spice-common/python_modules/spice_parser.py
Marc-Andre Lureau c5ed374a32 protocol: learn to describe fd passing in messages
Add a new type, "unix_fd", used to describe file descriptor sharing via
socket ancillary data (these messages are local only).

The marshaller/demarshaller can't serialize this in memory (consume_fd
implementation is empty), so it is the responsability of the marshaller
user to handle sending and receiving the handles, which are appended at
the end of the message with an extra stream byte (because some Unix
requires sending at least a byte with ancillary data).

Even if there is no fd to send (or if the fd is invalid etc), the
receiver side expects an extra byte anyway.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Frediano Ziglio <fziglio@redhat.com>

(cherry-picked from spice-protocol commit 267391c8fd7c90c067b3e4845ff0227a2580e2e2)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2016-03-10 16:01:42 +01:00

164 lines
8.1 KiB
Python

import six
try:
from pyparsing import Literal, CaselessLiteral, Word, OneOrMore, ZeroOrMore, \
Forward, delimitedList, Group, Optional, Combine, alphas, nums, restOfLine, cStyleComment, \
alphanums, ParseException, ParseResults, Keyword, StringEnd, replaceWith
except ImportError:
six.print_("Module pyparsing not found.")
exit(1)
from . import ptypes
import sys
cvtInt = lambda toks: int(toks[0])
def parseVariableDef(toks):
t = toks[0][0]
pointer = toks[0][1]
name = toks[0][2]
array_size = toks[0][3]
attributes = toks[0][4]
if array_size != None:
t = ptypes.ArrayType(t, array_size)
if pointer != None:
t = ptypes.PointerType(t)
return ptypes.Member(name, t, attributes)
bnf = None
def SPICE_BNF():
global bnf
if not bnf:
# punctuation
colon = Literal(":").suppress()
lbrace = Literal("{").suppress()
rbrace = Literal("}").suppress()
lbrack = Literal("[").suppress()
rbrack = Literal("]").suppress()
lparen = Literal("(").suppress()
rparen = Literal(")").suppress()
equals = Literal("=").suppress()
comma = Literal(",").suppress()
semi = Literal(";").suppress()
# primitive types
int8_ = Keyword("int8").setParseAction(replaceWith(ptypes.int8))
uint8_ = Keyword("uint8").setParseAction(replaceWith(ptypes.uint8))
int16_ = Keyword("int16").setParseAction(replaceWith(ptypes.int16))
uint16_ = Keyword("uint16").setParseAction(replaceWith(ptypes.uint16))
int32_ = Keyword("int32").setParseAction(replaceWith(ptypes.int32))
uint32_ = Keyword("uint32").setParseAction(replaceWith(ptypes.uint32))
int64_ = Keyword("int64").setParseAction(replaceWith(ptypes.int64))
uint64_ = Keyword("uint64").setParseAction(replaceWith(ptypes.uint64))
unix_fd_ = Keyword("unix_fd").setParseAction(replaceWith(ptypes.unix_fd))
# keywords
enum32_ = Keyword("enum32").setParseAction(replaceWith(32))
enum16_ = Keyword("enum16").setParseAction(replaceWith(16))
enum8_ = Keyword("enum8").setParseAction(replaceWith(8))
flags32_ = Keyword("flags32").setParseAction(replaceWith(32))
flags16_ = Keyword("flags16").setParseAction(replaceWith(16))
flags8_ = Keyword("flags8").setParseAction(replaceWith(8))
channel_ = Keyword("channel")
server_ = Keyword("server")
client_ = Keyword("client")
protocol_ = Keyword("protocol")
typedef_ = Keyword("typedef")
struct_ = Keyword("struct")
message_ = Keyword("message")
image_size_ = Keyword("image_size")
bytes_ = Keyword("bytes")
cstring_ = Keyword("cstring")
switch_ = Keyword("switch")
default_ = Keyword("default")
case_ = Keyword("case")
identifier = Word( alphas, alphanums + "_" )
enumname = Word( alphanums + "_" )
integer = ( Combine( CaselessLiteral("0x") + Word( nums+"abcdefABCDEF" ) ) |
Word( nums+"+-", nums ) ).setName("int").setParseAction(cvtInt)
typename = identifier.copy().setParseAction(lambda toks : ptypes.TypeRef(str(toks[0])))
# This is just normal "types", i.e. not channels or messages
typeSpec = Forward()
attributeValue = integer ^ identifier
attribute = Group(Combine ("@" + identifier) + Optional(lparen + delimitedList(attributeValue) + rparen))
attributes = Group(ZeroOrMore(attribute))
arraySizeSpecImage = Group(image_size_ + lparen + integer + comma + identifier + comma + identifier + rparen)
