--- name: "horst" section: "8" platform: "linux" package: "horst" version: "5.1-3" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/horst" --- # horst(8) Highly Optimized Radio Scanning Tool ## NAME horst - Highly Optimized Radio Scanning Tool ## SYNOPSIS **horst** \[**-v**\] \[**-h**\] \[**-q**\] \[**-D**\] \[**-a**\] \[**-c** *file*\] \[**-C** *channel*\] \[**-i** *interface*\] \[**-t** *sec*\] \[**-V** *view*\] \[**-d** *ms*\] \[**-b** *bytes*\] \[**-M** *file*\] \[**-s**\] \[**-u**\] \[**-N**\] \[**-n** *IP*\] \[**-p** *port*\] \[**-o** *file*\] \[**-X** *name*\] \[**-x** *command*\] \[**-e** *mac*\] \[**-f** *pkt\_name*\] \[**-m** *mode*\] \[**-B** *BSSID*\] ## DESCRIPTION **horst** is a small, lightweight IEEE802.11 wireless LAN analyzer with a text interface. Its basic function is similar to tcpdump, Wireshark or Kismet, but it's much smaller and shows different, aggregated information which is not easily available from other tools. It is mainly targeted at debugging wireless LANs with a focus on ad-hoc (IBSS) mode in larger mesh networks. It can be useful to get a quick overview of what's going on on all wireless LAN channels and to identify problems. - • Shows signal values per station. - • Calculates channel utilization ("usage") by adding up the amount of time the packets actually occupy the medium. - • "Spectrum Analyzer" shows signal levels and usage per channel. - • Text-based "graphical" packet history, with signal, packet type and physical rate - • Shows all stations per ESSID and the live TSF per node as it is counting. - • Detects IBSS "splits" (same ESSID but different BSSID - this is a common driver problem). - • Statistics of packets/bytes per physical rate and per packet type. - • Has some support for mesh protocols (OLSR and batman). - • Can filter specific packet types, source MAC addresses or BSSIDs. - • Client/server support for monitoring on remote nodes. - • Can be controlled via a named pipe. - See MONITOR MODE below for more information about the network interface setup. ## OPTIONS - **-v** Show version. - **-h** Show summary of options. - **-q** Quiet mode. Don't show user interface. This is only useful in conjunction when running in server mode (-C) or writing to a file (-o). - **-D** Show lot's of debugging output, including a full package dump. Only available when compiled with DEBUG=1. - **-a** Always add virtual monitor interface. Don't try to set existing interface to monitor mode. - **-c** *configfile* Use configfile instead of the default "/etc/horst.conf". - **-C** *channel* Set inital channel (number not frequency). - **-i** *intf* Operate on the given network interface instead of the default "wlan0". - **-t** *sec* Timeout (remove) nodes after not receiving packets from them for this time in seconds (default: 60 sec). - **-V** *view* Display 'view'. Valid view names are "history", "hist", "essid", "statistics", "stats", "spectrum", "spec". - **-d** *ms* Display update interval. The default value of 100ms can be increased to reduce CPU load caused by redrawing the screen. - **-b** *bytes* Receive buffer size. The receive buffer size can be set to tune memory consumption and reduce lost packets under load. - **-M** *filename* MAC address to host name mapping file. The file can either be a dhcp.leases file from dnsmasq or contain mappings in the form "MAC\name" (e.g.: "00:01:02:03:04:05 test") line by line (default filename: /tmp/dhcp.leases). - **-s** Show a poor mans "spectrum analyzer". The same can be achieved by running **horst** as normal and pressing the button 's' (Spec); then 'c' (Chan) and 'a' (Automatically change channel). - **-u** Upper channel limit for the automatic channel change. - **-N** Allow client connections. Server mode. Only one client connection is supported at the moment (default: