wifi-diag: Initial framework for script to diagnose wifi pcaps

End goal is to be able to find block-ack issues and provide useful
graphs to help debug complex wifi networks.

wifi_diag/Packet.pm

@@ -0,0 +1,150 @@
+package Packet;
+
+use warnings;
+use strict;
+
+sub new {
+  my $class = shift;
+  my %options = @_;
+
+  my $self = {
+	      type_subtype => "UNKNOWN",
+	      receiver => "UNKNOWN",
+	      transmitter => "UNKNOWN",
+	      %options,
+	      amsdu_frame_count => 0,
+	      ssi_sig_found => 0,
+	      tid => 17, # anything that does not specify a tid gets this.
+	     };
+
+  bless($self, $class);
+  return($self);
+}
+
+sub raw_pkt {
+  my $self = shift;
+  return $self->{raw_pkt};
+}
+
+sub append {
+  my $self = shift;
+  my $ln = shift;
+
+  $self->{raw_pkt} .= $ln;
+
+  if ($ln =~ /\s*Transmitter address: .*\((\S+)\)/) {
+    $self->{transmitter} = $1;
+  }
+  elsif ($ln =~ /\s*Receiver address: .*\((\S+)\)/) {
+    $self->{receiver} = $1;
+  }
+  elsif ($ln =~ /\s*Fragment number: (\d+)/) {
+    $self->{fragno} = $1;
+  }
+  elsif ($ln =~ /\s*Sequence number: (\d+)/) {
+    $self->{seqno} = $1;
+  }
+  elsif ($ln =~ /\s*Type\/Subtype: (.*)/) {
+    $self->{type_subtype} = $1;
+  }
+  elsif ($ln =~ /.* = Starting Sequence Number: (\d+)/) {
+    $self->{ba_starting_seq} = $1;
+  }
+  elsif ($ln =~ /.* = TID for which a Basic BlockAck frame is requested: (\S+)/) {
+    $self->{ba_tid} = $1;
+  }
+  elsif ($ln =~ /.*Block Ack Bitmap: (\S+)/) {
+    $self->{ba_bitmap} = $1;
+  }
+  elsif ($ln =~ /\s*Data Rate: (.*)/) {
+    $self->{datarate} = $1;
+  }
+  elsif ($ln =~ /\s*VHT information/) {
+    $self->{is_vht} = 1;
+  }
+  elsif ($ln =~ /\s*Bandwidth: (.*)/) {
+    $self->{bandwidth} = $1;
+  }
+  elsif ($ln =~ /\s*User 0: MCS (.*)/) {
+    $self->{mcs} = $1;
+  }
+  elsif ($ln =~ /.* = Spatial streams 0: (.*)/) {
+    $self->{nss} = $1;
+  }
+  elsif ($ln =~ /.* = TID: (.*)/) {
+    $self->{tid} = $1;
+  }
+  elsif ($ln =~ /.* = Payload Type: (.*)/) {
+    $self->{payload_type} = $1;
+  }
+  elsif ($ln =~ /\s+\[Data Rate: (.*)\]/) {
+    $self->{datarate} = $1;
+  }
+  elsif ($ln =~ /\s*SSI Signal: (.*)/) {
+    if ($self->{ssi_sig_found} == 0) {
+      $self->{ssi_combined} = $1;
+      $self->{ssi_sig_found}++;
+    }
+    elsif ($self->{ssi_sig_found} == 1) {
+      $self->{ssi_ant_0} = $1;
+      $self->{ssi_sig_found}++;
+    }
+    elsif ($self->{ssi_sig_found} == 2) {
+      $self->{ssi_ant_1} = $1;
+      $self->{ssi_sig_found}++;
+    }
+    elsif ($self->{ssi_sig_found} == 3) {
+      $self->{ssi_ant_2} = $1;
+      $self->{ssi_sig_found}++;
+    }
+    elsif ($self->{ssi_sig_found} == 4) {
+      $self->{ssi_ant_3} = $1;
+      $self->{ssi_sig_found}++;
+    }
+  }
+  # AMPDU and such...
+  elsif ($ln =~ /\s*A-MSDU Subframe #(\d+)/) {
+    if ($1 > $self->{amsdu_frame_count}) {
+      $self->{amsdu_frame_count} = $1;
+    }
+  }
+}
+
+sub frame_num {
+  my $self = shift;
+  return $self->{frame_num};
+}
+
+sub type_subtype {
+  my $self = shift;
+  return $self->{type_subtype};
+}
+
+sub transmitter {
+  my $self = shift;
+  return $self->{transmitter};
+}
+
+sub receiver {
+  my $self = shift;
+  return $self->{receiver};
+}
+
+sub tid {
+  my $self = shift;
+  return $self->{tid};
+}
+
+sub set_transmitter {
+  my $self = shift;
+  my $tx = shift;
+  $self->{transmitter} = $tx;
+}
+
+sub set_receiver {
+  my $self = shift;
+  my $rx = shift;
+  $self->{receiver} = $rx;
+}
+
+1;

