1/* $Xorg: lock.c,v 1.4 2001/02/09 02:05:59 xorgcvs Exp $ */
2/******************************************************************************
3
4Copyright 1994, 1998  The Open Group
5
6Permission to use, copy, modify, distribute, and sell this software and its
7documentation for any purpose is hereby granted without fee, provided that
8the above copyright notice appear in all copies and that both that
9copyright notice and this permission notice appear in supporting
10documentation.
11
12The above copyright notice and this permission notice shall be included in
13all copies or substantial portions of the Software.
14
15THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
18OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
19AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21
22Except as contained in this notice, the name of The Open Group shall not be
23used in advertising or otherwise to promote the sale, use or other dealings
24in this Software without prior written authorization from The Open Group.
25******************************************************************************/
26/* $XFree86: xc/programs/xsm/lock.c,v 3.4 2001/12/14 20:02:25 dawes Exp $ */
27
28#include "xsm.h"
29#include "lock.h"
30#include "choose.h"
31#include <sys/types.h>
32
33
34static const char *
35GetPath(void)
36{
37    const char *path = getenv ("SM_SAVE_DIR");
38
39    if (!path)
40    {
41	path = getenv ("HOME");
42	if (!path)
43	    path = ".";
44    }
45
46    return (path);
47}
48
49
50Status
51LockSession(const char *session_name, Bool write_id)
52{
53    const char *path;
54    char lock_file[PATH_MAX];
55    char temp_lock_file[PATH_MAX];
56    Status status;
57    int fd;
58
59    path = GetPath ();
60
61    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
62	      path, session_name);
63    snprintf (temp_lock_file, sizeof(temp_lock_file), "%s/.XSMtlock-%s",
64	      path, session_name);
65
66    if ((fd = creat (temp_lock_file, 0444)) < 0)
67	return (0);
68
69    if ((write_id &&
70        (write (fd, networkIds, strlen (networkIds)) != strlen (networkIds))) ||
71	(write (fd, "\n", 1) != 1))
72    {
73	close (fd);
74	return (0);
75    }
76
77    close (fd);
78
79    status = 1;
80
81    if (link (temp_lock_file, lock_file) < 0)
82	status = 0;
83
84    if (remove (temp_lock_file) < 0)
85	status = 0;
86
87    return (status);
88}
89
90
91void
92UnlockSession(const char *session_name)
93{
94    const char *path;
95    char lock_file[PATH_MAX];
96
97    path = GetPath ();
98
99    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
100	      path, session_name);
101
102    remove (lock_file);
103}
104
105
106char *
107GetLockId(const char *session_name)
108{
109    const char *path;
110    FILE *fp;
111    char lock_file[PATH_MAX];
112    char buf[256];
113    char *ret;
114
115    path = GetPath ();
116
117    snprintf (lock_file, sizeof(lock_file), "%s/.XSMlock-%s",
118	      path, session_name);
119
120    if ((fp = fopen (lock_file, "r")) == NULL)
121    {
122	return (NULL);
123    }
124    fcntl(fileno(fp), F_SETFD, FD_CLOEXEC);
125
126    buf[0] = '\0';
127    fscanf (fp, "%255s\n", buf);
128    ret = XtNewString (buf);
129
130    fclose (fp);
131
132    return (ret);
133}
134
135
136Bool
137CheckSessionLocked(const char *session_name, Bool get_id, char **id_ret)
138{
139    if (get_id)
140	*id_ret = GetLockId (session_name);
141
142    if (!LockSession (session_name, False))
143	return (1);
144
145    UnlockSession (session_name);
146    return (0);
147}
148
149
150void
151UnableToLockSession(const char *session_name)
152{
153    /*
154     * We should popup a dialog here giving error.
155     */
156
157#ifdef XKB
158    XkbStdBell(XtDisplay(topLevel),XtWindow(topLevel),0,XkbBI_Failure);
159#else
160    XBell (XtDisplay (topLevel), 0);
161#endif
162    sleep (2);
163
164    ChooseSession ();
165}
166