third_party/heimdal/lib/roken/write_pid.c

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