[PATCH] libosmocore[master]: gsm0808: Add utils for Cell Identifier List

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dexter gerrit-no-reply at lists.osmocom.org
Thu Mar 30 16:44:54 UTC 2017 

Review at  https://gerrit.osmocom.org/2181

gsm0808: Add utils for Cell Identifier List

The planned support for true A over IP requires the encoding of
the a Cell Identifier List element (see also BSS_MAP_MSG_PAGING).

This commt adds encoding/decoding functionality and tests for
the element mentioned above, however, it is not yet actively used.

Change-Id: I625245dd1dd396fc2bc189e8cd2c444a33042528
---
M include/osmocom/gsm/gsm0808_utils.h
M include/osmocom/gsm/protocol/gsm_08_08.h
M src/gsm/gsm0808_utils.c
M src/gsm/libosmogsm.map
M tests/gsm0808/gsm0808_test.c
5 files changed, 195 insertions(+), 1 deletion(-)


  git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/81/2181/1

diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index 2196f94..c9fd124 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -57,3 +57,10 @@
 /* Decode Encryption Information element */
 struct gsm0808_encrypt_info *gsm0808_dec_encrypt_info(const void *ctx,
 						      struct msgb *msg);
+
+/* Encode Cell Identifier List element */
+struct msgb *gsm0808_enc_cell_id_list(struct gsm0808_cell_id_list *cil);
+
+/* Decode Cell Identifier List element */
+struct gsm0808_cell_id_list *gsm0808_dec_cell_id_list(const void *ctx,
+						      struct msgb *msg);
diff --git a/include/osmocom/gsm/protocol/gsm_08_08.h b/include/osmocom/gsm/protocol/gsm_08_08.h
index d52af9f..ad7f8eb 100644
--- a/include/osmocom/gsm/protocol/gsm_08_08.h
+++ b/include/osmocom/gsm/protocol/gsm_08_08.h
@@ -452,3 +452,17 @@
 	uint8_t key[ENCRY_INFO_KEY_MAXLEN];
 	unsigned int key_len;
 };
+
+/* 3GPP TS 48.008 3.2.2.10 Cell Identifier List */
+struct gsm0808_cell_id_list {
+	uint8_t id_discr;
+	struct llist_head id_list;
+};
+
+/* 3GPP TS 48.008 3.2.2.10 Cell Identifier List
+ * (Coding of i-th Cell Identification for Cell
+ * identification discriminator = 0101) */
+struct gsm0808_cell_id_lac {
+	struct llist_head list;
+	uint16_t lac;
+};
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index 7dfe2e9..564f171 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -426,3 +426,87 @@
 
 	return ei;
 }
+
+/* Encode Cell Identifier List element */
+struct msgb *gsm0808_enc_cell_id_list(struct gsm0808_cell_id_list *cil)
+{
+	struct msgb *msg;
+	struct gsm0808_cell_id_lac *lac;
+
+	OSMO_ASSERT(cil);
+
+	/* FIXME: Implement support for all identifier list elements */
+	OSMO_ASSERT(cil->id_discr == CELL_IDENT_LAC
+		    || cil->id_discr == CELL_IDENT_BSS)
+
+	msg = msgb_alloc(ELEMENT_MSGB_MAXLEN, "Cell-ID list Element");
+	if (!msg)
+		return NULL;
+
+	msgb_put_u8(msg, cil->id_discr & 0x0f);
+
+	switch (cil->id_discr) {
+	case CELL_IDENT_LAC:
+		llist_for_each_entry(lac, &cil->id_list, list) {
+			msgb_put_u16(msg, lac->lac);
+		}
+		break;
+
+	case CELL_IDENT_BSS:
+		/* Does not have any list items */
+		break;
+
+	default:
+		/* Unspported encoding */
+		OSMO_ASSERT(false);
+	}
+
+	return msg;
+}
+
+/* Decode Cell Identifier List element */
+struct gsm0808_cell_id_list *gsm0808_dec_cell_id_list(const void *ctx,
+						      struct msgb *msg)
+{
+	uint8_t id_discr;
+	struct gsm0808_cell_id_list *cil;
+	struct gsm0808_cell_id_lac *lac;
+
+	if (!msg)
+		return NULL;
+
+	id_discr = msgb_pull_u8(msg) & 0x0f;
+
+	/* FIXME: Implement support for all identifier list elements */
+	if (id_discr != CELL_IDENT_LAC && id_discr != CELL_IDENT_BSS)
+		return NULL;
+
+	cil = talloc_zero(ctx, struct gsm0808_cell_id_list);
+	if (!cil)
+		return NULL;
+	INIT_LLIST_HEAD(&cil->id_list);
+
+	cil->id_discr = id_discr;
+
+	switch (id_discr) {
+	case CELL_IDENT_LAC:
+		while (msg->len >= 2) {
+			lac = talloc_zero(cil, struct gsm0808_cell_id_lac);
+			if (!lac) {
+				talloc_free(cil);
+				return NULL;
+			}
+			lac->lac = msgb_pull_u16(msg);
+			llist_add(&lac->list, &cil->id_list);
+		}
+
+	case CELL_IDENT_BSS:
+		/* Does not have any list items */
+		break;
+	default:
+		/* Unspported encoding */
+		OSMO_ASSERT(false);
+	}
+
+	return cil;
+}
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index e64fdd9..ac8d467 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -150,6 +150,8 @@
 gsm0808_dec_channel_type;
 gsm0808_enc_encrypt_info;
 gsm0808_dec_encrypt_info;
+gsm0808_enc_cell_id_list;
+gsm0808_dec_cell_id_list;
 
 gsm0858_rsl_ul_meas_enc;
 
diff --git a/tests/gsm0808/gsm0808_test.c b/tests/gsm0808/gsm0808_test.c
index e52cba7..c7e0d18 100644
--- a/tests/gsm0808/gsm0808_test.c
+++ b/tests/gsm0808/gsm0808_test.c
@@ -619,7 +619,6 @@
 	msgb_free(ct_enc);
 }
 
