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authorOle Troan <ot@cisco.com>2019-08-23 22:55:18 +0200
committerAndrew Yourtchenko <ayourtch@gmail.com>2019-09-03 20:04:13 +0000
commite5ff5a36dd126ee57dca4e0b03da2f7704e0a4f5 (patch)
tree2108baa60e8a697624288fe2c3050be29697bc88 /src/vpp-api/python
parentb6fde4a8bae474c6b73d08d223028f42e396d452 (diff)
api: enforce vla is last and fixed string type
Enforce that variable length fields are the last element of API messages. Add a 'fixed' version of string type, since dealing with multiple variable length strings turned out too painful for the C language bindings. The string type is now: { string name[64]; // NUL terminated C-string. Essentially decays to u8 name[64] string name[]; // Variable length string with embedded len field (vl_api_string_t) }; The latter notation could be made available to other types as well. e.g. { vl_api_address_t addresses[]; } instead of { u32 n_addr; vl_api_address_t addresses[n_addr]; }; Type: fix Change-Id: I18fa17ef47227633752ab50453e8d20a652a9f9b Signed-off-by: Ole Troan <ot@cisco.com>
Diffstat (limited to 'src/vpp-api/python')
-rwxr-xr-xsrc/vpp-api/python/vpp_papi/tests/test_vpp_serializer.py40
-rw-r--r--src/vpp-api/python/vpp_papi/vpp_serializer.py46
2 files changed, 70 insertions, 16 deletions
diff --git a/src/vpp-api/python/vpp_papi/tests/test_vpp_serializer.py b/src/vpp-api/python/vpp_papi/tests/test_vpp_serializer.py
index bddaa9e00c2..6ca8e6c4ff3 100755
--- a/src/vpp-api/python/vpp_papi/tests/test_vpp_serializer.py
+++ b/src/vpp-api/python/vpp_papi/tests/test_vpp_serializer.py
@@ -11,11 +11,47 @@ from ipaddress import *
class TestLimits(unittest.TestCase):
+ def test_string(self):
+ fixed_string = VPPType('fixed_string',
+ [['string', 'name', 16]])
+
+ b = fixed_string.pack({'name': 'foobar'})
+ self.assertEqual(len(b), 16)
+
+ # Ensure string is nul terminated
+ self.assertEqual(b.decode('ascii')[6], '\x00')
+
+ nt, size = fixed_string.unpack(b)
+ self.assertEqual(size, 16)
+ self.assertEqual(nt.name, 'foobar')
+
+ # Empty string
+ b = fixed_string.pack({'name': ''})
+ self.assertEqual(len(b), 16)
+ nt, size = fixed_string.unpack(b)
+ self.assertEqual(size, 16)
+ self.assertEqual(nt.name, '')
+
+ # String too long
+ with self.assertRaises(VPPSerializerValueError):
+ b = fixed_string.pack({'name': 'foobarfoobar1234'})
+
+ variable_string = VPPType('variable_string',
+ [['string', 'name', 0]])
+ b = variable_string.pack({'name': 'foobar'})
+ self.assertEqual(len(b), 4 + len('foobar'))
+
+ nt, size = variable_string.unpack(b)
+ self.assertEqual(size, 4 + len('foobar'))
+ self.assertEqual(nt.name, 'foobar')
+ self.assertEqual(len(nt.name), len('foobar'))
+
+
def test_limit(self):
limited_type = VPPType('limited_type_t',
- [['string', 'name', {'limit': 16}]])
+ [['string', 'name', 0, {'limit': 16}]])
unlimited_type = VPPType('limited_type_t',
- [['string', 'name']])
+ [['string', 'name', 0]])
b = limited_type.pack({'name': 'foobar'})
self.assertEqual(len(b), 10)
diff --git a/src/vpp-api/python/vpp_papi/vpp_serializer.py b/src/vpp-api/python/vpp_papi/vpp_serializer.py
index 9ce0287592f..ec6a06bb3d5 100644
--- a/src/vpp-api/python/vpp_papi/vpp_serializer.py
+++ b/src/vpp-api/python/vpp_papi/vpp_serializer.py
@@ -105,27 +105,42 @@ class BaseTypes(object):
class String(object):
- def __init__(self, options):
- self.name = 'string'
+ def __init__(self, name, num, options):
+ self.name = name
+ self.num = num
self.size = 1
self.length_field_packer = BaseTypes('u32')
- self.limit = options['limit'] if 'limit' in options else None
+ self.limit = options['limit'] if 'limit' in options else num
+ self.fixed = True if num else False
+ if self.fixed and not self.limit:
+ raise VPPSerializerValueError(
+ "Invalid argument length for: {}, {} maximum {}".
+ format(list, len(list), self.limit))
def pack(self, list, kwargs=None):
if not list:
+ if self.fixed:
+ return b"\x00" * self.limit
return self.length_field_packer.pack(0) + b""
- if self.limit and len(list) > self.limit:
+ if self.limit and len(list) > self.limit - 1:
raise VPPSerializerValueError(
"Invalid argument length for: {}, {} maximum {}".
- format(list, len(list), self.limit))
-
- return self.length_field_packer.pack(len(list)) + list.encode('utf8')
+ format(list, len(list), self.limit - 1))
+ if self.fixed:
+ return list.encode('ascii').ljust(self.limit, b'\x00')
+ return self.length_field_packer.pack(len(list)) + list.encode('ascii')
def unpack(self, data, offset=0, result=None, ntc=False):
+ if self.fixed:
+ p = BaseTypes('u8', self.num)
+ s = p.unpack(data, offset)
+ s2 = s[0].split(b'\0', 1)[0]
+ return (s2.decode('ascii'), self.num)
+
length, length_field_size = self.length_field_packer.unpack(data,
offset)
if length == 0:
- return b'', 0
+ return '', 0
p = BaseTypes('u8', length)
x, size = p.unpack(data, offset + length_field_size)
x2 = x.split(b'\0', 1)[0]
@@ -181,10 +196,6 @@ class FixedList_u8(object):
'Invalid array length for "{}" got {}'
' expected {}'
.format(self.name, len(data[offset:]), self.num))
- if self.field_type == 'string':
- s = self.packer.unpack(data, offset)
- s2 = s[0].split(b'\0', 1)[0]
- return (s2.decode('utf-8'), self.num)
return self.packer.unpack(data, offset)
@@ -473,12 +484,19 @@ class VPPType(object):
if fieldlen == 3: # list
list_elements = f[2]
if list_elements == 0:
- p = VLAList_legacy(f_name, f_type)
+ if f_type == 'string':
+ p = String(f_name, 0, self.options)
+ else:
+ p = VLAList_legacy(f_name, f_type)
self.packers.append(p)
- elif f_type == 'u8' or f_type == 'string':
+ elif f_type == 'u8':
p = FixedList_u8(f_name, f_type, list_elements)
self.packers.append(p)
size += p.size
+ elif f_type == 'string':
+ p = String(f_name, list_elements, self.options)
+ self.packers.append(p)
+ size += p.size
else:
p = FixedList(f_name, f_type, list_elements)
self.packers.append(p)