/*
- * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/unistd.h> /* For _PC_NAME_MAX */
#include <sys/uio_internal.h>
#include <sys/kauth.h>
-
-#include <bsm/audit_kernel.h>
-
+#include <kern/kalloc.h>
+#include <security/audit/audit.h>
+#include <sys/dtrace.h> /* to get the prototype for strstr() in sys/dtrace_glue.h */
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif
#define VOLFS_MIN_PATH_LEN 9
-static void kdebug_lookup(struct vnode *dp, struct componentname *cnp);
-
#if CONFIG_VOLFS
static int vfs_getrealpath(const char * path, char * realpath, size_t bufsize, vfs_context_t ctx);
+#define MAX_VOLFS_RESTARTS 5
+#endif
+
+static int lookup_traverse_mountpoints(struct nameidata *ndp, struct componentname *cnp, vnode_t dp, int vbusyflags, vfs_context_t ctx);
+static int lookup_handle_symlink(struct nameidata *ndp, vnode_t *new_dp, vfs_context_t ctx);
+static int lookup_authorize_search(vnode_t dp, struct componentname *cnp, int dp_authorized_in_cache, vfs_context_t ctx);
+static void lookup_consider_update_cache(vnode_t dvp, vnode_t vp, struct componentname *cnp, int nc_generation);
+static int lookup_handle_found_vnode(struct nameidata *ndp, struct componentname *cnp, int rdonly,
+ int vbusyflags, int *keep_going, int nc_generation,
+ int wantparent, int atroot, vfs_context_t ctx);
+static int lookup_handle_emptyname(struct nameidata *ndp, struct componentname *cnp, int wantparent);
+
+#if NAMEDRSRCFORK
+static int lookup_handle_rsrc_fork(vnode_t dp, struct nameidata *ndp, struct componentname *cnp, int wantparent, vfs_context_t ctx);
#endif
+
+
/*
* Convert a pathname into a pointer to a locked inode.
*
namei(struct nameidata *ndp)
{
struct filedesc *fdp; /* pointer to file descriptor state */
- char *cp; /* pointer into pathname argument */
struct vnode *dp; /* the directory we are searching */
struct vnode *usedvp = ndp->ni_dvp; /* store pointer to vp in case we must loop due to
heavy vnode pressure */
u_long cnpflags = ndp->ni_cnd.cn_flags; /* store in case we have to restore after loop */
- uio_t auio;
int error;
struct componentname *cnp = &ndp->ni_cnd;
vfs_context_t ctx = cnp->cn_context;
proc_t p = vfs_context_proc(ctx);
+#if CONFIG_AUDIT
/* XXX ut should be from context */
uthread_t ut = (struct uthread *)get_bsdthread_info(current_thread());
- char *tmppn;
- char uio_buf[ UIO_SIZEOF(1) ];
+#endif
+
+#if CONFIG_VOLFS
+ int volfs_restarts = 0;
+#endif
+ size_t bytes_copied = 0;
+
+ fdp = p->p_fd;
#if DIAGNOSTIC
if (!vfs_context_ucred(ctx) || !p)
if (cnp->cn_flags & OPMASK)
panic ("namei: flags contaminated with nameiops");
#endif
- fdp = p->p_fd;
+
+ /*
+ * A compound VNOP found something that needs further processing:
+ * either a trigger vnode, a covered directory, or a symlink.
+ */
+ if (ndp->ni_flag & NAMEI_CONTLOOKUP) {
+ int rdonly, vbusyflags, keep_going, wantparent;
+
+ rdonly = cnp->cn_flags & RDONLY;
+ vbusyflags = ((cnp->cn_flags & CN_NBMOUNTLOOK) != 0) ? LK_NOWAIT : 0;
+ keep_going = 0;
+ wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
+
+ ndp->ni_flag &= ~(NAMEI_CONTLOOKUP);
+
+ error = lookup_handle_found_vnode(ndp, &ndp->ni_cnd, rdonly, vbusyflags,
+ &keep_going, ndp->ni_ncgeneration, wantparent, 0, ctx);
+ if (error)
+ goto out_drop;
+ if (keep_going) {
+ if ((cnp->cn_flags & ISSYMLINK) == 0) {
+ panic("We need to keep going on a continued lookup, but for vp type %d (tag %d)\n", ndp->ni_vp->v_type, ndp->ni_vp->v_tag);
+ }
+ goto continue_symlink;
+ }
+
+ return 0;
+
+ }
vnode_recycled:
cnp->cn_pnlen = PATHBUFLEN;
}
#if LP64_DEBUG
- if (IS_VALID_UIO_SEGFLG(ndp->ni_segflg) == 0) {
+ if ((UIO_SEG_IS_USER_SPACE(ndp->ni_segflg) == 0)
+ && (ndp->ni_segflg != UIO_SYSSPACE)
+ && (ndp->ni_segflg != UIO_SYSSPACE32)) {
panic("%s :%d - invalid ni_segflg\n", __FILE__, __LINE__);
}
#endif /* LP64_DEBUG */
retry_copy:
if (UIO_SEG_IS_USER_SPACE(ndp->ni_segflg)) {
error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf,
- cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen);
+ cnp->cn_pnlen, &bytes_copied);
} else {
error = copystr(CAST_DOWN(void *, ndp->ni_dirp), cnp->cn_pnbuf,
- cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen);
+ cnp->cn_pnlen, &bytes_copied);
}
if (error == ENAMETOOLONG && !(cnp->cn_flags & HASBUF)) {
MALLOC_ZONE(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
cnp->cn_flags |= HASBUF;
cnp->cn_pnlen = MAXPATHLEN;
+ bytes_copied = 0;
goto retry_copy;
}
if (error)
goto error_out;
+ ndp->ni_pathlen = bytes_copied;
+ bytes_copied = 0;
+
+ /*
+ * Since the name cache may contain positive entries of
+ * the incorrect case, force lookup() to bypass the cache
+ * and call directly into the filesystem for each path
+ * component. Note: the FS may still consult the cache,
+ * but can apply rules to validate the results.
+ */
+ if (proc_is_forcing_hfs_case_sensitivity(p))
+ cnp->cn_flags |= CN_SKIPNAMECACHE;
#if CONFIG_VOLFS
/*
/* Attempt to resolve a legacy volfs style pathname. */
MALLOC_ZONE(realpath, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
if (realpath) {
+ /*
+ * We only error out on the ENAMETOOLONG cases where we know that
+ * vfs_getrealpath translation succeeded but the path could not fit into
+ * MAXPATHLEN characters. In other failure cases, we may be dealing with a path
+ * that legitimately looks like /.vol/1234/567 and is not meant to be translated
+ */
if ((realpath_err= vfs_getrealpath(&cnp->cn_pnbuf[6], realpath, MAXPATHLEN, ctx))) {
FREE_ZONE(realpath, MAXPATHLEN, M_NAMEI);
- if (realpath_err == ENOSPC){
+ if (realpath_err == ENOSPC || realpath_err == ENAMETOOLONG){
error = ENAMETOOLONG;
goto error_out;
}
}
}
}
- #endif /* CONFIG_VOLFS */
+#endif /* CONFIG_VOLFS */
+#if CONFIG_AUDIT
/* If we are auditing the kernel pathname, save the user pathname */
if (cnp->cn_flags & AUDITVNPATH1)
AUDIT_ARG(upath, ut->uu_cdir, cnp->cn_pnbuf, ARG_UPATH1);
if (cnp->cn_flags & AUDITVNPATH2)
AUDIT_ARG(upath, ut->uu_cdir, cnp->cn_pnbuf, ARG_UPATH2);
+#endif /* CONFIG_AUDIT */
/*
* Do not allow empty pathnames
ndp->ni_vp = NULLVP;
for (;;) {
- int need_newpathbuf;
- int linklen;
+#if CONFIG_MACF
+ /*
+ * Give MACF policies a chance to reject the lookup
+ * before performing any filesystem operations.
+ * This hook is called before resolving the path and
+ * again each time a symlink is encountered.
+ * NB: policies receive path information as supplied
+ * by the caller and thus cannot be trusted.