off). - **-n** *IP* Connect to a **horst** instance running in server-mode at the specified IP address. - **-p** *port* Use the specified port (default: 4444) for client/server connections. - **-o** *filename* Write a information about each received packet into file. Note that you can send to STDOUT by using **-o /dev/stdout**. See OUTPUT FILE FORMAT below. - **-X** Accept control commands on a named pipe (default /tmp/horst). - **-X** *name* Accept control commands on a named pipe with given name or set pipe name used with -x. - **-x** *command* Send control command to another **horst** process who was started with -X and then exit. Multiple commands can be concatenated with ';'. Currently implemented commands are: - pause Pause **horst** processing - resume Resume **horst** processing - reset Reset all history, statistics and views - channel=X Set channel channel number - channel\_scan=X Automatically change channels (1 or 0) - channel\_dwell=X Set channel dwell time when automatically changing channel (ms) - channel\_upper=X Set max channel when automatically changing channel - outfile=X Write to outfile named X. If the file is already open, it is cleared and re-openend. If filename is not specified ("outfile=") any existing file is closed and no file is written. - **-e** *MAC* Filter all MAC addresses except these, to show only packets originating from the specified MAC addresses. This option can be specified multiple times. - **-f** *pkt\_type* Filter all packets except these. This option can be specified multiple times. For valid packet names see NAMES AND ABBREVIATIONS below. - **-m** *(AP\|STA\|ADH\|PRB\|WDS\|UNKNOWN)* Only show/include packets and nodes of this mode. Note that the mode is infered by the information of packets we received and it may take some time until a node is properly classified. This option can be specified multiple times. - **-B** *BSSID* Only show/include packets which belong to the given BSSID. ## TEXT USER INTERFACE The ncurses-based text interface tries to display a lot of information, so it may look confusing at first. Below we describe the different screens and options. - Main screen The initial (main) screen is split into three parts. The upper area shows a list of aggregated "node" information, the most useful information about each sender which was discovered, one per line: - **/** "Spinner" to show activity - **Pk** Percentage of this node's packets in relation to all received packets - **Re%** Percentage of retried frames of all frames this node sent - **Cha** Channel number - **Sig** Signal value (RSSI) in dBm - **RAT** Physical data rate - **TRANSMITTER** MAC address of sender - **MODE** Operating Mode (AP, AHD, PRB, STA, WDS), see "NAMES AND ABBREVIATIONS" - **ENCR** Encryption (WPA1, WPA2, WEP) - **ESSID** ESSID - **INFO** Additional info like "BATMAN", IP address... The lower area shows a scrolling list of packets as they come in: - **Cha** Channel number - **Sig** Signal value (RSSI) in dBm - **RAT** Physical data rate - **TRANSMITTER** MAC address of sender - **BSSID** BSSID - **TYPE** Packet type, see "NAMES AND ABBREVIATIONS" - **INFO** Additional info like ESSID, TFS, IP address... The lower right box shows bar graphs for: - **Signal** of last received packet in green - **bps** Bits per second of all received packets - **Usage** Percentage of channel use The lower edge is the menu and status bar, it shows which keys to press for other screens. The status shows "\>" when **horst** is running or "=" when it is paused, then "F" when any kind of filter is active, the Channel, the monitor interface in use and the time. - Pause ('p' or \) Can be used to pause/resume **horst**. When **horst** is paused it will loose packets received in the mean time. - Reset ('r') Clears all history and aggregated