iconv.c

UNIX/LINUX下面的用户文件系统

/*
    fuse iconv module: file name charset conversion
    Copyright (C) 2007  Miklos Szeredi <[e-mail]>

    This program can be distributed under the terms of the GNU LGPL.
    See the file COPYING.LIB
*/

#define FUSE_USE_VERSION 26

#include <fuse.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <errno.h>
#include <iconv.h>
#include <pthread.h>
#include <locale.h>
#include <langinfo.h>

struct iconv {
    struct fuse_fs *next;
    pthread_mutex_t lock;
    char *from_code;
    char *to_code;
    iconv_t tofs;
    iconv_t fromfs;
};

struct iconv_dh {
    struct iconv *ic;
    void *prev_buf;
    fuse_fill_dir_t prev_filler;
};

static struct iconv *iconv_get(void)
{
    return fuse_get_context()->private_data;
}

static int iconv_convpath(struct iconv *ic, const char *path, char **newpathp,
                          int fromfs)
{
    size_t pathlen = strlen(path);
    size_t newpathlen = pathlen * 4;
    char *newpath = malloc(newpathlen + 1);
    size_t plen = newpathlen;
    char *p = newpath;
    size_t res;
    int err;

    if (!newpath)
        return -ENOMEM;

    pthread_mutex_lock(&ic->lock);
    do {
        res = iconv(fromfs ? ic->fromfs : ic->tofs, (char **) &path, &pathlen,
                    &p, &plen);
        if (res == (size_t) -1) {
            char *tmp;
            size_t inc;

            err = -EILSEQ;
            if (errno != E2BIG)
                goto err;

            inc = (pathlen + 1) * 4;
            newpathlen += inc;
            tmp = realloc(newpath, newpathlen + 1);
            err = -ENOMEM;
            if (!tmp)
                goto err;

            p = tmp + (p - newpath);
            plen += inc;
            newpath = tmp;
        }
    } while (res == (size_t) -1);
    pthread_mutex_unlock(&ic->lock);
    *p = '\0';
    *newpathp = newpath;
    return 0;

 err:
    iconv(fromfs ? ic->fromfs : ic->tofs, NULL, NULL, NULL, NULL);
    pthread_mutex_unlock(&ic->lock);
    free(newpath);
    return err;
}

static int iconv_getattr(const char *path, struct stat *stbuf)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_getattr(ic->next, newpath, stbuf);
        free(newpath);
    }
    return err;
}

static int iconv_fgetattr(const char *path, struct stat *stbuf,
                          struct fuse_file_info *fi)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_fgetattr(ic->next, newpath, stbuf, fi);
        free(newpath);
    }
    return err;
}

static int iconv_access(const char *path, int mask)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_access(ic->next, newpath, mask);
        free(newpath);
    }
    return err;
}

static int iconv_readlink(const char *path, char *buf, size_t size)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_readlink(ic->next, newpath, buf, size);
        if (!err) {
            char *newlink;
            err = iconv_convpath(ic, buf, &newlink, 1);
            if (!err) {
                strncpy(buf, newlink, size - 1);
                buf[size - 1] = '\0';
                free(newlink);
            }
        }
        free(newpath);
    }
    return err;
}

static int iconv_opendir(const char *path, struct fuse_file_info *fi)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_opendir(ic->next, newpath, fi);
        free(newpath);
    }
    return err;
}

static int iconv_dir_fill(void *buf, const char *name,
                          const struct stat *stbuf, off_t off)
{
    struct iconv_dh *dh = buf;
    char *newname;
    int res = 0;
    if (iconv_convpath(dh->ic, name, &newname, 1) == 0) {
        res = dh->prev_filler(dh->prev_buf, newname, stbuf, off);
        free(newname);
    }
    return res;
}

static int iconv_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                         off_t offset, struct fuse_file_info *fi)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        struct iconv_dh dh;
        dh.ic = ic;
        dh.prev_buf = buf;
        dh.prev_filler = filler;
        err = fuse_fs_readdir(ic->next, newpath, &dh, iconv_dir_fill, offset,
                              fi);
        free(newpath);
    }
    return err;
}

static int iconv_releasedir(const char *path, struct fuse_file_info *fi)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_releasedir(ic->next, newpath, fi);
        free(newpath);
    }
    return err;
}

static int iconv_mknod(const char *path, mode_t mode, dev_t rdev)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_mknod(ic->next, newpath, mode, rdev);
        free(newpath);
    }
    return err;
}

static int iconv_mkdir(const char *path, mode_t mode)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_mkdir(ic->next, newpath, mode);
        free(newpath);
    }
    return err;
}

static int iconv_unlink(const char *path)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_unlink(ic->next, newpath);
        free(newpath);
    }
    return err;
}

static int iconv_rmdir(const char *path)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_rmdir(ic->next, newpath);
        free(newpath);
    }
    return err;
}

static int iconv_symlink(const char *from, const char *to)
{
    struct iconv *ic = iconv_get();
    char *newfrom;
    char *newto;
    int err = iconv_convpath(ic, from, &newfrom, 0);
    if (!err) {
        err = iconv_convpath(ic, to, &newto, 0);
        if (!err) {
            err = fuse_fs_symlink(ic->next, newfrom, newto);
            free(newto);
        }
        free(newfrom);
    }
    return err;
}

static int iconv_rename(const char *from, const char *to)
{
    struct iconv *ic = iconv_get();
    char *newfrom;
    char *newto;
    int err = iconv_convpath(ic, from, &newfrom, 0);
    if (!err) {
        err = iconv_convpath(ic, to, &newto, 0);
        if (!err) {
            err = fuse_fs_rename(ic->next, newfrom, newto);
            free(newto);
        }
        free(newfrom);
    }
    return err;
}

static int iconv_link(const char *from, const char *to)
{
    struct iconv *ic = iconv_get();
    char *newfrom;
    char *newto;
    int err = iconv_convpath(ic, from, &newfrom, 0);
    if (!err) {
        err = iconv_convpath(ic, to, &newto, 0);
        if (!err) {
            err = fuse_fs_link(ic->next, newfrom, newto);
            free(newto);
        }
        free(newfrom);
    }
    return err;
}

static int iconv_chmod(const char *path, mode_t mode)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_chmod(ic->next, newpath, mode);
        free(newpath);
    }
    return err;
}

static int iconv_chown(const char *path, uid_t uid, gid_t gid)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_chown(ic->next, newpath, uid, gid);
        free(newpath);
    }
    return err;
}

static int iconv_truncate(const char *path, off_t size)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_truncate(ic->next, newpath, size);
        free(newpath);
    }
    return err;
}

static int iconv_ftruncate(const char *path, off_t size,
                           struct fuse_file_info *fi)
{
    struct iconv *ic = iconv_get();
    char *newpath;
    int err = iconv_convpath(ic, path, &newpath, 0);
    if (!err) {
        err = fuse_fs_ftruncate(ic->next, newpath, size, fi);
        free(newpath);
    }
    return err;
}

static int iconv_utimens(const char *path, const struct timespec ts[2])
{
    struct iconv *ic = iconv_get();