首页 > 其他分享> > UNP——TCP分析

UNP——TCP分析

2020-06-17 19:43:12 作者：互联网

在这里插入图片描述

3.1 传递时间示例代码

tcpserver.c

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <arpa/inet.h>
#include "proto.h"

#define bakc_log 50
#define praddr_size 50
#define buffer_size 1024
static void server_job(int sockfd)
{
    int len;
    char buffer[buffer_size];
    len = sprintf(buffer,FMT_STAMP, (long long)time(NULL));

    if(send(sockfd, buffer, len, 0)<0)
    {
        perror("send");
        exit(1);
    }
}

int main()
{
    int sd,std;
    int flag;
    pid_t pid;
    char p_raddr[praddr_size];
    struct sockaddr_in laddr,raddr;
    laddr.sin_family = AF_INET;
    laddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,"0.0.0.0",&laddr.sin_addr);

    socklen_t laddrsize = sizeof(laddr);
    socklen_t raddrsize = sizeof(raddr);
    sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }

    if(setsockopt(sd,SOL_SOCKET,SO_REUSEADDR,&flag,sizeof(flag))<0)
    {
        perror("setsocket");
        exit(1);
    }

    if(bind(sd, (void*)&laddr, laddrsize)<0)
    {
        perror("bind");
        exit(1);
    }

    if(listen(sd,bakc_log)<0)
    {
        perror("listen");
        exit(1);
    }

    while(1)
    {
            //accept返回三个值，std即可能是已连接套接字或错误信息，对端地址，对端地址大小
        std = accept(sd, (void*)&raddr,&raddrsize);  //返回值为全新文件描述符，代表与tcp对端连接，已连接描述符
        if(std < 0)
        {
            perror("accept");
            exit(1);
        }
        pid = fork();  //并发的时候，应该注意：fork之后，子进程和父进程均有已连接描述符和监听描述符，父进程中需close已连接描述符
                        //，将引用计数减为0
        if(pid == 0)
        {
            close(sd);
            inet_ntop(AF_INET,&raddr.sin_addr,p_raddr,praddr_size);
            fprintf(stderr,"Client addr is %s , port is %d\n",p_raddr,ntohs(raddr.sin_port));

            server_job(std);
            close(std);
            exit(0); //子进程结束必须exit0，否则会继续执行
        }
        close(std); //此处必须有，计数减为0，然后才会发送FIN，四次分手
    }

    close(sd);
    exit(0);
}

tcpclient.c

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdio.h>
#include "proto.h"
#define raddr_size 40
int main(int argc, char* argv[])
{

    FILE* fp;
    long long stamp;
    struct sockaddr_in laddr,raddr;
    char raddr_ip[raddr_size];
    if(argc < 2)
    {
        fprintf(stderr,"argc");
        exit(1);
    }

    int sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }
    raddr.sin_family = AF_INET;
    raddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,argv[1],&raddr.sin_addr);
    fprintf(stderr,"let's go");
    if(connect(sd,(void*)&raddr,sizeof(raddr))<0)  //conncet开始三次握手，可能出现三种情况1、FIN无ACK，75s后ETIMEOUT
    {
        perror("connect");
        exit(1);
    }

    //一切皆文件
    fp = fdopen(sd,"r+"); //将文件描述符转换成FILE指针打开,这里不能用w，w+，因无需创建fd

    if(fp==NULL)
    {
        perror("fdopen");
        exit(1);
    }

    if(fscanf(fp,FMT_STAMP,&stamp)<1) //返回成功读取的个数，这里只有一个item，正确为1
    {

        fprintf(stderr,"error FMT_STAMP");
    }
    else
    {
        fprintf(stderr,"stamp = %lld\n",stamp);
    }

    fclose(fp); //这里需要关闭fp，因为fdopen已经转成fp

    exit(0);
}

proto.h

#ifndef PROTO_H__
#define PROTO_H__

#define LOCALPORT 1990
#define FMT_STAMP "%lld\r\n"


#endif

3.2 传递图片代码

tcpserver.c

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <arpa/inet.h>
#include "proto.h"

