#!/usr/bin/perl

#Copyright (c) 2016 Wind River Systems, Inc.
#
#SPDX-License-Identifier: Apache-2.0
#
# parse_netstats
#
# Purpose: Summarize networking stats for each interface by parsing
#   output from /proc/net/dev.  Summarize rx and tx packet rates (pkt/s),
#   bandwidth (Mbit/s), and bytes per packet (B/pkt).
#   Calculates sample average and sample standard deviation.
#
# Modification history:
# - 2014-Feb-25 - Jim Gauld, prototype created.

use 5.10.0;
use warnings;
use strict;
use File::Spec ();
use Time::Local 'timelocal_nocheck'; # inverse time functions

# Timestamp variables
my ($wday, $month, $day, $hh, $mm, $ss, $yy, $ns) = ();

# Determine location of gunzip binary
our $GUNZIP = which('gunzip');
if (!(defined $GUNZIP)) {
   die "*error* cannot find 'gunzip' binary. Cannot continue.\n";
}
our $BUNZIP2 = which('bunzip2');
if (!(defined $BUNZIP2)) {
   die "*error* cannot find 'bunzip2' binary. Cannot continue.\n";
}

foreach my $file (@ARGV) {
	print "processing file: $file\n";
	if ($file =~ /\.gz$/) {
		open(FILE, "$::GUNZIP -c $file |") || die "Cannot open file: $file ($!)\n";
	} elsif ($file =~ /\.bz2$/) {
		open(FILE, "$::BUNZIP2 -c $file |") || die "Cannot open file: $file ($!)\n";
	} else {
		open(FILE, $file) || die "Cannot open file: $file ($!)\n";
	}

	my ($epoc, $epoc0, $dt, $uptime) = (0,0,0);
	my ($iface,$timestamp,$timestamp0, $time_fmt) = ("", "", "", "");
	my ($rx,$tx,$rx_B,$tx_B, $rx0,$tx0,$rx_B0,$tx_B0) = (0,0,0,0,  0,0,0,0);
	my ($rx_pps, $tx_pps, $rx_Mbps, $tx_Mbps, $rx_Bpp, $tx_Bpp);
	my $WARNING = "";
	my $Mpb = 1.0E6/8;

	# Wipe out data and statistics per file.
	my (%data, %stats, %series) = ();

	# Print header (per file)
	printf "%18s %5s | %9s %12s %9s | %9s %12s %9s | %s\n",
		"interface", "dt(s)",
		"rx(pkt/s)", "rx(Mbps)", "rx(B/pkt)",
		"tx(pkt/s)", "tx(Mbps)", "tx(B/pkt)",
		"date/time";
	my @var_list = ('dt', 'rx_pps', 'tx_pps', 'rx_Mbps', 'tx_Mbps', 'rx_Bpp', 'tx_Bpp');
	READ_LOOP: while($_ = <FILE>) {
		s/[\0\e\f\r\a]//g; chomp; # strip control characters if any

		# Hi-resolution timestamp
		# time:  Tue 2009-04-07 18:17:05.074387000 UTC +0000 uptime:  1153.09 897.13
		if (/time:\s+(\w+)\s+(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2})\.(\d{9})\s+\w+\s+\S+\s+uptime:\s+(\S+)\s+/) { # ignore timezone
			$wday = $1; $yy = $2; $month = $3; $day = $4; $hh = $5; $mm = $6; $ss = $7; $ns = $8; $uptime = $9;
			$timestamp0 = $timestamp; $epoc0 = $epoc; # store previous
			$timestamp = [($wday,$month,$day,$hh,$mm,$ss,$yy,$ns)];
			$epoc = $9;
			$dt = $epoc - $epoc0;
			next;
		}

		# Inter-|   Receive                                                |  Transmit
		# face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
		if (/\s*(\S+):\s*(\d+)\s+(\d+)\s+\d+\s+\d+\s+\d+\s+\d+\s+\d+\s+\d+\s+(\d+)\s+(\d+)\s+\d+\s+\d+\s+\d+\s+\d+\s+\d+\s+\d+/) {
			$iface = $1; $rx_B = $2; $rx = $3; $tx_B = $4; $tx = $5;
			($rx0,$tx0,$rx_B0,$tx_B0) = ($rx,$tx,$rx_B,$tx_B);
			if (!(defined $data{$iface}{'rx0'})) {
				$data{$iface}{'rx0'}   = 0; $data{$iface}{'tx0'}   = 0;
				$data{$iface}{'rx_B0'} = 0; $data{$iface}{'tx_B0'} = 0;
				foreach my $item (@var_list) {
					$stats{$iface}{$item}{'sumX'}  = 0.0;
					$stats{$iface}{$item}{'sumX2'} = 0.0;
					$stats{$iface}{$item}{'N'}     = 0;
					$stats{$iface}{$item}{'avg'}   = 0;
					$stats{$iface}{$item}{'stdev'} = 0;
				}
			} else {
				$data{$iface}{'rx0'}   = $data{$iface}{'rx'};
				$data{$iface}{'tx0'}   = $data{$iface}{'tx'};
				$data{$iface}{'rx_B0'} = $data{$iface}{'rx_B'};
				$data{$iface}{'tx_B0'} = $data{$iface}{'tx_B'};
			}
    
