udp server

src/udp_server.c

@@ -0,0 +1,83 @@
+#include "udp_server.h"
+
+#define BUF_SIZE 512
+#define UDP_READ_TIMEOUT_MS 500
+
+static int sockfd = -1;
+static struct pollfd poller;
+static struct sockaddr_in client_addr;
+static socklen_t client_len = sizeof(client_addr);
+
+static RDSModulator* mod = NULL;  // Store modulator pointer globally or pass it somehow
+
+int open_udp_server(int port, RDSModulator* rds_mod) {
+    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (sockfd < 0) return -1;
+
+    struct sockaddr_in server_addr;
+    memset(&server_addr, 0, sizeof(server_addr));
+
+    server_addr.sin_family = AF_INET;
+    server_addr.sin_addr.s_addr = INADDR_ANY;
+    server_addr.sin_port = htons(port);
+
+    if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
+        close(sockfd);
+        sockfd = -1;
+        return -1;
+    }
+
+    poller.fd = sockfd;
+    poller.events = POLLIN;
+
+    mod = rds_mod;  // Save mod pointer
+
+    return 0;
+}
+
+void poll_udp_server() {
+    static char buf[BUF_SIZE];
+    static char cmd_buf[BUF_SIZE];
+    static char cmd_output[BUF_SIZE];  // Buffer to collect output from process_ascii_cmd
+    ssize_t bytes_read;
+
+    if (poll(&poller, 1, UDP_READ_TIMEOUT_MS) <= 0) return;
+    if (!(poller.revents & POLLIN)) return;
+
+    memset(buf, 0, BUF_SIZE);
+    client_len = sizeof(client_addr);
+	bytes_read = recvfrom(sockfd, buf, BUF_SIZE - 1, 0,
+                      (struct sockaddr *)&client_addr, &client_len);
+    if (bytes_read <= 0) return;
+
+    buf[bytes_read] = '\0';
+
+    char *token = strtok(buf, "\r\n");
+    while (token != NULL) {
+        size_t len = strlen(token);
+        if (len > 0 && len < BUF_SIZE) {
+            memset(cmd_buf, 0, BUF_SIZE);
+            strncpy(cmd_buf, token, BUF_SIZE - 1);
+
+            memset(cmd_output, 0, BUF_SIZE);
+            // Pass cmd_output buffer to collect output from the command processor
+            process_ascii_cmd(mod, cmd_buf, cmd_output);
+
+            // Send cmd_output back to client (even if empty, send it)
+            size_t out_len = strlen(cmd_output);
+            if (out_len > 0) {
+                ssize_t sent = sendto(sockfd, cmd_output, out_len, 0,
+                                      (struct sockaddr *)&client_addr, client_len);
+                if (sent == -1) {
+                    perror("sendto");
+                }
+            }
+        }
+        token = strtok(NULL, "\r\n");
+    }
+}
+
+void close_udp_server() {
+    if (sockfd >= 0) close(sockfd);
+    sockfd = -1;
+}