lib/libvboxfs/handle.c

   1 /* Part of libvboxfs - (c) 2012, D.C. van Moolenbroek */
   2
   3 #include "inc.h"
   4
   5 /*
   6  * Create or open a file or directory.
   7  */
   8 int
   9 vboxfs_open_file(char *path, int flags, int mode, vboxfs_handle_t *handlep,
  10         vboxfs_objinfo_t *infop)
  11 {
  12         vbox_param_t param[3];
  13         vboxfs_path_t pathbuf;
  14         vboxfs_crinfo_t crinfo;
  15         int r, dir, rflag, wflag;
  16
  17         if ((r = vboxfs_set_path(&pathbuf, path)) != OK)
  18                 return r;
  19
  20         memset(&crinfo, 0, sizeof(crinfo));
  21
  22         /*
  23          * Note that the mode may not be set at all.  If no new file may be
  24          * created, this is not a problem.  The following test succeeds only if
  25          * the caller explicitly specified that a directory is involved.
  26          */
  27         dir = S_ISDIR(mode);
  28
  29         /* Convert open(2) flags to VirtualBox creation flags. */
  30         if (flags & O_APPEND)
  31                 return EINVAL;  /* not supported at this time */
  32
  33         if (flags & O_CREAT) {
  34                 crinfo.flags = VBOXFS_CRFLAG_CREATE_IF_NEW;
  35
  36                 if (flags & O_EXCL)
  37                         crinfo.flags |= VBOXFS_CRFLAG_FAIL_IF_EXISTS;
  38                 else if (flags & O_TRUNC)
  39                         crinfo.flags |= VBOXFS_CRFLAG_TRUNC_IF_EXISTS;
  40                 else
  41                         crinfo.flags |= VBOXFS_CRFLAG_OPEN_IF_EXISTS;
  42         } else {
  43                 crinfo.flags = VBOXFS_CRFLAG_FAIL_IF_NEW;
  44
  45                 if (flags & O_TRUNC)
  46                         crinfo.flags |= VBOXFS_CRFLAG_TRUNC_IF_EXISTS;
  47                 else
  48                         crinfo.flags |= VBOXFS_CRFLAG_OPEN_IF_EXISTS;
  49         }
  50
  51         /*
  52          * If an object information structure is given, open the file only to
  53          * retrieve or change its attributes.
  54          */
  55         if (infop != NULL) {
  56                 rflag = VBOXFS_CRFLAG_READ_ATTR;
  57                 wflag = VBOXFS_CRFLAG_WRITE_ATTR;
  58         } else {
  59                 rflag = VBOXFS_CRFLAG_READ;
  60                 wflag = VBOXFS_CRFLAG_WRITE;
  61         }
  62
  63         switch (flags & O_ACCMODE) {
  64         case O_RDONLY:  crinfo.flags |= rflag;          break;
  65         case O_WRONLY:  crinfo.flags |= wflag;          break;
  66         case O_RDWR:    crinfo.flags |= rflag | wflag;  break;
  67         default:        return EINVAL;
  68         }
  69
  70         if (S_ISDIR(mode))
  71                 crinfo.flags |= VBOXFS_CRFLAG_DIRECTORY;
  72
  73         crinfo.info.attr.mode = VBOXFS_SET_MODE(dir ? S_IFDIR : S_IFREG, mode);
  74         crinfo.info.attr.add = VBOXFS_OBJATTR_ADD_NONE;
  75
  76         vbox_set_u32(&param[0], vboxfs_root);
  77         vbox_set_ptr(&param[1], &pathbuf, vboxfs_get_path_size(&pathbuf),
  78             VBOX_DIR_OUT);
  79         vbox_set_ptr(&param[2], &crinfo, sizeof(crinfo), VBOX_DIR_INOUT);
  80
  81         r = vbox_call(vboxfs_conn, VBOXFS_CALL_CREATE, param, 3, NULL);
  82         if (r != OK)
  83                 return r;
  84
  85         if (crinfo.handle == VBOXFS_INVALID_HANDLE) {
  86                 switch (crinfo.result) {
  87                 case VBOXFS_PATH_NOT_FOUND:
  88                         /*
  89                          * This could also mean ENOTDIR, but there does not
  90                          * appear to be any way to distinguish that case.
  91                          * Verifying with extra lookups seems overkill.
  92                          */
  93                 case VBOXFS_FILE_NOT_FOUND:
  94                         return ENOENT;
  95                 case VBOXFS_FILE_EXISTS:
  96                         return EEXIST;
  97                 default:
  98                         return EIO;             /* should never happen */
  99                 }
 100         }
 101
 102         *handlep = crinfo.handle;
 103         if (infop != NULL)
 104                 *infop = crinfo.info;
 105         return OK;
 106 }
 107
 108 /*
 109  * Close an open file handle.
 110  */
 111 void
 112 vboxfs_close_file(vboxfs_handle_t handle)
 113 {
 114         vbox_param_t param[2];
 115
 116         vbox_set_u32(&param[0], vboxfs_root);
 117         vbox_set_u64(&param[1], handle);
 118
 119         /* Ignore errors here. We cannot do anything with them anyway. */
 120         (void) vbox_call(vboxfs_conn, VBOXFS_CALL_CLOSE, param, 2, NULL);
 121 }