talks.c

基于Linux操作系统的网络编程

#include<signal.h>
#include<sys/wait.h>
#include "talk.h"


struct word_list {
	char word[MAX_WORD_LEN + 1];
	struct word_list *next;
} *list = NULL;

int check_word(char *line)
{
	char buf[MAX_LINE];
	struct word_list *word = NULL;
	char *p = NULL, *p1 = NULL, *end = NULL;

	if (line == NULL)
		return 0;

	memset(buf, 0, sizeof(buf));
	strcpy(buf, line);

	if (buf[strlen(buf) - 1] == '\n')
		buf[strlen(buf) - 1] = '\0';

	p = buf;
	end = p + strlen(buf);
	while (((p1 = strchr(p, ' ')) != NULL) || 
		((p1 = strchr(p, '!')) != NULL) || 
		((p1 = strchr(p, ';')) != NULL) || 
		((p1 = strchr(p, ',')) != NULL) || 
		((p1 = strchr(p, '.')) != NULL) || 
		((p1 = strchr(p, '-')) != NULL) || 
		((p1 = strchr(p, '_')) != NULL) || 
		((p1 = strchr(p, ':')) != NULL) || 
		((p1 = strchr(p, '?')) != NULL) || 
		((p1 = strchr(p, '+')) != NULL) || 
		((p1 = strchr(p, '=')) != NULL) || 
		((p1 = strchr(p, '/')) != NULL) || 
		((p1 = strchr(p, '\'')) != NULL) || 
		((p1 = strchr(p, '\"')) != NULL) || 
		(p != end)) { 
		if (p1 != NULL)
			*p1 = '\0';
		if (p != p1) {
			printf("check word [%s]\n", p);
			for (word = list; word; word = word->next) {
				if (strcmp(p, word->word) == 0) {
					printf("match word [%s]\n", p);
					sprintf(line, "word [%s] is not permited in this room!\n", p);
					return -1;
				}
			}
		}
		p = p1 + 1;

		if (p1 == NULL)
			break;
	}

	return 0;

}

void join_user(char *line,char *name)
{
	strcpy(name,&line[1]);
	sprintf(line,"%s join the room!\n", name);
}

void add_user(char *line,char *name)
{
	char theline[MAX_LINE];
	
	sprintf(theline, "\"%s\" say: %s", name, line);
	strcpy(line,theline);
}

int free_user(int user_link[MAX_CLIENT])
{
	int i=0;
	
	while((user_link[i]!=0)&&(i<MAX_CLIENT))
		i++;
	
	if(i==MAX_CLIENT)
		return(-1);
	
	return(i);
}

void  add_sockset(fd_set *sockset,int sockfd,int *user_link,int *userfd)
{
	int i;
	
	FD_ZERO(sockset);
	FD_SET(sockfd,sockset);
	for(i=0;i<MAX_CLIENT;i++){
		if(user_link[i]==1){
			FD_SET(userfd[i],sockset);
		}
	}
}



int init_ser(int port) //if success,return sockfd,else return0
{
	int  SERV_TCP_PORT;
	int   sockfd;
	struct sockaddr_in serv_addr;

	SERV_TCP_PORT=port;
	if((sockfd=socket(AF_INET,SOCK_STREAM,0))<0){
		perror("socket:");
		printf("server:can't open stream socker.\n");
		fflush(stdout);
		return(0);
	}
	
	bzero((char*)&serv_addr,sizeof(serv_addr));
	serv_addr.sin_family   =AF_INET;
	serv_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	serv_addr.sin_port   =htons(SERV_TCP_PORT);
	
	if(bind(sockfd,(struct sockaddr*)&serv_addr,sizeof(serv_addr))<0){
		perror("bind:");
		printf("server:can't bind local address\n");
		fflush(stdout);
		return(0);
	}
	return(sockfd);//successful.
}

int maxvalue(int a,int b)
{
	int  themax;

