Snapshot of namei() cleanup:
1) Eliminate all of the null component name special cases; handle runs of slashes and leading and trailing slashes completely differently. 2) Return ENOENT when doing a lookup through an empty symlink. 3) Enforce that we're doing a lookup through a directory in in chdir() and lookup() rather than in foo_lookup(). Not yet finished.
This commit is contained in:
mycroft
parent
5482ee2d93
commit
07ba5e5ac3
|
|
@ -1,4 +1,4 @@
|
|||
/* $NetBSD: vfs_lookup.c,v 1.22 1997/04/08 16:11:48 kleink Exp $ */
|
||||
/* $NetBSD: vfs_lookup.c,v 1.23 1997/05/08 14:55:22 mycroft Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1982, 1986, 1989, 1993
|
||||
|
|
@ -85,7 +85,7 @@ namei(ndp)
|
|||
register struct vnode *dp; /* the directory we are searching */
|
||||
struct iovec aiov; /* uio for reading symbolic links */
|
||||
struct uio auio;
|
||||
int error, linklen, forcedir = 0;
|
||||
int error, linklen;
|
||||
struct componentname *cnp = &ndp->ni_cnd;
|
||||
|
||||
ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_proc->p_ucred;
|
||||
|
|
@ -125,20 +125,6 @@ namei(ndp)
|
|||
}
|
||||
ndp->ni_loopcnt = 0;
|
||||
|
||||
/*
|
||||
* If there are trailing '/'s, strip them off and require the last
|
||||
* path element to be a directory. This is heavily `2'-based:
|
||||
* ni_pathlen includes the trailing '\0', and at least the first
|
||||
* character of cn_pnbuf has to be preserved.
|
||||
*/
|
||||
if (ndp->ni_pathlen > 2 && cnp->cn_pnbuf[ndp->ni_pathlen - 2] == '/') {
|
||||
forcedir = 1;
|
||||
cnp->cn_flags |= FOLLOW;
|
||||
while (ndp->ni_pathlen > 2 &&
|
||||
cnp->cn_pnbuf[ndp->ni_pathlen - 2] == '/')
|
||||
cnp->cn_pnbuf[ndp->ni_pathlen-- - 2] = '\0';
|
||||
}
|
||||
|
||||
#ifdef KTRACE
|
||||
if (KTRPOINT(cnp->cn_proc, KTR_NAMEI))
|
||||
ktrnamei(cnp->cn_proc->p_tracep, cnp->cn_pnbuf);
|
||||
|
|
@ -149,23 +135,18 @@ namei(ndp)
|
|||
*/
|
||||
if ((ndp->ni_rootdir = fdp->fd_rdir) == NULL)
|
||||
ndp->ni_rootdir = rootvnode;
|
||||
dp = fdp->fd_cdir;
|
||||
VREF(dp);
|
||||
/*
|
||||
* Check if starting from root directory or current directory.
|
||||
*/
|
||||
if (cnp->cn_pnbuf[0] == '/') {
|
||||
dp = ndp->ni_rootdir;
|
||||
VREF(dp);
|
||||
} else {
|
||||
dp = fdp->fd_cdir;
|
||||
VREF(dp);
|
||||
}
|
||||
for (;;) {
|
||||
/*
|
||||
* Check if root directory should replace current directory.
|
||||
* Done at start of translation and after symbolic link.
|
||||
*/
|
||||
cnp->cn_nameptr = cnp->cn_pnbuf;
|
||||
if (*(cnp->cn_nameptr) == '/') {
|
||||
vrele(dp);
|
||||
while (*(cnp->cn_nameptr) == '/') {
|
||||
cnp->cn_nameptr++;
|
||||
ndp->ni_pathlen--;
|
||||
}
|
||||
dp = ndp->ni_rootdir;
|
||||
VREF(dp);
|
||||
}
|
||||
ndp->ni_startdir = dp;
|
||||
if ((error = lookup(ndp)) != 0) {
|
||||
FREE(cnp->cn_pnbuf, M_NAMEI);
|
||||
|
|
@ -175,22 +156,6 @@ namei(ndp)
|
|||
* Check for symbolic link
|
||||
*/
|
||||
if ((cnp->cn_flags & ISSYMLINK) == 0) {
|
||||
/*
|
||||
* If trailing '/'s implied a directory, verify this.
