Change in libosmocore[master]: add gsm0808_cell_id_from_cgi(), gsm0808_cell_id_to_cgi()

[Neels Hofmeyr]

Neels Hofmeyr has uploaded this change for review. ( https://gerrit.osmocom.org/13122


Change subject: add gsm0808_cell_id_from_cgi(), gsm0808_cell_id_to_cgi()
......................................................................

add gsm0808_cell_id_from_cgi(), gsm0808_cell_id_to_cgi()

For example, for Paging, osmo-msc has a CGI for a subscriber and needs to send
out a Cell Identifier IE. Makes sense to add this conversion here. While at it,
also provide the reverse conversion.

Change-Id: Ib9af67b100c4583342a2103669732dab2e577b04
---
M include/osmocom/gsm/gsm0808_utils.h
M src/gsm/gsm0808_utils.c
M src/gsm/libosmogsm.map
3 files changed, 91 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/22/13122/1

diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h
index 2b48be7..53f145c 100644
--- a/include/osmocom/gsm/gsm0808_utils.h
+++ b/include/osmocom/gsm/gsm0808_utils.h
@@ -84,6 +84,9 @@
 bool gsm0808_cell_ids_match(const struct gsm0808_cell_id *id1, const struct gsm0808_cell_id *id2, bool exact_match);
 int gsm0808_cell_id_matches_list(const struct gsm0808_cell_id *id, const struct gsm0808_cell_id_list2 *list,
 				 unsigned int match_nr, bool exact_match);
+void gsm0808_cell_id_from_cgi(struct gsm0808_cell_id *cid, enum CELL_IDENT id_discr,
+			      const struct osmo_cell_global_id *cgi);
+int gsm0808_cell_id_to_cgi(struct osmo_cell_global_id *cgi, const struct gsm0808_cell_id *cid);
 
 uint8_t gsm0808_enc_cause(struct msgb *msg, uint16_t cause);
 uint8_t gsm0808_enc_aoip_trasp_addr(struct msgb *msg,
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index 5477598..0426f78 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -1577,6 +1577,92 @@
 	return -1;
 }
 
+/*! Copy information from a CGI to form a Cell Identifier of the specified kind.
+ * \param [out] cid  Compose new Cell Identifier here.
+ * \param [in] id_discr  Which kind of Cell Identifier to compose.
+ * \param [in] cgi  Cell Global Identifier to form the Cell Identifier from.
+ */
+void gsm0808_cell_id_from_cgi(struct gsm0808_cell_id *cid, enum CELL_IDENT id_discr,
+			      const struct osmo_cell_global_id *cgi)
+{
+	*cid = (struct gsm0808_cell_id){
+		.id_discr = id_discr,
+	};
+
+	switch (id_discr) {
+	case CELL_IDENT_WHOLE_GLOBAL:
+		cid->id.global = *cgi;
+		return;
+
+	case CELL_IDENT_LAC_AND_CI:
+		cid->id.lac_and_ci = (struct osmo_lac_and_ci_id){
+			.lac = cgi->lai.lac,
+			.ci = cgi->cell_identity,
+		};
+		return;
+
+	case CELL_IDENT_CI:
+		cid->id.ci = cgi->cell_identity;
+		return;
+
+	case CELL_IDENT_LAI:
+		cid->id.lai_and_lac = cgi->lai;
+		return;
+
+	case CELL_IDENT_LAC:
+		cid->id.lac = cgi->lai.lac;
+		return;
+
+	case CELL_IDENT_NO_CELL:
+	case CELL_IDENT_BSS:
+	case CELL_IDENT_UTRAN_PLMN_LAC_RNC:
+	case CELL_IDENT_UTRAN_RNC:
+	case CELL_IDENT_UTRAN_LAC_RNC:
+	default:
+		return;
+	};
+}
+
+/*! Overwrite parts of cgi with values from a Cell Identifier.
+ * Place only those items given in cid into cgi, leaving other values unchanged.
+ * \param[out] cgi  Cell Global Identity to write to.
+ * \param[in] cid  Cell Identity to read from.
+ * \return a bitmask of items that were set: 0x1 == PLMN, 0x2 == LAC, 0x4 == CI; 0 if nothing was written to cgi.
+ */
+int gsm0808_cell_id_to_cgi(struct osmo_cell_global_id *cgi, const struct gsm0808_cell_id *cid)
+{
+	switch (cid->id_discr) {
+	case CELL_IDENT_WHOLE_GLOBAL:
+		*cgi = cid->id.global;
+		return 0x1 | 0x2 | 0x4;
+
+	case CELL_IDENT_LAC_AND_CI:
+		cgi->lai.lac = cid->id.lac_and_ci.lac;
+		cgi->cell_identity = cid->id.lac_and_ci.ci;
+		return 0x2 | 0x4;
+
+	case CELL_IDENT_CI:
+		cgi->cell_identity = cid->id.ci;
+		return 0x4;
+
+	case CELL_IDENT_LAI:
+		cgi->lai = cid->id.lai_and_lac;
+		return 0x1 | 0x2;
+
+	case CELL_IDENT_LAC:
+		cgi->lai.lac = cid->id.lac;
+		return 0x2;
+
+	case CELL_IDENT_NO_CELL:
+	case CELL_IDENT_BSS:
+	case CELL_IDENT_UTRAN_PLMN_LAC_RNC:
+	case CELL_IDENT_UTRAN_RNC:
+	case CELL_IDENT_UTRAN_LAC_RNC:
+	default:
+		return 0;
+	};
+}
+
 /*! value_string[] for enum CELL_IDENT. */
 const struct value_string gsm0808_cell_id_discr_names[] = {
 	{ CELL_IDENT_WHOLE_GLOBAL, "CGI" },
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 2d47d7a..3fadc5a 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -205,6 +205,8 @@
 gsm0808_dec_cell_id_list2;
 gsm0808_cell_id_list_add;
 gsm0808_cell_id_to_list;
+gsm0808_cell_id_to_cgi;
+gsm0808_cell_id_from_cgi;
 gsm0808_enc_cell_id;
 gsm0808_dec_cell_id;
 gsm0808_cell_id_name;

-- 
To view, visit https://gerrit.osmocom.org/13122
To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings

Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: Ib9af67b100c4583342a2103669732dab2e577b04
Gerrit-Change-Number: 13122
Gerrit-PatchSet: 1
Gerrit-Owner: Neels Hofmeyr <nhofmeyr at sysmocom.de>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osmocom.org/pipermail/gerrit-log/attachments/20190304/6cf7b638/attachment.htm>