connections

recv(), recvfrom()

http://lxr.free-electrons.com/source/net/socket.c

http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/7u40-b43/java/net/SocketInputStream.java?av=f

http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/file/34c594b52b73/src/solaris/native/java/net/SocketInputStream.c

http://www-numi.fnal.gov/offline_software/srt_public_context/WebDocs/Errors/unix_system_errors.html

http://lxr.free-electrons.com/ident?v=2.6.33;i=ECONNRESET

http://www.binarytides.com/linux-ss-command/

RFC 793 - Transmission Control Protocol

http://www.faqs.org/rfcs/rfc793.html

https://blogs.technet.microsoft.com/networking/2010/08/11/how-tcp-time-wait-assassination-works/

http://stackoverflow.com/questions/2004531/what-is-the-difference-between-socket-and-serversocket　

http://docs.oracle.com/javase/7/docs/technotes/guides/net/http-keepalive.html

http://serverfault.com/questions/421310/check-the-number-of-active-connections-on-port-80

http://www.tcpipguide.com/free/t_TCPConnectionPreparationTransmissionControlBlocksT.htm

http://www.cisco.com/c/en/us/about/press/internet-protocol-journal/back-issues/table-contents-34/syn-flooding-attacks.html

http://stackoverflow.com/questions/152457/what-is-the-difference-between-a-port-and-a-socket

https://tools.ietf.org/html/rfc2068#section-8

https://tools.ietf.org/html/rfc7230#section-6.3

https://tools.ietf.org/html/rfc7540#section-5

http://www.tutorialspoint.com/unix_system_calls/accept.htm

http://stackoverflow.com/questions/152457/what-is-the-difference-between-a-port-and-a-socket

https://en.wikipedia.org/wiki/HTTP_persistent_connection

http://stackoverflow.com/questions/410616/increasing-the-maximum-number-of-tcp-ip-connections-in-linux

TCP连接复用（TCP Connection Reuse）                          

http://blog.csdn.net/chdhust/article/details/12171263

使用netlink的NETLINK_INET_DIAG协议获取所有套接字信息出错 

http://bbs.chinaunix.net/thread-3766684-1-1.html

http://lxr.linux.no/linux+v3.2.8/Documentation/networking/ip-sysctl.txt#L464

http://www.linuxquestions.org/questions/linux-networking-3/tcp-ip-stack-source-code-322146/

http://www.binarytides.com/raw-sockets-c-code-linux/

https://linux.die.net/man/7/raw