lib/pid_output.c

   1 /*
   2  * Process id output.
   3  * Copyright (C) 1998, 1999 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24 #include <fcntl.h>
  25 #include <log.h>
  26 #include "version.h"
  27
  28 #ifndef HAVE_FCNTL
  29
  30 pid_t
  31 pid_output (const char *path)
  32 {
  33   FILE *fp;
  34   pid_t pid;
  35   mode_t oldumask;
  36
  37   pid = getpid();
  38
  39   oldumask = umask(0777 & ~LOGFILE_MASK);
  40   fp = fopen (path, "w");
  41   if (fp != NULL)
  42     {
  43       fprintf (fp, "%d\n", (int) pid);
  44       fclose (fp);
  45       umask(oldumask);
  46       return pid;
  47     }
  48   /* XXX Why do we continue instead of exiting?  This seems incompatible
  49      with the behavior of the fcntl version below. */
  50   zlog_warn("Can't fopen pid lock file %s (%s), continuing",
  51             path, safe_strerror(errno));
  52   umask(oldumask);
  53   return -1;
  54 }
  55
  56 #else /* HAVE_FCNTL */
  57
  58 pid_t
  59 pid_output (const char *path)
  60 {
  61   int tmp;
  62   int fd;
  63   pid_t pid;
  64   char buf[16];
  65   struct flock lock;
  66   mode_t oldumask;
  67
  68   pid = getpid ();
  69
  70   oldumask = umask(0777 & ~LOGFILE_MASK);
  71   fd = open (path, O_RDWR | O_CREAT, LOGFILE_MASK);
  72   if (fd < 0)
  73     {
  74       zlog_err("Can't create pid lock file %s (%s), exiting",
  75                path, safe_strerror(errno));
  76       umask(oldumask);
  77       exit(1);
  78     }
  79   else
  80     {
  81       size_t pidsize;
  82
  83       umask(oldumask);
  84       memset (&lock, 0, sizeof(lock));
  85
  86       lock.l_type = F_WRLCK;
  87       lock.l_whence = SEEK_SET;
  88
  89       if (fcntl(fd, F_SETLK, &lock) < 0)
  90         {
  91           zlog_err("Could not lock pid_file %s, exiting", path);
  92           exit(1);
  93         }
  94
  95       sprintf (buf, "%d\n", (int) pid);
  96       pidsize = strlen(buf);
  97       if ((tmp = write (fd, buf, pidsize)) != (int)pidsize)
  98         zlog_err("Could not write pid %d to pid_file %s, rc was %d: %s",
  99                  (int)pid,path,tmp,safe_strerror(errno));
 100       else if (ftruncate(fd, pidsize) < 0)
 101         zlog_err("Could not truncate pid_file %s to %u bytes: %s",
 102                  path,(u_int)pidsize,safe_strerror(errno));
 103     }
 104   return pid;
 105 }
 106
 107 #endif /* HAVE_FCNTL */