ftpserver.c

来自「linux下编程实现的基本FTP」· C语言 代码 · 共 480 行

#include <pthread.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>
#include <string.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include "ftp.h"

#define FTP_SERVER_PORT 21
#define MAX_INFO 1024
#define DIR_INFO 100
#define MSG_INFO 100

#define LISTEN_QENU 5

const char	default_user[] = "cs36";
const char	default_pass[] = "cs36";

int  ftp_server_sock;
int  ftp_data_sock;
char client_Control_Info[MAX_INFO];
char client_Data_Info[MAX_INFO];

char format_client_Info[MAX_INFO];


int translate_data_mode=FILE_TRANS_MODE_ASIC;


void *Handle_Client_Request(void* arg);
struct ARG{
	int client_sock;
	struct sockaddr_in client;	
};

void do_client_work(int client_sock,struct sockaddr_in client);
int login(int client_sock);
void handle_cwd(int client_sock);
void handle_list(int client_sock);
void handle_pasv(int client_sock,struct sockaddr_in client);
void handle_file(int client_sock);

struct sockaddr_in create_date_sock();
void send_client_info(int client_sock,char* info,int length);
int recv_client_info(int client_sock);


int main(int argc,char *argv[])
{
	//pid_t 	child_pid;
	pthread_t thread;
	struct ARG arg;
	struct sockaddr_in server;
	
	if((ftp_server_sock=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("Createing socket failed");
		exit(1);
	}
	
	int opt=SO_REUSEADDR;
	setsockopt(ftp_server_sock,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt));
	
	bzero(&server,sizeof(server));
	server.sin_family=AF_INET;
	server.sin_port=htons(FTP_SERVER_PORT);
	server.sin_addr.s_addr=htonl(INADDR_ANY);
	if(bind(ftp_server_sock,(struct sockaddr *)&server,sizeof(struct sockaddr))==-1)
	{
		perror("Bind error");
		exit(1);
	}
	
	if(listen(ftp_server_sock,LISTEN_QENU)==-1)
	{
		perror("listen error");
		exit(1);
	}
	
	int ftp_client_sock;
	struct sockaddr_in client;
	int sin_size=sizeof(struct sockaddr_in);
	while(1)
	{
		if((ftp_client_sock=accept(ftp_server_sock,(struct sockaddr *)&client,&sin_size))==-1)
		{
			perror("accept error");
			exit(1);
		}
		
		arg.client_sock=ftp_client_sock;
		memcpy((void*)&arg.client,&client,sizeof(client));

		if(pthread_create(&thread,NULL,Handle_Client_Request,(void*)&arg))
		{
			perror("thread create error ");
			exit(1);
		}
	}
	close(ftp_server_sock);
}


void *Handle_Client_Request(void* arg)
{
	struct ARG*info;
	info=(struct ARG*)arg;
	printf("Yor got a connection from %s\n",inet_ntoa(info->client.sin_addr));
	
	do_client_work(info->client_sock,info->client);
	
