--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sbr/m_update.c	Mon Apr 18 23:46:02 2005 +0900
@@ -0,0 +1,95 @@
+/* m_update.c - update the profile */
+#ifndef	lint
+static char ident[] = "@(#)$Id$";
+#endif /* lint */
+
+#include "../h/mh.h"
+#include <stdio.h>
+#include <signal.h>
+#ifndef	sigmask
+#define	sigmask(s)	(1 << ((s) - 1))
+#endif	/* not sigmask */
+
+static int	m_chkids();
+
+void m_update () {
+    int     action;
+#ifndef	BSD42
+    TYPESIG (*hstat) (), (*istat) (), (*qstat) (), (*tstat) ();
+#else	/* BSD42 */
+    int	    smask;
+#endif	/* BSD42 */
+    register struct node   *np;
+    FILE * out;
+
+    if (!(ctxflags & CTXMOD))
+	return;
+    ctxflags &= ~CTXMOD;
+
+    if ((action = m_chkids ()) > OK)
+	return;			/* child did it for us */
+
+#ifndef	BSD42
+    hstat = signal (SIGHUP, SIG_IGN);
+    istat = signal (SIGINT, SIG_IGN);
+    qstat = signal (SIGQUIT, SIG_IGN);
+    tstat = signal (SIGTERM, SIG_IGN);
+#else	/* BSD42 */
+    smask = sigblock (sigmask (SIGHUP) | sigmask (SIGINT)
+			| sigmask (SIGQUIT) | sigmask (SIGTERM));
+#endif	/* BSD42 */
+
+    if ((out = fopen (ctxpath, "w")) == NULL)
+	adios (ctxpath, "unable to write");
+    for (np = m_defs; np; np = np -> n_next)
+	if (np -> n_context)
+	    fprintf (out, "%s: %s\n", np -> n_name, np -> n_field);
+    (void) fclose (out);
+
+#ifndef	BSD42
+    (void) signal (SIGHUP, hstat);
+    (void) signal (SIGINT, istat);
+    (void) signal (SIGQUIT, qstat);
+    (void) signal (SIGTERM, tstat);
+#else	/* BSD42 */
+    (void) sigsetmask (smask);
+#endif	/* BSD42 */
+    if (action == OK)
+	_exit (0);		/* we are child, time to die */
+}
+
+/*  */
+
+/* This hack brought to you so we can handle set[ug]id MH programs.  If we
+   return NOTOK, then no fork is made, we update .mh_profile normally, and
+   return to the caller normally.  If we return 0, then the child is
+   executing, .mh_profile is modified after we set our [ug]ids to the norm.
+   If we return > 0, then the parent is executed and .mh_profile has
+   already be modified.  We can just return to the caller immediately. */
+
+
+static int  m_chkids () {
+    int     i,
+            child_id;
+
+    if (getuid () == geteuid ())
+	return (NOTOK);
+
+    for (i = 0; (child_id = fork ()) == -1 && i < 5; i++)
+	sleep (5);
+    switch (child_id) {
+	case NOTOK:
+	    break;
+
+	case OK:
+	    (void) setgid (getgid ());
+	    (void) setuid (getuid ());
+	    break;
+
+	default:
+	    (void) pidwait (child_id, NOTOK);
+	    break;
+    }
+
+    return child_id;
+}