Server.c

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

// Set up socket and listening loop

1. define DELAY 1 // normal operation is 0 for no delay
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 sock
8. include <sys/time.h> // for select()

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

1. endif

int processMessage(char* msg); int nonblocking(int socket);

// Set up structures for socket & select struct sockaddr_in addr; struct timeval to; fd_set *fdset; int sock, 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(atoi(*hash("port"))); addr.sin_addr.s_addr = htonl(INADDR_ANY);

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

// Function called by main network node in root reduction loop void server() {

// Check for new connection, if so create new stream-node FD_ZERO(fdset); FD_SET(sock,fdset); to.tv_sec = to.tv_usec = DELAY; if (select(sock+1, fdset, NULL, NULL, &to)>0) { int *stream = malloc(sizeof(int)); nonblocking(*stream = accept(sock, NULL, NULL));

// todo: change this to a single state with ptr-to-struct of these pointers nodeSetState(newNode, STREAM, stream); *nodeSetState(newNode, INBUF, malloc(BUFSIZE)) = '\0'; *nodeSetState(newNode, INPTR, malloc(sizeof(int*))) = 0; *nodeSetState(newNode, OUTBUF, malloc(BUFSIZE)) = '\0'; *nodeSetState(newNode, OUTPTR, malloc(sizeof(int*))) = 0; } }

// Function called by each stream in network's reduction loop void stream() { int i, *stream = nodeGetState(this, STREAM); char *inbuf = nodeGetState(this, INBUF); char *outbuf = nodeGetState(this, OUTBUF);

// Data to receive? FD_ZERO(fdset); FD_SET(*stream,fdset); to.tv_sec = to.tv_usec = DELAY; if (select(1+*stream, fdset, NULL, NULL, &to)>0) { // read a packet into inbuf if ((i = recv(*stream, inbuf+*inptr, PAKSIZE, 0)>0) { if (complete_message) { *inptr -= msg_size; // hook a process into the loop } } else if (i == 0) { // zero bytes to read, do orderly termination // todo: remove this stream node from loop free(stream); free(inbuf); free(inptr); free(outbuf); free(outptr); } else logErr("recv(): failed!"); }

// Data to send? FD_ZERO(fdset); FD_SET(*stream,fdset); to.tv_sec = to.tv_usec = DELAY; if (select(1+*stream, NULL, fdset, NULL, &to)>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 passed socket non-blocking so accept() returns straight away for multiplexed model // - if no incoming requests, returns EAGAIN or EWOULDBLOCK state int nonblocking(int socket) { int opts = fcntl(sock, F_GETFL); if (opts<0) logAdd("noblock() failed!"); opts = (opts|O_NONBLOCK); if (fnctl(socket,F_SETFL,opts)<0) logAdd("noblock() failed!"); return socket; }