#include "lib9.h"#include "logfs.h"#include "fcall.h"#include "local.h" char *logfsserverwstat(LogfsServer *server, u32int fid, uchar *stat, ushort nstat){	Fid *f;	uchar *p;	ushort len;	uchar *mep;	Qid qid;	u32int perm, mtime;	uvlong length;	char *name, *uname, *gname, *muname;	int qiddonttouch, permdonttouch, mtimedonttouch, lengthdonttouch;	Entry *e, *parent;	LogMessage s;	char *cuid, *ngid;	Group *eg, *ng;	char *cname;	char *errmsg;	char *nuid; 	if(server->trace > 1)		print("logfsserverwstat(%ud, %ud)\n", fid, nstat);	if(nstat < 49)		return Emsgsize;	p  = stat;	len = GBIT16(p); p += BIT16SZ;	if(len + BIT16SZ  != nstat)		return Emsgsize;	mep = p + len;	p += BIT16SZ + BIT32SZ;		/* skip type and dev */	qid.type = *p++;	qid.vers = GBIT32(p); p += BIT32SZ;	qid.path = GBIT64(p); p += BIT64SZ;	perm = GBIT32(p); p += BIT32SZ;	p += BIT32SZ;				/* skip atime */	mtime = GBIT32(p); p += BIT32SZ;	length = GBIT64(p); p+= BIT64SZ;	if(!logfsgn(&p, mep, &name) || !logfsgn(&p, mep, &uname)		|| !logfsgn(&p, mep, &gname) || !logfsgn(&p, mep, &muname))		return Emsgsize;	if(p != mep)		return Emsgsize;	qiddonttouch = qid.type == (uchar)~0 && qid.vers == ~0 && qid.path == ~(uvlong)0;	permdonttouch = perm == ~0;	mtimedonttouch = mtime == ~0;	lengthdonttouch = length == ~(uvlong)0;	if(server->trace > 1) {		int comma = 0;		print("logfsserverwstat(");		if(!qiddonttouch) {			comma = 1;			print("qid=0x%.2ux/%lud/%llud", qid.type, qid.vers, qid.path);		}		if(!permdonttouch) {			if(comma)				print(", ");			print("perm=0%uo", perm);			comma = 1;		}		if(!mtimedonttouch) {			if(comma)				print(", ");			print("mtime=%ud", mtime);			comma = 1;		}		if(!lengthdonttouch) {			if(comma)				print(", ");			print("length=%llud", length);			comma = 1;		}		if(name != nil) {			if(comma)				print(", ");			print("name=%s", name);			comma = 1;		}		if(uname != nil) {			if(comma)				print(", ");			print("uid=%s", uname);			comma = 1;		}		if(gname != nil) {			if(comma)				print(", ");			print("gid=%s", gname);			comma = 1;		}		if(muname != nil) {			if(comma)				print(", ");			print("muname=%s", muname);			comma = 1;		}		USED(comma);		print(")\n");	}	f = logfsfidmapfindentry(server->fidmap, fid);	if(f == nil)		return logfsebadfid;	e = f->entry;	if(e->deadandgone)		return Eio;	parent = e->parent;	if(name) {		Entry *oe;		if(parent == e)			return Eperm;		if(!logfsuserpermcheck(server, e->parent, f, DMWRITE))			return Eperm;		for(oe = parent->u.dir.list; oe; oe = oe->next) {			if(oe == e)				continue;			if(strcmp(oe->name, name) == 0)				return Eexist;		}	}	if(!lengthdonttouch) {		if(!logfsuserpermcheck(server, e, f, DMWRITE))			return Eperm;		if(e->qid.type & QTDIR) {			if(length != 0)				return Eperm;		}else if(length != e->u.file.length){			/*			 * TODO - truncate directory			 * TODO - truncate file			 */			return "wstat -- can't change length";		}	}	cuid = logfsisfindidfromname(server->is, f->uname);	/* TODO - change entries to have a group pointer */	eg = logfsisfindgroupfromid(server->is, e->uid);	if(gname) {		gname = logfsisustadd(server->is, gname);		if(gname == nil)			return Enomem;		ngid = logfsisfindidfromname(server->is, gname);		if(ngid == nil)			return Eunknown;	}	else		ngid = nil;	if(uname) {		uname = logfsisustadd(server->is, uname);		if(uname == nil)			return Enomem;		nuid = logfsisfindidfromname(server->is, uname);		if(nuid == nil)			return Eunknown;	}	else		nuid = nil;	if(!permdonttouch || !mtimedonttouch) {		/*		 * same permissions rules - change by owner, or by group leader		 */		if((server->openflags & LogfsOpenFlagWstatAllow) == 0 &&			e->uid != cuid && (eg == nil || !logfsisgroupuidisleader(server->is, eg, cuid)))			return Eperm;	}	if(!permdonttouch){		if((perm^e->perm) & DMDIR)			return "wstat -- attempt to change directory";		if(perm & ~(DMDIR|DMAPPEND|DMEXCL|0777))			return Eperm;	}	if(gname) {		int ok;		ng = logfsisfindgroupfromid(server->is, ngid);		ok = 0;		if(e->uid == cuid && logfsisgroupuidismember(server->is, ng, e->uid))			ok = 1;		if(!ok && eg && logfsisgroupuidisleader(server->is, eg, cuid)			&& logfsisgroupuidisleader(server->is, ng, cuid))			ok = 1;		if(!ok && (server->openflags & LogfsOpenFlagWstatAllow) == 0)			return Eperm;	}	if(!qiddonttouch)		return Eperm;	if(uname){		if((server->openflags & LogfsOpenFlagWstatAllow) == 0)			return Eperm;	}	if(muname)		return Eperm;	/*	 * we can do this	 */	if(mtimedonttouch && permdonttouch && lengthdonttouch		&& name == nil && uname == nil && gname == nil) {		/*		 * but we aren't doing anything - this is a wstat flush		 */		return logfsserverflush(server);	}	if(name) {		cname = logfsstrdup(name);		if(cname == nil)			return Enomem;	}	else		cname = nil;	/*	 * send the log message	 */	s.type = LogfsLogTwstat;	s.path = e->qid.path;		s.u.wstat.name = cname;	s.u.wstat.perm = perm;	s.u.wstat.uid = nuid;	s.u.wstat.gid = ngid;	s.u.wstat.mtime = mtime;	s.u.wstat.muid = cuid;	errmsg = logfslog(server, 1, &s);	if(errmsg) {		logfsfreemem(cname);		return errmsg;	}	if(!mtimedonttouch)		e->mtime = mtime;	if(!permdonttouch)		e->perm = (e->perm & DMDIR) | perm;	if(!lengthdonttouch) {		/* TODO */	}	if(name) {		logfsfreemem(e->name);		e->name = cname;	}	if(uname)		e->uid = nuid;	if(ngid)		e->gid = ngid;	return nil;}