ssh-console: only enable keepalive option

There was some further discussion on dc0eec8 after it was merged. The
consensus was that it may have gone a bit too far on client connection
restrictions. For example, why add the -I to disconnect a fully working
(but idle) session?

It was also clarified that the -K option enables a keepalive message
every X seconds. The client is disconnected after 3 keepalive timeouts.
Given this, it was agreed to reduce the value from 10 to 5 to give the
client a total of 15 seconds to keep a connection alive.

Tested:
- Loaded on a p10bmc system, connected multiple clients to 2200 and
  2201 and caused extensive traffic in both. No issues found.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I83dbda457f0de0a727434614539f5fee8c7c665d
1 file changed
tree: 6491d61fe9eb19db400a2dc226236bbe5d8751bb
  1. conf/
  2. test/
  3. .gitignore
  4. .travis.yml
  5. bootstrap.sh
  6. config.c
  7. configure.ac
  8. console-client.c
  9. console-server.c
  10. console-server.h
  11. console-socket.c
  12. LICENSE
  13. log-handler.c
  14. MAINTAINERS
  15. Makefile.am
  16. OWNERS
  17. README.md
  18. ringbuffer.c
  19. socket-handler.c
  20. tty-handler.c
  21. util.c
README.md

To Build

Note: In addition to a toolchain and autoconf tools, this requires autotools-archive to be installed.

To build this project, run the following shell commands:

./bootstrap.sh
./configure ${CONFIGURE_FLAGS}
make

To fully clean the repository, run:

./bootstrap.sh clean

To Run Server

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 Client

To connect to the server, simply run the client:

./obmc-console-client

To disconnect the client, use the standard ~. combination.

Underlying design

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
           +---+--+  | socket-id = "host0" |  |                     |  | socket-id = "host0"    |  +--------+-------+
               |     |                     |  +---------------------+  |                        |           |
               |     +---------------------+                           +------------------------+           |
               |                                                                                            |
               |                                                                                            |
               |                                                                                            |
               +--------------------------------------------------------------------------------------------+

This supports multiple independent consoles. The socket-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.