From 9c6fe571e9636ad46aab4129b47aa99943f7eda9 Mon Sep 17 00:00:00 2001
From: Freak 4L <freakxray@proton.me>
Date: Fri, 27 Sep 2024 23:20:53 +0330
Subject: [PATCH] Create optimize_tcp_params.c

---
 src/optimize_tcp_params.c | 148 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 src/optimize_tcp_params.c

diff --git a/src/optimize_tcp_params.c b/src/optimize_tcp_params.c
new file mode 100644
index 0000000..b4eaafa
--- /dev/null
+++ b/src/optimize_tcp_params.c
@@ -0,0 +1,148 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/time.h>
+
+#define MAX_ATTEMPTS 5
+#define TIMEOUT_SEC 5
+
+double measure_tcp_performance(const char *host, int port, int window_size, int mss) {
+    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;
+
+        // Set window size
+        if (setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &window_size, sizeof(window_size)) < 0) {
+            perror("setsockopt SO_RCVBUF");
+            close(sockfd);
+            continue;
+        }
+        if (setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &window_size, sizeof(window_size)) < 0) {
+            perror("setsockopt SO_SNDBUF");
+            close(sockfd);
+            continue;
+        }
+
+        // Set MSS
+        if (setsockopt(sockfd, IPPROTO_TCP, TCP_MAXSEG, &mss, sizeof(mss)) < 0) {
+            perror("setsockopt TCP_MAXSEG");
+            close(sockfd);
+            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]);
+    
+    int window_sizes[] = {65536, 131072, 262144, 524288, 1048576};
+    int mss_values[] = {536, 1460, 9000};
+    
+    double best_time = -1;
+    int best_window_size = 0;
+    int best_mss = 0;
+
+    for (int i = 0; i < sizeof(window_sizes) / sizeof(window_sizes[0]); i++) {
+        for (int j = 0; j < sizeof(mss_values) / sizeof(mss_values[0]); j++) {
+            double total_time = 0;
+            int successful_attempts = 0;
+
+            for (int attempt = 0; attempt < MAX_ATTEMPTS; attempt++) {
+                double connect_time = measure_tcp_performance(host, port, window_sizes[i], mss_values[j]);
+                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("Window Size: %d, MSS: %d, Average Time: %.6f\n", window_sizes[i], mss_values[j], average_time);
+
+                if (best_time < 0 || average_time < best_time) {
+                    best_time = average_time;
+                    best_window_size = window_sizes[i];
+                    best_mss = mss_values[j];
+                }
+            }
+        }
+    }
+
+    if (best_time >= 0) {
+        printf("Best configuration - Window Size: %d, MSS: %d, Time: %.6f\n", best_window_size, best_mss, best_time);
+        return 0;
+    } else {
+        fprintf(stderr, "All connection attempts failed\n");
+        return 1;
+    }
+}