+ */
+ error = mac_vnode_check_lookup_preflight(ctx, dp, cnp->cn_nameptr, cnp->cn_namelen);
+ if (error) {
+ goto error_out;
+ }
+#endif
ndp->ni_startdir = dp;
if ( (error = lookup(ndp)) ) {
goto error_out;
}
+
/*
* Check for symbolic link
*/
if ((cnp->cn_flags & ISSYMLINK) == 0) {
return (0);
}
- if ((cnp->cn_flags & FSNODELOCKHELD)) {
- cnp->cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(ndp->ni_dvp, NULL);
- }
- if (ndp->ni_loopcnt++ >= MAXSYMLINKS) {
- error = ELOOP;
+
+continue_symlink:
+ /* Gives us a new path to process, and a starting dir */
+ error = lookup_handle_symlink(ndp, &dp, ctx);
+ if (error != 0) {
break;
}
-#if CONFIG_MACF
- if ((error = mac_vnode_check_readlink(ctx, ndp->ni_vp)) != 0)
- break;
-#endif /* MAC */
- if (ndp->ni_pathlen > 1 || !(cnp->cn_flags & HASBUF))
- need_newpathbuf = 1;
- else
- need_newpathbuf = 0;
+ }
+ /*
+ * only come here if we fail to handle a SYMLINK...
+ * if either ni_dvp or ni_vp is non-NULL, then
+ * we need to drop the iocount that was picked
+ * up in the lookup routine
+ */
+out_drop:
+ if (ndp->ni_dvp)
+ vnode_put(ndp->ni_dvp);
+ if (ndp->ni_vp)
+ vnode_put(ndp->ni_vp);
+ error_out:
+ if ( (cnp->cn_flags & HASBUF) ) {
+ cnp->cn_flags &= ~HASBUF;
+ FREE_ZONE(cnp->cn_pnbuf, cnp->cn_pnlen, M_NAMEI);
+ }
+ cnp->cn_pnbuf = NULL;
+ ndp->ni_vp = NULLVP;
+ ndp->ni_dvp = NULLVP;
- if (need_newpathbuf) {
- MALLOC_ZONE(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
- if (cp == NULL) {
- error = ENOMEM;
- break;
- }
- } else {
- cp = cnp->cn_pnbuf;
+#if CONFIG_VOLFS
+ /*
+ * Deal with volfs fallout.
+ *
+ * At this point, if we were originally given a volfs path that
+ * looks like /.vol/123/456, then we would have had to convert it into
+ * a full path. Assuming that part worked properly, we will now attempt
+ * to conduct a lookup of the item in the namespace. Under normal
+ * circumstances, if a user looked up /tmp/foo and it was not there, it
+ * would be permissible to return ENOENT.
+ *
+ * However, we may not want to do that here. Specifically, the volfs path
+ * uniquely identifies a certain item in the namespace regardless of where it
+ * lives. If the item has moved in between the time we constructed the
+ * path and now, when we're trying to do a lookup/authorization on the full
+ * path, we may have gotten an ENOENT.
+ *
+ * At this point we can no longer tell if the path no longer exists
+ * or if the item in question no longer exists. It could have been renamed
+ * away, in which case the /.vol identifier is still valid.
+ *
+ * Do this dance a maximum of MAX_VOLFS_RESTARTS times.
+ */
+ if ((error == ENOENT) && (ndp->ni_cnd.cn_flags & CN_VOLFSPATH)) {
+ if (volfs_restarts < MAX_VOLFS_RESTARTS) {
+ volfs_restarts++;
+ goto vnode_recycled;
}
- auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ, &uio_buf[0], sizeof(uio_buf));
+ }
+#endif
- uio_addiov(auio, CAST_USER_ADDR_T(cp), MAXPATHLEN);
+ if (error == ERECYCLE){
+ /* vnode was recycled underneath us. re-drive lookup to start at
+ the beginning again, since recycling invalidated last lookup*/
+ ndp->ni_cnd.cn_flags = cnpflags;
+ ndp->ni_dvp = usedvp;
+ goto vnode_recycled;
+ }
- error = VNOP_READLINK(ndp->ni_vp, auio, ctx);
- if (error) {
- if (need_newpathbuf)
- FREE_ZONE(cp, MAXPATHLEN, M_NAMEI);
- break;
+
+ return (error);
+}
+
+int
+namei_compound_available(vnode_t dp, struct nameidata *ndp)
+{
+ if ((ndp->ni_flag & NAMEI_COMPOUNDOPEN) != 0) {
+ return vnode_compound_open_available(dp);
+ }
+
+ return 0;
+}
+
+static int
+lookup_authorize_search(vnode_t dp, struct componentname *cnp, int dp_authorized_in_cache, vfs_context_t ctx)
+{
+#if !CONFIG_MACF
+#pragma unused(cnp)
+#endif
+
+ int error;
+
+ if (!dp_authorized_in_cache) {
+ error = vnode_authorize(dp, NULL, KAUTH_VNODE_SEARCH, ctx);
+ if (error)
+ return error;
+ }
+#if CONFIG_MACF
+ error = mac_vnode_check_lookup(ctx, dp, cnp);
+ if (error)
+ return error;
+#endif /* CONFIG_MACF */
+
+ return 0;
+}
+
+static void
+lookup_consider_update_cache(vnode_t dvp, vnode_t vp, struct componentname *cnp, int nc_generation)
+{
+ int isdot_or_dotdot;
+ isdot_or_dotdot = (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') || (cnp->cn_flags & ISDOTDOT);
+
+ if (vp->v_name == NULL || vp->v_parent == NULLVP) {
+ int update_flags = 0;
+
+ if (isdot_or_dotdot == 0) {
+ if (vp->v_name == NULL)
+ update_flags |= VNODE_UPDATE_NAME;
+ if (dvp != NULLVP && vp->v_parent == NULLVP)
+ update_flags |= VNODE_UPDATE_PARENT;
+
+ if (update_flags)
+ vnode_update_identity(vp, dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, update_flags);
}
- // LP64todo - fix this
- linklen = MAXPATHLEN - uio_resid(auio);
- if (linklen + ndp->ni_pathlen > MAXPATHLEN) {
- if (need_newpathbuf)
- FREE_ZONE(cp, MAXPATHLEN, M_NAMEI);
+ }
+ if ( (cnp->cn_flags & MAKEENTRY) && (vp->v_flag & VNCACHEABLE) && LIST_FIRST(&vp->v_nclinks) == NULL) {
+ /*
+ * missing from name cache, but should
+ * be in it... this can happen if volfs
+ * causes the vnode to be created or the
+ * name cache entry got recycled but the
+ * vnode didn't...
+ * check to make sure that ni_dvp is valid
+ * cache_lookup_path may return a NULL
+ * do a quick check to see if the generation of the
+ * directory matches our snapshot... this will get
+ * rechecked behind the name cache lock, but if it
+ * already fails to match, no need to go any further
+ */
+ if (dvp != NULLVP && (nc_generation == dvp->v_nc_generation) && (!isdot_or_dotdot))
+ cache_enter_with_gen(dvp, vp, cnp, nc_generation);
+ }
- error = ENAMETOOLONG;
+}
+
+#if NAMEDRSRCFORK
+/*
+ * Can change ni_dvp and ni_vp. On success, returns with iocounts on stream vnode (always) and
+ * data fork if requested. On failure, returns with iocount data fork (always) and its parent directory
+ * (if one was provided).