			# Saver current measurement
			$data{$iface}{'rx'}   = $rx;
			$data{$iface}{'tx'}   = $tx;
			$data{$iface}{'rx_B'} = $rx_B;
			$data{$iface}{'tx_B'} = $tx_B;
			$data{$iface}{'dt'}   = $dt;

			if (($dt > 0) && (($data{$iface}{'rx0'} > 0) || ($data{$iface}{'tx0'} > 0))) {
				$data{$iface}{'rx_pps'}  = ($data{$iface}{'rx'} - $data{$iface}{'rx0'})/$dt;
				$data{$iface}{'tx_pps'}  = ($data{$iface}{'tx'} - $data{$iface}{'tx0'})/$dt;

				$data{$iface}{'rx_Mbps'} = ($data{$iface}{'rx_B'} - $data{$iface}{'rx_B0'})/$dt/$Mpb;
				$data{$iface}{'tx_Mbps'} = ($data{$iface}{'tx_B'} - $data{$iface}{'tx_B0'})/$dt/$Mpb;

				$data{$iface}{'rx_pps'}  =  ($data{$iface}{'rx_pps'}  < 0.0) ? -1.0 : $data{$iface}{'rx_pps'};
				$data{$iface}{'tx_pps'}  =  ($data{$iface}{'tx_pps'}  < 0.0) ? -1.0 : $data{$iface}{'tx_pps'};
				$data{$iface}{'rx_Mbps'} =  ($data{$iface}{'rx_Mbps'} < 0.0) ? -1.0 : $data{$iface}{'rx_Mbps'};
				$data{$iface}{'tx_Mbps'} =  ($data{$iface}{'tx_Mbps'} < 0.0) ? -1.0 : $data{$iface}{'tx_Mbps'};
			} else {
				$data{$iface}{'rx_pps'}  = -1;
				$data{$iface}{'tx_pps'}  = -1;
				$data{$iface}{'rx_Mbps'} = -1;
				$data{$iface}{'tx_Mbps'} = -1;
			}
			if (($data{$iface}{'rx0'} > 0) && ($data{$iface}{'rx_pps'} > 0) && ($data{$iface}{'rx_Mbps'} > 0)) {
				$data{$iface}{'rx_Bpp'} = ($data{$iface}{'rx_B'} - $data{$iface}{'rx_B0'}) / ($data{$iface}{'rx'} - $data{$iface}{'rx0'});
			} elsif (($data{$iface}{'rx_Mbps'} != -1)  && (abs($data{$iface}{'rx_pps'}) < 1.0E6)) {
				$data{$iface}{'rx_Bpp'} = 0.0;
			} else {
				$data{$iface}{'rx_Bpp'} = -1;
			}
			if (($data{$iface}{'tx0'} > 0) && ($data{$iface}{'tx_pps'} > 0) && ($data{$iface}{'tx_Mbps'} > 0)) {
				$data{$iface}{'tx_Bpp'} = ($data{$iface}{'tx_B'} - $data{$iface}{'tx_B0'}) / ($data{$iface}{'tx'} - $data{$iface}{'tx0'});
			} elsif (($data{$iface}{'tx_Mbps'} != -1)  && (abs($data{$iface}{'tx_pps'}) < 1.0E6)) {
				$data{$iface}{'tx_Bpp'} = 0.0;
			} else {
				$data{$iface}{'tx_Bpp'} = -1;
			}

			if (($dt > 0) && (($data{$iface}{'rx0'} > 0) || ($data{$iface}{'tx0'} > 0))) {
				foreach my $item (@var_list) {
					if ($data{$iface}{$item} >= 0.0) {
						$stats{$iface}{$item}{'sumX'}  += $data{$iface}{$item};
						$stats{$iface}{$item}{'sumX2'} += ($data{$iface}{$item} * $data{$iface}{$item});
						$stats{$iface}{$item}{'N'}     += 1;
					}
				}

