flaviar / netcat-music-kernel-expansion

Expansion on Brandon Lucia's Netcat project. Year 2015.

Original ♫ netcat - Cycles Per Instruction

by Brandon Lucia, Andrew Olmstead, and David Balatero

For more info go to: https://github.com/usrbinnc/netcat-cpi-kernel-module

I DO NOT OWN ANY OF THE SONGS WHICH ARE BEING DEMOED

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This project wasn't made to be incorporated into their github branch and as such this proj wasn't forked

New additions include:
1) Changing the creation of the device node to be read/write
2) Implemented a device_write routine to get user commands from a terminal
3) Implemented the device_read routine to deal with those commands
4) The following commands are accepted:
- Next song (n)
- Previous song (p)
- Go to track ( 0 … 9 )
- Random play (r)
- Go to the beginning of the track (b)
- Stop playing (s)
5) Implemented two C programs to convert from ogg to array and back from array to ogg
6) Created a bash script file which allows users to easily add songs to the kernel's playlist

AKA: You're using a kernel module to simulate an iPod's functions through a terminal

To run this version:

1. make //if not yet compiled
   
2. reload.sh
   
3. go to a different terminal, and call cmd.sh p, where p is you're desired parameter
   valid p:
   

   - next
   - prev
   - rand
   - beg
   - 0-9 (jump to track)
   - stop
   

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4. to add songs to the playlist Go to /music

   run createLib.sh music.ogg n //where n is the given track number, for example if you currently have track 1-9, and you want to add a tenth, call createLib.sh tenth.ogg 10 NOTE: this script is only valid for ogg files

   go to /tracks and open your newly created trk'n'.c file.

   update the track's length (the Array size value that was outputted when calling createLib.sh)

   Supposing we added a TENTH track to the playlist:

   Add "netcat-y+= tracks/trk10.o" to the Makefile

   Add "extern struct netcat_track netcat_cpi_trk10;" to netcat_main.c file Add "&netcat_cpi_trk10", to the netcat_track struct in netcat_main.c file

~Please check KernelMusicPlayerReport.odt for more descriptive information on how to use this kernel ~

=================================== See below for the original README - cheers

by Brandon Lucia, Andrew Olmstead, and David Balatero

Released April 2014

• http://netcat.co
• http://netcat.bandcamp.com
• http://tableandchairsmusic.com/artists/netcat

Cycles Per Instruction - The Kernel Module Edition

Welcome to the most unnecessarily complicated netcat album release format yet.

In this repository, you will be able to compile your own kernel module, create a /dev/netcat device and redirect its output into an audio player (tested with mplayer and play from SoX as well).

ogg123 - < /dev/netcat

This repository contains the album's track data in source files, that (for complexity's sake) came from .ogg files that were encoded from .wav files that were created from .mp3 files that were encoded from the mastered .wav files which were generated from ProTools final mix .wav files that were created from 24-track analog tape.

If complexity isn't your thing, you can go to our webpage and follow the links to a digital download or a cassette tape of our album.

Building

We've only tested this on Ubuntu Linux. Sure, it's real easy to grab another operating system ISO and test it out, but after a day toiling in the bitmines, who has the energy?

Other people report:

• @NicolasCARPi says it works on Arch 64-bit / kernel 3.14.1-1-ARCH. @diogoff shows you how to do it
• Intrepid explorer @jfilip feels good about his 64-bit Fedora 20 install
• @silviuvulcan Reports that we're up and running on slackware64-current
• @alinefr did make a howto explaining how she is enjoying netcat in her Gentoo Linux. She also explained how she did a http streaming from /dev/netcat to listen from MPD and possibily from any open source audio player.
• @pah got it running after increasing the Vmalloc limits to vmalloc=192M on a 32-bit i686 Debian machine (3.13-1-686-pae).
• @g0hl1n reports that it works on Debian 7.4 "wheezy" / Linux 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64 GNU/Linux
• @ciderpunx can compile and run it on Debian 8.0 "Jessie" / Linux 3.12-1-amd64 #1 SMP Debian 3.12.9-1 (2014-02-01) x86_64 GNU/Linux
• @f00stx slung some bits all the way from Brisbane, Australia to bring you a FreeBSD version (which he compiled on a G5 Mac, no less!) Check it out here.
• @dyfer had the foresight to save up all his turbo boost, so he could dunk a Linux Mint 16 √ report from half-court

First, install some dependencies:

sudo apt-get install build-essential vorbis-tools linux-headers-$(uname -r)

Check out the repo:

git clone https://github.com/usrbinnc/netcat-cpi-kernel-module.git
cd netcat-cpi-kernel-module

Next, build the module by running:

make

Building will take a long time. Hang with it. Building also requires several gigabytes of memory. We're not totally sure why, but we think it is because the compiler is making lots of copies of several large, static arrays that contain track data.

Listening

After you build, you need to load the module and see if it is working, so you can run:

sudo insmod netcat.ko
dmesg

You should see output like the following from dmesg:

[ 2606.528153] [netcat]: netcat - Cycles Per Instruction - Kernel Module Edition - 2014
[ 2606.528153] [netcat]: netcat is Brandon Lucia, Andrew Olmstead, and David Balatero
[ 2606.528153] [netcat]: 'ogg123 - < /dev/netcat' to play.

Finally, put on some headphones, and run:

ogg123 - < /dev/netcat 

Track information will show up in the output of dmesg:

[  612.411529] [netcat]: Now playing track 2 - The Internet is an Apt Motherfucker

If you've read this far, god help us all.

Troubleshooting

ERROR: could not insert module netcat.ko: Cannot allocate memory

Loading the module may fail due to kernel memory allocation limits:

insmod: ERROR: could not insert module netcat.ko: Cannot allocate memory

also indicated by the errors like the following in dmesg:

[195207.149213] vmap allocation for size 37806080 failed: use vmalloc=<size> to increase size.
[195207.149216] vmalloc: allocation failure: 37798136 bytes
[195207.149217] insmod: page allocation failure: order:0, mode:0xd2

This can happen especially on 32-bit kernels. The Vmalloc limit can be increased by passing vmalloc=<size> to your kernel command-line (typically 128Mb on 32-bit kernels, increasing it to vmalloc=192M should be sufficient). Some information how to overcome this problem can be found in the MythTV wiki.

People insane enough to contribute (thanks!!)

• @mark-bi added support for auto-creating our /dev/netcat device. Thanks, Mark!
• @arfar pointed out that not everyone wants to clone public repos over SSH, and updated the clone instructions to https. Thanks!
• @jmtd simplified the command to play audio by removing the extra instance of cat. Thanks!
• @gregkh for making our module coherent with standard Linux style and cleaning up some other loose ends.
• @silviuvulcan for testing with vlc and finding that we run and build on slackware64-current. Thanks!
• @pah dropped some knowledge for anyone struggling in the streets with 32-bit kernels and vmalloc limits