/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include 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 ; } }