Create tcp_connect_time.c

src/tcp_connect_time.c

@@ -0,0 +1,107 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <netdb.h>
+
+#define MAX_ATTEMPTS 3
+#define TIMEOUT_SEC 5
+
+double measure_connect_time(const char *host, int port) {
+    struct addrinfo hints, *res, *res0;
+    int sockfd;
+    struct timeval start, end, timeout;
+    double elapsed = -1;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+
+    char port_str[6];
+    snprintf(port_str, sizeof(port_str), "%d", port);
+
+    int err = getaddrinfo(host, port_str, &hints, &res0);
+    if (err != 0) {
+        fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(err));
+        return -1;
+    }
+
+    for (res = res0; res; res = res->ai_next) {
+        sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+        if (sockfd < 0) continue;
+
+        int flags = fcntl(sockfd, F_GETFL, 0);
+        fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
+
+        gettimeofday(&start, NULL);
+
+        if (connect(sockfd, res->ai_addr, res->ai_addrlen) < 0) {
+            if (errno == EINPROGRESS) {
+                fd_set fdset;
+                FD_ZERO(&fdset);
+                FD_SET(sockfd, &fdset);
+                timeout.tv_sec = TIMEOUT_SEC;
+                timeout.tv_usec = 0;
+
+                int rc = select(sockfd + 1, NULL, &fdset, NULL, &timeout);
+                if (rc > 0) {
+                    int error;
+                    socklen_t len = sizeof(error);
+                    if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &len) == 0 && error == 0) {
+                        gettimeofday(&end, NULL);
+                        elapsed = (end.tv_sec - start.tv_sec) + (end.tv_usec - start.tv_usec) / 1e6;
+                        close(sockfd);
+                        break;
+                    }
+                }
+            }
+        } else {
+            gettimeofday(&end, NULL);
+            elapsed = (end.tv_sec - start.tv_sec) + (end.tv_usec - start.tv_usec) / 1e6;
+            close(sockfd);
+            break;
+        }
+
+        close(sockfd);
+    }
+
+    freeaddrinfo(res0);
+    return elapsed;
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <host> <port>\n", argv[0]);
+        exit(1);
+    }
+
+    const char *host = argv[1];
+    int port = atoi(argv[2]);
+
+    double total_time = 0;
+    int successful_attempts = 0;
+
+    for (int i = 0; i < MAX_ATTEMPTS; i++) {
+        double connect_time = measure_connect_time(host, port);
+        if (connect_time >= 0) {
+            total_time += connect_time;
+            successful_attempts++;
+        }
+        usleep(100000);  // 100ms delay between attempts
+    }
+
+    if (successful_attempts > 0) {
+        double average_time = total_time / successful_attempts;
+        printf("%.6f\n", average_time);
+        return 0;
+    } else {
+        fprintf(stderr, "All connection attempts failed\n");
+        return 1;
+    }
+}