iconv.c

FUSE文件系统开发工具,将内核层面的文件系统开发过程平移到应用层面上来。

/*
  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 LGPLv2.
  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();