gtphub: make test code reusable for future tests.

Generalize to make the PDP ctx message definitions and "sending" of messages
from SGSN->gtphub->GGSN and back reusable in future tests.

Publish gsn_addr_from_sockaddr() in gtphub.h for use in gtphub_test.c.

Use an osmo_sockaddr for resolved_ggsn_addr, because one is needed for
comparison in probably every future test.

Add LVL2_ASSERT() to print assertion message and return instead of abort,
so that functions can be called from several tests without losing the
info of which test caused it from which line.

Use globals for struct gtphub and time_t now, to reduce nr of args that need to
be passed around when writing tests. Add a default test setup function.

Sponsored-by: On-Waves ehi

3 files changed, 246 insertions, 179 deletions

diff --git a/openbsc/include/openbsc/gtphub.h b/openbsc/include/openbsc/gtphub.h
index 514b1a375..79f138b0a 100644
--- a/openbsc/include/openbsc/gtphub.h
+++ b/openbsc/include/openbsc/gtphub.h
@@ -155,6 +155,10 @@ const char *gsn_addr_to_strb(const struct gsn_addr *gsna,
 /* Return 1 on match, zero otherwise. */
 int gsn_addr_same(const struct gsn_addr *a, const struct gsn_addr *b);
 
+/* Decode sa to gsna. Return 0 on success. If port is non-NULL, the port number
+ * from sa is also returned. */
+int gsn_addr_from_sockaddr(struct gsn_addr *gsna, uint16_t *port,
+			   const struct osmo_sockaddr *sa);
 
 /* expiry */
 
diff --git a/openbsc/src/gprs/gtphub.c b/openbsc/src/gprs/gtphub.c
index 76fe78add..f24fc042a 100644
--- a/openbsc/src/gprs/gtphub.c
+++ b/openbsc/src/gprs/gtphub.c
@@ -91,8 +91,6 @@ void gsn_addr_copy(struct gsn_addr *gsna, const struct gsn_addr *src)
 	memcpy(gsna, src, sizeof(struct gsn_addr));
 }
 
-/* Decode sa to gsna. Return 0 on success. If port is non-NULL, the port number
- * from sa is also returned. */
 int gsn_addr_from_sockaddr(struct gsn_addr *gsna, uint16_t *port,
 			   const struct osmo_sockaddr *sa)
 {
diff --git a/openbsc/tests/gtphub/gtphub_test.c b/openbsc/tests/gtphub/gtphub_test.c
index 7839050cd..0b3aeb54f 100644
--- a/openbsc/tests/gtphub/gtphub_test.c
+++ b/openbsc/tests/gtphub/gtphub_test.c
@@ -37,6 +37,16 @@
 
 #define EXPIRE_ALL ((60 * GTPH_TEI_MAPPING_EXPIRY_MINUTES) + 1)
 
+#define ZERO_STRUCT(struct_pointer) memset(struct_pointer, '\0', sizeof(*(struct_pointer)))
+
+#define LVL2_ASSERT(exp) LVL2_ASSERT_R(exp, return 0)
+#define LVL2_ASSERT_R(exp, ret)    \
+	if (!(exp)) { \
+		fprintf(stderr, "LVL2 Assert failed %s %s:%d\n", #exp, __FILE__, __LINE__); \
+		osmo_generate_backtrace(); \
+		ret; \
+	}
+
 void gtphub_init(struct gtphub *hub);
 
 void *osmo_gtphub_ctx;
@@ -323,6 +333,27 @@ static void test_expiry(void)
 #undef MAP3
 }
 
+char resolve_ggsn_got_imsi[GSM_IMSI_LENGTH];
+char resolve_ggsn_got_ni[GSM_APN_LENGTH];
+
+struct osmo_sockaddr resolved_ggsn_addr;
+static int resolve_to_ggsn(const char *addr, uint16_t port)
+{
+	LVL2_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_addr,
+					   addr, port)
+		    == 0);
+	return 1;
+}
+
+struct osmo_sockaddr sgsn_sender;
+static int send_from_sgsn(const char *addr, uint16_t port)
+{
+	LVL2_ASSERT(osmo_sockaddr_init_udp(&sgsn_sender,
+					   addr, port)
+		    == 0);
+	return 1;
+}
+
 
 
 /* override, requires '-Wl,--wrap=gtphub_resolve_ggsn_addr' */
@@ -330,17 +361,19 @@ struct gtphub_peer_port *__real_gtphub_resolve_ggsn_addr(struct gtphub *hub,
 							 const char *imsi_str,
 							 const char *apn_ni_str);
 
