dumps Bitcoin network traffic

bitdump.sh

#!/usr/bin/env sh

# bitdump.sh
#
# captures Bitcoin network traffic

SELF=`basename $0`

if [[ $1 = "" ]]; then
  DEFAULT="en1"
  echo "$SELF: no interface name provided as argument: using $DEFAULT as default"
else
  DEFAULT=$1
fi

connected_nodes() {
  netstat -an |
  awk '/8333/ && /ESTA/ { print $5 }' |
  sed 's/[.:]8333//'
}

# tcpdump config
IF="-i $DEFAULT"
ASCII="-A"
BINARY="-XX"
NO_DNS="-n"
FULL_PACKETS="-s 0"
NODES=($(connected_nodes))
PORT="8333"
FILE="bitdump.pcap"

if [[ -z "$NODES" ]]; then
  echo "$SELF: No peer found, check your internet connection and that Bitcoin is running"
else
  for (( i = 0; i < ${#NODES[*]}; i++ )); do
    ANY_NODE="host ${NODES[i]} and $ANY_NODE"
  done

  # -t : don't print a timestamp on each dump line
  # -q : stay quiet

  CMD="tcpdump $IF -w $FILE $FULL_PACKETS $BINARY $NO_DNS $ANY_NODE port $PORT"

  echo $CMD
  $CMD
fi