path: root/plugins/pychrysalide/analysis/scan/item.c

/* Chrysalide - Outil d'analyse de fichiers binaires
 * item.c - équivalent Python du fichier "analysis/scan/item.c"
 *
 * Copyright (C) 2022 Cyrille Bagard
 *
 *  This file is part of Chrysalide.
 *
 *  Chrysalide is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Chrysalide 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "item.h"


#include <pygobject.h>


#include <i18n.h>
#include <analysis/scan/item-int.h>
#include <plugins/pychrysalide/access.h>
#include <plugins/pychrysalide/helpers.h>


#include "context.h"



/* ------------------------ GLUE POUR CREATION DEPUIS PYTHON ------------------------ */


/* Initialise la classe des éléments appelables enregistrés. */
static void py_scan_registered_item_init_gclass(GScanRegisteredItemClass *, gpointer);

CREATE_DYN_ABSTRACT_CONSTRUCTOR(scan_registered_item, G_TYPE_SCAN_REGISTERED_ITEM, py_scan_registered_item_init_gclass);

/* Initialise une instance sur la base du dérivé de GObject. */
static int py_scan_registered_item_init(PyObject *, PyObject *, PyObject *);

/* Indique le nom associé à une expression d'évaluation. */
static char *py_scan_registered_item_get_name_wrapper(const GScanRegisteredItem *);

/* Lance une résolution d'élément à solliciter. */
static bool py_scan_registered_item_resolve_wrapper(GScanRegisteredItem *, const char *, GScanContext *, GScanScope *, GScanRegisteredItem **);

/* Réduit une expression à une forme plus simple. */
static bool py_scan_registered_item_reduce_wrapper(GScanRegisteredItem *, GScanContext *, GScanScope *, GScanExpression **);

/* Effectue un appel à une fonction enregistrée. */
static bool py_scan_registered_item_run_call_wrapper(GScanRegisteredItem *, GScanExpression **, size_t, GScanContext *, GScanScope *, GObject **);



/* ------------------------- CONNEXION AVEC L'API DE PYTHON ------------------------- */


/* Lance une résolution d'élément à appeler. */
static PyObject *py_scan_registered_item_resolve(PyObject *, PyObject *);

/* Fournit le désignation associée à un composant nommé. */
static PyObject *py_scan_registered_item_get_name(PyObject *, void *);



/* ---------------------------------------------------------------------------------- */
/*                          GLUE POUR CREATION DEPUIS PYTHON                          */
/* ---------------------------------------------------------------------------------- */


/******************************************************************************
*                                                                             *
*  Paramètres  : class  = classe à initialiser.                               *
*                unused = données non utilisées ici.                          *
*                                                                             *
*  Description : Initialise la classe des éléments appelables enregistrés.    *
*                                                                             *
*  Retour      : -                                                            *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static void py_scan_registered_item_init_gclass(GScanRegisteredItemClass *class, gpointer unused)
{
    class->get_name = py_scan_registered_item_get_name_wrapper;
    class->resolve = py_scan_registered_item_resolve_wrapper;
    class->reduce = py_scan_registered_item_reduce_wrapper;
    class->run_call = py_scan_registered_item_run_call_wrapper;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : self = objet à initialiser (théoriquement).                  *
*                args = arguments fournis à l'appel.                          *
*                kwds = arguments de type key=val fournis.                    *
*                                                                             *
*  Description : Initialise une instance sur la base du dérivé de GObject.    *
*                                                                             *
*  Retour      : 0.                                                           *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static int py_scan_registered_item_init(PyObject *self, PyObject *args, PyObject *kwds)
{
    int ret;                                /* Bilan de lecture des args.  */

#define SCAN_REGISTERED_ITEM_DOC                                    \
    "The *RegisteredItem* class is an abstract definition which is" \
    " the base for all keywords involved in a match condition"      \
    " expression.\n"                                                \
    "\n"                                                            \
    "Calls to the *__init__* constructor of this abstract object"   \
    " expect no particular argument.\n"                             \
    "\n"                                                            \
    "The following methods have to be defined for new classes:\n"   \
    "* pychrysalide.analysis.scan.RegisteredItem._resolve();\n"     \
    "* pychrysalide.analysis.scan.RegisteredItem._reduce();\n"      \
    "* pychrysalide.analysis.scan.RegisteredItem._call().\n"        \
    "\n"                                                            \
    "One item has to be defined as class attributes in the final"   \
    " class:\n"                                                     \
    "* pychrysalide.analysis.scan.RegisteredItem._name.\n"

