[PATCH] libosmocore[master]: gsm48.c: move to hex tmsi representation

[Vadim Yanitskiy]

Review at  https://gerrit.osmocom.org/199

gsm48.c: move to hex tmsi representation

Because we should save the backward compatibility with
other projects that use this library, there is one new
gsm48_mid_to_string() method which is similar to the
gsm48_mi_to_string() but uses the '0x%08x' format string
to convert TMSI.

Also there is one more gsm48_tmsi_from_string() method
that was moved here from OpenBSC/gsm_subscriber.h.

Change-Id: I9d05209e546d8692360860839fa0720fb7349385
---
M include/osmocom/gsm/gsm48.h
M src/gsm/gsm48.c
2 files changed, 58 insertions(+), 4 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/99/199/1

diff --git a/include/osmocom/gsm/gsm48.h b/include/osmocom/gsm/gsm48.h
index d6e58c2..3b6a80b 100644
--- a/include/osmocom/gsm/gsm48.h
+++ b/include/osmocom/gsm/gsm48.h
@@ -29,10 +29,12 @@
 int gsm48_generate_mid_from_tmsi(uint8_t *buf, uint32_t tmsi);
 int gsm48_generate_mid_from_imsi(uint8_t *buf, const char *imsi);
 
-/* Convert Mobile Identity (10.5.1.4) to string */
+/* Mobile Identity (10.5.1.4) related methods */
+const char *gsm48_mi_type_name(uint8_t mi);
 int gsm48_mi_to_string(char *string, const int str_len,
 			const uint8_t *mi, const int mi_len);
-const char *gsm48_mi_type_name(uint8_t mi);
+int gsm48_mid_to_string(char *string, const int str_len,
+			const uint8_t *mi, const int mi_len);
 
 /* Parse Routeing Area Identifier */
 void gsm48_parse_ra(struct gprs_ra_id *raid, const uint8_t *buf);
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index 8a46f76..0399aac 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -443,7 +443,10 @@
 	return 2 + buf[1];
 }
 
-/* Convert Mobile Identity (10.5.1.4) to string */
+/* Convert Mobile Identity (10.5.1.4) to string.
+ * Now it is outdated method because we are moving to
+ * hexadecimal TMSI representation, so we should use
+ * the gsm48_mid_to_string() instead of this one. */
 int gsm48_mi_to_string(char *string, const int str_len, const uint8_t *mi,
 		       const int mi_len)
 {
@@ -470,7 +473,7 @@
 	case GSM_MI_TYPE_IMEISV:
 		*str_cur++ = osmo_bcd2char(mi[0] >> 4);
 
-                for (i = 1; i < mi_len; i++) {
+		for (i = 1; i < mi_len; i++) {
 			if (str_cur + 2 >= string + str_len)
 				return str_cur - string;
 			*str_cur++ = osmo_bcd2char(mi[i] & 0xf);
@@ -487,6 +490,55 @@
 	return str_cur - string;
 }
 
+int gsm48_mid_to_string(char *string, const int str_len, const uint8_t *mi,
+		       const int mi_len)
+{
+	int i;
+	uint8_t mi_type;
+	char *str_cur = string;
+	uint32_t tmsi;
+
+	mi_type = mi[0] & GSM_MI_TYPE_MASK;
+
+	switch (mi_type) {
+	case GSM_MI_TYPE_NONE:
+		break;
+	case GSM_MI_TYPE_TMSI:
+		if (mi_len == GSM48_TMSI_LEN && mi[0] == (0xf0 | GSM_MI_TYPE_TMSI)) {
+			memcpy(&tmsi, &mi[1], 4);
+			tmsi = ntohl(tmsi);
+			return snprintf(string, str_len, "0x%08x", tmsi);
+		}
+		break;
+	case GSM_MI_TYPE_IMSI:
+	case GSM_MI_TYPE_IMEI:
+	case GSM_MI_TYPE_IMEISV:
+		*str_cur++ = osmo_bcd2char(mi[0] >> 4);
+
+		for (i = 1; i < mi_len; i++) {
+			if (str_cur + 2 >= string + str_len)
+				return str_cur - string;
+			*str_cur++ = osmo_bcd2char(mi[i] & 0xf);
+			/* skip last nibble in last input byte when GSM_EVEN */
+			if( (i != mi_len-1) || (mi[0] & GSM_MI_ODD))
+				*str_cur++ = osmo_bcd2char(mi[i] >> 4);
+		}
+		break;
+	default:
+		break;
+	}
+	*str_cur++ = '\0';
+
+	return str_cur - string;
+}
+
+uint32_t gsm48_tmsi_from_string(char *mi_string)
+{
+	/* It is not required to cut the '0x' because
+	 * the strtoul() can handle it automatically */
+	return strtoul(mi_string, NULL, 16);
+}
+
 void gsm48_parse_ra(struct gprs_ra_id *raid, const uint8_t *buf)
 {
 	raid->mcc = (buf[0] & 0xf) * 100;

-- 
To view, visit https://gerrit.osmocom.org/199
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I9d05209e546d8692360860839fa0720fb7349385
Gerrit-PatchSet: 1
Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Owner: Vadim Yanitskiy <axilirator at gmail.com>