tools/wireshark_be.py

   1 # -*- python -*-
   2 #
   3 #    File      : wireshark_be.py
   4 #
   5 #    Author    : Frank Singleton (frank.singleton@ericsson.com)
   6 #
   7 #    Copyright (C) 2001 Frank Singleton, Ericsson Inc.
   8 #
   9 #  This file is a backend to "omniidl", used to generate "Wireshark"
  10 #  dissectors from IDL descriptions. The output language generated
  11 #  is "C". It will generate code to use the GIOP/IIOP get_CDR_XXX API.
  12 #
  13 #  Please see packet-giop.h in Wireshark distro for API description.
  14 #  Wireshark is available at https://www.wireshark.org/
  15 #
  16 #  Omniidl is part of the OmniOrb distribution, and is available at
  17 #  http://omniorb.sourceforge.net
  18 #
  19 #  SPDX-License-Identifier: GPL-2.0-or-later
  20
  21
  22 # Description:
  23 #
  24 #   Omniidl Back-end which parses an IDL data structure provided by the frontend
  25 #   and generates packet-idl-xxx.[ch] for compiling as a dissector in Wireshark.
  26 #
  27 #
  28 # Strategy.
  29 #
  30 # Crawl all the way down all branches until I hit  "Operation", "Enum", "Attribute",
  31 # "Struct" and "Union" nodes.  Then store these nodes in lists.
  32 #
  33 # Pass these lists (via an object ref) to the src code
  34 # generator (wireshark_gen) class and let it do the hard work !
  35 #
  36 #
  37 # Don't forget structs can contain embedded structs etc .. so don't forget
  38 # to peek inside and check :-)
  39
  40
  41 """Wireshark IDL compiler back-end."""
  42
  43 from __future__ import print_function
  44
  45 import string
  46 import sys
  47 from os import path
  48
  49 from omniidl import idlast, idltype, output
  50
  51 from wireshark_gen import wireshark_gen_C
  52
  53
  54 class WiresharkVisitor:
  55     """This class finds the "Operation" nodes ,Enum Nodes, "Attribute" nodes, Struct Nodes
  56     and Union Nodes. Then it hands them off to an instance of the source code generator
  57     class "wireshark_gen" """
  58
  59     def __init__(self, st, debug=False):
  60         self.DEBUG = debug
  61         self.st = st
  62         self.oplist = []  # list of operation nodes
  63         self.enlist = []  # list of enum nodes
  64         self.atlist = []  # list of attribute nodes
  65         self.stlist = []  # list of struct nodes
  66         self.unlist = []  # list of union nodes
  67
  68     def visitAST(self, node):
  69         if self.DEBUG:
  70             print("XXX visitAST() node = ", node)
  71
  72         for n in node.declarations():
  73             if isinstance(n, idlast.Module):
  74                 self.visitModule(n)
  75             if isinstance(n, idlast.Interface):
  76                 self.visitInterface(n)
  77             if isinstance(n, idlast.Operation):
  78                 self.visitOperation(n)
  79             if isinstance(n, idlast.Attribute):
  80                 self.visitAttribute(n)
  81             if isinstance(n, idlast.Enum):
  82                 self.visitEnum(n)
  83             if isinstance(n, idlast.Struct):
  84                 self.visitStruct(n)
  85             if isinstance(n, idlast.Union):
  86                 self.visitUnion(n)
  87
  88             # Check for Typedef structs and unions
  89
  90             if isinstance(n, idlast.Typedef):
  91                 self.visitTypedef(n)  # who are you ?
  92
  93     def visitModule(self, node):
  94         if self.DEBUG:
  95             print("XXX visitModule() node = ", node)
  96
  97         for n in node.definitions():
  98             if isinstance(n, idlast.Module):
  99                 self.visitModule(n)
 100             if isinstance(n, idlast.Interface):
 101                 self.visitInterface(n)
 102             if isinstance(n, idlast.Operation):
 103                 self.visitOperation(n)
 104             if isinstance(n, idlast.Attribute):
 105                 self.visitAttribute(n)
 106             if isinstance(n, idlast.Enum):
 107                 self.visitEnum(n)
 108             if isinstance(n, idlast.Struct):
 109                 self.visitStruct(n)
 110             if isinstance(n, idlast.Union):
 111                 self.visitUnion(n)
 112
 113             # Check for Typedef structs and unions
 114
 115             if isinstance(n, idlast.Typedef):
 116                 self.visitTypedef(n)  # who are you ?
 117
 118     def visitInterface(self, node):
 119         if self.DEBUG:
 120             print("XXX visitInterface() node = ", node)
 121
 122         for c in node.callables():
 123             if isinstance(c, idlast.Operation):
 124                 self.visitOperation(c)
 125             if isinstance(c, idlast.Attribute):
 126                 self.visitAttribute(c)
 127
 128         for d in node.contents():
 129             if isinstance(d, idlast.Enum):
 130                 self.visitEnum(d)
 131
 132             if isinstance(d, idlast.Struct):
 133                 self.visitStruct(d)
 134
 135             if isinstance(d, idlast.Union):
 136                 self.visitUnion(d)
 137
 138             # Check for Typedef structs and unions
 139
 140             if isinstance(d, idlast.Typedef):
 141                 self.visitTypedef(d)  # who are you ?
