add osmo_mi_name(), for MI-to-string like "IMSI-123456"
We have gsm48_mi_to_string() and osmo_bcd2str(), but still lack a function that
conveniently prints both MI type and value in one function call.
Related: http://people.osmocom.org/neels/mi_mi_mi.jpg
Change-Id: I7798c3ef983c2e333b2b9cbffef6f366f370bd81
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index 190622f..853ea51 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -433,6 +433,42 @@
return get_value_string(mi_type_names, mi);
}
+/*! Return a human readable representation of a Mobile Identity in static buffer.
+ * \param[in] mi Mobile Identity buffer containing 3GPP TS 04.08 style MI type and data.
+ * \param[in] mi_len Length of mi.
+ * \return A string like "IMSI-1234567", "TMSI-0x1234ABCD" or "unknown", "TMSI-invalid"...
+ */
+const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
+{
+ static char mi_name[10 + GSM48_MI_SIZE + 1];
+ uint8_t mi_type;
+ uint32_t tmsi;
+ char mi_string[GSM48_MI_SIZE];
+
+ mi_type = (mi && mi_len) ? (mi[0] & GSM_MI_TYPE_MASK) : GSM_MI_TYPE_NONE;
+
+ switch (mi_type) {
+ case GSM_MI_TYPE_TMSI:
+ /* Table 10.5.4.3, reverse generate_mid_from_tmsi */
+ if (mi_len == GSM48_TMSI_LEN && mi[0] == (0xf0 | GSM_MI_TYPE_TMSI)) {
+ tmsi = osmo_load32be(&mi[1]);
+ snprintf(mi_name, sizeof(mi_name), "TMSI-0x%08" PRIX32, tmsi);
+ return mi_name;
+ }
+ return "TMSI-invalid";
+
+ case GSM_MI_TYPE_IMSI:
+ case GSM_MI_TYPE_IMEI:
+ case GSM_MI_TYPE_IMEISV:
+ osmo_bcd2str(mi_string, sizeof(mi_string), mi, 1, (mi_len * 2) - (mi[0] & GSM_MI_ODD ? 0 : 1), true);
+ snprintf(mi_name, sizeof(mi_name), "%s-%s", gsm48_mi_type_name(mi_type), mi_string);
+ return mi_name;
+
+ default:
+ return "unknown";
+ }
+}
+
/*! Checks is particular message is cipherable in A/Gb mode according to
* 3GPP TS 24.008 § 4.7.1.2
* \param[in] hdr Message header
