Setting up a normal bridged network generally doesn't work if you're bridging from a wireless card to VirtualBox. A simple script that utilises the parprouted tool will allow your VM full access to the wireless network.
You will require parprouted to do this:
sudo apt-get install parprouted
Next, using your favourite text editor, create and edit the script, for example:
sudo nano /etc/network/if-up.d/vbox_network
Then, enter the script (replacing $USER with your username (or whoever you intend to run virtualbox as)). Replace wlan0 with the name of your wireless interface. Use an available IP address on your network for tap0 (I have used 192.168.1.100 in this case):
VBoxTunctl -b -u $USER
ip link set tap0 up
ip addr add 192.168.1.100/24 dev tap0
parprouted wlan0 tap0
Finally, make sure the new file is executable by root:
sudo chmod 700 /etc/network/if-up.d/vbox_network
Now your networking script is installed, the virtual interface tap0 will be available on boot for VirtualBox. Rather than reboot, let's just run the script now:
The final thing to do is tell VirtualBox to use the new virtual device tap0. Open VirtualBox, highlight a VM and click settings. Now choose the network option and select Host Interface on the 'attached to' drop down menu. In the Interface Name text box, enter: tap0
Click ok and start your VM. The VM should now behave as though it was another physical machine on your network!!
Unfortunately, at the time of writing I don't think DHCP auto configuration will work in the VM, so make sure you set a static IP in the virtual machine.
For more information, please visit [WWW] Bridged Networking with VirtualBox on Linux Hosts http://home.nyc.rr.com/computertaijutsu/vboxbridge.html