I've looked at tutorials and many other places on how to do this however I'm still having trouble getting this to work. Interestingly enough I did find a tutorial (which is where I derived this code from) on how to setup a UDP chat program which was wonderful for a basic example.
However just as soon as I do non local testing (I switch the IP for the server the client is supposed to connect to from localhost to my real IP), the packet ends up not being received. I can't help but feel that I've setup the server portion of this code wrong.
So here's what I have so far.
Network.h //the UDP networking code.
#pragma once
#include "include/SDL2/SDL_net.h"
#include <cstring>
#include <iostream>
#include <fstream>
#include <sstream>
/*******************************************************************************************
Some things to note about the UDPConnection class.
Init this on both the client and/or server's excutable. No extra work required. Unless your
planning on tracking the activity and data between multiple clients (eg: for multiplayer).
At which point you just memorize and communicate between different ip's manually.
HINT: look at packet->ip;
*******************************************************************************************/
class UDPConnection
{
bool quit;
UDPsocket ourSocket;
IPaddress serverIP;
public:
UDPpacket *packet;
UDPConnection()
{
quit = false;
}
~UDPConnection()
{
SDLNet_FreePacket(packet);
SDLNet_Quit();
}
bool Init(const std::string &ip, int32_t remotePort, int32_t localPort)
{
std::cout << "Connecting to \n\tIP : " << ip << "\n\tPort : " << remotePort << std::endl;
std::cout << "Local port : " << localPort << "\n\n";
// Initialize SDL_net
if (!InitSDL_Net())
return false;
if (!OpenPort(localPort))
return false;
if (!SetIPAndPort(ip, remotePort))
return false;
if (!CreatePacket(65536))
return false;
/* bind server address to channel 0 */
if (SDLNet_UDP_Bind(ourSocket, 0, &serverIP) == -1)
{
printf("SDLNet_UDP_Bind: %s\n", SDLNet_GetError());
return false;
}
return true;
}
bool InitServer(int32_t remotePort, int32_t localPort) {
std::cout << "connecting to port" << remotePort << std::endl;
std::cout << "Local port : " << localPort << "\n\n";
// Initialize SDL_net
if (!InitSDL_Net())
return false;
if (!OpenPort(localPort))
return false;
if (!SetPort(remotePort))
return false;
if (!CreatePacket(65536))
return false;
SDLNet_UDP_Unbind(ourSocket, 0);
return true;
}
bool InitSDL_Net()
{
std::cout << "Initializing SDL_net...\n";
if (SDLNet_Init() == -1)
{
std::cout << "\tSDLNet_Init failed : " << SDLNet_GetError() << std::endl;
return false;
}
std::cout << "\tSuccess!\n\n";
return true;
}
bool CreatePacket(int32_t packetSize)
{
std::cout << "Creating packet with size " << packetSize << "...\n";
// Allocate memory for the packet
packet = SDLNet_AllocPacket(packetSize);
if (packet == nullptr)
{
std::cout << "\tSDLNet_AllocPacket failed : " << SDLNet_GetError() << std::endl;
return false;
}
// Set the destination host and port
// We got these from calling SetIPAndPort()
packet->address.host = serverIP.host;
packet->address.port = serverIP.port;
std::cout << "\tSuccess!\n\n";
return true;
}
bool OpenPort(int32_t port)
{
std::cout << "Opening port " << port << "...\n";
// Sets our sovket with our local port
ourSocket = SDLNet_UDP_Open(port);
if (ourSocket == nullptr)
{
std::cout << "\tSDLNet_UDP_Open failed : " << SDLNet_GetError() << std::endl;
return false;
}
std::cout << "\tSuccess!\n\n";
return true;
}
bool SetIPAndPort(const std::string &ip, uint16_t port)
{
std::cout << "Setting IP ( " << ip << " ) " << "and port ( " << port << " )\n";
// Set IP and port number with correct endianess
if (SDLNet_ResolveHost(&serverIP, ip.c_str(), port) == -1)
{
std::cout << "\tSDLNet_ResolveHost failed : " << SDLNet_GetError() << std::endl;
return false;
}
std::cout << "\tSuccess!\n\n";
return true;
}
bool SetPort(uint16_t port)
{
std::cout << "Setting up port ( " << port << " )\n";
// Set IP and port number with correct endianess
//IS THE ISSUE HERE?
if (SDLNet_ResolveHost(&serverIP, NULL, port) == -1)
{
std::cout << "\tSDLNet_ResolveHost failed : " << SDLNet_GetError() << std::endl;
return false;
}
std::cout << "\tSuccess!\n\n";
return true;
}
// Send data.
bool Send(const std::string &str)
{
// Set the data
// UDPPacket::data is an Uint8, which is similar to char*
// This means we can't set it directly.
