Add tcp server

This commit is contained in:
Andreas Tsouchlos 2025-04-19 02:35:03 +02:00
parent bbf039a596
commit 5121c2a27b
5 changed files with 409 additions and 139 deletions

View File

@ -43,8 +43,8 @@ FetchContent_MakeAvailable(googletest)
#
# add_executable(playground src/main.cpp src/tcp.cpp)
# target_link_libraries(playground PRIVATE spdlog::spdlog)
add_executable(playground src/main.cpp src/tcp.cpp)
target_link_libraries(playground PRIVATE spdlog::spdlog)
#

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@ -1,15 +1,48 @@
import socket
import sys
import logging
from time import sleep
def main():
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
logging.basicConfig(format='%(asctime)s %(levelname)s %(message)s',
datefmt='%H:%M:%S',
level=logging.DEBUG,
stream=sys.stdout)
sock.connect(("localhost", 1234))
sock.sendall(b"asdf")
data = sock.recv(1024)
print(data.decode())
host = "localhost"
port = 65432
while True:
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((host, port))
client_socket.send(b"""{
"jsonrpc": "2.0",
"id": "1",
"method": "SetLedPattern",
"params": {
"led": 19,
"pattern": 3.1
}
}
""")
try:
res = client_socket.recv(1024)
if not res:
logging.info("Client disconnected")
break
logging.info(f"SetLedPattern response: {res.decode()}")
except socket.timeout:
logging.error("Connection timed out")
break
client_socket.close()
sleep(1)
if __name__ == "__main__":
main()

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@ -1,101 +1,103 @@
#include "tcp.hpp"
#include <cstddef>
#include <spdlog/spdlog.h>
int main() {
spdlog::set_level(spdlog::level::debug);
tcp::NonBlockingClient client;
tcp::HostString host = {"192.168.0.12"};
uint16_t port = 123;
spdlog::info("Connecting to {}:{}", host.data(), port);
if (!client.connect(host, port)) std::terminate();
tcp::ConnectionStatus status = tcp::ConnectionStatus::AttemptingConnection;
while (status == tcp::ConnectionStatus::AttemptingConnection) {
auto statusRes = client.get_last_connection_status();
if (!statusRes) std::terminate();
status = statusRes.value();
tcp::NonBlockingServer server{{.port = 65432}};
if (auto res = server.start_listening(); !res) {
spdlog::error("Failed to start server: {}", res.error());
return 1;
}
switch (status) {
case tcp::ConnectionStatus::Successful:
spdlog::info("Connected successfully");
break;
case tcp::ConnectionStatus::Refused:
spdlog::error("Connection refused");
std::terminate();
case tcp::ConnectionStatus::NoRouteToHost:
spdlog::error("No route to host");
std::terminate();
case tcp::ConnectionStatus::TimedOut:
spdlog::error("Connection timed out");
std::terminate();
case tcp::ConnectionStatus::HostUnreachable:
spdlog::error("Host unreachable");
std::terminate();
case tcp::ConnectionStatus::OtherError:
spdlog::error("Other error");
std::terminate();
case tcp::ConnectionStatus::AttemptingConnection:
spdlog::error("Attempting connection");
std::terminate();
}
spdlog::info("Server started, waiting for connections...");
char buffer[1024];
while (true) {
while (!server.next_client_available())
;
while (!client.data_available())
;
auto recvRes = client.recv(std::span<char>(buffer, sizeof(buffer)));
if (!recvRes) {
switch (recvRes.error()) {
case tcp::Error::FailedToCreateSocket:
spdlog::error("Failed to create socket");
case tcp::Error::FailedToStartConnecting:
spdlog::error("Failed to start connecting");
case tcp::Error::FailedToReadSocketError:
spdlog::error("Failed to read socket error");
