#include <u.h>#include <libc.h>#include <oventi.h>#include "session.h" static char EAuthState[] = "bad authentication state";static char ENotServer[] = "not a server session";static char EVersion[] = "incorrect version number";static char EProtocolBotch[] = "venti protocol botch"; VtSession *vtServerAlloc(VtServerVtbl *vtbl){	VtSession *z = vtAlloc();	z->vtbl = vtMemAlloc(sizeof(VtServerVtbl));	setmalloctag(z->vtbl, getcallerpc(&vtbl));	*z->vtbl = *vtbl;	return z;} static intsrvHello(VtSession *z, char *version, char *uid, int , uchar *, int , uchar *, int ){	vtLock(z->lk);	if(z->auth.state != VtAuthHello) {		vtSetError(EAuthState);		goto Err;	}	if(strcmp(version, vtGetVersion(z)) != 0) {		vtSetError(EVersion);		goto Err;	}	vtMemFree(z->uid);	z->uid = vtStrDup(uid);	z->auth.state = VtAuthOK;	vtUnlock(z->lk);	return 1;Err:	z->auth.state = VtAuthFailed;	vtUnlock(z->lk);	return 0;}  static intdispatchHello(VtSession *z, Packet **pkt){	char *version, *uid;	uchar *crypto, *codec;	uchar buf[10];	int ncrypto, ncodec, cryptoStrength;	int ret;	Packet *p; 	p = *pkt; 	version = nil;		uid = nil;	crypto = nil;	codec = nil; 	ret = 0;	if(!vtGetString(p, &version))		goto Err;	if(!vtGetString(p, &uid))		goto Err;	if(!packetConsume(p, buf, 2))		goto Err;	cryptoStrength = buf[0];	ncrypto = buf[1];	crypto = vtMemAlloc(ncrypto);	if(!packetConsume(p, crypto, ncrypto))		goto Err; 	if(!packetConsume(p, buf, 1))		goto Err;	ncodec = buf[0];	codec = vtMemAlloc(ncodec);	if(!packetConsume(p, codec, ncodec))		goto Err; 	if(packetSize(p) != 0) {		vtSetError(EProtocolBotch);		goto Err;	}	if(!srvHello(z, version, uid, cryptoStrength, crypto, ncrypto, codec, ncodec)) {		packetFree(p);		*pkt = nil;	} else {		if(!vtAddString(p, vtGetSid(z)))			goto Err;		buf[0] = vtGetCrypto(z);		buf[1] = vtGetCodec(z);		packetAppend(p, buf, 2);	}	ret = 1;Err:	vtMemFree(version);	vtMemFree(uid);	vtMemFree(crypto);	vtMemFree(codec);	return ret;} static intdispatchRead(VtSession *z, Packet **pkt){	Packet *p;	int type, n;	uchar score[VtScoreSize], buf[4]; 	p = *pkt;	if(!packetConsume(p, score, VtScoreSize))		return 0;	if(!packetConsume(p, buf, 4))		return 0;	type = buf[0];	n = (buf[2]<<8) | buf[3];	if(packetSize(p) != 0) {		vtSetError(EProtocolBotch);		return 0;	}	packetFree(p);	*pkt = (*z->vtbl->read)(z, score, type, n);	return 1;} static intdispatchWrite(VtSession *z, Packet **pkt){	Packet *p;	int type;	uchar score[VtScoreSize], buf[4]; 	p = *pkt;	if(!packetConsume(p, buf, 4))		return 0;	type = buf[0];	if(!(z->vtbl->write)(z, score, type, p)) {		*pkt = 0;	} else {		*pkt = packetAlloc();		packetAppend(*pkt, score, VtScoreSize);	}	return 1;} static intdispatchSync(VtSession *z, Packet **pkt){	(z->vtbl->sync)(z);	if(packetSize(*pkt) != 0) {		vtSetError(EProtocolBotch);		return 0;	}	return 1;} intvtExport(VtSession *z){	Packet *p;	uchar buf[10], *hdr;	int op, tid, clean; 	if(z->vtbl == nil) {		vtSetError(ENotServer);		return 0;	} 	/* fork off slave */	switch(rfork(RFNOWAIT|RFMEM|RFPROC)){	case -1:		vtOSError();		return 0;	case 0:		break;	default:		return 1;	} 		p = nil;	clean = 0;	vtAttach();	if(!vtConnect(z, nil))		goto Exit; 	vtDebug(z, "server connected!\n");if(0)	vtSetDebug(z, 1); 	for(;;) {		p = vtRecvPacket(z);		if(p == nil) {			break;		}		vtDebug(z, "server recv: ");		vtDebugMesg(z, p, "\n"); 		if(!packetConsume(p, buf, 2)) {			vtSetError(EProtocolBotch);			break;		}		op = buf[0];		tid = buf[1];		switch(op) {		default:			vtSetError(EProtocolBotch);			goto Exit;		case VtQPing:			break;		case VtQGoodbye:			clean = 1;			goto Exit;		case VtQHello:			if(!dispatchHello(z, &p))				goto Exit;			break;		case VtQRead:			if(!dispatchRead(z, &p))				goto Exit;			break;		case VtQWrite:			if(!dispatchWrite(z, &p))				goto Exit;			break;		case VtQSync:			if(!dispatchSync(z, &p))				goto Exit;			break;		}		if(p != nil) {			hdr = packetHeader(p, 2);			hdr[0] = op+1;			hdr[1] = tid;		} else {			p = packetAlloc();			hdr = packetHeader(p, 2);			hdr[0] = VtRError;			hdr[1] = tid;			if(!vtAddString(p, vtGetError()))				goto Exit;		} 		vtDebug(z, "server send: ");		vtDebugMesg(z, p, "\n"); 		if(!vtSendPacket(z, p)) {			p = nil;			goto Exit;		}	}Exit:	if(p != nil)		packetFree(p);	if(z->vtbl->closing)		z->vtbl->closing(z, clean);	vtClose(z);	vtFree(z);	vtDetach(); 	exits(0);	return 0;	/* never gets here */}