linux null modem emulator v1.4
This is the tty0tty directory tree:
module
: linux kernel module null-modempts
: null-modem using ptys (without handshake lines)debian
: debian package build treessniffer
: simple serial sniffer using tty0tty driver portsWhen run connect two pseudo-ttys and show the connection names:
(/dev/pts/1) <-> (/dev/pts/2)
the connection is:
TX -> RX
RX <- TX
The module is tested in kernels from 3.10.2 to 5.3.15 (debian)
When loaded, create 8 ttys interconnected:
/dev/tnt0 <-> /dev/tnt1
/dev/tnt2 <-> /dev/tnt3
/dev/tnt4 <-> /dev/tnt5
/dev/tnt6 <-> /dev/tnt7
the connection is:
TX -> RX
RX <- TX
RTS -> CTS
CTS <- RTS
DSR <- DTR
CD <- DTR
DTR -> DSR
DTR -> CD
This is a simple serial sniffer program supporting handshake lines (using tty0tty module) with two working modes. In normal mode the data is displayed on the console as in the figure below. In ysplitter mode a third virtual port is connected and has access to the data sent by the device port and by the control application.
You can get precompiled tty0tty dkms module or ssniffer packages from the piduino.org repository for Debian or Ubuntu :
wget -O- http://www.piduino.org/piduino-key.asc | sudo apt-key add -
sudo add-apt-repository 'deb http://apt.piduino.org buster piduino'
sudo apt update
The repository added in the add-apt-repository
command is for the
Debian Buster distribution, but you can also choose bullseye,
bionic, focal or jammy.
These repositories provide packages for the amd64, armhf and
arm64 architectures.
If the add-apt-repository
command fails, install the software-properties-common
package like this:
sudo apt install software-properties-common
sudo apt install tty0tty-dkms
sudo apt install ssniffer
for module build is necessary kernel-headers or kernel source:
sudo apt-get update
sudo apt-get install linux-headers-`uname -r`
cd module
make
sudo make install
for debian package:
sudo apt-get install devscripts build-essential lintian debhelper
Download the archive file from https://github.com/lcgamboa/tty0tty/archive/refs/heads/master.zip
wget https://github.com/lcgamboa/tty0tty/archive/refs/heads/master.zip
unzip master.zip
cd tty0tty-master
dpkg-buildpackage
to clean:
dh_clean
make install
set the devices permissions automatically in udev creating the file /etc/udev/rules.d/99-tty0tty.rules with rules:
SUBSYSTEM=="tty", KERNEL=="tnt0", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt1", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt2", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt3", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt4", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt5", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt6", GROUP="dialout", MODE="0660"
SUBSYSTEM=="tty", KERNEL=="tnt7", GROUP="dialout", MODE="0660"
It's possible edit rules and create permanent symbolic names with the parameter SYMLINK:
SUBSYSTEM=="tty", KERNEL=="tnt0", GROUP="dialout", MODE="0660", SYMLINK+="ttyUSB10"
SUBSYSTEM=="tty", KERNEL=="tnt1", GROUP="dialout", MODE="0660", SYMLINK+="ttyUSB11"
The user must be in the dialout group to access the ports. To add your user to dialout group use the command:
sudo usermod -a -G dialout your_user_name
after this is necessary logout and login to group permissions take effect.
To dkms support use the scripts dkms-install.sh
and dkms-remove.sh
cd pts
make
then run with:
./tty0tty
cd ssnifer
make
make install
for debian package:
dpkg-buildpackage
then for normal mode run with:
ssniffer /dev/ttyUSB0 2 color
and connect application in /dev/tnt3 virtual port.
Or for ysplitter mode run with:
ssniffer /dev/ttyUSB0 2 ysplitter4
and connect application in /dev/tnt3 virtual port and second terminal in /dev/tnt5 virtual port.
For e-mail suggestions : lcgamboa@yahoo.com