Added socat-mux.sh for n-to-1 / 1-to-n communications

CHANGES

@@ -201,6 +201,10 @@ Features:
 	drive socks through TLS, or to use TLS over a serial line.
 	Tests: SOCAT_CHAIN_SOCKS4 SOCAT_CHAIN_SSL_PTY
 
+	Added script socat-mux.sh that performs n-to-1 / 1-to-n communications
+	using two Socat instances with multicasting.
+	Tests: SOCAT_MUX
+
 Corrections:
 	When a sub process (EXEC, SYSTEM) terminated with exit code other than
 	0, its last sent data might have been lost depending on timing of read/

Makefile.in

@@ -76,7 +76,7 @@ HFILES = sycls.h sslcls.h error.h dalan.h procan.h filan.h hostan.h sysincludes.
 
 
 DOCFILES = README README.FIPS CHANGES FILES EXAMPLES PORTING SECURITY DEVELOPMENT doc/socat.yo doc/socat.1 doc/socat.html FAQ BUGREPORTS COPYING COPYING.OpenSSL doc/dest-unreach.css doc/socat-openssltunnel.html doc/socat-multicast.html doc/socat-tun.html doc/socat-genericsocket.html
-SHFILES = socat-chain.sh \
+SHFILES = socat-chain.sh socat-mux.sh \
 	daemon.sh mail.sh ftp.sh readline.sh \
 	socat_buildscript_for_android.sh
 TESTFILES = test.sh socks4echo.sh proxyecho.sh readline-test.sh \
@@ -133,6 +133,7 @@ install: progs $(srcdir)/doc/socat.1
 	$(INSTALL) -m 755 socat $(DESTDIR)$(BINDEST)/socat1
 	ln -s socat1 $(DESTDIR)$(BINDEST)/socat
 	$(INSTALL) -m 755 socat-chain.sh  $(DESTDIR)$(BINDEST)
+	$(INSTALL) -m 755 socat-mux.sh    $(DESTDIR)$(BINDEST)
 	$(INSTALL) -m 755 procan $(DESTDIR)$(BINDEST)
 	$(INSTALL) -m 755 filan $(DESTDIR)$(BINDEST)
 	mkdir -p $(DESTDIR)$(MANDEST)/man1
@@ -143,6 +144,7 @@ uninstall:
 	rm -f $(DESTDIR)$(BINDEST)/socat
 	rm -f $(DESTDIR)$(BINDEST)/socat1
 	rm -f $(DESTDIR)$(BINDEST)/socat-chain.sh
+	rm -f $(DESTDIR)$(BINDEST)/socat-mux.sh
 	rm -f $(DESTDIR)$(BINDEST)/procan
 	rm -f $(DESTDIR)$(BINDEST)/filan
 	rm -f $(DESTDIR)$(MANDEST)/man1/socat.1

