
Broadcom/Cypress WiFi 칩용 C 기반 펌웨어 패칭 프레임워크로, 모니터 모드, 프레임 인젝션 및 그 외 다양한 기능을 지원합니다.

Nexmon은 Broadcom/Cypress WiFi 칩을 위한 C 기반 펌웨어 패칭 프레임워크로, radiotap 헤더가 포함된 모니터 모드와 프레임 주입을 활성화하는 등 자체 펌웨어 패치를 작성할 수 있게 해줍니다.
아래에서 nexmon으로 가능한 작업의 개요를 확인할 수 있습니다. 이 저장소는 주로 다양한 칩에서 모니터 모드와 프레임 주입을 활성화하는 데 초점을 맞춥니다. 추가 기능을 원한다면 다음 프로젝트들이 흥미로울 수 있습니다:
당사의 소프트웨어는 하드웨어를 손상시키거나 하드웨어 보증을 무효화할 수 있습니다! 도구 사용에 따른 모든 위험과 책임은 사용자에게 있습니다! 이 조건에 동의하지 않으면 nexmon을 사용하지 마세요!
현재 다음 기기들이 nexmon 펌웨어 패치에서 지원됩니다.
1 bcm43430a1은 과거에 bcm43438로 잘못 표기되었습니다.
2 ioctl을 통해 프레임을 주입하려면 LD_PRELOAD=libfakeioctl.so 대신 LD_PRELOAD=libnexmon.so를 사용하세요.
3 플래시 패치는 8바이트 길이여야 하며 8바이트 경계에 정렬되어야 합니다.
4 최초의 60 GHz Wi-Fi 라우터 Talon AD7200에 탑재된 802.11ad Wi-Fi 칩입니다. nexmon-arc를 사용하여 펌웨어를 패치하고, 당사의 사용자 정의 LEDE 이미지 lede-ad7200로 실행하세요.
5 nexmon 코드와 간섭하기 때문에 영역 1에서 실행 보호(Execute Never)를 비활성화했습니다(Section에 대한 Permission fault).
6 nexutil을 사용하려면 SELinux를 비활성화하거나 퍼미시브(permissive) 모드로 설정해야 합니다.
7 nexmon과 함께 Pico SDK를 사용하는 예제 애플리케이션은 pico-nexmon을 참조하세요.
8 플래시 패치는 16바이트 길이여야 하며 16바이트 경계에 정렬되어야 합니다.
9 펌웨어 설치, nexutil 및 SELinux 정책 설정에 Magisk 모듈을 사용합니다.
sudo apt-get install git gawk qpdf adb flex bisongit clone https://github.com/seemoo-lab/nexmon.gitcd nexmon
source setup_env.shmakecd patches/bcm4339/6_37_34_43/nexmon/
makemake backup-firmwaremake install-firmware (사전에 스마트폰을 컴퓨터에 연결했는지 확인하세요)make를 실행하여 소스에서 빌드할 수도 있습니다 (참고: 이를 위해서는 Android NDK가 올바르게 설치되어 있어야 합니다).adb shellnexutil -m2LD_PRELOAD=libfakeioctl.so tcpdump -i wlan0root 권한 없이 펌웨어와 통신할 수 있도록, 우리는 nexutil에서도 사용되는 libnexio를 통해 접근 가능한 UDP 인터페이스를 만들었습니다. 먼저 보안 쿠키를 설정하여 일반적으로 root 권한이 있음을 펌웨어에 증명해야 합니다. 그런 다음 UDP 기반 연결에 사용할 수 있습니다. wlan0 인터페이스에도 192.168.222.0/24 범위의 IP 주소가 필요하며, 그렇지 않으면 기본 nexutil broadcast-ip를 변경해야 합니다:
ifconfig wlan0 192.168.222.1 netmask 255.255.255.0nexutil -x<cookie (uint)>nexutil -X<cookie> -m1참고: 현재 커널 버전 4.4(사용되지 않음), 4.9, 4.14, 4.19, 5.4, 5.10 및 5.15를 지원합니다. Raspbian에는 bcm43455c0용 펌웨어 버전 7.45.154이 포함되어 있습니다. 또한 Cypress의 최신 펌웨어 릴리스 7.45.189도 지원합니다. Raspberry Pi OS에는 펌웨어 버전 7.45.206이 포함되어 있습니다. 어떤 것이 가장 잘 작동하는지 직접 시도해 보십시오.
