RF24Server.cpp

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/*
 RF24Server.cpp - Arduino implementation of a uIP wrapper class.
 Copyright (c) 2014 tmrh20@gmail.com, github.com/TMRh20
 Copyright (c) 2013 Norbert Truchsess <norbert.truchsess@t-online.de>
 All rights reserved.
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 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 General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
#include "RF24Ethernet.h"
#include "RF24Server.h"
 
extern "C" {
//#include "uip-conf.h"
}
 
/*************************************************************/
#if USE_LWIP < 1
RF24Server::RF24Server(uint16_t port) : _port(htons(port))
{
}
#elif USE_LWIP == 1
uint16_t RF24Server::_port;
struct tcp_pcb* RF24Server::sPcb;
EthernetClient::ConnectState* RF24Server::serverState;
 
RF24Server::RF24Server(uint16_t port)
{
    _port = port;
    // Allocate data for a second server/client
    RF24Client::incomingData[1] = (char*)malloc(INCOMING_DATA_SIZE);
}
 
#elif USE_LWIP == 2
 
    #include <zephyr/kernel.h>
    #include <zephyr/net/socket.h>
    #include <zephyr/logging/log.h>
    #include <zephyr/posix/fcntl.h>
    #include <errno.h>
 
LOG_MODULE_REGISTER(tcp_nonblock_listener, LOG_LEVEL_INF);
    #define BACKLOG 1
 
uint16_t RF24Server::_port;
bool RF24Server::serverListening;
bool RF24Server::connectionActive;
int RF24Server::serverSocket = -1;
RF24Client RF24Server::serverClient;
uint32_t RF24Server::timeoutTimer;
RF24Server::RF24Server(uint16_t port)
{
    _port = port;
}
 
#endif
/*************************************************************/
 
RF24Client RF24Server::available()
{
 
    Ethernet.tick();
#if USE_LWIP < 1
    for (uip_userdata_t* data = &RF24Client::all_data[0]; data < &RF24Client::all_data[UIP_CONNS]; data++)
    {
        if (data->packets_in != 0 && (((data->state & UIP_CLIENT_CONNECTED) && uip_conns[data->state & UIP_CLIENT_SOCKETS].lport == _port) || ((data->state & UIP_CLIENT_REMOTECLOSED) && ((uip_userdata_closed_t*)data)->lport == _port)))
        {
            return RF24Client(data);
        }
    }
#elif USE_LWIP == 1
    uint32_t data = 1;
    return RF24Client(data);
#elif USE_LWIP == 2
 
    uint32_t data = 1;
 
    if (millis() - timeoutTimer > RF24Client::serverConnectionTimeout) {
        connectionActive = false;
        if (RF24Client::_socket >= 0) {
            zsock_close(RF24Client::_socket);
            RF24Client::_socket = -1;
        }
        timeoutTimer = millis();
        return RF24Client(data);
    }
 
    if (!Ethernet.isInitialized || !serverListening || connectionActive || RF24Client::g_rf24client_instance->_socket > 0) {
        if (RF24Client(data)) {
            timeoutTimer = millis();
        }
        return RF24Client(data);
    }
 
    struct sockaddr_in client_addr;
    socklen_t client_addr_len = sizeof(client_addr);
 
    // Check once without blocking
    int client_sock = zsock_accept(serverSocket, (struct sockaddr*)&client_addr, &client_addr_len);
 
    if (client_sock < 0) {
        // Check if the "error" is just the expected non-blocking silence
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            // Absolutely normal. No one is connecting right now.
            if (RF24Client(data)) {
                timeoutTimer = millis();
            }
            return RF24Client(data);
        }
 
        // This is a REAL error (e.g., socket closed, invalid descriptor, stack crash)
        printk("CRITICAL Accept error: %d\n", errno);
        if (RF24Client(data)) {
            timeoutTimer = millis();
        }
        return RF24Client(data);
    }
 
    // Success! A client has successfully connected.
    printk("Connection accepted (FD: %d)\n", client_sock);
    connectionActive = true;
 
    serverClient._socket = client_sock;
    RF24Client::g_rf24client_instance = &serverClient;
    timeoutTimer = millis();
    return serverClient;
 
#endif
    return RF24Client();
}
 
/*************************************************************/
 
void RF24Server::begin()
{
#if USE_LWIP < 1
    uip_listen(_port);
#elif USE_LWIP == 1
 
