obmc-console: fix segfault on missing config The `obmc-console-client` allow to not specify configuration file for active session. But at the same time it does not tolerate null pointer passed as config. This leads to a segmentation fault due to a missing configuration file. Fix this small inconvenience. Added testcase to make sure that obmc-console-client doesn't segfault when invoked without any arguments. Output without the fix: ''' + /home/dev/obmc-console/build/obmc-console-client + grep Connection refused Segmentation fault (core dumped) ''' Output with the fix: ''' + /home/ninad/dev/1110_ghe/obmc-console/build/obmc-console-client + grep Connection refused + cleanup + cd - + rm -rf /tmp/test_console_client_no_args_3245394.DZqk0S ''' Change-Id: Ia83da8bca30e2be94e00066f20f2cbe2ccba23b6 Tested-by: Ninad Palsule <ninad@linux.ibm.com> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com> Signed-off-by: Igor Kononenko <i.kononenko.e@gmail.com>
To build this project, run the following shell commands:
meson setup build meson compile -C build
To test:
dbus-run-session meson test -C build
Running the server requires a serial port (e.g. /dev/ttyS0):
touch obmc-console.conf ./obmc-console-server --config obmc-console.conf ttyS0
To connect to the server, simply run the client:
./obmc-console-client
To disconnect the client, use the standard ~. combination.
This shows how the host UART connection is abstracted within the BMC as a Unix domain socket.
+---------------------------------------------------------------------------------------------+
| |
| obmc-console-client unix domain socket obmc-console-server |
| |
| +----------------------+ +------------------------+ |
| | client.2200.conf | +---------------------+ | server.ttyVUART0.conf | |
+---+--+ +----------------------+ | | +------------------------+ +--------+-------+
Network | 2200 +--> +->+ @obmc-console.host0 +<-+ <--+ /dev/ttyVUART0 | UARTs
+---+--+ | console-id = "host0" | | | | console-id = "host0" | +--------+-------+
| | | +---------------------+ | | |
| +----------------------+ +------------------------+ |
| |
| |
| |
+---------------------------------------------------------------------------------------------+
This supports multiple independent consoles. The console-id is a unique portion for the unix domain socket created by the obmc-console-server instance. The server needs to know this because it needs to know what to name the pipe; the client needs to know it as it needs to form the abstract socket name to which to connect.
In some hardware designs, multiple UARTS may be available behind a Mux. Please reference docs/mux-support.md in that case.
For developing obmc-console, we can use pseudo terminals (pty's) in Linux.
The socat command will output names of 2 pty's, one of which is the master and the other one is the slave. The master pty can be used to emulate a UART.
$ socat -d -d pty,raw,echo=0,link=pty1 pty,raw,echo=0,link=pty2 $ obmc-console-server --console-id dev $(realpath pty2) $ obmc-console-client -i dev # this message should appear for the client $ echo "hi" > pty1