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local overlay for wpa_supplicant

11 May 2015 • Leave Comments

Once for a while after an update, you system might bump into problem due to a new package version or to an unstable package. Thus the trouble-making packages should be downgraded to its old working version.

Recently, wpa_supplicant has upgraded from 2.3 to 2.4, resulting in unable to connecting to HUST_WIRELESS_AUTO. After days of surfing on the Internet, I found the solution: downgrade wpa_supplicant to 2.3. But before that, let's see how to position the problem. That is to say how do I get to know it is due to wpa_supplicant update causing no Wifi connection.

At the very beginning, I am in a mess on the Internet without any useful information since this problem is brand new. Even Google cannot search any clues. Af very first, I thought it was due to patches to kernel. So I reinstall the system with 4.0.0 instead of 4.0.0-r3, which turned out be in vain.

I searched on the Internet again for a day with nothing gain. I also read through the Gentoo wpa_supplicant wiki since this package is the key of no connection to Wifi. Then I used dmesg | tail -n 35 or the recommended debug mode wpa_supplicant -Dnl80211 -iwlp3s0 -C/var/run/wpa_supplicant/ -c/etc/wpa_supplicant/wpa_supplicant.conf -dd. Found an error message reason 15: 4 way handshake timeout, which is not useful at all when searching online.

Finally, on some Internet page, I was directed to an important link: wpa_supplicant Linux documentation page. Great! One step closer to solution.

From that link, you can find many useful information: development branch ChangeLog, stable branch ChangeLog, and New mailing list archives where the newest package related issues usually lies. Mailing list reports immediate package discussion even before Bug report system.

Following the mailing archives, I found Unable to connect to WPA2-Enterprise since 2.4-r1: WPA_ALG_PMK bug? which unfold the mystery on Wifi problem. Everything is there! Again, I searched the subject get another link Unable to connect to WPA2-Enterprise since 2.4-r1: WPA_ALG_PMK bug? which is fairly concise: wpa_supplicant >= 2.4 encountering problems with WPA2-Enterprise networks.

Through the discussion there, I found several solutions:

  1. Downgrade wpa_supplicant to 2.3 (<2.4) with the help of local overlay.
  2. Ask the university to update its FreeRadius server from to 2.2.6 to 2.2.7.
  3. Disable TLS v1.2 with phase1="tls_disable_tlsv1_2=1" in /etc/wpa_supplicant/wpa_supplicant.conf for HUST_WIRELESS_AUTO. That said, this does result in older TLS version being used and that is not really a good long term solution.
  4. Set key_mgmt_offload=0 to the wpa_supplicant configuration file (at global level, i.e., not within a network block).

Obviously, the 3rd method simple and effective. In reality, I prefer the 3rd method. But I would like to try the 1st instead since I want to try the process of creating a local overlay. I did not test the 4th option.

  1. Search wpa_supplicant version information:

    emerge --search wpa_supplicant

    But that returns only trouble versions >=2.4. That is to say, the old working version <2.4 is no longer in the official portage tree.

  2. Mask versions that does not work:

    echo ">=net-wireless/wpa\_supplicant-2.4" > /etc/portage/package.mask/wpa_supplicant

  3. From above two steps, we know there are no working versions in official portage tree. All the trouble versions in official portage are masked. How to handle this?

    Local overlay! The basic idea is to create local overlay and then download the old version .ebuild and corresponding supporting files.

  4. Create local overlay, refer to Overlay/Local overlay:
    1. # mkdir -p /usr/local/portage/{metadata,profiles}
    2. # echo 'zhtux' > /usr/local/portage/profiles/repo_name
    3. # echo 'masters = gentoo' > /usr/local/portage/metadata/layout.conf
    4. # chown -R root:portage /usr/local/portage
    5. # chmod g+s /usr/local/portage

    6. # nano -w /etc/portage/repos.conf/local.conf:

      [zhtux]
location = /usr/local/portage
masters = gentoo
auto-sync = no
  5. Adding an ebuild to the local overlay. Now we need to locate wpa_supplicant 2.3, 2.3-r1, or 2.3-r2 ebuild file and download it
    1. Go through /net-wireless/wpa_supplicant
    2. You cannot find wpa_supplicant-2.3*.ebuild since version 2.3 is out of portage tree: dead.
    3. Click on Show 78 dead files from which you will find old ebuild files: wpa_supplicant-2.3.ebuild, wpa_supplicant-2.3-r1.ebuild, and wpa_supplicant-2.3-r2.ebuild. Here I choose wpa_supplicant-2.3-r2.ebuild. Download this file from Links to HEAD: (view) (download) (annotate). Then click on Hide 78 dead files.
    4. # mkdir -p /usr/local/portage/net-wireless/wpa_supplicant
    5. # cd /usr/local/portage/net-wireless/wpa_supplicant
    6. # cp /path/to/downloaded/wpa_supplicant-2.3-r2.ebuild /usr/local/portage/net-wireless/wpa_supplicant/

    7. # cp /usr/portage/net-wireless/wpa_supplicant/metadata.xml .

      metadata.xml is a XML file denoting package information. Usually just a few lines.

    8. # repoman manifest (pay attention to: the current directory) or ebuild wpa_supplicant-2.3-r2.ebuild digest

      Calculate the package source (download from GENTOO_MIRROR or SRC_URI) checksum and put into Manifest.

    9. # repoman scan -d

    10. # repoman full -d -x

      Check if any errors. If successfull, get a line:

      RepoMan sez: "If everyone were like you, I'd be out of business!"

    11. # chown -R portage:portage /usr/local/portage
    12. # emerge -av –oneshot wpa_supplicant
      1. This will not install wpa_supplicant 2.3-r2 since it complains lacking files. If you go back to step 1, you will find a folder /net-wireless/wpa_supplicant/files. Items under this directory is supporting files like patches. Supporting files are downloaded when you sync the portage. For local overly, we need to put the files manually.
      2. On the other hand, emerge only downloads the source tarbar for wpa_supplicant-2.3-r2. It is specified in the ebuild file:

      # grep "SRC_URI=" /usr/local/portage/net-wireless/wpa_supplicant/wpa_supplicant-2.3-r2.ebuild

      The downloaded source file is kept under /usr/portage/distfiles/.

      1. The 3rd emerge optiono is number one, not character L. This means for one time installation.
    13. # mkdir files
      1. Now based the emerge error message, we go to step 1, and download the missing files.
      2. We can also read through the ebuild files to locate what supporting files needed.
      3. The top of the page in step 1 reminds that we can use cvs command to locate the files.
    14. Each time, change the ebuild, re-run repoman.

  6. GitHub

    It's useful to push local portage to Github for backup.

Reference:

  1. https://wireless.wiki.kernel.org/en/users/documentation/wpa_supplicant
  2. https://www.marc.info/?t=143013943600001&r=1&w=4
  3. http://lists.shmoo.com/pipermail/hostap/2015-April/032685.html

  4. https://www.marc.info/?l=hostap&m=143077239911058&w=4

    phase1="tls_disable_tlsv1_2=1"

  5. http://blog.csdn.net/zhuyingqingfen/article/details/7830624
  6. https://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/net-wireless/wpa_supplicant/
  7. https://wiki.gentoo.org/wiki/Overlay/Local_overlay

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