다음 명령이 root로 실행되는지 확인하세요: sudo su
Raspbian 설치를 업그레이드합니다: apt-get update && apt-get upgrade
드라이버와 일부 종속성을 빌드하기 위해 커널 헤더를 설치합니다: sudo apt install raspberrypi-kernel-headers git libgmp3-dev gawk qpdf bison flex make autoconf libtool texinfo
저장소를 클론합니다: git clone https://github.com/seemoo-lab/nexmon.git
저장소의 루트 디렉터리로 이동합니다: cd nexmon
/usr/lib/arm-linux-gnueabihf/libisl.so.10이 존재하는지 확인하고, 존재하지 않으면 소스에서 컴파일합니다:cd buildtools/isl-0.10, ./configure, make, make install, iw phy `iw dev wlan0 info | gawk '/wiphy/ {printf "phy" $2}'` interface add mon0 type monitorifconfig mon0 up.tcpdump -i mon0modinfo brcmfmac #the first line should be the full pathmv "<PATH TO THE DRIVER>/brcmfmac.ko" "<PATH TO THE DRIVER>/brcmfmac.ko.orig"cp /home/pi/nexmon/patches/bcm43430a1/7_45_41_46/nexmon/brcmfmac_kernel49/brcmfmac.ko "<PATH TO THE DRIVER>/"cp /home/pi/nexmon/patches/bcm43430a1/7_45_41_46/nexmon/brcmfmac_4.14.y-nexmon/brcmfmac.ko "<PATH TO THE DRIVER>/"depmod -aTo build the utilities such as nexmon or dhdutil for Android, you need to download the old NDK version 11c,
extract it and export the environment variable NDK_ROOT pointing to the directory where you extracted the NDK
files.
The Wi-Fi firmware consists of a read-only part stored in the ROM of every Wi-Fi chip and another part that is loaded by the driver into the RAM. To analyze the whole firmware, one needs to extract the ROM. There are two options to do this. Either you write a firmware patch that simply copies the contents of the ROM to RAM and then you dump the RAM, or you directly dump the ROM after loading the regular firmware into the RAM. Even though, the second option is easier, it only works, if the ROM can be directly accessed by the driver, which is not always the case. Additionally, the firmware loaded into RAM can contain ROM patches that overlay the data stored in ROM. By dumping the ROM after loading the original RAM firmware, it contains flash patches. Hence, the ROM needs to be dumped again for every RAM firmware update to be consistent. As a conclusion, we prefer to dump the clean ROM after copying it to RAM.
To dump the ROM directly, you need to know, where to find it and how large it is. On chips with Cortex-M3 it is usually at upper addresses such as 0x800000, while on chips with Cortex-R4 it is likely at 0x0. Run dhdutil to perform the dump:
dhdutil membytes -r 0x0 0xA0000 > rom.bin```
## Dumping a clean ROM after copying to RAM
For the BCM4339 and BCM4358, we created `rom_extraction` projects that load a firmware patch that copies ROM to
RAM and them dumps it using dhdutil. To dump the ROM simply execute the following in the project directory:
make dump-rom```
After ROM extraction, the rom.bin file will be copies to the corresponding firmwares subdirectory. To apply the
flash patches of a specific RAM firmware version, enter its directory and execute:
make rom.bin```
# Structure of this repository
* `buildtools`: Contains compilers and other tools to build the firmware
* `firmwares`
* `<chip version>`
* `<firmware version>`
* `<firmware file>`: The original firmware that will be loaded into the RAM of the WiFi Chip
* `definitions.mk`: Contains mainly firmware specific addresses
* `structs.h`: Structures only valid for this firmware version
* `Makefile`: Used to extract flashpatches and ucode
* `flashpatches.c` (generated by Makefile): Contains flashpatches
* `ucode.bin` (extracted by Makefile): Contains uncompressed Ucode
* `structs.common.h`: Structures that are common between firmware versions
* `patches`
* `<chip version>`
* `<firmware version>`
* `nexmon`
* `Makefile`: Used to build the firmware
* `patch.ld`: Linker file
* `src`
* `patch.c`: General patches to the firmware
* `injection.c`: Code related to frame injection
* `monitormode.c`: Code related to monitor mode with radiotap headers
* `ioctl.c`: Handling of custom IOCTLs
* ...