    /* Initialisation d'un objet GLib */

    ret = forward_pygobjet_init(self);
    if (ret == -1) return -1;

    return 0;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : item = élément d'appel à consulter.                          *
*                                                                             *
*  Description : Indique le nom associé à une expression d'évaluation.        *
*                                                                             *
*  Retour      : Désignation humaine de l'expression d'évaluation.            *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static char *py_scan_registered_item_get_name_wrapper(const GScanRegisteredItem *item)
{
    char *result;                           /* Désignation à retourner     */
    PyGILState_STATE gstate;                /* Sauvegarde d'environnement  */
    PyObject *pyobj;                        /* Objet Python concerné       */
    PyObject *pyname;                       /* Nom en objet Python         */
    int ret;                                /* Bilan d'une conversion      */

#define SCAN_REGISTERED_ITEM_NAME_ATTRIB_WRAPPER PYTHON_GETTER_WRAPPER_DEF  \
(                                                                           \
    _name,                                                                  \
    "Provide the keyword of the expression item to be evaluated.\n"         \
    "\n"                                                                    \
    "The result has to be a string."                                        \
)

    result = NULL;

    gstate = PyGILState_Ensure();

    pyobj = pygobject_new(G_OBJECT(item));

    if (PyObject_HasAttrString(pyobj, "_name"))
    {
        pyname = PyObject_GetAttrString(pyobj, "_name");

        if (pyname != NULL)
        {
            ret = PyUnicode_Check(pyname);

            if (ret)
                result = strdup(PyUnicode_AsUTF8(pyname));

            Py_DECREF(pyname);

        }

    }

    Py_DECREF(pyobj);

    PyGILState_Release(gstate);

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : item   = élément d'appel à consulter.                        *
*                target = désignation de l'objet d'appel à identifier.        *
*                ctx    = contexte de suivi de l'analyse courante.            *
*                scope  = portée courante des variables locales.              *
*                out    = zone d'enregistrement de la résolution opérée. [OUT]*
*                                                                             *
*  Description : Lance une résolution d'élément à solliciter.                 *
*                                                                             *
*  Retour      : Bilan de l'opération : false en cas d'erreur irrécupérable.  *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static bool py_scan_registered_item_resolve_wrapper(GScanRegisteredItem *item, const char *target, GScanContext *ctx, GScanScope *scope, GScanRegisteredItem **out)
{
    bool result;                            /* Bilan à retourner           */
    PyGILState_STATE gstate;                /* Sauvegarde d'environnement  */
    PyObject *pyobj;                        /* Objet Python concerné       */
    PyObject *args;                         /* Arguments pour l'appel      */
    PyObject *pyret;                        /* Bilan de consultation       */
    GObject *gobj_ret;                      /* Bilan natif de consultation */

#define SCAN_REGISTERED_ITEM_RESOLVE_WRAPPER PYTHON_WRAPPER_DEF         \
(                                                                       \
    resolve, "$self, target, ctx, scope, /",                            \
    METH_VARARGS,                                                       \
    "Abstract method used to resolve an item by name.\n"                \
    "\n"                                                                \
    "The *target* argument provide the name of the searched item;"      \
    " *ctx* is a pychrysalide.analysis.scan.ScanContext instance"       \
    " providing information about the current state; *scope* is a"      \
    " pychrysalide.analysis.scan.ScanScope offering a view on the"      \
    " current namespace for variables.\n"                               \
    "\n"                                                                \
    "The result has to be a pychrysalide.analysis.scan.RegisteredItem"  \
    " instance on success, or *None* in case of failure."               \
)

    result = false;

    gstate = PyGILState_Ensure();

    pyobj = pygobject_new(G_OBJECT(item));

    if (has_python_method(pyobj, "_resolve"))
    {
        args = PyTuple_New(3);
        PyTuple_SetItem(args, 0, PyUnicode_FromString(target));
        PyTuple_SetItem(args, 1, pygobject_new(G_OBJECT(ctx)));
        PyTuple_SetItem(args, 2, pygobject_new(G_OBJECT(scope)));

        pyret = run_python_method(pyobj, "_resolve", args);

        if (pyret != NULL)
        {
            gobj_ret = pygobject_get(pyret);

            if (G_IS_SCAN_REGISTERED_ITEM(gobj_ret))
            {
                *out = G_SCAN_REGISTERED_ITEM(gobj_ret);

                g_object_ref(G_OBJECT(*out));
                result = true;

            }

            Py_DECREF(pyret);

        }

        Py_DECREF(args);