|
||||
* Always check ndp->ni_vp: CREATE and RENAME may
|
||||
* succeed without returning a vnode!
|
||||
*/
|
||||
if (forcedir &&
|
||||
ndp->ni_vp != NULL &&
|
||||
ndp->ni_vp->v_type != VDIR) {
|
||||
if ((cnp->cn_flags & LOCKPARENT) &&
|
||||
ndp->ni_pathlen == 1)
|
||||
VOP_UNLOCK(ndp->ni_dvp);
|
||||
vput(ndp->ni_vp);
|
||||
FREE(cnp->cn_pnbuf, M_NAMEI);
|
||||
return (ENOTDIR);
|
||||
}
|
||||
|
||||
if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0)
|
||||
FREE(cnp->cn_pnbuf, M_NAMEI);
|
||||
else
|
||||
|
|
@ -218,16 +183,19 @@ namei(ndp)
|
|||
auio.uio_resid = MAXPATHLEN;
|
||||
error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred);
|
||||
if (error) {
|
||||
badlink:
|
||||
if (ndp->ni_pathlen > 1)
|
||||
free(cp, M_NAMEI);
|
||||
FREE(cp, M_NAMEI);
|
||||
break;
|
||||
}
|
||||
linklen = MAXPATHLEN - auio.uio_resid;
|
||||
if (linklen == 0) {
|
||||
error = ENOENT;
|
||||
goto badlink;
|
||||
}
|
||||
if (linklen + ndp->ni_pathlen >= MAXPATHLEN) {
|
||||
if (ndp->ni_pathlen > 1)
|
||||
free(cp, M_NAMEI);
|
||||
error = ENAMETOOLONG;
|
||||
break;
|
||||
goto badlink;
|
||||
}
|
||||
if (ndp->ni_pathlen > 1) {
|
||||
bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
|
||||
|
|
@ -238,6 +206,14 @@ namei(ndp)
|
|||
ndp->ni_pathlen += linklen;
|
||||
vput(ndp->ni_vp);
|
||||
dp = ndp->ni_dvp;
|
||||
/*
|
||||
* Check if root directory should replace current directory.
|
||||
*/
|
||||
if (cnp->cn_pnbuf[0] == '/') {
|
||||
vrele(dp);
|
||||
dp = ndp->ni_rootdir;
|
||||
VREF(dp);
|
||||
}
|
||||
}
|
||||
FREE(cnp->cn_pnbuf, M_NAMEI);
|
||||
vrele(ndp->ni_dvp);
|
||||
|
|
@ -296,6 +272,7 @@ lookup(ndp)
|
|||
int wantparent; /* 1 => wantparent or lockparent flag */
|
||||
int rdonly; /* lookup read-only flag bit */
|
||||
int error = 0;
|
||||
int slashes;
|
||||
struct componentname *cnp = &ndp->ni_cnd;
|
||||
|
||||
/*
|
||||
|
|
@ -313,6 +290,40 @@ lookup(ndp)
|
|||
ndp->ni_startdir = NULLVP;
|
||||
VOP_LOCK(dp);
|
||||
|
||||
/*
|
||||
* If we have a leading string of slashes, remove them, and just make
|
||||
* sure the current node is a directory.
|
||||
*/
|
||||
cp = cnp->cn_nameptr;
|
||||
if (*cp == '/') {
|
||||
do {
|
||||
cp++;
|
||||
} while (*cp == '/');
|
||||
ndp->ni_pathlen -= cp - cnp->cn_nameptr;
|
||||
cnp->cn_nameptr = cp;
|
||||
|
||||
if (dp->v_type != VDIR) {
|
||||
error = ENOTDIR;
|
||||
goto bad;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we've exhausted the path name, then just return the
|
||||
* current node. If the caller requested the parent node (i.e.
