source: mainline/uspace/lib/libc/generic/vfs/vfs.c@ c08c355

/*
 * 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 libc
 * @{
 */
/** @file
 */

#include <vfs/vfs.h>
#include <vfs/canonify.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <stdio.h>
#include <sys/types.h>
#include <ipc/ipc.h>
#include <ipc/services.h>
#include <async.h>
#include <atomic.h>
#include <futex.h>
#include <errno.h>
#include <string.h>
#include <ipc/devmap.h>
#include "../../../srv/vfs/vfs.h"

int vfs_phone = -1;
futex_t vfs_phone_futex = FUTEX_INITIALIZER;

futex_t cwd_futex = FUTEX_INITIALIZER;
DIR *cwd_dir = NULL;
char *cwd_path = NULL;
size_t cwd_size = 0;

char *absolutize(const char *path, size_t *retlen)
{
        char *ncwd_path;
        char *ncwd_path_nc;

        futex_down(&cwd_futex);
        size_t size = str_size(path);
        if (*path != '/') {
                if (!cwd_path) {
                        futex_up(&cwd_futex);
                        return NULL;
                }
                ncwd_path_nc = malloc(cwd_size + 1 + size + 1);
                if (!ncwd_path_nc) {
                        futex_up(&cwd_futex);
                        return NULL;
                }
                str_cpy(ncwd_path_nc, cwd_size + 1 + size + 1, cwd_path);
                ncwd_path_nc[cwd_size] = '/';
                ncwd_path_nc[cwd_size + 1] = '\0';
        } else {
                ncwd_path_nc = malloc(size + 1);
                if (!ncwd_path_nc) {
                        futex_up(&cwd_futex);
                        return NULL;
                }
                ncwd_path_nc[0] = '\0';
        }
        str_append(ncwd_path_nc, cwd_size + 1 + size + 1, path);
        ncwd_path = canonify(ncwd_path_nc, retlen);
        if (!ncwd_path) {
                futex_up(&cwd_futex);
                free(ncwd_path_nc);
                return NULL;
        }
        /*
         * We need to clone ncwd_path because canonify() works in-place and thus
         * the address in ncwd_path need not be the same as ncwd_path_nc, even
         * though they both point into the same dynamically allocated buffer.
         */
        ncwd_path = str_dup(ncwd_path);
        free(ncwd_path_nc);
        if (!ncwd_path) {
                futex_up(&cwd_futex);
                return NULL;
        }
        futex_up(&cwd_futex);
        return ncwd_path;
}

static void vfs_connect(void)
{
        while (vfs_phone < 0)
                vfs_phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_VFS, 0, 0);
}

static int device_get_handle(const char *name, dev_handle_t *handle,
    const unsigned int flags)
{
        int phone;
        
        if (flags & IPC_FLAG_BLOCKING)
                phone = ipc_connect_me_to_blocking(PHONE_NS, SERVICE_DEVMAP, DEVMAP_CLIENT, 0);
        else
                phone = ipc_connect_me_to(PHONE_NS, SERVICE_DEVMAP, DEVMAP_CLIENT, 0);
        
        if (phone < 0)
                return phone;
        
        ipc_call_t answer;
        aid_t req = async_send_2(phone, DEVMAP_DEVICE_GET_HANDLE, flags, 0,
            &answer);
        
        ipcarg_t retval = ipc_data_write_start(phone, name, str_size(name) + 1);
        
        if (retval != EOK) {
                async_wait_for(req, NULL);
                ipc_hangup(phone);
                return retval;
        }
        
        async_wait_for(req, &retval);
        
        if (handle != NULL)
                *handle = -1;
        
        if (retval == EOK) {
                if (handle != NULL)
                        *handle = (dev_handle_t) IPC_GET_ARG1(answer);
        }
        
        ipc_hangup(phone);
        return retval;
}

int mount(const char *fs_name, const char *mp, const char *dev,
        const unsigned int flags)
{
        int res;
        ipcarg_t rc;
        aid_t req;
        dev_handle_t dev_handle;
        
        res = device_get_handle(dev, &dev_handle, flags);
        if (res != EOK)
                return res;
        
        size_t mpa_size;
        char *mpa = absolutize(mp, &mpa_size);
        if (!mpa)
                return ENOMEM;
        
        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_2(vfs_phone, VFS_MOUNT, dev_handle, flags, NULL);
        rc = ipc_data_write_start(vfs_phone, (void *) mpa, mpa_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(mpa);
                return (int) rc;
        }
        
        rc = ipc_data_write_start(vfs_phone, (void *) fs_name, str_size(fs_name));
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(mpa);
                return (int) rc;
        }

        /* Ask VFS whether it likes fs_name. */
        rc = async_req_0_0(vfs_phone, IPC_M_PING);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(mpa);
                return (int) rc;
        }
        
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        free(mpa);
        
        return (int) rc;
}

static int _open(const char *path, int lflag, int oflag, ...)
{
        ipcarg_t rc;
        ipc_call_t answer;
        aid_t req;
        
        size_t pa_size;
        char *pa = absolutize(path, &pa_size);
        if (!pa)
                return ENOMEM;
        
        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_3(vfs_phone, VFS_OPEN, lflag, oflag, 0, &answer);
        rc = ipc_data_write_start(vfs_phone, pa, pa_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(pa);
                return (int) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        free(pa);

        if (rc != EOK)
            return (int) rc;
        return (int) IPC_GET_ARG1(answer);
}

int open(const char *path, int oflag, ...)
{
        return _open(path, L_FILE, oflag);
}

int close(int fildes)
{
        ipcarg_t rc;
        