    }

    Py_DECREF(pyobj);

    PyGILState_Release(gstate);

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : item  = élément d'appel à consulter.                         *
*                ctx   = contexte de suivi de l'analyse courante.             *
*                scope = portée courante des variables locales.               *
*                out   = zone d'enregistrement de la réduction opérée. [OUT]  *
*                                                                             *
*  Description : Réduit une expression à une forme plus simple.               *
*                                                                             *
*  Retour      : Bilan de l'opération : false en cas d'erreur irrécupérable.  *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static bool py_scan_registered_item_reduce_wrapper(GScanRegisteredItem *item, GScanContext *ctx, GScanScope *scope, GScanExpression **out)
{
    bool result;                            /* Bilan à retourner           */
    PyGILState_STATE gstate;                /* Sauvegarde d'environnement  */
    PyObject *pyobj;                        /* Objet Python concerné       */
    PyObject *args;                         /* Arguments pour l'appel      */
    PyObject *pyret;                        /* Bilan de consultation       */
    GObject *gobj_ret;                      /* Bilan natif de consultation */

#define SCAN_REGISTERED_ITEM_REDUCE_WRAPPER PYTHON_WRAPPER_DEF          \
(                                                                       \
    reduce, "$self, ctx, scope, /",                                     \
    METH_VARARGS,                                                       \
    "Abstract method used to replace the item by an equivalent reduced" \
    " value.\n"                                                         \
    "\n"                                                                \
    "The *ctx* argument is a pychrysalide.analysis.scan.ScanContext"    \
    " instance providing information about the current state; *scope*"  \
    " is a pychrysalide.analysis.scan.ScanScope offering a view on the" \
    " current namespace for variables.\n"                               \
    "\n"                                                                \
    "The result has to be a pychrysalide.analysis.scan.ScanExpression"  \
    " instance on success, or *None* in case of failure."               \
)

    result = false;

    gstate = PyGILState_Ensure();

    pyobj = pygobject_new(G_OBJECT(item));

    if (has_python_method(pyobj, "_reduce"))
    {
        args = PyTuple_New(2);
        PyTuple_SetItem(args, 0, pygobject_new(G_OBJECT(ctx)));
        PyTuple_SetItem(args, 1, pygobject_new(G_OBJECT(scope)));

        pyret = run_python_method(pyobj, "_reduce", args);

        if (pyret != NULL)
        {
            gobj_ret = pygobject_get(pyret);

            if (G_IS_SCAN_EXPRESSION(gobj_ret))
            {
                *out = G_SCAN_EXPRESSION(gobj_ret);

                g_object_ref(G_OBJECT(*out));
                result = true;

            }

            Py_DECREF(pyret);

        }

        Py_DECREF(args);

    }

    Py_DECREF(pyobj);

    PyGILState_Release(gstate);

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : item  = élément d'appel à consulter.                         *
*                args  = liste d'éventuels arguments fournis.                 *
*                count = taille de cette liste.                               *
*                ctx   = contexte de suivi de l'analyse courante.             *
*                scope = portée courante des variables locales.               *
*                out   = zone d'enregistrement de la résolution opérée. [OUT] *
*                                                                             *
*  Description : Effectue un appel à une fonction enregistrée.                *
*                                                                             *
*  Retour      : Bilan de l'opération : false en cas d'erreur irrécupérable.  *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static bool py_scan_registered_item_run_call_wrapper(GScanRegisteredItem *item, GScanExpression **args, size_t count, GScanContext *ctx, GScanScope *scope, GObject **out)
{
    bool result;                            /* Bilan à retourner           */
    PyGILState_STATE gstate;                /* Sauvegarde d'environnement  */
    PyObject *pyobj;                        /* Objet Python concerné       */
    PyObject *sub_args;                     /* Sous-arguments pour l'appel */
    size_t i;                               /* Boucle de parcours          */
    PyObject *py_args;                      /* Arguments pour l'appel      */
    PyObject *pyret;                        /* Bilan de consultation       */
    GObject *gobj_ret;                      /* Bilan natif de consultation */