statistical data. - History ('h') The history screen scrolls from right to left and shows a bar for each packet indicating the signal level. In the line below that, the packet type is indicated by one character (See NAMES AND ABBREVIATIONS below) and the rough physical data rate is indicated below that in blue. - ESSID ('e') The ESSID screen groups information by ESSID and shows the mode (AP, IBSS), the MAC address of the sender, the BSSID, the TSF, the beacon interval, the channel, the signal, a "W" when encrytoion is used and the IP address if known. - Statistics ('a') The statistics screen groups packets by physical rate and by packet type and shows other kinds of aggregated and statistical information based on packets. - Spectrum Analyzer ('s') The "poor mans spectrum analyzer" screen is only really useful when **horst** is started with the -s option or the "Automatically change channel" option is selected in the "Chan" settings, or the config option channel\_scan is set. It shows the available channels horizontally and vertical bars for each channel: - **Signal** in green - **Physical** rate in blue - **Channel** usage in orange/brown By pressing the 'n' key, the display can be changed to show only the average signal level on each channel and the last 4 digits of the MAC address of the individual nodes at the level (height) they were received. This can give a quick graphical overview of the distance of nodes. - Filters ('f') This configuration dialog can be used to define the active filters. - Channel Settings ('c') This configuration dialog can be used to change the channel changing behaviour of **horst** or to change to a different channel manually. - Sort ('o') Only active in the main screen, can be used to sort the node list in the upper area by Signal, Time, BSSID or Channel. ## NAMES AND ABBREVIATIONS - 802\.11 standard frames | | | | | --- | --- | --- | | **Management frames** | | a | ASOCRQ | Association request | | A | ASOCRP | Associaion response | | a | REASRQ | Reassociation request | | A | REASRP | Reassociation response | | p | PROBRQ | Probe request | | P | PROBRP | Probe response | | T | TIMING | Timing Advertisement | | B | BEACON | Beacon | | t | ATIM | ATIM | | D | DISASC | Disassociation | | u | AUTH | Authentication | | U | DEAUTH | Deauthentication | | C | ACTION | Action | | c | ACTNOA | Action No Ack | | | | | | --- | --- | --- | | **Control frames** | | w | CTWRAP | Control Wrapper | | b | BACKRQ | Block Ack Request | | B | BACK | Block Ack | | s | PSPOLL | PS-Poll | | R | RTS | RTS | | C | CTS | CTS | | K | ACK | ACK | | f | CFEND | CF-End | | f | CFENDK | CF-End + CF-Ack | | | | | | --- | --- | --- | | **Data frames** | | D | DATA | Data | | F | DCFACK | Data + CF-Ack | | F | DCFPLL | Data + CF-Poll | | F | DCFKPL | Data + CF-Ack + CF-Poll | | n | NULL | Null (no data) | | f | CFACK | CF-Ack (no data) | | f | CFPOLL | CF-Poll (no data) | | f | CFCKPL | CF-Ack + CF-Poll (no data) | | Q | QDATA | QoS Data | | F | QDCFCK | QoS Data + CF-Ack | | F | QDCFPL | QoS Data + CF-Poll | | F | QDCFKP | QoS Data + CF-Ack + CF-Poll | | N | QDNULL | QoS Null (no data) | | f | QCFPLL | QoS CF-Poll (no data) | | f | QCFKPL | QoS CF-Ack + CF-Poll (no data) | | \* | BADFCS | Bad frame checksum | - Packet types Similar to 802.11 frames above but higher level and as a bit field (types can overlap, e.g. DATA + IP) and including more information, like IP, ARP, BATMAN, OLSR... | | | | | --- | --- | --- | | **Packet types** | | CTRL | 0x000001 | WLAN Control frame | | MGMT | 0x000002 | WLAN Management frame | | DATA | 0x000004 | WLAN Data frame | | BADFCS | 0x000008 | WLAN frame checksum (FCS) bad | | BEACON | 0x000010 | WLAN beacon frame | | PROBE | 0x000020 | WLAN probe request or response | | ASSOC | 0x000040 | WLAN associaction