2023/9/1 -- 网络编程

基于UDP的网络聊天室：

cli.c

#include "people.h"

struct agreeMent
{
	char type;
	char name[20];
	char text[20];
};
struct agreeMent ag;

void * snd(void * arg)
{
	int sfd = *(int *)arg;
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	while(1)
	{
		bzero(ag.text,sizeof(ag.text));
		fgets(ag.text,sizeof(ag.text),stdin);
		ag.text[strlen(ag.text)-1] = 0;
		char buf[128];
		int len;
		bzero(buf,sizeof(buf));
		if(strcasecmp(ag.text,"quit")==0)
		{
			ag.type = 'Q';
			len	 = sprintf(buf,"%c%s",ag.type,ag.name);
		}
		else
		{
			ag.type = 'C';
			len = sprintf(buf,"%c%s%s%s%s%s",ag.type,"[",ag.name,"]","说:",ag.text);
		}
		if(sendto(sfd,buf,len,0,(struct sockaddr*)&sin,sizeof(sin))<0)
		{
			ERR_MSG("sendto");
			return NULL;
		}
		if(strcasecmp(ag.text,"quit")==0)
		{
			exit(0);
		}
	}
	pthread_exit(NULL);
}

void * rcv(void * arg)
{
	int sfd = *(int *)arg;
	struct sockaddr_in cin;
	int len = sizeof(cin);
	char buf[128];
	while(1)
	{
		bzero(buf,sizeof(buf));
		if(recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr *)&cin,&len)<0)
		{
			ERR_MSG("recvfrom");
			return NULL;
		}
		if(buf[0]=='C')
		{
			printf("%s\n",buf+1);
		}
		else
		{

        	printf("%s\n",buf);
		}
	}
	pthread_exit(NULL);
}

int main(int argc, const char *argv[])
{
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd<0)
	{
		ERR_MSG("socket");
		return -1;
	}
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	printf("请输入姓名>>>");
	fgets(ag.name,sizeof(ag.name),stdin);
	ag.name[strlen(ag.name)-1] = 0;
	ag.type = 'L';
	char buf[128];
	int len = sprintf(buf,"%c%s",ag.type,ag.name);
	if(sendto(sfd,buf,len,0,(struct sockaddr*)&sin,sizeof(sin))<0)
	{
		ERR_MSG("sendto");
		return -1;
	}
	pthread_t pth1,pth2;
	pthread_create(&pth1,NULL,snd,&sfd);
	pthread_create(&pth2,NULL,rcv,&sfd);
	pthread_join(pth1,NULL);
	pthread_join(pth2,NULL);
	return 0;
}

ser.c

#include "people.h"

struct agreeMent
{
	char type;
	char name[20];
	char text[20];
};

struct agreeMent ag;
struct people_head * phead;
void * snd(void * arg)
{

	int sfd = *(int *)arg;
	struct people_node * pnode = phead->pfirst;
	while(1)
	{
		fgets(ag.text,sizeof(ag.text),stdin);
		ag.text[strlen(ag.text)-1]=0;
		while(pnode!=NULL)
		{
			struct sockaddr_in sin;
			sin = pnode->data.sin;
			if(sendto(sfd,ag.text,sizeof(ag.text),0,(struct sockaddr*)&sin,sizeof(sin))<0)
			{
				ERR_MSG("sendto");
				return NULL;
			}
			pnode = pnode->pnext;
		}
		if(pnode==NULL)
		{
			break;
		}
	}
	pthread_exit(NULL);
}

void * rcv(void * arg)
{
	int sfd = *(int *)arg;
	struct sockaddr_in cin;
	int len = sizeof(cin);
	char buf[128];
	char str[128];
	int res;
	while(1)
	{
		bzero(buf,sizeof(buf));
		res = recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr *)&cin,&len);
		if(res<0)
		{
			ERR_MSG("recvfrom");
			return NULL;
		}
		if(buf[0]=='C')
		{
			struct people_node * pnode = phead->pfirst;
			bzero(str,sizeof(str));
			int s = sprintf(str,"%s%s%s%d%s%s","[",inet_ntoa(cin.sin_addr),":",ntohs(cin.sin_port),"]",buf+1);
			struct people_node * mynode = search_people_node(phead,cin);
			struct sockaddr_in sin;
			printf("%s\n",str);

			while(pnode!=NULL)
			{
				if(pnode==mynode)
				{
					pnode = pnode->pnext;
					continue;
				}
				sin = pnode->data.sin;
				if(sendto(sfd,buf,s,0,(struct sockaddr*)&sin,sizeof(sin))<0)
				{
					ERR_MSG("sendto");
					return NULL;
				}
				pnode = pnode->pnext;
			}
				}
		else if (buf[0]=='L')
		{
			struct people_node * pnode = phead->pfirst;
			bzero(str,sizeof(str));
			int s = sprintf(str,"%s%s",buf,"已上线");
			printf("%s\n",str+1);
			struct sockaddr_in sin;
			while(pnode!=NULL)
			{
				sin = pnode->data.sin;	
				if(sendto(sfd,str,sizeof(str),0,(struct sockaddr*)&sin,sizeof(sin))<0)
				{
					ERR_MSG("sendto");
					return NULL;
				}
				pnode = pnode->pnext;
			}
			struct peopleData data;
			data.sin = cin;
			struct people_node * pfirst = create_people_node(&data);
			insert_node_at_tail(phead,pfirst);
	