-
 static void test_gsm0808_enc_dec_encrypt_info(const void *ctx)
 {
 	struct gsm0808_encrypt_info ei;
@@ -655,6 +654,91 @@
 	msgb_free(ei_enc);
 }
 
+static void test_gsm0808_enc_dec_cell_id_list_lac(const void *ctx)
+{
+	struct gsm0808_cell_id_lac lac1;
+	struct gsm0808_cell_id_lac lac2;
+	struct gsm0808_cell_id_lac lac3;
+	struct msgb *msg;
+	struct gsm0808_cell_id_list cil;
+	struct gsm0808_cell_id_list *cil_decoded;
+	struct gsm0808_cell_id_lac *lac;
+
+	cil.id_discr = CELL_IDENT_LAC;
+	INIT_LLIST_HEAD(&cil.id_list);
+	lac1.lac = 0x1111;
+	lac2.lac = 0x2222;
+	lac3.lac = 0x3333;
+	llist_add(&lac1.list, &cil.id_list);
+	llist_add(&lac2.list, &cil.id_list);
+	llist_add(&lac3.list, &cil.id_list);
+
+	msg = gsm0808_enc_cell_id_list(&cil);
+	OSMO_ASSERT(msg);
+	cil_decoded = gsm0808_dec_cell_id_list(ctx, msg);
+	OSMO_ASSERT(cil_decoded);
+	OSMO_ASSERT(msg->len == 0);
+	OSMO_ASSERT(cil_decoded->id_discr == cil.id_discr);
+
+	llist_for_each_entry(lac, &cil_decoded->id_list, list) {
+		OSMO_ASSERT((lac->lac == lac1.lac) || (lac->lac == lac2.lac)
+			    || (lac->lac == lac3.lac))
+	}
+
+	talloc_free(cil_decoded);
+	msgb_free(msg);
+}
+
+static void test_gsm0808_enc_dec_cell_id_list_single_lac(const void *ctx)
+{
+	struct gsm0808_cell_id_lac lac_enc;
+	struct msgb *msg;
+	struct gsm0808_cell_id_list cil;
+	struct gsm0808_cell_id_list *cil_decoded;
+	struct gsm0808_cell_id_lac *lac;
+	uint8_t cil_enc_expected[] = {0x05, 0x23, 0x42};
+	cil.id_discr = CELL_IDENT_LAC;
+	INIT_LLIST_HEAD(&cil.id_list);
+	lac_enc.lac = 0x2342;
+	llist_add(&lac_enc.list, &cil.id_list);
+
+	msg = gsm0808_enc_cell_id_list(&cil);
+	OSMO_ASSERT(msg);
+	OSMO_ASSERT(memcmp(cil_enc_expected,msg->data,msg->len) == 0);
+
+	cil_decoded = gsm0808_dec_cell_id_list(ctx, msg);
+	OSMO_ASSERT(cil_decoded);
+	OSMO_ASSERT(msg->len == 0);
+	OSMO_ASSERT(cil_decoded->id_discr == cil.id_discr);
+
+	llist_for_each_entry(lac, &cil_decoded->id_list, list) {
+		OSMO_ASSERT(lac->lac == lac_enc.lac)
+	}
+
+	talloc_free(cil_decoded);
+	msgb_free(msg);
+}
+
+static void test_gsm0808_enc_dec_cell_id_list_bss(const void *ctx)
+{
+	struct msgb *msg;
+	struct gsm0808_cell_id_list cil;
+	struct gsm0808_cell_id_list *cil_decoded;
+
+	cil.id_discr = CELL_IDENT_BSS;
+
+	msg = gsm0808_enc_cell_id_list(&cil);
+	OSMO_ASSERT(msg);
+
+	cil_decoded = gsm0808_dec_cell_id_list(ctx, msg);
+	OSMO_ASSERT(cil_decoded);
+	OSMO_ASSERT(msg->len == 0);
+	OSMO_ASSERT(cil_decoded->id_discr == cil.id_discr);
+
+	talloc_free(cil_decoded);
+	msgb_free(msg);
+}
+
 int main(int argc, char **argv)
 {
 	void *ctx;
@@ -686,6 +770,9 @@
 	test_gsm0808_enc_dec_speech_codec_list(ctx);
 	test_gsm0808_enc_dec_channel_type(ctx);
 	test_gsm0808_enc_dec_encrypt_info(ctx);
+	test_gsm0808_enc_dec_cell_id_list_lac(ctx);
+	test_gsm0808_enc_dec_cell_id_list_single_lac(ctx);
+	test_gsm0808_enc_dec_cell_id_list_bss(ctx);
 
 	printf("Done\n");
 

-- 
To view, visit https://gerrit.osmocom.org/2181
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I625245dd1dd396fc2bc189e8cd2c444a33042528
Gerrit-PatchSet: 1
Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Owner: dexter <pmaier at sysmocom.de>

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