#define bakc_log 50
#define praddr_size 50
#define buffer_size 1024
static void server_job(int sockfd)
{
    int len;
    char buffer[buffer_size];
    size_t num;
    FILE* fp;
    //len = sprintf(buffer,FMT_STAMP, (long long)time(NULL));
    fp = fopen("/home/qianchen/Pictures/muniao.jpg","r");
    if(fp == NULL)
    {
        perror("fopen error");
        exit(1);
    }
    while(1)
    {
        num = fread(buffer,1,buffer_size,fp);
        if(num == 0)
        {
            perror("fread error");
            break;
        }
        if(send(sockfd, buffer, num, 0)<0) //输出重定向./tcpclient 127.0.0.1 > /home/qianchen/Videos/tcp/1.jpg
        {
            perror("send");
            exit(1);
        }
    }

    fclose(fp);
}

int main()
{
    int sd,std;
    int flag;
    pid_t pid;
    char p_raddr[praddr_size];
    struct sockaddr_in laddr,raddr;
    laddr.sin_family = AF_INET;
    laddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,"0.0.0.0",&laddr.sin_addr);

    socklen_t laddrsize = sizeof(laddr);
    socklen_t raddrsize = sizeof(raddr);
    sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }

    if(setsockopt(sd,SOL_SOCKET,SO_REUSEADDR,&flag,sizeof(flag))<0)
    {
        perror("setsocket");
        exit(1);
    }

    if(bind(sd, (void*)&laddr, laddrsize)<0)
    {
        perror("bind");
        exit(1);
    }

    if(listen(sd,bakc_log)<0)
    {
        perror("listen");
        exit(1);
    }

    while(1)
    {
            //accept返回三个值，std即可能是已连接套接字或错误信息，对端地址，对端地址大小
        std = accept(sd, (void*)&raddr,&raddrsize);  //返回值为全新文件描述符，代表与tcp对端连接，已连接描述符
        if(std < 0)
        {
            perror("accept");
            exit(1);
        }
        pid = fork();  //并发的时候，应该注意：fork之后，子进程和父进程均有已连接描述符和监听描述符，父进程中需close已连接描述符
                        //，将引用计数减为0
        if(pid == 0)
        {
            close(sd);
            inet_ntop(AF_INET,&raddr.sin_addr,p_raddr,praddr_size);
            fprintf(stderr,"Client addr is %s , port is %d\n",p_raddr,ntohs(raddr.sin_port));

            server_job(std);
            close(std);
            exit(0); //子进程结束必须exit0，否则会继续执行
        }
        close(std); //此处必须有，计数减为0，然后才会发送FIN，四次分手
    }

    close(sd);
    exit(0);
}

tcpclient.c

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdio.h>
#include "proto.h"
#define raddr_size 40
#define JPGBUFFERSIZE 1024



int main(int argc, char* argv[])
{

    FILE* fp;
    size_t num;
    long long stamp;
    char jpgbuffer[JPGBUFFERSIZE];
    struct sockaddr_in laddr,raddr;
    char raddr_ip[raddr_size];
    if(argc < 2)
    {
        fprintf(stderr，"argc error\n");
        exit(1);
    }

    int sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }
    raddr.sin_family = AF_INET;
    raddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,argv[1],&raddr.sin_addr);
    fprintf(stderr,"let's go");
    if(connect(sd,(void*)&raddr,sizeof(raddr))<0)  //conncet开始三次握手，可能出现三种情况1、FIN无ACK，75s后ETIMEOUT
    {
        perror("connect");
        exit(1);
    }

    //一切皆文件
    fp = fdopen(sd,"r+"); //将文件描述符转换成FILE指针打开,这里不能用w，w+，因无需创建fd

    if(fp==NULL)
    {
        perror("fdopen");
        exit(1);
    }
    fprintf(stderr,"Let's go!\n");
    while(1)
    {
        num = fread(jpgbuffer,1,JPGBUFFERSIZE,fp);
        if(num==0)
        {
            fprintf(stderr,"fread");
            break;
        }    
        fwrite(jpgbuffer,1,num,stdout);
        fprintf(stderr,"end\n");
    }

    fclose(fp); //这里需要关闭fp，因为fdopen已经转成fp

    exit(0);
}

proto.h

#ifndef PROTO_H__
#define PROTO_H__

#define LOCALPORT 1990
#define FMT_STAMP "%lld\r\n"


#endif

3.3 静态进程池tcp连接

tcppoolserver.c

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <time.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include "proto.h"

