UDP实现文件的发送、UDP实现全双工的聊天、TCP通信协议

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重要程序

1、UDP实现文件的发送

发端：

#include "head.h"int main(void)
{int sockfd = 0;struct sockaddr_in recvaddr;ssize_t nsize = 0;int ret = 0;int fd = 0;char pathname[1024] = {0};char tmpbuff[1024] = {0};ssize_t nret;sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}recvaddr.sin_family = AF_INET;recvaddr.sin_port = htons(33333);recvaddr.sin_addr.s_addr = inet_addr("192.168.1.167");memset(pathname, 0, sizeof(pathname));gets(pathname);nsize = sendto(sockfd, pathname, strlen(pathname), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (nsize == -1){perror("fail to sendto");return -1;}fd = open(pathname, O_RDONLY);if (fd == -1){perror("fail to open");return -1;}printf("pathname: %s\n", pathname);while (1){usleep(10);nret = read(fd, tmpbuff, sizeof(tmpbuff));nsize = sendto(sockfd, tmpbuff, nret, 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (nsize == -1){perror("fail to sendto tmpbuff");return -1;}if (nret <= 0){break;}}sprintf(tmpbuff, "|__quit__|");nsize = sendto(sockfd, tmpbuff, strlen(tmpbuff)+1, 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (nsize == -1){perror("fail to sendto tmpbuff");return -1;}printf("成功发送 %s 文件\n", pathname);close(fd);close(sockfd);return 0;
}

收端：

#include "head.h"int main(void)
{int ret = 0;int sockfd = 0;char tmpbuff[4096] = {0};struct sockaddr_in recvaddr;ssize_t nsize = 0;struct sockaddr_in sendaddr;socklen_t len = sizeof(sendaddr);sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (sockfd == -1){perror("fail to socket");return -1;}recvaddr.sin_family = AF_INET;recvaddr.sin_port = htons(33333);recvaddr.sin_addr.s_addr = inet_addr("192.168.1.167");ret = bind(sockfd, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (ret == -1){perror("fail to bind");return -1;}nsize = recvfrom(sockfd, tmpbuff, sizeof(tmpbuff), 0, (struct sockaddr *)&sendaddr, &len);if (nsize == -1){perror("fail to recvfrom");return -1;}//	printf("%s:%d>>接受到%ld个字节：%s\n",inet_ntoa(sendaddr.sin_addr),ntohs(sendaddr.sin_port),nsize,tmpbuff);int fd = 0;char ch[1024]= {0};fd = open(tmpbuff,O_WRONLY | O_CREAT | O_TRUNC, 0664);if (fd == -1){perror("fail to fopen");return -1;}while(nsize != 0){memset(ch, 0, sizeof(ch));nsize = recvfrom(sockfd, ch, sizeof(ch), 0, (struct sockaddr *)&sendaddr, &len);if (nsize == -1){perror("fail to recvfrom");return -1;}if (!strcmp(ch,"1")){break;}write(fd,ch,nsize);printf("写入%ld字节\n",nsize);}printf("接受完成!\n");close(fd);close(sockfd);return 0;
}

2、UDP实现全双工的聊天

发送端

#include "head.h"char name[32] = {0};
int sockfd = 0;
struct sockaddr_in recvaddr;
pthread_t tid_send;
pthread_t tid_recv;void *sendfun(void *arg)
{ssize_t nsize = 0;struct msgbuf sendmsg;while(1){memset(&sendmsg, 0, sizeof(sendmsg));sendmsg.type = MSG_TYPE_CHAT;sprintf(sendmsg.name, "%s", name);gets(sendmsg.text);    if (!strcmp(sendmsg.text, ".quit")){sendmsg.type = MSG_TYPE_END;}nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (nsize == -1){perror("fail to sendto");return NULL;}if (sendmsg.type == MSG_TYPE_END){break;}}pthread_cancel(tid_recv);return NULL;
}void *recvfun(void *arg)
{struct msgbuf recvmsg;ssize_t nsize = 0;while(1){memset(&recvmsg, 0, sizeof(recvmsg));nsize = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, NULL, NULL);if (-1 == nsize){perror("fail to recvfrom");return NULL;}if (recvmsg.type == MSG_TYPE_CHAT){printf("%s(%s:%d)>%s\n", recvmsg.name, RECV_ADDR, RECV_PORT, recvmsg.text);}else if (recvmsg.type == MSG_TYPE_END){break;}}pthread_cancel(tid_send);return NULL;
}int main(void)
{ssize_t nsize = 0;struct msgbuf sendmsg;/*设置接收方信息*/recvaddr.sin_family = AF_INET;recvaddr.sin_port = htons(RECV_PORT);recvaddr.sin_addr.s_addr = inet_addr(RECV_ADDR);/*输入昵称*/printf("请输入您的昵称:\n");gets(name);/*创建套接字*/sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (sockfd == -1){perror("fail to sockfd");return -1;}/*设置要发送的信息*/memset(&sendmsg, 0, sizeof(sendmsg));sendmsg.type = MSG_TYPE_START;sprintf(sendmsg.name, "%s", name);/*发送信息*/nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (nsize == -1){perror("fail to sendto");return -1;}pthread_create(&tid_send, NULL, sendfun, NULL);pthread_create(&tid_recv, NULL, recvfun, NULL);pthread_join(tid_send, NULL);pthread_join(tid_recv, NULL);close(sockfd);return 0;
}