-struct gsn_addr resolved_ggsn_addr = { 0 };
-uint16_t resolved_ggsn_port = 2123;
-char resolve_ggsn_got_imsi[256];
-char resolve_ggsn_got_ni[256];
 struct gtphub_peer_port *__wrap_gtphub_resolve_ggsn_addr(struct gtphub *hub,
 							 const char *imsi_str,
 							 const char *apn_ni_str)
 {
+	struct gsn_addr resolved_gsna;
+	uint16_t resolved_port;
+
+	OSMO_ASSERT(gsn_addr_from_sockaddr(&resolved_gsna, &resolved_port,
+					   &resolved_ggsn_addr) == 0);
+
 	struct gtphub_peer_port *pp;
 	pp = gtphub_port_have(hub, &hub->to_ggsns[GTPH_PLANE_CTRL],
-			      &resolved_ggsn_addr, resolved_ggsn_port);
+			      &resolved_gsna, resolved_port);
 	printf("Wrap: returning GGSN addr from imsi %s ni %s: %s\n",
 	       imsi_str, apn_ni_str, gtphub_port_str(pp));
 
@@ -460,14 +493,42 @@ static int _same_addr(const struct osmo_sockaddr *got,
 	return 0;
 }
 
-static void test_echo(void)
+
+time_t now;
+static struct gtphub _hub;
+static struct gtphub *hub = &_hub;
+
+static int setup_test_hub()
 {
-	struct gtphub _hub;
-	struct gtphub *hub = &_hub;
-	time_t now = 123;
+	/* Not really needed, but to make 100% sure... */
+	ZERO_STRUCT(hub);
 
 	gtphub_init(hub);
+
+	/* Tell this mock gtphub its local address for this test. */
+	LVL2_ASSERT(gsn_addr_from_str(&hub->to_sgsns[GTPH_PLANE_CTRL].local_addr,
+				      "127.0.1.1") == 0);
+	LVL2_ASSERT(gsn_addr_from_str(&hub->to_sgsns[GTPH_PLANE_USER].local_addr,
+				      "127.0.1.2") == 0);
+	LVL2_ASSERT(gsn_addr_from_str(&hub->to_ggsns[GTPH_PLANE_CTRL].local_addr,
+				      "127.0.2.1") == 0);
+	LVL2_ASSERT(gsn_addr_from_str(&hub->to_ggsns[GTPH_PLANE_USER].local_addr,
+				      "127.0.2.2") == 0);
+
 	hub->restart_counter = 0x23;
+	now = 345;
+	LVL2_ASSERT(send_from_sgsn("192.168.42.23", 423));
+	LVL2_ASSERT(resolve_to_ggsn("192.168.43.34", 434));
+
+	return 1;
+}
+
+
+static void test_echo(void)
+{
+	OSMO_ASSERT(setup_test_hub());
+
+	now = 123;
 
 	const char *gtp_ping_from_sgsn =
 		"32"	/* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
@@ -488,23 +549,20 @@ static void test_echo(void)
 		"0e23"	/* Recovery with restart counter */
 		;
 
-	struct osmo_sockaddr orig_sgsn_addr;
-	OSMO_ASSERT(osmo_sockaddr_init_udp(&orig_sgsn_addr,
-					   "192.168.42.23", 423) == 0);
 	struct osmo_fd *ggsn_ofd = NULL;
 	struct osmo_sockaddr to_addr;
 	int send;
-	send = gtphub_from_sgsns_handle_buf(hub, GTPH_PLANE_CTRL, &orig_sgsn_addr,
+	send = gtphub_from_sgsns_handle_buf(hub, GTPH_PLANE_CTRL, &sgsn_sender,
 					    buf, msg(gtp_ping_from_sgsn), now,
 					    &reply_buf, &ggsn_ofd, &to_addr);
 	OSMO_ASSERT(send > 0);
 	OSMO_ASSERT(to_addr.l);
-	OSMO_ASSERT(same_addr(&to_addr, &orig_sgsn_addr));
+	OSMO_ASSERT(same_addr(&to_addr, &sgsn_sender));
 	OSMO_ASSERT(reply_is(gtp_pong_to_sgsn));
 
 	struct gtphub_peer_port *sgsn_port =
 		gtphub_port_find_sa(&hub->to_sgsns[GTPH_PLANE_CTRL],
-				    &orig_sgsn_addr);
+				    &sgsn_sender);
 	/* We don't record Echo peers. */
 	OSMO_ASSERT(!sgsn_port);
 
