contrib/bind-9.2.4rc7/bin/rndc/unix/os.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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 1.5.2.1 2004/03/09 06:09:28 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <rndc/os.h>
  23
  24 #include <fcntl.h>
  25 #include <unistd.h>
  26 #include <sys/types.h>
  27 #include <pwd.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <sys/stat.h>
  31
  32 int
  33 set_user(FILE *fd, const char *user) {
  34         struct passwd *pw;
  35
  36         pw = getpwnam(user);
  37         if (pw == NULL) {
  38                 errno = EINVAL;
  39                 return (-1);
  40         }
  41         return (fchown(fileno(fd), pw->pw_uid, -1));
  42 }
  43
  44 FILE *
  45 safe_create(const char *filename) {
  46         int fd;
  47         FILE *f;
  48         struct stat sb;
  49         int flags = O_WRONLY;
  50
  51         if (stat(filename, &sb) == -1) {
  52                 if (errno != ENOENT)
  53                         return (NULL);
  54                 flags = O_WRONLY | O_CREAT | O_EXCL;
  55         } else if ((sb.st_mode & S_IFREG) == 0) {
  56                 errno = EOPNOTSUPP;
  57                 return (NULL);
  58         } else
  59                 flags = O_WRONLY | O_TRUNC;
  60
  61         fd = open(filename, flags, S_IRUSR | S_IWUSR);
  62         if (fd == -1)
  63                 return (NULL);
  64         f = fdopen(fd, "w");
  65         if (f == NULL)
  66                 close(fd);
  67         return (f);
  68 }