+ */
+static int
+lookup_handle_rsrc_fork(vnode_t dp, struct nameidata *ndp, struct componentname *cnp, int wantparent, vfs_context_t ctx)
+{
+ vnode_t svp = NULLVP;
+ enum nsoperation nsop;
+ int nsflags;
+ int error;
+
+ if (dp->v_type != VREG) {
+ error = ENOENT;
+ goto out;
+ }
+ switch (cnp->cn_nameiop) {
+ case DELETE:
+ if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
+ nsop = NS_DELETE;
+ } else {
+ error = EPERM;
+ goto out;
+ }
+ break;
+ case CREATE:
+ if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
+ nsop = NS_CREATE;
+ } else {
+ error = EPERM;
+ goto out;
+ }
break;
+ case LOOKUP:
+ /* Make sure our lookup of "/..namedfork/rsrc" is allowed. */
+ if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
+ nsop = NS_OPEN;
+ } else {
+ error = EPERM;
+ goto out;
+ }
+ break;
+ default:
+ error = EPERM;
+ goto out;
+ }
+
+ nsflags = 0;
+ if (cnp->cn_flags & CN_RAW_ENCRYPTED)
+ nsflags |= NS_GETRAWENCRYPTED;
+
+ /* Ask the file system for the resource fork. */
+ error = vnode_getnamedstream(dp, &svp, XATTR_RESOURCEFORK_NAME, nsop, nsflags, ctx);
+
+ /* During a create, it OK for stream vnode to be missing. */
+ if (error == ENOATTR || error == ENOENT) {
+ error = (nsop == NS_CREATE) ? 0 : ENOENT;
+ }
+ if (error) {
+ goto out;
+ }
+ /* The "parent" of the stream is the file. */
+ if (wantparent) {
+ if (ndp->ni_dvp) {
+ vnode_put(ndp->ni_dvp);
}
- if (need_newpathbuf) {
- long len = cnp->cn_pnlen;
+ ndp->ni_dvp = dp;
+ } else {
+ vnode_put(dp);
+ }
+ ndp->ni_vp = svp; /* on create this may be null */
+
+ /* Restore the truncated pathname buffer (for audits). */
+ if (ndp->ni_pathlen == 1 && ndp->ni_next[0] == '\0') {
+ ndp->ni_next[0] = '/';
+ }
+ cnp->cn_flags &= ~MAKEENTRY;
+
+ return 0;
+out:
+ return error;
+}
+#endif /* NAMEDRSRCFORK */
+
+/*
+ * iocounts in:
+ * --One on ni_vp. One on ni_dvp if there is more path, or we didn't come through the
+ * cache, or we came through the cache and the caller doesn't want the parent.
+ *
+ * iocounts out:
+ * --Leaves us in the correct state for the next step, whatever that might be.
+ * --If we find a symlink, returns with iocounts on both ni_vp and ni_dvp.
+ * --If we are to look up another component, then we have an iocount on ni_vp and
+ * nothing else.
+ * --If we are done, returns an iocount on ni_vp, and possibly on ni_dvp depending on nameidata flags.
+ * --In the event of an error, may return with ni_dvp NULL'ed out (in which case, iocount
+ * was dropped).
+ */
+static int
+lookup_handle_found_vnode(struct nameidata *ndp, struct componentname *cnp, int rdonly,
+ int vbusyflags, int *keep_going, int nc_generation,
+ int wantparent, int atroot, vfs_context_t ctx)
+{
+ vnode_t dp;
+ int error;
+ char *cp;
- tmppn = cnp->cn_pnbuf;
- bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
- cnp->cn_pnbuf = cp;
- cnp->cn_pnlen = MAXPATHLEN;
+ dp = ndp->ni_vp;
+ *keep_going = 0;
- if ( (cnp->cn_flags & HASBUF) )
- FREE_ZONE(tmppn, len, M_NAMEI);
- else
- cnp->cn_flags |= HASBUF;
- } else
- cnp->cn_pnbuf[linklen] = '\0';
+ if (ndp->ni_vp == NULLVP) {
+ panic("NULL ni_vp in %s\n", __FUNCTION__);
+ }
- ndp->ni_pathlen += linklen;
- cnp->cn_nameptr = cnp->cn_pnbuf;
+ if (atroot) {
+ goto nextname;
+ }
- /*
- * starting point for 'relative'
- * symbolic link path
- */
- dp = ndp->ni_dvp;
- /*
- * get rid of references returned via 'lookup'
- */
- vnode_put(ndp->ni_vp);
- vnode_put(ndp->ni_dvp);
+ /*
+ * Take into account any additional components consumed by
+ * the underlying filesystem.
+ */
+ if (cnp->cn_consume > 0) {
+ cnp->cn_nameptr += cnp->cn_consume;
+ ndp->ni_next += cnp->cn_consume;
+ ndp->ni_pathlen -= cnp->cn_consume;
+ cnp->cn_consume = 0;
+ } else {
+ lookup_consider_update_cache(ndp->ni_dvp, dp, cnp, nc_generation);
+ }
+
+ /*
+ * Check to see if the vnode has been mounted on...
+ * if so find the root of the mounted file system.
+ * Updates ndp->ni_vp.
+ */
+ error = lookup_traverse_mountpoints(ndp, cnp, dp, vbusyflags, ctx);
+ dp = ndp->ni_vp;
+ if (error) {
+ goto out;
+ }
+
+#if CONFIG_MACF
+ if (vfs_flags(vnode_mount(dp)) & MNT_MULTILABEL) {
+ error = vnode_label(vnode_mount(dp), NULL, dp, NULL, 0, ctx);
+ if (error)
+ goto out;
+ }
+#endif
- ndp->ni_vp = NULLVP;
+ /*
+ * Check for symbolic link
+ */
+ if ((dp->v_type == VLNK) &&
+ ((cnp->cn_flags & FOLLOW) || (ndp->ni_flag & NAMEI_TRAILINGSLASH) || *ndp->ni_next == '/')) {
+ cnp->cn_flags |= ISSYMLINK;
+ *keep_going = 1;
+ return (0);
+ }
+
+ /*
+ * Check for bogus trailing slashes.
+ */
+ if ((ndp->ni_flag & NAMEI_TRAILINGSLASH)) {
+ if (dp->v_type != VDIR) {
+ error = ENOTDIR;
+ goto out;
+ }
+ ndp->ni_flag &= ~(NAMEI_TRAILINGSLASH);
+ }
+
+#if NAMEDSTREAMS
+ /*
+ * Deny namei/lookup requests to resolve paths that point to shadow files.
+ * Access to shadow files must be conducted by explicit calls to VNOP_LOOKUP
+ * directly, and not use lookup/namei
+ */
+ if (vnode_isshadow (dp)) {
+ error = ENOENT;
+ goto out;
+ }
+#endif
+
+nextname:
+ /*
+ * Not a symbolic link. If more pathname,
+ * continue at next component, else return.
+ *
+ * Definitely have a dvp if there's another slash
+ */
+ if (*ndp->ni_next == '/') {
+ cnp->cn_nameptr = ndp->ni_next + 1;
+ ndp->ni_pathlen--;
+ while (*cnp->cn_nameptr == '/') {
+ cnp->cn_nameptr++;
+ ndp->ni_pathlen--;
+ }
+
+ cp = cnp->cn_nameptr;
+ vnode_put(ndp->ni_dvp);
ndp->ni_dvp = NULLVP;
- /*
- * Check if symbolic link restarts us at the root
+ if (*cp == '\0') {
+ goto emptyname;
+ }
+
+ *keep_going = 1;
+ return 0;
+ }
+
+ /*
+ * Disallow directory write attempts on read-only file systems.
+ */
+ if (rdonly &&
+ (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
+ error = EROFS;
+ goto out;
+ }
+
+ /* If SAVESTART is set, we should have a dvp */
+ if (cnp->cn_flags & SAVESTART) {
+ /*
+ * note that we already hold a reference
+ * on both dp and ni_dvp, but for some reason
+ * can't get another one... in this case we
+ * need to do vnode_put on dp in 'bad2'
*/
- if (*(cnp->cn_nameptr) == '/') {
- while (*(cnp->cn_nameptr) == '/') {
- cnp->cn_nameptr++;
- ndp->ni_pathlen--;
- }
- if ((dp = ndp->ni_rootdir) == NULLVP) {
- error = ENOENT;
- goto error_out;
- }
+ if ( (vnode_get(ndp->ni_dvp)) ) {
+ error = ENOENT;
+ goto out;
}
+ ndp->ni_startdir = ndp->ni_dvp;
}
+ if (!wantparent && ndp->ni_dvp) {
+ vnode_put(ndp->ni_dvp);
+ ndp->ni_dvp = NULLVP;
+ }
+
+ if (cnp->cn_flags & AUDITVNPATH1)
+ AUDIT_ARG(vnpath, dp, ARG_VNODE1);
+ else if (cnp->cn_flags & AUDITVNPATH2)
+ AUDIT_ARG(vnpath, dp, ARG_VNODE2);
+
+#if NAMEDRSRCFORK
+ /*
+ * Caller wants the resource fork.
+ */
+ if ((cnp->cn_flags & CN_WANTSRSRCFORK) && (dp != NULLVP)) {
+ error = lookup_handle_rsrc_fork(dp, ndp, cnp, wantparent, ctx);
+ if (error != 0)
+ goto out;
+
+ dp = ndp->ni_vp;
+ }
+#endif
+ if (kdebug_enable)
+ kdebug_lookup(ndp->ni_vp, cnp);
+
+ return 0;
+
+emptyname:
+ error = lookup_handle_emptyname(ndp, cnp, wantparent);
+ if (error != 0)
+ goto out;
+
+ return 0;
+out:
+ return error;
+
+}
+
+/*
+ * Comes in iocount on ni_vp. May overwrite ni_dvp, but doesn't interpret incoming value.
+ */
+static int
+lookup_handle_emptyname(struct nameidata *ndp, struct componentname *cnp, int wantparent)
+{
+ vnode_t dp;
+ int error = 0;
+
+ dp = ndp->ni_vp;
+ cnp->cn_namelen = 0;
/*
- * only come here if we fail to handle a SYMLINK...
- * if either ni_dvp or ni_vp is non-NULL, then
- * we need to drop the iocount that was picked
- * up in the lookup routine
+ * A degenerate name (e.g. / or "") which is a way of
+ * talking about a directory, e.g. like "/." or ".".
*/
- if (ndp->ni_dvp)
- vnode_put(ndp->ni_dvp);
- if (ndp->ni_vp)
- vnode_put(ndp->ni_vp);
- error_out:
- if ( (cnp->cn_flags & HASBUF) ) {
- cnp->cn_flags &= ~HASBUF;
- FREE_ZONE(cnp->cn_pnbuf, cnp->cn_pnlen, M_NAMEI);
+ if (dp->v_type != VDIR) {
+ error = ENOTDIR;
+ goto out;
}
- cnp->cn_pnbuf = NULL;
- ndp->ni_vp = NULLVP;
- if (error == ERECYCLE){
- /* vnode was recycled underneath us. re-drive lookup to start at
- the beginning again, since recycling invalidated last lookup*/
- ndp->ni_cnd.cn_flags = cnpflags;
- ndp->ni_dvp = usedvp;
- goto vnode_recycled;
+ if (cnp->cn_nameiop != LOOKUP) {
+ error = EISDIR;
+ goto out;
+ }
+ if (wantparent) {
+ /*
+ * note that we already hold a reference
+ * on dp, but for some reason can't
+ * get another one... in this case we
+ * need to do vnode_put on dp in 'bad'
+ */
+ if ( (vnode_get(dp)) ) {
+ error = ENOENT;
+ goto out;
+ }
+ ndp->ni_dvp = dp;
}
+ cnp->cn_flags &= ~ISDOTDOT;
+ cnp->cn_flags |= ISLASTCN;
+ ndp->ni_next = cnp->cn_nameptr;
+ ndp->ni_vp = dp;
+ if (cnp->cn_flags & AUDITVNPATH1)
+ AUDIT_ARG(vnpath, dp, ARG_VNODE1);
+ else if (cnp->cn_flags & AUDITVNPATH2)
+ AUDIT_ARG(vnpath, dp, ARG_VNODE2);
+ if (cnp->cn_flags & SAVESTART)
+ panic("lookup: SAVESTART");
- return (error);
+ return 0;
+out:
+ return error;
}
-
-
/*
* Search a pathname.
* This is a very central and rather complicated routine.
char *cp; /* pointer into pathname argument */
vnode_t tdp; /* saved dp */
vnode_t dp; /* the directory we are searching */
- mount_t mp; /* mount table entry */
int docache = 1; /* == 0 do not cache last component */
int wantparent; /* 1 => wantparent or lockparent flag */
int rdonly; /* lookup read-only flag bit */
- int trailing_slash = 0;
int dp_authorized = 0;
int error = 0;
struct componentname *cnp = &ndp->ni_cnd;
vfs_context_t ctx = cnp->cn_context;
- int mounted_on_depth = 0;
- int dont_cache_mp = 0;
- vnode_t mounted_on_dp = NULLVP;
- int current_mount_generation = 0;
int vbusyflags = 0;
int nc_generation = 0;
vnode_t last_dp = NULLVP;
+ int keep_going;
+ int atroot;
/*
* Setup: break out flag bits into variables.
*/
- if (cnp->cn_flags & (NOCACHE | DOWHITEOUT)) {
- if ((cnp->cn_flags & NOCACHE) || (cnp->cn_nameiop == DELETE))
- docache = 0;
+ if (cnp->cn_flags & NOCACHE) {
+ docache = 0;
}
wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
rdonly = cnp->cn_flags & RDONLY;
error = ENOENT;
goto bad;
}
- goto emptyname;
+ ndp->ni_vp = dp;
+ error = lookup_handle_emptyname(ndp, cnp, wantparent);
+ if (error) {
+ goto bad;
+ }
+
+ return 0;
}
dirloop:
+ atroot = 0;
ndp->ni_vp = NULLVP;
- if ( (error = cache_lookup_path(ndp, cnp, dp, ctx, &trailing_slash, &dp_authorized, last_dp)) ) {
+ if ( (error = cache_lookup_path(ndp, cnp, dp, ctx, &dp_authorized, last_dp)) ) {
dp = NULLVP;
goto bad;
}
* .. in the other file system.
*/
if ( (cnp->cn_flags & ISDOTDOT) ) {
+ /*
+ * if this is a chroot'ed process, check if the current
+ * directory is still a subdirectory of the process's
+ * root directory.
+ */
+ if (ndp->ni_rootdir && (ndp->ni_rootdir != rootvnode) &&
+ dp != ndp->ni_rootdir) {
+ int sdir_error;
+ int is_subdir = FALSE;
+
+ sdir_error = vnode_issubdir(dp, ndp->ni_rootdir,
+ &is_subdir, vfs_context_kernel());
+
+ /*
+ * If we couldn't determine if dp is a subdirectory of
+ * ndp->ni_rootdir (sdir_error != 0), we let the request
+ * proceed.
+ */
+ if (!sdir_error && !is_subdir) {
+ vnode_put(dp);
+ dp = ndp->ni_rootdir;
+ /*
+ * There's a ref on the process's root directory
+ * but we can't use vnode_getwithref here as
+ * there is nothing preventing that ref being
+ * released by another thread.
+ */
+ if (vnode_get(dp)) {
+ error = ENOENT;
+ goto bad;
+ }
+ }
+ }
+
for (;;) {
if (dp == ndp->ni_rootdir || dp == rootvnode) {
ndp->ni_dvp = dp;
error = ENOENT;
goto bad;
}
- goto nextname;
+ atroot = 1;
+ goto returned_from_lookup_path;
}
if ((dp->v_flag & VROOT) == 0 ||
(cnp->cn_flags & NOCROSSMOUNT))
goto lookup_error;
}
if ( (cnp->cn_flags & DONOTAUTH) != DONOTAUTH ) {
- if (!dp_authorized) {
- error = vnode_authorize(dp, NULL, KAUTH_VNODE_SEARCH, ctx);
- if (error)
- goto lookup_error;
- }
-#if CONFIG_MACF
- error = mac_vnode_check_lookup(ctx, dp, cnp);
- if (error)
+ error = lookup_authorize_search(dp, cnp, dp_authorized, ctx);
+ if (error) {
goto lookup_error;
-#endif /* CONFIG_MACF */
+ }
+ }
+
+ /*
+ * Now that we've authorized a lookup, can bail out if the filesystem
+ * will be doing a batched operation. Return an iocount on dvp.
+ */
+#if NAMEDRSRCFORK
+ if ((cnp->cn_flags & ISLASTCN) && namei_compound_available(dp, ndp) && !(cnp->cn_flags & CN_WANTSRSRCFORK)) {
+#else
+ if ((cnp->cn_flags & ISLASTCN) && namei_compound_available(dp, ndp)) {
+#endif /* NAMEDRSRCFORK */
+ ndp->ni_flag |= NAMEI_UNFINISHED;
+ ndp->ni_ncgeneration = dp->v_nc_generation;
+ return 0;
}
nc_generation = dp->v_nc_generation;
- if ( (error = VNOP_LOOKUP(dp, &ndp->ni_vp, cnp, ctx)) ) {
+ /*
+ * Note:
+ * Filesystems that support hardlinks may want to call vnode_update_identity
+ * if the lookup operation below will modify the in-core vnode to belong to a new point
+ * in the namespace. VFS cannot infer whether or not the look up operation makes the vnode
+ * name change or change parents. Without this, the lookup may make update
+ * filesystem-specific in-core metadata but fail to update the v_parent or v_name
+ * fields in the vnode. If VFS were to do this, it would be necessary to call
+ * vnode_update_identity on every lookup operation -- expensive!
