dexter has uploaded this change for review. (
https://gerrit.osmocom.org/c/pysim/+/34932?usp=email )
Change subject: runtime: refactor file selection methods select and select_file
......................................................................
runtime: refactor file selection methods select and select_file
The implementation of the methods select and select_file of class
RuntimeLchan is a bit complex. We access the card directly in several
places which makes it difficult to track the state changes. We should
clean this up so that we call self.rs.card.select_adf_by_aid/
self.scc.select_file from a single place only.
This means that the method select uses the method select_file. This
results in a much cleaner implementation. We also should take care
that the important states that we track (selected_file, selected_adf,
etc.) are updated by a single private method. Since the update always
must happen after a select _select_post is a good place to do this.
Related: OS#6210
Change-Id: I9ae213f3b078983f3e6d4c11db38fdbe504c84f2
---
M pySim/runtime.py
1 file changed, 89 insertions(+), 41 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/32/34932/1
diff --git a/pySim/runtime.py b/pySim/runtime.py
index 8660724..feaa355 100644
--- a/pySim/runtime.py
+++ b/pySim/runtime.py
@@ -64,7 +64,7 @@
self.mf.add_file(f)
# go back to MF before the next steps (addon probing might have
changed DF)
- self.card._scc.select_file('3F00')
+ self.lchan[0].select('3F00')
# add application ADFs + MF-files from profile
apps = self._match_applications()
@@ -110,6 +110,12 @@
# probe for those applications
for f in sorted(set(apps_profile) - set(apps_taken), key=str):
try:
+ # we can not use the lchan provided methods select, or
select_file
+ # since those method work on an already finished file model. At
+ # this point we are still in the initialization process, so it
is
+ # no problem when we access the card directly without caring
about
+ # updating other states. For normal selects at runtime, the
caller
+ # must use the lchan provided methods select or select_file!
data, sw = self.card.select_adf_by_aid(f.aid)
if sw == "9000":
print(" %s: %s" % (f.name, f.aid))
@@ -163,11 +169,14 @@
def __init__(self, lchan_nr: int, rs: RuntimeState):
self.lchan_nr = lchan_nr
self.rs = rs
+ self.scc = self.rs.card._scc.fork_lchan(lchan_nr)
+
+ # File reference data
self.selected_file = self.rs.mf
self.selected_adf = None
self.selected_file_fcp = None
self.selected_file_fcp_hex = None
- self.scc = self.rs.card._scc.fork_lchan(lchan_nr)
+
def add_lchan(self, lchan_nr: int) -> 'RuntimeLchan':
"""Add a new logical channel from the current logical channel. Just
affects
@@ -246,9 +255,17 @@
raise ValueError(
"Cannot select unknown file by name %s, only hexadecimal 4
digit FID is allowed" % fid)
+ self._select_pre(cmd_app)
+
try:
+ # We access the card through the select_file method of the scc
object.
+ # If we succeed, we know that the file exists and we may proceed
with
+ # creating a new file at run time. In case the file does not
exist, we
+ # just abort. The state on the card (selected file/application)
wont't
+ # be changed, so we do not have to update any state in that case.
(data, sw) = self.scc.select_file(fid)
except SwMatchError as swm:
+ self._select_post(cmd_app)
k = self.interpret_sw(swm.sw_actual)
if not k:
raise(swm)
@@ -267,8 +284,8 @@
desc="elementary file, manually added at
runtime")
self.selected_file.add_files([f])
- self.selected_file = f
- return select_resp, data
+
+ self._select_post(cmd_app, f, data)
def _select_pre(self, cmd_app):
# unregister commands of old file
@@ -276,7 +293,17 @@
for c in self.selected_file.shell_commands:
cmd_app.unregister_command_set(c)
- def _select_post(self, cmd_app):
+ def _select_post(self, cmd_app, file:CardFile = None, select_resp_data =
None):
+ # we store some reference data (see above) about the currently
selected file.
+ # This data must be updated after every select.
