/*
* Copyright (c) 2008 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup vfs
* @{
*/
/**
* @file vfs_register.c
* @brief
*/
#include <ipc/services.h>
#include <async.h>
#include <fibril.h>
#include <fibril_synch.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include <ctype.h>
#include <stdbool.h>
#include <adt/list.h>
#include <as.h>
#include <assert.h>
#include <stdatomic.h>
#include <vfs/vfs.h>
#include "vfs.h"
FIBRIL_CONDVAR_INITIALIZE(fs_list_cv);
FIBRIL_MUTEX_INITIALIZE(fs_list_lock);
LIST_INITIALIZE(fs_list);
static atomic_int fs_handle_next = 1;
/** Verify the VFS info structure.
*
* @param info Info structure to be verified.
*
* @return Non-zero if the info structure is sane, zero otherwise.
*
*/
static bool vfs_info_sane(vfs_info_t *info)
{
int i;
/*
* Check if the name is non-empty and is composed solely of ASCII
* characters [a-z]+[a-z0-9_-]*.
*/
if (!islower(info->name[0])) {
dprintf("The name doesn't start with a lowercase character.\n");
return false;
}
for (i = 1; i < FS_NAME_MAXLEN; i++) {
if (!(islower(info->name[i]) || isdigit(info->name[i])) &&
(info->name[i] != '-') && (info->name[i] != '_')) {
if (info->name[i] == '\0') {
break;
} else {
dprintf("The name contains illegal "
"characters.\n");
return false;
}
}
}
/*
* This check is not redundant. It ensures that the name is
* NULL-terminated, even if FS_NAME_MAXLEN characters are used.
*/
if (info->name[i] != '\0') {
dprintf("The name is not properly NULL-terminated.\n");
return false;
}
return true;
}
/** VFS_REGISTER protocol function.
*
* @param req Call structure with the request.
*
*/
void vfs_register(ipc_call_t *req)
{
vfs_info_t *vfs_info;
errno_t rc = async_data_write_accept((void **) &vfs_info, false,
sizeof(vfs_info_t), sizeof(vfs_info_t), 0, NULL);
if (rc != EOK) {
dprintf("Failed to deliver the VFS info into our AS, rc=%d.\n",
rc);
async_answer_0(req, rc);
return;
}
/*
* Allocate and initialize a buffer for the fs_info structure.
*/
fs_info_t *fs_info = (fs_info_t *) malloc(sizeof(fs_info_t));
if (!fs_info) {
dprintf("Could not allocate memory for FS info.\n");
async_answer_0(req, ENOMEM);
return;
}
link_initialize(&fs_info->fs_link);
fs_info->vfs_info = *vfs_info;
free(vfs_info);
dprintf("VFS info delivered.\n");
if (!vfs_info_sane(&fs_info->vfs_info)) {
free(fs_info);
async_answer_0(req, EINVAL);
return;
}
fibril_mutex_lock(&fs_list_lock);
/*
* Check for duplicit registrations.
*/
if (fs_name_to_handle(fs_info->vfs_info.instance,
fs_info->vfs_info.name, false)) {
/*
* We already register a fs like this.
*/
dprintf("FS is already registered.\n");
fibril_mutex_unlock(&fs_list_lock);
free(fs_info);
async_answer_0(req, EEXIST);
return;
}
/*
* Add fs_info to the list of registered FS's.
*/
dprintf("Inserting FS into the list of registered file systems.\n");
list_append(&fs_info->fs_link, &fs_list);
/*
* Now we want the client to send us the IPC_M_CONNECT_TO_ME call so
* that a callback connection is created and we have a phone through
* which to forward VFS requests to it.
*/
fs_info->sess = async_callback_receive(EXCHANGE_PARALLEL);
if (!fs_info->sess) {
dprintf("Callback connection expected\n");
list_remove(&fs_info->fs_link);
fibril_mutex_unlock(&fs_list_lock);
free(fs_info);
async_answer_0(req, EINVAL);
return;
}
/* FIXME: Work around problem with callback sessions */
async_sess_args_set(fs_info->sess, INTERFACE_VFS_DRIVER_CB, 0, 0);
dprintf("Callback connection to FS created.\n");
/*
* The client will want us to send him the address space area with PLB.
*/
ipc_call_t call;
size_t size;
if (!async_share_in_receive(&call, &size)) {
dprintf("Unexpected call\n");
list_remove(&fs_info->fs_link);
fibril_mutex_unlock(&fs_list_lock);
async_hangup(fs_info->sess);
free(fs_info);
async_answer_0(&call, EINVAL);
async_answer_0(req, EINVAL);
return;
}
/*
* We can only send the client address space area PLB_SIZE bytes long.
