Server.c

// good sock function ref at // http://www.opengroup.org/onlinepubs/009695399/idx/networking.html

// Set up socket and listening loop

1. define LISTENPORT 2012
2. define BACKLOG 10
3. define PAKSIZE 128 // keep packet-size small for non-multithreaded design
4. define BUFSIZE 10000 // max message size
5. define MAXCLIENTS 100
6. define MSG "stink ow!"

// - todo: don't exit on connect errors, keep trying every 10s // Includes for socket (trying to use one source cpp for osx,win32,*ux)

1. ifdef WINDOWS
2. include <winsock.h>
3. else
4. include <sys/socket.h>
5. include <netinet/in.h>
6. include <fcntl.h>

//#include <arpa/inet.h> //#include <netdb.h> //#include <unistd.h>

1. endif

int processMessage(char* msg);

// struct type to represent a currently connected stream typedef struct streamstruct { char* buf; int fileno; } streamInfo;

// set up socket struct struct sockaddr_in my_addr, client_addr; int sa_in_size = sizeof(struct sockaddr_in); memset((char *)&my_addr, 0, sa_in_size); // zero the struct my_addr.sin_family = PF_INET; my_addr.sin_port = htons(LISTENPORT); my_addr.sin_addr.s_addr = htonl(INADDR_ANY);

// get a socket int server; if ((server = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) { perror("socket"); exit(1); }

// make it reusable int sockopt_on = 1; if (setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &sockopt_on, sizeof(int)) < 0) { perror("setsockopt"); exit(1); }

// bind our socket to the port if (bind(server, (struct sockaddr *)&my_addr, sa_in_size) < 0) { perror("bind"); exit(1); }

// start listening for incoming connections if (listen(server, BACKLOG) < 0) { perror("listen"); exit(1); }

// make the server non-blocking so accept() returns straight away // - if no incoming requests, returns EAGAIN or EWOULDBLOCK state // - we need this for non-multithreaded design fcntl(server, O_NONBLOCK);

// array of current client connections streamInfo* streams[MAXCLIENTS];

int i, stream, nStreams = 0; while(1) {

// Wait for any incomming connection // O_NONBLOCK is set so, EAGAIN or EWOULDBLOCK returned if no requests stream = accept(server, (struct sockaddr *)&client_addr, &sa_in_size) if (stream == EAGAIN) { // No connection requests } else if (stream < 0) { perror("accept"); exit(1); } else { // New stream, create input buffer etc streamInfo si; si.buf = malloc(BUFSIZE); si.fileno = stream; streams[nStreams++] = &si; }

// loop thru streams and read a packet from any with data to read for (i = 0; i < nStreams; i++) { char* buf = streams[i].buf; int stream = streams[i].fileno; }

// log the connecter // - should get info for this stream, incl buf printf("got connection from %s\n", inet_ntoa(client_addr.sin_addr));

// get the reply // - should keep receiving until \r\n\0?, then call serverProcessMessage() if (recv(stream, buf, bufsize, 0) == -1) perror("recv"); else printf("The client says \"%s\"\n", buf);

close(stream); // should close when no more data on this stream (somehow)

}

// Parses a message content and responds to client int processMessage(char* msg) { // test if restart cmd first

// send response if (send(stream, MSG, strlen(MSG)+1, 0) == -1) { perror("send"); } else printf("Sent message MSG\n"); }