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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* 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 Hyra 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.
*/
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/errno.h>
#include <sys/mount.h>
#include <sys/device.h>
#include <fs/devfs.h>
#include <vm/dynalloc.h>
#include <string.h>
struct devfs_node {
const char *name;
uint8_t is_block : 1;
mode_t mode;
devmajor_t major;
dev_t dev;
TAILQ_ENTRY(devfs_node) link;
};
static TAILQ_HEAD(, devfs_node) devlist;
static inline int
cdevsw_read(void *devsw, dev_t dev, struct sio_txn *sio)
{
struct cdevsw *cdevsw = devsw;
return cdevsw->read(dev, sio, 0);
}
/*
* Get a devfs node by name.
*
* @name: Name to lookup.
*/
static struct devfs_node *
devfs_get_node(const char *name)
{
struct devfs_node *dnp;
TAILQ_FOREACH(dnp, &devlist, link) {
if (strcmp(dnp->name, name) == 0) {
return dnp;
}
}
return NULL;
}
static int
devfs_lookup(struct vop_lookup_args *args)
{
int vtype, error;
const char *name = args->name;
struct devfs_node *dnp;
struct vnode *vp;
if (*name == '/')
++name;
/* Make sure it isn't a path */
for (const char *p = name; *p != '\0'; ++p) {
if (*p == '/') {
return -ENOENT;
}
}
if ((dnp = devfs_get_node(name)) == NULL)
return -ENOENT;
/* Now, create a vnode */
vtype = (dnp->is_block) ? VBLK : VCHR;
if ((error = vfs_alloc_vnode(&vp, vtype)) != 0)
return error;
vp->data = dnp;
vp->vops = &g_devfs_vops;
*args->vpp = vp;
return 0;
}
static int
devfs_reclaim(struct vnode *vp)
{
if (vp->data != NULL)
dynfree(vp->data);
vp->data = NULL;
return 0;
}
static int
devfs_read(struct vnode *vp, struct sio_txn *sio)
{
struct devfs_node *dnp;
void *devsw;
if ((dnp = vp->data) == NULL)
return -EIO;
devsw = dev_get(dnp->major, dnp->dev);
if (!dnp->is_block)
return cdevsw_read(devsw, dnp->dev, sio);
/* TODO: Block devices */
return -EIO;
}
static int
devfs_init(struct fs_info *fip)
{
struct vnode *vp;
struct mount *mp;
int error;
/* Create a new vnode for devfs */
if ((error = vfs_alloc_vnode(&vp, VDIR)) != 0)
return error;
vp->vops = &g_devfs_vops;
TAILQ_INIT(&devlist);
mp = vfs_alloc_mount(vp, fip);
vfs_name_mount(mp, "dev");
TAILQ_INSERT_TAIL(&g_mountlist, mp, mnt_list);
return 0;
}
/*
* Create an entry within devfs.
*
* @name: Device name.
* @major: Device major.
* @dev: Device minor.
* @mode: Permissions mask
*/
int
devfs_create_entry(const char *name, devmajor_t major, dev_t dev, mode_t mode)
{
struct devfs_node *dnp;
dnp = dynalloc(sizeof(*dnp));
if (dnp == NULL)
return -ENOMEM;
dnp->name = name;
dnp->major = major;
dnp->dev = dev;
dnp->mode = mode;
TAILQ_INSERT_TAIL(&devlist, dnp, link);
return 0;
}
const struct vops g_devfs_vops = {
.lookup = devfs_lookup,
.reclaim = devfs_reclaim,
.read = devfs_read
};
const struct vfsops g_devfs_vfsops = {
.init = devfs_init
};
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