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
  18 /*
  19  * Always return EXIT_FAILURE (1), don't try to be smart!
  20  */
  21
  22 static void __attribute__((__noreturn__)) usage(void)
  23 {
  24         FILE *out = stdout;
  25         fputs(USAGE_HEADER, out);
  26         fprintf(out,
  27                 _(" %s [options]\n"), program_invocation_short_name);
  28
  29         fputs(USAGE_SEPARATOR, out);
  30         fputs(_("Politely refuse a login.\n"), out);
  31
  32         fputs(USAGE_OPTIONS, out);
  33         fputs(_(" -c, --command <command>  does nothing (for compatibility with su -c)\n"), out);
  34         printf(USAGE_HELP_OPTIONS(26));
  35
  36         printf(USAGE_MAN_TAIL("nologin(8)"));
  37         exit(EXIT_FAILURE);
  38 }
  39
  40 int main(int argc, char *argv[])
  41 {
  42         int c, fd = -1;
  43         struct stat st;
  44         enum {
  45                 OPT_INIT_FILE = CHAR_MAX + 1,
  46                 OPT_NOPROFILE,
  47                 OPT_NORC,
  48                 OPT_POSIX,
  49                 OPT_RCFILE
  50         };
  51         static const struct option longopts[] = {
  52                 { "command",     required_argument, NULL, 'c'           },
  53                 { "init-file",   required_argument, NULL, OPT_INIT_FILE },
  54                 { "interactive", no_argument,       NULL, 'i'           },
  55                 { "login",       no_argument,       NULL, 'l'           },
  56                 { "noprofile",   no_argument,       NULL, OPT_NOPROFILE },
  57                 { "norc",        no_argument,       NULL, OPT_NORC      },
  58                 { "posix",       no_argument,       NULL, OPT_POSIX     },
  59                 { "rcfile",      required_argument, NULL, OPT_RCFILE    },
  60                 { "restricted",  no_argument,       NULL, 'r'           },
  61                 { "help",        no_argument,       NULL, 'h'           },
  62                 { "version",     no_argument,       NULL, 'V'           },
  63                 { NULL, 0, NULL, 0 }
  64         };
  65
  66         setlocale(LC_ALL, "");
  67         bindtextdomain(PACKAGE, LOCALEDIR);
  68         textdomain(PACKAGE);
  69
  70         while ((c = getopt_long(argc, argv, "c:ilrhV", longopts, NULL)) != -1) {
  71                 switch (c) {
  72                 case 'c':
  73                 case OPT_INIT_FILE:
  74                 case 'i':
  75                 case 'l':
  76                 case OPT_NOPROFILE:
  77                 case OPT_NORC:
  78                 case OPT_POSIX:
  79                 case OPT_RCFILE:
  80                 case 'r':
  81                         /* Ignore well known shell command-line options */
  82                         break;
  83                 case 'h':
  84                         usage();
  85                 case 'V':
  86                         print_version(EXIT_FAILURE);    /* yes FAILURE! */
  87                 default:
  88                         errtryhelp(EXIT_FAILURE);
  89                 }
  90         }
  91
  92         fd = open(_PATH_NOLOGIN_TXT, O_RDONLY);
  93         if (fd < 0)
  94                 goto dflt;
  95
  96         c = fstat(fd, &st);
  97         if (c < 0 || !S_ISREG(st.st_mode))
  98                 goto dflt;
  99         else {
 100                 char buf[BUFSIZ];
 101                 ssize_t rd;
 102
 103                 while ((rd = read(fd, buf, sizeof(buf))) > 0)
 104                         ignore_result( write(STDOUT_FILENO, buf, rd) );
 105
 106                 close(fd);
 107                 return EXIT_FAILURE;
 108         }
 109
 110 dflt:
 111         if (fd >= 0)
 112                 close(fd);
 113         fprintf(stdout, _("This account is currently not available.\n"));
 114         return EXIT_FAILURE;
 115 }