#define SCAN_REGISTERED_ITEM_CALL_WRAPPER PYTHON_WRAPPER_DEF            \
(                                                                       \
    run_call, "$self, args, ctx, scope, /",                             \
    METH_VARARGS,                                                       \
    "Abstract method used to replace the item and its arguments by an"  \
    " equivalent reduced value.\n"                                      \
    "\n"                                                                \
    "The *args* argument is a tuple of already reduced"                 \
    " pychrysalide.analysis.scan.ScanExpression objects; ctx* argument" \
    " is a pychrysalide.analysis.scan.ScanContext instance providing"   \
    " information about the current state; *scope* is a"                \
    " pychrysalide.analysis.scan.ScanScope offering a view on the"      \
    " current namespace for variables.\n"                               \
    "\n"                                                                \
    "The result has to be a pychrysalide.analysis.scan.ScanExpression"  \
    " instance on success, or *None* in case of failure."               \
)

    result = false;

    gstate = PyGILState_Ensure();

    pyobj = pygobject_new(G_OBJECT(item));

    if (has_python_method(pyobj, "_call"))
    {
        sub_args = PyTuple_New(count);

        for (i = 0; i < count; i++)
            PyTuple_SetItem(sub_args, 1, pygobject_new(G_OBJECT(args[i])));

        py_args = PyTuple_New(3);
        PyTuple_SetItem(py_args, 0, sub_args);
        PyTuple_SetItem(py_args, 1, pygobject_new(G_OBJECT(ctx)));
        PyTuple_SetItem(py_args, 2, pygobject_new(G_OBJECT(scope)));

        pyret = run_python_method(pyobj, "_call", py_args);

        if (pyret != NULL)
        {
            gobj_ret = pygobject_get(pyret);

            if (G_IS_OBJECT(gobj_ret))
            {
                *out = gobj_ret;

                g_object_ref(G_OBJECT(*out));
                result = true;

            }

            Py_DECREF(pyret);

        }

        Py_DECREF(py_args);

    }

    Py_DECREF(pyobj);

    PyGILState_Release(gstate);

    return result;

}



/* ---------------------------------------------------------------------------------- */
/*                           CONNEXION AVEC L'API DE PYTHON                           */
/* ---------------------------------------------------------------------------------- */


/******************************************************************************
*                                                                             *
*  Paramètres  : self = élément d'appel à consulter.                          *
*                args = arguments fournis pour l'opération.                   *
*                                                                             *
*  Description : Lance une résolution d'élément à appeler.                    *
*                                                                             *
*  Retour      : Nouvel élément d'appel identifié ou None.                    *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static PyObject *py_scan_registered_item_resolve(PyObject *self, PyObject *args)
{
    PyObject *result;                       /* Bilan à retourner           */
    const char *target;                     /* Désignation de la cible     */
    GScanContext *ctx;                      /* Contexte d'analyse          */
    GScanScope *scope;                      /* Portée de variables locales */
    int ret;                                /* Bilan de lecture des args.  */
    GScanRegisteredItem *item;              /* Version native              */
    bool status;                            /* Bilan d'exécution           */
    GScanRegisteredItem *resolved;          /* Elément trouvé              */

#define SCAN_REGISTERED_ITEM_RESOLVE_METHOD PYTHON_METHOD_DEF           \
(                                                                       \
    resolve, "$self, target, /, ctx=None, scope=None",                  \
    METH_VARARGS, py_scan_registered_item,                              \
    "Resolve a name into a scan item."                                  \
    "\n"                                                                \
    "The *target* name is the only mandatory parameter and has to point"\
    " to only one item. The *ctx* argument points to an optional useful"\
    " storage for resolution lookup, as a"                              \
    " pychrysalide.analysis.scan.ScanContext instance. The *args* list" \
    " defines an optional list of arguments, as"                        \
    " pychrysalide.analysis.scan.ScanExpression instances, to use for"  \
    " building the resolved item. The *final* flag states if the"       \
    " scanning process is about to conclude or not."                    \
    "\n"                                                                \
    "The result is an object inheriting from"                           \
    " pychrysalide.analysis.scan.RegisteredItem or *None* if the"       \
    " resolution operation failed."                                     \
)

    ctx = NULL;
    scope = NULL;

    ret = PyArg_ParseTuple(args, "s|O&", &target,
                           convert_to_scan_context, &ctx);
    if (!ret) return NULL;

    item = G_SCAN_REGISTERED_ITEM(pygobject_get(self));

    status = g_scan_registered_item_resolve(item, target, ctx, scope, &resolved);

    if (!status)
    {
        result = NULL;
        PyErr_Format(PyExc_RuntimeError, _("Unable to resolve any target from the item"));
    }
    else
    {
        if (resolved != NULL)
        {
            result = pygobject_new(G_OBJECT(resolved));
            g_object_unref(G_OBJECT(resolved));
        }
        else
        {
            result = Py_None;
            Py_INCREF(result);
        }
    }

