/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <oventi.h>#include "session.h" static char EProtocolBotch[] = "venti protocol botch";static char ELumpSize[] = "illegal lump size";static char ENotConnected[] = "not connected to venti server"; static Packet *vtRPC(VtSession *z, int op, Packet *p); VtSession *vtClientAlloc(void){	VtSession *z = vtAlloc();		return z;} VtSession *vtDial(char *host, int canfail){	VtSession *z;	int fd;	char *na;	char e[ERRMAX]; 	if(host == nil) 		host = getenv("venti");	if(host == nil)		host = "$venti"; 	if (host == nil) {		if (!canfail)			werrstr("no venti host set");		na = "";		fd = -1;	} else {		na = netmkaddr(host, 0, "venti");		fd = dial(na, 0, 0, 0);	}	if(fd < 0){		rerrstr(e, sizeof e);		if(!canfail){			vtSetError("venti dialstring %s: %s", na, e);			return nil;		}	}	z = vtClientAlloc();	if(fd < 0)		strcpy(z->fderror, e);	vtSetFd(z, fd);	return z;} intvtRedial(VtSession *z, char *host){	int fd;	char *na; 	if(host == nil) 		host = getenv("venti");	if(host == nil)		host = "$venti"; 	na = netmkaddr(host, 0, "venti");	fd = dial(na, 0, 0, 0);	if(fd < 0){		vtOSError();		return 0;	}	vtReset(z);	vtSetFd(z, fd);	return 1;} VtSession *vtStdioServer(char *server){	int pfd[2];	VtSession *z; 	if(server == nil)		return nil; 	if(access(server, AEXEC) < 0) {		vtOSError();		return nil;	} 	if(pipe(pfd) < 0) {		vtOSError();		return nil;	} 	switch(fork()) {	case -1:		close(pfd[0]);		close(pfd[1]);		vtOSError();		return nil;	case 0:		close(pfd[0]);		dup(pfd[1], 0);		dup(pfd[1], 1);		execl(server, "ventiserver", "-i", nil);		exits("exec failed");	}	close(pfd[1]); 	z = vtClientAlloc();	vtSetFd(z, pfd[0]);	return z;} intvtPing(VtSession *z){	Packet *p = packetAlloc(); 	p = vtRPC(z, VtQPing, p);	if(p == nil)		return 0;	packetFree(p);	return 1;} intvtHello(VtSession *z){	Packet *p;	uchar buf[10];	char *sid;	int crypto, codec; 	sid = nil; 	p = packetAlloc();	if(!vtAddString(p, vtGetVersion(z)))		goto Err;	if(!vtAddString(p, vtGetUid(z)))		goto Err;	buf[0] = vtGetCryptoStrength(z);	buf[1] = 0;	buf[2] = 0;	packetAppend(p, buf, 3);	p = vtRPC(z, VtQHello, p);	if(p == nil)		return 0;	if(!vtGetString(p, &sid))		goto Err;	if(!packetConsume(p, buf, 2))		goto Err;	if(packetSize(p) != 0) {		vtSetError(EProtocolBotch);		goto Err;	}	crypto = buf[0];	codec = buf[1]; 	USED(crypto);	USED(codec); 	packetFree(p); 	vtLock(z->lk);	z->sid = sid;	z->auth.state = VtAuthOK;	vtSha1Free(z->inHash);	z->inHash = nil;	vtSha1Free(z->outHash);	z->outHash = nil;	vtUnlock(z->lk); 	return 1;Err:	packetFree(p);	vtMemFree(sid);	return 0;} intvtSync(VtSession *z){	Packet *p = packetAlloc(); 	p = vtRPC(z, VtQSync, p);	if(p == nil)		return 0;	if(packetSize(p) != 0){		vtSetError(EProtocolBotch);		goto Err;	}	packetFree(p);	return 1; Err:	packetFree(p);	return 0;} intvtWrite(VtSession *z, uchar score[VtScoreSize], int type, uchar *buf, int n){	Packet *p = packetAlloc(); 	packetAppend(p, buf, n);	return vtWritePacket(z, score, type, p);} intvtWritePacket(VtSession *z, uchar score[VtScoreSize], int type, Packet *p){	int n = packetSize(p);	uchar *hdr; 	if(n > VtMaxLumpSize || n < 0) {		vtSetError(ELumpSize);		goto Err;	}		if(n == 0) {		memmove(score, vtZeroScore, VtScoreSize);		return 1;	} 	hdr = packetHeader(p, 4);	hdr[0] = type;	hdr[1] = 0;	/* pad */	hdr[2] = 0;	/* pad */	hdr[3] = 0;	/* pad */	p = vtRPC(z, VtQWrite, p);	if(p == nil)		return 0;	if(!packetConsume(p, score, VtScoreSize))		goto Err;	if(packetSize(p) != 0) {		vtSetError(EProtocolBotch);		goto Err;	}	packetFree(p);	return 1;Err:	packetFree(p);	return 0;} intvtRead(VtSession *z, uchar score[VtScoreSize], int type, uchar *buf, int n){	Packet *p; 	p = vtReadPacket(z, score, type, n);	if(p == nil)		return -1;	n = packetSize(p);	packetCopy(p, buf, 0, n);	packetFree(p);	return n;} Packet *vtReadPacket(VtSession *z, uchar score[VtScoreSize], int type, int n){	Packet *p;	uchar buf[10]; 	if(n < 0 || n > VtMaxLumpSize) {		vtSetError(ELumpSize);		return nil;	} 	p = packetAlloc();	if(memcmp(score, vtZeroScore, VtScoreSize) == 0)		return p; 	packetAppend(p, score, VtScoreSize);	buf[0] = type;	buf[1] = 0;	/* pad */	buf[2] = n >> 8;	buf[3] = n;	packetAppend(p, buf, 4);	return vtRPC(z, VtQRead, p);}  static Packet *vtRPC(VtSession *z, int op, Packet *p){	uchar *hdr, buf[2];	char *err; 	if(z == nil){		vtSetError(ENotConnected);		return nil;	} 	/*	 * single threaded for the momment	 */	vtLock(z->lk);	if(z->cstate != VtStateConnected){		vtSetError(ENotConnected);		goto Err;	}	hdr = packetHeader(p, 2);	hdr[0] = op;	/* op */	hdr[1] = 0;	/* tid */	vtDebug(z, "client send: ");	vtDebugMesg(z, p, "\n");	if(!vtSendPacket(z, p)) {		p = nil;		goto Err;	}	p = vtRecvPacket(z);	if(p == nil)		goto Err;	vtDebug(z, "client recv: ");	vtDebugMesg(z, p, "\n");	if(!packetConsume(p, buf, 2))		goto Err;	if(buf[0] == VtRError) {		if(!vtGetString(p, &err)) {			vtSetError(EProtocolBotch);			goto Err;		}		vtSetError(err);		vtMemFree(err);		packetFree(p);		vtUnlock(z->lk);		return nil;	}	if(buf[0] != op+1 || buf[1] != 0) {		vtSetError(EProtocolBotch);		goto Err;	}	vtUnlock(z->lk);	return p;Err:	vtDebug(z, "vtRPC failed: %s\n", vtGetError());	if(p != nil)		packetFree(p);	vtUnlock(z->lk);	vtDisconnect(z, 1);	return nil;}