/*
* Occasionally, pathnames are created that look like .../x/../y
* Any of the 'x/..' sequences within the name can be eliminated.
* (but only if 'x' is not a symbolic link!!)
*/
void remove_dotdot(char *path)
{
char *end, *from, *to, **cp;
char *components[ MAXFILES ],
newpath[ BUFSIZ ];
boolean component_copied;
/*
* slice path up into components.
*/
to = newpath;
if (*path == '/')
*to++ = '/';
*to = '\0';
cp = components;
for (from=end=path; *end; end++)
if (*end == '/') {
while (*end == '/')
*end++ = '\0';
if (*from)
*cp++ = from;
from = end;
}
*cp++ = from;
*cp = NULL;
/*
* Recursively remove all 'x/..' component pairs.
*/
cp = components;
while(*cp) {
if (!isdot(*cp) && !isdotdot(*cp) && isdotdot(*(cp+1))
&& !issymbolic(newpath, *cp))
{
char **fp = cp + 2;
char **tp = cp;
do {
*tp++ = *fp; /* move all the pointers down */
} while (*fp++);
if (cp != components)
cp--; /* go back and check for nested ".." */
} else {
cp++;
}
}
/*
* Concatenate the remaining path elements.
*/
cp = components;
component_copied = FALSE;
while(*cp) {
if (component_copied)
*to++ = '/';
component_copied = TRUE;
for (from = *cp; *from; )
*to++ = *from++;
*to = '\0';
cp++;
}
*to++ = '\0';
/*
* copy the reconstituted path back to our pointer.
*/
strcpy(path, newpath);
}
static int
vnop_lookup_9p(struct vnop_lookup_args *ap)
{
struct componentname *cnp;
node_9p *dnp;
vnode_t *vpp, dvp;
fid_9p fid;
qid_9p qid;
int e;
TRACE();
dvp = ap->a_dvp;
vpp = ap->a_vpp;
cnp = ap->a_cnp;
dnp = NTO9P(dvp);
if(!vnode_isdir(dvp))
return ENOTDIR;
if (isdotdot(cnp) && vnode_isvroot(dvp))
return EIO;
if (islastcn(cnp) && !isop(cnp, LOOKUP) && vnode_vfsisrdonly(dvp))
return EROFS;
if (isdot(cnp)) {
if (islastcn(cnp) && isop(cnp, RENAME))
return EISDIR;
if ((e=vnode_get(dvp)))
return e;
*vpp = dvp;
return 0;
}
if (isdotdot(cnp)) {
*vpp = vnode_getparent(dvp);
if (*vpp == NULL)
return ENOENT;
return 0;
}
e = cache_lookup(dvp, vpp, cnp);
if (e == -1) /* found */
return 0;
if (e != 0) /* errno */
return e;
/* not in cache */
nlock_9p(dnp, NODE_LCK_EXCLUSIVE);
e = walk_9p(dnp->nmp, dnp->fid, cnp->cn_nameptr, cnp->cn_namelen, &fid, &qid);
if (e) {
if (islastcn(cnp)) {
if (isop(cnp, CREATE) || isop(cnp, RENAME))
e = EJUSTRETURN;
else if (ismkentry(cnp) && dnp->dir.qid.vers!=0)
cache_enter(dvp, NULL, cnp);
}
goto error;
}
e = nget_9p(dnp->nmp, fid, qid, dvp, vpp, cnp, ap->a_context);
if (e || *vpp==NULL || NTO9P(*vpp)->fid!=fid)
clunk_9p(dnp->nmp, fid);
if (*vpp)
nunlock_9p(NTO9P(*vpp));
error:
nunlock_9p(dnp);
return e;
}
Walkqid*
fswalk(Chan *c, Chan *nc, char **name, int nname)
{
int j, alloc;
Walkqid *wq;
Dir *dir;
char *n;
Cname *current, *next;
Qid rootqid;
if(nname > 0)
isdir(c); /* do we need this? */
alloc = 0;
current = nil;
wq = smalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid));
if(waserror()){
if(alloc && wq->clone!=nil)
cclose(wq->clone);
cnameclose(current);
free(wq);
return nil;
}
if(nc == nil){
nc = devclone(c);
nc->type = 0;
alloc = 1;
}
wq->clone = nc;
rootqid = FS(c)->rootqid;
current = FS(c)->name;
if(current != nil)
incref(¤t->r);
for(j=0; j<nname; j++){
if(!(nc->qid.type&QTDIR)){
if(j==0)
error(Enotdir);
break;
}
n = name[j];
if(strcmp(n, ".") != 0 && !(isdotdot(n) && nc->qid.path == rootqid.path)){ /* TO DO: underlying qids aliased */
//print("** ufs walk '%s' -> %s\n", current->s, n);
next = current;
incref(&next->r);
next = addelem(current, n);
dir = dirstat(next->s);
if(dir == nil){
cnameclose(next);
if(j == 0)
error(Enonexist);
strcpy(up->env->errstr, Enonexist);
break;
}
nc->qid = dir->qid;
free(dir);
cnameclose(current);
current = next;
}
wq->qid[wq->nqid++] = nc->qid;
}
// print("** ufs walk '%s'\n", current->s);
poperror();
if(wq->nqid < nname){
cnameclose(current);
if(alloc)
cclose(wq->clone);
wq->clone = nil;
}else if(wq->clone){
/* now attach to our device */
nc->aux = smalloc(sizeof(Fsinfo));
nc->type = c->type;
FS(nc)->rootqid = FS(c)->rootqid;
FS(nc)->name = current;
FS(nc)->fd = -1;
FS(nc)->root = FS(c)->root;
}else
panic("fswalk: can't happen");
return wq;
}
