contrib/bind-9.5.2/bin/rndc/unix/os.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: os.c,v 1.10 2007/06/19 23:46:59 tbox Exp $ */
  19
  20 /*! \file */
  21
  22 #include <config.h>
  23
  24 #include <rndc/os.h>
  25
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include <sys/types.h>
  29 #include <pwd.h>
  30 #include <errno.h>
  31 #include <stdio.h>
  32 #include <sys/stat.h>
  33
  34 int
  35 set_user(FILE *fd, const char *user) {
  36         struct passwd *pw;
  37
  38         pw = getpwnam(user);
  39         if (pw == NULL) {
  40                 errno = EINVAL;
  41                 return (-1);
  42         }
  43         return (fchown(fileno(fd), pw->pw_uid, -1));
  44 }
  45
  46 FILE *
  47 safe_create(const char *filename) {
  48         int fd;
  49         FILE *f;
  50         struct stat sb;
  51         int flags = O_WRONLY;
  52
  53         if (stat(filename, &sb) == -1) {
  54                 if (errno != ENOENT)
  55                         return (NULL);
  56                 flags = O_WRONLY | O_CREAT | O_EXCL;
  57         } else if ((sb.st_mode & S_IFREG) == 0) {
  58                 errno = EOPNOTSUPP;
  59                 return (NULL);
  60         } else
  61                 flags = O_WRONLY | O_TRUNC;
  62
  63         fd = open(filename, flags, S_IRUSR | S_IWUSR);
  64         if (fd == -1)
  65                 return (NULL);
  66         f = fdopen(fd, "w");
  67         if (f == NULL)
  68                 close(fd);
  69         return (f);
  70 }