#define POOL_SIZE 3
#define BAKC_LOG 50
#define PRADDER_SIZE 50
#define BUFFER_SIZE 1024
int sd;
int flag;
pid_t pid;
char p_raddr[PRADDER_SIZE];
struct sockaddr_in laddr,raddr;
socklen_t laddrsize = sizeof(laddr);
socklen_t raddrsize = sizeof(raddr);


static void do_it(int sockfd);

static void server_job(int sockfd)
{
    int len;
    char buffer[BUFFER_SIZE];
    size_t num;
    len = sprintf(buffer,FMT_STAMP, (long long)time(NULL));
    if(send(sockfd,buffer,len,0)<0)
    {
        perror("send");
        exit(1);
    }
}

int main()
{

    laddr.sin_family = AF_INET;
    laddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,"0.0.0.0",&laddr.sin_addr);


    sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }

    if(setsockopt(sd,SOL_SOCKET,SO_REUSEADDR,&flag,sizeof(flag))<0)
    {
        perror("setsocket");
        exit(1);
    }

    if(bind(sd, (void*)&laddr, laddrsize)<0)
    {
        perror("bind");
        exit(1);
    }

    if(listen(sd,BAKC_LOG)<0)  //多个c端握手，内核保证BAKC_LOG大小的两个队列，进行握手
    {
        perror("listen");
        exit(1);
    }
    for(int i=0; i<POOL_SIZE; i++)  //产生静态进程池，用这三个进程处理
    {

        pid = fork();
        if(pid<0)
        {
            perror("fork");
            exit(1);
        }
        if(pid == 0)
        {  
            do_it(sd);
            exit(0);
        } 
    }
    for(int i=0; i<POOL_SIZE; i++)
    {
        wait(NULL);
    }



    close(sd);
    exit(0);
}


static void do_it(int sockfd)
{
    int std;
    while(1)
    {	
        //accept返回三个值，std即可能是已连接套接字或错误信息，对端地址，对端地址大小
    std = accept(sockfd, (void*)&raddr,&raddrsize);  //返回值为全新文件描述符，代表与tcp对端连接，已连接描述符
    if(std < 0)
    {
        perror("accept");
        exit(1);
    }

    //close(sockfd); 注意，这里不能close(sockfd),否则在while里，运行POOL_SIZE次后，fd会被close掉
    inet_ntop(AF_INET,&raddr.sin_addr,p_raddr,PRADDER_SIZE);
    fprintf(stderr,"Client addr is %s , port is %d, pid is %d\n",p_raddr,ntohs(raddr.sin_port),getpid());

    server_job(std);
    close(std);
    //exit(0); //子进程结束必须exit0，否则会继续执行
    }
//    }
//    close(std); //此处必须有，计数减为0，然后才会发送FIN，四次分手
}

tcppollclient.c

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdio.h>
#include "proto.h"
#define raddr_size 40
int main(int argc, char* argv[])
{

    FILE* fp;
    long long stamp;
    struct sockaddr_in laddr,raddr;
    char raddr_ip[raddr_size];
    if(argc < 2)
    {
        fprintf(stderr,"argc");
        exit(1);
    }

    int sd = socket(AF_INET,SOCK_STREAM,0);
    if(sd<0)
    {
        perror("socket");
        exit(1);
    }
    raddr.sin_family = AF_INET;
    raddr.sin_port = htons(LOCALPORT);
    inet_pton(AF_INET,argv[1],&raddr.sin_addr);
    fprintf(stderr,"let's go");
    if(connect(sd,(void*)&raddr,sizeof(raddr))<0)  //conncet开始三次握手，可能出现三种情况1、FIN无ACK，75s后ETIMEOUT
    {
        perror("connect");
        exit(1);
    }

    //一切皆文件
    fp = fdopen(sd,"r+"); //将文件描述符转换成FILE指针打开,这里不能用w，w+，因无需创建fd

    if(fp==NULL)
    {
        perror("fdopen");
        exit(1);
    }

    if(fscanf(fp,FMT_STAMP,&stamp)<1) //返回成功读取的个数，这里只有一个item，正确为1
    {

        fprintf(stderr,"error FMT_STAMP");
    }
    else
    {
        fprintf(stderr,"stamp = %lld\n",stamp);
    }

    fclose(fp); //这里需要关闭fp，因为fdopen已经转成fp

    exit(0);
}

#ifndef PROTO_H__
#define PROTO_H__

#define LOCALPORT 1990
#define FMT_STAMP "%lld\r\n"


#endif

标签：UNP,分析,raddr,int,size,TCP,buffer,include,define
来源： https://blog.csdn.net/weixin_44537992/article/details/106772982