contrib/tcp_wrappers/try-from.c

   1  /*
   2   * This program can be called via a remote shell command to find out if the
   3   * hostname and address are properly recognized, if username lookup works,
   4   * and (SysV only) if the TLI on top of IP heuristics work.
   5   *
   6   * Example: "rsh host /some/where/try-from".
   7   *
   8   * Diagnostics are reported through syslog(3) and redirected to stderr.
   9   *
  10   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
  11   */
  12
  13 #ifndef lint
  14 static char sccsid[] = "@(#) try-from.c 1.2 94/12/28 17:42:55";
  15 #endif
  16
  17 /* System libraries. */
  18
  19 #include <sys/types.h>
  20 #include <stdio.h>
  21 #include <syslog.h>
  22 #include <string.h>
  23
  24 #ifdef TLI
  25 #include <sys/tiuser.h>
  26 #include <stropts.h>
  27 #endif
  28
  29 #ifndef STDIN_FILENO
  30 #define STDIN_FILENO    0
  31 #endif
  32
  33 /* Local stuff. */
  34
  35 #include "tcpd.h"
  36
  37 int     allow_severity = SEVERITY;      /* run-time adjustable */
  38 int     deny_severity = LOG_WARNING;    /* ditto */
  39
  40 main(argc, argv)
  41 int     argc;
  42 char  **argv;
  43 {
  44     struct request_info request;
  45     char    buf[BUFSIZ];
  46     char   *cp;
  47
  48     /*
  49      * Simplify the process name, just like tcpd would.
  50      */
  51     if ((cp = strrchr(argv[0], '/')) != 0)
  52         argv[0] = cp + 1;
  53
  54     /*
  55      * Turn on the "IP-underneath-TLI" detection heuristics.
  56      */
  57 #ifdef TLI
  58     if (ioctl(0, I_FIND, "timod") == 0)
  59         ioctl(0, I_PUSH, "timod");
  60 #endif /* TLI */
  61
  62     /*
  63      * Look up the endpoint information.
  64      */
  65     request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
  66     (void) fromhost(&request);
  67
  68     /*
  69      * Show some results. Name and address information is looked up when we
  70      * ask for it.
  71      */
  72
  73 #define EXPAND(str) percent_x(buf, sizeof(buf), str, &request)
  74
  75     puts(EXPAND("client address  (%%a): %a"));
  76     puts(EXPAND("client hostname (%%n): %n"));
  77     puts(EXPAND("client username (%%u): %u"));
  78     puts(EXPAND("client info     (%%c): %c"));
  79     puts(EXPAND("server address  (%%A): %A"));
  80     puts(EXPAND("server hostname (%%N): %N"));
  81     puts(EXPAND("server process  (%%d): %d"));
  82     puts(EXPAND("server info     (%%s): %s"));
  83
  84     return (0);
  85 }