From 30d28bdfd8aca4d6d3c70482ad9ebfdb753610aa Mon Sep 17 00:00:00 2001 From: Ole Troan Date: Fri, 23 Aug 2019 22:55:18 +0200 Subject: 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 (cherry picked from commit e5ff5a36dd126ee57dca4e0b03da2f7704e0a4f5) Signed-off-by: Ole Troan --- .../python/vpp_papi/tests/test_vpp_serializer.py | 40 ++++++++++++++++++- src/vpp-api/python/vpp_papi/vpp_serializer.py | 46 +++++++++++++++------- src/vpp-api/vapi/vapi_c_gen.py | 12 ++++-- src/vpp-api/vapi/vapi_json_parser.py | 5 ++- 4 files changed, 83 insertions(+), 20 deletions(-) (limited to 'src/vpp-api') 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) diff --git a/src/vpp-api/vapi/vapi_c_gen.py b/src/vpp-api/vapi/vapi_c_gen.py index 381dcba7f42..b9b9aa750a8 100755 --- a/src/vpp-api/vapi/vapi_c_gen.py +++ b/src/vpp-api/vapi/vapi_c_gen.py @@ -13,10 +13,16 @@ class CField(Field): return "vapi_type_%s" % self.name def get_c_def(self): - if self.len is not None: - return "%s %s[%d];" % (self.type.get_c_name(), self.name, self.len) + if self.type.get_c_name() == 'vl_api_string_t': + if self.len: + return "u8 %s[%d];" % (self.name, self.len) + else: + return "vl_api_string_t %s;" % (self.name) else: - return "%s %s;" % (self.type.get_c_name(), self.name) + if self.len is not None: + return "%s %s[%d];" % (self.type.get_c_name(), self.name, self.len) + else: + return "%s %s;" % (self.type.get_c_name(), self.name) def get_swap_to_be_code(self, struct, var): if self.len is not None: diff --git a/src/vpp-api/vapi/vapi_json_parser.py b/src/vpp-api/vapi/vapi_json_parser.py index a9d2c8186bc..d7669365ce8 100644 --- a/src/vpp-api/vapi/vapi_json_parser.py +++ b/src/vpp-api/vapi/vapi_json_parser.py @@ -177,12 +177,15 @@ class Message(object): p = field_class(field_name=field[1], field_type=field_type) elif l == 3: - if field[2] == 0: + if field[2] == 0 and field[0] != 'string': raise ParseError( "While parsing message `%s': variable length " "array `%s' doesn't have reference to member " "containing the actual length" % ( name, field[1])) + if field[0] == 'string' and field[2] > 0: + field_type = json_parser.lookup_type_like_id('u8') + p = field_class( field_name=field[1], field_type=field_type, -- cgit 1.2.3-korg