chatserver.c

linux网络程序设计 几个小程序以及编译命令

//程序比较简单,就全放在一个文件里了
//服务器维护一个用户列表,包括用户名和IP
//响应用户加入和离开请求.
//有新加入的用户或有用户离开,都要通知所有用户更新其用户列表
#include <stdio.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <string.h>
#include <signal.h>
#include <pthread.h>
#define SERV_PORT 7000
#define SUDP_PORT 7001
//#define CLET_PORT 2029
#define MESG_PORT 7002
#define SEG_SIZE  5000
#define err_sys printf
#define MAXSIZE 1024
#define NAMELEN   20
#define LEN sizeof(user)
typedef  struct _user
{
    char name[NAMELEN];
    char ip[16];
    struct _user *next;
    struct _user *prev;
}user;
static user *head;
user *tail;
user *p;
user *q;

int lock;
int usrnum;
void add(char * name,char *ip)
{
    int i;
    while(lock==1)
    i++;
    lock=1;
    if(head==NULL)
    {
        p=tail=head=(user *)malloc(LEN);
        head->prev=head->next=NULL;
    }
    else 
    {
        p=(user *)malloc(LEN);
        tail->next=p;
        p->prev=tail;
        p->next=NULL;
        tail=p;
    }
    strcpy(p->name,name);
    strcpy(p->ip,ip);
    usrnum++;
}


void UserList()
{
    int i;
    while(lock==1)
    i++;
    lock=1;
    if(head==NULL)
    {
        printf("\nNo User now!\n\n");
        return;
    }
    printf("The  user  list:\n\n");
    printf("\tName");
    printf("\t\t\t  IP\n");
    for(p=head;p!=NULL;p=p->next)
    {
        printf("\t%-15s",p->name);
        printf("%-20s\n",p->ip);
    }

    fflush(stdout);
    lock=0;
}


user *find(char *buf,int i)
{
    p=head;
    while(p!=NULL)
    {
        if(strcmp((i==1)?p->ip:p->name,buf)==0)
        return p;
        p=p->next;
    }
    return NULL;
}


void del(char *buf)
{
    int i;
    while(lock==1)
    i++;
    lock=1;
    user *result=find(buf,1);
    if(result==NULL)
    return;
    if(head==NULL)
    return;
    if(result==head)
    {
        head=result->next;
        if(head!=NULL)
        head->prev=NULL;
        else
        tail=NULL;
    }
    else if(result==tail)
    {
        tail=result->prev;
        tail->next=NULL;
    }
    else
    {
        result->prev->next=result->next;
        result->next->prev=result->prev;
    }
    free(result);
}


sendmessage(int type,char *ip,char *name)
{
    int sockfd;
    int len;
    struct sockaddr_in servaddr;
    char buf[50];
    memset(buf,0,50);
    if(type==0)
    {
        strcpy(buf,"+");
        strcat(buf,name);
        strcat(buf,"\r");
        strcat(buf,ip);
        strcat(buf,"\r\r");
    }
    else
    {
        strcpy(buf,"-");
        strcat(buf,ip);
        strcat(buf,"\r");
    }
    for(p=head;p!=NULL;p=p->next)
    {
        bzero(&servaddr, sizeof(servaddr));
        servaddr.sin_family = AF_INET;
        servaddr.sin_port = htons(MESG_PORT);
        inet_aton(p->ip,&servaddr.sin_addr);
        sockfd = socket(AF_INET, SOCK_DGRAM, 0);
        if(strcmp(ip,p->ip)==0)
        continue;
        len=sizeof(servaddr);
        sendto(sockfd,buf,sizeof(buf),0,(struct sockaddr *)&servaddr,len);
    }
    close(sockfd);
}


void sendall(int sock,struct sockaddr_in * pservaddr)
{
    char buf[5000];
    int len;
    memset(buf,0,5000);
    buf[0]='\0';
    if(head!=NULL)
    for(p=head;p!=NULL;p=p->next)
    {
        
        strcat(buf,p->name);
        strcat(buf,"\r");
        strcat(buf,p->ip);
        strcat(buf,"\r\r");
    }
    len=sizeof(*pservaddr);
    sendto(sock,buf,sizeof(buf),0,(struct sockaddr *)pservaddr,len);
  
}


//监听用户的加入消息
void* tcplisten(void)
{
    struct sockaddr_in	cliaddr, servaddr;
    socklen_t		clilen;
    int					listenfd;
    listenfd = socket(AF_INET, SOCK_STREAM, 0);
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family      = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port        = htons(SERV_PORT);
    bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
    listen(listenfd, 5);
    char    name[NAMELEN];
    char           ip[16];
    int connfd;
    int buflen;
    while(1)
    {
        memset(name,0,sizeof(name));
        memset(ip,0,sizeof(ip));
        clilen = sizeof(cliaddr);
        bzero(&cliaddr, sizeof(cliaddr));
        connfd = accept(listenfd, (struct sockaddr *) &cliaddr, &clilen);
        memset(name,0,NAMELEN);
        buflen=recv(connfd,name,NAMELEN,0);
        strcpy(ip,inet_ntoa(cliaddr.sin_addr));	  	
        if(strlen(name)==0)
        continue;
        printf("\nA new comer :\n\t%s\t%s\n",name,ip);
        fflush(stdout);
     
        add(name,ip);
        lock=0;
        sendall(connfd,&cliaddr); //所有用户信息发送到新加入的user
        sendmessage(0,ip,name);   //通知所有用户,有new comer
        close(connfd);             //tcp连接结束
    }
}


//udp监听用户的离开消息
void *udplisten(void)
{
    int sock;
    struct sockaddr_in servaddr, cliaddr;
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(SUDP_PORT); 
    if(bind(sock, (struct sockaddr *)&servaddr, sizeof(servaddr)) == -1)
    {
        perror("bind error");
        exit(1);
    }
    int len;
    char buf[1];
    char ip[16];
    while(1)
    {
        memset(buf,0,1);
       
        bzero(&cliaddr,sizeof(cliaddr)); 
        len = sizeof(cliaddr);
        len=recvfrom(sock,buf,1, 0,(struct sockaddr *)&cliaddr,&len);
        if(buf[0]=='-')
        {
            strcpy(ip,inet_ntoa(cliaddr.sin_addr));
            p=find(ip,1);
            fflush(stdout);
            if(p==NULL)
            printf("This user is not in the session,maybe in the last one!\n");
            else
            printf("\n%s has Left!\t \tIP: %s\n",p->name,p->ip);
            fflush(stdout);
            del(ip);
            lock=0;
            sendmessage(1,ip,NULL);  //通知所有用户有人离开
        }
    }
}

//主程序响应用户输入
int main(int argc, char **argv)
{
    int ret;
    tail=head=NULL;
    usrnum=0;
    lock=0;
    pthread_t tcplisten_t;
    pthread_t udplisten_t;
    ret=pthread_create(&tcplisten_t,NULL,(void *)tcplisten,NULL); 
    ret=pthread_create(&udplisten_t,NULL,(void *)udplisten,NULL); 
    int choice;
 
    
    while(1)
    {
        printf("\nChat Server is running!");
        printf("\nPlease input your choice:\n1.Show all user \n2.stop the server\n");
        fflush(stdout);
        scanf("%d",&choice);
       
        getchar();
        if(choice==1)
        {
            UserList();
            
        }
        else
        {
            //先清理结构
           pthread_cancel(tcplisten_t);
           pthread_cancel(udplisten_t);
           printf("the chat servert is stopped!\n\n");
           exit(0);
        }//else
    }//while
}