D2948: wireproto: syntax for encoding CBOR into frames

indygreg (Gregory Szorc) phabricator at mercurial-scm.org
Mon Mar 26 17:36:08 EDT 2018


indygreg updated this revision to Diff 7327.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST UPDATE
  https://phab.mercurial-scm.org/D2948?vs=7310&id=7327

REVISION DETAIL
  https://phab.mercurial-scm.org/D2948

AFFECTED FILES
  mercurial/debugcommands.py
  mercurial/wireprotoframing.py
  tests/test-wireproto-serverreactor.py

CHANGE DETAILS

diff --git a/tests/test-wireproto-serverreactor.py b/tests/test-wireproto-serverreactor.py
--- a/tests/test-wireproto-serverreactor.py
+++ b/tests/test-wireproto-serverreactor.py
@@ -35,6 +35,59 @@
                       framing.createcommandframes(stream, rid, cmd, args,
                                                   datafh))
 
+class FrameHumanStringTests(unittest.TestCase):
+    def testbasic(self):
+        self.assertEqual(ffs(b'1 1 0 1 0 '),
+                         b'\x00\x00\x00\x01\x00\x01\x00\x10')
+
+        self.assertEqual(ffs(b'2 4 0 1 0 '),
+                         b'\x00\x00\x00\x02\x00\x04\x00\x10')
+
+        self.assertEqual(ffs(b'2 4 0 1 0 foo'),
+                         b'\x03\x00\x00\x02\x00\x04\x00\x10foo')
+
+    def testcborint(self):
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:15'),
+                         b'\x01\x00\x00\x01\x00\x01\x00\x10\x0f')
+
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:42'),
+                         b'\x02\x00\x00\x01\x00\x01\x00\x10\x18*')
+
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:1048576'),
+                         b'\x05\x00\x00\x01\x00\x01\x00\x10\x1a'
+                         b'\x00\x10\x00\x00')
+
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:0'),
+                         b'\x01\x00\x00\x01\x00\x01\x00\x10\x00')
+
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:-1'),
+                         b'\x01\x00\x00\x01\x00\x01\x00\x10 ')
+
+        self.assertEqual(ffs(b'1 1 0 1 0 cbor:-342542'),
+                         b'\x05\x00\x00\x01\x00\x01\x00\x10:\x00\x05:\r')
+
+    def testcborstrings(self):
+        # String literals should be unicode.
+        self.assertEqual(ffs(b"1 1 0 1 0 cbor:'foo'"),
+                         b'\x04\x00\x00\x01\x00\x01\x00\x10cfoo')
+
+        self.assertEqual(ffs(b"1 1 0 1 0 cbor:b'foo'"),
+                         b'\x04\x00\x00\x01\x00\x01\x00\x10Cfoo')
+
+        self.assertEqual(ffs(b"1 1 0 1 0 cbor:u'foo'"),
+                         b'\x04\x00\x00\x01\x00\x01\x00\x10cfoo')
+
+    def testcborlists(self):
+        self.assertEqual(ffs(b"1 1 0 1 0 cbor:[None, True, False, 42, b'foo']"),
+                         b'\n\x00\x00\x01\x00\x01\x00\x10\x85\xf6\xf5\xf4'
+                         b'\x18*Cfoo')
+
+    def testcbordicts(self):
+        self.assertEqual(ffs(b"1 1 0 1 0 "
+                             b"cbor:{b'foo': b'val1', b'bar': b'val2'}"),
+                         b'\x13\x00\x00\x01\x00\x01\x00\x10\xa2'
+                         b'CbarDval2CfooDval1')
+
 class FrameTests(unittest.TestCase):
     def testdataexactframesize(self):
         data = util.bytesio(b'x' * framing.DEFAULT_MAX_FRAME_SIZE)
diff --git a/mercurial/wireprotoframing.py b/mercurial/wireprotoframing.py
--- a/mercurial/wireprotoframing.py
+++ b/mercurial/wireprotoframing.py
@@ -11,11 +11,13 @@
 
 from __future__ import absolute_import
 
+import __future__
 import struct
 
 from .i18n import _
 from .thirdparty import (
     attr,
+    cbor,
 )
 from . import (
     error,
@@ -156,6 +158,9 @@
 def makeframefromhumanstring(s):
     """Create a frame from a human readable string
 
+    DANGER: NOT SAFE TO USE WITH UNTRUSTED INPUT BECAUSE OF POTENTIAL
+    eval() USAGE. DO NOT USE IN CORE.
+
     Strings have the form:
 
         <request-id> <stream-id> <stream-flags> <type> <flags> <payload>
@@ -169,6 +174,11 @@
     named constant.
 
     Flags can be delimited by `|` to bitwise OR them together.
+
+    If the payload begins with ``cbor:``, the following string will be
+    evaluated as Python code and the resulting object will be fed into
+    a CBOR encoder. Otherwise, the payload is interpreted as a Python
+    byte string literal.
     """
     fields = s.split(b' ', 5)
     requestid, streamid, streamflags, frametype, frameflags, payload = fields
@@ -196,7 +206,31 @@
         else:
             finalflags |= int(flag)
 
-    payload = stringutil.unescapestr(payload)
+    if payload.startswith(b'cbor:'):
+        globs = {
+            r'__builtins__': {
+                r'None': None,
+                r'False': False,
+                r'True': True,
+                r'int': int,
+                r'set': set,
+                r'tuple': tuple,
+                # Don't need to expose dict and list because we can use
+                # literals.
+            },
+        }
+
+        # We can't use eval() directly because it inherits compiler
+        # flags from this module and we need unicode literals for Python 3
+        # compatibility.
+        code = compile(payload[5:], r'<string>', r'eval',
+                       __future__.unicode_literals.compiler_flag, True)
+        o = eval(code, globs, {})
+
+        payload = cbor.dumps(o, canonical=True)
+
+    else:
+        payload = stringutil.unescapestr(payload)
 
     return makeframe(requestid=requestid, streamid=streamid,
                      streamflags=finalstreamflags, typeid=frametype,
diff --git a/mercurial/debugcommands.py b/mercurial/debugcommands.py
--- a/mercurial/debugcommands.py
+++ b/mercurial/debugcommands.py
@@ -2785,7 +2785,10 @@
     or a flag name for stream flags or frame flags, respectively. Values are
     resolved to integers and then bitwise OR'd together.
 
-    ``payload`` is is evaluated as a Python byte string literal.
+    ``payload`` represents the raw frame payload. If it begins with
+    ``cbor:``, the following string is evaluated as Python code and the
+    resulting object is fed into a CBOR encoder. Otherwise it is interpreted
+    as a Python byte string literal.
     """
     opts = pycompat.byteskwargs(opts)
 



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