Protocol: implementation of device-side protocol.

Parts of protocol specific for device are implementepd to reflect the
fact that the device is a client. This effectively means that device
gets a single connection only and severe memory restrictions about
which the daemon might get informed about in the future.

Signed-off-by: Ramūnas Mažeikis <ramunasnezinomas@gmail.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/src/device/protocol_device.c b/src/device/protocol_device.c
new file mode 100755
index 0000000..3b3d8c8
--- /dev/null
+++ b/src/device/protocol_device.c
@@ -0,0 +1,86 @@
+#include "net.h"
+#include "protocol.h"
+#include "protocol_private.h"
+#include "protocol_device_private.h"
+#include "settings.h"
+#include <time.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define READ_AS(type, from)	(*((type*)(from)))
+
+static struct connection_t connection;
+
+cd_t protocol_init(void)
+{
+	connection.is_live = 1;
+	connection.nd = net_init(setting_port());
+	return 0;
+}
+
+static int push_bytes(cd_t cd, char *data, size_t size)
+{
+	int ret = 0;
+
+	if (cd >= MAX_CONNECTIONS) {
+		ret = E_IVALID_DESCRIPTOR;
+	} else if (connection.outp_crs + size >= sizeof(connection.outp_buf)) {
+		ret = E_PACKET_OVERFLOW;
+	} else {
+		memcpy(connection.outp_buf, data, size);
+		connection.outp_crs += size;
+	}
+	return ret;
+}
+
+static int push_tlv_header(cd_t cd, enum tlv_type type, size_t size)
+{
+	int ret = 0;
+
+	if (cd >= MAX_CONNECTIONS) {
+		errno = E_IVALID_DESCRIPTOR;
+		ret = NULL;
+	} else if (connection.outp_crs >= MAX_PACKET_SIZE_IN) {
+		errno = E_TLV_OVERFLOW;
+		ret = NULL;
+	} else {
+		READ_AS(enum tlv_type, connection.outp_buf + connection.outp_crs)
+			= type;
+		connection.outp_crs += sizeof(enum tlv_type);
+		READ_AS(size_t, connection.outp_buf + connection.outp_crs) = size;
+		connection.outp_crs += sizeof(size_t);
+	}
+	return ret;
+}
+
+struct tlv * get_tlv(cd_t cd)
+{
+	struct tlv *ret = &connection.next_tlv;
+	size_t offset = connection.inp_crs;
+	char *data = connection.inp_buf;
+
+	if (cd >= MAX_CONNECTIONS) {
+		errno = E_IVALID_DESCRIPTOR;
+		ret = NULL;
+	} else if (offset >= MAX_PACKET_SIZE_IN) {
+		errno = E_TLV_OVERFLOW;
+		ret = NULL;
+	} else {
+		ret->type = READ_AS(enum tlv_type, data + offset);
+		offset += sizeof(enum tlv_type);
+		ret->length = READ_AS(size_t, data + offset);
+		offset += sizeof(size_t);
+		ret->data = data + offset;
+		connection.inp_crs = offset;
+	}
+	return ret;
+}
+
+
+int get_last_data(cd_t cd)
+{
+	if (cd >= MAX_CONNECTIONS) {
+		return E_IVALID_DESCRIPTOR;
+	}
+	net_getlastdata(connection.nd, connection.inp_buf);
+}