+ if file:
+ self.selected_file = file
+ if isinstance(file, CardADF):
+ self.selected_adf = file
+ if select_resp_data:
+ self.selected_file_fcp_hex = select_resp_data
+ self.selected_file_fcp =
self.selected_file.decode_select_response(select_resp_data)
+
# register commands of new file
if cmd_app and self.selected_file.shell_commands:
for c in self.selected_file.shell_commands:
@@ -293,22 +320,31 @@
inter_path = self.selected_file.build_select_path_to(file)
if not inter_path:
raise RuntimeError('Cannot determine path from %s to %s' %
(self.selected_file, file))
-
self._select_pre(cmd_app)
- for p in inter_path:
+ # be sure the variables that we pass to _select_post contain valid
values.
+ selected_file = self.selected_file
+ data = self.selected_file_fcp_hex
+
+ for f in inter_path:
try:
- if isinstance(p, CardADF):
- (data, sw) = self.rs.card.select_adf_by_aid(p.aid,
scc=self.scc)
- self.selected_adf = p
+ # We now directly accessing the card to perform the selection.
This
+ # will change the state of the card, so we must take care to
update
+ # the local state (lchan) as well. This is done in the method
+ # _select_port. It should be noted that the caller must always
use
+ # the methods select_file or select. The caller must not
access the
+ # card directly since this would lead into an incoherence of
the
+ # card state and the state of the lchan.
+ if isinstance(f, CardADF):
+ (data, sw) = self.rs.card.select_adf_by_aid(f.aid,
scc=self.scc)
else:
- (data, sw) = self.scc.select_file(p.fid)
- self.selected_file = p
+ (data, sw) = self.scc.select_file(f.fid)
+ selected_file = f
except SwMatchError as swm:
- self._select_post(cmd_app)
+ self._select_post(cmd_app, selected_file, data)
raise(swm)
- self._select_post(cmd_app)
+ self._select_post(cmd_app, f, data)
def select(self, name: str, cmd_app=None):
"""Select a file (EF, DF, ADF, MF, ...).
@@ -317,9 +353,11 @@
name : Name of file to select
cmd_app : Command Application State (for unregistering old file
commands)
"""
+ # if any intermediate step failes, we must be able to go back where we
were
+ prev_sel_file = self.selected_file
+
# handling of entire paths with multiple directories/elements
if '/' in name:
- prev_sel_file = self.selected_file
pathlist = name.split('/')
# treat /DF.GSM/foo like MF/DF.GSM/foo
if pathlist[0] == '':
@@ -327,41 +365,29 @@
try:
for p in pathlist:
self.select(p, cmd_app)
- return
+ return self.selected_file_fcp
except Exception as e:
- # if any intermediate step fails, go back to where we were
self.select_file(prev_sel_file, cmd_app)
raise e
+ # we are now in the directory where the target file is located
+ # so we can now refer to the get_selectables() method to get the
+ # file object and select it using select_file()
sels = self.selected_file.get_selectables()
if is_hex(name):
name = name.lower()
- self._select_pre(cmd_app)
+ try:
+ if name in sels:
+ f = sels[name]
+ self.select_file(sels[name], cmd_app)
+ else:
+ self.probe_file(name, cmd_app)
+ except Exception as e:
+ self.select_file(prev_sel_file, cmd_app)
+ raise e
- if name in sels:
- f = sels[name]
- try:
- if isinstance(f, CardADF):
- (data, sw) = self.rs.card.select_adf_by_aid(f.aid,
scc=self.scc)
- else:
- (data, sw) = self.scc.select_file(f.fid)
- self.selected_file = f
- except SwMatchError as swm:
- k = self.interpret_sw(swm.sw_actual)
- if not k:
- raise(swm)
- raise RuntimeError("%s: %s - %s" % (swm.sw_actual, k[0], k[1]))
- select_resp = f.decode_select_response(data)
- else:
- (select_resp, data) = self.probe_file(name, cmd_app)
-
- # store the raw + decoded FCP for later reference
- self.selected_file_fcp_hex = data
- self.selected_file_fcp = select_resp
-
- self._select_post(cmd_app)
- return select_resp
+ return self.selected_file_fcp
def status(self):
"""Request STATUS (current selected file FCP) from card."""
--
To view, visit https://gerrit.osmocom.org/c/pysim/+/34932?usp=email
To unsubscribe, or for help writing mail filters, visit
https://gerrit.osmocom.org/settings
Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: I9ae213f3b078983f3e6d4c11db38fdbe504c84f2
Gerrit-Change-Number: 34932
Gerrit-PatchSet: 1
Gerrit-Owner: dexter <pma...@sysmocom.de>
Gerrit-MessageType: newchange