	close(info->client_sock);
	pthread_exit(NULL);
}

void do_client_work(int client_sock,struct sockaddr_in client)
{
	int login_flag;
	login_flag=login(client_sock);
	while(recv_client_info(client_sock)&&login_flag==1)
	{
		if((strncmp("quit", client_Control_Info, 4) == 0)||(strncmp("QUIT", client_Control_Info, 4) == 0))
		{	
				send_client_info(client_sock, serverInfo221, strlen(serverInfo221));
				break;
		}
		else if(strncmp("pwd", client_Control_Info, 3) == 0||(strncmp("PWD", client_Control_Info, 3) == 0))
		{	
				char 	pwd_info[MSG_INFO];
   			char 	tmp_dir[DIR_INFO];
    			snprintf(pwd_info, MSG_INFO, "257 \"%s\" is current location.\r\n", getcwd(tmp_dir, DIR_INFO));
				send_client_info(client_sock, pwd_info, strlen(pwd_info));
		}
		else if(strncmp("cwd", client_Control_Info, 3) == 0||(strncmp("CWD", client_Control_Info, 3) == 0))
		{
				handle_cwd(client_sock);
		}
		else if(strncmp("pasv", client_Control_Info, 4) == 0||(strncmp("PASV", client_Control_Info, 4) == 0))
		{
			   handle_pasv(client_sock,client);
		}
		else if(strncmp("list", client_Control_Info, 4) == 0||(strncmp("LIST", client_Control_Info, 4) == 0))
		{
			   handle_list(client_sock);
			   send_client_info(client_sock,serverInfo226, strlen(serverInfo226));	
		}
		else if(strncmp("type", client_Control_Info, 4) == 0||(strncmp("TYPE", client_Control_Info, 4) == 0))
		{
				if(strncmp("type I", client_Control_Info, 6) == 0||(strncmp("TYPE I", client_Control_Info, 6) == 0))
			  			translate_data_mode=FILE_TRANS_MODE_BIN;
			  	send_client_info(client_sock, serverInfo200, strlen(serverInfo200));
		}
		else if(strncmp("retr", client_Control_Info, 4) == 0||(strncmp("RETR", client_Control_Info, 4) == 0))
		{
				handle_file(client_sock);
				send_client_info(client_sock,serverInfo226, strlen(serverInfo226));	
		}
		else if(strncmp("stor", client_Control_Info, 4) == 0||(strncmp("STOR", client_Control_Info, 4) == 0))
		{
				handle_file(client_sock);
				send_client_info(client_sock,serverInfo226, strlen(serverInfo226));	
		}
		else if(strncmp("syst", client_Control_Info, 4) == 0||(strncmp("SYST", client_Control_Info, 4) == 0))
		{
				send_client_info(client_sock, serverInfo215, strlen(serverInfo215));
		}
		else if(strncmp("size", client_Control_Info, 4) == 0||(strncmp("SIZE", client_Control_Info, 4) == 0))
		{
				send_client_info(client_sock, serverInfo213, strlen(serverInfo213));
		}
		else if(strncmp("feat", client_Control_Info, 4) == 0||(strncmp("FEAT", client_Control_Info, 4) == 0))
		{
				send_client_info(client_sock, serverInfo211, strlen(serverInfo211));
		}
		else if(strncmp("rest", client_Control_Info, 4) == 0||(strncmp("REST", client_Control_Info, 4) == 0))
		{
				send_client_info(client_sock, serverInfo350, strlen(serverInfo350));
		}
		else 
		{
				send_client_info(client_sock, serverInfo, strlen(serverInfo));
		}
		
	}
}

int login(int client_sock)
{
//欢迎信息
	send_client_info(client_sock, serverInfo220, strlen(serverInfo220));
//得到用户名

	while(1)
	{
		if(recv_client_info(client_sock)==2)break;
		else	send_client_info(client_sock, serverInfo, strlen(serverInfo));

	}
	int flag=0;
	int i=0;
	int length=strlen(client_Control_Info);
	for(i=5;i<length;i++)
			format_client_Info[i-5]=client_Control_Info[i];
	format_client_Info[i-7]='\0';
	if(strncmp(format_client_Info, default_user, 4) != 0)
	{
		flag=1;
	}
   send_client_info(client_sock, serverInfo331, strlen(serverInfo331));
	recv_client_info(client_sock);
	
	length=strlen(client_Control_Info);
	for(i=5;i<length;i++)
			format_client_Info[i-5]=client_Control_Info[i];
	format_client_Info[i-7]='\0';
	if(strncmp(format_client_Info, default_pass, 4) == 0&&flag==0)
   	{
   	send_client_info(client_sock, serverInfo230, strlen(serverInfo230));
   	return 1;
   	}
   else
  	{ 
  		send_client_info(client_sock, serverInfo530, strlen(serverInfo530));
  		return 0;
  	}
}

void handle_cwd(int client_sock)
{
		char 	cwd_info[MSG_INFO];
   	char 	tmp_dir[DIR_INFO];
   	char 	client_dir[DIR_INFO];
   	
   	char t_dir[DIR_INFO];
   	int dirlength=-1;
   	int length=strlen(client_Control_Info);
     	int i=0; 	
   	for(i=4;i<length;i++)
			format_client_Info[i-4]=client_Control_Info[i];
		format_client_Info[i-6]='\0';
  
		if(strncmp(getcwd(t_dir, DIR_INFO),format_client_Info,strlen(getcwd(t_dir, DIR_INFO))-10)!=0)
		{
   		getcwd(client_dir, DIR_INFO);
   		dirlength=strlen(client_dir);
   		client_dir[dirlength]='/';
		}


   	for(i=4;i<length;i++)
   		{
   			client_dir[dirlength+i-3]=client_Control_Info[i];
   		}
		client_dir[dirlength+i-5]='\0';
		