+ *
+ * However, even with this in place, multiple lookups may occur in between this lookup
+ * and the subsequent vnop, so, at best, we could only guarantee that you would get a
+ * valid path back, and not necessarily the one that you wanted.
+ *
+ * Example:
+ * /tmp/a == /foo/b
+ *
+ * If you are now looking up /foo/b and the vnode for this link represents /tmp/a,
+ * vnode_update_identity will fix the parentage so that you can get /foo/b back
+ * through the v_parent chain (preventing you from getting /tmp/b back). It would
+ * not fix whether or not you should or should not get /tmp/a vs. /foo/b.
+ */
+
+ error = VNOP_LOOKUP(dp, &ndp->ni_vp, cnp, ctx);
+
+ if ( error ) {
lookup_error:
if ((error == ENOENT) &&
- (dp->v_flag & VROOT) && (dp->v_mount != NULL) &&
+ (dp->v_mount != NULL) &&
(dp->v_mount->mnt_flag & MNT_UNION)) {
- if ((cnp->cn_flags & FSNODELOCKHELD)) {
- cnp->cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(dp, NULL);
- }
tdp = dp;
- dp = tdp->v_mount->mnt_vnodecovered;
-
+ error = lookup_traverse_union(tdp, &dp, ctx);
vnode_put(tdp);
-
- if ( (vnode_getwithref(dp)) ) {
+ if (error) {
dp = NULLVP;
- error = ENOENT;
goto bad;
}
+
ndp->ni_dvp = dp;
dp_authorized = 0;
goto unionlookup;
if (ndp->ni_vp != NULLVP)
panic("leaf should be empty");
- /*
- * If creating and at end of pathname, then can consider
- * allowing file to be created.
+#if NAMEDRSRCFORK
+ /*
+ * At this point, error should be EJUSTRETURN.
+ *
+ * If CN_WANTSRSRCFORK is set, that implies that the
+ * underlying filesystem could not find the "parent" of the
+ * resource fork (the data fork), and we are doing a lookup
+ * for a CREATE event.
+ *
+ * However, this should be converted to an error, as the
+ * failure to find this parent should disallow further
+ * progress to try and acquire a resource fork vnode.
*/
- if (rdonly) {
- error = EROFS;
- goto bad;
- }
- if ((cnp->cn_flags & ISLASTCN) && trailing_slash && !(cnp->cn_flags & WILLBEDIR)) {
+ if (cnp->cn_flags & CN_WANTSRSRCFORK) {
error = ENOENT;
goto bad;
}
+#endif
+
+ error = lookup_validate_creation_path(ndp);
+ if (error)
+ goto bad;
/*
* We return with ni_vp NULL to indicate that the entry
* doesn't currently exist, leaving a pointer to the
return (0);
}
returned_from_lookup_path:
- dp = ndp->ni_vp;
+ /* We'll always have an iocount on ni_vp when this finishes. */
+ error = lookup_handle_found_vnode(ndp, cnp, rdonly, vbusyflags, &keep_going, nc_generation, wantparent, atroot, ctx);
+ if (error != 0) {
+ goto bad2;
+ }
- /*
- * Take into account any additional components consumed by
- * the underlying filesystem.
- */
- if (cnp->cn_consume > 0) {
- cnp->cn_nameptr += cnp->cn_consume;
- ndp->ni_next += cnp->cn_consume;
- ndp->ni_pathlen -= cnp->cn_consume;
- cnp->cn_consume = 0;
- } else {
- if (dp->v_name == NULL || dp->v_parent == NULLVP) {
- int isdot_or_dotdot;
- int update_flags = 0;
-
- isdot_or_dotdot = (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') || (cnp->cn_flags & ISDOTDOT);
-
- if (isdot_or_dotdot == 0) {
- if (dp->v_name == NULL)
- update_flags |= VNODE_UPDATE_NAME;
- if (ndp->ni_dvp != NULLVP && dp->v_parent == NULLVP)
- update_flags |= VNODE_UPDATE_PARENT;
-
- if (update_flags)
- vnode_update_identity(dp, ndp->ni_dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, update_flags);
- }
- }
- if ( (cnp->cn_flags & MAKEENTRY) && (dp->v_flag & VNCACHEABLE) && LIST_FIRST(&dp->v_nclinks) == NULL) {
- /*
- * missing from name cache, but should
- * be in it... this can happen if volfs
- * causes the vnode to be created or the
- * name cache entry got recycled but the
- * vnode didn't...
- * check to make sure that ni_dvp is valid
- * cache_lookup_path may return a NULL
- * do a quick check to see if the generation of the
- * directory matches our snapshot... this will get
- * rechecked behind the name cache lock, but if it
- * already fails to match, no need to go any further
- */
- if (ndp->ni_dvp != NULLVP && (nc_generation == ndp->ni_dvp->v_nc_generation))
- cache_enter_with_gen(ndp->ni_dvp, dp, cnp, nc_generation);
+ if (keep_going) {
+ dp = ndp->ni_vp;
+
+ /* namei() will handle symlinks */
+ if ((dp->v_type == VLNK) &&
+ ((cnp->cn_flags & FOLLOW) || (ndp->ni_flag & NAMEI_TRAILINGSLASH) || *ndp->ni_next == '/')) {
+ return 0;
}
- }
- mounted_on_dp = dp;
- mounted_on_depth = 0;
- dont_cache_mp = 0;
- current_mount_generation = mount_generation;
- /*
- * Check to see if the vnode has been mounted on...
- * if so find the root of the mounted file system.
- */
-check_mounted_on:
- if ((dp->v_type == VDIR) && dp->v_mountedhere &&
- ((cnp->cn_flags & NOCROSSMOUNT) == 0)) {
-
- vnode_lock(dp);
+ /*
+ * Otherwise, there's more path to process.
+ * cache_lookup_path is now responsible for dropping io ref on dp
+ * when it is called again in the dirloop. This ensures we hold
+ * a ref on dp until we complete the next round of lookup.
+ */
+ last_dp = dp;
- if ((dp->v_type == VDIR) && (mp = dp->v_mountedhere)) {
- struct uthread *uth = (struct uthread *)get_bsdthread_info(current_thread());
+ goto dirloop;
+ }
- mp->mnt_crossref++;
- vnode_unlock(dp);
+ return (0);
+bad2:
+ if (ndp->ni_dvp)
+ vnode_put(ndp->ni_dvp);
-
- if (vfs_busy(mp, vbusyflags)) {
- mount_dropcrossref(mp, dp, 0);
- if (vbusyflags == LK_NOWAIT) {
- error = ENOENT;
- goto bad2;
- }
- goto check_mounted_on;
- }
+ vnode_put(ndp->ni_vp);
+ ndp->ni_vp = NULLVP;
- /*
- * XXX - if this is the last component of the
- * pathname, and it's either not a lookup operation
- * or the NOTRIGGER flag is set for the operation,
- * set a uthread flag to let VFS_ROOT() for autofs
- * know it shouldn't trigger a mount.
- */
- if ((cnp->cn_flags & ISLASTCN) &&
- (cnp->cn_nameiop != LOOKUP ||
- (cnp->cn_flags & NOTRIGGER))) {
- uth->uu_notrigger = 1;
- dont_cache_mp = 1;
- }
- error = VFS_ROOT(mp, &tdp, ctx);
- /* XXX - clear the uthread flag */
- uth->uu_notrigger = 0;
- /*
- * mount_dropcrossref does a vnode_put
- * on dp if the 3rd arg is non-zero
- */
- mount_dropcrossref(mp, dp, 1);
- dp = NULL;
- vfs_unbusy(mp);
+ if (kdebug_enable)
+ kdebug_lookup(dp, cnp);
+ return (error);
- if (error) {
- goto bad2;
- }
- ndp->ni_vp = dp = tdp;
- mounted_on_depth++;
-
- goto check_mounted_on;
- }
- vnode_unlock(dp);
- }
+bad:
+ if (dp)
+ vnode_put(dp);
+ ndp->ni_vp = NULLVP;
-#if CONFIG_MACF
- if (vfs_flags(vnode_mount(dp)) & MNT_MULTILABEL) {
- error = vnode_label(vnode_mount(dp), NULL, dp, NULL,
- VNODE_LABEL_NEEDREF, ctx);
- if (error)
- goto bad2;
- }
-#endif
+ if (kdebug_enable)
+ kdebug_lookup(dp, cnp);
+ return (error);
+}
- if (mounted_on_depth && !dont_cache_mp) {
- mp = mounted_on_dp->v_mountedhere;
+/*
+ * Given a vnode in a union mount, traverse to the equivalent
+ * vnode in the underlying mount.
