Re: [Qemu-devel] multiple tun/tap instances no longer working

[Rick Vernam]

in vl.c, it looks like tap_open is called with an uninitialized ifname - 
instead of ifname[0] == '\0', or a valid ifname, it is a bunch of gibberish - 
in my 
case, "ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ"

I'm not all that great with gdbg yet, so it might take me a while to figure 
out where the bad call to tap_open is coming from...

On Tuesday 09 January 2007 10:57, Rick Vernam wrote:
> I recently built cvs, and found that I can no longer have multiple
> instances of qemu using tun/tap.
>
> the invocation of qemu includes, for each instance:
> -net nic -net tap,script=/etc/qemu-ifup
>
> /etc/qemu-ifup:
> #!/bin/sh
> sudo /sbin/ifconfig $1 192.168.2.196
> sudo brctl addif br0 $1
>
> strace of qemu-system-x86_64:
> ...
> open("/dev/net/tun", O_RDWR)            = 3
> ioctl(3, TUNSETIFF, 0x7fffca661bf0)     = -1 EBUSY (Device or resource
> busy) write(2, "warning: could not configure /de"..., 72warning: could not
> configure /dev/net/tun: no virtual network emulation
> ) = 72
> close(3)                                = 0
> write(2, "Could not initialize device \'tap"..., 34Could not initialize
> device 'tap'
> ) = 34
> exit_group(1)                           = ?
> Process 8206 detached
>
>
> The only thing that has changed is building qemu from cvs yesterday.  Prior
> to that, I had been using cvs from a few weeks ago.
>
> I'm not too familiar with qemu source, but I will start looking at some of
> the commits from the past few weeks for anything.
>
> Any ideas?
> Thanks.
>
>
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