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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: Device filesystem
* Author: Ian Marco Moffett
*/
#include <sys/errno.h>
#include <sys/mount.h>
#include <sys/syslog.h>
#include <os/vnode.h>
#include <os/kalloc.h>
#include <fs/devfs.h>
#include <string.h>
static struct vop devfs_vops;
static TAILQ_HEAD(, devfs_node) nodelist;
/*
* Find a node within the device filesystem
*/
static int
devfs_lookup(struct vop_lookup_args *args)
{
int error;
struct devfs_node *dnp = NULL;
struct vnode *vp;
if (args == NULL) {
return -EINVAL;
}
/* Need a pointer to write the result */
if (args->vpp == NULL) {
return -EINVAL;
}
TAILQ_FOREACH(dnp, &nodelist, link) {
if (dnp == NULL) {
continue;
}
if (strcmp(dnp->name, args->name) != 0) {
continue;
}
/* Found it! Create a vnode */
error = vfs_valloc(&vp, VTYPE_FILE, 0);
if (error < 0) {
return error;
}
vp->data = dnp;
*args->vpp = vp;
return 0;
}
return -ENOENT;
}
/*
* Register a new device to devfs
*/
int
devfs_register(const char *name, dev_type_t type, void *devsw, int flags)
{
struct devfs_node *dnp;
size_t devname_len;
struct vop_lookup_args args;
struct vnode *vp;
if (name == NULL || devsw == NULL) {
return -EINVAL;
}
if (type >= __DEVFS_NTYPE) {
return -EINVAL;
}
dnp = kalloc(sizeof(*dnp));
if (dnp == NULL) {
return -ENOMEM;
}
switch (type) {
case DEVFS_NONE:
case DEVFS_CDEV:
dnp->type = type;
break;
}
devname_len = strlen(name);
memcpy(dnp->name, name, devname_len);
TAILQ_INSERT_TAIL(&nodelist, dnp, link);
return 0;
}
/*
* Initialize the device filesystem
*/
static int
devfs_init(struct fs_info *fip)
{
(void)fip;
TAILQ_INIT(&nodelist);
return 0;
}
/*
* Mount the device filesystem
*/
static int
devfs_mount(struct fs_info *fip, struct mount_args *margs)
{
int error;
struct vnode *vp;
if (fip == NULL || margs == NULL) {
return -1;
}
error = vfs_valloc(&margs->vp_res, VTYPE_DIR, 0);
if (error < 0) {
return error;
}
vp = margs->vp_res;
vp->vops = &devfs_vops;
return 0;
}
static struct vop devfs_vops = {
.lookup = devfs_lookup
};
struct vfsops g_devfs_vfops = {
.init = devfs_init,
.mount = devfs_mount
};
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