#!/usr/bin/perl
# 
# Simple little program that takes the name of VM, parses its XML to find the 'vnetx' bridge links, 
# determines which bridge they're connected to and then takes the interfaces down, waits a few seconds, and 
# brings it back up. It cycles the interfaces connected to the BCN, then the SN and finally the IFN, always
# in that order.
#
# The goal of this program is to simplify testing the Striker and Anvil! node installer scripts when using 
# KVM/qemu based VMs.
# 
# Exit codes;
# 0 = Normal exit.
# 1 = Not run as root
# 2 = Server name not passed in
# 3 = Server not found
# 4 = Server not running
# 

use strict;
use warnings;

$| = 1;

our $debug = 1;
my  $server = defined $ARGV[0] ? $ARGV[0] : "";
if (not $server)
{
	print "[ Error ] - Server name required. Usage: '$0 <server>'\n";
	exit(2);
}
# Make sure we're running as 'root'
# $< == real UID, $> == effective UID
if (($< != 0) && ($> != 0))
{
	# Not root
	print "[ Error ] - This program requires root (or sudo) access.\n";
	exit(1);
}
#print "Searching: [$server] for 'vnetX' interfaces...\n";

# We don't read switches, as the only allowed switch is the server's name.
check_server_running($server);

# If we're here, the server was found and running.
my $nics = get_nic_list($server);

# Now cycle the NICs.
cycle_nics($server, $nics);

exit(0);


#############################################################################################################
# Functions                                                                                                 #
#############################################################################################################

# This does the work of cycling the NICs.
sub cycle_nics
{
	my ($server, $nics) = @_;
	print __LINE__."; [ Debug ] - server: [".$server."]\n" if $debug >= 2;
	
	print "Cycling network cables on the server: [".$server."]...\n";
	
	my $nics_processed = 1;
	my $say_network    = "";
	foreach my $bridge_type ("bcn", "sn", "ifn")
	{
		print __LINE__."; [ Debug ] - bridge_type: [".$bridge_type."]\n" if $debug >= 2;
		foreach my $network_number (sort {$a cmp $b} keys %{$nics->{$bridge_type}})
		{
			print __LINE__."; [ Debug ]  - network_number: [".$network_number."]\n" if $debug >= 2;
			foreach my $bridge_number (sort {$a cmp $b} keys %{$nics->{$bridge_type}{$network_number}})
			{
				if ($bridge_type eq "bcn")
				{
					$say_network = "Back-Chanel Network ".$network_number." - Bridge ".$bridge_number;
				}
				elsif ($bridge_type eq "sn")
				{
					$say_network = "Storage Network ".$network_number." - Bridge ".$bridge_number;
				}
				elsif ($bridge_type eq "ifn")
				{
					$say_network = "Internet-Facing Network ".$network_number." - Bridge ".$bridge_number;
				}
				
				print __LINE__."; [ Debug ]   - bridge_number: [".$bridge_number."]\n" if $debug >= 2;
				foreach my $this_vnet (sort {$a cmp $b} keys %{$nics->{$bridge_type}{$network_number}{$bridge_number}})
				{
					print __LINE__."; [ Debug ]    - this_vnet: [".$this_vnet."]\n" if $debug >= 2;
				
					my $this_mac = $nics->{$bridge_type}{$network_number}{$bridge_number}{$this_vnet};
					print __LINE__."; [ Debug ] - nics->${bridge_type}::${network_number}::${bridge_number}::${this_vnet}: [".$nics->{$bridge_type}{$network_number}{$bridge_number}{$this_vnet}."]\n" if $debug >= 2;
					
					# Down
					print "Unplugging: [".$this_vnet."] from: [".$say_network."]";
					my $shell_call = "virsh domif-setlink ".$server." ".$this_vnet." down";
					print "\n".__LINE__."; [ Debug ] - shell_call: [".$shell_call."]\n" if $debug >= 2;
					open (my $file_handle, $shell_call." 2>&1 |") or die "Failed to call: [$shell_call], error was: $!\n";
					while(<$file_handle>)
					{
						chomp;
						my $line = $_;
						print __LINE__."; [ Debug ] - line: [".$line."]\n" if $debug >= 2;
					}
					close $file_handle;
					
					for (1..3)
					{
						#print "- Sleeping briefly\n";
						print ".";
						sleep 1;
					}
					
					print " Reconnecting";
					$shell_call = "virsh domif-setlink ".$server." ".$this_vnet." up";
					print "\n".__LINE__."; [ Debug ] - shell_call: [".$shell_call."]\n" if $debug >= 2;
					open ($file_handle, $shell_call." 2>&1 |") or die "Failed to call: [$shell_call], error was: $!\n";
					while(<$file_handle>)
					{
						chomp;
						my $line = $_;
						print __LINE__."; [ Debug ] - line: [".$line."]\n" if $debug >= 2;
					}
					close $file_handle;
					
					print __LINE__."; [ Debug ] - nics_processed: [".$nics_processed."], nics->count: [".$nics->{count}."]\n" if $debug >= 2;
					if ($nics_processed < $nics->{count})
					{
						#print "- Sleeping briefly\n";
						for(1..3)
						{
							print ".";
							sleep 1;
						}
						print " Up\n";
					}
					else
					{
						print ". Up.\n";
					}
					$nics_processed++;
				}
			}
		}
	}
	print "- Done.\n";
	