* `obj` (generated by Makefile): Object files created from C files
* `log` (generated by Makefile): Logs written during compilation
* `gen` (generated by Makefile): Files generated during the build process
* `nexmon.pre` (generated by gcc plugin): Extracted at-attributes and targetregion-pragmas
* `nexmon.ld` (generated from nexmon.pre): Linker file use to place patch code at defined addresses in the firmware
* `nexmon.mk` (generated from nexmon.pre): Make file used take code from patch.elf and place it into firmware
* `flashpatches.ld` (generated from nexmon.pre): Linker file that places flashpatches at target locations in firmware ROM
* `flashpatches.mk` (generated from nexmon.pre): Make file used to insert flashpatch config and data structures into firmware
* `patch.elf` (generated from object files and linker scripts): contains the newly compiled code placed at predefined addresses
* `common`
* `wrapper.c`: Wrappers for functions that already exist in the firmware
* `ucode_compression.c`: [tinflate](http://achurch.org/tinflate.c) based ucode decompression
* `radiotap.c`: RadioTap header parser
* `helper.c`: Helpful utility functions
* `driver`: Patched brcmfmac driver
* `include`: Common include files
* `firmware_version.h`: Definitions of chip and firmware versions
* `patcher.h`: Macros use to perform patching for existing firmware code (e.g., BPatch patches a branch instruction)
* `capabilities.h`: Allows to indicate capabilities (such as, monitor mode and frame injection)
* `nexioctl.h`: Defines custom IOCTL numbers
# Related projects
* [bcmon](https://bcmon.blogspot.de/): Monitor Mode and Frame Injection for the bcm4329 and bcm4330
* [monmob](https://github.com/tuter/monmob): Monitor Mode and Frame Injection for the bcm4325, bcm4329 and bcm4330
* [P4wnP1](https://github.com/mame82/P4wnP1): Highly customizable attack platform, based on Raspberry Pi Zero W and Nexmon
* [kali Nethunter OS](https://github.com/nethunteros): ROM that brings Kali Linux to smartphones with Nexmon support
* [dustcloud-nexmon](https://github.com/dgiese/dustcloud-nexmon): Nexmon for Xiaomi IoT devices (ARM based)
* [InternalBlue](https://github.com/seemoo-lab/internalblue): Bluetooth experimentation framework based on Reverse Engineering of Broadcom Bluetooth Controllers
# Interesting articles on firmware hacks
If you know more projects that use nexmon or perform similar firmware hacks, let us know and we will add a link.
* [Project Zero](https://googleprojectzero.blogspot.de/2017/09/over-air-vol-2-pt-1-exploiting-wi-fi.html): Over The Air - Vol. 2, Pt. 1: Exploiting The Wi-Fi Stack on Apple Devices
* [broadpwn](https://blog.exodusintel.com/2017/07/26/broadpwn/): Remotely Compromising Android and IOS via a Bug in Broadcom's Wi-Fi Chipsets
* [Project Zero](https://googleprojectzero.blogspot.de/2017/04/over-air-exploiting-broadcoms-wi-fi_4.html): Over The Air: Exploiting Broadcom's Wi-Fi Stack (Part 1)
* [Project Zero](https://googleprojectzero.blogspot.de/2017/04/over-air-exploiting-broadcoms-wi-fi_11.html): Over The Air: Exploiting Broadcom's Wi-Fi Stack (Part 2)
# Read my PhD thesis
* Matthias Schulz. [**Teaching Your Wireless Card New Tricks: Smartphone Performance and Security Enhancements through Wi-Fi Firmware Modifications**](http://tuprints.ulb.tu-darmstadt.de/7243/). Dr.-Ing. thesis, Technische Universität Darmstadt, Germany, February 2018. [pdf](http://tuprints.ulb.tu-darmstadt.de/7243/7/dissertation_2018_matthias_thomas_schulz.pdf)
# Read our papers
* F. Gringoli, M. Schulz, J. Link, and M. Hollick. [**Free Your CSI: A Channel State Information Extraction Platform For Modern Wi-Fi Chipsets**](https://doi.org/10.1145/3349623.3355477). Accepted to appear in *Proceedings of the 13th Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization (WiNTECH 2019)*, October 2019. [code](https://nexmon.org/csi)
* D. Mantz, J. Classen, M. Schulz, and M. Hollick. [**InternalBlue - Bluetooth Binary Patching and Experimentation Framework**](https://dl.acm.org/citation.cfm?id=3326089). *In Proceedings of the 17th Annual International Conference on Mobile Systems, Applications, and Services (MobiSys '19)*. June 2019.