        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        rc = async_req_1_0(vfs_phone, VFS_CLOSE, fildes);
        
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        
        return (int)rc;
}

ssize_t read(int fildes, void *buf, size_t nbyte) 
{
        ipcarg_t rc;
        ipc_call_t answer;
        aid_t req;

        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_1(vfs_phone, VFS_READ, fildes, &answer);
        rc = ipc_data_read_start(vfs_phone, (void *)buf, nbyte);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                return (ssize_t) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        if (rc == EOK)
                return (ssize_t) IPC_GET_ARG1(answer);
        else
                return rc;
}

ssize_t write(int fildes, const void *buf, size_t nbyte) 
{
        ipcarg_t rc;
        ipc_call_t answer;
        aid_t req;

        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_1(vfs_phone, VFS_WRITE, fildes, &answer);
        rc = ipc_data_write_start(vfs_phone, (void *)buf, nbyte);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                return (ssize_t) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        if (rc == EOK)
                return (ssize_t) IPC_GET_ARG1(answer);
        else
                return -1;
}

off_t lseek(int fildes, off_t offset, int whence)
{
        ipcarg_t rc;

        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        ipcarg_t newoffs;
        rc = async_req_3_1(vfs_phone, VFS_SEEK, fildes, offset, whence,
            &newoffs);

        async_serialize_end();
        futex_up(&vfs_phone_futex);

        if (rc != EOK)
                return (off_t) -1;
        
        return (off_t) newoffs;
}

int ftruncate(int fildes, off_t length)
{
        ipcarg_t rc;
        
        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        rc = async_req_2_0(vfs_phone, VFS_TRUNCATE, fildes, length);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        return (int) rc;
}

DIR *opendir(const char *dirname)
{
        DIR *dirp = malloc(sizeof(DIR));
        if (!dirp)
                return NULL;
        dirp->fd = _open(dirname, L_DIRECTORY, 0);
        if (dirp->fd < 0) {
                free(dirp);
                return NULL;
        }
        return dirp;
}

struct dirent *readdir(DIR *dirp)
{
        ssize_t len = read(dirp->fd, &dirp->res.d_name[0], NAME_MAX + 1);
        if (len <= 0)
                return NULL;
        return &dirp->res;
}

void rewinddir(DIR *dirp)
{
        (void) lseek(dirp->fd, 0, SEEK_SET);
}

int closedir(DIR *dirp)
{
        (void) close(dirp->fd);
        free(dirp);
        return 0;
}

int mkdir(const char *path, mode_t mode)
{
        ipcarg_t rc;
        aid_t req;
        
        size_t pa_size;
        char *pa = absolutize(path, &pa_size);
        if (!pa)
                return ENOMEM;
        
        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_1(vfs_phone, VFS_MKDIR, mode, NULL);
        rc = ipc_data_write_start(vfs_phone, pa, pa_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(pa);
                return (int) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        free(pa);
        return rc; 
}

static int _unlink(const char *path, int lflag)
{
        ipcarg_t rc;
        aid_t req;
        
        size_t pa_size;
        char *pa = absolutize(path, &pa_size);
        if (!pa)
                return ENOMEM;

        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_0(vfs_phone, VFS_UNLINK, NULL);
        rc = ipc_data_write_start(vfs_phone, pa, pa_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(pa);
                return (int) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        free(pa);
        return rc; 
}

int unlink(const char *path)
{
        return _unlink(path, L_NONE);
}

int rmdir(const char *path)
{
        return _unlink(path, L_DIRECTORY);
}

int rename(const char *old, const char *new)
{
        ipcarg_t rc;
        aid_t req;
        
        size_t olda_size;
        char *olda = absolutize(old, &olda_size);
        if (!olda)
                return ENOMEM;

        size_t newa_size;
        char *newa = absolutize(new, &newa_size);
        if (!newa) {
                free(olda);
                return ENOMEM;
        }

        futex_down(&vfs_phone_futex);
        async_serialize_start();
        vfs_connect();
        
        req = async_send_0(vfs_phone, VFS_RENAME, NULL);
        rc = ipc_data_write_start(vfs_phone, olda, olda_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(olda);
                free(newa);
                return (int) rc;
        }
        rc = ipc_data_write_start(vfs_phone, newa, newa_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                async_serialize_end();
                futex_up(&vfs_phone_futex);
                free(olda);
                free(newa);
                return (int) rc;
        }
        async_wait_for(req, &rc);
        async_serialize_end();
        futex_up(&vfs_phone_futex);
        free(olda);
        free(newa);
        return rc;
}

int chdir(const char *path)
{
        size_t pa_size;
        char *pa = absolutize(path, &pa_size);
        if (!pa)
                return ENOMEM;

        DIR *d = opendir(pa);
        if (!d) {
                free(pa);
                return ENOENT;
        }

        futex_down(&cwd_futex);
        if (cwd_dir) {
                closedir(cwd_dir);
                cwd_dir = NULL;
                free(cwd_path); 
                cwd_path = NULL;
                cwd_size = 0;
        }
        cwd_dir = d;
        cwd_path = pa;
        cwd_size = pa_size;
        futex_up(&cwd_futex);
        return EOK;
}

char *getcwd(char *buf, size_t size)
{
        if (!size)
                return NULL;
        futex_down(&cwd_futex);
        if (size < cwd_size + 1) {
                futex_up(&cwd_futex);
                return NULL;
        }
        str_cpy(buf, size, cwd_path);
        futex_up(&cwd_futex);
        return buf;
}

/** @}
 */