|
||||
* it's a CREATE, DELETE, or RENAME), and we don't have one
|
||||
* (because this is the root directory), then we must fail.
|
||||
*/
|
||||
if (cnp->cn_nameptr[0] == '\0') {
|
||||
if (ndp->ni_dvp == NULL && wantparent) {
|
||||
error = EISDIR;
|
||||
goto bad;
|
||||
}
|
||||
ndp->ni_vp = dp;
|
||||
cnp->cn_flags |= ISLASTCN;
|
||||
goto terminal;
|
||||
}
|
||||
}
|
||||
|
||||
dirloop:
|
||||
/*
|
||||
* Search a new directory.
|
||||
|
|
@ -325,7 +336,7 @@ dirloop:
|
|||
*/
|
||||
cnp->cn_consume = 0;
|
||||
cnp->cn_hash = 0;
|
||||
for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++)
|
||||
for (cp = cnp->cn_nameptr; *cp != '\0' && *cp != '/'; cp++)
|
||||
cnp->cn_hash += (unsigned char)*cp;
|
||||
cnp->cn_namelen = cp - cnp->cn_nameptr;
|
||||
if (cnp->cn_namelen > NAME_MAX) {
|
||||
|
|
@ -340,45 +351,42 @@ dirloop:
|
|||
#endif
|
||||
ndp->ni_pathlen -= cnp->cn_namelen;
|
||||
ndp->ni_next = cp;
|
||||
cnp->cn_flags |= MAKEENTRY;
|
||||
if (*cp == '\0' && docache == 0)
|
||||
cnp->cn_flags &= ~MAKEENTRY;
|
||||
/*
|
||||
* If this component is followed by a slash, then move the pointer to
|
||||
* the next component forward, and remember that this component must be
|
||||
* a directory.
|
||||
*/
|
||||
if (*cp == '/') {
|
||||
do {
|
||||
cp++;
|
||||
} while (*cp == '/');
|
||||
slashes = cp - ndp->ni_next;
|
||||
ndp->ni_pathlen -= slashes;
|
||||
ndp->ni_next = cp;
|
||||
cnp->cn_flags |= REQUIREDIR;
|
||||
} else {
|
||||
slashes = 0;
|
||||
cnp->cn_flags &= ~REQUIREDIR;
|
||||
}
|
||||
/*
|
||||
* We do special processing on the last component, whether or not it's
|
||||
* a directory. Cache all intervening lookups, but not the final one.
|
||||
*/
|
||||
if (*cp == '\0') {
|
||||
if (docache)
|
||||
cnp->cn_flags |= MAKEENTRY;
|
||||
else
|
||||
cnp->cn_flags &= ~MAKEENTRY;
|
||||
cnp->cn_flags |= ISLASTCN;
|
||||
} else {
|
||||
cnp->cn_flags |= MAKEENTRY;
|
||||
cnp->cn_flags &= ~ISLASTCN;
|
||||
}
|
||||
if (cnp->cn_namelen == 2 &&
|
||||
cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.')
|
||||
cnp->cn_flags |= ISDOTDOT;
|
||||
else
|
||||
cnp->cn_flags &= ~ISDOTDOT;
|
||||
if (*ndp->ni_next == 0)
|
||||
cnp->cn_flags |= ISLASTCN;
|
||||
else
|
||||
cnp->cn_flags &= ~ISLASTCN;
|
||||
|
||||
|
||||
/*
|
||||
* Check for degenerate name (e.g. / or "")
|
||||
* which is a way of talking about a directory,
|
||||
* e.g. like "/." or ".".
