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laforge gerrit-no-reply at lists.osmocom.orglaforge has uploaded this change for review. ( https://gerrit.osmocom.org/c/pysim/+/23661 )
Change subject: pySim-shell: JSONpath support for updating files/records
......................................................................
pySim-shell: JSONpath support for updating files/records
Change-Id: Iad09b3d878b8b58ad34cb549c80f8a6eb3149faa
---
M docs/shell.rst
M pySim/filesystem.py
A pySim/jsonpath.py
M requirements.txt
M setup.py
5 files changed, 79 insertions(+), 2 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/61/23661/1
diff --git a/docs/shell.rst b/docs/shell.rst
index 2edebbf..3cfc849 100644
--- a/docs/shell.rst
+++ b/docs/shell.rst
@@ -226,6 +226,33 @@
:module: pySim.filesystem
:func: TransparentEF.ShellCommands.upd_bin_dec_parser
+In normal operation, update_binary_decoded needs a JSON document representing the entire file contents as
+input. This can be inconvenient if you want to keep 99% of the content but just toggle one specific
+parameter. That's where the JSONpath support comes in handy: You can specify a JSONpath to an element
+inside the document as well as a new value for tat field:
+
+Th below example demonstrates this by modifying the ofm field within EF.AD:
+
+::
+
+ pySIM-shell (MF/ADF.USIM/EF.AD)> read_binary_decoded
+ {
+ "ms_operation_mode": "normal",
+ "specific_facilities": {
+ "ofm": true
+ },
+ "len_of_mnc_in_imsi": 2
+ }
+ pySIM-shell (MF/ADF.USIM/EF.AD)> update_binary_decoded --json-path specific_facilities.ofm false
+ pySIM-shell (MF/ADF.USIM/EF.AD)> read_binary_decoded
+ {
+ "ms_operation_mode": "normal",
+ "specific_facilities": {
+ "ofm": false
+ },
+ "len_of_mnc_in_imsi": 2
+ }
+
cmd2 settable parameters
diff --git a/pySim/filesystem.py b/pySim/filesystem.py
index a65a764..f8443f3 100644
--- a/pySim/filesystem.py
+++ b/pySim/filesystem.py
@@ -35,6 +35,7 @@
from pySim.utils import sw_match, h2b, b2h, is_hex
from pySim.exceptions import *
+from pySim.jsonpath import js_path_find, js_path_modify
class CardFile(object):
"""Base class for all objects in the smart card filesystem.
@@ -418,10 +419,16 @@
upd_bin_dec_parser = argparse.ArgumentParser()
upd_bin_dec_parser.add_argument('data', help='Abstract data (JSON format) to write')
+ upd_bin_dec_parser.add_argument('--json-path', type=str,
+ help='JSON path to modify specific element of file only')
@cmd2.with_argparser(upd_bin_dec_parser)
def do_update_binary_decoded(self, opts):
"""Encode + Update (Write) data of a transparent EF"""
- data_json = json.loads(opts.data)
+ if opts.json_path:
+ (data_json, sw) = self._cmd.rs.read_binary_dec()
+ js_path_modify(data_json, opts.json_path, json.loads(opts.data))
+ else:
+ data_json = json.loads(opts.data)
(data, sw) = self._cmd.rs.update_binary_dec(data_json)
if data:
self._cmd.poutput_json(data)
@@ -574,10 +581,17 @@
upd_rec_dec_parser = argparse.ArgumentParser()
upd_rec_dec_parser.add_argument('record_nr', type=int, help='Number of record to be read')
upd_rec_dec_parser.add_argument('data', help='Data bytes (hex format) to write')
+ upd_rec_dec_parser.add_argument('--json-path', type=str,
+ help='JSON path to modify specific element of record only')
@cmd2.with_argparser(upd_rec_dec_parser)
def do_update_record_decoded(self, opts):
"""Encode + Update (write) data to a record-oriented EF"""
- (data, sw) = self._cmd.rs.update_record_dec(opts.record_nr, opts.data)
+ if opts.json_path:
+ (data_json, sw) = self._cmd.rs.read_record_dec(opts.record_nr)
+ js_path_modify(data_json, opts.json_path, json.loads(opts.data))
+ else:
+ data_json = json.loads(opts.data)
+ (data, sw) = self._cmd.rs.update_record_dec(opts.record_nr, data_json)
if data:
self._cmd.poutput(data)
diff --git a/pySim/jsonpath.py b/pySim/jsonpath.py
new file mode 100644
index 0000000..012d1d9
--- /dev/null
+++ b/pySim/jsonpath.py
@@ -0,0 +1,34 @@
+import json
+import pprint
+
+from jsonpath_ng import jsonpath, parse
+
+"""JSONpath utliity functions as needed within pysim.
+
+As pySim-sell has the ability to represent SIM files as JSON strings,
+adding JSONpath allows us to conveniently modify individual sub-fields
+of a file or record in its JSON representation.
+"""
+
+
+def js_path_find(js_dict, js_path):
+ """Find/Match a JSON path within a givne JSON-serializable dict.
+ Args:
+ js_dict : JSON-serializable dict to operate on
+ js_path : JSONpath string
+ Returns: Result of the JSONpath expression
+ """
+ jsonpath_expr = parse(js_path)
+ return jsonpath_expr.find(js_dict)
+
+def js_path_modify(js_dict, js_path, new_val):
+ """Find/Match a JSON path within a givne JSON-serializable dict.
+ Args:
+ js_dict : JSON-serializable dict to operate on
+ js_path : JSONpath string
+ new_val : New value for field in js_dict at js_path
+ """
+ jsonpath_expr = parse(js_path)
+ jsonpath_expr.find(js_dict)
+ jsonpath_expr.update(js_dict, new_val)
+
diff --git a/requirements.txt b/requirements.txt
index 978a3db..f203ed1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,3 +2,4 @@
serial
pytlv
cmd2
+jsonpath-ng
diff --git a/setup.py b/setup.py
index d9f742c..a02e327 100644
--- a/setup.py
+++ b/setup.py
@@ -13,6 +13,7 @@
"serial",
"pytlv",
"cmd2"
+ "jsonpath-ng"
],
scripts=[
'pySim-prog.py',
--
To view, visit https://gerrit.osmocom.org/c/pysim/+/23661
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Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: Iad09b3d878b8b58ad34cb549c80f8a6eb3149faa
Gerrit-Change-Number: 23661
Gerrit-PatchSet: 1
Gerrit-Owner: laforge <laforge at osmocom.org>
Gerrit-MessageType: newchange
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