/*
* bbftpd/bbftpd_check.c
* Copyright (C) 1999, 2000, 2001, 2002 IN2P3, CNRS
* bbftp@in2p3.fr
* http://doc.in2p3.fr/bbftp
*
* 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 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/****************************************************************************
Routines : void checkfromwhere()
int checkprotocol()
bbftpd_check.c v 2.0.0 2000/12/18 - Creation of the routine.
v 2.0.1 2001/04/23 - Correct indentation
v 2.1.0 2001/06/01 - Change file name
- Reorganise routines as in bbftp_
*****************************************************************************/
#include <errno.h>
#include <netinet/in.h>
#include <syslog.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <unistd.h>
#include <utime.h>
#include <bbftpd.h>
#include <common.h>
#include <daemon.h>
#include <daemon_proto.h>
#include <structures.h>
#include <version.h>
extern struct sockaddr_in his_addr;
extern struct sockaddr_in ctrl_addr;
extern int incontrolsock ;
extern int outcontrolsock ;
extern int recvcontrolto ;
extern int sendcontrolto ;
extern int checkstdinto ;
extern int protocolversion ;
extern int protocolmin ;
extern int protocolmax ;
extern int newcontrolport ;
extern int fixeddataport;
extern char currentusername[MAXLEN] ;
/*******************************************************************************
** checkfromwhere : *
** *
** This routine get a socket on a port, send a MSG_LOGGED_STDIN and *
** wait for a connection on that port. *
** *
** RETURN: *
** No return but the routine exit in case of error. *
*******************************************************************************/
void checkfromwhere()
{
int sock,ns,addrlen,retcode,nfds ;
struct sockaddr_in server ;
char buffer[MINMESSLEN] ;
struct message *msg ;
struct timeval wait_timer;
fd_set selectmask ;
struct linger li ;
int on = 1 ;
sock = socket ( AF_INET, SOCK_STREAM, IPPROTO_TCP ) ;
if ( sock < 0 ) {
syslog(BBFTPD_ERR, "Cannot create checkreceive socket : %s",strerror(errno));
reply(MSG_BAD,"Cannot create checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
exit(1) ;
}
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
if ( fixeddataport == 1 ) {
server.sin_port = htons(newcontrolport+1) ;
} else {
server.sin_port = 0 ;
}
if ( setsockopt(sock,SOL_SOCKET, SO_REUSEADDR,(char *)&on,sizeof(on)) < 0 ) {
syslog(BBFTPD_ERR,"Cannot set SO_REUSEADDR on checkreceive socket : %s\n",strerror(errno)) ;
reply(MSG_BAD,"Cannot set SO_REUSEADDR on checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
li.l_onoff = 1 ;
li.l_linger = 1 ;
if ( setsockopt(sock,SOL_SOCKET,SO_LINGER,(char *)&li,sizeof(li)) < 0 ) {
syslog(BBFTPD_ERR,"Cannot set SO_LINGER on checkreceive socket : %s\n",strerror(errno)) ;
reply(MSG_BAD,"Cannot set SO_LINGER on checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
if ( bind (sock,(struct sockaddr *) &server, sizeof(server) ) < 0 ) {
syslog(BBFTPD_ERR,"Error binding checkreceive socket : %s",strerror(errno)) ;
reply(MSG_BAD,"Cannot binding checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
addrlen = sizeof(server) ;
if (getsockname(sock,(struct sockaddr *)&server, &addrlen) < 0) {
syslog(BBFTPD_ERR,"Error getsockname checkreceive socket : %s",strerror(errno)) ;
reply(MSG_BAD,"Cannot getsockname checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
if ( listen(sock,1) < 0 ) {
syslog(BBFTPD_ERR,"Error listening checkreceive socket : %s",strerror(errno)) ;
reply(MSG_BAD,"Error listening checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
syslog(BBFTPD_INFO, "listen port : %d",ntohs(server.sin_port));
/*
** Send the MSG_LOGGED_STDIN message
*/
msg = (struct message *)buffer ;
msg->code = MSG_LOGGED_STDIN ;
#ifndef WORDS_BIGENDIAN
msg->msglen = ntohl(4) ;
#else
msg->msglen = 4 ;
#endif
if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error writing checkreceive socket part 1") ;
reply(MSG_BAD,"Error writing checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
/*
** Send the port number
*/
#ifndef WORDS_BIGENDIAN
msg->code = ntohl(ntohs(server.sin_port)) ;
#else
msg->code = server.sin_port ;
#endif
if ( writemessage(outcontrolsock,buffer,4,sendcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error writing checkreceive socket part 2") ;
reply(MSG_BAD,"Error writing checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
exit(1) ;
}
/*
** Now wait on the socket for a connection
*/
nfds = sysconf(_SC_OPEN_MAX) ;
