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vty telnet: consistently never change nodes upon CTRL-C 

Remove any special node exiting from the VTY CTRL-C handling.

From a curious VTY transcript test glitch, I noticed weird behavior by the VTY
telnet shell: usually, when the user hits CTRL-C, that means to cancel the
current command line and present a fresh, clean prompt. However, only on the
CONFIG_NODE and CFG_LOG_NODE, a CTRL-C also exits the current node and moves up
by one level. This behavior is unexplainable and makes zero sense.

No other nodes exit on CTRL-C:
- on the ENABLE node, a CTRL-C stays on the ENABLE_NODE and doesn't exit to the
  VIEW_NODE.
- any sub-nodes of the CONFIG_NODE stay unchanged, e.g. 'network' or 'bts' /
  'trx', etc.

There is no apparent special meaning of CTRL-C on CONFIG_NODE nor CFG_LOG_NODE
to justify this odd choice.

Particularly, the vty transcript tests using osmo_verify_transcript_vty.py rely
on sending CTRL-C to clear the command prompt, so that we can properly test
sending '?' to the VTY during transcripts. In a live session, a '?' prints
available options and then updates the prompt with identical command arguments.
In a transcript test, that doesn't make sense, because each time the transcript
writes out a new command to run. Consider e.g. a transcript test like:

	tdef_vty_test(config)# timer ?
	  tea       Tea time
	  test      Test timers
	  software  Typical software development cycle

	tdef_vty_test(config)# timer tea ?
	  [TNNNN]  T-number, optionally preceded by 't' or 'T'.

To be able to issue a fresh command after '?', osmo_verify_transcript_vty.py
explicitly sends a CTRL-C to clear the command buffer. Hence there we rely on
predictable behavior of CTRL-C.

More particularly, the upcoming osmo_tdef_vty transcript tests are apparently
the first that want to test '?' behavior on the CONFIG_NODE's root level and
fall on their face, because of the implicit exit that happens only there.

Change-Id: I4f339ba61f1c273fa7da85caf77ba116ae2697b1
This commit is contained in:
Neels Hofmeyr 2019-02-01 00:25:55 +01:00 committed by Neels Hofmeyr
parent 9ea9dd0d5f
commit 8d04f95d96
1 changed files with 0 additions and 18 deletions
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18
src/vty/vty.c
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@ -1217,24 +1217,6 @@ static void vty_stop_input(struct vty *vty)
vty->cp = vty->length = 0;
vty_clear_buf(vty);
vty_out(vty, "%s", VTY_NEWLINE);
switch (vty->node) {
case VIEW_NODE:
case ENABLE_NODE:
/* Nothing to do. */
break;
case CONFIG_NODE:
case VTY_NODE:
vty_config_unlock(vty);
vty->node = ENABLE_NODE;
break;
case CFG_LOG_NODE:
vty->node = CONFIG_NODE;
break;
default:
/* Unknown node, we have to ignore it. */
break;
}
vty_prompt(vty);
/* Set history pointer to the latest one. */