 142
 143     def visitOperation(self, opnode):
 144         """populates the operations node list "oplist" """
 145         if opnode not in self.oplist:
 146             self.oplist.append(opnode)  # store operation node
 147
 148     def visitAttribute(self, atnode):
 149         """populates the attribute node list "atlist" """
 150         if atnode not in self.atlist:
 151             self.atlist.append(atnode)  # store attribute node
 152
 153     def visitEnum(self, enode):
 154         """populates the Enum node list "enlist" """
 155         if enode not in self.enlist:
 156             self.enlist.append(enode)  # store enum node if unique
 157
 158     def visitTypedef(self, td):
 159         """Search to see if its a typedef'd struct, union, or enum
 160
 161         eg: typdef enum colors {red, green, blue } mycolors;
 162         """
 163
 164         d = td.aliasType()  # get Type, possibly Declared
 165         if isinstance(d, idltype.Declared):
 166             self.visitDeclared(d)
 167
 168     def visitDeclared(self, d):
 169         """Search to see if its a struct, union, or enum"""
 170         if isinstance(d, idltype.Declared):
 171             sue = d.decl()  # grab the struct or union or enum
 172
 173             if isinstance(sue, idlast.Struct):
 174                 self.visitStruct(sue)
 175             if isinstance(sue, idlast.Union):
 176                 self.visitUnion(sue)
 177             if isinstance(sue, idlast.Enum):
 178                 self.visitEnum(sue)
 179
 180     def visitStruct(self, stnode):
 181         # populates the struct node list "stlist"
 182         # and checks its members also
 183         if stnode not in self.stlist:
 184             self.stlist.append(stnode)  # store struct node if unique and avoid recursive loops
 185                                         # if we come across recursive structs
 186
 187             for m in stnode.members():  # find embedded struct definitions within this
 188                 mt = m.memberType()
 189                 if isinstance(mt, idltype.Declared):
 190                     self.visitDeclared(mt)  # if declared, then check it out
 191
 192     def visitUnion(self, unnode):
 193         # populates the struct node list "unlist"
 194         # and checks its members also
 195         if unnode not in self.unlist:
 196             self.unlist.append(unnode)  # store union node if unique
 197
 198             if unnode.constrType():  # enum defined within switch type
 199                 if isinstance(unnode.switchType(), idltype.Declared):
 200                     self.visitDeclared(unnode.switchType())
 201
 202             for c in unnode.cases():
 203                 ct = c.caseType()
 204                 if isinstance(ct, idltype.Declared):
 205                     self.visitDeclared(ct)  # if declared, then check it out
 206
 207
 208 def run(tree, args):
 209
 210     DEBUG = "debug" in args
 211     AGGRESSIVE = "aggressive" in args
 212
 213     st = output.Stream(sys.stdout, 4)  # set indent for stream
 214     ev = WiresharkVisitor(st, DEBUG)  # create visitor object
 215
 216     ev.visitAST(tree)  # go find some operations
 217
 218     # Grab name of main IDL file being compiled.
 219     #
 220     # Assumption: Name is of the form   abcdefg.xyz  (eg: CosNaming.idl)
 221
 222     fname = path.basename(tree.file())  # grab basename only, don't care about path
 223     nl = fname.split(".")[0]  # split name of main IDL file using "." as separator
 224                                       # and grab first field (eg: CosNaming)
 225
 226     if DEBUG:
 227         for i in ev.oplist:
 228             print("XXX - Operation node ", i, " repoId() = ", i.repoId())
 229         for i in ev.atlist:
 230             print("XXX - Attribute node ", i, " identifiers() = ", i.identifiers())
 231         for i in ev.enlist:
 232             print("XXX - Enum node ", i, " repoId() = ", i.repoId())
 233         for i in ev.stlist:
 234             print("XXX - Struct node ", i, " repoId() = ", i.repoId())
 235         for i in ev.unlist:
 236             print("XXX - Union node ", i, " repoId() = ", i.repoId())
 237
 238     # create a C generator object
 239     # and generate some C code
 240
 241     eg = wireshark_gen_C(ev.st,
 242                          nl.upper(),
 243                          nl.lower(),
 244                          nl.capitalize() + " Dissector Using GIOP API",
 245                          debug=DEBUG,
 246                          aggressive=AGGRESSIVE)
 247
 248     eg.genCode(ev.oplist, ev.atlist, ev.enlist, ev.stlist, ev.unlist)  # pass them onto the C generator
 249
 250 #
 251 # Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 252 #
 253 # Local variables:
 254 # c-basic-offset: 4
 255 # indent-tabs-mode: nil
 256 # End:
 257 #
 258 # vi: set shiftwidth=4 expandtab:
 259 # :indentSize=4:noTabs=true:
 260 #