I hate when applications go online without prior permission. What I hate even more is when they say that they will happily ignore you trying to disallow them to do so, just like the new 12.1 version of Xilinx ISE.
For those not familiar with Xilinx software, Webpack is the free of charge license of their design tools, that supports a limited range of devices. The Webtalk “feature” phones home every time you generate a programming file for their devices, and previous versions of ISE asked you whether you wanted to send Xilinx information about your design. What is new in version 12 is that Webpack users are forced to enable Webtalk, and even users of the paid version will have information about their designs sent to Xilinx should they use a device included in the Webpack license!
Fortunately, there is a simple and expedient solution to this problem. As it turns out, the Xilinx software people prefer to spend time trying to invade their customers’ privacy instead of making their tools easy to install (i.e. by providing packages for Linux distributions). Thus, ISE comes with its own version of the cURL library, that is used for the Webpack “feature”. Therefore, cutting off ISE’s internet access and thereby solving the Webtalk problem as well as potential others is as simple as doing:
rm -f /usr/Xilinx/12.1/ISE_DS/ISE/lib/lin/libCurl_Curl.so
rm -f /usr/Xilinx/12.1/ISE_DS/common/lib/lin/libCurl_Curl.so