1 files changed, 133 insertions, 0 deletions
diff --git a/src/common/tlv.c b/src/common/tlv.c
new file mode 100644
index 0000000..0002a96
--- /dev/null
+++ b/src/common/tlv.c
@@ -0,0 +1,133 @@
+/*
+ * Usurpataion --- clinet-server protocol implementation.
+ *
+ * Copyright (C) 2019 Ramūnas Mažeikis
+ *
+ * This program 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; version 2.1
+ * of the License.
+ *
+ * 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+/**
+ * Common parts of protocol implementation. Handling of anything that actually
+ * deals with connection descriptor has to be implemented by device and daemon
+ * separately.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "protocol.h"
+#include "protocol_private.h"
+#include "net.h"
+#include "utils.h"
+
+int tlv_get(struct tlv_parser *parser, struct tlv *ret)
+{
+	int retval = 0;
+
+	if (parser->offset + sizeof(ret->type) + sizeof(ret->length) >= parser->size) {
+		retval = E_TLV_OVERFLOW;
+	} else if (parser -> offset == parser->size) {
+		retval = END_OF_PACKET;
+	} else {
+		ret->type = memcpy(&ret->type, parser->data + parser->offset, sizeof(ret->type));
+		parser->size += sizeof(ret->type);
+		ret->length = memcpy(&ret->length, parser->data + parser->offset, sizeof(ret->length));
+		parser->offset += sizeof(ret->length);
+		if (parser->offset + ret->length >= parser->size) {
+			retval = E_TLV_OVERFLOW;
+		} else {
+			memcpy(ret->data, parser->data, ret->length);
+		}
+	}
+	return retval;
+}
+
+size_t tlv_data_size(struct tlv_parser *parser)
+{
+	size_t size;
+
+	if (parser->offset + sizeof(enum tlv_type) + sizeof(size_t) >= parser->size) {
+		size = 0;
+	} else {
+		memcpy(&size, parser->data + parser->offset + sizeof(enum tlv_type), sizeof(size_t));
+	}
+	return size;
+}
+
+void tlv_destroy(struct tlv *t)
+{
+	size_t i = 0;
+	size_t tlv_count;
+	struct tlv *arr;
+	switch (t->type)
+	{
+	case REGURAL:
+	case HEARTBEAT:
+	case DISCOVERY:
+		tlv_count = t->length / sizeof(struct tlv);
+		arr = t->data;
+		for (i = 0; i < tlv_count; i++) {
+			tlv_destroy(&arr[i]);
+		}
+	default:
+		free(t->data);
+		t->length = 0;
+		break;
+	}
+}
+
+size_t tlv_raw_size(const struct tlv *t)
+{
+	return sizeof(*t) + t->length;
+}
+
+int tlv_push_data(struct tlv *t, const char *data, size_t size)
+{
+	int ret = 0;
+	size_t final_size = tlv_raw_size(t) + size;
+	if (final_size > TLV_SZ_MAX_RAW) {
+		ret = E_TLV_OVERFLOW;
+	} else {
+		t->data = realloc(t->data, final_size);
+		memcpy(t->data + t->length, data, size);
+		t->length = final_size;
+	}
+	return ret;
+}
+
+void tlv_init(struct tlv *t, enum tlv_type type)
+{
+	t->type = type;
+	t->length = 0;
+	t->data = NULL;
+}
+
+int tlv_push_tlv(struct tlv *t, const struct tlv *other)
+{
+	int ret = 0;
+	size_t other_size;
+	size_t final_size;
+
+	other_size = tlv_raw_size(other);
+	final_size = tlv_raw_size(t) + other_size;
+	if (final_size > TLV_SZ_MAX_RAW) {
+		ret = E_TLV_OVERFLOW;
+	} else {
+		tlv_get_raw(other, t->data + t->length);
+		t->length = final_size;
+	}
+
+	return ret;
+}
+\ No newline at end of file