dexter has uploaded this change for review. ( https://gerrit.osmocom.org/c/pysim/+/37839?usp=email )

Change subject: pySim-shell: prevent opening/closing logical channel 0 ......................................................................

pySim-shell: prevent opening/closing logical channel 0

The basic logical channel 0 is always present. It cannot be created or closed. In case someone tries to create or close it anyway, we should reject such a command immediately since it might cause unexpected effects.

Related: OS#6531 Change-Id: I4eebd9f15fadd18e1caeb033fda36c59446fcab8 --- M pySim-shell.py 1 file changed, 4 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/39/37839/1

diff --git a/pySim-shell.py b/pySim-shell.py index 630d54a..5d99d48 100755 --- a/pySim-shell.py +++ b/pySim-shell.py @@ -970,6 +970,8 @@ @cmd2.with_argparser(open_chan_parser) def do_open_channel(self, opts): """Open a logical channel.""" + if opts.chan_nr == 0: + raise RuntimeError("Cannot create (always existing) basic logical lchan 0") (data, sw) = self._cmd.lchan.scc.manage_channel( mode='open', lchan_nr=opts.chan_nr) # this is executed only in successful case, as unsuccessful raises exception @@ -982,6 +984,8 @@ @cmd2.with_argparser(close_chan_parser) def do_close_channel(self, opts): """Close a logical channel.""" + if opts.chan_nr == 0: + raise RuntimeError("Cannot close (always existing) basic logical lchan 0") (data, sw) = self._cmd.lchan.scc.manage_channel( mode='close', lchan_nr=opts.chan_nr) # this is executed only in successful case, as unsuccessful raises exception