning" forever. The WICD log file is indicating "Exception in thread". I added a few print statements to wnettols.py to try to narrow down the problem ....
    m contains a nice list of SSID names (including a bunch of \\x00' for the 3rd SSID)
    iwlist_cmd looks correct for the first two SSIDs

                and I never see iwlist_cmd for the 3rd SSID

So I think I have come up against what you alrady predicted:
    "you'll find issues also with non-ascii characters in the ESSID"

I am not a Python programmer, so that's about as far as I got.

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