FD_ZERO(&selectmask) ;
FD_SET(sock,&selectmask) ;
/*
** Set the timer for the connection
*/
wait_timer.tv_sec = checkstdinto ;
wait_timer.tv_usec = 0 ;
retcode = select(nfds,&selectmask,0,0,&wait_timer) ;
if ( retcode < 0 ) {
syslog(BBFTPD_ERR,"Error select checkreceive socket : %s ",strerror(errno)) ;
reply(MSG_BAD,"Error select checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
if ( retcode == 0 ) {
/*
** Time out
*/
syslog(BBFTPD_ERR,"Time out select checkreceive socket ") ;
reply(MSG_BAD,"Time Out select checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
if ( (ns = accept(sock,0,0) ) < 0 ) {
syslog(BBFTPD_ERR,"Error accept checkreceive socket ") ;
reply(MSG_BAD,"Error accep checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(sock) ;
exit(1) ;
}
close(sock) ;
addrlen = sizeof(his_addr);
if (getpeername(ns, (struct sockaddr *) &his_addr, &addrlen) < 0) {
syslog(BBFTPD_ERR, "getpeername : %s",strerror(errno));
reply(MSG_BAD,"getpeername error") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(ns) ;
exit(1);
}
addrlen = sizeof(ctrl_addr);
if (getsockname(ns, (struct sockaddr *) &ctrl_addr, &addrlen) < 0) {
syslog(BBFTPD_ERR, "getsockname : %s",strerror(errno));
reply(MSG_BAD,"getsockname error") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(ns) ;
exit(1);
}
/*
** Now read the message
*/
if ( readmessage(ns,buffer,MINMESSLEN,recvcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error reading checkreceive socket") ;
reply(MSG_BAD,"Error reading checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(ns) ;
exit(1) ;
}
if (msg->code != MSG_IPADDR ) {
syslog(BBFTPD_ERR,"Receive unkown message on checkreceive socket") ;
reply(MSG_BAD,"Receive unkown message on checkreceive socket") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(ns) ;
exit(1);
}
/*
** Everything seems OK so send a MSG_IPADDR_OK on the
** control socket and close the connection
*/
msg->code = MSG_IPADDR_OK ;
msg->msglen = 0 ;
if ( writemessage(ns,buffer,MINMESSLEN,sendcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error writing checkreceive socket OK message") ;
reply(MSG_BAD,"Error writing checkreceive socket OK message") ;
syslog(BBFTPD_INFO,"User %s disconnected",currentusername) ;
close(ns) ;
exit(1) ;
}
/*
** set the port of ctrl_addr structure to the control port
*/
ctrl_addr.sin_port = htons(newcontrolport) ;
/*
** Wait a while before closing
*/
close(ns) ;
}
/*******************************************************************************
** checkprotocol : *
** *
** This routine send it protocol version and wait for the client prorocol *
** version. *
** *
** RETURN: *
** 0 OK *
** -1 calling program exit *
*******************************************************************************/
int checkprotocol()
{
char buffer[MINMESSLEN] ;
struct message *msg ;
int msglen ;
msg = ( struct message * ) buffer ;
msg->code = MSG_PROT_ANS ;
#ifndef WORDS_BIGENDIAN
msg->msglen = ntohl(MINMESSLEN) ;
#else
msg->msglen = MINMESSLEN ;
#endif
if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error writing MSG_PROT_ANS part 1") ;
return -1 ;
}
/*
** Send the min and max protocol version
*/
#ifndef WORDS_BIGENDIAN
msg->code = ntohl(protocolmin) ;
msg->msglen = ntohl(protocolmax) ;
#else
msg->code = protocolmin ;
msg->msglen = protocolmax ;
#endif
if ( writemessage(outcontrolsock,buffer,MINMESSLEN,sendcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error writing MSG_PROT_ANS part 2") ;
return -1 ;
}
/*
** And wait for the answer
*/
if ( readmessage(incontrolsock,buffer,MINMESSLEN,recvcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error waiting MSG_PROT_ANS") ;
return -1 ;
}
if ( msg->code == MSG_PROT_ANS ) {
#ifndef WORDS_BIGENDIAN
msglen = ntohl(msg->msglen) ;
#else
msglen = msg->msglen ;
#endif
if ( msglen == 4 ) {
if ( readmessage(incontrolsock,buffer,4,recvcontrolto) < 0 ) {
syslog(BBFTPD_ERR,"Error waiting MSG_PROT_ANS (protocol version)") ;
return -1 ;
}
#ifndef WORDS_BIGENDIAN
msglen = ntohl(msg->code) ;
#else
msglen = msg->code ;
#endif
protocolversion = msglen ;
return 0 ;
} else {
syslog(BBFTPD_ERR,"Unexpected length while MSG_PROT_ANS %d",msglen) ;
return -1 ;
}
} else if ( msg->code == MSG_BAD_NO_RETRY ) {
syslog(BBFTPD_ERR,"Incompatible server and client") ;
return -1 ;
} else {
syslog(BBFTPD_ERR,"Unexpected message while MSG_PROT_ANS %d",msg->code) ;
return -1 ;
}
}
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