/*********************************************************************** *    ftp.c: for downloading via ftp (File Transfer Protocol) *********************************************************************** * Copyright (C) 2007 metro <me_t_ro@yahoo.com> * * This file is part of msdl, media stream downloader * * This is just an very simple ftp implementation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. * ***********************************************************************/ #include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <ctype.h>#include <time.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <netdb.h>#include <arpa/inet.h>#include "msdl.h"#include "msdllib.h"#include "display.h"#include "network.h"#include "ftp.h"static int is_lf_terminated_line(char *buf);static inline int is_ftp_OK(int code);static int ftp_recv_response(struct stream_t *stream,struct ftp_response_t *fres);static int ftp_recv_response_ignore_message(struct stream_t  *stream);static int ftp_send_command(struct stream_t *stream,char *msg);static int ftp_read_welcome(struct stream_t *stream);static int ftp_user(struct stream_t *stream,const char *username);static int ftp_pass(struct stream_t *stream,const char *password);static int ftp_epsv(struct stream_t *stream,const char *connect_host,int *newsock);static int ftp_pasv(struct stream_t *stream,int *newsock);static int ftp_passive_mode(struct stream_t *stream,			    const char *current_host,int *newsock);static int ftp_tell_port(struct stream_t *stream,int *newsock);static int ftp_bin_mode(struct stream_t *stream);static int ftp_ask_size(struct stream_t *stream,const char *filepath,uint64_t *size);static int ftp_retr(struct stream_t *stream,const char *filepath);static int ftp_interpret_byterange(const char *str,uint64_t *begin,uint64_t *end,				   char **reason_ret);static const char ftp_default_passwd[] = "hugahuga@huhun.com";struct ftp_ctrl_t *new_ftp_ctrl_t(void){    struct ftp_ctrl_t *fctrl = xmalloc(sizeof(struct ftp_ctrl_t));    memset(fctrl,0,sizeof(struct ftp_ctrl_t));    fctrl->mode = PASSIVE_FTP; /* defualt passive mode (this is easyer)*/    return fctrl;}void free_ftp_ctrl_t(struct ftp_ctrl_t *fctrl){    if(fctrl->command_sock > 0) close(fctrl->command_sock);    if(fctrl->data_wait_sock > 0) close(fctrl->data_wait_sock);    if(fctrl->data_sock > 0) close(fctrl->data_sock);        free(fctrl);}struct ftp_response_t *new_ftp_response_t(void){    struct ftp_response_t *fres = xmalloc(sizeof(struct ftp_response_t));    fres->num_lines = 0;    fres->lines = NULL;        return fres;}void free_ftp_response_t(struct ftp_response_t *fres){    if(fres->lines) free_list_h(fres->lines,*free);    free(fres);}static int is_lf_terminated_line(char *buf){    if(buf == NULL) return 0;        if(strchr(buf,'\n')) {	return 1;    }    return 0;}static int ftp_recv_response(struct stream_t *stream,struct ftp_response_t *fres){    size_t linebuflen = 0;    char *linebuffer = NULL;    int i;    int total = 0;    int status_code;    do {	linebuflen = 0;	linebuffer = NULL;	total = 0;	char *lineend;		do {	    linebuflen += BUFSIZE_1K;	    linebuffer = (char *)xrealloc(linebuffer,					  linebuflen + 1);		    /*	      set zero to realloc()ed region	      +1 for NULL char at the end of buffer.	    */	    memset(linebuffer + total,0,linebuflen + 1 - total);	    	    	    i = recv_data(stream,linebuffer + total,linebuflen - total);	    if(i <= 0) {		display(MSDL_ERR,"xrecv error: xrecv() returned %d\n",i);		goto failed;	    }	    total += i;	} while(!is_lf_terminated_line(linebuffer));		lineend = strchr(linebuffer,'\n');	lineend++;		stream_data_push_back(stream,lineend,total - (lineend - linebuffer));	memset(lineend,0,total - (lineend - linebuffer));	list_h_append(&fres->lines,linebuffer);		fres->num_lines++;		display(MSDL_DBG,"FTP RESPONSE line ==================\n"		"%s"		"==(%d bytes)\n",linebuffer,lineend - linebuffer);		status_code = (linebuffer[0] - '0') * 100 + 	    (linebuffer[1] - '0') * 10 + (linebuffer[2] - '0');	    } while(isdigit(linebuffer[0]) && isdigit(linebuffer[1]) &&	    isdigit(linebuffer[2]) && (linebuffer[3] == '-') );        return status_code;      failed:    if(linebuffer) free(linebuffer);    return 0;}/* * return 1 if ftp message is positive  *        0 if negative (not OK message) */static inline int is_ftp_OK(int code){    return ((100 <= code) && (code < 400)) ? 