* M. Schuß, C. A. Boano, M. Weber, M. Schulz, M. Hollick, K. Römer. [**JamLab-NG: Benchmarking Low-Power Wireless Protocols under Controlable and Repeatable Wi-Fi Interference**](https://dl.acm.org/citation.cfm?id=3324331). *Proceedings of the 2019 International Conference on Embedded Wireless Systems and Networks (EWSN 2019)*, February 2019.
* M. Schulz, D. Wegemer, and M. Hollick. [**The Nexmon Firmware Analysis and Modification Framework: Empowering Researchers to Enhance Wi-Fi Devices**](https://doi.org/10.1016/j.comcom.2018.05.015). *Elsevier Computer Communications (COMCOM) Journal*. 2018.
* M. Schulz, J. Link, F. Gringoli, and M. Hollick. [**Shadow Wi-Fi: Teaching Smart- phones to Transmit Raw Signals and to Extract Channel State Information to Implement Practical Covert Channels over Wi-Fi**](https://dl.acm.org/citation.cfm?id=3210333). Accepted to appear in *Proceedings of the 16th ACM International Conference on Mobile Systems, Applications, and Services*, MobiSys 2018, June 2018.
* D. Steinmetzer, D. Wegemer, M. Schulz, J. Widmer, M. Hollick. [**Compressive Millimeter-Wave Sector Selection in Off-the-Shelf IEEE 802.11ad Devices**](https://dl.acm.org/citation.cfm?id=3143384). *Proceedings of the 13th International Conference on emerging Networking EXperiments and Technologies*, CoNEXT 2017, December 2017.
* M. Schulz, D. Wegemer, M. Hollick. [**Nexmon: Build Your Own Wi-Fi Testbeds With Low-Level MAC and PHY-Access Using Firmware Patches on Off-the-Shelf Mobile Devices**](https://dl.acm.org/citation.cfm?id=3131476). *Proceedings of the 11th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization (WiNTECH 2017)*, October 2017. [pdf](https://www.seemoo.tu-darmstadt.de/mschulz/wintech2017) [video](https://youtu.be/m5Zrk4n4hoE)
* M. Schulz, F. Knapp, E. Deligeorgopoulos, D. Wegemer, F. Gringoli, M. Hollick. [**DEMO: Nexmon in Action: Advanced Applications Powered by the Nexmon Firmware Patching Framework**](https://dl.acm.org/citation.cfm?id=3133333), Accepted for publication in *Proceedings of the 11th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization (WiNTECH 2017)*, October 2017. [pdf](https://www.seemoo.tu-darmstadt.de/mschulz/wintech2017demo)
* M. Schulz, F. Gringoli, D. Steinmetzer, M. Koch and M. Hollick. [**Massive Reactive Smartphone-Based Jamming using Arbitrary Waveforms and Adaptive Power Control**](https://dl.acm.org/citation.cfm?id=3098253). Proceedings of the *10th ACM Conference on Security and Privacy in Wireless and Mobile Networks (WiSec 2017)*, July 2017. [pdf](https://www.seemoo.tu-darmstadt.de/mschulz/wisec2017) [video](https://youtu.be/S2XPBK0KdiQ)
* M. Schulz, E. Deligeorgopoulos, M. Hollick and F. Gringoli. [**DEMO: Demonstrating Reactive Smartphone-Based Jamming**](https://dl.acm.org/citation.cfm?id=3106022). Proceedings of the *10th ACM Conference on Security and Privacy in Wireless and Mobile Networks (WiSec 2017)*, July 2017. [pdf](https://www.seemoo.tu-darmstadt.de/mschulz/wisec2017demo)
* M. Schulz. [**Nexmon - Wie man die eigene WLAN-Firmware hackt**](http://heise.de/-3538660),
c't 26/2016, S. 168, Heise Verlag, 2016.