		// printf("%s\r\n",client_dir);
		//printf("%s\r\n",client_Control_Info);	
		//printf("%s\r\n",getcwd(t_dir, DIR_INFO));	
		
   	if (chdir(client_dir) >= 0)
    		{
    		snprintf(cwd_info, MSG_INFO, "257 \"%s\" is current location.\r\n", getcwd(tmp_dir, DIR_INFO));
    		send_client_info(client_sock, cwd_info, strlen(cwd_info));
    		}
  		else
    		{
 			snprintf(cwd_info, MSG_INFO, "550 %s :%s\r\n",client_dir,strerror(errno));
  			perror("chdir():");
  			send_client_info(client_sock, cwd_info, strlen(cwd_info));
    		}    			
}
void handle_list(int client_sock)
{
   send_client_info(client_sock, serverInfo150, strlen(serverInfo150));
   
   int t_data_sock;
	struct sockaddr_in client;
	int sin_size=sizeof(struct sockaddr_in);
	if((t_data_sock=accept(ftp_data_sock,(struct sockaddr *)&client,&sin_size))==-1)
	{
		perror("accept error");
		return;
	}

	FILE *pipe_fp;
	char t_dir[DIR_INFO];
	char list_cmd_info[DIR_INFO];
	snprintf(list_cmd_info, DIR_INFO, "ls -l %s", getcwd(t_dir, DIR_INFO));
	
   if ((pipe_fp = popen(list_cmd_info, "r")) == NULL)
    	{
		printf("pipe open error in cmd_list\n");
		return ;
    	}
   printf("pipe open successfully!, cmd is %s\n", list_cmd_info);

	char t_char;
   while ((t_char = fgetc(pipe_fp)) != EOF)
    	{
		printf("%c", t_char);
		write(t_data_sock, &t_char, 1);
    	}
   pclose(pipe_fp);
   printf("close pipe successfully!\n");	
   close(t_data_sock);	
	printf("%s close data successfully!\n",serverInfo226);	
	close(ftp_data_sock);	
}

void handle_pasv(int client_sock,struct sockaddr_in client)
{

	char pasv_msg[MSG_INFO];
	char	port_str[8];
   char	addr_info_str[30];
	struct sockaddr_in user_data_addr;
	user_data_addr=create_date_sock();
	
	int		tmp_port1;
   int		tmp_port2;
   tmp_port1 = ntohs(user_data_addr.sin_port) / 256;
   tmp_port2 = ntohs(user_data_addr.sin_port) % 256;
   long ipNum=inet_addr(inet_ntoa(client.sin_addr));
   //printf("%s  %d\r\n",inet_ntoa(client.sin_addr),ipNum);
   																						
   snprintf(addr_info_str, sizeof(addr_info_str), "%ld,%ld,%ld,%ld,", ipNum&0xff,
   																					ipNum>>8&0xff,
   																					ipNum>>16&0xff,
																						ipNum>>24&0xff);
   snprintf(port_str, sizeof(port_str), "%d,%d", tmp_port1, tmp_port2);
   strcat(addr_info_str, port_str);
   snprintf(pasv_msg, MSG_INFO, "227 Entering Passive Mode (%s).\r\n", addr_info_str);
   send_client_info(client_sock, pasv_msg, strlen(pasv_msg));

