login-utils/nologin.c

   1 /*
   2  * Copyright (C) 2013 Karel Zak <kzak@redhat.com>
   3  */
   4
   5 #include <stdio.h>
   6 #include <sys/stat.h>
   7 #include <sys/types.h>
   8 #include <fcntl.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <stdlib.h>
  12 #include <getopt.h>
  13
  14 #include "c.h"
  15 #include "nls.h"
  16 #include "pathnames.h"
  17 #include "fileutils.h"
  18
  19 /*
  20  * Always return EXIT_FAILURE (1), don't try to be smart!
  21  */
  22
  23 static void __attribute__((__noreturn__)) usage(void)
  24 {
  25         FILE *out = stdout;
  26         fputs(USAGE_HEADER, out);
  27         fprintf(out,
  28                 _(" %s [options]\n"), program_invocation_short_name);
  29
  30         fputs(USAGE_SEPARATOR, out);
  31         fputs(_("Politely refuse a login.\n"), out);
  32
  33         fputs(USAGE_OPTIONS, out);
  34         fputs(_(" -c, --command <command>  does nothing (for compatibility with su -c)\n"), out);
  35         fprintf(out, USAGE_HELP_OPTIONS(26));
  36
  37         fprintf(out, USAGE_MAN_TAIL("nologin(8)"));
  38         exit(EXIT_FAILURE);
  39 }
  40
  41 int main(int argc, char *argv[])
  42 {
  43         int c, fd = -1;
  44         struct stat st;
  45         enum {
  46                 OPT_INIT_FILE = CHAR_MAX + 1,
  47                 OPT_NOPROFILE,
  48                 OPT_NORC,
  49                 OPT_POSIX,
  50                 OPT_RCFILE
  51         };
  52         static const struct option longopts[] = {
  53                 { "command",     required_argument, NULL, 'c'           },
  54                 { "init-file",   required_argument, NULL, OPT_INIT_FILE },
  55                 { "interactive", no_argument,       NULL, 'i'           },
  56                 { "login",       no_argument,       NULL, 'l'           },
  57                 { "noprofile",   no_argument,       NULL, OPT_NOPROFILE },
  58                 { "norc",        no_argument,       NULL, OPT_NORC      },
  59                 { "posix",       no_argument,       NULL, OPT_POSIX     },
  60                 { "rcfile",      required_argument, NULL, OPT_RCFILE    },
  61                 { "restricted",  no_argument,       NULL, 'r'           },
  62                 { "help",        no_argument,       NULL, 'h'           },
  63                 { "version",     no_argument,       NULL, 'V'           },
  64                 { NULL, 0, NULL, 0 }
  65         };
  66
  67         setlocale(LC_ALL, "");
  68         bindtextdomain(PACKAGE, LOCALEDIR);
  69         textdomain(PACKAGE);
  70
  71         while ((c = getopt_long(argc, argv, "c:ilrhV", longopts, NULL)) != -1) {
  72                 switch (c) {
  73                 case 'c':
  74                 case OPT_INIT_FILE:
  75                 case 'i':
  76                 case 'l':
  77                 case OPT_NOPROFILE:
  78                 case OPT_NORC:
  79                 case OPT_POSIX:
  80                 case OPT_RCFILE:
  81                 case 'r':
  82                         /* Ignore well known shell command-line options */
  83                         break;
  84                 case 'h':
  85                         usage();
  86                 case 'V':
  87                         print_version(EXIT_FAILURE);    /* yes FAILURE! */
  88                 default:
  89                         errtryhelp(EXIT_FAILURE);
  90                 }
  91         }
  92
  93         fd = open(_PATH_NOLOGIN_TXT, O_RDONLY);
  94         if (fd < 0)
  95                 goto dflt;
  96
  97         c = fstat(fd, &st);
  98         if (c < 0 || !S_ISREG(st.st_mode))
  99                 goto dflt;
 100         else {
 101                 ul_copy_file(fd, STDOUT_FILENO);
 102                 close(fd);
 103                 return EXIT_FAILURE;
 104         }
 105
 106 dflt:
 107         if (fd >= 0)
 108                 close(fd);
 109         fprintf(stdout, _("This account is currently not available.\n"));
 110         return EXIT_FAILURE;
 111 }