feat: add transport interface and tcp/udp sockets

.clang-tidy

@@ -7,6 +7,7 @@ Checks: "
     -cppcoreguidelines-avoid-magic-numbers,
     -cppcoreguidelines-non-private-member-variables-in-classes,
     -cppcoreguidelines-missing-std-forward,
+    -cppcoreguidelines-pro-type-vararg,
 "
 WarningsAsErrors: true
 HeaderFilterRegex: ".*"

include/runtime/cfdp_runtime/socket.hpp

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <arpa/inet.h>
+#include <sys/socket.h>
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace cfdp::runtime::sockets
+{
+enum class SocketType
+{
+    TCP = SOCK_STREAM,
+    UDP = SOCK_DGRAM,
+};
+
+class Socket
+{
+  public:
+    Socket(SocketType sType, uint16_t port, const std::string& ipAddr);
+
+    int handle;
+    sockaddr_in addr{};
+};
+
+class UDPClient
+{
+  public:
+    UDPClient(uint16_t port = 8000, const std::string& ipAddr = "127.0.0.1")
+        : socket(SocketType::UDP, port, ipAddr)
+    {}
+
+    void sendMessage(std::vector<uint8_t> message);
+
+  private:
+    Socket socket;
+};
+
+class UDPServer
+{
+  public:
+    UDPServer(uint16_t port = 8000, const std::string& ipAddr = "0.0.0.0")
+        : socket(SocketType::UDP, port, ipAddr)
+    {}
+
+    void socketBind();
+
+  private:
+    Socket socket;
+};
+} // namespace cfdp::runtime::sockets

include/runtime/cfdp_runtime/transport_interface.hpp

@@ -0,0 +1,5 @@
+#pragma once
+
+namespace cfdp::runtime::transport
+{
+}

src/cfdp_runtime/socket.cpp

@@ -0,0 +1,77 @@
+#include <cfdp_core/utils.hpp>
+#include <cfdp_runtime/socket.hpp>
+
+#include <fcntl.h>
+
+#include <bit>
+#include <stdexcept>
+#include <sys/fcntl.h>
+
+namespace
+{
+// IP converter related retcodes.
+constexpr int invalid_addr_in_addr_family = 0;
+
+// File descriptor related retcodes.
+constexpr int file_descriptor_error = -1;
+
+// Socket related retcodes.
+constexpr int socket_error = -1;
+} // namespace
+
+cfdp::runtime::sockets::Socket::Socket(SocketType sType, uint16_t port, const std::string& ipAddr)
+    : handle(socket(AF_INET, utils::toUnderlying(sType), 0))
+{
+    if (handle == socket_error)
+    {
+        throw std::runtime_error{"Could not create a socket."};
+    }
+
+    addr.sin_family = AF_INET;
+    addr.sin_port   = port;
+
+    auto result = inet_pton(AF_INET, ipAddr.c_str(), &addr.sin_addr);
+
+    if (result == invalid_addr_in_addr_family)
+    {
+        throw std::runtime_error{"Could not parse passed IP address."};
+    }
+
+    auto currentFlags = fcntl(handle, F_GETFL);
+
+    if (currentFlags == file_descriptor_error)
+    {
+        throw std::runtime_error{"Could not fetch file descriptor flags."};
+    }
+
+    auto status = fcntl(handle, F_SETFL, currentFlags | O_NONBLOCK);
+
+    if (status == file_descriptor_error)
+    {
+        throw std::runtime_error{"Could not set the socket to non-blocking."};
+    }
+}
+
+void cfdp::runtime::sockets::UDPClient::sendMessage(std::vector<uint8_t> message)
+{
+    auto length = message.size();
+    auto addr   = std::bit_cast<sockaddr*>(&socket.addr);
+
+    auto result = sendto(socket.handle, message.data(), length, 0, addr, sizeof(socket.addr));
+
+    if (result == socket_error)
+    {
+        throw std::runtime_error{"Could not send data via socket."};
+    }
+}
+
+void cfdp::runtime::sockets::UDPServer::socketBind()
+{
+    auto addr   = std::bit_cast<sockaddr*>(&socket.addr);
+    auto result = bind(socket.handle, addr, sizeof(socket.addr));
+
+    if (result == socket_error)
+    {
+        throw std::runtime_error{"Could not bind the socket."};
+    }
+}