+ */
+int
+lookup_traverse_union(vnode_t dvp, vnode_t *new_dvp, vfs_context_t ctx)
+{
+ char *path = NULL, *pp;
+ const char *name, *np;
+ int len;
+ int error = 0;
+ struct nameidata nd;
+ vnode_t vp = dvp;
- if (mp) {
- mount_lock(mp);
- mp->mnt_realrootvp_vid = dp->v_id;
- mp->mnt_realrootvp = dp;
- mp->mnt_generation = current_mount_generation;
- mount_unlock(mp);
- }
- }
+ *new_dvp = NULL;
- /*
- * Check for symbolic link
- */
- if ((dp->v_type == VLNK) &&
- ((cnp->cn_flags & FOLLOW) || trailing_slash || *ndp->ni_next == '/')) {
- cnp->cn_flags |= ISSYMLINK;
- return (0);
+ if (vp && vp->v_flag & VROOT) {
+ *new_dvp = vp->v_mount->mnt_vnodecovered;
+ if (vnode_getwithref(*new_dvp))
+ return ENOENT;
+ return 0;
}
- /*
- * Check for bogus trailing slashes.
- */
- if (trailing_slash) {
- if (dp->v_type != VDIR) {
- error = ENOTDIR;
- goto bad2;
- }
- trailing_slash = 0;
+ path = (char *) kalloc(MAXPATHLEN);
+ if (path == NULL) {
+ error = ENOMEM;
+ goto done;
}
-nextname:
/*
- * Not a symbolic link. If more pathname,
- * continue at next component, else return.
+ * Walk back up to the mountpoint following the
+ * v_parent chain and build a slash-separated path.
+ * Then lookup that path starting with the covered vnode.
*/
- if (*ndp->ni_next == '/') {
- cnp->cn_nameptr = ndp->ni_next + 1;
- ndp->ni_pathlen--;
- while (*cnp->cn_nameptr == '/') {
- cnp->cn_nameptr++;
- ndp->ni_pathlen--;
+ pp = path + (MAXPATHLEN - 1);
+ *pp = '\0';
+
+ while (1) {
+ name = vnode_getname(vp);
+ if (name == NULL) {
+ printf("lookup_traverse_union: null parent name: .%s\n", pp);
+ error = ENOENT;
+ goto done;
}
- vnode_put(ndp->ni_dvp);
+ len = strlen(name);
+ if ((len + 1) > (pp - path)) { // Enough space for this name ?
+ error = ENAMETOOLONG;
+ vnode_putname(name);
+ goto done;
+ }
+ for (np = name + len; len > 0; len--) // Copy name backwards
+ *--pp = *--np;
+ vnode_putname(name);
+ vp = vp->v_parent;
+ if (vp == NULLVP || vp->v_flag & VROOT)
+ break;
+ *--pp = '/';
+ }
- cp = cnp->cn_nameptr;
+ /* Evaluate the path in the underlying mount */
+ NDINIT(&nd, LOOKUP, OP_LOOKUP, USEDVP, UIO_SYSSPACE, CAST_USER_ADDR_T(pp), ctx);
+ nd.ni_dvp = dvp->v_mount->mnt_vnodecovered;
+ error = namei(&nd);
+ if (error == 0)
+ *new_dvp = nd.ni_vp;
+ nameidone(&nd);
+done:
+ if (path)
+ kfree(path, MAXPATHLEN);
+ return error;
+}
- if (*cp == '\0')
- goto emptyname;
+int
+lookup_validate_creation_path(struct nameidata *ndp)
+{
+ struct componentname *cnp = &ndp->ni_cnd;
- /*
- * cache_lookup_path is now responsible for dropping io ref on dp
- * when it is called again in the dirloop. This ensures we hold
- * a ref on dp until we complete the next round of lookup.
- */
- last_dp = dp;
- goto dirloop;
- }
-
/*
- * Disallow directory write attempts on read-only file systems.
+ * If creating and at end of pathname, then can consider
+ * allowing file to be created.
*/
- if (rdonly &&
- (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
- error = EROFS;
- goto bad2;
- }
- if (cnp->cn_flags & SAVESTART) {
- /*
- * note that we already hold a reference
- * on both dp and ni_dvp, but for some reason
- * can't get another one... in this case we
- * need to do vnode_put on dp in 'bad2'
- */
- if ( (vnode_get(ndp->ni_dvp)) ) {
- error = ENOENT;
- goto bad2;
- }
- ndp->ni_startdir = ndp->ni_dvp;
+ if (cnp->cn_flags & RDONLY) {
+ return EROFS;
}
- if (!wantparent && ndp->ni_dvp) {
- vnode_put(ndp->ni_dvp);
- ndp->ni_dvp = NULLVP;
+ if ((cnp->cn_flags & ISLASTCN) && (ndp->ni_flag & NAMEI_TRAILINGSLASH) && !(cnp->cn_flags & WILLBEDIR)) {
+ return ENOENT;
}
+
+ return 0;
+}
+
+/*
+ * Modifies only ni_vp. Always returns with ni_vp still valid (iocount held).
+ */
+static int
+lookup_traverse_mountpoints(struct nameidata *ndp, struct componentname *cnp, vnode_t dp,
+ int vbusyflags, vfs_context_t ctx)
+{
+ mount_t mp;
+ vnode_t tdp;
+ int error = 0;
+ uint32_t depth = 0;
+ vnode_t mounted_on_dp;
+ int current_mount_generation = 0;
+#if CONFIG_TRIGGERS
+ vnode_t triggered_dp = NULLVP;
+ int retry_cnt = 0;
+#define MAX_TRIGGER_RETRIES 1
+#endif
+
+ if (dp->v_type != VDIR || cnp->cn_flags & NOCROSSMOUNT)
+ return 0;
- if (cnp->cn_flags & AUDITVNPATH1)
- AUDIT_ARG(vnpath, dp, ARG_VNODE1);
- else if (cnp->cn_flags & AUDITVNPATH2)
- AUDIT_ARG(vnpath, dp, ARG_VNODE2);
+ mounted_on_dp = dp;
+#if CONFIG_TRIGGERS
+restart:
+#endif
+ current_mount_generation = mount_generation;
-#if NAMEDRSRCFORK
- /*
- * Caller wants the resource fork.
- */
- if ((cnp->cn_flags & CN_WANTSRSRCFORK) && (dp != NULLVP)) {
- vnode_t svp = NULLVP;
- enum nsoperation nsop;
+ while (dp->v_mountedhere) {
+ vnode_lock_spin(dp);
+ if ((mp = dp->v_mountedhere)) {
+ mp->mnt_crossref++;
+ vnode_unlock(dp);
+ } else {
+ vnode_unlock(dp);
+ break;
+ }
- if (dp->v_type != VREG) {
- error = ENOENT;
- goto bad2;
+ if (ISSET(mp->mnt_lflag, MNT_LFORCE)) {
+ mount_dropcrossref(mp, dp, 0);
+ break; // don't traverse into a forced unmount
}
- switch (cnp->cn_nameiop) {
- case DELETE:
- if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
- nsop = NS_DELETE;
- }
- else {
- error = EPERM;
- goto bad;
- }
- break;
- case CREATE:
- if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
- nsop = NS_CREATE;
- }
- else {
- error = EPERM;
- goto bad;
- }
- break;
- case LOOKUP:
- /* Make sure our lookup of "/..namedfork/rsrc" is allowed. */
- if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
- nsop = NS_OPEN;
- } else {
- error = EPERM;
- goto bad2;
+
+
+ if (vfs_busy(mp, vbusyflags)) {
+ mount_dropcrossref(mp, dp, 0);
+ if (vbusyflags == LK_NOWAIT) {
+ error = ENOENT;
+ goto out;
}
- break;
- default:
- error = EPERM;
- goto bad2;
+
+ continue;
}
- /* Ask the file system for the resource fork. */
- error = vnode_getnamedstream(dp, &svp, XATTR_RESOURCEFORK_NAME, nsop, 0, ctx);
- /* During a create, it OK for stream vnode to be missing. */
- if (error == ENOATTR || error == ENOENT) {
- error = (nsop == NS_CREATE) ? 0 : ENOENT;
- }
+ error = VFS_ROOT(mp, &tdp, ctx);
+
+ mount_dropcrossref(mp, dp, 0);
+ vfs_unbusy(mp);
+
if (error) {
- goto bad2;
- }
- /* The "parent" of the stream is the file. */
- if (wantparent) {
- if (ndp->ni_dvp) {
- if (ndp->ni_cnd.cn_flags & FSNODELOCKHELD) {
- ndp->ni_cnd.cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(ndp->ni_dvp, NULL);
- }
- vnode_put(ndp->ni_dvp);
- }
- ndp->ni_dvp = dp;
- } else {
- vnode_put(dp);
+ goto out;
}
- ndp->ni_vp = dp = svp; /* on create this may be null */
- /* Restore the truncated pathname buffer (for audits). */
- if (ndp->ni_pathlen == 1 && ndp->ni_next[0] == '\0') {
- ndp->ni_next[0] = '/';
+ vnode_put(dp);
+ ndp->ni_vp = dp = tdp;
+ if (dp->v_type != VDIR) {
+#if DEVELOPMENT || DEBUG
+ panic("%s : Root of filesystem not a directory\n",
+ __FUNCTION__);
+#else
+ break;
+#endif
}
- cnp->cn_flags &= ~MAKEENTRY;
+ depth++;
}
-#endif
- if (kdebug_enable)
- kdebug_lookup(dp, cnp);
- return (0);
-emptyname:
- cnp->cn_namelen = 0;
+#if CONFIG_TRIGGERS
/*
- * A degenerate name (e.g. / or "") which is a way of
- * talking about a directory, e.g. like "/." or ".".