接收端

#include "head.h"char name[32] = {0};
int sockfd = 0;
struct sockaddr_in recvaddr;
struct sockaddr_in sendaddr;
pthread_t tid_send;
pthread_t tid_recv;void *sendfun(void *arg)
{ssize_t nsize = 0;struct msgbuf sendmsg;while(1){memset(&sendmsg, 0, sizeof(sendmsg));sendmsg.type = MSG_TYPE_CHAT;sprintf(sendmsg.name, "%s", name);gets(sendmsg.text);    if (!strcmp(sendmsg.text, ".quit")){sendmsg.type = MSG_TYPE_END;}nsize = sendto(sockfd, &sendmsg, sizeof(sendmsg), 0, (struct sockaddr *)&sendaddr, sizeof(sendaddr));if (nsize == -1){perror("fail to sendto");return NULL;}if (sendmsg.type == MSG_TYPE_END){break;}}pthread_cancel(tid_recv);return NULL;
}void *recvfun(void *arg)
{struct msgbuf recvmsg;ssize_t nsize = 0;while(1){memset(&recvmsg, 0, sizeof(recvmsg));nsize = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, NULL, NULL);if (-1 == nsize){perror("fail to recvfrom");return NULL;}if (recvmsg.type == MSG_TYPE_CHAT){printf("%s(%s:%d)>%s\n", recvmsg.name, inet_ntoa(sendaddr.sin_addr), ntohs(sendaddr.sin_port), recvmsg.text);}else if (recvmsg.type == MSG_TYPE_END){break;}}pthread_cancel(tid_send);return NULL;
}int main(void)
{char tmpbuff[1024] = {0};struct msgbuf recvmsg;int ret = 0;socklen_t addrlen = sizeof(sendaddr);/*设置接收方信息*/recvaddr.sin_family = AF_INET;recvaddr.sin_port = htons(RECV_PORT);recvaddr.sin_addr.s_addr = inet_addr(RECV_ADDR);/*输入昵称*/printf("请输入您的昵称:\n");gets(name);/*创建套接字*/sockfd = socket(AF_INET, SOCK_DGRAM, 0);if (sockfd == -1){perror("fail to sockfd");return -1;}ret = bind(sockfd, (struct sockaddr *)&recvaddr, sizeof(recvaddr));if (-1 == ret){perror("fail to bind");return -1;}/*设置要发送的信息*/memset(&recvmsg, 0, sizeof(recvmsg));/*接收信息*/ret = recvfrom(sockfd, &recvmsg, sizeof(recvmsg), 0, (struct sockaddr *)&sendaddr, &addrlen);if (ret == -1){perror("fail to recvfrom");return -1;}pthread_create(&tid_send, NULL, sendfun, NULL);pthread_create(&tid_recv, NULL, recvfun, NULL);pthread_join(tid_recv, NULL);pthread_join(tid_send, NULL);close(sockfd);return 0;
}

head.h

#ifndef _HEAD_H
#define _HEAD_H#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <dirent.h>
#include <time.h>
#include <pwd.h>
#include <stdlib.h>
#include <grp.h>
#include <sys/wait.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <arpa/inet.h>struct msgbuf
{int type;      //消息类型char name[32]; //昵称char text[32]; //消息
};#define MSG_TYPE_START        100               //开始聊天消息类型
#define MSG_TYPE_END          200               //退出聊天消息类型
#define MSG_TYPE_CHAT         300               //聊天消息类型
#define RECV_ADDR             "192.168.1.172"   //接收端地址
#define RECV_PORT             50000             //接收端端口#endif

