ref: 95162babf731e1e431134879cb21bf5f8110b328
parent: 1f57b3a7d02117e5be29e358353191253f6b0004
author: Michael Forney <mforney@mforney.org>
date: Wed Mar 16 22:41:01 EDT 2022
fs: various wstat fixes Don't update Dent until btupsert succeeds. Fix permission check for changing mode, mtime, and name. Name permissions are checked against the parent directory, and mode and mtime are allowed iff we are the owner or group leader. Check that length is not negative, mode does not change DMDIR bit, and the new mode contains only valid bits. Keep qid.type in sync with upper mode byte. Implement group change.
--- a/dat.h
+++ b/dat.h
@@ -37,7 +37,7 @@
Nfidtab = 1024, /* number of fit hash entries */
Ndtab = 1024, /* number of dir tab entries */
Max9p = 16*KiB, /* biggest message size we're willing to negotiate */
- Nsec = 1000*1000*1000, /* nanoseconds to the second */
+ Nsec = 1000LL*1000*1000, /* nanoseconds to the second */
Maxname = 256, /* maximum size of a name element */
Maxent = 9+Maxname+1, /* maximum size of ent key, with terminator */
--- a/fs.c
+++ b/fs.c
@@ -648,6 +648,30 @@
}
static int
+groupleader(int uid, int gid)
+{+ User *g;
+ int i, lead;
+
+ lead = 0;
+ rlock(&fs->userlk);
+ g = uid2user(gid);
+ if(g != nil){+ if(g->lead == 0){+ for(i = 0; i < g->nmemb; i++)
+ if(g->memb[i] == uid){+ lead = 1;
+ break;
+ }
+ }else if(uid == g->lead)
+ lead = 1;
+ }
+ runlock(&fs->userlk);
+ return lead;
+
+}
+
+static int
mode2bits(int req)
{int m;
@@ -930,17 +954,16 @@
fswstat(Fmsg *m)
{char *p, *e, strs[65535], rnbuf[Kvmax], opbuf[Kvmax];
- int op, nm, sync, rename;
+ int op, nm, rename;
Fcall r;
Dent *de;
- Msg mb[3];
- Xdir o;
+ Msg mb[2];
+ Xdir n;
Dir d;
Fid *f;
Key k;
+ User *u;
- nm = 0;
- sync = 1;
rename = 0;
if((f = getfid(m->fid)) == nil){rerror(m, Efid);
@@ -947,9 +970,8 @@
return;
}
de = f->dent;
- k = f->dent->Key;
wlock(de);
- if(f->dent->qid.type & QTAUTH){+ if(de->qid.type & QTAUTH){rerror(m, Emode);
goto Out;
}
@@ -957,12 +979,13 @@
rerror(m, Edir);
goto Out;
}
- if(fsaccess(f, de->mode, de->uid, de->gid, DMWRITE) == -1){- rerror(m, Eperm);
- goto Out;
- }
- /* A nop qid change is allowed. */
+ n = de->Xdir;
+ n.qid.vers++;
+ p = opbuf+1;
+ op = 0;
+
+ /* check validity of updated fields and construct Owstat message */
if(d.qid.path != ~0 || d.qid.vers != ~0){ if(d.qid.path != de->qid.path){rerror(m, Ewstatp);
@@ -972,86 +995,158 @@
rerror(m, Ewstatv);
goto Out;
}
- sync = 0;
}
+ if(*d.name != '\0'){+ if(strcmp(d.name, de->name) != 0){+ rename = 1;
+ if(okname(d.name) == -1){+ rerror(m, Ename);
+ goto Out;
+ }
+ n.name = d.name;
+ }
+ }
+ if(d.length != ~0){+ if(d.length < 0){+ rerror(m, Ewstatl);
+ goto Out;
+ }
+ if(d.length != de->length){+ n.length = d.length;
+ op |= Owsize;
+ PBIT64(p, n.length);
+ p += 8;
+ }
+ }
+ if(d.mode != ~0){+ if((d.mode^de->mode) & DMDIR){+ rerror(m, Ewstatd);
+ goto Out;
+ }
+ if(d.mode & ~(DMDIR|DMAPPEND|DMEXCL|DMTMP|0777)){+ rerror(m, Ewstatb);
+ goto Out;
+ }
+ if(d.mode != de->mode){+ n.mode = d.mode;
+ n.qid.type = d.mode>>24;
+ op |= Owmode;
+ PBIT32(p, n.mode);
+ p += 4;
+ }
+ }
+ if(d.mtime != ~0){+ n.mtime = d.mtime*Nsec;
+ if(n.mtime != de->mtime){+ op |= Owmtime;
+ PBIT64(p, n.mtime);
+ p += 8;
+ }
+ }
+ if(*d.uid != '\0'){+ rlock(&fs->userlk);
+ u = name2user(d.uid);
+ if(u == nil){+ runlock(&fs->userlk);
+ rerror(m, Enouser);
+ goto Out;
+ }
+ n.uid = u->id;
+ runlock(&fs->userlk);
+ if(n.uid != de->uid){+ op |= Owuid;
+ PBIT32(p, n.uid);
+ p += 4;
+ }
+ }
+ if(*d.gid != '\0'){+ rlock(&fs->userlk);
+ u = name2user(d.gid);
+ if(u == nil){+ runlock(&fs->userlk);
+ rerror(m, Enouser);
+ goto Out;
+ }
+ n.gid = u->id;
+ runlock(&fs->userlk);
+ if(n.gid != de->gid){+ op |= Owgid;
+ PBIT32(p, n.gid);
+ p += 4;
+ }
+ }
+ op |= Owmuid;
+ n.muid = f->uid;
+ PBIT32(p, n.muid);
+ p += 4;
- /*
- * rename: verify name is valid, same name renames are nops.
