hal not parsing netlink messages properly

[Jon Nettleton]

On Sun, 2005-10-30 at 09:31 -0500, Jon Nettleton wrote:
> On 10/29/05, Kay Sievers <kay.sievers at vrfy.org> wrote:
>         On Fri, Oct 28, 2005 at 09:39:56PM -0400, Jon Nettleton wrote:
>         > In testing that Hal properly recognizes device inputs and
>         outputs, I
>         > have come across another bug.  Whenever I rebooted with
>         multiple ( 3 or
>         > mote ) removable media devices in my readers, something
>         would fail to
>         > mount when I logged in.  The problem reared it's ugly head
>         when
>         > gnome-volume-manager sent as many asynchronous mount
>         commands as
>         > necessary to mount all the media.  My findings show that
>         hal's osspec.c
>         > reads the message buffer and only reads the first null
>         terminated
>         > string.  Because the mounts were coming so fast some of the
>         messages are 
>         > actually 44bytes which is basically two messages, so the
>         second
>         > mount@/blah/blah/blah is being lost.  I have attached the
>         hald verbose
>         > output that illustrates this.
>         
>         Yup. That's a bug.
>         
>         > I am not sure this is a problem with netlink or hal.
>         
>         It's hal.
>         
>         > I started to write
>         > something to parse the buffer at null terminated strings and
>         then loop
>         > through the messages, but then thought I should ask you all
>         if this 
>         > makes sense.
>         
>         No, just call recvfrom() _once_ per processing loop. These are
>         datagrams
>         and it's wrong to read as long as the buffer has data if you
>         want only
>         a single message.
>         
>         > In the debug output there should have been 5 drives
>         mounted.  You can 
>         > see only 3 were mounted.  The last two having a message
>         length of
>         > 44bytes, which equals two "mount@/block/sdc/sdc1" with the
>         null
>         > terminators.
>         ...
>         
>         > 17:46:34.920 [I] osspec.c :243: total_read=22
>         buf='mount@/block/sda/sda1'
>         > 17:46:35.084 [I] osspec.c:243: total_read=44
>         buf='mount@/block/sdc/sdc1'
>         
>         Good catch! This is definitely broken. The whole read loop
>         with the total_read
>         logic in netlink_detection_data_ready() should be removed
>         completely. 
>         
>         Care to test it and send a patch? Otherwise let me know I can
>         do it.
>         
>         Thanks,
>         Kay
> 
> 
> Is it as easy as the attached patch?  This seems to work for me.
> Thanks for
> pointing me in the right direction.
> 
> Jon

okay let's try this again with a patch that isn't munged. :-)

Jon
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