Add utility to parse 2G GET_RESPONSE data

This format is described in 51.011 and the older 11.11.  It is not
supported by newer 3G UICC based devices & sim card combinations

drivers/atmodem/sim.c

@@ -50,7 +50,7 @@ static void at_crsm_info_cb(gboolean ok, GAtResult *result, gpointer user_data)
 	const guint8 *response;
 	gint sw1, sw2, len;
 	int flen, rlen;
-	enum ofono_sim_file_structure str;
+	int str;
 	unsigned char access[3];
 
 	dump_response("at_crsm_info_cb", ok, result);
@@ -82,17 +82,7 @@ static void at_crsm_info_cb(gboolean ok, GAtResult *result, gpointer user_data)
 
 	ofono_debug("crsm_info_cb: %02x, %02x, %i", sw1, sw2, len);
 
-	flen = (response[2] << 8) | response[3];
-	str = response[13];
-
-	access[0] = response[8];
-	access[1] = response[9];
-	access[2] = response[10];
-
-	if (str == 0x01 || str == 0x03)
-		rlen = response[14];
-	else
-		rlen = 0;
+	sim_parse_2G_get_response(response, len, &flen, &rlen, &str, access);
 
 	cb(&error, flen, str, rlen, access, cbd->data);
 }

src/simutil.c

@@ -573,3 +573,25 @@ struct sim_ef_info *sim_ef_db_lookup(unsigned short id)
 
 	return result;
 }
+
+gboolean sim_parse_2G_get_response(unsigned char *response, int len,
+					int *file_len, int *record_len,
+					int *structure, unsigned char *access)
+{
+	if (len < 14)
+		return FALSE;
+
+	*file_len = (response[2] << 8) | response[3];
+	*structure = response[13];
+
+	access[0] = response[8];
+	access[1] = response[9];
+	access[2] = response[10];
+
+	if (response[13] == 0x01 || response[13] == 0x03)
+		*record_len = response[14];
+	else
+		*record_len = 0;
+
+	return TRUE;
+}

src/simutil.h

@@ -106,3 +106,7 @@ void sim_adn_build(unsigned char *data, int length,
 			const char *identifier);
 
 struct sim_ef_info *sim_ef_db_lookup(unsigned short efid);
+
+gboolean sim_parse_2G_get_response(unsigned char *response, int len,
+					int *file_len, int *record_len,
+					int *structure, unsigned char *access);