ussd: Add a test case, switch parsing to use a gsm48_hdr and len

The current USSD code is not doing any size checks, add a test
case to find out how easily we access the data out of bounds.
Begin to use the length in some places.

1 files changed, 63 insertions, 0 deletions

diff --git a/tests/ussd/ussd_test.c b/tests/ussd/ussd_test.c
new file mode 100644
index 00000000..4d125ffd
--- /dev/null
+++ b/tests/ussd/ussd_test.c
@@ -0,0 +1,63 @@
+/*
+ * (C) 2010 by Holger Hans Peter Freyther
+ * (C) 2010 by On-Waves
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <osmocore/gsm0480.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static const uint8_t ussd_request[] = {
+	0x0b, 0x7b, 0x1c, 0x15, 0xa1, 0x13, 0x02, 0x01,
+	0x03, 0x02, 0x01, 0x3b, 0x30, 0x0b, 0x04, 0x01,
+	0x0f, 0x04, 0x06, 0x2a, 0xd5, 0x4c, 0x16, 0x1b,
+	0x01, 0x7f, 0x01, 0x00
+};
+
+static int parse_ussd(const uint8_t *_data, int len)
+{
+	uint8_t *data;
+	int rc;
+	struct ussd_request req;
+	struct gsm48_hdr *hdr;
+
+	data = malloc(len);
+	memcpy(data, _data, len);
+	hdr = (struct gsm48_hdr *) &data[0];
+	rc = gsm0480_decode_ussd_request(hdr, len, &req);
+	free(data);
+
+	return rc;
+}
+
+int main(int argc, char **argv)
+{
+	const int size = sizeof(ussd_request);
+	int i;
+
+	printf("Testing parsing a USSD request and truncated versions\n");
+
+	for (i = size; i > sizeof(struct gsm48_hdr); --i) {
+		int rc = parse_ussd(&ussd_request[0], i);
+		printf("Result for %d is %d\n", rc, i);
+	}
+
+	return 0;
+}