* M. Schulz, D. Wegemer, M. Hollick. [**DEMO: Using NexMon, the C-based WiFi
firmware modification framework**](https://dl.acm.org/citation.cfm?id=2942419),
Proceedings of the *9th ACM Conference on Security and Privacy in Wireless and
Mobile Networks (WiSec 2016)*, July 2016. [pdf](https://www.seemoo.tu-darmstadt.de/mschulz/wisec2016demo1)
* M. Schulz, D. Wegemer and M. Hollick. [**NexMon: A Cookbook for Firmware
Modifications on Smartphones to Enable Monitor Mode**](http://arxiv.org/abs/1601.07077),
CoRR, vol. abs/1601.07077, December 2015.
[bibtex](http://dblp.uni-trier.de/rec/bibtex/journals/corr/SchulzWH16)
[Get references as bibtex file](https://nexmon.org/bib)
# Reference our project
Any use of this project which results in an academic publication or other publication which includes a bibliography should include a citation to the Nexmon project and probably one of our papers depending on the code you use. Find all references in our [bibtex file](https://github.com/seemoo-lab/nexmon/blob/master/nexmon.bib). Here is the reference for the project only:
@electronic{nexmon:project, author = {Schulz, Matthias and Wegemer, Daniel and Hollick, Matthias}, title = {Nexmon: The C-based Firmware Patching Framework}, url = {https://nexmon.org}, year = {2017} }```
| WiFi 칩 | 펌웨어 버전 | 사용 기기 | 운영 체제 | M | RT | I | FP | UC | CT |
|---|
| bcm4330 | 5_90_100_41_sta | Samsung Galaxy S2 | Cyanogenmod 13.0 | X | X | X | X | O | |
| bcm4335b0 | 6.30.171.1_sta | Samsung Galaxy S4 | LineageOS 14.1 | X | X | X | X | O | |
| bcm4339 | 6_37_34_43 | Nexus 5 | Android 6 Stock | X | X | X | X | X | O |
| bcm43430a11 | 7_45_41_26 | Raspberry Pi 3 and Zero W | Raspbian 8 | X | X | X | X | X | O |
| bcm43430a11 | 7_45_41_46 | Raspberry Pi 3 and Zero W | Raspbian Stretch | X | X | X | X | X | O |
| bcm43439a07 | 7_95_49 (2271bb6 CY) | Raspberry Pi Pico W | Pico SDK | X | X | X | X | ||
| bcm43451b1 | 7_63_43_0 | iPhone 6 | iOS 10.1.1 (14B100) | X | X | ||||
| bcm43455 | 7_45_77_0_hw | Huawei P9 | Android 7 Stock | X | X | X | X | X | |
| bcm43455 | 7_120_5_1_sta_C0 | Galaxy J7 2017 | ? | X | X | ||||
| bcm43455 | 7_45_77_0_hw(8-2017) | Huawei P9 | Android 7 Stock | X | X | X | X | X | |
| bcm434555 | 7_46_77_11_hw | Huawei P9 | Android 8 China Stock | X | X | X | X | X | |
| bcm43455 | 7_45_59_16 | Sony Xperia Z5 Compact | LineageOS 14.1 | X | X | X | X | X | |
| bcm43455c0 | 7_45_154 | Raspberry Pi B3+/B4 | Raspbian Kernel 4.9/14/19 | X | X | X | X | ||
| bcm43455c0 | 7_45_189 | Raspberry Pi B3+/B4 | Raspbian Kernel 4.14/19, 5.4 | X | X | X | X | ||
| bcm43455c0 | 7_45_206 | Raspberry Pi B3+/B4 | Raspberry Pi OS Kernel 5.4 | X | X | X | X | X | |
| bcm43455c0 | 7_45_234 (4ca95bb CY) | Raspberry Pi B3+/B4/5 | Raspberry Pi OS | X | X | ||||
