class BIRDPrinter: def __init__(self, val): self.val = val @classmethod def lookup(cls, val): if val.type.code != cls.typeCode: return None if val.type.tag != cls.typeTag: return None return cls(val) class BIRDFValPrinter(BIRDPrinter): "Print BIRD\s struct f_val" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_val" codemap = { "T_INT": "i", "T_BOOL": "i", "T_PAIR": "i", "T_QUAD": "i", "T_ENUM_RTS": "i", "T_ENUM_BGP_ORIGIN": "i", "T_ENUM_SCOPE": "i", "T_ENUM_RTC": "i", "T_ENUM_RTD": "i", "T_ENUM_ROA": "i", "T_ENUM_NETTYPE": "i", "T_ENUM_RA_PREFERENCE": "i", "T_ENUM_AF": "i", "T_IP": "ip", "T_NET": "net", "T_STRING": "s", "T_PATH_MASK": "path_mask", "T_PATH": "ad", "T_CLIST": "ad", "T_EC": "ec", "T_ECLIST": "ad", "T_LC": "lc", "T_LCLIST": "ad", "T_RD": "ec", "T_PATH_MASK_ITEM": "pmi", "T_SET": "t", "T_PREFIX_SET": "ti", } def to_string(self): code = self.val['type'] if code.type.code != gdb.TYPE_CODE_ENUM or code.type.tag != "f_type": raise Exception("Strange 'type' element in f_val") if str(code) == "T_VOID": return "T_VOID" else: return "(%(c)s) %(v)s" % { "c": code, "v": self.val['val'][self.codemap[str(code)]] } def display_hint(self): return "map" class BIRDFValStackPrinter(BIRDPrinter): "Print BIRD's struct f_val_stack" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_val_stack" def to_string(self): cnt = self.val['cnt'] return ("Value stack (%(cnt)d):\n\t" % { "cnt": cnt }) + \ "\n\t".join([ (".val[%(n) 3d] = " % { "n": n}) + str(self.val['val'][n]) for n in range(cnt-1, -1, -1) ]) def display_hint(self): return "map" class BIRDFInstPrinter(BIRDPrinter): "Print BIRD's struct f_inst" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_inst" def to_string(self): code = self.val['fi_code'] if str(code) == "FI_NOP": return str(code) + ": " + str(self.val.cast(gdb.lookup_type("const char [%(siz)d]" % { "siz": self.val.type.sizeof }))) return "%(code)s:\t%(lineno) 6dL\t%(size)6dS\tnext = %(next)s: .i_%(code)s = %(union)s" % { "code": str(code), "lineno": self.val['lineno'], "size": self.val['size'], "next": str(self.val['next']), "union": str(self.val['i_' + str(code)]) } # def children(self): # children iterator def display_hint(self): return "map" class BIRDFLineItemPrinter(BIRDPrinter): "Print BIRD's struct f_line_item" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_line_item" def to_string(self): code = self.val['fi_code'] if str(code) == "FI_NOP": return str(code) + ": " + str(self.val.cast(gdb.lookup_type("const char [%(siz)d]" % { "siz": self.val.type.sizeof }))) return "%(code)s:\t%(lineno) 6dL\t%(flags)2dF: .i_%(code)s = %(union)s" % { "code": str(code), "lineno": self.val['lineno'], "flags": self.val['flags'], "union": str(self.val['i_' + str(code)]) } class BIRDFLinePrinter(BIRDPrinter): "Print BIRD's struct f_line" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_line" def to_string(self): cnt = self.val['len'] return ("FLine (%(cnt)d, args=%(args)d): " % { "cnt": cnt, "args" : self.val['args'] } + \ ", ".join([ ".items[%(n) 3d] = %(code)s" % { "n": n, "code": str(self.val['items'][n]['fi_code']), } if n % 8 == 0 else str(self.val['items'][n]['fi_code']) for n in range(cnt)])) class BIRDFExecStackPrinter(BIRDPrinter): "Print BIRD's struct f_exec_stack" typeCode = gdb.TYPE_CODE_STRUCT typeTag = "f_exec_stack" def to_string(self): cnt = self.val['cnt'] return ("Exec stack (%(cnt)d):\n\t" % { "cnt": cnt }) + \ "\n\t".join([ ".item[%(n) 3d] = %(retflag)d V%(ventry) 3d P%(pos) 4d %(line)s" % { "retflag": self.val['item'][n]['emask'], "ventry": self.val['item'][n]['ventry'], "pos": self.val['item'][n]['pos'], "line": str(self.val['item'][n]['line'].dereference()), "n": n } for n in range(cnt-1, -1, -1) ]) class BIRD: def skip_back(t, i, v): if isinstance(t, str): t = gdb.lookup_type(t) elif isinstance(t, gdb.Value): t = gdb.lookup_type(t.string()) elif not isinstance(t, gdb.Type): raise Exception(f"First argument of skip_back(t, i, v) must be a type, got {type(t)}") t = t.strip_typedefs() nullptr = gdb.Value(0).cast(t.pointer()) if isinstance(i, gdb.Value): i = i.string() elif not isinstance(i, str): raise Exception(f"Second argument of skip_back(t, i, v) must be a item name, got {type(i)}") if not isinstance(v, gdb.Value): raise Exception(f"Third argument of skip_back(t, i, v) must be a value, got {type(v)}") if v.type.code != gdb.TYPE_CODE_PTR and v.type.code != gdb.TYPE_CODE_REF: raise Exception(f"Third argument of skip_back(t, i, v) must be a pointer, is {v.type} ({v.type.code})") if v.type.target().strip_typedefs() != nullptr[i].type: raise Exception(f"Third argument of skip_back(t, i, v) points to type {v.type.target().strip_typedefs()}, should be {nullptr[i].type}") uintptr_t = gdb.lookup_type("uintptr_t") taddr = v.dereference().address.cast(uintptr_t) - nullptr[i].address.cast(uintptr_t) return gdb.Value(taddr).cast(t.pointer()) class skip_back_gdb(gdb.Function): "Given address of a structure item, returns address of the structure, as the SKIP_BACK macro does" def __init__(self): gdb.Function.__init__(self, "SKIP_BACK") def invoke(self, t, i, v): return BIRD.skip_back(t, i, v) BIRD.skip_back_gdb() class BIRDList: def __init__(self, val): ltype = val.type.strip_typedefs() if ltype.code != gdb.TYPE_CODE_UNION or ltype.tag != "list": raise Exception(f"Not a list, is type {ltype}") self.head = val["head"] self.tail_node = val["tail_node"] if str(self.head.address) == '0x0': raise Exception("List head is NULL") if str(self.tail_node["prev"].address) == '0x0': raise Exception("List tail is NULL") def walk(self, do): cur = self.head while cur.dereference() != self.tail_node: do(cur) cur = cur.dereference()["next"] class BIRDListLength(gdb.Function): """Returns length of the list, as in print $list_length(routing_tables)""" def __init__(self): super(BIRDListLength, self).__init__("list_length") def count(self, _): self.cnt += 1 def invoke(self, l): self.cnt = 0 BIRDList(l).walk(self.count) return self.cnt BIRDListLength() class BIRDListItem(gdb.Function): """Returns n-th item of the list.""" def __init__(self): super(BIRDListItem, self).__init__("list_item") class BLException(Exception): def __init__(self, node, msg): Exception.__init__(self, msg) self.node = node def count(self, node): if self.cnt == self.pos: raise self.BLException(node, "Node found") self.cnt += 1 def invoke(self, l, n, t=None, item="n"): self.cnt = 0 self.pos = n bl = BIRDList(l) try: bl.walk(self.count) except self.BLException as e: if t is None: return e.node else: return BIRD.skip_back(t, item, e.node) raise Exception("List too short") BIRDListItem() def register_printers(objfile): objfile.pretty_printers.append(BIRDFInstPrinter.lookup) objfile.pretty_printers.append(BIRDFValPrinter.lookup) objfile.pretty_printers.append(BIRDFValStackPrinter.lookup) objfile.pretty_printers.append(BIRDFLineItemPrinter.lookup) objfile.pretty_printers.append(BIRDFLinePrinter.lookup) objfile.pretty_printers.append(BIRDFExecStackPrinter.lookup) register_printers(gdb.current_objfile()) print("BIRD pretty printers loaded OK.")