internet problems

[pyzaist]

so, I have two programs, one for the client and one for the server. I am testing my programs between two computers, and if I have computer one be the client it works, but if computer two is the client it can't connect. Now, my internet is a bit glitchy, so is this an actual problem, or is it just my internet?

here's the client:

Code: [Select]

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#pragma lib "ws2_32.lib"

int main()
{
char recvstuff[100];
char sendstuff[100];
char ip[100];

printf("type friend's ip address: ");
fgets(ip, 25, stdin);


// intialise winsock

WSADATA wsaData;
if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0)
{
printf("error one");
getchar();
exit(1);
}


// getaddrinfo call

struct addrinfo *result = NULL, *ptr = NULL, hints;

ZeroMemory(&hints, sizeof (hints));
hints.ai_family=AF_UNSPEC;
hints.ai_socktype=SOCK_STREAM;
hints.ai_protocol=IPPROTO_TCP;

if (getaddrinfo(ip, "7772", &hints, &result) != 0)
{
printf("error two");
getchar();
exit(1);
}

int sock;

// make a socket
ptr=result;

sock=socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);

if (sock == -1)
{
printf("error three");
getchar();
exit(1);
}

// connect to a server
if (connect(sock, ptr->ai_addr, (int)ptr->ai_addrlen) == -1)
{
printf("error four");
getchar();
exit(1);
}

printf("connected\n\n\n\n");

freeaddrinfo(result);

// main send and recieve loop

while (strcmp(fgets(sendstuff, 102, stdin), "exit\n") != 0)
{

while (strcspn(sendstuff, "\n") == 102)
{
fgets(sendstuff, 102, stdin);
if (send(sock, sendstuff, sizeof (sendstuff), 0) == -1)
{
printf("error five");
getchar();
exit(1);
}
}

if (send(sock, sendstuff, sizeof (sendstuff), 0) == -1)
{
printf("error six");
getchar();
exit(1);
}

if (recv(sock, recvstuff, 100, 0) == -1)
{
printf("error seven");
getchar();
exit(1);
}
printf("%s\n", recvstuff);
}

// shut down winsock and end program

closesocket(sock);

WSACleanup();

return 0;
}

and here's the server:

Code: [Select]

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#pragma lib "ws2_32.lib"

int main()
{
char recvstuff[100];
char sendstuff[100]="hi daniel!";

// intialise winsock

WSADATA wsaData;
if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0)
{
printf("WSAStartup failed\n\n");
exit(1);
}


// getaddrinfo call

struct addrinfo *result=NULL, hints;

ZeroMemory(&hints, sizeof (hints));
hints.ai_family=AF_INET;
hints.ai_socktype=SOCK_STREAM;
hints.ai_protocol=IPPROTO_TCP;
hints.ai_flags=AI_PASSIVE;

if (getaddrinfo(NULL, "7772", &hints, &result) != 0)
{
printf("getaddrinfo failed\n\n");
exit(1);
}



// make a socket

int sock=socket(result->ai_family, result->ai_socktype, result->ai_protocol);

if (sock == -1)
{
printf("socket failed\n\n");
exit(1);
}




// bind the socket

if (bind(sock, result->ai_addr, result->ai_addrlen) == -1)
{
printf("bind failed\n\n");
exit(1);
}

freeaddrinfo(result);



// listen on the socket

if (listen(sock, SOMAXCONN) == -1)
{
printf("listen failed\n\n");
exit(1);
}



// wait for connection

int mainsock;

mainsock=accept(sock, NULL, NULL);

if (mainsock == -1)
{
printf("accept failed");
exit(1);
}

printf("connected\n\n\n\n");

closesocket(sock);

while (recv(mainsock, recvstuff, 100, 0) != -1)
{

if (send(mainsock, sendstuff, sizeof (sendstuff), 0) == -1)
{
printf("send failed\n\n");
exit(1);
}

printf("%s", recvstuff);
}

printf("they exited");
getchar();

closesocket(mainsock);
WSACleanup();
return 0;
}


to operate, have the server running first, and run the client. type in the ip of the server, then type stuff.

to find your ip for sure, go to command prompt, and type "ipconfig"

[pyzaist]

is there a reason it can't connect?

[sapero]

The reason is specific to your firewall, you need to add your server to allowed list.
On my XP I don't even see any popups from system firewall (which are enabled), the server is silently restricted to local clients.

[pyzaist]

oh yeah, the pop-up does come up and I click "unblock", and it unblocks it. I checked the exceptions in Windows Firewall and my program is not blocked.