C Bindings to BAP
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README.md

BAP Bindings

This project provides a C interface to BAP library and other components of the infrastructure. The interface is rather complete, although some functions may be omitted for a reason or accidentaly. By desing, everything that is possible to do in OCaml with the Bap.Std interface should be possible to implement in C, using bap.h. If you find any violations of this rule, please don't hesitate to file an issue.

Quick start

The following simple program is a good test that your installation works fine.

int main(int argc, const char *argv) {
    bap_init(argc, argv);
    printf("Welcome to BAP %s", bap_version());
}

The examples folder contains a set of small programs, that can be viewed as tutorials to BAP and BAP bindings. The following order is suggested:

  1. lift_insn - teaches how to disassemble, lift and print code;
  2. print_reachable - explains how to write simple analysis;
  3. show_image - uncovers low-level details of file parsing.

Requirements

  • BAP 1.x.x
  • OCaml 4.03+ with PIC runtime
  • GCC
  • Patience (it takes some time to generate the bindings)

The PIC runtime is usually installed with OCaml (at least in OPAM).

Compilation and installation

Nothing new here:

autoconf
./configure
make
make install

You can parametrize installation variables, e.g., prefix using the configure script, see ./configure --help for more information.

If the configure script is not available (e.g., when you just cloned the repo), then use autoconf to generate it.

Documentation

Lacks. The long story is the following. There is an official searchable documentation for OCaml library. You should consult it as a primary source of information. Although it is for OCaml, it should be understandable without a dictionary. We were trying to follow some conventions to make it easier to map C functions to their OCaml counterpart.

  1. Module namespaces are translated to the underscore delimited prefixes, with exception to Bap.Std that is translated just to bap, e.g., Project.Input.file is project_input_file. So to get the documentation for the project_input_file just type Project.Input.file in the search window of the OCaml documentation. The same is true for types. A type Project.t is defined as an opaque data structure bap_project_t. The name is typedefed into from the structure tag namespace to the symbol namespace, so no struct word is needed.

  2. The order of function parameters is preserved, except that optional parameters (prefixed with ? in OCaml) are specified after all required parameters. For example, Project.Input.file ?loader:string -> filename:string -> t is translated into project_input_file(char *filename, char *loader). The NULL value can be passed as an argument to the optional parameter.

  3. If there are too many optional parameters, then they are passed using a strcture. Field names of a structure correspond to the names of optional parameters. For example, bap_project_create corresponds to Project.create function that has the following interface:

    val create :
           ?disassembler:string ->
           ?brancher:brancher source ->
           ?symbolizer:symbolizer source ->
           ?rooter:rooter source ->
           ?reconstructor:reconstructor source ->
           input -> t Or_error.t
    In C land it corresponds to
    
    struct bap_project_t* bap_project_create(struct bap_project_input_t* input,
                                             struct bap_project_parameters_t* params);
    Where structure `params` is defined as:
    
    struct bap_project_parameters_t {
      bap_rooter_source_t* rooter;
      bap_brancher_source_t* brancher;
      bap_symbolizer_source_t* symbolizer;
      bap_reconstructor_source_t* reconstructor;
      char* disassember;
    };
    

    Each individual field of the params data structure can be NULL. Moreover, the params itself can be also NULL. That will denote that all optional arguments were omitted.

  4. Nontotal functions (those that return t Or_error.t or t option instead of t) may return NULL. If the OCaml counterpart was returning a value of t Or_error.t then the error can be retrieved with bap_error_get function.

  5. If a module XXX implements Printable.S interface, then the following functions are available:

    • bap_XXX_to_string(bap_XXX_t *) returns a string representation of a value;
    • bap_fprint(bap_XXX_t *value, FILE *) prints value into a stream;
    • bap_print(bap_XXX_t *) prints a value into stdout;
    • bap_eprint(bap_XXX_t *) prints a value into stderr;
  6. If a module XXX implements Data.S interface, then the following functions are available:

    • bap_XXX_data_version(void);
    • bap_XXX_data_size(bap_XXX_t *);
    • bap_XXX_copy(bap_XXX_t *value, char *data, int len);
    • bap_XXX_of_bytes(char *data, int len);
    • bap_XXX_input(const char *filename);
    • bap_XXX_output(const char *filename);
  7. If a module XXX implements Data.S interface, (that subsumes Printable.S and Data.S) then the following functions are also available:

    • bap_XXX_hash(bap_XXX_t *);
    • bap_XXX_equal(bap_XXX_t *x, bap_XXX_t *y);
    • bap_XXX_compare(bap_XXX_t *x, bap_XXX_t *y);
  8. Polymorphic operations are provided for certain type in a type-safe maner. A polymorphic operation OP defined in module M concretized for type XXX will be named bap_XXX_M_OP for example, Seq.map for a sequence of insn is named bap_insn_seq_map. Currenlty, all Regular types provide two polymorphic containers: set and seq. The set is implemented using mutable hash table, and seq is a generic sequence (that can be even infinte).

  9. Truly generic operatons, like Seq.length are provided as bap_seq_length, wher bap_seq_t is base class for all sequences (in the sense, bap_XXX_seq_t is an instance of bap_seq_t for all XXX). The instance relation is checked in runtime, a static cast is required at compile time.