case tcp::Error::FailedToResolveHost:
spdlog::error("Failed to resolve host");
case tcp::Error::OtherOperationInProgress:
spdlog::error("Other operation in progress");
case tcp::Error::SocketNotConnected:
spdlog::error("Socket not connected");
case tcp::Error::BufferFull:
spdlog::error("Buffer full");
case tcp::Error::NoDataAvailable:
spdlog::error("No data available");
case tcp::Error::SendFailed:
spdlog::error("Send failed");
case tcp::Error::RecvFailed:
spdlog::error("Recv failed");
break;
if (auto res = server.accept_next_client(); !res) {
spdlog::error("Failed to accept client: {}", res.error());
continue;
}
std::terminate();
}
spdlog::info("Client connected");
spdlog::info("Received {} bytes", recvRes.value());
if (recvRes.value() > 0) {
std::array<std::byte, 1024> buffer;
while (!server.data_available())
;
auto recvRes = server.recv(std::span(buffer));
if (!recvRes) {
spdlog::error("Failed to receive data: {}", recvRes.error());
break;
}
spdlog::info("Received message: {}",
std::string(buffer, recvRes.value()));
std::string(reinterpret_cast<const char*>(buffer.data()),
recvRes.value()));
const char* msg = "Hello, world!";
auto sendRes = server.send(std::as_bytes(std::span(msg, strlen(msg))));
if (!sendRes) {
spdlog::error("Failed to send message: {}", sendRes.error());
} else {
spdlog::info("Sent {} bytes", sendRes.value());
}
server.disconnect();
}
EAGAIN;
const char* msg = "Hello, world!";
auto sendRes = client.send(std::span<const char>(msg, strlen(msg)));
if (!sendRes) {
spdlog::error("Failed to send message");
std::terminate();
}
spdlog::info("Sent {} bytes", sendRes.value());
client.disconnect();
return 0;
}
// int main() {
// spdlog::set_level(spdlog::level::debug);
//
// tcp::NonBlockingClient client;
//
// tcp::HostString host = {"localhost"};
// uint16_t port = 65432;
//
// spdlog::info("Connecting to {}:{}", host.data(), port);
//
// if (!client.connect(host, port)) std::terminate();
//
//
// int status = EINPROGRESS;
// while (status == EINPROGRESS) {
// auto statusRes = client.get_last_connection_status();
// if (!statusRes) std::terminate();
// status = statusRes.value();
// }
//
// char buffer[1024];
//
// while (!client.data_available())
// ;
//
// auto recvRes = client.recv(std::span<char>(buffer, sizeof(buffer)));
//
// if (!recvRes) {
// std::terminate();
// }
//
// spdlog::info("Received {} bytes", recvRes.value());
// if (recvRes.value() > 0) {
// spdlog::info("Received message: {}",
// std::string(buffer, recvRes.value()));
// }
//
// EINPROGRESS;
//
// const char* msg = "Hello, world!";
// auto sendRes = client.send(std::span<const char>(msg,
// strlen(msg))); if (!sendRes) {
// spdlog::error("Failed to send message");
// std::terminate();
// }
// spdlog::info("Sent {} bytes", sendRes.value());
// client.disconnect();
//
// return 0;
// }

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@ -18,8 +18,8 @@
namespace {
std::expected<sockaddr_in, int> get_server_address(const char* host,
uint16_t port) {
std::expected<sockaddr_in, int> resolve_remote_address(const char* host,
uint16_t port) {
hostent* server = gethostbyname(host);
if (server == nullptr) {
spdlog::error("tcp: get_host_by_name() failed with h_errno={}",
@ -36,6 +36,15 @@ std::expected<sockaddr_in, int> get_server_address(const char* host,
return address;
}
inline auto get_local_address(uint16_t port) -> sockaddr_in {
sockaddr_in address{};
address.sin_addr.s_addr = htonl(INADDR_ANY);
