From 309cc9ecf51b082d6de8f1c3b0028c398daa395f Mon Sep 17 00:00:00 2001
From: Dave Brolley <brolley@redhat.com>
Date: Tue, 9 Dec 2008 15:31:00 -0500
Subject: [PATCH] Use netcat or nc, whichever is available.

---
diff --git a/stap-client b/stap-client
index 0ac9bd6..255551b 100755
--- a/stap-client
+++ b/stap-client
@@ -29,6 +29,11 @@ function configuration {
     tmpdir_prefix_client=stap.client
     tmpdir_prefix_server=stap.server
     avahi_service_tag=_stap._tcp
+
+    # We need either netcat or nc.
+    netcat=`which netcat 2>/dev/null`
+    test "X$netcat" = "X" && netcat=`which nc 2>/dev/null`
+    test "X$netcat" = "X" && fatal "ERROR: cannot find required program 'netcat' or 'nc' on PATH"
 }
 
 # function: initialization
@@ -386,7 +391,7 @@ function send_request {
     # Send the request file.
     for ((attempt=0; $attempt < 10; ++attempt))
     do
-	if nc -w10 $server $(($port+1)) < $tar_client > /dev/null 2>&1; then
+	if $netcat -w10 $server $(($port+1)) < $tar_client > /dev/null 2>&1; then
 	    return;
 	fi
 	sleep 1
@@ -405,7 +410,7 @@ function receive_response {
     # Retrieve the file. Wait for up to 5 minutes for a response.
     for ((attempt=0; $attempt < 300; ++attempt))
     do
-	if nc -d $server $(($port+1)) > $tar_server 2>/dev/null; then
+	if $netcat -d $server $(($port+1)) > $tar_server 2>/dev/null; then
 	    return;
 	fi
 	sleep 1
@@ -535,7 +540,7 @@ function choose_server {
 function connect_to_server {
     for ((attempt=0; $attempt < 10; ++attempt))
     do
-	if echo "request:" | nc -w10 $1 $2 >/dev/null 2>&1; then
+	if echo "request:" | $netcat -w10 $1 $2 >/dev/null 2>&1; then
 	    return 0
 	fi
 	sleep 1
diff --git a/stap-server b/stap-server
index 67573de..a06adc9 100755
--- a/stap-server
+++ b/stap-server
@@ -26,6 +26,11 @@ function configuration {
     tmpdir_prefix_server=stap.server
     port=$1
     test "X$port" = "X" && port=65001
+
+    # We need either netcat or nc.
+    netcat=`which netcat 2>/dev/null`
+    test "X$netcat" = "X" && netcat=`which nc 2>/dev/null`
+    test "X$netcat" = "X" && fatal "ERROR: cannot find required program 'netcat' or 'nc' on PATH"
 }
 
 # function: initialization
@@ -53,12 +58,12 @@ function receive_request {
 	fatal "ERROR: cannot create temporary tar file " $tar_client
 
     # Receive the file.
-    nc -ld $port > $tar_client 2>/dev/null &
+    $netcat -ld $port > $tar_client 2>/dev/null &
 
     # Wait for 10 seconds before timing out
     for ((t=0; $t < 10; ++t))
     do
-	if jobs '%nc -l' >/dev/null 2>&1; then
+	if jobs '%$netcat -l' >/dev/null 2>&1; then
 	    sleep 1
 	else
 	    return
@@ -384,12 +389,12 @@ function package_response {
 # Wait for the client to take the response file.
 function send_response {
     # Now send it.
-    nc -l $port < $tar_server > /dev/null 2>&1 &
+    $netcat -l $port < $tar_server > /dev/null 2>&1 &
 
     # Wait for 10 seconds before timing out
     for ((t=0; $t < 10; ++t))
     do
-	if jobs '%nc -l' >/dev/null 2>&1; then
+	if jobs '%$netcat -l' >/dev/null 2>&1; then
 	    sleep 1
 	else
 	    return
@@ -430,8 +435,8 @@ function cleanup {
 	rm -fr $tmpdir_stap
     fi
     
-    # Kill any nc job that may be running
-    kill -s SIGTERM %nc 2> /dev/null
+    # Kill any $netcat job that may be running
+    kill -s SIGTERM '%$netcat' 2> /dev/null
 }
 
 # function: terminate
diff --git a/stap-serverd b/stap-serverd
index 45aacf6..b46a425 100755
--- a/stap-serverd
+++ b/stap-serverd
@@ -23,13 +23,21 @@ trap 'terminate' SIGTERM SIGINT
 function initialization {
     # Default settings.
     avahi_type=_stap._tcp
+
+    # We need either netcat or nc.
+    netcat=`which netcat 2>/dev/null`
+    test "X$netcat" = "X" && netcat=`which nc 2>/dev/null`
+    test "X$netcat" = "X" && fatal "ERROR: cannot find required program 'netcat' or 'nc' on PATH"
+
+    # See if the given port, or the default port is busy. If so, select another.
     port=$1
     test "X$port" = "X" && port=65000
-    export port2=$(($port + 1))
-    if netstat -atn | awk '{print $4}' | cut -f2 -d: | egrep -q "^($port|$port2)\$"; then
+    port2=$(($port + 1))
+    while netstat -atn | awk '{print $4}' | cut -f2 -d: | egrep -q "^($port|$port2)\$"; do
         # Whoops, the port is busy; try another one.
-        initialization $((1024+($port + $RANDOM)%64000))
-    fi
+        port=$((1024+($port + $RANDOM)%64000))
+	port2=$(($port + 1))
+    done
 }
 
 # function: advertise_presence
@@ -57,8 +65,8 @@ function listen {
     do
 	for ((attempt=0; $attempt < 5; ++attempt))
 	do
-            nc -ld $port 2>/dev/null | process_request &
-	    wait '%nc -l'
+            $netcat -ld $port 2>/dev/null | process_request &
+	    wait '%$netcat -l'
 	    rc=$?
 	    if test $rc = 0 -o $rc = 127; then
 		break; # port was read ok
@@ -111,11 +119,11 @@ function terminate {
 
     # Kill any running 'stap-server' job.
     kill -s SIGTERM "%stap-server" 2> /dev/null
-    wait "%stap-server"  >/dev/null 2>&1
+    wait '%stap-server'  >/dev/null 2>&1
 
-    # Kill any running 'nc -l' job.
-    kill -s SIGTERM "%?nc -l" 2> /dev/null
-    wait "%?nc - l"  >/dev/null 2>&1
+    # Kill any running '$netcat -l' job.
+    kill -s SIGTERM '%$netcat -l' 2>/dev/null
+    wait '%$netcat -l'  >/dev/null 2>&1
 
     exit
 }
-- 
1.6.0.5