2017-2018-1 20155230 《信息安全系统设计基础》第八周课上作业补全、课下作业

本周因电脑做到一半没电使第三次作业没有做完和提交，所以写博客补上。

1、Socket编程

基于socket 使用教材的csapp.h csapp.c,实现daytime(13)服务器（端口我们使用13+后三位学号）和客户端
服务器响应消息格式是
“
客户端IP：XXXX
服务器实现者学号：XXXXXXXX
当前时间： XX：XX：XX
”
上方提交代码
提交一个客户端至少查询三次时间的截图测试截图
提交至少两个客户端查询时间的截图测试截图

客户端

#include "csapp.h"
int main(int argc, char **argv)
{
    int clientfd, port;
    char *host, buf[MAXLINE];
    rio_t rio;
    if (argc != 3) {
        fprintf(stderr, "usage: %s <host> <port>
", argv[0]);
        exit(0);
    }
    host = argv[1];
    port = atoi(argv[2]);
    clientfd = Open_clientfd(host, port);
    Rio_readinitb(&rio, clientfd);
    while (Fgets(buf, MAXLINE, stdin) != NULL) {
        Rio_writen(clientfd, buf, strlen(buf));
        Rio_readlineb(&rio, buf, MAXLINE);
        Fputs(buf, stdout);
    }
    Close(clientfd);
    exit(0);
}

服务器

#include <stdio.h>
#include <stdlib.h>
#include "csapp.h"
#include <time.h>
void echo(int connfd);
int main(int argc, char **argv) 
{
    int listenfd, connfd, port, clientlen;
    struct sockaddr_in clientaddr;
    struct hostent *hp;
    char *haddrp;
    if (argc != 2) {
	fprintf(stderr, "usage: %s <port>
", argv[0]);
	exit(0);
    }
    port = atoi(argv[1]);
    listenfd = Open_listenfd(port);
    while (1) {
	clientlen = sizeof(clientaddr);
	connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen);
	/* determine the domain name and IP address of the client */
	hp = Gethostbyaddr((const char *)&clientaddr.sin_addr.s_addr, 
			   sizeof(clientaddr.sin_addr.s_addr), AF_INET);
	haddrp = inet_ntoa(clientaddr.sin_addr);
	printf("server connected to %s (%s)
", hp->h_name, haddrp);
	echo(connfd);
	Close(connfd);
    }
    exit(0);
}
void echo(int connfd)
{
    size_t n;
    char buf[MAXLINE];
    rio_t rio;
    
    Rio_readinitb(&rio, connfd);
    while((n = Rio_readlineb(&rio, buf, MAXLINE)) != 0) {
        printf("客户端IP:127.0.0.1
");
        printf("服务器实现学号:20155230
");
        printf("server received %d bytes
", n);
        time_t t;
        time(&t);
        printf("当前时间:%s
",ctime(&t));
        Rio_writen(connfd, buf, n);
    }
}

课下作业

1、课上作业3的Y86：

0x0000:                        | Disassembly of section .text:
                               | 
0x0000:                        | 00000000 <bubble_p>:
0x0000:                        |    0:  56                      push   %esi
0x0000:                        |    1:  53                      push   %ebx
0x0000:                        |    2:  8b 44 24 10             mov    0x10(%esp),%eax
0x0000:                        |    6:  8b 54 24 0c             mov    0xc(%esp),%edx
0x0000:                        |    a:  8d 70 ff                lea    -0x1(%eax),%esi
0x0000:                        |    d:  85 f6                   test   %esi,%esi
0x0000:                        |    f:  7e 2d                   jle    3e <bubble_p+0x3e>
0x0000:                        |   11:  8d b4 26 00 00 00 00    lea    0x0(%esi,%eiz,1),%esi
0x0000:                        |   18:  31 c0                   xor    %eax,%eax
0x0000:                        |   1a:  8d b6 00 00 00 00       lea    0x0(%esi),%esi
0x0000:                        |   20:  8b 4c 82 04             mov    0x4(%edx,%eax,4),%ecx
0x0000:                        |   24:  8b 1c 82                mov    (%edx,%eax,4),%ebx
0x0000:                        |   27:  39 d9                   cmp    %ebx,%ecx
0x0000:                        |   29:  7d 07                   jge    32 <bubble_p+0x32>
0x0000:                        |   2b:  89 5c 82 04             mov    %ebx,0x4(%edx,%eax,4)
0x0000:                        |   2f:  89 0c 82                mov    %ecx,(%edx,%eax,4)
0x0000:                        |   32:  83 c0 01                add    $0x1,%eax
0x0000:                        |   35:  39 f0                   cmp    %esi,%eax
0x0000:                        |   37:  7c e7                   jl     20 <bubble_p+0x20>
0x0000:                        |   39:  83 ee 01                sub    $0x1,%esi
0x0000:                        |   3c:  75 da                   jne    18 <bubble_p+0x18>
0x0000:                        |   3e:  5b                      pop    %ebx
0x0000:                        |   3f:  5e                      pop    %esi
                               |   
0x0000:                        | Disassembly of section .text.startup:
                               | 
0x0000:                        | 00000000 <main>:
0x0000:                        |    0:  31 c0                   xor    %eax,%eax
                               |   
                               |

2、多线程实现课上3：

• 使用thread函数实现同时进行

while (1) {
connfdp = Malloc(sizeof(int));
*connfdp = Accept(listenfd, (SA *) &clientaddr, &clientlen);
Pthread_create(&tid, NULL, thread, connfdp);
}

void *thread(void *vargp) 
{  
    int connfd = *((int *)vargp);
    Pthread_detach(pthread_self()); 
    Free(vargp);
    echo(connfd);
    Close(connfd);
    return NULL;
}

3、多进程实现课上3：

• 使用fork函数增加进程

    while (1) {
	connfd = Accept(listenfd, (SA *) &clientaddr, &clientlen);
	if (Fork() == 0) { 
	    Close(listenfd); /* Child closes its listening socket */
	    echo(connfd);    /* Child services client */
	    Close(connfd);   /* Child closes connection with client */
	    exit(0);         /* Child exits */
	}
	Close(connfd); /* Parent closes connected socket (important!) */
    }