NAME
Packit - Packet analysis and injection tool
SYNOPSIS
Packet capture:
packit -m capture [-cGHnvsX] [-i interface] [-r|-w file] expression
Packet injection:
packit -m inject [-t protocol]
[-aAbcCdDeFgGhHjJkKlLmMnNoOpPqQrRsSTuUvwWxXyYzZ] [-i interface]
DESCRIPTION
Packit is a network auditing tool. It´s value is derived from its
ability to customize, inject, monitor, and manipulate IP traffic. By
allowing you to define (spoof) all TCP, UDP, ICMP, IP, ARP, RARP and
Ethernet header options, Packit can be useful in testing firewalls,
intrusion detection systems, port scanning, simulating network traffic
and general TCP/IP auditing. Packit is also an excellent tool for
learning TCP/IP.
PACKIT BASE OPTIONS
-m mode
Select a runtime mode. Currently supported modes
are capture, inject and trace. The default is inject.
PACKET CAPTURE OPTIONS
Packet capture options are as follows:
-c count
Specify the number of packets to capture
-e Display link-layer header data.
-G Display the timestamp in GMT rather than localtime.
-i interface
Listen on interface. If unspecified, packit will use the lowest
numbered device in the ’up’ state (excluding loopback).
-n Don’t resolve host addresses to names but resolve ports numbers.
Disables DNS lookups.
-nn Don’t resolve ports numbers to their protocol names but resolve
host addresses.
-nnn Don’t resolve host addresses or port numbers.
-r file
Read packet data from tcpdump formated binary log file. (example:
a file created with -w)
-s snaplen
Read snaplen bytes of data from each packet rather than the
default of 68.
-v Enables verbose packet capture.
-w file
Write the raw packets to file rather than displaying time to
stderr.
-X Display hexadecimal & ascii dump of each packet up to snap
length bytes.
expression
selects which packets should be displayed. If no expression is
given, all packets are displayed. See the tcpdump(1) man page for
more detailed information.
PACKET INJECTION / TRACE
Packet injection is used to define and inject IP based network traffic
onto your network. You have the ability to define essentially any ARP,
IP, TCP, UDP, ICMP and Ethernet header value. This can be valuable in a
number of ways, including testing firewalls, intrusion detection
systems, simulating traffic flow and general TCP/IP auditing.
CHOOSE YOUR PROTOCOL
-t protocol
Specify the type of packet to inject. Supported values are: ARP,
TCP, UDP and ICMP. This option defaults to TCP
in inject mode and ICMP in trace mode.
PACKET INJECTION / TRACE GENERAL
This section documents the operational command-line options.
-c count
The value of count is the total number of packets we would like
to inject (a count value of 0 means forver).
-w interval
The number of seconds to wait between sending each packet burst
(default: 1).
-b burst rate
Specifies the number of packets to inject every interval (defined
by -w). (A burst rate of 0 will send packets as quickly as
possible)
-h
Host response mode. Enabling this option will print any packet
you inject and then wait (see -H for timeout) to see if the remote
host responds.
-H timeout
Specify the timeout value (in seconds) to use with ’-h’.
This value defaults to ’1’ second.
-i interface
Specify the interface to transmit from, if the machine has
multiple interfaces.
-v
Verbose injection mode. Displays each packet you inject. It
also has the same effect as in capture mode while used with
the ’-h’ option.
-p payload
This option defines the payload portion of the header.
Hex payload should be prefixed with ’0x’ with each value
separated by a whitespace.
ASCII Example: -p ’hello, this is my packet’
Hex Example: -p ’0x 70 61 63 6B 69 74’
-w interval
Specify the number of seconds to wait between packet bursts.
This value defaults to ’1’ second.
-Z length
Specify the size of the packet(s) to inject. (Max: 65535)
IP HEADER OPTIONS
This section documents the IP header command-line options.
-s src address
The IP address the packet will appear to come from. If
unspecified, packit will default to the IP address of the
lowest numbered device in the ’up’ state (excluding loopback).
-sR Use a random source IP address.
-d dst address
The IP address of the machine you would like to contact.
-dR Use a random destination IP address.
-o type of service
TOS values are typically in hexidecimal format, however, packit
only accepts TOS values as integers.
Below are the 4 valid TOS bit values:
- Minimize delay: 16 (0x10)
- Maximize throughput: 8 (0x08)
- Maximize reliability: 4 (0x04)
- Minimize monetary cost: 2 (0x02)
-n ID number
The ID number is used to identify each datagram sent by a host.
It generally increments by one with each datagram sent. This
value is random by default.
-T TTL
The TTL value defines the upper limit on the number of devices
through which the datagram may pass to reach it’s destination.