学习笔记

TCP通信

TCP发端(客户端)

        socket -> connect -> send / recv-> close

TCP收端(服务端)

        socket -> bind -> listen -> accept -> send / recv -> close

 1、connect

#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>

int connect(int sockfd, const struct sockaddr *addr,socklen_t addrlen);

功能：发起链接请求

参数：

        sockfd：套接字的描述符

        addr：目的地址存放空间首地址

        addrlen：IP地址的大小

返回值：成功0，失败-1；

2、send

#include <sys/types.h>
#include <sys/socket.h>

ssize_t send(int sockfd, const void *buf, size_t len, int flags);

功能：发送数据

参数：

        sockfd：套接字描述符

        buf：发送数据空间的首地址

        len：发送数据的长度

        flags：属性默认为0

返回值：

        成功返回实际发送字节数

        失败返回-1；

3、recv

#include <sys/types.h>
#include <sys/socket.h>

ssize_t recv(int sockfd, void *buf, size_t len, int flags);

功能：接收数据

参数：

        sockfd：套接字描述符

        buf：存放数据空间首地址

        len：最大接收数据的长度

        flags：属性默认0

返回值：

        成功返回实际接收字节数，失败返回-1；

        若对方退出，返回0

客户端：

#include "head.h"int main(void)
{int ret = 0;int sockfd = 0;struct sockaddr_in serveaddr;char tmpbuff[1024] = {0};ssize_t nsize = 0;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (-1 == sockfd){perror("fail to socket");return -1;}serveaddr.sin_family = AF_INET;serveaddr.sin_port = htons(50000);serveaddr.sin_addr.s_addr = inet_addr("192.168.1.101");ret = connect(sockfd, (struct sockaddr *)&serveaddr, sizeof(serveaddr));if (ret == -1){perror("fail to connect");return -1;}gets(tmpbuff);nsize = send(sockfd, tmpbuff, strlen(tmpbuff), 0);if (nsize == -1){perror("fail to send");return -1;}memset(tmpbuff, 0, sizeof(tmpbuff));nsize = recv(sockfd, tmpbuff, sizeof(tmpbuff), 0);if (nsize == -1){perror("fail to recv");return -1;}printf("RECV: %s\n", tmpbuff);close(sockfd);return 0;
}

4、listen

#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>

int listen(int sockfd, int backlog);

功能：监听客户端发送的链接请求，不会阻塞

参数：

        sockfd：套接字描述符

        backlog：允许等待的尚未被处理的三次握手请求的最大个数

返回值：成功0，失败-1；

5、accept

#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>

int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);

功能：

       处理等待链接队列中的第一个链接请求，若没有人发送链接请求会阻塞等待，直到有连接请求

参数：

        sockfd：套接字描述符

        addr：存放IP地址的空间首地址

        addrlen：存放IP地址大小空间首地址

返回值：

        成功返回一个新的文件描述符

        失败返回-1；

服务端：

#include "head.h"int main(void)
{int sockfd = 0;struct sockaddr_in serveaddr;int ret = 0;int confd = 0;ssize_t nsize = 0;char tmpbuff[1024] = {0};serveaddr.sin_family = AF_INET;serveaddr.sin_port = htons(50000);serveaddr.sin_addr.s_addr = INADDR_ANY;sockfd = socket(AF_INET, SOCK_STREAM, 0);if (sockfd == -1){perror("fail to socket");return -1;}ret = bind(sockfd, (struct sockaddr *)&serveaddr, sizeof(serveaddr));if (ret == -1){perror("fail to bind");return -1;}ret = listen(sockfd, 10);if (-1 == ret){perror("fail to listen");return -1;}confd = accept(sockfd, NULL, NULL);if (-1 == confd){perror("fail to accept");return -1;}nsize = recv(confd, tmpbuff, sizeof(tmpbuff), 0);if (-1 == nsize){perror("fail to recv");return -1;}printf("RECV: %s\n", tmpbuff);memset(tmpbuff, 0, sizeof(tmpbuff));gets(tmpbuff);nsize = send(confd, tmpbuff, strlen(tmpbuff), 0);if (-1 == nsize){perror("fail to send");return -1;}close(confd);close(sockfd);return 0;
}