|
||||
*/
|
||||
if (cnp->cn_nameptr[0] == '\0') {
|
||||
if (dp->v_type != VDIR) {
|
||||
error = ENOTDIR;
|
||||
goto bad;
|
||||
}
|
||||
if (cnp->cn_nameiop != LOOKUP) {
|
||||
error = EISDIR;
|
||||
goto bad;
|
||||
}
|
||||
if (wantparent) {
|
||||
ndp->ni_dvp = dp;
|
||||
VREF(dp);
|
||||
}
|
||||
ndp->ni_vp = dp;
|
||||
if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF)))
|
||||
VOP_UNLOCK(dp);
|
||||
if (cnp->cn_flags & SAVESTART)
|
||||
panic("lookup: SAVESTART");
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Handle "..": two special cases.
|
||||
|
|
@ -435,6 +443,14 @@ unionlookup:
|
|||
|
||||
if (error != EJUSTRETURN)
|
||||
goto bad;
|
||||
/*
|
||||
* If this was not the last component, or there were trailing
|
||||
* slashes, then the name must exist.
|
||||
*/
|
||||
if (cnp->cn_flags & REQUIREDIR) {
|
||||
error = ENOENT;
|
||||
goto bad;
|
||||
}
|
||||
/*
|
||||
* If creating and at end of pathname, then can consider
|
||||
* allowing file to be created.
|
||||
|
|
@ -459,14 +475,16 @@ unionlookup:
|
|||
#endif
|
||||
|
||||
/*
|
||||
* Take into account any additional components consumed by
|
||||
* the underlying filesystem.
|
||||
* Take into account any additional components consumed by the
|
||||
* underlying filesystem. This will include any trailing slashes after
|
||||
* the last component consumed.
|
||||
*/
|
||||
if (cnp->cn_consume > 0) {
|
||||
cnp->cn_nameptr += cnp->cn_consume;
|
||||
ndp->ni_next += cnp->cn_consume;
|
||||
ndp->ni_pathlen -= cnp->cn_consume;
|
||||
ndp->ni_pathlen -= cnp->cn_consume - slashes;
|
||||
ndp->ni_next += cnp->cn_consume - slashes;
|
||||
cnp->cn_consume = 0;
|
||||
if (ndp->ni_next[0] == '\0')
|
||||
cnp->cn_flags |= ISLASTCN;
|
||||
}
|
||||
|
||||
dp = ndp->ni_vp;
|
||||
|
|
@ -488,28 +506,37 @@ unionlookup:
|
|||
}
|
||||
|
||||
/*
|
||||
* Check for symbolic link
|
||||
* Check for symbolic link. Back up over any slashes that we skipped,
|
||||
* as we will need them again.
|
||||
*/
|
||||
if ((dp->v_type == VLNK) &&
|
||||
((cnp->cn_flags & FOLLOW) || *ndp->ni_next == '/')) {
|
||||
if ((dp->v_type == VLNK) && (cnp->cn_flags & (FOLLOW|REQUIREDIR))) {
|
||||
ndp->ni_pathlen += slashes;
|
||||
ndp->ni_next -= slashes;
|
||||
cnp->cn_flags |= ISSYMLINK;
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Check for directory, if the component was followed by a series of
|
||||
* slashes.
|
||||
*/
|
||||
if ((dp->v_type != VDIR) && (cnp->cn_flags & REQUIREDIR)) {
|
||||
error = ENOTDIR;
|
||||
goto bad2;
|
||||
}
|
||||
|
||||
nextname:
|
||||
/*
|
||||
* Not a symbolic link. If more pathname,
|
||||
* continue at next component, else return.
|
||||
* Not a symbolic link. If this was not the last component, then
|
||||
* continue at the next component, else return.
|
||||
*/
|
||||
if (*ndp->ni_next == '/') {
|
||||
if (!(cnp->cn_flags & ISLASTCN)) {
|
||||
cnp->cn_nameptr = ndp->ni_next;
|
||||
while (*cnp->cn_nameptr == '/') {
|
||||
cnp->cn_nameptr++;
|
||||
ndp->ni_pathlen--;
|
||||
}
|
||||
vrele(ndp->ni_dvp);
|
||||
goto dirloop;
|
||||
}
|
||||
|
||||
terminal:
|
||||
/*
|
||||
* Check for read-only file systems.
