tcp

问题 When I use Javaa's Socket class to send out a byte array, does the write call in the following code block until it has verified that the recipient has received the data? byte data[] = ...; Socket socket = ...; socket.getOutputStream().write(data); // blocking ? The reason I ask, is if I have a list of sockets that I want to send the same data to, I want to send it as efficiently as possible, i.e., is there a better way than this: ArrayList<Socket> sockets = ...; byte data[] = ...; for(int i =

问题 When I use Javaa's Socket class to send out a byte array, does the write call in the following code block until it has verified that the recipient has received the data? byte data[] = ...; Socket socket = ...; socket.getOutputStream().write(data); // blocking ? The reason I ask, is if I have a list of sockets that I want to send the same data to, I want to send it as efficiently as possible, i.e., is there a better way than this: ArrayList<Socket> sockets = ...; byte data[] = ...; for(int i =

问题 I am working on TCP multithread server and client. I found some codes from Microsoft websites: http://msdn.microsoft.com/en-us/library/system.net.sockets.socketasynceventargs.aspx However I got the following error: The type or namespace name 'AsyncUserToken' could not be found (are you missing a using directive or an assembly reference?) I cant find what namespace to include even I searched it on Google, here are those I currently have: using System; using System.Collections.Generic; using

问题 I am working on TCP multithread server and client. I found some codes from Microsoft websites: http://msdn.microsoft.com/en-us/library/system.net.sockets.socketasynceventargs.aspx However I got the following error: The type or namespace name 'AsyncUserToken' could not be found (are you missing a using directive or an assembly reference?) I cant find what namespace to include even I searched it on Google, here are those I currently have: using System; using System.Collections.Generic; using

问题 Im trying configure the docker daemon so i can connect to it from inside the docker containers i start.. So i changed /etc/docker/daemon.json to { "hosts": ["unix:///var/run/docker.sock", "tcp://0.0.0.0:2375"] } So that i connect to it through the docker bridge.. However when i restart docker i get netstat -tunlp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 3728/mysqld tcp 0 0 127.0

问题 Why does UDP have a length field in the header and TCP does not? I am guessing that the length of the segment in TCP is inferred from the IP header but one should be able to do the same for a UDP datagram 回答1: According to TCP/IP Illustrated Volume 1 , the length field is redundant. That's all Stevens says on the matter. I personally believe it was to make the UDP header length (in bits) divisible by 32 :) 回答2: There is a 96 bit pseudo header conceptually prefixed to the TCP header that

问题 I am trying to extract TLS meta-data from a pcap using Scapy. I am able to successfully parse the packets and individual messages such as the client-hello, server-hello etc and their fields. What I am having trouble with is when the TLS record is spread across multiple TCP packets/segments. This happens mostly for large TLS messages, such as application data or when server sends multiple TLS messages (server hello, certificate, etc) in one TLS frame. In such cases, scapy says it has the TLS

问题 I'm trying to set tcp keepalive but in doing so I'm seeing the error "Protocol not available" int rc = setsockopt(s, SOL_SOCKET, TCP_KEEPIDLE, &keepalive_idle, sizeof(keepalive_idle)); if (rc < 0) printf("error setting keepalive_idle: %s\n", strerror(errno)); I'm able to turn on keepalive, set keepalive interval and count but keepalive idle which is keepalive time is throwing that error and I never see any keepalive packets being transmitted/received either with wireshark and the filter tcp

问题 I'm trying to set tcp keepalive but in doing so I'm seeing the error "Protocol not available" int rc = setsockopt(s, SOL_SOCKET, TCP_KEEPIDLE, &keepalive_idle, sizeof(keepalive_idle)); if (rc < 0) printf("error setting keepalive_idle: %s\n", strerror(errno)); I'm able to turn on keepalive, set keepalive interval and count but keepalive idle which is keepalive time is throwing that error and I never see any keepalive packets being transmitted/received either with wireshark and the filter tcp

问题 I'm trying to set tcp keepalive but in doing so I'm seeing the error "Protocol not available" int rc = setsockopt(s, SOL_SOCKET, TCP_KEEPIDLE, &keepalive_idle, sizeof(keepalive_idle)); if (rc < 0) printf("error setting keepalive_idle: %s\n", strerror(errno)); I'm able to turn on keepalive, set keepalive interval and count but keepalive idle which is keepalive time is throwing that error and I never see any keepalive packets being transmitted/received either with wireshark and the filter tcp