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : self    = classe représentant un composant nommé à manipuler.*
*                closure = non utilisé ici.                                   *
*                                                                             *
*  Description : Fournit le désignation associée à un composant nommé.        *
*                                                                             *
*  Retour      : Description courante.                                        *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

static PyObject *py_scan_registered_item_get_name(PyObject *self, void *closure)
{
    PyObject *result;                       /* Décompte à retourner        */
    GScanRegisteredItem *item;              /* Version native              */
    char *name;                             /* Désignation à convertir     */

#define SCAN_REGISTERED_ITEM_NAME_ATTRIB PYTHON_GET_DEF_FULL            \
(                                                                       \
    name, py_scan_registered_item,                                      \
    "Name linked to the registered item.\n"                             \
    "\n"                                                                \
    "The result should be a string, or *None* for the root namespace."  \
)

    item = G_SCAN_REGISTERED_ITEM(pygobject_get(self));

    name = g_scan_registered_item_get_name(item);

    if (name == NULL)
    {
        result = Py_None;
        Py_INCREF(result);
    }
    else
    {
        result = PyUnicode_FromString(name);
        free(name);
    }

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : -                                                            *
*                                                                             *
*  Description : Fournit un accès à une définition de type à diffuser.        *
*                                                                             *
*  Retour      : Définition d'objet pour Python.                              *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

PyTypeObject *get_python_scan_registered_item_type(void)
{
    static PyMethodDef py_scan_registered_item_methods[] = {
        SCAN_REGISTERED_ITEM_RESOLVE_WRAPPER,
        SCAN_REGISTERED_ITEM_REDUCE_WRAPPER,
        SCAN_REGISTERED_ITEM_CALL_WRAPPER,
        SCAN_REGISTERED_ITEM_RESOLVE_METHOD,
        { NULL }
    };

    static PyGetSetDef py_scan_registered_item_getseters[] = {
        SCAN_REGISTERED_ITEM_NAME_ATTRIB_WRAPPER,
        SCAN_REGISTERED_ITEM_NAME_ATTRIB,
        { NULL }
    };

    static PyTypeObject py_scan_registered_item_type = {

        PyVarObject_HEAD_INIT(NULL, 0)

        .tp_name        = "pychrysalide.analysis.scan.ScanRegisteredItem",
        .tp_basicsize   = sizeof(PyGObject),

        .tp_flags       = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_BASETYPE,

        .tp_doc         = SCAN_REGISTERED_ITEM_DOC,

        .tp_methods     = py_scan_registered_item_methods,
        .tp_getset      = py_scan_registered_item_getseters,

        .tp_init        = py_scan_registered_item_init,
        .tp_new         = py_scan_registered_item_new,

    };

    return &py_scan_registered_item_type;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : -                                                            *
*                                                                             *
*  Description : Prend en charge l'objet 'pychrysalide...ScanRegisteredItem'. *
*                                                                             *
*  Retour      : Bilan de l'opération.                                        *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

bool ensure_python_scan_registered_item_is_registered(void)
{
    PyTypeObject *type;                     /* Type 'ScanRegisteredItem'   */
    PyObject *module;                       /* Module à recompléter        */
    PyObject *dict;                         /* Dictionnaire du module      */

    type = get_python_scan_registered_item_type();

    if (!PyType_HasFeature(type, Py_TPFLAGS_READY))
    {
        module = get_access_to_python_module("pychrysalide.analysis.scan");

        dict = PyModule_GetDict(module);

        if (!register_class_for_pygobject(dict, G_TYPE_SCAN_REGISTERED_ITEM, type))
            return false;

    }

    return true;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : arg = argument quelconque à tenter de convertir.             *
*                dst = destination des valeurs récupérées en cas de succès.   *
*                                                                             *
*  Description : Tente de convertir en expression d'évaluation généraliste.   *
*                                                                             *
*  Retour      : Bilan de l'opération, voire indications supplémentaires.     *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

int convert_to_scan_registered_item(PyObject *arg, void *dst)
{
    int result;                             /* Bilan à retourner           */

    result = PyObject_IsInstance(arg, (PyObject *)get_python_scan_registered_item_type());

    switch (result)
    {
        case -1:
            /* L'exception est déjà fixée par Python */
            result = 0;
            break;

        case 0:
            PyErr_SetString(PyExc_TypeError, "unable to convert the provided argument to generic scan expression");
            break;

        case 1:
            *((GScanRegisteredItem **)dst) = G_SCAN_REGISTERED_ITEM(pygobject_get(arg));
            break;

        default:
            assert(false);
            break;

    }

    return result;

}