20060303a

1 files changed, 245 insertions, 0 deletions

diff --git a/liblogfs/wstat.c b/liblogfs/wstat.c
new file mode 100644
index 00000000..85f112da
--- /dev/null
+++ b/liblogfs/wstat.c
@@ -0,0 +1,245 @@
+#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;
+}
+