Userland: Add a simple utility for UDP testing.

Userland/uc.cpp

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+int main(int argc, char** argv)
+{
+    (void)argc;
+    (void)argv;
+
+    int fd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (fd < 0) {
+        perror("socket");
+        return 1;
+    } 
+
+    struct timeval timeout { 5, 0 };
+    int rc = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout));
+    if (rc < 0) {
+        perror("setsockopt");
+        return 1;
+    }
+
+    struct sockaddr_in dst_addr;
+    memset(&dst_addr, 0, sizeof(dst_addr));
+
+    dst_addr.sin_family = AF_INET;
+    dst_addr.sin_port = htons(8080);
+    dst_addr.sin_addr.s_addr = INADDR_ANY;
+
+    char buffer[BUFSIZ];
+    const char* msg = "Test message";
+
+    sendto(fd, (const char *)msg, strlen(msg), 0,(const struct sockaddr *)&dst_addr, sizeof(dst_addr));
+    printf("Message sent.\n");
+
+    struct sockaddr_in src_addr;
+    socklen_t src_addr_len = sizeof(src_addr);
+    ssize_t nrecv = recvfrom(fd, (char *)buffer, sizeof(buffer), 0, (struct sockaddr*)&src_addr, &src_addr_len);
+    if (nrecv < 0) {
+        perror("recvfrom");
+        return 1;
+    }
+    buffer[nrecv] = '\0';
+    printf("Server: %s\n", buffer);
+
+    close(fd);
+    return 0;
+}