sudo apt-get install bcmwl-kernel-source
我的无线网卡是BCM4312 802.11b/g
在12.04 会集成驱动，装完就能用，
现在用14.04，16.04里面没集成！
软件包: bcmwl-kernel-source (6.30.223.141+bdcom-0ubuntu2) [restricted]
yilai:
dkms
Dynamic Kernel Module Support Framework
libc6-dev
Embedded GNU C Library: Development Libraries and Header Files
linux-libc-dev
Linux Kernel Headers for development