*/
if (size != PLB_SIZE) {
dprintf("Client suggests wrong size of PFB, size = %zu\n", size);
list_remove(&fs_info->fs_link);
fibril_mutex_unlock(&fs_list_lock);
async_hangup(fs_info->sess);
free(fs_info);
async_answer_0(&call, EINVAL);
async_answer_0(req, EINVAL);
return;
}
/*
* Commit to read-only sharing the PLB with the client.
*/
(void) async_share_in_finalize(&call, plb,
AS_AREA_READ | AS_AREA_CACHEABLE);
dprintf("Sharing PLB.\n");
/*
* That was it. The FS has been registered.
* In reply to the VFS_REGISTER request, we assign the client file
* system a global file system handle.
*/
fs_info->fs_handle = atomic_fetch_add(&fs_handle_next, 1);
async_answer_1(req, EOK, (sysarg_t) fs_info->fs_handle);
fibril_condvar_broadcast(&fs_list_cv);
fibril_mutex_unlock(&fs_list_lock);
dprintf("\"%.*s\" filesystem successfully registered, handle=%d.\n",
FS_NAME_MAXLEN, fs_info->vfs_info.name, fs_info->fs_handle);
}
/** Begin an exchange for a given file system handle
*
* @param handle File system handle.
*
* @return Exchange for a multi-call request.
* @return NULL if no such file exists.
*
*/
async_exch_t *vfs_exchange_grab(fs_handle_t handle)
{
/*
* For now, we don't try to be very clever and very fast.
* We simply lookup the session in fs_list and
* begin an exchange.
*/
fibril_mutex_lock(&fs_list_lock);
list_foreach(fs_list, fs_link, fs_info_t, fs) {
if (fs->fs_handle == handle) {
fibril_mutex_unlock(&fs_list_lock);
assert(fs->sess);
async_exch_t *exch = async_exchange_begin(fs->sess);
assert(exch);
return exch;
}
}
fibril_mutex_unlock(&fs_list_lock);
return NULL;
}
/** End VFS server exchange.
*
* @param exch VFS server exchange.
*
*/
void vfs_exchange_release(async_exch_t *exch)
{
async_exchange_end(exch);
}
/** Convert file system name to its handle.
*
* @param name File system name.
* @param lock If true, the function will lock and unlock the
* fs_list_lock.
*
* @return File system handle or zero if file system not found.
*
*/
fs_handle_t fs_name_to_handle(unsigned int instance, const char *name, bool lock)
{
int handle = 0;
if (lock)
fibril_mutex_lock(&fs_list_lock);
list_foreach(fs_list, fs_link, fs_info_t, fs) {
if (str_cmp(fs->vfs_info.name, name) == 0 &&
instance == fs->vfs_info.instance) {
handle = fs->fs_handle;
break;
}
}
if (lock)
fibril_mutex_unlock(&fs_list_lock);
return handle;
}
/** Find the VFS info structure.
*
* @param handle FS handle for which the VFS info structure is sought.
*
* @return VFS info structure on success or NULL otherwise.
*
*/
vfs_info_t *fs_handle_to_info(fs_handle_t handle)
{
vfs_info_t *info = NULL;
fibril_mutex_lock(&fs_list_lock);
list_foreach(fs_list, fs_link, fs_info_t, fs) {
if (fs->fs_handle == handle) {
info = &fs->vfs_info;
break;
}
}
fibril_mutex_unlock(&fs_list_lock);
return info;
}
/** Get list of file system types.
*
* @param fstypes Place to store list of file system types. Free using
* vfs_fstypes_free().
*
* @return EOK on success or an error code
*/
errno_t vfs_get_fstypes(vfs_fstypes_t *fstypes)
{
size_t size;
size_t count;
size_t l;
fibril_mutex_lock(&fs_list_lock);
size = 0;
count = 0;
list_foreach(fs_list, fs_link, fs_info_t, fs) {
size += str_size(fs->vfs_info.name) + 1;
count++;
}
if (size == 0)
size = 1;
fstypes->buf = calloc(1, size);
if (fstypes->buf == NULL) {
fibril_mutex_unlock(&fs_list_lock);
return ENOMEM;
}
fstypes->fstypes = calloc(sizeof(char *), count);
if (fstypes->fstypes == NULL) {
free(fstypes->buf);
fstypes->buf = NULL;
fibril_mutex_unlock(&fs_list_lock);
return ENOMEM;
}
fstypes->size = size;
size = 0;
count = 0;
list_foreach(fs_list, fs_link, fs_info_t, fs) {
l = str_size(fs->vfs_info.name) + 1;
memcpy(fstypes->buf + size, fs->vfs_info.name, l);
fstypes->fstypes[count] = &fstypes->buf[size];
size += l;
count++;
}
fibril_mutex_unlock(&fs_list_lock);
return EOK;
}
/**
* @}
*/