blob: 6de55674823a55845df7679845ce7a0638e49043 [file] [log] [blame]
// Copyright 2020 The Pigweed Authors
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include "pw_assert/check.h"
#include "pw_hdlc/encoded_size.h"
#include "pw_hdlc/rpc_channel.h"
#include "pw_hdlc/rpc_packets.h"
#include "pw_log/log.h"
#include "pw_rpc_system_server/rpc_server.h"
#include "pw_stream/socket_stream.h"
namespace pw::rpc::system_server {
namespace {
// Hard-coded to 1055 bytes, which is enough to fit 512-byte payloads when using
// HDLC framing.
constexpr size_t kMaxTransmissionUnit = 1055;
uint16_t socket_port = 33000;
static_assert(kMaxTransmissionUnit ==
stream::SocketStream socket_stream;
hdlc::FixedMtuChannelOutput<kMaxTransmissionUnit> hdlc_channel_output(
socket_stream, hdlc::kDefaultRpcAddress, "HDLC channel");
Channel channels[] = {rpc::Channel::Create<1>(&hdlc_channel_output)};
rpc::Server server(channels);
} // namespace
void set_socket_port(uint16_t new_socket_port) {
socket_port = new_socket_port;
int GetServerSocketFd() { return socket_stream.connection_fd(); }
void Init() {
log_basic::SetOutput([](std::string_view log) {
std::fprintf(stderr, "%.*s\n", static_cast<int>(log.size()),;
hdlc::WriteUIFrame(1, as_bytes(span(log)), socket_stream)
.IgnoreError(); // TODO(b/242598609): Handle Status properly
PW_LOG_INFO("Starting pw_rpc server on port %d", socket_port);
rpc::Server& Server() { return server; }
Status Start() {
constexpr size_t kDecoderBufferSize =
// Declare a buffer for decoding incoming HDLC frames.
std::array<std::byte, kDecoderBufferSize> input_buffer;
hdlc::Decoder decoder(input_buffer);
while (true) {
std::array<std::byte, kMaxTransmissionUnit> data;
auto ret_val = socket_stream.Read(data);
if (!ret_val.ok()) {
if (ret_val.status() == Status::OutOfRange()) {
// An out of range status indicates the remote end has disconnected.
return OkStatus();
for (std::byte byte : ret_val.value()) {
auto result = decoder.Process(byte);
if (!result.ok()) {
// Non-OK means there isn't a complete packet yet, or there was some
// other issue. Wait for more bytes that form a complete packet.
hdlc::Frame& frame = result.value();
if (frame.address() != hdlc::kDefaultRpcAddress) {
// Wrong address; ignore the packet for now. In the future, this branch
// could expand to add packet routing or metrics.
} // namespace pw::rpc::system_server