1 /* $NetBSD: write_pid.c,v 1.2 2017/01/28 21:31:50 christos Exp $ */
2
3 /*
4 * Copyright (c) 1999 - 2001 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <config.h>
37
38 #include <krb5/roken.h>
39
40 #ifdef HAVE_UTIL_H
41 #include <util.h>
42 #endif
43
44 ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
pid_file_write(const char * progname)45 pid_file_write(const char *progname)
46 {
47 const char *pidfile_dir = NULL;
48 char *ret = NULL;
49 FILE *fp;
50
51 /*
52 * Maybe we could have a version of this function (and pidfile())
53 * where we get a directory from the caller. That would allow us to
54 * have command-line options for the daemons for this.
55 *
56 * For now we use an environment variable.
57 */
58 if (!issuid())
59 pidfile_dir = getenv("HEIM_PIDFILE_DIR");
60 if (pidfile_dir == NULL)
61 pidfile_dir = _PATH_VARRUN;
62
63 if (asprintf(&ret, "%s%s.pid", pidfile_dir, progname) < 0 || ret == NULL)
64 return NULL;
65 fp = fopen(ret, "w");
66 if (fp == NULL) {
67 free(ret);
68 return NULL;
69 }
70 fprintf(fp, "%lu\n", (unsigned long)getpid());
71 fclose(fp);
72 return ret;
73 }
74
75 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
pid_file_delete(char ** filename)76 pid_file_delete(char **filename)
77 {
78 if (*filename != NULL) {
79 unlink(*filename);
80 free(*filename);
81 *filename = NULL;
82 }
83 }
84
85 static char *pidfile_path;
86 static pid_t pidfile_pid;
87
88 static void
pidfile_cleanup(void)89 pidfile_cleanup(void)
90 {
91 if (pidfile_path != NULL && pidfile_pid == getpid())
92 pid_file_delete(&pidfile_path);
93 }
94
95 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
rk_pidfile(const char * bname)96 rk_pidfile(const char *bname)
97 {
98 /*
99 * If the OS has a pidfile(), call that, but still call
100 * pid_file_write(). Even if both want to write the same file,
101 * writing it twice will still work.
102 */
103 #ifdef HAVE_PIDFILE
104 pidfile(bname);
105 #endif
106
107 if (pidfile_path != NULL)
108 return;
109 if (bname == NULL)
110 bname = getprogname();
111 pidfile_path = pid_file_write(bname);
112 pidfile_pid = getpid();
113 #if defined(HAVE_ATEXIT)
114 if (pidfile_path != NULL)
115 atexit(pidfile_cleanup);
116 #elif defined(HAVE_ON_EXIT)
117 if (pidfile_path != NULL)
118 on_exit(pidfile_cleanup);
119 #endif
120 }
121