Basic script for initializing elab-* link characteristics based on

corresponding planet-* nodes.

One catch: I only did the backend, I didn't do the part that actually
looks up the plab nodes in the DB.  Once get_plabinfo() is filled in
with a real body, this will work!

pelab/init-elabnodes.pl

+#!/usr/bin/perl
+#
+# Based on pairwise characteristics of planet-* nodes (real planetlab nodes)
+# in a pelab experiment, set the delay characteristics for the corresponding
+# elab-* nodes.
+#
+# Elab nodes are in a "cloud" allowing you to set node-to-node characteristics
+# for all nodes within the cloud.  To do this for node N to node M:
+#
+#	tevc -e pid/eid now elabc-elab-N MODIFY DEST=<elab-M-elabc IP> \
+#		[ BANDWIDTH=<kbits/sec> ] [ DELAY=<ms> ] [ PLR=<prob> ]
+#
+# The characteristics are applied to the node->LAN pipe for node N.
+# Since this is one-way, you will have to apply the usual tricks to
+# convert round-trip delays and PLR.
+#
+
+my $TEVC = "/usr/testbed/bin/tevc";
+my $NLIST = "/usr/testbed/bin/node_list";
+my $pprefix = "planet-";
+
+#
+# Every source host has a list of <dest-IP,bw,delay,plr> tuples, one
+# element per possible destination
+#
+my %shapeinfo;
+
+if (@ARGV != 2) {
+    print STDERR "usage: init-elabnodes pid eid\n";
+    exit(1);
+}
+my ($pid,$eid) = @ARGV;
+
+#
+# XXX figure out how many pairs there are, and for each, who the
+# corresponding planetlab node is.  Can probably get all this easier
+# via XMLRPC...
+#
+my @nodelist = split('\s+', `$NLIST -v -e $pid,$eid`);
+chomp(@nodelist);
+my $nnodes = grep(/^${pprefix}/, @nodelist);
+if ($nnodes == 0) {
+    print STDERR "No planetlab nodes in $pid/$eid?!\n";
+    exit(1);
+}
+
+#
+# Get planetlab info for each planetlab node...
+#
+foreach (@nodelist) {
+    if (/^${pprefix}(\d+)/) {
+	get_plabinfo($1);
+    }
+}
+
+#
+# ...and send events to set the characteristics
+#
+send_events();
+
+exit(0);
+
+sub send_events()
+{
+    foreach my $src (keys %shapeinfo) {
+	foreach my $rec (@{$shapeinfo{$src}}) {
+	    my ($dst,$bw,$del,$plr) = @{$rec};
+	    my $cmd = "$TEVC -e $pid/$eid now elabc-$src MODIFY ".
+		"DEST=$dst BANDWIDTH=$bw DELAY=$del PLR=$plr";
+	    print "$cmd... ";
+	    if (system("$cmd") != 0) {
+		print "FAILED\n";
+	    } else {
+		print "OK\n";
+	    }
+	}
+    }
+}
+
+#
+# XXX testing...
+# Replace with real code that looks up IP of "planet-$ix" and
+# then looks in DB for info.
+#
+sub get_plabinfo($)
+{
+    my ($ix) = @_;
+
+    @{$shapeinfo{"elab-$ix"}} = ();
+    foreach my $i (1 .. $nnodes) {
+	next if ($i == $ix);
+
+	my $dst = "10.0.0.$ix";
+	my $bw = $i * 1000;
+	my $del = $i;
+	my $plr = $i / 100;
+
+	push(@{$shapeinfo{"elab-$ix"}}, [ $dst, $bw, $del, $plr ]);
+    }
+}