Created
April 2, 2019 15:18
-
-
Save nishidy/46f034239428d11f43ca6d5ea4205a3b to your computer and use it in GitHub Desktop.
TCP_DEFER_ACCEPT test program for server
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| #include <stdio.h> //printf(), fprintf(), perror() | |
| #include <sys/socket.h> //socket(), connect(), recv() | |
| #include <arpa/inet.h> // struct sockaddr_in, struct sockaddr, inet_ntoa(), inet_aton() | |
| #include <stdlib.h> //atoi(), exit(), EXIT_FAILURE, EXIT_SUCCESS | |
| #include <string.h> //memset() | |
| #include <unistd.h> //close() | |
| #include <linux/tcp.h> //TCP_DEFER_ACCEPT | |
| #include <time.h> // | |
| #define MSGSIZE 32 | |
| #define MAX_MSGSIZE 1024 | |
| #define BUFSIZE (MSGSIZE + 1) | |
| #define QUEUELIMIT 5 | |
| int main(int argc, char *argv[]){ | |
| int servSock; | |
| struct sockaddr_in servSockAddr; | |
| char recvBuffer[BUFSIZE]; | |
| char sendBuffer[BUFSIZE]; | |
| int byteRcvd; | |
| int clientSock; | |
| struct sockaddr_in clientSockAddr; | |
| unsigned int clientLen; | |
| unsigned int recvLen, sendLen; | |
| int defer = 1; | |
| time_t curtime; | |
| FILE *fp; | |
| char buf[BUFSIZE]; | |
| if((servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0){ | |
| perror("socket() failed"); | |
| exit(EXIT_FAILURE); | |
| } | |
| memset(&servSockAddr, 0, sizeof(servSockAddr)); | |
| servSockAddr.sin_family = AF_INET; | |
| servSockAddr.sin_addr.s_addr = htonl(INADDR_ANY); | |
| servSockAddr.sin_port = htons(8080); | |
| if(bind(servSock, (struct sockaddr *) &servSockAddr, sizeof(servSockAddr)) < 0){ | |
| perror("bind() failed."); | |
| exit(EXIT_FAILURE); | |
| } | |
| if(listen(servSock, QUEUELIMIT)<0){ | |
| perror("listen() failed."); | |
| exit(EXIT_FAILURE); | |
| } | |
| setsockopt(servSock, IPPROTO_TCP, TCP_DEFER_ACCEPT, &defer, sizeof(defer) ); | |
| while(1){ | |
| if((clientSock = accept(servSock, (struct sockaddr *) &clientSockAddr, &clientLen))<0){ | |
| perror("accept() failed."); | |
| exit(EXIT_FAILURE); | |
| } | |
| curtime = time(NULL); | |
| //printf("[%s] accept() unblocked.\n",ctime(&curtime)); | |
| if( (fp = popen("date +%T.%3N","r")) == NULL){ | |
| perror("popen() failed."); | |
| exit(EXIT_FAILURE); | |
| } | |
| fgets(buf, BUFSIZE, fp); | |
| buf[strlen(buf)-1]='\0'; | |
| printf("[%s] accept() unblocked.\n",buf); | |
| while(1){ | |
| if((recvLen = recv(clientSock, recvBuffer, BUFSIZE, 0)) < 0){ | |
| printf("recv() failed."); | |
| exit(EXIT_FAILURE); | |
| } else if (recvLen == 0){ | |
| printf("connection closed by foreign host.\n"); | |
| break; | |
| } | |
| if( (fp = popen("date +%T.%3N","r")) == NULL){ | |
| perror("popen() failed."); | |
| exit(EXIT_FAILURE); | |
| } | |
| fgets(buf, BUFSIZE, fp); | |
| buf[strlen(buf)-1]='\0'; | |
| printf("[%s] received: %s\n",buf,recvBuffer); | |
| sprintf(sendBuffer, "HTTP/1.1 200 OK"); | |
| if((sendLen = send(clientSock, sendBuffer, strlen(sendBuffer), 0)) < 0){ | |
| perror("send() failed."); | |
| exit(EXIT_FAILURE); | |
| } else if (sendLen == 0){ | |
| printf("connection closed by foreign host.\n"); | |
| break; | |
| } | |
| } | |
| close(clientSock); | |
| } | |
| return 0; | |
| } |
Author
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
I want to confirm if TCP_DEFER_ACCEPT recovers from a packet loss of final ACK.
However, even if TCP_DEFER_ACCEPT is not enabled, it recovers from the packet loss.
I drop the packet by iptables as follows.
You can see it works because FIN packets are re-sent continuously since ACK packet is discarded.
On the other hand, data packets are sent successfully.