package mopsa

  1. Overview
  2. Docs
package mopsa
Legend:
Page
Library
Module
Module type
Parameter
Class
Class type
Source

Source file base.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
(****************************************************************************)
(*                                                                          *)
(* This file is part of MOPSA, a Modular Open Platform for Static Analysis. *)
(*                                                                          *)
(* Copyright (C) 2017-2019 The MOPSA Project.                               *)
(*                                                                          *)
(* This program is free software: you can redistribute it and/or modify     *)
(* it under the terms of the GNU Lesser General Public License as published *)
(* by the Free Software Foundation, either version 3 of the License, or     *)
(* (at your option) any later version.                                      *)
(*                                                                          *)
(* This program is distributed in the hope that it will be useful,          *)
(* but WITHOUT ANY WARRANTY; without even the implied warranty of           *)
(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            *)
(* GNU Lesser General Public License for more details.                      *)
(*                                                                          *)
(* You should have received a copy of the GNU Lesser General Public License *)
(* along with this program.  If not, see <http://www.gnu.org/licenses/>.    *)
(*                                                                          *)
(****************************************************************************)

(** Base storage of scalar values. *)

open Mopsa
open Universal.Ast
open Ast


(** Kinds of bases *)
type base_kind =
  | Var    of var    (** Stack variable *)
  | Addr   of addr   (** Heap address *)
  | String of string * c_character_kind * typ (** String literal, with character kind and type of character *)

(** Bases *)
type base = {
  base_kind : base_kind;
  base_valid : bool;
  base_invalidation_range : range option;
}


let pp_base_kind fmt = function
  | Var v -> pp_var fmt v
  | Addr (a) -> pp_addr fmt a
  | String (s,k,_) -> Format.fprintf fmt "%a\"%s\"" Pp.pp_character_kind k (String.escaped s)

let pp_base fmt b =
  Format.fprintf fmt "%s%a"
    (if b.base_valid then "" else "✗")
    pp_base_kind b.base_kind

let compare_base_kind b b' = match b, b' with
  | Var v, Var v' -> compare_var v v'
  | Addr a, Addr a' -> compare_addr a a'
  | String (s,k,t), String (s',k',t') ->
    Compare.triple compare compare compare_typ (s,k,t) (s',k',t')
  | _ -> compare b b'

let compare_base b b' =
  Compare.compose [
      (fun () -> compare_base_kind b.base_kind b'.base_kind);
      (fun () -> compare b.base_valid b'.base_valid);
      (fun () -> Compare.option compare_range b.base_invalidation_range b'.base_invalidation_range)
    ]

let mk_base ?(valid=true) ?(invalidation_range=None) kind =
  { base_kind = kind;
    base_valid = valid;
    base_invalidation_range = invalidation_range; }


let mk_var_base ?(valid=true) ?(invalidation_range=None) v =
  mk_base (Var v) ~valid ~invalidation_range


let mk_addr_base ?(valid=true) ?(invalidation_range=None) a =
  mk_base (Addr a) ~valid ~invalidation_range

let mk_string_base ?(kind=C_char_ascii) ?(typ=(T_c_integer C_unsigned_char)) s =
  mk_base (String (s,kind,typ)) ~valid:true ~invalidation_range:None

let base_kind_uniq_name b =
  match b with
  | Var v -> v.vname
  | Addr a -> addr_uniq_name a
  | String (s,_,_) -> s


let base_uniq_name b =
  let name = base_kind_uniq_name b.base_kind in
  if b.base_valid then name else "✗" ^ name


let base_size b flow =
  match b.base_kind with
  | Var v -> sizeof_type v.vtyp flow
  | String (s,_,_) -> Z.of_int @@ String.length s
  | Addr a -> panic ~loc:__LOC__ "base_size: addresses not supported"

let base_mode b =
  match b.base_kind with
  | Var v -> v.vmode
  | Addr a -> a.addr_mode
  | String _ -> STRONG


type addr_opacity =
  | NotOpaque
  | OpaqueFrom of int (* offset *)

let addr_opaque_chain : (addr_kind -> addr_opacity) ref =
  ref (fun ak -> NotOpaque)
let addr_opaque a = !addr_opaque_chain a
let register_addr_opaque f = addr_opaque_chain := f !addr_opaque_chain

let is_base_readonly b =
  match b.base_kind with
  | String _ -> true
  | _ -> false


let is_var_base_expr e =
  match ekind e with
  | E_var(v,_)                -> is_c_type v.vtyp
  | _ -> false

let is_addr_base_expr e =
  match ekind e with
  | E_addr _                  -> true
  | _ -> false

let is_base_expr e =
  match ekind e with
  | E_var(v,_)                -> is_c_type v.vtyp
  | E_addr _                  -> true
  | E_constant (C_c_string _) -> true
  | _ -> false


let expr_to_base e =
  match ekind e with
  | E_var(v,_)                    -> mk_var_base v
  | E_addr (a,_)                  -> mk_addr_base a
  | E_constant (C_c_string (s,_)) -> mk_string_base s
  | _ -> assert false

let base_to_expr b range =
  match b.base_kind with
  | Var v          -> mk_var v range
  | Addr a         -> mk_addr a range ~etyp:(T_c_pointer void)
  | String (s,c,_) -> mk_c_string s ~kind:c range

(** Evaluate the size of a base in bytes *)
let eval_base_size ?(route=toplevel) base range (man:('a,'t) man) flow =
  match base.base_kind with
  | Var ({vkind = V_cvar cv} as var) when cv.cvar_scope = Variable_extern &&
                         (is_c_variable_length_array_type var.vtyp ||
                         is_c_no_length_array_type var.vtyp ) ->
    Cases.singleton (mk_int_general_interval (ItvUtils.IntBound.Finite Z.zero) ItvUtils.IntBound.PINF range) flow 

  | Var var
    when is_c_variable_length_array_type var.vtyp ||
         is_c_no_length_array_type var.vtyp
    ->
    let bytes_expr = mk_expr (Stubs.Ast.E_stub_builtin_call (BYTES, [mk_var var range])) range ~etyp:ul in
    man.eval ~route bytes_expr flow ~translate:"Universal"

  | Var var ->
    Cases.singleton (mk_z (sizeof_type var.vtyp flow) range) flow

  | String (str,_,t) ->
    (* length of the terminal 0 character *)
    let char_len = Z.to_int (sizeof_type t flow) in
    Cases.singleton (mk_int (String.length str + char_len) range) flow

  | Addr addr ->
    let bytes_expr = mk_expr (Stubs.Ast.E_stub_builtin_call (BYTES, [mk_addr addr range])) range ~etyp:ul in

    (* XXX for backward compatibility, the size is converted to Universal, but maybe it should be a C expression? *)
    man.eval ~route bytes_expr flow ~translate:"Universal"


module Base =
struct
  type t = base
  let compare = compare_base
  let print = unformat pp_base
end


module BaseSet = SetExt.Make(Base)
module BaseMap = MapExt.Make(Base)

let mk_lval base offset typ mode range =
  let base_addr = match base.base_kind with
    | Var v -> mk_c_address_of (mk_var v ~mode range) range
    | Addr a -> mk_addr ~mode a range
    | String (s,kind,t) -> mk_c_string s ~kind range in
  let addr =
    mk_c_cast
      ( add
          (mk_c_cast base_addr (T_c_pointer s8) range)
          offset
          ~typ:(T_c_pointer s8)
          range )
      (T_c_pointer typ)
      range in
  mk_c_deref addr range
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct