example/fusexmp.c

   1 /*
   2     FUSE: Filesystem in Userspace
   3     Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
   4
   5     This program can be distributed under the terms of the GNU GPL.
   6     See the file COPYING.
   7 */
   8
   9 #include <config.h>
  10
  11 #ifdef linux
  12 /* For pread()/pwrite() */
  13 #define _XOPEN_SOURCE 500
  14 #endif
  15
  16 #include <fuse.h>
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20 #include <fcntl.h>
  21 #include <dirent.h>
  22 #include <errno.h>
  23 #include <sys/time.h>
  24 #ifdef HAVE_SETXATTR
  25 #include <sys/xattr.h>
  26 #endif
  27
  28 static int xmp_getattr(const char *path, struct stat *stbuf)
  29 {
  30     int res;
  31
  32     res = lstat(path, stbuf);
  33     if (res == -1)
  34         return -errno;
  35
  36     return 0;
  37 }
  38
  39 static int xmp_access(const char *path, int mask)
  40 {
  41     int res;
  42
  43     res = access(path, mask);
  44     if (res == -1)
  45         return -errno;
  46
  47     return 0;
  48 }
  49
  50 static int xmp_readlink(const char *path, char *buf, size_t size)
  51 {
  52     int res;
  53
  54     res = readlink(path, buf, size - 1);
  55     if (res == -1)
  56         return -errno;
  57
  58     buf[res] = '\0';
  59     return 0;
  60 }
  61
  62
  63 static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
  64                        off_t offset, struct fuse_file_info *fi)
  65 {
  66     DIR *dp;
  67     struct dirent *de;
  68
  69     (void) offset;
  70     (void) fi;
  71
  72     dp = opendir(path);
  73     if (dp == NULL)
  74         return -errno;
  75
  76     while ((de = readdir(dp)) != NULL) {
  77         struct stat st;
  78         memset(&st, 0, sizeof(st));
  79         st.st_ino = de->d_ino;
  80         st.st_mode = de->d_type << 12;
  81         if (filler(buf, de->d_name, &st, 0))
  82             break;
  83     }
  84
  85     closedir(dp);
  86     return 0;
  87 }
  88
  89 static int xmp_mknod(const char *path, mode_t mode, dev_t rdev)
  90 {
  91     int res;
  92
  93     /* On Linux this could just be 'mknod(path, mode, rdev)' but this
  94        is more portable */
  95     if (S_ISREG(mode)) {
  96         res = open(path, O_CREAT | O_EXCL | O_WRONLY, mode);
  97         if (res >= 0)
  98             res = close(res);
  99     } else if (S_ISFIFO(mode))
 100         res = mkfifo(path, mode);
 101     else
 102         res = mknod(path, mode, rdev);
 103     if (res == -1)
 104         return -errno;
 105
 106     return 0;
 107 }
 108
 109 static int xmp_mkdir(const char *path, mode_t mode)
 110 {
 111     int res;
 112
 113     res = mkdir(path, mode);
 114     if (res == -1)
 115         return -errno;
 116
 117     return 0;
 118 }
 119
 120 static int xmp_unlink(const char *path)
 121 {
 122     int res;
 123
 124     res = unlink(path);
 125     if (res == -1)
 126         return -errno;
 127
 128     return 0;
 129 }
 130
 131 static int xmp_rmdir(const char *path)
 132 {
 133     int res;
 134
 135     res = rmdir(path);
 136     if (res == -1)
 137         return -errno;
 138
 139     return 0;
 140 }
 141
 142 static int xmp_symlink(const char *from, const char *to)
 143 {
 144     int res;
 145
 146     res = symlink(from, to);
 147     if (res == -1)
 148         return -errno;
 149
 150     return 0;
 151 }
 152
 153 static int xmp_rename(const char *from, const char *to)
 154 {
 155     int res;
 156
 157     res = rename(from, to);
 158     if (res == -1)
 159         return -errno;
 160
 161     return 0;
 162 }
 163
 164 static int xmp_link(const char *from, const char *to)
 165 {
 166     int res;
 167
 168     res = link(from, to);
 169     if (res == -1)
 170         return -errno;
 171
 172     return 0;
 173 }
 174
 175 static int xmp_chmod(const char *path, mode_t mode)
 176 {
 177     int res;
 178
 179     res = chmod(path, mode);
 180     if (res == -1)
 181         return -errno;
 182
 183     return 0;
 184 }
 185
 186 static int xmp_chown(const char *path, uid_t uid, gid_t gid)
 187 {
 188     int res;
 189
 190     res = lchown(path, uid, gid);
 191     if (res == -1)
 192         return -errno;
 193
 194     return 0;
 195 }
 196
 197 static int xmp_truncate(const char *path, off_t size)
 198 {
 199     int res;
 200
 201     res = truncate(path, size);
 202     if (res == -1)
 203         return -errno;
 204
 205     return 0;
 206 }
 207
 208 static int xmp_utimes(const char *path, const struct timespec ts[2])
 209 {
 210     int res;
 211     struct timeval tv[2];
 212
 213     tv[0].tv_sec = ts[0].tv_sec;
 214     tv[0].tv_usec = ts[0].tv_nsec / 1000;
 215     tv[1].tv_sec = ts[1].tv_sec;
 216     tv[1].tv_usec = ts[1].tv_nsec / 1000;
 217
 218     res = utimes(path, tv);
 219     if (res == -1)
 220         return -errno;
 221
 222     return 0;
 223 }
 224
 225 static int xmp_open(const char *path, struct fuse_file_info *fi)
 226 {
 227     int res;
 228
 229     res = open(path, fi->flags);
 230     if (res == -1)
 231         return -errno;
 232
 233     close(res);
 234     return 0;
 235 }
 236
 237 static int xmp_read(const char *path, char *buf, size_t size, off_t offset,
 238                     struct fuse_file_info *fi)
 239 {
 240     int fd;
 241     int res;
 242
 243     (void) fi;
 244     fd = open(path, O_RDONLY);
 245     if (fd == -1)
 246         return -errno;
 247
 248     res = pread(fd, buf, size, offset);
 249     if (res == -1)
 250         res = -errno;
 251
 252     close(fd);
 253     return res;
 254 }
 255
 256 static int xmp_write(const char *path, const char *buf, size_t size,
 257                      off_t offset, struct fuse_file_info *fi)
 258 {
 259     int fd;
 260     int res;
 261
 262     (void) fi;
 263     fd = open(path, O_WRONLY);
 264     if (fd == -1)
 265         return -errno;
 266
 267     res = pwrite(fd, buf, size, offset);
 268     if (res == -1)
 269         res = -errno;
 270
 271     close(fd);
 272     return res;
 273 }
 274
 275 static int xmp_statfs(const char *path, struct statvfs *stbuf)
 276 {
 277     int res;
 278
 279     res = statvfs(path, stbuf);
 280     if (res == -1)
 281         return -errno;
 282
 283     return 0;
 284 }
 285
 286 static int xmp_release(const char *path, struct fuse_file_info *fi)
 287 {
 288     /* Just a stub.  This method is optional and can safely be left
 289        unimplemented */
 290
 291     (void) path;
 292     (void) fi;
 293     return 0;
 294 }
 295
 296 static int xmp_fsync(const char *path, int isdatasync,
 297                      struct fuse_file_info *fi)
 298 {
 299     /* Just a stub.  This method is optional and can safely be left
 300        unimplemented */
 301
 302     (void) path;
 303     (void) isdatasync;
 304     (void) fi;
 305     return 0;
 306 }
 307
 308 #ifdef HAVE_SETXATTR
 309 /* xattr operations are optional and can safely be left unimplemented */
 310 static int xmp_setxattr(const char *path, const char *name, const char *value,
 311                         size_t size, int flags)
 312 {
 313     int res = lsetxattr(path, name, value, size, flags);
 314     if (res == -1)
 315         return -errno;
 316     return 0;
 317 }
 318
 319 static int xmp_getxattr(const char *path, const char *name, char *value,
 320                     size_t size)
 321 {
 322     int res = lgetxattr(path, name, value, size);
 323     if (res == -1)
 324         return -errno;
 325     return res;
 326 }
 327
 328 static int xmp_listxattr(const char *path, char *list, size_t size)
 329 {
 330     int res = llistxattr(path, list, size);
 331     if (res == -1)
 332         return -errno;
 333     return res;
 334 }
 335
 336 static int xmp_removexattr(const char *path, const char *name)
 337 {
 338     int res = lremovexattr(path, name);
 339     if (res == -1)
 340         return -errno;
 341     return 0;
 342 }
 343 #endif /* HAVE_SETXATTR */
 344
 345 static struct fuse_operations xmp_oper = {
 346     .getattr    = xmp_getattr,
 347     .access     = xmp_access,
 348     .readlink   = xmp_readlink,
 349     .readdir    = xmp_readdir,
 350     .mknod      = xmp_mknod,
 351     .mkdir      = xmp_mkdir,
 352     .symlink    = xmp_symlink,
 353     .unlink     = xmp_unlink,
 354     .rmdir      = xmp_rmdir,
 355     .rename     = xmp_rename,
 356     .link       = xmp_link,
 357     .chmod      = xmp_chmod,
 358     .chown      = xmp_chown,
 359     .truncate   = xmp_truncate,
 360     .utimes     = xmp_utimes,
 361     .open       = xmp_open,
 362     .read       = xmp_read,
 363     .write      = xmp_write,
 364     .statfs     = xmp_statfs,
 365     .release    = xmp_release,
 366     .fsync      = xmp_fsync,
 367 #ifdef HAVE_SETXATTR
 368     .setxattr   = xmp_setxattr,
 369     .getxattr   = xmp_getxattr,
 370     .listxattr  = xmp_listxattr,
 371     .removexattr= xmp_removexattr,
 372 #endif
 373 };
 374
 375 int main(int argc, char *argv[])
 376 {
 377     umask(0);
 378     return fuse_main(argc, argv, &xmp_oper, NULL);
 379 }