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 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 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 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 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