Initial TCP server

components/rpc/TCPServer.cpp

@@ -1,54 +1,199 @@
-#include <sys/socket.h>
-
-#include "esp_system.h"
-#include "esp_mac.h"
+#include <string.h>
+#include <sys/param.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_event.h"
 #include "esp_netif.h"
-#include "esp_log.h"
 
-#define HOST_IP_ADDR "192.168.0.196"
-#define PORT 3001
-#define TAG "SOCKET"
+#include "lwip/err.h"
+#include "lwip/sockets.h"
+#include "lwip/sys.h"
+#include <lwip/netdb.h>
 
-static const char *payload = "Message from board";
+#include "TCPServer.h"
 
-int tcp_client() {
-    char rx_buffer[128];
-    char host_ip[] = HOST_IP_ADDR;
-    int addr_family = AF_INET;
-    int ip_protocol = IPPROTO_IP;
+#include <bits/shared_ptr_base.h>
 
-    struct sockaddr_in dest_addr;
-    inet_pton(AF_INET, host_ip, &dest_addr.sin_addr); // Convert ipv4 address to binary
-    dest_addr.sin_family = AF_INET;
-    dest_addr.sin_port = htons(PORT);
+#include "constants/tcp.h"
 
-    int sock = socket(addr_family, SOCK_STREAM, ip_protocol);
-    if (sock < 0) {
-        ESP_LOGE(TAG, "Failed to create socket: %d", errno);
-        return sock;
-    }
+// todo: - add message routing to correct client
+//       - authenticate (don't just return true from the auth function)
+//       - tx from board
 
-    if (0 != connect(sock, (struct sockaddr *)&dest_addr, sizeof(dest_addr))) {
-        ESP_LOGE(TAG, "Failed to connect: %d", errno);
-    }
+TCPServer::TCPServer(const int port) {
+    this->m_port = port;
+    this->m_mutex = xSemaphoreCreateMutex();
+    this->m_clients = std::unordered_set<int>();
+    this->m_task = nullptr;
+    this->m_rx_task = nullptr;
+    this->m_tx_task = nullptr;
 
-    ESP_LOGI(TAG, "Connected");
+    xTaskCreate(tcp_server_task, "tcp_accept_server", 4096, this, 5, &this->m_task);
+    xTaskCreate(socket_monitor_thread, "tcp_rx", 4096, this, 5, &this->m_rx_task);
+}
 
-    while(1) {
-        int err = send(sock, payload, strlen(payload), 0);
-        if (err < 0) {
-            ESP_LOGE(TAG, "Error occurred during sending: %d", errno);
+TCPServer::~TCPServer() {
+    vTaskDelete(this->m_task);
+    vTaskDelete(this->m_rx_task);
+    vTaskDelete(this->m_tx_task);
+    vSemaphoreDelete(this->m_mutex);
+}
+
+[[noreturn]] void TCPServer::tcp_server_task(void *args) {
+    constexpr int keepAlive = 1;
+    constexpr int keepIdle = KEEPALIVE_IDLE;
+    constexpr int keepInterval = KEEPALIVE_INTERVAL;
+    constexpr int keepCount = KEEPALIVE_COUNT;
+
+    auto that = static_cast<TCPServer*>(args);
+
+    while (true) {
+        printf("Attempting to start TCP Server on port %d", that->m_port);
+
+        that->m_server_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
+        if (that->m_server_sock < 0) {
+            printf("Unable to create TCP socket: errno %d\n", errno);
+            vTaskDelay(SLEEP_AFTER_FAIL_MS / portTICK_PERIOD_MS);
+            continue;
         }
 
-        int len = recv(sock, rx_buffer, sizeof(rx_buffer) -1, 0); // blocking call
-        if (len < 0) {
-            ESP_LOGE(TAG, "Failed to receive: %d", errno);
-        } else {
-            rx_buffer[len] = 0; // temp: Null terminate to treat as a string
-            ESP_LOGI(TAG, "Received %d bytes", len);
-            ESP_LOGI(TAG, "%s", rx_buffer);
+        constexpr int opt = 1;
+        setsockopt(that->m_server_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+        printf("Socket created\n");
+
+        sockaddr_in server_addr = {
+            .sin_family = AF_INET,
+            .sin_port = htons(that->m_port),
+            .sin_addr = {
+                .s_addr = htonl(INADDR_ANY),
+                },
+        };
+
+        int err = bind(that->m_server_sock, reinterpret_cast<struct sockaddr *>(&server_addr), sizeof(server_addr));
+        if (0 != err) {
+            printf("Socket unable to bind: errno %d\n", errno);
+            close(that->m_server_sock);
+            that->m_server_sock = -1;
+            vTaskDelay(SLEEP_AFTER_FAIL_MS / portTICK_PERIOD_MS);
+            continue;
         }
 