address.sin_family = AF_INET;
address.sin_port = htons(port);
return address;
}
} // namespace
@ -43,11 +52,213 @@ std::expected<sockaddr_in, int> get_server_address(const char* host,
namespace tcp {
//
//
// Non blocking server
//
//
NonBlockingServer::NonBlockingServer(ServerSettings settings)
: m_settings{settings}, m_serverAddress(get_local_address(settings.port)) {
}
std::expected<void, int> NonBlockingServer::start_listening() {
/// Create socket
close_server_socket();
if (auto res = create_socket(); !res) {
return std::unexpected{res.error()};
}
/// Bin socket and start listening
if (::bind(m_serverSocket, (struct sockaddr*)&m_serverAddress,
sizeof(m_serverAddress)) != 0) {
spdlog::error("tcp::NonBlockingServer: bind() failed with errno={}",
errno);
close(m_serverSocket);
return std::unexpected{errno};
};
if (::listen(m_serverSocket, 1) != 0) {
spdlog::error("tcp::NonBlockingServer: listen() failed with errno={}",
errno);
close(m_serverSocket);
return std::unexpected{errno};
}
return {};
}
bool NonBlockingServer::next_client_available() {
int ret = poll(&m_serverPfdIn, 1, 0);
if (ret < 0) {
spdlog::error("tcp::NonBlockingServer: poll() failed with errno={}",
errno);
return false;
}
return (m_serverPfdIn.revents & POLLIN);
}
[[nodiscard]] std::expected<void, int> NonBlockingServer::accept_next_client() {
disconnect();
int result = ::accept(m_serverSocket, (struct sockaddr*)&m_clientAddress,
&m_clientAddrLen);
if (result < 0) return std::unexpected{errno};
m_clientSocket = result;
m_clientPfdIn.fd = m_clientSocket;
return {};
}
void NonBlockingServer::disconnect() {
close_client_socket();
}
// TODO: Do we need this?
// bool NonBlockingServer::socket_closed() const {
// }
[[nodiscard]] std::expected<std::array<char, 16>, int>
NonBlockingServer::get_client_ip_as_string() const {
std::array<char, 16> addrStr;
if (inet_ntop(AF_INET, &((struct sockaddr_in*)&m_clientAddress)->sin_addr,
addrStr.data(), addrStr.size()) == nullptr) {
spdlog::error(
"tcp::NonBlockingServer: inet_ntop() failed with errno={}", errno);
return std::unexpected{errno};
}
// if (inet_ntoa_r(((struct sockaddr_in*)&m_clientAddress)->sin_addr,
// addrStr.data(), addrStr.size()) == nullptr) {
// return std::unexpected{errno};
// }
return {addrStr};
}
[[nodiscard]] std::expected<int, int>
NonBlockingServer::send(std::span<const std::byte> data) const {
const int bytesWritten =
::send(m_clientSocket, (const char*)data.data(), data.size(), 0);
if (bytesWritten <= 0) {
spdlog::error("tcp::NonBlockingServer: send() failed with errno={}",
errno);
return std::unexpected{errno};
}
return bytesWritten;
}
[[nodiscard]] std::expected<int, int>
NonBlockingServer::recv(std::span<std::byte> buffer) const {
const int bytesReceived =
::recv(m_clientSocket, (char*)buffer.data(), buffer.size(), 0);
if (bytesReceived < 0) {
spdlog::error("tcp::NonBlockingServer: recv() failed with errno={}",
errno);
return std::unexpected{errno};
}
return {bytesReceived};
}
bool NonBlockingServer::data_available() {
int ret = poll(&m_clientPfdIn, 1, 0);
if (ret < 0) {
spdlog::error("tcp::NonBlockingServer: poll() failed with errno={}",
errno);
return false;
}
return (m_clientPfdIn.revents & POLLIN);
}
[[nodiscard]] std::expected<void, int> NonBlockingServer::create_socket() {
m_serverSocket = socket(AF_INET, SOCK_STREAM, 0);
if (m_serverSocket < 1) {
spdlog::error("tcp::NonBlockingServer: socket() failed with errno={}",
errno);
return std::unexpected{errno};
