wsc: Add WSC attribute iterator

Makefile.am

@@ -59,7 +59,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h linux/kdbus.h \
 					src/agent.h src/agent.c \
 					src/storage.h src/storage.c \
 					src/network.h src/network.c \
-					src/wsc.h \
+					src/wsc.h src/wsc.c \
 					iwd.h
 src_iwd_LDADD = ell/libell-internal.la
 

src/wsc.c

@@ -0,0 +1,68 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2015  Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdbool.h>
+
+#include <ell/ell.h>
+
+#include "wsc.h"
+
+void wsc_attr_iter_init(struct wsc_attr_iter *iter, const unsigned char *pdu,
+			unsigned int len)
+{
+	iter->pdu = pdu;
+	iter->max = len;
+	iter->pos = 0;
+}
+
+bool wsc_attr_iter_next(struct wsc_attr_iter *iter)
+{
+	const unsigned char *start = iter->pdu + iter->pos;
+	const unsigned char *end = iter->pdu + iter->max;
+	unsigned short type;
+	unsigned short len;
+
+	/* Make sure we have at least type + len fields */
+	if (iter->pos + 4 >= iter->max)
+		return false;
+
+	type = l_get_be16(start);
+	start += 2;
+
+	len = l_get_be16(start);
+	start += 2;
+
+	if (start + len > end)
+		return false;
+
+	iter->type = type;
+	iter->len = len;
+	iter->data = start;
+
+	iter->pos = start + len - iter->pdu;
+
+	return true;
+}

src/wsc.h

@@ -256,3 +256,32 @@ enum wsc_config_state {
 	WSC_CONFIG_STATE_NOT_CONFIGURED		= 0x01,
 	WSC_CONFIG_STATE_CONFIGURED		= 0x02,
 };
+
+struct wsc_attr_iter {
+	unsigned int max;
+	unsigned int pos;
+	const unsigned char *pdu;
+	unsigned short type;
+	unsigned short len;
+	const unsigned char *data;
+};
+
+void wsc_attr_iter_init(struct wsc_attr_iter *iter, const unsigned char *pdu,
+			unsigned int len);
+bool wsc_attr_iter_next(struct wsc_attr_iter *iter);
+
+static inline unsigned int wsc_attr_iter_get_type(struct wsc_attr_iter *iter)
+{
+	return iter->type;
+}
+
+static inline unsigned int wsc_attr_iter_get_length(struct wsc_attr_iter *iter)
+{
+	return iter->len;
+}
+
+static inline const unsigned char *wsc_attr_iter_get_data(
+						struct wsc_attr_iter *iter)
+{
+	return iter->data;
+}