@@ -540,187 +598,194 @@ static void test_echo(void)
 
 	struct gtphub_peer_port *ggsn_port =
 		gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
-				    &orig_sgsn_addr);
+				    &sgsn_sender);
 	/* We don't record Echo peers. */
 	OSMO_ASSERT(!ggsn_port);
 
-	gtphub_gc(hub, now + EXPIRE_ALL);
+	now += EXPIRE_ALL;
+	gtphub_gc(hub, now);
 }
 
-static void test_create_pdp_ctx(void)
-{
-	struct gtphub _hub;
-	struct gtphub *hub = &_hub;
-	time_t now = 345;
-
-	gtphub_init(hub);
-
-	/* Tell this mock gtphub its local address for this test. */
-	OSMO_ASSERT(gsn_addr_from_str(&hub->to_sgsns[GTPH_PLANE_CTRL].local_addr,
-				      "127.0.1.1") == 0);
-	OSMO_ASSERT(gsn_addr_from_str(&hub->to_sgsns[GTPH_PLANE_USER].local_addr,
-				      "127.0.1.2") == 0);
-	OSMO_ASSERT(gsn_addr_from_str(&hub->to_ggsns[GTPH_PLANE_CTRL].local_addr,
-				      "127.0.2.1") == 0);
-	OSMO_ASSERT(gsn_addr_from_str(&hub->to_ggsns[GTPH_PLANE_USER].local_addr,
-				      "127.0.2.2") == 0);
 
