the before mentioned random number generator.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/lib/libc/net/res_mkquery.c b/src/lib/libc/net/res_mkquery.c
index 5faba01748..2c244c24fc 100644
--- a/src/lib/libc/net/res_mkquery.c
+++ b/src/lib/libc/net/res_mkquery.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: res_mkquery.c,v 1.6 1997/03/13 19:07:39 downsj Exp $  */
+/*      $OpenBSD: res_mkquery.c,v 1.7 1997/04/13 21:30:46 provos Exp $  */
 
 /*
  * ++Copyright++ 1985, 1993
@@ -60,7 +60,7 @@
 static char sccsid[] = "@(#)res_mkquery.c       8.1 (Berkeley) 6/4/93";
 static char rcsid[] = "$From: res_mkquery.c,v 8.5 1996/08/27 08:33:28 vixie Exp $";
 #else
-static char rcsid[] = "$OpenBSD: res_mkquery.c,v 1.6 1997/03/13 19:07:39 downsj Exp $";
+static char rcsid[] = "$OpenBSD: res_mkquery.c,v 1.7 1997/04/13 21:30:46 provos Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -106,12 +106,17 @@ res_mkquery(op, dname, class, type, data, datalen, newrr_in, buf, buflen)
 #endif
         /*
          * Initialize header fields.
+         *
+         * A special random number generator is used to create non predictable
+         * and non repeating ids over a long period. It also avoids reuse
+         * by switching between two distinct number cycles.
          */
+
         if ((buf == NULL) || (buflen < HFIXEDSZ))
                 return (-1);
         bzero(buf, HFIXEDSZ);
         hp = (HEADER *) buf;
-        hp->id = htons(++_res.id);
+        hp->id = htons(_res.id=res_randomid());
         hp->opcode = op;
         hp->rd = (_res.options & RES_RECURSE) != 0;
         hp->rcode = NOERROR;