From e64b07d7a4e45330359a4950f3dd2fabaa2fcfd8 Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Wed, 31 Jul 2024 16:48:48 +0200
Subject: [PATCH] internet_checksum.run: don't use bad trafgen seeds

---
 repos/os/run/internet_checksum.run | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/repos/os/run/internet_checksum.run b/repos/os/run/internet_checksum.run
index 8801c98e5b..2187b3de27 100644
--- a/repos/os/run/internet_checksum.run
+++ b/repos/os/run/internet_checksum.run
@@ -17,13 +17,21 @@ proc exit {{code 0}} {
 build { core init lib/ld lib/vfs test/internet_checksum server/lx_fs }
 create_boot_directory
 
-set seed ""
+proc gen_seed { } {
+	set min_seed 0
+	set max_seed [expr 2**32]
+	return [expr int($min_seed + floor(rand() * $max_seed))]
+}
+
+set seed 0
 if {[info exists ::env(SEED)]} {
 	set seed $::env(SEED)
 } else {
-	set min_seed 0
-	set max_seed [expr 2**32]
-	set seed [expr int($min_seed + floor(rand() * $max_seed))]
+	# in some cases trafgen generates bad checksums in encapsulated packets
+	set bad_seeds [list 0 875727356 ]
+	while {[lsearch -exact $bad_seeds $seed] != -1} {
+		set seed [gen_seed]
+	}
 }
 puts "\nUse script with SEED=$seed in order to get reproducible results\n"