umts_cell_id: add umts_cell_id_to_str_buf()

Prepare for umts_cell_id_test.c: allow testing the to_str conversion
without using talloc.

Change-Id: I3cc0169593c73c2e658637e4116ddd578f83df6d
---
M include/osmocom/hnbgw/hnbgw.h
M src/osmo-hnbgw/hnbgw.c
2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/include/osmocom/hnbgw/hnbgw.h b/include/osmocom/hnbgw/hnbgw.h
index 2c7e014..87844f4 100644
--- a/include/osmocom/hnbgw/hnbgw.h
+++ b/include/osmocom/hnbgw/hnbgw.h
@@ -173,6 +173,8 @@
 	uint16_t sac;	/*!< Service Area Code */
 	uint32_t cid;	/*!< Cell ID */
 };
+int umts_cell_id_to_str_buf(char *buf, size_t buflen, const struct umts_cell_id *ucid);
+char *umts_cell_id_to_str_c(void *ctx, const struct umts_cell_id *ucid);
 const char *umts_cell_id_to_str(const struct umts_cell_id *ucid);
 int umts_cell_id_from_str(struct umts_cell_id *ucid, const char *instr);
 uint32_t umts_cell_id_hash(const struct umts_cell_id *ucid);
diff --git a/src/osmo-hnbgw/hnbgw.c b/src/osmo-hnbgw/hnbgw.c
index c41fb54..4f3fafa 100644
--- a/src/osmo-hnbgw/hnbgw.c
+++ b/src/osmo-hnbgw/hnbgw.c
@@ -232,15 +232,24 @@
 	return ctx;
 }
 
-const char *umts_cell_id_to_str(const struct umts_cell_id *ucid)
+int umts_cell_id_to_str_buf(char *buf, size_t buflen, const struct umts_cell_id *ucid)
 {
 	const char *fmtstr = "%03u-%02u-L%u-R%u-S%u-C%u";
 
 	if (g_hnbgw->config.plmn.mnc_3_digits)
 		fmtstr = "%03u-%03u-L%u-R%u-S%u-C%u";
+	return snprintf(buf, buflen, fmtstr, ucid->mcc, ucid->mnc, ucid->lac, ucid->rac,
+			ucid->sac, ucid->cid);
+}
 
-	return talloc_asprintf(OTC_SELECT, fmtstr, ucid->mcc, ucid->mnc, ucid->lac, ucid->rac,
-			       ucid->sac, ucid->cid);
+char *umts_cell_id_to_str_c(void *ctx, const struct umts_cell_id *ucid)
+{
+	OSMO_NAME_C_IMPL(ctx, 64, "ERROR", umts_cell_id_to_str_buf, ucid)
+}
+
+const char *umts_cell_id_to_str(const struct umts_cell_id *ucid)
+{
+	return umts_cell_id_to_str_c(OTC_SELECT, ucid);
 }
 
 /* Useful to index a hash table by struct umts_cell_id. */

