The DSP-w215 docs have a GPL Code Statement:
This D-Link product includes software code developed by third parties, including software code subject to the GNU General Public License (“GPL”) or GNU Lesser General Public License (“LGPL”). As applicable, the terms of the GPL and LGPL, and information on obtaining access to the GPL code and LGPL code used in this product, are available to you at: http://tsd.dlink.com.tw/GPL.asp
And indeed, "DSP-W215 A1_ver1.00b23_FOSS.tar.gz" can be download from that site.
-Enjoy