simple bot

gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define SERVER_ADDR "140.113.216.151"
#define SERVER_PORT 12345

int main()
{
    char host_addr[16];
    char hostname[128];
    char send_data[1024];
    char recv_data[1024];
    struct sockaddr_in server_addr, cli_addr;
    int sockfd, rc;

    // Connect to server
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("Can't open stream socket.");
        exit(-1);
    }

    // Set server_addr
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr(SERVER_ADDR);
    server_addr.sin_port = htons(SERVER_PORT);

    // Connect to server
    if((connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr))) < 0) {
        perror("Connect server error.");
        close(sockfd);
        exit(-1);
    }
    printf("Connect OK\n");
    printf("[initialAuthentication] Start Initial\n");

    // Get host ip address
    bzero(&cli_addr, sizeof(cli_addr));
    int len = sizeof(cli_addr);
    getsockname(sockfd, (struct sockaddr *)&cli_addr, &len);
    inet_ntop(AF_INET, &cli_addr.sin_addr, host_addr, sizeof(host_addr));

    // Step 0
    printf("[Authentication] Authentication Step 0\n");
    send_data[0] = 0x00;
    send_data[1] = 0x00;
    send_data[2] = 0x00;
    send_data[3] = 0x06;
    sprintf(&send_data[4], "/hello");
    if ((rc = write(sockfd, send_data, 10)) < 0) {
        close(sockfd);
        exit(-1);
    }

    // Step 1
    if ((rc = read(sockfd, &recv_data, 1024)) < 0) {
        close(sockfd);
        exit(-1);
    }
    recv_data[rc] = '\0';
    printf("[Authentication] Authentication Step 1\n");

    // Step 2
    printf("[Authentication] Authentication Step 2\n");
    send_data[3] = 0x11;
    sprintf(&send_data[4], "/sendIP %s", host_addr);
    if ((rc = write(sockfd, send_data, strlen(&send_data[4]) + 4)) < 0) {
        close(sockfd);
        exit(-1);
    }

    // Step 3
    if ((rc = read(sockfd, &recv_data, 1024)) < 0) {
        close(sockfd);
        exit(-1);
    }
    recv_data[rc] = '\0';
    printf("[Authentication] Authentication Step 3\n");
    printf("[Authentication] Authentication OK\n");

    printf("Authentication OK!\n");
    close(sockfd);
    return 0;
}