-	/* This is copied from a packet that sgsnemu sends. */
-	const char *gtp_req_from_sgsn =
-		"32" 	/* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
-		"10" 	/* type 16: Create PDP Context Request */
-		"0068"	/* length = 8 + 104 */
-		"00000000" /* No TEI yet */
-		"abcd"	/* Sequence nr */
-		"00"	/* N-PDU 0 */
-		"00"	/* No extensions */
-		/* IEs */
-		"02"	/* 2 = IMSI */
-		  "42000121436587f9"
-		"0e" "60" /* 14: Recovery = 96 */
-		"0f01"	/* 15: Selection mode = MS provided APN, subscription not verified*/
-		"10"	/* 16: TEI Data I */
-		  "00000123"
-		"11"	/* 17: TEI Control Plane */
-		  "00000321"
-		"1400"	/* 20: NSAPI = 0*/
-		"1a"	/* 26: Charging Characteristics */
-		  "0800"
-		"80"	/* 128: End User Address */
-		  "0002" /* length = 2: empty PDP Address */
-		  "f121" /* spare 0xf0, PDP organization 1, PDP type number 0x21 = 33 */
-		"83"	/* 131: Access Point Name */
-		  "0009" /* length */
-		  "08696e7465726e6574" /* "internet" */
-		"84"	/* 132: Protocol Configuration Options */
-		  "0015" /* length = 21 */
-		  "80c0231101010011036d69670868656d6d656c6967"
-		"85"	/* 133: GSN Address */
-		  "0004" /* length */
-		  "abcdef00"
-		"85"	/* 133: GSN Address (second entry) */
-		  "0004" /* length */
-		  "fedcba00"
-		"86"	/* 134: MS International PSTN/ISDN Number (MSISDN) */
-		  "0007" /* length */
-		  "916407123254f6" /* 1946702123456(f) */
-		"87"	/* 135: Quality of Service (QoS) Profile */
-		  "0004" /* length */
-		  "00"	/* priority */
+#define MSG_PDP_CTX_REQ(len, seq, restart, imsi, tei_u, tei_c, apn, gsn_c, gsn_u) \
+		"32" 	/* 0b001'1 0010: version 1, protocol GTP, with seq nr. */ \
+		"10" 	/* type 16: Create PDP Context Request */ \
+		len	/* msg length = 8 + len (2 octets) */ \
+		"00000000" /* No TEI yet */ \
+		seq	/* Sequence nr (2 octets) */ \
+		"00"	/* N-PDU 0 */ \
+		"00"	/* No extensions */ \
+		/* IEs */ \
+		"0e" restart /* 14: Recovery = 96 (restart counter: 1 octet) */ \
+		"02"	/* 2 = IMSI */ \
+		  imsi	/* (8 octets) */ \
+		"0f01"	/* 15: Selection mode = MS provided APN, subscription not verified*/ \
+		"10"	/* 16: TEI Data I */ \
+		  tei_u	/* (4 octets) */ \
+		"11"	/* 17: TEI Control Plane */ \
+		  tei_c	/* (4 octets) */ \
+		"1400"	/* 20: NSAPI = 0*/ \
+		"1a"	/* 26: Charging Characteristics */ \
+		  "0800" \
+		"80"	/* 128: End User Address */ \
+		  "0002" /* length = 2: empty PDP Address */ \
+		  "f121" /* spare 0xf0, PDP organization 1, PDP type number 0x21 = 33 */ \
+		"83"	/* 131: Access Point Name */ \
+                  apn	/* (2 octets length, N octets encoded APN-NI) */ \
+		"84"	/* 132: Protocol Configuration Options */ \
+		  "0015" /* length = 21 */ \
+		  "80c0231101010011036d69670868656d6d656c6967" \
+		"85"	/* 133: GSN Address */ \
+		  gsn_c /* (2 octets length, N octets addr) */ \
+		"85"	/* 133: GSN Address (second entry) */ \
+		  gsn_u /* (2 octets length, N octets addr) */ \
+		"86"	/* 134: MS International PSTN/ISDN Number (MSISDN) */ \
+		  "0007" /* length */ \
+		  "916407123254f6" /* 1946702123456(f) */ \
+		"87"	/* 135: Quality of Service (QoS) Profile */ \
+		  "0004" /* length */ \
+		  "00"	/* priority */ \
+		  "0b921f" /* QoS profile data */ 
+
+#define MSG_PDP_CTX_RSP(len, tei_h, seq, restart, tei_u, tei_c, gsn_c, gsn_u) \
+		"32" \
+		"11"	/* Create PDP Context Response */ \
+		len	/* msg length = 8 + len (2 octets) */ \
+		tei_h	/* destination TEI (sent in req above) */ \
+		seq	/* mapped seq */ \
+		"00" "00" \
+		/* IEs */ \
+		"01"	/* 1: Cause */ \
+		  "80"	/* value = 0b10000000 = response, no rejection. */ \
+		"08"	/* 8: Reordering Required */ \
+		  "00"	/* not required. */ \
+		"0e" restart /* 14: Recovery = 1 */ \
+		"10"	/* 16: TEI Data I */ \
+		  tei_u \
+		"11"	/* 17: TEI Control */ \
+		  tei_c \
+		"7f"	/* 127: Charging ID */ \
+		  "00000001" \
+		"80"	/* 128: End User Address */ \
+		  "0006" /* length = 6 */ \
+		  "f121" /* spare 0xf0, PDP organization 1, PDP type number 0x21 = 33 */ \
+		  "7f000002" \
+		"84"	/* 132: Protocol Configuration Options */ \
+		  "0014" /* len = 20 */ \
+		  "8080211002000010810608080808830600000000" \
+		"85"	/* 133: GSN Address (Ctrl) */ \
+		  gsn_c \
+		"85"	/* 133: GSN Address (User) */ \
+		  gsn_u \
+		"87"	/* 135: Quality of Service (QoS) Profile */ \
+		  "0004" /* length */ \
+		  "00"	/* priority */ \
 		  "0b921f" /* QoS profile data */
-		;
-
-	const char *gtp_req_to_ggsn =
-		"32" "10" "0068" "00000000"
-		"6d31"	/* mapped seq ("abcd") */
-		"00" "00" "02" "42000121436587f9" "0e60" "0f01"
-		"10" "00000001" /* mapped TEI Data I ("123") */
-		"11" "00000001" /* mapped TEI Control ("321") */
-		"1400" "1a" "0800" "80" "0002" "f121" "83"
-		"0009" "08696e7465726e6574" "84" "0015"
-		"80c0231101010011036d69670868656d6d656c6967" "85" "0004"
-		"7f000201" /* replaced with gtphub's address ggsn ctrl */
-		"85" "0004"
-		"7f000202" /* replaced with gtphub's address ggsn user */
-		"86" "0007" "916407123254f6"
-		"87" "0004" "00" "0b921f"
-		;
-
-	const char *gtp_resp_from_ggsn =
-		"32"
-		"11"	/* Create PDP Context Response */
-		"004e"	/* length = 78 + 8 */
-		"00000001" /* destination TEI (sent in req above) */
-		"6d31"	/* mapped seq */
-		"00" "00"
-		/* IEs */
-		"01"	/* 1: Cause */
-		  "80"	/* value = 0b10000000 = response, no rejection. */
-		"08"	/* 8: Reordering Required */
-		  "00"	/* not required. */
-		"0e" "01" /* 14: Recovery = 1 */
-		"10"	/* 16: TEI Data I */
-		  "00000567"
-		"11"	/* 17: TEI Control */
-		  "00000765"
-		"7f"	/* 127: Charging ID */
-		  "00000001"
-		"80"	/* 128: End User Address */
-		  "0006" /* length = 6 */
-		  "f121" /* spare 0xf0, PDP organization 1, PDP type number 0x21 = 33 */
-		  "7f000002"
-		"84"	/* 132: Protocol Configuration Options */
-		  "0014" /* len = 20 */
-		  "8080211002000010810608080808830600000000"
-		"85"	/* 133: GSN Address (Ctrl) */
-		  "0004" /* length */
-		  "7f000002"
-		"85"	/* 133: GSN Address (User) */
-		  "0004" /* length */
-		  "7f000002"
-		"87"	/* 135: Quality of Service (QoS) Profile */
-		  "0004" /* length */
-		  "00"	/* priority */
-		  "0b921f" /* QoS profile data */
-		;
-
-	const char *gtp_resp_to_sgsn =
-		"32" "11" "004e"
-		"00000321" /* unmapped TEI ("001") */
-		"abcd" /* unmapped seq ("6d31") */
-		"00" "00" "01" "80" "08" "00" "0e" "01"
-		"10" "00000002" /* mapped TEI from GGSN ("567") */
-		"11" "00000002" /* mapped TEI from GGSN ("765") */
-		"7f" "00000001" "80" "0006" "f121" "7f000002" "84" "0014"
-		"8080211002000010810608080808830600000000"
-		"85" "0004"
-		  "7f000101" /* gtphub's address towards SGSNs (Ctrl) */
-		"85" "0004"
-		  "7f000102" /* gtphub's address towards SGSNs (User) */
-		"87" "0004" "00" "0b921f"
-		;
-
-	/* Set the GGSN address that gtphub is forced to resolve to. */
-	const char *resolved_ggsn_str = "192.168.43.34";
-	resolved_ggsn_port = 434;
-	OSMO_ASSERT(gsn_addr_from_str(&resolved_ggsn_addr, resolved_ggsn_str)
-		    == 0);
-
-	/* A sockaddr for comparing later */
-	struct osmo_sockaddr resolved_ggsn_sa;
-	OSMO_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_sa,
-					   resolved_ggsn_str,
-					   resolved_ggsn_port)
-		    == 0);
-
-	struct osmo_sockaddr orig_sgsn_addr;
-	OSMO_ASSERT(osmo_sockaddr_init(&orig_sgsn_addr,
-				       AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP,
-				       "192.168.42.23", 423) == 0);
 