socat-mux.sh

@@ -0,0 +1,115 @@
+#! /usr/bin/env bash
+# Copyright Gerhard Rieger and contributors (see file CHANGES)
+# Published under the GNU General Public License V.2, see file COPYING
+
+# Shell script to build a many-to-one, one-to-all communication
+# It starts two Socat instances that communicate via IPv4 broadcast,
+# the first of which forks a child process for each connected client.
+
+# Example:
+
+# Consider a serial device connected to the Internet on TCP port 1234, it
+# accepts only one connection at a time.
+# On a proxy/relay server run this script:
+#   socat-mux.sh \
+#       TCP-L:1234,reuseaddr,fork \
+#       TCP:<addr-of-device>:1234
+# Now connect with an arbitrary number of clients to TCP:<proxy>:1234;
+# data sent by the device goes to all clients, data from any client is sent to
+# the device.
+
+ECHO="echo -e"
+
+usage () {
+    $ECHO "Usage: $0 <options> <listener> <target>"
+    $ECHO "Example:"
+    $ECHO "    $0 TCP4-L:1234,reuseaddr,fork TCP:10.2.3.4:12345"
+    $ECHO "Clients may connect to port 1234; data sent by any client is forwarded to 10.2.3.4,"
+    $ECHO "data provided by 10.2.3.4 is sent to ALL clients"
+    $ECHO "    <options>:"
+    $ECHO "\t-h\tShow this help text and exit"
+    $ECHO "\t-V\tShow Socat commands"
+    $ECHO "\t-q\tSuppress most messages"
+    $ECHO "\t-d*\tOptions beginning with -d are passed to Socat processes"
+    $ECHO "\t-l*\tOptions beginning with -l are passed to Socat processes"
+    $ECHO "\t-b|-S|-t|-T|-l <arg>\tThese options are passed to Socat processes"
+}
+
+VERBOSE= QUIET= OPTS=
+while [ "$1" ]; do
+    case "X$1" in
+	X-h) usage; exit ;;
+	X-V) VERBOSE=1 ;;
+	X-q) QUIET=1; OPTS="-d0" ;;
+	X-d*|X-l?*) OPTS="$OPTS $1" ;;
+	X-b|X-S|X-t|X-T|X-l) OPT=$1; shift; OPTS="$OPTS $OPT $1" ;;
+	X-) break ;;
+	X-*) echo "$0: Unknown option \"$1\"" >&2
+	     usage >&2
+	     exit 1 ;;
+	*) break ;;
+    esac
+    shift
+done
+
+LISTENER="$1"
+TARGET="$2"
+
+if [ -z "$LISTENER" -o -z "$TARGET" ]; then
+    echo "$0: Missing parameter(s)" >&2
+    usage >&2
+    exit 1
+fi
+
+shopt -s nocasematch
+if ! [[ "$LISTENER" =~ .*,fork ]] || [[ "$LISTENER" =~ .*,fork, ]]; then
+    LISTENER="$LISTENER,fork"
+fi
+
+case "$0" in
+    */*) SOCAT=${0%/*}/socat ;;
+    *) SOCAT=socat ;;
+esac
+
+PORT1=$($SOCAT -d -d -T 0.000001 UDP4-RECV:0 /dev/null 2>&1 |grep bound |sed 's/.*:\([1-9][0-9]*\)$/\1/')
+PORT2=$($SOCAT -d -d -T 0.000001 UDP4-RECV:0 /dev/null 2>&1 |grep bound |sed 's/.*:\([1-9][0-9]*\)$/\1/')
+if [ -z "$PORT1" -o -z "$PORT2" ]; then
+    echo "$0: Failed to determine free UDP ports" >&2
+    exit 1
+fi
+if [ "$PORT1" = "$PORT2" ]; then 	# seen on etch
+    PORT2=$((PORT1+1))
+fi
+
+IFADDR=127.0.0.1
+BCADDR=127.255.255.255
+
+
+pid1= pid2=
+trap '[ "$pid1" ] && kill $pid1 2>/dev/null; [ "$pid2" ] && kill $pid2 2>/dev/null' EXIT
+
+set -bm
+trap 'if kill -n 0 $pid1 2>/dev/null; then [ -z "$QUIET" ] && echo "$0: socat-listener exited with rc=$?" >&2; kill $pid1; else [ -z "$QUIET" ] && echo "$0: socat-multiplexer exited with rc=$?" >&2; kill $pid2 2>/dev/null; fi; exit 1' SIGCHLD
+
+if [ "$VERBOSE" ]; then
+    $ECHO "$SOCAT -lp muxfwd $OPTS \\
+	\"$TARGET\" \\
+	\"UDP4-DATAGRAM:$BCADDR:$PORT2,bind=$IFADDR:$PORT1,so-broadcast\" &"
+fi
+$SOCAT -lp muxfwd $OPTS \
+    "$TARGET" \
+    "UDP4-DATAGRAM:$BCADDR:$PORT2,bind=$IFADDR:$PORT1,so-broadcast" &
+pid1=$!
+
+if [ "$VERBOSE" ]; then
+    $ECHO "$SOCAT -lp muxlst $OPTS \\
+    	\"$LISTENER\" \\
+        \"UDP4-DATAGRAM:$IFADDR:$PORT1,bind=:$PORT2,so-broadcast,so-reuseaddr\" &"
+fi
+$SOCAT -lp muxlst $OPTS \
+    "$LISTENER" \
+    "UDP4-DATAGRAM:$IFADDR:$PORT1,bind=:$PORT2,so-broadcast,so-reuseaddr" &
+pid2=$!
+
+wait
+#wait -f

test.sh

@@ -18986,6 +18986,118 @@ esac
 N=$((N+1))
 