The default value is 128.
-V IP protocol number
Specify the IP protocol assocated with this packet (RAWIP only).
The default value is 255.
TCP HEADER OPTIONS
This section documents the TCP header command-line options.
-S src port
The port from which our source address is communicating from. This
value is random by default.
-D dst port
The port on the destination we would like to communicate on. In
inject mode this value is 0 by default while in trace mode this
value is random by default. You may also specify a range of
addresses in the format: -D 1:1024.
-f Do not fragment this packet.
-F tcp flags
There are 6 TCP header flag bits. They can be used in combination
with one another and are specified using the following
identifiers:
- S : SYN (Synchronization sequence number)
- F : FIN (Sender is finished)
- A : ACK (Acknowledgement number is valid)
- P : PSH (Receiver should push this data to the remote host)
- U : URG (The urgent pointer is valid)
- R : RST (Reset this connection)
As an example, to set the SYN and FIN bits use the
following: -F SF
-q sequence number
The sequence number is a 32-bit unsigned (positive) number used
to identify the byte in a stream of data from the sending TCP
to the receiving TCP that the first byte of data represents.
-a ack number
The acknowledgement (ack) number defines the next sequence
number that the sender of the ack expects to see. It is
typically the sequence number + 1 during valid TCP
communication. It is a 32-bit unsigned (positive) number.
-W window size
The window size provides flow control. It is a 16-bit
number that defines how many bytes the receiver is willing
to accept. The default value is 1500.
-u urgent pointer
In valid TCP communication, the urgent pointer is
only useful if the URG flag is set. Used with the
sequence number, it points to the last byte of urgent
data.
UDP HEADER OPTIONS
This section documents the UDP header command-line options. UDP is the
default IP protocol for TRACE mode.
-S src port
The port from which our source address is communicating from. This
value is random by default.
-D dst port
The port on the destination we would like to communicate on. In
inject mode this value is 0 by default while in trace mode this
value is random by default. You may also specify a range of
addresses in the format: -D 1:1024.
ICMP HEADER OPTIONS
This section documents the ICMP header command-line options.
-K type
Specify the ICMP type. See docs/ICMP.txt for details on types.
-C code
Specify the ICMP code. See docs/ICMP.txt for details on codes.
ECHO REQUEST / ECHO REPLY OPTIONS
-N id number
Define the 16-bit ICMP identification number. This value is
random by default.
-Q sequence number
Define the 16-bit ICMP sequence number. This value is random
by default.
UNREACHABLE / REDIRECT / TIME EXCEEDED OPTIONS
-g gateway
Define the gateway in which to redirect traffic to. This option
is only used for ICMP redirects (type 5).
-j address
Define the source address of the original packet.
-J src port
Define the source port of the original packet.
-l address
Define the destination address of the original packet.
-L dst port
Define the destination port of the original packet.
-m time to live
Define the Time To Live of the original packet. This option
defaults to 128.
-M id
Define the IP ID of the original packet. This option defaults
to random.
-O type of service
Define the Type of Service of the original packet. See the
-o option for the possible values.
-P protocol
Define the protocol of the original packet. This option
defaults to UDP.
MASK REQUEST / MASK REPLY OPTIONS
-N id number
Define the 16-bit ICMP identification number. This value is
random by default.
-Q sequence number
Define the 16-bit ICMP sequence number. This value is random
by default.
-G address mask
Define the address network mask. The default value for this
option is:255.255.255.0.
TIMESTAMP REQUEST / TIMESTAMP REPLY OPTIONS
-N id number
Define the 16-bit ICMP identification number. This value is
random by default.
-Q sequence number
Define the 16-bit ICMP sequence number. This value is random
by default.
-U original timestamp
Define the 32-bit original timestamp. This value is 0
by default.
-k recieved timestamp
Define the 32-bit recieved timestamp. This value is 0
by default.
-z transmit timestamp
Define the 32-bit transmit timestamp. This value is 0
by default.
ARP HEADER OPTIONS
This section documents the ARP header command-line options. In my
opinion, these options have the ability to do the most damage with the
least effort, especially on large cable and DSL networks. Use with
caution.
Packit only supports ARP protocol addresses in IPv4 format
-A operation type
Define the ARP / RARP / IRARP operation type. The valid options
are as follows:
- 1 : ARP Request
- 2 : ARP Reply
- 3 : Reverse ARP Request
- 4 : Reverse ARP Reply
- 5 : Inverse ARP Request
- 6 : Inverse ARP Reply
-y target IP address
The IP address of the target host.
-yR Use a random target host IP address.
-Y target ethernet address
The ethernet (hardware) address of the target host.
-YR Usage a random target host ethernet address.