}
m_serverPfdIn.fd = m_serverSocket;
auto currentFlags = fcntl(m_serverSocket, F_GETFL, 0);
if (currentFlags == -1) {
spdlog::error("tcp::NonBlockingServer: fcntl() failed with errno={}",
errno);
close_server_socket();
return std::unexpected{errno};
}
if (fcntl(m_serverSocket, F_SETFL, (currentFlags) | O_NONBLOCK) == -1) {
spdlog::error("tcp::NonBlockingServer: fcntl() failed with errno={}",
errno);
close_server_socket();
return std::unexpected{errno};
}
int flag = 1;
if (::setsockopt(m_serverSocket, SOL_SOCKET, SO_REUSEADDR, &flag,
sizeof(flag)) < 0) {
spdlog::error(
"tcp::NonBlockingServer: setsockopt() failed with errno={}", errno);
close_server_socket();
return std::unexpected{errno};
}
return {};
}
void NonBlockingServer::close_server_socket() {
if (shutdown(m_serverSocket, 0) < 0) {
spdlog::debug("tcp::NonBlockingServer: shutdown() failed with errno={}",
errno);
}
if (close(m_serverSocket) < 0) {
spdlog::debug("tcp::NonBlockingServer: close() failed with errno={}",
errno);
}
m_serverSocket = -1;
m_serverPfdIn.fd = -1;
}
void NonBlockingServer::close_client_socket() {
if (shutdown(m_clientSocket, 0) < 0) {
spdlog::debug("tcp::NonBlockingServer: shutdown() failed with errno={}",
errno);
}
if (close(m_clientSocket) < 0) {
spdlog::debug("tcp::NonBlockingServer: close() failed with errno={}",
errno);
}
m_clientSocket = -1;
m_clientPfdIn.fd = -1;
}
//
//
// Non blocking client
//
//
[[nodiscard]] std::expected<void, int>
NonBlockingClient::connect(HostString host, uint16_t port) {
/// Resolve host
auto addrRes = get_server_address(host.data(), port);
auto addrRes = resolve_remote_address(host.data(), port);
if (!addrRes) return std::unexpected{addrRes.error()};
sockaddr_in serverAddress = addrRes.value();
@ -63,7 +274,7 @@ NonBlockingClient::connect(HostString host, uint16_t port) {
int connectRes = ::connect(m_socket, (struct sockaddr*)&serverAddress,
sizeof(serverAddress));
if (connectRes < 0) {
if (connectRes < 0 && errno != EINPROGRESS) {
spdlog::error("tcp::NonBlockingClient: connect() failed with errno={}",
errno);
return std::unexpected{errno};
@ -74,7 +285,7 @@ NonBlockingClient::connect(HostString host, uint16_t port) {
return {};
}
[[nodiscard]] std::expected<ConnectionStatus, int>
[[nodiscard]] std::expected<int, int>
NonBlockingClient::get_last_connection_status() {
if (!m_startedNewConAttemt) return m_lastKnownConStatus;
@ -82,7 +293,7 @@ NonBlockingClient::get_last_connection_status() {
auto pendingOpRes = new_error_codes_available();
if (!pendingOpRes) return std::unexpected{pendingOpRes.error()};
if (pendingOpRes.value()) return ConnectionStatus::AttemptingConnection;
if (!pendingOpRes.value()) return EINPROGRESS;
m_startedNewConAttemt = false;
@ -97,25 +308,9 @@ NonBlockingClient::get_last_connection_status() {
}
if (err == 0) {
m_lastKnownConStatus = ConnectionStatus::Successful;
m_lastKnownConStatus = EISCONN;
} else {
switch (err) {
case ECONNREFUSED:
m_lastKnownConStatus = ConnectionStatus::Refused;
break;
case ENETUNREACH:
m_lastKnownConStatus = ConnectionStatus::NoRouteToHost;
break;
case ETIMEDOUT:
m_lastKnownConStatus = ConnectionStatus::TimedOut;
break;
case EHOSTUNREACH:
m_lastKnownConStatus = ConnectionStatus::HostUnreachable;
break;
default:
m_lastKnownConStatus = ConnectionStatus::OtherError;
break;
}
m_lastKnownConStatus = err;
}
return m_lastKnownConStatus;
@ -130,7 +325,7 @@ NonBlockingClient::send(std::span<const char> data) {
// TODO: Do we need this?
