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      1 /************************************************************
      2 
      3 Copyright 2008 Peter Hutterer
      4 
      5 Permission to use, copy, modify, distribute, and sell this software and its
      6 documentation for any purpose is hereby granted without fee, provided that
      7 the above copyright notice appear in all copies and that both that
      8 copyright notice and this permission notice appear in supporting
      9 documentation.
     10 
     11 The above copyright notice and this permission notice shall be included in
     12 all copies or substantial portions of the Software.
     13 
     14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
     17 AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
     18 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     19 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     20 
     21 Except as contained in this notice, the name of the author shall not be
     22 used in advertising or otherwise to promote the sale, use or other dealings
     23 in this Software without prior written authorization from the author.
     24 
     25 */
     26 
     27 /***********************************************************************
     28  * XGetDeviceProperties - get an input device's properties.
     29  */
     30 
     31 #ifdef HAVE_CONFIG_H
     32 #include <config.h>
     33 #endif
     34 
     35 #include <X11/Xlibint.h>
     36 #include <X11/extensions/XI.h>
     37 #include <X11/extensions/XIproto.h>
     38 #include <X11/extensions/XInput.h>
     39 #include <X11/extensions/extutil.h>
     40 #include "XIint.h"
     41 #include <limits.h>
     42 
     43 int
     44 XGetDeviceProperty(Display* dpy, XDevice* dev,
     45 			 Atom property, long offset, long length, Bool delete,
     46                          Atom req_type, Atom *actual_type, int *actual_format,
     47                          unsigned long *nitems, unsigned long *bytes_after,
     48                          unsigned char **prop)
     49 {
     50     xGetDevicePropertyReq   *req;
     51     xGetDevicePropertyReply rep;
     52     unsigned long           nbytes, rbytes;
     53     int                     ret = Success;
     54 
     55     XExtDisplayInfo *info = XInput_find_display(dpy);
     56 
     57     LockDisplay(dpy);
     58     if (_XiCheckExtInit(dpy, XInput_Initial_Release, info) == -1)
     59 	return 1;
     60 
     61     GetReq(GetDeviceProperty, req);
     62     req->reqType    = info->codes->major_opcode;
     63     req->ReqType    = X_GetDeviceProperty;
     64     req->deviceid   = dev->device_id;
     65     req->property   = property;
     66     req->type       = req_type;
     67     req->longOffset = offset;
     68     req->longLength = length;
     69     req->delete     = delete;
     70 
     71     if (!_XReply (dpy, (xReply *) &rep, 0, xFalse))
     72     {
     73 	UnlockDisplay (dpy);
     74 	SyncHandle ();
     75 	return 1;
     76     }
     77 
     78     *prop = (unsigned char *) NULL;
     79 
     80     if (rep.propertyType != None) {
     81 	/*
     82 	 * One extra byte is malloced than is needed to contain the property
     83 	 * data, but this last byte is null terminated and convenient for
     84 	 * returning string properties, so the client doesn't then have to
     85 	 * recopy the string to make it null terminated.
     86 	 *
     87 	 * Maximum item limits are set to both prevent integer overflow when
     88 	 * calculating the amount of memory to malloc, and to limit how much
     89 	 * memory will be used if a server provides an insanely high count.
     90 	 */
     91 	switch (rep.format) {
     92 	case 8:
     93 	    if (rep.nItems < INT_MAX) {
     94 		nbytes = rep.nItems;
     95 		rbytes = rep.nItems + 1;
     96 		if ((*prop = Xmalloc (rbytes)))
     97 		    _XReadPad (dpy, (char *) *prop, nbytes);
     98 		else
     99 		    ret = BadAlloc;
    100 	    }
    101 	    break;
    102 
    103 	case 16:
    104 	    if (rep.nItems < (INT_MAX / sizeof (short))) {
    105 		nbytes = rep.nItems << 1;
    106 		rbytes = rep.nItems * sizeof (short) + 1;
    107 		if ((*prop = Xmalloc (rbytes)))
    108 		    _XRead16Pad (dpy, (short *) *prop, nbytes);
    109 		else
    110 		    ret = BadAlloc;
    111 	    }
    112 	    break;
    113 
    114 	case 32:
    115 	    if (rep.nItems < (INT_MAX / sizeof (long))) {
    116 		nbytes = rep.nItems << 2;
    117 		rbytes = rep.nItems * sizeof (long) + 1;
    118 		if ((*prop = Xmalloc (rbytes)))
    119 		    _XRead32 (dpy, (long *) *prop, nbytes);
    120 		else
    121 		    ret = BadAlloc;
    122 	    }
    123 	    break;
    124 
    125 	default:
    126 	    /*
    127 	     * This part of the code should never be reached.  If it is,
    128 	     * the server sent back a property with an invalid format.
    129 	     */
    130 	    ret = BadImplementation;
    131 	}
    132 	if (! *prop) {
    133 	    _XEatDataWords(dpy, rep.length);
    134 	    if (ret == Success)
    135 		ret = BadAlloc;
    136 	    goto out;
    137 	}
    138 	(*prop)[rbytes - 1] = '\0';
    139     }
    140 
    141     *actual_type = rep.propertyType;
    142     *actual_format = rep.format;
    143     *nitems = rep.nItems;
    144     *bytes_after = rep.bytesAfter;
    145   out:
    146     UnlockDisplay (dpy);
    147     SyncHandle ();
    148 
    149     return ret;
    150 }
    151 
    152