XIQueryDevice.c revision 5bc19eeb 
1/*
2 * Copyright © 2009 Red Hat, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 */
24
25#if HAVE_CONFIG_H
26#include <config.h>
27#endif
28
29#include <limits.h>
30#include <stdint.h>
31#include <X11/Xlibint.h>
32#include <X11/extensions/XI2proto.h>
33#include <X11/extensions/XInput2.h>
34#include <X11/extensions/extutil.h>
35#include "XIint.h"
36
37extern int copy_classes(XIDeviceInfo* to, xXIAnyInfo* from, int *nclasses);
38extern int size_classes(xXIAnyInfo* from, int nclasses);
39
40XIDeviceInfo*
41XIQueryDevice(Display *dpy, int deviceid, int *ndevices_return)
42{
43    XIDeviceInfo        *info = NULL;
44    xXIQueryDeviceReq   *req;
45    xXIQueryDeviceReply reply;
46    char                *ptr;
47    char                *end;
48    int                 i;
49    char                *buf = NULL;
50
51    XExtDisplayInfo *extinfo = XInput_find_display(dpy);
52
53    LockDisplay(dpy);
54    if (_XiCheckExtInit(dpy, XInput_2_0, extinfo) == -1)
55        goto error_unlocked;
56
57    GetReq(XIQueryDevice, req);
58    req->reqType  = extinfo->codes->major_opcode;
59    req->ReqType  = X_XIQueryDevice;
60    req->deviceid = deviceid;
61
62    if (!_XReply(dpy, (xReply*) &reply, 0, xFalse))
63        goto error;
64
65    if (reply.length < INT_MAX / 4)
66    {
67	*ndevices_return = reply.num_devices;
68	info = Xmalloc((reply.num_devices + 1) * sizeof(XIDeviceInfo));
69	buf = Xmalloc(reply.length * 4);
70    }
71    else
72    {
73	*ndevices_return = 0;
74	info = NULL;
75	buf = NULL;
76    }
77
78    if (!info || !buf)
79        goto error;
80
81    _XRead(dpy, buf, reply.length * 4);
82    ptr = buf;
83    end = buf + reply.length * 4;
84
85    /* info is a null-terminated array */
86    info[reply.num_devices].name = NULL;
87
88    for (i = 0; i < reply.num_devices; i++)
89    {
90        int             nclasses;
91        size_t          sz;
92        XIDeviceInfo    *lib = &info[i];
93        xXIDeviceInfo   *wire = (xXIDeviceInfo*)ptr;
94
95        if (ptr + sizeof(xXIDeviceInfo) > end)
96            goto error_loop;
97
98        lib->deviceid    = wire->deviceid;
99        lib->use         = wire->use;
100        lib->attachment  = wire->attachment;
101        lib->enabled     = wire->enabled;
102        nclasses         = wire->num_classes;
103
104        ptr += sizeof(xXIDeviceInfo);
105
106        if (ptr + wire->name_len > end)
107            goto error_loop;
108
109        lib->name = Xcalloc(wire->name_len + 1, 1);
110        if (lib->name == NULL)
111            goto error_loop;
112        strncpy(lib->name, ptr, wire->name_len);
113        lib->name[wire->name_len] = '\0';
114        ptr += ((wire->name_len + 3)/4) * 4;
115
116        sz = size_classes((xXIAnyInfo*)ptr, nclasses);
117        lib->classes = Xmalloc(sz);
118        if (lib->classes == NULL)
119        {
120            Xfree(lib->name);
121            goto error_loop;
122        }
123        ptr += copy_classes(lib, (xXIAnyInfo*)ptr, &nclasses);
124        /* We skip over unused classes */
125        lib->num_classes = nclasses;
126    }
127
128    Xfree(buf);
129    UnlockDisplay(dpy);
130    SyncHandle();
131    return info;
132
133error_loop:
134    while (--i >= 0)
135    {
136        Xfree(info[i].name);
137        Xfree(info[i].classes);
138    }
139error:
140    Xfree(info);
141    Xfree(buf);
142    UnlockDisplay(dpy);
143error_unlocked:
144    SyncHandle();
145    *ndevices_return = -1;
146    return NULL;
147}
148
149void
150XIFreeDeviceInfo(XIDeviceInfo* info)
151{
152    XIDeviceInfo *ptr = info;
153    while(ptr && ptr->name)
154    {
155        Xfree(ptr->classes);
156        Xfree(ptr->name);
157        ptr++;
158    }
159    Xfree(info);
160}
161