	return(0);
}

# This parses the server's XML definition and returns a hash reference of interfaces to cycle.
sub get_nic_list
{
	my ($server) = @_;
	
	my $nic_count      = 0;
	my $nics           = {};
	my $bridge_number  = 0;
	my $network_number = 0;
	my $bridge_type    = "";
	my $this_vnet      = "";
	my $this_mac       = "";
	my $in_interface   = 0;
	my $shell_call     = "virsh dumpxml ".$server;
	print __LINE__."; [ Debug ] - shell_call: [".$shell_call."]\n" if $debug >= 2;
	open (my $file_handle, $shell_call." 2>&1 |") or die "Failed to call: [$shell_call], error was: $!\n";
	while(<$file_handle>)
	{
		chomp;
		my $line = $_;
		print __LINE__."; [ Debug ] - line: [".$line."]\n" if $debug >= 2;
		
		if ($line =~ /<interface type='network'>/)
		{
			$in_interface = 1;
		}
		
		if ($in_interface)
		{
			print __LINE__."; [ Debug ] - line: [".$line."]\n" if $debug >= 2;
			
			if (($line =~ /source network='(.*?)'/) or ($line =~ /bridge='(.*?)'/))
			{
				my $this_bridge = $1;
				print __LINE__."; [ Debug ] - this_bridge: [".$this_bridge."]\n" if $debug >= 2;
				
				($bridge_type, $network_number, $bridge_number) = ($this_bridge =~ /^(\D+)(\d+)_bridge(\d+)$/);
				print __LINE__."; [ Debug ] - bridge_type: [".$bridge_type."], network_number: [".$network_number."], bridge_number: [".$bridge_number."]\n" if $debug >= 2;
			}
			if ($line =~ /target dev='(.*?)'/)
			{
				$this_vnet = $1;
				print __LINE__."; [ Debug ] - this_vnet: [".$this_vnet."]\n" if $debug >= 2;
			}
			if ($line =~ /address='(.*?)'/)
			{
				$this_mac = $1;
				print __LINE__."; [ Debug ] - this_mac: [".$this_mac."]\n" if $debug >= 2;
			}
		}
		
		if ($line =~ /<\/interface>/)
		{
			# Record the details.
			print __LINE__."; [ Debug ] - bridge_type: [".$bridge_type."], network_number: [".$network_number."], bridge_number: [".$bridge_number."], this_vnet: [".$this_vnet."], this_mac: [".$this_mac."]\n" if $debug >= 2;
			
			$nics->{$bridge_type}{$network_number}{$bridge_number}{$this_vnet} = $this_mac;
			$nic_count++;
			print __LINE__."; [ Debug ] - nics->${bridge_type}::${network_number}::${bridge_number}::${this_vnet}: [".$nics->{$bridge_type}{$network_number}{$bridge_number}{$this_vnet}."]\n" if $debug >= 2;
			
			# Clear the variables.
			$in_interface   = 0;
			$bridge_number  = 0;
			$network_number = 0;
			$bridge_type    = "";
			$this_vnet      = "";
			$this_mac       = "";
		}
	}
	close $file_handle;
	
	$nics->{count} = $nic_count;
	print __LINE__."; [ Debug ] - nics->count: [".$nics->{count}."]\n" if $debug >= 2;
	
	return($nics);
}

# This checks to see if the name of the server was found and is running. It will exit if a problem is found.
sub check_server_running
{
	my ($server) = @_;
	
	my $found      = 0;
	my $shell_call = "virsh list --all";
	print __LINE__."; [ Debug ] - shell_call: [".$shell_call."]\n" if $debug >= 2;
	open (my $file_handle, $shell_call." 2>&1 |") or die "Failed to call: [$shell_call], error was: $!\n";
	while(<$file_handle>)
	{
		chomp;
		my $line = $_;
		   $line =~ s/\n$//;
		   $line =~ s/^\s+//;
		   $line =~ s/\s+$//;
		   $line =~ s/\s+/ /g;
		print __LINE__."; [ Debug ] - line: [".$line."]\n" if $debug >= 2;
		
		# Look for running servers
		if ($line =~ /^(\d+) (.*?) (.*)$/)
		{
			my $id          = $1;
			my $this_server = $2;
			my $state       = $3;
			print __LINE__."; [ Debug ] - id: [".$id."], server: [".$this_server."], state: [".$state."]\n" if $debug >= 2;
			
			if ($server eq $this_server)
			{
				# Found it
				$found = 1;
				last;
			}
		}
		
		# Look for stopped servers
		if ($line =~ /^- (.*?) (.*)$/)
		{
			my $this_server = $1;
			my $state       = $2;
			print __LINE__."; [ Debug ] - id: [-], server: [".$this_server."], state: [".$state."]\n" if $debug >= 2;
			
			if ($server eq $this_server)
			{
				print "[ Error ] - The server: [".$server."] is not running.\n";
				exit(4);
			}
		}
	}
	close $file_handle;
	
	if (not $found)
	{
		print "[ Error ] - The server: [".$server."] was not found.\n";
		exit(3);
	}
	
	return(0);
}