1 : 0;}/* *  get rtsp response but ignore its message *              return value:     status code */static int ftp_recv_response_ignore_message(struct stream_t  *stream){    struct ftp_response_t *ftp_response;    int status_code;    ftp_response = new_ftp_response_t();    status_code = ftp_recv_response(stream,ftp_response);    if(!is_ftp_OK(status_code) && ftp_response->lines) {	display(MSDL_ERR,"%s",ftp_response->lines->p);    }    free_ftp_response_t(ftp_response);        return status_code;}/* * send ftp command string. *              return value:     what xsend returned */static int ftp_send_command(struct stream_t *stream,char *msg){    int ret;        display(MSDL_DBG,"--------------------------\nsent: %s\n",msg);    ret = xsend(stream->stream_ctrl->ftp_ctrl->command_sock,msg,strlen(msg));    return ret;}/* * read first messgae from ftp server *              return value:     status code: normal case */static int ftp_read_welcome(struct stream_t *stream){    struct ftp_response_t *ftp_response;    int status_code;        ftp_response = new_ftp_response_t();    status_code = ftp_recv_response(stream,ftp_response);    if(ftp_response->lines) {	display(MSDL_VER,"%s\n",ftp_response->lines->p);    }    free_ftp_response_t(ftp_response);    return status_code;}/* * user name *              return value:     status code: normal case */static int ftp_user(struct stream_t *stream,const char *username){    char *sendbuffer = xmalloc(strlen(username) + 16);    int status_code;    snprintf(sendbuffer,BUFSIZE_1K,"USER %s\n",username);    ftp_send_command(stream,sendbuffer);    status_code = ftp_recv_response_ignore_message(stream);    free(sendbuffer);    return status_code;}/* * password verification *              return value:     status code: normal case */static int ftp_pass(struct stream_t *stream,const char *password){    struct ftp_response_t *ftp_response;    char *sendbuffer = xmalloc(strlen(password) + 16);    int status_code;    snprintf(sendbuffer,BUFSIZE_1K,"PASS %s\n",password);    ftp_send_command(stream,sendbuffer);        ftp_response = new_ftp_response_t();    status_code = ftp_recv_response(stream,ftp_response);    if(!is_ftp_OK(status_code) && ftp_response->lines) {	display(MSDL_ERR,"FTP login failed: %s\n",ftp_response->lines->p);    }    free_ftp_response_t(ftp_response);        free(sendbuffer);    return status_code;}/* * switch to extended passive mode. 'newsock' is new data_socket opened by * entering passive mode. needs current conneting host as argument *              return value:   status code */static int ftp_epsv(struct stream_t *stream,const char *connect_host,int *newsock){    struct stream_ctrl_t *stream_ctrl = stream->stream_ctrl;    struct ftp_response_t *ftp_response;    int status_code;    int data_sock = 0;    ftp_send_command(stream,"EPSV\n");    ftp_response = new_ftp_response_t();    status_code = ftp_recv_response(stream,ftp_response);    if(!is_ftp_OK(status_code)) {	/*ACTIVE mode*/	stream_ctrl->ftp_ctrl->mode = ACTIVE_FTP;	free_ftp_response_t(ftp_response);	*newsock = 0;	return status_code;    }    else {	/*	  rfc 2428	  <text indicating server is entering extended passive mode>	\	  (<d><d><d><tcp-port><d>)	*/	char *line = ftp_response->lines->p;	char *p;		p = strchr(line,')');	if(p) {	    int epsvport = 0;	    char delimiter;	    p--; /* backword skip ')' */	    while(*p == ' ') p--;	    delimiter = *p;	    p--; /* backword skip '|' */	    for(; (p >= line) && (*p != delimiter) ; p--);	    p++;	    for(; isdigit(*p) ; p++) {		epsvport *= 10;		epsvport += *p - '0';	    }	    	    data_sock = server_connect(connect_host,epsvport);	    free_ftp_response_t(ftp_response);	    *newsock = data_sock;	    return status_code;	}    }        free_ftp_response_t(ftp_response);    *newsock = data_sock;    return status_code;}/* * switch to passive mode. 