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authoritojun <itojun@openbsd.org>2003-12-10 07:21:00 +0000
committeritojun <itojun@openbsd.org>2003-12-10 07:21:00 +0000
commit7c5afa882790e29a8b82eabf056b59ce8ed5015c (patch)
tree048af0dae58a907b53e0f14207c8c4441120c20a /sys/netinet/ip_id.c
parent- fix a few exit cases that would exit with no log (diff)
downloadwireguard-openbsd-7c5afa882790e29a8b82eabf056b59ce8ed5015c.tar.xz
wireguard-openbsd-7c5afa882790e29a8b82eabf056b59ce8ed5015c.zip
correct non-repetitive ID code, based on comments from niels provos.
- seed2 is necessary, but use it as "seed2 + x" not "seed2 ^ x". - skipping number is not needed, so disable it for 16bit generator (makes the repetition period to 30000)
Diffstat (limited to 'sys/netinet/ip_id.c')
-rw-r--r--sys/netinet/ip_id.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/sys/netinet/ip_id.c b/sys/netinet/ip_id.c
index 0534d406e33..67208b89de9 100644
--- a/sys/netinet/ip_id.c
+++ b/sys/netinet/ip_id.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ip_id.c,v 1.7 2003/09/21 04:06:39 itojun Exp $ */
+/* $OpenBSD: ip_id.c,v 1.8 2003/12/10 07:21:00 itojun Exp $ */
/*
* Copyright 1998 Niels Provos <provos@citi.umich.edu>
@@ -174,10 +174,14 @@ ip_randomid(void)
if (!tmp)
tmp = arc4random();
+#if 0
/* Skip a random number of ids */
n = tmp & 0x3; tmp = tmp >> 2;
if (ru_counter + n >= RU_MAX)
ip_initid();
+#else
+ n = 0;
+#endif
for (i = 0; i <= n; i++)
/* Linear Congruential Generator */
@@ -185,5 +189,5 @@ ip_randomid(void)
ru_counter += i;
- return (ru_seed ^ pmod(ru_g,ru_seed2 ^ ru_x,RU_N)) | ru_msb;
+ return (ru_seed ^ pmod(ru_g,ru_seed2 + ru_x, RU_N)) | ru_msb;
}