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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/vfs.h>
#include <sys/errno.h>
#include <sys/mount.h>
#include <vm/dynalloc.h>
#include <string.h>
/* FNV-1a defines */
#define FNV_OFFSET 14695981039346656037ULL
#define FNV_PRIME 1099511628211ULL
/*
* FNV-1a hash function
* https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function
*/
static size_t
vfs_hash(const char *data)
{
size_t hash = FNV_OFFSET;
const char *p = data;
while (*p) {
hash ^= (size_t)(uint8_t)(*p);
hash *= FNV_PRIME;
++p;
}
return hash;
}
/*
* Hashes a path
*
* @path: Path to hash.
*
* Returns -1 on failure, >= 0 return values
* are valid.
*/
ssize_t
vfs_hash_path(const char *path)
{
char *name = NULL;
size_t i = 0, hash = 0;
if (strcmp(path, "/") == 0 || !vfs_is_valid_path(path)) {
return -1;
} else if (*path != '/') {
return -1;
}
do {
name = vfs_get_fname_at(path, i++);
if (name != NULL) {
hash += vfs_hash(name);
dynfree(name);
}
} while (name != NULL);
return hash;
}
/*
* This function checks if a path is valid.
*
* @path: Path to check.
*
* Returns true if valid, otherwise false.
*/
bool
vfs_is_valid_path(const char *path)
{
const char *ptr = path;
char c;
while (*ptr != '\0') {
c = *(ptr++);
switch (c) {
case '/':
case '-':
case '_':
case '.':
/* Valid char, can continue */
continue;
default:
/*
* This could be an alphabetical or "numeric" char which
* is valid. We want to handle this too. To make things
* easier we'll OR the char by 0x20 to convert it to
* lowercase if it is alphabetical.
*/
c |= 0x20;
if (c >= 'a' && c <= 'z')
continue;
else if (c >= '0' && c <= '9')
continue;
/* We got an invalid char */
return false;
}
}
return true;
}
/*
* Allocates a vnode
*
* @vnode: Pointer to vnode pointer where newly allocated
* vnode will be stored.
*
* @mp: Mountpoint this vnode is associated with.
* @type: Vnode type.
*
* This function will return 0 upon success and < 0 on failure.
*/
int
vfs_alloc_vnode(struct vnode **vnode, struct mount *mp, int type)
{
struct vnode *new_vnode = dynalloc(sizeof(struct vnode));
if (new_vnode == NULL) {
return -ENOMEM;
}
memset(new_vnode, 0, sizeof(struct vnode));
new_vnode->type = type;
new_vnode->mp = mp;
*vnode = new_vnode;
return 0;
}
/*
* Returns the rootname of a path
* For example, "/foo/bar/" will be "foo" and
* "/foo/bar/baz" will also be "foo"
*
* There will be no slashes in the returned string
* unless "/" is passed.
*
* XXX: Returns memory allocated by dynalloc,
* remember to free the memory with dynfree()
*
* @path: Path to get rootname of
* @new_path: New path will be placed here.
*/
int
vfs_rootname(const char *path, char **new_path)
{
char *tmp = NULL;
const char *ptr = path;
size_t len = 0;
if (!vfs_is_valid_path(path)) {
*new_path = NULL;
return -EINVAL;
}
if (*path == '/') {
/* Skip first '/' */
++ptr;
++path;
}
for (; *ptr != '\0' && *ptr != '/'; ++ptr) {
if (*ptr == '/') {
break;
}
++len;
}
tmp = dynalloc(sizeof(char) * len + 1);
if (tmp == NULL) {
*new_path = NULL;
return -ENOMEM;
}
if (len == 0) {
/* Handle input that is just "/" */
tmp[0] = '/';
tmp[1] = '\0';
} else {
memcpy(tmp, path, len + 2);
}
*new_path = tmp;
return 0;
}
int
vfs_vget(struct vnode *parent, const char *name, struct vnode **vp)
{
return parent->vops->vget(parent, name, vp);
}
ssize_t
vfs_read(struct vnode *vp, struct sio_txn *sio)
{
return vp->vops->read(vp, sio);
}
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