pam会话函数详解
http://www.xuebuyuan.com/2223069.html
http://blog.itpub.net/15480802/viewspace-1406088/
http://blog.csdn.net/yyyyangyang/article/details/6589086
http://blog.csdn.net/ermuzhi/article/details/7833701
http://bingeao.blog.51cto.com/4472089/1007458/
http://blog.csdn.net/chenyulancn/article/details/8023431
http://www.docin.com/p-1520258727.html
http://blog.chinaunix.net/uid-20384269-id-1954584.html
https://www.ibm.com/developerworks/cn/linux/l-pam/
http://www.361way.com/pam-tally2/4277.html
http://www.cnblogs.com/xxyxxb2080/p/7560635.html
ubuntu关于pam_tally2计数器在每次sudo时都增加的bug
http://misliang.blog.51cto.com/6973084/1710403