client.c~

linux下RFC 959 FTP客户端程序

#include<stdio.h>
#include<sys/socket.h>
#include<sys/types.h>
#include<sys/fcntl.h>
#include<stdlib.h>
#include<string.h>
#include<netdb.h>
#include<errno.h>
#include<arpa/inet.h>
#include<sys/stat.h>
#include<unistd.h> //to use read and write
#include<termios.h>
#include"echo.h"
#define DEFAULT_PORT 21
char user[64];
char password[40];
struct sockaddr_in ftp_server,local_host;
struct hostent * server_hostent;
int sock_control;
int mode=1;//1--PASV 0--PORT

//static struct termios stored_settings;

void cmd_err_exit(char* error_message,int error_code)
{
	printf("%s error code: %d\n",error_message,error_code);
	exit(error_code);
}

int fill_host_addr(char *host_ip_addr,struct sockaddr_in *host,int port)
{
	if(port<=0||port>=(1<<16))
		return 254;
	bzero(host,sizeof(struct sockaddr_in));//填充为0
	host->sin_family=AF_INET;
	host->sin_port=htons(port);
	if(inet_addr(host_ip_addr)!=-1)
		host->sin_addr.s_addr=inet_addr(host_ip_addr);
	else
	{
		if((server_hostent=gethostbyname(host_ip_addr))!=0)
		{
			memcpy(&host->sin_addr,server_hostent->h_addr,sizeof(host->sin_addr));
		}
		else
			return 253;
	}
	return 1;
}

int xconnect(struct sockaddr_in *s_addr,int type)
{
	struct timeval outtime;
	int set;
	int s=socket(AF_INET,SOCK_STREAM,0);
	if(s<0)
		cmd_err_exit("Creat socket error",249);
	if(type==1)
	{
		outtime.tv_sec=0;
		outtime.tv_usec=300000;
	}
	else
	{
		outtime.tv_sec=5;
		outtime.tv_usec=0;
	}
	set=setsockopt(s,SOL_SOCKET,SO_RCVTIMEO,&outtime,sizeof(outtime));
	if(set!=0)
		cmd_err_exit("set socket error",1);
	//connect to the server 
	if(connect(s,(struct sockaddr *)s_addr,sizeof(struct sockaddr_in))<0)
	{
		printf("Can't connet to the server:%s,port:%d\n",inet_ntoa(s_addr->sin_addr),ntohs(ftp_server.sin_port));
		exit(252);
	}
	else
		printf("Successfully connect to server:%s,port:%d\n",inet_ntoa(s_addr->sin_addr),ntohs(ftp_server.sin_port));
	return s;

}

//send command to server with sock_fd
int ftp_send_cmd(const char* s1,const char* s2,int sock_fd)
{
	char send_buf[256];
	int send_err,len;
	if(s1)
	{
		strcpy(send_buf,s1);
		if(s2)
		{
			strcat(send_buf,s2);
			strcat(send_buf,"\r\n");
		}
		else
			strcat(send_buf,"\r\n");

			len=strlen(send_buf);
			send_err=send(sock_fd,send_buf,len,0);
	}

			//在socket上发送数据
		//函数返回实际发送/接收的字节数,返回-1 表示出错,需要关闭此连接。
		//函数缺省是阻塞函数,直到发送/接收完毕或出错
		//注意:如果 send 函数返回值与参数 len 不相等,则剩余的未发送信息需要再次发送
		if(send_err<0)
			printf("send error\n");
		return send_err;
}

