#! /bin/sh
# source: ftp.sh
# Copyright Gerhard Rieger and contributors (see file CHANGES)
# Published under the GNU General Public License V.2, see file COPYING
# example how to write a shell script that communicates with stdio on the front
# end and with a socat address on the back end
# usage:
# ftp.sh [opts] server directory/ # show directory contents on stdout
# ftp.sh [opts] server file # print file contents to stdout
# opts:
# -socks socksserver # use given socks server, port 1080
# -proxy proxyserver # use given proxy server, port 8080
# # must be http proxy that accepts CONNECT
# # method to ports 21 and >=1024
# -user username # default: "ftp"
# -passwd password # default: "anonymous@domain.org"
# -t # shell script trace+debug
# -d # debug on control connection (use up to 4 times)
# -D # debug on data connection (use up to 4 times)
# -b # block size for data connection
# -v # verbose
# -l* # socat logging options
# example:
# ftp.sh -v -d -d -D -D -D -b 65536 -proxy proxy ftp.ftp.org /README >README
user="ftp"
passwd="anonymous@domain.org"
#method="socks4:socks" # socks4 is address spec, socks is socks server name
method=tcp
addropts=
# socat options
SO1=
SO2=
while :; do
case "$1" in
-socks|-socks4) shift;
case "$1" in
*:*) method="socks4:${1%%:*}"; addropts="socksport=${1#*:}" ;;
*) method="socks4:$1" ;;
esac ;;
-socks4a) shift;
case "$1" in
*:*) method="socks4a:${1%%:*}"; addropts="socksport=${1#*:}" ;;
*) method="socks4a:$1" ;;
esac ;;
-proxy) shift;
case "$1" in
*:*) method="proxy:${1%%:*}"; addropts="proxyport=${1#*:}" ;;
*) method="proxy:$1" ;;
esac ;;
-user) shift; user="$1" ;;
-passwd) shift; passwd="$1" ;;
-t) set -vx ;;
-d) SO1="$SO1 -d" ;;
-D) SO2="$SO2 -d" ;;
-b) SO2="$SO2 -b $2"; shift ;;
-v) SO1="$SO1 -v" ;;
-l*) SO1="$SO1 $1"; SO2="$SO2 $1" ;;
-*) echo "unknown option \"$1\"" >&2; exit 1;;
*) break ;;
esac
shift
done
export SO2
server="$1"
dir="$2"
echo "addr=$method:$server:21,$addropts"; exit
### this is the central part to establish communication with socat ###
### copy these lines to make new communication shell scripts
TMPDIR=$(if [ -x /bin/mktemp ]; then
/bin/mktemp -d /tmp/$USER/FTPSH.XXXXXX
else
(umask 077; d=/tmp/$USER/FTPSH.$$; mkdir $d; echo $d)
fi)
TO="$TMPDIR/to"; FROM="$TMPDIR/from"
socat $SO1 fifo:$TO,nonblock,ignoreeof!!fifo:$FROM $method:$server:21,$addropts &
S1=$!
while ! [ -p "$TO" -a -p "$FROM" ]; do sleep 1; done
exec 4>$TMPDIR/to 3<$TMPDIR/from
trap "S1=" 17
#trap "echo cleaning up...>&2; rm -r $TMPDIR; [ -n "$S1" ] && kill $S1" 0 3
trap "rm -r $TMPDIR" 0 3
### here the central part ends
# this function waits for a complete server message, checks if its status
# is in the permitted range (terminates session if not), and returns.
ftp_chat () {
local cmd="$1"
local errlevel="$2"; [ -z "$errlevel" ] && errlevel=300
if [ -n "$cmd" ]; then echo "$cmd" >&4; fi
while read status message <&3;
( case "$status" in [0-9][0-9][0-9]-*) exit 0;; [0-9][0-9][0-9]*) exit 1;; *) exit 1;; esac )
do :; done
#echo "got \"$status $message\"" >&2
if [ -z "$status" ]; then echo ftp data connection failed >&2; exit; fi
if [ "$status" -ge "$errlevel" ]; then
echo $message >&2
echo "QUIT" >&4; exit 1
fi
set +vx
}
# wait for server greeting
ftp_chat
ftp_chat "USER $user" 400
ftp_chat "PASS $passwd"
#ftp_chat "CWD $dir"
case "$dir" in
*/) ftp_chat "TYPE A" ;;
*) ftp_chat "TYPE I" ;;
esac
echo "PASV" >&4; read status message <&3
info=$(expr "$message" : '.*[^0-9]\([0-9]*,[0-9]*,[0-9]*,[0-9]*,[0-9]*,[0-9]*\).*')
echo $info |tr ',' ' ' |(read i1 i2 i3 i4 p1 p2
addr=$i1.$i2.$i3.$i4
port=$(echo "256*$p1+$p2" |bc)
#echo $addr:$port
trap : 20
# open data connection and transfer data
socat -u $SO2 $method:$server:$port,$addropts -
) &
S2=$!
case "$dir" in
*/) ftp_chat "NLST $dir" ;;
#*/) ftp_chat "LIST $dir" ;;
*) ftp_chat "RETR $dir" ;;
esac
case "$status" in
[45]*) kill $S2;;
esac
#echo "waiting for process $S2 to terminate" >&2
wait $S2
ftp_chat
ftp_chat "QUIT"
#echo "waiting for process $S1 to terminate" >&2
wait $S1
exit