| bcm43436b03 | 9_88_4_65 | Raspberry Pi Zero 2 W | Raspberry Pi OS Kernel 5.10 | X | X | X | X | X | |
| bcm4356 | 7_35_101_5_sta | Nexus 6 | Android 7.1.2 | X | X | X | X | O | |
| bcm4358 | 7_112_200_17_sta | Nexus 6P | Android 7 Stock | X | X | X | X | O | |
| bcm4358 | 7_112_201_3_sta | Nexus 6P | Android 7.1.2 Stock | X | X | X | X | O | |
| bcm43582 | 7_112_300_14_sta | Nexus 6P | Android 8.0.0 Stock | X | X | X | X | X | O |
| bcm43596a03 | 9_75_155_45_sta_c0 | Samsung Galaxy S7 | Android 7 Stock | X | O | X | |||
| bcm43596a03,2 | 9_96_4_sta_c0 | Samsung Galaxy S7 | LineageOS 14.1 | X | X | X | O | X | |
| bcm4375b13,5,6 | 18_38_18_sta | Samsung Galaxy S10 | 루팅됨 + SELinux 비활성화 | X | X | X | O | X | |
| bcm4375b13,5,6 | 18_41_8_9_sta | Samsung Galaxy S20 | 루팅됨 + SELinux 비활성화 | X | X | X | O | X | |
| bcm4389c15,8,9 | 20_82_42_sta (r994653) | Samsung Galaxy S22 Plus | Android 14, Magisk로 루팅됨 | X | X | ||||
| bcm4389c15,8,9 | 20_101_36_2 (r994653) | Google Pixel 7 and 7 Pro | Magisk로 루팅됨 | X | X | ||||
| bcm4389c15,8,9 | 20_101_57 (r1035009) | Google Pixel 7 and 7 Pro | Magisk로 루팅됨 | X | X | ||||
| bcm4398d05,8,9 | 24_671_6_9 (r1031525) | Google Pixel 8 | Magisk로 루팅됨 | X | X | ||||
| bcm6715b05 | 17_10_188_6401 (r808804) | Asus RT-AX86U Pro | 스톡 펌웨어 3.0.0.4_388.23565 | / | X | ||||
| qca95004 | 4-1-0_55 | TP-Link Talon AD7200 | 사용자 정의 LEDE 이미지 |
ln -s /usr/local/lib/libisl.so /usr/lib/arm-linux-gnueabihf/libisl.so.10/usr/lib/arm-linux-gnueabihf/libmpfr.so.4이 존재하는지 확인하고, 존재하지 않으면 소스에서 컴파일합니다:cd buildtools/mpfr-3.1.4, autoreconf -f -i, ./configure, make, make install, ln -s /usr/local/lib/libmpfr.so /usr/lib/arm-linux-gnueabihf/libmpfr.so.4sudo dpkg --add-architecture armhfsudo apt-get updatesudo apt-get install libc6:armhf libisl23:armhf libmpfr6:armhf libmpc3:armhf libstdc++6:armhfsudo ln -s /usr/lib/arm-linux-gnueabihf/libisl.so.23.0.0 /usr/lib/arm-linux-gnueabihf/libisl.so.10sudo ln -s /usr/lib/arm-linux-gnueabihf/libmpfr.so.6.1.0 /usr/lib/arm-linux-gnueabihf/libmpfr.so.4그런 다음 펌웨어 패치 컴파일을 위한 빌드 환경을 설정할 수 있습니다
source setup_env.shmakebcm43430a1/bcm43455c0/bcm43436b0 칩셋용 patches 폴더로 이동합니다: cd patches/bcm43430a1/7_45_41_46/nexmon/ / patches/bcm43455c0/<7_45_154 or 7_45_189>/nexmon/ / cd patches/bcm43436b0/9_88_4_65/nexmon/
makemake backup-firmwaremake install-firmwarenexutil 설치: 저장소의 루트 디렉터리에서 nexutil 폴더로 전환합니다: cd utilities/nexutil/. nexutil을 컴파일하고 설치합니다: make && make install.
선택 사항: WiFi 인터페이스를 더 잘 제어하려면 wpa_supplicant를 제거하세요: apt-get remove wpasupplicant
또한 전원 절약 기능을 비활성화하는 것(iw dev wlan0 set power_save off)은 펌웨어 충돌을 방지하는 데 도움이 될 수 있습니다.
참고: 일반 액세스 포인트에 연결하려면 먼저 nexutil -m0을 실행해야 합니다
reboot
* Note: It is possible to connect to an access point or run your own access point in parallel to the monitor mode interface on the wlan0 interface.