request/response frame | | AUTH | 0x000080 | WLAN authentication frame | | RTSCTS | 0x000100 | WLAN RTS or CTS | | ACK | 0x000200 | WLAN ACK or BlockACK | | NULL | 0x000400 | WLAN NULL Data frame | | QDATA | 0x000800 | WLAN QoS Data frame (WME/WMM) | | ARP | 0x001000 | ARP packet | | IP | 0x002000 | IP packet | | ICMP | 0x004000 | IP ICMP packet | | UDP | 0x008000 | IP UDP | | TCP | 0x010000 | IP TCP | | OLSR | 0x020000 | OLSR protocol | | BATMAN | 0x040000 | BATMAND Layer3 or BATMAN-ADV Layer 2 frame | | MESHZ | 0x080000 | MeshCruzer protocol | - Operating modes Bit field of operating mode type which is infered from received packets. Modes may overlap, i.e. it is common to see STA and PRB at the same time. | | | | | --- | --- | --- | | **Operating modes** | | AP | 0x01 | Access Point (AP) | | ADH | 0x02 | Ad-hoc node | | STA | 0x04 | Station (AP client) | | PRB | 0x08 | Sent PROBE requests | | WDS | 0x10 | WDS or 4 Address frames | | UNKNOWN | 0x20 | Unknown e.g. RTS/CTS or ACK | ## MONITOR MODE To capture and analyze 802.11 traffic, the interface needs to be in monitor mode. You can either setup the interface manually beforehand or let **horst** setup it automatically at startup. Usually, root privileges are required to modify an interface setup. **horst** should work with any wireleass LAN card and driver which supports monitor mode, with either "prism2" or "radiotap" headers. This includes most modern mac80211-based drivers. If the interface is not in monitor mode at startup, **horst** first tries to put the interface in monitor mode. If it fails (for example when the interface is already in use), a new virtual monitor interface (horst0) is added and used instead. The virtual monitor interface is removed when **horst** exits. Note that changing the channel via a virtual monitor interface is not allowed by the wireless driver, so options -C and -s do not work when virtual monitor interface is used. Examples of how to setup an interface manually: - Using iw: ``` iw wlan0 interface add mon0 type monitor or sudo iw wlan1 set type monitor sudo iw wlan1 set channel 6 ``` - Using iwconfig: ``` iwconfig wlan0 mode monitor iwconfig wlan0 channel 1 ifconfig wlan0 up ``` - Using madwifi: wlanconfig wlan0 create wlandev wifi0 wlanmode monitor - Using hostap: ``` iwconfig wlan0 mode monitor iwpriv wlan0 monitor_type 1 ``` ## NOTES Signal values and ranges may differ between wireless drivers and versions. ## OUTPUT FILE FORMAT The format of the output file (-o flag) is a comma separated list of the following fields in the following order, one packet each line. - timestamp Local time, including microseconds (e.g. 2015-05-16 15:05:44.338806 +0300) - packet\_type 802\.11 MAC packet type name as defined in the section "NAMES AND ABBREVIATIONS". - wlan\_src Source MAC address - wlan\_dst Destination MAC address - wlan\_bssid BSSID - pkt\_types Higher level packet name as defined in section "NAMES AND ABBREVIATIONS". - phy\_signal Signal strength in dBm - wlan\_len Packet length (MAC) - phy\_rate Physical data rate - phy\_freq Received while tuned to this frequency. - wlan\_tsf TFS timer value - wlan\_essid ESSID, network name - wlan\_mode Operating modes as defined in "NAMES AND ABBREVIATIONS". - wlan\_channel Channel number - wlan\_wep Encryption in use - wlan\_wpa WPA1 Encryption in use - wlan\_rsn RSN (WPA2) Encryption in use - ip\_src IP source address (if available) - ip\_dst IP destionation address (if available) ## SEE ALSO [**horst.conf**(5)](/horst.conf/5.md), [**tcpdump**(1)](/tcpdump/1.md), [**wireshark**(1)](/wireshark/1.md), [**kismet**(1)](/kismet/1.md), **README,** **http://br1.einfach.org/tech/horst** ## AUTHOR **horst** was written by Bruno Randolf \. This manual page was written by Antoine Beaupré \, for the Debian project (and may be used by others).