c windows connect() échoue. erreur 10049

Question

Les deux morceaux de code suivants compilent, mais j'obtiens une erreur connect() failed côté client. (compilé avec MinGW).

Code client:

// thanks to cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoClientWS.c 

#include <stdio.h> 
#include <winsock.h> 
#include <stdlib.h> 

#define RCVBUFSIZE 32 // size of receive buffer 

void DieWithError(char *errorMessage); 

int main(int argc, char* argv[]) 
{ 
    int sock; 
    struct sockaddr_in echoServAddr; 
    unsigned short echoServPort; 
    char *servIP; 
    char *echoString; 
    char echoBuffer[RCVBUFSIZE]; 
    int echoStringLen; 
    int bytesRcvd, totalBytesRcvd; 
    WSAData wsaData; 

    if((argc < 3) || (argc > 4)){ 
    fprintf(stderr, "Usage: %s <Sever IP> <Echo Word> [<Echo Port>]\n", argv[0]); 
    exit(1); 
    } 

    if (argc==4) 
    echoServPort = atoi(argv[3]); // use given port if any 
    else 
    echoServPort = 7; // echo is well-known port for echo service 

    if(WSAStartup(MAKEWORD(2, 0), &wsaData) != 0){ // load winsock 2.0 dll 
    fprintf(stderr, "WSAStartup() failed"); 
    exit(1); 
    } 

    // create reliable, stream socket using tcp 
    if((sock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) 
    DieWithError("socket() failed"); 

    // construct the server address structure 
    memset(&echoServAddr, 0, sizeof(echoServAddr)); 
    echoServAddr.sin_family = AF_INET; 
    echoServAddr.sin_addr.s_addr = inet_addr(servIP); // server IP address 
    echoServAddr.sin_port = htons(echoServPort); 
    // establish connection to the echo server 
    if(connect(sock, (struct sockaddr*)&echoServAddr, sizeof(echoServAddr)) < 0) 
    DieWithError("connect() failed"); 

    echoStringLen = strlen(echoString); // determine input length 

    // send the string, includeing the null terminator to the server 
    if(send(sock, echoString, echoStringLen, 0)!= echoStringLen) 
    DieWithError("send() sent a different number of bytes than expected"); 

    totalBytesRcvd = 0; 
    printf("Received: "); // setup to print the echoed string 
    while(totalBytesRcvd < echoStringLen){ 
    // receive up to the buffer size (minus 1 to leave space for a null terminator) bytes from the sender 
    if(bytesRcvd = recv(sock, echoBuffer, RCVBUFSIZE-1, 0) <= 0) 
     DieWithError("recv() failed or connection closed prematurely"); 
    totalBytesRcvd += bytesRcvd; // keep tally of total bytes 
    echoBuffer[bytesRcvd] = '\0'; 
    printf("%s", echoBuffer); // print the echo buffer 
    } 

    printf("\n"); 
    closesocket(sock); 
    WSACleanup(); 

    exit(0); 
} 

void DieWithError(char *errorMessage) 
{ 
    fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError()); 
    exit(1); 
} 

Code Serveur:

// thanks cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoServerWS.c 

#include <stdio.h> 
#include <winsock.h> 
#include <stdlib.h> 

#define MAXPENDING 5 // maximum outstanding connection requests 
#define RCVBUFSIZE 1000 

void DieWithError(char *errorMessage); 
void HandleTCPClient(int clntSocket); // tcp client handling function 

int main(int argc, char **argv) 
{ 
    int serverSock; 
    int clientSock; 
    struct sockaddr_in echoServerAddr; 
    struct sockaddr_in echoClientAddr; 
    unsigned short echoServerPort; 
    int clientLen; // length of client address data structure 
    WSAData wsaData; 

    if (argc!=2){ 
    fprintf(stderr, "Usage: %s <Server Port>\n", argv[0]); 
    exit(1); 
    } 

    echoServerPort = atoi(argv[1]); 

    if(WSAStartup(MAKEWORD(2, 0), &wsaData)!=0){ 
    fprintf(stderr, "WSAStartup() failed"); 
    exit(1); 
    } 

    // create socket for incoming connections 
    if((serverSock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))<0) 
    DieWithError("socket() failed"); 

    // construct local address structure 
    memset(&echoServerAddr, 0, sizeof(echoServerAddr)); 
    echoServerAddr.sin_family = AF_INET; 
    echoServerAddr.sin_addr.s_addr = htonl(INADDR_ANY); // any incoming interface 
    echoServerAddr.sin_port = htons(echoServerPort); // local port 

    // bind to the local address 
    if(bind(serverSock, 
     (struct sockaddr*)&echoServerAddr, 
     sizeof(echoServerAddr) 
    )<0) 
    DieWithError("bind() failed"); 

    // mark the socket so it will listen for incoming connections 
    if(listen(serverSock, MAXPENDING)<0) 
    DieWithError("listen() failed"); 

    for (;;){ // run forever 
    // set the size of the in-out parameter 
    clientLen = sizeof(echoClientAddr); 

    // wait for a client to connect 
    if((clientSock = accept(serverSock, (struct sockaddr*)&echoClientAddr, 
       &clientLen)) < 0) 
     DieWithError("accept() failed"); 

    // clientSock is connected to a client 

    printf("Handling client %s\n", inet_ntoa(echoClientAddr.sin_addr)); 

    HandleTCPClient(clientSock); 
    } 

    // NOT REACHED 
} 

void DieWithError(char *errorMessage) 
{ 
    fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError()); 
    exit(1); 
} 

void HandleTCPClient(int clientSocket) 
{ 
    char echoBuffer[RCVBUFSIZE]; // buffer for echostring 
    int recvMsgSize; // size of received message 

    // receive message from client 
    if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0) <0)) 
    DieWithError("recv() failed"); 

    // send received string and receive again until end of transmission 
    while(recvMsgSize > 0){ 
    // echo message back to client 
    if(send(clientSocket, echoBuffer, recvMsgSize, 0)!=recvMsgSize) 
     DieWithError("send() failed"); 

    // see if there's more data to receive 
    if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0)) <0) 
     DieWithError("recv() failed"); 
    } 

    closesocket(clientSocket); // close client socket 
} 

Comment puis-je résoudre ce problème?

Answer 1

Vous n'initialisez servIP:

servIP = argv[1]; 

Je pense que vous avez vraiment besoin de se familiariser avec votre débogueur, parce que vous auriez dû être en mesure de repérer ce genre d'erreur en quelques secondes avec un débogueur.

Answer 2

Le problème est du côté client.

1. servIP n'a pas été affecté avec une valeur correcte. Vous devriez le faire

   servIP = argv [1];

avant de charger winsock2 dll.

2, c'est un cas normal pour recv (...) retournant 0. Cela signifie que la connexion est fermée.