//get the server's reply message for sock_fd
int ftp_get_reply(int sock_fd)
{
	static int reply_code=0,count=0;
	char rcv_buff[512];
	count=read(sock_fd,rcv_buff,510);
	if(count>0)
		reply_code=atoi(rcv_buff);
	else
		return 0;
	while(1)
	{
		if (count<=0)
			break;
		rcv_buff[count]='\0';
		printf("%s",rcv_buff);
		count=read(sock_fd,rcv_buff,510);
	}
	return reply_code;
}

int get_port()
{
	char port_respond[512];
	char *temp;
	int count,port_num;
	ftp_send_cmd("PASV",NULL,sock_control);//进入被动模式
	count=read(sock_control,port_respond,510);
	if(count<=0)
		return 0;
	port_respond[count]='\0';
	if(atoi(port_respond)==227)//确定进入被动模式
	{
		temp=strrchr(port_respond,',');//在串中指定字符的最后一个出现位置以找出n6
		port_num=atoi(temp+1);
		*temp='\0';                   //截断n6来取n5;
		temp=strrchr(port_respond,',');
		port_num+=atoi(temp+1)*256;
		return port_num;
	}
	return 0;
}

int rand_local_port()
{
	int port;
	srand((unsigned)time(NULL));
	port = rand() % 40000 + 1025;
	return port;
}
int xconnect_ftpdata()
{
	if(mode)
	{
		int data_port = get_port();
		if(data_port != 0)
			ftp_server.sin_port=htons(data_port);
		return(xconnect(&ftp_server, 0));
	}
	else
	{
		int client_port, get_sock, opt, set;
		char cmd_buf[32];
		struct timeval outtime;
		struct sockaddr_in local;
		char local_ip[24];
		char *ip_1, *ip_2, *ip_3, *ip_4;
		int addr_len =  sizeof(struct sockaddr);
		client_port = rand_local_port();
		get_sock = socket(AF_INET, SOCK_STREAM, 0);
		if(get_sock < 0)
		{
			cmd_err_exit("socket()", 1);
		}

		//set outtime for the data socket
		outtime.tv_sec = 7;
		outtime.tv_usec = 0;
		opt = SO_REUSEADDR;
		set = setsockopt(get_sock, SOL_SOCKET,SO_RCVTIMEO, \
				&outtime,sizeof(outtime));
		if(set !=0)
		{
			printf("set socket %s errno:%d\n",strerror(errno),errno);
			cmd_err_exit("set socket", 1);
		}
		set = setsockopt(get_sock, SOL_SOCKET,SO_REUSEADDR, \
				&opt,sizeof(opt));
		if(set !=0)
		{
			printf("set socket %s errno:%d\n",strerror(errno),errno);
			cmd_err_exit("set socket", 1);
		}

		bzero(&local_host,sizeof(local_host));
		local_host.sin_family = AF_INET;
		local_host.sin_port = htons(client_port);
		local_host.sin_addr.s_addr = htonl(INADDR_ANY);
		bzero(&local, sizeof(struct sockaddr));
		while(1)
		{
			set = bind(get_sock, (struct sockaddr *)&local_host, \
					sizeof(local_host));
			if(set != 0 && errno == 11)
			{
				client_port = rand_local_port();
				continue;
			}
			set = listen(get_sock, 1);
			if(set != 0 && errno == 11)
			{
				cmd_err_exit("listen()", 1);
			}
			//get local host's ip
			if(getsockname(sock_control,(struct sockaddr*)&local,\
                               (socklen_t *)&addr_len) < 0)
				return -1;
			snprintf(local_ip, sizeof(local_ip), inet_ntoa(local.sin_addr));
			//change the format to the PORT command needs.
			local_ip[strlen(local_ip)]='\0';
			ip_1 = local_ip;
			ip_2 = strchr(local_ip, '.');
			*ip_2 = '\0';
			ip_2++;
			ip_3 = strchr(ip_2, '.');
			*ip_3 = '\0';
			ip_3++;
			ip_4 = strchr(ip_3, '.');
			*ip_4 = '\0';
			ip_4++;
			snprintf(cmd_buf, sizeof(cmd_buf), "PORT %s,%s,%s,%s,%d,%d", \
			ip_1, ip_2, ip_3, ip_4,	client_port >> 8, client_port&0xff);
			ftp_send_cmd(cmd_buf, NULL, sock_control);
			if(ftp_get_reply(sock_control) != 200)
			{
				printf("Can not use PORT mode!Please use \"mode\" change to PASV mode.\n");
				return -1;
			}
			else
				return get_sock;
		}
	}
}

