基于Linux的简易局域网聊天工具

/************************************************************************* > File Name: 01socket.c > Author: ma6174 > Mail: ma6174@163.com > Created Time: Mon 22 May 2017 05:10:00 PM CST ************************************************************************/ #include<stdio.h> #include<sys/socket.h> #include<arpa/inet.h> #include<string.h> #include<stdlib.h> #include<pthread.h> #include<fcntl.h> //用于保存用户连接套接字的数组 char clnt_socks[1024]; int clnt_cnt = 0; //互斥锁初始化 pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; //消息类型 enum MSGTYPE { REGISTER_REQ,REGISTER_OK,REGISTER_ERR, LOGIN_REQ,LOGIN_OK,LOGIN_ERR, SEND_ALL, }; //用户结构体，包括名字和密码 struct USER { char name[20]; char passwd[20]; }; //处理客户端的线程函数 void* handle_client(void*); //用户注册 int handle_register(char*,char*); //用户登录 int handle_login(char*,char*); //处理错误 void handle_error(char*); //网络初始化 void initnetwork(unsigned short port); //服务器转发消息给所有用户 void sendmsgtoall(char *msg,int len); //服务器监听套接字 int sockfd; int main(int argc,char *argv[]) { if(argc != 2) { printf("Usage:%s <Port> \n",argv[0]); return 0; } //网络初始化，需要命令行参数：端口号 unsigned short port = atoi(argv[1]); initnetwork(port); while(1) { int confd = accept(sockfd,NULL,NULL); if(confd < 0) { perror("accept"); return -1; } pthread_mutex_lock(&mutex); clnt_socks[clnt_cnt++] = confd; pthread_mutex_unlock(&mutex); pthread_t tid; pthread_create(&tid,NULL,handle_client,(void*)&confd); pthread_detach(tid); }//end while(1) close(sockfd); return 0; } //网络初始化 void initnetwork(unsigned short port) { //1. sockfd = socket(AF_INET,SOCK_STREAM,0); if(sockfd < 0) { perror("socket"); exit(1); } //2. struct sockaddr_in saddr; memset(&saddr,0,sizeof(saddr)); saddr.sin_family = AF_INET; saddr.sin_port = htons(port); saddr.sin_addr.s_addr = htonl(INADDR_ANY); //3. int res = bind(sockfd,(struct sockaddr*)&saddr,sizeof(saddr)); if(res < 0) { perror("bind"); exit(1); } printf("bind success!\n"); //4. res = listen(sockfd,10); if(res < 0) { perror("listen"); exit(1); } printf("init ok!!\n"); } void* handle_client(void *arg) { int confd = *((int*)arg); printf("confd = %d \n",confd); int res; enum MSGTYPE type; while(1) { res = read(confd,&type,sizeof(type)); if(res == 0) { //客户断线，移除其连接套接字 int i; pthread_mutex_lock(&mutex); for(i = 0; i < clnt_cnt; i++)//移除断线了的客户端 { if(confd == clnt_socks[i]) { while( i++ < clnt_cnt-1 ) { clnt_socks[i] = clnt_socks[i+1]; } break; } } clnt_cnt--; pthread_mutex_unlock(&mutex); close(confd); printf("confd %d is exited!\n",confd); pthread_exit(0); } if(type == REGISTER_REQ) { char username[20]; char passwd[20]; read(confd,username,sizeof(username)); read(confd,passwd,sizeof(passwd)); if(handle_register(username,passwd)) {//register ok type = REGISTER_OK; } else {//register error type = REGISTER_ERR; } write(confd,&type,sizeof(type)); }//end if register if(type == LOGIN_REQ) { char username[20]; char passwd[20]; read(confd,username,sizeof(username)); read(confd,passwd,sizeof(passwd)); if(handle_login(username,passwd)) {//login ok type = LOGIN_OK; write(confd,&type,sizeof(type)); write(confd,username,sizeof(username)); } else {//login error type = LOGIN_ERR; write(confd,&type,sizeof(type)); } }//end if login if(type == SEND_ALL) { char msg[2048] = {0}; int res = read(confd,msg,sizeof(msg)); sendmsgtoall(msg,res); }//end if type==send_all }//end while return NULL; } void sendmsgtoall(char *msg,int len) { printf("msg: %s \n",msg); int i; enum MSGTYPE type = SEND_ALL; pthread_mutex_lock(&mutex); for(i = 0; i < clnt_cnt; i++) { write(clnt_socks[i],&type,sizeof(type)); write(clnt_socks[i],msg,len); } pthread_mutex_unlock(&mutex); } void handle_error(char*errmsg) { perror(errmsg); exit(1); } int handle_register(char *username,char *passwd) { printf("register:%s %s \n",username,passwd); int fd = open("users.dat",O_RDWR | O_CREAT,0777); if(fd < 0) { handle_error("open register file"); } struct USER user; strcpy(user.name,username); strcpy(user.passwd,passwd); struct USER temp; int res; int is_exist = 0;//1:exist,0:not exist while(1) { res = read(fd,&temp,sizeof(temp)); if(res < 0) { perror("read userdatafile error"); exit(1); } printf("read res = %d \n",res); if(res == 0) { break; } if(strcmp(user.name,temp.name) == 0) { is_exist = 1; break; } } printf("exist = %d\n",is_exist); if(is_exist)//exist { return 0; } else { int res = write(fd,&user,sizeof(user)); if(res < 0) { perror("write username&passwd"); } printf("write res = %d\n",res); close(fd); return 1; } } int handle_login(char *username,char *passwd) { int fd = open("users.dat",O_RDONLY); if(fd < 0) { handle_error("open register file"); } struct USER user; strcpy(user.name,username); strcpy(user.passwd,passwd); struct USER temp; int res; int is_exist = 0;//1:exist,0:not exist while(1) { res = read(fd,&temp,sizeof(temp)); if(res == 0) { break; } if(strcmp(temp.name,username) == 0 && strcmp(temp.passwd,passwd) == 0) { is_exist = 1; break; } }//endl while if(is_exist) { return 1; } else { return 0; } }