1 files changed, 133 insertions, 0 deletions
diff --git a/src/common/protocol.c b/src/common/protocol.c
new file mode 100644
index 0000000..b2e0d40
--- /dev/null
+++ b/src/common/protocol.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 push_tlv(struct tlv_packet *packet, enum tlv_type type, char *data)
+{
+	int ret = 0;
+	size_t size;
+
+	switch (type) {
+	case TEXT:
+		size = strlen(data) + 1;
+		break;
+	case FPI1:
+		size = sizeof(fpi1_t);
+		break;
+	case TIMESTAMP:
+		size = sizeof(time_t);
+		break;
+	case REQUEST:
+		size = sizeof(msg_idx_t);
+		break;
+	case REPLY:
+		size = sizeof(msg_idx_t) + strlen(data + sizeof(msg_idx_t));
+		break;
+	case UUID:
+		size = sizeof(uuid_t);
+		break;
+	default:
+		ret = E_UNKNOWN_TYPE;
+	}
+	ret |= push_tlv_header(packet, type, size);
+	ret |= push_bytes(packet, data, size);
+	return ret;
+}
+
+void clear_data(struct tlv_packet *packet)
+{
+	packet->offset = 0;
+	packet->type = 0;
+	memset(packet->data, 0, packet->size);
+}
+
+static int push_bytes(struct tlv_packet *packet, char *data, size_t size)
+{
+	int ret = 0;
+
+	if (packet->offset + size >= packet->size) {
+		ret = E_TLV_OVERFLOW;
+	} else {
+		memcpy(packet->data + packet->offset, data, size);
+		packet->offset += size;
+	}
+}
+
+static int push_tlv_header(struct tlv_packet *packet, enum tlv_type type, size_t size)
+{
+	int ret = 0;
+
+	if (packet->offset + sizeof(type) + sizeof(size) >= packet->size) {
+		ret = E_TLV_OVERFLOW;
+	} else {
+		memcpy(packet->data + packet->size, type, sizeof(type));
+		packet->offset += sizeof(type);
+		memcpy(packet->data + packet->offset, size, sizeof(size));
+		packet->offset += sizeof(size);
+	}
+	return ret;
+}
+
+int get_tlv(struct tlv_parser *parser, struct tlv *ret)
+{
+	int ret = 0;
+
+	if (parser->offset + sizeof(ret->type) + sizeof(ret->length) >= parser->size) {
+		ret = E_TLV_OVERFLOW;
+	} else if (parser -> offset == parser->size) {
+		ret = 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) {
+			ret = E_TLV_OVERFLOW;
+		} else {
+			memcpy(ret->data, parser->data, ret->length);
+		}
+	}
+	return ret;
+}
+
+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;
+}