nemesis-dns - DNS Protocol (The Nemesis Project)

nemesis-dns [-kvZ?] [-a ack-number ] [-A number-of-authoritative-DNS-resource-records ] [-b number-of-DNS-answers ] [-d Ethernet-device ] [-D destination-IP-address ] [-f TCP-flags ] [-F fragmentation-options ] [-g DNS-flags ] [-H source-MAC-address ] [-i DNS-ID ] [-I IP-ID ] [-M destination-MAC-address ] [-o TCP-options-file ] [-O IP-options-file ] [-P payload-file ] [-q number-of-DNS-questions ] [-r number-of-additional-DNS-resource-records ] [-s sequence-number ] [-S source-IP-address ] [-t IP-TOS ] [-T IP-TTL ] [-u urgent-pointer ] [-w window-size ] [-x TCP/UDP-source-port ] [-y TCP/UDP-destination-port ]

The Nemesis Project is designed to be a command line-based, portable human IP stack for UNIX-like and Windows systems. The suite is broken down by protocol, and should allow for useful scripting of injected packets from simple shell scripts.

nemesis-dns provides an interface to craft and inject DNS packets allowing the user to specify any portion of a DNS packet as well as lower-level IP and TCP/UDP packet information.

-A number-of-authoritative-resource-records

Specify the number-of-authoritative-resource-records within the DNS header.

-b Number-of-answer-resource-records

Specify the number-of-answer-resource-records within the DNS header.

-g DNS-flags

Specify the DNS-flags within the DNS header.

"-i

Specify the DNS-ID within the DNS header.

-k TCP-transport-mode

Enables the use of TCP when injecting DNS packets.

-P payload-file

This will cause nemesis-dns to use the specified payload-file as the payload when injecting DNS packets. For packets injected using the raw interface (where -d is not used), the maximum payload size is 65443 bytes for DNS packets injected using TCP and 65455 for DNS packets injected using UDP. For packets injected using the link layer interface (where -d IS used), the maximum payload size is 1368 bytes for TCP DNS packets and 1420 bytes for UDP DNS packets. Payloads can also be read from stdin by specifying '-P -' instead of a payload-file.

Windows systems are limited to a maximum payload size of 1368 bytes for TCP DNS packets and 1420 bytes for UDP DNS packets.

The payload file can consist of any arbitary data though it will be most useful to create a payload resembling the structure of the DNS packet specified using the command-line options. In order to send real DNS packets, a payload containing the appropriate record data (as specified in the DNS header) must be created manually.

-q Number-of-questions

Specify the number-of-questions within the DNS header.

-r Number-of-additional-resource-records

Specify the number-of-additional-resource-records within the DNS header.

-v verbose-mode

Display the injected packet in human readable form. Use twice to see a hexdump of the injected packet.

-a Acknowledgement-Number

Specify the acknowledgement-number (ACK number) within the TCP header.

-f TCP flags (-fS/-fA/-fR/-fP/-fF/-fU/-fE/-fC)

Specify the TCP flags:

-fS (SYN)
-fA (ACK)
-fR (RST)
-fP (PSH)
-fF (FIN)
-fU (URG)
-fE (ECE)
-fC (CWR)

within the TCP header. Flags can be combined in the form '-fPA'.

-o TCP-options-file

This will cause nemesis-dns to use the specified TCP-options-file as the options when building the TCP header for the injected packet. TCP options can be up to 40 bytes in length. The TCP options file must be created manually based upon the desired options. TCP options can also be read from stdin by specifying '-o -' instead of a TCP-options-file.

-s sequence-number

Specify the sequence-number within the TCP header.

-u urgent-pointer-offset

Specify the urgent-pointer-offset within the TCP header.

-w window-size

Specify the window-size within the TCP header.

-x TCP-source-port

Specify the TCP-source-port packet within the TCP header.

-y TCP-destination port

Specify the TCP-destintion-port within the TCP header.

-x UDP-source-port

Source Port of injected packet.

-y UDP-Destination-Port

Target Port of injected packet.

-D destination-IP-address

Specify the destination-IP-address within the IP header.

-F fragmentation-options (-F[D],[M],[R],[offset])

Specify the fragmentation options:

-FD (don't fragment)
-FM (more fragments)
-FR (reserved flag)
-F <offset>

within the IP header. IP fragmentation options can be specified individually or combined into a single argument to the -F command line switch by separating the options with commas (eg. '-FD,M') or spaces (eg. '-FM 223'). The IP fragmentation offset is a 13-bit field with valid values from 0 to 8189. Don't fragment (DF), more fragments (MF) and the reserved flag (RESERVED or RB) are 1-bit fields.

NOTE: Under normal conditions, the reserved flag is unset.

-I IP-ID

Specify the IP-ID within the IP header.

-O IP-options-file

This will cause nemesis-dns to use the specified IP-options-file as the options when building the IP header for the injected packet. IP options can be up to 40 bytes in length. The IP options file must be created manually based upon the desired options. IP options can also be read from stdin by specifying '-O -' instead of an IP-options-file.

-S source-IP-address

Specify the source-IP-address within the IP header.

-t IP-TOS

Specify the IP-type-of-service (TOS) within the IP header. Valid type of service values:

2  (Minimize monetary cost)
4  (Maximize reliability)
8  (Maximize throughput)
24 (Minimize delay)

NOTE: Under normal conditions, only one type of service is set within a packet. To specify multiple types, specify the sum of the desired values as the type of service.

-T IP-TTL

Specify the IP-time-to-live (TTL) within the IP header.

-d Ethernet-device

Specify the name (for UNIX-like systems) or the number (for Windows systems) of the Ethernet-device to use (eg. fxp0, eth0, hme0, 1).

-H source-MAC-address

Specify the source-MAC-address (XX:XX:XX:XX:XX:XX).

-M destination-MAC-address

Specify the defination-MAC-address (XX:XX:XX:XX:XX:XX).

-Z list-network-interfaces

Lists the available network interfaces by number for use in link-layer injection.

NOTE: This feature is only relevant to Windows systems.

Nemesis-dns returns 0 on a successful exit, 1 if it exits on an error.

An interface for users to create DNS packet payloads should be created.

Send concise and clearly written bug reports to jeff@snort.org

Jeff Nathan <jeff@snort.org>

Originally developed by Mark Grimes <mark@stateful.net>

nemesis-arp(1), nemesis-ethernet(1), nemesis-icmp(1), nemesis-igmp(1), nemesis-ip(1), nemesis-ospf(1), nemesis-rip(1), nemesis-tcp(1), nemesis-udp(1)