S1AP: HACK: initial fuzzing test case for S1AP_SetupReq

Change-Id: Ib6c8d87a1118a99075d3f2a498f3af4bdc65e6ec

library/s1ap/S1AP_EncDec.cc

@@ -1,3 +1,5 @@
+#include <stdio.h>
+#include <stdlib.h>
 
 #include <string.h>
 #include <stdarg.h>
@@ -13,6 +15,7 @@ TTCN_Module S1AP__EncDec("S1AP_EncDec", __DATE__, __TIME__);
 
 OCTETSTRING enc__S1AP__PDU(const S1AP__PDU__Descriptions::S1AP__PDU &pdu)
 {
+	static unsigned long count = 0;
 	uint8_t *aper_buf;
 	int aper_buf_len;
 	TTCN_Buffer TTCN_buf;
@@ -27,6 +30,18 @@ OCTETSTRING enc__S1AP__PDU(const S1AP__PDU__Descriptions::S1AP__PDU &pdu)
 		TTCN_error("fftranscode failed.");
 	}
 
+	/* Observed srsEPC segfaults with:
+	 *  idx=1 && mask=0x1d
+	 *  idx=5 && mask=any */
+	if (count++ % 2 == 0) {
+		int idx = rand() % aper_buf_len;
+		uint8_t mask = (uint8_t) rand();
+
+		/* TUWAT! Mangle a random byte. */
+		printf("=== TUWAT: mangling octet %d with mask 0x%02x\n", idx, mask);
+		aper_buf[idx] ^= mask;
+	}
+
 	/* make octetstring from output buffer */
 	OCTETSTRING ret_val(aper_buf_len, aper_buf);
 
@@ -62,3 +77,9 @@ S1AP__PDU__Descriptions::S1AP__PDU dec__S1AP__PDU(const OCTETSTRING &stream)
 }
 
 }
+
+static __attribute__((constructor)) void on_dso_load(void)
+{
+	/* Use a static seed for reproduceable results */
+	srand(10000);
+}

library/s1ap/S1AP_Templates.ttcn

@@ -25,6 +25,37 @@ import from S1AP_PDU_Descriptions all;
  * 9.1.8 Management Messages 
  *********************************************************************************/
 
+/* 9.1.8.4 S1 SETUP REQUEST */
+template (value) S1AP_PDU
+ts_S1AP_SetupReq_fuzz(template (value) Global_ENB_ID p_global_ENB_ID,
+		 template (value) SupportedTAs p_supportedTAs,
+		 template (value) PagingDRX p_pagingDRXs,
+		 template (value) integer id := S1AP_Constants.id_SupportedTAs) := {
+	initiatingMessage := {
+		procedureCode := id_S1Setup,
+		criticality := reject,
+		value_ := {
+			S1SetupRequest := {
+				protocolIEs := {
+					{
+						id := S1AP_Constants.id_Global_ENB_ID,
+						criticality := reject,
+						value_ := { Global_ENB_ID := p_global_ENB_ID }
+					}, {
+						id := S1AP_Constants.id_SupportedTAs,
+						criticality := reject,
+						value_ := {SupportedTAs := p_supportedTAs}
+					}, {
+						id := S1AP_Constants.id_pagingDRX,
+						criticality := ignore,
+						value_ := {PagingDRX := p_pagingDRXs}
+					}
+				}
+			}
+		}
+	}
+}
+
 /* 9.1.8.4 S1 SETUP REQUEST */
 template (value) S1AP_PDU
 ts_S1AP_SetupReq(template (value) Global_ENB_ID p_global_ENB_ID,

mme/MME_Tests.ttcn

@@ -308,7 +308,8 @@ friend function f_init_handler(ConnHdlrPars pars, float t_guard := 30.0) runs on
 friend function f_s1ap_setup(integer idx := 0, template Cause cause := omit) runs on MTC_CT {
 	var template (present) Cause exp_cause;
 	var boolean exp_fail := false;
-	timer T := 5.0;
+	timer T := 2.0;
+
 	if (not istemplatekind(cause, "omit")) {
 		exp_fail := true;
 		exp_cause := cause;
@@ -323,12 +324,15 @@ friend function f_s1ap_setup(integer idx := 0, template Cause cause := omit) run
 		}
 	[not exp_fail] S1AP_UNIT[idx].receive(tr_S1AP_SetupResp) {
 		setverdict(pass);
+		mtc.stop;
 		}
 	[] S1AP_UNIT[idx].receive {
 		setverdict(fail, "Received unexpected S1AP");
+		mtc.stop;
 		}
 	[] T.timeout {
 		setverdict(fail, "Timeout waiting for S1AP Setup result");
+		mtc.stop;
 		}
 	}
 }
@@ -561,11 +565,52 @@ testcase TC_s1ap_attach() runs on MTC_CT {
 	vc_conn.done;
 }
 
+friend function f_s1ap_setup_fuzz(integer idx := 0, integer id) runs on MTC_CT {
+	var boolean exp_fail := false;
+	timer T := 0.5;
+
+	S1AP_UNIT[idx].send(ts_S1AP_SetupReq_fuzz(g_enb_pars[idx].global_enb_id,
+					     g_enb_pars[idx].supported_tas, v32, id));
+	T.start;
+	alt {
+	[] S1AP_UNIT[idx].receive(tr_S1AP_SetupFail) {
+		setverdict(pass);
+		}
+	[] S1AP_UNIT[idx].receive {
+		setverdict(fail, "Received unexpected S1AP");
+		mtc.stop;
+		}
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for S1AP Setup result");
+		log("Attempt #", id);
+		}
+	}
+}
+
+/* S1 Setup Request fuzzing */
+testcase TC_s1ap_setup_fuzz() runs on MTC_CT {
+	var charstring id := testcasename();
+	var integer i;
+
+	f_init_s1ap(id, 1);
+	g_enb_pars[0].global_enb_id.pLMNidentity := '62F224'O;
+
+	for (i := 0; i < 10000; i := i + 1) {
+		f_s1ap_setup_fuzz(0, i);
+		f_s1ap_setup(0, { misc := unknown_PLMN });
+	}
+}
+
+
+
 control {
 	execute( TC_s1ap_setup_wrong_plmn() );
 	execute( TC_s1ap_setup_wrong_tac() );
 	execute( TC_s1ap_setup() );
 	execute( TC_s1ap_attach() );
+
+	/* Fuzzing tests */
+	execute( TC_s1ap_setup_fuzz() );
 }