From 199bf7c9b0ac1af1e28540ea0d31fa84c6bbde82 Mon Sep 17 00:00:00 2001
From: bol-van <k@vodka.home.kg>
Date: Fri, 12 Mar 2021 15:44:25 +0300
Subject: [PATCH] nfqws: do not allow increasing scale factor
---
nfq/darkmagic.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/nfq/darkmagic.c b/nfq/darkmagic.c
index 054de60..3f8fd99 100644
--- a/nfq/darkmagic.c
+++ b/nfq/darkmagic.c
@@ -669,9 +669,15 @@ void tcp_rewrite_wscale(struct tcphdr *tcp, uint8_t scale_factor)
if (scale && scale[1]==3) // length should be 3
{
scale_factor_old=scale[2];
- scale[2]=scale_factor;
- if (scale_factor_old!=scale_factor)
- DLOG("Scale factor change %u => %u\n", scale_factor_old, scale_factor)
+ // do not allow increasing scale factor
+ if (scale_factor>=scale_factor_old)
+ DLOG("Scale factor %u unchanged\n", scale_factor_old)
+ else
+ {
+ scale[2]=scale_factor;
+ if (scale_factor_old!=scale_factor)
+ DLOG("Scale factor change %u => %u\n", scale_factor_old, scale_factor)
+ }
}
}
}