- * this is inserted into the tree as a pair of delete/create
- * messages.
- */
- if(d.name != nil && *d.name != '\0'){- if(okname(d.name) == -1){- rerror(m, Ename);
+ /* check permissions */
+ if(rename){+ if(fsaccess(f, f->dmode, f->duid, f->dgid, DMWRITE) == -1){+ rerror(m, Eperm);
goto Out;
}
- /* renaming to the same name is a nop. */
+ }
+ if(op & Owsize){+ if(fsaccess(f, de->mode, de->uid, de->gid, DMWRITE) == -1){+ rerror(m, Eperm);
+ goto Out;
+ }
+ }
+ if(op & (Owmode|Owmtime)){+ if(f->uid != de->uid && !groupleader(f->uid, de->gid)){+ rerror(m, Ewstato);
+ goto Out;
+ }
+ }
+ if(op & Owuid){+ /* FIXME: should allow during bootstrapping */
+ rerror(m, Ewstatu);
+ goto Out;
+ }
+ if(op & Owgid){+ if(!(f->uid == de->uid && ingroup(f->uid, n.gid))
+ && !(groupleader(f->uid, de->gid) && groupleader(f->uid, n.gid))){+ rerror(m, Ewstatg);
+ goto Out;
+ }
+ }
+
+ /* update directory entry */
+ nm = 0;
+ if(rename){mb[nm].op = Odelete;
- mb[nm].Key = f->dent->Key;
+ mb[nm].Key = de->Key;
mb[nm].v = nil;
mb[nm].nv = 0;
nm++;
- o = de->Xdir;
- o.name = d.name;
+
mb[nm].op = Oinsert;
- if(dir2kv(f->pqpath, &o, &mb[nm], rnbuf, sizeof(rnbuf)) == -1){+ if(dir2kv(f->pqpath, &n, &mb[nm], rnbuf, sizeof(rnbuf)) == -1){rerror(m, Efs);
goto Out;
}
k = mb[nm].Key;
- rename = 1;
- sync = 0;
nm++;
+ }else{+ opbuf[0] = op;
+ mb[nm].op = Owstat;
+ mb[nm].Key = de->Key;
+ mb[nm].v = opbuf;
+ mb[nm].nv = p - opbuf;
+ nm++;
}
-
- p = opbuf+1;
- op = 0;
- mb[nm].Key = k;
- mb[nm].op = Owstat;
- de->qid.vers++;
- if(d.length != ~0){- op |= Owsize;
- de->length = d.length;
- PBIT64(p, d.length);
- p += 8;
- sync = 0;
+ if((e = btupsert(f->mnt->root, mb, nm)) != nil){+ rerror(m, e);
+ goto Out;
}
- if(d.mode != ~0){- op |= Owmode;
- de->mode = d.mode;
- PBIT32(p, d.mode);
- p += 4;
- sync = 0;
- }
- if(d.mtime != ~0){- op |= Owmtime;
- de->mtime = d.mtime;
- PBIT64(p, (vlong)d.mtime*Nsec);
- p += 8;
- sync = 0;
- }
- op |= Owmuid;
- de->muid = f->uid;
- PBIT32(p, f->uid);
- p += 4;
- opbuf[0] = op;
- mb[nm].v = opbuf;
- mb[nm].nv = p - opbuf;
- nm++;
-
- if(sync){- rerror(m, Eimpl);
- }else{- if((e = btupsert(f->mnt->root, mb, nm)) != nil){- rerror(m, e);
- goto Out;
- }
- r.type = Rwstat;
- respond(m, &r);
- }
+ de->Xdir = n;
if(rename)
- cpkey(f->dent, &k, f->dent->buf, sizeof(f->dent->buf));
+ cpkey(de, &k, de->buf, sizeof(de->buf));
+
+ r.type = Rwstat;
+ respond(m, &r);
Out:
wunlock(de);
--- a/tree.c
+++ b/tree.c
@@ -361,6 +361,7 @@
}
if(op & Owmode){d.mode = GBIT32(p);
+ d.qid.type = d.mode>>24;
p += 4;
}
if(op & Owmtime){