一个简单的FTP客户端

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <sys/types.h> #include <sys/socket.h> #include <netdb.h> #include <netinet/in.h> #include <arpa/inet.h> #include <ctype.h> #include <unistd.h> #include <errno.h> #include <dirent.h> #include <curses.h> #include <termios.h> #include <sys/stat.h> #include <fcntl.h> #include <time.h> #define DEFAULT_FTP_PORT 21 extern int h_errno; char user[64]; //ftp usr char passwd[64]; //ftp passwd //ftp server address struct sockaddr_in ftp_server, local_host; struct hostent * server_hostent; int sock_control; int mode = 1; //ftp mode, 0 is PORT, 1 is PASV; //echo_off and echo_on for get usr password from stdin static struct termios stored_settings; void echo_off(void) { struct termios new_settings; tcgetattr(0,&stored_settings); new_settings = stored_settings; new_settings.c_lflag &= (~ECHO); tcsetattr(0,TCSANOW,&new_settings); return; } void echo_on(void) { tcsetattr(0,TCSANOW,&stored_settings); return; } void cmd_err_exit(char * err_msg, int err_code) { printf("%s\n", err_msg); exit(err_code); } int fill_host_addr(char * host_ip_addr, struct sockaddr_in * host, int port) { if(port <= 0 || port > 65535) return 254; bzero(host, sizeof(struct sockaddr_in)); host->sin_family = AF_INET; 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; } host->sin_port = htons(port); 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); //set outtime for the control socket 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) { printf("set socket %s errno:%d\n",strerror(errno),errno); cmd_err_exit("set socket", 1); } //connect to the server if (connect(s,(struct sockaddr *)s_addr,sizeof(struct sockaddr_in)) < 0) { printf("Can't connect to server %s, port %d\n",\ inet_ntoa(s_addr->sin_addr),ntohs(ftp_server.sin_port)); exit(252); } 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"); len = strlen(send_buf); send_err = send(sock_fd, send_buf, len, 0); } else { strcat(send_buf,"\r\n"); len = strlen(send_buf); send_err = send(sock_fd, send_buf, len, 0); } } if(send_err < 0) printf("send() error!\n"); return send_err; } //get the server's reply message from sock_fd int ftp_get_reply(int sock_fd) { static int reply_code = 0,count=0; char rcv_buf[512]; count=read(sock_fd, rcv_buf, 510); if(count > 0) reply_code = atoi(rcv_buf); else return 0; while(1) { if(count <= 0) break; rcv_buf[count]='\0'; printf("%s",rcv_buf); count=read(sock_fd, rcv_buf, 510); } return reply_code; } int get_port() { char port_respond[512]; char *buf_ptr; int count,port_num; ftp_send_cmd("PASV",NULL,sock_control); count = read(sock_control, port_respond, 510); if(count <= 0) return 0; port_respond[count]='\0'; if(atoi(port_respond) == 227) { //get low byte of the port buf_ptr = strrchr(port_respond, ','); port_num = atoi(buf_ptr + 1); *buf_ptr = '\0'; //get high byte of the port buf_ptr = strrchr(port_respond, ','); port_num += atoi(buf_ptr + 1) * 256; return port_num; } return 0; } int rand_local_port() { int local_port; srand((unsigned)time(NULL)); local_port = rand() % 40000 + 1025; return local_port; } //connect data stream 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; } } } //deal with the "list" command void ftp_list() { int i = 0,new_sock; int set = sizeof(local_host); int list_sock_data = xconnect_ftpdata(); if(list_sock_data < 0) { ftp_get_reply(sock_control); printf("creat data sock error!\n"); return; } ftp_get_reply(sock_control); ftp_send_cmd("LIST", NULL, sock_control); ftp_get_reply(sock_control); if(mode) ftp_get_reply(list_sock_data); else { while(i < 3) { new_sock = accept(list_sock_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. There is something wrong when the server connect to you.\n"); return; } ftp_get_reply(new_sock); close(new_sock); } close(list_sock_data); ftp_get_reply(sock_control); } //get filename(s) from user's command void ftp_cmd_filename(char * usr_cmd, char * src_file, char * dst_file) { int length, flag = 0; int i = 0, j = 0; char * cmd_src; cmd_src = strchr(usr_cmd, ' '); if(cmd_src == NULL) { printf("command error!\n"); return; } else {