# cf. http://trac.macports.org/wiki/InstallingMacPorts
/opt/local/bin/port info hping3
/usr/bin/sudo /opt/local/bin/port install hping3

hping3 --help


# Terminal window 1
alias sudo=/usr/bin/sudo
alias tcpdump=/usr/sbin/tcpdump
#sudo tcpdump -s0 -xX -i lo0 port 4678 and host localhost
sudo tcpdump -s0 -vvv -i lo0 port 4678 and host localhost


# Terminal window 2
alias sudo=/usr/bin/sudo
alias hping3=/opt/local/sbin/hping3
sudo hping3 -I lo0 -s 4678 -c 1 localhost -p 4678
sudo hping3 -S -I lo0 -d 995 -s 4678 -c 1 localhost -p 4678
sudo hping3 -SA -I lo0 -d 995 -w 200 -s 4678 -c 1 localhost -p 4678
sudo hping3 -SA -M 3000 -I lo0 -d 995 -w 65 -s 4678 -c 1 localhost -p 4678
sudo hping3 -DV -SA -I lo0 -s 4678 -a 192.168.1.100 -c 1 localhost -p 4678


#----------------------------------------


# some corresponding ipfw rules for testing purposes 
# (just place them at the beginning of your ipfw rule set)

# not me to me & me to not me
/sbin/ipfw -q add count log all from not me to me 4678 in
/sbin/ipfw -q add count log all from me to not me 4678 out

# any to me & me to any
/sbin/ipfw -q add count log all from any to me 4678 in
/sbin/ipfw -q add count log all from me to any 4678 out
    
# any to any
/sbin/ipfw -q add count log all from any to any 4678

# cf. Example ipfw ruleset, http://codesnippets.joyent.com/posts/show/1267

# choose appropriate numbers for num1 & num2 according to your ipfw ruleset

/usr/bin/sudo /sbin/ipfw list
/usr/sbin/sysctl -n net.inet.ip.fw.autoinc_step

function free_ipfw_rule_num() {
   declare -i num1=6701 num2=6799 lastipfwnum
   if [[ $(/usr/sbin/sysctl -n net.inet.ip.fw.autoinc_step) -ne 100 ]]; then 
      printf "%s\x21\n" "sysctl -n net.inet.ip.fw.autoinc_step is not set to 100"
      return 1
   fi
   lastipfwnum=$(/usr/bin/sudo /sbin/ipfw list | /usr/bin/tail -n 2 | /usr/bin/head -n 1 | /usr/bin/awk '{print $1}')
   if [[ $num2 -ge $lastipfwnum ]]; then 
      printf "%s\x21\n" "${num2} is greater than or equal to ${lastipfwnum}"
      return 1
   fi
   while $(/usr/bin/sudo /sbin/ipfw show ${num1} &>/dev/null) ; do
      let "num1 += 1"
      if [[ $num1 -gt $num2 ]]; then num1=; break; return 1; fi
   done
   printf "%s\n" "${num1}"
   return 0
}


function openport() {
   declare portnum rulenum
   if [[ $# -ne 1 ]]; then printf "%s\n" "Wrong number of arguments: $#"; return 1; fi
   portnum="${1//[^[:digit:]]/}"
   if [[ -z $portnum ]]; then printf "%s\n" "No valid port number given: ${1}"; return 1; fi
   if [[ $portnum -gt 65535 ]]; then printf "%s\n" "Given port number is greater than 65535: ${portnum}"; return 1; fi
   rulenum=$(free_ipfw_rule_num)
   /usr/bin/sudo /sbin/ipfw -q add ${rulenum} allow all from any to any dst-port ${portnum} keep-state
   printf "%s\n" "... opening ipfw rule no. ${rulenum} for internet access via port ${portnum}"
   return 0
}


function closeport() {
   declare portnum rulenum
   if [[ $# -ne 1 ]]; then printf "%s\n" "Wrong number of arguments: $#"; return 1; fi
   portnum="${1//[^[:digit:]]/}"
   if [[ -z $portnum ]]; then printf "%s\n" "No valid port number given: ${1}"; return 1; fi
   if [[ $portnum -gt 65535 ]]; then printf "%s\n" "Given port number is greater than 65535: ${portnum}"; return 1; fi
   rulenum=$(/usr/bin/sudo /sbin/ipfw list | /usr/bin/awk "/from +any +to +any +dst-port +${portnum} +keep-state[[:space:]]*$/ {print \$1}")
   if [[ -z "${rulenum}" ]]; then printf "%s\n" "No ipfw rule for port number: ${portnum}"; return 1; fi
   /usr/bin/sudo /sbin/ipfw -q delete ${rulenum}
   printf "%s\n%s\n" "... deleting ipfw rule no. ${rulenum//[[:cntrl:]]/ }" "... closing internet access via port: ${portnum}"
   return 0
}


openport 43
openport 43
openport 43

/usr/bin/sudo /sbin/ipfw show [rulenum]     # ... allow ip from any to any dst-port 43 keep-state

closeport 43

# first create a symbolic link
sudo ln -s "/Applications/Utilities/Network Utility.app/Contents/Resources/stroke" /bin/portscan

# usage: portscan address startPort endPort

portscan localhost 1 5000

portscan $(/usr/sbin/ipconfig getifaddr en0 2>/dev/null || /bin/echo localhost) 1 10000

No forking in background and verbose

ssh -2 -v -c blowfish -C -N user@servername.textdrive.com -L 3370/127.0.0.1/3306



Forking in background

ssh -2 -f -c blowfish -C -N user@servername.textdrive.com -L 3370/127.0.0.1/3306