+ * The triggered_dp check here is required but is susceptible to a
+ * (unlikely) race in which trigger mount is done from here and is
+ * unmounted before we get past vfs_busy above. We retry to deal with
+ * that case but it has the side effect of unwanted retries for
+ * "special" processes which don't want to trigger mounts.
*/
- if (dp->v_type != VDIR) {
- error = ENOTDIR;
- goto bad;
+ if (dp->v_resolve && retry_cnt < MAX_TRIGGER_RETRIES) {
+ error = vnode_trigger_resolve(dp, ndp, ctx);
+ if (error)
+ goto out;
+ if (dp == triggered_dp)
+ retry_cnt += 1;
+ else
+ retry_cnt = 0;
+ triggered_dp = dp;
+ goto restart;
}
- if (cnp->cn_nameiop != LOOKUP) {
- error = EISDIR;
- goto bad;
+#endif /* CONFIG_TRIGGERS */
+
+ if (depth) {
+ mp = mounted_on_dp->v_mountedhere;
+
+ if (mp) {
+ mount_lock_spin(mp);
+ mp->mnt_realrootvp_vid = dp->v_id;
+ mp->mnt_realrootvp = dp;
+ mp->mnt_generation = current_mount_generation;
+ mount_unlock(mp);
+ }
}
- if (wantparent) {
- /*
- * note that we already hold a reference
- * on dp, but for some reason can't
- * get another one... in this case we
- * need to do vnode_put on dp in 'bad'
- */
- if ( (vnode_get(dp)) ) {
- error = ENOENT;
- goto bad;
+
+ return 0;
+
+out:
+ return error;
+}
+
+/*
+ * Takes ni_vp and ni_dvp non-NULL. Returns with *new_dp set to the location
+ * at which to start a lookup with a resolved path, and all other iocounts dropped.
+ */
+static int
+lookup_handle_symlink(struct nameidata *ndp, vnode_t *new_dp, vfs_context_t ctx)
+{
+ int error;
+ char *cp; /* pointer into pathname argument */
+ uio_t auio;
+ union {
+ union {
+ struct user_iovec s_uiovec;
+ struct kern_iovec s_kiovec;
+ } u_iovec;
+ struct uio s_uio;
+ char uio_buf[ UIO_SIZEOF(1) ];
+ } u_uio_buf; /* union only for aligning uio_buf correctly */
+ int need_newpathbuf;
+ u_int linklen;
+ struct componentname *cnp = &ndp->ni_cnd;
+ vnode_t dp;
+ char *tmppn;
+
+ if (ndp->ni_loopcnt++ >= MAXSYMLINKS) {
+ return ELOOP;
+ }
+#if CONFIG_MACF
+ if ((error = mac_vnode_check_readlink(ctx, ndp->ni_vp)) != 0)
+ return error;
+#endif /* MAC */
+ if (ndp->ni_pathlen > 1 || !(cnp->cn_flags & HASBUF))
+ need_newpathbuf = 1;
+ else
+ need_newpathbuf = 0;
+
+ if (need_newpathbuf) {
+ MALLOC_ZONE(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
+ if (cp == NULL) {
+ return ENOMEM;
}
- ndp->ni_dvp = dp;
+ } else {
+ cp = cnp->cn_pnbuf;
}
- cnp->cn_flags &= ~ISDOTDOT;
- cnp->cn_flags |= ISLASTCN;
- ndp->ni_next = cp;
- ndp->ni_vp = dp;
+ auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ,
+ &u_uio_buf.uio_buf[0], sizeof(u_uio_buf.uio_buf));
- if (cnp->cn_flags & AUDITVNPATH1)
- AUDIT_ARG(vnpath, dp, ARG_VNODE1);
- else if (cnp->cn_flags & AUDITVNPATH2)
- AUDIT_ARG(vnpath, dp, ARG_VNODE2);
- if (cnp->cn_flags & SAVESTART)
- panic("lookup: SAVESTART");
- return (0);
+ uio_addiov(auio, CAST_USER_ADDR_T(cp), MAXPATHLEN);
-bad2:
- if ((cnp->cn_flags & FSNODELOCKHELD)) {
- cnp->cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(ndp->ni_dvp, NULL);
+ error = VNOP_READLINK(ndp->ni_vp, auio, ctx);
+ if (error) {
+ if (need_newpathbuf)
+ FREE_ZONE(cp, MAXPATHLEN, M_NAMEI);
+ return error;
}
- if (ndp->ni_dvp)
- vnode_put(ndp->ni_dvp);
- if (dp)
- vnode_put(dp);
- ndp->ni_vp = NULLVP;
- if (kdebug_enable)
- kdebug_lookup(dp, cnp);
- return (error);
+ /*
+ * Safe to set unsigned with a [larger] signed type here
+ * because 0 <= uio_resid <= MAXPATHLEN and MAXPATHLEN
+ * is only 1024.
+ */
+ linklen = MAXPATHLEN - (u_int)uio_resid(auio);
+ if (linklen + ndp->ni_pathlen > MAXPATHLEN) {
+ if (need_newpathbuf)
+ FREE_ZONE(cp, MAXPATHLEN, M_NAMEI);
+
+ return ENAMETOOLONG;
+ }
+ if (need_newpathbuf) {
+ long len = cnp->cn_pnlen;
+
+ tmppn = cnp->cn_pnbuf;
+ bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
+ cnp->cn_pnbuf = cp;
+ cnp->cn_pnlen = MAXPATHLEN;
+
+ if ( (cnp->cn_flags & HASBUF) )
+ FREE_ZONE(tmppn, len, M_NAMEI);
+ else
+ cnp->cn_flags |= HASBUF;
+ } else
+ cnp->cn_pnbuf[linklen] = '\0';
+
+ ndp->ni_pathlen += linklen;
+ cnp->cn_nameptr = cnp->cn_pnbuf;
+
+ /*
+ * starting point for 'relative'
+ * symbolic link path
+ */
+ dp = ndp->ni_dvp;
+
+ /*
+ * get rid of references returned via 'lookup'
+ */
+ vnode_put(ndp->ni_vp);
+ vnode_put(ndp->ni_dvp); /* ALWAYS have a dvp for a symlink */
-bad:
- if ((cnp->cn_flags & FSNODELOCKHELD)) {
- cnp->cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(ndp->ni_dvp, NULL);
- }
- if (dp)
- vnode_put(dp);
ndp->ni_vp = NULLVP;
+ ndp->ni_dvp = NULLVP;
- if (kdebug_enable)
- kdebug_lookup(dp, cnp);
- return (error);
+ /*
+ * Check if symbolic link restarts us at the root
+ */
+ if (*(cnp->cn_nameptr) == '/') {
+ while (*(cnp->cn_nameptr) == '/') {
+ cnp->cn_nameptr++;
+ ndp->ni_pathlen--;
+ }
+ if ((dp = ndp->ni_rootdir) == NULLVP) {
+ return ENOENT;
+ }
+ }
+
+ *new_dp = dp;
+
+ return 0;
}
/*
void
nameidone(struct nameidata *ndp)
{
- if ((ndp->ni_cnd.cn_flags & FSNODELOCKHELD)) {
- ndp->ni_cnd.cn_flags &= ~FSNODELOCKHELD;
- unlock_fsnode(ndp->ni_dvp, NULL);
- }
if (ndp->ni_cnd.cn_flags & HASBUF) {
char *tmp = ndp->ni_cnd.cn_pnbuf;
}
-#define NUMPARMS 23
-
/*
* Log (part of) a pathname using the KERNEL_DEBUG_CONSTANT mechanism, as used
* by fs_usage. The path up to and including the current component name are
* fails because /foo_bar_baz is not found will only log "/foo_bar_baz", with
* no '>' padding. But /foo_bar/spam would log "/foo_bar>>>>".
