main.c

#include "common.h"
#include "sysutil.h"
#include "session.h"
#include "configure.h"
#include "parse_conf.h"
#include "ftp_assist.h"

int main(int argc, const char *argv[])
{
    //使用root权限运行
    check_permission();

    //处理僵尸进程
    setup_signal_chld();

    //解析配置文件
    parseconf_load_file("ftpserver.conf");
    print_conf();

    init_hash();  

    //创建一个监听fd
    int listenfd = tcp_server(tunable_listen_address, tunable_listen_port);

    pid_t pid;
    Session_t sess;
    session_init(&sess);
    p_sess = &sess; //配置全局变量

    while(1)
    {
        //每当用户连接上，就fork一个子进程
       
        struct sockaddr_in addr;
        int peerfd = accept_timeout(listenfd, &addr, tunable_accept_timeout);
        if(peerfd == -1 && errno == ETIMEDOUT)
            continue;
        else if(peerfd == -1)
            ERR_EXIT("accept_timeout");

        //获取ip地址，并在hash中添加一条记录
        uint32_t ip = addr.sin_addr.s_addr;
        sess.ip = ip;
        add_clients_to_hash(&sess, ip);

        if((pid = fork()) == -1)
            ERR_EXIT("fork");
        else if(pid == 0)
        {
            close(listenfd);

            sess.peer_fd = peerfd;
            limit_num_clients(&sess);
            session_begin(&sess);
            //这里保证每次成功执行后退出循环
            exit(EXIT_SUCCESS);
        }
        else
        {
            //pid_to_ip
            add_pid_ip_to_hash(pid, ip);
            close(peerfd);
        }
    }

    return 0;
}