gsm0808: Add create functions for BSS_MAP_MSG_ASSIGMENT_RQST

gsm0808.h/c lacks functionality to generate BSS_MAP_MSG_ASSIGMENT_RQST messages.
These messages are required if the code is used in an MSC implementation.

This commit adds a gsm0808_create_assignment() function, that generates an
A/AoiP BSS_MAP_MSG_PAGING message.

Change-Id: I4d1d455a1e1cf95407e23ded7b7defbcf2dd6ff0

include/osmocom/gsm/gsm0808.h

@@ -42,6 +42,11 @@ struct msgb *gsm0808_create_cipher_reject(uint8_t cause);
 struct msgb *gsm0808_create_classmark_update(const uint8_t *cm2, uint8_t cm2_len,
 					     const uint8_t *cm3, uint8_t cm3_len);
 struct msgb *gsm0808_create_sapi_reject(uint8_t link_id);
+struct msgb *gsm0808_create_ass(const struct gsm0808_channel_type *ct,
+				const uint16_t *cic,
+				const struct sockaddr_storage *ss,
+				const struct gsm0808_speech_codec_list *scl,
+				const uint32_t *ci);
 struct msgb *gsm0808_create_ass_compl(uint8_t rr_cause, uint8_t chosen_channel,
 				      uint8_t encr_alg_id, uint8_t speech_mode,
 				      const struct sockaddr_storage *ss,

src/gsm/gsm0808.c

@@ -238,6 +238,62 @@ struct msgb *gsm0808_create_sapi_reject(uint8_t link_id)
 	return msg;
 }
 
+struct msgb *gsm0808_create_ass(const struct gsm0808_channel_type *ct,
+				const uint16_t *cic,
+				const struct sockaddr_storage *ss,
+				const struct gsm0808_speech_codec_list *scl,
+				const uint32_t *ci)
+{
+	/* See also: 3GPP TS 48.008 3.2.1.1 ASSIGNMENT REQUEST */
+	struct msgb *msg;
+	uint16_t cic_sw;
+	uint32_t ci_sw;
+
+	/* Mandatory emelent! */
+	OSMO_ASSERT(ct);
+
+	msg =
+	    msgb_alloc_headroom(BSSMAP_MSG_SIZE, BSSMAP_MSG_HEADROOM,
+				"bssmap: ass req");
+	if (!msg)
+		return NULL;
+
+	/* Message Type 3.2.2.1 */
+	msgb_v_put(msg, BSS_MAP_MSG_ASSIGMENT_RQST);
+
+	/* Channel Type 3.2.2.11 */
+	gsm0808_enc_channel_type(msg, ct);
+
+	/* Circuit Identity Code 3.2.2.2  */
+	if (cic) {
+		cic_sw = htons(*cic);
+		msgb_tv_fixed_put(msg, GSM0808_IE_CIRCUIT_IDENTITY_CODE,
+				  sizeof(cic_sw), (uint8_t *) & cic_sw);
+	}
+
+	/* AoIP: AoIP Transport Layer Address (MGW) 3.2.2.102 */
+	if (ss) {
+		gsm0808_enc_aoip_trasp_addr(msg, ss);
+	}
+
+	/* AoIP: Codec List (MSC Preferred) 3.2.2.103 */
+	if (scl)
+		gsm0808_enc_speech_codec_list(msg, scl);
+
+	/* AoIP: Call Identifier 3.2.2.105 */
+	if (ci) {
+		ci_sw = htonl(*ci);
+		msgb_tv_fixed_put(msg, GSM0808_IE_CALL_ID, sizeof(ci_sw),
+				  (uint8_t *) & ci_sw);
+	}
+
+	/* push the bssmap header */
+	msg->l3h =
+	    msgb_tv_push(msg, BSSAP_MSG_BSS_MANAGEMENT, msgb_length(msg));
+
+	return msg;
+}
+
 struct msgb *gsm0808_create_ass_compl(uint8_t rr_cause, uint8_t chosen_channel,
 				      uint8_t encr_alg_id, uint8_t speech_mode,
 				      const struct sockaddr_storage *ss,