void get_user()
{
	char buf[64];
	printf("User:(Press Enter for anonymous):");
	fgets(buf,sizeof(buf),stdin);
	if(buf[0]=='\n')
		strncpy(user,"anonymous",9);
	else
		strncpy(user,buf,strlen(buf)-1);
	printf("int get_user();user:%s\n",user);
}
void get_pass()
{
	char buf[40];
	printf("Password:(Press Enter for anonymous):");
	echo_off();
	fgets(buf,sizeof(buf),stdin);
	if(buf[0]=='\n')
		strncpy(password,"anonymous",9);
	else
		strncpy(password,buf,strlen(buf)-1);
	echo_on();
	printf("\n");
}

int ftp_login()
{
	int err;
	get_user();
	if(ftp_send_cmd("USER ", user, sock_control) < 0)
		cmd_err_exit("Can not send message",1);;
	err = ftp_get_reply(sock_control);
	if(err == 331)
	{
		get_pass();
//		printf("Ppppppppppppppp%s\n",password);
		if(ftp_send_cmd("PASS ", password, sock_control) <= 0)
			cmd_err_exit("Can not send message",1);
		else
			err = ftp_get_reply(sock_control);
		if(err != 230)
		{
			printf("Password error!\n");
			return 0;
		}
		return 1;
	}
	else
	{
		printf("User error!\n");
		return 0;
	}

}
void ftp_bye()
{
	ftp_send_cmd("QUIT",NULL,sock_control);
	ftp_get_reply(sock_control);
	close(sock_control);
}
int ftp_usr_cmd(char * cmd)
{
	if(strncmp(cmd,"ls",2)==0)
		return 1;
	if(strncmp(cmd,"pwd",3)==0)
		return 2;
	if(strncmp(cmd,"cd",2)==0)
		return 3;
	if(strncmp(cmd,"put",3)==0)
		return 4;
	if(strncmp(cmd,"get",3)==0)
		return 5;
	if(strncmp(cmd,"bye",3)==0)
		return 6;
	if(strncmp(cmd,"mode",4)==0)
		return 7;
	if(strncmp(cmd,"llist",5)==0)
		return 11;
	if(strncmp(cmd,"!",1)==0)
		return 8;
	if(strncmp(cmd,"lpwd",4)==0)
		return 12;
	if(strncmp(cmd,"lcd",3)==0)
		return 13;
	else
		return -1;
}
void ftp_list()
{
	int i=0,new_sock;
	int set=sizeof(local_host);
	int list_socket_data=xconnect_ftpdata();
	if(list_socket_data<0)
	{
		ftp_get_reply(sock_control);
		puts("creat data sock error int ftp_list()");
		return;
	}
		ftp_get_reply(sock_control);
		ftp_send_cmd("LIST",NULL,sock_control);
		ftp_get_reply(sock_control);
		if(mode==1)//被动模式
			ftp_get_reply(list_socket_data);
		else
		{
			while(i<3)
			{
				new_sock=accept(list_socket_data,(struct sockaddr*)&local_host,(socklen_t *)&set);
				if(new_sock==-1)
				{
					printf("accept return:%s errno: %d\n",strerror(errno),errno);
					i++;
					continue;
				}
				else break;
			}
			if(new_sock==-1)
			{
				printf("Sorry you can't use PORT mode..Wrong\n");
				return;
			}
			ftp_get_reply(new_sock);
			close(new_sock);
		}
		close(list_socket_data);
		ftp_get_reply(sock_control);
}
void ftp_pwd()
{
	ftp_send_cmd("PWD",NULL,sock_control);
	ftp_get_reply(sock_control);
}
void local_pwd()
{
	char temp[512];
	int size=sizeof(temp);
	if(getcwd(temp,size)!=NULL)
		printf("%s\n",temp);
	else
		printf("Can't get local dir\n");
}
void local_cd(char *usr_cmd)
{
	char *cmd =strchr(usr_cmd,' ');
	char dir[1024];
	while(*cmd==' ')
		cmd++;
	if(cmd==NULL||*cmd=='\0')
	{
		printf("Command error\n");
	}
	else
	{
		strncpy(dir,cmd,strlen(cmd));