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/*
* Copyright (c) 2025 Ian Marco Moffett and L5 engineers
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Description: File lookup algorithm
* Author: Ian Marco Moffett
*/
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/mount.h>
#include <sys/limits.h>
#include <sys/namei.h>
#include <string.h>
int
namei(struct nameidata *ndp)
{
struct mount *mp = NULL;
struct vnode *vp;
struct vop *vops;
struct vop_lookup_args lookup;
struct vop_create_args create;
struct nameidata nd_create;
struct fs_info *fip;
char namebuf[NAME_MAX];
size_t root_len;
const char *p, *pcur;
size_t i = 0;
int error;
if (ndp == NULL) {
return -EINVAL;
}
if ((p = ndp->path) == NULL) {
printf("namei: path is NULL\n");
return -EINVAL;
}
/* Get rid of leading slashes */
pcur = p;
while (*pcur == '/') {
++pcur;
}
/* Wait until we get the '/' */
while (*pcur != '/' && *pcur != '\0') {
++pcur;
}
/* Copy the root path e.g., /tmp */
root_len = (size_t)(pcur - p);
memcpy(namebuf, p, root_len);
error = mount_lookup(namebuf, &mp);
if (error < 0) {
error = mount_lookup("/", &mp);
}
if (error < 0) {
printf("namei: could not get mount %s\n", namebuf);
return error;
}
fip = mp->fs;
if ((vp = mp->vp) == NULL) {
return -EIO;
}
if ((vops = vp->vops) == NULL) {
return -EIO;
}
/*
* If this is an image we are looking up, then throw
* a path right at it.
*/
if (ISSET(fip->attr, FS_ATTR_IMAGE)) {
lookup.name = ndp->path;
lookup.dirvp = mp->vp;
lookup.vpp = &vp;
/* Return the result */
error = vops->lookup(&lookup);
if (error == 0 && ndp->vp_res != NULL) {
*ndp->vp_res = vp;
}
if (error == 0) {
return 0;
}
}
while (*pcur != '\0') {
/* Get out of the slashes */
while (*pcur == '/')
++pcur;
p = pcur;
/* Go back to the start */
memset(namebuf, 0, sizeof(namebuf));
while (*pcur != '/' && *pcur != '\0') {
namebuf[i++] = *pcur++;
if (i > sizeof(namebuf) - 1) {
return -ENAMETOOLONG;
}
}
i = 0;
/* Get the vops */
vp = mp->vp;
if ((vops = vp->vops) == NULL) {
return -EIO;
}
/* Create as we go? */
if (ISSET(ndp->flags, NAMEI_CREATE)) {
if (vops->create == NULL)
return -EIO;
nd_create.path = namebuf;
create.ndp = &nd_create;
error = vops->create(&create);
if (error < 0)
return error;
}
/* Do the lookup */
lookup.dirvp = vp;
lookup.vpp = &vp;
lookup.name = namebuf;
error = vops->lookup(&lookup);
if (error < 0) {
return -ENOENT;
}
}
*ndp->vp_res = vp;
return 0;
}
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