'newsock' is new data_socket opened by * entering passive mode. *              return value:   status code */static int ftp_pasv(struct stream_t *stream,int *newsock){    struct stream_ctrl_t *stream_ctrl = stream->stream_ctrl;    struct ftp_response_t *ftp_response;    int data_sock = 0;    int status_code;        ftp_send_command(stream,"PASV\n");        ftp_response = new_ftp_response_t();    status_code = ftp_recv_response(stream,ftp_response);    if(!is_ftp_OK(status_code)) {	/*ACTIVE mode*/	stream_ctrl->ftp_ctrl->mode = ACTIVE_FTP;	free_ftp_response_t(ftp_response);	*newsock = 0;	return status_code;    }    else {	char connect_host[INET6_ADDRSTRLEN + 4];	/* PASSIVE mode */	int pasvport;	int i;	int value[6] = {0,0,0,0,0,0};	char *line = ftp_response->lines->p;	char *p;		p = strrchr(line,',');	if(p) {	    for( ; (p >= line) && (isdigit(*p) || *p == ',') ; p--);	    if(p <= line) {		free_ftp_response_t(ftp_response);		return 0;	    }	    p++;	    	    for(i = 0; i < 6 ; i++) {		value[i] = 0;		for(; p && *p && isdigit(*p) ; p++) {		    value[i] *= 10;		    value[i] += *p - '0';		}		value[i] &= 0xff;		if(!p || !(*p)) {		    break;		}		else {		    p++;		}	    }	    	    if(p && *p) {		snprintf(connect_host,sizeof(connect_host) - 1,		         "%d.%d.%d.%d",value[0],value[1],value[2],value[3]);		pasvport = (value[4] << 8) + value[5];		data_sock = server_connect(connect_host,pasvport);		free_ftp_response_t(ftp_response);		*newsock = data_sock;		return status_code;	    }	}    }        /*cannot get port number from recv reply*/    display(MSDL_ERR,"cannot get port number from recv reply\n");    stream_ctrl->ftp_ctrl->mode = ACTIVE_FTP;    free_ftp_response_t(ftp_response);    *newsock = 0;    return status_code;}/* * switch to passive mode. 'newsock' is new data_socket opened by * current_host is needed by ftp_epsv. *              return value:   status code */static int ftp_passive_mode(struct stream_t *stream,const char *current_host,int *newsock){    struct sockaddr_storage ss;    socklen_t sslen;    int command_sock = stream->stream_ctrl->ftp_ctrl->command_sock;        /* choose same protocol family as command_sock */    memset(&ss,0,sizeof(ss));    sslen = sizeof(ss);    if(getsockname(command_sock,(struct sockaddr *)&ss,&sslen) < 0) {	perror("getsockname() failed");	*newsock = 0;	return -1;    }        if(ss.ss_family == AF_INET) {       /* IPv4 */	/*return ftp_epsv(stream,current_host,newsock);*/	return ftp_pasv(stream,newsock);    }    else if(ss.ss_family == AF_INET6) { /* IPv6 */	if(!current_host) {	    return -1;	}	return ftp_epsv(stream,current_host,newsock);    }    else {	display(MSDL_ERR,"unknown protocol family %d\n",ss.ss_family);    }        return -1;}/* * tell waiting port to ftp server, only used in active mode. *             return value:     status code: normal case *                                        -1: internal error */static int ftp_tell_port(struct stream_t *stream,int *newsock){    struct stream_ctrl_t *stream_ctrl = stream->stream_ctrl;    int command_sock = stream_ctrl->ftp_ctrl->command_sock;    int data_wait_sock;    char sendbuffer[INET6_ADDRSTRLEN + 32];    struct sockaddr_storage ss;    socklen_t sslen;    int local_port;        /* get ip address of myself */    memset(&ss,0,sizeof(ss));    sslen = sizeof(ss);    if(getsockname(command_sock,(struct sockaddr *)&ss,&sslen) < 0) {	perror("getsockname() failed");	*newsock = 0;	return -1;    }       /* for random port number */    srand(time(NULL));    local_port = 49152 + (rand() % (65535 - 49152));        /* use same protocol family as command_socket */    data_wait_sock = waiting_socket(ss.ss_family,local_port);    if(data_wait_sock < 0) {	*newsock = 0;	return -1;    }            if(ss.ss_family == AF_INET) {	struct sockaddr_in *sinp;	uint32_t local_ipv4addr;	    	sinp = (struct sockaddr_in *)&ss;		local_ipv4addr = ntohl(sinp->sin_addr.s_addr);	snprintf(sendbuffer,sizeof(sendbuffer) - 1,"PORT %d,%d,%d,%d,%d,%d\n",		 (local_ipv4addr >> 24) & 0xff,		 (local_ipv4addr >> 16) & 0xff,		 (local_ipv4addr >>  8) & 0xff,		 (local_ipv4addr      ) & 0xff,		 (local_port >> 8) & 0xff,		 (local_port     ) & 0xff);		/*	  {	  char local_ipv4addrstr[INET6_ADDRSTRLEN + 5];	  inet_ntop(sinp->sin_family,&(sinp->sin_addr.s_addr),	  local_ipv4addrstr,INET6_ADDRSTRLEN + 4);	  snprintf(sendbuffer,sizeof(sendbuffer) - 1,	  "EPRT  |1|%s|%d|\r\n",local_ipv4addrstr,local_port);	  }	*/