 
+# Test the socat-mux.sh script
+# Requires lo/lo0 to have broadcast address 127.255.255.255
+NAME=SOCAT_MUX
+case "$TESTS" in
+*%$N%*|*%functions%*|*%script%*|*%socat-mux%*|*%socket%*|*%udp%*|*%broadcast%*|*%$NAME%*)
+TEST="$NAME: test the socat-mux.sh script"
+# Start a simple TCP server
+# Start socat-mux.sh to connect to this server
+# Connect with two clients to mux, send different data records from both.
+# Check if both client received both records in order.
+if ! eval $NUMCOND; then :
+# Remove unneeded checks, adapt lists of the remaining ones
+elif ! cond=$(checkconds \
+		  "" \
+		  "" \
+		  "" \
+		  "IP4 UDP TCP LISTEN STDIO PIPE" \
+		  "TCP4-LISTEN TCP4-CONNECT PIPE STDIO UDP-DATAGRAM" \
+		  "so-reuseaddr" \
+		  "udp4 tcp4" ); then
+    $PRINTF "test $F_n $TEST... ${YELLOW}$cond${NORMAL}\n" $N
+    numCANT=$((numCANT+1))
+    listCANT="$listCANT $N"
+    namesCANT="$namesCANT $NAME"
+else
+    tf="$td/test$N.stdout"
+    te="$td/test$N.stderr"
+    tdiff="$td/test$N.diff"
+    newport tcp4
+    PORT0=$PORT
+    newport tcp4
+    PORT1=$PORT
+    CMD0="$TRACE $SOCAT $opts -lp server TCP-LISTEN:$PORT0 PIPE"
+    CMD1="./socat-mux.sh TCP-LISTEN:$PORT1 TCP-CONNECT:$LOCALHOST:$PORT0"
+    CMD2="$TRACE $SOCAT $opts -lp client STDIO TCP:$LOCALHOST:$PORT1"
+    da_a="test$N $(date) $RANDOM"
+    da_b="test$N $(date) $RANDOM"
+    printf "test $F_n $TEST... " $N
+    $CMD0 >/dev/null 2>"${te}0" &
+    pid0=$!
+    waittcp4port $PORT0 1
+    $CMD1 >/dev/null 2>"${te}1" &
+    pid1=$!
+    waittcp4port $PORT1 1
+    { sleep 1; echo "$da_a"; sleep 2; } </dev/null |$CMD2 >"${tf}2a" 2>"${te}2a" &
+    pid2a=$!
+    { sleep 2; echo "$da_b"; sleep 1; } |$CMD2 >"${tf}2b" 2>"${te}2b"
+    rc2b=$?
+    kill $pid0 $(childpids $pid1) $pid1 2>/dev/null
+    wait 2>/dev/null
+    kill $pid0 2>/dev/null; wait
+    if [ "$rc2b" -ne 0 ]; then
+	$PRINTF "$FAILED (rc2b=$rc2b)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	echo "$CMD1 &"
+	cat "${te}1" >&2
+	echo "{ sleep 1; echo \"\$da_a\"; sleep 2; } |$CMD2"
+	cat "${te}2a" >&2
+	echo "{ sleep 2; echo \"\$da_b\"; sleep 1; } |$CMD2"
+	cat "${te}2b" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    elif ! $ECHO "$da_a\n$da_b" |diff - "${tf}2a" >${tdiff}_a; then
+	$PRINTF "$FAILED (diff a)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	echo "$CMD1 &"
+	cat "${te}1" >&2
+	echo "{ sleep 1; echo \"\$da_a\"; sleep 2; } |$CMD2"
+	cat "${te}2a" >&2
+	echo "{ sleep 2; echo \"\$da_b\"; sleep 1; } |$CMD2"
+	cat "${te}2b" >&2
+	echo "// diff a:" >&2
+	cat "${tdiff}_a" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    elif ! $ECHO "$da_a\n$da_b" |diff - "${tf}2b" >${tdiff}_b; then
+	$PRINTF "$FAILED (diff b)\n"
+	echo "$CMD0 &"
+	cat "${te}0" >&2
+	echo "$CMD1 &"
+	cat "${te}1" >&2
+	echo "{ sleep 1; echo \"\$da_a\"; sleep 2; } |$CMD2"
+	cat "${te}2a" >&2
+	echo "{ sleep 2; echo \"\$da_b\"; sleep 2; } |$CMD2"
+	cat "${te}2b" >&2
+	echo "// diff b:" >&2
+	cat "${tdiff}_b" >&2
+	numFAIL=$((numFAIL+1))
+	listFAIL="$listFAIL $N"
+	namesFAIL="$namesFAIL $NAME"
+    else
+	$PRINTF "$OK\n"
+	if [ "$VERBOSE" ]; then echo "$CMD0 &"; fi
+	if [ "$DEBUG" ];   then cat "${te}0" >&2; fi
+	if [ "$VERBOSE" ]; then echo "$CMD1 &"; fi
+	if [ "$DEBUG" ];   then cat "${te}1" >&2; fi
+	if [ "$VERBOSE" ]; then echo "{ sleep 1; echo \"\$da_a\"; sleep 2; } |$CMD2"; fi
+	if [ "$DEBUG" ];   then cat "${te}2a" >&2; fi
+	if [ "$VERBOSE" ]; then echo "{ sleep 2; echo \"\$da_b\"; sleep 1; } |$CMD2"; fi
+	if [ "$DEBUG" ];   then cat "${te}2b" >&2; fi
+	numOK=$((numOK+1))
+    fi
+fi # NUMCOND
+ ;;
+esac
+N=$((N+1))
+
+
 # end of common tests
 
 ##################################################################################