*/
-static void
-kdebug_lookup(struct vnode *dp, struct componentname *cnp)
+#if (KDEBUG_LEVEL >= KDEBUG_LEVEL_IST)
+
+void
+kdebug_vfs_lookup(long *dbg_parms, int dbg_namelen, void *dp, uint32_t flags)
{
- unsigned int i;
int code;
+ unsigned int i;
+ bool lookup = flags & KDBG_VFS_LOOKUP_FLAG_LOOKUP;
+ bool noprocfilt = flags & KDBG_VFS_LOOKUP_FLAG_NOPROCFILT;
+
+ /*
+ * In the event that we collect multiple, consecutive pathname
+ * entries, we must mark the start of the path's string and the end.
+ */
+ if (lookup) {
+ code = VFS_LOOKUP | DBG_FUNC_START;
+ } else {
+ code = VFS_LOOKUP_DONE | DBG_FUNC_START;
+ }
+
+ if (dbg_namelen <= (int)(3 * sizeof(long)))
+ code |= DBG_FUNC_END;
+
+ if (noprocfilt) {
+ KDBG_RELEASE_NOPROCFILT(code, kdebug_vnode(dp), dbg_parms[0],
+ dbg_parms[1], dbg_parms[2]);
+ } else {
+ KDBG_RELEASE(code, kdebug_vnode(dp), dbg_parms[0], dbg_parms[1],
+ dbg_parms[2]);
+ }
+
+ code &= ~DBG_FUNC_START;
+
+ for (i=3, dbg_namelen -= (3 * sizeof(long)); dbg_namelen > 0; i+=4, dbg_namelen -= (4 * sizeof(long))) {
+ if (dbg_namelen <= (int)(4 * sizeof(long)))
+ code |= DBG_FUNC_END;
+
+ if (noprocfilt) {
+ KDBG_RELEASE_NOPROCFILT(code, dbg_parms[i], dbg_parms[i + 1],
+ dbg_parms[i + 2], dbg_parms[i + 3]);
+ } else {
+ KDBG_RELEASE(code, dbg_parms[i], dbg_parms[i + 1], dbg_parms[i + 2],
+ dbg_parms[i + 3]);
+ }
+ }
+}
+
+void
+kdebug_lookup_gen_events(long *dbg_parms, int dbg_namelen, void *dp,
+ boolean_t lookup)
+{
+ kdebug_vfs_lookup(dbg_parms, dbg_namelen, dp,
+ lookup ? KDBG_VFS_LOOKUP_FLAG_LOOKUP : 0);
+}
+
+void
+kdebug_lookup(vnode_t dp, struct componentname *cnp)
+{
int dbg_namelen;
char *dbg_nameptr;
long dbg_parms[NUMPARMS];
*(cnp->cn_nameptr + cnp->cn_namelen) ? '>' : 0,
sizeof(dbg_parms) - dbg_namelen);
}
-
- /*
- * In the event that we collect multiple, consecutive pathname
- * entries, we must mark the start of the path's string and the end.
- */
- code = (FSDBG_CODE(DBG_FSRW,36)) | DBG_FUNC_START;
+ kdebug_vfs_lookup(dbg_parms, dbg_namelen, (void *)dp,
+ KDBG_VFS_LOOKUP_FLAG_LOOKUP);
+}
- if (dbg_namelen <= 12)
- code |= DBG_FUNC_END;
+#else /* (KDEBUG_LEVEL >= KDEBUG_LEVEL_IST) */
- KERNEL_DEBUG_CONSTANT(code, (unsigned int)dp, dbg_parms[0], dbg_parms[1], dbg_parms[2], 0);
+void
+kdebug_vfs_lookup(long *dbg_parms __unused, int dbg_namelen __unused,
+ void *dp __unused, __unused uint32_t flags)
+{
+}
- code &= ~DBG_FUNC_START;
+static void
+kdebug_lookup(struct vnode *dp __unused, struct componentname *cnp __unused)
+{
+}
+#endif /* (KDEBUG_LEVEL >= KDEBUG_LEVEL_IST) */
- for (i=3, dbg_namelen -= 12; dbg_namelen > 0; i+=4, dbg_namelen -= 16) {
- if (dbg_namelen <= 16)
- code |= DBG_FUNC_END;
+int
+vfs_getbyid(fsid_t *fsid, ino64_t ino, vnode_t *vpp, vfs_context_t ctx)
+{
+ mount_t mp;
+ int error;
+
+ mp = mount_lookupby_volfsid(fsid->val[0], 1);
+ if (mp == NULL) {
+ return EINVAL;
+ }
- KERNEL_DEBUG_CONSTANT(code, dbg_parms[i], dbg_parms[i+1], dbg_parms[i+2], dbg_parms[i+3], 0);
+ /* Get the target vnode. */
+ if (ino == 2) {
+ error = VFS_ROOT(mp, vpp, ctx);
+ } else {
+ error = VFS_VGET(mp, ino, vpp, ctx);
}
-}
+ vfs_unbusy(mp);
+ return error;
+}
/*
* Obtain the real path from a legacy volfs style path.
*
struct mount *mp = NULL;
char *str;
char ch;
- unsigned long id;
+ uint32_t id;
ino64_t ino;
int error;
int length;
return (error);
}
#endif
+
+void
+lookup_compound_vnop_post_hook(int error, vnode_t dvp, vnode_t vp, struct nameidata *ndp, int did_create)
+{
+ if (error == 0 && vp == NULLVP) {
+ panic("NULL vp with error == 0.\n");
+ }
+
+ /*
+ * We don't want to do any of this if we didn't use the compound vnop
+ * to perform the lookup... i.e. if we're allowing and using the legacy pattern,
+ * where we did a full lookup.
+ */
+ if ((ndp->ni_flag & NAMEI_COMPOUND_OP_MASK) == 0) {
+ return;
+ }
+
+ /*
+ * If we're going to continue the lookup, we'll handle
+ * all lookup-related updates at that time.
+ */
+ if (error == EKEEPLOOKING) {
+ return;
+ }
+
+ /*
+ * Only audit or update cache for *found* vnodes. For creation
+ * neither would happen in the non-compound-vnop case.
+ */
+ if ((vp != NULLVP) && !did_create) {
+ /*
+ * If MAKEENTRY isn't set, and we've done a successful compound VNOP,
+ * then we certainly don't want to update cache or identity.
+ */
+ if ((error != 0) || (ndp->ni_cnd.cn_flags & MAKEENTRY)) {
+ lookup_consider_update_cache(dvp, vp, &ndp->ni_cnd, ndp->ni_ncgeneration);
+ }
+ if (ndp->ni_cnd.cn_flags & AUDITVNPATH1)
+ AUDIT_ARG(vnpath, vp, ARG_VNODE1);
+ else if (ndp->ni_cnd.cn_flags & AUDITVNPATH2)
+ AUDIT_ARG(vnpath, vp, ARG_VNODE2);
+ }
+
+ /*
+ * If you created (whether you opened or not), cut a lookup tracepoint
+ * for the parent dir (as would happen without a compound vnop). Note: we may need
+ * a vnode despite failure in this case!
+ *
+ * If you did not create:
+ * Found child (succeeded or not): cut a tracepoint for the child.
+ * Did not find child: cut a tracepoint with the parent.
+ */
+ if (kdebug_enable) {
+ kdebug_lookup(vp ? vp : dvp, &ndp->ni_cnd);
+ }
+}
projects / apple / xnu.git / blobdiff