tap-bsd.c has no test for Mac OS X

[Ted Lemon]

The Mac OS X tun/tap driver is equivalent to the FreeBSD driver, but bsd-tap.c uses the NetBSD/OpenBSD driver, which works differently. The fix is easy--just check for __APPLE__ in the same place where you check for FreeBSD in net/tap-bsd.c.

This problem exists in the current git tree, at least as of yesterday afternoon.

[Andreas Färber (afaerber)]

I've verified that the code still compiles warning-free on v10.5 with this patch applied.

Before:

$ qemu-system-sparc64 -M sun4u -m 2048 -net tap -net nic
warning: could not open /dev/tap: no virtual network emulation
qemu-system-sparc64: -net tap: Device 'tap' could not be initialized

After:

$ qemu-system-sparc64 -M sun4u -m 2048 -net tap -net nic
qemu-system-sparc64: -net tap: warning: could not open /dev/tap0 (No such file or directory): no virtual network emulation
qemu-system-sparc64: -net tap: Device 'tap' could not be initialized

Could you please resubmit it to qemu-devel using git-send-email and a full commit message with Signed-off-by?
If would also be helpful if you could supply instructions for me to properly setup and test this on Mac OS X. Thanks!

[Ted Lemon (mellon-fugue)]

This is really pathetic, but I'm afraid I have no clue how to do this:

> Could you please resubmit it to qemu-devel using git-send-email and a full commit message with Signed-off-by?

I tried googling and reading manuals, but I couldn't connect the dots. Can you send me a sample command line? I'm sure it's dead easy, but my experience with git is basically just downloading sources--all the projects I work on regularly still use cvs or svn.

To set this up on Mac OS X, you need to install the tun/tap drivers, because OSX doesn't come with any. These are available at tuntaposx.sourceforge.net. If you use Tunnelblick to run openvpn, it sets up tun/tap for you and then cleverly removes the kernel modules when you don't have a tunnel open, so that the drivers are there but not active. You will have to overcome this somehow; I have an older version of Tunnelblick that doesn't do this, so I don't know how to work around this problem. If you aren't using Tunnelblick, I think installing the tun/tap drivers will Just Work.

Once you have them installed, you can just start up qemu normally. I use the following script:

../qemu/sparc-softmmu/qemu-system-sparc -M SS-5 -bios ./ss5.bin -nographic -hda SunOS4.1.4 -net tap,script=tap1,vlan=0 -net nic,vlan=0

The startup script (tap1) is this:

#!/bin/sh
ifconfig tap1 192.5.5.1 netmask 255.255.255.0

Because it's running ifconfig, the whole thing has to be started as root; I think it would be fine to drop privs after that, though.

[boecko (andy-boeckler)]

this seems to be fixed in QEMU 0.14