diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/sbr/m_update.c

   1 /* m_update.c - update the profile */
   2 #ifndef lint
   3 static char ident[] = "@(#)$Id: m_update.c,v 1.7 1992/12/15 00:20:22 jromine Exp $";
   4 #endif  lint
   5
   6 #include "../h/mh.h"
   7 #include <stdio.h>
   8 #include <signal.h>
   9 #ifndef sigmask
  10 #define sigmask(s)      (1 << ((s) - 1))
  11 #endif  /* not sigmask */
  12
  13 static int      m_chkids();
  14
  15 void m_update () {
  16     int     action;
  17 #ifndef BSD42
  18     TYPESIG (*hstat) (), (*istat) (), (*qstat) (), (*tstat) ();
  19 #else   /* BSD42 */
  20     int     smask;
  21 #endif  /* BSD42 */
  22     register struct node   *np;
  23     FILE * out;
  24
  25     if (!(ctxflags & CTXMOD))
  26         return;
  27     ctxflags &= ~CTXMOD;
  28
  29     if ((action = m_chkids ()) > OK)
  30         return;                 /* child did it for us */
  31
  32 #ifndef BSD42
  33     hstat = signal (SIGHUP, SIG_IGN);
  34     istat = signal (SIGINT, SIG_IGN);
  35     qstat = signal (SIGQUIT, SIG_IGN);
  36     tstat = signal (SIGTERM, SIG_IGN);
  37 #else   /* BSD42 */
  38     smask = sigblock (sigmask (SIGHUP) | sigmask (SIGINT)
  39                         | sigmask (SIGQUIT) | sigmask (SIGTERM));
  40 #endif  /* BSD42 */
  41
  42     if ((out = fopen (ctxpath, "w")) == NULL)
  43         adios (ctxpath, "unable to write");
  44     for (np = m_defs; np; np = np -> n_next)
  45         if (np -> n_context)
  46             fprintf (out, "%s: %s\n", np -> n_name, np -> n_field);
  47     (void) fclose (out);
  48
  49 #ifndef BSD42
  50     (void) signal (SIGHUP, hstat);
  51     (void) signal (SIGINT, istat);
  52     (void) signal (SIGQUIT, qstat);
  53     (void) signal (SIGTERM, tstat);
  54 #else   /* BSD42 */
  55     (void) sigsetmask (smask);
  56 #endif  /* BSD42 */
  57     if (action == OK)
  58         _exit (0);              /* we are child, time to die */
  59 }
  60
  61 /* \f */
  62
  63 /* This hack brought to you so we can handle set[ug]id MH programs.  If we
  64    return NOTOK, then no fork is made, we update .mh_profile normally, and
  65    return to the caller normally.  If we return 0, then the child is
  66    executing, .mh_profile is modified after we set our [ug]ids to the norm.
  67    If we return > 0, then the parent is executed and .mh_profile has
  68    already be modified.  We can just return to the caller immediately. */
  69
  70
  71 static int  m_chkids () {
  72     int     i,
  73             child_id;
  74
  75     if (getuid () == geteuid ())
  76         return (NOTOK);
  77
  78     for (i = 0; (child_id = fork ()) == -1 && i < 5; i++)
  79         sleep (5);
  80     switch (child_id) {
  81         case NOTOK:
  82             break;
  83
  84         case OK:
  85             (void) setgid (getgid ());
  86             (void) setuid (getuid ());
  87             break;
  88
  89         default:
  90             (void) pidwait (child_id, NOTOK);
  91             break;
  92     }
  93
  94     return child_id;
  95 }