		}
		else if(buf[0]=='Q')
		{
			struct people_node * mynode = search_people_node(phead,cin);
			remove_people_node(phead,mynode);
			struct people_node * pnode = phead->pfirst;
			bzero(str,sizeof(str));
			int s = sprintf(str,"%s%s",buf,"已下线");
			printf("%s\n",str+1);
			struct sockaddr_in sin;
			while(pnode!=NULL)
			{
				sin = pnode->data.sin;
				if(sendto(sfd,str,s,0,(struct sockaddr*)&sin,sizeof(sin))<0)
				{
					ERR_MSG("sendto");
					return NULL;
				}
				pnode = pnode->pnext;
			}

		}
	}
	pthread_exit(NULL);
}

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


	phead = create_people_head();
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd<0)
	{
		ERR_MSG("socket");
		return -1;
	}
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	if(bind(sfd,(struct sockaddr *)&sin,sizeof(sin))<0)
	{
		ERR_MSG("bind");
		return -1;
	}
	pthread_t pth1,pth2;
	pthread_create(&pth1,NULL,snd,&sfd);
	pthread_create(&pth2,NULL,rcv,&sfd);
	pthread_join(pth1,NULL);
	pthread_join(pth2,NULL);
	destroy_people_head(phead);
	phead = NULL;
	return 0;
}

people.c

#include "people.h"

struct people_head * create_people_head()
{
	struct people_head * phead = (struct people_head *)malloc(sizeof(struct people_head));
	if(phead==NULL)
	{
		printf("people_head create failed");
		return NULL;
	}
	memset(phead,0,sizeof(struct people_head));
	phead->len = 0;
	return phead;
}
int destroy_people_head(struct people_head * phead)
{
	struct people_node * pnode = phead->pfirst;
	struct people_node * ptemp = NULL;
	while(pnode!=NULL)
	{
		ptemp = pnode->pnext;
		free(pnode);
		pnode = NULL;
		pnode = ptemp;
	}
	free(phead);
	phead = NULL;
	return 0;
}

struct people_node * create_people_node(struct peopleData * data)
{
	struct people_node * pnode =(struct people_node *)malloc(sizeof(struct people_node *));
	if(NULL==pnode)
	{
		printf("people_node create failed");
		return NULL;
	}
	memset(pnode,0,sizeof(struct people_node));
	memcpy(&pnode->data,data,sizeof(struct peopleData));
	return pnode;
}
int destroy_people_node(struct people_node * pnode)
{
	if(pnode!=NULL)
	{
		free(pnode);
		pnode = NULL;
	}
	return 0;
}

int insert_node_at_tail(struct people_head * phead,struct people_node * pnode)
{
	struct people_node * pfirst = phead->pfirst;
	while(pfirst!=NULL)
	{
		if(pfirst->pnext==NULL)
		{
			break;
		}
		pfirst = pfirst->pnext;
	}
	if(pfirst!=NULL)
	{
		pfirst->pnext = pnode;
	}
	else
	{
		phead->pfirst = pnode;
	}
	pnode->pnext = NULL;
	phead->len++;
	return 0;

}

struct people_node * search_people_node(struct people_head * phead,struct sockaddr_in sin)
{
	struct people_node * pnode = phead->pfirst;
	while(pnode!=NULL)
	{
		printf("%d\n",pnode->data.sin.sin_port);
		if(ntohs(pnode->data.sin.sin_port)==ntohs(sin.sin_port))
		{
			break;
		}
		pnode = pnode->pnext;
	}
	return pnode;
}
struct people_node * get_prev_node(struct people_head * phead,struct people_node * pnode)
{
	struct people_node * pprev = phead->pfirst;
	if(pprev==NULL)
	{
		return NULL;
	}
	else
	{
		if(pnode==pprev)
		{
			return NULL;
		}
		else
		{
			while(pprev!=NULL&&pprev->pnext!=pnode)
			{
				pprev = pprev->pnext;
			}
			return pprev;
		}
	}
	return pprev;
}
int remove_people_node(struct people_head * phead,struct people_node * pnode)
{
	struct people_node * pprev = get_prev_node(phead,pnode);
	if(pprev!=NULL)
	{
		pprev->pnext = pnode->pnext;
		pnode->pnext = NULL;
		destroy_people_node(pnode);
		pnode = NULL;
		phead->len--;
		return 1;
	}
	else if (pnode==phead->pfirst)
	{
		phead->pfirst = pnode->pnext;
		pnode->pnext = NULL;
		destroy_people_node(pnode);
		pnode = NULL;
		phead->len--;
		return 1;
	}
	return 0;
}

people.h

#ifndef __PEOPLE_H__
#define __PEOPLE_H__

#include 

#define ERR_MSG(msg) do{\
	printf("%d",__LINE__);\
	perror(msg);\
}while(0)

#define IP "192.168.114.153"
#define PORT 8888

struct peopleData
{
	struct sockaddr_in sin;
};
struct people_node
{
	struct peopleData data;
	struct people_node * pnext;
};
struct people_head
{
	int len;
    struct people_node * pfirst;
};
struct people_head * create_people_head();

int destroy_people_head(struct people_head * phead);

struct people_node * create_people_node(struct peopleData * data);

int destroy_people_node(struct people_node * pnode);

int insert_node_at_tail(struct people_head * phead,struct people_node * pnode);

struct people_node * search_people_node(struct people_head * phead,struct sockaddr_in sin);

int remove_people_node(struct people_head * phead,struct people_node * pnode);

#endif