//
// std::stringstreams let us add any data to it using << ( like std::cout )
// We can extract any data from a std::stringstream using >> ( like std::cin )
//
//str
memcpy(packet->data, str.c_str(), str.length());
packet->len = str.length();
// Send
// SDLNet_UDP_Send returns number of packets sent. 0 means error
//packet->channel = -1;
if (SDLNet_UDP_Send(ourSocket, -1, packet) == 0)
{
std::cout << "\tSDLNet_UDP_Send failed : " << SDLNet_GetError() << "\n"
<< "==========================================================================================================\n";
//msg.resize(0);
return false;
}
std::cout << "sent to: " << packet->address.host << "\n";
std::cout << "length is: " << packet->len << "\n";
}
inline UDPpacket* recievedData(){
// Check to see if there is a packet wauting for us...
if (SDLNet_UDP_Recv(ourSocket, packet))
{
/*for (int i = packet->len; i < 512; i++) {
//may only be needed for local testing.
packet->data[i] = 0;
}*/
//std::cout << "\tData received : " << packet->data << "\n";
return packet;
}return NULL;
}
inline bool WasQuit()
{
return quit;
}
};
clientSend.cpp //our client's exe.
#include "Network.h"
#include "Graphics.h"
#include <cstdlib>
UDPConnection *udpConnection;
using namespace std;
#define DISPLAY_STRING_ROWS 20
char displayString[DISPLAY_STRING_ROWS][256];
int main(int argc, char **argv){
setup(120, 120, 600, 400); //Inits SDL.
std::string IP = "72.49.67.66";
int32_t remotePort = 333;
int32_t localPort = 222;
udpConnection = new UDPConnection();
udpConnection->Init(IP, remotePort, localPort);
UDPpacket *packet;
for (int i = 0; i < DISPLAY_STRING_ROWS; i++) {
for (int j = 0; j < 256; j++) {
displayString[i][j] = 0;
}
}
while (!udpConnection->WasQuit()){
clear();
packet = udpConnection->recievedData();
#define PACKET_LEN packet->len
#define PACKET_DATA packet->data
static int currentRow = 0;
if (packet != NULL) {
for (int i = 0; i < PACKET_LEN; i++) {
displayString[currentRow][i] = udpConnection->packet->data[i];
}
displayString[currentRow][PACKET_LEN] = 0;
if (currentRow >= DISPLAY_STRING_ROWS) {
currentRow = 0;
}
else {
currentRow++;
}
}
for (int i = 0; i < currentRow; i++) {
if (displayString[i][0] != 0) {
text(displayString[i], 20, 20, PACKET_LEN * 16, 16, 0, 0, 0);
}
}
render();
std::string send;
getline(cin, send);
udpConnection->Send(send);
}
endGame();
}
void displayText() {
}
server.cpp //the server's exe.
#include "Network.h"
#include "Graphics.h"
#include <cstdlib>
//Right now i'm just assuming that the ip is givin every time it's sent to client/server.
UDPConnection *udpConnection;
using namespace std;
int main(int argc, char* args[]) {
//std::string IP = "0.0.0.0"; //Not necessary.
int32_t remotePort = 222;
int32_t localPort = 333;
udpConnection = new UDPConnection();
udpConnection->InitServer(remotePort, localPort);
UDPpacket *packet;
setup(120, 120, 600, 400); //Inits SDL.
char c[10][80000];
int cCount = 0;
int cLength[10];
bool running = true; //Is our game loop running?
while (running) { //--GAME LOOP!--//
clear(); //Clears garbage form SDL.
packet = udpConnection->recievedData();
#define PACKET_LEN packet->len
//#define PACKET_DATA packet->data
if (packet != NULL) {
cout << "we got a message" << endl;
packet->data[PACKET_LEN] = 0;
for (int i = 0; i <= PACKET_LEN; i++) {
c[cCount][i] = packet->data[i];
}
//*c[cCount] = udpConnection->packet->data;
cLength[cCount] = PACKET_LEN;
if (cCount == 9) {
cCount = 0;
}else{
cCount++;
}
}
for (int i = 0; i < cCount; i++) {
text(c[i], 20, i*16, cLength[i] * 16, 16, 0, 0, 0);
}
render(); //Causes SDL to draw what we made to our window.
}
endGame(); //Necessary to properly shutdown SDL.
}
I'd hope I won't have to include the graphic.c and graphics.h files however if this is necessary just ask and I'll post the whole project up on a repo for anyone to reference. I'm hoping however the answer is something really easy that I just kept glancing over.
Here's the link to the tutorial I got the code from. http://headerphile.com/sdl2/sdl2-part-12-multiplayer/
The goal is to have a udp server that's able to receive packets from anyone. The problem is that it simply won't receive over the internet even with the router's ports open.
