[src/trunk]: src/sys/rump/net/rumptest * add comment explaining why we random...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4fa794e35276
branches:  trunk
changeset: 751244:4fa794e35276
user:      pooka <pooka%NetBSD.org@localhost>
date:      Fri Jan 29 12:34:17 2010 +0000

description:
* add comment explaining why we randomize the last source ip octet
* fix bug in randomization (well, at least with the current configuration ..)

diffstat:

 sys/rump/net/rumptest/rumptest_net.c |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (25 lines):

diff -r 52095ca4808c -r 4fa794e35276 sys/rump/net/rumptest/rumptest_net.c
--- a/sys/rump/net/rumptest/rumptest_net.c      Fri Jan 29 12:22:00 2010 +0000
+++ b/sys/rump/net/rumptest/rumptest_net.c      Fri Jan 29 12:34:17 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumptest_net.c,v 1.18 2010/01/27 13:30:45 martti Exp $ */
+/*     $NetBSD: rumptest_net.c,v 1.19 2010/01/29 12:34:17 pooka Exp $  */
 
 /*
  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
@@ -114,9 +114,14 @@
        if (s == -1)
                err(1, "configuration socket");
 
+       /*
+        * Randomize last octet of source address.  This ~prevents
+        * source/dest 4-tuple re-use if this program is run a few
+        * times consecutively.
+        */
        srandom(time(NULL));
        myaddr = inet_addr(MYADDR);
-       myaddr = htonl(ntohl(myaddr) + (random() % 126 + 1));
+       myaddr = htonl(ntohl(myaddr) + (random() % 126 + 2));
 
        /* fill out struct ifaliasreq */
        memset(&ia, 0, sizeof(ia));