C++ Winsock Sending file [closed] - c++

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Closed 9 years ago.
a Simple Server and Client that I can send the file,
And I need you guys to see if this source are done.
Cuz I think it won't download the full file.
And maybe to this source have a limit ? Cuz I uploaded/downloaded 200K and a little bit more ..
Server:
#include <WinSock2.h>
#include <Windows.h>
#include <stdio.h>
#pragma comment(lib, "Ws2_32.lib")
SOCKET Socket, Sub;
WSADATA Winsock;
sockaddr_in Addr;
int Addrlen = sizeof(sockaddr_in);
char Buffer[256];
char *Str;
sockaddr_in IncomingAddress;
int AddressLen = sizeof(IncomingAddress);
int main()
{
WSAStartup(MAKEWORD(2, 2), &Winsock); // Start Winsock
if(LOBYTE(Winsock.wVersion) != 2 || HIBYTE(Winsock.wVersion) != 2) // Check version
{
WSACleanup();
return 0;
}
Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
ZeroMemory(&Addr, sizeof(Addr));
Addr.sin_family = AF_INET;
Addr.sin_port = htons(6091);
bind(Socket, (sockaddr*)&Addr, sizeof(Addr));
if(listen(Socket, 1) == SOCKET_ERROR)
{
printf("listening error\n");
}
else
{
printf("listening ok\n");
}
if(Sub = accept(Socket, (sockaddr*)&IncomingAddress, &AddressLen))
{
char *ClientIP = inet_ntoa(IncomingAddress.sin_addr);
int ClientPort = ntohs(IncomingAddress.sin_port);
printf("Client conncted!\n");
printf("IP: %s:%d\n", ClientIP, ClientPort);
printf("Sending file .. \n");
FILE *File;
char *Buffer;
unsigned long Size;
File = fopen("C:\\Prog.exe", "rb");
if(!File)
{
printf("Error while readaing the file\n");
goto End;
}
fseek(File, 0, SEEK_END);
Size = ftell(File);
fseek(File, 0, SEEK_SET);
Buffer = new char[Size];
fread(Buffer, Size, 1, File);
char cSize[MAX_PATH];
sprintf(cSize, "%i", Size);
fclose(File);
send(Sub, cSize, MAX_PATH, 0); // File size
send(Sub, Buffer, Size, 0); // File Binary
free(Buffer);
End:
closesocket(Sub);
closesocket(Socket);
WSACleanup();
}
getchar();
return 0;
}
Client:
#include <WinSock2.h>
#include <Windows.h>
#include <stdio.h>
#pragma comment(lib, "Ws2_32.lib")
SOCKET Socket;
WSADATA Winsock;
sockaddr_in Addr;
int Addrlen = sizeof(Addr);
int main()
{
WSAStartup(MAKEWORD(2, 2), &Winsock); // Start Winsock
if(LOBYTE(Winsock.wVersion) != 2 || HIBYTE(Winsock.wVersion) != 2) // Check version
{
WSACleanup();
return 0;
}
Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
ZeroMemory(&Addr, sizeof(Addr)); // clear the struct
Addr.sin_family = AF_INET; // set the address family
Addr.sin_addr.s_addr = inet_addr("127.0.0.1");
Addr.sin_port = htons(6091); // set the port
if(connect(Socket, (sockaddr*)&Addr, sizeof(Addr)) < 0)
{
printf("Connection failed !\n");
getchar();
return 0;
}
printf("Connection successful !\n");
printf("Receiving file .. \n");
int Size;
char *Filesize = new char[1024];
if(recv(Socket, Filesize, 1024, 0)) // File size
{
Size = atoi((const char*)Filesize);
printf("File size: %d\n", Size);
}
char *Buffer = new char[Size];
if(recv(Socket, Buffer, Size, 0)) // File Binary
{
FILE *File;
File = fopen("Prog.exe", "wb");
fwrite((const char*)Buffer, 1, Size, File);
fclose(File);
}
getchar();
closesocket(Socket);
WSACleanup();
return 0;
}
Thanks.

Answer 1

Your code may fail if you try to send/receive large amount of data. From the documentation of the send function:
Return value
If no error occurs, send returns the total number of
bytes sent, which can be less than the number requested to be sent in
the len parameter. Otherwise, a value of SOCKET_ERROR is returned, and
a specific error code can be retrieved by calling WSAGetLastError.
You have to check the return value of send(), and if it is less than the number of bytes requested to be sent, call send() again for the remaining data. Example:
char *data = Buffer; // data to be sent
int len = Size; // number of bytes to be sent
while (len > 0) {
int amount = send(Sub, data, len, 0);
if (amount == SOCKET_ERRROR) {
// handle error ...
} else {
len -= amount;
data += amount;
}
}
The same is true for the recv() call in the client.

Answer 2

This is the file send function which will read the file as binary and will send the data. This is an independent function just pass the value of the socket on which v need to send the data along with the file path which we need to send.
void FileSend(SOCKET FileSendSocket,char *FilePath)
{
streampos filesize = 0;
ifstream in(FilePath,ios::binary);
ZeroMemory( &sendbuf, sendbuflen);
if(in.is_open())
{
while(1)
{
in.read(sendbuf,sendbuflen);
if(in.eof())
{
cout << "End of File sending from Client" << endl;
in.close();
break;
}
else
{
send(FileSendSocket,sendbuf,sendbuflen,0);
ZeroMemory( &sendbuf, sendbuflen);
}
}
}
}
And this is the receive function on the client side and it should be called just next to the receive function this function will continuously write what ever data the server is sending.
ofstream out("C:\\Prog.exe",ios::binary);
void FileReceive(char* recvbuf, int recvbuflen)
{
if(out.is_open())
{
out.write(recvbuf,recvbuflen);
ZeroMemory(&recvbuf,recvbuflen);
}
}