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 0x10 // keep packet-size 2^n and small for non-multithreaded design
3. define svrBUFMASK 0x7f // dictates max message size-1 (2^n-1 because used as & mask)
4. define svrMAXCLIENTS 1000 // used by listen()
5. ifndef __WIN32__
6. define WSAGetLastError() errno
7. endif

// Socket structures and variables struct sockaddr_in addr; struct timeval to; fd_set fdset; unsigned long int sockopt_on; int sock;

// Function prototypes //void server(); // declared earlier in nodalHusk since called in root loop //void client(); void process(); int server_init(); int server_exit(); int nonblocking(int socket);

// Struct for a stream-node's state to point to typedef struct siStruct { int fd, iPtr, iMsg, iLen, oPtr; char *iBuf, *oBuf; } streamInfo;

// iBuf is circular, so best to use a wrapping cmp instead of copying/moving characters // - returns true if string pointed to by str is same as that in iBuf at offset i int siCmp(char *str, int i, streamInfo *info) { i--; char *buf = info->iBuf; while(*str) if (*str++ != buf[i=i+1&svrBUFMASK]) return 0; return 1; }

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

#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("socket() failed returning %d",WSAGetLastError()); if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char*)&sockopt_on,sizeof(int))<0) logErr("setsockopt() failed!"); if (bind(nonblocking(sock),(struct sockaddr*)&addr,szAddr)<0) logErr("bind() failed!"); if (listen(sock,svrMAXCLIENTS)<0) logErr("listen() failed!"); if (errno) logAdd("Server failed to start!");

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

// Perform any cleanup for socket int server_exit() { // 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; }

// Function called by each stream-node in network's reduction loop // - there is also a streams-container node containing zero or more stream nodes void server() { FD_ZERO(&fdset); FD_SET(sock,&fdset); to.tv_sec = to.tv_usec = svrDELAY; if (select(sock+1,&fdset,NULL,NULL,&to)>0) { // New connection request, accpet and create new stream-node int fd = nonblocking(accept(sock,NULL,NULL)); if (fd>0) { printf("New connection: Stream%d.\n",fd); streamInfo *newsi = malloc(sizeof(streamInfo)); newsi->fd = fd; newsi->iBuf = malloc(svrBUFMASK+1); newsi->oBuf = malloc(svrBUFMASK+1); newsi->iPtr = newsi->iMsg = newsi->oPtr = 0x30; node n = nodeGetValue(nodeCLIENTS,nodeLOOP); n = nodeLoopInsert(n,nodeNULL); nodeSetValue(nodeCLIENTS,nodeLOOP,n); nodeSetValue(n,nodeCODE,nodeTRUE); *nodeState(n,nodeNULL) = &client; *nodeState(n,nodeSTREAMINFO) = newsi; } else logErr("accept(): failed!"); } }

// Each of the stream nodes points to this function in its State void client() { // Get the info for this stream ready for reading/writing a packet if necessary streamInfo *info = *nodeState(this, nodeSTREAMINFO); char *iBuf = info->iBuf, *oBuf = info->oBuf; int i,l,fd = info->fd;

// If any data to recieve, read a packet FD_ZERO(&fdset); FD_SET(fd,&fdset); to.tv_sec = to.tv_usec = svrDELAY; if (select(fd+1,&fdset,NULL,NULL,&to)>0) { if ((i=recv(fd,iBuf+(info->iPtr&svrBUFMASK),svrPAKSIZE,0)) > 0) { printf("%d bytes read to %d (iMsg=%d)\n",i,info->iPtr&svrBUFMASK,info->iMsg); // Scan new packet for completed messages and process each // - problem if \r\n\r\n lies on packet-boundary while (i--) if (siCmp("\r\n\r\n",info->iPtr++,info)) process(info);

// can't do this - messages musn't be forced to pak-boundary as start already read info->iPtr = info->iMsg = (info->iPtr&~(svrPAKSIZE-1))+svrPAKSIZE&svrBUFMASK; printf("updated ptr: iPtr=%d\n",info->iPtr);

printf("2. ptr: iPtr=%d\n",info->iPtr); if ((info->iPtr&svrBUFMASK&~(svrPAKSIZE-1)) == info->iMsg) info->iPtr -= svrPAKSIZE; // Clip if iBuf overrun } else if (i == 0) { // zero bytes to read, do orderly termination printf("Stream%d closed.\n",fd); //nodeLoopRemove(this); // NOTE: reduction not handling PREV free(iBuf); free(oBuf); free(info); } else logErrNum("recv() failed returning %d",WSAGetLastError()); } return; // Data to send? FD_ZERO(&fdset); FD_SET(fd,&fdset); to.tv_sec = to.tv_usec = svrDELAY; if (select(fd+1,NULL,&fdset,NULL,&to)>0) { // write a packet from outbuf //int len = svrPAKSIZE; // or less //if (send(fd,oBuf+oPtr,len,0)<0) logErr("send() failed!"); }

}

// Process message in iBuf which should be a complete HTTP GET request void process(streamInfo *info) { int msg = info->iMsg; if (siCmp("GET /",msg,info)) {

// Extract request path & query-string msg += 4; char *s1 = malloc(50), *rqst = s1, *end = info->iBuf+msg; while((*s1++ = *++end) > ' '); *--s1 = '\0'; printf("Request:\"%s\"\n",rqst);

// Exit if /stop requested if (siCmp("/stop",msg,info)) { logAdd("/stop requested, stopping."); exit(EXIT_SUCCESS); }

// Send test response back send(info->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); free(rqst); } else { send(info->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!"); } }