-x sender IP address
The IP address of the sender host.
-xR Use a random sender host IP address.
-X sender ethernet address
The ethernet (hardware) address of the sender host.
-XR Usage a random sender host ethernet address.
ETHERNET HEADER OPTIONS
This section documents the Ethernet header command-line options.
-e src ethernet address
The ethernet (hardware) address the packet will appear to come
from.
-eR Use a random source ethernet address.
If you define this, you will most likely need to define the
destination ethernet header value as well. When using either -e or
-E, you enable link level packet injection and enable link level
packet injection and the destination cannot be auto-defined while
injecting in this manner.
-E dst ethernet address
The ethernet (hardware) of the next routable interface the packet
will cross while making it’s way to the destination.
-ER Use a random destination ethernet address.
The following two rules should be followed if you actually want the
destination to receive to receive the packets you’re sending:
1) If the destination exists beyond your default route (gateway),
the destination ethernet address should be set to the default
routes address should be set to the default routes ethernet
address. This can typically be found by using the arp(8) command.
2) If the destination exists on your subnet, the destination
ethernet address should be set to its ethernet address. This
can typically be found by using the arp command.
PACKET CAPTURE EXAMPLES
To print all TCP communications that doesn’t revolve around SSH (port
22).
packit -m cap ’tcp and not port 22’
To print the start and end packets (the SYN and FIN pack- ets) of
each TCP conversation that involves a non-local host, don’t resolve
addresses and display hex/ascii dump of the packet.
packit -m cap -nX ’tcp[tcpflags] & (tcp-syn|tcp-fin) != 0
and not src and dst net localnet’
To write the first 10 ICMP packets captured to a file.
packit -m cap -c 10 -w /tmp/mylog ’icmp’
PACKET INJECTION EXAMPLES
IMPORTANT: The ethernet address ’f:00:d:f:00:d’ in these examples is a
mock representation of the ethernet address of my default route. In
order for these examples to work properly, you would need to change it
to your correct default route ethernet address.
Inject 10 ICMP type 8 (echo request) packets from host ’3.1.33.7’ to
host ’192.168.0.1’ and watch for a response.
packit -t icmp -s 3.1.33.7 -d 192.168.0.1 -c 10 -h
Inject an ICMP type 18 (mask reply) packet with an ICMP id of 211 and
an address mask of 255.255.255.0.
packit -t icmp -K 18 -d 127.0.0.1 -N 211 -G 255.255.255.0
Inject 5 TCP packets from random hosts to ’www.microsoft.com’ with the
SYN flag set, a window size of 666, a random source ethernet address, a
destination ethernet address of f:00:d:f:00:d, with a payload of "HI
BILL", displaying each packet injected.
packit -sR -d www.microsoft.com -F S -c 5 -W 666
-eR -E f:00:d:f:00:d -p ’HI BILL’ -v
Inject a total of 1000 TCP packets in 20 packet per second bursts from
192.168.0.1 on port 403 to 192.168.0.20 on port 80 with the SYN and RST
flags set, a sequence number of 12345678910 and a source ethernet
address of 0:0:0:0:0:0.
packit -s 192.168.0.1 -d 192.168.0.20 -S 403 -D 80
-F SR -q 12345678910 -c 1000 -b 20 -e 0:0:0:0:0:0
Inject a TCP packets from 10.22.41.6 to 172.16.1.3 on ports ranging
from 1-1024 with the SYN flag set and display each packet we send.
packit -s 10.22.41.6 -d 172.16.1.3 -D 1-1024 -F S -v
Inject a broadcast ARP reply stating that 4.3.2.1 is at 5:4:3:2:1:0.
Also, spoof the source ethernet adddress for a little more authenticity
and supply the payload in hex.
packit -t arp -A 2 -x 4.3.2.1 -X 5:4:3:2:1:0 -e 5:4:3:2:1:0
-p ’0x 70 61 63 6B 69 74’
TRACE ROUTE EXAMPLES
Appear as a DNS response by using a UDP source port of 53 (DNS)
packit -m trace -t UDP -d 192.168.2.35 -S 53
Appear as HTTP traffic by using TCP port 80
packit -m trace -t TCP -d www.google.com -S 80 -FS
SEE ALSO
pcap(3), bpf(4), libnet(3), tcpdump(1)
BUGS
Due to limitations in some versions of *BSD, specifying arbitrary
ethernet and/or ARP header data may not be supported.
ARP capture data is incomplete.
Like this man page, packit is still very much a work in progress.
Please send bug reports, questions or requests to
dbounds@intrusense.com.
AUTHOR
Darren Bounds <dbounds@intrusense.com>
The latest version can be found at:
http://packit.sourceforge.net