Server.c
// This article and all its includes are licenced under LGPLTemplate:C // GPL: http://www.gnu.org/copyleft/lesser.html // SRC: http://www.organicdesign.co.nz/server.c
- define svrDELAY 0 // normal operation is 0 for no delay
- define svrPAKSIZE 128 // keep packet-size small for non-multithreaded design
- define svrPAKMAX 16384 // maximum packet size to allow for variable pak size at runtime
- define svrBUFSIZE 4096 // dictates max message size
- define svrMAXCLIENTS 1000 // used by listen()
- ifndef __WIN32__
- define WSAGetLastError() errno
- 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(); int streamOpen(int fd,char *resource); 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(svrPAKMAX); *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
// - if fd is NULL, then try and create one by resolving the resource string
void streamOpen(int fd, char *resource) {
if (fd == NULL) {
// if resource is /^[./]/ then its a file
// - file will have different packet size etc
// - may need to include &recv/&read etc in streamInfo struct
}
if (fd < 0) return logErrMsg("Couldn't open resource \"%s\"",resource);
logAddNum("New connection: Stream%d.",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,nodeSTREAM) = 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, nodeSTREAM); 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,NULL);
else logErrNum("server/accept() failed returning %d",WSAGetLastError());
}