-        vTaskDelay(1000 / portTICK_PERIOD_MS);
+        printf("Socket bound to port %d\n", that->m_port);
+
+        err = listen(that->m_server_sock, TCP_DEFAULT_LISTEN_BACKLOG);
+        if (0 != err) {
+            printf("Error occurred during TCP listen: errno %d\n", errno);
+            close(that->m_server_sock);
+            that->m_server_sock = -1;
+            vTaskDelay(SLEEP_AFTER_FAIL_MS / portTICK_PERIOD_MS);
+            continue;
+        }
+
+        while (is_network_connected()) {
+            sockaddr_in client_addr{};
+            socklen_t addr_len = sizeof(client_addr);
+            int client_sock = accept(that->m_server_sock, reinterpret_cast<struct sockaddr *>(&client_addr), &addr_len);
+            if (client_sock < 0) {
+                printf("Unable to accept TCP connection: errno %d\n", errno);
+                continue;
+            }
+
+            err = that->authenticate_client(client_sock);
+            if (0 != err) {
+                printf("Client failed authentication\n");
+            }
+
+            setsockopt(client_sock, SOL_SOCKET, SO_KEEPALIVE, &keepAlive, sizeof(int));
+            setsockopt(client_sock, IPPROTO_TCP, TCP_KEEPIDLE, &keepIdle, sizeof(int));
+            setsockopt(client_sock, IPPROTO_TCP, TCP_KEEPINTVL, &keepInterval, sizeof(int));
+            setsockopt(client_sock, IPPROTO_TCP, TCP_KEEPCNT, &keepCount, sizeof(int));
+
+            xSemaphoreTake(that->m_mutex, portMAX_DELAY);
+            that->m_clients.emplace(client_sock);
+            xSemaphoreGive(that->m_mutex);
+        }
+
+        close(that->m_server_sock);
+        vTaskDelay(SLEEP_AFTER_FAIL_MS / portTICK_PERIOD_MS);
     }
-}
+}
+
+[[noreturn]] void TCPServer::socket_monitor_thread(void *args) {
+    auto that = static_cast<TCPServer *>(args);
+
+    while (true) {
+        fd_set readfds;
+        FD_ZERO(&readfds);
+        int max_fd = -1;
+
+        xSemaphoreTake(that->m_mutex, portMAX_DELAY);
+        for (const auto sock : that->m_clients) {
+            FD_SET(sock, &readfds);
+            if (sock > max_fd) max_fd = sock;
+        }
+        xSemaphoreGive(that->m_mutex);
+
+        timeval timeout = {1, 0}; // 1 second timeout
+        int ret = select(max_fd + 1, &readfds, nullptr, nullptr, &timeout);
+
+        if (ret > 0) {
+            xSemaphoreTake(that->m_mutex, portMAX_DELAY);
+            std::vector<int> to_remove;
+            for (int sock : that->m_clients) {
+                if (FD_ISSET(sock, &readfds)) {
+                    // Handle socket
+                    char buffer[512];
+                    int len = recv(sock, buffer, sizeof(buffer) - 1, 0); // temp: for the null terminator
+
+                    if (len < 0) {
+                        printf("Error occurred during receiving: errno %d\n", errno);
+                    } else if (0 == len) {
+                        printf("Connection closed\n");
+                        close(sock);
+                        to_remove.emplace_back(sock);
+                    } else {
+                        // todo: send to rx queue instead of printing
+                        buffer[len] = 0; // temp: Null-terminate whatever is received and treat it like a string
+                        printf("TCP Server Received %d bytes: %s\n", len, buffer);
+                    }
+                }
+            }
+
+            for (const auto r : to_remove) {
+                that->m_clients.erase(r);
+            }
+
+            xSemaphoreGive(that->m_mutex);
+        }
+    }
+}
+
+bool TCPServer::is_network_connected() {
+    esp_netif_ip_info_t ip_info;
+    esp_netif_t *netif = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
+
+    if (netif != nullptr && esp_netif_get_ip_info(netif, &ip_info) == ESP_OK) {
+        return true;
+    }
+
+    if (0 != ip_info.ip.addr) {
+        return true;
+    }
+
+    netif = esp_netif_get_handle_from_ifkey("WIFI_AP_DEF");
+
+    if (netif != nullptr && esp_netif_get_ip_info(netif, &ip_info) == ESP_OK) {
+        return true;
+    }
+
+    if (0 != ip_info.ip.addr) {
+        return true;
+    }
+
+    return false;
+}
+
+bool TCPServer::authenticate_client(int sock) {
+    // todo: authentication (wait for a passphrase from the client)
+    return 0;
+}