#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/ip_icmp.h>

#define SRC_PORT 12000

void stream_socket() {
    printf("\n=== STREAM SOCKET (TCP) ===\n");

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("socket");
        return;
    }

    struct sockaddr_in src = {0};
    src.sin_family = AF_INET;
    src.sin_addr.s_addr = inet_addr("127.0.0.1");
    src.sin_port = htons(SRC_PORT);
    if (bind(sock, (struct sockaddr*)&src, sizeof(src)) < 0) {
        perror("bind");
        close(sock);
        return;
    }

    struct sockaddr_in server = {0};
    server.sin_family = AF_INET;
    server.sin_port = htons(12001);
    inet_pton(AF_INET, "127.0.0.1", &server.sin_addr);

    printf("[*] Connecting to 127.0.0.1:12001...\n");
    if (connect(sock, (struct sockaddr*)&server, sizeof(server)) == 0) {
        printf("[+] Connected successfully!\n");
        const char *msg = "привет никифор";
        send(sock, msg, strlen(msg), 0);
        char buf[256] = {0};
        recv(sock, buf, sizeof(buf) - 1, 0);
        printf("[Response]:\n%s\n", buf);
    } else {
        perror("connect");
    }

    close(sock);
}

void datagram_socket() {
    printf("\n=== DATAGRAM SOCKET (UDP) ===\n");

    int sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) {
        perror("socket");
        return;
    }

    struct sockaddr_in src = {0};
    src.sin_family = AF_INET;
    src.sin_addr.s_addr = inet_addr("127.0.0.1");
    src.sin_port = htons(SRC_PORT);
    if (bind(sock, (struct sockaddr*)&src, sizeof(src)) < 0) {
        perror("bind");
        close(sock);
        return;
    }

    struct sockaddr_in dest = {0};
    dest.sin_family = AF_INET;
    dest.sin_port = htons(12002);
    inet_pton(AF_INET, "127.0.0.1", &dest.sin_addr);

    const char *msg = "ялквмом!";
    printf("[*] Sending UDP datagram to 127.0.0.1:12002...\n");
    sendto(sock, msg, strlen(msg), 0, (struct sockaddr*)&dest, sizeof(dest));
    printf("[+] Datagram sent, waiting for response...\n");

    char buf[256];
    socklen_t addrlen = sizeof(dest);

    while (1) {
        ssize_t n = recvfrom(sock, buf, sizeof(buf) - 1, 0, (struct sockaddr*)&dest, &addrlen);
        if (n > 0) {
            buf[n] = '\0';
            printf("[Response]: \n%s\n", buf);
            break;
        } else {
            sleep(0.1);
        }
    }

    close(sock);
}

void raw_socket() {
    printf("\n=== RAW SOCKET (ICMP) ===\n");

    int sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
    if (sock < 0) {
        perror("socket");
        return;
    }

    struct sockaddr_in dest = {0};
    dest.sin_family = AF_INET;
    inet_pton(AF_INET, "8.8.8.8", &dest.sin_addr);

    struct icmphdr icmp_hdr = {0};
    icmp_hdr.type = ICMP_ECHO;
    icmp_hdr.code = 0;
    icmp_hdr.checksum = 0xFFFF;

    printf("[*] Sending ICMP echo request to 8.8.8.8...\n");
    ssize_t sent = sendto(sock, &icmp_hdr, sizeof(icmp_hdr), 0,
                          (struct sockaddr*)&dest, sizeof(dest));

    if (sent > 0)
        printf("[+] ICMP packet sent\n");
    else
        perror("sendto");

    close(sock);
}

int main() {
    stream_socket();
    sleep(1);
    datagram_socket();
    sleep(1);
    raw_socket();

    return 0;
}