Differences for page hping send -- hping network security tool

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Differences for page hping send

Current version compared with version Sun Sep 05 07:13:45 GMT 2004

...
  This command is used to send [TCP/IP] packets. It is able to send
  packets specified in the same format the command [hping recv] returns
  packets, this basically means that you can experiment with
- 'hping recv' in order to undrestand how to send a given packet.
+ 'hping recv' in order to understand how to send a given packet.
  Also note that a common pattern with [hping3] is to receive
- packets with [hping recv], modify this packets in some way
+ packets with [hping recv], modify these packets in some way
  and resend with [hping send]. This makes the creation of scripts
  to do [NAT] and all the sort of [TCP/IP] flow manipulation very easy.
  
...
  
  Note that the first two commands are used to get the outgoing interface
  address. From the example it should be clear that in the [hping3] world
- packets are strings rappresenting different layers of the packet.
- When a given layer is not specified by the user, hping try to set
- it at a reasonable value. For instance the user don't need to
+ packets are strings representing different layers of the packet.
+ When a given layer is not specified by the user, hping tries to set
+ it to a reasonable value. For instance the user doesn't need to
  specify [IP] and [TCP] checksums for normal packets because hping will
- compute it automatically. Of curse to create broken packets it can
+ compute them automatically. Of course to create broken packets it can
  be useful to specify a checksum field.
  
  Working with packets as strings, it is handy to create a packet
...
       hping send $syn
   }
  
- The *-nocompile* optional switch is used to tell hping to don't
+ The *-nocompile* optional switch is used to tell hping to not
  compile the packet (packet compilation calculate stuff like
  checksums, tot length, and so on), it is useful in order to
  send broken packets.
...

The following is the old page content

{hping send ?-nocompile? `packet`}

This command is used to send [TCP/IP] packets. It is able to send
packets specified in the same format the command [hping recv] returns
packets, this basically means that you can experiment with
'hping recv' in order to undrestand how to send a given packet.
Also note that a common pattern with [hping3] is to receive
packets with [hping recv], modify this packets in some way
and resend with [hping send]. This makes the creation of scripts
to do [NAT] and all the sort of [TCP/IP] flow manipulation very easy.

In order to send a [TCP] packet with the [SYN flag] set to the
host www.hping.org one can write:

hping3> set target www.hping.org               
 www.hping.org
 hping3> set myaddr [hping outifa $target]
 192.168.1.6
 hping3> hping send "ip(saddr=$myaddr,daddr=$target,ttl=255)+tcp(sport=123,dport=80,flags=s)"

Note that the first two commands are used to get the outgoing interface
address. From the example it should be clear that in the [hping3] world
packets are strings rappresenting different layers of the packet.
When a given layer is not specified by the user, hping try to set
it at a reasonable value. For instance the user don't need to
specify [IP] and [TCP] checksums for normal packets because hping will
compute it automatically. Of curse to create broken packets it can
be useful to specify a checksum field.

Working with packets as strings, it is handy to create a packet
starting with an empty string, adding a layer at a time: this makes
the code very simple to read. For example the previous code to
send a packet can be written this way:

set target www.hping.org
 set myaddr [hping outifa $target]
 set syn {}
 append syn "ip(saddr=$myaddr,daddr=$target,ttl=255)"
 append syn "+tcp(sport=123,dport=80,flags=2)"
 hping send $syn

You can cut and paste the code in a file called 'example.htcl', then
run it using:

hping3 exec example.htcl

Note that you can use all the features of [Tcl], for example
in order to send the same [SYN] packet with 10 different [TTL] values
it is possible to modify the previous script to obtain this:

set target www.hping.org
 set myaddr [hping outifa $target]
 for {set ttl 0} {$ttl < 10} {incr ttl} {
     set syn {}
     append syn "ip(saddr=$myaddr,daddr=$target,ttl=$ttl)"
     append syn "+tcp(sport=123,dport=80,flags=2)"
     hping send $syn
 }

The *-nocompile* optional switch is used to tell hping to don't
compile the packet (packet compilation calculate stuff like
checksums, tot length, and so on), it is useful in order to
send broken packets.