Linux fast open,Linux内核3.7 TCP Fast Open验证实例

Linux内核在3.6和3.7合入了TCP Fast Open特性，在3.7.3版本上验证了一下，I did it!

以下是C语言实例()：

server端代码：

#include /* See NOTES */

#include

#include

#include

int main(){

int portno = 5060;

socklen_t clilen;

char buffer[256];

struct sockaddr_in serv_addr, cli_addr;

int cfd;

int sfd = socket(AF_INET, SOCK_STREAM, 0);   // Create socket

bzero((char *) &serv_addr, sizeof(serv_addr));

serv_addr.sin_family = AF_INET;

serv_addr.sin_addr.s_addr = INADDR_ANY;

serv_addr.sin_port = htons(portno);

bind(sfd, &serv_addr,sizeof(serv_addr));      // Bind to well known address

int qlen = 5;                 // Value to be chosen by application

int err = setsockopt(sfd, IPPROTO_TCP/*SOL_TCP*/, 23/*TCP_FASTOPEN*/, &qlen, sizeof(qlen));

listen(sfd,1);                // Mark socket to receive connections

cfd = accept(sfd, NULL, 0);   // Accept connection on new socket

while(1){

int len = read(cfd,buffer,256);

if(len)

printf("tcp fast open: %s\\n",buffer);

else

break;

// read and write data on connected socket cfd

}

close(cfd);

}

client端代码：

#include

#include

#include

#include

int main(){

struct sockaddr_in serv_addr;

struct hostent *server;

char *data = "Hello, tcp fast open";

int data_len = strlen(data);

int sfd = socket(AF_INET, SOCK_STREAM, 0);

server = gethostbyname("localhost");

bzero((char *) &serv_addr, sizeof(serv_addr));

serv_addr.sin_family = AF_INET;

bcopy((char *)server->h_addr,

(char *)&serv_addr.sin_addr.s_addr,

server->h_length);

serv_addr.sin_port = htons(5060);

int len = sendto(sfd, data, data_len, 0x20000000/*MSG_FASTOPEN*/,

(struct sockaddr *) &serv_addr, sizeof(serv_addr));

printf("error: %s\\n",strerror(errno));

close(sfd);

sleep(5);

}

执行结果：

# ./server

tcp fast open: Hello, tcp fast open

# ./client

error: Success

环境：Fedora 18 升级内核到3.7.3；glibc 2.17；gcc 4.7.2

记得要执行： echo 1 > /proc/sys/net/ipv4/tcp_fastopen