arraySizeSpecBytes = Group(bytes_ + lparen + identifier + comma + identifier + rparen)
arraySizeSpecCString = Group(cstring_ + lparen + rparen)
arraySizeSpec = lbrack + Optional(identifier ^ integer ^ arraySizeSpecImage ^ arraySizeSpecBytes ^arraySizeSpecCString, default="") + rbrack
variableDef = Group(typeSpec + Optional("*", default=None) + identifier + Optional(arraySizeSpec, default=None) + attributes - semi) \
.setParseAction(parseVariableDef)
switchCase = Group(Group(OneOrMore(default_.setParseAction(replaceWith(None)) + colon | Group(case_.suppress() + Optional("!", default="") + identifier) + colon)) + variableDef) \
.setParseAction(lambda toks: ptypes.SwitchCase(toks[0][0], toks[0][1]))
switchBody = Group(switch_ + lparen + delimitedList(identifier,delim='.', combine=True) + rparen + lbrace + Group(OneOrMore(switchCase)) + rbrace + identifier + attributes - semi) \
.setParseAction(lambda toks: ptypes.Switch(toks[0][1], toks[0][2], toks[0][3], toks[0][4]))
messageBody = structBody = Group(lbrace + ZeroOrMore(variableDef | switchBody) + rbrace)
structSpec = Group(struct_ + identifier + structBody + attributes).setParseAction(lambda toks: ptypes.StructType(toks[0][1], toks[0][2], toks[0][3]))
# have to use longest match for type, in case a user-defined type name starts with a keyword type, like "channel_type"
typeSpec << ( structSpec ^ int8_ ^ uint8_ ^ int16_ ^ uint16_ ^
int32_ ^ uint32_ ^ int64_ ^ uint64_ ^ unix_fd_ ^
typename).setName("type")
flagsBody = enumBody = Group(lbrace + delimitedList(Group (enumname + Optional(equals + integer))) + Optional(comma) + rbrace)
messageSpec = Group(message_ + messageBody + attributes).setParseAction(lambda toks: ptypes.MessageType(None, toks[0][1], toks[0][2])) | typename
channelParent = Optional(colon + typename, default=None)
channelMessage = Group(messageSpec + identifier + Optional(equals + integer, default=None) + semi) \
.setParseAction(lambda toks: ptypes.ChannelMember(toks[0][1], toks[0][0], toks[0][2]))
channelBody = channelParent + Group(lbrace + ZeroOrMore( server_ + colon | client_ + colon | channelMessage) + rbrace)
enum_ = (enum32_ | enum16_ | enum8_)
flags_ = (flags32_ | flags16_ | flags8_)
enumDef = Group(enum_ + identifier + enumBody + attributes - semi).setParseAction(lambda toks: ptypes.EnumType(toks[0][0], toks[0][1], toks[0][2], toks[0][3]))
flagsDef = Group(flags_ + identifier + flagsBody + attributes - semi).setParseAction(lambda toks: ptypes.FlagsType(toks[0][0], toks[0][1], toks[0][2], toks[0][3]))
messageDef = Group(message_ + identifier + messageBody + attributes - semi).setParseAction(lambda toks: ptypes.MessageType(toks[0][1], toks[0][2], toks[0][3]))
channelDef = Group(channel_ + identifier + channelBody + attributes - semi).setParseAction(lambda toks: ptypes.ChannelType(toks[0][1], toks[0][2], toks[0][3], toks[0][4]))
structDef = Group(struct_ + identifier + structBody + attributes - semi).setParseAction(lambda toks: ptypes.StructType(toks[0][1], toks[0][2], toks[0][3]))
typedefDef = Group(typedef_ + identifier + typeSpec + attributes - semi).setParseAction(lambda toks: ptypes.TypeAlias(toks[0][1], toks[0][2], toks[0][3]))
definitions = typedefDef | structDef | enumDef | flagsDef | messageDef | channelDef
protocolChannel = Group(typename + identifier + Optional(equals + integer, default=None) + semi) \
.setParseAction(lambda toks: ptypes.ProtocolMember(toks[0][1], toks[0][0], toks[0][2]))
protocolDef = Group(protocol_ + identifier + Group(lbrace + ZeroOrMore(protocolChannel) + rbrace) + semi) \
.setParseAction(lambda toks: ptypes.ProtocolType(toks[0][1], toks[0][2]))
bnf = ZeroOrMore (definitions) + protocolDef + StringEnd()
singleLineComment = "//" + restOfLine
bnf.ignore( singleLineComment )
bnf.ignore( cStyleComment )
return bnf
def parse(filename):
try:
bnf = SPICE_BNF()
types = bnf.parseFile(filename)
except ParseException as err:
six.print_(err.line, file=sys.stderr)
six.print_(" "*(err.column-1) + "^", file=sys.stderr)
six.print_(err, file=sys.stderr)
return None
for t in types:
t.resolve()
t.register()
protocol = types[-1]
return protocol