lib/libvboxfs/attr.c

   1 /* Part of libvboxfs - (c) 2012, D.C. van Moolenbroek */
   2
   3 #include "inc.h"
   4
   5 /*
   6  * Convert a VirtualBox timestamp to a POSIX timespec structure.
   7  * VirtualBox' timestamps are in nanoseconds since the UNIX epoch.
   8  */
   9 static void
  10 get_time(struct timespec *tsp, u64_t nsecs)
  11 {
  12
  13         tsp->tv_sec = div64u(nsecs, 1000000000);
  14         tsp->tv_nsec = rem64u(nsecs, 1000000000);
  15 }
  16
  17 /*
  18  * Convert a POSIX timespec structure to a VirtualBox timestamp.
  19  */
  20 static u64_t
  21 set_time(struct timespec *tsp)
  22 {
  23
  24         return add64u(mul64u(tsp->tv_sec, 1000000000), tsp->tv_nsec);
  25 }
  26
  27 /*
  28  * Fill the given attribute structure with VirtualBox object information.
  29  */
  30 void
  31 vboxfs_get_attr(struct sffs_attr *attr, vboxfs_objinfo_t *info)
  32 {
  33
  34         if (attr->a_mask & SFFS_ATTR_SIZE)
  35                 attr->a_size = info->size;
  36         if (attr->a_mask & SFFS_ATTR_MODE)
  37                 attr->a_mode = VBOXFS_GET_MODE(info->attr.mode);
  38         if (attr->a_mask & SFFS_ATTR_ATIME)
  39                 get_time(&attr->a_atime, info->atime);
  40         if (attr->a_mask & SFFS_ATTR_MTIME)
  41                 get_time(&attr->a_mtime, info->mtime);
  42         if (attr->a_mask & SFFS_ATTR_CTIME)
  43                 get_time(&attr->a_ctime, info->ctime);
  44         if (attr->a_mask & SFFS_ATTR_CRTIME)
  45                 get_time(&attr->a_crtime, info->crtime);
  46 }
  47
  48 /*
  49  * Get file attributes.
  50  */
  51 int
  52 vboxfs_getattr(char *path, struct sffs_attr *attr)
  53 {
  54         vbox_param_t param[3];
  55         vboxfs_path_t pathbuf;
  56         vboxfs_crinfo_t crinfo;
  57         int r;
  58
  59         if ((r = vboxfs_set_path(&pathbuf, path)) != OK)
  60                 return r;
  61
  62         memset(&crinfo, 0, sizeof(crinfo));
  63         crinfo.flags = VBOXFS_CRFLAG_LOOKUP;
  64         /* crinfo.info.attr.add is not checked */
  65
  66         vbox_set_u32(&param[0], vboxfs_root);
  67         vbox_set_ptr(&param[1], &pathbuf, vboxfs_get_path_size(&pathbuf),
  68             VBOX_DIR_OUT);
  69         vbox_set_ptr(&param[2], &crinfo, sizeof(crinfo), VBOX_DIR_INOUT);
  70
  71         r = vbox_call(vboxfs_conn, VBOXFS_CALL_CREATE, param, 3, NULL);
  72         if (r != OK)
  73                 return r;
  74
  75         switch (crinfo.result) {
  76         case VBOXFS_PATH_NOT_FOUND:
  77                 /* This could also be ENOTDIR. See note in handle.c. */
  78         case VBOXFS_FILE_NOT_FOUND:
  79                 return ENOENT;
  80         case VBOXFS_FILE_EXISTS:
  81                 break;                  /* success */
  82         default:
  83                 return EIO;             /* should never happen */
  84         }
  85
  86         vboxfs_get_attr(attr, &crinfo.info);
  87
  88         return OK;
  89 }
  90
  91 /*
  92  * Set file size.
  93  */
  94 static int
  95 set_size(char *path, u64_t size)
  96 {
  97         vboxfs_objinfo_t info;
  98         vboxfs_handle_t h;
  99         int r;
 100
 101         if ((r = vboxfs_open_file(path, O_WRONLY, S_IFREG, &h, NULL)) != OK)
 102                 return r;
 103
 104         memset(&info, 0, sizeof(info));
 105         info.size = size;
 106
 107         r = vboxfs_getset_info(h, VBOXFS_INFO_SET | VBOXFS_INFO_SIZE, &info,
 108             sizeof(info));
 109
 110         vboxfs_close_file(h);
 111
 112         return r;
 113 }
 114
 115 /*
 116  * Set file attributes.
 117  */
 118 int
 119 vboxfs_setattr(char *path, struct sffs_attr *attr)
 120 {
 121         vboxfs_objinfo_t info;
 122         vboxfs_handle_t h;
 123         int r;
 124
 125         /*
 126          * Setting the size of a path cannot be combined with other attribute
 127          * modifications, because we cannot fail atomically.
 128          */
 129         if (attr->a_mask & SFFS_ATTR_SIZE) {
 130                 assert(attr->a_mask == SFFS_ATTR_SIZE);
 131
 132                 return set_size(path, attr->a_size);
 133         }
 134
 135         /*
 136          * By passing a pointer to an object information structure, we open the
 137          * file for attribute manipulation.  Note that this call will open the
 138          * file as a regular file.  This works on directories as well.
 139          */
 140         if ((r = vboxfs_open_file(path, O_WRONLY, 0, &h, &info)) != OK)
 141                 return r;
 142
 143         info.attr.add = VBOXFS_OBJATTR_ADD_NONE;
 144
 145         /* Update the file's permissions if requested. */
 146         if (attr->a_mask & SFFS_ATTR_MODE)
 147                 info.attr.mode =
 148                     VBOXFS_SET_MODE(info.attr.mode & S_IFMT, attr->a_mode);
 149
 150         /*
 151          * Update various file times if requested.  Not all changes may
 152          * be honered.  A zero time indicates no change.
 153          */
 154         info.atime = (attr->a_mask & SFFS_ATTR_ATIME) ?
 155             set_time(&attr->a_atime) : 0;
 156         info.mtime = (attr->a_mask & SFFS_ATTR_MTIME) ?
 157             set_time(&attr->a_ctime) : 0;
 158         info.ctime = (attr->a_mask & SFFS_ATTR_CTIME) ?
 159             set_time(&attr->a_ctime) : 0;
 160         info.crtime = (attr->a_mask & SFFS_ATTR_CRTIME) ?
 161             set_time(&attr->a_crtime) : 0;
 162
 163         r = vboxfs_getset_info(h, VBOXFS_INFO_SET | VBOXFS_INFO_FILE, &info,
 164             sizeof(info));
 165
 166         vboxfs_close_file(h);
 167
 168         return r;
 169 }