Avoid generating zero-length packets

I used the construct like f_rnd_octstring(f_rnd_int(100)) in a number
of places to generate random-length packets with randomized length.

The problem I didn't realize is that f_rnd_int() of course can also
return '0', which would generate zero-length packets.  This may be
permitted in some protocols, but it leads to problems e.g. when trying
to send a UDP packet of zero length (which the kernel will not do).

So let's introduce
* f_rnd_int_nonzero() for returning non-zero randomized integers
* f_rnd_octstring_rnd_len() for returning a random-length random payload
  octet string
* replace all f_rnd_octstring(f_rnd_int()) call sites with the new
  function.

Change-Id: I818a113ff8d2a2f7cab2ec7d9c8661607c6331d6
Closes: OS#5528

1 files changed, 3 insertions, 3 deletions

diff --git a/sccp/SCCP_Tests_RAW.ttcn b/sccp/SCCP_Tests_RAW.ttcn
index 5013ddf3..fd6bad9e 100644
--- a/sccp/SCCP_Tests_RAW.ttcn
+++ b/sccp/SCCP_Tests_RAW.ttcn
@@ -182,7 +182,7 @@ testcase TC_cr_cc() runs on SCCP_Test_RAW_CT {
 testcase TC_udt_without_cr_cc() runs on SCCP_Test_RAW_CT {
 	var SCCP_PAR_Address calling, called;
 	var SCCP_MTP3_TRANSFERind rx;
-	var octetstring data := f_rnd_octstring(f_rnd_int(100));
+	var octetstring data := f_rnd_octstring_rnd_len(100);
 
 	/* Keep recommended ratio of T(iar) >= T(ias)*2, but anyway no IT
 	   should be received in this case. */
@@ -215,7 +215,7 @@ testcase TC_udt_without_cr_cc() runs on SCCP_Test_RAW_CT {
 testcase TC_tiar_timeout() runs on SCCP_Test_RAW_CT {
 	var SCCP_PAR_Address calling, called;
 	var OCT3 remote_lref;
-	var octetstring data := f_rnd_octstring(f_rnd_int(100));
+	var octetstring data := f_rnd_octstring_rnd_len(100);
 
 	/* Set T(iar) in sccp_demo_user low enough that it will trigger before other side
 	   has time to keep alive with a T(ias). Keep recommended ratio of
@@ -320,7 +320,7 @@ private function f_tx_xudt_exp(SCCP_PAR_Address calling, SCCP_PAR_Address called
 /* Test if the IUT SCCP code processes an XUDT [treat it like UDT] and answers back. */
 testcase TC_process_rx_xudt() runs on SCCP_Test_RAW_CT {
 	var SCCP_PAR_Address calling, called;
-	var octetstring data := f_rnd_octstring(f_rnd_int(100));
+	var octetstring data := f_rnd_octstring_rnd_len(100);
 
 	f_init_raw(mp_sccp_cfg[0]);
 	f_sleep(1.0);