Server.c

// This article and all its includes are licenced under LGPL // GPL: http://www.gnu.org/copyleft/lesser.html // SRC: http://www.organicdesign.co.nz/server.c

1. define svrDELAY 0 // normal operation is 0 for no delay
2. define svrPAKSIZE 128 // keep packet-size small for non-multithreaded design
3. define svrBUFSIZE 4096 // dictates max message size
4. define svrMAXCLIENTS 1000 // used by listen()
5. ifndef __WIN32__
6. define WSAGetLastError() errno
7. endif

// Socket structures, globals and prototypes void server(); int serverInit(); int serverExit(); int nonblocking(int socket); fd_set *fdsetInit(int fd); fd_set fdset; int sock,fd; struct sockaddr_in addr; struct timeval to; unsigned long int sockopt_on;

// Client/Stream info structure, globals and prototypes char *pBuf; // Buffer to read/write data packets const char *term = "\r\n\r\n"; typedef struct siStruct { int fd; // File-descriptor for this stream char *iBuf, *oBuf; // Message buffers for this stream int iPtr; // Index into input-buffer for next packet to start at int tPtr; // Index into term (atomised strcmp incase terminator spans packet-boundary) int oPtr; } streamInfo; void client(); void streamOpen(int fd); void streamClose(streamInfo *stream); void streamProcess(streamInfo *stream);

// Initialise socket listening on specified port int serverInit() {

#if __WIN32__ WSADATA wsaData; if (WSAStartup(MAKEWORD(2,0),&wsaData)!=0) logErr("WSAStartup() failed!"); #endif

// Set up structures for socket & select sockopt_on = 1; int szAddr = sizeof(struct sockaddr_in); memset((char*)&addr, 0, szAddr); // zero the struct addr.sin_family = AF_INET; addr.sin_port = htons(port); addr.sin_addr.s_addr = htonl(INADDR_ANY); errno = 0;

// Do the usual socket polava: create,options,bind,listen if ((sock = socket(PF_INET,SOCK_STREAM,IPPROTO_TCP))<0) logErrNum("init/socket() failed returning %d",WSAGetLastError()); if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char*)&sockopt_on,sizeof(int))<0) logErrNum("init/setsockopt() failed returning %d",WSAGetLastError()); if (bind(nonblocking(sock),(struct sockaddr*)&addr,szAddr)<0) logErrNum("init/bind() failed returning %d",WSAGetLastError()); if (listen(sock,svrMAXCLIENTS)<0) logErrNum("init/listen() failed returning %d",WSAGetLastError());

if (WSAGetLastError() == 0) { char *msg = malloc(100); sprintf(msg,"Daemon \"%s\" started successfully and serving on port %d.",peer,port); logAdd(msg); free(msg); } else { logAdd("Server failed to start!"); return WSAGetLastError(); }

// Globals for server() and client() quantum-functions pBuf = malloc(svrPAKSIZE); *nodeState(nodeSERVER,0) = &server; nodeSetValue(nodeSERVER,nodeCODE,nodeTRUE);

return 0; }

// Perform any cleanup for socket int serverExit() { free(pBuf); // todo: close streams and free buffers etc #if __WIN32__ WSACleanup(); #endif return WSAGetLastError(); }

// 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) { #if __WIN32__ ioctlsocket(socket,FIONBIO,&sockopt_on); #else fcntl(socket,F_SETFL,fcntl(socket,F_GETFL)|O_NONBLOCK); #endif return socket; }

// Return pointer to fdset filled with passed file-descriptor ready for a select() call fd_set *fdsetInit(int fd) { FD_ZERO(&fdset); FD_SET(fd,&fdset); to.tv_sec = to.tv_usec = svrDELAY; return &fdset; }

// Process message in iBuf which should be a complete HTTP GET request // - iPtr is put back to 0 so next message fills from start of iBuf void streamProcess(streamInfo *stream) { char *rqst, *end, *msg = stream->iBuf; if (strncmp("GET /",msg,5)==0) {

