source: mainline/uspace/srv/fs/devfs/devfs_ops.c@ a095d20

/*
 * Copyright (c) 2009 Martin Decky
 * 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 devfs_ops.c
 * @brief Implementation of VFS operations for the devfs file system server.
 */

#include <ipc/ipc.h>
#include <bool.h>
#include <errno.h>
#include <malloc.h>
#include <string.h>
#include <libfs.h>
#include "devfs.h"
#include "devfs_ops.h"

#define PLB_GET_CHAR(pos)  (devfs_reg.plb_ro[pos % PLB_SIZE])

bool devfs_init(void)
{
        if (devmap_get_phone(DEVMAP_CLIENT, IPC_FLAG_BLOCKING) < 0)
                return false;
        
        return true;
}

void devfs_mounted(ipc_callid_t rid, ipc_call_t *request)
{
        /* Accept the mount options */
        ipc_callid_t callid;
        size_t size;
        if (!ipc_data_write_receive(&callid, &size)) {
                ipc_answer_0(callid, EINVAL);
                ipc_answer_0(rid, EINVAL);
                return;
        }
        
        char *opts = malloc(size + 1);
        if (!opts) {
                ipc_answer_0(callid, ENOMEM);
                ipc_answer_0(rid, ENOMEM);
                return;
        }
        
        ipcarg_t retval = ipc_data_write_finalize(callid, opts, size);
        if (retval != EOK) {
                ipc_answer_0(rid, retval);
                free(opts);
                return;
        }
        
        free(opts);
        
        ipc_answer_3(rid, EOK, 0, 0, 0);
}

void devfs_mount(ipc_callid_t rid, ipc_call_t *request)
{
        ipc_answer_0(rid, ENOTSUP);
}

void devfs_lookup(ipc_callid_t rid, ipc_call_t *request)
{
        ipcarg_t first = IPC_GET_ARG1(*request);
        ipcarg_t last = IPC_GET_ARG2(*request);
        dev_handle_t dev_handle = IPC_GET_ARG3(*request);
        ipcarg_t lflag = IPC_GET_ARG4(*request);
        fs_index_t index = IPC_GET_ARG5(*request);
        
        /* Hierarchy is flat, no altroot is supported */
        if (index != 0) {
                ipc_answer_0(rid, ENOENT);
                return;
        }
        
        /* This is a read-only filesystem */
        if ((lflag & L_CREATE) || (lflag & L_LINK) || (lflag & L_UNLINK)) {
                ipc_answer_0(rid, ENOTSUP);
                return;
        }
        
        /* Eat slash */
        if (PLB_GET_CHAR(first) == '/') {
                first++;
                first %= PLB_SIZE;
        }
        
        if (first >= last) {
                /* Root entry */
                if (lflag & L_DIRECTORY)
                        ipc_answer_5(rid, EOK, devfs_reg.fs_handle, dev_handle, 0, 0, 0);
                else
                        ipc_answer_0(rid, ENOENT);
        } else {
                if (lflag & L_FILE) {
                        count_t len;
                        if (last >= first)
                                len = last - first + 1;
                        else
                                len = first + PLB_SIZE - last + 1;
                        
                        char *name = (char *) malloc(len + 1);
                        if (name == NULL) {
                                ipc_answer_0(rid, ENOMEM);
                                return;
                        }
                        
                        count_t i;
                        for (i = 0; i < len; i++)
                                name[i] = PLB_GET_CHAR(first + i);
                        
                        name[len] = 0;
                        
                        dev_handle_t handle;
                        if (devmap_device_get_handle(name, &handle, 0) != EOK) {
                                free(name);
                                ipc_answer_0(rid, ENOENT);
                                return;
                        }
                        
                        free(name);
                        
                        ipc_answer_5(rid, EOK, devfs_reg.fs_handle, dev_handle, handle, 0, 1);
                } else
                        ipc_answer_0(rid, ENOENT);
        }
}

void devfs_read(ipc_callid_t rid, ipc_call_t *request)
{
        fs_index_t index = (fs_index_t) IPC_GET_ARG2(*request);
        off_t pos = (off_t) IPC_GET_ARG3(*request);
        
        if (index != 0) {
                ipc_answer_1(rid, ENOENT, 0);
                return;
        }
        
        /*
         * Receive the read request.
         */
        ipc_callid_t callid;
        size_t size;
        if (!ipc_data_read_receive(&callid, &size)) {
                ipc_answer_0(callid, EINVAL);
                ipc_answer_0(rid, EINVAL);
                return;
        }
        
        size_t bytes = 0;
        if (index != 0) {
                (void) ipc_data_read_finalize(callid, NULL, bytes);
        } else {
                count_t count = devmap_device_get_count();
                dev_desc_t *desc = malloc(count * sizeof(dev_desc_t));
                if (desc == NULL) {
                        ipc_answer_0(callid, ENOENT);
                        ipc_answer_1(rid, ENOENT, 0);
                        return;
                }
                
                count_t max = devmap_device_get_devices(count, desc);
                
                if (pos < max) {
                        ipc_data_read_finalize(callid, desc[pos].name, str_size(desc[pos].name) + 1);
                } else {
                        ipc_answer_0(callid, ENOENT);
                        ipc_answer_1(rid, ENOENT, 0);
                        return;
                }
                
                free(desc);
                bytes = 1;
        }
        
        ipc_answer_1(rid, EOK, bytes);
}

void devfs_write(ipc_callid_t rid, ipc_call_t *request)
{
        fs_index_t index = (fs_index_t) IPC_GET_ARG2(*request);
        off_t pos = (off_t) IPC_GET_ARG3(*request);
        
        /*
         * Receive the write request.
         */
        ipc_callid_t callid;
        size_t size;
        if (!ipc_data_write_receive(&callid, &size)) {
                ipc_answer_0(callid, EINVAL);
                ipc_answer_0(rid, EINVAL);
                return;
        }
        
        // TODO
        ipc_answer_0(callid, ENOENT);
        ipc_answer_2(rid, ENOENT, 0, 0);
}

void devfs_truncate(ipc_callid_t rid, ipc_call_t *request)
{
        ipc_answer_0(rid, ENOTSUP);
}

void devfs_destroy(ipc_callid_t rid, ipc_call_t *request)
{
        ipc_answer_0(rid, ENOTSUP);
}

/**
 * @}
 */