Subversion Repositories HelenOS

/*

 * 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 fs

 * @{

 */

/**

 * @file vfs.c

 * @brief VFS service for HelenOS.

 */

#include <ipc/ipc.h>

#include <ipc/services.h>

#include <async.h>

#include <errno.h>

#include <stdio.h>

#include <bool.h>

#include <string.h>

#include <as.h>

#include <libadt/list.h>

#include <atomic.h>

#include "vfs.h"

#define NAME "vfs"

static void vfs_connection(ipc_callid_t iid, ipc_call_t *icall)

{

    bool keep_on_going = true;

    /*

     * The connection was opened via the IPC_CONNECT_ME_TO call.

     * This call needs to be answered.

     */

    ipc_answer_0(iid, EOK);

    /*

     * Here we enter the main connection fibril loop.

     * The logic behind this loop and the protocol is that we'd like to keep

     * each connection open until the client hangs up. When the client hangs

     * up, we will free its VFS state. The act of hanging up the connection

     * by the client is equivalent to client termination because we cannot

     * distinguish one from the other. On the other hand, the client can

     * hang up arbitrarily if it has no open files and reestablish the

     * connection later.

     */

    while (keep_on_going) {

        ipc_call_t call;

        ipc_callid_t callid = async_get_call(&call);

        fs_handle_t fs_handle;

        int phone;

        switch (IPC_GET_METHOD(call)) {

        case IPC_M_PHONE_HUNGUP:

            keep_on_going = false;

            break;

        case IPC_M_CONNECT_ME_TO:

            /*

             * Connect the client file system to another one.

             */

            /* FIXME:

             * Prevent ordinary clients from connecting to file

             * system servers directly. This should be solved by

             * applying some security mechanisms.

             */

            fs_handle = IPC_GET_ARG1(call);

            phone = vfs_grab_phone(fs_handle);

            (void) ipc_forward_fast(callid, phone, 0, 0, 0,

                IPC_FF_NONE);

            vfs_release_phone(phone);

            break;

        case VFS_REGISTER:

            vfs_register(callid, &call);

            /*

             * Keep the connection open so that a file system can

             * later ask us to connect it to another file system.

             * This is necessary to support non-root mounts.

             */

            break;

        case VFS_MOUNT:

            vfs_mount(callid, &call);

            break;

        case VFS_OPEN:

            vfs_open(callid, &call);

            break;

        case VFS_CLOSE:

            vfs_close(callid, &call);

            break;

        case VFS_READ:

            vfs_read(callid, &call);

            break;

        case VFS_WRITE:

            vfs_write(callid, &call);

            break;

        case VFS_SEEK:

            vfs_seek(callid, &call);

            break;

        case VFS_TRUNCATE:

            vfs_truncate(callid, &call);

            break;

        case VFS_MKDIR:

            vfs_mkdir(callid, &call);

            break;

        case VFS_UNLINK:

            vfs_unlink(callid, &call);

            break;

        case VFS_RENAME:

            vfs_rename(callid, &call);

            break;

        default:

            ipc_answer_0(callid, ENOTSUP);

            break;

        }

    }

    /* TODO: cleanup after the client */

}

int main(int argc, char **argv)

{

    printf(NAME ": HelenOS VFS server\n");

    /*

     * Initialize the list of registered file systems.

     */

    list_initialize(&fs_head);

    /*

     * Initialize VFS node hash table.

     */

    if (!vfs_nodes_init()) {

        printf(NAME ": Failed to initialize VFS node hash table\n");

        return ENOMEM;

    }

    /*

     * Allocate and initialize the Path Lookup Buffer.

     */

    list_initialize(&plb_head);

    plb = as_get_mappable_page(PLB_SIZE);

    if (!plb) {

        printf(NAME ": Cannot allocate a mappable piece of address space\n");

        return ENOMEM;

    }

    if (as_area_create(plb, PLB_SIZE, AS_AREA_READ | AS_AREA_WRITE |

        AS_AREA_CACHEABLE) != plb) {

        printf(NAME ": Cannot create address space area\n");

        return ENOMEM;

    }

    memset(plb, 0, PLB_SIZE);

    /*

     * Set a connectio handling function/fibril.

     */

    async_set_client_connection(vfs_connection);

    /*

     * Register at the naming service.

     */

    ipcarg_t phonead;

    ipc_connect_to_me(PHONE_NS, SERVICE_VFS, 0, 0, &phonead);

    /*

     * Start accepting connections.

     */

    printf(NAME ": Accepting connections\n");

    async_manager();

    return 0;

}

/**

 * @}

 */