socat/proxy.sh
2023-10-26 16:36:26 +02:00

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#! /usr/bin/env bash
# source: proxy.sh
# Copyright Gerhard Rieger and contributors (see file CHANGES)
# Published under the GNU General Public License V.2, see file COPYING
# perform primitive simulation of a proxy server.
# accepts and answers correct HTTP CONNECT requests on stdio, and tries to
# establish the connection to the given server.
# it is required for socats test.sh
# for TCP, use this script like:
# socat TCP-L:8080,reuseaddr,fork EXEC:"proxy.sh",nofork
# 20130622 GR allow hostnames, not only IP addresses
if [ -z "$SOCAT" ]; then
if type socat >/dev/null 2>&1; then
SOCAT=socat
else
SOCAT="./socat"
fi
fi
if [ $(echo "x\c") = "x" ]; then E=""
elif [ $(echo -e "x\c") = "x" ]; then E="-e"
else
echo "cannot suppress trailing newline on echo" >&2
exit 1
fi
ECHO="echo $E"
CR=$($ECHO "\r")
#echo "CR=$($ECHO "$CR\c" |od -c)" >&2
case `uname` in
HP-UX|OSF1)
# their cats are too stupid to work with unix domain sockets
CAT="$SOCAT -u stdin stdout"
;;
*)
CAT=cat
;;
esac
SPACES=" "
while [ -n "$1" ]; do
case "$1" in
-w) n="$2"; while [ "$n" -gt 0 ]; do SPACES="$SPACES "; n=$((n-1)); done
shift ;;
#-s) STAT="$2"; shift ;;
esac
shift
done
badrequest () {
$ECHO "HTTP/1.0${SPACES}500 Bad Request$CR"
$ECHO "$CR"
}
# read and parse HTTP request
read m a h
#echo "\"$m\" \"$a\" \"$h\"" >&2
if [ "$m" != 'CONNECT' ]; then
badrequest; exit 1
fi
if [[ "$a" == [0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:[0-9]+ ]]; then
: go on below
elif [[ "$a" == [0-9a-zA-Z-.][0-9a-zA-Z-.]*:[0-9][0-9]* ]]; then
: go on below
else
badrequest; exit 1
fi
if [[ "$h" == HTTP/1.[01][[:space:]]* ]]; then
: go on below
else
badrequest; exit 1
fi
# read more headers until empty line
while [ "$l" != "$CR" ]; do
read l
done
# send status
$ECHO "HTTP/1.0${SPACES}200 OK$CR"
# send empty line
$ECHO "$CR"
# perform proxy (relay) function
$SOCAT $SOCAT_OPTS - tcp:$a || {
$ECHO "HTTP/1.0${SPACES}500 Failed to connect to $a$CR"
$ECHO $CR
}