	if(a>b)
		themax=a;
	else
		themax=b;
	return themax;
}



int main(void)
{
	int sockfd;
	int new_sockfd;
	int user_link[MAX_CLIENT];
	int userfd[MAX_CLIENT];
	char username[MAX_CLIENT][MAX_NAME];
	char line[MAX_LINE];
	int userCount;
	unsigned int cli_len;
	struct sockaddr_in cli_addr;
	FILE *file;
	int port;
	int length,i,j;
	fd_set sockset;
	int maxfd=0;

	struct word_list *word = NULL;
	char wordbuf[MAX_WORD_LEN + 1];
	int len, num;

	file = fopen("word", "r");
	if (file == NULL) {
		printf("open word file error!\n");
		//exit(1);
	}

	memset(wordbuf, 0, sizeof(wordbuf));
	while (fgets(wordbuf, sizeof(wordbuf) - 1, file)) {
		word = (struct word_list *)malloc(sizeof(struct word_list));
		if (word == NULL) {
			printf("malloc error\n");
			exit(1);
		}
		memset(word, 0, sizeof(struct word_list));

		len = strlen(wordbuf);
		if (wordbuf[len - 1] == '\n')
			wordbuf[len - 1] = '\0';

		strcpy(word->word, wordbuf);

		word->next = list;
		list = word;

		memset(wordbuf, 0, sizeof(wordbuf));
	}
	fclose(file);

	if (list)
		printf("get word list:\n");

	num = 0;
	for (word = list; word; word = word->next) {
		num++;
		printf("%d %s\n", num, word->word);
	}


	file=fopen("config","r");
	fgets(line,MAX_LINE,file);
	fscanf(file,"%d",&port);
	fclose(file);
	
	sockfd=init_ser(port);
	if(sockfd==0){
		printf("init serve socket error\n");
		fflush(stdout);
		exit(1);
	}//Socker init done

	listen(sockfd,MAX_CLIENT);
	cli_len=sizeof(cli_addr);
	for(i=0;i<MAX_CLIENT;i++){
		user_link[i]=0;
		username[i][0] ='\0';
	}
	userCount=0;

	FD_ZERO(&sockset);
	FD_SET(sockfd, &sockset);
	maxfd = maxvalue(maxfd, sockfd + 1);

	for(;;){
		select(maxfd,&sockset,NULL,NULL,NULL);
		if (FD_ISSET(sockfd, &sockset)
			       && ((userCount = free_user(user_link)) >= 0)) {
			new_sockfd=accept(sockfd,(struct sockaddr *)&cli_addr,&cli_len);
			if(new_sockfd<0){
				user_link[userCount]=0;
				printf("accept error\n");
			}else{
				user_link[userCount]=1;
				userfd[userCount]=new_sockfd;
				FD_SET(new_sockfd,&sockset);
				maxfd=maxvalue(maxfd,new_sockfd+1);
			}
		}//if userCount>0
		
		for (i = 0; i < MAX_CLIENT; i++) {
			if ((user_link[i] == 1) && (FD_ISSET(userfd[i], &sockset))) {
				length = read(userfd[i], line, MAX_LINE);
				if (length == 0) {//socket is closed.
					user_link[i] = 0;
					username[i][0] = '\0';
					FD_CLR(userfd[i], &sockset);
				} else if (length > 0) {
					line[length] = '\0';
					//printf("get line:%s\n", line);
					if ((line[0] == '/') && (username[i][0] == '\0')) {
						join_user(line, username[i]);
					} else {
						if (check_word(line) < 0) {
							write(userfd[i], line, strlen(line));
							break;
						}
						add_user(line, username[i]);
					}
					for (j = 0; j < MAX_CLIENT; j++) {
						if ((j != i) && (user_link[j] == 1)) {
							write(userfd[j], line, strlen(line));
						}
					}
				}//length>0
			}//user_link[i]==1
		}//for
		add_sockset(&sockset, sockfd, user_link, userfd);
	}//for
	return 0;
}