From becae5915aeb55a67067e3a33ae4970a5401c5d7 Mon Sep 17 00:00:00 2001
From: Sapan Bhatia <sapanb@cs.princeton.edu>
Date: Tue, 4 Aug 2009 03:12:30 +0000
Subject: [PATCH] Debugged version of reserve_tcp_port

---
 exec/reserve_tcp_port | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/exec/reserve_tcp_port b/exec/reserve_tcp_port
index 30ca1e2..a9043ea 100755
--- a/exec/reserve_tcp_port
+++ b/exec/reserve_tcp_port
@@ -12,7 +12,6 @@ my $pid;
 my @vinfo;
 my $foo;
 my $real_xid;
-my $cat_cmd;
 
 $slicename = $ARGV[0];
 $xid = int(`id -u $slicename`) || die("Could not determine xid of $slicename\n");
@@ -23,10 +22,17 @@ if ($portnumber!~/^\d+$/) {
         die("$portnumber is not a port number");
 }
 
-$fuser_cmd = "ncontext --nid $xid --migrate -- vcontext --xid $xid --migrate fuser -n tcp $portnumber";
+if ($portnumber<61001 || $portnumber>65535) {
+	die("$portnumber lies in the local port-rover range\n");
+}
+
+$fuser_cmd = "ncontext --nid $xid --migrate -- vcontext --xid $xid --migrate fuser -n tcp $portnumber 2>/dev/null";
 $pid = `$fuser_cmd` || die("Please bind to port $portnumber, e.g. run nc -l $portnumber."); 
+$pid=~s/\s+//g;
+
+my $cat_cmd;
 
-$cat_cmd = "cat /proc/$pid/vinfo";
+$cat_cmd = "chcontext --ctx 1 cat /proc/$pid/vinfo";
 $_ = `$cat_cmd`;
 @vinfo = split /\n/;
 ($#vinfo>0) || die("Port reservation failed. Please try again.\n");
@@ -39,4 +45,17 @@ if (int($real_xid)!=$xid) {
     die("Port $portnumber belongs to user $real_xid, not to you.\n"); 
 }
 
-close CMD;
+# OK. We're good
+# Only, slices are allowed only 1 port reservation/session
+
+if ( -f "/dev/shm/$slicename-port" ) {
+	print "You have already reserved the following port:\n";
+	system("cat /dev/shm/$slicename-port");
+	exit(1);
+}
+
+open FIL,">/dev/shm/$slicename-port";
+print FIL "$portnumber";
+close FIL;
+
+system("iptables -t mangle -A INPUT -m tcp -p tcp --dport $portnumber -j MARK --set-mark $xid");
-- 
2.43.0