|
||||
*/
|
||||
|
|
@ -525,18 +552,20 @@ nextname:
|
|||
goto bad2;
|
||||
}
|
||||
}
|
||||
if (cnp->cn_flags & SAVESTART) {
|
||||
ndp->ni_startdir = ndp->ni_dvp;
|
||||
VREF(ndp->ni_startdir);
|
||||
if (ndp->ni_dvp != NULL) {
|
||||
if (cnp->cn_flags & SAVESTART) {
|
||||
ndp->ni_startdir = ndp->ni_dvp;
|
||||
VREF(ndp->ni_startdir);
|
||||
}
|
||||
if (!wantparent)
|
||||
vrele(ndp->ni_dvp);
|
||||
}
|
||||
if (!wantparent)
|
||||
vrele(ndp->ni_dvp);
|
||||
if ((cnp->cn_flags & LOCKLEAF) == 0)
|
||||
VOP_UNLOCK(dp);
|
||||
return (0);
|
||||
|
||||
bad2:
|
||||
if ((cnp->cn_flags & LOCKPARENT) && *ndp->ni_next == '\0')
|
||||
if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN))
|
||||
VOP_UNLOCK(ndp->ni_dvp);
|
||||
vrele(ndp->ni_dvp);
|
||||
bad:
|
||||
|
|
@ -603,22 +632,8 @@ relookup(dvp, vpp, cnp)
|
|||
* which is a way of talking about a directory,
|
||||
* e.g. like "/." or ".".
|
||||
*/
|
||||
if (cnp->cn_nameptr[0] == '\0') {
|
||||
if (dp->v_type != VDIR) {
|
||||
error = ENOTDIR;
|
||||
goto bad;
|
||||
}
|
||||
if (cnp->cn_nameiop != LOOKUP || wantparent) {
|
||||
error = EISDIR;
|
||||
goto bad;
|
||||
}
|
||||
if (!(cnp->cn_flags & LOCKLEAF))
|
||||
VOP_UNLOCK(dp);
|
||||
*vpp = dp;
|
||||
if (cnp->cn_flags & SAVESTART)
|
||||
panic("lookup: SAVESTART");
|
||||
return (0);
|
||||
}
|
||||
if (cnp->cn_nameptr[0] == '\0')
|
||||
panic("relookup: null name");
|
||||
|
||||
if (cnp->cn_flags & ISDOTDOT)
|
||||
panic ("relookup: lookup on dot-dot");
|
||||
|
|
@ -679,7 +694,6 @@ relookup(dvp, vpp, cnp)
|
|||
/* ASSERT(dvp == ndp->ni_startdir) */
|
||||
if (cnp->cn_flags & SAVESTART)
|
||||
VREF(dvp);
|
||||
|
||||
if (!wantparent)
|
||||
vrele(dvp);
|
||||
if ((cnp->cn_flags & LOCKLEAF) == 0)
|
||||
|
|
|
|||
|
|
@ -1,4 +1,4 @@
|
|||
/* $NetBSD: namei.h,v 1.12 1996/10/25 23:14:15 cgd Exp $ */
|
||||
/* $NetBSD: namei.h,v 1.13 1997/05/08 14:55:25 mycroft Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1985, 1989, 1991, 1993
|
||||
|
|
@ -137,6 +137,7 @@ struct nameidata {
|
|||
#define ISSYMLINK 0x10000 /* symlink needs interpretation */
|
||||
#define ISWHITEOUT 0x20000 /* found whiteout */
|
||||
#define DOWHITEOUT 0x40000 /* do whiteouts */
|
||||
#define REQUIREDIR 0x80000 /* must be a directory */
|
||||
#define PARAMASK 0xfff00 /* mask of parameter descriptors */
|
||||
/*
|
||||
* Initialization of an nameidata structure.
|
||||
|
|
|
|||
Loading…
Reference in New Issue