WinePcap
wpcap is the win version of the libpcap library, this version is a wrapper that forwards the calls in Wine from wpcap to libpcap. This enables e.g. the win version of wireshark to work in Wine.
Status
It's now upstream and you should simply use Wine 1.7.25 or later!!!
Download
The included patch in my Download is against the latest git at creation time
Qian Hong set up a Project at Google code that enhances my code to run more Applications with focus on Network Authentication Clients