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 PAKSIZE 128 // keep packet-size small for non-multithreaded design
3. define BUFSIZE 10000 // dictates max message size
4. define MAXCLIENTS 1000

// - 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 <sys/select.h>
6. include <netinet/in.h>
7. include <fcntl.h> // needed for O_NONBLOCK option on server
8. include <sys/time.h> // for select()

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

1. endif

int processMessage(char* msg); void noblock(int socket);

// Set up structures for socket & select struct sockaddr_in addr; struct timeval timeout; fd_set *fdset; int server, sockopt_on = 1, szAddr = sizeof(struct sockaddr_in); memset((char*)&addr, 0, szAddr); // zero the struct addr.sin_family = PF_INET; addr.sin_port = htons(LISTENPORT); addr.sin_addr.s_addr = htonl(INADDR_ANY);

// Do the usual socket polava: create,options,bind,listen if ((server = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) logAdd("socket() failed!"); if (setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &sockopt_on, sizeof(int)) < 0) logAdd("setsockopt() failed!"); noblock(server); if (bind(server, (struct sockaddr*)&addr, szAddr) < 0) logAdd("bind() failed!"); if (listen(server, MAXCLIENTS) < 0) logAdd("listen() failed!");

// Declare the nodal server-iteration function void network() {

// NOTE: no need for si struct, just use individual States in streamNode-assocs

int i; int stream = *nodeGetState(this,STREAM); char *inbuf = nodeGetState(this,INBUF); char *outbuf = nodeGetState(this,OUTBUF); timeout.tv_sec = 1; // later use 0 for min time timeout.tv_usec = 0;

// Check for new connection FD_ZERO(fdset); FD_SET(server,fdset); if (select(server+1,fdset,NULL,NULL,&timeout)>0) { // New connection, create new stream & node int *newstream = malloc(sizeof(int)); noblock(*newstream = accept(server,NULL,NULL)); // newNode = ... nodeSetState(newNode,STREAM,newstream); *nodeSetState(newNode,INBUF,malloc(BUFSIZE)) = '\0'; *nodeSetState(newNode,OUTBUF,malloc(BUFSIZE)) = '\0'; }

// Data to receive? FD_ZERO(fdset); FD_SET(stream,fdset); if ((i=select(stream+1, fdset, NULL, NULL, &timeout))>0) { // read a packet into inbuf // hook a process into the loop if a msg complete } else if (i<0) { // close connection // - remove this stream node from loop // - free the si struct }

// Data to send? FD_ZERO(fdset); FD_SET(stream,fdset); if (select(stream+1, NULL, fdset, NULL, &timeout)>0) { // write a packet from outbuf }

}

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

// send response // - NOTE: this should put the msg in si.out if (send(stream, MSG, strlen(MSG)+1, 0) == -1) logAdd("send() failed!"); else logAdd("Sent message"); }

// 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 // - this may need to be done for each new incomming stream...? // - some examples use fcntl(server, F_SETFL, FNDELAY) or fcntl(server, F_SETFL, O_NONBLOCK); void noblock(int socket) { int opts = fcntl(server, F_GETFL); if (opts<0) logAdd("noblock() failed!"); opts = (opts|O_NONBLOCK); if (fnctl(socket,F_SETFL,opts)<0) logAdd("noblock() failed!"); }