}
struct sockaddr_in create_date_sock()
{

	int t_client_sock;
	struct sockaddr_in t_data_addr;
 	t_client_sock = socket(AF_INET, SOCK_STREAM, 0);
   if (t_client_sock < 0)
    	{
		printf("create data socket error!\n");
		return;
    	}
    srand((int)time(0));
    int a=rand()%1000+1025;
    bzero(&t_data_addr, sizeof(t_data_addr));
    t_data_addr.sin_family = AF_INET;
    t_data_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    t_data_addr.sin_port = htons(a);		//随机 
	
    if (bind(t_client_sock, (struct sockaddr*)&t_data_addr, sizeof(struct sockaddr)) < 0)
    	 {
			printf("bind error in create data socket:%s\n",strerror(errno));
			return;
    	  }
    listen(t_client_sock, LISTEN_QENU);
    
    ftp_data_sock=t_client_sock;
    return t_data_addr;
}
void handle_file(int client_sock)
{
	send_client_info(client_sock, serverInfo150, strlen(serverInfo150));
   
   int t_data_sock;
	struct sockaddr_in client;
	int sin_size=sizeof(struct sockaddr_in);
	if((t_data_sock=accept(ftp_data_sock,(struct sockaddr *)&client,&sin_size))==-1)
	{
		perror("accept error");
		return;
	}
	int i=0;
	int length=strlen(client_Control_Info);
	for(i=5;i<length;i++)
		format_client_Info[i-5]=client_Control_Info[i];
	format_client_Info[i-7]='\0';

	
	FILE* fp;
	int file_fd;
	int n;
	char t_dir[DIR_INFO];
	
	char file_info[DIR_INFO];
	
	snprintf(file_info, DIR_INFO, "%s/%s", getcwd(t_dir, DIR_INFO),format_client_Info);
	
	//printf("%s\r\n",file_info);
	//printf("%s\r\n",format_client_Info);	
	//printf("%s\r\n",getcwd(t_dir, DIR_INFO));	
	char file_mode[3];
	if(strncmp("retr", client_Control_Info, 4) == 0||(strncmp("RETR", client_Control_Info, 4) == 0))
   	{
   	file_mode[0]='r';
   	file_mode[1]='b';
   	file_mode[2]='\0';
   	}
   else
   	{
   	file_mode[0]='a';
   	file_mode[1]='b';
   	file_mode[2]='\0';
   	}
	if(strncmp(getcwd(t_dir, DIR_INFO),format_client_Info,strlen(getcwd(t_dir, DIR_INFO))-1)==0)
		fp = fopen(format_client_Info, file_mode);
	else
		fp = fopen(file_info, file_mode);
		
	if (fp == NULL)
	{
			printf("open file error:%s\r\n",strerror(errno));
			char 	cwd_info[MSG_INFO];
			snprintf(cwd_info, MSG_INFO, "550 %s :%s\r\n",format_client_Info,strerror(errno));
  			send_client_info(client_sock, cwd_info, strlen(cwd_info));
  			close(t_data_sock);
   		close(ftp_data_sock);	
			return;
	}
   int cmd_sock=fileno(fp);
   memset(client_Data_Info, 0, MAX_INFO);	
   if(strncmp("retr", client_Control_Info, 4) == 0||(strncmp("RETR", client_Control_Info, 4) == 0))
   	{
  		 while ((n = read(cmd_sock, client_Data_Info, MAX_INFO)) > 0)
		{
	    	if (write(t_data_sock, client_Data_Info, n) != n)
	    		{
				printf("retr transfer error\n");
				return;
	  		}
		}
	}
	else
	{
		while ((n = read(t_data_sock, client_Data_Info, MAX_INFO)) > 0)
		{
	    	if (write(cmd_sock, client_Data_Info, n) != n)
	    		{
				printf("stor transfer error\n");
				return;
	  		}
		}
	}
	fclose(fp);
   close(t_data_sock);
   close(ftp_data_sock);	
}

void send_client_info(int client_sock,char* info,int length)
{
   int len;
	if((len = send(client_sock, info, length,0))<0)
	{
			perror("send info error ");
			return;
	}	
}
int recv_client_info(int client_sock)
{
   int num;
	if((num=recv(client_sock,client_Control_Info,MAX_INFO,0))<0)
	{
			perror("receive info error ");
			return;
	}
	client_Control_Info[num]='\0';
	printf("Client %d Message:%s\n",pthread_self(),client_Control_Info);
	if(strncmp("USER", client_Control_Info, 4) == 0||strncmp("user", client_Control_Info, 4) == 0)return 2;
	return 1;
}