auto conRes = get_last_connection_status();
if (!conRes) return std::unexpected{conRes.error()};
if (conRes != ConnectionStatus::Successful) {
if (conRes != EISCONN) {
spdlog::error("tcp::NonBlockingClient: Socket not connected");
return std::unexpected{ENOTCONN};
}
@ -150,7 +345,7 @@ NonBlockingClient::send(std::span<const char> data) {
bool NonBlockingClient::data_available() {
auto conRes = get_last_connection_status();
if (!conRes) return false;
if (conRes != ConnectionStatus::Successful) return false;
if (conRes != EISCONN) return false;
int ret = poll(&m_pfdIn, 1, 0);
if (ret < 0) {
@ -230,7 +425,7 @@ NonBlockingClient::new_error_codes_available() {
return std::unexpected{errno};
}
return (ret == 0);
return (ret != 0);
}

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@ -24,27 +24,65 @@
namespace tcp {
enum class ConnectionStatus {
AttemptingConnection,
Successful,
Refused,
NoRouteToHost,
TimedOut,
HostUnreachable,
OtherError,
using HostString = std::array<char, 64>;
//
//
// Non blocking server
//
//
struct ServerSettings {
uint16_t port = 0;
};
class NonBlockingServer {
public:
NonBlockingServer(ServerSettings settings);
[[nodiscard]] std::expected<void, int> start_listening();
bool next_client_available();
[[nodiscard]] std::expected<void, int> accept_next_client();
void disconnect();
// bool socket_closed() const;
[[nodiscard]] std::expected<int, int>
send(std::span<const std::byte> data) const;
[[nodiscard]] std::expected<int, int>
recv(std::span<std::byte> buffer) const;
bool data_available();
[[nodiscard]] std::expected<std::array<char, 16>, int>
get_client_ip_as_string() const;
private:
ServerSettings m_settings;
const struct sockaddr_in m_serverAddress;
int m_serverSocket = -1;
pollfd m_serverPfdIn = {.fd = -1, .events = POLLIN};
pollfd m_clientPfdIn = {.fd = -1, .events = POLLIN};
int m_clientSocket = -1;
struct sockaddr m_clientAddress;
socklen_t m_clientAddrLen = sizeof(m_clientAddress);
[[nodiscard]] std::expected<void, int> create_socket();
void close_server_socket();
void close_client_socket();
};
using HostString = std::array<char, 64>;
// struct ServerSettings {
// uint16_t port = 0;
// };
//
// class NonBlockingServer {
// public:
// NonBlockingServer(ServerSettings settings);
// };
//
// Non blocking client
//
//
class NonBlockingClient {
public:
@ -55,11 +93,12 @@ public:
void disconnect();
[[nodiscard]] std::expected<ConnectionStatus, int>
[[nodiscard]] std::expected<int, int>
get_last_connection_status();
bool data_available();
// TODO: Make this std::byte
[[nodiscard]] std::expected<int, int> recv(std::span<char> buffer);
[[nodiscard]] std::expected<int, int> send(std::span<const char> data);
@ -69,7 +108,7 @@ private:
pollfd m_pfdIn = {.fd = -1, .events = POLLIN};
bool m_startedNewConAttemt = false;
ConnectionStatus m_lastKnownConStatus = ConnectionStatus::OtherError;
int m_lastKnownConStatus = 0;
void close_socket();
@ -77,4 +116,5 @@ private:
[[nodiscard]] std::expected<bool, int> new_error_codes_available();
};
} // namespace tcp