bom-d-van

# https://www.percona.com/blog/2008/11/07/poor-mans-query-logging/

tcpdump -i eth0 -s 0 -l -w - dst port 3306 | strings | perl -e '
while(<>) { chomp; next if /^[^ ]+[ ]*$/;
  if(/^(SELECT|UPDATE|DELETE|INSERT|SET|COMMIT|ROLLBACK|CREATE|DROP|ALTER)/i) {
    if (defined $q) { print "$q\n"; }
    $q=$_;
  } else {
    $_ =~ s/^[ \t]+//; $q.=" $_";
  }

bom-d-van

Detecting and Mitigating DDOS Attacks

#List all Finish (FIN) packets
machine1 : sudo /usr/sbin/tcpdump -Nnn -i any -s0 'tcp[13] & 1 != 0'


#List all SYN and SYN-ACK packets
machine1 : sudo /usr/sbin/tcpdump -Nnn -i any -s0 'tcp[13] & 2 != 0' 

bom-d-van

Using nc and protoc as protobuf client and server

Inspiration: Linux and Unix nc command

Example protobuf definition:

message Person {
  required string name = 1;
  required int32 id = 2;

bom-d-van

Use TCPDUMP to Monitor HTTP Traffic

1. To monitor HTTP traffic including request and response headers and message body:

tcpdump -A -s 0 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)'

2. To monitor HTTP traffic including request and response headers and message body from a particular source:

tcpdump -A -s 0 'src example.com and tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)'

bom-d-van

# osx
lsof -iTCP -sTCP:LISTEN

# linux: tuna please!
netstat -tunapl

bom-d-van

// +build ignore

package main

import (
	"fmt"
	"os"
	"runtime"
	"syscall"
)

bom-d-van

# deploy (example)
rpm -iv pkg-{version}-x86_64.rpm

# list current version
rpm -qi pkg

# uninstall
rpm -ev pkg

bom-d-van

# osx
cat test.http | nc -l -p 8000

# linux
cat test.http | nc -l 8000

# centos fix
# http://serverfault.com/a/729768/71640
# Removes the old package
yum erase nc

bom-d-van

# set up shared folder
VBoxManage sharedfolder add "VM name" --name "sharename" --hostpath "/path"

# test mounting
mkdir ~/path
sudo mount -t vboxsf sharename ~/path

# error: /sbin/mount.vboxsf: mounting failed with the error: No such file or directory
sudo apt-get install dkms build-essential linux-headers-$(uname -r) virtualbox-guest-additions-iso
sudo reboot

bom-d-van

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname