我想实现过滤tcp数据包中端口22上的所有数据我在代码中使用了tcpdump生成的bpf代码来应用它，但它不起作用
下面是我的测试代码

int main()
{
    /* From the example above: tcpdump -d host 127.0.0.1 and  port 22 -i lo */
    struct sock_filter code[] = {
        {0x28, 0, 0, 0x0000000c},
        {0x15, 0, 16, 0x00000800},
        {0x20, 0, 0, 0x0000001a},
        {0x15, 2, 0, 0x7f000001},
        {0x20, 0, 0, 0x0000001e},
        {0x15, 0, 12, 0x7f000001},
        {0x30, 0, 0, 0x00000017},
        {0x15, 2, 0, 0x00000084},
        {0x15, 1, 0, 0x00000006},
        {0x15, 0, 8, 0x00000011},
        {0x28, 0, 0, 0x00000014},
        {0x45, 6, 0, 0x00001fff},
        {0xb1, 0, 0, 0x0000000e},
        {0x48, 0, 0, 0x0000000e},
        {0x15, 2, 0, 0x00000016},
        {0x48, 0, 0, 0x00000010},
        {0x15, 0, 1, 0x00000016},
        {0x6, 0, 0, 0x00040000},
        {0x6, 0, 0, 0x00000000},
    };

    struct sock_fprog bpf = {
        .len    = ARRAY_SIZE(code),
        .filter = code,
    };

    int sock = socket(AF_INET, SOCK_RAW, IPPROTO_TCP);

    int enable_hdrincl = 1;
    setsockopt(sock, IPPROTO_IP, IP_HDRINCL, &enable_hdrincl, sizeof(enable_hdrincl));

    int ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf));

    char buffer[4096];
    while (1) {
        memset(buffer, 0, sizeof(buffer));
        ssize_t recv_len = recv(sock, buffer, sizeof(buffer), 0);
        if (recv_len < 0) {
            perror("recv failed");
            close(sock);
            exit(-1);
        }
        printf("xxx\r\n");
    }
    return 0;
}

当我在命令行上使用tcpdump时，它会正常过滤

lcx@lcx-virtual-machine:/mnt/hgfs/share/tcp_demo/test$ sudo tcpdump  host 127.0.0.1 and  port 22 -i lo
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on lo, link-type EN10MB (Ethernet), snapshot length 262144 bytes
10:50:34.761640 IP lcx-virtual-machine.2222 > localhost.ssh: Flags [S], seq 1234, win 65535, length 0