    #if defined RF24ETHERNET_CORE_REQUIRES_LOCKING
    if (Ethernet.useCoreLocking) {
        ETHERNET_APPLY_LOCK();
    }
    #endif
 
    bool closed = false;
 
    if (sPcb == nullptr) {
        sPcb = tcp_new();
    }
 
    if (sPcb != nullptr) {
        tcp_err(sPcb, RF24Client::error_callback);
    }
 
    err_t err = tcp_bind(sPcb, IP_ADDR_ANY, RF24Server::_port);
 
    if (err != ERR_OK) {
        //Debug print
        IF_RF24ETHERNET_DEBUG_CLIENT(Serial.println("Server: Unable to bind to port"););
    }
 
    if (serverState == nullptr) {
        serverState = new RF24Client::ConnectState;
    }
 
    RF24Client::gState[1]->stateActiveID = 1;
 
    if (serverState != nullptr) {
        serverState->connected = false;
        serverState->result = 0;
        serverState->waiting_for_ack = false;
    }
    sPcb = tcp_listen_with_backlog(sPcb, 1);
 
    if (sPcb != nullptr) {
        tcp_arg(sPcb, serverState);
        tcp_accept(sPcb, RF24Client::accept);
    }
    else {
        IF_RF24ETHERNET_DEBUG_CLIENT(Serial.println("Server: Failed to initialize"););
    }
 
    #if defined RF24ETHERNET_CORE_REQUIRES_LOCKING
    if (Ethernet.useCoreLocking) {
        ETHERNET_REMOVE_LOCK();
    }
    #endif
 
#elif USE_LWIP == 2
 
    struct sockaddr_in bind_addr;
 
    serverSocket = zsock_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (serverSocket < 0) {
        printk("Socket creation failed: %d", errno);
        return;
    }
 
    // Bind to port
    memset(&bind_addr, 0, sizeof(bind_addr));
    bind_addr.sin_family = AF_INET;
    bind_addr.sin_port = htons(_port);
    bind_addr.sin_addr.s_addr = INADDR_ANY;
 
    if (zsock_bind(serverSocket, (struct sockaddr*)&bind_addr, sizeof(bind_addr)) < 0) {
        printk("Bind failed: %d", errno);
        zsock_close(serverSocket);
        return;
    }
 
    // Start listening FIRST while the socket is still in default blocking state
    if (zsock_listen(serverSocket, BACKLOG) < 0) {
        printk("Listen failed: %d", errno);
        zsock_close(serverSocket);
        return;
    }
 
    // CRITICAL MOVE: Set to non-blocking mode ONLY AFTER listening is active
    int flags = zsock_fcntl(serverSocket, F_GETFL, 0);
    if (flags < 0 || zsock_fcntl(serverSocket, F_SETFL, flags | O_NONBLOCK) < 0) {
        printk("Failed to set non-blocking flag: %d", errno);
        zsock_close(serverSocket);
        return;
    }
 
    serverListening = true;
    printk("Server initialized successfully!");
 
#endif
    RF24Ethernet.tick();
}
 
/*************************************************************/
#if defined(ESP32)
void RF24Server::begin(uint16_t port)
{
    _port = port;
    begin();
}
#endif
 
/*************************************************************/
 
size_t RF24Server::write(uint8_t c)
{
    return write(&c, 1);
}
 
/*************************************************************/
 
size_t RF24Server::write(const uint8_t* buf, size_t size)
{
    size_t ret = 0;
#if USE_LWIP < 1
    for (uip_userdata_t* data = &RF24Client::all_data[0]; data < &RF24Client::all_data[UIP_CONNS]; data++)
    {
        if ((data->state & UIP_CLIENT_CONNECTED) && uip_conns[data->state & UIP_CLIENT_SOCKETS].lport == _port)
            ret += RF24Client::_write(data, buf, size);
    }
#else
    uint8_t data;
    RF24Client::_write(&data, buf, size);
#endif
    return ret;
}
 
/*************************************************************/
 
void RF24Server::setTimeout(uint32_t timeout)
{
#if USE_LWIP < 1
    #if UIP_CONNECTION_TIMEOUT > 0
    for (uint8_t i = 0; i < UIP_CONNS; i++) {
        uip_userdata_t* data = &RF24Client::all_data[i];
        if (data) {
            data->connectTimeout = timeout;
        }
    }
    #endif
#else
    RF24Client::serverConnectionTimeout = timeout;
#endif
}