+#define msg_from_sgsn_c(A,B,C,D) msg_from_sgsn(GTPH_PLANE_CTRL, A,B,C,D)
+#define msg_from_sgsn_u(A,B,C,D) msg_from_sgsn(GTPH_PLANE_USER, A,B,C,D)
+static int msg_from_sgsn(int plane_idx,
+			 struct osmo_sockaddr *_sgsn_sender,
+			 struct osmo_sockaddr *ggsn_receiver,
+			 const char *hex_from_sgsn,
+			 const char *hex_to_ggsn)
+{
 	struct osmo_fd *ggsn_ofd = NULL;
 	struct osmo_sockaddr ggsn_addr;
 	int send;
-	send = gtphub_from_sgsns_handle_buf(hub, GTPH_PLANE_CTRL, &orig_sgsn_addr,
-					    buf, msg(gtp_req_from_sgsn), now,
+	send = gtphub_from_sgsns_handle_buf(hub, plane_idx, _sgsn_sender, buf,
+					    msg(hex_from_sgsn), now,
 					    &reply_buf, &ggsn_ofd, &ggsn_addr);
-	OSMO_ASSERT(send > 0);
-	OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_sa));
-	OSMO_ASSERT(reply_is(gtp_req_to_ggsn));
-	OSMO_ASSERT(was_resolved_for("240010123456789", "internet"));
+	LVL2_ASSERT(send > 0);
+	LVL2_ASSERT(same_addr(&ggsn_addr, ggsn_receiver));
+	LVL2_ASSERT(reply_is(hex_to_ggsn));
+	return 1;
+}
 