// Extract request path & query-string rqst = end = msg+4; while(*++end > ' '); *end = '\0'; printf("Request:\"%s\"\n",rqst);

// Exit if /stop requested if (strcmp("/stop",rqst)==0) nodeExit();

// Send test response back send(stream->fd,"HTTP/1.1 200 OK\r\nDate: Mon, 31 Jul 2006 22:27:14 NZST\r\nContent-Type: text/html\r\nConnection: keep-alive\r\nContent-Length: 9\r\n\r\nStink eh?",134,0); } else { send(stream->fd,"HTTP/1.1 200 OK\r\nDate: Mon, 31 Jul 2006 22:27:14 NZST\r\nContent-Type: text/html\r\nConnection: keep-alive\r\nContent-Length: 9\r\n\r\nNo GET!!!",134,0); logAdd("Peerd only supports GET requests currently!"); } stream->iPtr = 0; // reset iPtr ready for next message }

// Create new client-node and streamInfo structure from passed file-descriptor void streamOpen(int fd) { printf("New connection: Stream%d.\n",fd);

// Create new streamInfo structure and allocate buffers streamInfo *stream = malloc(sizeof(streamInfo)); stream->fd = fd; stream->iBuf = malloc(svrBUFSIZE); stream->oBuf = malloc(svrBUFSIZE); stream->iPtr = stream->oPtr = stream->tPtr = 0;

// Create new client-node in clients-loop and add the new streamInfo node nc = nodeGetValue(nodeCLIENTS,nodeLOOP); nc = nodeLoopInsert(nc,0); nodeSetValue(nodeCLIENTS,nodeLOOP,nc); nodeSetValue(nc,nodeCODE,nodeTRUE); *nodeState(nc,0) = &client; *nodeState(nc,nodeSTREAMINFO) = stream; }

// Close the passed stream, free its resources and remove from clients-loop void streamClose(streamInfo *stream) { printf("Stream%d closed.\n",stream->fd); //nodeLoopRemove(this); // NOTE: reduction not handling PREV free(stream->iBuf); free(stream->oBuf); free(stream); }

// Each of the stream nodes points to this function in its State void client() {

// Get pointer to the streamInfo structure in current nodal context (this) streamInfo *stream = *nodeState(this, nodeSTREAMINFO); fd = stream->fd; char *iBuf = stream->iBuf, *oBuf = stream->oBuf; int n, i = 0;

// If any data to recieve, read a packet if (select(fd+1,fdsetInit(fd),NULL,NULL,&to)>0) { if ((n = recv(fd,pBuf,svrPAKSIZE,0)) > 0) { // Some bytes were read, append to current message (loop last packet if msg too big) if (stream->iPtr > svrBUFSIZE-svrPAKSIZE) stream->iPtr -= svrPAKSIZE; while (n--) // Append current msg, for each complete msg, process it & reset iPtr if ((iBuf[stream->iPtr++] = pBuf[i++]) != term[stream->tPtr++]) stream->tPtr = 0; else if (term[stream->tPtr] == 0) streamProcess(stream); } else if (n == 0) streamClose(stream); // Zero bytes were read, do orderly termination else logErrNum("client/recv() failed returning %d",WSAGetLastError()); }

// Data to send? //if (select(fd+1,NULL,fdsetInit(fd),NULL,&to)>0) { // write a packet from outbuf //int len = svrPAKSIZE; // or less //if (send(fd,oBuf+oPtr,len,0)<0) logErr("send() failed!"); // }

}

// Function called by each stream-node in network's reduction loop // - Checks if any new connections waiting on listening socket, // if so accept and call streamOpen() with new file-descriptor void server() { if (select(sock+1,fdsetInit(sock),NULL,NULL,&to)>0) if ((fd = nonblocking(accept(sock,NULL,NULL)))>0) streamOpen(fd); else logErrNum("server/accept() failed returning %d",WSAGetLastError()); }