GSUP/SMS: introduce MO-/MT-FORWARD-SM messages

According to 3GPP TS 29.002, there are two services:

  - MAP-MO-FORWARD-SHORT-MESSAGE (see 12.2),
  - MAP-MT-FORWARD-SHORT-MESSAGE (see 12.9),

which are used to forward MO/MT short messages.

This change replicates both services as GSUP messages:

  - OSMO_GSUP_MSGT_MO_FORWARD_SM_*,
  - OSMO_GSUP_MSGT_MT_FORWARD_SM_*.

Please note, that only the 'must-have' IEs are introduced
by this change, in particular the following:

  - OSMO_GSUP_SM_RP_MR_IE (see note below),
  - OSMO_GSUP_SM_RP_DA_IE (see 7.6.8.1),
  - OSMO_GSUP_SM_RP_OA_IE (see 7.6.8.2),
  - OSMO_GSUP_SM_RP_UI_IE (see 7.6.8.4),
  - OSMO_GSUP_SM_RP_MMS_IE (see 7.6.8.7),
  - OSMO_GSUP_SM_RP_CAUSE_IE (see GSM TS 04.11, 8.2.5.4),

where both SM_RP_DA and SM_RP_OA IEs basically contain
a single nested TV of the following format:

  - T: identity type (see 'osmo_gsup_sms_sm_rp_oda_t'),
  - V: encoded identity itself (optional).

According to GSM TS 04.11, every single message on the SM-RL has
an unique message reference (see 8.2.3), that is used to link
an RP-ACK or RP-ERROR message to the associated (preceding)
RP-DATA or RP-SMMA message transfer attempt.

In case of TCAP/MAP, this message reference is being mapped to the
Invoke ID. But since GSUP has no 'Invoke ID' IE, and it is not
required for other applications (other than SMS), this change
introduces a special 'SM_RP_MR' IE that doesn't exist in MAP.

Change-Id: Ibe325c64ae2d6c626b232533bb4cbc65fc2b5d71
Related Change-Id: (docs) Ie0150756c33c1352bc4eb49421824542c711175c
Related Change-Id: (TTCN) Ibf49474a81235096c032ea21f217170f523bd94e
Related: OS#3587

1 files changed, 72 insertions, 1 deletions

diff --git a/tests/gsup/gsup_test.c b/tests/gsup/gsup_test.c
index 9712d77b..09368933 100644
--- a/tests/gsup/gsup_test.c
+++ b/tests/gsup/gsup_test.c
@@ -217,6 +217,69 @@ static void test_gsup_messages_dec_enc(void)
 				0x02, 0x01, 0x47,
 	};
 
+	static const uint8_t send_mo_forward_sm_req[] = {
+		0x24, /* OSMO_GSUP_MSGT_MO_FORWARD_SM_REQUEST */
+		TEST_IMSI_IE,
+
+		/* SM related IEs */
+		0x40, 0x01, /* SM-RP-MR (Message Reference) */
+			0xfa,
+		0x41, 0x08, /* SM-RP-DA (Destination Address) */
+			0x03, /* SMSC address */
+				0x91, 0x52, 0x75, 0x47, 0x99, 0x09, 0x82,
+		0x42, 0x01, /* SM-RP-OA (Originating Address) */
+			0xff, /* Special case: noSM-RP-OA */
+		0x43, 0x04, /* SM-RP-UI (TPDU) */
+			0xde, 0xad, 0xbe, 0xef,
+	};
+
+	static const uint8_t send_mt_forward_sm_req[] = {
+		0x28, /* OSMO_GSUP_MSGT_MT_FORWARD_SM_REQUEST */
+		TEST_IMSI_IE,
+
+		/* SM related IEs */
+		0x40, 0x01, /* SM-RP-MR (Message Reference) */
+			0xfa,
+		0x41, 0x09, /* SM-RP-DA (Destination Address) */
+			0x01, /* IMSI */
+				0x21, 0x43, 0x65, 0x87, 0x09, 0x21, 0x43, 0xf5,
+		0x42, 0x08, /* SM-RP-OA (Originating Address) */
+			0x03, /* SMSC address */
+				0x91, 0x52, 0x75, 0x47, 0x99, 0x09, 0x82,
+		0x43, 0x04, /* SM-RP-UI (TPDU) */
+			0xde, 0xad, 0xbe, 0xef,
+		0x45, 0x01, /* SM-RP-MMS (More Messages to Send) */
+			0x01,
+	};
+
+	static const uint8_t send_mo_mt_forward_sm_err[] = {
+		0x25, /* OSMO_GSUP_MSGT_MO_FORWARD_SM_ERROR */
+		TEST_IMSI_IE,
+
+		/* Session related IEs */
+		0x30, 0x04, /* Session ID */
+			0xde, 0xad, 0xbe, 0xef,
+		0x31, 0x01, /* Session state (END) */
+			0x03,
+
+		/* SM related IEs */
+		0x40, 0x01, /* SM-RP-MR (Message Reference) */
+			0xfa,
+		0x44, 0x01, /* SM-RP-Cause value */
+			0xaf,
+	};
+
+	static const uint8_t send_mo_mt_forward_sm_rsp[] = {
+		0x2a, /* OSMO_GSUP_MSGT_MT_FORWARD_SM_RESULT */
+		TEST_IMSI_IE,
+
+		/* SM related IEs */
+		0x40, 0x01, /* SM-RP-MR (Message Reference) */
+			0xfa,
+		0x43, 0x04, /* SM-RP-UI (TPDU) */
+			0xde, 0xad, 0xbe, 0xef,
+	};
+
 	static const struct test {
 		char *name;
 		const uint8_t *data;
@@ -256,6 +319,14 @@ static void test_gsup_messages_dec_enc(void)
 			send_ussd_req, sizeof(send_ussd_req)},
 		{"SS/USSD processUnstructuredSS-Request / ReturnResult",
 			send_ussd_res, sizeof(send_ussd_res)},
+		{"MO-ForwardSM (MSC -> SMSC) Request",
+			send_mo_forward_sm_req, sizeof(send_mo_forward_sm_req)},
+		{"MT-ForwardSM (MSC -> SMSC) Request",
+			send_mt_forward_sm_req, sizeof(send_mt_forward_sm_req)},
+		{"MO-/MT-ForwardSM Response",
+			send_mo_mt_forward_sm_rsp, sizeof(send_mo_mt_forward_sm_rsp)},
+		{"MO-/MT-ForwardSM Error",
+			send_mo_mt_forward_sm_err, sizeof(send_mo_mt_forward_sm_err)},
 	};
 
 	printf("Test GSUP message decoding/encoding\n");
@@ -323,7 +394,7 @@ static void test_gsup_messages_dec_enc(void)
 				 * FIXME: share the maximal IE value somehow
 				 * in order to avoid manual updating of this
 				 */
-				OSMO_ASSERT(t->data[j+0] <= OSMO_GSUP_SS_INFO_IE);
+				OSMO_ASSERT(t->data[j+0] <= OSMO_GSUP_SM_RP_MMS_IE);
 				OSMO_ASSERT(t->data[j+1] <= ie_end - j - 2);
 
 				ie_end = j;