+#define msg_from_ggsn_c(A,B,C,D) msg_from_ggsn(GTPH_PLANE_CTRL, A,B,C,D)
+#define msg_from_ggsn_u(A,B,C,D) msg_from_ggsn(GTPH_PLANE_USER, A,B,C,D)
+static int msg_from_ggsn(int plane_idx,
+			 struct osmo_sockaddr *ggsn_sender,
+			 struct osmo_sockaddr *sgsn_receiver,
+			 const char *msg_from_ggsn,
+			 const char *msg_to_sgsn)
+{
 	struct osmo_fd *sgsn_ofd;
 	struct osmo_sockaddr sgsn_addr;
-	send = gtphub_from_ggsns_handle_buf(hub, GTPH_PLANE_CTRL, &ggsn_addr,
-					    buf, msg(gtp_resp_from_ggsn), now,
+	int send;
+	send = gtphub_from_ggsns_handle_buf(hub, plane_idx, ggsn_sender, buf,
+					    msg(msg_from_ggsn), now,
 					    &reply_buf, &sgsn_ofd, &sgsn_addr);
-	OSMO_ASSERT(send > 0);
-	OSMO_ASSERT(same_addr(&sgsn_addr, &orig_sgsn_addr));
-	OSMO_ASSERT(reply_is(gtp_resp_to_sgsn));
+	LVL2_ASSERT(send > 0);
+	LVL2_ASSERT(same_addr(&sgsn_addr, sgsn_receiver));
+	LVL2_ASSERT(reply_is(msg_to_sgsn));
+	return 1;
+}
+
+static int create_pdp_ctx()
+{
+	const char *gtp_req_from_sgsn = MSG_PDP_CTX_REQ("0068",
+							"abcd",
+							"60",
+							"42000121436587f9",
+							"00000123",
+							"00000321",
+							"0009""08696e7465726e6574", /* "(8)internet" */
+							"0004""c0a82a17", /* same as default sgsn_sender */
+							"0004""c0a82a17"
+						       );
+	const char *gtp_req_to_ggsn = MSG_PDP_CTX_REQ("0068",
+						      "6d31",	/* mapped seq ("abcd") */
+						      "60",
+						      "42000121436587f9",
+						      "00000001", /* mapped TEI Data I ("123") */
+						      "00000001", /* mapped TEI Control ("321") */
+						      "0009""08696e7465726e6574",
+						      "0004""7f000201", /* replaced with gtphub's address ggsn ctrl */
+						      "0004""7f000202" /* replaced with gtphub's address ggsn user */
+						     );
+
+	LVL2_ASSERT(msg_from_sgsn_c(&sgsn_sender,
+				    &resolved_ggsn_addr,
+				    gtp_req_from_sgsn,
+				    gtp_req_to_ggsn));
+	LVL2_ASSERT(was_resolved_for("240010123456789", "internet"));
+
+	const char *gtp_resp_from_ggsn = MSG_PDP_CTX_RSP("004e",
+							 "00000001", /* destination TEI (sent in req above) */
+							 "6d31", /* mapped seq */
+							 "01", /* restart */
+							 "00000567", /* TEI U */
+							 "00000765", /* TEI C */
+							 "0004""c0a82b22", /* GSN addresses */
+							 "0004""c0a82b22"  /* (== resolved_ggsn_addr) */
+							);
+	const char *gtp_resp_to_sgsn = MSG_PDP_CTX_RSP("004e",
+						       "00000321", /* unmapped TEI ("001") */
+						       "abcd", /* unmapped seq ("6d31") */
+						       "01",
+						       "00000002", /* mapped TEI from GGSN ("567") */
+						       "00000002", /* mapped TEI from GGSN ("765") */
+						       "0004""7f000101", /* gtphub's address towards SGSNs (Ctrl) */
+						       "0004""7f000102" /* gtphub's address towards SGSNs (User) */
+						      );
+	LVL2_ASSERT(msg_from_ggsn_c(&resolved_ggsn_addr,
+				    &sgsn_sender,
+				    gtp_resp_from_ggsn,
+				    gtp_resp_to_sgsn));
+
+	return 1;
+}
+
+static void test_create_pdp_ctx(void)
+{
+	OSMO_ASSERT(setup_test_hub());
+
+	OSMO_ASSERT(create_pdp_ctx());
 
 	struct gtphub_peer_port *ggsn_port =
 		gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
-				    &resolved_ggsn_sa);
+				    &resolved_ggsn_addr);
 	OSMO_ASSERT(ggsn_port);
 	struct gtphub_peer *ggsn = ggsn_port->peer_addr->peer;
 	/* now == 345; now + 30 == 375.