src/gsm/libosmogsm.map

@@ -124,6 +124,7 @@ gsm0503_mcs9;
 gsm0808_att_tlvdef;
 gsm0808_bssap_name;
 gsm0808_bssmap_name;
+gsm0808_create_ass;
 gsm0808_create_assignment_completed;
 gsm0808_create_ass_compl;
 gsm0808_create_assignment_failure;

tests/gsm0808/gsm0808_test.c

@@ -262,6 +262,55 @@ static void test_create_sapi_reject()
 	msgb_free(msg);
 }
 
+static void test_create_ass()
+{
+	static const uint8_t res1[] =
+	    { 0x00, 0x0a, 0x01, 0x0b, 0x04, 0x01, 0x0b, 0xa1, 0x25, 0x01, 0x00,
+	      0x04 };
+	static const uint8_t res2[] =
+	    { 0x00, 0x20, 0x01, 0x0b, 0x04, 0x01, 0x0b, 0xa1, 0x25, 0x01, 0x00,
+	      0x04, GSM0808_IE_AOIP_TRASP_ADDR, 0x06, 0xc0, 0xa8, 0x64, 0x17,
+	      0x04, 0xd2, GSM0808_IE_SPEECH_CODEC_LIST, 0x07, 0x5f, 0xab, 0xcd,
+	      0xef, 0xa5, 0x9f, 0xf2, GSM0808_IE_CALL_ID, 0xaa, 0xbb, 0xcc,
+	      0xdd };
+
+	struct msgb *msg;
+	struct gsm0808_channel_type ct;
+	uint16_t cic = 0004;
+	struct sockaddr_storage ss;
+	struct sockaddr_in sin;
+	struct gsm0808_speech_codec_list sc_list;
+	uint32_t call_id = 0xAABBCCDD;
+
+	memset(&ct, 0, sizeof(ct));
+	ct.ch_indctr = GSM0808_CHAN_SPEECH;
+	ct.ch_rate_type = GSM0808_SPEECH_HALF_PREF;
+	ct.perm_spch[0] = GSM0808_PERM_FR3;
+	ct.perm_spch[1] = GSM0808_PERM_HR3;
+	ct.perm_spch_len = 2;
+
+	memset(&sin, 0, sizeof(sin));
+	sin.sin_family = AF_INET;
+	sin.sin_port = htons(1234);
+	inet_aton("192.168.100.23", &sin.sin_addr);
+
+	memset(&ss, 0, sizeof(ss));
+	memcpy(&ss, &sin, sizeof(sin));
+
+	setup_codec_list(&sc_list);
+
+	printf("Testing creating Assignment Request\n");
+	msg = gsm0808_create_ass(&ct, &cic, NULL, NULL, NULL);
+	OSMO_ASSERT(msg);
+	VERIFY(msg, res1, ARRAY_SIZE(res1));
+	msgb_free(msg);
+
+	msg = gsm0808_create_ass(&ct, &cic, &ss, &sc_list, &call_id);
+	OSMO_ASSERT(msg);
+	VERIFY(msg, res2, ARRAY_SIZE(res2));
+	msgb_free(msg);
+}
+
 static void test_create_ass_compl()
 {
 	static const uint8_t res1[] = {
@@ -786,6 +835,7 @@ int main(int argc, char **argv)
 	test_create_cipher_reject();
 	test_create_cm_u();
 	test_create_sapi_reject();
+	test_create_ass();
 	test_create_ass_compl();
 	test_create_ass_compl_aoip();
 	test_create_ass_fail();

tests/gsm0808/gsm0808_test.ok

@@ -9,6 +9,7 @@ Testing creating Cipher Complete
 Testing creating Cipher Reject
 Testing creating CM U
 Testing creating SAPI Reject
+Testing creating Assignment Request
 Testing creating Assignment Complete
 Testing creating Assignment Complete (AoIP)
 Testing creating Assignment Failure