wifi_diag/PeerConn.pm

@@ -0,0 +1,80 @@
+package PeerConn;
+
+use warnings;
+use strict;
+
+use Tid;
+
+sub new {
+  my $class = shift;
+  my %options = @_;
+
+  my $self = {
+	      %options,
+	      tids => [],
+	     };
+
+  bless($self, $class);
+  return($self);
+}
+
+sub hash_str {
+  my $self = shift;
+  return $self->{local_addr} . "." .  $self->{peer_addr};
+}
+
+sub local_addr {
+  my $self = shift;
+  return $self->{local_addr};
+}
+
+sub peer_addr {
+  my $self = shift;
+  return $self->{peer_addr};
+}
+
+sub add_pkt {
+  my $self = shift;
+  my $pkt = shift;
+
+  my $tidno = $pkt->tid();
+
+  my $tid = $self->find_or_create_tid($tidno);
+  $tid->add_pkt($pkt);
+}
+
+sub find_or_create_tid {
+  my $self = shift;
+  my $tidno = shift;
+
+  my $tid;
+
+  if (exists $self->{tids}[$tidno]) {
+    $tid = $self->{tids}[$tidno];
+  }
+  else {
+    $tid = Tid->new(tidno => $tidno);
+    $self->{tids}[$tidno] = $tid;
+  }
+  return $tid;
+}
+
+sub printme {
+  my $self = shift;
+  my $tid_count = @{$self->{tids}};
+
+  print "hash-key: " . $self->hash_str() . " tid-count: " . $tid_count . "\n";
+  my $i;
+  for ($i = 0; $i < $tid_count; $i++) {
+    #print "Checking tid: $i\n";
+    if (exists $self->{tids}[$i]) {
+      #print "Printing tid: $i\n";
+      $self->{tids}[$i]->printme();
+      #print "Done printing tid: $i\n";
+    }
+  }
+  #print "Done peer-conn printme\n";
+  return;
+}
+
+1;

wifi_diag/Tid.pm

@@ -0,0 +1,42 @@
+package Tid;
+
+use warnings;
+use strict;
+
+sub new {
+  my $class = shift;
+  my %options = @_;
+
+  my $self = {
+	      pkts => [],
+	      %options,
+	     };
+
+  bless($self, $class);
+  return($self);
+}
+
+sub tidno {
+  my $self = shift;
+  return $self->{tidno};
+}
+
+sub add_pkt {
+  my $self = shift;
+  my $pkt = shift;
+
+  push(@{$self->{pkts}}, $pkt);
+}
+
+sub get_pkts {
+  my $self = shift;
+  return @{$self->{pkts}};
+}
+
+sub printme {
+  my $self = shift;
+  print "  tidno: " . $self->tidno() . "\n";
+  print "   pkt-count: " . $self->get_pkts() . "\n";
+}
+
+1;

wifi_diag/wifi_pcap_diag.pl

@@ -0,0 +1,89 @@
+#!/usr/bin/perl -w
+
+# Read in a decoded pcap file and generate report
+# Usage:  tshark -V -r wifi.pcap | ./wifi_pcap_diag.pl
+
+use strict;
+use warnings;
+use diagnostics;
+use Carp;
+
+use PeerConn;
+use Packet;
+
+my %peer_conns = ();
+
+my $cur_pkt = Packet->new(raw_pkt => "");
+my $last_pkt = Packet->new(raw_pkt => "");
+
+while (<>) {
+  my $ln = $_;
+  if ($ln =~ /^Frame (\d+):/) {
+    if ($cur_pkt->raw_pkt() ne "") {
+      processPkt($cur_pkt);
+    }
+    $cur_pkt = Packet->new(frame_num => $1,
+			   raw_pkt => $ln);
+  }
+  else {
+    $cur_pkt->append($ln);
+  }
+}
+
+if ($cur_pkt->raw_pkt() ne "") {
+  processPkt($cur_pkt);
+}
+
+# Print out all peer-conns we found
+for my $conn (values %peer_conns) {
+  $conn->printme();
+}
+
+exit 0;
+
+
+sub processPkt {
+  my $pkt = shift;
+
+  # Find which station (or AP) sent this pkt.
+  # Add graph point for mcs vs time
+  # Add graph point for retransmits
+  # Check sequence-no gap
+
+  # If pkt is an ACK, it will not have a sender address.  Guess based on
+  # previous packet.
+  if ($pkt->type_subtype() eq "Acknowledgement (0x001d)") {
+    if ($last_pkt->transmitter() eq $pkt->receiver()) {
+      $pkt->set_transmitter($last_pkt->receiver());
+    }
+    else {
+      print "ERROR:  Frame " . $pkt->frame_num() . " is ACK for unknown packet.\n";
+      $last_pkt = $pkt;
+      return;
+    }
+  }
+
+  my $hash = $pkt->receiver() . "." . $pkt->transmitter();
+  my $hash2 = $pkt->transmitter() . "." . $pkt->receiver();
+
+  my $peer_conn;
+  if (exists $peer_conns{$hash}) {
+    $peer_conn = $peer_conns{$hash};
+  }
+  else {
+    if (exists $peer_conns{$hash2}) {
+      $peer_conn = $peer_conns{$hash2};
+    }
+    else {
+      $peer_conn = PeerConn->new(local_addr => $pkt->receiver(),
+				 peer_addr => $pkt->transmitter());
+      $peer_conns{$hash} = $peer_conn;
+    }
+  }
+
+  $peer_conn->add_pkt($pkt);
+
+  $last_pkt = $pkt;
+
+  #print "pkt: rcvr: " . $pkt->receiver() . " transmitter: " . $pkt->transmitter() . "\n";
+}