				push @{$series{$iface}}, [ ($dt,
					$data{$iface}{'rx_pps'}, $data{$iface}{'rx_Mbps'}, $data{$iface}{'rx_Bpp'},
					$data{$iface}{'tx_pps'}, $data{$iface}{'tx_Mbps'}, $data{$iface}{'tx_Bpp'},
					$timestamp)];
			}
			next;
		}
	}

	foreach $iface (keys %series) {
		while (my $elem = shift @{$series{$iface}}) {
			($dt,	$data{$iface}{'rx_pps'}, $data{$iface}{'rx_Mbps'}, $data{$iface}{'rx_Bpp'},
			 $data{$iface}{'tx_pps'}, $data{$iface}{'tx_Mbps'}, $data{$iface}{'tx_Bpp'}, $timestamp) = @{$elem};
			($wday,$month,$day,$hh,$mm,$ss,$yy,$ns) = @$timestamp;
			$time_fmt = sprintf("%04d-%02d-%02d %02d:%02d:%02d.%03d", $yy, $month, $day, $hh, $mm, $ss, $ns/1.0E6);
			printf "%18s %5.2f | %9.1f %12.5f %9.0f | %9.1f %12.5f %9.0f | %21s\n",
				$iface, $dt,
				$data{$iface}{'rx_pps'}, $data{$iface}{'rx_Mbps'}, $data{$iface}{'rx_Bpp'},
				$data{$iface}{'tx_pps'}, $data{$iface}{'tx_Mbps'}, $data{$iface}{'tx_Bpp'},
				$time_fmt;
		}

		# Calculate final stats
		foreach my $item (@var_list) {
			# Calculate sample mean
			if ($stats{$iface}{$item}{'N'} > 0) {
				$stats{$iface}{$item}{'avg'} = $stats{$iface}{$item}{'sumX'} / $stats{$iface}{$item}{'N'};
			} else {
				$stats{$iface}{$item}{'avg'} = 0.0;
			}
			# Calculate sample standard deviation
			if ($stats{$iface}{$item}{'N'} > 2) {
				$stats{$iface}{$item}{'stdev'} = ($stats{$iface}{$item}{'sumX2'}
					- ($stats{$iface}{$item}{'sumX'}**2)/$stats{$iface}{$item}{'N'})
					/ ($stats{$iface}{$item}{'N'} - 1);
				if ($stats{$iface}{$item}{'stdev'} > 0.0) {
					$stats{$iface}{$item}{'stdev'} = sqrt( $stats{$iface}{$item}{'stdev'} );
				} else {
					$stats{$iface}{$item}{'stdev'} = 0.0;
				}
			} else {
				$stats{$iface}{$item}{'stdev'} = 0.0;
			}
		}

		# Print summary (average and standard deviation)
		printf "%18s %5s | %9s %12s %9s | %9s %12s %9s | %s\n",
			'-'x18, '-'x5, '-'x9, '-'x12, '-'x9, '-'x9, '-'x12, '-'x9, '-'x31;
		printf "%18s %5.2f | %9.1f %12.5f %9.0f | %9.1f %12.5f %9.0f | %21s %s\n",
			$iface, $stats{$iface}{'dt'}{'avg'},
			$stats{$iface}{'rx_pps'}{'avg'}, $stats{$iface}{'rx_Mbps'}{'avg'}, $stats{$iface}{'rx_Bpp'}{'avg'},
			$stats{$iface}{'tx_pps'}{'avg'}, $stats{$iface}{'tx_Mbps'}{'avg'}, $stats{$iface}{'tx_Bpp'}{'avg'},
			$time_fmt, 'Average';
		printf "%18s %5.1f | %9.1f %12.5f %9.0f | %9.1f %12.5f %9.0f | %21s %s\n",
			$iface, $stats{$iface}{'dt'}{'stdev'},
			$stats{$iface}{'rx_pps'}{'stdev'}, $stats{$iface}{'rx_Mbps'}{'stdev'}, $stats{$iface}{'rx_Bpp'}{'stdev'},
			$stats{$iface}{'tx_pps'}{'stdev'}, $stats{$iface}{'tx_Mbps'}{'stdev'}, $stats{$iface}{'tx_Bpp'}{'stdev'},
			$time_fmt, 'StdDev';
		print "\n";
	}
	
	# Print blank line between files
	if ($WARNING) {print $WARNING, "\n";};
	print "\n";
}
exit 0;

#######################################################################################################################
# Lightweight which(), derived from CPAN File::Which
sub which {
   my ($exec) = @_;
   return undef unless $exec;
   my $all = wantarray;
   my @results = ();
   my @path = File::Spec->path;
   foreach my $file ( map { File::Spec->catfile($_, $exec) } @path ) {
      next if -d $file;
      if (-x _) { return $file unless $all; push @results, $file; }
    }
    $all ? return @results : return undef;
}

1;